Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1

Industrial revolution, a consequence of the rapid economic growth, has contributed to ever increasing demand for energy and has resulted in about 40% rise in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 400 ppm in 2015. Abundant use of fossil fuels has become a cause of concern due to their adverse effects on the environment, particularly related to the emission of carbon dioxide (CO2), a major contributor of GHG. In this context, CO2 capture and is storage or transformation gained significance in the recent research scenario. Various matured CO2 capture technologies such as amine based capture, needs high energy input, especially in desorption process and are also not sustainable in nature. Alternatively, carbonic anhydrase (CA) proved to be more efficient in capturing CO2 at faster rate and also needs less energy input for desorption process. However, utilization of the captured CO2 is more important rather than its capture, to close the carbon cycle and recycle it. In this direction, bioelectrochemical system (BES) is presenting an exciting opportunity with a possibility of simultaneous CO2 capture and biotransformation to value-added products in a sustainable way. Both microbes and enzymes were studied as catalyst in BES, though the application of enzymes is less foreseen. Present study demonstrates the biotransformation of CO2 to ethanol using a cascade of dehydrogenases [formate dehydrogenase (FateDH), formaldehyde dehydrogenase (FaldDH) and alcohol dehydrogenase (AlcDH)] together on the electrode of BES. Further to that, carbonic anhydrase (CA) was also included in the cascade and found that the product yield increased by 15% contributing to ethanol production rate of ∼0.6 kg/m³/h along with current density of ∼2 A/m². When the FaldDH was excluded from the cascade also, there is no reduction in productivity of ethanol. It was surprising to get ethanol instead of methanol but based on literature, it is also possible for the production of ethanol directly from formic acid, which is economically more viable.

Characterizing the content and understanding the distribution of organic carbon in sediments is a key element for the exploration and the production of new or revisited petroleum prospects.

Developed by Total, the LIPS has a set of unique features:

∘ it is poorly destructive: indeed, the laser impact affects only 1 mm³ of material,

∘ it generates very large datasets / big data (typically 10,000 data points and more for 100 meters of core). Statistical treatment on such data sets provide more significant and more representative description than discrete and low resolution sampling. This opens completely new perspectives to understand organic matter deposition and distribution. Thus, descriptive and inductive statistics may be used to infer laws and to detect:

  - trends, behaviors and dependencies,

  - relationships with lithology, rock type, Milankowitch cycles …

∘ it provides high resolution data allowing more accurate location and a better quantitative evaluation of the organic carbon in cores.

The LIPS equipment currently installed in Doha (Fig. 1) addresses typical issues in the Middle East.

Figure 1: LIPS equipment installed in TRC-Q, Doha, Qatar

The high resolution data acquisition allows exhaustive location of permeability barriers in carbonate reservoirs also known by petroleum engineers as tar mats. It also contributes to the identification of all the sweet spots in source rocks layers for non conventional plays in exploration and development. As such it is a tool contributing significantly to the economical exploitation of shales gases and shale oils.

“Milanković-type“ climate cycles are due to variation of Earth rotation. They are known to control fluctuation of sedimentary organic carbon. The data presented in Fig. 2 indicate that the resolution of LIPS data is high enough to highlight the climate change induced variations of organic carbon in the Jordan oil shale play. It also shows the added value of the LIPS in comparison with the conventional Rock Eval data.

Figure 2: High resolution LIPS data (1/cm) highlights the climate induced variations of organic carbon in the Jordan oil shale

In light of successful results obtained for GCC issues, new developments involving local staff are expected in Doha with the support of Total's Headquarter. Indeed, specific applications to carbonate reservoirs and resources are underway, for instance:

∘ new methods for performing quantitative analysis of bitumen forming tarmat in carbonate reservoirs. Middle East is the ideal trial field, since all tarmat configurations and formation pathways exist in these countries,

∘ new and simple devices for specific compound detection (e.g. CO2, organo-sulfur compounds...). The goal is to make a distinction between fossil organic carbon, tarmat, heavy oil and oil. Automatic measurement High resolution correlation between TOC and of residual permeability may be performed,

∘ hyphenated techniques from the coupling of the LIPS with on-line spectroscopic detection technologies (e.g. isotope ratios mass spectrometer).

The LIPS is a real breakthrough in terms of both its technological originality and its unique ability to characterize carbon deposits.

Aquatic ecosystems across the globe are under significant threat, suffering from various forms of anthropogenic disturbances, which is greatly impacting global biodiversity, economy and human health. Reliable monitoring of species is crucial for data-driven management actions in this context, but remains a challenge owing to non-standardized and selective methods relaying on physical identification of species by visual surveys and counting of individuals. However, traditional monitoring techniques remain problematic due to difficulties associated with correct identification of cryptic species or juvenile life stages, These traditional methods depend on practical and taxonomic expertise, which is steadily declining. In an attempt to come up with new objective solutions for monitoring biodiversity, recent and ongoing studies in Qatari waters, uses and further develops novel environmental DNA (eDNA) methods for Monitoring aquatic biodiversity in the Gulf and elsewhere.

Previous studies have shown that diversity of rare and threatened European freshwater animals - representing amphibians, fish, mammals, insects and crustaceans - can be detected and quantified based on environmental DNA (eDNA) obtained directly from small water samples of lakes, ponds and streams (Thomsen et al. 2012a).

Subsequently, for the first time, we investigated the potential of using metabarcoding of eDNA obtained directly from seawater samples to account for marine fish and mammal biodiversity. We show that such marine eDNA can account for fish biodiversity using high-throughput sequencing. Promisingly, eDNA covered the fish diversity better than any of 9 methods, conventionally used in marine fish surveys. Additionally, we show that even short fish eDNA sequences in seawater degrades beyond detectable levels within days, in accordance with results obtained from freshwater eDNA (Thomsen et al. 2012b). Controlled mesocosm experiments have also shown that eDNA becomes undetectable within 2 weeks after removal of animals, indicating that eDNA traces are near contemporary with species presence. Our findings underpin the ubiquitous nature of eDNA traces in the environment and support the use of eDNA as a tool for monitoring rare, threatened and economically important species across a wide range of taxonomic groups.

A particularly interesting study focuses on the large whale shark aggregation at the Al Shaheen Oil Field, located in the offshore area called “Block 5”, in the NE of the Exclusive Economic Zone (EEZ) of Qatar. Maersk Oil Qatar is currently operating several oil and gas production platforms within this field, and also take active part in a large whale shark research project studying many aspect about the aggregation. Quantitative PCR (qPCR) and high-throughput sequencing of sea water from the area have successfully been employed to gain new information about the occurrence, abundance and biology of the aggregation. More specifically, data from 2013 and 2014 showed that whale shark eDNA concentrations follows visual observations of abundance, and that degradation of eDNA occur rapidly, supporting that the obtained genetic material is of local origin. Our findings confirm that seawater samples can contain key information on populations of oceanic species, and demonstrate a general potential of eDNA for studying populations of marine organisms.

Although further studies are needed to validate the eDNA approach under varying environmental conditions, our findings provide a strong proof-of-concept with great perspectives for future monitoring of aquatic biodiversity and resources in the Gulf.

References

Thomsen PF, Kielgast J, Iversen LL, Wiuf C, Rasmussen M, Gilbert MTP, Orlando L, Willerslev E (2012a). Monitoring Endangered Freshwater Biodiversity using Environmental DNA. Molecular Ecology 21, 2565–2573.

Thomsen PF, Kielgast J, Iversen LL, Møller PR, Rasmussen M, Willerslev E (2012b). Detection of a Diverse Marine Fish Fauna using Environmental DNA from Seawater Samples. PLOS ONE 7(8), e41732.

In the present work we examine how recent progress at our collaborating laboratories, over various solar thermochemical technologies, can be brought to bear on the advancement of renewable resource utilization in Qatar.

Specific examples of such technologies include solar water splitting for H2 production, solar CO2 splitting thermochemical energy storage in reduced metal oxides, solar cracking of CH4 for production of carbon nanoparticles and hydrogen, and production of metal nanoparticles to be employed as renewable fuel. Where feasible the potential of using locally sourced materials is stressed and particular examples are given (e.g. the use of Qatar's CaCO3). Enabling technologies over all scales (from the lab to the demonstration scale) include advanced instrumentation and testing platforms (e.g, solar simulators, solar furnaces, etc). Reactor concepts and system designs are formulated and analyzed and promising designs from the user's perspective are identified for advancing to the next level. Here we describe results and future directions from three such examples.

A low energy, zero-effluent system for clean water production, employing a concentrated solar thermal aquatic stream processing module is described. The projected specific electric energy consumption of the system does not exceed 1 kWh/m³, which in fact can be largely produced by the system itself. The system can exhibit an unprecedented (>99%) clean water recovery from any aquatic stream (seawater, brines, wastewater). At the same time the salt/solids content of the aquatic stream is separated in dry-form, thus being transformed from a waste-to-be-managed into a raw material ready for further commercial exploitation. The system is based on a modular design hence it is applicable over a range of scales, from standalone applications to large scale industrial water plants as well as an add-on to existing large scale producers and/or users of water, for further recovery of water and residual solids (salts, valuable metals from brine/wastewater effluents).

Production of hydrogen can be achieved via photo- and electro-chemical water splitting processes. In order for such processes to be feasible, they employ sacrificial electron donors which also bind oxygen molecule. Then, they have to be regenerated, via thermochemical reactions, and also release the oxygen. So the whole process operates in a cyclic mode, thus called water-splitting cycle. The use of solar energy for the realization of the thermochemical steps increases the overall solar-to-hydrogen efficiency. The Hybrid Sulfur Ammonia cycle, described here, uses ammonium sulfate as the sacrificial donor and a mixture of alkali-metal sulfates and pyrosulfates, which help to recover oxygen at lower temperatures and higher efficiency. We present the of thermal analysis experiments conducted for the calculation of the respective thermodynamic properties (heat capacity and enthalpy). In addition, with the use of advanced thermodynamic tools (FacTSAGE etc), and experimental thermal analysis, we completed the thermodynamic analysis, and selected the reaction temperatures in a range from 350°C to 900°C.

The crucial drawback of solar energy is its intermittent character. At the same time, pollution caused by the release of CO2, mainly in power plants and cement production, results in a series of problems such as global warming and poor air quality. Thermal Energy Storage (TES) can provide an escape route for both the aforementioned problems. TES can be used in order to store heat during periods of high solar irradiation and release it during the night or periods of low activity. Carbonate systems, such as calcite and dolomite, can be utilized for TES. In this study we focus on the reversible calcination/carbonation cycle of (CaMg)CO3, because it is a very strong candidate as a high efficiency thermochemical material. Its energy density is the highest among other materials. It can be found in vast quantities in Qatar, according to its geological formation, thus can be easily used as low cost/high added value material. Furthermore, it is a non-toxic and safe material with easy separation of the phases. In addition, the cycle involves CO2 capture during the discharge stage. This ends up in both energy release and greenhouse gases elimination. So far, we have characterized thermally, chemically and morphologically local raw surface carbonates. Results show that dolomitic powder, (CaMg)CO3 from Northern Qatar and subsurface rocks have an average capacity of 6 mmol CO2/g, but sintering deactivates material significantly after 20 cycles. Currently, we are designing a potential TES process coupled to cement production. In parallel, we are investigating experimentally the available methods to enhance the capacity of the raw material and improve its stability.

Present research contributes towards the solution of the Global Challenges that our societies face today, and in particular it provides access to safe and clean water and energy. These can be achieved with improved performance, energy efficiency and ease of usability.

Petroleum refining, not only consumes large quantities of water but also generates large quantities of wastewater. Large quantities of petroleum refinery wastewater are generated worldwide, approximately 3.5–5 m³ of wastewater generated per ton of crude oil processed. This wastewater is considered as a major source of environmental pollution. Various chemical and biologically based technologies have been developed for the treatment of petroleum refinery wastewater such as reverse osmosis, membrane filtration, electrocoagulation, anaerobic tank, anaerobic baffled reactor, aerated filter and bio-contact oxidation. In the last decade, biological treatment methods of petroleum refinery wastewater were developed because of the high cost of chemical treatment methods and these methods are also more environmental friendly.

In this study, we demonstrate for the first time that it is possible to remove salt from saltwater and generate electricity while using petroleum refinery wastewater as an anodic substrate in the three chamber microbial desalination cell (MDC). MDC insinuates a new method for treating petroleum refinery wastewater and concurrently salt removal from seawater with bioelectricity generation. MDC was developed from microbial fuel cell (MFCs) concept. In this device, desalination and wastewater treatment are conducted in one system. MDC has an enormous potential as a low-cost desalination process with wastewater treatment and other benefits. MDC is a new technique in which saltwater can be desalinated without using any external energy source. The exoelectrogenic-bacteria are used in MDC reactor to oxidize biodegradable substrate in the anodic chamber and transfer the produced electrons to the anode electrode.

In this study, petroleum refinery wastewater was treated in MDC using three different initial salt concentrations of 5 g/l, 20 g/L and real seawater in desalination chamber along with two separate catholyte (phosphate buffer solution and acidified water). All the three chamber MDC operations were carried out in batch mode. The maximum % COD removals of 71 and 64 were obtained using initial salt concentration of 20 g/L with MDC operated with acidified and phosphate buffer solution as catholyte respectively. The maximum desalination efficiency of 19.9% and 19.1 % were obtained in MDC operated with real seawater using PBS and acidified water as catholyte respectively. The scanning electron microscope images investigation confirmed the presence of microbial biofilm on the anode electrode and anion exchange membrane surface. The MDC performed better with acidified water compared to PBS as catholyte. The above obtained results demonstrated the feasibility of using MDC technologies to generate bioelectricity, seawater desalination and simultaneously treat complex petroleum refinery wastewater, although further studies are required to scale up and optimize the process. The MDCs are emerged as a self-energy driven device for wastewater treatment and seawater desalination at the lab scale. But still MDCs needs further research before it can be implemented at large scale. Acknowledgements: This work was made possible by NPRP grant # 6-289-2-125 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.

The availability of fresh water and energy is the key factor of the development of many countries particularly those of over-populated arid areas. Potable water supply shortage and recent technological development have led to wider application of conventional, and yet advanced saline/brackish water desalination plants. Today, desalination methods require large amounts of energy, which is costly both in environmental pollution and in money terms. This study defines the main economic parameters used in estimation of desalination costs and limitation of the stand-alone, small size SWRO plants powered by photovoltaic at the North West cost of Egypt. Moreover, techno-economic study is made to estimate the actual cost of m³/fresh water production on real field measurements. All cost estimations are based on the prevailing prices during 2012–2013. The average unit cost of desalted water with the desalination unit powered by photovoltaic battery is 9.3–5.6 LE/m³, which is very high, but when using the unit with battery, the cost is reduced to be between 2.3–1.7 LE/m³ by increase working hours to 24 hours. Economical strategies should be developed for more reduction in cost taking into account all phases from site selection and design to operation and maintenance and most importantly increasing the local manufacturing. Keywords: Production cost, Economic analysis, Stand-Alone, Reverse osmosis, photo voltaic, Desalination, Egypt.

The catalytic decomposition of methane (CDM) on suitable surfaces offers the prospect for lower or zero-carbon routes to energy using natural gas or methane derived via biomass options. The carbon from the decomposition could be stored (buried), used for specific applications or perhaps converted to electricity using carbon fuel cells, according to which the overall process is near-zero or low carbon dioxide producing in character. A large volume of work now describes the action of supported nickel in the CDM reaction. However, the basic ground rules governing activity, longevity (closely related to carbon yield) and carbon morphology as well as issues around practical reactor systems for the sustained catalytic action of solid catalysts remain to be developed. In nickel/titania systems the carbon type and yield are dependent on nickel loading levels, with lower Ni loadings favouring higher carbon yields per unit of Ni. The carbon yield per unit mass of catalyst in nickel-titania systems is largely independent of Ni loading. Carbon yields are greatly influenced by the nature of the catalytic solid. Addition of Cu or La can lead to unusually high carbon yields in excess of 2000 g/gNi, some of the highest ever reported. The nature of zeolite morphology in Cu-Ni systems also greatly influences the carbon yield and examples of this behaviour will be presented and discussed. Considerations of how to regenerate CDM catalysts, or slowing their deactivation in the first place are demanded if sustained practical CDM is to be achieved and some ideas on the issue may be developed from experiences with other methane decomposition systems, including non-catalytic approaches that have been pursued using concentrated solar energy, for example.

The ability of date palm tree to survive under adverse abiotic conditions renders it as an important fruit tree growing in hot and dry regions. Nevertheless, the optimal conditions for date palm growth and production are also suitable for fungal growth leading to major diseases such as black scorch. The aim of this work was to develop a genetic control of date palm to Thielaviopsis punctulata, the causal agent of black scorch, through understanding molecular interactions between the plant host and the pathogen. Genomics and bioinformatics tools were used to sequence, assembly and annotate the whole genome of the pathogen and to decipher the molecular mechanisms of date palm resistance to the pathogen. The whole fungal genome was assembled and functionally annotated with an estimated size of 28.1 Mb containing 5,480 predicted genes. Some of the annotated genes belong to toxin-related genes such as necrosis inducing protein (NPP1) and Cerato-platanin, reflecting a potential functional role of fungal toxins in inducing disease symptoms. On the host side, real-time PCR and RNA-Seq approaches were used to quantify the fungal infection and profile the genome expression of date palm in response to the pathogen infection in two cultivars at 1, 2, 3 and 4 day post infection (dpi). Results from real-time PCR showed that the fungal infection started early at one dpi and the highest level of infection was detected at three dpi for both cultivars. Results also showed that Khalas cultivar is less infected by the pathogen compare to Kinzy cultivar reflecting a degree of resistance in Khalas cultivar. Data from RNA-Seq is being analyzed to identify regulatory genes involved in resistance to black scorch disease. Information from the current study will lead to further understanding of the molecular interactions between T. punctulata and date palm, assisting in deriving effective genetic control strategies for black scorch disease.

Air pollution, global greenhouse gases (GHG), water pollution and water resources degradation are among the most serious environmental concerns that encounter the Qatar country. In nowadays, it is commonly known that the effects of environment degradation exceed its direct negative impacts on climate changes to cover its impacts on Human health, nation livelihood and cultural integrity. So, we advocate that understanding and determining factors explaining environmental degradation remain an important question of research. Moreover, by determining factors that explain environment degradation, policymakers, researchers and international institutions can help on recommending the adequate economic policies that can improve the environment quality and the live standing of inhabitants. In the empirical literature, the Environmental Kuznets Curve (EKC) is the most powerful tool used to investigate the relationship between environment degradation and some macroeconomics and financial variables. Following the EKC hypothesis, the relationship between economic growth and environment degradation is inverted-U shaped. From the economic perspective, this means that initially economic growth increases environment degradation and then declines it after a threshold point of income per capita. More specifically, at initial level of economic growth, an increase in income is linked with an increase in energy consumption that raises environment degradation. After reaching a critical level of income, the spending on environment protection is increased, and hence environment degradation tend to decrease. From an econometrical or statistical perspectives, the EKC hypothesis have been firstly tested using the basic EKC equation which relies the environment degradation proxy to the real GDP and to a nonlinear term of the real GDP (the squared real GDP). If the EKC hypothesis holds then the real GDP and the squared real GDP have respectively a positive and negative signs. This EKC hypothesis has been firstly introduced by Kuznets (1955) when examining the relationship between economic growth and income inequality which shows that this relationship is inverted U-shaped. Grossman and Krueger (1995) are the first to examine this relationship between environment degradation and economic growth in their seminal paper published on the Quarterly Journal of Economics. They found that this relationship is inverted U-shaped which validates the EKC hypothesis. Empirically, until now no consensus has been reached about the true nature of the relation between real GDP and environment degradation. Evidence for the EKC hypothesis is very mixed. Overall, the results seem to depend in many factors including the specification, the pollutants and the econometrics technique used. First, empirical studies show that the results in term of positive and negative relationships as well as in term of magnitude differ significantly for the same country depend on the specification studied, linear, quadratic or cubic. Moreover, the inclusion of other factors in the right hand of the regression such as urbanization, trade openness, financial development and political stability have a significant impact on the magnitude of the income per capita variables coefficients. Second, the results differ significantly following the environment degradation proxy used. For instance, Horvath (1997) and Holtz-Eakin and Selden (1995) suggest that the use of global pollutants leads to continuously rise the levels of environment degradation or to a high levels of income per capita turning point, see also Esteve and Tamarit (2011). Third, the results also seem to depend in the econometric approach employed. In this paper, we investigate the case of the Qatar economy for several reasons. First, Qatar 2030 vision has given a high importance to questions related to air pollution, climate change and their impacts on economic sustainability. Second, the rapid increase of economic growth of the Qatar economy in the last two decades has been accompanied with an increase in energy consumption, urbanization and international trade. These factors are among the most important factors largely used in theoretical and empirical literature to explain environment degradation. Third, following the world health organization (WHO), local air pollution levels in Qatar has frequently exceeded recommended levels and are more time higher than the international standards. In fact, compared to the WHO's standards for PM10 for the 24-hour average and for the annual average concentration of 50 ug/m³ and 20 ug/m³ the Qatar's national air quality standards are far from these values. For instance, the values for PM10 is around 150 ug/m³ for 24 hours average concentration and to 50 ug/m³ for the annual average concentration. The data set used in this paper consists on macroeconomics and financial data, including CO2 emissions, ecological foot print, real GDP per capita, energy use, urbanization, financial development and openness trade, to investigate the EKC hypothesis for the Qatar economy. All the dataset except the ecological foot print variable are collected from the world Bank's development indicators (WDI). The ecological footprint data is obtained from the National Footprint Accounts (NFAs) of the Global Footprint Network. This variable is employed as second proxy of environment quality measures. This data set used is a quarterly data and covers the period 1975Q1 to 2007Q4 for variables used for ecological footprint equation and covers the periods 1980Q1 to 2010Q4 for the CO2 emissions equations variables. This paper contributes to the empirical literature of the EKC hypothesis in many ways. First, to our knowledge this paper is the first to consider the case of the Qatar economy as a single country to test the EKC hypothesis as well as the different directions of causality between variables. Second, in addition to the CO2 emissions largely employed in the empirical literature, in this paper we employ also the ecological footprint as a new proxy of environmental degradation. Third, we use recent development of cointegration approach with structural breaks which is also rarely used for the case of EKC hypothesis. As tests of cointegration with shifts in the cointegration vector, we use the Gregory and Hansen (1996), Hatemi-J (2008) and to investigate the causal relationship between all variables using standard Granger causality tests. Fourth, to our knowledge this paper is the first study that uses Markov Switching Equilibrium Correction Model with shifts in both the intercept and the income per capita coefficient for the long run relationship between environment degradation and its key determinants. The empirical findings of this paper are useful for Qatari policymakers and especially for the ministry of environment of the Qatar government. Moreover, economic implications and economic policy are proposed and discussed. [1] P.O.Box: 2713-Doha-Qatar. Email: [email protected]. Office: (+974) 4403-7764(+974) 4403-7764, Fax: (+974) 4403-5081. 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In this study a decentralized combined cooling-heating-and-power (CCHP) plant fueled with liquefied natural gas (LNG) is integrated with photovoltaic (PV) technology to reduce fuel consumption and improve the economics of the CCHP plant. In their previous publications the authors have investigated the potential of an LNG-fueled CCHP at different configurations and system capacities, where the inclusion of PV technology was not investigated in detail. In this study the penetration of PV technology is analyzed in detail to reveal possible benefits. The modular nature of PV technology allows an opportunity for investigating power generation at different configurations. Additionally this combination shows a potential for reducing emissions and suggests a new concept of integrating an intermittent source of energy, such as solar energy. The proposed system is based on a realistic gas turbine cycle, integrated with a cooling plant and a district energy network. The detailed analysis of this study shows the thresholds of the proposed system to become an ideal candidate for distributed generation applications, especially in locations which are distant from centralized power plants. Therefore apart from reducing transmission and distribution losses, waste heat could be recovered effectively to generate heating, or cooling (absorption refrigeration technology). The system considers fueling with LNG, which is a safe and transportable fuel option. The simulation results show a potential for further investigation of the proposed system, since its performance results in significant thermodynamic and environmental improvements. The system can be operated in two modes: (a) winter operation, where recovered heat is distributed to the district energy network, (b) summer operation, where recovered heat is used to drive an absorption chiller-based cooling plant to generate cooling, which is also distributed to the district energy network. The average primary energy ratio of the proposed system is near 90%, which shows a potential for operation at high efficiencies. The cost analysis shows that the payback period is within a reasonable time frame; approximately 4 years. The system is modeled based on theoretical and experimental, including data from manufacturers’ datasheets and other assumptions. Each component and/or subsystem is modeled separately and coupled to every adjacent component, as described in the system configuration. All details, including specific assumptions are provided in the study. The values for all system input parameters are given, followed by a description of all subsystem and/or component models, i.e. CCHP plant, heat exchangers, cooling plant and district energy network. The cost model is described in detail, with all necessary cost functions and their input values, and also to allow a more realistic analysis of the feasibility potential of the proposed system a rigorous cost model is formulated. The main economic parameters evaluated are: projected total lifecycle cost (LCC), investment cost, operating cost and PP. The system model is validated using two commercially available gas turbines as reference cases, which include measured data from their respective manufacturer. Therefore the model input values correspond to the values taken from the references. The results of the model validation are given in detail in the study. The calculated error between the system simulation and the manufacturers’ data is low (0 to about 5%). Thereby, it can be assumed that the proposed system is modeled within an acceptable level of accuracy. The proposed CCHP system can be applied using different operational strategies, which may be based on either thermal energy (heating/cooling) or electricity demand. However to allow complete utilization of the generated thermal energy, the system must be based on a thermal energy-led operation. Therefore if it is assumed that the system operates at a constant, full power capacity (which also allows maximum net electrical efficiency), all generated thermal energy is delivered to buildings. The system is grid-interconnected to allow import/export of electricity, while the buildings are equipped with vapor-compression heat pumps, which will be operated the thermal energy supplied from the CCHP system is insufficient. The heat pumps are operated with electricity generated from the CCHP system. In the case of a CCHP system it is important to choose the set of consumers (buildings) that will allow an efficient matching of the generated vectors of energy with demand. The reason is that for example in the case of heating mode, high heat is required during the evening and early morning hours in households (due to high occupancy and low ambient temperature), while high heat demand occurs during daytime working hours in weekdays. A proposed small-scale, decentralized CCHP system is considered as alternative to conventional large-scale centralized, electricity-only generating power plants. The system is designed, modeled and analyzed in terms of thermodynamics, including cost analysis and exergy analysis. The results of the system model simulation show the potential of the proposed system in terms of efficiency. The system performs efficiently, with a PER of near 90%, and therefore the proposed system may become a significant candidate in the energy market, since fuel consumption and CO2 emissions can be reduced. The considered fuel is LNG, and with the proposed design approach of its regasification, the cooling energy can be used to cool the feed air before compression, which results to a net electrical efficiency of almost 2%, which is an attractive system modification for areas with prolonged summer-like weather conditions. Overall, when the proposed system is compared to an equivalent conventional system, results show significant improvement in CO2 emissions reduction (almost 40%) and primary energy savings (more than 40%). The exergy analysis shows that there is a potential for improvement of the exergetic efficiency through design modifications. Exergy destruction is higher in the combustor, the cooling plant and the heat exchangers responsible for recovering waste heat (i.e. HEx2 and HEx3). In the case of the cooling plant and the heat exchangers, the irreversibility is due to the conversion of high quality waste heat to low quality useful heating (or cooling). This is an unavoidable result due to the purpose of the proposed system, although exergetic efficiency could improve with the replacement of the double-effect absorption chiller with a triple-effect one. Also, theoretically, net electrical efficiency (and also exergetic efficiency) can be improved with the introduction of a combined cycle configuration, which is however a more complex and costly, and thereby an unfavorable option for distributed generation applications. The only possible and feasible modification for the current system design could be the optimization of the combustion process, by preheating the reactants or minimizing the use of excess air, although this could result in an impractical (or inflexible) system configuration.

Background & Objective: Air pollution is a major problem that has been recognised throughout the world for hundreds of years. In the middle ages, the burning of coal in cities released increasing amounts of smoke and sulphur dioxide to the atmosphere. In the late 18th century, the Industrial Revolution, beginning in the UK, led to escalation in pollutant emissions based around the use of coal by both homes and industry.Pollutant emissions continued to grow through the 19th and early 20th centuries leading to poor Air Quality (AQ). In more recent times, pollution from motor vehicles has become the most recognised AQ issue. Present pollution monitoring is revealing that if we don't act swiftly then vehicle pollution could harm our environment and reduce the quality of life for future generations. The number of cars, both in Qatar and in most countries around the world, is currently steadily increasing, and a speed up in technological development is required to combat the pollution problem. Poor AQ has negative effects on the environment and thus on our wellbeing. Air pollution from transport vehicles includes emissions of carbon monoxide, particulates, nitrogen oxides and dioxide, hydrocarbons and so on. Whilst much attention has been directed towards poor outdoors AQ we sometimes forget that we spend up to 90% of our time indoors. Consequently, keeping the air which we breathe at home clean is crucial, particularly for vulnerable people including babies, children, pregnant women and the unborn babies, the elderly, and those suffering from respiratory or allergic diseases such as asthma. Although in the majority of homes the indoor AQ (IAQ) is fairly good, CO, SO2, NO2 etc… are just some of the indoor air pollutants which can give cause for concern. The level of indoor air pollutants depends on factors such as outdoor air pollutants, construction materials and interior finishing, poorly-designed air conditioning and ventilation systems, and households and furniture (via outgassing from fabrics, paints, pets, etc.). Over-ventilation, as often thought, does not solve the problem. Nevertheless, this illusory solution is not adequate in the hot climate of the Gulf region as it leads to unacceptable levels in power demand. Sustaining economic and social growth is impossible without a holistic environmental vision that places environmental preservation for Qatar's future generations at the forefront. The QNV2030 aim to strike a balance between developmental needs (human, society, economy) and the protection of its natural environment, whether land, sea or air. Echoing international initiatives, Qatar has recently undertaken relentless intensive steps in an attempt to address the problem of AQ. The QNV2030 associated Qatar National Development Strategy 2011-2016 (QNDS 2011-2016), through a set of well-defined recommendations, stresses on the need to address the issues of environment and air pollution. To meet these needs, in this extended abstract we present SERENO (SEnsor and REceiver Node), a renewable energy-harvested sensor node that intelligently monitors air quality continuously without human intervention. This paper discusses the challenges of designing an autonomous system powered by ambient energy harvesting. Preliminary results demonstrate that, the presented platform could effectively report and trace air quality levels in a sort of set and forget scenario using a mesh network topology to cover as large as possible area deploying from tens to thousand nodes. Methods: The advances in low power electronics and in electrochemical sensors have enabled the development of low cost and power efficient air quality monitoring systems (dedicated to specific target gas and analysis) suitable for even stringent environments and disruptive locations, where air quality assessment is required without human intervention. Environmental energy harvesting technologies has been developed to maximize wireless sensor systems' lifetime and minimize energy consumption by adopting ultra-low power electronics (i.e. ultra-low power controller, low-power AO and CMOS switches). The use of virtually no-power consumed sensors (e.g. electrochemical sensors connected to signal conditioning electronics with supply current around 1 uA) coupled with wireless communication, working on the principle duty cycling (i.e. the device remains in low power SLEEP mode for almost 100% of the time) helps in maximizing the power efficiency and lifetime of the system. It makes the system operative only to perform designated tasks i.e. sensor warm-up, sampling, data processing and wireless data transmission or communication. The top view diagram of the renewable energy harvested system for air quality monitoring named SERENO is given below. Figure 1 shows the 6 sensors operative on the PCB. The general description of the proposed system is described below.

Fresh fruit and vegetables are an important part of a healthy diet as they are a significant source of vitamins and minerals. However, fresh fruits and vegetables can also be a source of toxic substances such as pesticides. Pesticides are a several and diverse group of chemical compounds, which applied to crops at various stages of cultivation and during production and post-harvest treatment of agricultural commodities. Recently, the government of Qatar has attempted to encourage agricultural production. Despite a noticeable increase in agricultural production in Qatar, however, this increase does not fulfill the need of residents in Qatar. Therefore, Qatar imports large amounts of food products from other countries which are large agricultural producers. The lack of information regarding pesticide residues in food in Qatar implies the necessity to determinate their concentrations in food items. Organochlorine pesticides (also known as chlorinated hydrocarbons) are primarily insecticides with relatively low mammalian toxicity, fat soluble and normally persistent in the environment. Many chlorinated hydrocarbons have the ability to accumulate inside the body due to their lipophilic nature. The study was aimed to examine the occurrence of organochlorine pesticides residues in some local and imported vegetables and fruits in Qatar, as a prelude to assess the risks related to their consumption. In order to achieve this aim, the following specific objectives were carried out: (i) determine the amount of 10 organochlorine pesticides (Heptachlor, aldrin, dieldrin, Endrin, a-chlordane, g-chlordane, endosulfane I, methoxychlor, α-BHC and β-BHC) in seven mostly consumed vegetables and fruits in Qatar using Gas chromatography-electron capture detector (GC-ECD), (ii) screen the residues of pesticides in these vegetables and fruits using scan mode of Gas chromatography- mass spectrometry (GC-MS), and (iii) perform statistical analyses to data obtained. A total of 127 samples of most 7 consumed fresh vegetables and fruit from local and import production were analyzed. The samples included: 26 samples of fruits and 101 samples of vegetables. Samples were extracted within 24 hours and stored at 4°C until the analysis. The simple random sampling and stratified random sampling were used as sampling procedures for collecting the vegetables and fruits. For all vegetables and fruits except strawberries, simple random sampling was used. For strawberries sampling, the stratified random sampling procedure was used. The EPA Method 8081 was chosen as a reference method for the preparation and extraction method with some modification. Additionally, the Dionex Application Note 332 “Accelerated solvent extraction of pesticide residues in food products”, 2012, was used as extraction method for vegetables and fruits. The fresh fruits and vegetables samples were collected from farms and market a day before extraction. Each sample was divided in to two groups: washed sample with water and unwashed sample. No sample digestion was needed prior to extraction. A clean-up procedure is usually carried out to remove co-extracted compounds that may cause interference in the chromatographic determination or be detrimental to the analytical instrumentation. Following extraction, 5 g of anhydrous sodium sulfate were added to the collection vial to adsorb co-extracted water. The vial was shaken for 15 s and the water-free extract was decanted into a clean vial. Two solid phase extraction techniques were used (Florisil and Silica Gel). The EPA method 3620C- Florisil Cleanup and Method 3630C- Silica Gel Cleanup were used as reference methods for cleaning the samples. All samples were cleaned up using 2 g Florisil Clean-Prep Cartridge. However, some interferants that are not removed by Florisil Cartridge would be removed by a second cleanup technique which was Silica Gel cleanup. For the Quality Control and Quality Assurance measures (QC/QA), the Limit of detection and limit of quantitation were calculated for all analytes. The LOD and LOQ were calculated using 10 samples of the lowest concentration of spike (10 ppb). The evaluation of the recoveries of studied pesticides were done by adding known concentration of an internal standard (Decachlorobiphenyl) to about 10% of total number of samples. The range from 93.6% to 106.6% was the percent recoveries in spiked samples. Residues of 10 OCPs (Heptachlor, aldrin, dieldrin, Endrin, a-chlordane, g-chlordane, endosulfane I, methoxychlor, α-BHC and β-BHC) were identified using GC/ECD. The GC/ECD analyses were performed on an Agilent 6890 N equipped with a splitless injector and a 7683 autoinjector. The analysis by GC/MS was carried out on an Agilent 7890A MSD 5973 equipped with a split/splitless Inlet and a 7683B autoinjector. Separations were conducted using an HP-1 30 m 0.25 mm 0.25 μm column for GC/ECD and Rxi-5SILMS 30 m 0.25 mm 0.25 μm column for the GC/MS. The GC/MS data were acquired and processed with a wiley7n.1 and NIST98 Libraries. The most frequently detected OCPs in the samples were heptachlor, g-chlordane and a-chlordane. Two statistical analysis tests were used to determine significance (pair-difference t-test and analysis of variance (ANOVA)). In most of the comparisons between the washed and unwashed samples, no-significant differences were observed (P > 0.05). Here, there is a dire require for controlling program for residues of pesticides in food products. Since florisil and silica were used for cleanup, heavy matrix interferences were observed in most of the samples, consisting primarily of fatty acids. Thus the detection and identification of trace levels of pesticides in this complex profile can be very time-consuming and laborious. The level of pesticide residues contamination may be considered a potential public health problem, since pesticides are characterized by various degrees of toxicity to non-target species, including human beings. The results underscore the need for regular monitoring of large samples to determine the pesticide residues, especially for the imported samples. This research can be implemented as a regular monitoring for the presence of OCPs in fruits and vegetables. Also the results of this research can be used as reference for future work. Future studies should consider the processing factors other than washing with tap water in order to account for the reduction or removal of pesticides such as: washing (with acetic acid, sodium chloride and soap) and peeling. Also as a recommendation, we need to look to other types of food that are sold in Qatar and may contain pesticides residues, such as grains and dates. Future studies also should look to the presence of other type of pesticides such as organophosphorous and carbamates compounds.

Fadwa El Mellouhi1, Akinlolu Akande2, Sergey Rashkeev1, Mohamed El-Amine Madjet1, Golib Berdiyorov2, Carlo Motta2, Stefano Sanvito2 and Sabre Kais1, Fahhad Alharbi1

1Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar

2School of Physics and CRANN, Trinity College Dublin, Ireland

In the past four years, the solar cell field has experienced an unprecedented meteoritic emergence of a new family of solar cell technologies; namely, perovskites solar cells (PSC) using (CH3NH3)PbI3 as absorber. [1] However, two main challenges prevent deploying PSC technology: the presence of the toxic element lead (Pb) and their structural instability.

The CRANN-QEERI initiative for Solar Energy Harvesting Materials (CRAQSolar project) aims at establishing a new research protocol for the rational and rapid design of advanced materials for solar energy harvesting. This will drastically accelerate the time necessary for materials discovery and will allow us to produce a new generation of photovoltaic compounds displaying high efficiency, ease of manufacturability, longevity and low costs. Our research protocol is based on the rational design of new compounds by means of state-of-the-art high-throughput electronic structure theory, followed by synthesis, processing and characterization. In particular we will target both chemical synthesis and liquid phase processing, two protocols, which guarantee handling of materials at low temperature and low costs. The grand objective of CRAQSolar is that of revolutionizing such cycle and to provide a way for producing a significant pallet of new promising compounds for further optimization. In particular the project has two targets:

Objective 1: Developing new hybrid organic/inorganic perovskites (HOIPs) with robust solar harvesting efficiency but also useful thermal and mechanical stability. These should be synthesized/processed chemically and have mobility superior to their all-organic counterparts.

Objective 2: Developing a range of compounds made of 2D materials (such as MoS2, TiS2, GaS, etc.) with strong light absorption properties and long-living excitons. These will be processed from the liquid phase so that solar cells devices may be produced by ink-jet printing.

We conducted extensive density functional theory (DFT) calculations on the prototypical light absorbing perovskite, CH3NH3PbI3, in its cubic phase, by taking into consideration the experimentally reported evidence of the fast rotation of CH3NH3 at room temperature. This compound has the standard AMX3 perovskite structure, where the cation position, A, is taken by methyl-ammonium, CH3NH3.

Ground-state total energies and forces were computed using DFT calculations with the FHI-aims all-electron quantum chemistry code [2]. These were used to optimize the crystal geometry, without the use of constraints. The GGA in the Perdew-Burke-Ernzerhof (PBE) parameterization was employed. Long-range van der Waals interactions have been taken into account via the Tkatchenko and Scheffler (TS) scheme [3]. The reciprocal space integration was performed over an 8 × 8 × 8 Monkhorst-Pack grid after performing convergence tests on the energy and forces.

Our pioneering work for this class of material consisted of lifting the limitation imposed in previous studies on the orientation of the organic molecule. This means that we did not limit our analysis to CH3NH3 oriented along the (100) or the (111) direction, for which the high Oh symmetry is maintained, but we also explore cases where the symmetry was lowered. Our main conclusion was that such symmetry lowering has profound consequences on the electronic structure namely that the bandgap changes from direct to indirect depending on the orientation of the CH3NH3 group.[4] Crucially such symmetry-lowering configurations represent local minima in the free energy surface of the crystal and they are stabilized by van der Waals (vdW) interactions. These are the key ingredients not only for obtaining accurate lattice parameters but also for the internal geometry. Our calculations then return a picture of the CH3NH3PbI3 as a “dynamical” bandgap semiconductor, in which the exact position of the conduction band minimum depends on the particular spatial arrangement of the molecules. Importantly our results are robust against bandgap corrections and spin-orbit interaction, and deliver an absorption spectrum in good agreement with experimental data near absorption edge.

These preliminary studies suggest that better efficiency might be achieved by seeking novel molecules maybe combined with different halides in order to enhance the symmetry breaking in these compounds. Our finding thus offers a design strategy to increase the efficiency of hybrid halide perovskites. This also lays a foundation in screening and designing alternative nontoxic lead-free materials.

The two classes of compounds selected for CRAQSolar's exploration encompass some among the most promising materials for developing a solar energy harvesting technology. In particular, since both can be grown and processed chemically from the liquid phase, they offer the possibility of achieving high energy-conversion efficiency, while maintaining low fabrication costs. Furthermore, these are families of compounds comprising a vast number of members with highly tunable properties, so that they are the ideal platform for a large-scale search.

Our efforts to design lead free family of hybrid materials demonstrate that the design of hybrid materials containing organic cations might require careful considerations among them the size of the cell used during the screening process. Our strategy will be presented as well as some resulting promising compounds.

Acknowledgement

Computational resources are provided by research computing at Texas A&M University at Qatar and the Swiss Super Computing Center(CSCS). This work is supported by the Qatar National Research Fund (QNRF) through the National Priorities Research Program (NPRP 8-090-2-047)

References

[1] M. Peplow, “The perovskite revolution [news],” Spectrum, IEEE, vol. 51, no. 7, pp. 16–17, 2014.

[2] V. Blum, R. Gehrke, F. Hanke, P. Havu, V. Havu, X. Ren, K. Reuter and M. Scheffler, Ab initio molecular simulations with numeric atom-centered orbitals, Comp. Phys. Comm. 180, 2175 (2009).

[3] A. Tkatchenko and M. Scheffler, Accurate molecular van der Waals interactions from ground-state electron density and free-atom reference data, Phys. Rev. Lett. 102, 073005 (2009).

[4] C. Motta, F. El Mellouhi, S. Kais, N. Tabet, F. Alharbi, and S. Sanvito, Revealing the role of organic cations in hybrid halide perovskites CH3NH3PbI3, Nature Communications 6, Article number:7026 (2015) (doi:10.1038/ncomms8026)

Karst is ubiquitous on the peninsula of Qatar, including depressions, sinkholes, and caves. Faulting and fractures play a major role in the development of karst, where fluids find pathways through limestone and dissolve the host rock. The resulting fissures may grow larger as more surface water is funneled through to form cavities or karst. Sinkholes may also form, when cavern roofs collapse, and it is this last characteristic that is of concern to rapidly growing metropolitan areas, that expand in heretofore unexplored regions. Qatar has seen a recent boom in construction, including the planning and development of complete new sub-sections of metropolitan areas. Before planning and construction can commence, the development areas need to be investigated to determine their suitability for the planned project. Of particular concern are ubiquitous karst features that are prone to collapse, particularly when surface loading is increased due to the construction of new buildings. In this paper, we present the results of a study to demonstrate a variety of seismic techniques to detect the presence of a karst analog in form of a vertical water-collection shaft located on the campus of Qatar University, Doha, Qatar. Seismic waves are well suited for karst detection and characterization. Voids represent high-contrast seismic objects that exhibit strong responses due to incident seismic waves. However, the complex geometry of karst, including shape and size, makes their imaging nontrivial. While karst detection can be reduced to the simple problem of detecting an anomaly, karst characterization can be complicated by the 3D nature of the problem of unknown scale, where irregular surfaces can generate diffracted waves of different kind. In our current paper we build upon previous results (Gritto et al, 2015) and employ a variety of seismic techniques to demonstrate the detection and characterization of a vertical water collection shaft analyzing the phase, amplitude and spectral information of seismic waves that have been scattered by the object. The experiment consisted of seismic transmission and reflection surveys, using a 10 kg sledge hammer as a source and three-component 10 Hz geophones to record the data. We used the reduction in seismic wave amplitudes and the delay in phase arrival times in the geometrical shadow of the vertical shaft to independently detect and locate the object in space. Additionally, we use narrow band-pass filtered data combining two orthogonal transmission surveys to detect and locate the object. Our analysis showed that ambient noise recordings may generate data with sufficient signal-to-noise ratio to successfully detect and locate subsurface voids. This is a result of the low intrinsic attenuation of seismic waves by the limestone and dolomite rocks that are ubiquitous throughout Qatar. Being able to use ambient noise recordings would eliminate the need to employ active seismic sources that are time consuming and more expensive to operate.

Bimetallic catalyst shows distinct physical and chemical properties differ from its monometallic catalyst due to the high synergy between the monometals. Bimetals of transition metals shows different applications in the field of catalysis, batteries and solar energy conversion etc. CuCo bimetallic catalysts are excellent candidate for the applications in the field of heterogeneous catalysis, solid state sensor, energy storage devices, and lithium-ion batteries. With the increase in fuel cell application, need of H2 source also rises. H2 can be extracted from the hydrogen rich precursors of light alcohol such as methanol and ethanol that can be produced from corn stover, starch containing materials and other biomass byproducts. Ethanol is low toxic and easy handling renewable source for H2 production for fuel cell applications and the production of ethanol is environmentally sustainable. Transition metal possess high C-C cleavage bond which is an indispensable property in ethanol conversion. Steam reforming, partial oxidation, dehydrogenation and decomposition are the main routes for the hydrogen generation from ethanol. Out of these, decomposition technique is a low temperature process and suitable for small scale fuel cell applications e.g. charging cell phones, computers etc. We follow decomposition route for H2 production along with other necessary byproducts. Bimetallic CuCo catalyst shows good performance during ethanol decomposition for hydrogen production in the temperature range of 50°C-400°C. Various physical and chemical techniques (such as thermal method, precipitation methods, pyrolysis process, sonochemical method, polyol method, microwave irradiation, sol-gel process, combustion method etc.) have been reported for the synthesis of different morphological structures of bimetallic nanoparticles In this work we are following combustion synthesis method to prepare cobalt catalysts which have been reported to be active for ethanol-hydrogen production. This work focuses primarily on understanding the reaction mechanism leading to various products using in situ DRIFTS studies. Combustion synthesis was opted for synthesis due to various advantages such as low energy requirement, single step, fast and economic synthesis process as it does not require expensive equipment. In Solution Combustion Synthesis (SCS) the precursors were mixed to form a homogenous solution and heated it over the hotplate heater to initiate the combustion process which resulted in the synthesis of nanoparticles with uniform properties. Typically, it consist a redox reaction of the homogeneous mixture of metal nitrate (oxidizing agent) and oxygen containing fuels (reducing agent) such as glycine, urea, glucose, citric acid etc. The reaction between NH3 and HNO3 released during decomposition of glycine and metal nitrate respectively produces the energy required for single step combustion synthesis. At higher value of φ, the reactive medium generates H2 rich reducing environment to convert metal oxide to metallic form Bimetallic CuCo were synthesized from the aqueous solution of cobalt nitrate (Co(NO3)2·6H2O), copper nitrate (Cu(NO3)2·6H2O) and glycine (C2H5NO2) in solution combustion synthesis (SCS) method using a fuel to oxidizer ratio of φ 0.5, 1, 1.75 and 2.5. The amount of precursors was calculated based on the synthesis of 1.5 g product in the output. These precursors were mixed in 75 ml of water and stir continuously for 1 hr to form a homogenous mixture. The solution was heated over a hot plate heater until all the water got evaporated. Once it reaches the ignition temperature, the combustion reaction started locally at one point and then spread inside the beaker. The resulted powder was grinded using a mortar and pestle to get a uniform powder to be used for catalytic investigations. Synthesized particles were characterized using XRD, SEM and TEM. Ethanol decomposition over bimetallic CuCo were conducted using in situ diffuse reflectance infrared fourier transform spectroscopy (DRIFT) study under N2 flow at different temperatures (50, 100, 200, 300, 400°C). Temperature-time profile of CuCo shows an increase in combustion temperature with increase in fuel ratio with maximum temperature at φ =  1 (stoichiometric ratio) and after that it decreases. The XRD shows the presence of copper-cobalt component in their oxidized states. Theoretical studies shows increase in particle size with maximum flame temperature. Crystalline size calculation using Scherrer formula shows the same trend in particle size calculation as in Table 1. SEM of as-synthesized nanoparticles of cobalt oxide at different molar ratios from 0.5 to 2.5 in SCS mode shows the nanoparticles of high porosity that are randomly distributes as well as agglomerated. Mostly this high porosity is due to the escaping of excess gases during combustion process. Also the EDS results are in consistent with the XRD results showing higher amount of oxide in the synthesized CuCo compound. TEM image in Fig. 1 also shows agglomeration that is common in solution combustion mode with non-uniform sized particles. Copper-cobalt oxide synthesized using combustion technique has been reduced to pure nanocrystal by passing hydrogen in the reaction chamber at 300°C. An FTIR spectrum at 50 and 100°C shows the presence of adsorbed ethanol and ethoxy species over the reduced catalyst. IR band at 3669 cm^− 1 indicates the presence of OH from adsorbed ethanol on the catalyst surface. At higher temperature the molecularly adsorbed ethoxy species is converted into acetate species along with the presence of carbonate species. After increasing the temperature from 200°C the intensity CO2 band at 2335-2367 cm^− 1 is evident. At this temperature the acetate species are dehydrogenated to acetaldehyde and other intermediate species. Strong acetate band of 1760 cm^− 1 above 200°C could be due to the transformation of acetaldehyde formed by the dehydrogenation of ethanol to either ethyl acetate or acetic acid though the nucleophilic reaction of ethoxy or hydroxyl species with the surface aldehyde. The presence of IR band between 2830-2695 cm^− 1 shows the presence of aldehyde group in the decomposition reaction. At higher temperature, the presence of carbonate species is evident with the carbonate layer formation from SEM and TEM images. This carbon layer at higher temperature hinders the action of catalyst in ethanol decomposition reaction.

Acknowledgement

This publication was made possible by JSREP grant (JSREP-05-004-2-002) from the Qatar national research fund (a member of Qatar foundation). The statements made herein are solely the responsibility of the author(s). The authors also wish to acknowledge the technical services granted by Central Laboratory Unit (CLU) and Gas Processing Centre (GPC) at Qatar University along with QU internal grant (QUUG-CENG-CHE-14/15-9) to support this research

Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total U.S. GHG emissions in 2013. This is why the adoption of hybrid and all-electric vehicles (EVs) instead of conventional gasoline powered vehicles with renewable source of power has been identified as the most effective GHG emissions mitigation strategy. This strategy not only saves considerable amounts of transportation-related CO2, but also reduces the demand for electricity in buildings, which is mainly supplied by coal-fired generation. Since solar energy is the only source of renewable energy that can be applied at a small scale (e.g. directly to the roof decking or solar window), this paper focuses only on the mitigation strategies in which EVs are powered by solar energy. One reason mitigation strategies are having difficulty delivering the desired outcome sought by policy makers is that many factors that affect the success or scale of GHG emissions reductions are uncertain and complex. Vehicle's specification (e.g. battery capacity, weight, and optimal energy use), road type and driving behavior (e.g. average speed), and environmental conditions (e.g. temperature and sunlight) are among the many factors affecting either energy consumption or generation and characterized by a significant degree of uncertainty. Thus, urban community planners and policy makers are confounded with huge amounts of unknown parameters, in which they wish to find the best solution from all feasible solutions (e.g. the largest GHG emissions reduction that a mitigation strategy can achieve) in the presence of uncertainty. The objective of this paper is to develop a stochastic mathematical model for energy consumption and mitigation strategy analysis that maximizes GHG emissions reductions based on the current demand trend and market prices. In this model, we consider EV and solar system costs, as well as the human activities (e.g. time spent in the building, time spent driving, and distance traveled) and environmental impacts (e.g. temperature, humidity, and sunlight) under uncertain conditions. What makes this study different from previous energy management or GHG emissions mitigation research is its focus on small-scale energy system and its validation process. Although mitigation actions through large-scale changes in energy system (e.g. new renewable energy power plant) will undoubtedly result in the largest GHG emissions reductions, but they also require major changes in the generation part of the energy sector and definitely need more investment. One the other hand, small-scale GHG emissions mitigation actions (e.g. EVs powered by solar energy) can be accomplished by local communities and characterized by a short decision making cycle, need much less investment, and also eliminate electricity losses in transmission and distribution systems. These all make small-scale GHG emissions mitigation strategies more practical and feasible. Another principal problem with prior energy management or GHG emissions mitigation research is that optimization models have not been validated with real data. In contrast, the proposed optimization approach is validated by comparing the estimated values of the optimal decision and actual values as realizations of the uncertain elements become known. Problem Statement The use of hybrid or EVs alone does not necessarily reduce the transportation's GHG emissions and it depends on the energy source. A conventional gasoline powered vehicle with 30 miles per gallon (mpg) fuel efficiency emits about 0.65 pounds CO2 per mile driven. In contrast, an EV with an average energy use of 3 mile per kWh emits about 0.71 pounds CO2 per mile driven when coal-fired electricity is used, and it emits 0.40 pounds CO2 per mile driven when natural gas-fired electricity is used. In order to optimize the mitigation strategies in which EVs are powered by solar energy (EV + solar power strategy), both energy supply (electricity generation) and demand (electricity consumption) sides must be considered. Research Methodology There are three primary solar systems: off-grid, grid-tied, and hybrid. Off-grid solar systems feed the extra energy the solar panels produce into batteries, while grid-tied solar systems send excess power to the electrical grid. Both off-grid and grid-tied systems yield the same amount of CO2 emissions reduction when the solar panels produce enough power for charging EV's batteries. When the solar panels are not producing the power required for charging an EV (e.g. during cloudy weather or night), however, grid-tied systems use electricity from the grid but off-grid systems use electricity stored in batteries. Depending on the electrical grid energy source in this case, a mitigation strategy using grid-tied systems may add a significant amount of CO2 to the atmosphere. Hybrid solar systems offer the flexibility of using a battery backup and being connected to the grid. Therefore, the outcome of a mitigation strategy using hybrid systems depends largely on the power generation capacity of the solar system. The area of solar panels, the solar cell efficiency and temperature coefficient, irradiance of input light, and temperature are the main factors affecting the capacity of a solar system. In the present problem, the decisions variables are the type of EV, which determines the optimal EV's energy use, the capacity of the solar system in the case of grid-tied system as well as the solar system storage capacity in the case of off-grid and hybrid system. Under a pre-specified budget constraint, the objective is to find these decision variables in such way to maximize GHG emissions reductions. The present model starts the optimization process by identifying the energy source of electricity generation. The electrical grid energy source is determined by the electricity demand at time t, Load t, and the electric power plants generating capacity, PPCj. The time index t takes integer values between 1 and N, where N is the time horizon of the analysis and the units of time measurement are hours. For instance, Load30 indicates the electricity demand on day 2, 6 AM. Smaller time horizons for the analysis and the prediction require less computation efforts but they are less accurate. To obtain a perfect reference for the best possible GHG emissions mitigation strategy, we solve a stochastic optimization problem with a prediction horizon of 1 hour over a year, thus N is 1 ×  365 × 24 = 8760 hours. The power plant index j indicates the respective set of the renewable (j = 1), nuclear- (j = 2), natural-gas (j = 3), coal- (j = 4), and oil-fired (j = 5) power plant. Load t is a probabilistic variable because it is unknown at the time the decision should be made; however, PPCj is a deterministic variable and is known for the analysis region. It is assumed that the supply level is sufficient to meet peak demand. The CO2 emissions at time t are then calculated for each type of solar system. For a grid-tied system, the CO2 emissions (measured in lb or kg) are calculated which may be positive or negative. A Negative value indicates a reduction in the CO2 emissions. When an EV is charging at time t, the energy generated by solar panel will be used in transportation sector. However, when an EV is not charging, all the energy will be used in the building. For an off-grid system, the factor that can seriously affect the CO2 emissions is the solar battery's state of charge. This factor is a function of the solar system storage capacity, and the charging duration, which starts at the last prediction horizon, and ends at time t. Once the solar batteries are fully charged, the extra energy the solar panels produce will be used only in the building. Since off-grid solar systems are not connected to the electrical grid, the energy produced by the system can meet at most the building's demand (DB) and the rest is wasted. This happens when the solar batteries are fully charged and the system is producing more energy than building's load. In the off-grid system, the EV is charged using the electricity stored in batteries. When the energy required to fully charging the EV exceeds the electricity stored in batteries, the EV will be charging using both the batteries and the electrical grid. In contrast to an off-grid solar system, no extra power is wasted in hybrid systems because they can send excess power to the electrical grid. In order to reduce more GHG emissions, the energy generated by solar panel must preferably be used to charge EV's vehicle batteries. For a grid-tied system, this happens when the EV is charging right when the solar system is producing energy. Off-grid and hybrid solar systems offer the flexibility of using a battery backup to charge the EV even when the solar system is not producing enough energy, for example during cloudy weather or night. Thus, it is assumed that the power from the solar system is first used to charge the batteries and then excess power is used in the building or fed into the electrical grid. In order to estimate the electricity generated by solar system, the distributions of stochastic variables such as solar irradiance and temperature are obtained from the weather records over the last 20 years from 1994 to 2014. Also, a database of 46 solar panels from 15 manufacturers is used to obtain solar cell efficiency and temperature coefficient. The average efficiency of 15.86% and temperature coefficient of -0.44 %/°C are used in the analysis. In order to estimate the electricity demand at a given time, the distributions of hourly load are obtained from the operable electric generating plants with a combined rated capacity of 1 MW or more over the last 18 years from 1996 to 2014. The Energy Information Administration (EIA) was the primary sources of hourly load data. Results and Conclusions Results show that among three primary solar systems (i.e. off-grid, grid-tied, and hybrid), a hybrid system consists of 7 modules of solar panels with 6 kWh storage capacity was found to be the best solution. Hybrid solar systems overcome the disadvantage of off-grid solar systems by sending the excess power to the electrical grid and reduce more CO2 emissions than grid-tied solar systems by using the electricity stored in batteries in transportation sector instead of buildings. The presented model is also capable of estimating CO2 emissions reductions from mitigation strategies in which EVs are powered by solar energy. With this capability, urban community planners and policy makers will know how long it will take for their strategy to meet GHG emissions reduction targets. The stochastic optimization problem was solved with a prediction horizon of an hour over a month. Then, CO2 emissions reductions estimated by the presented stochastic model were compared with actual data collected on an hourly basis for the analysis period of one month (720 hours). The results showed an accuracy of about 4% when the EV is powered by a grid-tied or hybrid solar system. When applied to an EV + off-grid solar power strategy, the stochastic model estimated CO2 emissions reductions 11% lower than the actual reductions. Overall, the presented stochastic model had better performance than deterministic methods for different types of solar systems.

In the present architecture of the electric power grids, energy is generated in large-scale that is remotely located from consumers and transmitted using passive high-voltage transmission networks to substations. The electric power is then delivered to consumers via medium and low-voltage distribution systems. Line frequency transformers (LFTs) enable high-efficiency and long-distance power transmission by stepping up the voltage on the transmission side. On the distribution side, the voltage is stepped down for industrial, commercial, and residential consumers. Furthermore, the traditional electric power system is characterized by hierarchical control structures with minimal feedback, limited energy storage, and passive loads. In recent years, the electric power system has been facing increasing stress due to fundamental changes in demand growth, technology change, and consumer preference. There has been a paradigm shift from centralized generation and control to distributed generation, storage and local control; in particular, there has been a global growth of investments in Renewable Energy Sources (RES) such as wind and solar. These RES generate fluctuating electric power and therefore they require Energy Storage Systems (ESS) to enable a time-shift between energy production and consumption. The high penetration of RES and other Distributed Generation (DG) types such as fuel cells (FCs) and Micro-Turbines (MTs) impose significant challenges on the operation of power system and coordination of supply and demand in real time. At the same time, the power system will need to react to events for which it was not designed for. Microgrids (MGs), being controllable small scale power networks, have become popular in distributed systems by facilitating an effective and smooth integration of distributed energy resources, loads, and energy storage devices into existing power systems. They help reduce expenditure by reducing network congestion, line losses and line costs and thereby higher energy efficiency. Power electronics converters are used in microgrids to control the routing of electricity and also provide flexible distributed generation sources interfaces to the distribution network to ensure stable and secure operation of the grid. These power converters rely on the type of microgrid (AC or DC), as well as on other features of the devices (voltage levels, power flow direction, etc.). In addition, they usually include a transformer in order to obtain galvanic isolation. The solid state transformer (SST), which is also called Electronic Power Transformer (EPT), Active Power Electronics Transformer (APET) and Intelligent TRansformer (ITR), has been proposed to replace the traditional line frequency distribution transformers. The basic operation of the SST is first to change the 50Hz AC voltage to high frequency (normally in the range of several to tens of kilohertz), then this high frequency voltage is stepped up/down by a high frequency transformer with significantly decreased volume and weight, and finally shaped back into the desired 50Hz voltage to feed the load. The SST is a power electronics circuit that provides a flexible method for interfacing microgrids with the existing Medium-Voltage (MV) power distribution system. It achieves voltage transformation via a high-frequency isolated transformer, therefore the mass and volume of the system can be reduced. Current and voltage are independently controlled via power semiconductor devices which enables grid support functions not present in the traditional LFT, including voltage and power factor regulation, fault isolation and limitation, filtering harmonic, reactive power compensation, power flow control and voltage and load disturbance rejection. However, at the present time, the commercial success of SSTs has been limited. Efforts have been made to design and implement SSTs with satisfactory performance, as well as explore its use at the distribution system level. The SST can functionally replace the traditional LFT and some power electronics converters, thus indicating a potentially more integrated and compact system. Although the concept of the SST can be seen straight forward, its implementation is a challenge. The SST combines the high voltage, high power, and high frequency operation, which make its design and operation a real challenge. To implement the SST, different power devices can be combined with different circuit topologies in different configurations. In addition, different core materials and transformer structures may be considered to build the high frequency transformer with different phase connections. Furthermore, due to power rating limitation of the semiconductor devices and magnetic components, SST topologies may have several SST cells connected in series or in parallel. Numerous degrees of freedom for the SST modularization are available, which lead to a vast amount of possible arrangements depending on the different levels of modularization in the three modularization axes: degree of power conversion partitioning; degree of phase modularity and number of levels or series/parallel connected cells. Since the level of modularity in each of these different directions is independent, these three axes can be considered to be orthogonal to each other and each element represents a specific design with a certain degree of modularization in each of the axes. The SST can be used as an enabling tool for interfacing microgrids (AC and DC) to medium voltage distribution network. For a SST-based microgrid, the performance of the microgrid mainly depends on the control algorithms of the SSTs. Generally, there are three SST control levels: system level, equipment level, and switch level. For a well-designed SST, the equipment level and firing level control strategies are well defined. However, the system level control strategy can be changed to fit different applications. In order to operate a microgrid properly and reliably, SST- based power control strategies should be developed to accommodate the modes of operation: grid-connected mode and standalone mode. That is why, the development of a controller that manages active and reactive power flow between the DC microgrid, the AC microgrid and the main distribution network is one of the most important research topic for the SST. Furthermore, investigating the effect of grid faults on the stability and performance of the SST is another hot research topic in the same area. Also, the SST can be used in different applications, such as: oil and gas and electric transportation applications. To give an overview of the SST, this work will present a review of the different levels of modularization, all possible control algorithms for the different control levels. Furthermore, stability and reliability analysis for grid connected SST will be reviewed. Finally, all possible application of the SST will be presented.

Qatar peninsula is an arid country with limited water resources. With little rainfall of approximately 80 mm per year and no surface water, aquifers are the only source of natural water in Qatar. The groundwater aquifer receives around 50 million m³ per year as natural recharge, whereas annual groundwater abstraction is more than 220 million m³, mainly used for agriculture. Groundwater occurs in a form of fresh lenses mainly in the northern part of the country, sitting atop of brackish and saline groundwater. Seawater has progressively intruded inland over the last decades because of over-pumping. As a result, the water table has dramatically dropped to unprecedented levels and salinity increased, in addition to other adverse environmental impacts. Because of its karstic nature, Qatar aquifer is prone to different sources of adverse environmental impacts. The concept of aquifer vulnerability is based on the idea that some areas above an aquifer provide more resistant to contamination than others (Vrba and Zaporozec 1994). Mapping groundwater vulnerability using hydrogeological settings gives a clear understanding of natural variation from one point to another within an aquifer. Vulnerability mapping is a powerful tool that can be used for groundwater protection and land management. In this study, vulnerability map was created based on hydrogeological parameters, land use and natural groundwater quality. All maps have been prepared and manipulated within Geographical Information System (GIS). The final vulnerability map was obtained as a sum of different rated maps using Raster Calculator. Two different approaches were used to create vulnerability maps (a) DRASTIC approach, which depends on general hydrogeological settings, and (b) EPIK approach, which focuses on karst hydrogeology. DRASTIC approach uses seven rated maps of: depth to water table, recharge, aquifer media, soil media, topography, vadose zone and hydraulic conductivity to calculate a weighted index map of vulnerability (Aller et al., 1987). EPIK approach is based on (1) epikarst, (2) protection cover, (3) infiltration rate and (4) karstic network. Depth to water table varies from a few meters near the coast to tens of meters further inland and recharge occur mainly in the many land depressions that spread all over the country. These land depressions vary in diameter from a few meters to more than two kilometers. These depressions were formed as a result of land collapse due to cavities underneath. The cavities are the result of dissolution of limestone over thousands of years. In all cases, these depressions have a high weight in vulnerability assessment. Soil may provide some sort of aquifer protection depending on its type and thickness. The dominant soil in Qatar is lithosol, which is composed of rocky soil and provide no protection. Some loamy sand exists in farm lands, which is normally derived by rainfall runoff and provide some protection cover. Aquifer media comprises limestone with dolomite, chalk and clay of variable thicknesses. Three main layers of limestone occur in Qatar. These layers are from top to bottom (1) Dam and Dammam Formation, (2) Rus Formation and (3) Umm Alraduma Formation. Results of aquifer tests show aquifer is highly heterogeneous, which is typical in karst environment with high variation of hydraulic conductivity values. A thick layer of gypsum occurs within the middle layer of limestone (Rus) in the southern part of the country and has a great implication on water quality. This layer is soluble in water, which deteriorates the groundwater quality. All the previously discussed hydrogeological settings have been used to create vulnerability maps in Qatar. While DRASTIC laid more weight on coastal sediments, as they appear to be highly vulnerable in the final map, EPIK approach laid more weights on karst formations in the middle of the country. DRASTIC approach shows high vulnerability areas occur along the coastline and in land depressions Results of both approaches show the high vulnerable areas are those were land depressions occur.

Qatar seeks to generate 2% of its electricity from solar power by 2020 (Bryden et al., 2013, REN 2015), and 20% by either 2024 (PV Insider, 2014) or 2030 (REN, 2015). Since electricity is produced almost entirely from natural gas in Qatar, these renewable energy targets introduce the prospect of natural gas savings that can be made use to increase trade and/or reduce carbon emissions. Electricity production in Qatar has been growing at a very fast pace since the mid-nineties. An estimated 7.3 millions of tons of oil equivalent (Mtoe) of natural gas were used in 2013 to produce 34.7 terawatt-hours (TWh), double the amount in 2007 and over five times as compared to 1997 (Table 1).

Table 1: Electricity production with associate natural gas (NG) use in Qatar 1971–2013. Source for electricity data: http://www.iea.org. Gas usage calculated as the estimated average efficiency for power plants using natural gas in the US for the period 2003–2013 (40.84%) estimated by the U.S. Energy Information Administration (http://www.eia.gov/electricity/annual/html/epa_08_01.html). Year – TWh produced in Qatar – NG used (Mtoe)1971 0.285 0.0601972 0.358 0.0751973 0.380 0.0801974 0.413 0.0871975 0.513 0.1081976 0.717 0.1511977 0.835 0.1761978 1.196 0.2521979 1.877 0.3951980 2.351 0.4951981 2.700 0.5691982 2.998 0.6311983 3.194 0.6731984 3.507 0.7381985 3.918 0.8251986 4.249 0.8951987 4.329 0.9121988 4.592 0.9671989 4.624 0.9741990 4.818 1.0141991 4.643 0.9781992 5.153 1.0851993 5.522 1.1631994 5.815 1.2241995 5.976 1.2581996 6.575 1.3841997 6.869 1.4461998 8.122 1.7101999 8.584 1.8072000 9.134 1.9232001 9.951 2.0952002 10.940 2.3042003 12.012 2.5292004 13.233 2.7862005 14.396 3.0312006 17.080 3.5962007 19.462 4.0982008 21.616 4.5512009 24.158 5.0872010 28.144 5.9262011 30.730 6.4702012 34.787 7.3252013 34.668 7.300

Ten-year forward projections, with cap limits of 200 Mtoe on yearly natural gas production, indicate that electricity production will peak at 48.4 TWh in 2021, with an associated natural gas use of 10.2 Mtoe (Table 2). Cap limits on natural gas production are necessary to prevent early depletion of natural gas reserves in Qatar, which have been estimated at 138 year at current output rates (QNB 2015).

Table 2: Ten-year projections (2014–2024) for electricity production and associated natural gas (NG) use in Qatar (Sanfilippo & Pedersen, in preparation). These projections assume that yearly NG production will not grow beyond 200 Mtoe. Year – Energy production (TWh) – NG needed for energy production (Mtoe) 2013 34.67 7.32014* 32.55 6.92015* 23.30 4.92016* 24.48 5.22017* 23.06 4.92018* 31.96 6.72019* 43.97 9.32020* 48.04 10.12021* 48.41 10.22022* 47.97 10.12023* 45.96 9.72024* 43.61 9.2.

The foreseen use of solar power to generate of electricity could yield a natural gas surplus of 0.2 Mtoe in 2020 and up to 1.8 Mtoe by 2024 or 2030, to reach 3.9 Mtoe thereafter, assuming a PV market peak of 43% in electricity generation – over 3.35% of Qatar total natural gas exports in 2013. This surplus could be repurposed for natural gas trade, and countries in the Far East stand as the most natural trading partners. Exports to Japan, Korea & China accounted for 41% of Qatar's NG world trade in 2013 (http://www.iea.org). Japan and Korea have historically been some of the greatest importers of natural gas from Qatar, and China is quickly emerging as a strong trading partner due to its growing need for energy. China's share in Total Primary Energy Supply (TPES) worldwide has grown from 7% in 1971 to 22% in 2013 (http://www.iea.org). China is now the world largest energy consumer with a 5% lead over the United States, the country that topped the list with 29% share of the world TPES in 1971. China's natural gas imports from Qatar rose from 0.5 to 8.8 Mtoe in only 5 years, from 2009 to 2013. Moreover, China is quickly becoming a major trading partner for Qatar. For the period 2009–2014, the trade between the two nations grew at a Compound Annual Growth Rate (CAGR) of 35.38%, as compared to 28.92% for the period 2003–2008 (http://data.imf.org). Across the same periods, Qatar's trade shows a sharp CAGR decline with both Japan (2009–2014 CAGR: 12.6 vs. 2003–2008 CAGR: 25.37%) and Korea (2009–2014 CAGR: 33.12 vs. 2003–2008 CAGR: 22.1%). Considering these market trends, China appears the most likely candidate partner for additional natural gas trade from Qatar. While the recent turbulence in Asian markets signals a slowdown in China's economy, it is unlikely that China's position as the world largest energy consumer will change in the years to come. Moreover, foreign natural gas is playing an increasingly important role in Chinese energy market (Higashi 2009). Despite plans by the Chinese government to expand domestic production, the internal Chinese natural gas market remains unbalanced (Li et al., 2014). The development and implementation of a new strategic roadmap are needed to manage the local production, marketing and transportation of gas efficiently. These changes may take decades to come to fruition, during which reliance on natural gas imports is bound to grow. In terms of carbon emissions, the amount of CO2 equivalent to the prospected 3.9 Mtoe of natural gas replaced by solar energy (see above) is 9,053,724 US tons, assuming the IEA estimate that each million British thermal units (MBtu) of energy generated by natural gas generate 117 pounds of CO2 emissions (http://www.eia.gov/tools/faqs/faq.cfm?id = 73&t = 11).

References

Bryden, J. Riahi, l., Zissler, R., (2013). MENA: Renewables Status Report. United Arab Emirates Ministry of Foreign Affairs, REN 21. International Renewable Energy Agency (IRENA).

Higashi, N. (2009). Natural gas in China. IEA Energy Markets and Security Working Papers.

Li, Z., Zhang, Q., Farfan Reyes, S., Wang, Z., (2014) Natural Gas Development strategy modeling in China. 4th International Association for Energy Economics Asian Conference, Beijing, China, September 19–21, 2014.

PV Insider, (2014). PV in MENA: Turning Policy into Projects. Retrieved on Nov 1, 2015 from http://www.pv-insider.com/menasol/pdf/policyintoplants.pdf. QNB, (2015).

QNB Economic Commentary, 21 June, 2015. REN21, (2015).

Renewables 2015 Global Status Report. http://www.ren21.net/status-of-renewables/global-status-report/. Sanfilippo, A. & Pederson, L., (in preparation).

Impacts of PV Adoption in Qatar on Natural Gas Exports to the Far East. In Lester, L. & Efird, B. (eds.) Energy Relations and Policy Making in Asia: The benefits of mutual interdependence, Palgrave Macmillan.

Among the diverse catalytic processes, the heterogeneous catalytic CO oxidation is an important reaction for removal of small amounts of poisoning CO in fuel cell applications and environmental remediation. Therefore, there is a great need to develop highly active and stable nanocatalysts for catalytic CO oxidation at low temperature. Plasmonic nanocatalysts supported on reducible metal oxide such as CeO2 and TiO2 have been known for their superior catalytic activity at very low temperature but they are expensive and could suffer from particle agglomeration and sintering at high operating temperature (Veith, Lupini et al. 2009). Transition metals supported on reducible metal oxides are good substituents catalysts because of their low cost and wide-use along with activities per unit surface area similar to those of noble metal catalysts. They been shown to possess high oxygen release capacity at high range of temperature and have been shown as good candidate materials for oxygen storage and to provide oxygen for combustion and oxidation reaction at high temperature. (Royer and Duprez 2011; Hedayati, Azad et al. 2012; Song, Liu et al. 2013). In particular, supported CuO nanostructures have received a great deal of attention as non-expensive and non-plasmonic catalysts for oxidation reaction. (Caputo, Lisi et al. 2007; Hornes, Hungria et al. 2009; Royer and Duprez 2011; In, Vaughn et al. 2012; Komarneni, Shan et al. 2012; Chen, Xu et al. 2015; Fang, Xing et al. 2015; Kim and Liu 2015) In this study, we have developed a highly stable and active CuO-TiO2 nanocatalyst that can catalyze the CO oxidation at low temperature window between 80–200°C. The CuO-TiO2 nanocatalysts were prepared by the hydrothermal synthesis of TiO2 nanotubes followed by the deposition precipitation of CuO nanoparticles in alkaline conditions. We first prepared the TiO2 nanotube support by the hydrothermal treatment of TiO2 spherical particles in strong alkaline solution at 140°C. We then synthesized a series of CuO-TiO2 catalysts by deposition precipitation at constant pH, with sodium carbonate as the alkali precipitating agent and different loading ratios of Cu to TiO2 between 2% and 30 wt.%. We studied the morphological and structural properties of prepared nanocatalysts using standard physical techniques including SEM, EDX, TEM, TGA, XRD and XPS in order to understand the structure-property relationship and to optimize their catalytic activity. We carried out multiple catalytic CO oxidation cycles in a continuous flow fixed-bed reactor at low temperature range (25–300°C) and studied the catalytic activity of the different CuO-TiO2 nanocatalysts and their stability under stream. We also studied the effect of shape of the TiO2 support and the effect of the mole ratio of CuO loading on the CO conversion rates. The catalytic activity of the single counterparts of CuO and TiO2 were measured for comparison. The experimental results revealed that the CuO nanoparticles supported on TiO2 nanostructures exhibited higher activity and enhanced CO conversion rates at lower temperature, compared to un-supported CuO nanoparticles. The increased activity at lower activation temperature is probably due to the increased degree of dispersion of the active CuO phase on the TiO2 support as concluded from the EDX mapping study. Moreover, the results showed that the correlation between the catalytic activity of CuO-TiO2 nanocatalysts and both the shape and crystalline phase of the TiO2 support. The CuO supported on TiO2 nanotubes demonstarted enhanced CO conversion rates at lower temperature compared to that supported on TiO2 nanospheres. In all samples the CuO-TiO2 nanocatalysts calcined at 400°C exhibited the anatase phase of the TiO2 nanotubes support and demonstrated higher activity. The results also showed that increasing the Cu to Ti ratio could lower the activation temperature needed for CO to CO2 conversion probably due to the enhanced synergetic effect of the two mixed metal oxides. In addition, the XPS study of the CuO-TiO2 composite oxide structure indicated high degree of oxygen deficiency in CuO-TiO2 nanocatalysts with higher Cu to TiO2 loading and this could result in CO oxidation rates. The prepared CuO-TiO2 nanocatalyst demonstrated a high stability for CO oxidation for test periods of up to 5 h under stream at 200°C. The prepared CuO-TiO2 nanocatalysts could have potential applications in hydrogen purification in fuel cell systems and for CO removal in carbon dioxide lasers and in air quality industries.

References

Caputo, T., L. Lisi, et al. (2007). “Kinetics of the Preferential Oxidation of CO over CuO/CeO2 Catalysts in H2-Rich Gases.” Industrial & Engineering Chemistry Research 46(21): 6793–6800.

Chen, G., Q. Xu, et al. (2015). “Facile and Mild Strategy to Construct Mesoporous CeO2-CuO Nanorods with Enhanced Catalytic Activity toward CO Oxidation.” ACS Applied Materials & Interfaces 7(42): 23538–23544.

Fang, B., Y. Xing, et al. (2015). “Hierarchical CuO-TiO2 Hollow Microspheres for Highly Efficient Photodriven Reduction of CO2 to CH4.” ACS Sustainable Chemistry & Engineering 3(10): 2381–2388.

Hedayati, A., A.-M. Azad, et al. (2012). “Evaluation of Novel Ceria-Supported Metal Oxides As Oxygen Carriers for Chemical-Looping Combustion.” Industrial & Engineering Chemistry Research 51(39): 12796–12806.

Hornes, A., A. B. Hungria, et al. (2009). “Inverse CeO2/CuO Catalyst As an Alternative to Classical Direct Configurations for Preferential Oxidation of CO in Hydrogen-Rich Stream.” Journal of the American Chemical Society 132(1): 34–35.

In, S.-I., D. D. Vaughn, et al. (2012). “Hybrid CuO-TiO2 − xNx Hollow Nanocubes for Photocatalytic Conversion of CO2 into Methane under Solar Irradiation.” Angewandte Chemie International Edition 51(16): 3915–3918.

Kim, H. Y. and P. Liu (2015). “Complex Catalytic Behaviors of CuTiOx Mixed-Oxide during CO Oxidation.” The Journal of Physical Chemistry C 119(40): 22985–22991.

Komarneni, M., J. Shan, et al. (2012). “Adsorption Dynamics of CO on Silica Supported CuOx Clusters: Utilizing Electron Beam Lithography To Study Methanol Synthesis Model Systems.” The Journal of Physical Chemistry C 116(9): 5792–5801.

Royer, S. and D. Duprez (2011). “Catalytic Oxidation of Carbon Monoxide over Transition Metal Oxides.” ChemCatChem 3(1): 24–65.

Song, Q., W. Liu, et al. (2013). “A high performance oxygen storage material for chemical looping processes with CO2 capture.” Energy & Environmental Science 6(1): 288–298.

Veith, G. M., A. R. Lupini, et al. (2009). “Thermal stability and catalytic activity of gold nanoparticles supported on silica.” Journal of Catalysis 262(1): 92–101.

The current study is a laboratory investigation to estimate the levels of activity concentrations of Naturally Occurring Radioactive Materials (NORM) in groundwater in the Dukhan area in the State of Qatar. The primary radionuclide associated with clear gamma-ray decay signatures of concern in NORM wastes is 226Ra (from the 238U decay series) and its decay progenies 214Pb and 214Bi. Previous studies which were conducted on radioactivity concentration in soil in the State of Qatar have shown elevated levels of enhanced radioactivity in the area, North-West Dukhan, known for its oil fields. With the original aim of investigating the correlation between the underlying geological background and any measured elevation in the activity concentration of 226Ra, an anomalously high value of 226Ra activity had been observed for a number of measured samples in our earlier work, in this particular area and in particular. The weighted mean value of the activity concentrations of 226Ra in one of the samples was found to be around approximately a factor of 10 higher than the accepted worldwide average value of 35 Bq/kg. Our first study reported a value of about 201.9 ± 1.5Stat. ± 13Syst. Bq/kg for 226Ra in one sample,¹ while our further and focused (smaller grids) investigation in the latest work determined a measured value for 226Ra of about 342.00 ±  1.9Stat. ± 25Syst. Bq/kg in a sample taken from the same locality.² This is significantly higher than all the other investigated soil samples in the current and previous work and was likely to be in a heterogeneous distribution. This was found to be attributed to the weak correlation between the levels of activity concentration of 226Ra and the type of soil in this area implying that the increased 226Ra concentration arises from discharging co-produced water directly to land surface in this area. A preliminary study on the level of natural radionuclides in eight groundwater samples for this specific area using five cutting edge techniques in the national and collaborating laboratories will be presented. About half of those samples were collected from Dukhan farms where the groundwater was used for irrigation. Measurements for 222Rn concentrations in groundwater will be conducted using Rad-7 and a Liquid Scintillator Counter (LSC) at the Physics Department, Faculty of Sciences, Princess Nora Bint Abdul Rahman University, KSA. The activity concentration of 210Po and 210Pb will also be analyzed using alpha spectrometry and LSC at the National Physical Laboratory, UK. Gamma measurements using Low-level HPGe Detector will focus on activity concentration levels of 228, 226Ra and their decay progenies 214Bi, 214Pb, 228Ac, 212Pb and 208Tl and they will be conducted at the Radiation Measurements Laboratory, Ministry of Environment, Qatar. A general chemical analysis using ICP-MS will be conducted at the laboratory of Qatar Environment and Energy Research Institute (QEERI) in order to support the radiological analysis in the project. The results of this study will be essential to further clarify the reasons behind this elevation in this area. In addition, it will help in characterizing the areas of concern and explore the beneficial use and the suitable and feasible treatment options of the co-produced water and positively contributing to the water security target.

References

1. Al-Sulaiti, H., Regan P. H., Bradley D. A., Malain D., et al., A preliminary report on the determination of natural radioactivity levels of the State of Qatar using high-resolution gamma-ray spectrometry. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (NIM-A), 2010. 619(1–3): p. 427–431.

2. Huda Al-Sulaiti, Tabassum Nasir, K.S. AlMugren, et al., Determination of the Natural Radioactivity Levels in North West of Dukhan, Qatar Using High-Resolution Gamma-ray Spectrometry, Proceedings of the 8th International Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications (IRRMA-8) Applied Radiation and Isotopes, July 2012, Volume 70, Issue 7, p. 1344–1350.

Abstract Background: The plant growth and production rely on the supporting favorable environmental conditions throughout its growing stages. In harsh environmental conditions such as in Qatar, agricultural growth is limited by water availability, salinity and drought, leading to low yield. In soil, there are different kinds of microbiota including fungi, bacteria, actinomycetes, algae as well as various types of plant species. Fungi are important components of the soil microbiota. For example, soil-borne fungi cause a significant yield loss for many vegetable and fruit crops in Qatar including tomatoes, cucumbers, legumes, limes, strawberries and others. Several recent studies have demonstrated that the adaptation of plants to severe environmental conditions is attributed to genetic abilities of their associated microbes. For example, all plants in natural ecosystems are thought to be symbiotic with mycorrhizal and/or endophytic fungi reflecting fitness benefits conferred by fungi that contribute to or are responsible for plant adaptation to stress. In Qatar, there are many plant species that can survive under adverse abiotic conditions of salinity and drought rendering them as rich resources for structuring their associated microbes. Objectives: The aims of this study were to: (i) investigate the effect of different ecosystems on the structure and distribution of soil-borne fungi; (ii) inspect the ability of plant-associated microbes to tolerate harsh environmental conditions; and (iii) examine the effectiveness of isolated fungi as potential biological control agents. The ultimate goal of this study is to improve the sustainable agriculture in Qatar through the implementation of plant-associated microbes for biological control of important diseases and enhance plant tolerance to abiotic stress. Materials and Methods-Isolation of plant associated microbes: Samples from plant rhizosphere and soil were collected from four different plant species grown under different ecosystems in Qatar. Qatar University Farm (Al-Zubara Area, Qatar) exemplifies the agricultural ecosystem; in addition to six private farms represent different ecosystems. Four plant species were considered in this study namely Launae capitata, Lycium shawii, Ziziphus lotus and Zygophyllum qatarense (Tetraena qatarense). Samples from plant rhizosphere and soil were collected in January. Soil-borne fungi were isolated from the rhizosphere and soil using direct plate method. About 0.5 g of homogenized soil sample was plated on melted potato dextrose agar supplemented with Rose Bengal. Plates were incubated at 25°C for 3–7 days and colonies with different morphological characters were isolated and purified. Fungal isolates were identified morphologically using light microscopy. DNA was extracted using QIAGEN kit for molecular analysis. Effect of abiotic stress on the growth of Trichoderma spp.: different concentrations of sodium chloride (NaCl) were used to induce salinity stress. NaCl concentrations include 0 (control), 10 mM, 50 mM, 100 mM, 250 mM, 500 mM, 1 M, 1.25 M, 1.5 M, 1.75 M, 2 M, 2.25 M, 2.5 M, 2.75 M and 3 M. Fifty ml of potato dextrose broth medium, with different salt level, was inoculated with five mm disc of Trichoderma spp. Poly Ethylene Glycol (PEG) was used to induce drought effect on Trichoderma spp. Different percentages of PEG were performed including 0% (control), 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100%. In 100 ml conical flask; 50 ml of PDB medium with different percentages of PEG was inoculated with five mm disc of Trichoderma spp. The antagonistic effect of the fungal isolates was tested using the direct opposition method. Antagonistic test was performed between Trichoderma spp. which has an effective biocontrol activity towards many soil-borne pathogenic fungi and Ceratocystis radicicola (Thielaviopsis paradoxa), which causes many diseases in date palm trees. The test was performed in dual culture on PDA medium. Five mm disc of each fungus was placed at peripheral end (five cm between each other) of Petri plate. The plates were incubated at 25°C for 7 days. Three replicates were considered. Results: Tthirty-nine of fungal genera were isolated from the plant rhizosphere and soil. Results showed that the most dominant genus was Aspergillus niger (48.5%) followed by Rhizopus spp. (26.8%). Other fungal communities were also detected such as Aspergillus vesicolory, Aspergillus sydowii, Aspergillus wentii, Fusarium oxysporum, Penicillia oxalicum, and Rhizoctonia solani. Results also showed that Aspergillus terreus is associated with rhizosphere of plant species growing in harsh conditions. However, plants grown under agricultural conditions showed a biodiversity in their associated-fungal species, the most common fungi are Fusarium sp. and Trichoderma sp., which were isolated from rhizosphere of Launaea capitata and Ziziphus lotus grown in harsh conditions. In vitro, Trichoderma spp. was able to grow in high concentrations of salt (2 M) and PEG (80%) reflecting a high adaptation of plant associated microbes to both salinity and drought stresses. Results from the antagonistic test showed that Trichoderma spp. caused a remarkable growth inhibition of C. radicicola the causal agent of many diseases in date palm trees. Conclusion: Data obtained from the current study will lead to the initiation of a Qatari fungal culture collection, which will help conserve the biodiversity and could be essential for future studies. Additionally, plant-associated microbes isolated from different ecosystems can further be used for biological control of important plant diseases and enhancing plant tolerance to abiotic stress. Altogether, results from the current study suggest a prospective implementation of plant-associated microbes for a sustainable agriculture in Qatar.

Municipal solid waste management is one of the major challenges facing Qatar with more than 2.5 million tons of municipal solid waste each year, a very high waste generation rate in a country with small land mass. Solid waste in Qatar consists mostly of organic materials (60%) with the remaining made up of recyclables, such as glass, metals and plastics. Qatar's ambitious development strategy targets environmental sustainability and invests in research on key grand challenges including water/food security. Fortunately both can be addressed through value-added conversion of solid organic waste into biochars. Solid municipal wastes such as newspaper, cardboard, woodchips and plant residues from landscaping can be converted to biochar for mitigation of their environmental impact and value-addition. On the other hand, agricultural soils have significant deficiencies in a range of essential trace elements and macronutrients and often exhibit low water holding capacity. These deficiencies impact both the yield and the nutritional quality of edible crops with direct consequences cost-effectiveness and human health. Fortunately, these challenges can be advantageously addressed by production of biochars from organic sources such as mixed organic solid waste from municipalities as well as agricultural and landscaping operations. The landfill and composting of these solid municipal wastes generate greenhouse gases that contribute to climate changes. Biochars prepared from solid municipal wastes can greatly benefit the carbon content of soil. Additionally, biochar may interact with fertilizers to deliver indirect improvements in plant growth and reduce the emission of greenhouse gases from native organic matter. Biochars can also be custom-designed to increase/decrease native soil pH to bring it closer to the optimum range for microbial and plant growth. These applications give solid organic municipal wastes promising potential as precursors for value-added biochars with varied physicochemical characteristics allowing them to be used not only as an alternative to bio-waste management and greenhouse gas mitigation but also as means to improve depleted soil. We hypothesize that soil deficiencies in soil can be remedied by the application of biochars that are custom-designed to possess the right physicochemical characteristics suitable to improve soil fertility. The aim of this study was to: (1) produce biochars from mixed solid organic waste for use in soil quality enhancement, (2) investigate the effect of biochar addition to soil on plant germination and growth and (3) evaluate the potential of biochars in mitigating green house gas (GHGs) emissions. Select solid organic municipal wastes (newspaper, cardboard, woodchips and landscaping residues) were used as a precursor for biochar preparation. A blend of 25% of each precursor was used and pyrolyzed at 700°C for 2 hrs under N2 gas at a flow rate of 0.1 mL min^− 1 using a Lindberg box programmable furnace equipped with an air-tight retort. Soil fertility parameters such as pH, water retention and macro and micronutrients were analyzed. Fine sandy clay loam soil from the Ap horizon (0-15 cm deep) was amended with biochar at the rate of 2% (w/w). To test the germination rate in soils, with and without biochars (produced from municipal solid waste precursors of 25% blend of four types of waste materials), hybrid savoyed spinach seeds were sown in germination trays (3 seeds/well) for two weeks in climate controlled greenhouse settings. Trays were watered twice daily to maintain moisture level between 10 and 12 percent. The percentage of seed germination was calculated and the plant growth measured as dry biomass. Incubation experiments were conducted to measure GHGs production in sealed glass vials containing soil with and without biochar or raw materials from which this biochar was produced. Greenhouse gases emission differential between the biochars and their corresponding raw feedstocks in treated soil was used as indicator of GHGs emission by biochars during the incubation period Biochars prepared from blends produced at 700°C pyrolysis temperatures and used at 2% application rate to soil showed higher pH (6.8), increased water retention, and high K and NO3-N content. The net effect of these changes in soil properties positively impacted both seed germination and biomass yield of the plants (up to two folds in soil amended with biochars). At the same time, conversion of solid organic wastes into biochar enabled 14% reduction in GHGs emission compared to the solid waste precursors, as indicated by lower CO2 emission. Biochar amendment in soil significantly reduced the CO2 emission (14%), which would otherwise have increased greenhouse gas due to solid waste decomposition in soil. This differential is mainly due to respiration controlled by microbes. Soil amended with biochar closely followed the trend of soil treatment signifying no additional contribution to CO2 efflux. The increase in CO2 efflux seen in feedstock-amended soil can be attributed to the decomposition of feedstock during the time incubation period. In summary, biochars from mixed solid organic wastes at 2% carbon to soil ratio improved seed germination, increased plant biomass yield, and reduced GHGs emission compared to precursors. To reach the maximum benefits, pyrolysis conditions and feedstock selection are critical steps to produce biochars with desirable properties for specific soil amendment. From the present study, it is clear that constituents of municipal solid organic wastes hold promising potential as inexpensive precursor for value-added biochar manufacturing with varied and customizable physicochemical characteristics that would be beneficial in soil amendments while alleviating the problem of solid waste disposal and contributing to mitigation of GHGs. Further studies are need needed to confirm the reported advantages in natural field settings.

The Northeastern Qatari coast is comprised of diverse and sensitive flora and fauna such as seagrass meadows, turtles, algae, and coral reefs/patches that tolerate harsh environmental conditions. In the near future, this area may see a rise in anthropogenic activity in the form of coastal development projects, which will add to the existing natural stresses, such as high temperature, high salinity and low rates of precipitation. Therefore, there is a need to characterize the area and assess the potential impacts that these anthropogenic activities may have on the region. Eco-hydrological models are theoretical, mathematical representations of natural systems, made to help understand their functionalities under physical forcing. Site-specific data, hydrodynamic models, and ecological and physical phenomena are combined to build a functional ecosystem model that mimics real environments. These models can then be used to predict the impacts of anthropogenic and natural stressors on real systems. There are two main types of Eco-hydrological models: analytic and computational. Analytic models are usually less complex since they have an analytical solutions, and are used to represent simple or abstract systems with well-known behaviors. Alternatively, computational models are considered to be more ecologically sensible, as they can be used to solve complex systems that require the use of numerical techniques. The results of the computational model can vary between different numerical techniques or modeling software, resulting in uncertainty and variability that should be estimated. Given the complex nature of the environmental system in the Northeastern Qatari coast, numerical solutions using modeling software are developed to establish an adequate representation. There are three main modeling programs that have been used for the development of Ecological Response Models in Qatar (SWAN, GEMSS, and TELEMAC-2D). GEMSS provides a set of hydrodynamic, transportation and water quality modules allowing for the development of an integrated Eco-hydrological model according to the needs of each modeling application, which makes it the most appropriate software to use in this study. The aim of this study is to develop hydrodynamic and sediment transport models for a stretch of the Jabal Fuwairat Coastline in Qatar, using GEMSS and bathymetric LIDAR data processed with ArcGIS. The hydrodynamic model (HDM), which will be calibrated and tested using field data, simulates the spatial and temporal dynamics of the water, while the sediment transport model (STM) identifies, under present or simulated scenarios, the fate of the suspended sediments in the studied coastal zone. The STM provides data about sediment typologies, suspended particulate matter and currents that are near the seafloor (shear stress). The developed models will be tested using potential scenarios of future anthropogenic activities forecasted to take place in the area. The results will show the effects on water and sediment behavior, and provide a scientific basis for key stakeholders to make decisions with respect to the management of the considered coastal zone. It also provides a tool/framework that can be utilized in future hydrodynamic studies along other areas of the Qatari coastal zone. Furthermore, the outcomes are fundamental to developing a complete and accurate Eco-hydrological model. Keywords: Hydrodynamic Model, Sediment Transport Model, Anthropogenic stressors, coastal dynamics, GEMSS, ArcMap, LIDAR.

Organic electronic devices based on polymers received significant attention in the last decade, especially for organic photovoltaics (OPVs) and field-effect transistors (OFETs) despite their performances and stability clearly falling short of today's state-of-the-art crystalline silicon or copper indium germanium selenide (CIGS)-based devices. Flexibility in the manufacturing, light weight, lower fabrication cost, ease of integration into various devices, and large area coating are some of the major potential advantages of polymers over inorganic devices.

1 Among organic polymers, conjugated polymers attracted widespread attention for a wide range of applications. Thiophene-containing conjugated polymers, especially, poly(3-alkylthiophne) (P3AT) has been subjected to intensive research over last decade due to their excellent optical and electronic properties.

2 Moreover, poly(thienylenevinylene) (PTV) class of polymers displays high charge carrier mobilities in OFETs and promising performances in OPVs.

3 When a single solubilizing alkyl chain is included onto the PTV backbone, the resulting copolymer can be solution processed for optical devices. One simple strategy to manipulate the copolymer property is by changing the heteroatom of the thiophene from sulfur to other chalcogens, selenium or tellurium.

4 Theoretical calculations indicated that substitution with selenium or tellurium may reduce the optical band gap of the resulting polymer in comparison to their sulfur-containing analogues. Inclusion of larger and more polarizable selenium or tellurium also expected to have a strong influence on the charge transport properties. Notably, Heeney and co-workers showed that the band gap of P3AT can be reduced by as much as 0.3 eV by only substituting sulfur with selenium in the polymer backbone.

5 The reduction of band gap resulted from larger and more polarizable selenium facilitate better π orbital overlap with the polymer backbone and thus stabilize the polymer LUMO (lowest unoccupied molecular orbital). Low-lying LUMO levels are believe to facilitate both electron injection and transport. Recently, PBDTT-SeDPP polymer showed a high Jsc of 16.8 mA/cm², a Voc of 0.69 V, and a FF of 62%, enabling the best PCE of 7.2%.

6 However, despite fascinating properties of selenium substituted polymers, tellurium containing polymers are less explored, may be due to challenging tellurium chemistry. Jahnke and co-workers recently reported first soluble tellurophene polymer, poly(3-alkyltellurophene) (P3ATe), prepared by both electrochemical and Kumuda coupling polymerization method.

7 Even though, preliminary PCE (1.1%) was modest, tellurium substitution resulted in red-shifted film absorption. In this contribution, we report the synthesis and characterization of vinylene copolymers containing 3-alkylthiophene, selenophene or tellurophene. This allows us systematically investigate the role of selenium or tellurium on the polymer properties. Here, we report the first synthesis of novel 2,5-dibrominated 3-alkyltellurophene monomer and its Pd[0]-catalyzed copolymerization with (E)1,2-bis(tributylstannyl)ethylene to afford poly(3-alkyltellurophenylenevinylene) (P3ATeV).

8 We compare the optoelectronic properties of P3ATeV with analogous sulfur (P3ATV) and selenium (P3ASV) containing polymers. Preliminary OFET data will also be incorporated. Scheme 1. Structures of P3AX, P3AXV copolymers.

References

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8. M. Al-Hashimi, Y. Han, J. Smith, H. S. Bazzi, S. Y. A. Alqaradawi, S. Watkins, T. D. Anthopoulos, M. Heeney, Chem. Sci. 2015, DOI: 10.1039/C5SC03501E.

In order to ensure long-term sustainability of the reservoir, the gas industry in Qatar is faced with the challenge of reducing the volume of produced and process water (PPW) sent to disposal wells by 50% [1-3]. Recently, Qatargas initiated a project to recycle process water and thus, reduce disposal volumes using commercial advanced water treatment technologies [4]. One emerging technology, “osmotic concentration” (OC) has been identified that offers a low-energy alternative to conventional thermal or membrane volume reduction methods. Osmotic concentration is a membrane filtration process that mimics first step in a forward osmosis (FO) system. It requires a high salinity draw solution (DS) which passes on one side of a semi-permeable FO membrane while the feed passes on the other side. Water from the feed is drawn through the membrane, via natural osmosis, reducing the feed volume and increasing the volume of the draw solution. This paper summarizes the results of bench-scale volume reduction tests with PPW collected from Qatar's North Field operations as the feed and either seawater or the concentrated brine from thermal desalination plants as the draw solution. While in conventional forward osmosis, the draw solution is regenerated, in OC, there is no regeneration of the draw solution. The diluted seawater or brine would be simply discharged to the Arabian Gulf. For future projects/developments, the authors have proposed OC for PPW volume reduction, which can be a cost-efficient alternative to achieve 50% reduction in disposal volumes (Fig. 1). This approach is particularly applicable in Qatar due to close proximity of desalination plants and gas processing facilities. In all membrane processes, the driving force for permeation is pressure. The mechanism by which the pressure is created differentiates various membrane processes: Reverse osmosis: static pressure generated by a pump Membrane distillation: vapor pressure differential due to a difference in temperature Osmotic concentration: osmotic pressure differential due to a difference in salinity. In these examples, the driving force or transmembrane pressure (TMP) can be measured in units of kPa or bar. In reverse osmosis, the TMP ranges from 15 to 60 bar depending on the salinity of the feed. In osmotic concentration, a comparable TMP of 15 to 60 bar is generated simply by high salinity the draw solution, i.e. without any static pressure being required and hence the low energy requirements for OC processes. In addition to significantly lower operating energy requirements [5], an OC process offers the following advantages over reverse osmosis (RO): Lower capital cost because pressure-rated vessels and high pressure pumps are not required [6]; There is strong evidence that FO membranes are less prone to irreversible fouling than RO membranes and foulants can be removed by simple flushing with clean water with no addition of chemicals [7,8]; The water discharged to the Arabian Gulf is of lower salinity and that provides an environmental benefit. The primary disadvantages of OC are that there is no water recovery after the separation process and there is limited experience from full-scale water treatment installations. The main objective of this study was to investigate the feasibility of OC to concentrate PPW from gas operations by 50% using brine from thermal desalination plants as draw solution. The PPW was a combination of gas field produced water extracted from an offshore reservoir and process water from onshore operations. The blending ratio between produced and process water was approximately 1:5. The PPW underwent deoiling, H2S removal and cartridge filtration (2 mm). The detailed composition of PPW and brine from thermal desalination plant are shown in Table 1. During this study, experiments were conducted to evaluate OC performance in treating PPW in the following areas: membrane configuration membrane fouling effect of pretreatment process optimization long-term stability/performance. In all tests, the active layer faced the feed solution (AL-FS mode) since this configuration provides better control of feed-side fouling. Membrane configuration During this project, two membrane configurations were evaluated: Flat sheet (FS) membranes, commercially available [9]Hollow fiber (HF) membranes, Singapore Membrane Technology Centre [10, 11]. The membrane surface areas were 0.014 and 0.0106 m² for the FS and HF modules, respectively. Experiments were conducted using two feed solutions: DI water and PPW. Results showed that the HF membranes had improved performance from both the water flux and reverse solute flux (RSF) perspectives. The HF membrane flux was ≈ 35 to 45% higher for both DI water and PPW (Fig. 2). With PPW as feed at 25?°C, the RSF was measured for both membranes and the results showed that HF membranes exhibited ≤ 3 mmol/m² h RSF for Na⁺ and Cl⁻  while FS membranes showed a RSF of ≈ 20 mmol/m²h for both ions. RSF is highly sensitive to operating temperature. Because HF membranes showed superior performance and there are also commercial advantages (higher packing density, lower fabrication cost), experiments focused on evaluating HF performance in treating PPW. Membrane fouling: To assess if membrane fouling occurred, a benchmark test with DI water as feed solution and 1M NaCl as draw solution at 25?°C was conducted before and after each fouling test. A decline in the benchmark flux after treating PPW would indicate that membrane fouling had occurred. The fouling tests were conducted on two feed streams: synthetic PPW (mimicking only the inorganic content of PPW) and real PPW. During the experiments, the initial volume of PPW was reduced by 50% and the draw solution (DS) was 1M NaCl. The DS concentration, for both benchmark and fouling tests, was maintained constant throughout the experiments by adding concentrated NaCl solution based on conductivity measurements. While the results for synthetic PPW showed that no fouling had occurred, the results showed that PPW could cause fouling on the membrane surface since the benchmark flux decreased from 17.5 to 15 L/m^2?h (Fig. 3). The fouling was attributed to the organics present in the PPW since no flux decline was observed on the when synthetic PPW was used as feed. These results highlighted the need for effective pretreatment to remove organics. Effect of pretreatment: To determine if pretreatment could remove the organics responsible for fouling, a number of methods were screened and ultimately powdered activated carbon (PAC) was selected for pretreatment of the PPW. PAC is widely used for organics removal and previously evaluated for similar applications [12]. Lab results showed that at a dosage of 500 mg/L PAC, the TOC from the PPW was reduced from 132 to 45 mg/L. The PAC dosage was considered very high for a full-scale application and further pretreatment optimization is needed before field implementation. OC performance experiments showed no decline in benchmark flux when the volume of pretreated PPW was reduced by 50% indicating that pretreatment is essential for the successful implementation OC to reduce PPW disposal volumes. Results also showed that the HF membranes have good rejection for organics. For both the treated and untreated PPW, the TOC in the draw solution after OC treatment was below the 1 mg/L detection limit indicating that the membrane rejection of the organics was >99%. Process optimization: Box-Behnken design: The main operating parameters for this application were optimized using a Box-Behnken design (BBD) [13, 14]. BBD is a response surface methodology that explores the effect of different input variables (temperature, draw solution concentration and feed crossflow velocity) on the output response (flux). This statistical tool takes into consideration the combined effects and interdependence of the input variables and significantly reduces the number of tests required as compared to the conventional factorial experimental design. The following parameters and test values were used during the BBD experiments: Temperature: 25, 35 and 45?°C Draw solution concentrations: 40, 55 and 70 g/L NaCl Feed crossflow velocity: 40, 60, 80 cm/s. Results showed that the temperature has the greatest impact on the flux, since it influences the water viscosity. DS concentration directly affects the osmotic pressure, influencing the flux. The feed crossflow velocity did not affect the process performance over the range tested. These results are consistent with authors’ expectations and general published results. Based on the BBD analysis, the optimized process conditions were: 45°C temperature, 70 g/L draw solution concentration and 80 cm/s feed crossflow velocity. Figure 4 shows the comparison of the OC performance, to achieve 50% feed volume reduction, at benchmark (25?°C, 70 cm/s, 58.5 g/L NaCl) and optimized (45?°C, 80 cm/s, 70 g/L NaCl) conditions. Long-term performance and water quality: The elimination of the water recovery step in osmotic concentration makes it an energy efficient process [5]. To confirm if the brine from thermal desalination plants is a suitable DS for the treatment of PPW, a long-term experiment was performed simulating full-scale operation. In earlier experiments, the concentration of the DS was maintained constant, by adding concentrated DS. Since this is not feasible in full-scale applications, a process stability experiment was carried out without controlling the DS's concentration, allowing it to dilute with time as water permeates through the FO membrane. The experiment was conducted using pretreated PPW as feed and brine from thermal desalination plant as DS. The solution temperature was 45?°C since this is the expected temperature of the brine discharged from the desalination plant. The feed and draw solutions crossflow velocities were 80 and 40 cm/s respectively. The test was conducted for 80 hours. The PPW initial volume was 42 L and it was reduced in volume by 50% while the volume of the draw solution, initially 21 L, was increased to 42 L, reducing its salinity by 50%. A relatively stable performance was observed throughout the experiment with a 30% decrease in flux (from 28 to 20 L/m²?h) due to the decrease of the effective osmotic pressure and to the influence of the internal concentration polarization (ICP). After a sharp initial decline in osmotic pressure differential, the decline in flux almost tracked the decline in the osmotic pressure differential (Fig. 5). DI water fluxes during benchmark tests conducted before and after the experiment remained constant at 19.4 L/m²?h indicating that negligible fouling occurred. To evaluate the ability of HF membranes to reject specific contaminants, various water quality analyses were performed. Results showed that HF membranes have high rejection capabilities. The ions with the highest solute fluxes values were sodium and chloride with a RSF of 120 and 91 mmol/(m²?h) respectively at 45?°C (Table 2). Although a small amount of nitrogen passed through the membrane from the PPW to the draw solution, at the levels found (5.8 mg/L), it was below the discharge limits set by the State of Qatar and the European commission (10 mg/L) [15]. The results also showed that the organic carbon present in the PPW was rejected by the membrane and retained in the PPW. A slightly increase in the TOC concentration in the DS was observed and it could be attributed to uncertainties in the analysis since the results were at the low end of the measurement accuracy. Finally, preliminary cost estimates and energy calculations showed that OC is economically feasible to reduce PPW injection volumes from gas fields in an environmentally sustainable manner. The research team is currently evaluating different pilot testing opportunities to further demonstrate the cost-effectiveness of this technology under relevant field conditions.

The Khor Al-Adaid “Inland sea” in Qatar is a unique desert lagoon, located in the South east of Qatar and is characterized by a distinct salinity gradient (ca. 4% halite salt to saturated conditions). In the framework of the QNRF funded NPRP project, researchers from Qatar, Germany and Austria have succeeded to isolate and cultivate a new unicellular eukaryote (protist) from Qatar's unique Inland Sea (Khor Al-Adaid). Initial genetic marker analyses pointed to the novelty of this organisms and morphological characterization confirmed that this isolated organism is not yet known and described from any other place in the world. Even though only 1/50th of a mm in length, this organism may hold secrets worth unlocking: the Qatar's Inland Sea is characterized by extremely high salt concentrations. With the discovery of this new organism from the Inland Sea the team of researchers hold in their hands a valuable unique treasure from Qatar's natural heritage. Future efforts will be to exploit this treasure for its genomic and biotechnological potential. The new species belongs to the genus Euplotes, and is coined the name Euplotes qatarensis nov. spec.

GCC's climate has a high ambient temperatures throughout most of the year, therefore, the air conditioning is not optional or luxury, it is a necessity. Residential sector in those countries represents the largest portion of electricity consumption. According to Qatar National Development Strategy (QNDS) 2011-2016, two-thirds (67 percent) of total residential power consumption in Qatar is due to air conditioning units (AC), Such heavy cooling demand is expected to approximately triple by 2030. Thereby, the fuel needed to power air-conditioning units in the GCC will is expected to 1.5 million barrels of oil per day. Energy efficient system is basically depending on two different categories; technological modification program and behavioral modification program. Both programs are required for energy efficient air conditioner systems. Existing air conditioner systems are based on conventional technological modification systems without considering the behavioral modification program which are impacted by the cost of implementation, impact on running systems as well as providing a fixed step algorithm of closed loop control between utility and residential customer. Therefore, we present a novel embedded real-time, smart, active energy and efficient air conditioning system for minimizing energy consumption, and minimizing energy cost per day while considering residential customer preferences, comfort level in behavioral modification program and health aspect, which provides opportunity for residential customer to reduce energy consumption improve energy efficiency with cost effective manners and healthcare concept. The proposed algorithm automatic adjustment air conditioning temperature below the outdoor temperature as recommended from physiologists. In addition the proposed energy efficient Air-conditioning system equipped with embedded tools to collects and monitor energy information for each air conditioning through measurements of current, voltages, frequency, active power (kW), reactive power (kVAR), apparent power (kVA), power factor (PF), total harmonic distortion (THD) to increased awareness of the importance of energy efficiency and energy saving benefits. The system has three modes of operation; automatic, semi-automatic and manual. The automatic status i.e. the system smartly and completely controls airflow/energy consumption of air conditioner at all times based on Psychrometric Chart; semi-automatic status is designed to quickly and efficiently controlled energy usage with fixed selected temperature value. The manual status is considered as a conventional, delivery and use of energy without any control. The Smart energy efficiency algorithm is set based on psychrometric chart, load importance, comfort level, room temperature, and internet weather service. The proposed novel system leads to achieve comfortable temperature with less energy consumption over many hours during the day. The proposed energy management strategy aims to save around 15-26% of daily energy consumption. Index Terms -Energy-efficient, air conditioning, Energy saving.

The coalescence of a water drop in a dieletric oil phase at a water layer interface in the presence of an electric field is simulated by solving the Navier-Stokes and charge conservation equations with the finite element method. The proprietary software Comsol Multiphysics is used for this purpose. The interface between the oil and water phases is tracked by implementing a level-set approach. Preliminary simulations to assess the sensitivity of the model with respect to some input parameters are reported. In particular, the calculations are very sensitive to the size of the computational grid elements and the interface thickness parameter. Nevertheless, the model is able to reproduce the occurrence of partial coalescence for the experimental case examined. Good quantitative agreement can be obtained if the parameters are suitably tuned.

Introduction

The application of an external electric field is a technique currently used in the oil industry to promote migration and enhance coalescence of droplets in the water-in-oil emulsions formed during the oil extraction process [1, 2]. It is generally acknowledged that the effect of the electric field is to increase film drainage and hence the thinning rate between two coalescing droplets [1]. However, an excessive value of the field strength can reduce the quality of coalescence, as secondary droplets form [3-6] as a result of an incomplete coalescence process. The efficiency of the process would be significantly improved if the operating conditions to prevent partial coalescence from occurring were known. In this regard, it has been shown [5] that the ratio between the volume of the secondary droplet formed and the initial drop volume can be described as a function of a dimensionless number which is the product of the Weber and Onhesorge numbers. The same authors have recently addressed the effect of the electric field type on the coalescence quality. Their experimental results have revealed that the volume of the secondary droplet decreases if pulse-DC fields are applied, leading to the transition from partial to complete coalescence under certain conditions [6]. These findings can have an important impact on the development of compact electrocoalescer designs. The aim of this work is to provide a mathematical description of the phenomenon. For this purpose, a finite element approach combined with the level-set method [7] is adopted in this work to analyse the process of partial coalescence. To the authors' knowledge, there are no attempts at predicting numerically the occurrence of incomplete coalescence in the presence of an electric field. The proprietary software Comsol Multiphysics (Comsol, Sweden) software has been used for this purpose, in an attempt to assess the capability of the proposed approach to reproduce and analyses the phenomenon.

Model Equations

A level-set approach is employed to track the boundaries between different phases. The evolution of the boundary is described by the equation: where is a smooth step function which varies from 0 to 1 across different phase domains, is a reinitialization parameter which gives stability to the solution and is related to the thickness of the interface. The fluid velocity is denoted by u (bold letters denote vectors). It should be noted that Eq. (1) is the non-conservative formulation of the level-set equation, which attains convergence more easily but introduces some errors in the calculations. However, the non-conservative formulation is more suitable for a rapid test of the model capabilities. Navier-Stokes and continuity equations are solved using average physical properties for the two phases: where and are the volume fraction weighted density and viscosity, which differ from the pure liquids properties only at the interface. In eq. (2), forces due to surface tension and induced by the electric field are included. The force due to surface tension is calculated as: where is the surface tension coefficient, the local surface curvature, n the outward pointing interface normal vector and d is a smooth approximation of the Dirac function which is non-zero only at the interface. The electric force is calculated from the divergence of the Maxwell tensor: where is the average permittivity. The electric field E is computed by satisfying the charge conservation equation: where is the average conductivity. With reference to the computational domain depicted in Fig. 1, the following boundary conditions have been applied in order to solve this set of equations: the upper boundary is kept at a fixed electric potential while the opposite one is earthed and no-slip conditions are prescribed for both boundaries; the domain is axisymmetric; slip conditions are considered on the right boundary, as this allows significant reduction of the simulation domain. The properties of the two liquids correspond to the sunflower oil/water system investigated experimentally by Mousavichoubeh et al. [5] and are reported in Table 1. The interfacial tension is equal to 25 mN mm^–1, as measure experimentally. In order to assess the effect of and the mesh element size, the following case is analysed. The initial drop size is 1.196 mm and the electric field strength is 373 V mm^–1. Under these conditions, partial coalescence occurs and the ratio between the volume of the secondary droplets formed and the initial drop volume is equal to about 0.088, as measured by Mousavichoubeh et al. [3].

Results

The calculated values of this ratio are reported in Table 2. For all cases, the reinitialization parameter is set equal to 1 m/s, which is comparable to the maximum fluid velocity in the system. The results shown in Table 2 reveal that the tuning of the interface thickness, is strictly connected to the level of mesh refinement (hmax/D is the maximum element size in the computational grid). With, the calculated volume of secondary droplets becomes invariant with the grid element size when this is sufficiently small. In this case the volume ratio of the secondary droplet to that of the initial drop is very close to the experimental value. However, the phenomenology described in the two simulations is different, and the results are compared in Figs. 2 and 3. The value of does not produce realistic results and convergence fails in a number of cases of the behaviour observed experimentally is also reported in Fig. 4. The numerical results obtained with reproduce the experimental observations exactly, whereas with a jet-like behavior is reproduced. This may be due to the larger interface thickness, which makes the droplet more deformable and the break-up process more difficult, although the predicted volume ratio is very close to the experimental value. problems, and a solution is obtained only for, which, however, provides a higher value of the secondary droplet volume formed as compared to the experiments. Decreasing further the grid element size to 0.02 causes non-convergence again, as should usually be smaller than the maximum grid size. This requirement becomes more critical when is small.

Conclusions

A model to describe partial coalescence in the presence of an electric field has been proposed. It has proved to be capable of reproducing the phenomenon observed in experimental work previously reported in the literature. A satisfactory quantitative agreement can be achieved by the right selection of the interface thickness parameter and computational grid size. This study constitutes the basis for the development of a reliable mathematical description which can be used for the design of a compact and efficient electrocoalescer.

Acknowledgement

This work was made possible by NPRP grant #5-366-2-1435-366-2-143 from the Qatar National Research Fund (A Member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors.

References

[1] Mhatre, S., Vivacqua, V., Ghadiri, M., Abdullah, A.M., Al-Marri, M.J., Hassanpour, A., Hewakandamby, B., Azzopardi, B., Kermani B., 2015. Electrostatic phase separation: A review. Chem Eng Res Des, 96, 177-195.

[2] Vivacqua V., Mhatre S., Ghadiri M., Abdullah A. M., Hassanpour A., Al-Marri M. J., Azzopardi B., Hewakandamby B., Kermani B. (2015). Electrocoalescence of water drop trains in oil under constant and pulsatile electric fields Chem Eng Res Des, doi:10.1016/j.cherd.2015.10.006.

[3] Aryafar H., Kavehpour H.P. (2009). Electrocoalescence: Effects of DC electric fields on coalescence of drops at planar interfaces, Langmuir 25 (21), 12460-12465.

[4] Mousavichoubeh M., Ghadiri M. and Shariaty-Niassar M., 2011a. Electro-coalescence of an aqueous droplet at an oil–water interface, Chem Eng Process, 50, 338-344.

[5] Mousavichoubeh M., Shariaty-Niassar M. and Ghadiri M., 2011b. The effect of interfacial tension on secondary drop formation in electrocoalescence of water droplets in oil, Chem Eng Sci, 66, 5330-5337.

[6] Mousavi, S.H., Ghadiri, M. and Buckley, M., 2014. Electro-coalescence of water drops in oils under pulsatile electric fields. Chem Eng Sci, 120, 130-142.

[7] Sethian, James A. (1999). Level Set Methods and Fast Marching Methods: Evolving Interfaces in Computational Geometry, Fluid Mechanics, Computer Vision, and Materials Science. Cambridge University Press. ISBN 0-521-64557-3.

Background & Objectives

Drilling systems are used to identify geological reservoirs and carry out extraction of oil or natural gas from these reservoirs. Deep wells are drilled by using rock-cutting tools driven from the surface by a slender structure of pipes called a drill string. These slender rotating structures can experience undesired dynamics, which can be detrimental to the drilling system. As an example, it is mentioned that stick-slip oscillations can be an important cause for drilling inefficiency and failure of drill-string components, as violent torsional motions and large amplitude lateral motions can occur during these oscillations. As a step towards the development of appropriate vibration attenuation schemes, it is intended to study the nonlinear behavior of slender rotating structures representative of drill strings. In particular, efforts underway at Qatar University to develop a laboratory scale experimental arrangement to study these structures will be presented and discussed. Prior efforts undertaken in this area will also be briefly reviewed. Brief Review and Qatar University Experimental Arrangement Drill-string motions are important to understand the complex system behavior of a drilling system, in particular, as they relate to downhole vibration phenomena. As shown in Fig. 1, the drill string is a complex, flexible structure, which consists of hollow steel pipes screwed together to form a long continuous structure. Large diameter sections, which are referred to as stabilizers, are inserted between two drill pipes to help keep the drill string centered in the borehole. The base of the drill string is made up of two main components, namely, the drill collar and the drill bit. The drill bit, a tool which breaks down the rock and soil, is secured at the end of the drill-collar assembly. The composition of drill pipes, stabilizers, and drill collars is referred to as the bottom-hole assembly (BHA). The entire drill-string assembly is rotated at the surface by using a rotary table and a motor. This actuation is transmitted down the drill string and to the drill bit, which acts to crush the rock and soil. Throughout the drilling process, a hydraulic fluid, known as drill mud, is pumped down through the center of the drill string and collars. This drill mud serves two purposes. It not only keeps the drill bit cool and lubricated, but it is also used to wash away the soil and cut rock. After the mud flows through the drill-strings and the collars, it flows then in the annulus between the drill-string and borehole carrying the cuttings to the surface. During operations, a drill string can experience a whole range of vibrations, including axial, torsional, and lateral vibrations. Drill-string vibrations are sometimes further grouped together as vibrations without contact without the borehole, whirling motions (forward and backward) during which there can be rolling and sliding contact with the borehole, and snaking motions which are a form of lateral vibrations during which a part of the drill string rolls over a borehole contact point. Given that drill strings are long, slender structures, the first torsion natural frequency and the first bending natural frequency are typically in close proximity. In addition, the nature of the system allows for coupling and energy exchange between torsional and lateral motions. In order to focus on the behavior of drill strings in the BHA region, a number of studies have been conducted, with several including studies with scaled laboratory scale arrangements. A partial list of references is included at the end of this paper. Focusing on some of them from this list, in earlier work conducted at the University of Maryland, Liao (2011), Liao, Balachandran, Karkoub, and Abdel-Magid (2011), Liao, Vlajic, Karki, and Balachandran (2012), the focus was on stick-slip motions and whirling. Comparisons were made between experimental and numerical results. It was shown that the nonlinear nature of the contact force interactions is critical for capturing some of the associated phenomena. In a follow up study conducted by Vlajic (2014), forward and backward whirling motions were explored and the development of appropriate reduced-order models was continued. In the work carried out by Shyu (1989), which include validation with laboratory and field studies, a focus was on the coupling between lateral and axial vibrations. Later motion instabilities were experimentally investigated in the work of Berlioz, Der Hagopian, R. Dufour, and E. Draoui (1996). Other notable examples include the studies of Antunes, Axisa, and Hareux (1992), Kust (1998), Mihajlovic (2005), Gao and Miska (2008), and Khulief and Al-Sulaiman (2009). These studies will be reviewed during the conference presentation. In order to build further on previous experimental efforts and related analytical and numerical studies, efforts are underway at Qatar University to build a laboratory scale arrangement to focus on stick-slip oscillations and whirling. Some representative motions of interest are shown in Fig. 2. The proposed system, which is to be used to capture the dynamics in the BHA region, is also shown in Fig. 1 with dimensions. Details of this arrangement will be presented at the conference. It is expected that the proposed arrangement will help explore stick-slip interactions further and gain insights into different aspects including drilling mud that can be beneficial for drill-string vibration attenuation and realizing desired BHA dynamics.

Keywords

Rotor-stator interaction, Dry friction, Stick-slip motions, Torsional vibration, Whirling

Acknowledgment

The authors would like to gratefully acknowledge the support received from the Qatar National Research Fund for NPRP Project 7-083-2-041, to pursue this collaborative work between the University of Maryland, College Park, MD, USA and Qatar University, Doha, Qatar.

References

Antunes, J., F. Axisa, and F. Hareux. “Flexural vibrations of rotors immersed in dense fluids, Part II: Experiments,” Journal of Fluids and Structures 6 (1), 1992, pp. 3-21.

Berlioz, A., J. Der Hagopian, R. Dufour, and E. Draoui. “Dynamic behavior of a drill-string: experimental investigation of lateral instabilities,” Journal of Vibration and Acoustics 118 (3), 1996, pp. 292-298.

Gao, G. and S. Miska. “Dynamic buckling and snaking motion of rotating drilling pipe in a horizontal well,” SPE Journal 15(3), 2010, pp. 867-877.

Khulief, Y. A., and F. A. Al-Sulaiman. “Laboratory investigation of drillstring vibrations,” Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223 (10), 2009, pp. 2249-2262.

Kust, O. “Selbsterregte Drehschwingungen in Schlanken Torsionssta”- ben-Nichtlineare Dynamik und Regelung. PhD Dissertation, University of Hamburg-Harburg, Hamburg-Harburg, Germany, 1998.

Liao, C.-M. “Experimental and numerical studies of drill-string dynamics,” PhD Dissertation, University of Maryland, College Park, 2011.

Liao, C.-M., B. Balachandran, M. Karkoub, and Y. L. Abdel-Magid. “Drill-string dynamics: reduced-order models and experimental studies,” Journal of Vibration and Acoustics 133 (4), 2011, pp. 041008-1-041008-8.

Liao, C.-M., N. Vlajic, H. Karki, and B. Balachandran. “Parametric studies on drill-string motions,” International Journal of Mechanical Sciences 54 (1), 2012, pp. 260-268.

Mihajlovic, N. “Torsional and lateral vibrations in flexible rotor systems with friction.” PhD Dissertation, Technische Universiteit Eindhoven, 2005.

Shyu, R.-J. “Bending vibration of rotating drill strings,” PhD Dissertation, Massachusetts Institute of Technology, 1989. Vlajic, N. A. “Dynamics of slender, flexible structures,” PhD Dissertation, University of Maryland, College Park, 2014.

The wide spread application of boron in various industries such as glass and fiberglass, ceramics, abrasives, detergents and soaps, fertilizer, enamels, insecticides, semiconductors, cosmetics and pharmaceuticals has left many surface and waste water streams polluted. Thus, there is a growing global demand for new chelating materials and efficient separation systems for removal of boron from different water streams. This is because the existing boron removal technologies are challenged by slow performance coupled with high treatment cost caused by strict low boron concentration required in water bodies and discharged wastewater to meet the newly imposed regulation [1]. Selective adsorbents obtained by modification of polymeric fibres with radiation induced grafting of functionalized monomers are potential materials for improving the performance of current ion exchange systems operated based on granular chelating resins for boron removal to desired low levels [2]. In this work, a new adsorbent having microfibrous structure was prepared by radiation induced grafting of 4-chloromethylstyrene (CMS) onto nylon-6 fibres waste followed by functionalisation with N-methyl-D-glucamine (NMDG) and testing for boron removal from solutions in batch and continuous column modes as schematised in Fig. 1. The degree of grafting (DOG) in the adsorbent precursor was tuned by variation of reaction parameters and and optimum DOG of 130% was achieved at a CMS concentration of 20 vol% in methanol, a total dose of 300 kGy, a temperature of 30 °C and a reaction time of 3 h. A maximum glucamine density of 1.7 mmol/g was loaded in the adsorbent at 121% DG, 10.60% NMDG concentration, 81 °C reaction temperature and 47 min reaction time. The chemical composition, morphology and structural changes in nylon-6 fibres caused by grafting of CMS and subsequent glucamine treatment were monitored by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The thermal properties were determined using differential scanning calorimetry (DSC) and the thermal stability was evaluated by thermogravimetric analysis (TGA). The mechanical properties were investigated with a universal mechanical tester. The obtained fibrous adsorbent displayed an increase in the average fibre diameter compared to original and grafted fibres (Fig. 2). The adsorbent showed 100% removal efficiency for boron removal from solutions at an initial concentration of 100 mg/L, temperature 30 °C, reaction time 2 h and pH of 7. The new adsorbent can also achieve a maximum adsorption capacity of 13.8 mg/g at pH 7, which is 20% higher than that of commercial granular resins. The adsorption isotherm of boron on the fibrous adsorbent was best fitted to Redlich-Peterson isotherm model whereas the adsorption kinetic behaviour is well fitted by the pseudo-second-order model. The new fibrous adsorbent also showed rapid kinetics compared to commercial resin as indicated by the reduction in the adsorption equilibrium time from 60 min for commercial resins to 30 min. The breakthrough curves obtained from column studies conducted under dynamic conditions (initial concentration 10 mg/L and pH 7) shown in Fig. 3 suggest that the fibrous adsorbent is about 2.2 times faster than granular resin. The adsorption capacity of boron remained almost constant after five cycles of adsorption/desorption cycles suggesting a good chemical stability. Considering the essential properties such as high external surface area, rapid kinetics, high adsorption capacity, mechanical strength and chemical stability, it can be suggested that the new fibrous adsorbent obtained from nylon-6 fibres waste is highly promising for boron removal from solutions. The technology developed in this work can be harnessed for preparation of various types of adsorbents for chemical decontamination of industrial waste water, surface water and underground water using a variety of waste polymer materials of different morphologies (fibres, fabric and films).

References:

[1] Nasef, M.M., Nallapan, M., Ujang Z. Polymer-based chelating adsorbents for the selective removal of boron from water and wastewater: A Review. Reactive and Functional Polymers 2014. 85, 54–68.

[2] Nasef, M.M., Guven, O. Radiation-grafted copolymers for separation and purification purposes: status, challenges and future directions, Progress in Polymer Science 2012, 37 (12) 1597–1656.

The Arabian Gulf surrounding Qatar is a unique marine environment with high insolation and salinity. Over 2000 strains of yeasts and filamentous fungi were isolated during 4 samplings in the context of a QNRF funded NPRP project. Approximately 1200 of the isolates were yeasts and over 800 were molds. All isolates were identified by molecular barcodes based on the ribosomal DNA. In addition the yeast isolates were also identified by MALDI-TOF MS with success rates varying from 42% [1st batch] to 80% [3rd batch] due to improvement of the yeast panel in CBS MALDI-TOF MS database. Among the yeasts the carotenoid containing red yeasts were abundant together with Candida tropicalis, Debaryomyces hansenii, Clavispora lusitaniae, and Kondoa sp. Also the black yeast genera Aureobasidium and Hortaea were frequently isolated. Among the molds, the melanized genera Cladosporium with the Cl. cladosporioides complex and Alternaria section Alternata were most abundant. Note that melanized and carotenoid containing fungi were the most prevalent fungi isolated, which may relate to the local extreme environmental conditions. Seasonal differences were observed between summer and winter samplings, but also spatial divergence between plots was observed. Potential new species were found in the genera Aspergillus, Penicillium, Alternaria, Cladosporium [all molds], Aureobasidium [black yeasts], Pseudozyma, Rhodotorula/Rhodosprodium and Kondoa [all basidiomycetous yeasts].

In 2009, the average energy consumption was about 16.1 TW. 81 % of it was supplied by non-renewable fossil fuels with emission of 29 × 1012tons of the carbon dioxide (CO2) into the atmosphere.1 Predicting the rise of energy consumption, the world is facing an urgent need for environmentally friendly and renewable energy technologies. As the direct exploitation of the ultimate energy source of the earth surface, solar power is a critical objective for our future. With recent $1 Billion investment in the polycrystalline silicon solar cell production, Qatar is clearly building a global leadership position in the alternative energymarketplace.2Current solar materials is primarily based on crystalline silicon, which is expensive on the energy- and water-intensive production processes due to the nature of the inorganic deposition.3 The newly developed large-scale and low-cost materials/technologies are thus needed for the next-generation solar energy production. The earth-abundant, non-toxic organic polymeric materials (“plastics”) have recently attracted much attention because of their cost-effectivity, flexibility, light weight and potential use in large- area flexible devices. In addition, organic active layers offer versatile design space for the polymer architectures, providing potential for layer designs and tunability to suit specific energy supply criteria.3Indigo is the most produced natural dye with a highly planer bis-lactam structure.4 Such kind of planer bis-lactam structures, such as perylene diimide (PDI), 2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione (DPP), and their structure derivatives, have attracted considerable interests as acceptor materials among various optelectronic devices in past decades.3In addition to the structure benefit, its isomer, isoindigo has better conjugate prosperity since its lactam ring conducting with an extended π system throughout the bis-oxindole framework, which results in the strong electron-withdrawing nature alongside their high degree of coplanarity.3,4 Isoindigo was first introduced into organic semiconductors in 20105 and has been widely studied in the following years. More than 100 isoindigo-based molecules had been developed by 2014 and up to ∼7% organic photovoltaic (OPV) efficiencies and 3.62 cm2V-1s-1 hole mobilities in organic field-effect transistor (OFET) have been reached.6,7Among the various modifications of isoindigo-based molecules, the low bandgap donor-acceptor copolymers containing thienoisoindigos (TIIs) and thiazolisoindigos are particularly of interest to us. Replacing the outer phenyl rings of isoindigo with thiophene and thiazole rings, these molecules could further enhance planarity (via S-O interactions) along the backbone,5 resulting in better packing and higher mobilities for both holes and electrons with very low bandgaps through internal charge transfer interactions.Another indigo derivative, 7,14-diphenyldiindolo[3,2,1-de:3′,2′,1′-ij][1,5]naphthyridine-6,13-dione, containing the core of another synthetic dye cibalackrot, is also of interest to us. The cibalackrot was first synthesized by the condensation reaction of nature abundant indigo andarylacetyl chloride in 1914 but its potential usages in semiconductorswas not noticed until 2014.8,9 Our research team is one of the pioneers in this area. Recently, we published a polymer exhibiting OFET devices with holes and electrons exhibiting mobilities of 0.23 and 0.48 cm2V-1s-1, respectively. The OPV device efficiencies reached 2.35% with the light absorbance up to 950 nm, suggesting the potential of this novel monomer unit for implementation in near-IR OPV devices.4 Othercibalackrot containing copolymers are currently being explored.Reference:1. International Energy Agency, Key World Energy Statistics, IEA, Paris, 2011.2. https://www.jccp.or.jp/international/conference/docs/14assessment-of-solar-and-wind-energy-potential-in.pdf3. Guo, X.; Facchetti, A.; Marks, T. J. Chem. Rev. 2014, 114, 8943-9021.4. Fallon, K. J.; Wijeyasinghe, N.; Yaacobi-Gross, N.; Ashraf, R. S.; Freeman, D. M. E.; Palgrave, R. G.; Al-Hashimi, M.; Marks, T. J.; McCulloch, I.; Anthopoulos, T. D.; Bronstein, H. Macromolecules 2015, 48, 5148-5154.5. Mei, J.; Graham, K. R.; Stalder, R.; Reynolds, J. R. Org. Lett. 2010, 12, 660.6. Wang, E.; Mammo, W.; Andersson, M. R. Adv. Mater. 2014, 26, 1801-1826.7. Dutta, G. K.; Han, A.-R.; Lee, J.; Kim, Y.; Oh, J. H.; Yang, C. Adv. Funct. Mater. 2013, 23, 5317-5325.8. He, B.; Pun, A. B.; Zherebetskyy, D.; Liu, Y.; Liu, F.; Klivansky, L. M.; McGough, A. M.; Zhang, B. A.; Lo, K.; Russell, T. P.; Wang, L.; Liu, Y. J. Am. Chem. Soc. 2014, 136, 15093 − 15101.9. http://www.nano2014.org/thesis/view/4220

One-dimensional nanoscale materials continue to attract much attention, not only for a better understanding of the physical properties at low dimensionality, but also for their potential in nanodevice applications. Carbon nanotubes (CNT) are of particular interest because of their unique molecular geometry and of their excellent electronic, thermal, and mechanical properties. Various carbon nanostructures have been successfully used as templates for the growth of novel hybrid nanomaterials, exhibiting highly interesting and unprecedented properties. These nanohybrids mainly consist of carbon nanostructures (mostly nanotubes) decorated by nanostructures of either metallic or semiconductor materials such as Au, Pt, TiO2, ZnO or SnO2. They are often obtained via various conventional chemical processing or through chemical functionalization approaches. In particular, nanohybrids consisting of carbon nanostructures decorated with ZnO nanoparticles have been shown to be promising for applications such as photocatalysts, field emitters, solar cells, and electro-photonic nanodevices. Here we report the successful growth of zinc oxide (ZnO)/single walled carbon-nanotubes (SWCNTs) nanohybrids using a two-step laser process. First, an ultraviolet (UV) excimer laser (ArF, λ = 193 nm) was used to grow SWCNTs using the UV-laser ablation method. Second, ZnO nanostructures were grown onto the SWCNTs by means of the CO2 laser-induced chemical liquid deposition technique (LICLD). High resolution transmission electron microscopy (HRTEM) revealed that the SWCNTs mainly consist of nanotubes featuring a high aspect ratio (diameter around 1.2 nm and length of up to several microns), while the ZnO nanostructures consisted of various morphologies, including nanorods, polypods, and nanoparticles sometimes with a size as small as 2 nm. On the other hand, the x-ray photoelectron spectroscopy (XPS) spectrum of the as-prepared ZnO/SWCNT sample showed clearly core level peaks of Zn, O and C, while the high-resolution XPS C 1s peak at 284.5 eV was attributed to the graphitic carbon C–C bonds abundantly present in the SWCNTs. The O 1s peak at 531 eV was attributed to O2– in the ZnO crystal lattice (i.e., O–Zn bonds), and the strong peak at 1022 eV could be attributed to Zn²⁺ (i.e., Zn–O bonds in the ZnO crystal). The observed peaks at 286.2 eV and 290 eV are considered to originate from the C–OH and O–C–O groups, respectively, and the one at about 533 eV was attributed to surface O–C groups. The presence of oxygen components in the high-resolution XPS C 1s spectrum and the presence of carbon components in the O 1s spectrum suggest that oxygen is directly bonded to the SWCNTs structure through the formation of strong covalent bonds between carbon and oxygen atoms, especially when no Zn–C bonding has been detected. However, these XPS data, along with the microscopy results, highly suggest that the growth of ZnO nanocrystals takes place directly on the walls of the SWCNTs through the formation of –Zn–O–C– bonds, as also reported in the case of other metal oxide/CNT composite materials [1, 2]. The ZnO/SWCNTs nanohybrids were found to exhibit a polychromatic photoluminescent (PL) emission, at room temperature, comprising a narrow near-UV band centered around 390 nm, a broad visible to near infrared band (500–900 nm), and a relatively weak emission band centered around 1000 nm. These PL results are compared to those of individual components (SWCNT and ZnO) and discussed in terms of carbon defect density and charge transfer between the ZnO nanocrystals and the carbon nanotubes. In fact, visible PL of the SWCNT is believed to originate from the combination (or at least one) of the three following phenomena: (i) the presence of short single-walled nanotubes which are known to generate a visible PL, (ii) multiple radiative transitions between energy states of the Van Hove singularities (VHS) of the carbon nanotubes, and (iii) the presence of amorphous and/or disordered sp2 carbon which is known to exhibit broad band visible PL. The PL spectrum of the nanohybrids basically combines the emission features of the separate components (i.e. SWCNT and ZnO) with, however, three main differences. Firstly, the PL peak due to the ZnO nanostructures slightly red-shifts to ∼410 nm, while exhibiting some peak broadening (FWHM of ∼55 nm). Secondly, its intensity was drastically diminished by a factor of about 100 (in comparison with that of ZnO alone). Finally, the relatively broad PL peak centered at ∼1000 nm is more defined and slightly increased in intensity. Thus, the observed quenching of the ZnO PL emission when laser-deposited onto the SWCNTs is believed to be due to charge transfer of photoexcited electrons from ZnO nanocrystals to the empty electronic states of the SWCNTs and/or to partial re-absorption into the complex hybrid structures (i.e., lattice distortions and defective nanostructures acting as non-radiative recombination centers). Quenching and red-shifting of the ZnO near band edge (NBE) in UV-excited PL has already been observed but to a lesser extent in electrochemically grown ZnO/CNT deposits [3]. Such charge exchange is highly promising for photovoltaic PV applications, where the photocurrent generated into such hybrid nanomaterials can be collected whenever the underlying SWCNTs network is appropriately deposited and electrically connected. As a matter of fact, the possibility of photocurrent generation by ZnO nanoparticles anchored to chemically functionalized carbon nanotubes in a photo electrochemical cell has been recently reported [4]. In sum, this clear indication of charge transfer occurring between ZnO nanostructures and SWCNTs is paving the way towards the development of novel ZnO/SWCNTs nanohybrids-based photovoltaic devices.

References:

[1] N. I. Kovtyukhova, T. E. Mallouk, L. Pan and E. C. Dickey: Individual Single-Walled Nanotubes and Hydrogels Made by Oxidative Exfoliation of Carbon Nanotube Ropes. J. Am. Chem. Soc. 125, 9761 (2003).

[2] M. Liu, Y. Yang, T. Zhu and Z. Liu: Chemical modification of single-walled carbon nanotubes with peroxytrifluoroacetic acid. Carbon 43, 1470 (2005).

[3] R. Zhang, L. Fan, Y. Fang, and S. Yang: Electrochemical route to the preparation of highly dispersed composites of ZnO/carbon nanotubes with significantly enhanced electrochemiluminescence from ZnO. J. Mater. Chem. 18, 4964 (2008).

[4] F. Vietmeyer, B. Seger, P. V. Kamat: Anchoring ZnO Particles on Functionalized Single Wall Carbon Nanotubes. Excited State Interactions and Charge Collection. Adv. Mater. 19, 2935 (2007).

Qatar is firmly committed to conserving its biodiversity and is party to the Convention on Biological Diversity and within this the Global Strategy for Plant Conservation (GSPC), and has developed its own National Biodiversity Strategy and Action Plan (NBSAP). Based on an assessment of the status of biodiversity in the country, Qatar's NBSAP identified a total of 11 strategic goals that identify the most pressing biodiversity issues in Qatar including; protected areas, agro biodiversity and desertification, scientific research, education and public awareness. Qatar is home to unique and important habitats, but due to changes in land use and increased development, habitat reduction has emerged as a significant threat to its biodiversity. Qatar is distinguished for its diverse flora that consists of nearly 420 plant species which pave the way for the establishment of the basis gene bank. In accordance with the international conventions which Qatar has recently joined and ratified, the gene bank has conducted ecogeographical surveys about the plant genetic resources. As a result of conducting these surveys, a complete set of seed plants of the Qatari plants genetic resources are conserved as well as integrated database is created to facilitate electronic exchange among relevant stakeholders and countries to use the resources for studies, research, food security and development. A conservation plan is addressed to conserve plant genetic resources to face the challenges of food security in Qatar. This plan is based on Qatar national biodiversity strategy and action plan 2004 and Ministry of Environment national strategy projects 2011–2016. In this study, we focus on the project of Plant Genetic Resources Conservation in Qatar, the project has addressed in five key objectives; plant and seed conservation, molecular genetic characterization, training and capacity building, documentation of Qatar plant genetic resources, and increasing awareness of plant genetic resource's value. We reported that genetic resources department “gene bank” have been collected and conserved 210 seed accessions, 2800 herbarium specimens, and 287 Plant sample for Genetic characterization. On the other hand department of agricultural research start developing field gene bank. Plant genetic resources conservation, including all seed processing and treatments in gene bank “seed cleaning, seeds drying, seed quality test, seeds viability test, seeds germination test as well as store seed at storage rooms. Gene bank make available the conserved germplasm (genetic resources) to several groups of breeders, researchers, graduate and undergraduate students, farmers and other stakeholders. On the other side, we implemented several workshops and training courses about seed conservation in gene bank and access to plant genetic resources and sharing of benefits arising from their utilization. Finally, In fact, Qatar does not have a traditional food insecurity “Lack of access to adequate food during the year due to limited of money”. But food insecurity in Qatar means that Limited resources of biodiversity and agriculture biodiversity resources. As well as it linked to self-sufficiency. Finally, Plant genetic resources provided powerful tools for humanity to control our child's future, and yet not too much been at risk for Qatari genetic resources to be unsustainable, so it is necessary to preserve the natural plant genetic resources on which development is based. Plant genetic resources can be helpful in the achievement of a world without hunger “Food insecurity”.

Arid and semi-arid areas where desertification mainly occurs cover up to 40? of the world's land area. Mongolia is one of the arid and semi-arid areas, which 90? of the land is in effect of desertification. The government of Mongolia recognizes the need of afforestation for combating desertification, however, there are very limited practical afforestation techniques in Mongolia. Nitrogen fertilization, a major technique for afforestation, generally improves growth and physiological characteristics of plants. The optimal fertilizer application scheme may vary by locations due to the different responses of plants to nitrogen fertilization. Therefore, it is necessary to determine the optimal amount and the type of the nitrogen fertilizers for successful afforestation in the desertification area of Mongolia. The objective of this study was to investigate the effects of nitrogen fertilizer (three levels of amount and two types) on growth rate, photosynthesis and transpiration of Populus sibirica seedlings, a representative afforestation species, in Mongolia. In May, 2015, five plots (6 m ×  7 m) were installed at about 2 m distance apart and 2-year-old P. sibirica seedlings were planted in each plot; four plots for nitrogen fertilization and one plot for the control. Nitrogen fertilizers were applied to each seedling with 5 g (N1), 15 g (N2) and 30 g (N3) of urea and 33 g of ammonium sulfate (NS; same amount of nitrogen with N2). The number of seedlings in each plot was 22 for the control, 21 for N1, 29 for N2, 30 for N3 and 24 for NS plots, respectively. Each seedling was drip irrigated with 3 L per day for the first month and with 9 L at 3 day-interval for the rest of the period. Soil inorganic (NH4 ⁺ and NO3 ⁻ ) nitrogen concentration (mg kg^− 1), when measured 3 weeks after the fertilization, increased with the increasing amounts of nitrogen applied (Control: 2.16, N1: 4.33, N2: 4.84, N3: 5.97, NS: 5.53). Root collar diameter (RCD) and height of seedlings were measured in May and August, 2015. Growth rate of RCD and height were calculated as the increase of RCD or height from May to August divided by the initially measured value in May. Net photosynthetic rate and transpiration rate were measured by handheld photosynthesis system (CI-340, CID Bio-Science, USA) at 8:00?10:00 in June and at 16:00?18:00 in July (n?3). The differences in growth rate of RCD and height following nitrogen fertilization were analyzed using analysis of covariance and the differences in soil nitrogen concentration, net photosynthetic rate and transpiration rate following nitrogen fertilization were analyzed using one-way analysis of variance (SAS 9.3 software). Growth rate of RCD (?) was significantly higher only in the NS plot (14.99) than in the control plot (10.42). Growth rate of RCD of urea-fertilized plots did not significantly increase compared to the control plot and showed a tendency to decrease as the amount of urea increased (N1; 13.01, N2: 12.97, N3: 11.17). The decrease in growth rate of RCD with the increasing amounts of urea might be influenced by ammonia toxicity. When ammonium ion from urea is converted to ammonia in alkaline soils, ammonia toxicity which restricts growth of plants occurs. Although 33 g of ammonium sulfate (NS) has the same content of ammonium ion as 15 g of urea (N2), the growth rate of RCD was significantly increased in the NS plot. It can be explained that ammonium sulfate decreased soil pH which resulted in the decline of ammonia toxicity and improved uptake of nitrogen by roots. Growth rate of height (?) was 8.47 for the control, 8.42 for N1, 10.30 for N2, 9.29 for N3 and 8.74 for NS plots, respectively. There were no significant differences in growth rate of height among plots. It was related to the fact that trees concentrate more on diameter growth than height growth in arid environments. In June, net photosynthetic rate (μmol m^− 2 s^− 1) was significantly higher in the N2 (10.79) and NS (11.15) plots than in the control plot (4.05). There were no significant changes in net photosynthetic rate among plots in July, however, net photosynthetic rate showed relatively high values in the N2 (14.26) and NS plots (15.20), similar to the result of June. It seemed that nitrogen fertilization increased net photosynthetic rate. However, net photosynthetic rate was lower in the N3 plot, which had the highest amount of nitrogen, than in the N2 and NS plots. The reason for the lower net photosynthetic rate of the N3 plot can be related to the fact that excessive nitrogen decreases photosynthesis. In June, nitrogen fertilization significantly increased transpiration rate (mmol m^− 2 s^− 1) compared to the control plot (0.68). Transpiration rate of fertilized plots was highest in the N2 plot (2.79), followed by N1 (2.46), N3 (2.03) and NS plots (1.89). Transpiration rate in July revealed no significant differences among plots. Generally, transpiration rate might be increased by nitrogen fertilization with the increase of photosynthesis. However, the change of transpiration by nitrogen fertilization was significant in June, but not in July. It can be explained by the fact that the increase of transpiration occurs at the early stage after nitrogen fertilization. Growth rate of RCD was only increased in the NS plot, although net photosynthetic rate of the N2 and NS plots were higher than that of the control plot. This result might be related to the high transpiration rate of the N2 plot. It was reported that transpiration was decreased in order to reduce the water loss in dry environments. Although our study site is also a dry environment, transpiration was increased by nitrogen fertilization. We speculated that water stress caused by the increase of transpiration limits growth of seedlings. In conclusion, the response of growth and physiological characteristics of P. sibirica seedlings differed with the amount and the type of nitrogen fertilizer. 15 g of urea increased net photosynthetic rate and transpiration compared to other amounts of urea, but growth rate of seedlings did not differed with the amount of urea. Thus, the optimal amount of urea cannot be determined with the three amounts (5 g, 15 g, 30 g) used in this study. Ammonium sulfate and urea which have the same amount of nitrogen increased net photosynthetic rate. However, growth rate of seedlings was increased by ammonium sulfate. Ammonium sulfate seems to be more suitable fertilizer than urea for the early growth of seedlings in the desertification area of Mongolia. However, the effects of urea and ammonium sulfate on growth and physiological characteristics of P. sibirica seedlings were different. Therefore, further studies would be necessary to determine the optimal amount of ammonium sulfate.

Pre-combustion flue gas capture has been emerged as an efficient alternative to circumvent the costly procedures of materials regeneration utilized by the energy industry for CO2 capture and separation. Stability of the porous structure and repeated use at high pressure and high temperature are among the essential requirements for the efficient materials to be used for industrial level CO2 separation. Herein we report the CO2 adsorption-desorption performance of nanoporous covalent organic polymers (COPs), which can operate efficiently and repeatedly at elevated pressure of 200 bars and above. Since, pre-combustion capture also requires removal of hydrogen along with CO2; therefore, nanoporous COP was also tested for hydrogen removal at high pressure. COP material prepared with simple technique from building block monomers of cyanuric chloride and linked with 1,3-bis(4-piperidinyl)propane has enough surface area and pore volume which makes the material capable to store large quantity of syngas at high temperature and pressure. Results indicated that the newly synthesized COP material can adsorbed exceptionally large quantity of CO2 and very little hydrogen at 200 bars and 35°C. Additionally, the adsorption isotherm was exactly matched with the desorption isotherm, suggesting the material has excellent adsorption-desorption characteristics. Similarly, the material has shown very stable performance when used repeatedly and alternatively for CO2 and hydrogen after regeneration at 50°C. The capturing performance of material was also investigated for other gases like methane and nitrogen at various pressures and temperatures. Experimental results revealed that COP material has exceptional CO2 adsorption efficiency, very good selectivity, and strong stability and can be manufacture with simple techniques. Lastly, material is economically attractive when it is compared with the commercially available materials and has exceptional performance contrary to activated carbon, metal organic frame work and monoethanole amine.

Due to the continued growth in hydrocarbon demand, operators in the oil and gas industry are always looking to drill deeper wells in order to access previously unattainable hydrocarbons. High-Pressure High-Temperature (HPHT) wells are now broadly present in places like the Gulf of Mexico, the North Sea, and the Middle East. At such conditions, the effect of salts on the properties and performance of water-based drilling fluids cannot be reliably extrapolated from moderate conditions.

Oil and gas wells are referred to as HPHT wells if their bottomhole conditions are greater than 300°F (150°C) or 10,000 psi (69 MPa). As drillers get into HPHT formations, a number of unique problems are introduced. Well control, for example, becomes more complicated due to narrow pressure margins and higher bottomhole pressures and temperatures.

As a result, this research aimed to test and investigate the rheological behavior of various water-based drilling fluids with a variety of different salinities at HPHT conditions using a state-of-the-art HPHT viscometer. The main equipment for these experiments is CHANDLER Model 7600 High Pressure High Temperature Viscometer. There are only 8 such equipment that exists in the whole world and our university in Qatar has one of them. Working on this experimental research will train the participating students to use one-of-a-kind high end viscometers in the world. The parameters that are gauged in this experiment are viscosity, yield point and gel strength of the drilling fluid when subjected to these conditions. To model this experiment, water based muds of varying salinity were experimented with two different types of salts – NaCl and CaCl2. Also, two percentages, 15 and 25, of each of these two salts are proposed to be used in formulating the water-based fluid samples which corresponds to approximately 9.3 and 10.0 ppg. 25? concentration of NaCl will result in full saturation of the water-based fluid system and thus this percentage represents a maximum value. 15? concentration, however, can represent a middle value between the maximum concentration (25?) and the minimum (0?). Overall, the results attained in this experiment were useful in coming to several conclusions regarding the effects of salinity on the rheological properties of water-based mud. As shown in Fig. 4, the average dial reading increases with the set pressure. It levels off at a maximum pressure of 18,000 psi and then decreases. This was the case for all the samples apart from the CaCl2 at 25?. Salinity is the total of all non- carbonate salts dissolve in water, unlike chloride concentration that represented only by its content. Therefore, the summation of all the salts in the mud can be expressed by salinity. Amani and Hassiba (2012) performed HPHT tests on water-based drilling fluids containing different concentrations of Sodium and Potassium Chloride (NaCl and KCl). They showed that the fluids with these salts followed the Power Law model up to pressures of 20,000 psi. Above that pressure, the shear rate started to vary linearly with shear stress (best modeled by the Bingham Plastic equation). In the presence of different kinds of salt additives to initially increase the weight of the mud, the junction to the point of separation between water and other solids creates and breaks the stable suspension and produces flocculation.

Therefore, at the end it will decrease the viscosity of the mud. Up to some extent, modified starches becomes anionic and free in hydrated water. The flow properties of the drilling fluid must be controlled so that the fluid can function properly. Properties of the fluid such as the plastic viscosity and the yield stress are very important for the success of the rotary-drilling operations and are therefore constantly measured. Viscosity is the measure of a fluid's resistance to flow and is defined as the ratio of shear stress to shear rate. Newtonian fluids are fluids where the proportionality between the shear stress and the shear rate is independent of the shear rate. Newtonian fluids are usually water or fluids with low molecular weight material. However, most drilling fluids are non-Newtonian and experience shear thinning with increased shear rate as shown in Fig. 20. The Bingham plastic and the power law rheological models are non-Newtonian models that were used in the past and are still used today to approximate the behavior of drilling fluids and cement slurries. The majority of the behavioral models for drilling fluids and cement slurries used today include a yield stress. One of these rheological models that fits this kind of behavior at both high and low shear rates is the Herschel-Bulkley model.

The mud was found to start losing its intrinsic properties at 24,000 psi and the concentration of Calcium Chloride was found to have a more profound impact on the rheology than Sodium Chloride. Out of the used rheological models, Herschel-Bulkley had the best fit and could be used to predict the viscosity. Although the cost of calcium chloride is more than sodium chloride per unit, it is still feasible to use this salt as it has a profound effect on the shear stress and other rheological properties of the fluids. In future iterations of this experiment it would perhaps be more useful to record more data points for the salinity level. Observing the results for more salt concentration levels will give a clearer picture of the effect of salinity on the rheological properties of the fluids. Acknowledgement: “This report was made possible by a UREP award [UREP 13-031-2-014] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the author.”

1. Abstract: Silica nanoparticles functionalized with three different active functional groups (C-8, cyano-propyl, and methacrylate (MA)) were synthesized, characterized and applied for the removal of ten carbamate pesticides from aqueous solution. Two methods were used for the synthesis of functionalized silica (grafting and sol-gel method). SEM, FTIR, and HCN were used for the characterization of the particles, while LC-MS/MS was used for the quantitative analysis of carbamate pesticides in the non-treated and treated aqueous solutions. The characterization results indicated the formation of uniformed, spherical and mono-dispersed particles when the cyano and MA particles were prepared by the Sol-gel. Also, results indicated that all of the synthesized particles were enhances for the removal of carbamate pesticides, and MA prepared by the Sol-gel methods had the highest ? removal for most of the carbamate pesticides tested. 2. Introduction: Active functional groups such as C8 and cyano-propyl have good recovery and can selectively react with carbamate pesticides [1]. Also, previous works [2] have shown that methyl methacrylate have some selectivity and high efficiency to bind with carbamate pesticides. Yet, investigations are still needed to improve the selectivity and efficiency of solid phase extraction via surface modifications. Successful identification of the host functional groups that will selectively react with the guest (contaminant or analyte) will be highly important for the purpose extraction and quantification of the specific analyte. Also, the success to immobilize host molecules that react specifically with pollutants in aqueous solution will allow the remediation of water. The objective of this work is to prepare modified silica-nanoparticles by immobilizing reactive functional groups as hosts on the surface of these particles and to characterize and apply these particles for the removal of pesticides from contaminated water. 3. Experimental: 3.1. Material

All the reagents and chemicals used in this study were obtained commercially from Sigma-Aldrich company. The chemicals used were methanol LC-MS grade, octyl-triethoxysilane, 3-cyanopropyltrimethylsilane, trimethylsilyl-methacrylate, silicon dioxide nanoparticles, xylene, hexane, ammonium hydroxide, 3-methacryloxypropyl trimethoxysilane, tetra-ethoxysilane, ethanol, and carbamate standard (46856-U). Using these chemicals, five particles were synthesized: 1. silica grafted with cyano-group; 2. silica grafted with methacrylate particles; 3. silica grafted with C8; 4. cyano-particles synthesized by Sol-gel method; and 5. propyl methacrylate particles synthesized by sol-gel method.

3.2. Preparation of particles

The particles were prepared following previously developed methods by other scientists [3,4].

3.2.1. Preparation of cyano grafted particles Prior to preparation, the silicon oxide (SiO2) was activated by heating overnight. 5.0 g of the activated SiO2 was mixed with 0.347 mL of 3-cyanopropyltrimethyl-silane, and 100 mL of xylene. The mixture was places in sonicator for one hour, and then was heated overnight. After that, the mixture was centrifuged for ten minutes with 5000 rpm. The particles were finally washed with methanol for three times.

3.2.2. Preparation of methacrylate grafted particles 5.0 g of the activated SiO2 was mixed with 0.237 mL of trimethyl-silyl methacrylate, and 100 mL of xylene. The mixture was places in sonicator for one hour, and then was heated overnight. After that, the mixture was centrifuged for ten minutes with 5000 rpm. The particles were finally washed with methanol for three times.

3.2.3. Preparation of C-8 grafted particles 5.0 g of the activated SiO2 was mixed with 0.414 mL of octyltriethoxysilane, and 100 mL of xylene. The mixture was places in sonicator for one hour, and then was heated overnight. After that, the mixture was centrifuged for ten minutes at 5000 rpm. The particles were finally washed with methanol for three times.

3.2.4. Preparation of cyano and methacrylate particles by Sol-gel-method 40 mL of ethanol was transferred into a flask, and both 1.0 mL of ultrapure water, and 25 mL of NH4OH were added to the ethanol. The mixture solution was then stirred for 14 minutes at 4000 rpm. After that, 1.0 ml tetraethyl-orthosilicate diluted in 4.0 ml of ethanol was added to the solution. Finally, the mixture solution above was divide equally into two different bottles. In one of the bottles, 0.578 mL of 3-cyanopropyltrimethyl-silane was added in order to prepare the SolGel-Cyano particles and in the other bottle 0.444 ml of trimethyl-silylmethyl methacrylate was added in order to prepare SolGel-MA particles. 3.3. Instrumentation: The synthesized nanoparticles were characterized by an FEI Quanta 200, USA scanning electron microscope at an accelerating voltage of 3 kV was used for these analyses. Fourier-transform infrared spectroscopic measurements of the samples were obtained in the range from 400 to 4000 cm^–1 using a Perkin Elmer Spectrum 400 FTIR with an ATR detector at a resolution of 4 cm^–1. The elemental analysis were carried out by using CHN analyzer. Then, the synthesized particles examined for their ability to remove pesticides from water. The pesticides were separated and analyzed by LC-MS/MS (Agilent,1290). 3.4. Pesticide treatments and analysis: Six 15-mL tubes were prepared. 1.0 mL of carbamate in acetone was added into each tube and kept to dry overnight in order to avoid the presence of acetone, which is expected to compete with the particles in extracting the pesticides. Then 2.0 mL of deionized water was added into each tube. One of the tube was kept as control (not treated), while the carbamate solutions in the other five tubes were treated with the five synthesized nanoparticles. 0.25 g of the five different nanoparticles were added to the five tubes. The tubes were vortexed for 1 minute, and left to settle for 10 minutes, and then were centrifuged for two minutes at 4500 rpm. The solutions in each tube were transferred into new tubes and analyzed by LC-MS/MS. 4. Results and Discussions: 4.1. Characterization results

The nanoparticles were synthesized and characterized by SEM, FTIR, TGA, and EDX. The results of SEM indicated the formation of relatively small (nano-size) particles (Fig. 1 a-e). Both the cyano and MA particles that were prepared by sol-gel method appeared to be uniformly and homogenously spherical (Fig. 1 d,e), unlike the other particles, which were prepared by the grafting method. According to the CHN analysis results (Table 1), the amount of C, H, and N elements were relatively high in the particles prepared by Sol-gel methods compared to those prepared by the grafting methods, with highest percentage found in the MMA particles prepared by the sol-gel methods. According to the FTIR results (Fig. 2 and Fig. 3), different patterns were observed for the different synthesized particles and there was indication of OH present in the MMA particles that was prepared by sol-gel method, The different structures of the synthesized particles were clearly in the fingerprint region of the FTIR spectra. 4.2. Pesticide treatments and analysis results: The carbamate pesticides were fully separated as observed in the chromatogram in Fig. 4. Retention times of the pesticides belonging to the chromatogram are shown in Table 2. Also, the table shows the areas of the peaks belonging to the pesticides in the chromatogram before and after treatments with the five synthesized particles. It is clearly observed that the concentration of pesticides significantly went down after treatment with the particles. For most pesticides, the MA particles prepared by the Sol-gel methods showed the highest removal of pesticides. 5. Conclusion: Both cyano and MA particles prepared by the Sol-gel appeared to more uniformed, spherical and monodispersed under the scanning electron microscope and gave higher relative amounts of C, H, and N elements. MA particles prepared by the Sol-gel was the most efficient in removing the pesticides, although all synthetically prepared nanoparticles showed promising result in removing the pesticides. More investigation is required to determine the prober dose of these particles and to examine the effect of pH, temperatures, contact times, as well as the concentration of pesticides. Also, more invistigations are needed to determine the efficiency of these particles to remediate solutions contaminated with other pesticides such orgonophosphorous and chlorinated pesticides. Acknowledgement: This article was made possible by grant QU [QUST-CAS-SPR-13/14-23]. The statements made herein are solely the responsibility of the authors. References: M. Ferna'ndez, Y. Pico', J. Manes, “Determination of carbamate residues in fruits and vegetables by matrix solid-phase dispersion and liquid chromatography–mass spectrometry,” Journal of Chromatography A, 871 (2000) 43–56.

C. Baggiani, L. Anfossi, P. Baravalle, C. Giovannoli, C. Tozzi,” Selectivity features of molecularly imprinted polymers recognizing the carbamate group” Anal. Chim. Acta, 2005, 531, 199.

E. Effati, B. Pourabbas, “One-pot synthesis of sub-50 nm vinyl- and acrylate-modified silica nanoparticles,” Powder Technology, 2012, 219, 276–283.

R. Brambilla, G. P. Pires, J. H. Z dos Santos, M. S. L. Miranda, B. Chorink. “Octadecylsilane-modified silicas prepared by grafting and sol–gel methods,” Journal of Electron Spectroscopy and Related Phenomena, 2007, 156–158, 413–420

Introduction: Industrial pipelines for multiphase transportation can result in unstable flows which often cause major operational problems. Due to liquid wave growth and phase interactions (hydrodynamic slugs), liquid arriving in larger, intermittent chunks may cause flow instabilities in pipelines. At an increased air volumetric flow rate, the surface wave amplitudes become larger to the pipe/conduit and wave forms frothy slug where it touches the wall of the pipe. When the slugs travel at a velocity higher than average liquid velocity, it can cause severe vibration that could reduce the integrity of or damage equipment. In order to tackle the problems associated with slug flows, there is a clear need to better understand the multiphase flow leading to various flow phenomenon in the pipelines. The multiphase flows are characterized by flow patterns or regimes that define a particular distribution of phase volume fraction in pipeline.

While there are several numerical models characterized the development and evolution of slugs and slug flows, studies which describe the stress analysis of these slug flows and their effects are scarce. This study compares two CFD codes (ANSYS CFX and FLUENT) in slug development in jumper and the stress analysis of slug movement in jumper. As well, the effects of flow parameters such as fluid superficial velocity, fluid density ratio, and viscosity on slug were investigated.

The model considered in the present study is based on a quasi-3D formulation where the governing equations are based on volume averaging and ensemble averaging of Navier-Stokes equation. In present study, proposed benchmark relies on focusing on two CFD tools, FLUNT and CFX, to simulate surface instabilities and slugs on stratified flow in a horizontal channel considering slip, surface tension, and frictional momentum transfer between the phases (liquid and gas).

FLUENT Set-up The setup mimics the modified version of the experimental study previously investigated by Vallee and Hohne (2007), the flow channel with rectangular cross-section was modelled using Computational Fluid Dynamics (CFD) package, FLUENT code. The dimension of the model are 4000 ×  300 ×  30 mm³ (length ×  height ×  width). The simulation was performed by a grid consists of 4 ×  462 hexahedral elements and 4 ×  46152 nodes applying a quasi-3D model that consider the wall effect of channel in a 2D model. The volume-of-fluid (VOF) model is used for modeling the fluid domain with air and water. This model is well suited for separated flows with no mixing at the interface. The fluid interface shape is represented by geometric reconstruction scheme. For the two-phase flow, 1.0–1.5 m/s superficial velocity of water and 5.0–11.5 m/s of air were chosen for the CFD calculations. The model inlet was divided into two parts: in the lower half of the inlet cross–section, water was injected and in the upper half air. An initial water level of 50 mm was assumed for the entire model length. As well, initial inlet velocity 1 m/s was considered for water and air, and the velocity of air was increased gradually to simulate different scenarios until final velocity 11.5 m/s considered in this work. The reference pressure considered during the simulation was 1 bar and surface tension of 0.072 N/m. A hydrostatic pressure was also assumed for the liquid phase. For surface instability generation with subsequent slugs, the interfacial momentum exchange and turbulent parameters had to be modeled accurately (Razavi and Namin). In this regard, turbulent model of K-ε model was chosen as the viscosity that is able to model surface instabilities and turbulence of slug flow. Solution for calculating 15s of simulation time on 6-processors lasted for 48 hours. Selected discretization schemes were PRESTO for pressure, Geo-Reconstruction for volume fraction, and First Order Upwind for other cases. Variable time step between 10–6 and 10–3 was appropriate steps for the simulation.

CFX Set-up Building the geometry in ICEM, the mesh was then imported to the ANSYS CFX-Pre in order to define the simulation parameters. Air and water were defined as the two gaseous and liquid phase and using the expressions, the height of water is set to 0.05 (half of the area section) through the entire domain. According to (Frank, 2005), Shear Stress Transport (SST) turbulence model was selected for the simulation and the term “Production and Dissipation” was added to the equations. Surface tension coefficient was set to the value of 0.072 (N/m), interface length scale to 1 (mm), and drag coefficient to 0.44 ( − ) (Frank, 2005). The mixture model was chosen for the interphase transfer. The inflow type was chosen as ‘inlet” and the fractional intensity was set to the value of 0.05 with the eddy length scale equal to the liquid height at the upstream (Razavi & Namin, 2011). The mass flow rate of air and water were set to the values of 0.074 (kg/s) and 7.83 (kg/s), respectively. Several simulations were conducted in order to improve the simulation results and due to the blockage of the outlet in the previous runs, the outflow boundary type was set to “opening” instead of “outlet” with a pressure controlled and medium intensity (5%) turbulence in the boundary details.

The liquid and gaseous phases were defined based on their volume fraction in downstream at outflow. The wall boundary type was set to “wall” and for both phases “no slip wall” and “smooth wall” options were assigned to the mass and momentum and the wall roughness, respectively (Hohne, 2009). The analysis type was set to transient with the total simulation time of 8 (s) and time steps of 0.001 (s), according to the similar study conducted by (Razavi & Namin, 2011). In the solver control, a second order backward Eulerian approach was chosen with high resolution turbulence. Due to the instability and fatal errors in the previous simulations, the minimum and maximum number of loops were set to 1 and 200 (due to divergence problem), respectively with the convergence criteria of 1 × 10^–4.

Figure 1: Abnormal flow simulations (L =  4 m, D =  0.3m, Ug =  9 m/s and Ul = 1 m/s). References: S.Y. Razavi and M. M. Namin. Numerical Model of Slug Development on Horizontal Two-phase Flow, Proc. of Int. Conf. on Recent Trends in Transportation, Environmental and Civil Engineering 2011.

A. Ashrafian, J-C. Barbier and S.T. Johansen. Quasi-3D Modeling of Two-Phase Slug Flow in Pipes. 9th International conference on CFD in the minerals and process industries CSIRO, Melbourne, Australia, 2012.

T. Frank. 2005. Numerical Simulation of Slug Flow regime for an air-water two-phase flow in horizontal pipes, The 11th International Topical Meeting on Nuclear Thermal Hydrualics (NURETH-11), Avignon, France, 2006.

R.E.M. Morales et al. 2013. A comprehensive Analysis on Gas-Liquid Slug Flows in Horizontal Pipes. Offshore Technology Conference, Brazil. OTC 24437.

D. Duraivelan, Y. Dai and M. Agrawal 2013. CFD Modeling of Bubbly, Slug, and Annular Flow Regimes in Vertical Pipelines. Offshore Technology Conference. OTC 24245.

Photovoltaic distributed generation (PV-DG) systems are one of the fastest-growing types of renewable energy resources being integrated worldwide onto distribution networks. As the price of solar cells continues to decrease, residential and utility-scale PV installations are becoming popular energy options in the United States and other Western countries. Similarly, in line with the National Vision 2030, Qatar is aiming to embrace solar technology by 20% to meet its growing demand and reduce carbon emissions. The short-term goal for KAHRAMAA Utility in Qatar is to reach 10 MW solar generation in the next years. Qatar resides in the Arabian Peninsula and is blessed with abundant solar resources. For instance, the Global Horizontal Irradiance for Qatar is measured as 2140 kWh/m²/year in 2012, which is one of the highest in the world. However, local weather conditions significantly degrade the performance of the PV output. Some of the major issues include: (1) the temperature on PV panels is significantly higher than the ambient temperature. This affects the performance of the power electronics devices that are attached to the PV panels, such as inverters, and also the PV output due to the stress on the materials; (2) Qatar is prone to frequent foggy weather during the Winter. Thus often leads to sudden drops in the PV outputs; (3) PV panels often need cleaning in Qatar due to soiling; and (4) during winter months, the humidity increases significantly in Qatar, and the scheduling of anti-dust cleaning as well as considering the impact of late cleaning become more important. The above region-specific issues further emphasize the challenges in integrating PV-DGs in Qatar and the potential need for modeling the impacts of weather conditions on the generation out of PV-DGs on the distribution network. The main goals are to devise probability distribution functions for overloading of transformers and cables and failures of different system components. The outcome of this work will be used to (1) quantify the costs of poor power quality on customer premises and system elements; (2) compute the electric system average interruption duration index (SAIDI) and the system average interruption frequency index (SAIFI); and (3) create rare event techniques to simulate the adverse impacts of PV integration. Moreover, the developed model can be used to find the relationship between the energy storage size, which are likely to assist PV integration at the distribution network, and the unexpected weather events.

I. Introduction

Gas to Liquids (GTL) is one of clean alternative fuels which loosely defined terms that is generally used to describe the chemical conversion of natural gas to some type of liquid products. As such, it excludes the production of liquefied natural gas (LNG), but includes the conversion of gas to methanol, liquid fuels, and petrochemicals, being the most common applications. In other words, Gas to liquids (GTL) technology is used to convert a carbon containing feedstock such as natural gas, to synthetic diesel fuels and further developed by oil companies. Fewer studies investigated the use of GTL diesel with the existing diesel engines to study the effect of using this new alternative fuel on the efficiency and emissions in these engines. Hence, the objectives of this study are to investigate the behavior of the GTL – diesel fuel blends in context of different combustion characteristics, engine performance and emissions. It is expected that the outcomes of this study will shed further light on GTL diesel fuel as a clean alternative fuel.

II. Experimental Methods

The experiments were carried out on a T85D single cylinder, four stoke, water cooled, direct injection, compression ignition engine attached to DIDACTA ITALIA engine test bed. An electric dynamometer with motor and a load cell was coupled to engine. Engine specifications are shown in Table 1. Two fuel tanks were assembled in the test bed; one tank was used for convention diesel fuel and the other was used for GTL Diesel. The properties of the used fuel are mentioned in Table 2. It can be observed that the GTL fuel has a lower density and viscosity and high cetane number in comparison with conventional diesel fuel as demonstrated in Table. 2. All these properties are in favor of improving fuel evaporation and mixing with air, which lead to better combustion characteristics.

The engine test bed and the measuring devices are shown schematically in Fig. 1. The in-cylinder pressure was measured by using a water cooled piezoelectric pressure transducer AVL QH 33D which was mounted flush at cylinder head and connected via AVL charge amplifier. The output signal was displayed on Instek GDS-3152 Digital Storage Oscilloscope with 150 MHz sampling rate. Then, the data was transferred to a laptop which saved for further analysis. The crank shaft position was measured using a digital shaft encoder.

The engine speed was measured by using a speed tachometer that used the pulse counting principle to detect the crank shaft speed, while the fuel flow rate was measured by using a calibrated burette and a stop watch. The engine torque was measured by using a load cell. Engine NOx emission was measured by a long life electrochemical sensor at NOVA-7465PK portable engine exhaust emission analyzer. This electrochemical sensor has anodes, cathodes and suitable electrolyte sealed inside it which, when exposed to gasses, produces a small output current. This output is directly proportionally to the amount of NO gas in the sample. A Pre-Amplifier board directly mounted on the top of the sensor boosts the small signal and converts it to an output of 1 mV per PPM. This output is then sent the main microprocessor board, corrected for the calibration then displayed on the LCD display meter. The resolution of the NOx sensor is ±  1 PPM. The test rig is also equipped with a type-K thermocouples to measure air inlet manifold, engine cooling temperatures and exhaust temperatures which were mounted at relevant points. Normal engine test bed safety features are also included. Atmospheric conditions (temperature and pressure) were monitored during the tests.

III. Results and Discussion

In this section, a comparison between the new manifold designs and the standard manifold of the engine in terms of engine performance and emissions is presented. A number of experiments have been conducted when the engine runs at different loads and different speeds. In addition, the results of using conventional diesel, GTL and 50%–50% blends of both fuels will be presented to show the fuel effect on the above mentioned parameters.

A. Engine Performance

Figure 2. Shows the effect of in cylinder pressure change with crank angle for the diesel at 1700 rpm with variable loads fuels. It was obvious when load increases, the pressure increases. The maximum pressure occurs 18.7 ATDC at no load condition. As load increases the combustion duration increases which lead to long the ignition delay period. It can be observed from Fig. 3 that the maximum pressure values of both fuels and their blends are comparable over the whole range of operation. This proves the suitability of the combustion characteristics of GTL fuel and its blends with conventional diesel to be used with the existing engine designs.

One of the important performance parameters of internal combustion engines is Brake thermal efficiency which indicates how energy conversion added by heat is transferred into a net useful output work. The engine brake thermal efficiency, not shown here, increases with increasing of load. In case of variant load constant speed at 1700 rpm operation condition, the efficiency of GTL fuel was slightly lower than conventional diesel and 50%–50% blend with about (1.5%–8%) and (1.3%–7.75%) compared with diesel, respectively. Higher cetane number, Low viscosity and density of GTL fuel properties leads to efficiency degradation compared with diesel fuel. On the other hand, the engine brake thermal efficiency decreases with increasing of speed. In case of constant load variable speed operation condition, the efficiency of GTL fuel was slightly lower than conventional diesel and 50%–50% blend with about (5%–1.7%) and (2%–4%) compared with conventional diesel, respectively.

Figure 4 illustrates that the engine brake specific fuel consumption (BSFC) decreases with increase in load. In addition, it was observed that by using GTL fuel the BSFC decreases by approximately (4.8–17) % and (0.7–6%) compared with GTL and 50%–50% blend. The higher heating value of GTL fuel than conventional diesel improved the BSFC. Besides, as shown in the bellow figure 5. It was observed that GTL fuel had lower BSFC comparable to conventional diesel and 50%–50% blend. It had been found that while speed increases, BSFC decreases. GTL fuel has the lowest BSFC compared with conventional diesel and 50%–50% GTL by approximately average 31.28% and 5.2%, respectively.

B. Engine emissions

Figure 5 shows the version in CO emissions for conventional diesel, GTL and 50%–50% blend at various loads constant speed 1700 rpm. On average, GTL fuel has the lowest CO emissions of about 43% lower than the other tested fuels. It is obvious that the GTL fuel in 50%–50% blended fuel has a significant effect to reduce CO emissions. This is probably due to higher GTL hydrogen to carbon ratio leading to improve the combustion process in addition to the very low aromatic content and higher cetane number in GTL fuel. The variation of CO emission with speed at constant load is displayed in Fig. 5. It shows that a slight decreasing of CO formation whereas the engine speed increases. In general, GTL fuel shows 42% less CO emissions than conventional diesel. The results also demonstrates that 50%–50% blended fuel has a lower CO emissions than conventional diesel by about 24%.

Figure 6 shows the relation between NOx emissions with load variation at constant speed 1700 rpm. The results indicate a gradual increase in NOx emission with load. GTL fuel has the lowest NOx emissions compared with conventional diesel and 50%–50% blends by about 12.8% and 34.6%, respectively. This is considered to be a significant advantage of using GTL fuel. This NOx reduction can be linked with the high cetane number, which reduces ignition delay duration. Figure 6 gives a relation of NOx emission with the engine speed for conventional diesel, GTL and blends at a constant engine load with variation of speed. Overall, NOx emissions decrease as the speed increases. Moreover, it can be observed that the GTL fuel ratio in the blends contributes to greater NOx emission reduction. The 50%–50% GTL blends and the pure GTL fuel give about 4.6% and 10.5% reduction in NOx emissions, respectively, comparing with diesel fuel.

Sulfur content is one of the fuel property that is responsible of sulfur oxides (SOx) emissions which attracted the researchers and engine manufacturers to test a new fuels. In the combustion process, most of Sulphur content in diesel fuel is being oxidized to SO2. These emissions together with exhaust gas from the exhaust system are then mostly vented into the atmosphere where they can be subject to other reactions contributing to the creation of photochemical smog and acid rain. However, some of SO2 in a presence of oxygen can be unfavorably oxidized to SO3. The high temperature of exhaust gas means that SO3 stays in a vapor state and easily combines with after formed in the combustion process. Figure 7 depicts the variation of SO2 exhaust emissions for the tested fuels at constant speed 1700 rpm with load variation. The results show a slight increase of SO2 emissions as the load increases. GTL fuel has a very low SO2 emissions comparing with conventional diesel and 50%–50% blends by approximately 50.1% and 79.6%, respectively.

Figure 7 compares SO2 emissions of the test fueled by conventional diesel, GTL and 50%–50% blends at constant load variable speed operating conditions. On average, GTL fuel gives the lowest emissions, while 50%–50% blended fuel shows about 52.2% reduction. Adding GTL to conventional diesel has a positive effect to enhance the reduction in SO2 emissions. The reduction in SO2 emissions can be explained by the fact that GTL has almost no Sulfur content. Moreover, some SO2 formed during the combustion process combine with hydrocarbons or metals forming sulphates as it can be occurred while using GTL fuel. Metals originate from the products of the engine reciprocating and rubbing abrasion as well as from lubricating oil, fuel (catalyst residue) or erosion of the catalytic emission control system.

IV. Conclusions

In this work, GTL fuel has been used in direct injection diesel engine as a pure fuel and blended with conventional diesel fuel. In cylinder pressure was measured for a wide range of operating conditions to investigate the combustion characteristics of both fuels and their blends. Moreover, engine performance and emissions have been studied in order to evaluate the suitability of GTL fuel as an alternative fuel for engines. The results show that comparable maximum in cylinder pressure for both GTL and diesel fuels. However, the engine efficiency is slightly lower with GTL fuel than diesel fuel. BSFC shows improvements with GTL fuel in comparison with diesel fuel and blends. CO and NOx emissions have reduced significantly when using GTL and 50%–50% blends. SO2 emissions is the lowest reduction due to the fact that the Sulfur content in GTL fuel is close to 0%.

Acknowledgments

This abstract was made possible by a NPRP award [NPRP 7 – 036 – 2 – 018] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors.

The need of transporting petroleum products has resulted in increased erosion of pipeline steel components. For decades, pipeline systems have been used for transporting petroleum products. Carbon steel is commonly used for constructing long-distance pipeline projects due to its mechanical durability and economic aspect. However, the erosion of oil and gas transmission pipeline continues to be a great concern to the petroleum industry because of increasing pipeline maintenance cost and failure. Pipeline steels are often subjected to severe erosion during transportation of petroleum products containing a broad range of erodent particles. The process of transporting petroleum product through the pipeline often results in mechanical removal of the oxide film from the pipeline surface, leaving the surface directly exposed to stress and degradation.

Material removal due to solid particle erosion is believed to be a series of impact events that occur in pipelines and cause extensive damage due to change in the solid-liquid flow direction. Erosion of oil and gas pipeline is a complex phenomenon, characterized by the impacting erodent particles on the pipeline walls due to solid-liquid flow, flow restrictions or change in flow direction. The erosion of steel surface by stream of solid particles can result in high material loss and maintenance costs. Unfortunately, there is no universal model that can effectively predict all erosion situations and development of a reliable and effective model for solid erosion process still remains a challenge. Several attempts have been made to understand the effect of different parameters, such as; temperature, particles size and microstructure of both the impinging and eroding surface on the solid particles erosion process. However, each parameter behaves peculiar to each process and is often complex due to interrelated variables involved. Most of these works were focused on lower carbon steel. The results obtained from these works showed that the target material, temperature, impact angle, particle velocity, shapes and sizes play critical roles in the erosion mechanisms. The angle at which the erodent particles impinge the target material accounts a greater percentage of the erosion damage. Levy studied the solid particle erosion behaviors of 1020 and 1075 low carbon steels using SiC particles as erodent at different impingement angles and speeds. The result showed that the microstructure of the steel materials had a significant influence on the crack growth observed on the eroded steel surfaces. Similarly, Green et al. investigated the erosion mechanisms of low carbon AISI 1050 steel material in relation to the carbon content and microstructure. The result revealed that thermally hardened martensitic structures behave better than the pearlitic steels of the same carbon content under normal temperature range. McCabe also studied the effect of microstructure on the erosion of AISI 1078 and 1050 steels at different angles and speeds using 240 grit A12O3 erodent particles. The result exhibited that the erosion mechanisms assumed a brittle mode with increase in particle velocity. Liebhard and Levy conducted a study on the influence of the shapes of erodent particle on the erosion of 1018 steel. The result showed that angular particles caused higher order of erosion compared to spherical particles. However, the impact of these parameters on the erosion characteristics and mechanisms significantly depend on the material pairs and testing equipment.

In another direction, significant efforts have been made to improve the erosion resistance of the pipeline steel over the years. Results indicated that micro-alloying of carbon steels with small amount of carbide and nitrate forming elements have achieved significant success in the erosion resistance of the carbon steels. Micro-alloying with application-specific elements in combination with judicious process control (e.g. shape-forming and heat-treatment etc.) provided carbon steels of high yield stresses and desirable toughness, for example, high strength low alloy (HSLA) steels. Interestingly, HSLA steels are becoming the material of choice for the projects requiring larger pipeline because of their appreciably low price-to-yield ratio. API X-70 and API X80 have been of the commonly used pipeline grades steels due their ability of withstanding the basic erosion-corrosive environment. However, recently, petroleum industry has witnessed an outstanding demand for higher strength pipeline steels e.g., API X100 in order to combat more stringent environment in terms of erosion-corrosion. Recently, TransCanada, one of the frontiers amongst the steel manufacturing industries has produced API X120 steel which is considered as highest grade pipeline steel available in today's market. The erosion behaviour of this newly developed pipeline material has not yet been investigated in detail. It is of essence to understand the erosion mechanism of this newly developed high strength steel, and under various incidence angle and erodent particle velocities. Conducting detailed analysis on interaction of API X120 steel with various erodent particles (e.g. aluminum oxide) at different velocities would be worthwhile in order to understand the erosion characteristics and mechanisms. Understanding the effects of particle velocity and erosion behavior associated with the API X120 in simulated pipeline environment is necessary to minimize the rate of erosion in the petroleum industry and would be helpful in efficient pipeline material selection and design. This study has been made to facilitate understanding of erosion mechanism and its transition with particle velocity which has a direct relation with the erosion damage.

In this study, dry erosion test was performed in order to investigate the erosion mechanism of API X120 steel by employing particle velocities over a range of 43–167 m/s at normal impact angle for different durations within 0–10 min. A dry sand blaster erosion tester was used to study the erosion behaviour of API X120 steel impinged with aluminium oxide particles at room temperature. The equipment was designed to impinge the targeted sample surface with solid particles at different velocities under controlled erosion conditions. Scanning electron microscope and profilometry techniques were used to characterize the eroded API X120 steel surface. The results indicated plastic deformation and embedment of the erodent particle on the target material surface to be the predominant erosion mechanism observed at lower speed, while at high particle speeds the dominant erosion mechanism was observed to be metal cutting of the target API X120 steel surface.

Qatar is undergoing rapid economic growth fueled by its ambitious national vision 2030 which specifically aims to achieve sustainable development. To achieve the latter, durable and sustainable alternatives for municipal solid waste management are needed, especially since Qatar tops most nations in terms of per capita solid waste generation with nearly 2.5 million tons/year of which 60% consists of organic waste. Current disposal methods include incineration, composting, and land filling which generate greenhouse gases that contribute to global warming. At the same time, the soils in most of the country are poor with weak aggregation, low in organic matter, and low water holding capacity. Hence, it makes economic and environmental sense to convert solid organic wastes generated by municipalities into biochars that improve soil quality and act as carbon sink. The suitability of biochar as an effective soil amendment has been related to but not limited to boosting soil fertility by raising soil pH, increasing water holding capacity (WHC) and retention of nutrients in soil, providing a habitat for beneficial fungi and microbes, improving Cation Exchange Capacity (CEC), and reducing nutrients leaching. In addition, biochar has the ability to reduce the emission of the most potent greenhouse gases such as methane (CH4) and nitrous oxide (N2O). The objectives of this study were to: (1) produce and characterize biochars from solid organic wastes commonly found in Qatar municipal waste streams, (2) determine the effects of solid waste-based biochars on major soil fertility characteristics of normal and sabkha soils of Qatar, (3) select the best performing biochars for use in plant growth experiments.

Four feedstocks [paper, landscape waste, wood, and a mixture of all three) were pelletized, dried, and used as precursors for the production of biochars following a 4 × 3 × 3 factor factorial design consisting of the type of precursor (four different municipal solid organic precursors), pyrolysis temperatures (300, 500, and 750°C) and residence time (2, 4, and 6 hours). Feedstocks were pyrolyzed under N2 gas at a flow rate of 0.1 mL min^− 1 using a Lindberg box furnace equipped with an air tight retort. Yields, surface area, and chemical properties [ash content, pH, surface charge, Electrical Conductivity (EC), Total Carbon (TC), and elemental analysis] of biochars with relevance to soil applications were determined. Qatari sandy soils (Normal and Sabkha) from the Ap horizon (0–15 cm deep) were collected, air dried, and 2-mm sieved. The incubation experiment was conducted in greenhouse pots. To each pot, sufficient amount of 0.25-mm sieved biochar was mixed with soil to yield carbon to soil ratios of 0, 1, and 2% (wt/wt). Box-Behnken experimental design was used instead of the full factorial to decrease the number of treatments to a manageable level (126 treatments) with three replications at the center. The biochar-amended soils (Normal sandy and Sabkha soils) were incubated for 120 days in a greenhouse at a 10% (wt/wt) moisture level. Samples of incubated soils were collected at time 0 (T0: after 8hrs) and at time120 (T120: after 120 days of incubation) for evaluation of soil fertility characteristics (pH, EC, WHC, aggregate stability, TCN content, macro, and micronutrients composition). In addition, pots were leached at days 60 and 120 and their leachates weighed, filtered, and analyzed for total organic carbon (TOC), pH, EC, micro, and macronutrients.

The application of biochars from different precursors to normal soil at different application rates showed a slight increase in pH of treated soil compared to the soil control at T0 and T120, particularly for biochars produced at high temperature and application rate. The increased soil pH is attributable to buffering effect of biochars pH which typically increases as the pyrolysis temperature increases. The same trend was observed for EC where the pyrolysis temperature of biochars seems to be the most influential on the normal soil EC, especially as it ages. The aggregate stability for the normal soil did not increase as the biochar application rate increases, except for hard wood-based biochar produced at high temperature which had a positive effect on the aggregate stability. However for sabkha soil, the pyrolysis temperature and biochar rate significantly increased the aggregate stability of this soil regardless of the precursor. This can be explained by the accumulation of organic matter that was favored by the binding of organic biochar compounds to abundant soil minerals through cation bridging and the formation of microaggregates that would then form large soil aggregates. The addition of biochars has significantly increased the total carbon (TC) of both soil types compared to the control soils. The total carbon increased with both application rate and pyrolysis temperature. Biochar pyrolysis temperature and application rates favored increased TC with variation depending on the type of precursor, soil type, and duration of incubation. This may be attributed to the oxidation and microbial activity processes that speeded up the process of mineralization in the soil. Overall, the TC in normal soil was higher compared to the sabkha soil which may be due to the fact that the starting carbon concentration in the normal soil was higher than that of sabkha soil. In terms of water holding capacity, it significantly increased in both soil types following biochar amendment, especially those produced at high pyrolysis temperature. The positive effect of soil amendment with biochars on WHC was most pronounced in the sabkha soil which exhibited markedly increased ability to absorb and retain water after biochar addition. This is likely due to the high surface area and porosity of the biochars combined with the effect of the polarity of compounds on the surface of biochars which physically retain water and/or improve soil aggregation thereby retaining more water in the soil. The addition of biochars to soil had a positive effect on the pH of normal soil leachates but less so on leachates from sabkha soil. Some pH variations were also observed within the pH of the same soil leachates as a function of the type of precursors used to produce biochars, most likely due to difference in initial composition of the precursors. This implies that biochars with greater liming capacity can provide greater benefit to arable soils that require liming. The results of cluster analysis were used to determine the group of biochar-amended soils which are the most significantly different from the control treatment in terms of soil fertility parameters (pH, EC, TC, WHC, aggregate stability, leachate pH, micro and macronutrients). From the four precursors, only two (soft and mixed materials) were found to be most effective for normal soil and all improved sabkha soil. To further narrow the selection, a secondary selection was carried out based on the biochars precursor type, yield, and energy required for biochar production. Two biochars emerged as the best performing biochars for normal and sabkha soils. Biochars produced from mixed materials pyrolyzed at 500–750°C for 4–6 hours of pyrolysis time and used 2% application rate are best for amendment of normal soil while soft and mixed materials pyrolyzed at 300–500°C for 4 hours and used at 0.5–1% application rates as most suitable for the amendment of sabkha soil. These biochars were found to improve all soil fertility parameters, especially in terms of pH and WHC.

From the above discussion, it is clear that Biochar characterization and short-term soil incubations can provide insights into the potential effectiveness of biochar as soil fertility enhancer and aid in the selection of potential biochars that can improve crop productivity. Overall, normal soil seems to require mixed material produced at high temperature and longer time and applied at high rate while sabkha soil required softer materials produced at lower temperature and shorter time and applied a low application rate. This is encouraging results for carbon depleted soil in Qatar where the application of biochar to agricultural soils has the potential to greatly improve soil physical and chemical conditions while serving as a long term carbon sink. These best performing biochars are being tested in plant growth experiments designed to assess their impact on plant biomass and productivity as indicator or their potential in field agriculture in Qatar.

This study to identify the best pre-treatments to improve seed germination of Capparis spinosa according to standard seeds germination protocols and seeds viability test methods.

Capparis spinosa L. (Capparidaceae) Native to the Mediterranean region and Arabian Peninsula. Locally known ‘Shafallah’ and also known as ‘Caper’ both names used throughout the Arab countries for various Capparis species. The plant is very common in the rodat in northern Qatar in the deep alluvial soil. But at last 10 years Capparis spinosa plants Are in danger of extinction from habitat degradation and changes in environmental conditions. The younger flower buds are collected and pickled in salt solutions. They are used as a condiment in many Mediterranean and Arab countries. Young fruits and young shoots with small leaves may be pickled for use as a condiment. Capers has a sharp piquant flavor, which comes from methyl isothiocyanate, arising from crushed plant tissues. The tender young shoots and the small leaves may also be cooked and eaten as a vegetable.

Based on the literature author reported that Capparis spinosa has high economic and medicinal value in many medicine pharmacies, including Arabian medicine, traditional knowledge, and Chinese medicine. Traditional knowledge of Arabian countries Capparis species were used for treatment wounds and problems in the spleen, liver, kidneys and intestines, to dispel gases, for treat skin diseases, to strengthen teeth and relieve backaches. The plant growth Accompanied mainly by Ziziphus nummalaria, Acacia tortilis and Lycium shawii.

In this study, seeds of Shafallah treated with different dormancy treatments included, concentrated sulfuric acid H2SO4 98%, 0.1% and 0.2% potassium nitrate KNO3, hydrogen peroxide H2O2, boiling water, tap water 24 hours, mechanical scarification “removing part of the seed coat without damaging the embryo”, and gibberellic acid GA3 100 ppm, and 200 ppm to improve seed germination of very important native medicinal plants in Qatar. Capparis spinosa seeds used for production and restoration seedling in some protected area and rodat. Pre-treatments have been done with old seed stored in standard gene bank conditions, and fresh collected seeds, this study carried out in Genetic resources Department, Agricultural Research Department, Ministry of Environment.

Viability test of old storage seeds using 2,3,5-Triphenyltetrazolium chloride has given 80%, but the germination percentage of seeds without any treatments gave 8% after 30 days in automated growth chamber machines. Fresh collected seed viability test has given 100%.

The highest germination percentages 98% and the fasting germination rate was obtained using mechanical scarification with fresh collected seeds after germinated in 10 days under automated standard germination conditions in laboratory growth chamber machines. Results visibly suggest the fresh seeds of caper have highest viability and germination percentage more than old storage seeds.

Finally, Qatar is home to unique and important plant genetic resources, but due to changes in land use and increased development, habitat reduction has emerged as a significant threat to its biodiversity. Capparis spinosa showed in different areas in Qatar as green color to our yellow deserts in the summer, The plant is green and flowering in the very dry regions, and the plant gives fruits two times in Qatar. We can use plant in food security and sustainability programmes. We need more education and public awareness to increase awareness about Qatari native important medicinal plants. Keywords: Dormancy, Capparis spinosa L., Germination, Viability, Germination, Qatar.

Although PV has made remarkable progress in reducing costs, the absolute cost is highly related to the reliability of system components, which is determined by the life span in which PV remains fully functioning. Longer life is especially required for the solar panels when their initial cost is relatively high and therefore longer life guarantees their pay back and increases their profit. Indeed great efforts have been spent by manufacturers to make the panels more reliable and durable to the hard environmental conditions. In spite of careful design and production conditions during manufacturing, the environmental cyclic stresses cause irreversible changes in the solar cells that cause them to partially totally malfunction gradually with time. An accurate measurement of power drop over time, (or degradation rate), is essential to all stakeholders, industry, and investors.

What are the factors affecting the reliability of solar PV technology in harsh environments?

PV technologies are designed to deliver amounts of solar electricity, which is varying differently when submitted to harsh environments (temperature, soiling, UV radiation, wind). The temperature is one of the main factors affecting the power output of a PV system. Researchers may explore the so-called NOCT rating or “normal operating cell temperature” which is indicative of module temperature.

Based on the difference between module temperature and ambient temperature, NOCT can be calculated for crystalline Silicon [1], and thin films [2]. However the influence of other environmental factors must be taken into account when determining the amount of energy (in watt-hour or Wh) produced during a period of time to ensure the consistency and performance criteria of PV systems. Solar Test Facilities in Qatar Foundation: In Qatar, prediction of PV performance can be improved through statistical data collected from PV fields. QEERI is collaborating with Qatar Science & Technology Park and GreenGulf on research at the Solar Test Facility, and developing state of the art solar test laboratory facilities, in order to provide information to stakeholders and industry for better deployment of PV technology in Qatar to meet the Energy grand challenges of the country. A wide variety of equipment, tools, and techniques are used to explore and follow-up failures of PV modules for different technologies. Since March 2013 around 20 photovoltaic technologies have been continually tested at the outdoor Solar Test Facility at Qatar Science & Technology Park. Solar energy technologies at the STF include: Crystalline, thin film, including concentrating (thermal Linear Fresnel collector) as well as battery storage. Overview of Solar Test Facility in QEERI: Two years of investigations have revealed the relative performance of different solar technologies in Qatar's climate, their reliability and degradation, and the impact of heat and dust on their efficiency. We found that flat-plate PV yields more energy than concentrating PV, due to diffuse light conditions at the STF [3]. Crystalline silicon and thin film PV had similar average yields. Of all PV technologies tested, only one-showed signs of severe degradation in the first two years. Dust and heat significantly reduced power output, but high levels of insolation in Qatar compensated this problem. Roadmap: • 2010: Initiated by QSTP, GreenGulf and Chevron

• 2011–12: Systems installed

• 2013: Testing commenced

• 2014: QEERI joins collaboration Final Remarks: • We observed from our experimental data analysis that ordinary flat-plate PV is well suited to Qatar's conditions, provided it is cleaned occasionally.

• Still a need to explore NOCT taking into account module and ambient temperature, available solar irradiance.

• Correlation with simulated yearly module generation, module temperature, solar irradiation (GHI, DNI,) as well as soiling conditions. Acknowledgements: We thank GreenGulf and QSTP for providing data from the STF for this study References: [1] International Standard EN-61215; 1993–04.

[2] International Standard EN 61646; 1996–11.

[3] Daniel Perez-astudillo and Dunia Bachour. (2014). Solar Resource Measurements In Doha, Qatar. Qatar Foundation Annual Research Conference Proceedings: Vol., EEPP0697.

Dugongs (“bugarah al bahr” or “cow of the sea”) in Qatar and the wider Arabian Gulf, are animals of both historic and cultural significance to the people in the region. Historically hunted in Qatar, today they are seen as a symbol for conservation in a country that is trying to balance rapid modernization and coastal development with protection of marine biodiversity, as outlined in the Qatar National Vision 2030.

Qatar and the Arabian Gulf are home to the largest population of dugongs outside of Australia and is the most important region for dugongs in the western portion of their range. As long-lived large mammals with low reproductive output dugongs are vulnerable to exploitation and are listed as Vulnerable to Extinction by the IUCN (International Union for the Conservation of Nature). Currently, dugongs in Qatar face many threats including incidental fisheries bycatch and habitat degradation. The extreme marine and physical environment of the Arabian Gulf, as well as the northern limit of dugong distribution, likely means that their life-history differs from populations in Australia. However, there are virtually no life history data for Qatari dugongs and the species remains mostly unstudied.

A solid understanding of dugong natural history is necessary to develop a successful management and conservation program. Our knowledge of dugong natural history in Qatar and the Arabian Gulf is poor compared to our knowledge of dugongs in Australia (where the largest population exists). Although approximately 6000 dugongs were estimated to live in the Arabian Gulf including Qatar, this number has not been verified. Sporadic research has been conducted on the Qatari population, including work in 1986 which recorded the largest single dugong group of 577 individuals in the waters between Qatar and Bahrain. More recently, in 2008, the Qatar Ministry of Environment conducted surveys that expanded the area around Qatar where dugongs were observed.

Our current study applies similar techniques from the past (boat-based and beach surveys) with newer techniques (aerial surveys using Unmanned Aerial Vehicles [UAVs], histological analyses) to provide an updated understanding of when, where, and how many dugongs are present in Qatari waters, along with preliminary information on their population demographics. From our 2014–2015 surveys, we have enumerated individuals in a large herd, consistently spotted in the winter months in similar areas to the 1986 and 2008 surveys. A total of 508 individuals (including 51 cow-calf pairs) were counted using images taken from a UAV. Underwater surveys verified that the major activity was foraging upon a mixed stand of seagrasses, Halodule univernis and Halophila ovalis, in clear, shallow water (

Nowadays, new trends have made possible to reconfigure the traditional power systems in a more efficient way while world energy consumption is being continuously increased. To meet future energy demands, a more flexible, smart and configurable power system is required. To create such systems, microgrids are emerging and becoming a more attractive solution. The microgrid is a weak grid formed with different energy sources (renewable and conventional), energy storages, power electronics, power control systems and different loads. The microgrids are also particularly suitable for communities and regions where adequate renewable energy sources are available such as in Qatar. Therefore, the energy cost can be significantly decreased, energy security ensured, and energy production become environmental friendly with lower carbon footprints.

The energy sources are the major part of the microgrid systems. As a result of increasing environmental awareness and as a consequence of the exhaustible nature of fossil fuels, renewable energy sources (RES) are playing an important role in modern microgrid systems. The RES based power generation systems have several advantages compared to the conventional power generation systems. Some of these advantages are sustainability, pollution-free operation and the possibility of being installed closer to the end users. In the last decades, especially the wind and photovoltaic (PV) based power generation systems have become more popular than other RESs. However, intermittent and stochastic nature of the wind and solar affect the stability, reliability and power quality of the microgrids. For instance, the PV based system cannot produce energy at night or during cloudy conditions, and wind-based systems generate energy that depends on the wind condition. To overcome these limitations, two or more (hybrid) RES, in addition to proper storage technologies, are needed to provide reliable, stable and continuous power to the customers. However, using different types of renewable energy sources in the same microgrid leads to complex control structure because these sources have different dynamic characteristics and need different control structures. Hence, a well-designed energy management and power flow control systems are essential to ensure the extraction of maximum power from these energy sources.

Another part of the microgrid systems is an energy storage system (ESS) that plays a vital role to maintain stability and robustness as well as to improve the power quality of those systems. For these reasons, an effective ESS must characterize high power density as well as high energy density. In recent years, various types of battery technologies are used for energy storage systems. In spite of their maturity and variety, batteries still have limited lifecycle and poor power density, which is an important element for balancing the renewable based power generation systems. Thus, to support and improve the battery performance, lifetime and system cost, hybrid energy storage systems (HESS) can be suggested while comprising supercapacitors (SCs) and batteries. SCs have a number of advantages related to high efficiency (95%), high power density (up to 10000 W/kg),

tolerance for deep discharges, and long life-cycle (500000 cycles at 100% depth-of-discharge). The combination of SCs and batteries allows to have the advantages of both solutions by obtaining high energy density, high power density, high life-cycle, high efficiency HESS and ensuring better power stability when interfacing with the grid. However, batteries and SCs have different charge and discharge characteristics. Therefore, a well-designed energy management and power flow control system is essential for that system to provide efficient operation and long life cycle.

In the microgrid system, power flow should be bi-directional. For example, in case of insufficient energy, the utility grid can support the microgrid, vice versa, in case of exceed energy, microgrid can inject this energy to another microgrid(s) and/or to the utility grid. Therefore, in such systems, power electronic converters are important to allow the power flow between energy sources, energy storage devices, loads, and the utility grid. These power electronic converters not only allow to connect different electric devices together (whether they are loads, generators or storage devices), but also to provide suitable control for optimizing and protecting the whole system. Furthermore, to ensure the power connection between these different units, a direct current (dc) microgrid or an alternating current (ac) microgrid can be used. However, as mentioned above, most of these units are controlled by power converters, and each of these converters requires a dc-link. For this reason, one common dc-link can obtain appreciable savings for such systems.

To ensure power flow between energy storage devices, energy sources, loads, and the utility grid (if needed), energy management algorithm is essential. A well-configured energy management algorithm increases energy efficiency, system stability, and battery life cycle. Therefore, the energy management algorithm and control structures must be defined properly according to system requirements. Several research activities focus on the energy management algorithm for HESS and power flow control algorithm. Types of the developed algorithms depend on the system power, storage techniques, types of energy sources, and operating modes such as grid-connected and/or standalone. However, most of these studies focused on only one microgrid and its control. In reality, more than one microgrid in the same region and different types of distributed generation units in these microgrids are common. Typically, the energy management control structure can be divided into three categories; centralized, distributed, and multi-level control structures. In all three cases, each energy sources and energy storage devices are controlled by the local controller to determine the optimal operating point locally. To increase the impact of the microgrids, the microgrids should be controlled by the same centralized controller. The microgrids also should have monitoring facilities to observe and reconfigure the energy consumption of the consumers.

The main goal of this study is to design, develop and implement novel smart energy management and power control strategy for two grid-connected microgrids. The presented two microgrids have different charactersitics in terms of renewable energy sources and energy storage technologies. Thus, by the proposed smart energy management and power control strategy, the two different microgrids operate at their best efficiency points regardless of different conditions. They can also operate in bidirectional with each other and/or utility grid. For example, if there is exceed power in one of the microgrids, this energy will be transferred to the other microgrid and/or the utility grid, vice versa if there is insufficient power for the local loads, microgrids request power from the utility grid. This innovative feature of the study will be an effective solution for growing microgrids toward securing the increased power demand. Furthermore, this study presents condition monitoring to adjust and reconfigure the energy consumption of the consumers.

To verify the proposed smart energy management and power flow control system, two laboratory-scale microgrids are designed and implemented. As shown in Fig. 1, the proposed prototype consists of two microgrids connected to the utility grid through the grid interactive inverters. These microgrids can also connect to each other through isolated bi-directional converter. In addition to these, each microgrid consists of four subsystems. (1) Wind energy conversion subsystem, (2) PV energy conversion subsystem, (3) Hybrid energy storage subsystem, and (4) Power electronics interface for AC load. Each subsystem has own local controller that can communicate with centralized controllers in order to increase system efficiency. Furthermore, whole system is controlled by a central controller to ensure optimal power flow between Microgrid I, Microgrid II and utility grid. The results of the study will not only benefit the energy management of multi microgrids but will also benefit the power grid operation especially the distribution system creating positive environmental impacts paving the road for future large-scale integration of the smart grid flexible load technology in Qatar.

The solar photovoltaic industry is dominated by crystalline silicon with a global PV market share of 90%. The global PV module production has reached about 40 GW in 2013. Competing with Si PV, thin film photovoltaic modules have reached a market share just below 10%, with dominance by two companies: First Solar for CdTe and Solar Frontier for Cu(In,Ga)(S,Se)2. Derived by the technological learning and economies of scale, solar photovoltaics industry has seen remarkable cost reductions over the past decades. One possible route to further reduce the price of the photovoltaic (PV) module and reach the grid parity is to develop an efficient PV technology based on low cost materials and processes. Thin film PV has a higher potential for cost effective production in the economy of scale than the other technologies in the market today. The competitiveness of thin film technology currently faces three significant challenges in order to achieve widespread market acceptance and adoption:

• Increasing the record efficiencies toward the theoretical limit and beyond

• Increasing the efficiency of modules (particularly, decreasing the gap between lab scale champion cells and production modules)

• Reducing direct materials and processes costs, specifically by reducing the usage of scarce materials resources

At QEERI, the recently launched grand challenge project ATHLOC-PV (Advanced Thin film Low Cost PV) aims to tackle these issues by developing in Qatar an emerging alternative PV technology. Following a roadmap towards thinner, cheaper and more efficient thin film solar cells, the main objective of ATHLOC-PV is to obtain lower cost, lighter weight and durable photovoltaic modules and to accelerate the decrease in the cost/efficiency ratio for thin film PV modules. The overall aim is to demonstrate a new-type of thin-film solar cell of conversion efficiency in the region of 20% capable of environmentally acceptable large-scale production at a manufacturing cost of below 0.5 $/watt with potential for further significant improvements in the future. To reach this objective, two alternative thin film materials are targeted in ATHLOC namely: Cu2ZnSn(S,Se)4 (CZTSSe) and Cu(In,Ga)(S,Se)2 (CIGSSe). The key advantages include favourable optical band gap (1–1.5 eV), low materials usage and consequently a lower energy-payback time, usage of flexible substrates leading to lightweight and the potential of cost-effective roll-to-roll manufacturing, high conversion efficiency potential. In addition CZTSSe has the advantage not to suffer from abundance issues compared to CIGSSe.

Table 1 compares record efficiencies from laboratory research

Thin-film PV permits a higher cost-reduction potential when up scaling to GW production volumes [2] compared to Si wafer technology. However, the limited supply of some elements (i.e. In in CIGSe) and related costs upon considerably increased production volumes present a constraint that has to be addressed. The overall aim of ATHLOC project is to reduce the use of scarce elements and still reach high efficiencies by developing low cost roll-to-roll inkjet printing processes for the fabrication of CZTSSe solar cells [3], we expect to significantly reduce the manufacturing costs of the modules. In this contribution, the objectives and the roadmap of the ATHLOC-PV project will be presented, as well as the strategy foreseen to improve the efficiency and reduce the cost of the Kesterite solar cells.

References

[1] M.A. Green, K. Emery, Y. Hishikawa, W. Warta, and E.D. Dunlop, ‘Solar cell efficiency tables (version 46)’, Prog. Photovolt: Res. Appl. 22, 701 (2014).

[2] C. Wadia, A.P. Alivisatos, and D.M. Kammen, Materials Availability Expands the Opportunity for Large-Scale Photovoltaics Deployment, Environ. Sci. Technol. 43, 2072 (2009).

[3] Xianzhong Lin, Jaison Kavalakkatt, Martha Ch. Lux-Steiner, and Ahmed Ennaoui, (2015) “Inkjet-Printed Cu2ZnSn(S,Se)4 Solar Cells, Advanced Sciences, 2, 1500028 (1–6).

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