Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1

With growing climate change concerns, depleting natural resources and decrease in oil and gas prices, it is more vital than ever to efficiently manage natural resource allocation. Methane, the key component in natural gas and a raw material for numerous chemicals, is Qatar's more abundant resource. Natural gas can be monetized through many alternative paths. It can be sold as natural gas, either through pipelines or in liquefied form, or converted into diverse sets of fuels and materials using many alternative processing technologies. In the meantime, concerns of the effects of increased carbon dioxide concentration in the atmosphere, majority of which are emitted from large industrial stationary sources and fuel consumption, have caused the global society to seek ambitious emission reduction targets.

While on the one hand natural gas provides a clean fuel associated and enables carbon dioxide emissions through fuel switching globally, its local processing is associated with significant footprints. In the case of Qatar and its small population, this has resulted in very high per capita emissions. Most of the emissions are stationary and spatially concentrated in industrial clusters, where they originate mainly from natural gas processing, hydrocarbon processing, petrochemicals and metals production, and power and water generation.

The industrial sector is challenged to balance profit making activities from natural gas monetization with increasing pressures to reduce overall carbon dioxide emissions. Conventional design of industrial parks centering on natural gas are carried out in an ad-hoc process that depends on the expertise of designers, available capital, market demand and regulations. Reduction methods in the past have been limited in technology, energy integration or geographical proximity to apply carbon capture and sequestration (CCS).

Recently, carbon integration (Al-Mohannadi and Linke, 2015a,b) has been introduced as a systematic approach to determine the most efficient carbon dioxide reduction options in industrial parks by considering multiple carbon dioxide sources, potential carbon sinks, the layout of the city and the associated costs of transmission and conditioning. Carbon integration looks into the various conversion routes that take carbon dioxide into value added products, which can be converted chemically, biologically or through geographical utilization such as Enhanced Oil Recovery (EOR) applications. This creates incentives to reduce carbon emissions, to create synergies between firms and to produce additional products in the cluster, while adhering to required emission reduction targets.

Beyond focusing on low cost carbon dioxide emissions reduction, the broader design challenge for a natural gas monetizing industrial cluster is to identify the most promising configurations from the vast number of alternatives that exist from the possible combinations of many alternative natural gas monetization processes, and the many alternative carbon management options that could be applied, whilst exploiting synergies between natural gas conversion and carbon management. Most previous works have focused on different aspects of the overall problem: optimizing gas conversion processes, and managing carbon dioxide emissions reductions. Very few works have considered monetization in industrial clusters, and there is no published work on how to systemically make gas monetization decisions under carbon dioxide emissions constraints.

This work introduces the first systematic approach to allocate natural resource under carbon dioxide footprint constraints. The approach yields integrated natural gas and carbon dioxide management schemes that yield the maximum profit for the given gas monetization and carbon dioxide management options and constraints that exist in the industrial cluster. The work explores different carbon dioxide emission reduction scenarios; expansion plans and determines most profitable product mix from an industrial cluster. By taking into consideration the tradeoff between environmental performance and potential profitability of natural resource allocation, it provides valuable information to decision makers from an optimization based tool. Policy makers and regulators can use the tool for developing strategies and for planning of more sustainable industrial clusters, parks or cities.

The work is illustrated using a case study to demonstrate the application of the method on industrial cluster resembling a configuration of gas monetization options often observed in oil and gas centered economies.

Keywords

Resource Allocation, Climate Change, Carbon Dioxide emissions, Carbon Integration, Natural Gas Allocation, Gas Monetization, Carbon Reduction, Process Integration, Industrial Parks, Planning, Modeling, Optimization.

References

Al-Mohannadi, D.M., P. Linke (2015). On the Systematic Carbon Integration of Industrial Parks for Climate Footprint Reduction. Journal of Cleaner Production, DOI: 10.1016/j.jclepro.2015.05.094.

Al-Mohannadi, D.M., S.K. Bishnu, P. Linke, S.Y. Alnouri (2015b). Systematic Multi-Period Carbon Integration in an Industrial City. Chemical Engineering Transactions 45, 1219–1224.

The surge in the field of renewable energy aiming to develop clean energy technology is continuing to rise. Quest for a H2-based economy derived from non-fossil resources remains at the forefront of future fuels. During the past few decades there has been intense research on the utilization of electrical energy to produce H2 in an energy efficient and environmentally benign way. Electrocatalytic hydrogen generation via water electrolysis provides an important alternative to that extracted from hydrocarbon resources. One of the most crucial components which could revolutionize H2 production is that the design and development of a novel electrocatalyst that can efficiently split water to generate H2. Currently, platinum (Pt) is known as the state-of-the art electrocatalyst for hydrogen evolution reaction (HER). However, due to cost and scarcity of Pt, research focus shifted to precious-metal-free based materials for efficient HER reaction. As results, a wide variety of transition-metal-based electrocatalysts have been developed and investigated. To this end and due to unique d-band electronic structure, Mo-based electrocatalyst such as, Mo2C and MoS2 has been the subject of intense investigation for HER reaction. Yet, functional and robust catalysts operating with reasonable current densities (J) at low overpotential in brine water are still scarce.

Herein, we demonstrate a facile synthesis of β-Mo2C embedded on mesoporous carbon support; Metal Organic Framework (MIL 53(Al)) was utilized as a novel source for mesoporous carbon support. Microscopic studies revealed the formation of monodisperse Mo2C with

Background

Chlorine is extensively used as a powerful oxidizing agent in the countries surrounding the Arabian Gulf for water treatments and biofouling control. The usage has been increasing significantly as demand for water grows considerably both in industry and domestic use. This is due to the fact that it is a well-tested technology, has had a history of long-term worldwide industrial use and is of acceptable cost. Sodium hypochlorite (NaOCl, commonly termed chlorine) is a common form of chlorine that is used and in all cases it is produced on site by means of an electro-chlorination plant (ECP). In seawater, chlorine produces a mixture of hypochlorous acid (HOCl) and hypochlorite ion (OCl − ). These rapidly react with the bromide ion to form a mixture of hypobromous acid (HOBr) and hypobromite ion (OBr − ). The acute oxidants formed by chlorination are therefore short lived and are not persistent in seawater, but can be quite toxic. Further complicating the environmental concern of chlorination is the production of numerous, and more persistent, compounds formed by complex reactions between chlorine/bromine and the organic constituents of seawater, collectively described as chlorination by-products (CBPs). Many CBPs are persistent and may be toxic to marine organisms subjected to long-term exposures. The Gulf waters support a range of coastal and marine habitats including mangrove swamps, seagrass beds and coral reefs. However, marine organisms in the Arabian Gulf are living close to their tolerance limits due to the extreme environmental stressors of temperature and salinity. Anthropogenic stressors such as chlorine may further exacerbate these natural stressors.

Objectives

In order to evaluate the risks of chlorine exposure to Arabian Gulf marine organisms, the aims of this study were to 1) develop protocols for acute and chronic toxicity tests involving native species at different trophic levels, 2) correlate sensitivity to other marine organisms used as indicator species in risk assessments, 3) draw conclusion from the results and explore ways that this could be used for informing environmental management activities.

Methodology

Materials and methods

Stock solution of calcium hypochlorite was prepared in filtered artificial seawater (0.45 μm filter paper) daily in dark bottles. Concentration of chlorine in the experimental chambers were verified daily by the N,N-diethyl-p-phenlenediamine (DPD) colorimetric method. Different concentrations of chlorine were either administered as a continuous flow through or via daily renewal.

Exposure to test species

Species were collected from different location around the coastal areas of Qatar. They were then cultured in the laboratory using conditions of the Arabian Gulf. Species used in the tests include phytoplankton (Synechococcus sp.), zooplankton (Uterpina acutifrons), pearl oysters (Pinctada radiata), sea urchins (Diadema setosum) and killifish embryos (Aphanius dispar).

Results

Sensitivity varied across the trophic levels for each species and was found to be in line with other test organisms that are used in established toxicity procedures. All five species used were found to be useful for certain types of toxicity testing. For example, Pinctada radiata and Diadema setosum were excellent in testing for successful fertilization and early development stages, while local Aphanius dispar embryos were useful for following sub-lethal effects such as malformation and hatchability. Embryos of oysters and urchins were found to be the most sensitive to chlorine (Fig. 1.). Effect of chlorine was only observed near or after hatching has occurred. Continuous exposure showed more effective than the semi-renewal method.

Discussion and conclusion

While chlorine continues to be used heavily globally, available toxicology data are either very limited or out dated especially those based on the Arabian Gulf. The purpose of this study was to increase the knowledge of chlorine chemistry and toxicity especially the sensitivity towards the Arabian Gulf species. Results obtained reveal that the sensitivities of all five species used in this study are in line with species used internationally in similar tests. LC50s were determined for all species and are currently being used in modelling tools to determine the fate and environmental risks of chlorine. Chlorine being a powerful oxidizing agent asserted its effect immediately after contact. It loses its potency within the first hour in seawater and this may contribute to the low effect shown in this study compared those in fresh water. Given the short-lived nature of chlorine as an oxidant in seawater, our attention has also been focused on the sub-lethal effects that may be attributed from the by-products. Work is ongoing in this area. Expanding tests with species used in this study to evaluate their sensitivity towards chlorine by-products will further increase our understanding of their chemistry and environmental risk in the Arabian Gulf and will provide a science-based tools for making management decisions.

The amount of water below 1000 m³ per capita per annum is considered as the water poverty zone. With business as usual scenario it is estimated that by the year 2025 half the world's people will live in countries with high water stress. Based on Global averages irrigation water demands accounts for about 70% of all water uses. Meanwhile water use efficiencies of irrigated projects are generally very low particularly those under traditional surface methods. On the other hand conveyance losses vary within a range of 25–50% of the total diversion. Generally canal lining can save about 75% of the conveyance losses. However, high quality linings were found to practically eliminate such losses. The paper reviews the benefits of canal lining, which include hydraulic, economic and environmental benefits. Since seepage from irrigation canals is the most important factor in lining considerations the paper presents some review on the phenomenon. Canal lining is usually classified into four main types: hard surface linings, membrane linings, earth linings and soil sealants. The paper critically discusses the different types and highlights the criteria for selecting the appropriate lining technique. The paper also reviews the recent technical developments and research at the global level in this field; these include the development of new materials and techniques. Finally the paper presents a review of the canal lining related research executed by the National Centre for Research, Sudan during the last 20 years. These include development of low cost lining (building) materials using locally available aggregates (sand and gravel), lining irrigation canals on expansive soils and development of low cost concrete pipes and production of precast canal-lets. Canal lining was found conserve irrigation water, reduce fuel consumption, reduce irrigation time and reduce labour requirements. Development of Low Cost Building Materials for Canal Lining:: Four low cost building materials have been studied, these are namely khafgi, ferrocement, kenaf sheets and concrete made of small-sized gravel available near RDRC. Kenaf sheets were rejected because of the low durability expected. The other three materials were found to be feasible based on strength, permeability and durability. Water transported sand near RRS was found to be suitable for building works including lining whereas wind transported sand can hardly be recommended for such works.

Hand placement cast in-situ was adopted using the semicircular configuration, as besides improving structural integrity of the canal, it is the most hydraulically efficient section particularly for small canals. A semi circular cast-in situ form was made to construct channel sections that accommodate maximum discharges at RDRC. The work is done in alternate sections and the lap-joint technique was used. Pipe Casting:: It have been noticed that some desert farms the canalization system is liable to be buried by wind-blown sand. To avoid this problem the system should adopt pipes instead of open channels; however, traditional farmers cannot afford to cover such expenses since such pipes are relatively expensive in the local market. To overcome such problems the study was extended to develop intermediate technologies for pipe casting. A form was designed and constructed in a local workshop. The form is made of PVC pipe equipped with a handle as an internal unit the external unit is made of sheet metal also a wooden base is used. The external unit is composed of two semi-cylinders; a steel channel is welded to each end of each semi-cylinder to facilitate fastening meanwhile a rubber strip used to prevent water leakage. Again locally available aggregates were used. Laboratory tests (Impact Value and Crushing Value) showed that locally available gravel is suitable for pipe casting. The internal unit of the form is removed about an hour after the end of the casting process and the external one after a day. The pipes were then cured for 7 days. Compressive Strength and permeability tests proved that the produced pipes comply with the Known International Standards. Additionally the pipes were tested in the field by passing a tractor, which represent the maximum expected load in such farms without being damaged. Lining Irrigation Canals on Expansive Soils:: Um Jawaseer Desert Farm Project, which is located in Wadi El Magadam, the Northern State was established in the year 1989 for the settlement of the nomads of El Hawaweer Tribe. The project harnesses water from an aquifer of about 40 m below ground surface for irrigation and other purposes. Evaluation studies showed that the project is successful in creating better livelihood for the people of the area.

Huge water losses were encountered in the first two phases. In the third phase the project adopted stone lining, which is estimated to conserve about 1/3 of the irrigation water. However, stone lining is known to be one of the least effective lining techniques. Identification tests were carried out in accordance with the British Standards and showed that Um Jawaseer soil possesses swelling properties.

To reduce (mitigate) the expansive potential of Um Jawaseer soil some additives (cement, lime, bituminous emulsion and refuse oil) were tested, these additives were added to the soil at a rate of 6% by weight as recommended by some authors.

To avoid damage the linings a combination of soil treatment and construction technique was used for the lining of Um Jawaseer irrigation system. The soil was first excavated to a depth of 60 cm and mixed with the additive (cement). Water is added to the soil/ cement mixture till the optimum moisture content (plastic limit) was reached. Finally the mixture was compacted into two layers (30 cm each). As for the construction technique the semi-circular channel cross section was used since it produces integrity in structure and the channels so constructed can resist external forces. This combination gave very encouraging results since it is found to mitigate upheaval damage and produce strong and efficient conduits. Precast concrete canal-lets:: The merits of precasting are attributed to the high quality control coupled with the technique. Precasting was advised by some authors for mass production of tertiary canals. The J- Section was selected for ease of casting the form is made of metal sheets.

The form was filled of concrete, while being compacted with steel rod, left for an hour to allow for setting of concrete and then released. The finished section is allowed to dry for 24 hours and then cured for 7 days by wetted kenaf sacks. Keyword: Seepage, Irrigation, Canal lining, Pre-casting, efficiency

Atmospheric concentration of CO2, which is considered as one of the major greenhouse gases (GHGs), has increased up to 398 ppmv as of 2015. CO2 concentration in atmosphere was 280 ppmv in pre-industrial era, and due to the continuous discharge, it is expected to increase up to 550 ppmv by 2050. Many of the major industrial sources of CO2 emissions are natural gas fired power plants, synthesis gas used in integrated gasification combined cycle (IGCC) and power generation, gas streams produced after combustion of fossil fuels or other carbonaceous materials, and oxyfuels. Reactive absorption of CO2 from the industrial off gases by using chemical solvents is considered as one of the most common, efficient, and cost effective technologies utilized by the industry for CO2 capture. The captured CO2 can be stored by using the geological or oceanic sequestration approaches. As an alternative to geological or oceanic sequestration, the captured CO2 can be re-energized into CO by using solar energy and combined with H2, which can be generated from different methods, to produce syngas. The syngas produced can be further processed to liquid fuels such as methanol, gasoline, jet fuel, etc. via the catalytic Fischer-Tropsch process.

In past, a variety of chemical solvents (mostly aqueous amines and there derivatives) have been used for CO2 capture from different gaseous streams via reactive absorption. Though the amines are attractive for the CO2 capture application, there are several disadvantages such as very strong corrosion to equipment and piping, high energy requirement during the stripping of CO2 and they are prone to oxidative and thermal degradation. Recently, use of aqueous potassium carbonate (K2CO3) as a solvent for the absorption of CO2 has gained widespread attention. The usage of K2CO3 has been employed in a number on industries for the removal of CO2 and H2S. Due to its high chemical solubility of CO2, low toxicity and solvent loss, no thermal and oxidative degradation, low heat of absorption, and absence of formation of heat stable salts, K2CO3 seems to be more attractive compared to the conventional amines towards CO2 capture. However, K2CO3 solvent shows slow rate of reaction with CO2 and, consequently, low mass transfer in the liquid phase as compared to the amine solvents. Hence, several investigators are focused towards improving the rate of reaction of CO2 in K2CO3 solvent with the help of different types of promoters.

In this paper, the kinetics of absorption of CO2 into an aqueous K2CO3 (20 wt %) promoted by ethylaminoethanol (EAE) solution (hereafter termed as APCE solvent) was studied in a glass stirred cell reactor using a fall in pressure method. Reactive absorption of CO2 in EAE promoted aqueous K2CO3 solution (APCE solvent) was studied at different initial EAE concentrations (0.6 to 2 kmol/m³) and reaction temperatures (303 to 318 K). The reaction between the CO2 and APCE solvent was very well represented by the zwitterion mechanism. The N2O analogy was employed for the determination of H_(CO2) in the APCE solvent. The H_(CO2) was observed to be decreased by 5 and 31% due to the increase in the EAE concentration from 0.6 to 2 kmol/m³ and reaction temperature from 303 to 318 K, respectively. The D_(CO2) in the APCE solvent was also decreased by 21% due to the similar increase in the initial EAE concentration. In contrast, the D_(CO2) increased with the rise in the reaction temperature from 303 to 318 K by a factor of 1.678. The rate of absorption of CO2 in the APCE solvent was observed to increase by 35.10% and 47.59% due to the increase in EAE concentration (0.6 to 2 kmol/m³) and reaction temperature (303 to 318 K). The absorption kinetics was observed to be of overall second order i.e. first order with respect to both CO2 and EAE concentrations, respectively. The rate constant (k_2) for the absorption of CO2 in the APCE solvent was observed to be equal to 45540 m³/kmol√s at 318 K. The temperature dependency of k_2 for the CO2 – APCE solvent system was experimentally determined as: k_2 = (1.214 × [10]^18)√exp(( − 9822.7)/T). Findings of this study indicate EAE as a promising promoter for the aqueous K2CO3 solution.

Lithium ion batteries (LIB) are widely applied to energy storage systems, like electric vehicles, ships. While limited reserves of lithium and cost of lithium enforced to explore new materials. Hence, Low cost and abundance of sodium has made Sodium ion batteries (SIBs) an attractive alternative for energy storage. Li ion replacement with Na ion will not require change of design in present LIBs, except change of cathode material (based on Na) and respective electrolyte. But the challenge exists to develop sodium cathode with good electrochemical performance and excellent thermal stability. Therefore, various crystal structure for sodium cathode material were explored to meet these challenges. Among cathode materials, pyrophosphate family represented high theoretical capacity due to existence of two sodium ions in a repeating unit. In this report we synthesized mixed pyrophosphate cathode, Na2Fe1/2Mn1/2P2O7, via simple solid state process. The precursors, Na2CO3 (Aldrich), (NH4)2HPO4 (Aldrich), FeC2O4.2H2O (Aldrich) and MnC2O4.2H2O (Aldrich), were mixed in stoichiometric ratio and extensively grinded in mortar and pestle. The fine powder was subjected to heat treatment under inert atmosphere at 350 °C, cooled, grinded and then annealed in inert atmosphere at 600 °C for 6 hours. The compositional and structural analyses confirmed the formation of a crystalline pure phase. The optimization of operation temperature, time and atmosphere (inert); and the formation of mixed component systems (i.e., incorporation of more than one transition metal) not only lead to single phase mode but also tune the voltage potential for high energy density. The X-ray diffraction (XRD) data of as-synthesized Na2Fe1/2Mn1/2P2O7 was indexed to a triclinic structure. This triclinic structure has open framework which facilitated diffusion of Na-ions during charging and discharging. Thermogravimetric Analysis (TGA) showed negligible weight loss (∼5%) when heated to 550 °C, indicating decent thermal stability of the material and differential thermal Analyses (DTA) hardly observed any endothermic or exothermic peak. Carbon coating of Na2Fe1/2Mn1/2P2O7 was proceeded to impregnate electrical conductance in the material. SEM images showed the difference between pristine Na2Fe1/2Mn1/2P2O7 and carbon coated Na2Fe1/2Mn1/2P2O7. The carbon coated Na2Fe1/2Mn1/2P2O7 was, then, casted on aluminum to prepare cathode. The casted material (cathode) was dried at 70 °C under vacuum for two hours. The materials was then assembled into coin cell as a cathode in the glove box. The electrochemical measurements confirmed that Na2Fe1/2Mn1/2P2O7 is electrochemically active at room temperature. It showed a single-phase reaction during cycling. This single phase reaction is changed by the Na environment through a change in Na/Vacancy ordering. The Na2Fe0.5Mn0.5P2O7 cathode represented discharge capacity of 80 mAh/g at C/20 in the voltage range of 2.0 to 4.5 V. The average redox potential was observed to be approximately 3.2 V (vs. Na/Na⁺). The capacity retention of Na2Fe0.5Mn0.5P2O7 is 84% over 90 cycles. Between first charge capacity and second charge capacity, Na2Fe0.5Mn0.5P2O7 cathode showed a difference of 5mAh/g only. This employs that sodium based mixed iron-manganese pyrophosphate (Na2Fe0.5Mn0.5P2O7) cathode has increased occupancy. The rate capability of Na2Fe0.5Mn0.5P2O7 shows 70% retention from 0.05 C to 0.5 C. Synthesis of Na2Fe1/2Mn1/2P2O7 in nanometric size may result in further improvement in its electrochemical performance.

Environmental conditions such as irradiance, temperature, humidity and dust accumulation have impact on PV performance and reliability. In this paper, we will focus on the effect of temperature and how to mitigate this effect by using passive cooling approach.

Qatar is rich with solar irradiance favored for photovoltaic; however, the high temperature (a module temperature of 50°C was measured during summer months) has a negative impact on the power output of a PV module. Operation of solar PV systems under extremely high temperatures and high humidity in hot climates represents one of the major challenges to guarantee higher system's reliability. Therefore, thermal management in hot climates is crucial for reliable application of PV systems, as it has a potential to increase the efficiency and life expectancy and to stabilize the output power characteristics.

Apart from that, dust accumulation on PV module is known to be also as one of the challenges that affect the PV power output. Due to the difference in ambient temperature between day and night, water condensation on PV modules was observed. Dust accumulated on a PV module together with water condensation may cause a thick layer of mud that is difficult to be removed. In this paper, we will show that, condensation of water on the cell surface during night can be prevented by maintaining the temperature of solar PV panels above the dew point during night.

Application of Phase Change Materials (PCM) for passive or combined active-passive cooling systems offers various options for adequate thermal management solutions. The present research focuses on utilization of PCM for passive thermal management of solar systems. Passive cooling can be realized by integration of PCM layers with the back side of PV panels. Passive cooling use the high temperature differences between day and night in arid desert regions, due to sky radiation in the night. The high thermal capacity of PCM accumulates coolness during night to keep the PV cells at a moderate temperature during the day. This also can help maintaining the PV panel temperature well above the dew point to prevent condensation during day and night, thereby avoiding mud formation on the panel surface. In some instances, active cooling may still be needed during peak solar radiation hours around noon time in summer, however integration of PCM can also reduce significantly the pumping power required to circulate the cooling medium as well as the external thermal/cool storage size and cost.

Although PCM provides high energy storage density and nearly isothermal behavior around the phase change temperature, they suffer from low thermal conductivity, which limits the power density during charging and discharging. The low thermal conductivity of a PCM can be increased by combining them with highly conductive heat transfer structures. One advanced option is the application of cellular materials like metal fibers, which allow a significant enhancement of the PCM absorber thermal conductivity by more than 100 times. Hence it is proposed to hybridize PCM with cellular metallic matrices to enhance the thermal conductivity and provide a practical solution for easy encapsulation and integration with the PV panels.

The main focus of this study is therefore to explore the effect of utilization of PCM based cooling elements incorporating cellular metallic heat conducting structures on the thermal behavior of solar PV panels.

Preliminary laboratory experimental investigations have been carried out to characterize the thermal resistances between the PV panel and the PCM matrix absorber using different coupling mechanisms attached to the backside of PV panels. The coupling mechanisms include mechanical clamping, adhesive bonding, and double side thin and thick adhesive tapes. Based on the measured data, design recommendations for the desired performance will be discussed. The outcomes of the laboratory experimental investigations provide important input parameters that are needed in numerical analysis and design optimization of such systems under weather conditions in Qatar and elsewhere.

Beside the laboratory experimental work, theoretical analysis to optimize the properties of the PCM matrix absorber for application of solar PV systems in Qatar has been carried out. The simulation model has been developed using homogenization based on volume averaging techniques and interpenetration continua approach. Due to complexity of the underlying transport phenomena, solution of highly nonlinear coupled system of equations with moving boundaries is required as a function of space and time. Hence, numerical modeling and optimization of large scale PCM storage is both challenging and computationally expensive. However, in engineering systems microscopic details are neither easy to be captured nor needed, instead, the macroscopic aspects are much more interesting. Therefore, dealing with a large-scale PCM storage, a fundamental question arises as how to bridge the computational scale and reduce the problem to a simple one. A simplified modeling approach and numerical procedures shall be proposed to determine the macroscopic transport and time history of the PCM temperature field in a PCM thermal storage. The model is fairly general to be applied as a design and optimization tool for thermal energy storage and thermal management systems. Preliminary results of the numerical simulation shall be presented and discussed.

Due to similarity of climatic conditions in the GCC, the solution can be easily adapted to suit other countries in the Gulf. The fibrous porous structure can be manufactured using wastes of metals processing such as in manufacturing aluminum profiles. PCM candidates with low temperature and desired thermo-physical properties, such as paraffin waxes, are abundantly available with reasonable cost. Further cost reductions for manufacturing of PCM matrix absorbers can be achieved by integration with the PV support structure. This an important part of the ongoing research in collaboration with local industry partners in Qatar in order to produce these systems locally on a commercial scale effectively with lower costs. Preliminary analysis shows that the passive thermal management can increase both instantaneous conversion efficiency by 3–5%, while it can considerably increase the life span of PV modules and reduces maintenance and cleaning costs. These factors hold a great promise for supporting the economic viability of passive thermal management using PCM matrix absorbers. However, detailed technoeconomic analysis will be elaborated within the framework of this project and will be published later.

The main target of membrane technologies such as the Ultrafiltration (UF), Nanofiltration (NF) and Reverse osmosis (RO) is to produce better filtration and separation of organic and inorganic substance from water as well as for longer life of the membrane. The phase inversion method is a well-known method to fabricate UF, NF and RO membranes for different application. The UF membrane is widely used in separation of macromolecules from solution as pretreatment stage with higher efficiency in hybrid process. The UF membrane made by pure polymer showed low flux, which affect on process performance of separation. The Polysulphone (PSF) is the most common polymer used in UF membrane which a hydrophobic material is making its surface prone to fouling due to adsorptive mechanism. This limitation of UF membranes have been solved by blended with nanoparticles incorporated membranes which showed significant enhancement on permeability, surface hydrophilicity, mechanical properties and other properties such as the selectivity. The main objective of this study to modify of UF membrane by blended with new composite nano-material for higher rejection of salt and organic substances. The graphene-zinc iron oxide composite as new nano-material was synthesized by sol gel method at low temperature of preparation. The composite was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) to show the structure, morphology and particle size of nanoparticles. Thermal decomposition was determined using thermogravimetric–differential scanning calorimetry (TGDSC). The results showed that cubic system of zinc iron oxide nanoparticles with 8 nm of crystal size was obtained using XRD. The morphology using TEM showed zinc iron oxide composite graphene as layer of nanoparticles with size lower than 10 nm which confirmed the XRD results. The novel synthesized of zinc iron oxide nanoparticles embedded in graphene incorporated into polysulfone (PSF) with 0.5 wt. % loading which significant impact on the UF membrane properties was investigated. The effect of composite additive on membrane properties was investigated in terms of permeability, hydrophilicity (contact angle), zeta potential, porosity and pore size. However, the membrane cross section, surface, EDX and mapping were also analyzed using FESEM include EDX analyzer. This composite incorporated PSF showed significant improvement in terms of surface hydrophilicity with reduction of about 25% (reduce contact angle from 82 to 62°). This improvement confirms by increasing the zeta potential values and surface negatively charge of blended PSF with composite compared to pure PSF membrane. The permeability results showed that significant increased more than two times compared to pure PSF membrane. The phenomenon of permeability increasing was attributed to increase of porosity of blended membrane which becomes lower resistance of water permeation. Generally, the rate of pore production has been reported directly affected by rate of solvent and non-solvent exchange in phase inversion process. However, higher rejections of organic substances such as the dyes and humic acid as well as the salt such as Sodium sulfate (Na2SO4) were maintained using UF at low pressure. This enhancement affects on time and load of process especially when hybrid with Nanofiltration (NF) which can increase of membrane life and reduce of overall process cost. The results of this study will have bigger impact in the future for different application including for water treatment and desalination.

With around 60–80% of electricity used for air conditioning, and around 99% of potable water production being supplied by desalination plants, sustaining life in Qatar, as well as GCC and hot arid countries around the world, is uniquely energy intensive.

As District Cooling Plants (DCPs) have a potential to reduce energy consumption and CO2 emissions, Qatar and GCC are continuously shifting paradigm towards adoption of DC plants to satisfy the rapidly growing demand in all sectors. However, DC plants usually rely on wet cooling towers for disposing the excess heat to the ambient. Thus the heat disposal is accompanied by considerable loss of fresh water, a common problem in hot arid countries with highest demand for air cooling and also relies on costly and energy intensive desalination processes for securing fresh water supply. In addition to this, evaporative cooling devices and wet cooling towers can spread humidifier fever, a serious health risk with similar symptoms as mild influenza, and Legionella, which can be deadly. Hence huge evaporation loss in densely populated urban centers in Qatar and GCC is an imperative environmental issue which necessitates effective and practical solutions.

This study presents an invention, which involves an innovative process called the “SELF-SUSTAINABLE DISTRICT COOLING AND DESALINATION (SSDD)”. The patented solution is directed to construct a totally new concept for maximization of water and energy use efficiency in district cooling plants in hot arid countries while preserving the environment. The system couples district cooling plants with polishing of treated sewage effluents (TSE) using hybrid reverse osmosis and thermal desalination technologies with the district cooling plant. The desalination process is equipped with a zero liquid discharge (ZLD) system to achieve full recovery of the TSE resource and eliminate the common environmental problem related to brine disposal. The invention closes the water and energy circuits in DC plants, which considerably enhances the overall water and energy efficiencies.

The techno-economic analysis of the SSDD technology has revealed a breakthrough in the technology in terms of reducing energy consumption by 20–30% and water consumption by more than 50%. Considering, for instance, a planned capacity of 1.6 million refrigeration ton DCPs to be added in Qatar by 2022, the SSDD can save up to 200,000 m³/day evaporation losses and 650 MW of electrical power together with elimination of water distribution power needed for pumping potable water from desalination plants to the DCPs. The total energy saving corresponds with 3.5 Million ton reduction of CO2 emissions and more than 1.5 Billion QAR/year excluding the environmental benefits. Considering the ambitious development plans of other GCC states, the SSDD technology may play a significant role in achieving sustainable development goals not only in the region but also worldwide. Thus it holds a great promise for energy and water securities as well as combating global climate change.

The new RO/ZLD concept can be used for applications other than DC, e.g. waste water treatment and reuse, aquifer recharge, football stadia, irrigation for the Qatar National Food Security Program (QNFSP). Moreover, this process can be applied around GCC, Middle East and North Africa (MENA) as well as other hot parts of the world.

Abstract

The present paper evaluates the composite risk of anthropogenic and climate change on the future water status in Jordan during the period 2030–2050. The projected water status in the country is evaluated based on the more likely population growth and climate change scenarios. The most likely figure for the population of Jordan, excluding refugees from neighboring countries, in 2040 would be ∼15 million people. Given this likely projection, though conservative, annual water needs for the domestic sector alone are expected to be between 700 and 800 million m³, with the current level of water consumption. A rise in near surface air temperature by 2 °C and a drop in total precipitation by 15%, as projected by most Global Circulation Models, would diminish renewable water resources in the mountainous region by ∼ < /AσΣETHιγηλιγητ>25–40%, being more severe as aridity increases.

1. Introduction

There is almost a consensus among earth scientists that the buildup of greenhouse gases in the atmosphere is leading to a global warming. Documented evidence suggests that global temperature observed over continental and marine regions has been rising for the past several decades (IPCC, 2007). The increased air temperature will intensify the hydrological cycle due to increased water vapor release into the atmosphere. Recent unprecedented severe meteorological events such as large scale torrential rains in many parts of the world and the recurrent tropical cyclones invading the southern parts of the Arabian Sea could be cited as a strong evidence of a global climate change. A climate change towards warmer conditions is expected to increase precipitation over the Arabian Peninsula due to the northward extension of the Monsoon Trough which will enhance the Red Sea Trough during the transitional periods, Fall and Spring.

There is almost a consensus among most GCM that a global warming will be most severe in the eastern Mediterranean, with a significant drop in precipitation and a large temperature rise (Zhang et al., 2005; IPCC, 2007; Kelley et al., 2012). Model results suggest that near surface air temperature will increase by 2–3.5 °C following an equivalent doubling of Carbon Dioxide in the atmosphere (Kelley et al., 2012). The projections for precipitation amount, its temporal distribution and variability are not as certain. Due to the northward retreat of the polar front during the winter months, however, the eastern Mediterranean is expected to experience less cyclogenic activities, and as such less winter storms, leading to a precipitation decline (Schulz et al., 2008). It is also projected that the timing and frequency of precipitation in this region will be more erratic, less frequent but more intense. Statistical evidence show a strong reduction in the number of rainy days with precipitation in excess of one mm day-1.

Population growth adds another negative dimension to the water crisis. This includes more water demands for the domestic, agricultural, tourism, and industrial sectors. Additionally, increased population causes severe deterioration to surface and underground water quality through large scale land use changes, release of large volumes of waste, gaseous and liquid effluents and solid waste disposal. It is clear that anthropogenic and natural forcings work hand in hand to adversely impact Jordan's limited water resources. As such, two operational questions need to be answered:

1- What is the near future water needs in the country?,

2- What is the water availability for the near future following a climate change?

Answering these two questions adequately is essential for a better assessment of the relative impacts of climate change and population growth on water availability, demands, and stress during the near future. This projection can be used to minimize the potential risks of the projected climate change and population growth.

2. Current water availability in jordan

Around 70% of precipitation in Jordan falls in the winter months, December through February, due mainly to cyclogenic activities; the other 30% fall in the transitional periods. Average annual precipitation in the country ranges from a ∼600 mm in a small enclave in northwestern Jordan to less than 5 mm near the Saudi borders (Fig. 1). Additionally, this area receives large quantities of solar radiation year around due to persistently clear skies triggered by large scale subsidence. The combination of scanty precipitation along with a large global radiation enhances direct evaporation and substantially limits blue water availability. The average annual renewable water resources in Jordan are estimated at about 800–850 million cubic meters (M m³) (Ministry of Water and Irrigation, Jordan, 2015).

There is observational evidence that precipitation in the country is declining; Fig. 2 shows a time series of precipitation in two stations, one in northern Jordan during the period, 1945 through 2005, and the other one in central Jordan, Rabbah in the Karak Plateau. Both linear regression and Mann-Kendall non-parametric tests reveal that annual precipitation in all stations in the country is declining.

3. Future population

The population of Jordan experienced a large growth during the past 60 years due to natural growth and as a result of political conflicts. The population of the country, however, swelled by about 20 times during the past 60 years. The invasion of Iraq caused a mass movement of Iraqis towards Jordan. The current civil war in Syria paints another unpleasant, in fact very gloomy, portrait of the population dynamics in Jordan, with current population close to 11 million people.

The population growth was paralleled by a similar increase in irrigated agriculture. The area of irrigated lands in the Jordan Valley increased from ∼15 thousand hectares in the early 1960's to ∼38 thousand hectares in 2011. Likewise, irrigated agriculture in the desert region increased from virtually nil in the early 1970's to ∼17 thousand hectares in 2008 (Ministry of Water and Irrigation, 2012). The substantial increase in the irrigated agricultural land caused further demands on freshwater. The availability of irrigation water will shrink in the near future, however, because of growing demands on this resource from other sectors, mainly the domestic sector. The future water status in the country would indeed look quite bleak should population growth continues unabated and a climate change towards warmer and/or drier conditions prevail in the near future.

4. Future Water Needs

Official figures provided by the Ministry of Water and Irrigation, Jordan (2015) indicated that current domestic freshwater supply is ∼150 liters per person/day, which gives a total annual freshwater need of 370 M m³. Nowadays, with only 7.5 million inhabitants (excluding fresh refugees), most households in Jordan receive a specified amount of water during the summer months, and domestic water is supplied once (few hours) per week. Renewable water resources in the country were not enough to meet the water demands, and as such non-renewable fossil freshwater resources have been intensively exploited during the past several decades. These measures have caused steady drop in the level of underground aquifers and resulted in poor water quality. The Dissi Project, conveying fossil water is expected to provide freshwater for several decades before it dries up completely.

Projections based on future population growth scenarios indicate that annual domestic water needs alone will range from a minimum of 550 M m³ to a value close to 1100 M m³ by 2050. A more likely figure would probably be between 700–800 M m³. Thus, renewable freshwater resources of the entire country will barely meet domestic water needs even without a climate change.

Currently, the agricultural sector accounts for about 65% of total freshwater consumed in Jordan (MWI, 2015). Paradoxically, the amount of water allocated for irrigation must drop in the near future because of demands by relatively more needy sectors, the domestic one in

particular. Based on population growth alone, it is obvious that the future water status in the country looks quite bleak even without a climate change. Should the climate of the eastern Mediterranean become warmer and/or drier or both, the country will face a serious, probably tragic, freshwater dilemma in the very near future which will ultimately lead to economic, social and political unrest. The anticipated climate change will seriously influence the future water crisis in Jordan.

5. Projected climate change impact

A climate change in the eastern Mediterranean will impact water resources in at least three ways: 1) reduces blue water availability due to increase direct evaporation from soils, 2) intensifies irrigation water demands, and 3) increases evaporation losses from dams and open water canals. The impact of climate change on the available water resources in Jordan is investigated using a water balance model with a temporal resolution of one day. The model is run over the mountainous areas of Jordan where around 65% to 70% of blue water is generated (Oroud, 2015). A detailed description of the model is presented elsewhere (Oroud, 2008; 2011). Figure 4 shows the linkage between annual blue water availability and annual precipitation as calculated by the daily model. Conservative calculations show that a 2 °C temperature increase along with a 15% reduction in precipitation decreases water availability, on average, by ∼ 25%–40% depending on the level of aridity, being more sever as in more arid regions. This means that renewable water resources in the country following a warmer, drier climate will probably be between 500–650 M m³ by 2050. This conclusion is commensurate with those presented by other investigators (e.g., IPCCk 2007; Margane et al. 2008; Suppan et al. 2008; Giorgi and Lionello, 2008; Kelley et al., 2012).

Irrigation water needs under current climate conditions and following a climate change were simulated for the Jordan Valley using a spatially distributed daily model. Following a climate change, the irrigation water needs will increase by around 15%. This is equivalent to 40 to 50 M m³ of extra irrigation water needed to maintain the irrigation water demands in the Jordan Valley at the current land use regime.

References

Giorgi, F., Lionello, 2008, Climate change projections for the Mediterranean region, Global and Planetary Change, 63, 90–104.

Inter Governmental Panel on Climate Change (IPCC), 2007, The physical science basis, Geneva.

Margane A., et al., 2008, Water resources protection efforts in Jordan and their contribution to a sustainable water resources management. In F. Zereini and H. Hotzl (eds) Climatic Changes and Water Resources in the Middle East and North Africa, Springer, pp. 325–345.

Kelley, C., et al., 2012, Mediterranean precipitation climatology, seasonal cycle and trend as simulated by CMIP5, Geophysical Research Letters, 39, DOI: 10.1029/2012GL053416

Oroud, I. M., 2008. The impact of climate change on water resources in Jordan. In: F. Zereini and H. Hotzl (eds) Climatic Changes and Water Resources in the Middle East and North Africa, Springer, pp 109–123.

Oroud, I. M., 2012a, The relative impacts of climate change on water resources in Jordan, in: National Security and Human Health Implications of Climate Change (H. Fernando et al., eds.), DOI 10.1007/978-94-007-2430-3-31, Springer Science.

Oroud, I. M., 2012b, Climate change impact on green water fluxes in the eastern Mediterranean.: pp 3–15. In: Leal Filho, W. (ed) “Climate Change and the Sustainable Management of Water Resources.

Oroud, I. M. and Alrousan, N., 2004, Urban encroachment on agricultural lands in Jordan during the second half of the twentieth Century, The Arab World Geographer, 7, 165–180.

Oroud, I. M., 2015, Water budget assessment within a typical semiarid watershed in the Eastern Mediterranean, Environmental Process 06/2015; 3(2):1–15. DOI: 10.1007/s40710-015-0072-8

Suppan, P. et al. 2008, Impact of climate change on water availability in the Near East. In F. Zereini and H. Hotzl (eds) Climatic Changes and Water Resources in the Middle East and North Africa.

6- Schulz, O., Busche, H., Benbouziane, A. (2008) Decadal precipitation variances and reservoir inflow in the semi-arid upper Draa basin. In: F. Zereini and H. Hotzl (eds) Climatic Changes and Water Resources in the Middle East and North Africa, Springer, pp. 165–178.

Zhang, X., et al., 2005, Trends in Middle East climate extremes indices from 1950 to 2003. J. Geophys. Res. 110.

Buildings represent one of the most significant sources of negative impacts to the natural ecosystems on which Qatar's inhabitants health and environmental quality depend. The market has identified Qatar as one of the busiest construction areas in the world (Ibrahim 2011), While rapid economic development, population growth, and construction boom are positive indicators of growth, they may also present issues related to the negative impact on the socio-environmental components of cities. Such is the case of the Gulf Cooperation Council (GCC) countries where increasing economic prosperity has led to a surge in tall building construction and a sense of competition to erect the tallest skyscrapers in the world (Mahgoub and Abarra 2012).

While tall buildings are a source of national pride and cultural identity enabled by economic prosperity, they pose several challenges to integrate with the urban fabric of the city while also having a tremendous environmental impact. Tall buildings are especially massive consumers of energy (Ali and Armstrong 2008). They are the dominant elements in urban architecture due to their scale and purpose, and should be the focus of sustainable design. With large number of towers constructed and to be constructed in Al Dafna and West Bay areas of Doha, these buildings affect different aspects of the built and urban environment, i.e., city image, traffic, urban spaces and physical conform. Therefore, more architectural design strategies have to be planned well ahead in order to tackle the issues of sustainability and adaptability to climate change and to foster sustainable built environment in the state of Qatar.

With Qatar slated to host a ‘zero carbon’ World Cup in 2022, Qatar Green Building Council (QGBC) has set up a group to foster green infrastructure as a national resource. Qatar is utilizing Leadership in Energy and Environmental Design (LEED) and the Global/Qatar Sustainability Assessment System (GSAS/QSAS) to this end. Furthermore, shortages in raw materials between 2013 and 2017 are expected to challenge the construction sector, as the period is expected to be the peak for the sector. Therefore, the sector will have to bridge the gap during this period by mutual agreements with the companies in Saudi Arabia and the UAE (QCB 2012).

The objectives of this paper are as follows: 1- to Identify sustainability metrics for tall buildings with focus on construction materials and methods used in Qatar; 2- Explore existing literature and identify analogies in optimization consistent with design variables; 3- to examine sustainability of construction materials used in Qatar by utilizing software which is based on currently available databases to perform life cycle assessment.

To meet the objectivess described above, the currently available software platforms to perform life cycle analysis of building materials were explored. A commercial software, SimaPro, which utilizes the environmental impact database Ecoinvent, was chosen for its flexibility in defining custom mix designs for concrete, as well as database information on steel and many other building materials. With SimaPro, a sustainability model for concrete and steel was developed which reflects the environmental implications of manufacture of materials in Qatar as appropriate. Quantitative results from the model for the sustainability of constituents of building materials were extracted, to form the basis of sustainability metrics in the forthcoming tall building topology optimization protocol.

Furthermore, Blanco-Carrasco et al (2010) outline reduced use of Portland cement, increased use of alternate cementitious materials, and reduced water use to improve the sustainability of the concrete industry in Qatar. Using structural models and the SimaPro model, ultra-high performance concrete was explored as a potential solution for all these problems, to be applied in the gravity/lateral structural components of Qatar tall buildings. In addition to identifying a novel material which fits well with the current tall building designs of the region, the process of examining the structural and environmental improvements from using ultra-high performance concrete has resulted in the formation of a procedure to compare multiple materials used in Qatar.

This paper is a result of a funded research project by QNRF, entitled “Multi–Objective Tall Building Topologies – Optimizing for Structural Performance, Economy, and Sustainability” and a jointly collaboration between researchers from Qatar University, Virginia Tech, Johns Hopkins University, Optim Design Inc, and MZ & Partners.

“This research/publication was made possible by a National Priority Research Program NPRP award [NPRP- 7 - 1518 - 2 – 549] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the author(s).”

Qatar is the biggest exporter of liquefied natural gas, LNG, in the world and is a main oil-producing member of The Organization of Petroleum Exporting Countries, OPEC. A fossil fuel-based industry emerged around the ports of Ras Laffan and Mesaieed, Qatar's industrial cities, perusing industrial diversity and maximising the huge fossil fuel reserves that serve as the primary feedstock for the industrial sector. LNG, crude oil, and petroleum products has given Qatar a per capita GDP that ranks among the highest in the world with the lowest unemployment. This also has given Qatar a per capita CO2 emissions among the highest in the world. A recent report from The World Health Organisation, stated that the capital of Qatar, Doha, is one of the world's most polluted cities and its air ranked the 12th highest average levels of small and fine particles which are particularly dangerous to health [1]. The people and wise leadership of Qatar recognizes the significance of the problem and made environmental development one of the four pillars of Qatar National Vision 2030. The vision places environmental preservation for Qatar's future generations at the forefront. Qatar Carbonates and Carbon Storage Research Centre is an example demonstrating Qatar's commitment to preserve the envioronment by investigating and implementing key technologies such as carbon capture and storage (CCS) to address the next step in climate change. CCS in deep saline aquifers is an important process for CO2 reduction on industrial scales. The aim of CCS is to safely sequester CO2 generated from stationary sources, such as power-plants, into aquifers and depleted oil reservoirs. It is considered a valuable option to reduce greenhouse gases and has been proposed as a practical technology to tackle climate change [2–4]. The importance of CCS as a key option to mitigate CO2 emissions and combat climate change has been highlighted also in a report by the International Energy Agency (IEA) and suggests that CCS could contribute to a 17% reduction in global CO2 emissions by 2035 [5]. Previously, carbon dioxide injection into the subsurface has mainly been used for enhanced oil recovery (EOR) purposes. That gave rise to Carbon capture, utilization and storage (CCUS) processes in mature oil reservoirs where CO2 is first used to enhance oil recovery and then ultimately stored in the reservoir. The incremental hydrocarbon recoveries associated with CCUS make it more attractive to implement compared to CCS. It have significant energy, economic and environmental benefits and is considered an important component in achieving the widespread commercial deployment of CCS technology. Residual trapping of CO2 through capillary forces within the pore space of the reservoir is one of the most significant mechanisms for storage security and is also a factor determining the ultimate extent of CO2 migration within the reservoir. Observations and modelling have shown how capillary, or residual, trapping leads to the immobilisation of CO2 in saline aquifer reservoirs, limiting the extent of plume migration, enhancing the security and capacity of CO2 storage [6,7]. In contrast, carbonate hydrocarbon reservoirs are characterised by a mixed-wet state in which the capillary trapping of nonpolar fluids have been observed to be significantly reduced relative to trapping in rocks typical of saline aquifers unaltered by the presence of hydrocarbons [8,9]. There are, however, no observations characterising the extent of capillary trapping that will take place with CO2 in mixed-wet carbonate rocks, the same rock type found in Qatar's subsurface geological formations and many other giant oil reservoirs in the Middle East that hold most of the oil in the world [10, 11]. Experimental tests of CO2 and brine in carbonate rocks at reservoir conditions are very challenging due to the complex and reactive nature of carbonates when dealing with corrosive fluids pair of CO2 and brine. In this study, we compare residual trapping efficiency in water-wet and mixed-wet carbonates systems on the same rock sample before and after wettability alteration by aging with oil mixture of Arabian medium crude oil. The experimental work was conducted using a state of the art multi-scale imaging laboratory (core and pore scale) developed at Imperial College London designed to characterise reactive transport and multiphase flow, with and without chemical reaction for CO2-brine systems in both sandstone and carbonate rocks at reservoir conditions [12]. The flow loop included stir reactor to equilibrate rock with fluids, high precision pumps, temperature control, the ability to recirculate fluids for weeks at a time and an x-ray CT scanner and micro x-ray scanner for in situ saturation monitoring. The wetted parts of the flow-loop are made of anti-corrosive material that can handle co-circulation of CO2 and brine at reservoir conditions with the ability to preserve the rock sample from reacting to carbonic acid. We report the initial-residual CO2 saturation curve and the resulting parameterisation of hysteresis models for both water-wet and mixed-wet systems. A novel core-flooding approach was used, making use of the capillary end effect to create a large range in initial CO2 saturation in a single core-flood. Upon subsequent flooding with CO2-equilibriated brine, the observation of residual saturation corresponded to the wide range of initial saturations before flooding resulting in a rapid construction of the initial residual curve. Observations were made on a single Estaillades limestone core sample. It was made first on its original water-wet state, then were measured again after altering the wetting properties to a mixed-wet system. In particular, CO2 trapping was characterized before and after wetting alteration so that the impact of the wetting state of the rock is observed directly on both core and pore scales. A carefully designed wettability alteration programme was designed in this study to replicate a mixed-wet carbonate system similar to those found in Qatari oil reservoirs. At the pore level, oil can precipitate asphaltene and other heavy components after long exposure with the rock changing the wetting state of the surface to oil-wet. A mixture of the evacuated crude oil with an organic precipitant, n-heptane, was used to deposit a stable oil-wet film. The precipitant substituted some of the evaporated and oxidised light hydrocarbon originally existed in the crude and deposited asphaltene to generate a stable strongly oil-wet film layer. Filtration experiments were carried out to sensibly precipitate enough asphaltene for a stable and strong oil-wet film without over precipitating and causing fine migration that can damage the core sample. The weight fraction of asphaltene precipitated with different fractions of crude-precipitant mixtures were measured. The diluent consisted of toluene as the solvent and heptane as the precipitant. 40 ml of the diluent was thoroughly mixed with 1 ml of Arabian Medium crude oil at 11 different precipitant/solvent volume ratios ranging from 0–100% at 10% increments and then left in the dark for 48 hours to allow the system to come to equilibrium. The mass of precipitated asphaltenes was measured in each mixture by vacuum filtration using a 0.45 micron polytetrafluoroethylene hydrophobic filter paper (Millipore) and evaporation of any remaining liquid oil from the filter paper. No asphaltene was precipitated at low precipitant volume fraction and only above the onset of precipitation, a linear relationship was seen between the wt% precipitated asphaltenes and the volume % of the precipitant in the mixture. The onset for asphaltene precipitation for an oil mixture of Arabian Medium crude oil and heptane alone without solvent was calculated at the onset using the volume fractions of the components with the mixing rule. The sample's wettability was altered to a mixed-wet using the appropriate oil mixture as measured using the filtration test and the oil was then removed from the sample by CO2 enhanced oil recovery injected above the minimum miscibility pressure. This allowed for producing unique dataset and a great complement to the more theoretical analysis. That is if we make a surface oil-wet (to water), how does it behave in the presence of a gas. Here we show that residual CO2 trapping in mixed-wet carbonate rocks characteristic of hydrocarbon reservoirs is significantly less than trapping in water-wet systems characteristic of saline aquifers. We found that in the native water-wet state of the carbonate sample, the extent of trapping of CO2 and N2 were indistinguishable, consistent with past studies of trapping and multiphase flow properties in water-wet sandstones [13, 14]. After alteration of the wetting state of the same rock sample with oil, the residual trapping of N2 was reduced compared to the amount in the pre-altered rock. Surprisingly, the trapping of CO2 was reduced even further. The unique results were complemented with pore scale observations to investigate the balance of interfacial tensions and contact angles in three-phase flow. Our results show that one of the key processes for maximising CO2 storage capacity and security is significantly weakened in hydrocarbon reservoirs relative to saline aquifers. We anticipate this work to highlight a key issue for the early deployment of carbon storage – that those sites which are economically most appealing as initial project opportunities are the very locations in which the contribution of capillary trapping to storage security will be minimised. This should serve as a starting point for modelling studies to incorporate the reduced impact of capillary trapping on CO2 injection projects using hydrocarbon reservoirs.

References

World Health Organization. “Ambient (outdoor) air pollution in cities database 2014.” (2014).

Bernstein, L., P. Bosch, O. Canziani, Z. Chen, R. Christ, O. Davidson, W. Hare “IPCC, 2007: Climate Change 2007: Synthesis Report. Contribution of Working Groups I.” II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change, Geneva. http://www.ipcc.ch/ipccreports/ar4-syr.htm (2007).

Orr, F. “Storage of Carbon Dioxide in Geologic Formations.” Journal of Petroleum Technology 56, no. 9 (2004): 90–97.

Bachu, S., W. Gunter, and E. Perkins. “Aquifer Disposal of CO2: Hydrodynamic and Mineral Trapping.” Energy Conversion and Management 35, no. 4 (1994): 269–79.

IEA, WEO. “IEA World Energy Outlook 2012.” International Energy Agency, Paris France (2012).

IPCC, 2005. IPCC Special Report on Carbon Dioxide Capture and Storage, Prepared by Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom/New York, NY, USA.

Krevor, S., Blunt, M., Benson, S., Pentland, C., Reynolds, C., Al-Menhali, A., Niu, B., 2015. “Capillary trapping for geologic carbon dioxide storage -From pore scale physics to field scale implications”. International Journal of Greenhouse Gas Control, Volume 40, Pages 221–237, ISSN 1750–5836, http://dx.doi.org/10.1016/j.ijggc.2015.04.006.

Chillenger, V. and Yen, F. 1983. “Some Notes on Wettability and Relative Permeability of Carbonate Rocks”. II. Energy and Sources 7 (1):67–75.

Salathiel, A. 1973. “Oil recovery by surface film drainage in mixed-wettability rocks”. Journal of Petroleum Technology 25.10: 1–216.

Roehl, P., and Choquette, W., 1985, “Carbonate petroleum reservoirs”. Springer Science & Business Media.

Akbar, M., Vissapragada, B., Alghamdi, A., et al. 2000. “A Snapshot of Carbonate Reservoir Evaluation”. Oilfield Review 12 (4):20–21.

Al-Menhali, A., C. Reynolds, P. Lai, B. Niu, N. Nicholls, J. Crawshaw, and S. Krevor. “Advanced Reservoir Characterization for CO2 Storage.” International Petroleum Technology Conference, (2014).

Niu, B., Al-Menhali, A., and Krevor, S. (2015), “The impact of reservoir conditions on the residual trapping of carbon dioxide in Berea sandstone”, Water Resour. Res., 51, doi:10.1002/2014WR016441.

Al-Menhali, A., B. Niu, and S.Krevor (2015), “Capillarity and wetting of carbon dioxide and brine during drainage in Berea sandstone at reservoir conditions”, Water Resour. Res., 51, doi:10.1002/2015WR016947.

Non-Linear loads such as Compact Fluorescent lamps (CFLs), Light Emitting diodes (LEDs),Solid state voltage regulators, and variable speed electric drives are increasingly being added tothe domestic, residential and industrial power network. These light sources and other house-hold appliances using power electronic converters are termed as non-linear loads and they introduce distortion in the power network by generating harmonics in the current, leading to poor power quality [1 − 4]. Power quality issues are now becoming a major concern because of several reasons: a) Increasing dependence on electrical supply and even small disruption or interruption are not bearable because it can halt the modern lifestyle, b) new modern electrical equipment are highly sensitive to the power quality and c) the power electronic components such as variable speed drives and switched mode power supplies poses new disturbance challenges to the electrical supply network [5 − 7]. Power quality standards such as IEEE 519 is proposed to: a)assure that the electric supply company should deliver clean electric power to the consumers, b) assure that the electric supply company can protect electrical equipment from excessive voltage stress, overheating and loss of operational life of equipment. The IEEE 591 standard is in place that puts a limit on the allowed harmonic distortion of 3% on individual harmonic components and 5% on total harmonic distortion (THD). This standard is of utmost importance on the present day situation due to increasing non-linear loading. Although the distortion limits are not applied to specific equipment, however, with a high penetration of non-linear loads, it is likely that some harmonic suppression may be necessary [8 − 12]. The power quality problem is a distortion in the voltage waveform of the power source which is deviation from sine wave. Another power quality problem is a change in the amplitude from an established reference level. Other disturbance can be caused by harmonics in the current. With increasing the number of harmonics generating devices in a power system network, the problem of their impact on the performance of system components like induction motors needs is becoming a serious problem that need further consideration. It is well known that approximately 60–70% of loads in all over the world are motor loads. Most of the motors used in the world are three-phase induction motors. However, single-phase induction motors are major load in a domestic or residential setup. The modern day home uses large number of house hold appliances that uses different kind of single-phase motors as given in Table 1. A power network is shown for a domestic house in Fig. 1. Mix of loads are connected across the line. The effects of increasing non-linear loads in residential setting can be significant especially on single-phase motors connected to the same line. This paper investigate the effect of increasing distortion in the supplied voltage on the performance of single-phase induction motor behavior. Firstly the effect of increasing distortion in the applied voltage waveform on stator current is investigated. It is found that increasing a small %age of 3rd harmonic in the applied stator voltage significantly increases the 3rd harmonic component in the stator current. When voltage is pure sine wave, the current contains 1.7% 3rd harmonic. When the stator voltage is injected with 2.5% of 3rd harmonic the resulting current contain 11% 3rd harmonic. Hence it is concluded that current harmonic content is strongly dependent on the harmonic content in the stator voltage waveform. A Matlab/Simulink model is developed with single-phase capacitor start machine. The procedure adopted is as follows:

• Pure sine wave is applied to a capacitor start single-phase induction motor.

• Distorted supply is produced from inverter using appropriate PWM scheme and supplied to a capacitor start single-phase induction motor Non-linear loads such as CFLs and LEDs are emulated using thyristor based converter.

The thyristors are switched at different firing angle in order to vary the harmonic content in the supply voltage. The behavior of single-phase induction motor under distorted voltage conditionis recorded. The setup shown in Fig. 2 is consist of a single phase capacitor start induction motor supplied with PWM Converter. The motor is rated for 110V rms, 1500 rpm and 0.5 HP. The reference of the converter is generated by adding 3rd and 5th harmonic component to the fundamental component. The loads are switched in this order: Fig. 2. Single-phase induction machine (capacitor start) setup. a) At t = 0, the controlled rectifier with thyristor switching at 30° is turned on. This rectifier will always be on. The current drawn from the supply is analyzed for harmonic components. Each harmonic component contribution becomes input for reference generation for PWM Inverter. b) At t = 2 Sec, the controlled rectifier with thyristor switching at 60° is turned on. Now we have two controlled rectifier connected to the same ac supply. The resultant current is analyzed for harmonic component contribution. c) At t = 4 Sec, the controlled rectifier with thyristor switching at 90° is turned on. d) At t = 6 Sec, the controlled rectifier with thyristor switching at 120° is turned on. Efficiency estimation, a) The output of the system is calculated by multiplying load torque with the motor speed (in rad/sec). b) The input of the system is calculated by extracting P, Q, S from the bridge output voltage and current drawn by the motor from the block as shown below in Fig. 3. Efficiency computation of a single-phase capacitor start machine. c) Fundamental frequency, 3rd harmonic and 5th harmonic power is estimated by using the above block. The resultant power is calculated as: d) With the resultant absolute power drawn from the system, efficiency is calculated as: The simulation results are presented in Fig. 4–6. Ripple is seen in the current, torque and speed when voltage is distorted. The FFT of stator current (main winding) is shown in Fig. 7. Strong 3rd harmonic current is seen and also 5th harmonics.Sinusoidal Supply: Fig. 4. Single-phase IM behavior when pure sine wave is applied. Supply from a single-phase Inverter with Fundamental frequency (50 Hz) only: Fig. 5. Single-phase IM behavior when supplied from a DC/AC inverter. Supply from a single-phase Inverter with Fundamental, third and fifth harmonic: Fig. 6. Single-phase IM behavior when supplied from a DC/AC inverter with distorted waveform Fig. 7. Harmonic spectrum of stator current under distorted voltage source. Different powers are measured and shown in Fig. 8 for pure sine-wave supply and distorted voltage supply to a single-phase capacitor start induction machine. It is observed that the requirement of active, reactive and apparent power increases and efficiency decreases with the increase in the voltage distortion.

Acknowledgment

This publication was made possible by UREP grant # [17-061-2-017] from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.

References

[1] B.K. Bose, “Global Energy Scenario and Impact of Power Electronics in 21st Century”, IEEE Trans. On Ind. Elect. Vol. 60, Issue. 7, pp. 2638–2651, 2013.

[2] J. Mc Calley, V. Krishnan, K. Gkritza, R. Brown, D. Mejia-Giraldo, “Planning for the Long Haul: Investment Strategies for National Energy and Transportation Infrastructures”, IEEE Power and Energy Magazine, Vol. 11, Issue 5, pp. 24–35, 2013.

[3] M.K. Richard, P.K. Sen, “Compact Fluorescent Lamps and Their Effect on PowerQuality and Application Guidelines”, IEEE Industry Applications Society Annual Meeting (IAS), pp. 1–7, 2010.

[4] C. Keyer, R. Timens, F. Buesink, F. Leferink, “DC pollution of AC mains due tomodern compact fluorescent light lamps and LED lamps”, Int. Symposium on Electromagnetic Compatibility (EMC EUROPE), pp. 632–636, 2013.

[5] A.M. Eltamaly, “Power quality considerations of heavy loads of CFL on distribution system” IEEE Int. Symposium on Industrial Electronics (ISIE), pp. 1632–1638, 2011.

[6] Kesharvani, S.K.; Singh, A.; Badoni, M., “Conductance based fryze algorithm for improving power quality for non-linear loads,” in Signal Propagation and Computer Technology (ICSPCT), 2014 International Conference on, vol., no., pp. 703–708, 12–13 July 2014.

[7] Pattnaik, M.; Kastha, D., “Power quality improvement in a speed sensorless stand-alone DFIG feeding general unbalanced non-linear loads,” in Renewable Power Generation Conference (RPG 2014), 3rd, vol., no., pp.1–6, 24–25 Sept. 2014.

[8] Sharma, R.; Singh, A.; Jha, A.N., “Performance evaluation of tuned PI controller for power quality enhancement for linear and non linear loads,” in Recent Advances and Innovations in Engineering (ICRAIE), 2014, vol., no., pp. 1–6, 9–11 May 2014.

[9] Singh, A.; Baredar, P., “Power quality analysis of shunt active power filter based on renewable energy source,” in Advances in Engineering and Technology Research (ICAETR), 2014 International Conference on, vol., no., pp. 1–5, 1–2 Aug. 2014.

[10] Priyadharshini, K.M.; Srinivasan, S.; Srinivasan, C., “Power quality disturbance detection and islanding in micro grid connected distributed generation,” in Computational Intelligence and Computing Research (ICCIC), 2014 IEEE International Conference on, vol., no., pp. 1–6, 18–20 Dec. 2014.

[11] Arya, A.K.; Manocha, A.K.; Arya, J.S.; Kumar, M., “Compensation scheme for power quality improvement in present power system,” in Engineering and Computational Sciences (RAECS), 2014 Recent Advances in, vol., no., pp. 1–6, 6–8 March 2014.

[12] Ejlali, A.; Arab Khaburi, D., “Power quality improvement using non linear-load compensation capability of variable speed DFIG based on DPC-SVM method,” in Power Electronics, Drive Systems and Technologies Conference (PEDSTC), 2014 5th, vol., no., pp. 280–284, 5– Feb. 2014.

Drilling in deeper formations and in high pressure and high temperature (HPHT) environments is a new frontier for the oil industry. Fifty years ago, no one would have imagined drilling in more than 10,000 feet of water depth like we do today. However, more issues need to be researched, tested, and studied in order to maintain a good drilling efficiency as deeper depths are drilled. One of these issues is the great effect that drilling at HPHT conditions has on the behavior of drilling fluids. The goal of this research was to study fluid loss properties of water based mud and its effect on permeability under HPHT dynamic conditions utilizing advanced laboratory equipment that allows for wide ranges of pressure and temperature. Filtration tests were performed at both ambient and HPHT conditions. After several laboratory evaluations of fluid loss additives available in the market, Polysal HT was found to be the most effective in reducing the fluid loss of the water based mud for both static and dynamic tests at HPHT conditions. It is economically designed to be saturated in salt and other brine system. An additive that encapsulates particles with protective polymer coating as colloid. Drilling fluid stabilizer especially in drilling hydratable shale and a remarkable effectiveness in wide range make up water (high saline and high hardness). The fluid loss behavior of the mud and the characteristics of the filter cake produce dare the basic factors that need to be considered when determining mud treatment. A detailed workflow of experiments using equipment from OFITE HPHT Fluid Apparatus with differential pressure of 500 psi under 230 °F with 2.5” filter paper (30 minutes) as well as OFITE Permeable Plugging Tester with 1,200 psi differential pressure @ 230 °F using a ceramic disc were conducted. Also tests were conducted using the Low Temperature- Low Pressure API Filter Press at 100 psi @77 °F with 3.5” filter paper for the purpose of comparison. Drilling fluid behavior should be studied and researched in order to get better drilling efficiency and less fluid losses. This topic has been for years the subject of research and many laboratory studies. Most of these studies focused on the methods and parameters involved in the study of drilling fluid characteristics. Mud can act unexpectedly under HPHT conditions and testing its properties at these conditions produces results that differ from those obtained from testing under static conditions. Drilling fluids' interaction with the spacer fluid is also critical. Krueger found out that the API filter loss tests (standard and high pressure) shouldn't be considered accurate when testing for the losses in mud that has viscosity reducers under dynamic conditions. He also studied the quantities of dynamic fluid loss in water based muds when adding substances to the drilling fluid such as CMC, starch, polyacrylate, and viscosity reducers. He found that–in dynamic system-starch and viscosity reducers were the most useful additives. However, when using API fluid test, the results deduced that CMC, starch and polyacrylate were the most beneficial additives. So he deduced that industry was paying so much on the API filter loss test (standard or at high temperature high pressure) expecting it to be accurate, instead of focusing on the dynamic filtration tests (at HPHT) whose results were more accurate since their conditions were very similar to the reservoir conditions. This is an experimental study of the impact of having HPHT reservoirs on the drilling fluids loss. Three different cases will be studied at different conditions. An API Filtration and fluid loss equipment will be used in order to test the mud capacity to withhold its filtrates under the HTHP as well as from static to dynamic condition. Experiment #1 consist of low pressure, low temperature conditions. The second one is at HTHP using static model. Finally, the last experiment will also be at HTHP conditions but using a dynamic model. Fluid loss models (beyond the conventional such as viscosity, gel strength, yield point and so forth) will then be compiled. The Polysal HT, a modified starch that serve as the fluid loss control additive along with Bentonite and Polypac UL will generally do the job. Roodhart stated that the commonly used 30 minutes API filtration test was inadequate especially in dynamic conditions. Also, he concluded that the range for fluid data testing (1,000 psi [7-MPa] differential) was lacking and deficient. Shadravan and Amani investigated the HPHT challenges in drilling and completions. Lee et al. researched the rheological properties of an extreme HPHT drilling fluids. Amani et al. compared the rheological properties of oil based and water based drilling fluids under HPHT conditions. Shadravan et al. looked at the possibility of fluid loss in underbalanced situations. Bland et al. mentioned that there were many parameters that need to be taken into consideration while designing and monitoring drilling fluids for HPHT conditions. These parameters included pressure and temperature effects on hydraulic calculations (while drilling under HPHT conditions at large depths, mud is subjected to high pressures and temperatures for long period of time) and PVT behavior of the base fluid (where the usual conditions considered by industry in fluid PVT measurements ranged from 15 psi per 750 °F to 20,000 psi/350 °F, but this range was exceeded while drilling under HPHT conditions). In addition, drilling efficiency was affected greatly by HPHT conditions where the use of additives like barite to increase the mud weight for such conditions caused lower drilling efficiency where the percentage of dispersed solids increased. This has many disadvantages (like decreasing hydraulic and cutting efficiency) during drilling high compressive formations under HPHT conditions. Elkatatny and Nasr-El-Din studied the formation of filter cake under static and dynamic conditions. They deduced that the same filtrate quantity was formed during dynamic and static conditions. However, dynamic conditions' spurt volume exceeded that under static conditions and when the filtration process reached an end, the part of the filtrate near to the drilling fluid had zero porosity and permeability. Further results by the CT scan proved that ceramic disk properties (like permeability and porosity) varied significantly during filtration and this should be taken into account during filter cake calculation. Properties of water based drilling fluids under HPHT dynamic testing conditions that can be measured include spurt loss, quality of plugging, total fluid loss, and cake formation thickness. Crespo et al. looked at some fluid loss related problems such as formation fracture, lost circulation, and well-control problems as a result of surge and swab pressures for yield-power-law drilling fluids. As the results show, permeability is proportional to the flow rate per unit cross sectional area. This can be translated into pore throats in subsurface rock. Therefore, the greater the pore size through which the fluid is going to flow at a constant flow rate, the higher the capacity of the fluid to flow and therefore its permeability. It can be deduced that as the concentration of the Polysal HT increased, less and less filtrate was lost into the formations. Same results were obtained from the low temperature low pressure API test where smaller filtrate volume was obtained as the concentration of the used Polysal HT increased. Thus, water based mud under HTHP conditions undergoes many changes in its main parameters like spurt loss, fluid loss, and filter cake thickness. Fluid loss control additives are therefore required in order to handle these changes and maintain the required properties of the used drilling fluid where Polysal HT was the required additive in this case. Dynamic as well as static API filtration tests should be performed before choosing the best additive. Numerous trials has been set up to test the fluid loss effectivity of the mud used in drilling but a very limited resources targeted the HTHP course due to its collaborative safety and productivity concerns, they call it “Drilling in the Dark” (a time to time check of properties).

Torsional vibrations experienced by drill strings can be detrimental to drilling operations. With a goal of understanding torsional vibrations experienced by drill strings and determining means to attenuate undesired vibrations, the authors have studied the effect of adding a sinusoidal modulation to a constant rotation speed of a drill string. A combination of modeling, analysis, and experiments is used to explore the influence of this rotation input modulation on the system response. The drill string is modeled as a modified Jeffcott rotor, which is described by a system with three degrees of freedom. Considering the case of forward whirling of a rotor in continuous contact with a stator, the equations of motion are reduced to a single degree-of-freedom nonlinear oscillator describing the torsional motions. In order to understand the fast time scale and slow time scale components of the motion, the method of direct partitions of motions is used to determine an approximate response to the nonlinear oscillator. The obtained results of the analysis illustrate that with the sinusoidal modulation of the rotor drive speed, the equivalent torsion stiffness can be enhanced and the character of the friction force at the contact can be made smooth. The analyses helps bring forth the stabilizing influence of the added sinusoidal input to the rotor drive speed. Over the considered parameter ranges, the numerical results obtained with the full three degree-of-freedom model and the reduced single degree-of-freedom model are found to be in agreement with each other. Furthermore, the results from these models are found to compare well with those obtained by using the method of direct partition of motions. Experiments with a laboratory scale drill-string arrangement are to be carried out to validate the analytical and numerical findings and further explore the effectiveness of the drive speed modulation on the rotor dynamics.

Introduction

Slender rotating structures are used in many engineering applications. Drill strings are long rotating slender structures, which are used in drilling operations. A schematic of a rotary drill rig is shown in Fig. 1 (e.g., Liao, Balachandran, Karkoub, and Abdel-Magid, 2011). Drill strings experience different types of vibrations (axial, torsional, and lateral vibrations) that may lead to detrimental failures of a drilling system. Drill-string vibrations have attracted the attention of many researchers, and many models have been developed to understand them. Since drill strings have a large length-to-diameter ratio, typically, the first torsional natural frequency and first lateral natural frequency are close to each other. This frequency proximity and the nature of the system allows for coupling and energy transfer between the associated vibration modes. Here, as a step towards developing further understanding, a drill string is modeled as an extended planar Jeffcott rotor with gravity acting normal to the rotor. Due to the planar motions, no gyroscopic effects are considered. The extended model, which was earlier considered in the work of Vlajic, Liu, Karki, and Balachandran (2014), is shown in Fig. 2. The model is described with three degrees of freedom (DOF), namely, x and y to account for lateral motions, and theta to account for torsional motion. A large number of research efforts have focused on controlling drill-string vibrations by using different feedback control algorithms, which need measurements along the drill string. In this work, the authors propose a different control approach to mitigate whirling motions during continuous rotor-stator contact. This can be compared to a situation of a drill string being in continuous contact with the borehole. The approach is open loop in implementation and this approach is based on adding a high frequency input to the drive speed of the drill string. Given the open-loop nature, the method does not depend on any measurements along the drill string or rotary table, which could be attractive for a practical stand point. Although the current focus is on motions of a rotor with continuous stator contact, it is planned to study stick-slip and non-contact cases in the future.

System Modeling, Studies, and Results

As previously mentioned, the drill string is modelled as a Jeffcott rotor with three DOF. Proceeding along the lines of the group's prior work (Vlajic, Liu, Karki, and Balachandran, 2014), after some approximations for the continuous rotor-stator contact case, the 3 DOF system is reduced to a single second-order nonlinear differential equation governing the torsional motion. In Fig. 3, for a representative case with a constant drive speed, the torsional state histories obtained for the full model and the reduced model are plotted. It is noted that the final state of the motion is captured quite well. To further analyze the response during forward whirling, the reduced-order model was nondimensionalized and an approximate solution was obtained by using the method of direct partitions. This method allows one to separate slow scale motions from fast scale motions. As discussed, in the group's prior work, this method can be useful to examine whirling motions. The results obtained by directly integrating the full model as well as the reduced-order model have been compared with that obtained by using the method of direct partitions of motions. It is seen that the perturbation analyses is able to provide an approximate solution that compares well with the numerical results obtained through direct integrations. Next, this analysis is used to examine the influence of the addition of secondary frequency component. It is seen that the addition of the secondary frequency, a high-frequency one, helps smooth out the friction coefficient variation with respect to the relative speed at contact. This is found to have a beneficial effect on the motion and helps suppress large-amplitude torsional motions. Stability analysis was also conducted to examine this effect.

Concluding Remarks

A study has been conducted to examine the influence of sinusoidal modulation of rotor drive speed in a system, wherein the rotor experiences continuous stator contact. A single degree of-freedom reduced model is developed to study the torsion response and it is found that the addition of a high frequency input can be beneficial in attenuating rotor motions. This is believed to be useful for developing open-loop control schemes for attenuating forward whirling motions of drill strings. Results obtained from a lab scale experimental arrangement will be used to examine the effect of this drive speed modulation further and they will be reported in the conference presentation. Future studies could build on the current effort to examine cases of backward 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

1. Liao, C.-M., Balachandran, B., Karkoub, M., and Abdel-Magid, Y., Drill-String Dynamics: Reduced-Order Models and Experimental Studies, ASME Journal of Vibration and Acoustics, Vol. 133, 2011, pp. 041008-1-041008-8.

2. Vlajic, N., Liu, X., Karki, H., and Balachandran, B., Torsion Oscillations of a Rotor with Continuous Stator Contact, International Journal of Mechanical Sciences, Vol. 83, pp. 65 − 75, 2014.

The growing energy demand across the globe has resulted in an increase in the deep water oil exploration activities which in turn has increased the risk of occurrence of associated accidental oil releases. Oil and Gas offshore businesses are important to Qatar's economy. Further, the country is heavily dependent on its marine water resources for fulfilling its potable water needs through the desalination process. So, it is imperative to safeguard the marine environment during an unfavorable accidental oil release, which essentially would put entire ecosystem into peril. Development of reliable models can assist in predicting the extent of damage caused to the environment and can further help in deciding the mitigating strategies during such events. The current research focusses on exploring the of capabilities of Multiphase Computational Fluid Dynamics (CFD) models in simulating various transport processes associated with deep water oil spills. The accidental release of oil in deep oceans results in formation of the plume. The interaction of inertial oil mass with surrounding water results in the formation of droplets which rises in the water column due to buoyancy. Dispersant addition is one of the preferred methods of oil spill remediation which causes the lowering of interfacial tension at the oil/water interface and under the action of local turbulence, it enhances the droplet disintegration process. In deep spill scenarios, droplets spend large amounts of time in the water column, hence, the dissolution process of soluble hydrocarbons which otherwise is detrimental to aquatic life, becomes important. The objective of this work is to develop integrated numerical models which can effectively guide us in predicting the fate of oil mass in such scenarios and help us is estimating the overall impact of such accidents on the environment. Before taking a leap into full scale modelling, it is imperative to grasp a good understanding of above mentioned transport processes at a more fundamental scale. Hence, in the first phase of this project, single droplet dynamics in quiescent systems were studied. We primarily investigated the effect of surfactant (the chief component of a dispersant), on the dynamics of a crude oil droplet rising in a stagnant column. Laboratory scale experiments were performed and a multiphase CFD model based on Volume of fluid method was developed to capture the shape dynamics of the droplet rising in a surfactant laden environment. To capture the subsurface dissolution of hydrocarbons from oil droplet, a unique experiment was devised wherein a binary organic mixture, representing a pseudo oil droplet comprising of volatile and non-volatile hydrocarbons, was employed to study the effect of unsteady mass transport on the overall dynamics of the droplet. Based on the experimental observations, correlations were proposed to estimate the mass transfer rate at various stages of droplet motion. A CFD model capable of evaluating concentration fields of the transported species in both dispersed as well as continuous phases, was developed by coupling VOF approach with species transport model. The above models were also employed to study the jet breakup dynamics in the laminar regime. The next challenge was to extend the applicability of developed models to large scale scenarios. Turbulence is inherent to oceanic environment and hence incorporating it into existing models becomes important. In a real deep spill scenario, a swarm of bubbles and droplets often interact with each other in a turbulent environment and this leads to occurrence of a sequence of coalescence and disintegration processes. The information on size of droplets serves as an important parameter for the evaluation of approximate rise velocities and overall mass transfer rates in the system. Thus, a model capable of predicting droplet size distribution can be employed for determining the fate of droplets in the event of accidental subsea releases. In current work, this objective was achieved by integrating traditional multiphase CFD models and turbulence models, with a population balance (PB) approach. The developed model was validated against the experimental observations reported in Johansen et al (Marine Pollution Bulletin. 2013;73(1), 327–335). Through this work, we were able to demonstrate the capability of an integrated CFD+PB model in analyzing the effect of dispersed (oil) phase flow rates, the presence of dispersants and the presence of air (introduced along with the dispersed phase) on the overall size distribution of oil droplets.

Due the movement of the sun throughout the day, the insolation level incident on the fixed panel surface varies largely. The maximum level of insolation occurs only around noon. This leads to the panel to be under-utilised. To maximise the utilisation of the panel during the day, mechanical solar tracking is used. This method not only increases the utilisation of the, but increases the power being extracted from the panel. Solar tracking using one axis tracking increases the energy yield from the solar panel by 40 percent.

Extended Abstract

During the span of a day the sun's movement has been shown in figure 1. As the day passes by, the level of incident solar radiation (insolation) changes. This change takes place due to position of the sun. The angle at which the sun's rays fall on the photovoltaic panel affects the insolation level available for the panel to convert into electrical energy. For the fixed panel, the sun's rays are not normal to plane of the panel most of the time. This causes the panel to be under-utilised. To extract more energy from the same panel, solar tracking is required. This follows the sun's movement thereby increasing the insolation level throughout the day. This increase in the insolation level is due to the fact that the angle between the normal to the solar panel and incident light is to be kept minimum.

Figure 1: Sun's movement throughout the day

The principle of a single axis solar tracking has been shown in figure 2. The solar tracking can be accomplished by four methods: active tracking, passive tracking, chronological tracking and manual tracking [1]. Active trackers measure the light intensity from the sun using light sensors which give signal to the controller and driving mechanism. Passive trackers commonly make use of a low boiling point compressed gas. This gas is filled in two canisters each placed in east and west directions. The heating of the fluids cause the panel to tilt over to the side with more sunshine. These will have viscous dampers to prevent excessive motion in response to wind gusts [2]. A chronological tracker uses a rotation mechanism to counteract the effect of Earth's rotation. A simple rotation mechanism, turning at a constant speed of one revolution per day or 15 degrees per hour, is adequate for many purposes, such as keeping a photovoltaic panel pointing within a few degrees of the Sun. This can easily be achieved by the use of a stepper motor control.

Figure 2: Principle of single axis solar tracking

The data for the insolation level and temperature for the whole year have been obtained from the NASA website for Aligarh and Doha [3]. The simulations have been run assuming that there is no condition of partial shading. For the purpose of simulation of energy output during the day, five solar panels of 250 Wp were taken in parallel to give a total of 1.25 kWp of power under STC. The energy outputs for the months throughout the year were obtained for two conditions: first for the fixed panel condition, and second for the panel with continuous one-axis solar tracking. The results have been compared and shown for Aligarh and Doha in Figs. 3 and 4 respectively. In Fig. 5, the percentage increase in the energy output for each month has been shown for both the cities.

Figure 3: Daily energy yield from a 1.25 kWp solar array on a monthly basis in Aligarh

Figure 4: Daily energy yield from a 1.25 kWp solar array on a monthly basis in Doha

Figure 5: Increase in daily energy yield on a monthly basis

References

[1] B H Khan ‘Non-Conventional Energy Resources’ Tata McGraw Hill, 2009.

[2] Kamala J. and Alex J., 2014, ‘Solar Tracking for Maximum and Economic Energy Harvesting’, Int. J. of Engg. and Tech, Vol. 5(6), pp 5030–5037.

[3] NASA Surface meteorology and Solar Energy website: https://eosweb.larc.nasa.gov

In this paper an open ended seven phase stator winding drive is considered for analysis that is to be fed from matrix converter controlled by space vector pulse width modulation scheme. Open-end winding variable speed drives with dual matrix converter supply have been extensively investigated for various applications in the past, based on a three-phase machine configuration. This topology is relatively simple for practical realization. It offers a higher number of switching states without the need for capacitor voltage balancing algorithms, when compared to the equivalent standard multi-level converter in single sided supply mode. This paper considers a seven-phase open-end winding topology. A relatively simple SVM algorithm, based on already developed seven-phase two level drive SVM method, is used for operation of both converters. The proposed modulation technique is straight forward to implement and is capable of generating pure sinusoidal output voltages, without any low-order harmonic components. The method offers superior harmonic performance when compared to seven-phase topology in single-sided supply mode. The developed scheme is verified by simulation, using a seven phase induction machine operated under V/f control. The proposed drive topology find application in high power ac drives such as in oil & gas industries, electric/hybrid electric vehicles, ship propulsion, traction etc. The simulation results support the proposed idea.

Abstract Objective: In this era of increasing antibiotic resistance (WHO)[1], we are running out of time as common bacterial infections are progressively rejecting drugs that would be standard for treatment. It is due to these reasons that research regarding bacteriophages, viruses that infect bacteria has seen a sudden revival. The Science Education Alliance- Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) headed by Dr. Graham Hatful from the Howard Hughes Medical Institute (HHMI)[2], University of Pittsburgh and Carnegie Mellon University has begun a nationwide initiative to discover, categorize and study the billions of bacteriophages that surround us. This initiative aims to create a thorough database containing genomic data for as many bacteriophages as possible. The study of these viruses is virtually new, and thus requires a significant effort; there is a novel, virtually untapped resource of genes and proteins that could greatly benefit our understanding of genomes and be used as treatments to bacterial infections that are resistant to antibiotics. Studying the bacteriophages is of great importance. The same protocols and procedures from the SEA-PHAGES program were applied to search for bacteriophages in Qatar within the sand and soil at Carnegie Mellon University Qatar. This is the first research of its kind to be carried out in Qatar and possibly at the Gulf region. Bacteriophages, which infect Arthrobacter.sp, were discovered in the sand from Al-Rayyan, Doha Qatar (Diversity of Bacteriophages in the ecology of Qatar). Following this, the viral plaques obtained were purified, isolated using a QIAamp MinElute Virus Kit[3] (Qiagen) and finally sequenced using Next Generation sequencing methods at Weil Cornell Medical University Qatar. Method: The sequenced DNA of phages were assembled using a Short Oligonucleotide Analysis Package- Denovo (SOAP-Denovo) software package. A program called Velvet has been also used in conjunction to ensure the best results were obtained using the optimal k-mer, providing the longest contig length. The longest length obtained was a contig of 12,380 at a k-mer of 59, along with a large number of smaller contigs. The largest 201 contigs have been annotated; gene nucleotide and protein sequences were collected, using the gene prediction software, GeneMarkS available online. Each of the genes from the contigs were then searched against the entire non redundant protein (NR) database of available annotated genes at the National Centre for Biotechnology Information (NCBI's) online database using Basic Local Alignment Search Tool (BLAST-p). They were also searched against non-submitted phage genomes collected at SEA-PHAGES. That result in about 558 annotated genes/proteins. All the proteins are being studied to understand better what the bacteriophage genome comprises of and how the proteins allow them to survive and infect bacteria in the sand collected from Al Rayyan in Doha. Results: So far three different bacteriophage contigs were found from the sequenced DNA, containing a total of 14 genes, most of which are derived from the Enterobacteriophage T7 cluster. However the individual genes displayed some variation from the original genes due to the small rate of mutations that naturally occurs with bacteriophages during replication. In addition to this, variations could be due to natural exchange of genetic information between viruses to form mosaic genomes. Thus each bacteriophage is unique due to this variation and each has proteins that can perform a slightly different function. One such gene was found had a 99% identity with Gene 3.5 from the Enterobacteriophage T7 family (phages that can infect Escherichia coli (E.coli) bacteria, which are commonly responsible for foodborne illnesses). This particular gene was searched against the PDB (protein database) from the same NCBI BLAST tool, to search for mutations. The query returned results of 100% identity with a (Chain L) T7 RNA Polymerase complexed with T7 lysozyme (interplay between an RNA polymerase and lysozyme). One particular bacteriophage contains a gene originating from a bacteriophage of the Yersinia species (phiA1122). This gene codes for a head-to-tail joining protein, which is a major component of a phage. This bacteriophage principally infects and neutralizes, Yersinia pestis, which is the causative agent of the Bubonic plague in humans[4] (Garcio.E). This particular gene must have been transferred during naturally occurring gene exchange between bacteriophages that infect the same organism simultaneously (Fleischmann, W) [5]. Discussion: The findings strongly suggest that Gene 3.5 has a function in breaking down the bacterial cell wall during infection. A further search on the Research Collaboratory for Structural Bioinformatics (RSCB) PDB was carried out to find a structural view of the protein. Upon studying the protein, it was found that the fragment containing the mutation is not seen in the crystal structure, which means it is a flexible loop. If this section of the protein moves in the crystal structure then it most probably moves in nature as well. This strongly suggests that the flexible mutated loop on the protein surface could affect of protein-protein interaction; and may result in slight changes in the mechanism (or temperature) by which the phage ligates or transfers genetic information from one phage to another. Future work: Future work aims to further study the Qatari bacteriophage genes and their proteins, their mutations and functions. Characterizing the remainder of the bacteriophage will allow us to better understand and annotate its genome. The relevance of these phages in a practical application could be in medical, industrial or agricultural uses. It could possibly have a role in treating E.coli infections or to prevent the contamination of such bacteria in the food industry. Further research could be done to sample more sand from various parts of Qatar (and various depths within the sand) to search for more bacteriophages. It is very likely that there are bacteriophages that could have more significant applications present within the sand. The same procedures could be followed to determine the functions and the nature of these phage genes.

References

[1] World Health Organization. 2015. Antimicrobial Resistance. Available at: http://www.who.int/mediacentre/factsheets/fs194/en/. Accessed on 13 November 2015.

[2] Howard Hughes Medical Institute. Science Education Alliance. Available at: http://www.hhmi.org/programs/science-education-alliance. Accessed on 13 November 2015.

[3] Qiagen.com. 2015. QIAamp MinElute Virus Kit. Available at: https://www.qiagen.com/us/shop/sample-technologies/combined-sample-technologies/preparation/qiaamp-minelute-virus-spin-kit/. Accessed on 13 November 2015.

[4] Garcio.E. 2003. The Genome Sequence of Yersinia pestis Bacteriophage φA1122 Reveals an Intimate History with the Coliphage T3 and T7 Genomes. Journal of Bacteriology. [Online]. Available at: http://jb.asm.org/content/185/17/5248.full. Accessed on 13 November 2015.

[5] Fleischmann. W.R. 1996. Chapter 43: Viral Genetics. Medical Microbiology 4th edition. Available at: http://www.ncbi.nlm.nih.gov/books/NBK8439/. Accessed on 13 November 2015.

Nanocrystalline metals -with grain sizes less than 100 nm- have proven to attain exceptional mechanical properties such as strengths that exceed those of coarse-grained and alloyed metals with grain size greater than 1 μm. As a result, such materials are to be acknowledged as the new class of high-performance engineering materials and to be implemented in various structural applications. The main reason behind the ultrahigh strength of this class of materials is mainly grain refinement, as in this mechanism, reducing grain size means introducing more grain boundaries. Grain boundaries act as barriers to the intra-grain dislocation motion, which is the main cause for the ductility of materials. Hence in its absence, the material is said to be strong and hard to deform. However, the strength associated with the new reduced grain size is associated with a penalty that leads to microstructural instabilities. This is because the atoms that lie in the grain boundary region are not as ordered and stabile as inside the grains. Hence those atoms are occupying unfavorable interfacial positions energetic wise, which means that they have high energy. As a result of the high volume fraction of grain boundaries, the system tends to pursue stabilization by seeking a configuration that shall allow for the lowest energy possible. The atomic system tends to eliminate the root of the problem which is the large number of grain boundaries and solve the problem by grain growth. Thus the removal of grain boundaries becomes the driving force to decreasing the system's energy. Hence an obstacle is yet to be overcome in order for those materials to be fully utilized to the maximum, as those nano-materials are prone to grain growth at lower temperatures than their conventional counterparts, which limits their service temperatures and expected lifetime. Grain growth can be slowed or even eliminated either thermodynamically, for example by adding solute atoms that segregate to the high energy sites in the grain boundaries, occupying it and lowering the free energy of the grain boundaries, or kinetically by the presence of second phase particles which results in grain boundary pinning, reducing the mobility of the grain boundaries and hence grain growth. This research aimed to studying the effect of adding 1% strontium (Sr) on stabilizing the grain boundaries of an aluminum-based alloy (Al-Mg-Li) which has a very low density yet a specific strength higher than that of steel. In order to achieve the goals of this research, a comparison must be made between the two samples of Al-5Mg-4Li and Al-5Mg-4Li-1Sr. Samples were prepared in a SPEX 8000 shaker mill and annealed at various temperatures up to 600 °C. To study the effect of Sr under various thermal conditions, both the as milled and annealed samples were analyzed using various experimental characterization methods such as X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) to perform a structural analysis and calculate the grain size of each sample. Using the Williamson-Hall model to calculate the average grain size for both samples based on the obtained XRD patterns, the results showed that for the as milled samples of Al-5Mg-4Li and Al-5Mg-4Li-1Sr, the average grain size was calculated to be 36.59 nm and 25.86 nm, respectively. The previous results were further proven when the TEM average grain size calculations gave similar results of 33 nm and 21 nm for the as-milled Al-5Mg-4Li and Al-5Mg-4Li-1Sr samples respectively. The thermal stability of the samples was proven when the grain size was measured after annealing at different temperatures for both Al-5Mg-4Li and Al-5Mg-4Li-1Sr samples. The average grain size was measured for Al-5Mg-4Li (annealed at 400 °C) and Al-5Mg-4Li-1Sr (annealed at 600 °C) to be 172.05 nm and 38.90 nm respectively. This shows that even at a higher temperature, the grain size for the sample that has Sr is much smaller and is still the nano-range. To verify the previous results of thermal stability, Vickers-hardness was measured for each sample after annealing as the mechanical properties of the thermally stabilized sample is expected to exceed those of the conventional sized sample. The plot of hardness variation of the nanocrystalline samples as a function of annealing temperatures showed that at room temperature, the hardness values for Al-5Mg-4Li and Al-5Mg-4Li-1Sr samples were 2.85 GPa and 3.24 GPa, respectively. With increasing annealing temperature, the hardness of Al-5Mg-4Li decreases gradually and reaches a low value of 0.8 GPa after annealing at 600 °C. In contrast, Al-5Mg-4Li-1Sr showed excellent thermal stabilization with increasing annealing temperature. Increasing the annealing temperature to 600 °C decreased the hardness value to 2.73 GPa. This hardness value is almost as high as the hardness of the as milled Al-5Mg-4Li (2.85 GPa) at room temperature. Since the XRD patterns did not show any traces of second phase particles, we suggest that the stabilization of the grain size and hence other mechanical properties such as hardness at high temperatures can be attributed to solute drag or the thermodynamic mechanism. Grain Growth does not only limit the nano-crystalline materials service temperatures, but also its unique technological applications as a consequence. Hence we anticipate that the results of this research will have implications in the development of thermally stabilized ultra-tough nanostructured materials for technological applications.

Thermoelectric (TE) is the science associated with converting the thermal energy into electricity based on the Seebeck effect. The attractive features of thermoelectric devices are their long life, low maintenance, highly reliable and they do not produce emissions harmful to the environment. Thermoelectric generators are used to provide electrical power in medical, military, and space applications where their desirable properties outweigh their relatively high cost and low operating efficiency. However, the widespread use of thermoelectric components is presently limited by the low figure-of-merit of presently known materials. Bismuth telluride Bi2Te3 (which has a peak ZT value of 1.1) is currently regarded as the state-of-the art TE material with high efficiency and is therefore attractive for energy harvesting processes. The objective of the work is to demonstrate a new route to the realization of highly efficient bulk Bi2Te3 structures at the nanoscale. Nanostructures provide a chance to disconnect the linkage between thermal and electrical transport by introducing some new scattering mechanisms. This will help in increasing figure of merit and then the efficiency. We present in this work novel versions of both p-type and n-type Bi2Te3 alloy materials with significantly enhanced figures of merit (ZT) between 25 °C and 125 °C.

There is considerable investment in construction industry in Qatar for civil infrastructures and taking into account the severe environmental conditions, they would entail for proper maintenance, repair and strengthening for safe, continuous, uninterrupted, and efficient functionality. Reinforced concrete (RC) structural members, which constitute majority of construction works in Qatar, can be easily deteriorated by the deleterious effect of seawater exposure in the form of humidity or direct splashing for sea-level and offshore structures. Such deterioration can also be due to the exposure to extreme high temperatures, severe humidity and high chloride. All such environmental effect can significantly reduce the life-span of RC structures by up to 10-15 years.

The cost of rehabilitation and strengthening is usually estimated in millions of dollars. Traditional methods of strengthening corrosion-damaged structures involve the replacement of the corroded bars and the substitution of deteriorated concrete layers with new concrete. Our study proposes an “optimum strengthening technique” for RC structures to mitigate the prevailing conditions of Qatar. This relatively new technique utilizes “textile-reinforced mortar (TRM)” to strengthen concrete beams. TRM systems consist of one or more layers of textiles made of carbon, glass, or Polyparaphenylene benzobisoxazole (PBO) grids that are sandwiched between layers of associated cementitious mortars. The cement-based mortar used in TRM acts as a barrier against chloride ions penetration thus protecting the main reinforcing bars from corrosion attack. Textiles' lightweight, high tensile strength, corrosion resistance, and ease of application make the strengthening system appealing. The potential of TRM for the repair and strengthening of concrete structures is not just the result of its physio-mechanical performance but also the ease and simplicity of installation that does not require any sophisticated equipment or retraining of the construction work. In addition, the compatibility between the mortar used and the concrete substrate is inherited since both materials have the cement as a common “base”. TRM systems, with their innovative features, ensure the endurance of the rehabilitation process and consequently the sustainability of the strengthened structure.

Recently in the last few years, several research works in the USA and Europe in the field of TRM strengthening technique have been reported for masonry and concrete structural members. Majority of these works is limited to single type of textile (either carbon, PBO or glass) and on limited types of reinforcement levels. The work presented here compares two different types of TRM systems in the same domain, performed on three different levels of reinforcement ratios representing flexural deficient, lightly reinforced and typical under-reinforced beams.

Experimental works were done to state the efficiency and effectiveness of textile reinforced mortar (TRM) in increasing the ductility and the flexural capacity of reinforced concrete (RC) beams. The aim of the experimental work was to investigate the parameters that contribute to the increase in the load carrying capacity of beams strengthened with TRM system. Eighteen medium-scale rectangular RC beam specimens, 2500 mm long, 150 mm wide and 260 mm deep, were prepared at three different reinforcement ratios of “ “ρ” _“s” ^“1” “ = 0.5%;” o “ρ” _“s” ^“2” “ =  0.72%;” f: “ρ” _“s” ^“1” “ = 0.5%; “ “ρ” _“s” ^“2” “ =  0.72%; “ “ρ” _“s” ^“3” “ = 1.27%.” The strengthened beams utilized two TRM types namely carbon and Polyparaphenylene benzobisoxazole (PBO) TRM systems respectively. The RC beam specimens were tested in flexure under four point loading until failure with a clear span of 2.2 m. The strengthening technique was applied to the soffit of the beam (flat type) altering the number of layers of textile. Three beams (of three different reinforcement ratios) without TRM strengthening were used as control specimens. Nine beams were externally reinforced by one (“ρ” _“T-c” ^“1” “ =  0.014%”), two (“ρ” _“T-c” ^“2” “ =  0.028%”) and three (“ρ” _“T-c” ^“3” “ =  0.041%”) layers of carbon TRM system. Six beams were strengthened with one (“ρ” _“T-PBO” ^“1” “ =  0.009%”) and two (“ρ” _“T-PBO” ^“2” “ =  0.018%”) layers of PBO TRM system.

From Based on the experimental observations, a reasonable gain in flexural strength and energy absorption was achieved for both the TRM systems. An increase of the initial stiffness was achieved for strengthened specimens; however, an apparent decrease in the overall ductility was observed with TRM strengthening. Results showed that the flexural capacity of strengthened beams increased to an average of 38% for carbon TRM system and an average of 26.7% for PBO TRM system over that of their control (un-strengthened) specimens. The highest increase in the load carrying capacity was 77.51% for a specimen having with the main reinforcement ratio of D12 (“ρ” _“s” ^“2” “ =  0.72%)” and was strengthened with carbon TRM system using three layers of carbon textile.

Ductility index (ΔI) and energy absorption (Ψ) values were also calculated in order to know the behavior of ductility and flexural capacity in each of the beam specimen. The term ductility index (ΔI) is defined as the ratio between the deflection at the ultimate load and that at yield load, representing its ability to stretch/deform under sustained load before fracture. During experimentation, it was observed that the average values of ductility indices of using carbon as strengthening material were 1.1 × , 1.2 ×  and 0.5 ×  for “ρ” _“s” ^“1” “ = 0.5%,” “ρ” _“s” ^“2” “ =  0.72% and “ “ρ” _“s” ^“3” “ = 1.27%” beam specimens respectively to that of their control specimen. Similarly the average values of ductility indices of using PBO as strengthening material were 2.42 × , 0.75 ×  and 0.56 ×  for “ρ” _“s” ^“1” “ = 0.5%,” “ρ” _“s” ^“2” “ =  0.72% and “ “ρ” _“s” ^“3” “ = 1.27%” specimens respectively to that of the control specimen. Also the term energy absorption (Ψ) is defined as the area under the load- deflection curve up to the ultimate load, representing the amount of energy absorbed by the specimen before complete failure. The average values of energy absorption for using carbon as strengthening material were 1.8 × , 1.2 ×  and 1.6 ×  for “ρ” _“s” ^“1” “ = 0.5%,” “ρ” _“s” ^“2” “ =  0.72% and “ “ρ” _“s” ^“3” “ = 1.27%” beam specimens respectively to that of the control specimen. Similarly the average values of energy absorption for using PBO as strengthening material were 2.0 × , 1.0 ×  and 1.5 ×  for “ρ” _“s” ^“1” “ = 0.5%,” “ρ” _“s” ^“2” “ =  0.72% and” “ρ” _“s” ^“3” “ = 1.27%” specimens respectively to that of the control specimen.

Therefore, both the adopted TRM systems performed exceptionally well within the scope of the work, with carbon TRM system showing a relatively higher increase in the capacity of strengthened specimens and PBO TRM systems exhibiting relatively more ductile failure with higher bond strength between the TRM surface and concrete substrate. Moreover, crack patterns for the strengthened beam showed effective distribution of cracks/damage over the length of beam as compared to severe and concentrated damage in the associated control un-strengthened beams. Further, during the experimentation, it was seen that the technique of applying the TRM system also considers the contractor's ease where the construction workers (although not very skilled) can easily implement the technique after being given simple demonstrations.

The study puts forth proper procedures and standards to the construction industry on the rehabilitation and strengthening of the existing concrete structures using innovative TRM strengthening technique. Successful implementation of the project will result in “state-of-the-art recommendations for design and construction specifications”, which will place Qatar and research at Qatar University in a leadership position not only limited to the Gulf region. Furthermore, this can potentially act as an “important initiation for the development of new industrial opportunities” in the country.

Keywords

Reinforced concrete beams, textile reinforced mortar, flexural strengthening, ductility index, energy absorption.

Introduction: Pathogen attacks impose natural selection on plants to evolve complex arrays of defensive strategies. Among the diverse defensive mechanisms evolved by plants to withstand pathogen attack, the ability to synthesize an arsenal of low-molecular weight volatile and non-volatile chemicals including phenolics helps them to prepare a robust defense response against pathogen entry. Systemic induction and accumulation of low molecular weight phenolics is observed in response to various diseases and thus are studied as markers for resistance to pathogens. Phenolics that exhibit anti-oxidant activity exert their inhibitory effects on pathogen colonization via protein precipitation and iron depletion.

Phytochemical analysis have been proved that date palm is rich source of phenol. Very little information is available on the inherent Date palm phenolic content that has been involved as resistance factors. All the studies are focused on phenolic content from date palm fruit and its property. Here we focusing on comparative analysis of phenolics from different cultivars leaf and how it affect the different pathogenic fungi. Material and Methods: We conducted a genome mining analysis of date palm whole genome available in the NCBI site, to detect the presents of enzyme involved in the secondary metabolite pathway. Analyzed the presents of receptor protein specific for the recognition of fungal pathogen.

Five date palm pathogens were isolated from the diseased date palm and surrounding soil from the date palm field located in northern region of Qatar. Leaf, shoot and root samples collected from the diseased date palm and rhizosphere soil collected from near the diseased date palm. Samples were stored at 40?C in aseptic condition until further use. Sterilized plant samples were plated in the potato dextrose agar (PDA) for the fungal isolation and the soil were plated on molten agar for fungal isolation. The plates were incubated at 250?C until single colony appeared. The isolated fungi were examined under microscope. Based on the microscopic and physical characteristics fungi were identified.

The pathogenicity were determined with detached leaf inoculation analysis and in vivo pathogenicity analysis with three date palm cultivar varieties. Detached leaf inoculation analysis performed in laboratory condition and the in vivo pathogenicity conducted in green house with controlled growth condition. The date palm varieties used in this current study are Khalas, Khneezi and Barhi. All the four pathogens, Fusarium solani, Fusarium oxysporum, Rhizectonia solani Fusarium sp and Ceratocystis radicicola were used for pathogenicity analysis.

Total phenolic were extracted from three date palm culvars through water extraction procedure. Extraction performed with different temperature range. Comparative analysis of antifungal property of total phenolics from different date palm cultivars such as Khalas, Khneezi and Barhi was carried out after optimizing extraction temperature. Antifungal activity is determined with disc diffusion analysis. 100 μl of extract impregnated filter disc (10 mm in diameter) placed on the PDA plate followed by fungal disc placed on the disc. Plates were incubated at 250?C and the fungal growth monitored. Experiment repeated in triplicate along with control. Results and conclusion: The genome mining analysis of date palm result revealed 45 enzyme sequences from shikimate pathway, which is a support for the active synthesis of phenolic content in date palm. Plant phenolics synthesize via shikimate-phenylpropanoid-flavonoid pathways and include phenolic acids, flavanoids, tannins and less common stilbenes and lignins. Presents of chitin elicitor receptor kinase in date palm indicate the phytopathogenic fungal detection ability of date palm.

From the isolated fungi, the date palm pathogenic fungi were screened and subcultured. Five pathogenic fungi were isolated, Fusarium solani, Fusarium oxysporum, Rhizectonia solani, Fusarium sp and Ceratocystis radicicola. Pathogenicity of all the five isolated fungi were confirmed by analyzing necrosis caused on the date palm leaf (Fig. 1). The frequency of necrotic lesion and disease susceptibility found more in Khneezi than Khalas and Barhi.

Water extraction procedure conducted at 400?C for 24 hrs were accepted as standardized phenolic extract for antifungal activity. Growths of the fungi were measured after 3 day and 5 days of incubation to determine the antifungal activity of phenolic extract (table 1). Phenolic extract from the Khalas showed more antagonistic activity against Rhizectonia solani whereas phenolic extract from Barhi showed more inhibitory activity against Fusarium solani, Fusarium oxysporum and Ceratocystis radicicola. In all the experiment Khneezi showed week inhibitory activity this supports our previous susceptibility study (not published) in that Khneezi showed more susceptible to C.radicicola. This result is an evident for the disease resistant activity of date palm phenolics.

Automotive researchers attempts to simulate combustion of fuels in order to improve engine performance.[1] Conventional fuels are difficult to represent in these simulations due to their complex composition. Surrogates that meet American Society of Testing and Materials (ASTM) standards are a good alternative to conventional fuels. This study aims at design and analyzing surrogate mixtures for both gasoline and diesel. Surrogates were designed through a computer aided model developed at the Technical University of Denmark.[2] The model architecture has four structures viz., (i) problem definition (ii) property model identification (iii) mixture blend design and (iv) model-based verification.

Surrogate diesel, comprised of five paraffinic compounds viz., n-dodecane, n-tetradecane, tetralin, cyclo-octaneand iso-cetane in different volumetric ratios. Surrogate gasoline comprised of six different chemicals viz. n-butane, n-heptane, iso-octane, 1-pentene, methyl cyclopentane and toluene in different volumetric ratios. Target physical properties of these fuel surrogates were measured using advanced analytical equipment and experimental techniques developed at Texas A&M University at Qatar.[3] Diesel surrogate was tested for the target properties employed in the model viz. density, viscosity, heat content, flash point, vapor pressure, pour point, cloud point and distillation curve. Butane present in the gasoline surrogate hampers handling and testing since it is extremely critical to prepare a homogeneous blend that comprises of both liquids and a permanent gas. Also, the conventional sampling technique was found to be ineffective to prevent loss of permanent gas in the surrogate. Therefore, a novel sampling methodology and advanced blending technique was developed to minimize loss of butane and volatile components such as 1-pentene. Detailed Hydrocarbon Analysis (DHA) for gasoline surrogate was carried out by Gas Chromatography (GC) according to ASTM D6730 to verify the efficacy of blending technique as well as sampling method. The composition analysis through DHA confirmed that the blending and sampling methodology was accurate with maximum relative standard deviation of approx. 5.82%. Subsequently gasoline surrogate was tested for density, viscosity, vapor pressure, heat content, distillation curve and compositional attributes.

The surrogate mixtures prepared in this study complied well with their respective ASTM standards for the properties measured. The work would further be continued to investigate the engine performance and emission characteristics for diesel surrogate. Engine performance will be evaluated in terms of Power/Torque and Theoretical Brake Specific Fuel Consumption (BSFC). Emissions of Carbon Monoxide (CO), Hydrocarbon (HC) and Nitrogen Oxides (NOx) will be determined. Results of this study provide a basis to further improving the computer aided models used to design the surrogates and for design of future generations of efficient fuels of different composition obtained from both conventional sources (petroleum) and non-conventional sources (e.g. from natural gas via gas-to-liquid (GTL), coal via coal-to-liquid (CTL) or biofuels). Also, the outcome of this study will be used to optimizing the design of fuel blends obtained from the aforementioned sources.

References

[1] Pitz, W. J., & Mueller, C. J. (2011). Recent progress in the development of diesel surrogate fuels. Progress in Energy and Combustion Science, 37(3), 330–350.

[2] Yunus, N. A., Gernaey, K. V., Woodley, J. M., & Gani, R. (2014). A systematic methodology for design of tailor-made blended products. Computer and Chemical Engineering, 66, 201–213.

[3] Elmalik, E.E., Raza, B., Warrag, S., Ramadhan, H., Alborzi, E., Elbashir, N.O. (2014). Role of Hydrocarbon Building Blocks on Gas-to-Liquid Derived Synthetic Jet Fuel Characteristics. Industrial & Engineering Chemistry Research, 53, 1856–1865.

Hybrid Perovskites (HP) recently emerged as alternative light harvesting layer to fabricate high efficiency thin film solar cells. The perovskite based solar cells took advantage of the experience gained in the field of the dye sensitizes solar cells and the extremely thin absorber (ETA) solar cells. It is worth mentioning that the structure of the perovskite solar cell is very similar to a dye sensitized solar cell and ETA solar cell. These cells are composed of the transparent conducting layer (TCO), the electron transport material (ETM) the absorber, the hole transport material, and the back contact. Our work focuses on the deposition and characterization of two components of the perovskite based solar cell. These components are the ETM which is titanium dioxide layer (TiO2) in this case and the absorber material which is the perovskite layer. Dip coating technique was used to grow compact and pinhole free TiO2 films from a solution of Titanium alkoxide diluted in isopropanol. The dip coating technique is particularly attractive for thin film solar cell application due to its simplicity, low cost, and good quality of films. For a compact film, dipping was restricted to two dips and four dips. The films were structurally and morphologically characterized by X-ray diffraction and scanning electron microscope (SEM). XRD analysis showed the deposited TiO2 films have anatase structure. SEM results showed a full coverage of the films with less pinholes. The two step sequential physical vapour deposition was performed to grow HP thin films using thermal evaporation technique. Thin films of HP were deposited using thermal evaporator under high vacuum from two sources namely lead iodide and methylamine iodide. Firstly, Lead iodide was deposited which acts as a template for the crystallization of perovskite layers. Then methylamine iodide was deposited for the desired film. X-ray diffraction of the as deposited film showed the presence of mixed phases of lead iodide and perovskites. This indicates at room temperature methylamine iodide diffused deep enough in the lead iodide film to form the perovskite structure. Films were then annealed at 110 °C for 1 hour in nitrogen atmosphere for better crystallinity which is proven by the sharper and high pick intensities. Also, varying the ratio of both organic and inorganic sources did not influence the presence of lead iodide phases as confirmed by XRD. Further optimization are in progress to form single perovskite phase formation.