Qatar Foundation Annual Research Conference Proceedings Volume 2018 Issue 1
- تاريخ المؤتمر: 19-20 Mar 2018
- الموقع: Qatar National Convention Center (QNCC), Doha, Qatar
- رقم المجلد: 2018
- المنشور: ١٢ مارس ٢٠١٨
101 - 120 of 142 نتائج
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Screening of Qatari Microalgae and Cyanobacteria for Application in CO2 Utilization
CO2 fixation by phototrophic microalgae and cyanobacteria is seen as a possible global carbon emissions reducer, which could also be applied to produce useful products. In Qatar, the prospect of using microalgae is very promising: high solar irradiance, large areas of non-arable land, and large amounts of CO2 sources make it an ideal place for algae cultivation. Nonetheless, application of algae in the region is limited, primarily due to a lack of suitable algae which can grow under relevant outdoor conditions, such as high temperatures, increased salinities, as well as elevated CO2 concentrations when using industrial CO2 sources. Furthermore, such algae also need to be able to produce commercially valuable products. One of the most comprehensive resources for novel algae strains in the region is the Qatar University Culture Collection of Cyanobacteria and Microalgae (QUCCCM), which houses a large diversity of strains, the potential of which still remains largely unexplored. This research focused on evaluation of biomass productivity of four novel marine strains from this culture collection, under elevated temperatures and CO2 concentrations. The strains were also evaluated for their carbon capture potential, as well as commercial potential, through biomass analysis. Two strains were identified as cyanobacteria (Leptolyngbya sp. and Pleurocapsa sp.) and two were identified as microalgae (Tetraselmis sp. and Picochlorum maculatum). As cyanobacterial strains in some cases are known to produce toxins, both cyanobacteria were analyzed for presence of genes for cylindrospermopsin, microcystin and saxitoxin production, and found to be negative for all three. All four strains were then cultivated under various temperatures, ranging from 30 to 45˚C. The most productive strain was Tetraselmis sp., with a maximum biomass productivity of 157.7 ± 10.9 mg L-1 d-1 at 30˚C, with a decreasing productivity for increasing temperatures. Leptolygnbya sp. showed an opposite trend, increasing in productivity from 91.4 ± 10.2 to 106.6 ± 7.1 mg L-1 d-1 with increasing temperature from 30 to 40˚C respectively. None of the strains were able to grow at 45 ˚C. The biomass of the four strains cultivated under different temperatures was analyzed for lipid, protein and carbohydrate content, as well as total carbon and nitrogen content. Picochlorum maculatum was found to have the highest lipid and protein content, with 24.0 ± 1.3, 28.0 ± 1.4 and 27.0 ± 1.4 % (w/w) lipids and 21.2 ± 0.2, 23 ± 0.1, and 20 ± 0.9 % (w/w) proteins for cultivation at 30, 35 and 40˚C respectively. This strain also had the highest nitrogen content (12.2 ± 0.05 % at 40˚C) and carbon content (51.2 ± 0.25 % at 45˚C). Compared to Picochlorum maculatum, Tetraselmis sp. showed a slightly lower lipid content (25.6 ± 0.64 and 22.5 ± 0.78% for 30 and 35˚C respectively) and total carbon content (46.9 ± 0.8 and 47.6 ± 0.9% C (w/w) for 30 and 35˚C respectively), however due to the higher productivity, the carbon capture rate for Tetraselmis sp. was the highest of the tested strains, at 270 mg CO2 L-1 d-1 at 30˚C. Pleurocapsa sp. showed the lowest nitrogen content, at 4.4% N (w/w) for 30˚C. There is indication that this strain is capable of fixating atmospheric nitrogen. This is very beneficial for large-scale cultivation, as it reduces the requirements for nitrogen fertilizer, which can greatly reduce costs and improve production sustainability. Furthermore, spectrophotometric analysis of Pleurocapsa sp. and Leptolyngbya sp. showed production of phycobilin proteins, which can have a high commercial value. The tolerance of the strains to increased concentrations of CO2 in the gas phase was also studied for CO2 concentrations ranging from 5% to 30% (v/v). With productivities of 53.7 ± 11.4, 162.2 ± 5.4, 333.8 ± 29.1 and 312.8 ± 12.8 mg L-1 d-1 for 5, 10, 20 and 30% CO2 respectively, Tetraselmis sp. showed that a significant productivity increase could be obtained with increased CO2 concentrations. Picochlorum maculatum showed a similar trend, with slightly lower productivities of 67.1 ± 0.2, 160.5 ± 21.8, 244.1 ± 20.9 and 219.9 ± 15.6 mg L-1 d-1 for 5, 10, 20 and 30% CO2 respectively. Leptolyngbya sp. showed similar productivities for CO2 concentrations ranging from 5-30%, indicating that the strain was not influenced by increasing CO2 concentrations as were the other two strains. Pleurocapsa sp. on the other hand showed no growth at 30% CO2, and stable similar productivities at 5, 10 and 20% CO2. Overall, it can be concluded that for both microalgal strains (Tetraselmis sp. and Picochlorum maculatum) increased CO2 concentrations resulted in a significantly increased productivity, and as of such they would be the most interesting to further investigate for direct coupling to enriched CO2 gas sources, such as industrial flue gasses. Furthermore, besides having the highest productivities of the four investigated strains, Tetraselmis sp. is generally known to have promising characteristics for feed purposes (amino acid profiles and presence of omega-3 fatty acids) as well as for biofuel purposes due to high lipid amounts. Based on these results, Tetraselmis sp. is a very interesting candidate for CO2 capture and production of valuable products in Qatar. Further investigation into this strain is necessary to confirm the presence of such components in this particular strain, as well as to identify conditions which increase specific product productivity, and the capability of direct coupling to industrial flue gas.
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The state of the art prototype design and optimized process conditions for clathrate hydrate based desalination HyDesal process
المؤلفون: Praveen Linga, Ponnivalavan Babu and Abhishek NambiarDesalination is one of the most promising technologies to mitigate an emerging water crisis. Thermal desalination and reverse osmosis are two of the most widely employed desalination technologies in the world. However, these technologies are energy intensive. In countries like Singapore which lack natural water and energy resources, it is imperative to develop innovative energy efficient technologies to strengthen the energy – water nexus. Clathrate hydrate based desalination (HyDesal) is one such technology. Clathrate hydrate based desalination (HyDesal) process is based on a liquid to solid phase change by employing a suitable guest gas/ gas mixture for the phase change. In the HyDesal process, water molecules form cages around a guest gas/liquid component effectively rejecting salts present in the brine solution at temperatures slightly higher than normal freezing temperature of water. These crystals when dissociated or melted are essentially fresh water and the guest component can be re-used for the process again. While HyDesal process was proposed almost 70 years ago, it was never commercialized primarily due to the high energy requirement for low temperature operation, slow hydrate formation kinetics and inefficient hydrate crystal separation from brine. Recently, we reported an enhanced hydrate formation kinetics in fixed bed reactor with silica sand as porous media when hydrate is formed from gas mixture consisting propane as co-guest. Based on the ability of propane to draw dispersed water from sand bed towards the gas phase for hydrate growth, we proposed a conceptual hydrate based desalination (ColdEn-HyDesal) process employing fixed bed reactor configuration to minimize the energy requirement. The ability of propane as a co-guest to draw water from the silica sand bed can be effectively used for the HyDesal process to address the slow kinetics and effective separation of the hydrate crystals. In this presentation, our state of the art prototype design and optimized process conditions will be presented. With our innovative reactor design, we carried out water recovery experiments to find the suitable guest gas mixture containing propane as co-guest. The other constituent in the gas mixture employed were methane, argon, nitrogen and carbon dioxide. Further kinetic experiments were carried out to optimize the silica sand particle size, bed height. Our recent knowledge on enhancing the kinetics of hydrate formation and innovative approach to offset the refrigeration cost for the HyDesal process can be applied to efficiently desalinate seawater to produce potable water. With our innovative reactor design and utilizing waste LNG cold energy, HyDesal can be a sustainable solution for desalination. The ColeEn-HyDesal process utilizing waste LNG cold energy will have a huge impact globally as well due to the expanding number of LNG terminals and the potential to mitigate the potable water issues.
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Effect of NaCl on clathrate hydrate based desalination HyDesal process with fixed bed approach
المؤلفون: Praveen Linga, Ponnivalavan Babu and Abhishek NambiarAcute shortage of water has become one of the biggest problem facing many countries in the world. Safe and drinkable water is a basic necessity for survival. Hence, water resource management has become need of the hour. Since, seawater is the most abundant source of water available on the earth, desalination is one of the most promising technology to produce potable water. Desalination is the process of removal of salts and other impurities from seawater and brackish water. Thermal distillation and Reverse Osmosis (RO) are two of the most widely employed desalination technologies in the World. Thermal desalination uses energy inefficiently and also suffers from corrosion problems. RO on the other hand is used in more than 50% of the desalination plants in the World. In a typical RO desalination plant, water recovery from seawater is less than 55%. However, RO suffers from fouling problems which increase maintenance cost. Since, these technologies are energy intensive there is a need to address water-energy nexus by employing innovative energy efficient solutions. Clathrate hydrate based process which is based on freeze desalination approach has been proposed as a potential desalination technology to alleviate shortage of potable water in many parts of the World. Clathrate hydrate are non-stoichiometric crystalline solid compounds made up of water and gas. Similar to freeze desalination, clathrate hydrate excludes salts and other impurities present in seawater and brackish water from crystals. After separating formed hydrate crystals from left over brine, there is potential to get pure water and gas by decomposing hydrate crystals. Gas released during decomposition of hydrate can be recycled. In general, salts present in seawater act as thermodynamic inhibitor for gas hydrate formation. One of the major challenges faced by freeze desalination is ice crystal contamination due to crystal contact with left over brine. Similarly, hydrate contamination by left-over brine has prevented successful commercialization of HyDesal technology. Hence, efficient separation of hydrate crystals from brine and faster kinetics of hydrate formation play a major role in clathrate hydrate based desalination process. In order to strengthen energy-water nexus, waste cold energy from Liquefied Natural Gas (LNG) regasification terminals is being incorporated to mitigate energy requirement of this process. Previously, it has been reported that propane has shown ability to draw water out of fixed bed to form hydrates away from unreacted brine solution. Hence, there is a need to identify suitable co-guest gas with propane to maximize water recovery from HyDesal process. In the present work, an innovative approach has been employed by using Propane/ Nitrogen gas mixture in fixed bed made up of silica sand. Fixed bed approach in presence of propane enables natural separation of hydrate from left over brine which has been reported in an earlier work, which helps in minimizing hydrate contamination by salts present in left over brine. Faster kinetics has also been reported in fixed bed approach. In this work, water recovery from 1.5 wt% NaCl solution and 3 wt% NaCl solution has been studied and comparison has been made with kinetics of hydrate formation in deionized pure water. In this study, salt was found to act as kinetic inhibitor for hydrate formation.
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The Role of Tariffs in Reducing Residential Water Demand in Qatar
المؤلفون: Hamish R Mackey, Huda Alkandari and Gordon MckayQatar is a hyper-arid country located in the Middle East suffering extreme water scarcity. More than 99% of municipal demand comes from seawater desalination while existing groundwater reserves are under severe pressure from over-abstraction. Despite these water resource limitations, per capita water demand is amongst the highest globally with recent Ministry of Development Planning and Statistics values placing per capita consumption at roughly 550 L/p.d in 2014. Such high demand could be due to a variety of cultural, social and political factors. The Qatar population is unique in its composition, with roughly 85% of the population being non-citizen residents coming from a diverse set of cultures including a large portion of low-skilled labourers. Therefore, promoting conservation in a consistent and effective manner can be challenging. The high average personal wealth in the country may also lead to greater luxury use of water. Cultural and environmental issues may also play a key role. For instance, the majority of the population are adherents of Islam, which has strict ablution requirements for purification prior to prayer and holds a high regard on cleanliness, which in the extreme weather conditions of the Arabian Gulf leads to increased water use for washing. However, the traditional welfare orientated governance of the Gulf States is frequently regarded as a primary cause for high water consumption prevalent in the region. Qatari citizens are granted tariff free use of domestic water on one dwelling while historically residents have been offered a heavily subsidized flat rate of only 4.40 QAR/m3 ($1.21 USD/m3). In 2015, the countries sole water utility provider, the General Electricity and Water Company (Kahramaa), revised the tariffs to various user groups including residents who now pay a tiered structure which still starts at 4.40 QAR m/3, but rises to 5.40 QAR/m3 after the first 20 m3 and has a final tier rate of 9.40 m3 reflecting a cost close to the true cost for supply. This study evaluated the effectiveness of this tariff restructuring by assessing changes in water consumption before and after the tariff changes across 547 residential properties including citizens and residents; flats and villas, and rented vs owned. Metering data was provided directly by Kahramaa following screening to ensure the same tenant was registered for two full years, one year prior and one year following the price restructuring. Data was analysed using SPSS statistical software (IBM), using non-parametric methods due to non-normality of the data. It was found that a statistically significant reduction in water consumption occurred following the tariff restructuring with a total reduction of 17% observed. Surprisingly, the most significant reductions were observed among Qatari rented flats, with resident rented flats and villas the next most responsive to tariff changes. The responsiveness of users was also assessed based on their previous water consumption by considering three groups, low water users (set as the 10th percentile users), medium water users (set as the median water users) and high water users (set as the 90th percentile users). While response varied significantly among household tenant types, overall it was found low water users responded significantly more to the changes in tariffs. This study highlights the importance of tariff use in Qatar as one effective tool to complement a broad and holistic approach to bring domestic water consumption to more sustainable levels and highlights the role tariff changes have on even those exempt from tariffs, possibly through increased discussion, awareness and feeling of responsibility.
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Selective Catalytic Valorisation of Carbon Dioxide Towards Building Block Molecules
The development of sustainable technologies for successful exploitation of C-1 feedstock such as carbon dioxide (CO2) is a thought-provoking challenge for effective utilisation of this abundant renewable resource. In an industrial prospective, new catalytic concept are vital to add value stream and to bring sustainability to this resource to mitigate the challenges associated with growing energy demands and increased responsiveness for climate control. Notably, catalysis is a key technology for achieving sustainable processes and the future development of humankind. Our recent efforts in developing catalytic methodologies towards selective valorisation of CO2 towards building block molecules will be discussed.
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Efficient Inhibition of SulfateReducing Bacteria in Inject Sea Water by “Green” Chitosan/ZnO nanocomposite
المؤلفون: Kashif RasoolOil producing companies utilize water injection as a common oil recovery method for decades, especially for offshore fields, where seawater is typically used as inject water. Due to the size and complexity of the injection system and the high salinity of the water (∼55,000 mg/L); several challenges are faced during this process including microbial growth, fouling and corrosion in the pipeline. Biofilms accelerate corrosion in a biologically conditioned metal–solution interface. Oil producing companies including those in Qatar use biocides to disinfect the water and inhibit biofilm formation caused mainly by sulfate reducing bacteria (SRB). However, traditional biocides may induce bacterial resistance and/or be detrimental to environment. In this study we synthesized chitosan/ZnO nanocomposite (CZNCs) and evaluated its antimicrobial activity against SRB biofilm in inject seawater. CZNCs showed stable behavior when exposed to higher salt concentrations of inject water. The inhibition of SRB activity was concentration-dependent and more than 73% and 43% inhibition of sulfate reduction and TOC removal, respectively, was observed at 250 μg/mL CZNCs at 10% initial ZnO loading. Scanning electron microscopy (SEM) coupled with lactate dehydrogenase (LDH) release assay indicated obvious damages to the cellular membrane which resulted in release of cytoplasmic materials from the bacterial cells. Significant decrease in concentration of EPS extracts was obtained. This work has demonstrated that the exposure of synthesized CZNCs could cause significant SRB anti-biofouling properties. This is the first ever study of antimicrobial potential of chitosan based biocides for SRB inhibition. We are confident that this work will make the scientific as well as the industrial communities to appreciate the application of nanomaterials based biocides. This is the first ever study of antimicrobial potential of any ENM generally, and chitosan based biocides, particularly, for SRB enriched biofilm inhibition. Taking into account tremendous interest to nanomaterials as antimicrobial agents, we anticipate a major impact from a much better material reported in his paper.
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CO2 Utilization through Dry Reforming of Methane Process
المؤلفون: Nimir Elbashir, Shaik Afzal, Debalina Sengupta and Mahmoud El-HalwagiDry Reforming of Methane (DRM) is one of the CO2 utilization processes in which CO2 reacts with methane to produce syngas (a mixture of CO and H2). The DRM process faces 3 major challenges. Firstly, the highly endothermic nature of DRM (ΔH°298 K = 247 kJ/mol) is much higher than that of the conventional Steam Methane Reforming (SMR) which produces a higher quality syngas (higher H2/CO ratio). Secondly, due to low O/C and H/C ratios in the reaction mixture, catalyst deactivation due to coke formation is a major concern for the DRM process. Thirdly, the syngas ratio (H2/CO ratio) obtained from DRM is ≤ 1. This low syngas ratio is only suited for the production of few chemicals and cannot be extended to Fischer-Tropsch process or petrochemicals like methanol. Despite these obstacles, DRM has received a considerable amount of interest by both academia and industry. Using an Optimization approach, this study aims to better understand the CO2 balance of a process incorporating DRM and compare the performance with existing conventional processes. The objective is to ascertain the regions of operation where DRM helps reduce overall CO2 emissions of syngas production. In the first step of the study, all required data pertaining to CO2 emissions related to existing process was collected from various sources. Emission data for oxidant production (steam, oxygen) and upstream emissions for natural gas were taken GREET® software. In the next step, reformer modeling was performed in LINGO® software. A previously developed Gibbs Free Energy Minimization model [1] has been modified to include fugacity coefficients so that equilibrium calculations can be done at 20 bar pressure. Existing processes considered in the study were Steam Methane Reforming (SMR), Partial Oxidation of Methane (POx) and Auto-Thermal Reformer (ATR). These processes mainly differ in the oxidant/methane ratios and steam-to-carbon ratios used. These constraints have been set to simulate industrial reformer conditions. In the cases which involve DRM, 3 cases were used – stand-alone DRM, DRM+SMR in parallel and DRM+POx in parallel. Though CO2 utilization is the main objective of this study, it is essential to note that an objective function only involving CO2 minimization might result in lower syngas production which is undesirable as it directly reduces plant throughput. Hence, an epsilon method approach was used to iteratively reduce the overall CO2 emissions while maximizing overall syngas production. This method was repeated for each syngas ratio for each reformer case. Results indicate that stand-alone DRM helps achieve a near zero carbon footprint but only at syngas ratio close to 1. Combining equally sized DRM with SMR and POx units does not appreciably reduce overall CO2 emissions. The operating costs of reforming networks involving DRM are highly sensitive to the CO2 purification cost. This assessment shows that incorporating a DRM unit directly into any generic syngas production infrastructure does not have an appreciable reduction in CO2 emissions. Nevertheless, there could still be certain special scenarios where DRM helps in achieving the CO2 reduction objective. To investigate this further, case studies have been used to study the CO2 balance for different processing plants utilizing syngas of different H2/CO ratios. Preliminary findings show that in certain specific regions of operation, DRM assisted reforming helps in overall CO2 reduction objective. The operating cost comparison of these options will be the major criterion which will decide the future of these processing options incorporating DRM. REFERENCES [1] M. M. B. Noureldin, N. O. Elbashir, and M. M. El-Halwagi, “Optimization and selection of reforming approaches for syngas generation from natural/shale gas,” Ind. Eng. Chem. Res., vol. 53, no. 5, pp. 1841–1855, 2014. ACKNOWLEDGMENTS This work was supported by Qatar National Research Fund (QNRF), member of Qatar Foundation (NPRP X – 100 – 2 – 024). The statements made herein are solely the responsibility of the authors. The authors would like to appreciate the continuous support of our industrial partner, Total.
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Water Resources and Use in Qatar Prior to the Discovery of Oil
المؤلفون: Andrew Duncan PetersenQatar is known as one of the most arid countries in the world with all of the land characterised as dessert which in geographical terms is defined as territory with no surface water. Despite this unpromising situation people have lived on the Qatar peninsula for thousands of years carefully conserving, harvesting and using the scarce water resources. This paper will argue that a better understanding of the conservation and utilisation of fresh water in the past may have implications for the future development of agriculture and water management in Qatar. All the water resources in the past were fed either directly by scarce and sporadic rainfall events or through sub-surface water (fossil water) which formed a fresh water lens floating above a predominantly saline aquifer. The presence of shallow wadis located throughout the country but particularly near the coast are indicative of the occasionally heavy rainfall.This paper will investigate the methods used to provide water to the traditional settlements and more ancient archaeological sites throughout the country. The paper will begin by reviewing the hydrological structure of the Qatar peninsula and its condition prior to the modern over exploitation of water resources from the 1950's onwards. The paper will pay particular attention to the location of settlements around the northern coast where particularly favourable conditions exist as a result of the north Qatar arch. The settlements of the northern coast employed a variety of water catchment methods including modifying shallow natural depressions (rawdhas) to provide either grazing land or in some cases agricultural zones. In some cases such as at Jifara extensive sunken field systems enclosed within mud brick walls were created fed by a series of shallow wells taking advantage of both rainfall catchment and fossil rainwater. In some cases such as at Ruwayda on the north Qatar coast an existing rawdah appears to have been modified to create a garden with trees enclosed by a fortified masonry wall. A variety of well forms were created including shaft wells where water was accessed by buckets or other receptacles lowered by rope (two example of traditional leather buckets with goat hair rope have been found in archaeological excavations in Qatar) and wide shallow stepped wells which allowed direct access to the water either for humans or animals. In the centre of the country access to water has always been more difficult because the freshwater acquifer has been closest to the surface near the coast. As a consequence the majority of human settlement in Qatar has always been close to the coast. Where inland settlement do exist they are usually located either within or next to some geographical feature such as a wadi or a large depression which will act as a catchment area for rainfall. Such settlements are nearly always supplemented with wells which tend to be larger and much deeper than those on the coast. Examples of inland wells include those associated with gardens at Umm Salal Muhammad. The transformation of inland wells with motorised pumps from the 1950's onwards was one of the causes for the depletion and subsequent salinization of the freshwater aquifer in Qatar.In addition to wells and modified rawdahs a number of other forms of water catchment exist. One of the most surprising water sources is the perennial spring (naba‘a) which following periods of heavy or sustained rainfall may result in water literally spring out from the ground. Another unusual source are fresh water springs located off the coast which were traditionally exploited by fishermen and pearl divers. A rare form of water catchment exists in the Jabal Jassasiya rock formations on the north-east coast of Qatar where the natural contours of the rock are modified to form a cistern blocked on one side by a masonry dam. Masonry dams- possibly of medieval date- have also been documented near Umm Salal Muhammad.
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Challenges and Solutions for Treated Sewage Effluent Reuse
The purpose of this work is to identify challenges associated with the treated sewage effluent (TSE) reuse in Qatar and the region. Ultimately this work aims to create a thorough knowledge base for policy makers and end users to maximise the reuse of TSE for non-potable applications. The role of TSE reuse as an alternative source of water supply is well acknowledged in Qatar. TSE generation has increased more than 3.5 times over the past seven years, and it is estimated that the surplus would reach 77 million m3 per year by 2030 [1, 2]. After adequate treatment, TSE can be effectively used for urban, agricultural and industrial applications. The degree of treatment is dictated by the end use water quality requirement. For example, nutrient free TSE is needed for district cooling applications to prevent biological growth within the system, while agricultural applications would benefit from the presence of these nutrients. Presently, district cooling industries use TSE and potable water blend for their operations. For any application, potential wastewater pollutants such as pathogens (e.g. bacteria, protozoa and virus), heavy metals (e.g. lead, mercury, arsenic, and cadmium), nutrients (e.g. phosphorus and nitrogen) and chemical of emerging concerns (Pharmaceuticals, personal care products PPCPs and endocrine disrupting chemicals EDCs) can pose significant threats to living organisms and environment. Currently, the irrigation sector and district cooling industries are the primary users of TSE in Qatar. Considering the potential benefits of TSE reuse in the agriculture sector, a pilot scheme was developed [3] and commissioned targeting the removal of emerging contaminants from TSE. Pilot train includes coagulation, flocculation, sedimentation, advanced oxidation (ozone-peroxide), UV-peroxide, sand filtration, polymer and ceramic ultrafiltration treatment processes. The concentrations of trace elements present in TSE were determined by inductively coupled plasma atomic emission spectroscopy, and the results were compared with the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) reuse guidelines. Moreover, contaminants of TSE that hindered its maximum reuse potential, especially for district cooling applications, were identified by reviewing the make-up and process affected TSE water quality data. Technology screening for removing TSE contaminants was performed by considering water treatment plant footprint and costs. Experimental studies were conducted using coagulation and ion-exchange methods for phosphate removal in TSE for district cooling applications. References: [1] S.Y. Jasim, J. Saththasivam, K. Loganathan, O.O. Ogunbiyi, S. Sarp, Reuse of Treated Sewage Effluent (TSE) in Qatar, Journal of Water Process Engineering 11 (Supplement C) 2016, 174-182. [2] Hajar Farzaneh, Jayaprakash Saththasivam, Kavithaa Loganathan, Oluwaseun Ogunbiyi, Sarper Sarp, and Gordon McKay. (2016). Reuse of treated sewage effluent (TSE) in Qatar and its impact on sustainability and the environment. QScience Proceedings: Vol. 2016, QULSS 2016: Biodiversity, sustainability, and climate change, with perspectives from Qatar, 40. [3] Saad Jasim, Jayaprakash Saththasivam, Kavithaa Loganathan, Advanced Oxidation Processes for Treated Sewage Effluent 2017, Patent application no. PCT/US17/38155.
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Energy Demand Estimation and Forecasting in Qatar
المؤلفون: Ahmed Ali KhalifaThe economic theory provides a rationale for linking the energy demand to a number of variables that might affect it. Starting from that, the empirical analyses specify a number of alternative specifications of the energy demands (water, electricity and fuel). For instance, Zarnikau (2003) suggests three possible forms. First, a linear specification involving the levels of the variables, where the energy demand is a linear function of production factors or of other elements affecting demand. The second form is still a linear specification, but where the log-levels of the variables replace the levels. These two forms are coherent with production (or consumption) functions being additive or multiplicative, respectively, in the underlying factors. The third case focuses on the share equations, most common in a production-based framework, where the share cost of energy, over the total cost of production, depends on the production factors in a linear fashion. We provide an estimation for energy demand and forecasting. We will use the Auto Regressive Distribute Lag (ARDL) specification. The ARDL model might be estimated again by least squares methods. Notably, this specification allows computing short-run elasticities, the parameters, as well as long-run elasticities, which can be obtained by standardizing the coefficients by the autoregressive polynomial, i.e.. A further advantage of the ARDL specifications comes from their coherence with the existence of a long-run equilibrium relation across the modelled variables. In fact, if we assume that the variables of interest are possibly cointegrated (and are thus non-stationary in their levels) and also characterized by short-term dynamic, we might recast the ARDL model into the so-called Error Correction Model representation (ECM) for the series first difference.The estimation approach of such a model might follow the bounds testing approach to cointegration of Pesaran and Shin (1999) and Pesaran et al. (2001). Despite its appealing form, the ECM representation of the ARDL model is appropriate when only a single cointegration relation exist across the modelled variables. A more general structure is that associated with Vector Error Correction Model (VECM) where the dynamic of a set of variables is jointly estimated. The estimation and testing for cointegration might follow the approaches proposed by Johansen (1988, 1991, 1992, 1994 and 1995). Moving back to the three approaches listed by Zarnikau (2003), we now briefly discuss the estimation of share equations. This approach focuses on the estimation of the share cost of various inputs with respect to the total cost of production for a specific good. We express energy demand as a function of energy prices, the appropriate price should be a weighted average of the prices of the underlying energy sources (electricity, gas, oil…etc.). The weights might be interpreted as share costs, and therefore the approaches for the estimation of share equations turn out to be relevant in this case, see Fuss (1986). Share equations are nothing more than linear equations for the share of the specific energy source on the total energy demand. However, the crucial aspect to be here considered is the presence of constraints: the shares must be positive and must sum up to one. However, various approaches have been proposed to introduce the appropriate constraints, see for instance the methods by Zellner (1962 and 1963). Further, we can take gasoline price as an indicator for energy price in the demand function. We close this set of methodological approaches by taking into account the use of structural time series methods, see Harvey (1989).Such an approach might be extended with the presence of stochastic cyclical and seasonal components and could represent an alternative approach to classical time series methods.Building on an ARDL specification with a latent trend, Dilaver and Hunt (2011a) provide a scenario analysis for Turkey industrial energy demand and Dilaver and Hunt (2011b) analyze scenarios for residential electricity demand in Turkey. Both studies consider three scenarios, the reference one and two opposite cases representing an increase/decrease in the energy demand due to changes in the production levels, the energy efficiency and the prices. Jiang and Li (2012) provide three different scenarios for the evolution of China energy demand starting from a static long-run relation and using scenarios for the underlying factors. Li et al. (2010) analyze the evolution of energy demand and CO2 emissions in Shanghai under two alternative scenarios, one associated with energy conservation policies. Tajudeen (2015) performs a forecast and scenario analysis for aggregated energy demand. He consider three scenarios, the reference one and two alternatives with increases/decreases in the factors affecting energy demand. Zachariadis and Taibi (2015) provide a scenario analysis for Cyprus energy demand based on different projections of underlying macroeconomic factors as well as in terms of energy efficiency improvements.The estimation and the results wil lbe presented in the conference
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Improving Vegetable Crop Production in Qatar: Strategies to determine optimum planting time minimise production risk and maximise water and nutrient use efficiency
Introduction The research developed strategies to be adopted in Qatar to enhance agricultural production and improve the food security situation of the country. The government of Qatar has instituted plans to boost its food security and, as part of the wider food security plan, the country needs improved agricultural technologies and in-country farming techniques to increase crop yields. This QNRF-funded food security project sought to apply innovative technologies and decision support tools to provide strategies for successful vegetable food production on the local Qatari scene. The research has provided methodologies to assist Qatari researchers and Policy makers to make informed decisions about appropriate crops and timing for profitable in-country farming. Rationale The agricultural production problems faced by Qatar are similar to many other arid and semi-arid countries. The challenges faced by Qatar in improving agricultural production represent a wide range of sustainable agriculture issues including limited arable land and water resources, high temperatures associated with high humidity, salinity, plant pests and plant diseases. This research addresses these problems by contributing to the application of innovative ways of maximizing water and nutrient use efficiency for agriculture, and choosing the appropriate planting times for vegetable cultivation. Appropriate preservation of soils for agricultural purposes is not practiced in Qatar. Therefore, this research was carried out to showcase modern technological innovations with the potential to accelerate in-country vegetable production so as to enhance food security in Qatar. Methods The project consisted of four sub-projects, namely Sub-Project 1 (crop management), Sub-Project 2 (soil management and desertification), Sub-Project 3 (financial risk management) and Sub-Project 4 (combination of the three sub-Projects). The respective tasks of the sub-Projects were as follows Sub-Project 1 developed a decision-making framework for sustainable and profitable cropping in Qatar, and used the FAO AquaCrop model to carry out crop growth simulations of cucumber, squash, and tomato (Qatar), and wheat (Australia). Sub-Project 2 utilised the Soil Constraints and Management Package (SCAMP) to assess intrinsic soil and site constraints for sustainable production. The sub-Project also identified several strategies to improve crop productivity. Sub-project 3 derived an integrated drought derivative model that incorporated geo-specific weather factors, crop-growth cycles, and soil management practices to minimize financial risk. Sub-Project 4 combined the climate, crop, soil and financial components to develop an integrated decision-making framework as well as a targeted partner engagement and communication strategy. Results and Discussion The AquaCrop model is recommended for use in simulating yields of crops to assess the effects of agronomic practices including planting dates, soil characteristics, and water/nutrient use efficiency. Months for optimum vegetable planting are September and December. March planting can produce similar yields but more water is required. Because of higher temperatures and greater vapour pressure deficits during the March to June period, field crop yields from these planting dates are highly variable, resulting in very inefficient use of water. It is therefore recommended that planting during this time period in the field should be avoided. It is critically important to maximize water use efficiency in irrigated field crops in Qatar because of the link between water use efficiency and nitrogen use efficiency. It is essential that N fertilizer inputs closely match crop N requirements, and ammonium-based N fertilizers be used in preference to nitrate-N fertilizers. Regular monitoring of the salinity of the irrigation water is required to ensure that it does not exacerbate the current soil salinity status. As nutrient budgets of field-grown squash and tomato have identified a mismatch between nutrient inputs and crop demand in current management practices, the key soil fertility analyses of extractable phosphorus, organic carbon and exchangeable potassium should be undertaken to inform fertilizer management.The Financial Drought model developed using the reconnaissance drought index (RDI) can be used. A policy brief is available on the operation of derivative systems to protect farmers from production risk.The optimization model developed by incorporating a risk measure is recommended for further application. The developed user-friendly output interface for the model can be used for effective application. Significance The project initiated new dialogue between Government and private sector stakeholders in Qatar on food security strategies. Stakeholders were made aware of the lack of current information on the fertility of soils and quality of irrigation water used for vegetable crops in Qatar. The project concentrated on field production of vegetable crops (cucumber, squash and tomato) identified by a preliminary survey of local consumers. Training opportunities were provided for six students in Qatar, Canada and Australia. Results were presented at eight international conferences where QNRF was acknowledged. An analysis of evapotranspiration data for Qatar was conducted and results published. This is the first study of its type for Qatar (Issaka et al. 2017). Conclusions The research has developed a strategy that is in alignment with QNRS Grand Challenge # 1 - Water Security, by focusing on water use efficiency for crop production. It also informs on the optimal times for planting vegetable crops, and reduces fertilizer inputs and costs by avoiding excessive fertilizer use. A key component of the strategy is the need for fertilizer inputs to be closely matched to crop nutrient requirements using a nutrient budget and soil test approach. Regular monitoring of irrigation water salinity is essential to avoid increased salinization. The Financial Drought model will be beneficial in protecting farmers from production risk. Finally, the optimization model will be beneficial in improving farming decisions. Recommendations for Future Research and Development There are major advances in water and nutrient use efficiency that could be applied in both open field and greenhouse agriculture in Qatar, with the objective of making maximum effective use of their very limited water and arable soil resources. Examine how project outputs (AquaCrop/economic and crop selection model, soil / water/ nutrient/ solar radiation use efficiency, communication packages) can be embedded in Qatar's Research and Educational programs. Engage more actively with the Department of Agriculture of the Ministry of Municipality and Environment, and its particular interests in both the broader food security issues, and the tools being offered by the project. Acknowledgement This research was made possible by a NPRP award [NPRP 6-064-4-001] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements in the Report are solely the responsibility of the authors.
References A.K.S. Huda, A.I. Issaka, S. Kaitibie, M. M. Haq, I. Goktepe, A. Moustafa, K. Abdella, M. Pollanen, P.W. Moody, N. Vock, N. Huda, and K.J. Coughlan (2017). Improving Food Security in Qatar: Assessing Alternative Cropping Systems Feasibility and Productivity in Variable Climates, Soil and Marketing Environments (NPRP 6-064-4-001). Final Report, Qatar National Research Foundation, 79pp A. I. Issaka, J. Paek, K. Abdella, M. Pollanen, A. Huda, S. Kaitibie, I. Goktepe, M. Haq and A. Moustafa (2017). «Analysis and Calibration of Empirical Relationships for Estimating Evapotranspiration in Qatar: Case Study.» Journal of irrigation and drainage engineering 143(2): 05016013.
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Dual Stage Pressure Retarded Osmosis: Potential and Applicability
المؤلفون: ALI Mohammed AltaeeA dual stage PRO process has been proposed for power generation from a salinity gradient across a semi-permeable membrane. Both closed-loop and open-loop dual stage PRO system were evaluated using 2 M NaCl and Dead Sea as draw solutions, whereas the feed solution was either fresh water or seawater. The impact of feed salinity gradient resource and feed pressure on the net power generation and water flux were evaluated. The results showed that power density in stage one reached a maximum amount at, but the maximum net power generation occurred at. This result was mainly attributed to the variation of net driving pressure in stage one and two of the PRO process. The dual stage PRO process was found to perform better at high osmotic pressure gradient across the PRO membrane, for example when Dead Sea brine or highly concentrated NaCl was the draw solution. Total power generation in the dual stage PRO process was up to 40% higher than that in the conventional PRO process. This outcome was achieved through harvesting the rest of the energy remaining in the diluted draw solution. Therefore, a dual stage PRO process has the potential of maximizing power generation from a salinity gradient resource by 20%. DSPRO can be combined with desalination plant using seawater brine as the draw solution either in closed-loop or open-loop. This hybridization has multiple applications such as reducing the impact of discharging concentrated brine to sea, energy storage, and increase the recovery rate of the desalination. Power generation by DSPRO will reduce the energy consumption by the desalination processes. Waste heat from power plants can be used for the regeneration of the draw solution in the closed-loop DSPRO. Process modelling has been performed and shown promising results for DSPRO application for power generation. The impact of module configuration, area and length, with relation to draw solution concentration have shown to have significant impact on osmotically driven processes and should be counted for.
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Accessing dark states optically through excitationferrying states
المؤلفون: Sabre Kais, Zixuan Hu and Gregory S. EngelThe efficiency of solar energy harvesting systems is largely determined by their ability to transfer excitations from the antenna to the energy trapping center before recombination. Dark state protection, achieved by coherent coupling between subunits in the antenna structure, can significantly reduce radiative recombination and enhance the efficiency of energy trapping. Because the dark states cannot be populated by optical transitions from the ground state, they are usually accessed through phononic relaxation from the bright states. In this study, we explore a novel way of connecting the dark states and the bright states via optical transitions. In a ring-like chromophore system inspired by natural photosynthetic antennae, the single-excitation bright state can be optically connected to the lowest energy single-excitation dark state through certain double-excitation states. We call such double-excitation states the ferry states and show that they are the result of accidental degeneracy between two categories of double-excitation states. We then mathematically prove that the ferry states are only available when N, the number of subunits on the ring, satisfies (N = 4l+2, l being an integer). Numerical calculations confirm that the ferry states enhance the energy transfer power of our model, showing a significant energy transfer power spike at N = 6 compared with smaller N values, even without phononic relaxation. The proposed mathematical theory for the ferry states is not restricted to this one particular system or numerical model. In fact, it is potentially applicable to any coherent optical system that adopts a ring-shaped chromophore arrangement. Beyond the ideal case, the ferry state mechanism also demonstrates robustness under weak phononic dissipation, weak site energy disorder, and large coupling strength disorder.
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Modeling Residential Adoption of Solar Energy in the Arabian Gulf Region
المؤلفون: Antonio Sanfilippo, Nassma Mohandes and Marwa Al FakhriModeling the diffusion of residential solar photovoltaic (PV) systems in their social, political and economic context is crucial to help policymakers assess which policies may best support adoption. Current models of renewable energy adoption [1, 2, 3, 4] assume regulatory and incentive frameworks that do not apply to Gulf Cooperation Council (GCC) states, where energy tariffs are strongly subsidized, tax credits are not viable due to the lack of personal income tax, and support for distributed generation through grid access policies such as the Feed-in Tariff and Net Metering is not available. The goal of this study is to address this gap by analyzing the impact of home ownership, the falling cost of PV, the reduction of electricity subsidies, the introduction of a carbon tax, and the diffusion of innovation on the residential adoption of solar PV technologies in Qatar. Our objective is to develop a social simulation platform that helps policymakers and other stakeholders assess the optimal regulatory framework to promote the adoption of building-integrated PV systems in Qatar and other countries which share a similar geographical, political, economic and social context. We present an agent-based model for residential adoption of solar photovoltaic (PV) systems in the state of Qatar as a case study for the Arabian Gulf Region. Agents in the model are defined as households. Each household corresponds to a dwelling in the Al Rayyan municipality of Qatar that is either owned (by citizens) or rented (by expatriates). The objective of the model is to evaluate PV adoption in terms of these two household cohorts under diverse regulatory and incentive scenarios. In the present state of affairs, only Qatari citizens can own property in Al Rayyan and Qatari households are exempt from electricity charges. Therefore, home owners are Qataris who have free electricity, while renters tend to be expatriates who pay for electricity. The more competitive the cost of electricity from residential PV systems is as compared to the electricity tariff, the more likely are household agents to adopt solar PV. Several factors can contribute to make the cost of electricity from residential PV more competitive, including:the falling cost of PV due to increasing technology maturitythe reduction of subsidies for electricity and the gas used for electricity productionthe introduction of a carbon taxthe extension of the electricity tariff to Qatari householdsthe neighborhood effect, which implements peer effects on the diffusion of PV innovation as a percent discount on residential PV cost.We compute solar PV adoption as resource limited exponential growth. Households adopt solar PV with a probability established by the logistic function in (1), where L is a scaling constant, e is the natural logarithm, x is the cost of electricity from residential PV systems and k is a parameter which determines the slope of the adoption curve. We set L = 1 to normalize the output of the logistic function as a probability. For the k parameter, we select a value (k = 0.59) that in the null-hypothesis scenario yields a PV market share that is equivalent to the innovator cohort of adopters in Rogers’ adoption/innovation curve (2.5%) [5]. According to Rogers, “innovators are active information seekers about new ideas”, who are close to the scientific community and other innovators, have financial liquidity, and are willing to take high risks to pursue their vision. The rationale for restricting adopters to innovators in the null hypothesis scenario is that only eco-warriors with financial means and high technology awareness would adopt in the absence of incentives, with high PV costs.(1) f (x) = L / 1+e^( − k∗x) At each simulation tick, each household agent that has not adopted yet, is presented with the opportunity of doing so. Adoption is determined randomly according to the output of the logistic function in (2): a random probability p is generated, and if the probability of adoption as calculated by (1) is greater or equal to p, adoption occurs.We analyze three alternative simulation scenarios:Scenario 1 — Business as usual: no measures are introduced to incentivize PV, the neighborhood effect is active, and the price of PV falls due to increasing technology maturityScenario 2 — 40% of gas and electricity subsidies are curtailed, the neighborhood effect is active, a carbon tax of $8/tCO2e is introduced, the price of PV falls due to increasing technology maturity, and citizens continue to have free electricityScenario 3 — same as scenario 2, with the variant that citizens too pay for electricity. As baseline, we establish a null hypothesis scenario, which is the same as scenario 1, except that the price of PV does not fall due to increasing technology maturity. Details of the simulation results are provided in the attached file to this submission. Our study suggests that Qatar's residential PV adoption is strongly promoted by the falling cost of PV and can be further facilitated through the reduction of electricity subsidies and the extension of the electricity tariff to Qatari households, which are currently exempt. The introduction of a carbon tax can also play a role in accelerating residential PV adoption, if above $8 per metric ton of carbon dioxide equivalent. The ensuing PV adoption rates would help facilitate the national targets of 2% electricity production from solar energy by 2020 and 20% by 2030. References: [1] Zhao, J., E. Mazhari, N. Celik, Y.-J. Son. “Hybrid agent-based simula- tion for policy evaluation of solar power generation systems”. Simulation Modeling Practice and Theory 19, (2011): 2189–2205. [2] Paidipati, J., L. Frantzis, H. Sawyer, A. Kurrasch. “Rooftop photovoltaics market penetration scenarios”. Navigant Consulting, Inc., for NREL: February, (2008). [3] Drury, E., P. Denholm, R. Margolis. “Modeling the US rooftop photo- voltaics market”. In National Solar Conference 2010, 17–22 May 2010, Phoenix, USA, (2010). [4] Graziano, M. and K. Gillingham. “Spatial patterns of solar photovoltaic system adoption: the influence of neighbors and the built environment”. Journal of Economic Geography 15, (2015): 815–839. [5] Rogers, E. M.. Diffusion of innovations. New York, Free Press of Glencoe, RS(N), (2010)
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Novel AGREOR Integration for Enhancing Gas Loading Saving Energy Maximizing Oil Production and CO2 Emissions Mitigation
المؤلفون: Abdukarem Ibrahim Amhamed and Ahmed Mohamed Gamal AbotalebModeling the diffusion of residential solar photovoltaic (PV) systems in their social, political and economic context is crucial to help policymakers assess which policies may best support adoption. Current models of renewable energy adoption [1, 2, 3, 4] assume regulatory and incentive frameworks that do not apply to Gulf Cooperation Council (GCC) states, where energy tariffs are strongly subsidized, tax credits are not viable due to the lack of personal income tax, and support for distributed generation through grid access policies such as the Feed-in Tariff and Net Metering is not available. The goal of this study is to address this gap by analyzing the impact of home ownership, the falling cost of PV, the reduction of electricity subsidies, the introduction of a carbon tax, and the diffusion of innovation on the residential adoption of solar PV technologies in Qatar. Our objective is to develop a social simulation platform that helps policymakers and other stakeholders assess the optimal regulatory framework to promote the adoption of building-integrated PV systems in Qatar and other countries which share a similar geographical, political, economic and social context. We present an agent-based model for residential adoption of solar photovoltaic (PV) systems in the state of Qatar as a case study for the Arabian Gulf Region. Agents in the model are defined as households. Each household corresponds to a dwelling in the Al Rayyan municipality of Qatar that is either owned (by citizens) or rented (by expatriates). The objective of the model is to evaluate PV adoption in terms of these two household cohorts under diverse regulatory and incentive scenarios. In the present state of affairs, only Qatari citizens can own property in Al Rayyan and Qatari households are exempt from electricity charges. Therefore, home owners are Qataris who have free electricity, while renters tend to be expatriates who pay for electricity. The more competitive the cost of electricity from residential PV systems is as compared to the electricity tariff, the more likely are household agents to adopt solar PV. Several factors can contribute to make the cost of electricity from residential PV more competitive, including:the falling cost of PV due to increasing technology maturitythe reduction of subsidies for electricity and the gas used for electricity productionthe introduction of a carbon taxthe extension of the electricity tariff to Qatari householdsthe neighborhood effect, which implements peer effects on the diffusion of PV innovation as a percent discount on residential PV cost.We compute solar PV adoption as resource limited exponential growth. Households adopt solar PV with a probability established by the logistic function in (1), where L is a scaling constant, e is the natural logarithm, x is the cost of electricity from residential PV systems and k is a parameter which determines the slope of the adoption curve. We set L = 1 to normalize the output of the logistic function as a probability. For the k parameter, we select a value (k = 0.59) that in the null-hypothesis scenario yields a PV market share that is equivalent to the innovator cohort of adopters in Rogers’ adoption/innovation curve (2.5%) [5]. According to Rogers, “innovators are active information seekers about new ideas”, who are close to the scientific community and other innovators, have financial liquidity, and are willing to take high risks to pursue their vision. The rationale for restricting adopters to innovators in the null hypothesis scenario is that only eco-warriors with financial means and high technology awareness would adopt in the absence of incentives, with high PV costs.(1) f (x) = L / 1+e^( − k∗x) At each simulation tick, each household agent that has not adopted yet, is presented with the opportunity of doing so. Adoption is determined randomly according to the output of the logistic function in (2): a random probability p is generated, and if the probability of adoption as calculated by (1) is greater or equal to p, adoption occurs.We analyze three alternative simulation scenarios:Scenario 1 — Business as usual: no measures are introduced to incentivize PV, the neighborhood effect is active, and the price of PV falls due to increasing technology maturityScenario 2 — 40% of gas and electricity subsidies are curtailed, the neighborhood effect is active, a carbon tax of $8/tCO2e is introduced, the price of PV falls due to increasing technology maturity, and citizens continue to have free electricityScenario 3 — same as scenario 2, with the variant that citizens too pay for electricity. As baseline, we establish a null hypothesis scenario, which is the same as scenario 1, except that the price of PV does not fall due to increasing technology maturity. Details of the simulation results are provided in the attached file to this submission. Our study suggests that Qatar's residential PV adoption is strongly promoted by the falling cost of PV and can be further facilitated through the reduction of electricity subsidies and the extension of the electricity tariff to Qatari households, which are currently exempt. The introduction of a carbon tax can also play a role in accelerating residential PV adoption, if above $8 per metric ton of carbon dioxide equivalent. The ensuing PV adoption rates would help facilitate the national targets of 2% electricity production from solar energy by 2020 and 20% by 2030.
References
[1] Zhao, J., E. Mazhari, N. Celik, Y.-J. Son. “Hybrid agent-based simula- tion for policy evaluation of solar power generation systems”. Simulation Modeling Practice and Theory 19, (2011): 2189–2205.
[2] Paidipati, J., L. Frantzis, H. Sawyer, A. Kurrasch. “Rooftop photovoltaics market penetration scenarios”. Navigant Consulting, Inc., for NREL: February, (2008).
[3] Drury, E., P. Denholm, R. Margolis. “Modeling the US rooftop photo- voltaics market”. In National Solar Conference 2010, 17–22 May 2010, Phoenix, USA, (2010).
[4] Graziano, M. and K. Gillingham. “Spatial patterns of solar photovoltaic system adoption: the influence of neighbors and the built environment”. Journal of Economic Geography 15, (2015): 815–839.
[5] Rogers, E. M.. Diffusion of innovations. New York, Free Press of Glencoe, RS(N), (2010).
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Estimation of Groundwater Recharge in Arid Regions Using GIS: A Case Study from Qatar
المؤلفون: Husam Musa Baalousha, Nicolas Barth, Fanilo H Ramasomanana and Said AhziAquifers are important sources of water in arid areas, where no surface water exist. Estimation of groundwater recharge from rainfall is a big challenge for hydrogeologists, due to the high uncertainty involved. It is even harder to estimate recharge in arid areas, due to high variability of meteorological parameters in space and time. Unlike recharge in humid and sub-humid areas, recharge in arid areas occurs indirectly after rainfall-runoff accumulates in low lands such as land depressions and recharges the aquifer. A new method for recharge estimation in arid areas has proposed in this study based on soil-water budget model and utilizing geoprocessing tools in GIS. The method uses Digital Elevation Model (DEM), land-cover and rainfall distribution to estimate runoff accumulation in depressions. The soil-water budget model is then applied to estimate the groundwater recharge in areas of runoff accumulation. The geoprocessing tools in GIS such as flow direction and flow accumulation in Spatial Analyst were utilised. The application of the proposed methodology in GIS makes it easy to cover the entire area of study, and to run maps algebra. The method was applied to the entire area of Qatar. The proposed methodology was applied on Qatar as a case study. The spatial resolution of raster maps was 350 by 350 m and the temporal resolution is one day. Data requirements for this study include daily records of rainfall, Digital Elevation Model (DEM) for topography, soil-moisture holding capacity, land-use map and potential evapotranspiration. Recharge is calculated for each cell and summed to provide the total amount. The proposed methodology was applied on the entire country of Qatar using the hydrological year 2013-2014 and daily time steps. This year was selected because enough daily rainfall data was available for this period, with a good coverage of the entire country. Results obtained in this study for the hydrological year 2013/2014 show the total groundwater recharge is approximately 14 million m3, and concentrated more in the northern part of Qatar. The method can be applied on any arid region.
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Vertical zonation and functional diversity of fish assemblages revealed by ROV videos at oil platforms in The Gulf
About one third of the oil and gas extracted worldwide comes from offshore sources. There is currently thousands of large-scale oil and gas platforms spread across the seas and coastal oceans, from the North Sea to the seas of South Asia. Although their primary purpose is not related to enrichment of biodiversity, gas and oil platforms can act as large and complex artificial marine habitats for a wide range of marine organisms, including sessile invertebrates and fishes. These structures have shown to enhance ecosystem function, especially secondary fish production, relative to adjacent natural reefs, besides being among the most productive marine fish habitats globally. Indeed oil platforms constitute important fish aggregating devices, especially in areas subjected to a range of environmental perturbations. Hard substratum availability combined with exclusion zones around these structures allows for the development of diverse fish assemblages. We carried out the first assessment of vertical distribution, diel migration, taxonomic and functional diversity of fishes at offshore platforms in the Arabian Gulf. Video footages were recorded at the Al Shaheen Oil Field, between 2007 and 2014 using a Remotely Operated Vehicle (ROV). Indeed diving and snorkeling are strictly forbidden in the exclusion zone around offshore platforms, precluding conventional monitoring techniques such as underwater visual census, collection of sessile organisms, etc. Routine inspection and maintenance surveys, however, are conducted to monitor the state of underwater structures using ROVs. A total of 4,510 video files, containing 120 hours of underwater video recordings, were provided by Maersk Oil Qatar A/S. These videos were recorded over six years (2007, 2009, 2010, 2011, 2012 and 2014), during day and night, at the 9 platform locations (A-I) within the Al Shaheen Oil Field using a ROV of the model SAAB Seaeye Surveyor Plus 229. To assess the local fish community, a total of 242 videos amounting to twenty-one hours of observation were selected randomly, however, if no fish appear in a selected video a new video was randomly selected from the list. This work represents the first assessment of reef fish communities inhabiting oil and gas platforms in the Arabian Gulf. A total of 12,822 fish, belonging to 83 taxonomic groups were recorded around the platforms. Among them, two species are first recorded for Qatari waters: Cyclichthys orbicularis and Lutjanus indicus. In addition two chondrichthyes, one endangered (Stegostoma fasciatum) and a vulnerable species (Taeniurops meyeni), were also observed across the platforms. Several trends were found in the vertical distribution of the fish community, most species were observed between 20 and 50 m depth and higher fish abundance recorded in the upper layers, down to 40 m depth and decreasing with depth. Vertical variation, however, in fish diversity was generally not accompanied by differences in vertical movements. The vertical variation, however, in fish diversity was not accompanied by differences in vertical movements of the fish. These results suggest that the vertical zonation pattern does not change, or only changes slightly, on a daily basis. The mean centers of mass of the most abundant fish species did not overlap, likely due to potential competition or niche differences. The dominant trophic groups were carnivores and invertivores, being well represented at each depth range (each spanning 10 m) from surface to seabed. Diel vertical movement was observed only for Acanthopagrus bifasciatus, which was concentrated at shallow depths during the daytime but migrated to deeper layers at night. The functional indices showed no significant differences between water depths or diel cycles (day / night). Besides the temperature variation, the reduced light penetration due to platform structures makes difficult the algal growth necessary for browsing herbivorous fish. Thereby, the effect of sunlight penetration may be reflected in the vertical distribution of herbivorous fish, which are rare in deeper layers. Planktivores are densely grouped within and just below the thermocline, which is located around 18 m during summertime. The study demonstrates that oil platforms represent a hotspot of fish diversity and interesting sites for studying fish communities, abundance and behaviour.
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Modeling a regional energy system in a smart city & low emissions perspective: Scenarios for energy transition in Qatar
المؤلفون: Maxime Schenckery, Frederic Babonneau and Alain HaurieThis paper deals with the modeling of a regional energy system, based on the example of Qatar, over a time horizon of 35 years or more, taking into account the possible transition toward a smart city paradigm of the Doha region and the probable climate regime that could result from COP21 and the coming rounds of international climate negotiations. The impact on the energy system of a transition toward smart city could take many forms: (i) by providing two-way communications between consumers and electricity producers, the smart city will foster demand response and distributed energy resource management; (ii) new forms of demand for energy services will materialize in the transport, housing and service sectors that could contribute to lower the environmental footprint of the energy sector; (iii) the smart-grid connection of distributed energy resources and the possibility to provide secondary reserve through grid storage and distributed system service, like e.g. reactive power compensation, will facilitate the penetration of variable renewable energy in the energy system. Qatar is the world-class leader in the export of liquefied natural gas (LNG). It has also access to crude oil reserves. As the economy of Qatar developed, as in other Gulf countries, the energy system expanded assuming an unlimited supply of very low cost fossil fuels. However, the very economic success of the gas and oil exporting countries in the Gulf region is starting to impose a limit on this form of development of the energy system. The share of gas that is used in the region and thus not available for export is increasing sharply. The local pollution due to the burning of fossil fuels in transport, residential, service and industry sectors, has to be curbed. Finally, at COP21 in Paris, more than 160 nations, including Qatar, have agreed to reduce GHG emissions in order to reach a goal of limiting the temperature change at the end of 21st century at 1.5oC. At COP21 Qatar has made a commitment to reduce its per-capita emission level, which is one of the highest in the world. To deal with these challenges, the Gulf countries count on a substitution from fossil fuel source to variable renewable ones (as well as some extent to nuclear power generation in UAE, KSA and Iran). This is exemplified by the location of IRENA headquarters[1] in Abu Dhabi, inaugurated in May 2015. Indeed, harnessing wind and solar energy sources seems promising in the region, with some caveats due to intermittency of wind blowing and sand storms reducing the efficiency of solar panels. There is another game changing phenomenon represented by the drive toward smart cities. The cities in Gulf countries are very modern and they are ready to embrace the smart city paradigm and concept. Abu Dhabi and more generally the UAE, Qatar and Saudi Arabia have announced pilot projects for fully integrated “smart-city” districts. The development of the “internet of things”, which characterizes smart cities, will translate for the energy system into a development of smart-grid connected, distributed energy resources and this should help tremendously the penetration of variable renewable energy sources. The model ETEM-SC[2] used in this research has been designed to help in assessing the policies that could be used to define, up to the horizon 2050, an environmentally friendly energy system in Qatar. ETEM-SC is a technology rich cost-efficiency model, which permits an exploration of the future of the regional energy system under different environmental and economic constraints. The model is derived from the shell-model ETEM (Energy-Technology-Environment-Model), developed at ORDECSYS[3]. This shell has a structure of a linear program, as in MARKAL, MESSAGE or TIMES, with an extensive description of technology and energy choices in the region into consideration. The new additions that have been made for our purpose (SC for Smart Cities) concern: (i) the modeling of constraints and options at the power distribution level, due to the introduction of smart grids, distributed energy resource and demand response; (ii) the consideration of the impact on demand for energy services of the development of a smart city environment, and (iii) the explicit consideration of uncertainty in the scenario building, through the use of stochastic programming and robust optimization techniques. Some technical aspects of these modeling advances have been described in two parent papers (Babonneau et al. (2016a) and (2016b)). The present research will focus on the description of the scenarios for Qatar that result from the use of this model. These scenarios are based on publicly available data and should not be considered as a representation of the energy policy of the state of Qatar. The purpose of this exercise is to demonstrate the potential offered by ETEM-SC to assess the possible penetration of variable renewable energy in regional energy systems with smart-city development, in order to reduce drastically the GHG emissions. [1] The International Renewable Energy Agency. www.irena.org [2] Energy Technology Environment Model-Smart-Cities. [3] See www.ordecsys.com for details.
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Adaptive model of thermal comfort for office buildings in GCC
المؤلفون: Madhavi Indraganti and Djamel BoussaaThe Gulf Cooperation Council (GCC) nations top the world in CO2 emissions/ capita. However, plummeting oil prices and increasing energy demands necessitate rethinking on thermal comfort delivery. This region has warm desert climate throughout. In GCC states, the adaptive comfort standard or the precursor field studies to develop one are non-existent. We carried out thermal comfort field studies in Qatar for thirteen months. In ten typical air-conditioned office buildings, 1175 voluntary subjects completed 3742 questionnaires, while their thermal environments were simultaneously measured. This paper proposes the adaptive model of thermal comfort for GCC. Adopting variable indoor comfort standards that track the outdoor conditions may be effectual in meeting the sustainability goals of the GCC and Qatar Vision 2030.
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Power to the People: A New Trend in Regulation
المؤلفون: Robert HahnSee e.g., https://www.brookings.edu/wp-content/uploads/2017/05/es_20170531_hahnregulation.pdfPower to the People: A New Trend in Regulation Robert Hahn, Robert Metcalfe and Florian Rundhammer* * Mr. Hahn is Professor and Director of Economics at the Smith School, University of Oxford. Mr. Metcalfe is a Postdoctoral Research Scholar at the Becker Friedman Institute, University of Chicago. Mr. Rundhammer is a doctoral student in economics at Georgia State University. We would like to thank Jonathan Ashley, Harry Bush, Paul Joskow, Clement Lapeyre, Stephen Littlechild, Matthew O'Keefe, Cathryn Ross, Anna Rossington, Jon Stern and Dale Whittington for very helpful feedback. This research was funded by Ofwat and by the Smith School at Oxford. The authors, and not the institutions with which they are affiliated, are responsible for the findings of this research and any remaining errors. © 2017 by the authors. All rights reserved. Abstract This paper traces a new development in regulation that encourages utilities to engage more directly with their customers. We make four contributions: First, we perform the most comprehensive analysis to date of how regulators are using customer engagement, and offer a simple model for understanding different customer engagement initiatives. Second, we review assessments of customer engagement. We find that there are no quantitative, empirically robust assessments of the effectiveness of customer engagement as a regulatory tool. Third, we develop two detailed case studies of an energy regulator and a water regulator that are in the forefront of customer engagement efforts. We find that there is no direct link between the engagement strategy used and the economic incentives received by a firm. Finally, we propose a framework for improving the customer engagement process. The new framework relies on microeconomics, modern tools of program evaluation, and supplying the regulated firm with direct incentives to do customer engagement.
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