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Qatar Foundation Annual Research Conference Proceedings Volume 2018 Issue 1
- Conference date: 19-20 Mar 2018
- Location: Qatar National Convention Center (QNCC), Doha, Qatar
- Volume number: 2018
- Published: 12 March 2018
41 - 60 of 142 results
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The Influences of Produced Water Irrigation on Soil microbial succession and Turfgrass Grass Establishment in Qatar
The Influences of Produced Water Irrigation on Soil microbial succession and Turfgrass Grass Establishment in Qatar Sameera S. Shaikh, Mohammed H. Abu-Dieyeh*, Fatima A. Al Naemi, Talaat Ahmed, and Mohammad A. Alghouti Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University. *Corresponding author: [email protected] Abstract: Water scarcity around the world has necessitated the use of alternative water resources such as wastewaters, for irrigation purposes. Landscaped areas and turf grass systems provide varied environmental benefits including phytoremediation, erosion control and mitigation of heat island effects. They also provide safe, shady and cool places for athletic activities, exercise, and provide area for outdoor gatherings. Use of wastewater for turfgrasses has been conceptualized in the last decades and applied in various parts of the world. In this study, we attempted to use produced water (PW) to irrigate two turfgrass species, Cynodon dactylon and Paspalum sp., which are grown in local parks, green spaces and roadsides in Doha, Qatar. Effect of PW irrigation on established grasses, microbial succession, heavy metal accumulation and germination tests for weeds and turf grass seeds were investigated in greenhouse and field experiments. The two species of grass tested - C. dactylon and Paspalum sp. depicted different tolerance capacities towards PW. C. dactylon showed lower tolerance while Paspalum sp. depicted better tolerance capacity towards PW. C. dactylon grown from seeds under greenhouse conditions were not able to tolerate more than 30% concentration of PW. In comparison to tap water irrigated turfgrass, Paspalum sp. was found to accumulate higher concentrations of V and Pb in shoots and Cr, Ni and As in roots. For soil microbial succession studies, results from greenhouse experiment, using Cynodon dactylon turfgrass and after 14-weeks of produced water irrigation regimes, showed a significant reduction in bacterial colony forming units (CFU) at all produced water treatments compared with tap water irrigation. However, a significant increase through time in CFU occurred in all treatments. It was observed that PW irrigation caused changes in fungal species present in PW irrigated soil. The study of fungal succession in soil showed presence of certain species in 10%PW–30%PW treated soil that were absent in soil treated with tap water. Based on germination tests it was recommended that irrigation with PW be performed after turf grass establishment. Studies on weed germination suggested that PW could discourage growth of weeds - Amaranthus viridis and Launaea mucronata while promote growth of Chloris virgata. Based on the study conducted, it is suggested that PW could be used as alternative water resource to grow some species, but only after further research is conducted on the long term to assess any environmental toxicity.
Acknowledgement: This research was made possible by TOTAL, Qatar grant. The statements made herein are solely the responsibility of the authors.
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Study of polyaniline-silver nanocomposite as humidity sensor
By Jolly BhadraStudy of polyaniline-silver nanocomposite as humidity sensor J. Bhadra, A. Popelka, N. J. Al-Thani, A. Abdulkareem Center for Advanced Materials, Qatar University, Qatar Abstract In this piece of work focus on fabrication of resistive type humidity sensor using polyaniline-silver nanocomposite (PPVA-Ag). Four different nanocomposites using four concentrations of silver (0.5,1.0, 1.5 and 2.0 M) and polyaniline (PANI) dispersed in polyvinyl alcohol matrix (PVA). PANI, and PVA concentrations are kept constant. Thin PPVA-Ag film on interdigited gold electrode fingers gives excellent sensitivity towards humidity at room temperature. 1. Introduction Since last few decades the information of nanoscience and nanotechnology has been explored extensively to obtain functionalized nanomaterials. One such category of nanomaterial is the polymer- metal nanocomposite, with enhanced mechanical, elastic, optical, electrical and dielectric properties [1]. Polymer nanocomposites are materials with nanosized one dimensional inorganic filler particles (around 10–100 ˚A), dispersed in an organic polymer matrix. An important parameter which has significant importance in many industries such as food, agricultural, clinical equipment and electronics is humidity, it is considered to be one of the most frequently measured physical parameters [2-3]. With the advancement in moisture sensitive technologies, research to achieve high efficient, low cost, reliable and miniature size of material sensitive to humidity change has gained acceleration. As among metal nanoparticles, Ag has high electrical and thermal conductivities, so the composite of Ag dispersed in PANI-PVA matrix gives rise to a functional materials, with improved antimicrobial activity and sensitivity towards humidity. This paper we focus on surface analysis of the thin film obtained using scanning electron microscopy and study on the humidity sensitivity. 2. Methods 2.1 Synthesis of Ag nanoparticles Four different concentrations of silver nitrate (AgNO3) is dispersed in aqueous PVA solution under constant stirring and heating at 60°C followed by photo reduction using UV-lamp having wavelength 390 nm for 24 hours. After exposing the above solutions with UV light for 24 hours, finally, yellowish-red colloid of Ag nanoparticles with average diameters of ∼30 nm and ∼70 nm uniformly dispersed in PVA are obtained. 2.2. Synthesis of PANI-Ag nanocomposite and pure PANI: The PANI-Ag nanocomposite blend is synthesized by in-situ chemical polymerization (Figure-1) of aniline monomer in the colloid solution obtained from section 2.1. During this process, aniline-DBSA is added to the Ag-PVA colloidal solution, followed by addition of the aqueous APS solution dropwise. The resulting blend mixture is left to react for 24 h under constant stirring at 5–10 °C. The colloidal solution obtained are used to prepare thin film on glass slide and interdigitated gold electrode washed with DI water and acetone and dried. Keeping the other concentrations and methods constant four different PPVA-Ag nanocomposites are prepared with 0.5, 1.0,1.5 and 2.0 M of AgNO3.
Figure 1: Steps followed to prepare PANI-Ag nanocomposites 2.3. Study of Effect of humidity on the PPVA-Ag nanocomposites A homemade setup is used to study of effect of humidity on the PPVA-Ag nanocomposites coated on the interdigited gold electrode fingers using dropcast method. The humidity chamber consists of transparent polymer with three holes for nitrogen gas inlet, humidity inlet and electrical wires for conductivity measurement. The schematic diagram of the setup is shown in the Figure 2. Humidity meter and the polymer coated electrodes are placed inside the chamber. The control of humidity inside the chamber has been done using humidifier and N2 gas during the experiment. And keithley sourcemeter 2400 has been used to measure the resistivity.
Figure 2: Schematic diagram of humidity measurement setup 3.1 Scanning Electron Microscopy studies The results of surface morphology analysis using SEM are shown in Figure 3. From the images it is seen that Ag nanoparticles are well dispersed in PANI-PVA matrix. Such results are observed because chemical method of preparation has been adopted. With the increase of Ag concentration there are not much changes in the particle size, however the degree of agglomeration increase, that causes the increase in surface roughness.
Figure 3: SEM images of (a) PPVA-Ag-0.5, (b) PPVA-Ag-1.0, (c) PPVA-Ag-1.5 and (d) PPVA-Ag-2.0. 3.2 Effect of Humidity We have used all the four types of composites for this measurement. For this measure at first the humidity chamber is blown with N2 gas for few minutes to reduce the humidity to RH 20 % at room temperature. Once the reading in the humidity meter is stable, resistance of the thin film has been measured. Each time for resistance measurement voltage reading for 10 mA current has been repeated for 10 times with time sweep of 500 ms. In order to reduce the error we repeated the whole measurement for 15 times at each RH measured, shown in Figure 4 for PPVA-Ag 1.0M sample. During the experimental process each step is maintained at constant parameters till the electrical signals reading reached a steady value. All the four plots describing resistance change as a function of humidity for each composite measured has been shown in inset of Figure 4. It is has been observed that, there is not much difference between the resistance curves as a function humidity for all the four composites. As the humidity increases water vapour contributes to the reducing the conductivity in two ways, firstly water molecules donate electrons to the valence band of PANI molecules, therefore decreasing the number of holes and increasing the bandgap and secondly as PVA is hydrophilic, so it absorbs water molecules and get expanded, this leads to increase the interparticular distances between the conducting fillers of the composites, and reducing the conductivity. Because of these two reasons higher the RH level lower the electrical conductivity.
Figure 4: The effect of Relative humidity on the resistance of PPVA-Ag-1.0M, Inset The effect of Relative humidity on the resistance of four PPVA-Ag samples.4. Reference: [1] M. Joulazadeh, A. H. Navarchian, Advances in Polymer Technology, 33, 2014, 21461. [2] A. T. Ramaprasad, V. Rao, Sens. Actuat. B, 148, 2010, 117–125. [3] J. Wang, X. Wang, X. Wang, Sens. Actuat. B, 108, 2005, 445–449
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Environmental Evaluation Risk Assessment and Management options of Abu Nakhla Treated Sewage Effluent TSE Unlined Pond Doha Qatar
The rapid economic and population growth of Qatar during the last few decades led to generation of substantial volume of municipal treated sewage effluent (TSE). Most of this water was disposed into Abu Nakhla depression at the outskirt of Doha city since 1985. Abu Nakhla depression is situated at the south-west of Doha. The mixture of these effluents with surface and ground waters during rainy seasons created a conspicuous water body of around 2 by 3 km. For many years, this pond was the source of many adverse environmental effects such as bad odor, vermin and elevated groundwater levels in the neighboring residential areas. The claims that some of the disposed water was untreated aggravated the situation and the local community considered the pond as impure body of water. A multiproxy study was carried out during 2014 and 2015, including remote sensing, geological, geophysical (resistivity-tomography) and geotechnical investigation of the pond origin and evolution. Hydrogeological and hydrochemical analyses of water samples collected from 24 observation wells drilled around the pond. These studies revealed that, the upper part of the subsurface geology of the pond site is composed of Tertiary carbonate rocks of the Simsima/Umm Bab member and Midra shale member of the Dammam Formation, which is underlain by the Rus Formation, both of Eocene age. In Qatar, the Simsima/Umm Bab member represents the shallow groundwater aquifer, while the Rus is the upper principal aquifer. The upper part of the Simsima/Umm Bab member is characterized by the presence weathered weak zones, cracks and fissures, which enable infiltration of the pond water to recharge the aquifers. The pond has a rich and diverse population birds, fish and frogs, hosting about 260 bird species, such as 150+ Greater Flamingo (Phoenicopterus roseus). It also hosts about 10% of the total plants species in Qatar, such as: Phragmites australis, Typha dominguensis. Water analyses have shown that, the water in the pond was of good quality, in terms of physiochemistry and biological and microbial contaminants. This is due to Qatar's use of advanced wastewater treatment technologies, with ultrafiltration and ultraviolet (UV). Heavy metals concentration in the water of the pond, was very low. Analyses conducted in May 2014 indicate that most of the heavy metals levels were below the international FAO limits for irrigation water (FAO,1985), such as: Ni concentration was 2.4 mgL-1, FAO limit is 200 mgL-1. As concentration was 1.0 mgL-1, FAO limit is 100 mgL-1. Pb concentration was 0.8 mgL-1, FAO limit is 5000 mgL-1. Cd concentration was 0.0 mgL-1, FAO limit is 10 mgL-1. The results of our 3D groundwater numerical modelling, indicated the loses of about 5% of the pond water per day, due to high infiltration and evaporation rate. This causes the rising of water table in the neighboring areas. The pond represents a breeding ground for mosquitos. The presence of snails may also act as incubators for some parasites. Management options of the pond site, have been recommended. These include, changing the area into natural reserve, artificial oasis, and can serve as a meteorological station.
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Cost of energy inefficiency in Qatar
By Athar KamalEnergy policy and security of a country heavily depends on its resources, geography, demographics and economic structure. While most active strategies include the discovery, extraction and utilization (through new infrastructure) of energy resources, a more subtle approach to reduce energy demand and increase energy security is to use the resources more efficiently and conserve them to increase the life span in which they can be used. This understated approach is the implementation of energy efficiency policy. Energy efficiency taken holistically includes the improvements in technology as well as changes in human behavior to do a task with less amount of energy. While different studies have shown the impact of efficiency policies and programs on individual economic sectors (i.e. industrial, commercial, residential, agriculture and transport), a complete overview of the impact of efficiency on economy has received little attention. This approach overlooks the interdependence of each economic sector and their influence on each other. Similarly, the rebound effect, a consequence and a major element of efficiency is avoided in these studies as well. Rebound effect is the increase in energy consumption because of lower prices of energy commodities due to increase in efficiency. The rebound effect not only has a direct impact on the individual sector, like driving more miles because of a more efficient vehicle, it has also indirect consequences, such as going to a vacation because of the money being saved through efficiency. Thus, the study of efficiency, its dynamic influence and calculating a realistic magnitude are required to ideally approach the costs and benefits of implementing an efficiency program or policy. This research looks into the economy wide impacts of energy efficiency and the dynamic interaction and impacts of each sector on the other. First, a hierarchal list of variables, which influence the energy supply and demand of any economy, is created. Second, a list of indicators which measure the health of an economy is formed. Using data for the top 10, oil and gas producing countries (these countries give a good mix of economies which heavily rely on oil and gas rents such as Qatar, UAE, Saudi Arabia as well as economies, which produce some of the highest energy resources, while relying very little on its influence on their economies, such as US, Norway), the magnitude and impact of each variable to the economy is calculated. These variables are then used to create a system dynamics model which includes the production, conversion and transportation of energy from different sources to consumption in different sectors. Estimated energy efficiency measures and impacts are then incorporated into the systems model to see the effect of efficiency as well as the rebound effect on the economy. A major goal of this study is to find the future impacts of energy efficiency policies and the consequences of these policies, if they are not implemented because of financial constraints or present gains (such as more revenues from greater resource production). The cost benefits as well as the effective implementation of efficiency measures are calculated and compared using the economic indicators obtained in the second step. Finally, these indicators can be used to determine as to why some countries are more efficient with their energy resources as compared to others.
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Plasmonically Enhanced Schottky Solar Cell
Authors: MOHAMED Farhat, Sabre Kais and Fahhad AlharbiPlasmonics is an emerging broad area of research, which studies the exceptional optical properties of metallic 2D and 3D nano-structures, i.e. confinement of electromagnetic waves (surface plasmon polaritons) [1]. During the past years, there has been a huge interest in employing plasmonic structures for sunlight harvesting [2], i.e. for example in thermal photovoltaics, thin-film solar cells, or solar thermoelectrics, etc. All these applications exploit the exceptional capabilities of plasmonic structures to concentrate electromagnetic energy and generate “hot” electrons. In this proposal [3], we aim to use plasmonic light confinement to build Schottky solar cells. The photovoltaic effect in these cells is induced by the metal (insulator) semiconductor interface (see figure below). And the presence of the plasmonic metal will increase the generated current in the active silicon layer and thus increase the overall efficiency of the cell.We wish to stress here that previous works using the plasmonic effect in solar cells, considered mainly the p-n junction [4], except the one using graphene with another semiconductor but not considering plasmonic effects [5]. In addition, we should mention, that the mechanism of the cell proposed here is intrinsically different from hot-electrons based plasmonic solar cells [6]. The novelty of this work is to use metallic strips for two functions simultaneously, i.e. as contact for electrons and as junction (Schottky barrier between metal and semiconductor). This permits a good efficiency with very simple structure (no need for having expensive semiconductor nor both doping, i.e. p and n for Silicon).We will discuss limitations and potentials of this kind of solar cells, in particular ease of fabrication.
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Enhancing District Cooling Plants Efficiency in Qatar Using Desiccant Air Dehumidification
More LessEnergy consumption for air conditioning purposes accounts for 60-80% of electricity used in Qatar. As District Cooling Plants (DCPs) has 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. Hence the efficiency of DCPs is significantly influenced by the cooling tower effectiveness in heat disposal, which is dominated by latent heat or evaporation of water in a counter atmospheric current air stream. Operation district cooling plants (DCPs) under extremely high humidity in summer represents one of the major thermodynamic limitations in terms of maintain the outlet water temperature of cooling towers (i.e. chiller's condenser cooling water) as low as possible to guarantee higher efficiency of DCPs. The cooling tower efficiency degrades considerably at higher relative humidity of air, which approaches saturation limits in summer, where the cooling demand is high. The ambient wet-bulb (WB) temperature is a limiting factor for the capacity of cooling towers (CT), which determines the inlet cooling water temperature to the chiller's condenser (outlet water temperature from the CT). Due to prevailing weather conditions in Qatar and GCC, this temperature is designed based on 31 °C WB temperature in summer, which result in a 34 °C inlet condenser cooling water temperature. This represents a thermodynamic limitation to reduce the energy consumption of chillers, which lies under the focus of this study. Desiccant cooling is an environmentally attractive alternative to conventional mechanical air-conditioning, especially for air dehumidification purposes. It does not require ozone depleting refrigerants and it can be run off low temperature solar heat or waste heat. The electrical coefficient of performance of desiccant cooling can be above 20, making it over 6 times more efficient than conventional air cooled vapor compression system. This project seeks to develop new processes to reduce air humidity and WB temperature by around 6 °C prior to entering the CT to break the above mentioned thermodynamic limitation. Air dehumidification takes place using liquid to air membrane (3-fluid LAMEEs) for further dehumidification of air. A hybrid solar PV-Thermal system is used for regeneration of both desiccant systems. Lumped and numerical analysis has been conducted using COMSOL Multiphysics software to predict the outlet air temperature and humidity for 3-fluid LAMEEs when used for air cooling and dehumidifying. Results of the numerical and lumped analysis showed that the 3-fluid LAMEE alone can effectively decrease the humidity content of ambient air by up to 40%, while the outlet air temperature can be reduced by 6 °C. Accordingly, the inlet cooling water temperature to the chiller's condenser (outlet water temperature from the CT) can be reduced to 27-28 C, which provides a potential saving of around 25% in energy consumption of the Chiller in district cooling plants.
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Passive Thermal Management of Photovoltaic Modules in Qatar by Utilizing PCMMatrix Absorbers
More LessPerformance and reliability is essential factor for deploying the solar Photovoltaic (PV) technology in desert environment due to the high ambient temperature and high humidity. During daytime, the PV conversion efficiency decreases considerably due to high temperature and weak natural cooling effects on PV modules. During night, sky radiation cooling promotes atmospheric water vapor condensation on PV modules surface, where dust accumulates and consequently, leading to cementation of dust that necessitates manual or mechanical cleaning in absence of rainfall. Therefore, thermal management in hot climates is crucial for reliable application of PV systems to prevent the efficiency drop due to high temperature rise during day time and to keep the module temperature above the dew point during night time to avoid mud formation on PV modules surface. Thermal management of PV modules in hot climates can be achieved by either active or passive cooling. Active cooling includes air-cooling, through natural or forced air flow, and water cooling. In hot summer, air-cooling would be less effective as the ambient temperature reaches up to 50°C, hence water cooling or passive thermal management of PV cells become a necessity. The present research focuses on utilization of Phase Change Materials (PCM) for passive thermal management of solar PV systems. The main focus is to explore the effect of utilization of PCM-based cooling elements on the thermal behavior of solar PV modules. By attaching PCM-Absorbers to the back side of PV modules, the modules temperature can be regulated by the virtue of PCM to extract and accumulate heat at high density, as PCM have a high specific heat density capacity due to latent heat of fusion during melting and solidification. Moreover, the PCM absorber can help reducing atmospheric water vapor condensation during night on the surface of PV module by releasing the absorbed thermal energy during the daytime to keep the PV module on a temperature above the dew point. Some of the important advantages of the proposed solution include, simplicity, no moving parts such as coolant circulation pumps or air blowers are needed, low tech and can be manufactured locally from aluminum waste and oil waste, zero self-energy consumption, involves no hazards such as chemical toxicity, flammability or explosivity, and has a longer life time than the life span of top quality PV modules available in the international market. The PV module and PCM material have been modelled using Finite Element method in COMSOL Multiphysics software. A macro scale transient model has been developed to capture the underlying physics related to energy and heat transfer balances. The setup contains six main sections; transparent top glass cover, PV cells, aluminum back sheet, heat conduction film, PCM matrix absorber and aluminum heat fins. The effect of PCM thickness, i.e. heat storage capacity, PCM melting temperature, fiber porosity and thermal conductivity of matrix absorber with/without heat fins has been extensively studied. The numerical simulation results showed that there are optimum thermos-physical properties for PCM Absorbers for cooling of PV modules under Qatar weather conditions. It has been concluded that the ideal PCM-Absorber should have a melting temperatures of 53–54 °C, 30 mm PCM thickness, and 85 % fiber porosity of metallic aluminum fiber structure and with aluminum heat fins. With the optimum design of PCM-Absorber, the PV module's peak temperature can be reduced by 16 °C during daytime and at night it can be maintained at 3-5 °C higher than conventional modules, which reduces water vapor condensation tendency. Furthermore, depending on the temperature coefficient of a PV module, the power production can be increased by up to 6–8% for mono and poly crystalline cells respectively, and up to 5% for thin film technology. The module's instantaneous efficiency can be increased by 1–2%. In addition, study of the effect of passive thermal management on PV modules lifetime is ongoing and preliminary results revealed that a significant increase in lifetime would be expected. A techno-economic analysis for commercial scale application of the proposed thermal management solution has also revealed promising results, especially under local manufacturing in Qatar utilizing oil waste, which makes it economically viable.
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Passive House Design Alternatives for Labor Camps in Modern AgroIndustrial Communities in Qatar
More LessThe consumption of electricity in residential buildings exceeds 20% in Qatar and can go up to 50% in other hot countries like Kuwait. The air-conditioning systems in hot countries like Qatar consumes around 60–80% of the total energy demand in buildings. This triggers researchers and industry experts in the built environment to explore new avenues towards reducing the cooling load on a building and study influential factors to enhance energy efficiency in buildings in such extreme climatic conditions. The carbon foot print of buildings can be reduced by reducing the cooling load through passive building design, using high efficiency equipment and incorporating renewable energy technologies such as solar systems, air source heat pumps, wind generators and ground source heat pumps are few to name that are widely used among many other available renewable technologies. The focus of this research work is on the Passivehouse building design incorporating solar hybrid Photovoltaic Thermal collectors (PV/T) as a source of renewable electricity and solar hot water for domestic use. Two different designs of a residential building for Modern Agro-Industrial Communities in Qatar were considered i.e. Pyramidal Shaped Building and Square Shaped Building. 3D energy models were created for both type of buildings using the IES software (Integrated Environmental Solutions) in virtual environment and thermal analysis was carried out. For the same building type, orientation and structure, two different criteria were applied to the model i.e. Passivehouse design vs. Conventional design. Pyramid shaped buildings are more stable but tend to cost more to construct when compared to traditional buildings. The sloping external walls tend to gain more solar energy and daylight through windows installed on the external walls. This provides an opportunity for solar panels installation on the external walls. The solar gain through external windows can be reduced to a minimum by effective solar shading and the daylight harvesting system can further reduce the artificial lighting gain inside the building. The results show that the passive house design of a building can save more than 70% of the cooling plant load, the as installed plant size and associated infrastructure. This will also considerably reduce the annual operational and maintenance cost of the building with just an extra 15% in construction cost. The cost analysis of passive house in comparison with a conventional house was carried out by QGBC (Qatar Green Building Council). In a nutshell this research work demonstrates how buildings' cooling load and carbon foot print can be reduced by effective solar shading, lower infiltration rates (air tight building design), highly insulated building fabric, natural ventilation, daylight harvesting system (that can help reduce artificial lighting gain inside the building) and heat recovery system.
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Compartmentalization and production allocation study of a carbonate field using molecular fingerprinting
Authors: Frank Haeseler, Damien Couteyen-Carpaye and Fatima MahdaouiIn multi layered reservoirs the fluid composition may differ from one layer to another. The knowledge of the lateral and vertical fluid heterogeneities may help to better understand the fluid distribution in the field and consequently contribute to enlighten production. Several mechanisms can affect the fluid composition, like origin, maturity, alteration or physical conditions. The objective of this study is to present a methodology aiming at characterizing and quantifying the compositional differences between fluids from different layers in an oil reservoir. It allows mapping the vertical and lateral heterogeneities in fluid composition. In order to measure the hydrocarbon composition, samples are analyzed by HRGC (High Resolution Gas Chromatography). In a first step this method aims at finding the peak ratios discriminating the oils from different reservoirs. Data are processed for peak recognition and statistical comparison is performed to compare samples. This statistical interpretation allows identifying similarities and differences between chromatograms e.g. oils. The results allowed identification of two end members. All the other samples of the field could be described as a mixture of these two fluids. Different cross-sections have been analyzed aiming at better understanding the field by linking geochemical data with geological features. By coupling the result with geological (lithology, cross-sections, logs…) and reservoir data (porosity, permeability, saturation…), different explanations could be proposed: Possibility of having different end members originating from a same fluid.Water washing as a possible process affecting fluids from different layers in similar and continuous way.“Structural heights” susceptible to reduce the water washing effect for some wells.The dip of the layers might increase water washing effect on fluids. This study showed the possibility to allocate the production in a carbonate field and allowed a better understanding of the fluids distribution. The molecular fingerprinting made it possible to understand the origin of fluids in comingled wells and particularly to identify the most producing part of the well in horizontal drains.
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Application of Value Engineering approach for Improving the Quality and Productivity of Ready Mixed Concrete Used in Construction and Hydraulic Projects
More LessThe paper studies the effectiveness of applying value engineering to concrete mixtures. It was conducted in the State of Qatar on a number of strategic construction projects for the 2022 World Cup projects, in order to generally improve the quality and productivity of ready-mixed concrete used in construction and hydraulic projects. The application of value engineering to such concrete mixtures resulted in the following: Improving the quality of concrete mixtures and increasing the durability of buildings; Optimizing the use of resources, and enhancing sustainability; Reducing the use of cement, thus reducing CO2 emissions which ensure the protection of environment and public health; And Increasing the market share and competitiveness of concrete producers The research shows that applying of value engineering to concrete is an effective way to save around 5% of the total costs of concrete mixtures and, in turn, reducing the costs of construction projects.
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Heterojunction Solar Cells Exceeding 20% Efficiency Using Gettered Monolike Silicon Wafers
Silicon heterojunction (SHJ) solar modules are an attractive and suitable option for application in high temperature environment such as in the state of Qatar. This is mainly related to their high open-circuit voltage (Voc) [1], which is essential for achieving better performance at high temperatures. High efficiency SHJ solar cells are usually made from high-quality n-type monocrystalline silicon wafers, which increases the cost of the device. If lower-cost materials such as high performance multicrystalline and mono-like silicon wafers could be used, significant reduction in the cost of PV electricity can be achieved. In this work, electrical properties of industrial-scale n-type and p-type mono-like silicon wafers have been investigated for use in high efficiency SHJ solar cells. The wafer's electrical resistivity were measured by four-point probe as 1–3 Ω-cm for n-type and ∼1 Ω-cm for p-type wafers. Since minority carrier lifetimes in as-grown (un-gettered) cast silicon, including mono-like silicon is usually low (i.e. inadequate for application in high efficiency solar cells), phosphorus diffusion gettering in a POCl3 furnace and/or bulk passivation by SiNx:H were used for enhancement of electrical properties. SHJ solar cells were then fabricated using the gettered wafers and as-grown sister wafers to assess the effectiveness of the gettering treatments. Figure 1. Injection dependent minority carrier lifetime for as-grown wafers and for gettered sister-wafers, after passivation with i/n and i/p amorphous silicon layers Figures. 1 shows minority carrier lifetimes measured by Quasi Stead-State Photoconductivity (QSSPC), on wafers as-grown, gettered and gettered with SiNx:H bulk passivation. As-grown lifetimes are low, being < 170 μs for p-type wafers and < 370 μs for n-type wafers, at 1 × 1015 cm-3 injection level. After passivation, significant improvement (up to 520 μs for p-type and 1900 μs for n-type) was achieved at 1 × 1015 cm-3 injection level. Despite the significant enhancement in overall lifetime, lifetimes at low-injection level is still limited, particularly for the p-type silicon. Nevertheless, very high carrier lifetime (up to 2400 μs) was recorded at 1 × 1015 cm-3 injection level (Figure 1(a)), and a SHJ cell with VOC of 720 mV and a photo-conversion efficiency of 20.3 % were successfully achieved, by gettering and bulk passivation. In conclusion, we demonstrated that electrical properties of industrial-scale mono-like silicon wafers can be efficiently optimized by gettering and bulk passivation treatments for application in high efficiency solar cells. A silicon heterojunction solar cell with efficiency exceeding 20% was produced. References [1] S. De Wolf, A. Descoeudres, Z. C. Holman, and C. Ballif, «High-efficiency silicon heterojunction solar cells: A review,» Green, vol. 2, pp. 7–24, 2012.
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A Noval Self Healing Control System for Next Generation Electric Grid with Big Data Platform
Authors: Shady Khalil, Mostafa Shahin, amira Mohamed and Haitham Abu-RubNowadays, many electrical utilities are moving towards self-healing distribution grid. This is realized by adding to distribution system various sensors, intelligent electronic devices (IEDs), phasor measurement units (PMU), sequence of event recorders (SERs), reclosers, detectors, measurement units, automated controllers, and other automation equipment. Those elements provide a continuous stream of data to support grid performance and improve its reliability. Huge amount of data obtained from different smart grid sources satisfy all the Big Data (BD) characteristics. The success of future electric grid depends mainly on the effective utilization of the huge amount of the data flow. This mass of information is essential to make next generation electric grid more efficient, reliable, secure, independent, and supportive during normal conditions and contingencies. The self-healing grid requires a robust real-time computation system that monitors, processes, provides predictive analytics, performs data mining and statistics, and makes faster decisions of the diverse and complex data collected within the traditional and nextgeneration electric grid. This helps to detect, locate, and isolate various faults, reconfigure and reroute power of the distribution network to minimize service disruptions and outages.Implementation of self-healing control system is associated with big data utilization which is a persisting challenge. Computational complexity challenges is associated with processing huge amounts of data during operation of the electric power system. Therefore, this paper presents acomprehensive studies of the impact of implementing a smart real-time dynamic self-healing control strategy using BD process platform with deep learning technique on the distribution system for current grid and future smart grid. The deep learning technique is a subfield of machine learning. The deep learning is shown to be highly efficient solution for the analysis of massive amounts of data which is performed by discovering and utilizing available regularities in the inputs to help self-healing control system to network reconfiguration, and coordination of various distributed energy resourcesin the smart grid. The deep learning system complexity does notdepend on the number of grid buses, this is because the power flow solving time is approximately linear with respect to the number of system buses. However, the complexity of the system depends on the number of the system inputs. The Long Short Term Memory (LSTM) recurrent neural network will be used in modeling sequential data such as time series data. Such network has the ability to learn contextual information over the history of the input sequence. The BD analyticswill be used as a key to deal with the uncertainties and different sizes of structured and unstructured data. The advanced analytics techniques such as predictive analytics, in addition to data mining, statistics, and faster decisions making will be utilized for data coming from sensors within the traditional and next-generation electric grid. The studies performed are based on real-time monitoring and control of the network topology and operating conditions taking into account different power sources and hybrid renewable energy sources which usually have different characteristics on the electric power grid. Finally, the real-time implementations of the proposed system will achieve dynamic resources optimization, network reconfiguration, and optimum operation of power grid using LSTM with big data platform.
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Synthesis and Properties of Novel NiBAlN Nanocomposite Coatings
Degradation of materails due to corrosion has now emerged as an international challenge which is compelling the community to trace out some smart solutions on priority basis. Corrosion mitigation is not only important as it results in wastage of our natural resources, time, money and efforts, but more importantly its inadequate handling may lead to the safety threats. Some, such sad incidents have been reported in the past. That is why many countries of the world are paying special attention to address this challenge by investing a lot of money. Although, we can notice corrosion everywhere around us, however, mining, mineral processing, oil & gas and many other processing industries are facing severe corrosion challenges. In many applications, it is only the surface of the material that is directly exposed to the corrosive medium, hence modifying the surface properties may lead to control the corrosion phenomenon. Towards this goal, the development of various types of nanocomposite coatings has proven to be a an economic and viable option. The present research work addresses the synthesis and characterization of novel Ni-B-AlN nanocomposite coatings. The Ni-B and Ni-B-AlN nanocomposite coatings were electrodeposited on the mild substrate. A comparison of structural, surface, mechanical and electrochemical properties are presented to elucidate the beneficial role of the incorporation of AlN nanoparticles into the Ni-B matrix. We have noticed that the addition of AlN nanoparticles to Ni-B matrix has a remarkable effect on its properties. Ni-B-AlN nanocomposite coatings demonstrate superior structural, mechanical and anticorrosion properties when compared to Ni-B coatings which make them attractive for many industrial applications.
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GridConnected CapacitorTapped MultiModule Voltage Source Converter
Authors: Ahmed Abbas Elserougi, Shehab Ahmed and Ahmed MassoudIn this work, a new dc-ac converter is proposed for grid integration purposes, namely, capacitor-tapped multi-module dc-ac voltage source converter. The main advantages of the proposed converter when compared with the conventional dc-ac modular multilevel converter (assuming the same voltage rating of semiconductor devices) are: (i) employment of a lower number of semiconductor devices, but with a higher current rating hence it provides operation with a lower number of gate driver circuits, and (ii) employment of a lower number of dc capacitors which reduces the number of measured variables, which affects positively the cost and reduces the computational burden of the employed controller.
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Solar Thermal System for Heating and Cooling Requirements of Commercial Building in Doha: A Case Study
Authors: shoukat alim Khan, Majid Aziz and Muammer KocThe demand for cooling in Gulf region is the direct effect of its high atmospheric temperature. Around 60% of the electricity demand in GCC is for cooling purpose. The main source of cooling and air-conditioning in these countries are conventional electric compression cycle, which leads to the increase in the GHG emission, directly in the form of leaked gases from these systems and indirectly in the form of fossil fuel used for the production of the used electricity for these systems. Solar energy in general and solar thermal energy specifically can be a promising and sustainable solution to the cooling and air-conditioning requirement for the buildings in Qatar and GCC. Absorption cooling and air-conditioning is a mature and promising technology with respect to its efficiency and results on the industrial scale. However, the use of technology with solar thermal energy is new in the market. In this paper, the feasibility analysis of solar thermal technology has been done for the cooling, heating and hot water requirement of a commercial building in Doha, Qatar. Heating and hot water requirement for winter and cooling requirement for summer season were calculated and used as a load. Solar thermal collectors (STC) were used as the main source of thermal energy collection form sunlight. Along with STC, thermally driven adsorption chiller was designed to fulfill the cooling requirement in the summer season. The design and selection of the different components and parameters such as Solar thermal collector area, storage tank size, adsorption chiller etc. have been done in detail. The result, obtained for building's energy demand and its supply from the designed solar thermal system, gives a clear sign for the successful implementation of this technology.
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Counting the Carbon: Assessing Qatar's Carbon Dioxide Emissions
Authors: Mona Al-Asmakh and Nadya Al-AwainatiClimate change is the most pressing global environmental issue today, with a potentially devastating impact on human development. According to the Intergovernmental Panel on Climate Change (IPCC) reports, Qatar is ranked as the highest CO2 per capita emitter globally. Qatar is contributing to the reductions of anthropogenic carbon dioxide (CO2) by supplying the world with Liquid Natural Gas (LNG), yet Qatar is being negatively imaged as highest CO2 per capita emitter. The reading of the highest CO2per capita has affected Qatar's ability to attract green investments and to improve the country's attraction in the tourism market. Qatar's position as the leader CO2 per capita has made it unattractive for investors both internally and externally because of the perception that the investment would not be ‘green’. The per capita emissions are a result of two main factors: the total absolute emissions and the total population. Two major and significant factors, consumption and population, should be taken into consideration when discussing the total absolute emissions for Qatar: The assumption for this equation is that the population uses all the produced energy, which is the denominator. This assumption is a disadvantage to Qatar due both to its low population and the fact that it is an energy producer. CO2emission would be much lower for Qatar if a consumption-based accounting system was used for the calculation of the per capita value. The use of emissions accounting measure is of vital importance to individual countries. There are two feasible carbon emissions accounting units: production-based accounting and consumption-based accounting systems. Production-based accounting is linked to economic system boundaries (greenhouse gas emissions from resident institutional units, analogous to gross domestic product). It involves measuring the emissions occurring within a country's boarder and does not take into account production chains extended across boundaries. An illustration of a production-based system examines the emissions generated from fuel purchases and allocates them the country producing the fuel, not the country consuming the fuel (OECD, 2016). While the Consumption based accounting system is related to how much this country emit for its domestic uses. Data are more difficult to obtain for the consumption-based approach because the computations are more complicated to compile as it relies on input-output tables, which includes all steps in production from raw material extraction through the final assembly and ultimately the final sale of the product (General Secretariat for Development Planning, 2009).The controversy comes in determining responsibility: is it the player initiating the polluting process (consumer) or the player producing the pollution (producer)? Consumption-based measures are preferred by developing countries while production-based measures are preferred by developed countries. Qatar is unfairly portrayed as the highest carbon dioxide emitter in the world in terms of per capita measures. Qatar's carbon footprint takes into account Qatar's energy production rather than the country's domestic consumption. The main argument of the paper is to discuss Qatar's CO2 emissions per capita compared to other reporting measures, and to examine the difference between using a consumption based CO2 emissions accounting system versus a production-based one for Qatar. The paper discusses the complications of using a production-based accounting versus a consumption-based accounting system for Qatar carbon dioxide emissions calculations. The research applies both of Quantitative and Qualitative Analysis. The Quantitative analysis is related to roughly re-estimate Qatar's CO2 Per Capita emissions figure based on Consumption based accounting system. The qualitative analysis focuses on creating different comparisons to compare Qatar's CO2 emissions in terms of different reporting measures to three different categories. First category is comparing Qatar's emissions against GCC countries; these countries have the major common attribute that they are mainly dependent on oil and gas revenues, similar demographic location, weather and lifestyle. The analysis outcomes of this category illustrates that KSA has the highest emissions for CO2 intensity and for the absolute emissions. The second comparison category is comparing Qatar's CO2 emissions against major Liquified Natural Gas (LNG) producers which are Australia and Malaysia. These comparisons showed that Australia has the highest emissions of Absolute CO2, CO2 intensity as well as the emissions per GDP. The third category was to compare Qatar's position related to the major global emitters, such as China, India, Russia, and USA. This comparison resulted in China having the highest absolute emissions, CO2Intensity as well as emissions per GDP. The Analysis outcome of the comparisons highlights that Qatar is not the highest CO2emitter in terms of absolute CO2 emissions, emissions intensity, and emissions per GDP compared to the GCC countries, major LNG producers and the world largest emitters. Qatar has the highest CO2 emissions per Capita due to two main factors: Qatar is the largest LNG producer and Qatar has a relatively small population when compared to other countries. Qatar is a developing country, it is the largest LNG exporter and it has third highest natural gas reserves in the world. Qatar makes an indirect contribution to mitigating the impact of climate change, which is done though exporting a clean form of energy, i.e., Liquefied Natural Gas. Even though Qatar is a major contributor for the supplying the world with clean energy, Qatar has taken other initiatives to minimize its carbon emissions. Continuous research and development will be a key element to Qatar overcoming the climate change challenges through Research and Development Centres. In summary, the research paper has four main sections. The first section of the paper includes a background on climate change, its impact and mitigations. The second section discusses Qatar's global position using different CO2 emission reporting measures, including Absolute CO2emissions (kt), CO2emissions per GDP (kg per PPP$ of GDP), CO2intensity (kg per kg of oil equivalent energy use), CO2emissions per capita (metric tons per capita). The third part explores Qatar's CO2 per capita calculation incorporating the consumption-based accounting system and assessing the complications of using a production-based accounting versus a consumption-based accounting system for Qatar carbon dioxide emissions calculations. The last section covers Qatar's clean initiatives and offers recommendation towards net zero emissions and improving Qatar sustainability figures.
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Production of hazardous gas sensors using spinel ferrite nanoparticles
Authors: Jocelyn Ayesh and Mohammad Abu HaijaThis work reports on sensitive and selective gas sensors based on copper ferrite (CuFe2O4) nanoparticles. The nanoparticles were produced different methods including: colloid microwave assisted hydrothermal method, and co-precipitation method. Those methods enable a precise control of nanoparticle size, The produced nanoparticles were annealed at different temperatures. Structural analysis were carried out using x-ray diffraction (XRD) and transmission electron microscopy (TEM), and they revealed that the asprepared nanoparticle exhibit cubic structure. The nanoparticles undergo crystal structure transformation to tetragonal structure upon annealing. Furthermore, the nanoparticle were found to grow in size upon annealing. The tetrahedral and octahedral absorption bands which are characteristic of the spinel ferrite were determined using Fourier Transform Infra-Red Spectroscopy (FTIR) measurements. Gas sensors were fabricate by pressing the produced nanoparticle powder into disks. The sensor device was produced utilizing capacitor structure, with the top electrode stainless steel of grid structure. The produced sensors were characterized to be sensitive to both H2S and H2 gases, with greater sensitivity to H2S at low temperatures, where these sensors could detect H2S concentrations of 10 ppm at 80°C. The low optimal operation temperature reveals the low power requirements for sensor operation. Thus, those sensors exhibit the potential to be used for industrial applications, especially for the petrochemical industry the Petroleum Institute under a grant number RIFP-14312 and Qatar University.
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A new ELLAM implementation for modeling solute transport in fractured porous media
Authors: Fanilo Heninkaja Ramasomanana, Marwan Fahs, Husam Baalousha, Nicolas Barth and Said AhziThe fluid flow and solute transport through fractures in rocks are processes that have importance for many areas of the geosciences, ranging from groundwater hydrology to petroleum engineering. It is well known that fractures play an important role in flow and transport processes through geologic formation and number of environmentally relevant problems require the analysis of mass transport in subsurface systems. As Qatar»s aquifer is Karstic, the development of an appropriate numerical model is necessary to take account the high contrast between the fractures and the porous matrix. Fractures are the set of rock discontinuities that can occur in geological formations at different scales. They intensively affect the transport processes because they represent the preferential flow and mass migration paths. In this study, we introduce an adaptation of the Eulerian Lagrangian Localized Adjoint Method (ELLAM) [1] for the simulation of mass transport in fractured porous media. The fractures are represented explicitly using the discrete fracture model (DFM) which handles explicitly the fractures and matrix. It involves describing each fracture individually and discretizing fractures as well as matrix [2]. Specific physical and geometrical properties are imposed for the fractures and matrix domains. This model can be used in the domains where a relatively small number of fractures exist. DFM is the most accurate model because fractures are considered without any simplification. However, this model requires enormous computational time and memory due to the dense meshes resulting from the explicit discretization of the fractures. As a consequence, its use requires highly efficient numerical methods for solving the flow and mass transport. The flow problem is solved using the Mixed Hybrid Finite Element Method (MHFEM) [3] which is well known to be accurate and efficient for complex geometries. It provides consistent and accurate velocity even in highly heterogeneous domain, which is a relevant property for flow in FPM. The obtained velocity field is then used to solve the mass transport problem with ELLAM. ELLAM combines an Eulerian and Lagrangian treatments without any splitting procedure by considering trial functions that depend on time and space. The results obtained by Celia et al. [1] demonstrated the mass conservation of the ELLAM in its formulation and its high computational efficiency compared to classical numerical method. In this work, a new ELLAM implementation is developed to address numerical artifacts (spurious oscillations and numerical dispersion) arising from the high contrast of velocities between fractures and porous matrix. Moreover, the efficiency of the developed ELLAM implementation was improved, taking advantage of the parallel computing on shared memory architecture for the tasks related to particles tracking and linear system resolving. The performance of ELLAM was tested by comparison against the Eulerian discontinuous Galerkin method based on several benchmarks dealing with different fracture configurations. The results highlight the robustness and accuracy of ELLAM, as it allows the use of large time steps, and overcomes the Courant-Friedrichs-Lewy (CFL) restriction. This work contribute to the Aquifer Storage and Recovery (ASR) project of Qatar which aims at artificially storing water in the aquifer for future use by developing an efficient and accurate model for mass transport in fractured porous media. References [1] Celia, M.A., Russell, T.F., Herrera, I., Ewing, R.E.: An Eulerian-Lagrangian localized adjoint method for the advection-diffusion equation. Advances in Water Resources. 13, 187–206 (1990). doi:10.1016/0309-1708(90)90041-2 [2] Karimi-Fard, M., Durlofsky, L.J., Aziz, K.: An Efficient Discrete-Fracture Model Applicable for General-Purpose Reservoir Simulators. SPE Journal. 9, 227–236 (2004). doi:10.2118/88812-PA [3] Younes, A., Ackerer, P., Delay, F.: Mixed finite elements for solving 2-D diffusion-type equations. Reviews of Geophysics. 48, (2010). doi:10.1029/2008RG000277
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Hydrodynamic Modelling of a complex marine system: Application for the Inland Sea Khor AlAdaid Qatar
More LessPhysical Oceanography is the study of the conditions and processes that govern the movement of ocean water, and its interaction with coastal, seafloor, and atmospheric boundaries. Understanding these processes helps to provide deeper insight into various ecological and physical phenomena that affect the earth's near-surface systems. Furthermore, consideration of physical oceanography is critical for sustainable development and effective urban planning, as most human settlements are along coastlines and thus they experience the combined effects of marine weather, waves, tides, and coastal currents. To help understand the response of marine systems to physical forcing, such as changes in temperature, wind, and humidity, computational eco-hydrological models are created. These models seek to mimic the real environment by using both general and site-specific data related to the hydrodynamics and ecological / physical phenomena, which are then combined with mathematical principles to describe a functional ecosystem.
Most modeling software are designed to simulate flow in “normal marine” systems, i.e. relatively deep systems with near-normal seawater salinities. Khor Al-Adaid (including the Inland Sea), Qatar, however, presents a globally unique marine system, as it is aerially extensive, very shallow (mostly less than 5 m), and hyper-saline. It is surrounded by Eocene rock outcrops, sandy sabkhas, and large mobile dunes which migrate into the Inland Sea water. This marine embayment can be divided into three main areas including: (i) an inner lagoon less than 2 m in depth but 53.5 km2 in extent, with salinity reaching 90 ppt in the summer season, (ii) a 74 km2 outer lagoon up to 18 m in depth with typical salinities of 60 ppt in the summer season, and (iii) a linear channel that is about 10 km long, less saline (∼45 ppt), and it is connected to the Arabian Gulf. The varying range in average salinity, depth, and temperature between these three areas, makes the Inland Sea an intricate system, and thus the hydrodynamics of this system cannot be characterized using existing commercial modeling software, which typically handle more homogenous systems.
This work presents a proposed workflow that will be developed through iteration and testing of existing software, which will account for the modeling challenges faced with a complex heterogeneous system like the Inland Sea. As a starting point, GEMSS (Generalized Environmental Modeling System for Surface waters) will be used, as it provides a set of hydrodynamic, sediment transport and water quality modules, and has been used and calibrated previously in various locations around the Qatari coast to date. Comprehensive field data will be collected and processed to help understand the flow dynamics of the system. Measurements will be made using current meters, ADCPs (Acoustic Doppler Current Profiler), tidal gauges as well as temperature and salinity meters deployed throughout the study area. The data will then be used to build and calibrate the model to assess whether the system can be handled as a whole using GEMSS, or if the areas should be subdivided and treated separately.
The findings of this work will act as a stepping stone to help understand current flow dynamics in the system and how these flows shape the salinity profiles and physical structures. In turn, this will offer insight into the important habitat features currently observed in the system, and add better understanding as to how these may be altered naturally and potentially by anthropogenic means.
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Ecogenotoxicological Impact of Marine Pollutants on Qatari Bivalves: An Experimental Approach
Authors: Zenaba Khatir, Radhouane Ben Hamadou, Pedro Range, Hajer Alnaimi and Alexandra LeitãoThe geographical and hydrological characteristics and industrial activities of the Arabian/Persian Gulf contribute to its classification as a stressed marine environment. The persistency of some contaminants released by human activity is putting additional pressure on this already fragile system. Several studies have assessed the chemical contamination levels in Qatari coastal sediments but this is one of a few studies that assessed their eco-genotoxicological impacts, by using cytogenetic endpoints in a local model bivalve species. Bivalves were specifically selected for this study due to their role as filter feeders, high tolerance for harsh environmental conditions, and availability around Qatar. In this project, determination of Polycyclic Aromatic Hydrocarbons (PAHs), Total Petroleum Hydrocarbons (TPHs) and trace metals in surface sediments and pearl oyster -Pinctada radiata- was conducted in samples collected from 3 coastal locations in Qatar: Umm Bab, Dukhan and Al-Wakra. The selected sites were expected to be dissimilar in regard to the chemical pollutant level and contaminants distribution due to the different anthropogenic activities. Initial aneuploidy levels –numerical abnormality in chromosomes- in oysters were examined between December 2015 to February 2016 through randomly selecting 140 well spread metaphases. Metaphases with 26 chromosomes were recorded as diploid or normal and the ones with less or more number of chromosomes considered aneuploidy (Ebied, 1999). The ability of the oysters to adapt in terms of chemical contaminants accumulation and aneuploidy level when moved between sites with different levels of chemical pollution was assessed in the second sampling in April 2016, and using experimental approach with three treatments (control, transplanted, and translocated). The control treatments were collected from the original site and kept there, the transplanted treatments consisted of individuals composed from the other two sites and moved to Al-Wakra and the opposite, while the translocated treatment were the ones moved from Dukhan to Umm Bab and versa vise. Statistical analysis showed significant difference between sediment in the three sites; TPHs concentrated in Umm Bab, higher concentrations of metals found in Dukhan, while PAHs concentrated the most in AL-Wakra. Hydrocarbons and metals were detected in higher doses in oyster tissues collected in first sampling comparing to those analyzed in the second sampling with consistency of accumulating same contaminants. Predation by gastropod whelks caused high mortality of oyster during the second stage of the study especially in Dukhan control while transplanted animals from Al-Wakra were the least selected by gastropods. Mortality rates in Dukhan were generally higher than in other sites, except for oysters transplanted from Al-Wakra to Dukhan. Positive correlation was found between the high levels of contaminants and aneuploidy during the first phase. Unexpectedly, to the usually observed in bivalves, there was a bigger percentage of abnormal cells with chromosomal gain (hyperdiploids) than with chromosomal loss (hypodiploids) in all treatments. Among all the treatments, transplanted oysters showed the lowest level of aneuploidy followed by translocated, then control. In other words: oysters moved from site to another, regardless of the contamination levels at origin and destination, showed some recovery from initial aneuploidy levels. Further research is needed to determine the underlying mechanisms for this pattern.
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