bluuebunny/crossref_metadata_2025 huggingface dataset:
A new normalized digital feedback control for grid connected distributed generation system
Authors: TRABELSI Mohamed Abdallah
Published: November 2013

Background & Objectives Distributed Generation systems such as fuel cells, solar, and wind play a crucial role in producing energy with low or zero CO2 emissions and are explored for various stand-alone and grid connected applications. Inverters (conditioners) play an important role in interfacing the DG sources to the grid as they link them with controlling the power flow. Therefore, control techniques for inverters should achieve high performance not only during normal operating conditions of the grid, but also under fault conditions. This work proposes a newly designed Real Time Digital Feedback Controller for a grid connected PV system. A multilevel Flying Capacitors Inverter along with inductor and step-up transformer is used as an interface between the PV system and grid. The proposed controller is Deadbeat type controlling simultaneously the grid current and capacitor voltages variables using a weighting factor to ensure a proper balancing among the controlled variables. Furthermore, the proposed approach is offering the possibility of duty cycles normalization when the reference is not achievable within the sampling period. The newly designed controller transfers the power to the grid even under voltage fluctuations resulting from grid faults. This Voltage Ride Through capability is made possible without any noticeable current overshoot, while maintaining unity power factor and low harmonic distortion. Methods: In this work, a new normalized Deadbeat control technique with VRT capability is proposed to transfer power to the grid with unity power factor. Unlike other control techniques, the proposed control is based on a hybrid model taking into consideration duty cycles, state variables, and external disturbances (voltage sags). Furthermore, a normalization of the control vector is presented when the calculated duty cycles do not satisfy the physical condition. The validated approach consists of a serial of mathematical calculations (min, max) in order to ensure the generation of duty cycles within the physical domain. Results & Conclusion: An experimental power conditioning unit was developed to transfer the power from a DG system to the grid. Simulation and experimental results obtained on 1kW prototype validate the high performance of the proposed control under grid voltage sag. Smooth transition between normal and faulty operation is achieved. Keywords: Normalized Deadbeat Controller, Voltage Ride Through Capability, Grid connection, Unity power factor, Solar Energy Interfacing.
Status of worldwide renewable energy installation and guidelines for the connection of PV systems to the power grid
Authors: Abu-Rub Haitham
Published: November 2013

The increasing price of conventional fossil fuel and the need to reduce green-house gas emissions have prompted the adoption of clean electrical energy generation sources. The abundance of renewable energy, particularly solar and wind, over the world combined with increasing efficiency of the Photovoltaic (PV) cells has led to reducing cost per kWh of generated green electricity and created potential for establishing high power renewable energy systems at medium voltage scale. The design, fabrication, installation and testing of a large PV power generation systems still, however, pose great challenge in term of obtaining highly-efficient, highly-reliable, transformer-less with buck/boost voltage capabilities, and reduced cost and maintenance. This work is aimed to present the status of renewable energy installation worldwide and to discuss grid connected issues. The increasing penetration of PV energy has motivated the establishment of grid connection requirements. The requirements for power injection should be clearly defined: The grid requires sinusoidal AC with stable voltage and frequency, and the harmonics content should be kept within limits as addressed in various standards, codes, and guidelines. Hence, PV plants connected to the public grid give rise to two highly important requirements: the power quality of the grid should not be reduced when solar power is fed into the grid; and personal safety must be ensured in the event of mains interference. Large PV systems are usually tied at high-voltage level. Such systems consist of generation, transmission, distribution phases, and consumers at the end [1]. This proposed work will discuss the status of renewable energy worldwide installation at high level and will [resent the standards and regulations for the connection of PV renewable energy sources to electric grid. Different technical and non-technical issues related to the installation and the operation of such systems will be carefully discussed, analyzed and related problems investigated. There is a pressing need to review and to evaluate the design and operational constraints of large-scale renewable energy systems, therefore this work aims to discuss and open-up new avenues in this direction. References [1] H. Abu-Rub, M. Malinowski, K. Al-Haddad, Power Electronics for Renewable Energy Systems, Transportation and Industrial Applications. Hoboken, NJ: John Wiley & Sons, 2014 (in press).
Monitoring efficiency: Metrology systems for temperature dependent semiconductor characterization
Authors: Pernau Hans-Fridtjof
Published: November 2013

Since more than two decades Fraunhofer IPM works on metrology systems for semiconductor characterization. The physical transport properties and their determination are fundamental for the development and improvements of semiconductors regarding solar and thermoelectric applications. Therefore special designed setups for temperature dependent measurement of Hall-coefficient, charge carrier concentration and mobility as well as Seebeck-coefficient, electrical and thermal conductivity were developed and high accuracy reached. A wide range of metrology systems have been developed to measure thin films as well as bulk samples over a broad temperature range from below 100 K to over 1000 K. In this presentation we will show the interplay of these transport parameters and the critical influences regarding their determination. In closed collaboration with national and international metrological instituts Fraunhofer IPM developed a standardized measurement method[1] as well as reference samples for the so called power factor, a number for the conversion efficiency of thermoelectric semiconductor materials. These efforts will also presented.
Isolation and characterization of fungal pathogens causing date palm black scorch and false smut in Qatar
Authors: Al-Naemi Fatima
Published: November 2013

Isolation and characterization of fungal pathogens causing date palm black scorch and false smut in Qatar Fatima A. Al-Naemi1, Resna K. Nishad1, Talaat A. Ahmed1 and Osman Radwan2 1Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar 2Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, IL, USA The ability of date palm (Phoenix dactylifera L.) to grow in hot and dry regions of the world makes it an important subsistence crop in most arid areas. Nevertheless, the conditions for date palm growth and production are optimal for some fungal diseases that cause significant yield loss. In Qatar, fungal diseases affecting the productivity of dates are black scorch, which is caused by necrotrophic fungal pathogen, Thielaviopsis punctulata and false smut, which is caused by biotrophic fungal pathogen, Graphiola phoenecis. This study aims to ultimately reduce the yield loss attributing to palm diseases by increasing our knowledge about pathogen, host, host-pathogen interactions and the factors that alter disease severity. In order to isolate and identify these two fungal pathogens, infected date palm samples were collected from 8 agricultural farms located in northern and southern Qatar and the fungal pathogens were isolated. Microscopic examination and physiological characterization revealed that T. punctulata (anamorph of Ceratocystic radicicola) is the causal fungal pathogen of black scorch disease. Although previous reports have showed that the closer species, Thielaviopsis paradoxa, as the causal agent of this diseases; this is the first report from Qatar demonstrated the involvement of T. Punctulata in black scorch disease. To examine the pathogenicity of this fungal pathogen, date palm healthy tissues, were infected by the pathogen and typical disease symptoms manifested within two weeks. On the other hand, characterization of the false smut disease showed yeast-like fungal colony reflecting the hallmark of Graphiola phoenecis. Molecular characterization of the isolated fungal pathogens is being performed by using sequences from the ribosomal region spanning internal transcribed spacers region 1 and 4 (ITS1 and ITS4). Additionally, real-time RT-PCR is being conducted to early identify the most important pathogens of date palm. Information from this study will help scientists to design effective strategies in controlling date palm diseases. Keywords: date palm, black scorch, false smut, Thielaviopsis punctulata, Graphiola phoenecis
Viability Test For Wild Plants In Qatr
Authors: Elazazi Elsayed
Published: November 2013

Abstract: Preservation seeds of wild plants for longest period with high viability is a great challenge in gene bank. Germination test is one of seed viability tests methods to determine percentage of seeds in an accession will germinate under favorable conditions and generate normal seedlings capable of development into reproductively complete plants. Different methods have been developed successful to determine germination of seeds especially for endanger and rare species. Germination test is an important factor in order to determine the ability of seeds to be preserved in gene bank for long term. This study showed initial germination of some wild plants which collected from wild habitat and were processed for ex-situ conservation in short-term conservation and long-term conservation units at plant genet resources unit. Seed germination tests were carried out in seed viability unit, under favorable environmental conditions for each species. The aim of this work was to evaluate the seeds germination in the first stage of ex-Situ conservation processing. Seeds were collected according to the principals and guidelines of plant genetic resources collections set by Biodiversity International and international gene banks. The germination tests process according the international conservation rules, and International Seed Testing Association. Results showed that some species gave highly germination percentage without any treatments for example: Anastatica hierochuntica (100%), Lycium shawii (85 %), Ochradenus baccatus, (65%), Blepharis edulis (70%). On the other hand other species gave low germination percentage for example: Acacia ehrenbergiana (41%), Prosopis juliflora (50%) and Citrullus colocythsis (0%). Key words:Viability, Seeds, Germination, Wild plants, Gene Bank, Qatar.
Energy Efﬁcient Cross-Layer Design For Wireless Body Area Monitoring Networks
Authors: Abdellatif Alaa
Published: November 2013

The rapid increase in the number of patients with chronic diseases requiring constant monitoring has created a major impetus to developing scalable Body Area Sensor Networks (BASNs) for remote health applications. In this paper, to anatomize, control, and optimize the behavior of the wireless EEG monitoring system under the energy constraint, we develop an Energy- Delay-Distortion cross-layer design. This cross-layer design aims at minimizing the total energy consumption subject to data delay deadline and distortion threshold constraints. The source encoding and data transmission are the two dominant power consuming operations in wireless EEG monitoring system. Therefore, in the proposed cross-layer design, the optimal encoding and transmission energy are computed to minimize the energy consumption in a delay constrained wireless BASN. This cross- layer framework is proposed, across Application-MAC-Physical layers, under a constraint that all successfully received packets must have their delay smaller than their corresponding delay deadline and with maximum distortion less than the application distortion threshold. In addition to that, to decrease the computational complexity, a distributed algorithm that finds the optimum encoding and transmission parameters for each sensor node is proposed.
Design Of Shunt Active Power Filter For 3X5 Matrix Converters To Eliminate Harmonic Distortion In Input Current
Authors: Thavot Moidu
Published: November 2013

The matrix converters are silicon based converters without bulky and expensive DC link capacitors other than its counterpart voltage source inverter (VSI) converters as an ideal voltage source and feed to ideal current source. Power electronic converters are a typical source of harmonic currents and during each switching cycle, the matrix converters produce unwanted harmonics and this will inject back to the AC mains. This harmonic current effect the overall operations of an AC supply. The main approach to the mitigation of this power quality problem is providing a filter in input side of the converter. Conventionally, passive filters with LC component were the choice for the elimination of harmonics and to improve power factor. These passive filters have the disadvantages such as large size, series and parallel resonance and fixed compensation. Active filters avoid the disadvantages of passive filters by using a switch mode power electronic converter to supply harmonic currents equal to those in the load currents. Active power filters can compensate both harmonic and reactive power simultaneously. In design of an active filter for matrix converter, a high displacement angle of input line current may compensated by matrix converter itself setting as reference for the input current a lagging displacement angle. It makes the reduced voltage transfer ratio for the system. So the control of the impedance interaction between the input filter and the voltage converter is mandatory. This paper propose a shunt active power filter for a 3x5 matrix converters to eliminate harmonic currents and to compensate reactive power for linear and non-linear loads. The paper presents the various design aspects of shunt active power filter for a 3x5 matrix converter. The control logic is made by using p-q theory and calculated the reference currents in order to compensate zero, harmonic and reactive currents (Fig. 1). To validate the proposed filter design, matlab simulation tests are conducted and results are presented. Simulations are carried out for the RL load and analysed the output with and without filter. These results shows less harmonic distortion in input current as well as reduced total harmonic distortion by using a simple active filter in input side. This proposed methodology has good results as compared with the conventional input filter. Fig. 2 presents simulation results of 3x5 matrix converter without any input filter. 80% of total harmonic distortion (THD) is reduced after accommodating an active input filter in to the same system (Fig.3).
Propagation of potential native plants for urban landscape in Gulf countries
Authors: Bhatt Arvind
Published: November 2013

Gulf Countries have an arid/hyper arid climate with little precipitation, a low groundwater recharge rate and no reliable, perennial surface water resources. The total consumption of ground water resources in these countries exceeds with times its natural recharge capacity. However, urbanization expansion and the need for green landscapes in most of the Gulf cities increase the demand on the irrigation water. This puts great stress on the limited water resources in the Gulf Countries. One way for the sustainable use of the limited water resources is through the use of native desert plants in landscaping the cities. Native plants are those that have evolved naturally under the harsh environmental conditions of the GCC countries. They can tolerate very high temperatures, drought (water deficit) and high salinity. Native plants provide a beautiful, hardy, drought resistant, low maintenance landscape while benefiting the environment. Besides that they are adapted to the local climate, geography and hydrology and should require little or no fertilizers and water for growth and maintenance, given that native plants have adapted and evolved to local conditions over thousands of years. In addition, the beauty of native wildflowers and grasses creates a sense of place. The native plants increase our connection to nature and provide a beautiful place to relax. Native plants are also resistant to most kinds of local insects and resistant to most pathogens. Consequently, using native plants would reduce the use of the hazardous chemicals and hence save the environment in a sustainable way. In the present study, we screened more than 100 plants native to the GCC region to select the most potential in landscaping. Plants are selected based on their appearance, texture and tolerances to drought and salinity, fit as ornamental plants. Priorities are given for species that have wide ecological amplitudes. These species can tolerate wide range of environmental (especially soil factors) and hence would be more successful under new conditions in of the urban environment. The main challenge facing the use of native plants in landscaping is the great dormancy in their seeds, which results in very low germination rate. In addition, there is a lack of propagation information for most of the native desert plants used in the urban landscaping. Our results showed that large number of studied plants have little dormancy and can germinate in a wide condition of temperatures and light. However, many other potential plants have very deep dormancy. Treatments with different growth regulators, such gibberellic acid, kinetin and thiourea and fusicoccin are currently in progress to break physiological dormancy. Other treatments, such as sulfuric acid, are also carried out to break physical seed coat dormancy. In addition, seeds are stored under different conditions to break the morphological dormancy.
Building a workforce for a sustainable developement based on a national global scientific & hightech improvement
Authors: Elouadi Brahim
Published: November 2013

Indeed human resources, national technological projects and energy are the three main pillars for any sustainable social-economical development of all our societies at the national-local, regional and international levels. In a global modern World with already existing means of communication and technologies' transfer, the improvement of the materials and economical welfare could be enhanced in order to show visible results even after half a decade form the starting of the projects even in the sectors where times needed has been counted by decades in the western presently developed countries. It must be underlined that the presence of energy resources and global financial capabilities does not lead automatically to a sustainable harmonious social development. However in such conditions, the latter can be easily conceived provided that a voluntary driving force of human resources is made available to fix clear and timed goals. Indeed, imported technologies and managing experts can make a national technology starting with some welfare. Notwithstanding sustainable development requires building a sound national strategy for rooting the desired technology with all its requirements: i) human force, ii) advanced technology education, iii) energy resources, iv) appropriate research institutions, v) economical motivation, vi) workers qualifications, v) etc. It is worth to underline the importance of the national technological project. The historical review of the human technological evolution showed that the so far sustainable development of the technologically advanced communities has been started around some key projects like steel industry, machine tools, etc. The present situation of the humanity is crucial as with population increase and natural resources decrease. Therefore recycling of raw materials and new energy sources will be the driving forces for the future environmentally compatible life and existence survival. Advanced education and scientific research within a peaceful and healthy society are the tools to achieve such goal. There is a room for developing countries to access to materials welfare, if investment is made in time. The success can be expected only for a community where emerged a Wise Central Force (WCF) capable to monitor the following main centrifugal forces: i) Societies & Increasing Young Individuals, ii) Sciences & Technology Fundamental and R&D, iii) Education & Qualification for Employment iv) Healthy & Friendly Environment Some comparative examples will be given from developed, emerging and economically advances countries. Recent results of the OECD programme like PISA (Programme for International Student Assessment) will discussed for comparative purpose of international performances of comparable countries.
Economic viability of exploiting oil wells for electricity generation in Qatar: Performance and parametric investigation
Authors: Kharseh Mohamad
Published: November 2013

Owning to the awareness of the correlation between fossil fuel consumption and the ongoing climate changes, there is general acceptance that deploying more renewable energy resources is an urgent issue. Recently, geothermal power plant has been introduced as a smart solution to reduce fossil fuel consumption. Unlike other renewable energy resources, the available energy of geothermal energy is constant all year long. Geothermal refers to existing heat energy in deep rock and sedimentary basins. This energy can be used to drive a power turbine to generate electricity. The depth and temperature of hot rock remain the major obstacles to the commercial viability of enhanced geothermal energy. The fact that such energy is only available at high depth creates technical and economic problems. From an economic viewpoint, the high initial capital cost of geothermal power plants is the main barrier to commerciality of geothermal energy. Exploration and drilling of wells account for up to 40% of the total cost of the project. On the other side, oil wells are drilled to the depth where the temperature could be higher than 100 C. Since organic Rankine cycles (ORC) can operate between smaller temperature difference, harvesting energy from a low temperature source such as oil wells is possible. Thus, utilizing these wells means a significant part of initial capital cost of geothermal power plants can be eliminated. This way the economic viability of geothermal power plant becomes bigger. The current study presents thermodynamic and economic analyses of a binary geothermal power generation system for commercial electricity generation in Qatar. The optimal working fluid and optimal design at working conditions of Qatar are defined. The levelized cost of electricity and the payback period of geothermal POWER plant will be calculated for optimal working design.
The ecology of Qatari barchan dunes
Authors: Abdul Majid Sara
Published: November 2013

The mobile Barchan dunes in Qatar are restricted to the southeastern region of the country. They are currently a disappearing natural habitat, due to the northwesterly Al Shamal winds which are scouring the landscape and spreading desertification as they pass. The study's aim was to understand the ecology of an active dune, in terms of resident species and their populations. Traps were placed along three dunes and animals were collected over a period of three months. Species captured included the skink (Sincus mitranus), a number of Tenebrionidae beetles, in addition to geckos, scorpions, and spiders. The skinks were PIT tagged in order to estimate population size, along with life history data. Recapture data showed that there has been no migration between dunes, indicating that each dune represents it's own self-contained ecosystem. We are currently sequencing skink DNA to determine familial relationships between skink populations on individual dunes. It has been observed that skinks exhibit colonial behaviour in individual dunes. This is one of the initial efforts to determine skink populations on mobile dunes, and forms a baseline to future studies on the ecology of these unique ecosystems.
Ab initio study of the reactivity of edge sites of phyllosilicate clays
Authors: Kabalan Lara
Published: November 2013

Natural waters, permeability reduction in reservoir rocks, groundwater flow and clay rheology [1]. In addition, pyrophyllite clays have a number of industrial applications due to their distinctive surface chemical properties. The edge sites play an important role for pH dependent sorption of ions from solutions of electrolytes. For a full understanding of pyrophyllite formation and properties, a study of the chemistry of the system, the dynamical interactions between the components and the mesostructure are necessary. While experimentally it is difficult to determine the structure of these clays due to their disordered nature, molecular computer simulation has become an extremely useful, if not essential, tool for understanding the underlying principals behind surface chemistry [2,3]. As each property is associated with separate time and length scale, multiscale approaches such as DFT Molecular dynamics MD, classical molecular dynamics and Coarse Grained molecular dynamics are needed. In this talk, we will present a first principles molecular dynamics FPMD studies on hydrated Phyrophyllite clays which is the simplest structural prototype for 2:1 dioctahedral phyllosilicates. Octahedral (Mg for Al) and tetrahedral (Al for Si) substitutions allowing to a charged structure named Montmorollonite are also presented in this study.
Investigation of temperature distribution along subsea pipelines during shutdown scenarios
Authors: Khan Zurwa
Published: November 2013

Rising global energy demand and advancements in subsea engineering technology has made subsea oil and gas systems the dominant source for energy. The critical challenges in subsea systems included the associated external pressures and cold temperatures in ultra-deep water. Both of these challenges directly influence the safety and production of subsea oil and gas. Specifically, the design of a subsea pipeline must not only provide the structural integrity to withstand high external pressures but must be durable with respect to corrosion, and guarantee the flow of hydrocarbons. The latter two issues can only be investigated using temperature models that capture the heat transfer from the oil/gas mixture, through the pipeline and to the seawater. To predict temperatures along a pipeline during shutdown, software tools are available which provide numerical solutions based on the solution of mass, momentum and energy conservation equations. However, due to the complexity of these equations, it takes hours to generate results with no clear indication that the resulting simulations are correct. The objective of this project is to develop a low dimensional model that can accurately predict temperatures along pipelines during offshore oil production system shutdown. To develop the model, energy conservation of the fluid within the pipeline is considered. To solve this energy conservation equation, analytical and numerical methods, centered upon lumped capacitance method and finite difference method, are explored. These results are then compared with the developed low dimensional model. The low dimensional model is based on a modified finite difference method used for the energy conservation equation solution, which is integrated with a one dimensional heat conduction equation along a hollow composite cylinder. Steady state temperature profiles are also explored in order to generate the initial conditions for this modified finite difference method. Furthermore, the accuracy of this model is verified by comparing with the results generated by commercial software. The accuracy of this model could be further increased by using a finer mesh for which temperatures are to be determined. However, this would increase its computation time.
Dilute surfactant flooding studies in a low-permeability oil-wet carbonate reservoir
Authors: Bennetzen Martin
Published: November 2013

The vast majority of surfactant flood applications to date have been targeted to high permeability sandstone reservoirs containing formation brine with moderate salinity and hardness. Surfactant flooding in oil-wet, low-permeability carbonate rock is only reported sparsely throughout the literature. In the present work we aimed at identifying an efficient enhanced oil recovery strategy using a dilute surfactant solution. The dilution is highly beneficial in order to reduce not only chemical costs but in particular the environmental footprint. The work contains results from laboratory core flood tests performed on a highly oil-wet, low permeable carbonate reservoir rock material. The rock material investigated had approximately 30% porosity and 5 mD permeability, whereas the formation brine had a high salinity of about 120,000 ppm with a hardness of about 10,000 ppm. Initial combinations of several commercial surfactants, co-surfactant and alkalis were tested for brine compatibility and from these tests two cost-effective surfactant systems were identified. The first system, denoted ITR, was capable of reducing the interfacial tension below 0.001 mN/m at reservoir salinity and hardness. The second system, referred to as WA, altered the wettability from strongly oil-wet to intermediate-wet without altering the interfacial tension. Adsorption of the surfactants was measured to be low for both systems. No mobility control agents, such as polymers, were used in any of the systems because of low rock permeability. Both surfactant systems yielded significant incremental oil, when injected in tertiary as well as in secondary mode. The ITR system recovered almost 95% of OIIP but required many pore volumes since the cores remained oil-wet. Strikingly the WA system recovered approx. 85% of OIIP in secondary mode but achieved this with much fewer pore volumes using a very low concentration of surfactant. The promising WA system was subjected to extensive analysis involving relative permeability function estimation and flooding simulations using UTCHEM. In summary, we have designed an efficient surfactant system capable of recovering significant amounts of oil from low-permeability carbonate reservoir rock material. Wettability alteration of highly oil-wet rock using dilute surfactant solutions may assist in unlocking significant volumes of additional oil from a variety of carbonate reservoirs.
Identification Of Gender-Associated Molecular Markers In The Date Palm (Phoenix Dactylifera) Genome
Authors: Torres Maria
Published: November 2013

Date palm (Phoenix dactylifera) is one of the most distributed and well-adapted fruit crops in the Middle East, and plays an important role in the history and diet of the Arab world. Dates constitute the primary exportable agricultural product in Qatar and current efforts are being made to improve its production. Over the years, clonal propagation has been used to maintain selected varieties with desirable morphological traits, leading to the establishment of uniform palm orchards. This, however, significantly reduces genetic diversity among palm plantations, making them potentially more susceptible to pests and diseases. Improvement of date production through date palm breeding is highly challenging due to the long regeneration times and the lack of knowledge about the genetic markers responsible for desirable agricultural traits. In commercial plantations, one hundred fruit bearing female trees can be pollinated with a single non-bearing male tree. Still, half of the date palm offspring planted from seeds are expected to be male individuals. One of the biggest challenges that date production encounters is that female trees can only be distinguished after flowering, which occurs five to eight years after planting. Previous cytological studies have suggested the presence of heteromorphic sex chromosomes in date palm, however enzymatic approaches intended to anticipate gender determination have been unsuccessful. The recent genome sequencing of different individuals from the commercial varieties Khalas, Deglet Noor and Medjool, allowed the identification of a gender-linked genomic region. This single nucleotide polymorphism (SNP)-rich region was shown to segregate with gender, and is predicted to extend to 24 scaffolds. Only a limited amount of information about this region is currently available, and this study proposes the use of a deep-sequencing approach to significantly improve the date palm genome assembly, with an emphasis on the male/female segregating region. A bacterial artificial chromosome (BAC) library, with a 12x genome coverage and an average insert size of 125 Kb was constructed. BAC-end sequencing of at least 96 clones, associated with the polymorphic sex-linked region, will allow the generation a complete physical and sequence map of the sex-determination region. Our main goal is to detect the critical mutation that gave rise to male and female separation. This is the firs time such level of detail in a dioecious plant will be achieved. Furthermore, standardization of this sequencing procedure, will also allow us to characterize other genomic regions associated with desirable commercial properties of these fruits. This in turn, will provide a valuable tool for the development of marker-assisted selection programs, for the improvement of date palm production.
Effects Of Graphene Materials On The Performance Of Ester Based Drilling Fluid
Authors: Yunus Robiah
Published: November 2013

The idea of pushing the limits of drilling oil and gas wells by improving drilling fluids using conventional macro and micro type fluid additives is very crucial tasks especially to fulfill certain functional tasks. This is due to inadequate information on the physical, chemical, thermal and environmental characteristics of the additives. The industries are currently looking for cost efficient drilling operations, thus many researches are focusing on the wonders of nanotechnology in the drilling fluids which forms the basis of the work presented here. This project will describe the preliminary test results of graphene oxide (GO) and R-graphene oxide (RGO) enhancement as nano additive in drilling fluid formulation. This project is basically to test whether incorporation of graphene materials gives significant improvement to the ester based drilling fluid it terms of its rheological properties. Besides using commercial GO, RGO was synthesized by refluxing the palm oil methyl ester (POME) with graphene oxide for 24 hours. UV-VIS results verified the attachment of R group from POME to the graphene oxide. Both materials then were added to the newly synthesized ester based drilling fluid and then formulations and characterization were performed with different percentages of GO and RGO. The advantages of adding nano-sized molecules of GO and RGO to ester based drilling fluid are evidenced in the improvement in fluid permeability rate into porous formation which contribute to the stability of wellbore.
Ex-Situ Conservation Of Some Plant Genetic Resources From Qatari Protectorates
Authors: Elazazi Elsayed
Published: November 2013

Qatar biodiversity is under the pressure by the effects of environmental pollution, overgrazing, desertification as well as the climatic change. In order to rescue wild plant genetic resources of Qatar and in the line of Qatar Strategic action plan of Genetic resources, the present investigation aims at ex-situ conservation of some wild plant genetic resources from Rawdat Umm Al-Kharq. A total number of 17 accessions have collected from Rawdat Umm Al-Kharq, which represent 13 family and 16 Genus,17 Species, during the season of 2013 to target a fully maturated seeds, herbarium specimens and DNA samples. The collection missions follow the principals and guidelines of Plant genetic resources collections set by Biodiversity International and international gene banks. The collected materials are subjected to characterization, documentation and preservation process. According the international conservation rules, cleaning, drying, viability test, packaging and storing were applied for seeds. Highly seeds viability recorded with Cucumis prophetarum, Malva parviflora, and Salvia aegyptica. All information derived from conservation process was documented in the Biotechnology Center. Key words: Biodiversity,Plant Genetic Resources, gene bank, Conservation, Qatar.
An Experimental and Computational Approach On Avoiding Gas Hydrate Problems in Qatar's Oil and Gas Industry
Authors: Atilhan Mert
Published: November 2013

Qatar's one of the biggest problem in processing its natural resource, which is natural gas, is the often occurring blockage in the pipelines caused due to uncontrolled gas hydrate formation in the pipelines. Several millions of dollars are being spent at the process site to dehydrate the blockage safely by using chemical inhibitors. We aim to establish national database, which addresses the physical conditions that promotes Qatari natural gas to form gas hydrates in the pipelines. Moreover, we aim to design and test novel hydrate inhibitors that are suitable for Qatari natural gas and its processing facilities. From these perspectives we are aiming to provide more effective and sustainable reservoir utilization and processing of Qatari natural gas. In this work, we present the initial finding of a big project, which deals with the natural gas hydrate formation characteristics of Qatari type gas in both experimental (PVTx) and computational (molecular simulations) methods. We present the commissioning of the new fully automated gas hydrate autoclave and measurements of hydrate equilibrium curves including growth/dissociation conditions for multi-component systems for several gas mixtures with and without the presence of well known kinetic and thermodynamic hydrate inhibitors.
Nanosorbents For The Selective Removal Of Boron From Seawater
Authors: Mahmoud Khaled
Published: November 2013

The rejection efficiency of boron by RO membranes is poor, especially when a large proportion of boron in feedwater exists as uncharged boric acid which can diffuse through most of the available RO membranes.1,2 Among the methods suggested for boron removal from water and wastewater, adsorption is a very useful and economical technique. Magnetic adsorbents containing chelating precursors that are selective for boron have been used as a smart, fast and simple method for the separation and pre-concentration of boron3. After adsorption, the adsorbents can be isolated from the medium by simple magnetic separation. Here, we present novel magnetic nanocomposites for the selective removal of boron from seawater. The nanocomposites have been synthesized and fully characterized using scanning electron microscopy (SEM), tunneling electron microscopy (TEM), Fourier transformed infrared (FTIR) and powder x-rat diffraction (PXRD). This technology provides a simple method for the adsorption of boron and separation of magnetic nanoparticles from a solution using an easy magnetic procedure. The effect of different nanosorbents, sorbent amount and pH on the sorption of boron was studied. The magnetic sorbent that provided the highest boron sorption efficiency was used for the subsequent experiments investigating the most effective magnetic sorbent amount and pH for the sorption of boron. Experimental results indicate that boron sorption increases with increasing sorbent dosage up to a sorbent amount of approximately 0.6 g, after which the difference in removal efficiency was found to be negligible. The effect of pH on boron removal efficiency using the nanosorbents was studied at initial boron concentrations of 4-5 ppm, amounts commonly found in seawater. The sorption of boron was found to be highest at a pH range of 7-7.5 with a sorption efficiency of 77.6 ± 1%.
Performance Analysis Of Empty Container Logistics At Qatalum Smelter
Authors: Mutlu Fatih
Published: November 2013

This project aims at identifying and validating the performance measurements of container logistics at Qatalum Smelter. The project investigates two different cases that Qatalum has implemented to manage the empty container logistics using simulation. The first case is to keep a limited empty container buffer; and the second case is to provide empty containers in a just-in-time fashion. Accordingly, a field research was conducted at Qatalum to collect required data. Quantitative and informative data were collected though meetings, on-site observations, and time and motion measurements to develop spaghetti diagrams that show all possible flows and flow charts of container logistics in order to develop the simulation models. Both situations were simulated using Arena software. Optimal buffer size of empty containers inside the cast house was determined, in which different empty containers buffer sizes were tried to choose the optimum buffer size. The vehicle fleet utilization in both cases was determined and scenario testing was implemented, in which the effect of adding additional resources was observed. The results show that the optimal buffer size of empty containers inside the cast house is 14 containers. The vehicle fleet utilization in the current case is less than its utilization in sand case and the most utilized vehicles in both cases are trucks and the container mover. The impact of additional resources is also studied via simulation.
Reactive Nanoparticle-Supported Dead-End Flow Ultrafiltration For Removal Of Mercury From Water: Effect Of Solution Composition
Authors: Han Dong Suk
Published: November 2013

Reactive Nanoparticle-Supported Dead-End Flow Ultrafiltration for Removal of Mercury from Water: Effect of Solution Composition
Modeling A Seawater Flash Distillation Process With The Q-Electrolattice Equation Of State
Authors: Al-Qahtani Faiha
Published: November 2013

Modeling a Seawater Flash Distillation Process with the Q-Electrolattice Equation of State
Unsignalized Intersection: Assessment, Forecast And Performance Measures
Authors: Salem Roba
Published: November 2013

Vehicles at Qatar university road networks are subject to pass through multiple roundabouts and intersections in order to reach their destination. Since the traffic volume is relatively low, unsignalized controlled intersections are used to regulate the flow of vehicles (sign-controlled) .T shaped intersections and multiple lane roundabouts are utilized throughout Qatar University closed loop system. This study has been conducted to measure the current performance of some unsignalized intersections at Qatar University roads. Two roundabouts and one TWSC intersection were selected for the study. The methods presented in the Highway Capacity Manual (HCM 2000) were employed in this study and were used to compute the various approaches and movements capacities and the related performance measures .e.g. Control Delays (s), Queue lengths (veh ) and Level of service (LOS). To this end we will base our capacity analysis on Gap acceptance method and on simple, empirical, lane-based, regression model for multiple lane roundabouts. Data inputs collected for the selected method involved the critical traffic volumes (veh/hr) which occur in the peak hour .15 peak minute flow rates were recorded to obtain the peak hour flow rates. In addition the methods were used to make future projection of the capacities and the related performance measure based on forecasted demand in 2022. The results show that the current performance of the roundabouts is satisfactory for which the Level of service was graded A for all approaches in the two roundabouts given that the computed delays never exceeds 10 s / vehicle in any approach. The current results for the roundabouts coincide with the actual performance of the intersections where very little delays are encountered while driving and very short queues are formed during the peak hour. Regarding the T intersection the performance of the Left turn of the major street was found satisfactory and was graded A while the performance of the shared lane of the minor road was graded C. Based on forecasting results, the increase in entry and conflicting flow rates have resulted in decreasing the expected capacities of the various approaches on the studied intersections. In general for the roundabouts no significant difference in performance is to be experienced in year 2022 when current demand is expected to experience over 50 % increase and still the performance will be satisfactory. The same conclusion was drawn for the Left turn movement from Major Street that no major difference in performance is projected in future. But this conclusion was not applicable on the shared lane where it was very much affected by the increase in demand and the performance has rapidly dropped from its current level.
Seasonal Changes In Biodiversity And Abundance Of Invertebrates In Different Ecological Environments
Authors: Alhajri Salma
Published: November 2013

ABSTRACT Biodiversity is a natural quality that must be measured to be understood. It is the measurement of the quantity and diversity of the biota in an area. Each area of the world has its own unique biodiversity as defined by its' species diversity index number (SDIN) including the state of Qatar. This study was designed to add to the base knowledge on the ground fauna data of Qatar that can be used to compute this species diversity index number. The purpose of this study was to create a baseline data on the occurrence, dominance, diversity, biomass and seasonal abundance of primarily ground dwelling invertebrates (primarily Arthropods) and to record this in different ecological habitats during seasonal changes in the Northern part of Qatar. The samples were collected weekly from June 2012 through December 2012 in the north of Qatar. Passive pitfall traps were used and placed in three different habitats and a farm site. A total of 4953 specimens were captured. Of the specimens collected, 4468 were member of Class Insecta, 110 different species belonging to 10 orders and 49 families of insects. The most numerous taxa were ants (family Formicidae) 54% followed by family Tenebrionidae (darkling beetles) which is 93.5% of beetles, and 28.8% of total catch invertebrate totals. Simpson diversity indexes in the sites differed among the different habitats and generally were high. The total dry biomass of all the insects caught was 226g. The most numerous taxa in terms of biomass were darkling beetles (Tenebrionidae), which made up more than 80%. It is recommended that systematic and long term collection of invertebrates in other areas of Qatar be carried out and the identification of more difficult species is needed. This is only a beginning of the understanding the invertebrate biodiversity of Qatar. It is much more diverse than anticipated.