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Qatar Foundation Annual Research Forum Volume 2013 Issue 1
- Conference date: 24-25 Nov 2013
- Location: Qatar National Convention Center (QNCC), Doha, Qatar
- Volume number: 2013
- Published: 20 November 2013
251 - 300 of 541 results
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Factors Influencing Breast Cancer Screening Practices Among Arabic Women Living in the State of Qatar: The Health Care Providers' Perspective
More LessBACKGROUND: Breast cancer is the most common cancer contributing to morbidity and mortality among Arabic women in Qatar. Arabic women are at risk primarily due to their low participation rates in breast cancer screening practices and subsequent delayed diagnosis of the disease. Therefore, there must be a strong emphasis on the health care providers and the health care system to increase efforts in early detection of breast cancer. METHODS: This Master's thesis study is a part of a larger, mixed methods study entitled "Factors Influence Breast Cancer Screening Practices Amongst Arabic Women Living in the State of Qatar" conducted by Dr. Tam Truong Donnelly, the lead principal investigator, and funded by the Qatar National Research Fund under the National Priorities Research Program. Following the theoretical frameworks of the main research study, this qualitative research based its theoretical foundation on an ecological perspective and Kleinman's explanatory model to explore, understand, and describe factors influencing Arabic women's breast cancer screening practices from the health care providers' perspective. Using Carspecken's critical ethnography, fifteen health care providers from three health care sites who work at various levels of the health care system in Qatar were interviewed individually and face to face. RESULTS: An analysis of the data revealed factors that either hinder or facilitate women's breast health and health care practices in Qatar. The influences of the factors are coalesced into four major themes: influences of (a) knowledge and awareness, pain associated with mammogram, and perception of 'no pain, no illness', (b) cultural beliefs, attitudes, and practices with regard to female breasts, body, illness, and unhealthy women and religious beliefs regarding modesty, health, and illness (c) unequal gender relations of power, female roles and responsibilities, and spousal support, and (d) systemic (health care and social resource) factors on women's breast cancer screening practices. CONCLUSIONS: As with many women worldwide, the study findings suggest that Arabic women's health cannot be understood in isolation from the environment in which they live. Rather, the health of Arabic women in Qatar is both constrained and fostered by health care and social systems that are embedded in culture. Addressing problems on a personal level isolated from the context will not be adequate and effective. Therefore, what seems immediately personal must be examined within its context; solutions need to address the context and not be limited to the individual. Authors offer implications for the health care, health care professionals, education, and research.
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Combining neonatal stress with schizophrenia susceptibility gene, dysbindin-1, is required for phenotypic changes in adulthood.
More LessAdult neurogenesis exists in two brain regions: the subventricular zone (SVZ) and the hippocampal dentate gyrus. In schizophrenia, hippocampal neurogenesis has been widely characterized, however no evidence exists for whether SVZ neurogenesis might be involved in the disease. This is particularly interesting since antipsychotic drugs were already shown to increase SVZ neurogenesis in rats [1, 2]. Here, I have investigated adult neurogenesis in three mouse models of schizophrenia: transgenic mice overexpressing neuregulin-1 type 1 (NRG1type1-tg); Snap-25 mutant (SNAP25+/-) mice and dysbindin-1 mutant or Sandy (Sdy-/-) mice. Using immunohistochemistry, I found no quantitative change in the number of proliferative cells that were positive for phosophohistone (PHi3) in the SVZ, rostral migratory stream (RMS) and hippocampus in both the NRG1type1-tg and SNAP25+/- mice. Similarly, I found no significant change in the surface area of migrating neuroblasts (doublecortin, Dcx+ cells) in the RMS of NRG1type1-tg and SNAP25+/- mice. The third model, Sdy-/- mice, were systemically injected with either saline or a viral mimic, polyI:C, from postnatal day 5 (P5) to P9 and this model represents gene vs. environment interactions in schizophrenia. Interestingly, I found a significant reduction in the number of proliferative (PHi3+) cells in the medial and subcallosal SVZ of Sdy-/- mice after inflammation. Also, I have found a decrease in the surface area of migratory (Dcx+) cells in the RMS of Sdy-/- (+polyI:C). Furthermore, I sought to find whether neonatal stress causes morphological changes in astroyctosis (i.e. GFAP) and microglia activation (i.e. Iba1) in the SVZ of Sdy-/- mice but found no apparent differences in comparison to wild-type (WT) littermates. Our collaborators from Prof. Lalit Srivastava's laboratory (McGill University) have shown that these observations in Sdy-/- mice (+polyI:C) were correlated with behavioural abnormalities, such as prepulse inhibition (PPI), reduced locomotor activity and object-recognition deficit although the latter was not statistically significant. In conclusion, I have shown here that a combination of both neonatal inflammation and mutation in a gene relevant to schizophrenia was important for triggering long-term effects in SVZ neurogenesis that was also correlated with behavioural deficits. Future studies will further examine SVZ neurogenesis in postnatal Sandy mice and will also look at brain integrity and cytokine infiltration in both postnatal and adult Sandy mice following neonatal inflammation. Functional studies will determine whether knocking-down toll-like receptor-3 (TLR3), which is the receptor for polyI:C, might rescue SVZ neurogenesis in postnatal Sandy mice after inflammation. 1. Kippin, T.E., S. Kapur, and D. van der Kooy, Dopamine specifically inhibits forebrain neural stem cell proliferation, suggesting a novel effect of antipsychotic drugs. J Neurosci, 2005. 25(24): p. 5815-23. 2. Wakade, C.G., et al., Atypical neuroleptics stimulate neurogenesis in adult rat brain. J Neurosci Res, 2002. 69(1): p. 72-9.
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The Development Of Athlete-Specific Hematological Reference Intervals And The Effect Of Ethnicity On Key Hematological Markers
More LessBackground and Objectives: The development of athlete-specific hematological reference ranges are essential for sports physicians in the diagnosis of pathologies. Due to unique genetics and training modalities, athletes are known to have atypical hematologic profiles in comparison to the general population and between ethnic groups. The aims of this study were 1) to develop athlete-specific reference ranges and 2) to demonstrate the effect of ethnicity on key hematological variables, in order to improve athlete care. Methods: From a reference population of 2082 healthy male (M) (23.28 ± 4.89 years of age) and 140 healthy female (F) (21.16 ± 4.61 years of age) athletes screened at Aspetar hospital, the reference intervals (2.5 and 97.5 percentiles) were established for the following hematological parameters: mean cell volume (MCV, fL), mean corpuscular hemoglobin (MCH, pg), mean corpuscular hemoglobin concentration (MCHC, g/dL), hemoglobin concentration ([Hb], g/dL), hematocrit (HCT, L/L), red blood cell count (RBC, x1012/L), red blood cell distribution width (RDW, %), reticulocyte percentage (RET, %), ferritin (FRT, µg/L), iron (FE, µmol/L), transferrin (TF, g/L), total iron binding capacity (TIBC, µmol/L) and soluble transferrin receptor (STFR, g/L). Additionally, differences in the mean value of each hematological variable between five major ethnic groups were investigated. Results: The calculated overall reference intervals for the majority of the hematological parameters appear to trend lower in comparison to those currently in use, only STFR and RDW yielded slightly higher reference values (Table 1). The athlete population comprised of 104 different nationalities, which were subsequently characterized into five major ethnic groups: Arabic (1145 M, 89 F), Asian (43 M, 4 F), Black (519 M, 43 F), Caucasian (302 M, 4 F) and Mixed (73 M, 0 F). Significant between group differences was found for the male Arabic population (p<0.005). Arabic athletes were found to have lower mean MCV (83.0 ± 6.9), MCH (28.3 ± 2.4), [Hb] (14.6 ± 1.1), HCT (0.43 ± 0.03) and FRT (78.3 ± 57.1) counts and higher RBC (5.2 ± 0.5), RDW (14.9 ± 1.0), TIBC (57.8 ± 9.1) and STFR (2.1 ± 1.6) counts (mean ± standard deviation) in comparison to Black, Caucasian or Mixed males, suggesting a higher prevalence of hematologic disorders, iron deficiency, anemia and/or hemoglobinopathy in this population. In addition, male Black athletes presented with lower mean values for MCV (84.7 ± 5.0), MCH (28.6 ± 2.0) and [Hb] (14.5 ± 1.0) and higher RET (0.99 ± 0.42) and STFR (2.3 ± 3.3) values when compared to male Caucasians. Conclusions: The developments of population-specific athlete hematological indices are important for the sports medicine community, in order to not only improve athlete health and performance, but also to assist in the diagnosis of hemopathologies and other blood related disorders. Additionally, an athlete's ethnicity has a significant impact upon their hematological profile and consequently, published reference ranges are not applicable to certain ethnicities.
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Hybrid Nanocomposite Polymers For Tissue Engineering
By Ali MohammedThe purpose of this project was to further investigate the characteristic properties of an inorganic-organic hybrid material with respect to its potential application in the field of tissue engineering. The organic component chosen for this project was a co-polymer 2-hydroxyethyl methacrylate (HEMA) and 3-trimethoxysilyl propylmethacrylate (TMSPMA), able to crosslink the polymer to the silica network via hydrolysis and condensation of the alkoxysilane functional group. Copolymers of HEMA-TMSPMA were made by the process of free radical polymerization (FRP), using azobisisobutyronitrile (AIBN) as a thermal initiator. Hybrid monoliths were then produced by the sol-gel process with hydrolysed tetraethyl orthosilicate (TEOS) and HCL solution as the inorganic precursor. The HEMA:TMSPMA ratios used for this study were 200:1, 100:1, 50:1, 20:1 and pure HEMA, at a concentration of 60wt% organic, to allow for comparison on the effect of crosslinking on the hybrids properties. Characterization of the copolymer and hybrid monoliths determined their chemical and physical properties. Characterisation techniques included Proton Nuclear Magnetic Resonance (HNMR), Gel Permeation Chromatography (GPC), Fourier Infrared Spectroscopy (FTIR), dissolution study in TRIS solution and which was analysed using Inductively Coupled Plasma (ICP), Thermo-Gravimetric Analysis (TGA), X-Ray Diffraction (XRD), compressive strength testing and Scanning Electron Microscopy (SEM). These methods were used to determine the molecular composition, mechanical properties and characteristic degradation of the copolymers and monoliths. HNMR showed that the FRP process produced highly polymerised copolymers. The sol-gel process produced successful crack-free monoliths with an average gelation/drying period of 3weeks and average of 4 crack free monoliths from samples of 10 for the optimised sol-gel process. The 3 week dissolution study showed a reduction in silica ions release rate and plateaued at a lower concentration with increasing TMSPMA content and hence a higher degree of cross-linking, with a plateau of Si release between week 2 and 3. XRD shows that no crystalline structures formed on the surface of the hybrids, which is expected as TRIS doesn't contain phosphorus or calcium meaning that no precipitates are expected. Mechanical testing shows that the 200:1 HEMA-TMSPMA monoliths have the highest compressive strength, and Pure HEMA monoliths are the most brittle as expected by the materials natural character, with values of 134.6 ± 19.80 MPa and 42.6 ± 17.39 MPa respectively.
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Mutation Analysis Of Kras And Braf Hotspots In Moroccan Patients With Colorectal Cancer
By Hajar JaddaBackground: Oncogenic activation of the RAS/RAF signaling pathway induces resistance to anti-epidermal growth factor receptor targeted therapies in patients with colorectal cancer. We investigated the occurrence of BRAF exon 15 and KRAS codons 12 and 13 mutations in patients with colorectal cancer. Patients and Methods: Forty-seven samples from patients with metastasic colorectal adenocarcinomas were studied for BRAF exon 15 and KRAS codons 12 and 13 mutations. From formalin-fixed paraffin-embedded tissue specimens, macrodissection was used to remove specifically the tumor tissue. After DNA extraction, conventional PCR was performed and the DNA was analyzed by direct sequencing. Results: KRAS codon 12 or 13 mutations were present in 51% of patients. Gly12Val mutation was present in 21% of all patients, Gly12Asp in 15%, Gly13Asp in 6%, Gly12Arg in 4%, Gly12Cys in 2% and Gly12Ala in 2%. No BRAF mutation was highlighted. Conclusion: Our data suggest that KRAS mutations are more frequently than BRAF mutations in Moroccan patients with colorectal carcinomas. To our knowledge, we are the first to report such a high proportion (more than 50%) of potentially non responsive patients for the anti-EGFR treatment in Morocco. These results show that, without doubt, the method we used was accurate, cost-effective and time-efficient.
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Ability of Qatar’s native plant species to phytoremediate industrial wastewater in an engineered wetland treatment system for beneficial water re-use
Engineered wetland (EWL) is a land treatment system that utilizes natural processes to improve water quality. The EWL system consists of vegetation, aquatic organisms, soils and the associated microbes designed to assist in improving water quality through phytoremediation. Engineered wetlands are commonly utilized to improve municipal wastewater quality however, such technology is not common in treating industrial wastewater (IWW) from oil and gas operations and further, EWL technology has not been tested or implemented in Qatar. EWL technology is promising for Qatar due to land availability, hardy native plant species and suitable climate. The efficiency and sustainability of EWL is highly influenced by its treatment media. A joint project between ExxonMobil Research Qatar (EMRQ) and the Environmental Studies Center of Qatar University (ESC) is carried out to investigate the abilities of native and/or cultivated plant species to improve IWW quality through phytoremediation. Experiments using selected plants were conducted using soil cultures and sand cultures in the first stage of the project, while the second stage will be expanded to include water cultures. The change in the microbial flora in sand cultures and soil cultures at the rhizosphere was also monitored during the course of the growth of plants. This presentation will report results for the effectiveness of the the native plants potential in removing, degrading and eliminating constituents from IWW. Results indicate that IWW had detrimental impact on all plants studied in the sand culture. On the other hand, the results of soil culture indicate that only barley was negatively affected by IWW. The results also showed that common reed (Phragmites Australis) could be a promising aquatic native plant in any phytoremediation project in the future.
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Matrix acid stimulation: What are the gaps to bridge from lab to field?
Acidizing core flooding experiments in carbonates are typically performed in the laboratory in order to observe different physical phenomena and to design acid stimulation jobs in the field. The experiments are usually well defined in terms of mineralogy, permeability, porosity, pressure, temperature and salinity. During the tests, key parameters are analyzed such as the pore volume of acid needed to create wormholes and breakthrough as well as pressure and permeability time-evolution. In reality, the result of an acid stimulation in the field is difficult to predict because of the heterogeneous nature of carbonate formations, complexity of such reactive transport phenomenon, and more importantly the uncertainties related to subsurface well conditions. Stimulation models and numerical tools can help bridge the gap between the laboratory observations and real field applications. We utilize selected core flooding results obtained from the QP - TOTAL collaboration on acid stimulation and use these measurements as input for different acid stimulation software. Subsequently, a benchmarking of commercial and academic acid stimulation software at the well scale is performed. The main criteria for this comparison are the capacity of modeling improved acid stimulation under constant or varying pumping rates, the capability of modeling complex fluids such as chemical diverters and relative permeability modifiers and the ability to simulate different well configurations. Then, a sensitivity analysis on selected key parameters such as the dissolution model, pore volume to breakthrough and solute velocities is conducted. Finally, predictions from numerical models are compared to acid stimulation field results from literature, for Middle Eastern carbonate. We try to history match the results and we identify main areas of improvement for future development of acid stimulation software.
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Environmentally-friendly smart coatings for materials protection: State of the art and future perspectives
More LessThe huge economic impact of the corrosion of metallic structures is a very important issue for all modern societies. Reports on the corrosion failures of bridges, buildings, aircrafts, automobiles, and gas and oil pipelines are not unusual. It is estimated that corrosion and its consequences cost developed nations between 3% and 5% of their gross domestic product. The process involving hexavalent chromates is the most effective and most widely used conversion coatings for corrosion protection for many metals and alloys. However, the carcinogenic effect and environmental waste due to chromates are well documented. The concept of 'self-healing', 'self-repairing' or 'smart' materials has in recent years been developed experimentally in new types of manufactured materials creating a new class of multifunctional materials of self healing properties. Such properties add functionality to the materials to heal themselves automatically after mechanical, physical or chemical damages caused, for example, by scratch, impact, abrasion, erosion, friction, corrosion, wear, fire, ice, etc. The development of active corrosion protection systems for steels, Al and Mg substrates is an issue of prime importance in key industries, including petroleum, chemicals, transportation. The present work provides new insights towards the development of new protective systems with self-healing functionality. The proposed coatings characterize with the self-healing ability, ease of application at low cost and safety. When the new chromate-free surface treatments are applied prior to Fluoropolymer top coating, the coatings exceed 2000-hour salt spray tests. The approach described herein can be used in many industrial applications where active corrosion protection of materials is required.
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Constructing a green Qatar: A case study
More LessThe rapidly developing infrastructure in Qatar requires an increasing supply of quality construction materials. Qatar has limited resources of quality natural aggregate and has to import coarse aggregate for use in asphalt and concrete applications. At the same time, vast quantities of alternative and recycled aggregates are available with limited use in the construction industry. The innovative use of recycled aggregate in construction is to be demonstrated to further support the construction of a sustainable and green Qatar. This leading building trial demonstrates the use of new aggregate materials in three one-story buildings. Alternative materials are sourced from recycled aggregate such as excavation waste (EW), construction & demolition waste (CDW), secondary aggregate of incinerator bottom ash (IBA) from municipal waste, and crushed rock fines (CRF) as crushed limestone rock for use in structural concrete and concrete blocks. Construction specifications need to consider locally available materials and exposure conditions in the Middle East. This leading trial is to provide practical evidence on the performance of local materials when exposed to actual weather conditions in Qatar. The performance of the newly developed concrete products made with alternative aggregates will be monitored for one year. The findings will be used for updating the Qatar Construction Specifications (QCS 2010).
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Techno-economic assessment of CO2 Quality Effect on its Storage and Transport (CO2QUEST)
Authors: Haroun Mahgerefteh, Solomon Brown, Sergey Martynov, Michael Fairweather, Robert Woolley, Mohamed Pourkashanian, Richard Porter, Nilay Shah, Niall Mac Dowell, Heike Ruetters, Susanne Stadler, Thomas Novak, Regis Farret, Christophe Proust, Jerome Hebrard, Philippe Gombert, Celine Dupuis, Dimitrios Tsangaris, Ioannis Economou, Jeroen Van Wittenberghe, Martin Liebeherr, Dennis Van Hoecke, Joachim Antonissen, Muhammad Arafin, Jacob Bensabat, Auli Niemi, Yu Jianliang and Shaoyun ChenThe ultimate composition of the CO2 stream captured from fossil fuel power plants or other CO2 intensive industries and transported to a storage site using high pressure pipelines will be governed by safety, environmental and economic considerations. So far, most of the studies performed on this topic have been limited in scope, primarily focusing on investigating the impact of the CO2 stream impurities on each part of the Carbon Capture and Sequestration (CCS) chain in isolation. This is a significant drawback given the markedly different sensitivities of the pipeline, well bore materials and storage sites to the various impurities. For example, given the risk of water table contamination, trace elements such as Lead, Mercury and Arsenic in the CO2 stream are of far greater concern in an aquifer storage site than compared to the pipeline. On the other hand, even small concentrations of water in the CO2 stream are detrimental to the pipeline due to corrosion, but of benefit even at high concentrations during storage given the immobilisation effect of water on CO2. 'What is good for the pipeline is not necessarily good for storage'. It is clear that the optimum composition and concentration of the impurities in the captured CO2 stream involves a delicate balance between the different requirements within the CCS chain, spanning capture, transportation and storage, with cost and safety implications being the over-arching factor. Pivotal to these considerations is an understanding of the impact of the impurities on the physico-chemical properties of CO2 and its hazard profile. This paper presents and overview of the current FP7 European Commission CO2QUEST project involving the collaboration of 12 industry and academic partners in Europe, China and Canada aimed at addressing fundamentally important and urgent issues regarding the impact of the typical CO2 streams impurities captured from fossil fuel power plants on its safe and economic transportation and storage. The work programme, spanning 36 months, focuses on the development of state-of-the-art mathematical models, backed, by laboratory and industrial-scale experimentation using unique EC-funded test facilities to perform a comprehensive techno-economic, risk-based assessment of the impact of the CO2 stream impurities on the phase behaviour and the physico-chemical reactions governing the pipeline and storage site integrities. The above involves the determination of the important CO2 mixtures that have the most profound impact upon the pipeline pressure drop, compressor power requirements, pipeline propensity to ductile and brittle facture propagation, corrosion of the pipeline and well bore materials, geochemical interactions within the well bore and storage site, and the ensuing health and environmental hazards. Based on a cost/benefit analysis and whole system approach, the results will in turn be used to provide recommendations for tolerance levels, mixing protocols and control measures for pipeline networks and storage infrastructure thus contributing to the development of relevant standards for the safe design and operation of CCS. Acknowledgement: The CO2QUEST project has received funding from the European Union 7th Framework Programme FP7-ENERGY-2012-1-2STAGE under grant agreement number 309102.
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Towards development of world-class standards for designing surface water infrastructure in Qatar: Derivation of design rainfalls
Authors: Abdullah Al-Mamoon, Niels E Joergensen, Ataur Rahman and Hassan QasemThe Qatar National Vision (QNV 2030) defined long-term vision of developing a world class and sustainable infrastructure network in Qatar. In order to achieve goals of QNV, Ministry of Municipality and Urban Planning (MMUP) of Qatar has carried out a comprehensive rainfall study for estimation of design rainfall for Qatar. This study is aimed at development of guidelines and standards for the design of storm and surface water infrastructure in Qatar. For design and operation of water infrastructure, erosion control and many other environmental and stormwater management tasks, design rainfall is a fundamental input. The developed countries have spent millions of dollars to derive national standards of design rainfalls, generally known as intensity-duration-frequency (IDF) curves. For Qatar, the old IDF data was developed in 1991 based on a limited data set and basic statistical approaches. Since then there have been significant developments in statistical techniques to derive IDF data and moreover at many locations in Qatar, the length of the observed rainfall data has increased notably. These have given the opportunity to derive new sets of IDF data for Qatar. This paper presents an overview of the derivation of new set of IDF data for Qatar. The adopted approach uses method of L-moments, which reduces the impacts of sampling variability on the analysis. This also adopts index regional frequency approach with the mean rainfall as the scaling factor. The daily rainfall data from 32 stations located in Qatar and nearby Gulf countries has been used to form a homogeneous region based on the criteria of Hosking and Wallis. The application of goodness-of-fit criteria resulted in the selection of the Pearson Type 3 distribution as the best-fit distribution for the 24-hour duration annual maximum rainfall data in the Qatar region. To apply the developed regional method for any arbitrary un-gauged location, a prediction equation is developed where mean annual maximum rainfall is expressed as a function of physiographic characteristics. From a leave-one-out validation approach, it has been found the developed prediction equation can be used to estimate mean annual maximum rainfall with a median relative error of 5.5%. Finally, an empirical approach is used to obtain design rainfalls for other durations due to the limitations of continuous pluviograph data. The newly derived set of IDF curves are based on a larger dataset and more advance statistical techniques than the existing 1991 IDF curves, thus these new IDF data presents a solid scientific basis for stor mwater system design, flood and environmental studies.
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Independent verification of fossil-fuel based CO2 and other greenhouse gas emissions: Example from the Netherlands and possibilities for Qatar
Authors: Harro A.J. Meijer and Wouter PetersGrowing concern about anthropogenic influence on the climate system due to emissions of greenhouses gases into the atmosphere causes governments everywhere around the world to adopt fossil fuel use reduction policies. However, to test if various government-launched measures and incentives really are effective, the fossil fuel based CO2 emissions into the atmosphere should be independently verified. To date, independent verification schemes are still far from common and both national policy and commerical carbon trading relies instead on self-reported emissions, and emission reductions. Such reports are based on inventories: summation of the emissions of all (known!) sources. True independent verification, however, should be based on atmospheric observations and supporting atmospheric transport models such that the sum of reported emissions matches the highly accurately measured concentrations in the atmosphere. The atmosphere is our ultimate record of the real GHG emissions: it neither misreports nor misdetects any GHG emissions. So far, however, only prototypes of such verification schemes are reported in the literature, the most noteworthy example being the "Megacities Carbon" initiative (Duren and Miller, 2011). In our group in Groningen, the Netherlands, we have recently demonstrated the first atmospheric observation based verification of greenhouse gas emissions for the Netherlands (Meesters et al., 2012, van der Laan et al., 2010, 2009). The methodology we used was based on the continuous observations of greenhouse gas concentrations at our atmospheric monitoring tower Lutjewad, in the north of the Netherlands. Additionally, in the case for CO2, we used radiocarbon (14C) and carbon monoxide (CO) observations, which enabled us to discriminate fossil fuel based CO2 from natural sources (and sinks) of CO2. Key to the verification scheme, however, was the way in which we could lead back observed concentrations to fluxes from the land to the atmosphere. We used the tracer Rn for this. Rn is a radio-active, but inert gas that emanates from soils at a more or less constant rate. Using this rate, and monitoring the Rn concentration, enabled use to translate greenhouse gas concentrations back into surface fluxes. To achieve this, we also made use of an atmospheric transport model, with which we could both calibrate our results, and test them for robustness. Our efforts produced total emissions (in a 3-year average) for the Netherlands for CH4, N2O and fossil fuel derived CO2 with a combined uncertainty of about 25% Improving the accuracy of such an effort is certainly possible. New, accurate and low-maintenance measurement instruments facilitate the efficient implementation of monitoring stations. Better, higher resolution atmospheric modelling is available, too. Using such advanced tools would make the independent verification to a level of ±10% possible on a yearly basis. Qatar, and especially the Doha agglomeration, would form a perfect testbed for such an excercise. The city, with its strong emissions is relatively isolated, and biospheric sources and sinks, which are much larger than the anthropogenic sources almost everywhere else in the world, are very small in Qatar, thanks to the barren desert.
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Advanced techniques for characterization of Qatari coral physiology and health under variable environmental conditions
Authors: Nayla Mohammed Al-Naema, Suhur Saeed Cécile Richard, Edouard Hörli and Eric FebboBackground: Research at ExxonMobil Research Qatar (EMRQ) includes studies on sensitive ecosystems such as coral reefs, which are a key component of Qatar's marine environment. Understanding the potential impacts from industrial activities and changes in the natural environment, as well as the development of effective monitoring technologies are needed for environmental management of these resources. Using conventional monitoring techniques it can be difficult to identify changes in coral health at early stages, or to obtain objective quantitative data for use in predicting and possibly managing impacts. EMRQ is conducting research to advance a cutting-edge technology - Pulse Amplitude Modulation fluorometry (PAM) that determines health of coral by analyzing the photosynthetic efficiency of algae that live within the coral. EMRQ has shown this technology to be effective for use in the Qatar marine environment through field missions and is currently validating and expanding understanding and application of this technology through unique laboratory studies under controlled conditions. Coral (Acropor sp.) samples collected from mother colonies in Umm Al-Arshan (North of Qatar) are maintained in controlled aquarium conditions. Lab based PAM was used to closely monitor health of corals under baseline conditions and by varying environmental stressors. The study demonstrated for the first time the successful culture of Qatari Acropora in a laboratory setting in Qatar and was used to obtain detailed visual images of photosynthesis processes of the algae associated with the coral under variable conditions. Objective: The specific objectives of the work presented here were to: a) detect biological responses of corals (Acropora and Porites sp.) to different levels of stress stimulants including light, salinity and temperature. b) Monitor coral health including protein and chlorophyll concentrations, zooxanthellae density, and growth rate using microscope imagery and PAM data. c) Compare PAM results from diving cameras to PAM used in laboratory conditions. Methods: Coral (Acropor and Porites) samples were cultured in a pre-acclimatized laboratory aquarium and baseline health was assessed utilizing PAM to indicate photosynthetic conditions. Two aquariums (control and testing) were used to conduct the studies and light conditions, salinity and temperature were varied in the testing aquarium. Other water quality parameters were consistently maintained for both tanks. Coral growth rate and PAM measurements were executed monthly, protein concentration was determined using UV analysis and zooxanthellae were enumerated using a hemocytometer at the beginning and end of the experiment. Results: This study showed that light and temperature conditions are critical factors that have an effect on the Acropora and Porites health. Acropora showed high sensitivity to these conditions, whereas the Porties are found to be more tolerant. Extreme conditions can increase corals susceptibility to disease and eventually bleaching. Conclusion: This study reveals the effect of the varying conditions of light, temperature and salinity on the growth and health of different species of the Qatari corals in a laboratory controlled set-up, different species have different reactions to the same stress conditions. Collected parameters including protein content, zooxanthellae density, growth rate and PAM were used to obtain detailed conclusions about coral health status.
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CO2 and renewable electricity as feedstock for fuels production: New pathways using existing technologies
Authors: Ruud Van Den Brink, Wim Haije and Stephane WalspurgerThe case for CO2-based fuels Coal and natural gas are still the main fuels for electricity generation. Traditional power plants have many advantages: they are very reliable and can relatively easily be ramped up and down to follow the electricity demand. However, their one disadvantage, their huge CO2 emission, is so big that they are replaced by alternatives. These alternative electricity generation sources, like solar and wind power, do not emit CO2. However, they are intermittent and cannot be used to follow the electricity demand. With the growth of renewable electricity production, the demand for storage of renewable electricity also increase. Oil-based transportation fuels also have many advantages: they can be stored and transported easily and they can be used to propel any transportation device, from mopeds to ocean liners and from passenger cars to airplanes. However, their high CO2 emission makes an alternative necessary. In many cases electric transport is an excellent alternative, but for long-distance heavy transport, shipping and aviation, hydrocarbon-based fuels will still be in demand. All these pressing problems can in principle be solved by using CO2 and renewable electricity to produce hydrocarbon-based transportation fuels. Costs of CO2-based fuels An inventory of CO2 utilization options shows that commercial options do exist and are ready to be deployed at commercial large scale. The major unit operations in the chain from renewable power and CO2 to fuels are PV-panels, CSP-plants, wind turbines, water electrolysis, CO2 capture, syngas conditioning, and Fischer-Tropsch synthesis (see Figure below). Source: Haije & Geerlings dx.doi.org/10.1021/es203160k. Environ. Sci. Technol, 2011 In this paper we present results of a study in which we have compared the costs of the production of certain CO2 based fuels (hydrogen, methanol, methane, and petrol) with the current market prices of the fossil counterparts of these fuels. As expected, the costs of the CO2-based fuels is in general higher, but the gap seems bridgeable. For example, for producing methanol from CO2 from renewable electricity costs 800 to 1500 USD per ton, while methanol from natural gas costs around 500 USD per ton. A major factor determining the costs, are the investments in electrolyzers to convert the renewable power into hydrogen. Especially, at low availabilities of renewable power, the electrolyzer costs drives up the costs of the CO2-based fuels. Development needs Adaptation of existing technology or development of novel technology is necessary to reduce costs and to cope with the intermittent nature of renewables (e.g., rapid ramp-up and ramp-down). The development of improved electrolyzers at lower costs and high efficiency is important. ECN is developing technology for the conversion of CO2 and hydrogen (a separation-enhanced reversed water-gas-shift process), that is especially suited for the CO2-based fuel applications. Conclusion The production of CO2-based fuels using commercially available technologies is possible. These fuels not only re-cycle CO2, but also store renewable electricity and replace fossil-based transportation fuels. The costs are still higher than fossil-based fuels, but by developing novel technologies, this gap can be reduced.
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Renewable energy in the GCC: Reducing the fuel and carbon footprint
Authors: Rabia Ferroukhi, Arslan Khalid and Shashi PrakashThe harsh climate of GCC, rapid industrialisation and energy subsidies have led to a per capita energy consumption that is much higher than the larger economies of the US, China and the EU. The situation is likely to become worse as more electricity, desalinated water and gasoline will be needed to fuel the ambitious national plans for industrial and economic growth. Localised shortages of natural gas already exist, and the long term viability of a fossil fuel based economy is being discussed at different levels of decision making. Therefore, in order to diversify their energy mix, increase energy security, and save the national fossil fuel sources for export, the GCC countries are setting up targets for deployment of renewable energy (RE). The objective of this paper is to analyse the impacts of these targets on the CO2 emissions and fuel savings. The paper addresses commitments of the GCC governments to their diversification targets by reviewing their recent efforts in renewable energy project implementation, investments in local RE industry, institutional developments, and support to research institutions. Based on the national renewable energy targets for 2020 and 2030, the paper estimates the impacts of the diversification of the GCC energy mix on CO2 emissions and fuel savings. The monetory value of these savings is also estimated based on assumptions of future carbon and fuel prices. Some of the GCC countries have already defined their choice of renewable energy technologies, for others, we develop a potential RE mix comprising of solar, wind and waste to energy technologies. Our findings indicate that the implementation of the RE targets in the GCC can result in very large cumulative CO2 emission savings and fuel savings. The opportunity costs from fuel savings alone would be substantial. In addition, our work shows that the renewable energy targets of the GCC governments are backed by practical efforts that include RE project development, local industry support and domestic capacity building programmes. Successful implementation of these national targets can result in significant savings of valuable fossil fuel resources while significantly reducing the per capita carbon footprint of region.
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Isolation of promoters for specific temporal and spatial genetic engineering against nematodes (Heterodera glycines) in soybean (glycine max)
More LessNematodes cause billions of dollars of damage each year to agricultural crops worldwide. Nematicides are costly and environmentally detrimental. Crop rotation does not eliminate nematodes, but merely decreases crop damage. For successful engineering of transgenic plants for nematodes resistance, it is important to regulate plant resistance through promoters that over-express resistance genes or produce RNAi in the correct cells at the proper time. Data from our previous microarray experiments showed a number of genes that are responsive and activated at feeding site upon nematode infection after 3, 6 and 9 days. In this investigation, we identified and isolated seven different promoter regions, supposedly harboring different regulatory elements upstream to seven responsive genes that are highly expressed in the nematode feeding site. The upstream promoter regions were cloned, sequenced and tested in our newly developed expression vectors series, pJan25S (NCBI: KC416200), pJan25T (NCBI: KC416201) and pJan25X (NCBI: KC416202), that are an enhancements of pGWB533 for pro- moter testing.. Accumulation of the products of reporter genes encoding green fluorescent protein and b-glucuronidase (GUS) was monitored after transformation of onion cells using biolistics gene transfer. These promoter constructs were also prepared for transformation in Arabidopsis and soybean. These promoters will provide scientists with useful regulators for expressing genes and gene products that may inhibit the life cycle of the nematode at nematode feeding site. The same approach can be used for enhancing resistance of Qatari important plants against different pathogen.
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Microbial dolomite formation in the Dohat Faishakh Sabkha, Qatar
More LessDolomite is a common sedimentary mineral in the geological record and common in hydrocarbon reservoirs. However, its origins have remained a controversial problem in sedimentology for more than 200 years. In the 1960's, the hypersaline coastal sabkha of Dohat Faishakh (Qatar) was one of the first settings recognized as a rare modern geological environment where dolomite formation occurs. Studies conducted in the Arabian Gulf led to the development of the first models for low temperature dolomite formation. However, numerous laboratory experiments, which utilized the physico-chemical parameters recorded in modern hypersaline environments to replicate conditions for dolomite formation at Earth surface temperatures and pressures, proved unsuccessful. Since the mid-1990's, the discovery of specific microbes that can mediate dolomite precipitation added a new "biological dimension" to the study of this enigmatic mineral. Based on this biological approach, we returned to the Dohat Faishakh sabkha to test the hypothesis that microbial activity plays an important role for minerals formation in this apparently inhospitable environment. The study of sediments collected in short cores taken along a transect from intertidal to supratidal zones revealed a close association between microbial mats and dolomite. Authigenic dolomite occurs within surface and buried microbial mats, which are composed of exopolymeric substances (EPS). The cation-binding effect of the EPS molecules apparently plays a crucial role for the biomineralization process, influencing the composition of the precipitate. Mineral formation within EPS appears to be enhanced by evaporation with consequent supersaturation of the pore waters with respect to dolomite. Partial EPS degradation during diagenesis may also provide an additional source of cations. These results suggest that the main factor controlling the occurrence of dolomite within the sediments of the Dohat Faishakh sabkha is the presence of an organic matrix (i.e., the buried microbial mats constituted of EPS) and not, as proposed in previous studies, a replacement process transforming primary aragonite into dolomite. Aragonite and dolomite likely precipitate nearly simultaneously from evaporated marine waters. The presence vs. absence of EPS determines whether the carbonate minerals will have a dolomitic or an aragonitic composition, respectively. The next step of our research will be to characterize the chemical composition of the EPS molecules present in the microbial mats and possibly identify the specific molecule involved in dolomite formation. The study of this poorly understood biomineralization process can provide new insights for interpreting micritic dolomite, which is common in oil and gas reservoirs. This research is also relevant for the search of life on other planets, such as Mars, where recent observations have identified the presence of vast evaporitic sedimentary deposits.
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Composition and origins of polycyclic aromatic hydrocarbons (PAHs) in the coastal sediments of Qatar
More LessThe spatial distribution of Polycyclic Aromatic Hydrocarbons (PAHs)was investigated in sediments from 16 sites from the east coast of the Arabian Gulf of Qatar. Sixteen US-EPA priority PAHs and their alkylated homolog were determined. The highest PAHs concentrations were found in sediments inside fishing Harbors as well as at offshore locations close to an oil fields. Most inshore coastal locations showed low PAHs concentrations (95.4- 27.88 ng.g-1). Concentrations of PAHs in Qatar coastal sediments indicated that the area has low contaminate concentrations (<100 ng/g-1) except inside the fishing Harbor and offshore where moderate levels of pollution were detected (100=SPAHs=1000 ng.g-1). The spatial distribution of the concentrations of 16 parent PAHs and their alkyl homologs are presented and the possible sources of the PAHs have been elucidated using diagnostic ratios. Contaminant patterns and diagnostic ratios indicated that the PAHs were mainly from petrogenic sources, with higher contributions of pyrogenic PAHs near industrialized and urban areas.
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Traffic-speed pavement structural evaluation to enhance mobility and road safety
More LessPavement evaluation is performed to assess the functional and structural conditions of roadways for routine monitoring in order to select proper corrective actions. Functional condition is related to the roughness and ride quality of a highway section. Structural condition deals with a pavement's ability to withstand traffic loads and environmental conditions, which can be measured by determining material properties, layer thicknesses, and surface deflections. The evaluation of pavement structural capacity and integrity is an important component of Pavement Management System (PMS) to assist in the selection of suitable maintenance and rehabilitation strategies. However, testing of in-service pavements is a major challenge due to traffic delays, lane closure, and safety of the travelling public and the highway workers. Traffic-speed pavement evaluation methods offer the potential to cost-effectively characterize the structural capacity of the road network without major delays or safety risks during measurements. These evaluation devices include innovative technologies such as continuous deflection testing including the Rolling Wheel Deflectometer (RWD) that collect data at traffic speeds that can be used to evaluate pavement structures. This study describes a detailed field evaluation of the RWD system in Louisiana in which pavement sites representing a wide array of pavement conditions were tested. The RWD consists of semitrailer applying a standard load on the pavement structure by means of a regular dual-tire assembly over the rear single axle. The RWD measures wheel deflections at the pavement surface by means of a spatially coincident method, which compares the profiles of the surface in both undeflected and deflected states. As the RWD travels on top of the pavement, triangulation lasers mounted are used to measure surface deflections. In this study, field measurements were used to assess the repeatability of RWD measurements, the effect of truck speeds, and to study the relationship between RWD and falling weight deflectometer (FWD) deflection measurements and pavement conditions. Based on the results of the experimental program, it was determined that the repeatability of RWD measurements was acceptable with an average coefficient of variation at all test speeds of 15 percent. In addition, the influence of the testing speed on the measured deflections was minimal. This study also developed and validated a direct and simple model for determining the pavement structural number (SN) using RWD deflection data. To develop this model, the relationship between the average RWD surface deflection and the peak FWD deflection was investigated. The developed model correlates a pavement's SN to two RWD-measured properties (average RWD deflection and RWD index). Results showed a good agreement between SN calculations obtained from FWD and RWD deflection testing. While the developed model is independent of the pavement thickness and layer properties, it provides promising results as an indicator of structural integrity of the pavement structure at the network level. The fitting statistics support the use of the proposed model as a screening tool for identifying structurally deficient pavements at the network level.
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Managing of invasive species of red palm weevil (Rhynchophorus ferrugienus)
More LessRed palm weevil-RPW (Rhynchophorus ferrugienus Olive, Coleoptera, Curculionidae) was first observed in India in 1917 as a serious pest on date palm (Phoenix dactylifera L.). It was introduced in Arabian Gulf countries in the mid-1980s and now considered to be one of the most destructive insects on date palm. The larvae are responsible for damaging and they cause the death of palm tree. There is no data available about the loss caused by this insect. This study showed the strategies used to control invasive species of RPW. These strategies include the following methods: (1) Declare the infested area as a quarantine or isolated area prohibiting the movement of plants, persons, animals or others. (2) Eradicate invasive species as soon as it is discovered quickly and population levels remain low. (3) Mechanical control involves using machinery or fire to remove the insect. (4) Keeping potentially damaging out in the first place where it was observed. (5) Biological control involves introducing a predator or parasite in an attempt to lower the population dynamic. (6) Chemical control involves using chemical pesticides to kill all the stages. (7) The newest technology for managing invaders species of RPW is using pheromone traps.
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Size-dependent elemental analysis of particulate matter pollutants in the UAE
More LessWe report on the study of industrial and natural aerosol pollutants in various UAE locations. Both indoor and outdoor atmospheres were sampled at residential and work places. The eventual goal of this study is to identify potential health risks of airborne pollutants. The size-dependent distributions of various elements and source apportionment of aerosol particulate matter was determined. Sampling was done using a multi-stage cascade impactor capable of sorting sizes with aerodynamic cut-off diameters ranging from 16 to .0625 micro-m in 9 steps. The samples collected on membrane filters, were studied using X-ray fluoresce (XRF), micro-XRF, Scanning Electron Microscopy (SEM), and optical microscopy. Results obtained so far show the main two sources of particulate matter pollutants are: airborne desert dust and airborne dust from building materials. Trace elements on the other hand are related to industrial pollution. Microscopy methods show that mass concentration of fine particles is considerably higher than that of coarse particles. Elemental analysis obtained with micro-XRF show that Ca, Si, Al, and Fe are present on all membranes but dominant on large cut-off membranes ( > 2 micro-m) while Si, P, Zn, S, Cu, K, and Ti are found on small cut-off membranes (< 1 micro-m). Elements appearing in trace quantities are: Zn, Fe, Cu, Br, Pb, Mn and mainly attributed to industrial pollution. It is noted that Ti, for example, is found mainly indoors possibly resulting from wall paints. On the other hand, elements such as Mg, Na, Cl, are originating from sea salts and hence are found both indoors and outdoors. Future work is underway to include complimentary methods such as ion beam techniques such as Proton Induced X-ray Emission(PIXE) and Proton Induced Gamma-ray Emission (PIGE) to identify lighter elements and synchrotron X-ray Absorption Spectroscopy( XAS) for chemical analysis.
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Trace metals in urine of farm workers in Qatar: Health implications
By Nora KuiperHuman biomonitoring (HBM) is an emerging risk assessment tool that can be used to decipher the exposure and possible health effects of environmental chemicals. This report presents the results of a pilot HBM study involving 239 farmers in Qatar exposed to chemical fertilizers and pesticides as well as other environmental contaminants associated with the rapidly growing energy industry in the country. This cross-sectional study is based on urine as a biomarker and the objectives are to a) introduce HBM as a research tool in Qatar, b) quantify levels of trace elements and organic contaminants in urine from farmers and c) determine risks associated with the exposure to these contaminants using a detailed exposure questionnaire and biomarker results. This presentation focuses on results of 14 elements (V, Cr, Mn, Fe, Co, Ni, Cu, As, Se, Mo, Cd, Ba, Pb and U) in urine samples; results of the organic contaminants are being presented separately. The data set associated with this study is the first of its kind in Qatar. All results were within normal global ranges for farmers with the exception of Mo (elevated) and Fe, Cu and Co (depressed levels). The mean and range of these four elements are: Mo (108 µg/L, 9.59 - 737 µg/L), Fe (54.1 µg/L, 2.68 - 4071 µg/L), Cu (14.6 µg/L, 2.82 - 111 µg/L) and Co (0.505, <0.016 - 3.95 µg/L). Mo is a common constituent of oil and gas processes and this study suggests that it can be used as a biomarker of the energy industry in Qatar. The significance of the low levels of Cu, Co and Fe in terms of potential metabolic or dietary deficiencies is being investigated. This pilot study can serve as a model for future population scale human biomonitoring within the country and region.
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New synthetic pathway for preparation of cyclic-substituted bridged bicycopentadiene derivatives
By Hind MAMLOUKSince their discovery in the 1950's, cyclopentadiene-based metallocene complexes have attracted considerable attention in biochemistry as well as in catalytic processes in the chemical and pharmaceutical industries and more recently in the field of medicine as a potential treatment for cancer. Amongst them, complexes containing saturated cycles as substituents on the cyclopentadienyl ring itself (Figure 1) are particularly interesting as precursors to a-olefins polymerization catalysts. Their interest might lie in the greater stability or increased activity or differentiated selectivity of the resulting catalyst and in the better control of the catalyst residues. The unsaturated ligands and most specifically the ?5-indenyl types might be directly available, while the classical way to obtain the saturated ones is via the catalytic hydrogenation of the parent molecules. However, catalytic hydrogenation reactions usually require severe conditions that are not always compatible with the stability of the target molecules. We are interested in developing versatile, flexible and efficient routes to ligands containing saturated ring systems attached to the cyclopentadienyl ring. This type of ligands, characterized by new structures, allows the synthesis of differentiated metallocene complexes, having outstanding performance in catalytic processes for the polymerization of a-olefins. We report here the synthetic protocols for saturated ligands precluding the hydrogenation step, starting from cycloalkanones. Elegant synthetic routes have been studied. However, the overall yields were often low or the method used was of limited applicability.
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Integrated crop and environmental management for improved productivity and food security
By Abul HudaImproved productivity requires informed decisions on a number of issues including crop, water, soil and financial risk management. In this paper, we use some case-study examples to illustrate how crop simulation models can be used to analyze the threats and opportunities arising from climate variability, climate change, and market variation for a focus crop at selected locations. We then demonstrate how this analysis can be coupled with site-specific soil information to inform soil and crop management strategies so that crop yield potential can be realised. Two sites in eastern Australia, Dalby (27 degrees S) and Corowa (36 degrees S) were used as a case study to analyse wheat growing conditions at two contrasting locations. Average annual rainfall ranged from 540 mm in Corowa to 675 mm in Dalby, with rainfall summer dominant in the north and winter (growing season) dominant in the south. Simulated crop growth parameters were assessed using APSIM (Agricultural Production Systems Simulator) and the data set was split into two time periods (1957-1983 and 1984-2011) to allow comparison. Dalby in the north showed a shift to decreasing simulated grain yield in the later period. For example the median grain yield at Dalby was reduced from 4000 kg/ha to a little over 3000 kg/ha. The decreased yield probabilities were accompanied by increased water stress during critical growth stages at Dalby. APSIM simulations highlight the climate change/ variability at Dalby with current 80 percentile yield of about 4000 kg/ha whereas at Corowa, there is no evidence of climate change/ variability and the 80 percentile yield is about 6000 kg/ha. The soil at the Dalby location is a Vertisol, while that at Corowa is a Solonetz. We used the paper-based DSS (Decision-Support Systems) called SCAMP (Soil Constraints and Management Package). Management strategies for ameliorating production constraints are identified, including the use of amendments such as gypsum and soil analyses to give fertiliser recommendations. Fertiliser management (fertilizer rate, timing and placement) can then be optimised using the CD-based DSS SafeGauge for Nutrients to maximise nutrient use efficiency and to minimise the environmental risk associated with off-site nutrient movement. Climate variability and economic return considerations indicate Corowa is the better choice for long term food security and economic returns than Dalby. SCAMP and SafeGauge for Nutrients indicate that different soil management practices would be needed at the two sites to realise yield potential. This case study thus demonstrates the principles of our new research project, funded by the Qatar National Research Fund (QNRF) through its National Research Priority Program, in that the climate of a site of interest is analysed using a crop growth model to firstly indicate if the crop can grow there, what would be the likely yield, and what would be the likely effects of climate change on yield potential. Economics then dictate if the yield is high enough and stable enough to warrant development. SCAMP and other relevant models are then used to identify soil constraints that will need to be mitigated to maintain productivity.
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Adaptive water resources management under global environmental change: Examples from a small semiarid Mediterranean municipal district
Authors: Ioannis Tsanis and Aristeidis G. KoutroulisClimate change is expected to have a significant impact on the hydrologic cycle, creating changes in freshwater resources. Globally, the supply of freshwater far exceeds human requirements. However, by the end of the 21st century, these requirements will begin to approach the total available water. Regionally, water demand for various sectors already exceeds supply. This will most probably get worse with increasing population and societies' changing water demands. On the other hand, many experts believe that we are currently (2013) on the 4°C path and the 2°C target has become unrealistic because it would require reductions in greenhouse gas emissions that would be too deep and too abrupt to be sustained by the world's economy. Thus, policymakers, businesses and other decision-makers need to plan ahead for adaptation to changes in climate associated with higher levels of global warming. This requires coherent information on the new conditions which must be adapted to, and the consequences of different courses of adaptation action. The Mediterranean has been described as one of the main climate change "hot-spots", with recent simulations showing a collective picture of substantial drying and warming. This effect appears more pronounced during warm periods, when the seasonal decrease of precipitation can exceed control climatology by 25-30%. State-of-the-art climate model projections combined with local hydrological modeling for the island of Crete, Greece, for the period 1970-2100 reveals an overall decreasing precipitation trend (Fig 1.) which, combined with a temperature rise (Fig. 1), leads to substantial reduction of water availability (Fig. 2). Due to projected climate changes the region may face intense droughts that will intensify regional environmental problems. The changes in magnitude and frequency of precipitation will cause severe problems to the water availability which is currently being achieved through traditional methods such as groundwater exploitation, surface water storage and water transport amongst neighboring regions. An alternative method to tackle these water shortages is the exploitation of treated wastewater in the water demanding sector of irrigation which can be proved to be a low-cost and technically feasible solution. The present study deals with the evaluation of water resources availability and wastewater reuse perspectives in the water resources management for the small Mediterranean municipal district of Akrotiri, in northwest Crete. Alternative measures, like transportation of water from distant springs, effluent reuse and desalination are compared via a simple cost-benefit analysis. Wastewater reclamation and reuse cost is favorably compared to the existing practice of surface or/and groundwater use and is far more cost effective than desalination. Moreover, wastewater reuse for irrigation has the main advantage of coastal protection, i.e., zero effluent discharge in coastal areas, while it provides a water source that is not dependent on climate variability. Quantitative analysis provides the data required to develop appropriate strategies on water shortage mitigation through effluent reuse, under a changing climate and increased water demand perspectives.
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Nearshore current and pollutant transport in the island of Crete
More LessThe three dimensional hydrodynamic pollutant transport model IDOR3D was used to simulate the nearshore current structure and pollutant dispersion from various sources. These sources can be municipal or industrial discharges and if are not properly designed will eventually cause environmental problems in the coastal areas. The inflows from sewage treatment plants and creeks affect the current structure within a small distance from the source. Their influence was studied in a high resolution of 100 m model in map sections E1 to E4 (Fig. 1). For the circulation of the northern coasts of Crete were the major urban centers are located, a grid size of 2 km was used. Local meteorological stations provided the wind speed and direction. The bathymetric files and coastlines were obtained from hydrographic digital files and the Digital Bathymetric Model (DBM) produced the gridded data obtained via GIS. Additional information from the Digital Elevation Model (DEM) of Crete with the aid of GIS technology can provide information of point sources discharging at the exit of watersheds in the near shores of the island. Further watershed analysis (hydrological/hydraulic/ pollutant concentration analysis) for rain events provides the pollutographs of ephemeral creeks discharging to the coastal areas that are used as input to IDOR3D. By employing different receiving water conditions (isothermal and stratified) and pollutant source conditions, simulations were performed in the areas E3 to E4 of Fig. 1. The bay in map section E4 was used to simulate the fate of a pollutant discharged over a four-hour period from an ephemeral creek under sea isothermal conditions and a 5m/s NW wind. The environmental impact on the nearshore area and mitigation measures are discussed. The bay in the map region E3 was used to examine the behavior of a contaminant discharged continuously into the bay from a submerged outfall source at two different locations (a) at 10m deep, positioned 250m offshore and (b) at 27 m depth positioned 2 km offshore, with the purpose to analyze the movement of the contaminant with respect to the island and the relative impact to nearshore areas. Concentration time series for a continuous conservative pollutant released with a concentration of 1000ppm into Chania bay under sea isothermal conditions and a 5m/s NW wind for the case (b), are shown in Fig. 2. In the case (a) the contaminant will dispersed between the island and the mainland shallow passage which will potentially cause environmental problems in a highly touristic area. The dilution is less under stratified conditions due to the buoyant forces of the pollutant generated by temperature and density differences, which reduces the amount of mixing due to the contaminant moving quickly to the surface. Complete results from all the cases will be presented in the conference.
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Impact of periodic drought stress on photosynthesis changes in Haloxylon aphyllum
More LessImpact of periodic drought stress on photosynthesis changes was examined in branchlets of Haloxylon aphyllum. Parameters F0, Fm, Fv, and the amounts of chlorophyll a and chlorophyll b were the traits that were measured in this experiment. Drought stress factor was considered as lack of irrigation of potted-seedlings of two haloxylon species in periods 0, 2, 4, 6... 26 and 28 days, and each drought period were repeated 6 times. Analysis of variance showed that drought stress had significant impact on the parameters F0, Fm, Fv, Fv/Fm and t1/2 with 99% probability in the haloxylon. Drought stress intensity was significantly effective on the amount of both chlorophyll a and b and total chlorophyll at 99% level in Haloxylon aphyllum. Drought stress was extremely affected on values of chlorophyll a and b, and reduced them up to more than 50% compared to the control. The obtained data were reviewed within the format of a Randomized Complete Design. Analysis of data was made by using two-side variance analysis; and comparison of averages was made by using Duncan's test. Key words: Haloxylon, photosynthesis, stress, drought, fluorescence
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Assessment of a SIFT-based DEM extraction approach using GEOEYE-1 satellite stereo-pairs in flood mapping of an ungauged basin
Authors: Ioannis Tsanis and Ioannis N. DaliakopoulosA module for Digital Elevation Model (DEM) extraction from Very High Resolution (VHR) satellite stereo-pair imagery is developed and used for a flood plain mapping applications at an ungauged basin. A procedure for parallel processing of cascading image tiles is used for handling the large datasets requirements of VHR satellite imagery. The Scale-Invariant Feature Transform (SIFT) algorithm is used to detect potentially homogeneous features in the members of the stereo-pair. The resulting feature pairs are filtered using the RANdom SAmple Consensus (RANSAC) algorithm by using a variable distance threshold. Finally, homogeneous pairs are converted to point cloud ground coordinates for DEM generation. A 0.5 m × 0.5 m Geoeye-1 stereo-pair acquired over an area of 25 km2 in the island of Crete, Greece is used as input for the module. The resulting 1.5 m × 1.5 m DEM has superior detail over previously developed 2 m and 5 m DEMs that are used as reference, and yields a Root Mean Square Error (RMSE) of about 1 m compared to ground truth measurements. 1D and 2D hydraulic models are used to simulate the rainfall-runoff characteristics and the flood wave kinematics, of the flash flood event of October 17th, 2006 that occurred in Almirida basin, by using the 1.5 m VHR-DEM as an input. Results show that the hydraulic simulation based on the generated VHR-DEM, calibrated and validated via field data, produces an accurate extent and water level of the flooded area, proving that Remote Sensing stereo reconstruction is a promising alternative to the traditional survey methods in flood mapping applications.
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Enhanced assessment of naturally occurring tarmat in hydrocarbon reservoirs using a new laser-induced pyrolysis system
More LessStakes: Tarmat is a dark brown to black, thick, semisolid to viscous mixture of heavy hydrocarbons (bitumen) enriched in asphaltenes, that occurs naturally in hydrocarbon reservoirs. Tarmat has impact on reservoir connectivity, on petrophysical properties, on electrical logs, on hydrocarbon reserves calculation and on water flooding. Estimating the amount and the distribution of tarmat in reservoirs is key to a proper assessment of the viability of and oil and/or gas field development. Objective: Acquire quantitative and high resolution (centimetric or sub-centimetric)measurements of the organic carbon present in a core, at the laboratory or at the coring site, using a new pyrolysis instrument developed by Total (LIPS: "Laser Induced Pyrolysis System". Principle: The LIPS consists in 4 main parts: 1/ A bench for core examination and for acquiring the X,Y,Z coordinates of the laser impact on the core surface, 2/ A core Box Storage Unit (CBSU), allowing to store up to 30 core boxes, 3/ A core Box Sampler, used to carry the core boxes from CBSU to Acquisition Unit and vice-versa, 4/ An cquisition Unit, including a laser gun, several detector(s), a mechanism for moving the laser head and a device for extracting organic vapors. Results: on the contrary to conventional methods, not always satisfactory in tarmat detection, the LIPS provide the following: o A high resolution log of the % of bitumen in the porosity, o The precise location of permeability barriers in reservoirs. o The detection of huge variations and heterogeneities of the bitumen content within the rock porosity. o A better representativeness of the vertical and lateral tarmat distribution in the geological formation. In addition, the high resolution provides a better correlation between tarmat occurrence and lithology, rock type and petrophysics, allowing better models for tarmat occurrence in Oil and Gas reservoirs. Initially developed for petroleum applications, the LIPS could be used for other applications (e.g. mapping of trace amounts of organic material on solid objects).
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LIPS: A new instrument performing high resolution core logs of organic carbon
More LessObjective: This paper describes a new pyrolysis instrument (LIPS: "Laser Induced Pyrolysis System") performing high resolution (centimetric or less) logs of organic carbon on ancient sediment cores . Stakes: the usual methods for determining the quantity of carbon in sediment samples (Rock-Eval, Leco, analysis of thin sections, etc.) are quite expensive, provide low resolution results (typically: one sample every 30cm to 2m) and are time and sample consuming. The processing of geophysical well logs provides low-resolution logs (about 30-50 cm). The characterization of organic carbon on cores needs high resolution, because its abundance may show huge variations at the millimetre or centimetre scale. One of the parameters driving the organic carbon quantity in ancient sediment is the climate. Principle: The LIPS performs automatic core analysis of organic carbon. The principle of the instrument consists in the pyrolysis of organic carbon using a beam of an infrared radiation emitted by power laser diodes focused on a small area of core (up to 20 MW/m2). Different power ranges can be used to adapt the instrument to the material analyzed. The organic vapors, oxidized compounds, micro- and nano-particles emitted during the very short impact (typically, 1-2 seconds) can be detected by various detectors (Photo ionization Detector, Flame Ionization Detector, Mass Spectrometer, Gas Analyzer, etc.) allowing high resolution logs of organic carbon. One hundred data points on a 1 meter core can be acquired in less than one hour. In order to obtain logs of organic carbon the method requires a calibration on a few points using, for instance, Rock-Eval or Organic Carbon Analyser on a limited number of samples. This new instrument consists in 4 main parts: 1/Bench for core examination and for acquiring the X,Y,Z coordinates of the laser impact on the core surface, 2/Core Box Storage Unit (CBSU), allowing to store up to 30 core boxes, 3/Core Box Sampler, used to carry the core boxes from CBSU to Acquisition Unit and vice-versa, 4/Acquisition Unit, including laser gun, detector(s), mechanism for moving the laser head and device for extracting organic vapors. Results: Initially developed for unconventional resources and tarmat in reservoirs, the LIPS is successfully applied for palaeoclimate recording.
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Field testing of membrane distillation for desalination of brines discharge from thermal plants
More LessMembrane Distillation (MD) is a hybrid thermal-membrane process that produces a high quality distillate from concentrated brine. It utilizes either low grade waste heat or solar energy to generate a vapor pressure difference across a hydrophobic membrane. A consortium composed of ConocoPhillips - Global Water Sustainability Center (GWSC), Qatar University (QU) and Qatar Electricity & Water Company (QEWC), was formed to conduct a pilot testing program to assess the suitability of MD at pilot scale to treat brines from thermal desalination plants. This research project aims toward ensuring a sustainable water supply in Qatar, one of the twelve grand research challenges identified recently by Qatar National Research Strategy (QNRS). This presentation summarizes the outcomes of the project including the most relevant conclusions and findings from the field testing program. Bids from the five leading MD technology providers were evaluated and the two most suitable technologies for Qatar environment were selected: a vacuum multi-effect MD unit from memsys in Germany and a single stage air gap MD unit from Xzero in Sweden. Initially, hydraulic testing was conducted at QU and then the pilots were relocated to the QEWC power/desalination plant at Ras Abu Fontas to operate under field conditions. Globally, this is the first study that benchmark MD technologies side by side at pilot scale. The performance of the MD pilot units was evaluated under different operating conditions (temperature, flowrate and feed salinity up to 70,000 mg/L TDS) with the objective of maximizing water production and lowering operational costs. The product stream was of distilled water quality (TDS < 10 ppm), independent of feed salinity. Typical flux values of 5 - 6 LMH were obtained at feed / cooling temperatures of 70oC / 20oC. Results also showed that pretreatment plays an important role on system performance. An important outcome of the project was related to the energy efficiency of the systems. Detailed energy balance showed that a multi-effect design significantly improves energy efficiency. The multi effect system has a performance ratio of 3.0, which was 3 times higher than the single stage system. The projected outcome of the testing program includes: * Sustainable augmentation of water production in Qatar * Reduction of environmental impact * Capacity building in Qatar
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Zero energy and emission building laboratory Qatar: Experimental study and calorimetric measurements on building envelopes under outdoor exposure
More LessIntelligent building envelopes can significantly reduce the environmental impact of our buildings during their whole life cycle. Intelligent means that user comfort is reached through subtle use of devices to manage indoor climate (temperature, air quality, humidity and light) in the most energy-efficient way while involving outdoor conditions as suitable. A promising methodology consists in keeping the building services as basic and user-friendly as possible without compromizing energy efficiency and minimal environmental impact. This is achieved through active control of the building skin functions, adapting them to the constantly changing outdoor conditions. This approach not only fits to new buildings, but can be implemented as well on existing building stock, for example in the context of a renovation/refurbishment project. Qatar will see intensive building activities taking place in the coming years. A great challenge and opportunity to put the intellectual approach into practice. Since end of 2012, the ZERO ENERGY AND EMISSION BUILDING LABORATORY of Hydro Building Systems GmbH which has been set up at Qatalum can be used for experimental researches on façade systems under natural weathering conditions. The target of the first series of measurement is to analyse the energetic efficiency of four different types of façades. Reference is a SSG façade with insulating double glazing with a g-value of 0.16. Optionally, an external blind can be operated. Further façade types are a SSG façade identical to the reference façade, fitted with a fixed external brise-soleil made up of aluminium blades, a high insulation stick type façade with triple glazing and Venitian blind in the pane interspace as well as a box-type window with turn/tilt sash inside and parallel outward sash outside with a Venetian blind fitted in-between. Calorimetric measurements regarding the required energy needs show that a fixed brise-soleil (blades) reduces the cooling energy requirements by approx. 22%. An external venetian blind offers potential savings of approx. 40%. Replacing a standard stick type façade with double insulating glass by a high insulation façade with coated triple glazing and integrated sun protection, the cooling energy consumption can be reduced by more than 57%. A double skin box-type window solution with sun protection in the interspace cuts the energy consumption for cooling the room by 40%.
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Study of radioactivity levels in the marine environment along the exclusive economic zone (EEZ) of Qatar
More LessRadioactivity levels in the marine environment, specifically along the EEZ of Qatar have been measured. The EEZ of Qatar encompasses numerous marine resources like fisheries, corals, mangrove swamps, extensive sea grass meadows, shrimp, oyster beds and sponge, all of which needs protection and conservation. During the last 30 years, the Gulf marine environment have been subjected to several threats, especially from the Gulf war events which exerted a great pressure on the marine environment and exposed its resources to damage. Despite the availability of scientific data on the contamination of the environment with metals and hydrocarbons, at present there is very limited information on the exposure of the Gulf environment to radioactive material. This is particularly important, especially with the increase in the number of nuclear power activated vessels visiting the Gulf, the continuous international threat for destroying the Iranian nuclear facilities and the competition between Gulf states to own nuclear facilities in the near future for peaceful use and power generation. Radionuclides have been released to the environment from a multiplicity of sources, both planned and accidental. A very large part of this project has been to collect samples from the marine environment, and measuring and analyzing them for gamma-emitting radionuclides. These samples include water filters, sediments as well as biota samples. As no similar study has been conducted previously in Qatar, the results should provide a useful baseline level for future reference and any further projects. The concentration factors are below the recommended ones by IAEA. At present there is no significant impact on human health from radioactivity point of view through consumption of marine food from the Persian Gulf. The current baseline data generated of 137Cs, 40K and other radioncuclides of interest suggested that, there is no exceptional natural or anthropogenic radionuclide concentrations found in the marine environment of Qatar. This is backed up by the comparison of the results with similar studies from other countries.
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Marine environmental legislation in Qatar: Current mechanism and future challenges
More LessMarine Environmental Legislation in Qatar: Current Mechanism and Future Challenges Max-Planck Foundation, Heidelberg,Germany Omar Mohammed-Faraj, LL.M. Research Fellow The state of Qatar witnessed rapid developments in the last decade, booming economy and solid steps towards the building of a prosper state. These changes in economy and the market demands for Qatari gas and oil put the country's marine environment under serious threats. It is so hard to assess the magnitude of the threats to the marine environment in Qatar and to Qatar's coastal waters; however potential threats can be identified. Over exploitation of fish stocks, (catch of fish in Qatar increased from 4271.3 tons in 1995 to 7139.6 tons in 2000 according to State's report in 2000) for an increase of approximately 67% since 1995. Many marine species like turtles are under serious danger. This constitutes a threat to the marine ecosystem in this country. Critical effects for onshore, offshore discharges including oil spills, ship ballast and pipeline releases damages severely the marine environment. This paper is to examine the marine environment legislation in power at the State of Qatar. Environment Law No.30 of 2002 and Law No.4 of 1983 together with many other decrees, regulations will be examined. The focus will be on pipelines releases and the liability according to the Qatari marine environmental legislation. The existing law did not provide a clearly identifiable responsible party, matters like the compensation for damages to the marine environment must clearly clarified. The paper will include a comparative study of the liability for any pipelines releases in other maritime jurisdictions with an overview to the legal status of marine cables and pipelines in the United Nations Convention on the Law of the Sea 1982 (UNCLOS) which Qatar is a member since December 2002. Qatar needs a unified marine environmental legislation to replace the existing marine environment protection regulations which can be modified or referred to in the new legislation. The methods used to conduct this study are comparative legal analysis, various updated surveys, and existing laws. The aim of this study is to put a focus on the legal mechanism for countering marine pollution in the State of Qatar and identify the needs for improvements in the existing marine environmental legislation. Extending the protection given by law to the marine protected areas (only 0.25% of marine areas in Qatar are protected according to a report by the State of Qatar in 2010) and encouraging legal research in the field of marine pollution is important tool to fill any gaps in the current mechanism. The role of the international conventions ratified by the State of Qatar will be substantial in modulating the current statutory mechanism. The study paper will develop recommendations regarding the identified points of discussion taking into consideration the Qatari context.
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Exploiting the potential of halophytes for third generation biofuel production
By Ajmal KhanExploiting the potential of halophytes for third generation biofuel production M. Ajmal Khan Qatar Shell Professorial Chair for Sustainable Development and Professor, Department of International Affairs, College of Arts and Sciences, Qatar University, PO Box 2713, Doha, Qatar Author for correspondence: [email protected] ABSTRACT Increasing urbanization and industrial developments are accompanying intense utilization of fossil fuel such as petroleum and natural gas. Combustion of these conventional fuels causes environmental pollution especially the emission of green-house gases. Atmospheric concentrations of these green-house gases have increased substantially since the first industrial revolution. These green-house gases cause global warming which in turn is linked to many environmental problems such as sea-level rise and weather anomalies. As a result, researchers are looking for sustainable and environment-friendly energy alternatives. Biofuels - bioethanol and biodiesel from halophytes (naturally salt tolerant plants) may provide such an alternative. The argument used against bio-fuel crops that they are competing with human food resources, is not applicable to halophytes as they utilize saline resources which are considered as waste. Besides, the production of energy from plant biomass would be less detrimental to environment than conventional fossil fuels, as it would emit the same amount of CO2, which would have been fixed during photosynthesis. The potential of halophytes as a source of biofuel is now under investigation. We are reporting here an initial screening of coastal halophytes from Pakistan, which could be useful as bioethanol feedstock.
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Atomistic molecular dynamics simulations for CO2 - H2O - NaCl at conditions relevant to CCS processes
More LessEmissions of long-lived greenhouse gases are believed to be a major driver of climate change. Carbon dioxide is the most important greenhouse gas[1] and one of the most prominent strategies to lower its emissions is carbon capture and sequestration (CCS)[2]. CO2 can be stored in geological repositories, in which sodium chloride (NaCl) is the most common dissolved salt. For the optimum design of any CCS process, accurate experimental data and computational models are necessary. This study focuses on generating and validating molecular-based models and methodologies to allow for reliable prediction of the thermodynamic and transport properties of CO2-brine mixtures over a broad range of temperatures and pressures relevant for geological storage. We employ Atomistic Molecular Dynamics (MD) simulations, which is widely used to predict phase equilibria, transport, and other properties of gases, liquids etc. The current study aims at: (a)Determining the accuracy of current molecular models over a broad range of temperatures, pressures and salt concentration relevant to CCS processes with respect to phase behavior and transport properties of CO2 - H2O - NaCl mixture, (b)Developing efficient computational methods and improved potential models for these properties, (c) Assessing the accuracy of SAFT/PC-SAFT based models for the phase behavior of CO2-H2O-NaCl mixture and improving the models using also data generated through molecular simulations and (d)Developing appropriate engineering models for the correlation of viscosity and self-diffusion coefficient experimental and molecular simulation data for the CO2-H2O-NaCl mixture. More specifically, in this work, we study the mutual solubility and interfacial tension in the CO2-H2O-NaCl system over a broad range of temperatures, pressures and NaCl concentrations, using direct interfacial MD simulations. Also we calculate transport properties such as viscosity, self-diffusion coefficient, thermal conductivity. Additionally, we assess the predictive abilities of several combinations of existing H2O, CO2 and NaCl models. To describe water, CO2 and NaCl we use various intermolecular potential models[4,5,6,7,8] that provide property predictions for the CO2-H2O-NaCl mixture over a broad range of temperature, pressure and composition. In addition, the estimated accuracy of the model for each property and for specific conditions will be reported. Our group takes advantage of recent developments of efficiently parallelized codes such as LAMMPS[9] and GROMACS[10]. [1] Metz B, Intergovernmental Panel on Climate Change. Working Group III. Climate Change 2007: Mitigation of Climate Change: Contribution of Working Group III to the Fourth Assessment Report of the IInter-governmental Panel on Climate Change. Cambridge; New York: Cambridge University Press (2007). [2] International Energy Agency, A Policy Strategy for Carbon Capture and Storage (2012). [3] Jorgensen, W.L. J. Am. Chem. Soc., 103(2), 335 - 340 (1981). [4] Berendsen, H.J.C., Grigera, J.R. and Straatsma, T.P., J. Chem. Phys., 91(24), 6269 - 6271 (1987). [5] Harris, J.G. and Yung, K.H. J. Phys. Chem., 99(31), 12021 - 12024 (1995). [6] Potoff, J.J. and Siepmann, J.I. AlChE J., 47(7), 1676 - 1682 (2001). [7] Smith, D.E. and Dang, L.X. J. Chem. Phys., 100(5), 3757 - 3766 (1994). [8] Deublein, S., Reiser, S., Vrabec, J. and Hasse H. to appear (2012). [9] See: http://lammps.sandia.gov/. [10] See: http://www.gromacs.org/.
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Investigation of the mechanical and chemical properties of aluminum waste incorporated concrete
More LessPortland cement-based products (primarily concretes) are the world's most commonly used building materials, and due to its huge production world-wide, especially in developing countries like Qatar, the Portland cement industry is faced economic, energy and environmental problems, such as 7% of total world-wide CO2 emissions. For sustainable development, within the scientific community, major international concern over how to reduce CO2 emissions has given rise to a growing interest in the development of materials and technologies able to reduce the impact of Portland cement. One of the possible alternative ways of sustainable development in construction industry is to replace a large percentage of cement with other materials like industrial wastes, slag and fly ash which reduce the environmental impact of manufacturing an equivalent amount of cement and allow industry wastes to be safely recycled into a permanent structure rather than into a landfill site. It is the objective of this project is to investigate the mechanical and chemical behavior of new concrete type obtained by adding aluminum slag which is an impure aluminum mixture that results from metals melting and mixing with flux. The main advantage of this type of concrete over the conventional ones is the reduction in the quantity of raw materials.
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Molecular level simulations of clathrate hydrates: Recent progress with Monte Carlo studies
More LessHydrates are non-stoichiometric inclusion compounds that mainly consist of water molecules that form three dimensional cavities that are stabilized by entrapped guest molecules. Hydrates have been under investigation for many years due to their wide variety of applications in engineering and scientific problems. In particular, their characteristic to encage selectively large amounts of gas into the crystalline structure has attracted significant attention for possible practical applications including the separation of gas mixtures, desalination, storage and transportation of gases (e.g., methane, hydrogen). Vast amounts of natural gas hydrates that contain significant amount of methane could possibly be used as a future energy source. Assessing thermodynamic properties of hydrate-containing systems, such as the hydrate equilibrium pressure and temperature conditions or the exact amount of gas stored in the hydrate structure has been addressed by either molecular level simulations (e.g., Monte Carlo) or continuum level modeling. In either case the Lorentz-Berthelot (LB) combining rules are by far the most common used for the parameters between different types of atoms. This is a result of their success in describing fluid mixtures of nonpolar molecules. However, the LB combining rules perform inadequately when describing the gas - H2O interactions without using a correction factor. An extensive discussion on the use of combining rules is provided in the studies of Delhommelle and Millie (2001), and Haslam et al. (2008). The effect of combining rules has not been addressed adequately in the hydrate-related literature. The vast majority of studies have considered the LB combining rules. In the current study we report two series of Grand Canonical Monte Carlo (GCMC) simulations: (i) simulations along the three phase (H-Lw-V) equilibrium curve, and (ii) simulations at pressure and temperature conditions that are off-hydrate-equilibrium. For both cases the exact geometry of hydrate crystals is known from diffraction experiments and therefore, the formation of hydrates can be simulated as a process of gas adsorption in a solid porous material. In the first case, we examine the effect of deviations from the LB combining rules on the cavity occupancy of Argon hydrates. The specific system is selected as a result of the characteristic behavior of Argon to form hydrates of different structures depending on the prevailing pressure. In particular, sII hydrate is formed at lower pressures, while sI hydrate is formed at intermediate pressures, and finally sH hydrate is formed at higher pressures. In the second case, an extensive series of GCMC simulations for the case of all the known hydrate structures, sI, sII, and sH that hydrogen is known to form, is performed. During the simulations a number of water force-fields are examined regarding their effect on the storage capacity of hydrates. In particular, the following popular water force-fields are considered: SPC/E, TIP4P, TIP4P/Ice, and TIP5P. The Langmuir constants for each type of cavity and hydrate structure are reported as a function of temperature and pressure. Therefore, the storage-capacity of the different hydrate structures can be calculated. Acknowledgment Financial support by Qatar National Research Fund (project NPRP 6-1547-2-632) is gratefully acknowledged.
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Conversion of carbon dioxide to useful fuels using photoelectrochemical technology
By Dong Suk HanProduction and use of hydrocarbon energy result in enormous release of carbon dioxide (CO2) into the atmosphere, eventually causing the global climate change. Furthermore, the world is now facing a dual energy challenge, which is to minimize use of fossil fuels to decrease the impact of CO2 on climate change while meeting the growing global energy demand. To solve these challenges, development of an innovative technology capable of reducing or reusing CO2 as well as producing environmental-benign and sustainable energy using renewable energy sources is urgently required. As such, a technology that can produce solar fuel energy using water oxidation and CO2 reduction that mimics natural photosynthesis has been attracting extensive interest (Figure 1). Many approaches for solar-driven fuel production using artificial photosynthesis have been suggested and developed. Among them, a promising one is to use semiconductor-based photoelectrochemistry (PEC) because there are much potential to meet the requirement for sustainable, selective, and efficient production of solar-driven fuels and the proton-coupled electron transfer to CO2 by enhancing light absorption, charge generation, and separation through construction of a junction between semiconductors. For CO2 reduction, bare and Cu-electrodeposited p-Si electrodes were immersed in 0.1 M borate (pH 9.2) or 0.1 M bicarbonate (pH 7.2) electrolytes, to which AM 1.5 light of 100 mW/cm2 (1 Sun) was irradiated. Chopped linear sweep voltammograms showed that the onset potential is anodically shifted by 0.5 V and the photocurrent is significantly enhanced by Cu deposition. To examine the competitive reaction between water reduction (hydrogen evolution) and CO2 reduction occurring on p-Si/Cu, three different gases (O2, N2, CO2) were purged into the bicarbonate electrolyte solution. The purged gases change little the onset potentials. A high photocurrent with N2 compared to O2 indicates that water reduction becomes a primary electron-quenching process in the absence of dissolved oxygen. At low potential range, CO2 is most effective whereas N2 becomes more effective with increasing the negative potentials. Because the two-electron reduction potentials of H2O (H2 evolution) and CO2 (CO evolution) are very similar (only ~100 mV difference), the high photocurrent with CO2 at low potential range implies that the CO evolution may be the primary process. Instead of p-Si, a novel photocathode, p-CuFeO2 was also synthesized and its PEC performance was tested. The onset potential was around -0.2 V vs. SCE and the photocurrent increased with increasing the film thickness. Due to its transparency, this photocathode can be coupled with other transparent photoanodes for CO2 conversion.
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Remote gas detection system for identifying fugitive emissions
More LessIdentifying fugitive emissions from large scale LNG and gas processing and handling facilities is a difficult time and resource intensive process. Because of the limitations of hand held gas detection devices, and the sheer size and complexity of these facilities, smaller leaks may go undetected for extended periods of time and unintended releases may occur when plant personnel are not present or the area monitored. While fugitive emissions are typically not of immediate safety and human health concern taken individually, reducing the total emissions from a large plant or a regional industry footprint could very well have an appreciable positive impact on the environment. ExxonMobil Research Qatar (EMRQ) has developed a Remote Gas Detection (RGD) system that integrates computer vision algorithms and infrared (IR) optical technology that can autonomously scan for and identify small leaks such as those associated with fugitive emissions. Efficient identification of these emission sources will lead to better control and maintenance activities. The RGD system utilizes a custom build component based IR camera and integrated cooler assembly, and a computer vision algorithm that analyses the video output from the IR imagers to determine the presence of hydrocarbon plumes. Most hydrocarbon plumes have strong absorption peaks in the narrow mid-wave IR region. The algorithm takes advantage of the difference in contrast between a hydrocarbon plume and the background in each pixel of an IR image and the temporal changes due to plume behavior for the analysis. The algorithm compares sequentially collected IR images and uses a multi-stage confirmation process to confirm the detection and has built-in multiple filters that mitigate interferences like steam, and other moving objects such as humans and trees. Early field tests indicate that a 4 lb/hr propane leak could be autonomously detected from a distance of up to 800 feet. Also, initial testing comparing the RGD system to point and path detectors showed that a 2 lb/hr propane leak was successfully detected from 60 feet using the RGD system but did not elicit any response from a point detector located downwind 18 feet away. Multiple deployment opportunities at process facilities are currently underway. Results from field testing at these process facilities will help researchers investigate the effect of temperate and harsh weather conditions, the effect of varying temperatures and gain a better understanding of equipment wear and tear, maintenance requirements and possible life expectancies. These data sets will produce an accurate assessment of the performance of the RGD system under actual working conditions and will be used to qualify the technology for widespread adoption within the industry.
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Techniques for isolation and purification of marine microalgae from the coast of Qatar
By Sarah BachaBackground Unicellular algae, at the base of aquatic food chains, are particularly sensitive to a wide range of pollutants and are therefore important in toxicity tests for hazard assessment and aquatic environment protection. EMRQ (ExxonMobil Research Qatar) in collaboration with ESC (Environmental Studies Center, Qatar) and the Ministry of Environment, Qatar, is investigating the impact of common toxicants on the performance (growth and survival) of microalgae found in the coastal regions of Qatar. The present work was undertaken to establish the techniques for the isolation and purification of four microalgal species in order to culture them under specific laboratory conditions. Objectives * To conduct laboratory experiments to determine the most appropriate method for the isolation and purification of different microalgal species found in the coastal waters of Qatar. * To establish axenic cultures of the purified unialgae at EMRQ. * To conduct chronic toxicity tests of certain toxicants commonly found in seawaters on the microalgal species isolated and cultured. Methodology Different phytoplankton species were identified and isolated from freshly collected seawater from various sites around the coast of Qatar. * Unialgal isolates were obtained by four major techniques: streaking, spraying, serial dilution, and single-cell isolations by capillary method * Purifications of the unialgal samples to obtain axenic cultures were realized by micropipette washing technique followed by streak-plating technique and using antibiotics. Results The isolation by streak-plating showed to be the most suitable method for the small non motile microalgal species (<10mm) that grow well on a substrate. The serial-dilution technique looked to be ideal for all types of microalgae, specially the small motile species. The isolation by picking-up a single cell was found to be more adequate for the large phytoplankton species. A mixture of antibiotics showed to be more effective than the use of any individual antibiotic. Conclusion and Discussion A few microalgae have been successfully isolated and purified using the techniques mentioned above. The streak-plating method seems to be the most promising technique for the species found in Qatari waters. At present we are doing experiments to determine the specific biological and physical conditions for culturing the purified microalgae species for optimum growth at EMRQ. The purpose of obtaining axenic cultures of phytoplankton is to study the impact of specific toxicants on these species by performing chronic toxicity tests.
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Effective management of future smart grids
By Linda StegWorldwide, the current energy system increasingly shows economic, social and environmental drawbacks and it does not appear to be sustainable. Among the most pressing problems are climate change due to CO2 emissions, the depletion of fossil resources, the security of energy supply, and threats to economic development. These problems can be addressed by moving towards energy systems that increasingly rely on renewable and sustainable energy sources. At the same time, the rapid progress in renewable energy harvesting and information and telecommunication technologies offer unprecedented opportunities for energy generation, distribution and management, and to more strongly involve people in the process of energy generation and management, which is needed to further enhance the sustainable energy systems. Indeed, renewable and sustainable energy sources are likely to be produced and distributed in a decentralised manner, and require energy management systems that differ greatly from the current centralised system. Hence, the integration of renewable sources has major implications for the design and management of energy systems, relying on innovative ICT solutions and stronger user involvement that facilitate supply and demand matching. Effective energy management requires the active participation and support of end users, who should accept the energy management systems, and adapt their energy use to the available demand as to enhance the efficiency and stability of the energy system. Hence, the design of future smart grids should be based on sound behavioural models, which should be integrated in ICT centred solutions that facilitate supply and demand matching. More specifically, we need to understand how truly complex information on energy production, use and storage can be effectively communicated among relevant actors, and what type of information and incentives should be provided to realise effective supply and demand matching. In addition, we need to understand how to take into account cultural specifics in the design of energy management systems, to enhance effective energy management across the world. The active and aware involvement of the end-user can only be achieved if a scalable and reliable ICT infrastructure is in place, which naturally interfaces the energy flows with the decision autonomy of the people. Hence, the design of effective energy management systems should be take into account key behavioural as well as ICT requirements in an integrated way. Our proposal is thus to investigate (1) ICT based solutions for monitoring and controlling the power grid focusing on the distribution networks (medium-low voltage) and buildings (offices and residential complexes) specific to the Qatar context; (2) behavioural models on effective and acceptable incentives to match energy supply and demand; (3) cultural specificities in the design of energy management systems by comparing results from research in Qatar to similar research in other parts of the world, in particular Europe. Together, these will provide important insights in how to promote efficient and stable renewable energy systems that meet Qatar's sustainability goals.
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Modeling of thermodynamic derivative and transport properties of CO2 mixtures for pipeline transportation
More LessIntroduction Carbon Capture and Sequestration (CCS) is one of the most promising technologies for the reduction of CO2 accumulation in the atmosphere. Continuous research on the topic develops methods for utilising the captured CO2 for enhanced oil and gas recovery (EOR and EGR). Through the research in this field, challenges that regard the mitigation of environmental pollutants such as CO2, as well as the increase of efficiency of oil and gas production processes can be addressed. Quite an important role in the design of these processes, and especially for the transport of CO2 streams via pipelines, is held by the thermodynamic modeling of pure CO2 and CO2 mixtures. The stream in the pipeline contains mainly CO2, together with many other gases, depending on the source of the stream, and the capture technology that precedes the transport. Typical impurities include CH4, N2, O2, SO2, Ar, and H2S, all of which can have a substantial impact on the thermodynamic behavior of the stream, both in the pipeline and out of it, in the unwanted event of a fracture. Methodology In this work, cubic and SAFT-based equations of state are used in combination with specific models for the calculation of phase equilibria, derivative thermodynamic properties and transport properties of CO2 mixtures. Their performance is evaluated against available experimental data from the literature. Especially for transport properties, established viscosity models from the literature based on friction theory, are combined with the above mentioned equations, in order to assess their ability of predicting viscosity of CO2 mixtures of interest to the CCS and EOR processes. Diffusivity and thermal conductivity are also investigated with the use of models combined with a range of equations of state, towards a unified approach of the thermodynamic properties prediction for CO2 containing systems. Conclusion In most cases, the higher order EoS are more accurate than the cubic EoS in the case of predictive calculations (no binary parameters used) of phase equilibria. Nevertheless, the two classes of EoS provide similarly good results when using a temperature independent binary interaction parameter. Derivative properties are more accurately captured by the SAFT family EoS, due to the higher physical content that they have over the cubic EoS. The pure components viscosity calculations with the different types of EoS compared in this study do not exhibit great deviations, owing that to the fitting procedure that was necessary for each EoS. On a related note, the need for more experimental data of derivative and transport properties of CO2 mixtures at conditions that cover the design and operation of CO2 pipelines becomes obvious. Acknowledgment The authors acknowledge financial support from the 7th European Commission Framework Program for Research and Technological Development for the projects "Quantitative failure consequence hazard assessment for next generation CO2 pipelines" (CO2PipeHaz, Project No.: 241346) and "Techno-economic Assessment of CO2 Quality Effect on Capture, Transport and Storage" (CO2Quest, Project No.: 309102).
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Integrated environmental research to support Qatar industrial development
By Eric FebboIncreasing development along the coastline and offshore Qatar results in continuous interaction between industrial activities and the biodiverse Qatar Marine Zone. Enhancing the understanding of this environment and the potential for impacts is essential to Qatar. The ExxonMobil Research Qatar (EMRQ) Environmental Management Research Program is working with local and international partners to develop the scientific knowledge needed to better understand environmental risks specific to this region, and is developing technologies to enhance environmental management capabilities. Scientists at EMRQ are using state-of-the-art research labs combined with field studies and eco-risk model development to understand, assess, predict and mitigate potential impacts to the local marine environment that may occur as a result of Qatar's industrial activities. In addition, we are developing state of the art technologies and data acquisition / management systems that will allow for effective identification of baseline environmental resources, monitoring ecosystems to identify change, and analyzing environmental data to support rapid and successful decision making. Taken together, the projects undertaken in this integrated program are supporting Qatar's ability to understand and manage its resources responsibly. Several projects are described in detail within the framework of how the information and tools developed are integrated into the environmental management process. Sensitive ecosystem monitoring, laboratory based ecosystem risk assessment tool development, hydrodynamic modeling, ecological baseline surveys, remote sensing and mapping are the main projects to be discussed. Monitoring Qatari corals and seagrass over the last few years with the use of new technology as well as in-situ temperature monitoring devices has provided insight into the factors affecting these sensitive ecosystems. The development of laboratory based environmental risk studies provides methods to utilize indigenous species to determine the potential effects of chemicals and other parameters in the environment. Three dimensional modeling of hydrodynamic processes in the Qatar marine zone allows visualization of fate and transport of pollutants and can be used to assess and predict impacts. Baseline surveys provide a great deal of data cataloguing biodiversity, and documenting physical and chemical processes in land, sea and the interface in-between. New cutting edge techniques like remote sensing from space born satellites or small autonomous vehicles deployed in the sea allow large or targeted areas to be studied and classified in a more rapid manner than traditional field studies. This data, if properly formatted and managed, allows for accurate mapping and temporal analysis by acquiring imagery at timed intervals. The system used to integrate environmental data and modeling analysis tools is a geographical information system (GIS). In today's world, a single development project can result in tens or hundreds of thousands of electronic files and terabytes of data characterizing the environment. A structured file geo-database and GIS system provides a mechanism to manage and analyze enormous amounts of information and to provide reports and visual tools for managers within government and industry to make informed decisions for environmental management or risk assessment purposes.
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Optimization Of Splits Spectrum And Multi-Junction Photovoltaic Cells Using Cuckoo Search Inspired Hybridization Of The Nelder- Mead Simplex Algorithm
More LessIn the recent years the performance of photo-voltaic (PV) cells has been significantly improved by using multi-cell devices. In such systems, few layers of different cells are combined to maximize the efficiency by exploiting the use of different wave lengths of light. Using this approach efficiency of over 40% has been achieved. The two most promising methods are splits spectrum and multi-junction photo-voltaic cells. With the development of new technologies it has become possible to create more complex PV sells consisting of a higher number of layers. For future development of such PV cells it is of significant importance to have bounds for the optimal possible efficiency. While it is relatively simple to find them in case of two or three layers it becomes significantly more complex in case of a higher number of layers. This is due to the fact that it is necessary to find the of a multi-parameter function, which is computationally expensive. The problem becomes even more complex because it is hard to find the corresponding gradient that could simplify the calculation. There is a wide range of non-gradient based methods like simulated annealing, genetic algorithms, particle swarm optimization, Nelder-Mead Simplex method[1] that are generally used solve this type of problems. The performance of such methods is highly dependent on the function that we wish to minimize. In the case of the problem of interest, initial test have shown that Nelder-Mead Simplex algorithm manages to out preform mentioned more complex population based methods. One of the reasons for this is the fact that due to physical properties of the problem we have a good initial guess of the solution. Our research has focused on improving the performance of this algorithm by incorporating some type of swarm intelligence. Previously, similar hybridization of Nelder-Mead simplex algorithm using genetic algorithms[2], ant colony optimization[3] and particle swarm optimization[4] have proven to be very efficient. In the recent years the Cuckoo Search[5] algorithm has been gaining on popularity as an optimization method due to its good performance, robustness and simplicity of implementation. One of the main problems of hybridized methods is that although they achieve better results they often become very complex for implementation. In our work we introduce a cuckoo search inspired hybridization of the Nelder-Mead simplex algorithm that manages to avoid this drawback but still achieves significantly better results than the original method. In our tests we show that the proposed method also achieves good results on standard benchmark functions. The cuckoo search is often a competing method to the particle swarm optimization; because of this we also give a comparison to previously published results of hybridization of Nelder-Mead simplex using this method.
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Channel Coordination In Supply Chains Under Carbon Emission Considerations
By Adel ElomriAn increasing number of firms are integrating carbon emission concerns into their operational decision-making. Some of these actions are motivated by individual initiatives towards corporate environmentalism. While some other are driven by environmental regulation pressures. Policies such as carbon caps under the Kyoto Protocol and carbon tax have been introduced in many countries as mechanisms to induce firms to adopt the low carbon society. In this setting, we present a model for analyzing the impact of carbon emission considerations on the coordination between two/or more different business entities. In the absence of carbon emission considerations, channel coordination has been widely studied in the supply chain management literature. It has been shown that both entities are often better off under the coordinated channel. Several mechanisms and contracts have been then studied to settle down such coordination under different scenarios. The purpose of this research is to investigate these traditional (cost driven) results under carbon emissions considerations. In other terms our objective is to illustrate how the incentives for the coordination are affected by the presence of carbon emission firms' concerns. In our initial analysis we consider traditional buyer-vendor coordination by associating carbon emission parameters with ordering and holding decision variables. We examine how the values of these parameters as well as the considered regulatory emission control policies affect cost and emissions. The corresponding carbon emissions are incorporated into the model through the consideration of various regulatory policies that include : (1) strict emission caps: both of the supplier and the buyer are subject to mandatory caps on the amount of carbon they emit, (2) carbon tax policy: the supplier and the buyer are taxed on the amount of emissions they emit and (3) cap and trade system: the supplier and the buyer are subject to carbon caps but are rewarded /penalized for emitting less/more than their caps. Under carbon emission considerations, the centralized solution remains profit-optimal but not necessarily emission-optimal. This means that the joint profit is often increased when the channel is coordinated. However, the amount of total carbon emissions may be higher than what could be emitted by the retailer and the supplier when they work individually. We identify conditions on cost and emission parameters under which the joint policy is both profit and emission optimal. We also show that the outcome of the coordination is very sensitive to the type of the regulatory policy, for instance some policies are providing greater incentives than others for coordination.
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Developments in green sustainable data center infrastructure management (DCIM) energy tools
More LessEnergy management and reduction is one of the major challenges in the Cloud industry's data centres. The Uptime Institute's 2012 report, the industry's leading authority, highlighted the crisis in data centre energy management. 30% of data centres will run out of power, space and cooling in 2012. On average there's a 90% energy overhead in data centre operations, yet 55% of servers use less than 10% of their capacity. The 500,000 data centres worldwide have a server electricity consumption of 400 Billion kWh/year (approx $40 Billion ) which is growing at 12% CAGR, yet only 11% of the centres monitor their consumption. The global CO2 emissions of these centres, is equivalent to the airline industry, 2% of global emissions. It is expected that by 2020 20% of Europe's electrical energy will be data centre related. Data centre cooling requirements also have an enormous hydro footprint. A 1 MW data centre in a U.S-type climate has an annual hydro footprint of 99 million litres/annum Yet studies have shown that operational energy savings of 40% and substantial reductions in physical space, cooling requirements and water consumption can be achieved, where comprehensive and effective energy monitoring and management systems are employed. These can deliver a ROI within months, and further savings which extend over the centre's lifetime. The technologies which have the potential to deliver these benefits, DCIM (Data Centre Infrastructure Management) systems have only emerged in the last 3 to 4 years and are still in their infancy. Not surprisingly, a new global industry providing innovative, green, sustainable data centre technologies will be worth €45 Billion by 2016. The main barriers to effective monitoring/management is instrumentation and training. Vast volumes of data are gathered and must be competently analysed. Most monitoring systems, involve some form of physical metering and cabling and downtime, a major challenge when 10's thousands of servers are involved. Furthermore, all approaches physical and hybrid approaches limit the level of monitoring visibility to the server, individual processes cannot be monitored. A spin-out company from University College Dublin Ireland, Stratergia, has developed a unique data centre energy management system PAPILLON. It is totally software-based, measuring every server's energy consumption in real-time. It is intuitive to use, operates on any platform and can be installed in hours without any downtime or retrofitting. It uses a client-server type architecture. Software agents on servers communicate periodically, to a master server which has power models for each server type. Using the power models, the master computes in real-time and saves in a data base, all relevant energy information of the centre. In operation, Papillon identifies and quantifies energy saving actions that can be implemented, and coupled with electricity network data, more sustainable energy sources can be introduced into the power input of the centre. Papillon has been trialled at Swedish Compare Testlab and is one of the core tools being installed at state-of-the-art data centres at Kajaani, Finland and Cenit, Spain for a new international EU-funded Masters programme in green, sustainable data centre management.
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Microencapsulation for self healing of concrete
By Marwa HassanConsiderable interest has been directed in recent years toward the use of self-healing materials in concrete. The concept of microcapsule healing is based on a healing agent being encapsulated and embedded in the concrete. The objective of this study was to evaluate the effects of preparation parameters, namely, temperature, agitation rate, and pH on the shell thickness and size (diameter) of the microcapsules; as well as to evaluate the self-healing mechanism in concrete through experimental testing performed in laboratory. Two healing agents were evaluated in this study, i.e., dicyclopentadiene (DCPD) and sodium silicate. The experimental test matrix used in this study is shown in table 1. The anatomy of the microcapsules is shown in figure 1. Based on the results of the experimental program, it was determined that, as the pH was increased, the shell thickness increased for sodium silicate, while the shell thickness reached a minimum at a pH value of 3.4 for DCPD. Sodium silicate shell thickness was almost twice the shell thickness for DCPD. The most uniform and coherent microcapsules were produced at a temperature of 55°C. For the DCPD microcapsules and up to 49°C, the solution remained an emulsion and no encapsulation took place. The increase in agitation rate resulted in a decrease in the average diameter of the microcapsules for DCPD as shown in figure 2. On the other hand, the diameter of the microcapsules remained constant for sodium silicate microencapsulation as the agitation rate was increased. Testing of concrete specimens modified with the two healing agents (DCPD and sodium silicate microcapsules) was conducted. For sodium silicate, improvement in the modulus of elasticity of the concrete before and after healing was observed at a pH value of 3.1 and sodium silicate content of 5.0%. At other pH values, the effect of the sodium silicate microcapsules on the concrete performance was negligible. For DCPD and sodium silicate microcapsules, the healing agent was effective in increasing the modulus of elasticity of concrete after cracking as shown in figure 3.
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A new normalized digital feedback control for grid connected distributed generation system
More LessBackground & 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.
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Status of worldwide renewable energy installation and guidelines for the connection of PV systems to the power grid
More LessThe 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).
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