bluuebunny/crossref_metadata_2025 huggingface dataset:
Metformin Protects Against Glucose-Induced Mouse Microvascular Endothelial Cell (Mmec) Death
Authors: Ding Hong
Published: November 2013

Background and Objectives: Type 1 and type 2 diabetes are associated with an elevated incidence of cardiovascular disease. An early indicator of cardiovascular disease is endothelial dysfunction wherein there is a blunted blood flow response following activation of the endothelium. The elevated blood glucose associated with diabetes is thought to be a key factor associated with endothelial dysfunction and, in particular, the development of microvascular disease. Elevated blood glucose also has a negative effect on endothelial cell survival and thus enhances the ageing effect of diabetes on cardiovascular function. Clinical data suggests that metformin, a widely used orally effective hypoglycaemic drug, has an endothelial cell protective action. Metformin may also be beneficial in preventing endothelial cell death via a cellular pathway(s) that involves the activation of AMP-activated kinase (AMPK) - a master metabolic sensor for glucose and lipid metabolism. However, a link between metformin and AMPK and a protective action against high glucose-induced microvascular endothelial cell death has not been established. Methods: In the current study, we designed experimental protocols utilizing cell cultures of mouse microvascular endothelial cells (MMECs) that were exposed to high glucose, 40 mM, equivalent to those observed in the db/db mouse model of type 2 diabetes and in the absence and presence of metformin. Results: Exposure of the MMECs to high glucose for 48 h decreased the phosphorylation of AMPK and activated the endoplasmic reticulum (ER) stress and caspase-dependent apoptotic pathways. The presence of metformin (100 micromole/l) enhanced the phosphorylation of AMPK and prevented the activation by high glucose of the ER stress and caspase-dependent apoptotic pathways. Conclusion: Taken together, these data indicate that metformin, in addition to it's well known hypoglycaemic action, may also be beneficial for the improvement of endothelial cell survival via the up-regulation of AMPK and the down-regulation of ER stress and caspase-dependent apoptotic pathways. Further studies are required to fully elucidate the cellular pathways involved and determine the clinical implications. Supported by NPRP 5-149-3-040 and NPRP 4-910â€”3-244
Epidemiology of candidemia in Qatar: Performance of MALDI-TOF MS for identification of candida species, species distribution, outcome and susceptibility pattern
Authors: Taj-Aldeen Saad
Published: November 2013

Blood stream infections due to Candida species cause significant morbidity and mortality in health care settings. This surveillance analysis describes the epidemiology, trend in species distribution and outcomes of candidemia in patients at Hamad hospital, Doha, Qatar. From January 2004 to December 2010, a total of 187 patients with 201 episodes of candidemia were identified. C. albicans was the most common species isolated 33.8% (n=68), whereas non-albicans Candida species represented 66.2 % (n=133) of the episodes. The latter consisted of C. glabrata 18.9% (n=38), C. tropicalis 17.9% (n=36), C. parapsilosis 16.9% (n=34), C. orthopsilosis 4% (n=8) and C. dubliniensis 1.5% (n=3). Rare occurring cases of Pichia kudriavzevii , Meyerozyma guilliermondii, Clavispora lusitaniae, Wickerhamomyces anomalus and C. pararugosa (n=2 each) caused (4.9%) of infections. Uncommon yeast species such as C. intermedia, Yarrowia lipolytica, Kluyveromyces lactis , Lidnera fabianii, and Loddermyces elongisporus were found in single cases of candidemia (2.4%). The species distribution and outcome of candidemia showed a difference in crude mortality between patients infected with C. albicans (n=30, 45.5%) and non-albicans Candida species, e.g. C. parapsilosis candidemia was associated with the lowest mortality rate (40.6%), and patients with other non-albicans species had the highest mortality rate (68-71.4%). High mortality rates were observed among pediatric (<1year) and elderly patients (>60 years). All strains showed low MICs (≤ 1%) to isavuconazole. Overall reistance to voriconazole in vitro antifungal activity was 2.5%. Higher resistant rates were only observed for itraconazole (10.9%), C. glabata (n=38) was susceptible dose dependent to fluconazole. Except 0.5%, all isolates were susceptible to anidulafungin and 81.1% to caspofungin. Resistance to anidulafungin was detected in 1/8 (12.5%) isolates of C. orthopsilosis. According to new CLSI breakpoints, C. glabrata n=38 showed 100% resistance, and 37/68 (54.4%) of C. albicans were SDD to caspofungin. Identification by MALDI-MS was 100% in concordance with molecular identification.
QBB: The first Qatar public biobank: Participant feedback and observations
Authors: Afifi Nahla
Published: November 2013

Qatar Biobank (QBB), the first very large scale, long-term public biorepository in Qatar, is designed to build a powerful research infrastructure for future investigations of the lifestyle, metabolic and genetic risk factors for the most frequent medical conditions in Qatar, namely diabetes, cardiovascular and respiratory diseases, obesity and cancer. Qatar Biobank's recruitment approach provides a model for public involvement in biomedical research. Through inviting the public to contribute, Qatar Biobank promotes Qatar as dedicated to raising awareness and committed to engaging the community in shaping the health of their future generations. During the pilot phase, between December 2012 and June 2013, 503 participants have completed their baseline visit at the QBB Center. 67.9% of participants are Qatari nationals, the remaining are Qatar long term residents (> 15 years). There is a balanced participation of males (51.8%) and females (48.2%). Attitudes, perceptions and feedback are captured through a structured post-appointment participant questionnaire. Analysis of the feedback shows that upon giving consent the highest area of concern for participants is providing blood samples (47%), a further (46%) demonstrate concern over the physical measurements and (39%) are uneasy with contributing urine samples. An overwhelming (96%) of participants rate their experience at Qatar Biobank as very positive. A significant proportion (72%) of participants decide to contribute to Qatar Biobank due to word of mouth recommendations from friends (41.4%) and family (30.4%) emphasizing that the majority of participants value and enjoy their experience and are empowered to actively recruit within their communities.
Do Qatar Community Pharmacists Prescribe And Dispense Acute Community-Acquired Gastroenteritis Medications Rationally To Patrons? A Mystery Patient Study
Authors: Mohamed Ibrahim Mohamed Izham
Published: November 2013

Do Qatar Community Pharmacists Prescribe and Dispense Acute Community-Acquired Gastroenteritis Medications Rationally to Patrons? A Mystery Patient Study
Low-Complexity Wireless Monitoring Of Respiratory Movements Using Ultra-Wideband Impulse Response Estimation
Authors: Sana Furrukh
Published: November 2013

Monitoring of respiratory rate and amplitudes of a human being has important medical applications such as in health monitoring as well as in diagnosis of respiratory illnesses and disorders such as the sleep apnea disorder. Currently used techniques for respiratory monitoring require patients to wear sensors and electrodes across the chest to measure the respiratory effort. Such techniques not only cause discomfort to the patient but also require expert supervision. It is desirable to have a low-cost wireless monitoring equipment that is able to measure the respiratory rate and amplitudes through a non-contact and non-invasive methodology. Ultra-wideband (UWB) technology offers promising features for wireless monitoring in medical environments. However, there are several challenges that need to be addressed to enable development of a cost effective and reliable product capable of operating in realistic environments. Such challenges include low signal-to-noise ratios (SNR), interference from moving background objects (clutters) and the need for expensive sampling equipment. We propose a comprehensive scheme for wireless monitoring of the respiratory movements using UWB technology. Our scheme overcomes all the three challenges mentioned above. The proposed scheme is based on the estimation of the ultra-wideband channel impulse response. We exploit the sparsity inherent in the UWB channel to estimate the respiratory movements while operating in a Bayesian framework. We suggest techniques for dealing with background clutter in situations when it might be time variant. We also present a novel methodology for reducing the required sampling rate of the system significantly while achieving the accuracy offered by the Nyquist rate. Results from simulations conducted with pre-recorded respiratory signals demonstrate the robustness of our scheme for tackling the above challenges and providing a low-complexity solution for the monitoring of respiratory movements in harsh operating environments. Equipment based on our technique will be particularly useful to hospitals for clinical diagnosis purposes and also for commercial household usage by people in need of continuous monitoring of their health status. Measurements acquired through the equipment can potentially be communicated to a remote terminal/station for analysis by physicians. The equipment will also be useful in search and rescue scenarios for detecting and monitoring the vital signs of survivors trapped under debris and rubble in disaster management scenarios as well as in surveillance operations such as detecting people behind a wall.
Continuous And Noninvasive Hemoglobin Monitoring Reduces Red Blood Cell Transfusion During Neurosurgery: A Prospective Cohort Study
Authors: Awada Wael
Published: November 2013

Context: Continuous, noninvasive hemoglobin (SpHb) monitoring provides clinicians with real-time trending of changes or lack of changes in hemoglobin, which has the potential to alter red blood cell transfusion decision making. Objective: The objective was to evaluate the impact of SpHb monitoring on blood transfusions in high blood loss surgery. Design: Prospective cohort study. Setting: Tertiary academic hospital in Cairo, Egypt from February to August, 2012 Patients: Convenience sample of adult neurosurgical patients were enrolled (n=111) with 106 completing the study. Exclusion criteria included significant liver or renal disease, coagulopathy, pregnancy, anemia, and patients scheduled for procedures with excepted low blood loss. Interventions: Patients were enrolled into either a  Control Group or a SpHb Group. The Control Group received standard anesthesia care including intraoperative blood sampling when estimated blood loss was ≥15% of total blood volume and transfusion when hemoglobin was ≤10 g/dL.  In the SpHb Group, the anesthesiologist was guided by the addition of SpHb monitoring. Main Outcome Measures: The effect of SpHb on transfusion practice and absolute and trend accuracy of SpHb compared to laboratory hemoglobin were evaluated. Potential cost savings from reduced red blood cell utilization were estimated. Results: Compared to the Control Group,  the SpHb Group had fewer of units of blood transfused (1.0 vs 1.9 units for all patients; p≤0.001, and 2.3 vs 3.9 units in patients receiving transfusions; p≤0.01),  fewer patients receiving >3 units (32 vs 73%; p≤0.01) and a shorter time to transfusion after the need was established (9.2±1.7 vs 50.2±7.9 min; p≤0.001). The absolute accuracy of SpHb was 0.0±0.8 g/dL and trend accuracy yielded a coefficient of determination of 0.93. SpHb monitoring could save $470,000 to $1,065,000 per 1,000 surgeries performed. Conclusions: SpHb monitoring resulted in decreased blood utilization and decreased transfusion costs in high blood loss neurosurgery, while facilitating earlier transfusions.
Analyzing Electrocardiograms Via Smartphone To Detect Cardiovascular Abnormalities
Authors: Makki Mustapha
Published: November 2013

Cardiovascular diseases (CVD) are the leading cause of death globally. According to the World Health Organization, around 17.3 million people died from CVD in 2008, which is estimated to increase to 23 million annually by 2030. This calls for the exploitation of the latest technology to analyze and detect heart diseases in a timely fashion. Electrocardiogram (ECG) records the electrical activity of heart, and any irregularities in the heart rhythm are used as indicators of possible heart diseases. However, the process of acquiring an ECG and visually inspecting it is laboursome and time consuming. It is in this context that developing a mobile ECG monitoring system based on smart phones and automated diagnostic algorithms prove significant. The ECG acquiring system being developed by our team transmits ECG from the human body to the patient's smart phone in real-time via Bluetooth. This is completed by an application running on the phone. Two approaches are being developed to process the data received. The first is to send the data from the phone to a Webserver where the data will be analyzed and processed and lastly send the results back; this can be done through Wi-fi or a 3G connection. The second approach is to run the algorithm within the application on the smart phone itself. This way, the data can be processed locally, and the results can be displayed in case of no network. Both approaches are being compared for pros and cons. In the first approach, the Webserver can be updated frequently without modifying the application. Moreover, the usage of RAM memory will be efficient, and the code can be preserved from corruption. Nevertheless, this process will not succeed if the server fails or if the network interrupts. The second approach can process the data without network connectivity. However, it is more demanding on the phone, more susceptible to bugs and more difficult to update and debug the C code. The necessary hardware to acquire ECG and transmit it to the smart phone has been developed. Also, a robust diagnostic algorithm and an interactive smart phone application are being built. On integration, the system will be capable of analyzing ECG in real time and providing early warning to patients under cardiac risk saving valuable time and effort in their treatment.
Comparison Of Different Assays To Measure Antioxidant Capacity In Qatari Grown Food
Authors: Jaganjac Morana
Published: November 2013

Comparison of different assays to measure antioxidant capacity in Qatari grown food
Synthesis And Pharmacological Screening Of Novel Piperine Derivatives As Potential Therapeutic Agents To Treat Chronic Kidney Disease
Authors: Hammad Ayat
Published: November 2013

Synthesis and pharmacological screening of novel piperine derivatives as potential therapeutic agents to treat chronic kidney disease
Ige-Mediated Mast-Cell Renin Release
Authors: Levi Roberto
Published: November 2013

IgE-mediated mast-cell renin release
Real-Time Gpu Implementation Of Correlation-Based Dense Matching Of Stereo Endoscopic Images For Surface Reconstruction
Authors: Peyrat Jean-Marc
Published: November 2013

Real-Time GPU Implementation of Correlation-Based Dense Matching of Stereo Endoscopic Images for Surface Reconstruction
Patient-Specific Anatomy And Tissue Texture Models For Surgical Simulations
Authors: Peyrat Jean-Marc
Published: November 2013

Patient-Specific Anatomy and Tissue Texture Models for Surgical Simulations
Non-Motor Manifestations In Parkinson'S Disease: The Link Between Sense Of Smell, Subjective Visual Vertical (Svv) Perception And Micrographia
Authors: Khattab Ali
Published: November 2013

Non-motor manifestations in Parkinson's disease: The link between Sense of smell, subjective visual vertical (SVV) perception and micrographia
Characterization Of Growth Factor Receptor Signaling Upon Loss Of Endoplasmic Reticulum Chaperones
Authors: Mesaeli Nasrin
Published: November 2013

Characterization of growth factor receptor signaling upon loss of endoplasmic reticulum chaperones
Development And Characterization Of Poly (Diol-Co-Tricarballylate) Biodegradable Matrices For Implantable Controlled Drug Delivery, Tissue Engineering And Other Biomedical Applications
Authors: Hassouna Youmna
Published: November 2013

Development and characterization of poly (diol-co-tricarballylate) biodegradable matrices for implantable controlled drug delivery, tissue engineering and other biomedical applications
Associations Of Single Nucleotide Polymorphisms(Rs2383207) On Chromosome 9P21 With Coronary Artery Diseases In Qatar
Authors: Bakhsh Fadheela
Published: November 2013

Associations of single nucleotide polymorphisms(rs2383207) on chromosome 9p21 with coronary artery diseases in Qatar
Ultra-Wideband Mimo Channel Characterization For Healthcare Applications
Authors: Qaraqe Marwa
Published: November 2013

The idea of deploying multiple wireless sensors around the human body to enable ubiquitous healthcare by measuring continuously all the physiological data of interest has received considerable attention. Ultra-wideband (UWB) is a promising communication technology for short-range communication scenarios like body-centric wireless network (BCWN) (i.e, in the area of medical healthcare). UWB is characterized by low-power which makes it suitable for human body exposure and extends the life of the system. UWB is a high data rate technology that provides immunity to multipath interference, which facilitates the compatibility of such technology in body-centric applications. High data-rate wireless communications, nearing 1 Gb/s transmission rates, are of greater interest in emerging wireless technologies. The demand for higher data rate is increasing with the passage of time. To achieve higher data rates, greater than 50 Mb/s, multiple transmit and multiple receive antennas (MIMO) is recommended in IEEE 802.11n. To reach the target of 1 Gb/s, more advanced techniques like Ultra-wideband (UWB) technology combined with MIMO is an attractive research area now-a-days [1]. For BCWN, the use of multiple antennas at transmitter and receiver can simply be considered as a tool to further increase the signal to noise/interference ratio and additional diversity against fading. BCWN mainly experience fading due to relative movements of body parts, polarisation mismatch, shadowing, diffraction, and scattering from the body parts and surrounding environments. Multiple antennas can be used to combat fading and multipath effects. There has been an increasing interest in diversity and multiple-input, multiple output (MIMO) techniques for enhanced mobile and wireless communications in recent years. There are some studies presented in the open literature, where the benefits of multiple antenna techniques for body-centric communications in narrow-band systems have been investigated. The aim of this work is to investigate channel characterization (i.e having comprehensive radio channel knowledge and accurate channel model) and improve channel capacity provided by a UWB MIMO antenna system in body centric communication systems. The work will specifically investigate how UWB radio signals are affected by body shadowing and what kind for of improvement can be achieved in terms of channel capacity by using MIMO technology for BCWN. This is done by incorporating two different models on the measured data in an indoor environment (Fig. 1 shows the MIMO antenna position during measurements), and calculating various parameters like Rician factor, average received power, shadowing deviation, polarization loss for each spatial sub-channel. In addition, water filling is used in place of uniform distribution which provides higher capacity even at low SNR.
Knowledge of Risk Factors for Spontaneous Abortion among Qatari Arab Women
Authors: Patel Nish
Published: November 2013

Spontaneous abortion affects one in four of all pregnancies (Crenin, 2001). The rate of spontaneous abortion among Qatari Arab women presenting to Women's Hospital, Doha, Qatar is 34% (Women's Hospital, 2012) compared to the next highest ethnic minority (Egyptian Arab women) at 18%. Understanding and modifying risk factors for spontaneous abortion may prevent future miscarriages. Purpose: To assess the level of knowledge of risk factors for spontaneous abortion among Qatari Arab women. Methods: A cross-sectional self-administered survey was completed by 290 Qatari Arab women. The questionnaire assessed knowledge of modifiable lifestyle risk factors of spontaneous abortion. Univariate and bivariate analysis of the data was conducted. Odds ratios were used as a measure of association between categorical variables; confidence intervals and the chi-square test were used to determine whether or not the association was statistically significant. All tests were 2-sided and findings considered significant at p < 0.05. Results: Only 2.6% of the participants were aware of all 11 modifiable lifestyle risk factors. Most women (56%) had knowledge of only 5 or fewer risk factors of spontaneous abortion. Women who had a high school education and were younger than 25 years were two times more likely to know 5 or fewer risk factors than college educated women over 26 years of age (OR=2; CI: 1.2 - 3.3, p<.05). Conclusion: There is a significant lack of knowledge of the risk factors of spontaneous abortion among Qatari Arab women who attended the Antenatal Clinic at Women's Hospital, Doha, Qatar. Targeted and repeated health education during regular clinic visits may increase awareness. This may lead to a behavioral change preventing future spontaneous abortions.
Analysis Of Whole Genome Sequencing Data Of The Arabian, Percheron And Miniature Horse
Authors: Al Abri Mohammed
Published: November 2013

Whole genome sequencing provides a rich and unprecedented collection of the existing genetic variation in a genome. The development of next generation sequencing (NGS) technologies has enabled a rapid and relatively inexpensive method for whole genome sequencing. The current archive of genetic variations in the horse is mostly based on the Thoroughbred mare used to generate the reference sequence (EquCab2.0). Therefore, we have used Illumina paired-end NGS technology to sequence three horse genomes from diverse breeds; an Arabian, a Percheron and an American Miniature Horse. Our objective is to catalog newly identified variations within these three individuals and in comparison to the reference. After filtering the reads, we used BWA to align them to the reference and the Genome Analysis Tool Kit (GATK) HaplotypeCaller to call Single Nucleotide Polymorphisms (SNPs) and insertion/deletion polymorphisms (In/Dels). We also used ControlFreec to obtain regions predicted to contain copy number variations on each of the three genomes. Finally, we used BreakDancer to detect structural variations like inversions and translocations. These newly detected variations will enrich the database of genetic variations in the horse and could potentially have a phenotypic impact related to the biology of each of the three horse breeds. Here we will be presenting preliminary findings on our analysis and highlight the important steps in our pipeline.
Design And Synthesis Of New Monoamine Oxidase Inhibitors As Potential Neuroprotective Agents
Authors: Khalil Ashraf
Published: November 2013

Background and Objectives: Monoamine oxidase (MAO) catalyzes the biodegradation of biogenic amine neurotransmitters and a variety of xenobiotic amines. Selective MAO B inhibitors are used in the treatment of Parkinson's disease and other neurodegenerative diseases while selective MAO A inhibitors are known antidepressants. Piperazine and pyrazole rings are common moieties in several MAO inhibitors. The chronic nature of these diseases raises a compelling need for new MAO inhibitors with improved pharmacokinetics and safety profiles. Therefore, the aim of this project is to design, synthesize, purify and elucidate the structure of a series of new piperazine and pyrazole derivatives with potential MAO inhibitory activity. Methods: Based on the literature review, a series of compounds was proposed for their potential MAO inhibitory activity. Different piperazine and pyrazole derivatives were chemically synthesized by conventional method or by the use of microwave initiator. The reactions were monitored with TLC and purified by liquid-liquid extraction and column chromatography. The structures were confirmed by FTIR and GC/MS. Results: The microwave-assisted synthesis gave a better yield comparing to the conventional synthesis. The structures of the new compounds were confirmed by FTIR and GCMS. All the data will be presented. Conclusions: Microwave assisted synthesis of the proposed compounds improved the obtained yield. FTIR confirmed the formation of new products and the disappearance of the starting materials while the GCMS confirmed the molecular weight of the obtained products. More compounds will be prepared and evaluated for their MAO inhibitory activity.
Investigating The Function And Substrate Specificity Of Histone Deacetylase Enzymes:New Synthetic Tools To Investigate The Role Of Hdacs In Cancer
Authors: Aljabiry Ameera
Published: November 2013

Investigating the Function and Substrate Specificity of Histone Deacetylase Enzymes:New Synthetic Tools to Investigate the Role of HDACs in Cancer
Microbial dolomite formation in the Dohat Faishakh Sabkha, Qatar
Authors: Bontognali Tomaso
Published: November 2013

Dolomite 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.
Nearshore current and pollutant transport in the island of Crete
Authors: Tsanis Ioannis
Published: November 2013

The 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.
LIPS: A new instrument performing high resolution core logs of organic carbon
Authors: Dessort Daniel
Published: November 2013

Objective: 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.
Field testing of membrane distillation for desalination of brines discharge from thermal plants
Authors: Minier Matar Joel
Published: November 2013

Membrane 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
Zero energy and emission building laboratory Qatar: Experimental study and calorimetric measurements on building envelopes under outdoor exposure
Authors: Baumler Armin
Published: November 2013

Intelligent 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%.
Study of radioactivity levels in the marine environment along the exclusive economic zone (EEZ) of Qatar
Authors: Al-Qaradawi Ilham
Published: November 2013

Radioactivity 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.
Investigation of the mechanical and chemical properties of aluminum waste incorporated concrete
Authors: Ozerkan Nesibe Gozde
Published: November 2013

Portland 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.
Optimization Of Splits Spectrum And Multi-Junction Photovoltaic Cells Using Cuckoo Search Inspired Hybridization Of The Nelder- Mead Simplex Algorithm
Authors: Jovanovic Raka
Published: November 2013

In 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.
Microencapsulation for self healing of concrete
Authors: Hassan Marwa
Published: November 2013

Considerable 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.