The University of Bahrain is the largest public university in the Kingdom of Bahrain. In post-nominals it is typically abbreviated as UoB.UoB is primarily, but not exclusively, an undergraduate institution offering postgraduate programs under specific conditions. It is the only national higher education institution in the Kingdom that offers mainly undergraduate B.Sc. degrees and some graduate degrees. Wikipedia.
Dakhel A.A.,University of Bahrain
Thin Solid Films | Year: 2010
Thin films of Fe-doped CdO with 1.3, 2.0, 2.3, 3.0, and 5.7 wt.% were prepared by a vacuum evaporation method on glass and Si wafer substrates. The prepared films were characterised by X-ray fluorescence and diffraction. Results show that doping of CdO with Fe enhances the film's  preferred orientation and causes slight shifts in the (111) Bragg angle towards higher values. The samples were investigated with a UV-VIS-NIR absorption spectroscopy and dc-electrical measurements. It was observed that there is a complicated dependence of bandgap on the Fe wt.% content in the film. In addition, light doping with Fe improves the dc-conduction parameters of CdO, so that with 1.3 wt.% Fe doping, the mobility increases by about 6 times, conductivity by 24 times, and carrier concentration by about 4 times, relative to undoped CdO film. The observations were analysed by using the available models (with a slight modification) for the coexistence of bandgap widening and bandgap narrowing. © 2009 Elsevier B.V. All rights reserved.
Musaiger A.O.,University of Bahrain
Journal of Obesity | Year: 2011
The objective of this paper was to explore the prevalence of overweight and obesity among various age groups as well as discuss the possible factors that associated with obesity in the Eastern Mediterranean Region (EMR). A systematic review of published papers between 1990 and 2011 was carried out. Obesity reached an alarming level in all age groups of the EMR countries. The prevalence of overweight among preschool children(<5 years) ranged from 1.9% to 21.9%, while the prevalence of overweight and obesity among school children ranged from 7% to 45%. Among adults the prevalence of overweight and obesity ranged from 25% to 81.9%. Possible factors determining obesity in this region include: nutrition transition, inactivity, urbanization, marital status, a shorter duration of breastfeeding, frequent snacking, skipping breakfast, a high intake of sugary beverages, an increase in the incidence of eating outside the home, long periods of time spent viewing television, massive marketing promotion of high fat foods, stunting, perceived body image, cultural elements and food subsidize policy. A national plan of action to overcome obesity is urgently needed to reduce the economic and health burden of obesity in this region. © 2011 Abdulrahman O. Musaiger.
Haji S.,University of Bahrain
Renewable Energy | Year: 2011
The performance of a fuel cell is characterized by its i-V curve. In this study, the performance of a bench scale fuel cell stack, run on hydrogen/air, is measured experimentally for different air flow rates and temperatures. The experimental data, obtained from the 40-W proton exchange membrane fuel cell (PEMFC), are used in estimating the parameters of a completely analytical model that describes the i-V curve. The analytical model consists of the three fundamental losses experienced by a fuel cell, namely: activation, ohmic, and concentration losses. The current loss is also considered in the model. While the Tafel constants, ohmic resistance, and the concentration loss constant are estimated through regression, the limiting current density and the current loss are obtained through measurements. The effect of temperature on the fuel cell performance, exchange current density, and current loss is also investigated. Both the exchange current density and the current loss are plotted against temperature on an Arrhenius-like plot and the related parameters are estimated. The theoretical equations derived in the literature, which model fuel cell performance, are found to reasonably fit the obtained experimental data. © 2010 Elsevier Ltd.
Naser H.A.,University of Bahrain
Marine Pollution Bulletin | Year: 2013
The Arabian Gulf is considered among the highest anthropogenically impacted regions in the world. Heavy metals contamination in coastal and marine environments is becoming an increasingly serious threat to both the naturally stressed marine ecosystems and humans that rely on marine resources for food, industry and recreation. Heavy metals are introduced to coastal and marine environments through a variety of sources and activities including sewage and industrial effluents, brine discharges, coastal modifications and oil pollution. The present paper reviews heavy metal contamination in a variety of marine organisms, and sediments, and suggests measures for environmental management of heavy metal pollution in the Arabian Gulf. Most of the reviewed literature confirmed that heavy metal concentrations in marine organisms were generally within allowable concentrations and pose no threat to public health. Likewise, studies suggested that levels of heavy metals in marine sediments are similar or lower compared to other regions. However, localized hotspots of chronic metal pollution in areas influenced by industrial facilities, desalination plants, and oil refineries have been reported. Holistic spatial and temporal monitoring and comprehensive national and regional strategies are critical to combat and manage heavy metal pollution in the Arabian Gulf. © 2013 Elsevier Ltd.
Dakhel A.A.,University of Bahrain
Materials Chemistry and Physics | Year: 2011
Ce-doped CdO thin films with different Cd compositions were prepared on glass and Si wafer substrates by a vacuum evaporation technique. The effects of Ce doping on the structural, electrical, and optical properties of the host CdO films were systematically studied. The X-ray diffraction study shows that some of Ce4+ ions substituted for Cd2+ and the solubility of Ce in CdO is very limited and may be around ∼1.3 at%. The cerium doping influences all optoelectrical properties of CdO. The bandgap of Ce-doped CdO suffers narrowing by about 27% with a small (0.5 at%) doping level. The electrical behaviours show that all the prepared Ce-doped CdO films are degenerate semiconductors. Their dc-conductivity, carrier concentration and mobility increase compare with undoped CdO film. The largest mobility of 66.7 cm2 V-1 s was observed for 3.8% Ce-doped CdO film. From transparent-conducting-oxide point of view, Ce is sufficiently effective for CdO doping. © 2011 Elsevier B.V. All rights reserved.