Khalifa University

About: Khalifa University is a education organization based out in Abu Dhabi, United Arab Emirates. It is known for research contribution in the topics: Computer science & Adsorption. The organization has 3752 authors who have published 10909 publications receiving 141629 citations.

Enhanced Sensitivity of Patterned Graphene Strain Sensors Used for Monitoring Subtle Human Body Motions

Abstract: With the growth of the wearable electronics industry, structural modifications of sensing materials have been widely attempted to improve the sensitivity of sensors. Herein, we demonstrate patterned graphene strain sensors, which can monitor small-scale motions by using the simple, scalable, and solution-processable method. The electrical properties of the sensors are easily tuned via repetition of the layer-by-layer assembly, leading to increment of thickness of the conducting layers. In contrast to nonpatterned sensors, the patterned sensors show enhanced sensitivity and the ability to distinguish subtle motions, such as similar phonations and 81 beats per minute of pulse rate.

The potential of glycerol and phenol towards H2 production using steam reforming reaction: A review

Abstract: Hydrogen production via the steam reforming of glycerol, the main by-product of biodiesel production, and the pyrolysis/gasification route of biomass are two processes that have drawn considerable attention by the scientific community due to their potential in reducing our dependence on fossil based sources and in mitigating the effects of greenhouses gases on our planet. However, the commercial exploitation of the processes depends on the development of cheap, active and stable catalysts. In the present review, the key literature on the glycerol and phenol steam reforming reactions is presented and discussed. The impact of crucial variables for both the reactions at hand are discussed, such as active metal nature, metal loading, support, reaction temperature, method of preparation, poisoning resistance and coking tolerance. For catalytic systems design purposes the aspect of how the catalyst physicochemical characteristics affect the catalytic performance is addressed. Particular attention is given at the issue of coke resistance of the catalysts due to its detrimental effect for the reactions at hand. Natural materials, such as calcites, dolomites and olivines, utilized for the phenol steam reforming reaction are discussed.

Dew as a Detrimental Influencing Factor for Soiling of PV Modules

Abstract: Soiling of photovoltaic (PV) modules can significantly reduce their energy yield by reflecting or absorbing the incident light and is of great importance for operation and maintenance of PV systems in dusty environments. In this paper, we examine the influence of dew—which is formed on PV modules during night and early morning hours—on soiling processes. Outdoor experiments were performed in desert conditions in Qatar using unheated and heated glass samples supplied with different heating powers, as well as outdoor microscopy studies. In addition, laboratory soiling experiments were performed using different dust types, controlled dust removal by centrifugal forces at different relative humidity levels, and defined dew cycles. Results from both the field tests and laboratory soiling experiments showed a significant impact of dew on particle adhesion, removal, and corresponding soiling rates, which was independent of the dust type. Microstructural investigations using electron microscopy were performed to determine the cause of increased particle adhesion. Heating of glass surfaces during the night can significantly reduce the processes of cementation, particle caking, and capillary aging and, thus, reduce soiling. This study indicates that the prevention of condensation can be a method to mitigate soiling.