M. El Haj Assad

Bio: M. El Haj Assad is an academic researcher from University of Sharjah. The author has contributed to research in topics: Exergy & Renewable energy. The author has an hindex of 16, co-authored 31 publications receiving 931 citations. Previous affiliations of M. El Haj Assad include Australian College of Kuwait.

Enhancing the performance of automotive radiators using nanofluids

Abstract: Advanced heat removal technologies are critical for high-performance automotive engines. The conventional fluids being used today are based on a mixture of distilled water (DW) and ethylene glycol (EG), which widens the operational temperature range but at the same time limits the heat removal. Therefore, the use of nanofluids for improving heat transfer performance has soared over the past few years. The problem is that most of the reports highlight the short-term heat transfer results which may not be true over time. In this paper, a suggested best practice for analyzing the usage of nanofluids in heat transfer applications is presented, specifically for an actual car radiator. This work investigates the use of aluminum oxide (Al2O3) and titanium dioxide (TiO2) nanoparticles dispersed in DW and EG at 50:50 volumetric proportions. The choice of these oxide-based nanofluids is motivated by their anti-corrosive properties that are usually not analyzed or discussed in most of the articles. Furthermore, the emphasis is given on the presentation of a comprehensive characterization of the nanofluids including thermophysical properties (size, density, viscosity, thermal conductivity, corrosive behavior) and long-term stability (zeta potential) which are essential for an end-user to have. The results showed a maximum enhancement of the thermal performance by 24.21% using Al2O3 at a volume fraction of 0.3%. Friction factor and performance evaluation criterion (PEC) for the radiator experiments are calculated in order to determine the penalty in the pressure drop and to evaluate it properly. Finally, it is found that the values of PEC lie in the range of 1.03–1.31 which indicates significant flow enhancement.

On the technical challenges affecting the performance of direct internal reforming biogas solid oxide fuel cells

Abstract: Fuel cells (FCs) are electrochemical devices that can be used for the direct generation of electrical energy from the chemical energy in fuels with high efficiency, and low or no environmental impact. In particular, high temperature FCs such as solid oxide FCs (SOFCs) are also recognized for their cost-effectiveness and the fact that they can be fed with complex fuels such as methane or biogas which makes them ideal technologies for simultaneous waste treatment and energy generation. Directly fed SOFCs are known as direct internal reforming SOFCs (DIR SOFC) where the reforming of the biogas fuel occurs at the inlet of the cell producing carbon monoxide and hydrogen, which consequently react with oxygen ions along the anode side, and thereby producing electricity. DIR SOFCs integrated with biogas fermenter in wastewater treatment plants or other biological processes offer a window of opportunity for widespread utilization of SOFCs on commercial scale as a green energy source capable of producing several kWs to MWs. However, the performance degradation rate is one of the key issues that directly affects the long-term costs of SOFCs. In addition to the traditional problems, i.e. thermal cycling, oxidation cycling, and incompatibility of components, the DIR biogas SOFC is also affected by the thermal stresses resulting from endothermic reforming reactions and exothermic electrochemical oxidation reactions at the anode surface, the formation of carbon deposits, and the poisoning with impurities such as H 2 S , siloxanes, and halides. This review paper presents an up-to-date summary of the different processes and mechanisms leading to most of the issues encountered with the operation of DIR biogas SOFC, and advises on the methods and strategies that can be applied to mitigate these problems.

Application of graphene in energy storage device – A review

Abstract: Most applications in energy storage devices revolve around the application of graphene. Graphene is capable of enhancing the performance, functionality as well as durability of many applications, but the commercialization of graphene still requires more research activity being conducted. This investigation explored the application of graphene in energy storage device, absorbers and electrochemical sensors. To expand the utilization of graphene, its present limitations must critically be addressed to improve their current performance. Again, in terms of applications, the advantages of graphene has widened their application in both electroanalytical and electrochemical sensors. These good characteristics of graphene must be extended further and improved to make them suitable for other applications. Critical study of facile synthesis of graphene coupled with detailed investigation into the structure of graphene oxide at the molecular level will equally improve the performance of this novel material. Effects of defects on the performance of graphene oxide was also identified as another key area of research that needs much attention to accelerate the commercialization of this material. With the rapid growth in the application of the graphene in different energy storage/conversion applications, it is essential to summarize and discuss the up-to-date progress in the application of graphene in these fields.