MHD mixed convection flow adjacent to a vertical plate with prescribed surface temperature

The steady MHD mixed convection flow adjacent to a bounding surface immersed in an incompressible viscous fluid is considered. The governing system of partial differential equations is first transformed into a system of ordinary differential equations, before being solved numerically by a finite-difference scheme. The features of the flow and heat transfer characteristics for different values of the governing parameters are analyzed and discussed. Numerical results are obtained for the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles. It is found that dual solutions exist for both assisting and opposing flows. The range of the mixed convection parameter for which the solution exists increases in the presence of a magnetic field.     

Microbial community analysis of mixed anaerobic microflora in suspended sludge of ASBR producing hydrogen from palm oil mill effluent

This study investigated the microbial community of an anaerobic sequencing batch reactor (ASBR) operating at mesophilic temperature under varying hydraulic retention times (HRTs) for evaluating optimal hydrogen production conditions, using palm oil mill effluent (POME) as substrate. POME sludge enriched by heat treatment with hydrogen-producing bacteria was used as inoculum and acclimated with the POME. The microbial community was determined by first isolating cultivable bacteria at each operating HRT and then using polymerase chain reaction (PCR). The PCR products were sequenced and sequence identification was performed using the BLAST algorithm and Genbank database. The findings revealed that about 50% of the isolates present were members of the genus Streptococcus, about 30% were Lactobacillus species and around 20% were identified as species of genus Clostridium. Scanning electron microscopy (SEM) analysis also confirmed the presence of spherical and rod-shaped microbial morphologies in the sludge samples of bioreactor during prolonged cultivation.     

Recent advances in cleaner hydrogen productions via thermo-catalytic decomposition of methane: Admixture with hydrocarbon

A continuous increase in the greenhouse gases concentration due to combustion of fossil fuels for energy generation in the recent decades has sparked interest among the researchers to find a quick solution to this problem. One viable solution is to use hydrogen as a clean and effective source of energy. In this paper, an extensive review has been made on the effectiveness of metallic catalyst in hydrocarbon reforming for CO_X free hydrogen production via different techniques. Among all metallic catalyst, Ni-based materials impregnated with various transition metals as promoters exhibited prolonged stability, high methane conversions, better thermal resistance and improved coke resistance. This review also assesses the effect of reaction temperature, gas hour space velocity and metal loading on the sustainability of thermocatalytic decomposition TCD of methane. The practice of co-feeding of methane with other hydrocarbons specifically ethylene, propylene, hydrogen sulphide, and ethanol are classified in this paper with the detailed overview of TCD reaction kinetics over an empirical model based on power law that has been presented. In addition, it is also expected that the outlook of TCD of methane for green hydrogen production will provide researchers with an excellent platform to the future direction of the process over Ni-based catalysts.     

Multi-objective scheduling of MapReduce jobs in big data processing

Multimedia Tools and Applications - Data generation has increased drastically over the past few years due to the rapid development of Internet-based technologies. This period has been called the...     

Investigating corrosion effects and heat transfer enhancement in smaller size radiators using CNT-nanofluids

Nanofluids have been extensively studied in the past to enhance the heat transfer performance and efficiency of systems. However, corrosion effects have been paid very little attention and thus this work presents an experimental study on the effect of carbon nanotubes (CNT) on corrosion of three different metals under study such as aluminium alloy, stainless steel and copper, respectively. The work was further extended to study the heat transfer performance in a car radiator of two different sizes. Both the studies were performed using four different fluids such as water, ethylene glycol, 0.02 % CNT-nanofluid and 0.1 % CNT-nanofluid, respectively. It was observed that among the three metals, the highest rate of corrosion occurs to aluminium, followed by stainless steel and copper, irrespective of the fluid used. The rate of corrosion increased with the increase in temperature (27–90 °C) in all cases. The experimental results showed that the stable CNT-nanofluids prepared in this work showed better heat transfer performance in both engines. Moreover, the smaller radiator using the CNT-nanofluids depicted enhanced heat transfer rates compared to the standard radiator using water and ethylene glycol.     

Electrochemical-assisted photodegradation of mixed dye and textile effluents using TiO2 thin films

Mixed dye consists of six commercial dyes and textile effluents from cotton dyeing process were treated by electrochemical-assisted photodegradation under halogen lamp illumination. Two types of effluents were collected which are samples before and after undergone pre-treatment at the factory wastewater treatment plant. The photodegradation process was studied by evaluating the changes in concentration employing UV-vis spectrophotometer (UV-vis) and total organic carbon (TOC) analysis. The photoelectrochemical degradation of mixed dye was found to follow the Langmuir Hinshelwood pseudo-first order kinetic while pseudo-second order kinetic model for effluents by using TOC analyses. The chemical oxygen demand (COD) and biochemical oxygen demand (BOD) values of mixed dye and raw effluents were reported. Photoelectrochemical characteristic of pollutants was studied using the cyclic voltammetry technique. Raw effluent was found to exhibit stronger reduction behaviour at cathodic bias potential but slightly less photoresponse at anodic bias than mixed dye.     

Investigation on the effect of different design of SCR on the change of resistance in piezoresistive micro cantilever

This paper presents the investigation on the effect of different designs of Stress Concentration Region (SCR) on the change of resistance in piezoresistive microcantilever using Finite Element (FE) analysis. Two steps solution using memMech and memPzr solvers in Conventor is used in FE analysis in order to obtain the resistance change directly from microcantilever. Simulation results show that cantilever with SCR circle design gives the desired highest magnitude and broader stress distribution region thus contributing to the most significant result for piezoresistive effect.