Papers by Zadariana Jamil Osman
Ni/GDC a b s t r a c t A novel fabrication method using electroless and electrodeposited Ni/Ag/GD... more Ni/GDC a b s t r a c t A novel fabrication method using electroless and electrodeposited Ni/Ag/GDC for SOFC anodes is presented. First a porous Ce 0.9 Gd 0.1 O 2Àx (GDC) scaffold was deposited on a YSZ electrolyte by screen printing and sintering. The scaffold was then metallized with silver using Tollens' reaction, followed by electrodeposition of nickel from a Watt's bath. The electrodes (Ni/Ag/GDC) were tested in both symmetrical and fuel cell configurations. The microstructures of the Ni/Ag/GDC anodes were analyzed using scanning electron micro-scopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Nano-particles of Ni formed in the porous GDC scaffold provided triple phase boundaries (TPB). The electronic conductivity of the Ni/Ag/GDC (3.5/24.7/71.8 vol%) electrode was good even at relatively low Ni volume fractions. The electrochemical performance was examined in different concentrations of humidified hydrogen (3% H 2 O) and over a range of temperatures (600e750 C). The total area specific resistance (ASR) of the anode at 750 C in humidified 97 vol% H 2 was 1.12 U cm 2 , with low-frequency polarization (R_l) as the largest contributor. The electrodes were successfully integrated into a fuel cell and operated in both H 2 and syngas.
The objective of this study was to find the optimum conditions for anaerobic co-digestion of food... more The objective of this study was to find the optimum conditions for anaerobic co-digestion of food waste and sewage sludge and hydrogen (H 2 ) production. The selected parameters for optimization of H 2 production (e.g. temperature, initial pH, inoculum size) were analysed using Response Surface Methodology with Full Factorial Design. Two types of substrates were tested; food waste as a sole substrate and food waste mixed with palm oil mill effluent (POME) at volume ratio1:1. The optimized conditions for food waste as a sole substrate were pH 4.5, temperature of 35°C and inoculum size of 20% (v/v), with maximum predicted cumulative hydrogen production (MPCHP) of 0.22 ml H 2 /ml substrate. On the other hand, for food waste mixed with POME, pH 4.5, temperature of 35°C and inoculum size of 20% were the optimum conditions with MPCHP of 0.26 ml H 2 /ml substrate. Subsequently, verification experiments at optimal parameter values yielded cumulative H 2 of 0.28 ml H 2 /ml substrate for food waste only, and 0.33 ml H 2 /ml substrate for food waste mixed with POME.
A study of H+ production using metal hydride and other compounds by means of laser ion source Rev... more A study of H+ production using metal hydride and other compounds by means of laser ion source Rev. Sci. Instrum. 83, 02B318 Anaerobic fermentation hydrogen production from apple residue: Effects of sludge pretreatments J. Renewable Sustainable Energy 4, 013104 Mott insulators: An early selection criterion for materials for photoelectrochemical H2 production J. Renewable Sustainable Energy 3, 053101 High-purity hydrogen generation by ultraviolet illumination with the membrane composed of titanium dioxide nanotube array and Pd layer Appl. Phys. Lett. 99, 123107 (2011) Additional information on J. Renewable Sustainable Energy
Rhodopseudomonas palustris POME Response surface methodology a b s t r a c t Phototrophic hydroge... more Rhodopseudomonas palustris POME Response surface methodology a b s t r a c t Phototrophic hydrogen production by indigenous purple non-sulfur bacteria, Rhodopseudomonas palustris PBUM001 from palm oil mill effluent (POME) was optimized using response surface methodology (RSM). The process parameters studied include inoculum sizes (% v/v), POME concentration (% v/v), light intensity (klux), agitation (rpm) and pH. The experimental data on cumulative hydrogen production and COD reduction were fitted into a quadratic polynomial model using response surface regression analysis. The path to optimal process conditions was determined by analyzing response surface three-dimensional surface plot and contour plot. Statistical analysis on experimental data collected following Box-Behnken design showed that 100% (v/v) POME concentration, 10% (v/v) inoculum size, light intensity at 4.0 klux, agitation rate at 250 rpm and pH of 6 were the best conditions. The maximum predicted cumulative hydrogen production and COD reduction obtained under these conditions was 1.05 ml H 2 /ml POME and 31.71% respectively.
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Papers by Zadariana Jamil Osman