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Aims and Scope
Editorial Board

1. Novel design of a disk-shaped compacted micro-structured air-breathing PEM fuel cell

Maher A.R. Sadiq Al-Baghdadi

Fuel Cell Research Center, International Energy & Environment Foundation, Al-Najaf, P.O.Box 39, Iraq.

Abstract: The presence of microelectromechanical system (MEMS) technology makes it possible to manufacture the miniaturized fuel cell systems for application in portable electronic devices. The majority of research on micro-scale fuel cells is aimed at micro-power applications. There are many new miniaturized applications which can only be realized if a higher energy density power source is available compared to button cells and other small batteries. In small-scale applications, the fuel cell should be exceptionally small and have highest energy density. One way to achieve these requirements is to reduce the thickness of the cell (compacted-design) for increasing the volumetric power density of a fuel cell power supply. A novel, simple to construct, air-breathing micro-structured PEM fuel cell which work in still or slowly moving air has been developed. The novel geometry enables optimum air access to the cathode without the need for pumps, fans or similar devices. In addition, the new design can achieve much higher active area to volume ratios, and hence higher volumetric power densities. Three-dimensional, multi-phase, non-isothermal CFD model of this novel design has been developed. This comprehensive model account for the major transport phenomena in an air-breathing micro-structured PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields. The model is shown to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Fully three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analyzed with a focus on the physical insight and fundamental understanding. They can provide a solid basis for optimizing the geometry of the PEM micro fuel cell stack running with a passive mode.

Volume 3, Issue 2, 2012, pp.161-180.

2. Atmospheric mercury dispersion modelling from two nearest hypothetical point sources

Khandakar Md Habib Al Razi, Moritomi Hiroshi, Kambara Shinji

Environmental and Renewable Energy System (ERES), Graduate School of Engineering, Gifu University, Yanagido, Gifu City, 501-1193 Japan.

Abstract: The Japan coastal areas are still environmentally friendly, though there are multiple air emission sources  originating as a consequence of several developmental activities such as automobile industries, operation of thermal power plants, and mobile-source pollution. Mercury is known to be a potential air pollutant in the region apart from SOX, NOX, CO and Ozone. Mercury contamination in water bodies and other ecosystems due to deposition of atmospheric mercury is considered a serious environmental concern. Identification of sources contributing to the high atmospheric mercury levels will be useful for formulating pollution control and mitigation strategies in the region. In Japan, mercury and its compounds were categorized as hazardous air pollutants in 1996 and are on the list of "Substances Requiring Priority Action" published by the Central Environmental Council of Japan. The Air Quality Management Division of the Environmental Bureau, Ministry of the Environment, Japan, selected the current annual mean environmental air quality standard for mercury and its compounds of 0.04 μg/m3. Long-term exposure to mercury and its compounds can have a carcinogenic effect, inducing eg, Minamata disease. This study evaluates the impact of mercury emissions on air quality in the coastal area of Japan. Average yearly emission of mercury from an elevated point source in this area with background concentration and one-year meteorological data were used to predict the ground level concentration of mercury. To estimate the concentration of mercury and its compounds in air of the local area, two different simulation models have been used. The first is the National Institute of Advanced Science and Technology Atmospheric Dispersion Model for Exposure and Risk Assessment (AIST-ADMER) that estimates regional atmospheric concentration and distribution. The second is the Hybrid Single Particle Lagrangian Integrated trajectory Model (HYSPLIT) that estimates the atmospheric concentration distribution in the vicinity of industrial facilities.

3. Evaluation of different weather files on energy analysis of buildings

Apostolos Michopoulos, Vassiliki Voulgari, Konstantinos Papakostas, Nikolas Kyriakis

Process Equipment Design Laboratory, Mechanical Engineering Department, Aristotle University of Thessaloniki – POB 487 – 541 24 Thessaloniki, Greece.

Abstract: The building energy demand simulation tools consist the compass of the roadmap towards the energy efficient building. Apart from the software itself, the result of the simulation strongly depends on the degree the data used represent the actual situation, among which the climate data of the area are a key factor. In this work, the energy demand of a large building complex is estimated, using the widely accepted EnergyPlus building simulation software in combination with two, also widely accepted, weather files. The simulation results for heating are compared with the actual fuel consumption of a three-year operation period. The comparison reveals that the weather file and the size of the simulation domain significantly affect the simulation representativeness.

4. Natural convection unsteady magnetohydrodynamic mass transfer flow past an infinite vertical porous plate in presence of suction and heat sink

S. S. Das¹, S. Parija², R. K. Padhy³, M. Sahu⁴

1 Department of Physics, K B D A V College, Nirakarpur, Khurda-752 019 (Orissa), India.

2 Department of Physics, Nimapara (Autonomous) College, Nimapara, Puri-752 106 (Orissa), India.

3 Department of Physics, D A V Public School, Chandrasekharpur, Bhubaneswar-751 021 (Orissa), India.

4 Department of Physics, Jupiter +2 Women’s Science College, IRC Village, Bhubaneswar-751 015 (Orissa), India.

Abstract: This paper investigates the natural convection unsteady magnetohydrodynamic mass transfer flow of a viscous incompressible electrically conducting fluid past an infinite vertical porous flat plate in presence of constant suction and heat sink. Using multi parameter perturbation technique, the governing equations of the flow field are solved and approximate solutions are obtained. The effects of the flow parameters on the velocity, temperature, concentration distribution and also on the skin friction and rate of heat transfer are discussed with the help of figures and table. It is observed that a growing magnetic parameter or Schmidt number or heat sink parameter leads to retard the transient velocity of the flow field at all points, while the Grashof numbers for heat and mass transfer show the reverse effect. It is further found that a growing Prandtl number or heat sink parameter decreases the transient temperature of the flow field at all points while the heat source parameter reverses the effect. The concentration distribution of the flow field suffers a decrease in boundary layer thickness in presence of heavier diffusive species (growing S_c) at all points of the flow field. The effect of increasing Prandtl number P_r is to decrease the magnitude of skin-friction and to increase the rate of heat transfer at the wall for MHD flow, while the effect of increasing magnetic parameter M is to decrease their values at all points.

5. Treatment of semi-aerobic landfill leachate using durian peel-based activated carbon adsorption- Optimization of preparation conditions

Mohamad Anuar Kamaruddin¹, Mohd Suffian Yusoff¹, Mohd Azmier Ahmad²

1 School of Civil Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia.

2 School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia.

Abstract: The treatability of semi-aerobic landfill leachate parameters using durian peel-based activated carbon (DPAC) was investigated. An ideal experimental design was conducted based on central composite design (CCD) using response surface methodology to evaluate individual and interactive effects of operational variables namely activation temperature, activation time and carbon dioxide (CO2) flow rate on treatment performance in terms of chemical oxygen demand (COD) and colour removal efficiencies. The DPAC was prepared using physical activation method which consists of CO2 gasification. The adsorptions of COD and colour were described by Langmuir and Freundlich isotherm models. Based on the CCD, quadratic model was developed to correlate preparation variables to the two responses. The optimum DPAC preparation conditions were obtained using 800 °C activation temperature, 2.1 h activation time and 68.68 ml/s of CO2 flow rate. From the experimental work, the maximum removal of COD and colour obtained were 41.98 and 39.86%, respectively.

6. Municipal solid waste disposal by using metallurgical technologies and equipments

Jiuju Cai, Wenqiang Sun

State Environmental Protection Key Laboratory of Eco-industry, Institute of Thermal and Environmental Engineering, Northeastern University, Shenyang 110819, P. R. China.

Abstract: Pyrolysis of municipal solid waste can take full advantage of energy and resource and avoid producing hazardous material during this period. In combination with mature metallurgical technologies of coking by coke oven, regenerative flame furnace technology and melting by electric arc furnace, technologies of regenerative fixed bed pyrolysis technology for household waste, co-coking technology for waste plastic and blend coal, and incineration ash melting technology by electric arc technology for medical waste were respectively developed to improve current unsatisfied sorting status of waste. The investigation results of laboratory experiments, semi-industrial experiments and industrial experiments as well as their economic benefits and environmental benefits for related technologies were separately presented.

7. A computational study to investigate the effects of insulation and EGR in a diesel engine

Syed Yousufuddin1, K.Venkateswarlu2, Naseeb Khan3

1 Department of Mechanical Engineering, Jubail University College, Royal Commission - Jubail , P.O. Box 10074, Jubail Industrial City- 31961, Kingdom of Saudi Arabia.

2 Department of Mechanical Engineering, K.L University Vaddeswaram, Guntur(Dist), Andhra Pradesh -522502, India.

3 Shaaz College of Engg. & Tech. Himayatnagar, Moinabad Mandal, Ranga Reddy (Dist) - 500 075, Andhra Pradesh, India.

Abstract: Higher heat losses and brake specific fuel consumption (BSFC) are major problems in an indirect injection (IDI) diesel engine, which can be overcome by means of insulation. However, insulation increases combustion temperature by about 200-2500 compared to an identical standard IDI diesel engine. Consequently, the NOx emission increases extremely due to this temperature increment. With the proper adjustment of cold EGR mass fraction, it is possible to partially offset the adverse effect of insulation on heat release rate and hence to obtain improved performance and lower NOx than the baseline engine. At the first step of this work, the effects of insulation (without heat flux) on the performance and emissions are studied at both part and full loads by a three dimensional model. The results show that in the adiabatic case, BSFC is approximately 18% and 23% lower than baseline at the full and part loads respectively. Also, soot emission shows 36% reduction at full load, while at the part load, the value of which remains unchanged. At the second step of the present work, for reduction of NOx production in the insulated engine, cold exhaust gas recirculation (EGR) method is utilized. Thus, the model is studied at various cold EGR mass fractions, in which the EGR mass fraction increases from 0% to 30% at the same speed and operating loads. The optimum cold EGR mass fraction is obtained as 10% for part load operation. Results show that with adding this optimum EGR, the BSFC and NOx decrease by 15% and 6.5 % respectively at full load compared to the baseline and these reductions are reached to 21% and 29% in the case of part load respectively, while it causes increment in soot emission at full load operation and decreases slightly in the part load compared to the baseline engine. As an engine is generally operated for a short time interval at full load condition, this increment can be omitted when improvements in BSFC and decrease in NOx are considered together. The results of the model for baseline engine are in good agreement with the corresponding experimental data. This agreement makes the model a reliable tool that can be used for exploring new engine concepts.

8. Photodegradation and removal of phenol and phenolic derivatives from petroleum refinery wastewater using nanoparticles of TiO₂

F. Shahrezaei¹, A. Akhbari^{2, 3}, A. Rostami⁴

1Academic Center for Education, Culture & Research (ACECR), Kermanshah, Iran

2 Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran

3 Water and Wastewater Research Center (WWRC), Razi University, Kermanshah, Iran

4 Kermanshah Oil Refinery company, R&D department(KORC), Kermanshah, Iran

Abstract: This study explores the potential application of TiO2 photocatalysis as primary degradation system of phenol and phenolic derivatives from refinery wastewater. The removal of phenol was investigated in terms of various parameters namely: pH, temperature and catalyst concentration. Determination of phenol and phenolic derivatives compounds is carried out by gas chromatography using a flame ionization detector. In order to analyze the process, chemical oxygen demand fraction (R) was studied. The region of the exploration for the process was taken as the area enclosed by pH (2-10), temperature (293-318 k) and catalyst concentration (10-200 mg/l) boundaries. The optimum conditions for phenol and phenolic derivatives removal were found to be 3, 318 k and 100 mg/l, respectively, for pH, temperature and catalyst concentration. The results showed that, at optimum conditions, remarkable removal of 90% of phenol after 2 h can be achieved. The main feature of this work is the use of inexpensive and recoverable catalyst and may be considered for preliminary application in the refinery wastewater treatments after physicochemical treatments to avoid solids and colloids.

9. Modeling and performance evaluation of an electromechanical valve actuator for a camless IC engine

Eid Mohamed

Automotive and Tractors Engineering, Faculty of Engineering, Helwan University, Cairo, Egypt.

Abstract: Valve train control is one of the best strategies for optimizing efficiency and emissions of Internal Combustion (IC) engines. Applications of solenoid valve actuators in (IC) engines can facilitate operations such as variable valve timing and variable valve lifting for improved the engine performance, fuel economy and reduce emission, the electromechanical valve actuator (EMVA) uses solenoid to actuate valve movement independently for the application of (IC) engine. In this work presents the effects of design and operating parameters on the system dynamic performances of the actuator and the proposed an (EMVA) structure by incorporating the hybrid magneto-motive force (MMF) implementation in which the magnetic flux is combined by the coil excitation and permanent magnets. A two-degree-of-freedom lumped parameter model is used to simulate the response of valve actuator system in the opening and closing. The model and control of an electromagnetic valve (EMV) are described. This is done using electromagnetic force to open and close the valve and a controller regulates the motion specifications required. The developments controller is based on a state-space description of the actuator that is derived based on physical principles and parameter identification. Linear-quadratic regulator design (LQR) optimal control is designed with the evaluation reasonable the performance and energy of (EMV) valve are obtained with the design.

10. Development of a site-independent mathematical model for the estimation of global solar radiation on earth’s surface around the globe

Iranna Korachagaon¹, V.N. Bapat²

1 Annasaheb Dange College of Engineering and Technology, Ashta – 416 301, Sangli, India.

2 Ganga Institute of Technology and Management, Kablana, Jhajjar, Haryana – 124 104, India.

Abstract: Measured air temperature, relative humidity, wind and moisture measurements for 210 sites around the earth were used for the model development. The models were formulated using multi-parameter input regression type empirical relations. The estimation of Global Solar Radiation (GSR) were made using various combinations of data sets, with use of 1 parameter to 11 parameters. After validation with 665 data sites on these models, finally two candidate models have been proposed. These models are capable of covering 50% of the land area on earth surface between latitude ± 30º, enabling estimation accuracy to 93% of sites, with RMSE limiting to 15%.

11. Endoreversible Meletis-Georgiou cycle

Chang Liu, Lingen Chen, Fengrui Sun

College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033, P. R. China.

Abstract: An endoreversible Meletis-Georgiou (MG) cycle model with constant specific heat of working fluid is established and the analytical formulae of performance parameters including working fluid temperatures, work output and efficiency are derived using the finite time thermodynamic theory. The performance of the endoreversible MG cycle is analyzed and optimized. The characteristics of the work output versus compression ratio, efficiency versus compression ratio, and work output versus efficiency are obtained, respectively, by detailed numerical examples, and the effects of changeover ratio, over-expansion ratio, heating value of fuel, heat transfer loss coefficient, initial temperature of working fluid, and the transferred volume ratio on the relationship mentioned above are also discussed. The maximum work output and the corresponding optimal compression ratio, changeover ratio, over-expansion ratio as well as the maximum efficiency and the corresponding optimal changeover ratio and over-expansion ratio are obtained by taking the cycle work output and efficiency as the optimization objectives, respectively. Moreover, the effects of the parameters such as the heating value of fuel, heat transfer loss coefficient, initial temperature of working fluid, and the transferred volume ratio on the maximum work output, the maximum efficiency and the corresponding optimal ratios are analyzed. The results may provide guidelines for the optimal design of practical MG engine.