A Comparative Thermodynamic Analysis of Organic Rankine Cycles (ORC) and Kalina Cycle for Low-Grade Energy Resources
Exergy Efficiency and Exergy Destruction Assessment of Heat Transfer and Fluid Flow through Spiral Passages using Source-Sink Model
Innovative Approach: Empowering Contextual Consulting in Industry 4.0 through a Hybrid Data Analytics Framework
Study of Corrosion and its Preventive Measures
Green Hydrogen Feasibility in Oman
Chemistry and Chemical Engineering: Approaches, Observations, and Outlooks
Integration of PMS Software and Decision Matrix Tool Based on Data Acquired from Latest IT Advanced Sensors and 3D CAD Models in Marine Operations Field
Dynamic Changes in Mangrove Forest and Lu/Lc Variation Analysis over Indian Sundarban Delta in West Bengal (India) Using Multi-Temporal Satellite Data
The Impacts of Climate Change on Water Resources in Hilly Areas of Nepal
Development and Performance Evaluation of Magnetic Abrasive Finishing Setup for Thick Cylinders
An Analysis of Machining Forces On Graphite/Epoxy, Glass/Epoxy and Kevlar/Epoxy Composites Using a Neural Network Approach
Deformation Behaviour of Fe-0.8%C-1.0%Si-0.8%Cu Sintered P/M Steel during Powder Preform Forging
A Series of Tool-Life Studies on Aluminium Matrix Hybrid Composites
Achieving Manufacturing Excelence by Applying LSSF Model – A Lean Six Sigma Framework
Design and Analysis of Piezo- Driven Valve-Less Micropump
A direct methanol fuel cell (DMFC) directly converts the chemical energy stored in methanol to electricity. DMFCs have received considerable attention as a new power source for electric portable devices because of their high theoretical energy densities. In particular, passive DMFCs can provide a higher energy density then active one, since they do not need pumps for fuel feeding and blowers for air breathing. However, the actual energy density of the passive DMFCs under development is still far from that expected because of the methanol crossover (MCO) and the high overvoltage at the electrode. Due to the MCO, the passive DMFCs usually show the highest performance at low concentrations of methanol about 5M under passive conditions and that’s why diluted methanol (3M-5M) is used in the fuel cartridge. Filling the fuel reservoir with a low-methanol concentration means that the specific energy of the fuel cell system is low, which not only leads to a short operation time for each fuel charge, but also results in a rapid decrease in the pre-set methanol concentration in the fuel reservoir. Hence, filling in the fuel reservoir with a high-methanol concentration is desired, as it increases the volumetric energy density and discharging time of the DMFC system. This paper focuses on the progress and current status of research in the passive DMFCs fed with concentrated methanol. The paper reviews more than 40 journal and conference papers in this area and will be very useful to the researchers working in this direction.
“It is not the strongest of the species that survive, not the most intelligent, but the one most responsive to change. ”__ Charles Darwin With increasing gap between the energy requirement of the industrialized world and inability to replenish such needs from the limited sources of energy like fossil fuels, an ever increasing levels of greenhouse pollution from the combustion of fossil fuels in turn aggravate the perils of global warming and energy crisis. Motor vehicles account for a significant portion of urban air pollution in much of the developing world. The paper describes how bio-fuels are important because they replace petroleum fuels. A number of environmental and economic benefits are claimed for bio-fuels. Bio-ethanol is by far the most widely used bio-fuel for transportation worldwide. Production of bio-ethanol from biomass is one way to reduce both consumption of crude oil and environmental pollution. Using bio-ethanol blended gasoline fuel for automobiles can significantly reduce petroleum use and exhaust greenhouse gas emission.
Aluminum matrix composite is the innovation of high performance material technology and it has superior interfacial integrity and thermodynamic stability between the matrix and reinforcement. Making the engineering components from this composite material require machining operations. Therefore, addressing the mach inability issues of the composite is very important. This paper proposes an approach to optimize the machining parameters in turning of Al 6061-10% ZrB2 Metal Matrix Composite (MMC) with performance characteristics by using desirability analysis. The effect of ZrB2 reinforcement particles on machinability behavior need to be studied. The machining parameters, namely cutting speed, feed rate and depth of cut are optimized with considerations of multiple performance characteristics including surface roughness and power consumed. It is concluded that the feed rate has the strongest effect. The confirmation experiment indicates that there is a good agreement between the estimated value and experimental Value of the desirability function grade.
Waveguide dispersion can be tailored but not the material dispersion. Hence the total dispersion can be shifted at any desired band by adjusting the waveguide dispersion. Waveguide dispersion is proportional to and need to be found numerically. In this paper we have tried to compute analytical expression for in terms of. To compute accurately, should be accurate enough up to decimal point. This constraint sometimes generates the error in calculation of waveguide dispersion. In this paper we have tried to compute analytical expression for in terms of. It reveals that we can compute waveguide dispersion enough accurately for various modes having known only -
The most popular method of nonparametric spectral density is the Weighted Segment Overlap Averaging (WOSA). Because of the unequal weighting of observed samples, its variance estimate is non monotonic function of fraction of overlap. Simple theoretical analysis of the mean and the variance of the WOSA have been presented nicely. Selecting the optimal fraction of overlap, which minimizes the variance, is in general difficult since it depends on the window used. The main objective in this paper is to avoid the nonmonotonic behavior of the variance for the Welch power spectrum estimator (PSE) by introducing circular overlap to the Welch method. With slight modification, the mean and the variance of Welch Circular Overlap Segment Averaging (WCOSA) have been presented. With the help of simulation, the performance evaluations of WOSA and WCOSA have been presented and finally, it is observed that the variance estimate based on WCOSA is a monotonically decreasing function of the fraction of overlap.
The main objective of this paper is to develop and standardize the production method of Arthrospira platensis (Spirulina sp.) and to transform the algal oil to biodiesel by transesterification. The development of technique for the production of algal oil involves following three steps. The primary step is the preparation of BG 11 medium for the growth of micro algae. The second step involves the harvesting and extraction of the algal biomass using hexane and ether solvents and the reaction is maintained at 60oc for 24 hrs. The final step is the transesterification of the extracted algal oil using Sodium hydroxide (NaOH) as alkaline catalyst and methanol at 75oc for 48 hrs. The fatty acid methyl ester thus produced is separated from glycerin using an inverted separator. The physio-chemical properties were found to be within ASTM standards.
This article presents a method to predict the equilibrium composition and temperature of a reaction mixture in gas phase as found in the reaction furnace of the Claus Sulphur Recovery Unit (SRU). The proposed method is useful for process design as well as plant performance optimization. An expression for the Gibbs free energy of the system in terms of temperature is derived by using the Soave-Redlich-Kwong (SRK) equation of state. Temperature correlations for Gibbs free energy of formation of various components in the reaction mixture are obtained using standard heat capacity (Cp) temperature correlations. Initial assumption for the furnace outlet temperature is made to calculate the value for the Gibbs free energy of the system. Solver function minimizes this value by varying the composition of the outlet stream using mathematical optimization methods for non-linear systems. The outlet stream composition corresponding to this value is the equilibrium composition as the Gibbs free energy of a system reaches minimum at equilibrium. Application of Gibbs free energy minimization method using the Solver feature present in the Microsoft Excel spreadsheet program is found to predict effectively the equilibrium composition and temperature of the outlet streams of reaction mixtures in three plant case studies of Claus Sulphur Recovery Unit.
