Soni D.K.,MANIT |
Journal of Cleaner Production | Year: 2017
The main objective of the present study is to find the need of technology transformation from hemispherical bowl piston geometry to re-entrant piston bowl geometry. The two different piston bowl geometries were examined by the application of different spray angles. The NO and Soot emission characteristics for both geometries were measured and performance parameters were also evaluated to justify the use of geometry as a part of combustion study. A commercial CFD simulation software AVL FIRE was used to evaluate re-entrant and hemispherical bowl piston geometry. Easily available hemispherical bowl piston geometry of Kirloskar single cylinder diesel engine was used for comparison and validation purpose. The effect of spray angles such as 120°, 140° and 160° tested on both geometry, while comparison has drawn for emissions and performance parameters. Results indicated that, NO and Soot mass fraction of 120° and 160° spray angle is lowest respectively. Whereas, NO emissions are reduced to 66% at 120° spray angle in case of a Re-entrant piston bowl than hemispherical bowl piston geometry. However, the soot mass fraction shows same response for both geometry at 160° spray angle. © 2017 Elsevier Ltd
Gupta K.K.,Medi Caps Institute of Science and Technology |
Rehman A.,MANIT |
Renewable and Sustainable Energy Reviews | Year: 2010
Due to depletion of fossil fuel, bio-fuels have generated a significant interest as an alternative fuel for the future. The use of bio-fuels to fuel gas turbine seems a viable solution for the problems of decreasing fossil-fuel reserves and environmental concerns. Bio-fuels are alternative fuels, made from renewable sources and having environmental benefit. In recent years, the desire for energy independence, foreseen depletion of nonrenewable fuel resources, fluctuating petroleum fuel costs, the necessity of stimulating agriculture based economy, and the reality of climate change have created an interest in the development of bio-fuels. The application of bio-fuels in automobiles and heating applications is increasing day by day. Therefore the use of these fuels in gas turbines would extend this application to aviation field. The impact of costly petroleum-based aviation fuel on the environment is harmful. So the development of alternative fuels in aviation is important and useful. The use of liquid and gaseous fuels from biomass will help to fulfill the Kyoto targets concerning global warming emissions. In addition, to reduce exhaust emission waste gases and syngas, etc., could be used as a potential gas turbine fuel. The term bio-fuel is referred to alternative fuel which is produced from biomass. Such fuels include bio-diesel, bio-ethanol, bio-methanol, pyrolysis oil, biogas, synthetic gas (dimethyl ether), hydrogen, etc. The bio-ethanol and bio-methanol are petrol additive/substitute. Bio-diesel is an environment friendly alternative liquid fuel for the diesel/aviation fuel. The gas turbine develops steady flame during its combustion; this feature gives a flexibility to use alternative fuels. Therefore so the use of different bio-fuels in gas turbine has been investigated by a good number of researchers. The suitability and modifications in the existing systems are also recommended. © 2010 Elsevier Ltd. All rights reserved.
Kalambe S.,M.A.N.I.T. |
Renewable and Sustainable Energy Reviews | Year: 2014
Distribution system provides a link between the high voltage transmission system and low voltage consumers thus I2R loss in a distributed system is high because of low voltage and high current. Distribution companies (DISCOs) have an economic enticement to reduce losses in their networks. Usually, this enticement is the cost difference between real and standard losses. Therefore, if real losses are higher than the standard ones, the DISCOs are economically penalized or if the opposite happens, they obtain a profit. Thus loss minimization problem is a well researched topic and all previous approaches vary from each other by selection of tool for loss minimization and thereafter either in their problem formulation or problem solution methods employed. Many methods of loss reduction exist like feeder reconfiguration, capacitor placement, high voltage distribution system, conductor grading, Distributed Generator (DG) Allocation etc. This paper gives a bibliographical survey, general background and comparative analysis of three most commonly used techniques (i) Capacitor Placement, (ii) Feeder Reconfiguration, (iii) and DG Allocation for loss minimization in distribution network based on over 147 published articles, so that new researchers can easily find literature particularly in this area. © 2013 Elsevier Ltd.
Agrawal D.,MANIT |
IET Image Processing | Year: 2010
The present day camera systems have the limitation of acquiring the clearer image of a scene having objects at different distances. This limitation can be overcome by fusion of multiple images of the scene taken with different camera settings. The fusion of these images comes under the category of multifocus image fusion. In the existing method of image, fusion partitioned source image blocks are fused by pulse coupled neural network (PCNN) based on their clarity measure. PCNN plays an important role in the image fusion process in choosing the best-quality image block for fused image. Fusion method becomes tedious and time consuming because of the inherent complexity of PCNN. In this study, a modified approach of PCNN suitable for application in image fusion technique is proposed by reducing the processing time and computational complexity. The modifications proposed are in linking and feeding field of PCNN. This study presents a method for multifocus image fusion by using modified PCNN (MPCNN) with spatial frequency (SF) and energy of Laplacian (EOL) as clarity measures. The proposed method of image fusion using MPCNN results in better quality of fused image with reduced root mean square error (RMSE) and computational time requirements as compared to conventional PCNN. © 2010 The Institution of Engineering and Technology.
Kushwaha S.K.,MANIT |
Journal of Theoretical Biology | Year: 2010
In host-parasite diseases like tuberculosis, non-homologous proteins (enzymes) as drug target are first preference. Most potent drug target can be identified among large number of non-homologous protein through protein interaction network analysis. In this study, the entire promising dimension has been explored for identification of potential drug target. A comparative metabolic pathway analysis of the host Homo sapiens and the pathogen M. tuberculosis H37Rv has been performed with three level of analysis. In first level, the unique metabolic pathways of M. tuberculosis have been identified through its comparative study with H. sapiens and identification of non-homologous proteins has been done through BLAST similarity search. In second level, choke-point analysis has been performed with identified non-homologous proteins of metabolic pathways. In third level, two type of analysis have been performed through protein interaction network. First analysis has been done to find out the most potential metabolic functional associations among all identified choke point proteins whereas second analysis has been performed to find out the functional association of high metabolic interacting proteins to pathogenesis causing proteins. Most interactive metabolic proteins which have highest number of functional association with pathogenesis causing proteins have been considered as potential drug target. A list of 18 potential drug targets has been proposed which are various stages of progress at the TBSGC and proposed drug targets are also studied for other pathogenic strains. As a case study, we have built a homology model of identified drug targets histidinol-phosphate aminotransferase (HisC1) using MODELLER software and various information have been generated through molecular dynamics which will be useful in wetlab structure determination. The generated model could be further explored for insilico docking studies with suitable inhibitors. © 2009 Elsevier Ltd. All rights reserved.
Yadav S.,Indian Institute of Technology Indore |
Renewable and Sustainable Energy Reviews | Year: 2015
Abstract Access to safe, fresh and clean drinking water is one of the major problems in different parts of the world. Among many water purification technologies solar desalination/distillation/purification is one of the most sustainable and attractive method employed to meet the supply of clean drinkable water in remote areas at a very reasonable cost. Over the past three decades, there have been numerous designs of solar still system developed worldwide. However the technology is not commercialized and standardized because of its lower yield. This article provides a comprehensive review of the various designs of solar stills used at domestic level. Performance parameters like heat transfer analysis, energy analysis, exergy analysis, thermal efficiency and economic analysis have been presented for the domestic designs of solar stills. Though solar still have not been successfully commercialized as yet, with the ongoing research efforts, they can be modified and improved for future domestic applications. © 2015 Elsevier Ltd. All rights reserved.
Lalji M.K.,P.A. College |
Sarviya R.M.,MANIT |
Renewable and Sustainable Energy Reviews | Year: 2012
In view of above present investigation is planned with the following. The present investigation has been carried out with the following objectives: To study performance of packed bed solar air heater for high porosity range and for different shapes of matrices.Development of correlations for heat transfer coefficient and friction factor for packed bed solar air heater and its comparison with conventional design.Exergy analysis of packed bed solar air heater. The present study involved outdoor experimental work for generation of heat transfer and friction data for flow in a packed bed solar air heater at different mass flow rates of air for various porosities and shapes of matrices. Data is also collected for conventional smooth duct under similar operating conditions for ensuring accuracy of experimental data. Six matrices had been tested for seven values of flow rates corresponding to flow Reynolds number of about 1000-4700 and data is collected under steady state condition. Ranges of parameters covered in this experimental investigation are as follows:Reynolds number, Re=1000-4700Porosity, P=0.9614-0.9984Number of layers, n=3-6 It is found that in the entire range of Reynolds number, Colburn factor decreases with an increase of packing Reynolds number and volumetric heat transfer increased monotonically with a decrease in porosity. Also from the various matrices studied hexagonal shaped matrix performed lowest of all other matrices. Square shaped matrix performed best amongst the matrices studied. Following correlations have been developed for Colburn factor and friction factor in terms of porosity and operating parameters: Jh=0.1765[( 1/nP)0.6156)( pt/dw)0.1229] 0.6651Rep-0.4767 fp=2.0291[( 1/nP)0.3521)( pt/dw)0.0686] 0.6759Rep-0.3897.
Kumar L.,MANIT |
International Journal of Electrical Power and Energy Systems | Year: 2013
Suitable integration of more than one energy sources is an interesting and challenging task that attracts attention of the researchers. Integration of several energy sources profoundly depends on the power electronic converters which interface multiple energy sources having different V-I characteristics. Therefore, suitable integration and better utilization of energy source demands, well designed and efficient interfacing circuitry. In this paper, a non isolated multiple source DC/DC converter (MSC) is proposed. The generation of MSC using pulsating source cells as a building block has been discussed briefly. The proposed converter is proficient for energy diversification from renewable and storage energy sources individually or simultaneously. It has the capability to operate either in buck, boost or buck-boost mode of operation with possibility of bidirectional power flow. It offers simplicity in structure with inherent bypass circuit, flexibility in control scheme and reliability in operation. In addition, a power management control algorithm for proposed converter has also been discussed. The proposed concept has been investigated through detailed device level simulation using MATLAB/Simulink environment. Experimental implementation and validation have been carried out on a low power prototype using digital signal processor (DSP) TMS320F2812. © 2013 Elsevier Ltd. All rights reserved.
Gupta K.K.,M.A.N.I.T |
IET Power Electronics | Year: 2014
As multilevel inverters are gaining increasing importance, newer topologies are being proposed to reduce part count for large number of levels in output voltage. A simplified five-level inverter has been recently reported in the literature to reduce component count. The topology comprises of floating input DC sources connected in opposite polarities through power switches. The structure requires lesser active switches as compared with conventional cascaded H-bridge topology with much reduced switching losses. Available literature present generalisation of the topology with symmetrical sources, but no investigations are made for equal load sharing and asymmetrical configurations. This study presents a comprehensive analysis of the aforementioned topology, referred to as cross-connected sources-based multilevel inverter (CCS-MLI). The topology is analysed for both symmetric and asymmetric source configurations. Also, a new algorithm for asymmetric source configuration suitable for CCS-MLI is proposed. A control scheme is also proposed for equal load sharing in five-level topology. Investigations are made for possibility of equal load sharing in higher level structures and fundamental frequency switching of switches bearing higher voltage stresses. Various concepts are verified with simulations and experimental studies. © The Institution of Engineering and Technology 2014.
Sahu J.N.,Bharat Heavy Electricals Ltd. |
Materials Today: Proceedings | Year: 2016
A hard Nano crystalline surface was produced by simultaneous surface mechanical attrition treatment (SMAT) and mechanical alloying (MA) with activated carbon, followed by low temperature annealing below 500°C. The thermal stability of surface Nano crystals produced by SMAT and low temperature diffusion of carbon into Nano crystals were also investigated by annealing 200°C to500°C for 1h. Ni-Cr-Mo casehardening steel was used in the present study. The formation of Nano crystals and surface alloying with activated carbon by SMAT, microstructural changes during annealing, thermal stability of the Nano crystals and the surface hardness were been investigated by using Optical microscope, SEM, XRD and microvicker's hardness tester. Experimental results had showed 20-50 nm crystals by SMAT operation by enhancing 0.19C to 0.4C. Enhanced diffusion kinetics of Nano crystals observed during the annealing process even at 200°C. The simultaneous SMAT and MA with carbon increased the surface hardness from 1.5 to 3.0 GPa in 20 minutes and subsequent annealing further increased the hardness steadily up to 450°C. A maximum hardness of 4.5 GPa was achieved by annealing treatment. The hardness decreased considerably at 500°C indicating grain growth at thistemperature. The results had clearly demonstrated that the surface Nano crystals formed by SMAT were found stable up to 450°C. © 2016 Elsevier Ltd.