Faculty Publications
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Item Design of haul road lighting system. Part II: Design based on optimal cost considerations(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.The proper selection of lighting installations is very important for the provision of cost-effective lighting systems without compromising light quality. In this study a computer program was developed to evolve a cost-effective lighting system for haul roads in surface mines. This program is beneficial in assessing the viability of various lighting installations in order to achieve cost-effective solutions. Using the program, illumination design was studied for an 800 m long stretch of haul road. Nine different types of light sources were considered at mounting heights of 12 m and 16 m. The study shows that at a 12 m mounting height, 100 W high-pressure sodium vapour (HPSV) lamps offer the most cost-effective design, followed by 250 W HPSV lamps. In the case of 16 m pole heights the annual lighting cost is minimum for 150 W HPSV lamps, followed by 250 W HPSV lamps. This work also shows that optimum design based on energy consumption need not be the same as design based on optimum cost considerations as cost parameters may vary widely with location.Item Design of haul road lighting system. Part I: Design based on optimal energy considerations(2006) Karmakar, N.C.; Mangalpady, M.; Rao, Y.V.; Yaragatti, U.R.Electrical energy consumption is a major cost component of haul road lighting. Haul road lighting depends on many parameters such as type and wattage of sources, mounting height and tilt angle of light fixtures. In this study a computer model has been developed for optimum energy consumption of any haul road lighting system. Using the program, illumination design was studied for a stretch of 800m long haul road. Nine different types of light sources were considered for mounting heights of 12 and 16m. High-pressure sodium vapour (HPSV) lamps of 100W proved to be energy efficient at a 12m height whereas at 16m height, energy consumption was minimum for 150 W HPSV lamps. Thus the developed computer program proved to be successful in evaluating the performance of lighting designs from the point of view of energy consumption.Item Combustion characteristics of diesel engine operating on jatropha oil methyl ester(Serbian Society of Heat Transfer Engineers, 2010) Dhananjaya, D.A.; Sudhir, C.V.; Mohanan, P.Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as jatropha oil, linseed oil, mahua oil, rice bran oil, karanji oil, etc., are potentially effective diesel substitute. Vegetable oils have reasonable energy content. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in diesel engines with very little or no engine modifications. This is because it has combustion characteristics similar to petroleum diesel. The current paper reports a study carried out to investigate the combustion, performance and emission characteristics of jatropha oil methyl ester and its blend B20 (80% petroleum diesel and 20% jatropha oil methyl ester) and diesel fuel on a single-cylinder, four-stroke, direct injections, water cooled diesel engine. This study gives the comparative measures of brake thermal efficiency, brake specific energy consumption, smoke opacity, HC, NOx, ignition delay, cylinder peak pressure, and peak heat release rates. The engine performance in terms of higher thermal efficiency and lower emissions of blend B20 fuel operation was observed and compared with jatropha oil methyl ester and petroleum diesel fuel for injection timing of 20° bTDC, 23° bTDC and 26° bTDC at injection opening pressure of 220 bar.Item An analysis of cycle-by-cycle fluctuation in combustion parameter in CI engine operation for various bio-fuels(2011) Bekal, S.; Ashok Babu, T.P.A.The cycle-by-cycle fluctuations in peak pressure of combustion in a CI engine were studied for lower and higher blends of diesel and ester, and water-in-ester emulsions, at four injection timings and three injection pressures using coefficient of variation. The sunflower ester-diesel blends are found to have lower cycle-by-cycle fluctuations than pongemia ester-diesel blends. The fluctuations are found to be higher than that of diesel for higher blend proportions of ester. The water-in-ester emulsion show higher cycle-by-cycle fluctuations than that of ester-diesel blends. In most cases, the Brake specific energy consumption is also found to be higher where the coefficient of variation has higher values. Copyright © Taylor & Francis Group, LLC.Item Rural electrification in India and feasibility of Photovoltaic Solar Home Systems(2011) Kamalapur, G.D.; Yaragatti, U.R.Rural electrification is an integral component of poverty alleviation and rural growth of a nation. In India, electricity has not played effective role in the socio-economic growth of village. Gross Domestic Product (GDP) is increasing with 8% where as contribution of agriculture sector is 1.9%. Government of India has ambitious target of providing electricity to all villages by 2008 and all rural households by 2012. Steps are already initiated with Rural Electric Corporation, Rural Electricity Supply Technology mission, State Electricity Boards, Reforms in Power sector. An attempt has been made in this paper to assess the features of rural electrification in India and the feasibility of Photovoltaic Solar Home Systems (PV SHS). © 2010 Elsevier Ltd. All rights reserved.Item New CPS-PPEES blend membranes for CaCl2 and NaCl rejection(Techno Press technop2@chollian.net, 2012) Hegde, C.; Isloor, A.M.; Padaki, M.; A.F., A.F.; Lau, L.W.Carboxylated polysulfone (CPS), poly (1,4-phenylene ether ethersulfone) (PPEES), membranes were prepared and used for the separation of NaCl and CaCl2 in efficient way with less energy consumption. In this work, nanofiltration and reverse osmosis membranes were employed to the salt rejection behavior of the different salt solutions. The influence of applied pressure (1-12 bar), on the membrane performance was assessed. In CM series of membranes, CM1 showed maximum of 97% water uptake and 36% water swelling, whereas, CM4 showed 75% water uptake and 28% water swelling. In RCM series, RCM1 showed 85% water uptake and 32% water swelling whereas, in RCM4 it was 68% for water uptake and 20% for water swelling. Conclusively reverse osmosis membranes gave better rejection whereas nanofiltration membrane showed enhanced flux. CM1 showed 58% of rejection with 12L/(m2h) flux and RCM1 showed 55% of rejection with 15L/(m2h) flux for 0.1wt.% NaCl solution. Whereas, in 0.1wt.% CaCl22 solution, membrane CM11 showed 78% of rejection with 12L/(m2h) flux and RCM1 showed 63% rejection with flux of 9L/(m2h).Item Efficiency improvement on the multicrystalline silicon wafer through six sigma methodology(2012) Saravanan, S.; Mahadevan, M.; Suratkar, P.; Gijo, E.V.Crystalline silicon solar cell technology continues to be dominant in the photovoltaic (PV) technology due to its novel process flow and the clear understanding of the material. Being a mature material-based technology; on the one hand, it has quite a few opportunities for improvement, on the other hand, the expansion of solar energy should depend on this technology. Due to increase in the global energy consumption and high competition level in the market, it has become necessary to show significant improvement in the performance of the present process/product. The demand for high efficiency solar cells at low costs with shorter cycle times forced the manufacturing industries to improve their processes by applying systematic methodologies such as Six Sigma. This paper illustrates the importance of anti-reflective coatings (ARCs) on the silicon solar cell processes and the successful implementation of Six Sigma to improve the efficiency of the silicon solar cells. The different phases of the Six Sigma DMAIC approach applied to the process and the results are interpreted. © 2012 Copyright Taylor and Francis Group, LLC.Item Digital signature-based secure node disjoint multipath routing protocol for wireless sensor networks(2012) Shiva Murthy, G.; D'Souza, R.J.; Varaprasad, G.The objective of energy efficient routing protocol is to increase the operational lifetime of the wireless sensor networks. Multipath routing protocols enhance the lifetime of the wireless sensor networks by distributing traffic among multiple paths instead of a single optimal path. Transmission of secured data is also an important research concern in the wireless sensor networks. In this paper, a secure node disjoint multipath routing protocol for wireless sensor networks is proposed. Here, the data packets are transmitted in a secure manner by using the digital signature crypto system. It is compared with an ad hoc on-demand multipath distance vector routing protocol. It shows better results in terms of packet delivery fraction, energy consumption, and end-to-end delay compared to the ad hoc on-demand multipath distance vector routing. © 2012 IEEE.Item Network lifetime analytical model for node-disjoint multipath routing in wireless sensor networks(Inderscience Publishers, 2013) Murthy, S.G.; D'Souza, R.J.; Varaprasad, G.The objective of every sensor node in a sensor network is to send the sensed data in the phenomena to a sink node. The network lifetime is maximal, when the energy consumption of each node is uniform. Many routing protocols select an optimal path to increase the network lifetime in sensor networks. The energy of the nodes along this optimal path is consumed more, causing their early death. In the multipath routing, data traffic is distributed among the multiple paths, instead of a single optimal path. This work proposes a theoretical frame work to study the node-disjoint multipath wireless sensor network reliability. With higher reliability, higher network lifetime can be achieved. Simulation results show that when the data is transmitted through multiple paths with different data rates, the network lifetime increases. The node criticality factor enhances the network lifetime analysis effectively. © 2013 Inderscience Enterprises Ltd.Item Performance analysis of energy efficient modulation and coding schemes for wireless sensor networks(2013) Shivaprakasha, K.S.; Kulkarni, M.; Patkar, R.Sensor nodes of a typical wireless sensor network (WSN) are battery driven, so energy conservation is a critical factor for node's life time. Thus optimisation of energy consumption is a major objective in the area of WSNs. One such method is asymmetric communication which uses different channel codes and modulation schemes for downlink (base station (BS) to node link) and uplink (node to BS link). In this paper, a performance analysis of different channel code-modulation pair for energy efficient asymmetric communication is carried out followed by the field programmable gate array implementation of channel codes required at the node. The per information bit node energy for the uplink has been calculated for efficient channel code-modulation pair, for three different channels, viz. additive white gaussian noise, Rayleigh flat-fading and log-normal shadowing channels, resulting in reduction in energy consumption at sensor nodes. © 2013 Copyright Taylor and Francis Group, LLC.