Faculty Publications

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    A Crossbar Interconnection Network in DNA
    (Institute of Electrical and Electronics Engineers Inc., 2015) Talawar, B.
    DNA computers provide exciting challenges and opportunities in the fields of computer architecture, neural networks, autonomous micromechanical devices, and chemical reaction networks. The advent of digital abstractions such as the seesaw gates hold many opportunities for computer architects to realize complex digital circuits using DNA strand displacement principles. The paper presents a realization of a single bit, 2×2 crossbar interconnection network built using seesaw gates. The functional correctness of the implemented crossbar was verified using a chemical reaction simulator. © 2015 IEEE.
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    Bio-fuel variants for use in CI engine at design and off-design regimes: An experimental analysis
    (2008) Bekal, S.; Ashok Babu, T.P.A.
    In this work an attempt has been made to study the ester based fuel variants derived from edible and inedible oil sources for identifying the most appropriate fuel variant and operating mode for running a CI engine based on performance and emission parameters. The twenty four fuel variants tested included esters obtained from the edible sunflower oil, inedible pongamia oil, and their higher and lower proportional blends with diesel. Besides, several other fuel variants obtained from the emulsification of water-in-ester (W/E) with different water proportions have been tested. Basing upon three operational variables, namely, injection timing, injection pressure, and load, comparisons are made in aspects of smoke emissions, NOX emissions, BSEC, and exhaust gas temperatures at the best injection timing. 21.5°, 23°, 24.5° and 27.5° bTDC as the four injection timings and 190, 220 and 250 bar as three injection pressures are considered for the overall study. The 264 sets of experiments conducted with these combinations, focussing on the full and partial load characteristics of the engine, show that both sunflower and pongamia oil esters exhibited similar characteristics in their engine performance, and in both the cases the best BSEC occurred with 220 bar injection pressure for most of the fuel variants, and for straight fuels the ideal injection timing found to be slightly retarded (1.5° crank angle) compared to diesel. However, 24.5° bTDC, normal for the engine, was found to be the most appropriate for the lower blends like B2 (2% ester by volume), B5 and emulsion with 10% water proportion. © 2008 Elsevier Ltd. All rights reserved.
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    Combating corrosion degradation of turbine materials using HVOF sprayed 25% (Cr3C2-25(Ni20Cr)) + NiCrAlY coating
    (2013) Jegadeeswaran, N.; Ramesh, M.R.; Bhat, K.
    High velocity oxy fuel process (HVOF) is an advanced coating process for thermal spraying of coatings on to components used in turbines. HVOF process is a thermal spray coating method and is widely used to apply wear, erosion, and corrosion protective coatings to the components used in industrial turbines. 25% (Cr3C2-25(Ni20Cr)) + NiCrAlY based coatings have been sprayed on to three turbine materials, namely, Ti-31, Superco-605, and MDN-121. Coated and uncoated substrates were subjected to hot corrosion study under cyclic conditions. Each cycle consisted of 1 hour heating at 800°C followed by 20 minutes air cooling. Gravimetric measurements were done after each cycle and a plot of weight gain as a function of number of cycles is drawn. Parabolic rate constants were estimated for the understanding of corrosion behaviour. It was observed that coated Ti-31 and MDN-121 were more resistant compared to the uncoated ones. Uncoated superco-605 was undergoing sputtering during corrosion study and hence comparison between coated and uncoated superco-605 was difficult. The cross-sectional analysis of the corroded, coated samples indicated the presence of a thin layer of chromium oxide scale on the top of the coating and it imparted better corrosion resistance. Parabolic rate constants also indicated that coating is more beneficial to Ti-31 than to MDN-121. © 2013 N. Jegadeeswaran et al.
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    Thermo-catalytic degradation of low density polyethylene to liquid fuel over kaolin catalyst
    (Inderscience Publishers, 2014) Panda, A.K.; Singh, R.K.
    Waste low-density polyethylene samples were subjected to thermo-catalytic degradation using kaolin as catalyst in a batch reactor at temperature range of 400 to 500°C and atmospheric pressure. The quality and yield of the condensable product has been studied as a function of temperature and amount of catalyst. Both in thermal and catalytic degradation, the condensable fraction was less viscous liquid oil at low temperatures (up to 450°C), whereas with increase of temperature (from 475°C) the fraction became viscous and waxy. The recovery of condensable fraction increased from 30.8 wt.% at 400°C to 71.45% at 450°C and further increased to a maximum of 86.65wt.% at 500°C in absence of catalyst. The catalyst increased the yield of the condensable product and decreased the reaction time. The highest yield of liquid fraction at 450°C was 79.5 wt.% with 1:2 catalyst to plastics ratio. The composition of the oil obtained at optimum reaction condition was characterised by gas chromatography-mass spectroscopy (and found consisting of paraffins and olefins with mainly C10-C16 components. Fuel properties of the oil obtained by different standard methods are similar to petrochemical fuels. © 2014 Inderscience Enterprises Ltd.
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    Evaluation of combustion, performance and emissions of a diesel engine fueled with bio-fuel produced from cashew nut shell liquid
    (Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2015) Dinesha, P.; Mohanan, P.
    Presently, energy security and food security are two major problems of developing countries. The use of edible oils as an alternative fuel for internal combustion may lead to a food crisis. The non-edible plant-based alternative fuel not only results in energy security but also helps to keep the environment free from pollution. In this experimental investigation, a non-edible plant-based bio-fuel cardanol produced from cashew nut shell liquid (CNSL) is used to study the combustion, performance and emissions of a single-cylinder diesel engine. The test conditions of the engine are 200 bar injection pressure and 27.5 degree bTDC injection timing. The bio-fuel blends B10M10 (10% cardanol + 80% diesel + 10% methanol), B20M10, and B30M10 (30% cardanol + 60% diesel + 10% methanol) were tested at 25%, 50%, 75%, and full load conditions. The results were compared with baseline diesel operation. From the experimental work, it was observed that the brake thermal efficiency of B10M10 and B20M10 (20% cardanol + 70% diesel + 10% methanol) is comparatively similar to that of diesel. The lower emissions of CO, hydrocarbon, and smoke are encouraging to recognize B20M10 as an optimized fuel blend for a compression ignition engine at 200 bar injection pressure and 27.5 degree bTDC. The significant factors of cardanol bio-fuel include its low cost, non-edible, abundance, and it is a by-product of the cashew nut industries. © © 2015 Taylor & Francis.
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    Experimental Investigation of Variations in Spark Timing using a Spark-Ignition Engine with Hydrogen-Blended Gasoline
    (Wiley-VCH Verlag info@wiley-vch.de, 2015) Shivaprasad, K.V.; Chitragar, P.R.; Kumar, G.N.
    This study describes an experiment conducted using an electronically controllable single-cylinder high-speed gasoline engine to analyze the performance and emissions characteristics of various hydrogen-gasoline blends. The experiments have been conducted for various engine speeds and spark timings at the wide open throttle position. The experimental results revealed that the engine brake thermal efficiency and brake mean effective pressure first increase and then decrease with the increase engine speed at all spark timings. The minimum amount of brake specific energy consumption was observed for 20% hydrogen addition in the total fuel blend at 3000rpm engine speed and 14°crank angle (CA) before top dead center (BTDC) spark timing. Hydrocarbon and carbon monoxide emissions were reduced with the retardation of spark timings. Nitrogen oxide emissions were continuously increased with the addition of hydrogen in the fuel blend as well as spark timing advance. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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    High temperature corrosion behaviour of HVOF sprayed WC-CrC-Ni coatings
    (Inderscience Publishers, 2016) Somasundaram, B.; Kadoli, R.; Ramesh, M.R.; RAMESH, C.S.
    The present work aims to study the hot corrosion resistance of high velocity oxy-fuel (HVOF) sprayed WC-CrC-Ni coating developed on three types of boiler tube materials such as SA213-T22, MDN-310 and Superfer 800 H steels. Hot corrosion studies were conducted in a molten salt environment of Na2SO4-60%V2O5 at 700°C and thermogravimetric analysis was used to establish kinetics of corrosion. Corrosion kinetics of coated steels followed nearly parabolic behaviour and showed a lower corrosion rate in comparison to uncoated alloys. It is concluded that corrosion is restricted to the external surface of the coating and the formation of thick scale composed of oxides of Cr, Ni and their spinel oxides, acts as a diffusion barrier to the transportation of corrosive species into the coating. The carbides of tungsten and chromium uphold the strength of the coating. © © 2016 Inderscience Enterprises Ltd.
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    An experimental investigation on performance and emission parameters of a multi-cylinder SI engine with gasoline–LPG dual fuel mode of operation
    (Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2017) Nayak, V.; Shankar, K.S.; Dinesha, P.; Mohanan, P.
    The present study deals with the performance and emission characteristics of a multi-point fuel injection (MPFI) spark ignition (SI) engine in gasoline–liquefied petroleum gas (LPG) dual fuel mode of operation. The LPG–gasoline ratio varied from 0 to 100% by controlling the injector signals at various speed and load conditions. Experiments show that the power output decreases with increase in speed and LPG content at lower load marginally due to lower volumetric efficiency. At higher load and lower speed conditions as the percentage of LPG increases there is not much difference in the power output. Results also reveal that 50% LPG flow gives maximum efficiency at full load condition and 4000 rpm due to lower fuel consumption. With 50% usage of LPG, the average increase in brake thermal efficiency (BTE) is 2% till the engine speed of 4000 rpm at full load (100%) and half load (50%) conditions. As the LPG ratio increases the engine will work in the lean region for all speed and load conditions. For all load and speed conditions, results reveal that 100% LPG will give minimum hydrocarbon (HC) and carbon monoxide (CO) emissions. Oxide of nitrogen (NOX) emissions are higher for 100% LPG. However 50% LPG flow gives good agreement of NOX, HC and CO emissions when compared with gasoline operation. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
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    Porous nickel telluride nanostructures as bifunctional electrocatalyst towards hydrogen and oxygen evolution reaction
    (Elsevier Ltd, 2017) Bhat, K.S.; Barshilia, H.C.; Nagaraja, H.S.
    Electrochemical water splitting technology has attracted researchers for the development of next generation fuels. Herein, we report the synthesis of nanostructured porous hollow nickel telluride nanosheets and their use as bifunctional electrocatalyst towards hydrogen and oxygen evolution reaction, anticipating an enhanced performance owing to their 2D sheet like morphology, conductivity, porous nature providing larger catalytic surface for water splitting reaction. In this regard, nickel telluride nanostructures were synthesized via an anion-exchange-reaction between pre-synthesized nickel hydroxide hexagonal nanosheets and tellurium ions under hydrothermal conditions. The as-synthesized nanostructures were characterized for structural, morphological and compositional properties using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. Nickel telluride modified electrodes were tested as bifunctional electrocatalyst under acidic and alkaline conditions, through linear sweep voltammetry and constant current chronopotentiometry methods. The modified electrodes revealed an onset potential of ?422 mV and 87.4 mV dec?1 Tafel slope towards HER and overpotential of 679 mV and 151 mV dec?1 Tafel slope towards OER. The lower onset potentials are complimented with excellent electrocatalytic stability. © 2017 Hydrogen Energy Publications LLC
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    Retention of high dielectric constant sodium beta alumina via solution combustion: Role of aluminum ions complexation with fuel
    (Elsevier Ltd, 2018) Gupta, B.; Pujar, P.; Mal, S.S.; Gupta, D.; Mandal, S.
    In the present study, solution combustion technique has been explored to synthesize Sodium ?-alumina (SBA; NaAl11O17) powder and thin films. Three fuels namely urea, glycine and citric acid have been used to seek the feasibility of synthesizing crystalline SBA powder at low temperature. Also, the effect of nature of fuels used as well as calcination treatment on phase evolution and morphology of the as-combusted powder was investigated. Thermal analysis and X-ray diffraction studies suggest the formation of crystalline SBA powder at temperature as low as 259 °C, using urea in the combustion reaction whereas other fuels resulted in amorphous SBA phase and this variation in phase was found due to difference in exothermicity of the fuel used. Thermodynamic and spectroscopic analyses showed that the exothermicity of fuel depends on various factors like (i) standard heat of formation of fuel and (ii) the complexation offered by fuel to metal cations. Furthermore, sodium ?-alumina thin film capacitor (metal-insulator-metal) was also fabricated using urea via spray combustion synthesis. The sodium ?-alumina thin film showed a high dielectric value (?r) of ~21. © 2017 Elsevier Ltd and Techna Group S.r.l.