Faculty Publications
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Item Synthesis of Fatty Acid Methyl Esters (FAME) from Schizochytrium Marine Microalgae oil(Elsevier Ltd, 2018) Reddy, B.R.P.; Reddy, N.R.; Manne, B.Fatty acid methyl esters (FAME) also called and accepted as biodiesel, obtained prominent importance in this new era as an alternate fuel for petro-diesel. Microalgae are identified as few of such feedstock for the production of biodiesel. Higher volumes of production per hectare area, fast growing ability and high oil contents are the major advantages of microalgae over the conventional oil yielding crops. Schizochytrium is one of marine microalgae and high lipid content of this microalga is ideal for production of biofuels. Also, Schizochytrium oil is found to have 0.1% free fatty acid content which is well within the recommended value for one-step alkaline transesterification. In this work, the synthesis of bio-diesel was carried out from Schizochytrium oil with the addition of potassium methoxide (a mixture of methanol and KOH). Aiming at the higher yield of FAME, essential amounts of methanol, catalyst, and reaction time were optimized. The yielding of FAME was confirmed by Gas Chromatography with Mass Spectroscopy (GC-MS) for each trial of experiment. A conversion efficiency of 99.99% was observed through GC-MS analysis for a 30% v/v methanol, 0.4% w/v KOH and 90 min reaction time at reaction temperature of 60°C. The results were complemented by proton nuclear magneto resonance (1H NMR) spectra and it is found that the synthesized fuel properties are well within the limits of ASTM standards. © 2018 Elsevier Ltd.Item Crystallisation kinetics study in stabilisation treatment of sol-gel derived 45S5 bioglass(American Institute of Physics Inc. subs@aip.org, 2018) Sampath, S.; Matin, M.; Kiran, P.; Manne, B.; Ramesh, M.R.Solgel gel derived bioglasses require stabilisation heat treatment to decompose nitrates and to improve mechanical stability. While decomposing nitrate phases especially in solgel derived 45S5 bioglass, it is difficult to avoid crystallisation of silicate crystalline phases (Na2CaSi2O6, Na2Ca2Si3O9) due to overlapping of nitrates decomposition and silicates crystallisation temperatures. Control of such crystallinity amount in bioglasses is at most important during stabilisation as it affects the dissolution rates of bioglassesin body fluids. Controlling and quantifying of this crystallinity helps in engineering bioglasses for specific period in application. In this work, synthesis of 45S5 bioglass through solgel method is presented. Here, temperature and time dependent crystallisation kinetics were estimated using a quality parameter derived from X-ray diffraction (XRD) patterns of bioglass during stabilisation treatment. Quality parameter derived from XRD patterns is termed as IPB which is the ratio of integral area of peaks to the integral area of background. It is proposed that IPB can be used as quality parameter to assess crystallinity and to study crystallisation kinetics in bioglasses. © 2018 Author(s).Item Solid state amorphization of Mg-Zn-Ca system via mechanical alloying and characterization(Elsevier B.V., 2017) Manne, B.; Bontha, S.; Ramesh, M.R.; Krishna, M.; Balla, V.K.Magnesium based bulk metallic glasses have attracted significant attention of researchers due to better mechanical and corrosion properties when compared to their crystalline counterparts especially for biomedical applications. Scaling up the part size and production volumes of such materials through liquid metallurgy route is challenging. In this work amorphous Ca5Mg60+xZn35?x (X = 0, 3 and 7) alloys have been successfully synthesized through solid state amorphization using a high energy planetary ball mill. X-ray diffraction was used to identify the crystalline phases of the powder during reaction. Evolution of amorphous phase was analysed using a parameter involving the ratio of integral area of peaks to the integral area of background (IPB) obtained from XRD patterns. Results showed reaction time increases with decreasing Zn content in Ca5Mg60+xZn35?x (X = 0, 3 and 7) alloy to obtain maximum amorphous structure with a small amount of residual crystalline phase. Prolonged milling of these powders, to eliminate residual crystalline phases, resulted in the nucleation of Mg102.08Zn39.6 phase. The composition dependent characteristic temperatures and thermal stabilities were studied using differential scanning calorimetry. © 2016 The Society of Powder Technology JapanItem Surface design of Mg-Zn alloy temporary orthopaedic implants: Tailoring wettability and biodegradability using laser surface melting(Elsevier B.V., 2018) Manne, B.; Thiruvayapati, H.; Bontha, S.; Motagondanahalli Rangarasaiah, R.; Das, M.; Balla, V.K.Magnesium-based alloys have attracted significant attention for biomedical applications due to its biodegradability as well as density and elastic modulus which are close to those of human bone. However, the uncontrolled biodegradation and hydrogen evolution are of major concern. In this work, laser surface melting (LSM) has been carried out to tailor initial corrosion rates of Mg-2.2Zn alloy implants. Melt pool dimensions, microstructure and surface topography of the LSM samples were analysed. The wettability and in vitro degradation characteristics of untreated and treated alloy were compared. LSM resulted in much finer cellular microstructural features than as-cast alloy and the melted region depths between 65 and 115 ?m. Higher treatment depths helped to extend the corrosion protection time by suppressing the corrosion front movement. Polished LSM samples resulted in overall corrosion rates of 0.5–0.62 mm/year which was about 40%–50% reduction compared to the as-cast alloy. Accelerated biomineralisation of the surface via enhancements in the surface energy due to microstructural refinement as well as microstructural homogeneity and Zn enrichment in ?-Mg, favoured improvement of the overall corrosion performance of LSM-treated alloy. © 2018 Elsevier B.V.Item Acetone and Diethyl ether: Improve cold flow properties of Dairy Washed Milkscum biodiesel(Elsevier Ltd, 2019) Srikanth, H.V.; Venkatesh, J.; Godiganur, S.; Manne, B.The trend in utilizing biological industrial wastes to produce biofuels has been increasingly popular over the past decades. The dairy washed milk scum (DWMS) is one of such potential industrial waste, which can be used as feedstock for the production of biodiesel. One of the inherent problems of DWMS biodiesel is its poor low temperature properties. In this investigation, the influence of two solvents namely, Acetone (ACE) and Diethyl ether (DEE) was tested as cold flow improvers (CFI's) on low temperature properties of DWMS biodiesel. It was observed that the addition of 20% (v/v) of ACE and DEE to DWMS biodiesel improved the low temperature properties. The crystallization characteristics of biodiesel and its blends with CFIs were determined using differential scanning calorimetry (DSC). Other fuel properties were within the permissible limits of biodiesel standard (ASTM D6751-15C) with all the blends of ACE and DEE. © 2018 Elsevier LtdItem Optimization of ball-burnishing process parameters on surface roughness, micro hardness of Mg-Zn-Ca alloy and investigation of corrosion behavior(Institute of Physics Publishing helen.craven@iop.org, 2019) Ramesh, S.; Aditya Kudva, S.; Anne, G.; Manne, B.; Arya, S.In this work, optimization of ball burnishing parameters (depth of press, feed, burnishing force, number of passes) and their effect on surface roughness, microhardness and corrosion behavior of Mg-4%Zn-1%Ca alloy is investigated. The Taguchi optimization technique was used to determine the number of experiments and by considering S/N ratios, right combination of ball burnishing parameters were selected. Results obtained from the experiments were investigated and it is understood that depth of press, feed and number of passes have a significant effect on surface roughness, microhardness and consequently improves corrosion resistance of Mg-4%Zn-1%Ca alloy. From ball burnishing experiments it is deduced that there is large increase in microhardness of 107 Hv and surface roughness of 129 nm, achieved for the depth of press 0.45 mm, burnishing force 250 N, feed 450 mm min-1 and number of passes: 2. Corrosion behavior of the alloys were analyzed using potentiodynamic polarization and electrochemical impedance spectroscopy techniques in Hank's balanced salt solution. The lowest corrosion rate was observed in DFN 442 sample (1.43 mm y-1) which is 4.7 times better than the homogenized alloy (6.73 mm y-1). It has been found that the ball burnishing plays an important role on surface roughness, microhardness and corrosion behavior of Mg-4%Zn-1%Ca alloy. © 2019 IOP Publishing Ltd.Item Combustion, performance, and emission characteristics of dairy-washed milk scum biodiesel in a dual cylinder compression ignition engine(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2020) Srikanth, H.V.; Venkatesh, J.; Godiganur, S.; Manne, B.; Bharath Kumar, S.; Spurthy, S.The present work has been carried out to study the suitability of milk dairy waste scum (MDWS) biodiesel as a fuel for diesel engine. The investigations were carried out on performance, emission and combustion characteristics of a direct injection dual cylinder diesel engine fueled with MDWS methyl ester, and their blends. Two-step transesterification process was used to synthesize the MDWS biodiesel, characterization according to specified ASTM D6751-15C standards. The performance characteristics studies showed an increased brake thermal efficiency of B20 (3%) and B30 (0.94%) blends in comparison to fossil diesel. However, the increased brake specific fuel consumption (BSFC) was also found with all the fuel blends and an higher (9%) BSFC was obtained with B50 compared to diesel fuel at full load condition. The emissions of blends were found to be lower in comparison with diesel fuel, except for nitrogen oxides. A 32% increase in NOx emission was found with B50 blend compared to diesel fuel at maximum load condition. However, improved combustion characteristics would found with MDWS blends with respect to in-cylinder pressure, ignition delay, and heat release rate compared to fossil diesel. © 2019 Taylor & Francis Group, LLC.Item Performance, combustion and emission characteristics of a diesel engine fuelled with Schizochytrium micro-algae biodiesel and its blends(Taylor and Francis Ltd., 2022) Rajendra Prasad Reddy, B.; Rana Prathap Reddy, N.; Manne, B.; Srikanth, H.V.The use of the third-generation feedstock for biodiesel production has become increasingly popular over the past decade. Among the various third-generation feedstock identified, biodiesel synthesised from the microalgae attracted the attention of researchers throughout the world. The present research includes a study on the suitability of Schizochytrium microalgae biodiesel as an alternative fuel for the diesel engine. The investigation was carried out on the production, characterisation of Schizochytrium microalgae biodiesel through the transesterification process followed by performance, combustion and emission characteristics of a diesel engine fuelled with Schizochytrium microalgae biodiesel and its blends. The study revealed that the properties of biodiesel were obtained to meet the specified ASTM D6751 standards. The engine performance, combustion and emission characteristics were found to be satisfactory than those of fossil diesel. © 2020 Informa UK Limited, trading as Taylor & Francis Group.