Faculty Publications
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Item BaCu(C2O4)2 · 6 H2O is triclinic, P1, with a = 6.5405(9), b = 9.202(3), c= 10.939(1) Å, ? = 8546(2), ? = 79.22(1), ? = 80.45(2), V = 636.99(1) Å3, Z=2, D0, = 2.14, Dc = 2.465 g · cm-3, R = 0.074. wR = 0.0746 for 2219 significant reflections |F0| = 6.0?F0. The barium has eleven coordinations and the coordination polyhedra is a capped antiprism. Six water oxygen atoms are coordinated whereas the other five are coming from the oxalate group. In the unit cell the molecules form a polymeric network. One lattice water molecule belongs to the coordinating water. The barium oxygen distances vary from 2.75 Å to 3.15 Å.(Wiley-VCH Verlag, The crystal structure of hydrated barium copper oxalate) Kasthuri, V.B.; Rao, P.M.; Nethaji, M.1996Item Compression testing of Ti-6Al-4V in the temperature range of 303-873 K(2008) Srinivasan, K.; Venugopal, P.Compression testing of Ti-6Al-4V alloy has been carried out at temperatures between 303 K to 873 K. To prevent embrittlement due to atmospheric oxygen and nitrogen, the samples were given a glass coating, which also acts as a lubricant simultaneously. Dynamic Strain Aging was observed to occur in the temperature range of 600 K to 800 K. Below 600 K stresses were high. Warm working has to be done above 800 K but below 1163 K (0.6 Tm where Tm = 1940 K) which is the recrystallization temperature. Based on these conclusions, warm extrusion has been successfully carried out in the Materials Forming Laboratory of I.I.T., Madras, Chennai, India.Item Evaluation of water quality index for drinking purposes for river Netravathi, Mangalore, South India(2008) Avvannavar, S.M.; Shrihari, S.An attempt has been made to develop water quality index (WQI), using six water quality parameters Dissolved oxygen (DO), Biochemical oxygen Demand (BOD), Most Probable Number (MPN), Turbidity, Total Dissolved Solids (TDS) and pH measured at eight different stations along the river basin. Rating curves were drawn based on the tolerance limits of inland waters and health point of view. Bhargava WQI method and Harmonic Mean WQI method were used to find overall WQI along the stretch of the river basin. Five point rating scale was used to classify water quality in each of the study areas. It was found that the water quality of Netravathi varied from Excellent to Marginal range by Bhargava WQI method and Excellent to Poor range by Harmonic Mean WQI method. It was observed that the impact of human activity was severe on most of the parameters. The MPN values exceeded the tolerable limits at almost all the stations. It was observed that the main cause of deterioration in water quality was due to the lack of proper sanitation, unprotected river sites and high anthropogenic activities. © Springer Science+Business Media B.V. 2007.Item Modelling for organics and nutrients release during Benthal sludge stabilisation : Part I -organics(2008) Bhargava, D.S.; Shrihari, S.Settleable solids in the untreated and partially treated domestic and industrial effluents discharged into a river system undergoes settling and decomposition in the form of benthal sludge deposits, Early models of biochemical oxygen demand (BOD) assimilation in rivers do not account for the BOD contribution by these benthal sludge deposits. In this paper, a model for computations of the BOD contribution by benthos (both from the top aerobic layers and the leached portion of BOD from the bottom anaerobic layers) was presented. Observations from three sets of experiments at the chosen overlying water flow rates (500 ml/min, 1000ml/ min and 1500 ml/min) show a higher BOD contribution by benthos at higher overlying water flow rates. The ratio of the BOD contributions by benthos to the volatile solids in the top aerobic layers was lower when compared to the similar ratio in respect of the bottom layer volatile solids showing that a higher contribution was made by the top layers.Item Oxygen mass transfer coefficients in a three-phase pulsed plate bioreactor(Berkeley Electronic Press, 2010) Shetty K, K.V.; Srinikethan, G.Volumetric oxygen mass transfer coefficient is a decisive parameter for the selection of any contactor as an aerobic bioreactor. A pulsed plate column with fixed bed of solids in interplate spaces is a recent innovation in the field of immobilized cell bioreactors. Volumetric oxygen mass transfer coefficients are determined in a three-phase pulsed plate column involving air and water phases and with a fixed bed of glass particles, which can serve as a surface for cell immobilization packed in the interplate spaces. The volumetric mass transfer coefficients obtained in this column range from 0.067 to 0.1495 s-1la with these variables was developed. The volumetric oxygen mass transfer coefficient values in the three-phase pulsed plate column are found to be similar or higher than the literature reported values for conventional two-phase pulsed plate columns. The values of volumetric oxygen mass transfer coefficients in the three-phase pulsed plate column are of higher order of magnitude than the literature reported values of volumetric oxygen mass transfer coefficient for many other three-phase gas-liquid-solid reactors. The pulsed plate column with fixed bed of solids is proven to have all the potential to be used as an aerobic bioreactor with immobilized cells due to its better gas-liquid mass transfer characteristics. Copyright © 2010 The Berkeley Electronic Press. All rights reserved.Item One-step synthesis of biaryls under mild conditions(Wiley-VCH Verlag, 2013) Bhat, A.P.I.; Inam, F.; Badekai Ramachandra, B.A one-step synthesis of symmetrical biaryls was developed and uses a nickel(III) complex containing a Schiff base and dithiolate ligands as a catalyst for the homocoupling of in situ generated Grignard reagents. The coupling reaction was performed at room temperature with molecular oxygen as the oxidant, which renders the reaction energy-efficient and environmentally friendly. The catalytic methodology is compatible with diverse functionalities, including chlorido, nitro, nitrile, and heteroatoms, and provides biaryls in appreciable yields. A practical, room-temperature nickel(III) catalytic system has been developed for the synthesis of biaryls in one step from the homocoupling of in situ generated Grignard reagents. The use of molecular oxygen as the oxidant makes the system environmentally friendly. The reaction system is compatible with diverse functionalities and affords biaryls in appreciable yields. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Item Single-step oxidative homocoupling of aryl Grignard reagents via Co(II), Ni(II) and Cu(II) Complexes under air(John Wiley and Sons Ltd Southern Gate Chichester, West Sussex PO19 8SQ, 2014) Bhat, A.P.I.; Badekai Ramachandra, B.R.A simple catalytic system of direct synthesis for the symmetrical biaryls using catalytic amounts of Co(II), Ni(II) and Cu(II) complexes has been developed. The reaction system involves in situ synthesis of Grignard reagents. The complexes, containing bidentate Schiff base and dmit (2-thioxo-1,3-dithiole- 4,5-dithiolate) ligands, were compatible with diverse functionalities and afford a high yield of biaryls in a single step, proving to be promising catalysts in homocoupling reactions. Atmospheric oxygen is used as an oxidant which renders a green, simple and economical catalytic route. Copyright © 2014 John Wiley & Sons, Ltd.Item Effect of oxygen enrichment on the performance, combustion, and emission of single cylinder stationary CI engine fueled with cardanol diesel blends(Korean Society of Mechanical Engineers, 2014) Dinesha, P.; Nayak, V.; Mohanan, P.We investigated the effect of intake air enrichment on the performance, combustion, and emission characteristics of a single cylinder direct-injection stationary diesel engine fueled with non- edible alternative fuel, namely, cardanol - diesel - methanol blend (B20M10). The results were compared with baseline diesel operations under standard operating conditions. The bio-fuel blend B20M10 (20% cardanol, 10% Methanol, and 70% diesel) was used as fuel and the combustion, performance, and emission characteristics were investigated by oxygen enriching of intake air with 3, 5, and 7 percentage by weight. With the increase of intake air oxygen concentration, CO, HC, and smoke were found to be decreased. But BTE and NOx emission were considerably increased. The blended fuel B20M10 with 7% oxygen enrichment of intake air was compared with diesel operation. The results show a 0.5% lesser BTE, 28% more NOx emission at full load condition. There is not much variation of smoke emission to be noticed for this fuel combination compared to diesel. © 2014 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.Item Electrodeposition and electro-catalytic study of nanocrystalline Ni-Fe alloy(Elsevier Ltd, 2014) Ullal, Y.; Hegde, A.C.This paper presents the electrodeposition protocol for development of a stable, inexpensive and efficient electrode material for water splitting reaction. Nanocrystalline Ni-Fe alloy coatings were deposited on copper electrode from acidic bath, at different cathode current densities (c.d). Coatings were tested for their electro-catalytic behaviours, namely for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 6 M KOH by cyclic voltammetry and chrono-potentiometry techniques. Experimental results demonstrated that these coatings can be used as potential material for water electrolysis. The corrosion stability of these coatings has also been tested in their working conditions (6 M KOH) by DC polarization method. The deposition conditions of Ni-Fe alloy were optimized for peak performance for both electro-catalytic reactions and corrosion stability. Ni-Fe alloy coatings deposited towards low and high c.d limits were found to be the better materials for OER and HER, respectively from same electrolytic solution. Further, Ni-Fe coating deposited at 6.0 Ad m-2 was found to be the most corrosion resistant. The structure-property relationship of electrodeposited coatings has been discussed by exploring PXRD, EDX and FESEM study. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.