1. Journal Articles
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Item Aqueous corrosion behaviour of ductile iron and ductile iron containing 1 wt. pct. chromium(1997) Surendranathan A.O.; Hebbar, K.R.; Sudhaker Nayak, H.V.Ductile irons with graphite in spheroidal form enjoy the processing characteristics of grey iron and mechanical properties of steel. This paper describes the corrosion behaviour of ductile iron containing 1 wt. % chromium in sea water, dilute sulphuric acid and dilute sodium hydroxide solutions and compares with that of unalloyed ductile iron. Study is made in as-cast, annealed and cold worked (upto 28% reduction in thickness) conditions at three different temperatures. Since the alloying addition brings changes in the proportion of phases, the corrosion behaviour of the two materials studied were different, though alloying addition is small, indicating corrosion behaviour to be structure sensitive.Item �ber den Einflu� von Schwefelwasserstoff auf die Korrosion des Eisens in sauren L�sungen(1979) Ramchandran, T.; Bohnenkamp, K.An Eisenelektroden wurden in anges�uerten Perchlorat und Sulfatl�sungen nach Einleiten von Schwefelwasserstoff erheblich ver�nderte Stromdichte?Potentialkurven beobachtet. Gegen�ber den reinen L�sungen ergeben sich mit Schwefelwasserstoff stark erh�hte anodische Stromdichten und bis um den Faktor 10 erh�hte Korrosionsgeschwindigkeiten. Dabei sind die anodischen Tafelgeraden log iA = f (E) mit H2S nur rund halb so steil wie ohne H2S. Wahrscheinlich wirken die SH??Ionen �hnlich wie die OH??Ionen als Katalysator der Eisenaufl�sung, sind aber bis fast zur S�ttigung absorbiert. Copyright � 1979 Verlag GmbH & Co. KGaA, WeinheimItem Transportation of granite statues(1989) Basavarajaiah, B.S.This paper deals with the problems faced during the transportation of two large granite monolith statues weighing 180 t and 120 t respectively through the narrow and winding country-roads on the western plains of the state of Karnataka. A brief resume of the problems faced during this operation and how these were overcome successfully have been presented.Item Wood burning cook stoves(1989) Nijaguna, B.T.; Uppin, S.B.The major domestic energy needs of people in the under-developed and developing countries are met by burning wood in cook stoves. The quest for energy conservation and its efficient use has motivated researchers the world over to look for improvements in wood burning cook stoves. Even a marginal increase in efficiency can contribute considerably to a total saving in energy consumption and therefore conservation. Analysis of cooking using wood shows that better energy efficiency can be achieved by complete and controlled combustion of wood, maximum energy transfer to food cooked and reducing the energy losses. The various component design features that contribute to better utilisation of wood energy are discussed. These can be of use in emerging designs, or in the modifications to the existing designs. In addition to dealing with the sizing factors, the rating or performance testing of wood stoves is detailed, thus providing a basis for comparison of different stoves. Operational guidelines that contribute to increased efficiency during cooking are provided.Item WAVE FORCE COEFFICIENTS ON SUBMARINE PIPELINES - AN OVERVIEW.(1984) Pranesh, M.R.; Somanatha, G.S.The use of submarine pipelines for economical and safe transportation of hydrocarbons is inevitable. As the applicability of pipelines are extended to other purposes, pipeline mileage is increasing alarmingly and into more hostile environment. Since wave force on submarine pipelines is identified to be a major force estimation of wave forces is of vital importance for design purposes. In this paper, an attempt has been made to identify possible reasons for discrepancies in the results of hydrodynamic coefficients. Various experimental results of wave forces on pipelines in newly constructed 2 m wide wave flume are also compared with the results available in literature. Based on the analysis, hydrodynamic coefficients to be used in the design are suggested.Item Vapor phase oxidation of p?xylene(1978) Mathur, B.C.; Viswanath, D.S.The kinetics of the vapor phase oxidation of p?xylene over ferric molybdate catalyst were studied in an isothermal, differential, tubular flow reactor in the temperature range of 360 to 420� C. The major product obtained was p?tolualdehyde with small amounts of maleic anhydride and p?toluic acid. No terephthalic acid or CO2 were observed. The reaction rate data collected fit the redox model given by Equation 1. The values of activation energies Ex, Eo and frequency factors Ax, Ao obtained are 72, 63 kJ/mol and 0.64, 2.89 m3/kg catalyst s respectively. The reaction mechanism was established by studying the oxidation of p?tolualdehyde, toluic and terephthalic acids. It is concluded that the reaction follows a parallel?consecutive scheme. Copyright � 1978 Canadian Society for Chemical EngineeringItem Solid substrate fermentation of coconut coir pith for cellulase production(1994) Muniswaran, P.K.A.; Charyulu, N.C.L.N.Coconut pith, available in abundance, especially in tropical countries, can be an excellent new substrate for the production of cellulase enzyme by solid substrate cultivation of Trichoderma viride NCIM 1051. The effect of type of pretreatment, type and level of nutrient medium, inoculum volume, average substrate particle size, and time of fermentation on cellulase enzyme production by T. viride in coconut pith solid culture was studied. The hydrogen peroxide-pretreated coconut pith was found to be a better substrate. Reese and Mandels' mineral solution mixed with coconut pith in the ratio of 10:1 (v/w; ml g-1) supported maximum cellulase activity. The effect of inoculum volume on enzyme production was only marginal. An average substrate particle size of 375 ?m resulted in better enzyme production. The highest filter paper activity and carboxymethylcellulase activities of 4.27 and 12.05 IU g-1, respectively, were obtained in 7 days of fermentation, and the maximum cellobiase activity that could be obtained was 1.8 IU g-1 in 8 days. 1994.Item Thermomechanical treatment of spinodal Cu-32Ni-2Cr alloy(1994) Bhat, R.Raghavendra; Rao, P.PrasadProgress in spinodal decomposition of a Cu-32Ni-2Cr alloy subjected to quench?age and quench?work?age treatments have been studied through hardness measurements as well as by X-ray diffraction techniques. It is found that recovery processes occur during early stages of aging which are interpreted in terms of the migration of matrix dislocations to interfaces. The kinetics of spinodal decomposition is found to be enhanced by prior deformation. Thermomechanical treatment results in a substantial increase in strength.Item The crystal structure of hydrated barium copper oxalate(1996) Kasthuri, V.B.; Rao, P.M.; Nethaji, M.BaCu(C2O4)2 6 H2O is triclinic, P1, with a = 6.5405(9), b = 9.202(3), c= 10.939(1) , ? = 8546(2), ? = 79.22(1), ? = 80.45(2), V = 636.99(1) 3, 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 to 3.15 .Item Texture dependent stress corrosion failure of commercial titanium sheets in bromine-methanol solution(1980) Sudhaker, Nayak, H.V.; Vasu, K.I.; Prasad, Y.V.R.K.The stress corrosion cracking (SCC) characteristics of ?-titanium sheets in a bromine-methanol solution have been studied in the annealed and cold-rolled conditions using longitudinal and transverse specimens. The times to failure for annealed longitudinal specimens were longer than those for similarly tested transverse specimens. The cold-rolled specimens developed resistance to SCC, but failed by cleavage when notched, unlike the intergranular separation in annealed titanium. The apparent activation energy was found to be texture dependent and was in the range 30 to 51 kJ mol-1 for annealed titanium, and 15kJ mol-1 for cold-rolled titanium. The dependence of SCC behaviour on the texture is related to the changes in the crack initiation times. These are caused by changes in the passivation and repassivation characteristics of the particular thickness plane. The thickness planes are identified with the help of X-ray pole figures obtained on annealed and cold-rolled material. On the basis of the activation energy and the electrochemical measurements, the mechanism of SCC in annealed titanium is identified to be the one involving stress-aided anodic dissolution. On the other hand, the results on the cold-rolled titanium are in support of the hydrogen embrittlement mechanism consisting of hydride precipitation. The cleavage planes identified from the texture data match with the reported habit planes for hydride formation. 1980 Chapman and Hall Ltd.