Faculty Publications
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Item Virgin and waste polymer incorporated concrete mixes for enhanced neutron radiation shielding characteristics(Elsevier, 2018) Malkapur, S.M.; Narasimhan, M.C.Several attempts have been made in the past to develop newer concrete mixes with enhanced neutron radiation shielding characteristics. The composition of the concrete mixes becomes very important in this context, and it is extensively reported that the hydrogen content in the hydrated concrete mixes is one of the important constituents determining the neutron radiation shielding capabilities of the mixes. It is professed that higher the hydrogen content, better is the neutron radiation shielding. The use of different types of hydrogen sources in the past such as hydrogenous mineral aggregates and liquid polymers, and polymer impregnation, has been discussed. The feasibility issues and concerns while using virgin and waste pulverized high-density polyethylene (HDPE) polymeric materials as partial replacement to fine aggregates for making concrete mixes with enhanced neutron radiation shielding characteristics have been discussed. The fresh and hardened properties of these mixes and hydrogen loading and its effect on neutron radiation shielding have been discussed. © 2019 Elsevier Ltd. All rights reserved.Item An Experimental Study on Combustion and Emission Analysis of Four Cylinder 4-Stroke Gasoline Engine Using Pure Hydrogen and LPG at Idle Condition(Elsevier Ltd, 2016) Chitragar, P.R.; Shivaprasad, K.V.; Nayak, V.; Bedar, P.; Kumar, G.N.Fluctuation in oil prices and stricter exhaust emission norms were the main reasons wakening every researcher to search for suitable and feasible alternative fuels for automotive use. Among the available option gaseous fuels find their best position because of their compatible physical-chemical properties and ecofriendly nature than present fossil fuels. Hydrogen's combustion properties like high energy content, high heating value, wide range of flammability and low ignition energy with almost least toxic emissions are favorable to use in an IC engine as an alternative fuel. Liquid petroleum gas (LPG) has lower carbon content, higher calorific value, octane number and flame propagation speed will improve the emission results compared to gasoline fuel. This paper describes an experimental results carried out to evaluate the combustion and emission performance of a Maruti Suzuki make, spark ignited four cylinders, four stroke engines at idle condition by using pure hydrogen, LPG and gasoline. The engine was adjoined with Electronic Control Unit (ECU) assisting hydrogen and LPG injector system keeping gasoline line unchanged. Tests were carried out by using compressed hydrogen gas regulated by two stage pressure reduction from cylinder to atmospheric value and by using vaporizer pressure for LPG. For comparison engine was run first by gasoline and then by pure hydrogen and LPG. Study revealed that there was increment of 13% cylinder pressure for pure hydrogen and decrement of 4.5% cylinder pressure for LPG when compared to gasoline. The burn duration for pure hydrogen, LPG and gasoline were found to be increasing respectively which infers that hydrogen has very short combustion duration and gasoline higher. It was observed that toxic emissions like Carbon monoxide (CO), Hydrocarbons (HC) and Oxides of Nitrogen (NOx) were improved for pure hydrogen than LPG and gasoline. © 2016 The Authors.Item The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over various transition metals impregnated on MCM-41 and activated carbon. Copper-, iron-, and vanadium-impregnated on activated carbon gave better yields of phenol when compared to the corresponding reactions using cobalt-, nickel-, manganese-, and titanium-impregnated catalysts. Comparison of the MCM-41 and activated carbon-supported catalysts showed that activated carbon-supported catalysts gave a higher yield of phenol than did the MCM-41-supported catalysts. The activity of the transition metals supported on activated carbon in the production of phenol was V > Fe > Cu; the corresponding activity of the transition metals supported on MCM-41 was Cu > Fe > V. In addition to the role of transition metals in catalyzing the hydroxylation reaction, the hydrophobic nature of the activated carbon surface seems to enhance the performance of these catalysts relative to the MCM-41-supported catalysts.(Benzene hydroxylation to phenol catalyzed by transition metals supported on MCM-41 and activated carbon) Choi, J.-S.; Kim, T.-H.; Saidutta, M.B.; Sung, J.-S.; Kim, K.-I.; Jasra, R.V.; Song, S.-D.; Rhee, Y.-W.2004Item Liquid-liquid equilibrium of poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water at different temperatures(2008) Amaresh, S.P.; Murugesan, S.; Iyyaswami, I.; Murugesan, T.Liquid-liquid equilibrium for an aqueous two-phase system containing poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water was studied at four different temperatures of (25, 30, 35, and 45)°C. The binodal curve was fitted to three different empirical equations relating the concentrations of PEG 4000 and diammonium hydrogen phosphate, and the coefficients were estimated for the respective temperatures for all three equations. The effective excluded volume values were obtained from the binodal model for the present system, and salting-out ability of the salt was discussed. Tie line compositions were correlated using the Othmer-Tobias and Bancroft equations, and the parameters are also reported. Further, the experimental binodal data of the poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water system were compared to poly(ethylene glycol) 6000 + diammonium hydrogen phosphate + water for (25, 35, and 45)°C. © 2008 American Chemical Society.Item Miscibility of polymethylmethacrylate and polyethyleneglycol blends in tetrahydrofuran(2009) Muthu, M.S.; Bhat, D.K.; Renganathan, N.G.The miscibility of polymethylmethacrylate (PMMA) and polyethyleneglycol (PEG) blends in tetrahydrofuran. (THF) has been investigated by viscosity, density, refractive index, and ultrasonic velocity studies. Various interaction parameters such as polymer-solvent and blend-solvent interaction parameters and heat of mixing have been calculated using the viscosity, density, and ultrasonic velocity data. The results indicated the existence of positive interactions in the blend polymer solutions and that they are miscible in THF in the entire composition range. The study also revealed that variation in the temperature does not affect the miscibility of PMMA and PEG blends in THF significantly. The presence of hydrogen bonding in the blends in the solid state has also been indicated by FTIR studies. © 2008 Wiley Periodicals, Inc.Item Densities and viscosities of poly(ethylene glycol) 4000 + diammonium hydrogen phosphate + water systems(2009) Iyyaswami, I.; Murugesan, S.; Amaresh, S.P.; Govindarajan, R.; Murugesan, T.The densities and viscosities of binary and ternary solutions of the poly(ethylene glycol) 4000 (PEG4000) + diammonium hydrogen phosphate + water system were determined at different temperatures [(298.15, 303.15, 308.15, 313.15, and 318.15) K]. The measured density and viscosity data of all the binary and ternary systems were fitted to available empirical correlations, for the corresponding temperatures. The density data show a linear variation with mass fraction of the polymer for all temperatures. The viscosity data of all the solutions were correlated as a function of their mass fraction, using a nonlinear equation, for the five different temperatures covered in the present work. Densities and viscosities of PEG4000 - diammonium hydrogen phosphate two-phase systems have been measured at (298.15, 303.15, 308.15, 313.15, and 318.15) K. The tie line lengths (TLL) of the aqueous two-phase systems have also been estimated, and the effect of the physical properties on the TLL is also reported. © 2009 American Chemical Society.Item Molecular dynamics investigation of dipeptide - Transition metal salts in aqueous solutions(American Chemical Society service@acs.org, 2010) Santosh, M.S.; Lyubartsev, A.; Mirzoev, A.; Bhat, D.K.Molecular dynamics (MD) simulations of glycylglycine dipeptide with transition metal ions (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) in aqueous solutions have been carried out to get an insight into the solvation structure, intermolecular interactions, and salt effects in these systems. The solvation structure and hydrogen bonding were described in terms of radial distribution function (RDF) and spatial distribution function (SDF). The dynamical properties of the solvation structure were also analyzed in terms of diffusion and residence times. The simulation results show the presence of a well-defined first hydration shell around the dipeptide, with water molecules forming hydrogen bonds to the polar groups of the dipeptide. This shell is, however, affected by the strong electric field of divalent metal ions, which at higher ion concentrations lead to the shift in the dipeptide-water RDFs. Higher salt concentrations lead also to increased residence times and slower diffusion rates. In general, smaller ions (Cu2+, Zn2+) demonstrate stronger binding to dipeptide than the larger ones (Fe2+, Mn 2+). Simulations do not show any stronger association of peptide molecules indicating their dissolution in water. The above results may be of potential interest to future researchers on these molecular interactions. © 2010 American Chemical Society.Item Liquid-liquid equilibrium of poly(ethylene glycol) 2000 + diammonium hydrogen citrate + water system at different temperatures(2011) Iyyaswami, I.; Srikanth, C.K.; Sindhu, N.Phase diagrams and liquid-liquid equilibrium (LLE) data of the aqueous poly(ethylene glycol) (PEG-2000) + diammonium hydrogen citrate system (aqueous two-phase system) has been determined experimentally at (298.15, 303.15, 308.15, 313.15, and 318.15) K. The effects of temperature on the binodal curve and tie-lines have been studied. The binodal curve was fitted to an empirical equation relating the concentrations of PEG 2000 and diammonium hydrogen citrate, and the coefficients were estimated for the respective temperatures. Tie line compositions were estimated and correlated using Othmer-Tobias and Bancroft equations, and the parameters are reported. The effect of temperature on the phase-forming ability in the investigated system has been studied based on a salting-out coefficient; obtained from fitting the binodal data to a Setschenow-type equation for each temperature. The effective excluded volume values were also calculated from the binodal data. © 2011 American Chemical Society.Item Influence of 2-(4-chlorophenyl)-2-oxoethyl benzoate on the hydrogen evolution and corrosion inhibition of 18 Ni 250 grade weld aged maraging steel in 1.0 M sulfuric acid medium(2012) Sanatkumar, B.S.; Nayak, J.; Nityananda Shetty, A.N.Electrochemical corrosion behavior and hydrogen evolution reaction of weld aged maraging steel have been investigated, in 1.0 M sulfuric acid solution containing different concentrations of 2-(4-chlorophenyl)-2-oxoethyl benzoate (CPOB). The data obtained from polarization technique showed that the corrosion current density (i corr) and the hydrogen evolution rate decrease, indicating a decrease in the corrosion rate of weld aged maraging steel as well as an increase in the inhibition efficiency (?%) with the increase in inhibitor concentration. Changes in impedance parameters were indicative of adsorption of CPOB on the metal surface, leading to the formation of protective film. Both activation (E a) and thermodynamic parameters (?G ads 0, ?H ads 0 and ?S ads 0) were calculated and discussed. The adsorption of CPOB on the weld aged maraging steel surface obeyed the Langmuir adsorption isotherm model. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) study confirmed the formation of an adsorbed protective film on the metal surface. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.