NOPR Collection:

Thermodynamic view of hydrophobic association of side chains of aromatic amino acids

Thu, 01 Jun 1989 00:00:00 GMT

Title: Thermodynamic view of hydrophobic association of side chains of aromatic amino acids Authors: Iyengar, RR; Bhattacharya, P K Abstract: The hydrophobic association constants, K. for the side chains of phenylalanine, tyrosin and tryptophan betains have been evaluated employing the difference in the mode of self-association of the optically pure -betains and their -mixtures and using the equation of Rose and Drago. The corresponding association free energy, G, values for benzyl-, p-hydroxybenzyl- and (3-indolyl)methyl groups have been determined as - 15.90, - 19.92 and - 20.21 kJmol^-1 respectively, after correcting for partial overlap of aromatic ring in -/ - dimers. Page(s): 445-451

Pressure dependence of catalysed and inhibited burning rate of composite solid propellants

Thu, 01 Jun 1989 00:00:00 GMT

Title: Pressure dependence of catalysed and inhibited burning rate of composite solid propellants Authors: Rastogi, R P; Syal, V; Singh, Haridwar; Nerlekar, K A Abstract: Data on ambient temperature burning rates for an aluminized HTPB composite propellant family with bimodal AP and a total solids loading of roughly 80% over the pressure range from 35 to 105 kg/cm² have been reported. Data are also reported for the additive free base line formulation and formulations with individual rate modifying additives (Fe₂O₃, copper oxide, CaCO₃, SrCO₃) at 2% level. Results have been correlated with rate expressions of Summerfield, Rice, Rastogi and several other empirical relations and relative merits of different equations have been assessed. Further, the experimental data of Blair on pressure and temperature dependence and of Singh on formulation dependence of burning rate have also been analysed. The results show that burning rate is directly proportional to (T_i)^1/4, in agreement with the prediction based on burning rate expression of Rastogi et al. (T_i, is the initial temperature in kelvin). Page(s): 452-457

Catalytic redox reaction of nitric oxide and carbon monoxide on perovskites

Thu, 01 Jun 1989 00:00:00 GMT

Title: Catalytic redox reaction of nitric oxide and carbon monoxide on perovskites Authors: Salker, A V; Chakrabarty, D K; Keer, H V Abstract: Kinetics of oxidation-reduction reaction between CO and NO over perovskite catalysts LaMnO₃) and LaCoO₃), prepared by ceramic and wet methods, has been studied in the temperature range of 473-1000 K. Results have been discussed in the light of X-ray powder diffraction, atomic absorption spectrometry, gas chromatography, electrical conductivity and surface area measurements. The rate-controlling step in the catalytic reduction of NO by CO is presumably the active site reduction process. Page(s): 458-462

Physicochemical studies on thermal analysis of magnesium tris(malonato) ferrate(III) decahydrate

Thu, 01 Jun 1989 00:00:00 GMT

Title: Physicochemical studies on thermal analysis of magnesium tris(malonato) ferrate(III) decahydrate Authors: Randhawa, B S; Kaur, Sandeep; Bassi, P S Abstract: Thermal decomposition of magnesium tris(malonato)ferrate(III) decahydrate, i.e. Mg₃[Fe(CH₂C₂O₄)₃]₂.10H₂O has been studied in the temperature range of 300-1073 K in static air atmosphere using Mossbauer, IR, TGDTA- DTG and XRD techniques. Thermolysis of the above salt proceeds without the salt undergoing reduction to Fe(II) intermediate, The particle size of ɑ-Fe₂O₃, formed as an intermediate increases with increase in decomposition temperature from 473 K to 773 K, At higher temperature, fine particles of magnesium ferrite, MgFe₂O₄ are formed as a result of solid state reaction between ɑ-Fe₂O₃ and magnesium oxide. Page(s): 463-466