http://nopr.niscpr.res.in/handle/123456789/24321 2026-10-08T18:00:34Z http://nopr.niscpr.res.in/handle/123456789/24359 Title: Effect of acidic environment on slake durability of iron ore — An experimental approach Authors: Singh, T N; Madhusudhan, N; Monjezi, M Abstract: Forces of weathering and erosion reduce the strength of rocks leading to various types of failures in slopes and strata. The present paper deals with the variation in the strength of iron ore bearing rocks with the acidity of the solutions to which they are exposed. Slake durability index is a measure of the durability of the rock when exposed to a slaking fluid medium. The variations in the slake durability indices of iron ore samples were studied by exposing them to acidic solutions of different pH values. The results indicate that the slake durability of iron ore rocks decreases with increase in the acidity of the solutions to which they are exposed. This behaviour is attributed to combined forces of weathering and corrosion acting on iron ore in acidic slaking media. Page(s): 182-184 2001-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/24358 Title: Electrical properties of MoO₃ films Authors: Rao, K Srinivasa; Madhuri, K V; Uthanna, S; Naidu, B S; Hussain, O M Abstract: DC conductivity of thin films of MoO₃, prepared by activated reactive evaporation technique, revealed electron hopping conduction at lower temperature and the intrinsic thermally activated process at higher temperature. The dielectric properties of Al/MoO₃/Al<i> </i>thin film sandwich structures were studied in the frequency range 0.050-100 kHz and in the temperature range 80-400 K. The frequency and temperature dependences of capacitance and dielectric loss were also studied. Page(s): 177-181 2001-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/24357 Title: Selective flocculation separation of iron and titanium from Kutch kaolins (India) Authors: Kumar, G V S S; Menon, S K; Agrawal, Y K; Vora, S B Abstract: A new selective flocculation separation (SFS) scheme has been described for upgrading Mamuara kaolins of Gujarat (Kutch district), India. The process embodies the implementation of polvinylpyrrolidone (PVP) as dispersant, carboxymethyl cellulose(CMC) as flocculant and new class of supramolecules such as hexasulfonato calix(6)arene [HSC(6)] as enriching agent. Page(s): 170-176 2001-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/24356 Title: Effect of structure of nadimides on properties of glass fibre reinforced composites* Authors: Srivastava, Anju; Varma, I K Abstract: The paper describes fabrication of glass fibre reinforced laminates based on three structurally different nadimide oligomers containing phosphine oxide in the backbone and a low molecular weight low viscosity allyl nadicimide resin. Fabrication of laminates was done using methyl ethyl ketone solvent. Interlaminar shear strength and flexural strength of laminates, containing 0.67-0.5 volume fraction of fibres, depended on the structure of the resin and was found to be higher in laminates based on resins with higher polarity and having phosphine oxide in backbone. Properties of composites based on blends of these resins could be predicted on the basis of rule of mixtures. A marginal synergism was observed in one case. <i>T</i>_g<i> </i>was in the range of 230-270°C and was found to increase marginally in blends. Effect of oven aging and boiling water treatment on the properties of composites is also reported. Page(s): 165-169 2001-06-01T00:00:00Z