NOPR Collection:

Studies on (non) energetic compounds (Part 22) - Preparation and thermal decomposition of ring substituted arylammonium fluorides

2013-12-02T16:31:40Z

Title: Studies on (non) energetic compounds (Part 22) - Preparation and thermal decomposition of ring substituted arylammonium fluorides Authors: Singh, Gurdip; Kapoor, Inder Pal Singh; Kaur, Jaspreet Abstract: Ring substituted arylammonium fluorides (RSAF) have been prepared and characterised. The thermal decomposition of these salts has been investigated by thermoanalytical techniques and kinetic parameters are evaluated. The thermal decomposition pathways have also been proposed. Page(s): 229-235

Variable temperature powder XRD study on C₃₂H₆₆ hydrocarbon

2013-12-03T16:45:58Z

Title: Variable temperature powder XRD study on C₃₂H₆₆ hydrocarbon Authors: Shashikanth, P B; Prasad, P B Abstract: A powder X-ray diffraction study was made on dotriacontane, a saturated chain hydrocarbon, at different temperatures, that ranged from ambient to (close to) melting point. Strength of the phases was estimated. Possibility or the existence of intermediate phase during the onset of phase transition, from monoclinic state, was examined. Inferences were made on the formation and nature of chain defects. Page(s): 225-228

Influence of aggregate type on mortar thermal stability

2013-12-05T16:45:55Z

Title: Influence of aggregate type on mortar thermal stability Authors: Shoaib, M M; Balaha, M M; Ahmed, S A Abstract: The contributions of components, especially aggregates, to the fire resistance of mortar and concrete have been studied. Blast-furnace slag, as a by-product from iron and steel industries, is allowed to cool slowly in air to form dense slag or to cool very rapidly in water to form granulated slag. The present work aims to study the effect of using crushed air-cooled and water-quenched slags as a line aggregate for replacement of sand on the mechanical and chemical properties of mortars exposed to lire at different temperatures. Mortar mixes were prepared with three different water cement ratios (0.4, 0.5, and 0.6) and cured in potable water for 90 days, then kept in laboratory atmosphere conditions for about four months. They were exposed to lire at temperatures of 300,400, 500, and 600°C for 2 h soaking time followed by rapid cooling in water. Results of this investigation indicated that the compressive strength of mortars exposed to lire was gradually decreasing with increasing temperature of fire up to 500°C, while it significantly decreased when temperature reached 600°C. The use of air cooled slag improved the thermal stability of mortar. Page(s): 217-224

Effect of perovskite and spinel additives on zinc oxide varistors by sol-gel route

2013-12-04T16:45:03Z

Title: Effect of perovskite and spinel additives on zinc oxide varistors by sol-gel route Authors: Reddy, N Kishan; Reddy, K Bhupal; Mulay, V N Abstract: Synthesis of zinc oxide (ZnO) varistors using sol-gel (SG) route is reported here. Multicomponent oxides, perovskites and spinels have been used as dopants in various mole percentages. Nonlinear coefficients for the three types of dopants are of the order 25, 35 and 18, respectively. SEM characteri zation of the samples prepared by SG route indicates a change in the grain- size of the order 4-30 μm with respect to the sintering temperature 1000- 1200 °C. Similarly, perovskite and spinel dopants show a variation in the grain-size of the varistors as characteristic of temperature. Also, there is an improvement in the bulk density at lower sintering temperatures for the powders prepared by SG route. Page(s): 212-216

NOPR Collection:

Studies on (non) energetic compounds (Part 22) - Preparation and thermal decomposition of ring substituted arylammonium fluorides

Variable temperature powder XRD study on C32H66 hydrocarbon

Influence of aggregate type on mortar thermal stability

Effect of perovskite and spinel additives on zinc oxide varistors by sol-gel route

Variable temperature powder XRD study on C₃₂H₆₆ hydrocarbon