http://nopr.niscair.res.in/handle/123456789/5184 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/5472 Title: Supported lanthanum cobaltate as vehicular exhaust cleaning catalyst: Oxidation of propylene <br/> <br/>Authors: Sharma, Anil Kumar <br/> <br/>Abstract: Lanthanum cobaltate binary oxidic species supported on alumina and zirconia were tested for their catalytic activity for propylene oxidation reaction. The synthesized catalyst was supported by dry impregnation of prepared perovskite oxide on alumina or ziconia. The higher activity of zirconia supported catalyst compared to alumina supported catalyst may be attributed to homogeneous and higher dispersion on zirconia, ionic oxygen carrying capacity of zirconia and larger ionic size of Zr⁴⁺ ion for propylene oxidation. The light off temperature, T₅₀ is minimum for 25 per cent LaCoO₃/ZrO₂ catalyst and that 90 per cent propylene oxidation is obtained at 400^oC. <br/> <br/>Page(s): 614-617 Mon, 28 Jun 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/5471 Title: Studies on the effect of silane coupling agent (2.0 per cent) on the mechanical properties of flyash filled polybutadiene rubber <br/> <br/>Authors: Alkadasi, Nabil A N; Hundiwale, D G; Kapadi, U R <br/> <br/>Abstract: Flyash, a waste product of thermal power stations, generated in huge quantities has been posing problems of its disposal.As such it contains a variety of inorganic oxides and is available in finely powdered form. Attempts have been made for its utilization, as filler in elastomers and plastics. It is important to note that, flyash in untreated form does not contribute in enhancing mechanical properties of composites significantly. In this work, flyash treated with silane coupling agent (Si-69) is used as a filler in PBR. The comparison of properties of composites filled with treated and untreated flyash revealed that the composites with treated flyash showed better reinforcing properties. Flyash treated with silane coupling agent gave greater reinforcement than untreated flyash. The treatment resulted in enhancement of mechanical properties of composites of the said rubber. In this work, properties of composites filled with treated and untreated flyash (separately) are compared. The properties under consideration were tensile strength, modulus at 100 per cent, and 400 per cent, Young’s modulus, hardness, etc. Tensile strength was improved by 193 per cent while modulus at 400 per cent was improved by 700 per cent. Young’s modulus was also improved by 170 per cent. <br/> <br/>Page(s): 603-609 Mon, 28 Jun 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/5459 Title: Studies on the properties of carboxymethylated polyvinyl alcohol <br/> <br/>Authors: Mukherjee, G S; Shukla, N; Singh, R K; Mathur, G N <br/> <br/>Abstract: Polyvinyl alcohol (PVA) has been chemically modified to its carboxymethylated form and the product, designated as CPVA are cast into transparent films. It was observed that the mechanical strength of CPVA film was much higher than that of PVA. The wide angle X-ray diffraction (WAXD) pattern showed a higher molecular order in CPVA compared to that in PVA. Influence of water towards CPVA was found to be quite different as revealed from the studies based on DSC, FTIR, WAXD and mechanical strength evaluation. Because of higher molecular order, water sorption of CPVA membrane was found to be lower than that of PVA. The interplaner distance for PVA was found to be higher than that of CPVA. Interestingly, DSC profile of PVA and CPVA showed different features; PVA underwent an exothermic change at a peak exothermic temperature of <i style="">T</i>_p=76.7^o followed by two distinct endothermic changes. Interestingly, CPVA neither showed any such initial exothermic nor any initial endothermic change unlike showed by PVA but it did exhibit only one distinct endothermic change at trough melting temperature of <i style="">T</i>_t2=207.3^o. The value of entropy of melting for PVA and CPVA corroborates with their respective WAXD pattern. <br/> <br/>Page(s): 596-602 Mon, 28 Jun 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/5458 Title: Assessing the status of sealed fire in underground coal mines <br/> <br/>Authors: Ray, S K; Singh, R P; Sahay, N; Varma, N K <br/> <br/>Abstract: The paper highlights the different aspects of gas sampling in sealed mine fire area. Different fire ratios along with their limitations are also described, in detail. The paper also deals with different methods to determine the explosibility of gas mixtures with suitable examples. Recently obtained field data are also being analysed in respect of fire-ratios and explosibility diagram. <br/> <br/>Page(s): 579-591 Mon, 28 Jun 2004 22:58:59 GMT