http://nopr.niscair.res.in/handle/123456789/6827 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/7062 Title: Study on defluoridation of drinking water by impregnation of metal ions in activated charcoal <br/> <br/>Authors: Janardhana, C; Rao, G Nageswara; Sathish, R Sai; Lakshman, V Sai <br/> <br/>Abstract: Defluoridation of drinking water was carried out by the continuous down flow adsorption mode at room temperature. Five columns were prepared by the impregnation of ZrOCl₂, CaO, Alum, CaCl₂ and Borax in activated coconut shell charcoal. Known fluoride influent water was run into the column at a constant rate of 4.0 L/h and a constant level of water was maintained. Samples of the treated water were collected for analysis by the ion selective electrode method. In this study zirconium ion impregnated coconut shell charcoal (ZICSC) showed maximum fluoride uptake and proved to be the most effective defluoridating agent followed by CaO and Alum. <br/> <br/>Page(s): 414-416 http://nopr.niscair.res.in/handle/123456789/7061 Title: Cetyldimethyl benzyl ammonium cerium nitrate as a phase-transfer oxidant in the oxidation of alcohols to carbonyl compounds <br/> <br/>Authors: Baruah, Smriti Rekha; Kakati, Dilip Kumar <br/> <br/>Abstract: Oxidation of organic substrates by inorganic reagents is restricted by mutual insolubility of the two. However, this problem of mutual insolubility can be alleviated by the use of oxidants in the form of phase transfer reagents, like tetra-alkylammonium salts. Tetra-alkylammonium salt has a polar (N+) group and hydrocarbon side chains (alkyl groups). The ammonium salt allows a low concentration of oxidant to pass into the organic layer where they act as oxidizing agent. In the present case, the synthesis of a phase transfer oxidant cetyldimethyl benzyl ammonium cerium nitrate (CDBACN) and its use in the oxidation of alcohols to carbonyl compounds has been reported. CDBACN was synthesized from cetyldimethyl benzyl ammonium chloride (CDBACl) and ammonium ceric nitrate (CAN). The reagent was characterized by elemental analysis and spectral studies. The solubility and electronic spectra of the oxidant in various solvents were studied. This oxidant was successively utilized in the oxidation of different alcohols. <br/> <br/>Page(s): 411-413 http://nopr.niscair.res.in/handle/123456789/7060 Title: Studies on yield improvement of High Melting Explosive (HMX) <br/> <br/>Authors: Das, S; Raut, V D; Gawande, N M; Khopade, R S; Narasimhan, V L <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> In India, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine, commonly known as HMX (High Melting Explosive), is manufactured by the modified Bachmann combination method using continuous nitrolysis of hexamine in a cascade of four stirred tank reactors. In this laboratory, the technology was established more than three decades ago with an overall yield of about 40%. However, as the reported yield of HMX is around 55%, it was considered essential to systematically study the Bachmann reaction system to improve the yield. As such a detailed study on quantities/ratios of raw materials and process conditions was carried out to improve the yield. Optimized ratios of raw materials, use of nitric acid having strength >99%, proper control of temperature and optimal nitration and residence time gave an yield of 60-65%. </smarttagtype></smarttagtype> <br/> <br/>Page(s): 404-410 http://nopr.niscair.res.in/handle/123456789/7059 Title: Enhancement of viscosity index of mineral base oils <br/> <br/>Authors: Tanveer, Sabiha; Prasad, Ram <br/> <br/>Abstract: Multigrade engine oils of high viscosity index (VI) are required for modern internal-combustion engines. Such a high VI is difficult to achieve by the conventional processing of petroleum fractions. Therefore, VI improvers are added in the mineral base oils to achieve the desired VI. The enhancement of VI of mineral base oils (100 N, 150 N and 500 N) by the addition of VI improvers [polyisobutylene(PIB), polybutadiene rubber (PBR)] has been studied. VI of blended oils, made from the mineral base oils 100 N, 150 N and 500 N by the addition of PIB and PBR, is found to pass through maximum. It was observed that the occurrence of maximum depends on the mineral base oil used and the type and concentration of VI improver. <br/> <br/>Page(s): 398-403