http://nopr.niscair.res.in/handle/123456789/11607 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/11625 Title: Studies on fire and toxicity potential of bromo-butyl rubber of respiratory mask in a simulated closed environment <br/> <br/>Authors: Kannan, G K; Kumar, N S <br/> <br/>Abstract: This study aimed at evaluation of emission and fire characteristics of bromo-butyl rubber in closed and cone calorimetric conditions. Time to ignition was 30 s in cone calorimeter combustion, and flame out occurred at 315 s. Peak heat release rate (806.34 kW/m²) occurred at 68 s. CO and CO₂ started to build up at 40 s. In closed environment, peak pressure build up was gradually raising from the negative pressure (-200 mbar) conditions, to highest positive pressure conditions (400 mbar). Temperature rise observed to be 10.5-21°C. Peak CO emissions ranged from 34-55 ppm in case of positive pressure experiments. In TGA study, <i style="">T</i>_max was 440°C where 73% weight loss observed. Major observed emissions of bromo-butyl rubber were water vapour, CO, NO, CH₄ and CO₂. Risk hazard of bromo-butyl rubber based on flashover propensity, was high risk (<i style="">x</i> = 26.87) and based on total heat release was intermediate risk (<i style="">y</i> = 77.9) category. Computed toxicity index was very low in open controlled environment (0.02) and closed environment (0.06-0.18) conditions. <br/> <br/>Page(s): 152-160 Sat, 26 Feb 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11624 Title: Comparison of various eucalyptus species for their morphological, chemical, pulp and paper making characteristics <br/> <br/>Authors: Dutt, Dharm; Tyagi, C H <br/> <br/>Abstract: Eleven eucalyptus species are characterized for morphological, chemical, pulp and paper-making characteristics to get high pulp yield of good strength through social forestry in north Indian topological conditions. <i>Eucalyptus grandis</i> of Bhadrachalam and Saharanpur origins give very good fibre dimensions, especially slenderness ratio, which is directly comparable to <i>Pinus kesiya</i>. Other eucalyptus species have shorter fibres and narrow lumen with thick wall resulting to poorer flexibility, higher Runkel ratio and rigidity coefficient. The chemical analysis of eucalyptus species reveal satisfactory levels of holocellulose (except <i>Eucalyptus camaldulensis</i>) and Klason lignin content (<i><</i>30%) (except <i>Eucalyptus camaldulensis</i> and <i>E. ‒348</i> hybrid). Relatively increased (>25%) lignin content except <i>E. ‒413</i> (hybrid) might require additional pulping time and chemical charge compared to other species. Kappa number (<22), pulp yield (>48%) and higher strength properties<i> </i>of <i>E. grandis</i> of Bhadrachalam and Saharanpur origins, <i>Eucalyptus torrelliana, Eucalyptus camaldulensis </i>and<i> Eucalyptus alba</i> showed their suitability for social forestry. <br/> <br/>Page(s): 145-151 Sat, 26 Feb 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11623 Title: Kinetics and thermodynamics study of copper ions removal by natural clinoptilolite <br/> <br/>Authors: Ćurković, Lidija; Trgo, Marina; Rožić, Mirela; Medvidović, Nediljka Vukojević <br/> <br/>Abstract: The process of removal of copper ions by means of clinoptilolite type natural zeolite has been studied as a function of the particle size and temperature. Results indicate that increase in temperature and decrease of particle size improves the removal of copper from aqueous solutions. The parabolic diffusion model is well described process in all examined range of time and it shows that the calculated diffusion coefficient increases with temperature. This increase is more visible at higher particle sizes what assume diffusion through zeolite particle as main mass transfer mechanism. The film diffusion model provides calculation of initial sorption rate (<i style="">k</i>´) and dimensionless parameter proportional to the diffusion film thickness (<i style="">x</i>_i), in relation of particle size and temperature. Diffusion from the surface of zeolite particles through the micro and macro pores is well described with homogenous diffusion model, where change of the calculated overall rate constant is observed at »60 min of the process. This indicates the change of mass transfer rate through porous zeolite particle. The activation energy (<i style="">E</i>_a), activation enthalpy (<img src='/image/spc_char/delta.gif' border=0><i style="">H</i>), activation entropy (<img src='/image/spc_char/delta.gif' border=0><i style="">S</i>) and free energy of activation (<img src='/image/spc_char/delta.gif' border=0><i style="">G</i>) have been calculated based on kinetic data. These thermodynamic parameters characterize process as diffusion dependent, weakly endothermic and nonspontaneous, where structural changes in structure of natural zeolite particle are not observed. <br/> <br/>Page(s): 137-144 Sat, 26 Feb 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/11622 Title: Kinetics and mechanism of the reaction of ranitidine hydrochloride with trans-(diaqua)(N,N^’-ethylene-bis-salicylamide) chromium(III) and hexa-aquachromium(III) ion – a comparative study <br/> <br/>Authors: Dash, S C; Das, N N; Mohanty, P <br/> <br/>Abstract: The substitution reactions of [Cr(SALM)(OH₂)₂]⁺ (SALM =N, N^’– ethylene–bis-salicylamide) and Cr(H₂O)₆^3<b>+</b> with ranitidine hydrochloride, an antacid have been studied spectrophotometrically over the range 0.5 ´ 10^-4 £ [Cr(III)complex]_T £ 3 ´10^-4, 3.6 £ pH £ 4.2, 25^oC £ <i style="">t</i> £ 45^oC and <i style="">I</i> = 0.5 mol dm^-3 [Cr(III)complex] = ([Cr (III)(SALM)(OH₂)₂]⁺or [Cr(H₂O)₆]^3<b>+</b>]<b>)</b> . This reaction follows a mechanism which takes place via an outer sphere association between [Cr (III)(SALM)(OH₂)₂]⁺, [Cr(H₂O)₆]^3<b>+</b> and ranitidine hydrochloride followed by transformation of outer into inner sphere complex by slow interchange. The anation rate constant at 25^oC and <i style="">I</i> = 0.5 mol dm^-3 (NaClO₄) is found to be 4.43 ´ 10^-4 s^-1 for [Cr(III)(SALM) (OH₂)₂]⁺and 3.05´10^-4 s^-1 for Cr(H₂O)₆^3<b>+</b> . The D<i style="">H</i>^# for <i style="">k</i>_an path are found to be 48.2 ± 0.6, 41.2 ±0.2 kJmol^-1and <img src='/image/spc_char/delta.gif' border=0><i style="">S</i>^# –147.6 ± 2.0, -174.2 ± 0.6 JK^-1mol^-1 for Cr(III)SALM(OH₂)₂⁺ and Cr(H₂O)₆^3<b>+</b> ion respectively. <br/> <br/>Page(s): 132-136 Sat, 26 Feb 2011 22:58:59 GMT