http://nopr.niscair.res.in/handle/123456789/5183 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/5456 Title: An economical, simple and high yield procedure for the immobilization/ stabilization of peroxidases from turnip roots <br/> <br/>Authors: M, Syed Musthapa; Akhtar, Suhail; Khan, Amjad Ali; Husain, Qayyum <br/> <br/>Abstract: Ammonium sulphate fractionated peroxidases from turnip roots (<i style="">Brassica rapa</i>) were entrapped in calcium alginate gels for high yield immobilization of enzymes. Enzymes were cross-linked with 0.5 per cent glutaraldehyde to increase the molecular dimension of the enzyme; this resulted in the loss of 8 per cent of enzyme activity. Alginate entrapped soluble and cross-linked peroxidases exhibited high stability against temperature, pH, urea and storage than the soluble preparation and were markedly more stable as compared to directly entrapped soluble enzyme preparation. Entrapped cross-linked peroxidase preparation showed retention of very high enzyme activity after six repeated uses. Alginate entrapped soluble peroxidase preparation rapidly lost its activity after each use. The results suggested that such preparations have great potential in the construction of bioreactors to be used for the removal of aromatic compounds from polluted wastewaters/industrial effluents. <br/> <br/>Page(s): 540-547 Sat, 29 May 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/5455 Title: Studies on total chlorine free bleaching to get +90 brightness of mixed kraft pulp of <i style="">E. tereticornis,</i> <i style="">B. aurandacea</i> and <i style="">P. roxumbergi</i> <br/> <br/>Authors: Dutt, Dharm; Tyagi, C H; Kumar, Dinesh <br/> <br/>Abstract: Mixed kraft pulp of <i style="">E. tereticornis, B. aurandacea and P. roxumberghi</i> in the ratio of 80: 15:05 was bleached by total chlorine free bleaching sequences (TCF). Various bleaching sequences like OZ, OQP, OQPP, OZQP, OQPZ and OZQPP were used to produce pulp of brightness of + 90 per cent. The effect of bleach chemicals on polysaccharide was also studied by determining the viscosity of finally bleached pulp. The bleaching sequences were also interchanged in order to observe the effect on brightness and pulp viscosity. <br/> <br/>Page(s): 536-539 Sat, 29 May 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/5454 Title: Characterization of chlorinated organic material in Eucalyptus pulp bleaching effluents <br/> <br/>Authors: Roy, M; Chakrabarti, S K; Bharadwaj, N K; Chandra, Sandip; Kumar, Sanjay; Singh, Sarabjeet; Bajpai, P K; Jauhari, M B <br/> <br/>Abstract: Elemental chlorine and chlorine compounds are commonly used in the developing countries for bleaching of pulp. The study deals with the bleaching of eucalyptus pulp with chlorine, hypochlorite, and chlorine dioxide and identification of various organochlorine compounds generated in the bleach effluents at different stages. Molecular weight distribution of macromolecules present in bleach effluents at different stages have also been studied <br/> <br/>Page(s): 527-535 Sat, 29 May 2004 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/5453 Title: Effect of chemical charges in cooking and their effectiveness on pulp bleaching <br/> <br/>Authors: Islam, M N <br/> <br/>Abstract: The screened<i style=""> Eucalyptus camendulensis </i>chips were cooked in the laboratory at various alkalinities (14, 16, 18 and 20 per cent) and sulphidity (20, 30 and 40 per cent). Due to the variation in chemical charge, the pulp yield was found to be different. The average pulp yield was 50.6 per cent after washing and the final yield was obtained 40 per cent, which followed the normal kraft yield trend. Bleaching was done with the pulp of maximum final yield obtained. By avoiding oxygen delignification stage, pulp was bleached directly by using D₀ED₁ sequence of elementary chlorine free bleaching. The average brightness and viscosity after final stage were 79.9 per cent ISO and 614 mL/g, respectively. Improvement in brightness was remarkable, but the viscosity decreased. <br/> <br/>Page(s): 522-526 Sat, 29 May 2004 22:58:59 GMT