NOPR Collection:

Biopulping and Biobleaching by White Rot Fungi

Wed, 01 May 2002 00:00:00 GMT

Title: Biopulping and Biobleaching by White Rot Fungi Authors: Helmy, Samia M; El-Meligi, Magda Abstract: The potentials of white-rot fungi namely Coriouls versicolor NRRL 6102, Phanerochaete chrysosporium NRRL 6359, P. chrysosporium NRRL 6361 and P. chrysosporium NRRL 6370 are evaluated for brightness of banana waste. The banana fruit stalk is used as a sale carbon source under sterilized solid state fermentation (SSF) at 35°C for one month. Of these, P. chrysosporium NRRL 6370 cultured supported maximum brightness (30.5 per cent than under control 117.8 per cent). This fungus degrades lignin and hemicellulose with does not effect on cellulose fibres (55.4 per cent than under control 40.01 per cent). The three useful types of paper are prepared from biopuling banana fruit stalk. The two types of them are bleached by hydrogen peroxide (writing and printing 40 S^oR and greasy paper 80-82 S^oR). While the board is prepared from unbleached biopulping in 25 S^oR. The strength properties of biopulping increases from 15-20 per cent for the hand-made sheet. Also the brightness is higher,. i.e., > 20 per cent than under control. Results show that biopulping controls yield and avoids losses in viscosity and strength properties. Page(s): 376-381

New Insights into CaO-swelling Cements

Wed, 01 May 2002 00:00:00 GMT

Title: New Insights into CaO-swelling Cements Authors: Appah, Dulu Abstract: Influence of CaO in improving slurry swelling is studied, using high pressure-high temperature (HP-HT) expansion cells, and compared with previous results. For varying temperatures and pressures the beginning and end of expansion and the duration, of expansion are observed. The expansion values are determined. The extent to which cement shrinks is found to be a balance between the chemical reaction of water and clinker mineral, and the physical reaction of gel dipole water attached to the electrically charged cement surfaces. An optimum water cement factor (WCF) of 0.45 ensures pumpability during oil well cementing, without causing increased hardened-paste porosity and permeability. Specially stable matrix is needed to use the swelling agent, and the smaller the CaO reactivity, the earlier the ‘‘Time-window’’ attains high temperature. Depending on the retarders used to suppress shrinkage, cement expands at an average value of 6 per cent for 19, 16, 15 and 6 min, at 60, 80, 90 and 105^oC, respectively. Calcium oxide quantity between 12 and 14 per cent by weight of cement is recommended for good swelling. A second method of gradually mixing cement slurry components in stages represents an improvement of the CaO swelling ability over the old lump method which is quite useful. Page(s): 370-375

Development and Evaluation of Matrix and Two Layered Sustained Release Suppositories of Nimesulide

Wed, 01 May 2002 00:00:00 GMT

Title: Development and Evaluation of Matrix and Two Layered Sustained Release Suppositories of Nimesulide Authors: Ravi, M; Sa, B; Bandyopadhyay, A K Abstract: Nimesulide loaded conventional suppositories, sustained release matrix suppositories and sustained realesed two layered suppositories were prepared using polyethyleneglycol (PEG) -4000 and ethylcellulose. In vitro characteristics of these suppositories were evaluated. In comparison to conventional suppositories the release of drug from sustained release matrix suppositories was gradual and extended over a period of time. On the other hand, two layered suppositories produced an initial quick release followed by ex tended release of drug. Page(s): 366-369

Enzymatic Preparation of L-Glucose, L-Galactose and L-Xylose Using Galactose oxidase Immobilised on Crab-shell Particles

Wed, 01 May 2002 00:00:00 GMT

Title: Enzymatic Preparation of L-Glucose, L-Galactose and L-Xylose Using Galactose oxidase Immobilised on Crab-shell Particles Authors: Yadav, K K; Vernwal, S K; Afaq, Z; Yadav, K D S Abstract: Galactose oxidase has been immobilised on a solid support developed by modification and activation of surfaces of crab-shell particles. The conversion of D-sorbitol to L-glucose, galactitol to L-galactose and xylitol to L-xylose using the immobilised galactose oxidase have been demonstrated. The performance of the immobilised galactose oxidase for the conversion of D-sorbitol to L-glucose in a mini batch reactor has been studied. The advantages of this method for preparing L-sugars have been discussed. Page(s): 361-365