http://nopr.niscair.res.in/handle/123456789/9994 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/10004 Title: Novel methods for the spectrophotometric determination of colchicoside <br/> <br/>Authors: Narayana, B; Divya, N S <br/> <br/>Abstract: Two novel methods are presented for the spectrophotometric determination of colchicoside (COLSID). Method A involves the reaction of COLSID with Fe(III) to form complex and method B is based on the reaction of the drug with NH₂OH.HCl, the absorbances of which are measured at 458 nm and 395 nm respectively. The calibration graphs are found to be linear over 20.00-120.00 and 20.00-100.00 µgmL^-1 for methods A and B respectively. The apparent molar absorptivity for COLSID-Fe(III) and COLSID-NH₂OH.HCl are 0.146 ×10⁴ and 1.449×10⁴Lmol^-1cm^-1 respectively. The methods are successfully applied to the assay of COLSID in pharmaceutical preparations. <br/> <br/>Page(s): 317-320 http://nopr.niscair.res.in/handle/123456789/10003 Title: Effect of base paper characteristics on coated paper quality <br/> <br/>Authors: Sood, Y V; Tyagi, Sanjay; Tyagi, Renu; Pande, P C; Tandon, Rajnish <br/> <br/>Abstract: The quality of coated paper is mainly governed by the characteristics of base paper. The three main base paper properties which contribute to the variations on coat weight and print non-uniformity in coated paper are roughness, absorbency and sheet matrix formation. Increase in roughness of base paper gives coated paper of lower smoothness and gloss at a particular coat weight. Along with roughness the compressibility of base paper also plays important role. Porosity and sizing degree which affect absorbency of base paper also affect the coated paper quality. Porosity of base paper has minor effect on coated paper roughness. The gloss of coated paper is improved with sizing and sheet densification. Sheet matrix non-uniform formation has little effect on coated paper gloss, however, it adversely affects the smoothness and print uniformity. Loading of base paper with PCC gives better effect on brightness, picking velocity and print saturation density than GCC and Talc. <br/> <br/>Page(s): 309-316 http://nopr.niscair.res.in/handle/123456789/10002 Title: Linde Type-A zeolite synthesis and effect of crystallization on its surface acidity <br/> <br/>Authors: Khan, G M Arifuzzaman; Arafat, S M Y; Reza, M N; Razzaque, S M Abdur; Alam, Md. Shamsul <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> An alumino-silicate zeolite, Linde Type-A (LTA) has been prepared from aluminium powder and sodium metasilicate by hydrothermal process. The zeolite was characterized by FTIR and X-ray diffraction (XRD) analysis and by measuring the surface acidity using KOH as adsorbate. The surface acidity of LTA zeolite varied greatly with varying synthesized conditions such as crystallization temperature, crystallization time and K⁺ ion adsorption period. The Bronsted acid site on the zeolite surface increased with increasing crystallization temperature and the maximum surface acidity was obtained at 100^oC. Crystal growth was also dependent on the crystallization time. The surface acidity increased with increasing crystallization time. The maximum surface acidity due to the maximum consumption of the K⁺ ion was observed at 48 h adsorption time and the value was found to be 0.9 meq/g when Si:Al was 50:50. It was seen that the surface acidity was more pronounced when ammonium hydroxide solution as adsorbate and agitated crystallization condition were used. The surface acidity of the commercial LTA zeolite was compared with the surface acidity of the synthesized LTA zeolite. It was found that the surface acidity of synthesized LTA zeolite is slightly greater than commercial LTA zeolite</smarttagtype></smarttagtype> <br/> <br/>Page(s): 303-308 http://nopr.niscair.res.in/handle/123456789/10001 Title: Size-dependent growth kinetics of continuous mass crystallization of L-sorbose from its water solutions <br/> <br/>Authors: Wierzbowska, B; Piotrowski, K; Hutnik, N; Matynia, A <br/> <br/>Abstract: The kinetics of<b> </b>a<b> </b>continuous mass crystallization of L-sorbose from its water solutions was studied. A precise kinetic model assuming size-dependent growth (SDG) mechanism was employed. Influences of concentration of L-sorbose in a feeding mixture and mean residence time of suspension on the minimum and maximum values of linear growth rate and on nucleation rate were established. Comparison with kinetic data provided by size–independent growth (SIG) kinetic model was also made. All G_¥ values predicted by SDG model (2.43×10^–8–12.10×10^–8 ms^–1) are of the same magnitude as G values provided by the simplest SIG model (1.89×10^–8–7.61×10^–8 ms^–1). Nucleation rate values, B, estimated from SIG model are, however, highly devaluated (B = 1.85×10⁷–18.87×10⁷ m^–3s^–1) compared to the ones provided by SDG approach (B = 5.45×10¹⁸–1.10×10²¹ m^–3s^–1) in which the n(L) predictions are more compatible with the experimental n(L) data in a whole size range tested. <br/> <br/>Page(s): 296-302