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Cs Content (cs + content)
Selected AbstractsMetal ion permeation properties of silk fibroin/chitosan blend membranesPOLYMER INTERNATIONAL, Issue 4 2006Chun-Hui Du Abstract Silk fibroin/chitosan (SF/CS) blend membranes were prepared and characterized by infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy. It was found that SF and CS were compatible in the blend membranes and that the membranes were dense without microscopic phase separation. Swelling experiments showed that the swelling ratio of the blend membranes increased with CS content and reached the highest value when CS content was 70 wt%. Experiments indicated that the permeability coefficient of K+ through the blend membrane was 2,4 times higher than that of pure CS membrane, and 10 times higher than that of pure SF membrane. The permeation rate of K+ increased linearly with CS content in the blend membrane for the lower concentration feeding solution. For different metal ions, the permeability through SF/CS blend membranes was in the sequence K+ > Ca2+ > Cd2+ > Pb2+ > Cu2+ > Ni2+. Copyright © 2006 Society of Chemical Industry [source] Chondroitin sulphate proteoglycans in the vitreous gel of sheep and goatBIOMEDICAL CHROMATOGRAPHY, Issue 5 2007Spyros S. Skandalis Abstract In the present study, the amounts and the fine structural characteristics of chondroitin sulphate proteoglycans (CSPGs) present in sheep and goat vitreous gels were determined. The results showed that in both examined species hyaluronan was the predominant glycosaminoglycan (GAG), whereas CSPGs were present in minor amounts. CSPGs were identified as versican and collagen IX with versican being the predominant PG type. Fine structural characterization indicated that the CS chains of versican in both mammalian species were of smaller size than those found in collagen IX. The difference in the sulphation pattern of CS chains between versican and collagen IX was also of particular interest. The results indicated that the predominant disaccharide type in CS side chains of versican and collagen IX from both sheep and goat vitreous gels was the 4-sulphated disaccharide. CS chains of versican were found to be richer in 4-sulphated disaccharide units than those in collagen IX, which also contained a significant proportion of non-sulphated disaccharides. These findings showed that, firstly, the CS content and the hydrodynamic size of the CS chain and, secondly, the sulphation pattern of CS chains from versican and collagen IX in both sheep and goat vitreous gels are PG type-dependent. Copyright © 2007 John Wiley & Sons, Ltd. [source] Crystal structure and thermal behaviour of (Rb,Cs)BSi2O6 solid solutionsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2006M. G. Krzhizhanovskaya Abstract The crystal chemistry of Rb-Cs boroleucites has been studied by means of X-ray powder diffraction at room and elevated temperatures. The cubic I-43d , cubic Ia3d phase transition was investigated using a series of samples prepared by solid-state reaction along the pseudobinary system RbBSi2O6 - CsBSi2O6. The Rietveld refinement of the structures of Rb1-xCsxBSi2O6 solid solutions (x = 0.2, 0.4, 0.6, 0.8) demonstrates that the solutions with a high Rb content crystallise in the cubic I-43d space group, and the boroleucites with a considerable Cs content have Ia3d symmetry. Rb can substitute Cs in a wide range of compositions. Within a narrow range of x = 0.5 - 0.6 immiscibility was revealed. Under Rb-Cs substitution the cubic lattice parameter, the (Rb,Cs)-O distances, and the angles between tetrahedra of the I-43d phase change clearly, while those of the Ia3d phase change slightly. The HTXRD data shows that the I-43d phase transforms into a Ia3d phase on heating analogously to a change of the composition. As the Cs content increases the transition temperature decreases. The low temperature I-43d phase shows a higher thermal expansion than the high temperature Ia3d phase. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim [source] Cs8,xSi46: A Type-I Clathrate with Expanded Silicon FrameworkCHEMISTRY - A EUROPEAN JOURNAL, Issue 24 2009Aron Wosylus Dipl.-Chem. Abstract The synthesis of the new binary Cs8,xSi46 (shown here) completes the series of binary alkali metal silicides with a clathrate-I structure M8,xSi46 (M=Na, K, Rb, Cs). In contrast with the lighter homologues, Cs8,xSi46 can be prepared only at elevated pressures. The compound was obtained at 1200,°C between 2,10,GPa and the Cs content rises with applied pressure. [source] | ||||||||||