NOPR Collection:

Thermodynamics of interaction between -cystine and sodium/magnesium chloride in aqueous solution

Sat, 01 Jun 2002 00:00:00 GMT

Title: Thermodynamics of interaction between -cystine and sodium/magnesium chloride in aqueous solution Authors: Li, Dacheng; Yu, Qingjiang; Wang, Yong; Sun, Dezhi Abstract: Interactions of -cystine with sodium chloride and magnesium chloride have been studied by determining the solubility of cystine in aqueous salt solutions of different concentration at varying temperatures. The interaction thermodynamic parameters have been estimated with the solubility data. The results show that both NaCl and MgCl₂ in water is beneficial to dissolution of -cystine. Enthalpy or entropy of interaction between -cystine and NaCl is negative while that between -cystine and MgCl₂ is positive. These interesting results are discussed in the light of static electricity theory as well as hydration of ions. Page(s): 1126-1130

Silica enriched faujasitic zeolite-Y from flyash

Sat, 01 Jun 2002 00:00:00 GMT

Title: Silica enriched faujasitic zeolite-Y from flyash Authors: Meshram, S U; Rayalu, S S; Munshi, K N; Hasan, M Z Abstract: Various process modifications to enrich silica in zeolite-Y have been carried out by increasing substantially the SiO₂ /Al₂O₃ ratio from 1.8-2.0 to 2.5-3.0 with consequent increase in thermal stability. Some new phases of zeolites have been observed with improved silica alumina ratio up to 3.0 to 3.5. Crystallinity has been monitored by XRD analysis, ranging from 70-99% for different samples. Page(s): 1212-1216

A study of the underpotential deposited hydrogen on the nickel deposited electrode in alkaline media

Sat, 01 Jun 2002 00:00:00 GMT

Title: A study of the underpotential deposited hydrogen on the nickel deposited electrode in alkaline media Authors: Jafarian, M; Mahjani, M G; Hoseni, M; Gohal, F Abstract: Hydrogen evolution reaction has been studied on the nickel deposited electrode. Two reduction peaks at -1 V/Ag-AgCl and -1.3V/Ag-AgCl and one oxidation peak at - 1.3V/Ag-AgCl have been observed. Shift due to oxidation peak arises from change of cathodic limit, attributed to the two competitive reactions on the surface. The peak located on the more anodic side is due to the oxidation of H_UPD and the second peak due to the oxidation of H_OPD The sodium ion has no effect on the hydrogen evolution reaction. The diffusion coefficient of hydrogen is calculated to be D=2.88×10^-10 cm² s^-1 using impedance technique. Page(s): 1208-1211

Spectral and thermal studies of homodinuclear and heterodinuclear glutathione complexes

Sat, 01 Jun 2002 00:00:00 GMT

Title: Spectral and thermal studies of homodinuclear and heterodinuclear glutathione complexes Authors: Garg, Bhagwan S; Kumar, Deo Nandan; Singh, B K Abstract: The complexes of the types [M₂LSO₄.2H₂O] where L=GSH, M = Co(II), Cu(II), Zn(II), Cd(II) and [MM'LSO₄.2H₂O] where L = GSH, M = Cu(II), M' = Zn(II) and M = Co(II), M' = Cd(II)] have been prepared and characterized by elemental analysis, magnetic susceptibility measurements, JR, EPR, electronic spectral studies and thermal analysis. Deprotonation and coordination of thiol group occurs and glycine residue binds with the metal ions in all the complexes. Copper(II) and cobalt(II) complexes show low magnetic moment. EPR spectral data show that complexes have planar geometry. Ligand to metal charge transfer are observed in all the complexes and d-d transition are also observed in copper(II) and cobalt(II) complexes. Thermal decomposition of all the complexes proceeds via first order kinetics. Page(s): 1205-1207