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, c...

Since the discovery of zeolites there has been a consistent interest in the potential applications of these microporous structures. Of current particular interest is the possible use of zeolites as storage devices for fuel cells in the hydrogen economy. The adsorption kinetics of zeolites are not fully understood, and therefore the potential of such materials has not been optimized. In this stu...

Using the chemical reduction method, silver nanoparticles (Ag NPs) were effectively synthesized into the zeolite framework in the absence of any heat treatment. Zeolite, silver nitrate, and sodium borohydride were used as an inorganic solid support, a silver precursor, and a chemical reduction agent, respectively. Silver ions were introduced into the porous zeolite lattice by an ion-exchange pa...

Ever since C.R.Berry found quantum size effect on nanometer-sized AgX grain and made studies on its anomalous absorption behaviour, much effort has been made on different aspects of nanometer-sized grain emulsion. H.Thiry, M.Iwasaki and his coworkers prepared nanometer-sized AgBr or AgBrI grain emulsion below 30nm scale and made some attempts on spectral sensitization; Investigated the mixture ...

The electrode reactions of haloargentates were investigated in an aprotic and hydrophobic amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) the presence halide ions. Silver halides, AgX (X – = Cl , Br I ) found to be soluble BMPTFSA containing 0.5 M BMPX form halogenocomplex, [AgX 3 ] 2– . cathodic reduction metallic Ag was observed within electr...

GIS-NaP1 zeolite samples were synthesized using seven different Si/Al ratios (5-11) of the hydrothermal reaction mixtures having chemical composition Al2O3:xSiO2:14Na2O:840H2O to study the impact of Si/Al molar ratio on the water vapour adsorption potential, phase purity, morphology and crystal size of as-synthesized GIS-NaP1 zeolite crystals. The X-ray diffraction (XRD) observations reveal tha...

6,7-Dimethyllumazine more selectively binds to adenine (A) base opposite the abasic site in DNA duplexes (5'-TCC AGX[combining low line] GCA AC-3'/3'-AGG TCN CGT TG-5', X = AP site (Spacer C3), N= A, T, C and G) than the other three nucleobases with a dissociation constant K(d) of ca. 1.0 microM; substituted methyl groups enhance the binding affinity to A and the selectivity for A over T, compa...

Introduced by Kraitchik and Lehmer, an x-pseudosquare is a positive integer n ≡ 1 (mod 8) that is a quadratic residue for each odd prime p ≤ x, yet is not a square. We give a subexponential upper bound for the least x-pseudosquare that improves on a bound that is exponential in x due to Schinzel. We also obtain an equi-distribution result for pseudosquares. An x-pseudopower to base g is a posit...

We show how the software Comsol Multiphysics can be used to solve PDE-constrained optimal control problems. We give a general formulation for such kind of problems and derive the adjoint equation and optimality system. Then these preliminaries are specified for the stationary Navier-Stokes equations with distributed and boundary control. The main steps to define and solve a PDE with Comsol Mult...

Pervaporation (PV) dehydration of isopropanol (IPA) using modified chitosan membranes was studied. The membranes were prepared from chitosan and were modified by using zeolite-A. Pre-weighed amount of zeolite-A was added into acidic solvent and stirred to produce homogeneous solution. Chitosan flakes were then added into the solution and stirred overnight. Various ratios of zeolite-A and chitos...