An infinite-dimensional integral identity for the Segal-Bargmann transform

We prove an infinite-dimensional integral identity equating the integral of a function on a subspace of a linear space to the integral of its Segal-Bargmann transform over the orthogonal complement.

     

First Example of Te-C Bond Cleaved Product in the Reaction of C8 H 8 TeI 2 with Ammonium Pipertidine Dithiocarbamate

Abstract

A series of 1,3-dihydro-2λ⁴-benzotellurole-2,2-diyl di-thiocarbamates C₈H₈TeR₂ and C₈H₈TeIR ( R═ S ₂CNC₅H₁₀, S₂CNHC₆H₅, S₂CNC₄H₈O) have been synthesised by the reactions of C8H8TeI₂ with the corresponding ammonium salts of piperidine-, aniline- and morpholine- dithiocarbamates in 1:1 and 1:2 molar ratio, respectively. They have been characterized by FT-IR and (¹H, ¹³C) NMR spectroscopy. The reaction of C₈H₈TeI₂ with (NH₄S₂CNC₅H₁₀) in 1:2 molar ratio gives C₈H₈Te(S₂CNC₅H₁₀)₂ [IR, (¹H, ¹³C)NMR evidence] and X-ray quality crystals of Te(S₂CNC₅H₁₀)₂ in very low yield, demonstrating the formation of the first Te–C bond-cleaved product.The monomers of Te(S₂CNC₅H₁₀)₂ are connected through intermolecular Te…S secondary bonds and it exists as a dimer in the solid state. These dimers are interconnected through intermolecular S…S secondary bonds to yield 3D-supramolecular network.     

A New Redox Initiating System for the Polymerization of Vinyl Monomers

Abstract

A new redox system, dioxane-ascorbic acid, has been investigated for the homopolymerization of vinyl monomers. Detailed kinetic studies on the aqueous polymerization of acrylamide by this initiating system have been done iodometrically at 35 ± 0.2°C. The effect of various additives, such as organic solvents, inorganic salts, surfactants, etc., on the rate of polymerization has been studied. The retardation constants for organic solvents have been evaluated by the “intercept method.” The overall energy of activation has been found to be 8.75 kcal/deg/mol, within the temperature range 25–45°C. A suitable mechanism has been suggested. The following rate expression: R_p α [acrylamide]^1.0 [dioxane]^1.0 [ascorbic acid]⁰, has been observed.     

Equilibrium Sorption of Hexavalent Chromium from Aqueous Solution Using Iron(III)-Loaded Chitosan-Magnetite Nanocomposites As Novel Sorbent

This work describes magnetic separation of hexavalent chromium by iron(III)-loaded chitosan-magnetite nanocomposites. The Cr(VI) uptake data, studied at 25°C and 45°C, was well fitted into the Freundlich isotherm. The values of constant K_F and 1/n were found to be 1.515, 1.266 and 1.006 (mg g^?1) (l mg^?1)^1/n and 0.76, 0.77, and 0.71, respectively. The Dubinin-Kaganer-Radushkevich isotherm was applied to determine mean sorption energy E. The value of E was found to be in the 8.977 to 9.90 kJ mol^?1 range, thus indicating the chemical nature of the sorption process. The kinetics of Cr(VI) uptake was best interpreted by the Power function model. The intraparticle diffusion of sorbate was confirmed by the Bangham equation, and various thermodynamic parameters were also evaluated. Finally, a plausible mechanism has been suggested to understand the sorption process. The intraparticle diffusion was found to occur and later on confirmed by the Bangham equation. Finally, a plausible mechanism has been suggested for the observed Cr(VI) uptake on this newly developed sorbent. The various thermodynamic parameters were also evaluated.     

Examination of the Higuchi Model for the Release of Vitamin B2 from Multilayered Calcium Alginate/Chitosan Beads in Varying pH Medium

The release of model drug vitamin B₂ from calcium alginate/chitosan multi‐layered beads has been studied in the media of varying pH (3 h in the medium of pH 1.0 and for the remaining time in pH 7.4) at 37°C. The quantitative deviation of experimental data from the Higuchi model has been interpretated by using a newly developed ‘curve area measurement’ (CAM) approach. The higher deviation in the initial phase has been explained on the basis of porous structure of beads due to the use of low molecular weight polymers in the preparation of beads.     

Investigation of Water Uptake Behavior of Superabsorbent Polymers Composed of N‐Vinyl‐2‐pyrrolidone and Partially Neutralized Acrylic Acid

Fast‐swelling micrometer sized superabsorbents were synthesized through a rapid solution polymerization of n‐vinyl‐2‐pyrrolidone (NVP) and partially neutralized acrylic acid (PNAAc) under normal atmospheric conditions using N,N'‐methylene bisacrylamide (MB) as crosslinker and sodium bicarbonate as porogen. The effect of various parameters such as crosslinker concentration, degree of neutralization of monomer acid, concentration of initiator have been evaluated. Water retention capacity of superabsorbents under varying loads was also examined. The drying behavior of polymers at 37°C was also studied. The gels showed sharp volume transition in solutions of divalent metal ions. The superabsorbents were also characterized by FTIR and TGA.     

Polymerization of Acrylamide Initiated by the Redox System Potassium Persulfate/Lactic Acid,Catalyzed by Silver Ions

The aqueous polymerization of acrylamide initiated by the potassium persulfate/lactic acid system catalyzed by Ag⁺ ions has been studied iodometrically over the temperature range from 35 to 50 ± 0.2°C. The rate of polymerization is governed by the expression R_p ∞ [M]^0.8[K₂S₂O₈]^1.0[Ag]^1.0 The deviation from normal kinetics has been studied. A tentative mechanism of initiation is suggested. The overall energy of activation is 5.52 kcal/mol.     

Removal of Cobalt Ions from Aqueous Solution by Adsorption onto Cross-Linked Calcium Alginate Beads

The removal of cobalt ions from dilute aqueous solutions using cross linked calcium alginate beads as the adsorbent is reported in this article. The influence of various experimental parameters such as pH, initial metal ion concentration, contact time and solid to liquid ratio were studied. The adsorption data were applied to Langmuir and Freundlich isotherm equations and various static parameters were calculated. It was observed that the uptake of cobalt ions was found to increase with time and that maximum adsorption was obtained within the first 60 minutes of the process. These results indicate that the cross linked calcium alginate beads have potential for removing cobalt ions from industrial waste water.     

Designing Gelatin Based Blood Compatible Materials with Hydrophilic and Hydrophobic Macromolecular Chains

Polymer matrices based on poly 2-hydroxyethyl methacrylate (PHEMA) have emerged as promising materials for developing applications in biomedical and tissue engineering fields. The major criteria of a material to be used as a support matrix in tissue engineering application rests on its biocompatible, hydrophilic, and mechanically strong nature. Although a great deal of research efforts have been put into designing such materials, achieving these properties together for such a material still remains a challenge. Thus, by a judicious combination of natural and synthetic polymers, such as gelatin and copolymers of PHEMA and PAN, respectively, it has been attempted to synthesize a polymer material by redox polymerization method. The prepared polymer matrix was characterized by FTIR, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) techniques. The prepared polymeric biomaterials were assessed for their water sorption potential under varying experimental conditions such as chemical composition, pH, and temperature of the swelling bath. The diffusion mechanism of transport of water molecules arising due to solvent–polymer interaction was analyzed to predict the behavior of continuously relaxing macromolecular chains. The in vitro blood compatibility of the prepared polymeric materials was determined by methods such as blood clot formation, platelet adhesion, percent hemolysis assay, and protein–adsorption on the surface of the prepared biomaterials.