Ab-initio study of electronic and elastic properties of B2-type ductile YM (M=Cu, Zn and Ag) intermetallics

A theoretical study of structural, electronic, elastic, thermal and mechanical properties of nonmagnetic intermetallics YM (M=Cu, Zn and Ag), which crystallize in CsCl-type structure, is performed using first principles density functional theory based on full potential linearized augmented plane wave (FP-LAPW) method. The calculations are carried out within the generalized gradient approximation (GGA) for the exchange correlation potential. The calculated ground state properties such as lattice constants, bulk modulus and elastic constants agree well with the experiment. From energy dispersion curves, it is found that these compounds are metallic in nature. The ductility of these intermetallics is determined by calculating the bulk to shear ratio B/G_H. The calculated results indicate that YAg is the most ductile amongst the present YM compounds. The results obtained are compared with the available experimental and theoretical results. The mechanical and thermal properties are predicted from the calculated values of elastic constants.     

Nuclear effects in multiparticle production in 800 GeV and 400 GeV proton-nucleus interactions

We study nuclear effects in multiparticle production in proton-emulsion nuclei interactions at 800 GeV and 400 GeV. The observed pseudorapidity distributions are compared with the predictions of a simple quark model. The predicted dependence of the ratio of the normalised multiplicity distribution of the produced shower particles in hadron-nucleus (hA) to hadron-hadron (hh) interactions on the mean number of inelastic collisions in the central region is in good agreement with the experimental data.     

Proteome-Based Profiling of Hypercellulase-Producing Strains Developed Through Interspecific Protoplast Fusion Between Aspergillus nidulans and Aspergillus tubingensis

Thirty heterokaryons, formed by protoplast fusion of Aspergillus nidulans and Aspergillus tubingensis, were selected on the basis of their ability to grow on 2-deoxyglucose (0.2 %, w/v) and intermediate spore color. These heterokaryons were studied for cellulase production using shake flask and solid substrate cultures at 40 °C. Fusants 51 and 28 exhibited appreciably higher levels of endoglucanase, cellobiohydrolase, β-glucosidase, and FPase activities when compared with parental strains. Employing proteomic-based approaches, the differential expression of proteins in secretome of fusants and parental strains were analyzed using two-dimensional electrophoresis. The expression of some of the proteins in the fusants was found to be up/downregulated. The upregulated proteins in the fusant 51 were identified by liquid chromatography–mass spectroscopy as endoxylanase, endochitinase, β-glucosidase, as well as hypothetical proteins. The cellulases produced by fusants 28 and 51 showed improved saccharification of alkali treated rice straw when compared with the parental strains.     

Nonelectrolyte-Induced Micellar Shape Changes in Aqueous Solutions of Silicone Surfactants

Dynamic light scattering, cloud point (CP), and surface tension studies have been carried out to examine the influence of six (including two acetates, two alkoxyethanols, and two sugars) nonelectrolyte additives on two silicone surfactants based on poly (dimethyl siloxane)—graft—polyethers in aqueous solutions. The results indicate that the presence of alkoxyethanols induced the oblate ellipsoidal to spherical micellar transition, while sugars increase the size of the ellipsoidal micelles. The effect of cosolvent or additives on critical micelle concentration (CMC) and CP is discussed on the basis of water structure making and breaking effect. The thermodynamic and surface active parameters were calculated from the surface tension isotherm curves.     

Freshwater-durable and marine-degradable cellulose nanofiber reinforced starch film

Cellulose - Cellulose can replace single-use petrochemical packaging; however, its lack of freshwater durability restricts its applicability. This study used a wet pulverization process to prepare...     

Cellulose Nano Whiskers (CNWs) Loaded-Poly(sodium acrylate) Hydrogels. Part-I. Effect of Low Concentration of CNWs on Water Uptake

In this work, de-watered cellulose pulp(DCP), obtained from a paper mill, have been acid-hydrolyzed to yield cellulose nano-whiskers (CNWs). As revealed from FESEM measurements, these CNW were found to possess a median length of 258.5 nm, diameter of 35.2 nm, and an aspect ratio of 7.3. The CNWs were also characterized by TGA, XRD and FTIR analysis. The CNWs were found to possess a fairly high Crystallinity Index (CI) of 0.925. The addition of cellulose at low concentration range, i.e., from 25 to 125 mg (nearly 1.25 to 6.25 weight percent of polymer sodium acrylate) caused an enhancement in water uptake of resulting hydrogels .The CNWs-loaded poly(SA) hydrogels showed chain relaxation controlled swelling in the medium of pH 7.4 as was confirmed from the swelling exponent ‘n’ values obtained using power function law‥ The second order kinetic model was found to fit well to the kinetic water uptake data. However, all the samples, when prepared in the form of films, did not show any remarkable increase in their mechanical strength.     

pH-enzyme di-dependent chronotherapeutic drug delivery system of theophylline for nocturnal asthma

The purpose of this research work was to develop and evaluate a chronotherapeutic based colon-targeted drug delivery system of theophylline (THEO) exploiting pH-enzyme sensitive property for the prevention of episodic attack of asthma in early morning. Guar gum microspheres of theophylline were prepared by emulsification technique. Coating of microspheres was performed using solvent evaporation method with pH sensitive Eudragit(?) polymers. The particle size and surface morphology, entrapment efficiency and degree of swelling of microspheres were examined. The in vitro drug release studies were performed in pH progression medium and also in the presence of 2% rat caecal content. Theophylline was efficiently microencapsulated in guar gum microspheres at different polymer concentrations (1-4%). Fourier transform infrared (FT-IR)-spectroscopy confirmed the intermolecular interactions between guar gum and glutaraldehyde. Coating of guar gum microspheres by Eudragit led to decelerate the in vitro drug release of THEO. Moreover in vitro drug release studies also performed with 2% rat caecal content showed marked increment in drug release. The controlled release of THEO after a lag time was achieved with developed formulation for chronotherapeutic delivery. The pH dependent solubility behavior of Eudragit and gelling properties of guar gum are found to be responsible for delaying the release.     

Effect of temperature and pressure on growth and methane utilization by several methanotrophic cultures

Several methanotrophic microorganisms, i.e.,Methylococcus capsulatus (Bath),Methylomonas albus (BG-8),Methylosinus trichosporium OB3b, andMethylocystis parvus (OBBP), were evaluated for growth and methane utilization. The effect of temperature was examined in the range of 25 to 45°C for growth and methane utilization. The temperature variations (25–35°C) had minimal effect on growth ofM. albus and M. parvus. Methane consumption varied at different temperatures with a maximum of 0.67 mol%/h and 0.53 mol%/h. at 30 and 35°C, respectively, forM. albus and M. parvus. The growth and methane consumption was slower forM. trichosporium OB3b as a maximum methane consumption of 0.07 mol%/h was obtained at 25°C and growth was inhibited at 35°C.M. capsulatus grew the best at 37°C and growth was affected at higher temperature of 45°C. Of the different cultures examined,M. albus andM. capsulatus grew the best and were further evaluated for the effect of pressure in the range of 10–50 psi. The results obtained usingM. albus demonstrated an enhancement in methane consumption rate by fourfold and final cell concentration by 40% at a pressure of 20 psi by injecting a methane/oxygen mixture, however further increase in the pressure up to 50 psi inhibited the growth. The inhibition was not seen with nitrogen incorporated mixture of oxygen and methane, which suggest that the high partial pressure of methane and/or oxygen are inhibitory for the growth ofM. albus. M. capsulatus was more sensitive to pressure as evidenced by inhibition at the relatively low pressure of 10 psi     

Phosphorylation and Thiophosphorylation of 2-Substituted Benzoxazoles and Their Biological Activities

Novel organophosphorus compounds have been conveniently prepared using 2-(2′-hydroxynapthyl)benzoxazole and 2-(2′-aminophenyl)benzoxazole as starting materials. Phosphorylation and thiophosphorylation was performed using different molar ratio (1:1, 1:2 and 1:3) of phosphorus oxychloride/thiophosphoryl chloride and substituted benzoxazole. The toxicity of newly synthesized phosphorylated/thiophosphorylated compounds was tested on Aspergillus niger and Fusarium oxysporium. All were found antifungal agents. Plausible structures have been proposed on the basis of IR, ¹ H NMR, ³¹ P NMR spectral studies.