Deen Dayal Upadhyay Gorakhpur University

About: Deen Dayal Upadhyay Gorakhpur University is a education organization based out in Gorakhpur, Uttar Pradesh, India. It is known for research contribution in the topics: Thermal decomposition & Lymnaea acuminata. The organization has 1032 authors who have published 1591 publications receiving 21734 citations. The organization is also known as: Gorakhpur University.

Anisotropic Bianchi Type-II Massive String Cosmological Models with Time-Decaying Λ Term and Thermodynamic Parameters

Abstract: The present paper envisages a spatially homogeneous and anisotropic Bianchi II massive string cosmological models with time-decaying Λ term in general relativity. By using the variation law of Hubble’s parameter, the Einstein’s field equations have been solved for two general cases. The first case involving a power law solution describes the dynamics of universe from big bang to present epoch while the second case admit an exponential solution seems reasonable to project dynamics of future universe. We observed that massive strings dominate in early universe and eventually disappear at late time, which is consistent with the current astronomical observations. It has been found that the cosmological constant (Λ) is a decreasing function of time and it approaches to small positive value at sufficiently large time. The thermodynamic properties of anisotropic Bianchi II universe are studied and also the absolute temperature and entropy distribution are given explicitly. The relations between thermodynamic parameters and cosmological constant Λ has been established. Physical behavior of the derived model is elaborated in detail.

Molecular Interaction between Naphthalene and 2,4-Dinitrophenol in Solid State

Abstract: Kinetics of the solid-state reaction between naphthalene and 2,4-dinitrophenol have been studied at different temperatures (30–50°C), and it was found that naphthalene diffuses toward 2,4-dinitrophenol. When naphthalene enters into the crystal lattice of 2,4-dinitrophenol, a 1:1 addition compound is formed with an orthorhombic crystal lattice, and the unit cell volume is much higher than the sum of the unit cell volumes of the components. As a result of this, cracks are formed and the reaction goes to completion. Computer calculations have shown that charge-transfer interaction occurs between the two components during the reaction.

Structure of an ABC transporter solute-binding protein specific for the amino sugars glucosamine and galactosamine.

Abstract: The uptake of exogenous solutes by prokaryotes is mediated by transport systems embedded in the plasma membrane. In many cases, a solute-binding protein (SBP) is utilized to bind ligands with high affinity and deliver them to the membrane-bound components responsible for translocation into the cytoplasm. In the present study, Avi_5305, an Agrobacterium vitis SBP belonging to Pfam13407, was screened by differential scanning fluorimetry (DSF) and found to be stabilized by d-glucosamine and d-galactosamine. Avi_5305 is the first protein from Pfam13407 shown to be specific for amino sugars, and co-crystallization resulted in structures of Avi_5305 bound to d-glucosamine and d-galactosamine. Typical of Pfam13407, Avi_5305 consists of two α/β domains linked through a hinge region, with the ligand-binding site located in a cleft between the two domains. Comparisons with Escherichia coli ribose-binding protein suggest that a cation–π interaction with Tyr168 provides the specificity for d-glucosamine/d-galactosamine over d-glucose/d-galactose.

Analysis of pair interaction in a bipolar mesogen 4-(4-hydroxylbutyloxy)-4′-cyano-biphenyl: A comparative study based on semiempirical and DFT methods

Abstract: Structure of 4-(4-hydroxylbutyloxy)-4′-cyano-biphenyl (H4CBP) molecule has been optimized using density functional B3LYP with 6-31G (d) basis set taking crystallographic geometry as input. Using the optimized geometry, electronic structure of the H4CBP molecule has been evaluated on the basis of semiempirical methods and DFT calculations. Intermolecular interaction energy between a pair of H4CBP molecules has been evaluated by using Rayleigh–Schrodinger perturbation theory modified with multicentered multipole expansion method for the electrostatic part while dispersion and repulsion terms have been calculated using Kitaigorodskii formula. The results obtained through semiempirical and DFT calculations have been compared for various interacting conditions, viz.: (a) stacking, (b) in-plane, and (c) terminal interactions. A comparative analysis of the results has been carried out with a view to examine suitability of different methods to study molecular aggregations in moderately large organic systems. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011

Fractal growth and morphological transitions during crystallization of amino acids in presence of glucose

Abstract: Two-dimensional fractal and spherulitic patterns have been developed on microslides during the crystallization of amino acids in the absence and presence of glucose and agar-agar from their aqueous solutions. Lysine crystallized uniformly in the form of ringed spherulite, but in the presence of glucose it crystallized in the form of branched morphologies. Dependence of glucose concentrations on morphology of glutamic acid has also been studied. Morphology of glutamic acid was found to depend on glucose concentration. Due to interaction between glutamic acid and glucose, following morphological transitions were observed depending on glucose concentrations: spherulite → ringed spherulite → Fractal geometry → DLA-like pattern (D ≈ 1.725). Growth morphologies were characterized by measuring the location of bands (xn) as a function of band number n obeying the relation xn = mn + c, where m and n are slope and intercept respectively, and calculating the fractal dimension at different conditions. Influence of agar-agar on the morphology was also studied. Results showed that branched morphologies were more dominant in the presence of agar-agar. In case of glycine, irregular growth patterns were observed. Interaction between amino acids and glucose was studied by viscosity measurements. It has been inferred that interaction is maximum in case of interaction of glucose with glutamic acid (acidic) and minimum in case of glycine (neutral).