Stationary rotating string world models with a magnetic field

Following the techniques used by Letelier and Stachel some new physically relevant stationary solutions of string cosmology with magnetic field are presented. In these solutions, the flow vector of matter has non-zero rotation and the cosmological constant is taken to be non-zero. Previously known solutions are derived as particular cases from our class of solutions. Some string models with vanishing cosmological constant are also discussed.     

Catalysis of ascorbic acid oxidation with peroxynitrite by biomimetic Cu -complexes

Different mononuclear and dinuclear Cu complexes show high catalytic activity at concentrations 1-10 mM in the oxidation of ascorbic acid by peroxynitrite. Their activity is similar to the activity of Mn-porphyrin complexes and weakly depends on ligand environment, provided at least one free coordination site is available. The proposed reaction mechanism involves the intermediate formation of a copper-peroxynitrito complex, which reacts directly with ascorbic acid.     

()‐Tartaric acid

()‐Tartaric acid, C₄H₆O₆, crystallized from ethanol in space group P. The structure is characterized by five hydrogen bonds, including the formation of a centrosymmetric carbox­ylic acid dimer which forms infinite chains along the body diagonal. These chains form sheets via hydrogen bonding between α‐hydroxyl groups. The sheets are connected through a bifurcated hydrogen bond. Structural comparisons are made with homochiral (2R,3R)‐(+)‐tartaric acid.     

Optical observations of layer ordering in helial smectic A* liquid crystals

We report the first optical microscopic observation of characteristic textures and the associated layer ordering in a recently discovered, helical smectic A* phase on a multiple domain substrate. The experimental results are quite unusual but consistent with a mean-field model of the twisted grain boundary phase.     

Vibration analysis of laminated cross-ply oval cylindrical shells

Here, free vibrations and transient dynamic response analyses of laminated cross-ply oval cylindrical shells are carried out. The formulation is based on higher order theory that accounts for the transverse shear and the transverse normal deformations, and includes zig-zag variation in the in-plane displacements across the thickness of the multi-layered shells. The contributions of inertia effect due to in-plane and rotary motions, and the higher order function arising from the assumed displacement models are included. The governing equations obtained using Lagrangian equations of motion are solved through finite element approach. A detailed parametric study is conducted to bring out the influence of different shell geometry, ovality parameter, lay-up and loading environment on the vibration characteristics related to different modes of vibrations of oval shell.     

Calculation of the hadron spectrum in lattice QCD

We present Monte Carlo results for the hadron mass-spectrum in lattice SU(3) using the Wilson action and the quenched approximation. We show that on a 6³· 10 lattice at β=6.0, there exist long-lived metastable states of the gauge-field, characterized by the eigenvalues of Z(3) and associated with the first-order deconfining phase transition. The hadron masses are very different in these state if the quark paths that wind around the lattice are not removed. We demonstrate two methods which eliminate a significant fraction of such quark paths. The final results for hadron masses do not agree with the experimental values. We find that the π and ?, as well as the proton and the Δ are degenerate.     

The optimized separation of aromatic carboxylic acids by HPLC

The optimization of the separation of eight aromatic carboxylic acids, using Hypersil SAS and MOS reverse phase columns, with respect to eluent (methanol : water) composition, pH, and temperature, is described. Window diagram techniques are used and the pH of the aqueous buffer and elution temperature are shown to be more critical than eluent composition.     

A class of stationary rotating string cosmological models

We obtain a one parameter class of stationary rotating string cosmological models of which the well-known Gödel universe is a particular case. By suitably choosing the free parameter function, it is always possible to satisfy the energy conditions. The rotation of the model hinges on the cosmological constant which turns out to be negative. String-dust distribution in Gödel-type universes is also briefly discussed.     

On effectiveness of Morse and Lippincott potential functions forA andX states of MgH

Molecular properties like potential curve,r-centroids, dissociation energy for theA ²II-X ² Σ band system of MgH are studied using Morse and Lippincott functions. Calculations for potential curve and dissociation energy indicate that the Lippincott function is not very appropriate forA andX states of MgH.r-centroids calculated using graphical as well as numerical methods agree well with each other. A smooth relationship between wavelength andr-centroid is obtained. Based on the dissertation submitted to the South Gujarat University by GKP in partial fulfilment of M. Phil. degree, 1976.