Radiation damping in an anharmonic oscillator

The effect of radiation damping in an anharmonic oscillator has been calculated using the technique of Kryloff and Bogolituboff. It is found that the intensity distribution of the emitted spectral line is asymmetric about its intensity maximum. The index of asymmetry agree with the experimental data on x-rayK _{a 1,2}lines.     

The phase structure of SU(n)/Zn × SU(n)/Zn spin systems in two dimensions

The ground state of the two-dimensional chiral adjoint spin systems is studied using the most general nearest-neighbor ansatz for the eigenfunctions of the transfer matrix. The parameters entering this ansatz are determined variationally and the resulting phase structure is in close agreement with the results of Monte Carlo simulations.     

Equilibrium studies on binary and ternary Cu(II) complexes containing ethylenediaminediacetic acid and a series of O?-O?, N-O? and N-N donor ligands

The formation constants for ternary metal complexes (MLA) where L = ethylenediaminediacetic acid (EDDA), M = Cu(II) and A = glycine, alanine, leucine, serine, threonine, methionine, proline, phenylalanine, tryptophan, histidine, aspartic acid, ethylenediamine, histamine, 2,2′-bipyridyl, 1,10-phenanthroline, imidazole, oxalic acid, malonic acid, pyrocatechol and nitropyrocatechol have been investigated by pH-metric method at 35°C andμ = 0.2 M (KNO₃). With respect to the donor atoms on ligand A, the stabilities of the ternary complexes increase in the order O⁻-O⁻ < N-O⁻≈N-N. The stabilities of the various ternary complexes decrease with the increasing number of carboxylate groups on the ligand in the order ethylenediamine (EN) < ethylenediamine monoacetic acid (EDMA) < EDDA. Various factors influencing the formation and stabilities of ternary complexes are discussed.     

On the details of the variational investigations of SU(2) euclidean lattice gauge theories

We present in this article various details of the application of Rayleigh-Ritz variational techniques with one-parameter ansätze to SU(2) euclidean lattice gauge theories in three and four dimensions.     

Effective lagrangians with U(1) axial anomaly (I)

The effective lagrangian which includes the U(1) axial anomaly is discussed. The lagrangian describes the interaction of physical mesons of spin-zero and spin-one fields and an effective Kogut-Susskind four-vector anomaly field. The interactions are constructed which satisfy all the anomalous Ward identities for vertices which accommodate arbitrary amounts of chiral and SU(3) symmetry breaking consistent with U(3) × U(3) current algebra.     

Synthesis of 3,5-disubstituted 1,3,4-oxadiazole-2-thiones as potential fungicidal agents

Sixteen new 3-arylaminomethyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole-2-thione and six 3-alkyl aryl alkyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole-2-thiones were synthesised and characterised by their sharp melting points, elemental analysis, ir, ¹H nmr and mass spectra. These substituted oxadiazolethiones were screened for their fungitoxic properties. Most of the compounds showed toxicity against two test organisms, Curvularia verruciformis and Alternaria tenuis. The degree of inhibition ranged from 38--100% for a few compounds.     

Passage from a pure state description to the microcanonical ensemble description for closed quantum systems

We have addressed the foundational issue of how a macroscopic quantum system starting off as a pure state tends towards a mixed state described by the microcanonical ensemble. The earlier works of von Neumann and Van Kampen are also reviewed. A simple criterion is given as to when the above mentioned passage can take place.     

Non-linear axisymmetric transient analysis of an orthotropic thin circular plate with an elastically restrained edge

Results are presented for the geometrically non-linear axisymmetric transient elastic stress and deflection responses of a cylindrically orthotropic thin circular plate with an elastically restrained edge, including both rotational and in-plane displacements. In the analysis the dynamic analogue of the von Kárman governing differential equations in terms of the normal displacement w and the stress function ψ are employed. The displacement w and stress function ψ are expanded in finite power series. The orthogonal point collocation method in the space domain and the Newmark-β scheme in the time domain are used. Four types of uniformly distributed transient loadings have been considered: step function, sinusoidal and N-shaped pulses, and exponentially decaying loads. The influence of the orthotropic parameter β and the elastic rotational and in-plane edge restraint parameters (K_b, K_i) on the large amplitude response has been investigated. The effect of a prescribed in-plane displacement on the non-linear transient response has also been studied.     

The Lyapunov matrix equation SA+A1S=S1B1BS

The matrix equation $\text{SA+A}{}^1\text{S=S}{}^1\text{B}{}^1\text{BS}$ is studied, under the assumption that (A, B¹) is controllable, but allowing nonhermitian S. An inequality is given relating the dimensions of the eigenspaces of A and of the null space of S. In particular, if B has rank 1 and S is nonsingular, then S is hermitian, and the inertias of A and S are equal. Other inertial results are obtained, the role of the controllability of (A¹, B¹S¹) is studied, and a class of D-stable matrices is determined.