XANES and EXAFS study of some metal-metalloid glasses

XANES and EXAFS techniques are proving very popular in the study of local environment in disordered systems. Results of such studies in a large number of metal (Fe, Co, Ni, etc)-metalloid (B, Si, C, etc) glasses are reported. Experiments were done with synchrotron radiation as well as an x-ray tube. The values of bond lengths and co-ordination numbers computed from one-electron single scattering Fourier transform method turn out substantially smaller. The values of bondlength determined from the other EXAFS calculation method and the multiple-scattering computation scheme show good agreement. Importance of choice of suitable reference materials for analysis of data is emphasized. The experimental work was done at EXAFS 5.1 Station at Daresbury Laboratory, U.K.     

Infra-red spectroscopic studies of solvent-solute interactions in parachlorophenol and thiophenol with tertiary amides

Hydrogen bonding of O-H ... O=C and S-H ... O=C type has been studied in parachlorophenol and thiophenol with dimethyl and diphenyl amides and from the equilibrium constants, variation in the integrated absorption intensities and frequency shifts, the strength of the interaction in these complexes is discussed. In these systems diphenyl amides form weaker H-bond compared to that with the corresponding dimethyl amides. In dimethyl amides, the interaction is in the order dimethyl acetamide > dimethyl propionamide > dimethyl formamide. Similar results are obtained with diphenyl amides.     

Volume compression of CuCl to 7 GPa

The unit cell volume of CuCl as a function of pressure has been measured up to 7 GPa (giga Pascals). The compression behaviour is quite normal. The analysis of the compression data gives 40·3±1·5 GPa for the bulk modulus of the zinc blende phase. The zinc blende phase transforms to a tetragonal phase at 5·5 GPa, the volume change associated with the transformation being 12%. A comparison of the bulk modulus of CuCl with those of CuBr and CuI indicates that an anomaly exists in this group.     

Gauge-Invariant Chiral Schwinger Model with Faddeevian Regularization: Stueckelberg Term, Operator Solution, and Hamiltonian and BRST Formulations

A chiral Schwinger model with the Faddeevian regularization à la Mitra is studied in one-space one-time dimension in the conventional form of dynamics (on the hyperplanes x ⁰ = constant) called the Instant-Form (IF) dynamics. The original IF theory is seen to be gauge-noninvariant (GNI). Corresponding to this GNI model, a gauge-invariant (GI) theory is constructed through the so-called Stueckelberg term. The operator solution and the Hamiltonian and BRST formulations of the resulting GI theory, obtained by the inclusion of the Stueckelberg term in the action of the original GNI theory, are then investigated with some specific gauge choices. The physical contents of the original GNI theory are also recovered from the newly constructed GI theory under a special gauge.     

Hamiltonian and BRST Formulations of a Two-Dimensional Abelian Higgs Model in the Broken Symmetry Phase

The Hamiltonian and BRST formulations of an Abelian Higgs model involvingthe electromagnetic vector gauge field are investigated in one-space, one-timedimension in the broken symmetry phase, where the phase (x, t) of the complexmatter field (x, t) carries the charge degree of freedom of the complex matterfield and is, in fact, akin to the Goldstone boson.     

Facile new industrial process for synthesis of teneligliptin through new intermediates and its optimization with control of impurities

Research on Chemical Intermediates - The present study is related to a commercially practicable new synthetic process for production of teneligliptin hydrobromide hydrate (1), a dipeptidyl...