Structural disorder model for amorphous semiconductor; Absorption edge in hydrogenated a-Si

The effect of structural disorder on the width of the Urbach edge E₀, the energy band gap E_G and dE_G/dT in hydrogenated a-Si has been analysed in terms of a simple structural disorder model and has been found to be in satisfactory agreement with the experimental data.     

Polyhydroxylated homoazepanes and 1-deoxy-homonojirimycin analogues: Synthesis and glycosidase inhibition study

The Johnson-Claisen rearrangement of D-gluco and L-ido-derived allylic orthoesters afforded gamma,delta-unsaturated ester that on ester reduction, epoxidation, regioselective oxirane opening by sodium azide and hydrogenation led to sugar amino alcohols--immediate precursors for 1-deoxy-homonojirimycin 3a,b, and polyhydroxylated homoazepanes 4a,b. Our synthetic approach and glycosidase inhibitory activity is reported.     

Intermediate Energy Coulomb Excitation of Neutron-Rich Nuclei

We reinvestigate the collective effects of the retardation as well as the bending on the Coulomb excitation cross sections and also on the B（E2） strengths of some neutron-rich isotopes using the intermediate energy Coulomb excitation theory. It is found that the B（E2） strengths extracted from the experimental Coulomb excitation cross section data get suppressed approximately by 6%. Furthermore, the obtained B（E2） strengths in the energy range 30-100 MeV/A are found to be in better agreement with the corresponding values known from other sources, than those obtained by using the recoil-corrected relativistic Coulomb excitation theory.     

Desorption to delamination: dynamics of detachment in a colloidal thin film

Colloidal thin films of varying rigidity detaching from a substrate under an electric field induced stress are studied by video microscopy. For soft films, the process of detachment shows single-particle dynamics, analogous to desorption. For rigid films, a collective delamination spanning hundreds of particles occurs. A competition among the rigidity of the film, the interaction with the substrate, and the external stress leads to a correlation length over which the film delaminates at a critical stress. The phenomenon is described as a dynamical transition in a disordered elastic medium.     

The Schur multiplier of central product of groups

Let G be a central product of two groups H and K. We study second cohomology group of G, having coefficients in a divisible abelian group D with trivial G-action, in terms of the second cohomology groups of certain quotients of H and K. In particular, for $D={\mathbb{C}}^{?}$, some of our results provide a refinement of results from Wiegold (1971) [10] and Eckmann et al. (1973) [2].     

The quadratic-phase Fourier wavelet transform

In this paper, we define the quadratic-phase Fourier wavelet transform (QPFWT) and discuss its basic properties including convolution for QPFWT. Further, inversion formula and the Parseval relation of QPFWT are also discussed. Continuity of QPFWT on some function spaces are studied. Moreover, some applications of quadratic-phase Fourier transform (QPFT) to solve the boundary value problems of generalized partial differential equations.     

Optical behaviour of swift heavy ions irradiated poly(vinyl alcohol) films

Polyvinyl alcohol films were irradiated to 90 MeV O ⁶⁺ and 150 MeV Si ¹⁴⁺ ions at fluence ranging from 10¹⁰ to 10¹² ions/cm². The observed changes in optical energy gap of this polymer have been investigated and results are tried to be explained in terms of energy transferred by the incident ions. It has been noticed that the value of optical energy gap decreases with increasing energy loss during the ion–polymer interaction process.     

Defect centres and thermoluminescence in SrS:Bi phosphor

Thermoluminescence (TL) and electron spin resonance studies have been carried out on SrS:Bi phosphor. The TL glow curve is broad and indicates a dominant peak at 120 ^°C with two additional peaks, not clearly resolved, appearing as shoulders at around 180 and 250 ^°C. Two defect centres are observed at room temperature. One of them is characterized by an isotropic g-value 2.0034 and is assigned to an F⁺ centre. Step annealing measurements indicate a possible association between the F⁺ centre and the three TL peaks.