Analysis of two neutron (proton) transfer reaction data in the Zr-region

The spectroscopic amplitudes, form factors, angular distributions and total cross-sections for two nucleon transfer reactions in Zr-region in the zero range distorted wave Born approximation are calculated using consistent set of shell model wave functions. A single normalisation factor gives a good fit to all the two neutron transfer reaction data whereas the corresponding fit for the two-proton transfer reaction data is less satisfactory.     

Magnetization transfer and T2 quantitation in normal appearing cortical gray matter and white matter adjacent to focal abnormality in patients with traumatic brain injury

Traumatic brain injury (TBI) is one of the commonest causes of morbidity and mortality in the developed countries with posttraumatic epilepsy and functional disability being its major sequelae. The purpose of this study was to test the hypothesis whether the normal appearing adjacent gray and white matter regions on T2 and T1 weighted magnetization transfer (MT) weighted images show any abnormality on quantitative imaging in patients with TBI. A total of 51 patients with TBI and 10 normal subjects were included in this study. There were significant differences in T2 and MT ratio values of T2 weighted and T1 weighted MT normal appearing gray matter regions adjacent to focal image abnormality compared to normal gray matter regions in the normal individuals as corresponding contralateral regions of the TBI patient's group (p < 0.05). However the adjoining normal appearing white matter quantitative values did not show any significant change compared to the corresponding contralateral normal white matter values. We conclude that quantitative T2 and MT ratio values provide additional abnormality in patients with TBI that is not discernable on conventional T2 weighted and T1 weighted MT imaging especially in gray matter. This additional information may be of value in overall management of these patients with TBI.     

Inhomogeneous ferromagnetism and unconventional charge dynamics in disordered double exchange magnets

We solve the double exchange model in the presence of arbitrary substitutional disorder by using a self-consistently generated effective Hamiltonian for the spin degrees of freedom. The magnetic properties are studied through classical Monte Carlo while the effective exchange, D(ij), is calculated by solving the disordered fermion problem, and renormalized self-consistently with increasing temperature. We present results on the conductivity, magnetoresistance, optical response, and "real space" structure of the inhomogeneous ferromagnetic state, and compare our results with charge dynamics in disordered La1-xSrxMnO3. The large sizes, O(10(3)), accessible within our method allows a complete, controlled calculation on the disordered strongly interacting problem.     

An ab initio study of ground state, electronic and thermodynamical properties of GaP and Ga2P

In the present paper, we report an ab initio calculation of the ground state, electronic and thermodynamical properties like constant volume lattice specific heat, vibrational energy, internal energy, and entropy for GaP and Ga₂P is presented. These properties are obtained after calculating the phonon spectrum over the entire Brillouin zone. The calculations were performed using the ABINIT program package, which is based on density functional theory (DFT) method and the use of pseudopotentials and plane wave expansion. Difference in the ground state properties such as electronic structure and thermodynamical properties are discussed. The thermodynamical properties follow the expected trend. There is a good agreement between present theoretical and limited available experimental data in the case of ground state such as lattice constant and bulk modulus and electronic properties. With the increase of Ga atoms in the unit cell the semiconducting nature of Ga₂P turns to metallic. There is a noticeable difference in the thermodynamical properties in the case of both gallium compounds.     

Development and validation of a highly sensitive LC‐MS/MS‐ESI method for the determination of bicalutamide in mouse plasma: application to a pharmacokinetic study

A highly sensitive, rapid assay method has been developed and validated for the estimation of bicalutamide in mouse plasma using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative‐ion mode. The assay procedure involves extraction of bicalutamide and tolbutamide (internal standard, IS) from mouse plasma with a simple protein precipitation method. Chromatographic separation was achieved using an isocratic mobile phase (0.2% formic acid:acetonitrile, 35:65, v/v) at a flow rate of 0.5 mL/min on an Atlantis dC₁₈ column (maintained at 40 ± 1°C) with a total run time of 3.0 min. The MS/MS ion transitions monitored were m/z 428.9 → 254.7 for bicalutamide and m/z 269.0 → 169.6 for IS. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 1.04 ng/mL and the linearity range extended from 1.04 to 1877 ng/mL. The intra‐ and inter‐day precisions were in the ranges of 0.49–4.68 and 2.62–4.15, respectively. Copyright © 2012 John Wiley & Sons, Ltd.     

Analytical approximation solutions for 3-D optical waveguides: Review

The rectangular dielectric waveguide is the most commonly used structure in integrated optics, especially in semi-conductor diode lasers. Demands for new applications such as high-speed data backplanes in integrated electronics, waveguide filters, optical multiplexers and optical switches are driving technology toward better materials and processing techniques for planar waveguide structures. The infinite slab and circular waveguides that we know are not practical for use on a substrate because the slab waveguide has no lateral confinement and the circular fiber is not compatible with the planar processing technology being used to make planar structures. The rectangular waveguide is the natural structure. In this review, we have discussed several analytical methods for analyzing the mode structure of rectangular structures, beginning with a wave analysis based on the pioneering work of Marcatili. We study three basic techniques with examples to compare their performance levels. These are the analytical approach developed by Marcatili, the perturbation techniques, which improve on the analytical solutions and the effective index method with examples. T Srinivas received the B.Sc. (Hon.) degree from Nehru Science College, Hydrabad and M.E. (Int.) and Ph.D. dgrees from the Indian Institute of Science, Bangalore, India. He was a Postdoctoral Research Fellow at Toyohashi University of Technology, Japan from 1992 to 1996. He is currently an Associate Professor with the Department of Electrical Communication Engineering, Indian Institute of Science. His areas of interests are optical communication networks, integrated optics, micro-opto-electrical-mechanical systems (MOEMS) and fiberoptic sensors     

Tree-level breaking of SU(2)×U(1) in general SUGRA theories

It is shown that SU(2)×U(1) can be broken at the tree level, without the occurrence of global potential minima that break U(1)_e.m., in supergravity models that are more general than those proposed by Nilles, Srednicki and Wyler. The study comprises an analysis of models with a general soft supersymmetry-breaking structure as well as those of the Hall-Lykken-Weinberg type.     

1-Decanethiol, a new reagent for the odorless deprotection of aryl methyl ethers

1-Decanethiol has been found to be an excellent reagent for the deprotection of aryl methyl ethers. This newly developed protocol afforded the corresponding phenols in good to excellent yields. A clear advantage of 1-decanethiol over the more commonly used thiols is the easy extraction of both the deprotecting reagent and the reaction byproduct into the aqueous phase, which allows an essentially odorless work-up.     

Rapidity distribution as a probe for elliptical flow at intermediate energies

The interplay between spectator and participant matter in heavy-ion collisions is investigated within the isospin-dependent quantum molecular dynamics (IQMD) model in terms of the rapidity distribution of light charged particles. The effect of different types and sizes of rapidity distributions is studied in elliptical flow. The elliptical-flow patterns show the important role of nearby spectator matter on the participant zone. This role is further explained on the basis of the passing time of the spectator and the expansion time of the participant zone. The transition from in-plane to out-of-plane emission is observed only when the mid-rapidity region is included into the rapidity bin. Otherwise no transition occurs. The transition energy is found to be highly sensitive to the size of the rapidity bin, while it is only weakly dependent on the type of the rapidity distribution. These theoretical findings are found to be in agreement with experimental results.     

Improved electrical parameters of vacuum annealed Ni/4H-SiC (0 0 0 1) Schottky barrier diode

The reported work has been focused on the improvement of electrical parameters of Schottky diode using vacuum annealing at mild temperature in Ar gas ambient. Nickel Schottky barrier diodes were fabricated on 50 μm epitaxial layer of n-type 4H-SiC (0 0 0 1) substrate. The values of leakage current, Schottky barrier height (?_B), ideality factor (η) and density of interface states (N_SS) were obtained from experimentally measured current–voltage (I–V) and capacitance–voltage (C–V) characteristics before and after vacuum annealing treatment. The data revealed that ?_B, η and reverse leakage current for the as-processed diodes are 1.25 eV, 1.6 and 1.2 nA (at ?100 V), respectively, while for vacuum annealed diodes these parameters are 1.36 eV, 1.3 and 900 pA (at same reverse voltage). Improved characteristics have been resulted under the influence of vacuum annealing because of lesser number of minority carrier generation due to incessant reduction of number of available discrete energy levels in the bandgap of 4H-SiC substrate and lesser number of interface states density at Ni/4H-SiC (0 0 0 1) interface.