The polynomial representation of the type An−1 rational Cherednik algebra in characteristic p | n

We study the polynomial representation of the rational Cherednik algebra of type A_n?1 with generic parameter in characteristic p for p | n. We give explicit formulas for generators for the maximal proper graded submodule, show that they cut out a complete intersection, and thus compute the Hilbert series of the irreducible quotient. Our methods are motivated by taking characteristic p analogues of existing characteristic 0 results.     

Synthesis, Structural, Thermal and Photo-Physical Properties of Triazine Based NLO Material

Three novel triazine based organic chromophores with D-π-A (Donor-π system- Acceptor) push-pull type have been synthesized from 2, 4-diamino-6-phenyl-1,3,5-triazine as a starting material. Structures of all the three compounds have been confirmed by UV-Visible absorption, FT-IR, NMR and Mass spectral techniques. Their photo physical and thermal properties have been investigated. Among the three compounds, 6-phenyl-2,4-((4-amino-1,5-dimethyl-2-phenyl pyrazol-3-ylidene)(4-nitro benzylidene))-diamino-1, 3, 5-triazine (NDP) showed positive solvatochromism compared to the other two compounds. The absorption in the UV region of these three compounds were found to be less dependent on solvent polarities, whereas the red shifted fluorescence was strongly dependent on solvent polarities. The TGA data indicates that all the three compounds are stable up to 160 °C. Measurement of non linear optical properties showed that there is an increased second harmonic generation (SHG) efficiency with respect to urea indicating the existence of high molecular nonlinearity in NDP.     

Synthesis,Characterization, Catalytic and Antibacterial Activity of Two Series of Dinuclear Ruthenium Sulphoxide Complexes Using 5,5¢‐Methylenebis(pyridine) as Bis‐chelating Bridging Ligand

The reaction of a new heterocyclic bidentate N containing spacer, (ligand) 5,5′‐methylenebis(pyridine) with ruthenium sulphoxide precursors resulted, dinuclear complexes. We herein report three formulations; [{cis,fac‐RuCl₂(so)₃}₂(μ‐mbp)].3so; [{trans,mer‐RuCl₂(so)₃₂}₂(μ‐mbp)].3so and [{trans‐RuCl₄(so)}₂(μ‐mbp)]^2?[X]₂⁺; where so = dimethyl‐sulfoxide/tetramethylenesulfoxide; mbp = 5,5′‐methylenebis(pyridine) and [X]⁺ = [(dmso)₂H]⁺, Na⁺ or [(tmso)H]⁺. These complexes were characterized on the basis of elemental analyses, molar conductance measurement, magnetic susceptibility, FT‐IR, ¹H‐NMR, ¹³C{¹H}‐NMR, electronic spectroscopy and FAB‐Mass spectrometry. Catalytic activity of these complexes has been investigated in hydrolysis of benzonitrile. All the complexes exhibit good antibacterial activity against gram‐negative bacteria Escherichia coli in comparison to Chloramphenicol.     

Kaluza-Klein Universe with Cosmic Strings and Bulk Viscosity in a Scalar-Tensor Theory of Gravitation

A five dimensional Kaluza-Klein space-time is considered in the frame work of a scalar-tensor theory proposed by Saez and Ballester (Phys. Lett. A 113, 467, 1985) when the source for energy momentum tensor is a bulk viscous fluid containing one dimensional strings. A barotropic equation of state for the pressure and density is assumed to get a determinate solution of the field equations. Also the bulk viscous pressure is assumed to be proportional to the energy density. The physical and kinematical properties of the model are also discussed.     

Phase transitions and electrical characteristics of tungsten substituted barium titanate

In the present work, phase transitions and electrical characteristics of tungsten substituted barium titanate are reported. Structural analysis of the prepared samples was carried out to confirm the formation of the compounds in proper phase. Scanning electron micrographs of the compounds have been used to investigate the grain morphology of the material. The dielectric properties of the samples have been studied as a function of temperature and frequency. The variation of dielectric constant (ε_r) with temperature shows a diffuse kind of ferro–paraelectric phase transition. The diffusitivity of the phase transitions has been calculated. Complex impedance spectroscopy analysis was carried out to investigate the electrical characteristics of the specimen.     

Self-assembled monolayers on electrode surfaces: a probe for redox kinetics

The formation and characterization of self-assembled monolayers of organosulfur compounds like alkanethiols and dialkyl (di)sulfides on metal surfaces such as gold are areas of current research interest. The presence of an aromatic ring in a thiol molecule can enhance the binding between Au and the thiol, resulting in the formation of compact and impervious self-assembled monolayers. The formation of a monolayer of 2-mercaptobenzothiazole (MBT), containing an aromatic group with a fused thiazole ring but no long alkyl chain, is achieved on a gold electrode surface. Voltammetric investigations of ferro/ferricyanide and ferrous/ferric redox systems carried out on this Au|MBT electrode are reported. Further, the possibility of using such an Au|MBT electrode to distinguish between inner and outer sphere electron transfer reactions is indicated. Received: 2 January 1998 / Accepted: 14 May 1998     

Polymer-based bilayer interfaces for electrochemical rectification

In this paper, the electrochemical current rectification phenomenon exhibited at an electrochemical interface constituted by a glassy carbon electrode covered with a bilayer of polymer films is discussed. The authors have shown that Methylene Blue (MB) redox species can be confined to a very thin insulating polymer film formed from orthophenylene diamine. The poly(opd) film exhibited excellent blocking properties to redox molecules in solution. On the other hand, the insulating poly(opd) film trapped with MB could mediate electron transfer between the redox molecules in solution and the electrode. Further, a second polymeric layer (Nafion film) trapped with ferrocene redox species was formed as the outer layer over the inner poly (opd) film containing MB. This bilayer-modified electrode, due to the significant difference in the redox potentials of the MB and ferrocene species immobilized in the inner and outer layers, respectively, exhibits unidirectional current flow and the results of the voltammetric investigations on the modified electrodes are described in this communication.     

Hydrostatic pressure on optical absorption and refractive index changes of a shallow hydrogenic impurity in a GaAs/GaAlAs quantum wire

The effect of hydrostatic pressure on the binding energy of a hydrogenic impurity in a GaAs/GaAlAs quantum wire is discussed. Calculations have been performed using Bessel functions as an orthonormal basis within a single band effective mass approximation. Pressure induced photoionization cross section of the hydrogenic impurity is investigated. The total optical absorption and the refractive index changes as a function of normalized photon energy between the ground and the first excited state in the presence of pressure are analysed. The optical absorption coefficients and the refractive index changes strongly depend on the incident optical intensity and the pressure.