Electron transfer reactions of V(IV) with Cl(I), Br(I) and I(I). A kinetic study

A kinetic study on the oxidation of V(IV) by chloramine-T (CAT) at pH 6.85 by N-bromo succinimide (NBS) in aqueous acetic acid–perchloric acid media and by N-iodo succinimide (NIS) in aqueous perchloric acid medium has been carried out. In all the systems studied the order with respect to the oxidant is unity. NBS and CAT oxidation reactions exhibited Michaelis–Menten type kinetics, and the NIS study indicated unit dependence on [substrate]. Independence on acidity has been observed in the case of CAT and NBS reactions, but NIS reactions exhibited inverse unit dependence on [acid]. Novel solvent influences have been noticed in the case of CAT reactions, but with NIS and NBS reactions retardation in the rate has been observed with an increase in the percentage of acetic acid. Plausible mechanisms consistent with the results have been postulated, and suitable rate laws in consonance with the postulated mechanisms have been derived.     

The effect of exchange in autoionization processes

The effect of including distortion (with and without exchange) in the wavefunction for the continuum electron while calculating the probability of autoionization of 2s ^{2 1} S. 2s2p ^1,3 P, 2p ^{2 1} D and 2p ^{2 1} S states of He and Li⁺ has been studied.     

Study of the induction period of the thermal decomposition of irradiated barium bromate

The influence of -irradiation upto 200 Mrad on the thermal decomposition of barium bromate has been studied in the temperature range 553–583 K. The fraction decomposed //-time /t/ characteristics for irradiated barium bromate exhibit stages, viz. initial gas and decay stages. Irradiation shortens the induction period conforming to the relation I=C₁–C₂ lg dose. All experimental data for induction period are tested against the values obtained from the theoretical calculations by making use of this induction-period dose relation. The topochemical aspect of the validity of the above relation has been considered to be due to the linear growth of nuclei during irradiation and subsequent exponential growth during the induction period.     

An O(k2 + kh2 + h4) arithmetic average discretization for the solution of 1‐D nonlinear parabolic equations

This article develops a new two‐level three‐point implicit finite difference scheme of order 2 in time and 4 in space based on arithmetic average discretization for the solution of nonlinear parabolic equation ε u_xx = f(x, t, u, u_x, u_t), 0 < x < 1, t > 0 subject to appropriate initial and Dirichlet boundary conditions, where ε > 0 is a small positive constant. We also propose a new explicit difference scheme of order 2 in time and 4 in space for the estimates of (?u/?x). The main objective is the proposed formulas are directly applicable to both singular and nonsingular problems. We do not require any fictitious points outside the solution region and any special technique to handle the singular problems. Stability analysis of a model problem is discussed. Numerical results are provided to validate the usefulness of the proposed formulas. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007     

The effects of magnetic field oscillations on the boundary layer flow past a magnetized plate

The effects of harmonic oscillations of amplitude in the magnitude of the magnetic field on the steady boundary layer flowO( ²) due to a uniform free stream past a semi-infinite magnetized flat plate have been discussed. It is observed that the magnetic field distribution does not affect the surface current distribution.

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Zusammenfassung Die Effekte einer harmonischen Schwingung der Amplitude im Betrag des Magnetfeldes auf die Grenzschicht entlang einer halb-unendlichen magnetischen Platte in gleichförmiger Strömung wird diskutiert. Man findet, daß die magnetische Feldverteilung die Oberflächenströme nicht beeinflußt.

     

Which rational numbers are binding numbers?

The concept of the binding number of a graph was introduced by Woodall in 1973. in this paper we characterize the set F_n of all pairs (a, b) of integers such that there is a graph G with n vertices and binding number a/b that has a realizing set of b vertices.     

Kinetics of base hydrolysis ofO-bonded pentaammineglycinatocobalt(III) and pentaammine-β-alaninatocobalt(III) ions

Transition Metal Chemistry - The kinetics and mechanism of the base hydrolysis ofO-bonded pentaammineglycinatocobalt(III) and pentaammine-β-alaninatocobalt(III) ions have been studied...     

On the quantum theory of stimulated Raman scattering

A fully quantum mechanical density-matrix formalism of stimulated Raman scattering is presented. The effects of atomic motion, non-linear parameters and loss are included. The equations are solved to fourth-order in atom-field coupling constant. The steady-state Stokes-photon distribution is studied. A study of an approximate time-dependent case is also discussed. The results show that only a fraction of incident pump photons can be converted to Stokes photons.