Rotational excitation of H2 and N2 molecules by electron impact

The rotational excitation of the H₂ and N₂ molecules from (J→J+2,J=0) and (J→J+2,J=1) states by electron impact is studied, in the framework of the regional-plane-wave approximation. The empirical cut-off parameterρ, involved in these calculations, is varied to give the best fit to the experimental data of Srivastava and co-workers.     

Diffuse reflectance spectrum of some Nd3+ aromatic acids

The Nd³⁺ complexes of β-diketonates have been studied earlier, ^1–3 but those of aromatic acids have not been studied in detail. The present communication reports the study of two of such complexes.     

Conservation of channel spin in transfer reactions

The conservation of channel spin implying that the spin of the initial bound pair coupled to that of the initial free particle should result in the same channel spin as the spin of the final bound pair coupled to the spin of the final free particle, follows as a consequence of three-body theory of transfer reactions with the assumption of separability of two-bodyt-matrix. To test the validity of this principle we look at the experimental data on stripping reactions on even-even nuclei. We find that although reactions to channels not conforming to channel spin conservation are not altogether ruled out, the cross-sections of reactions violating channel spin conservation are much smaller than those conforming to channel spin conservation.     

Limited volume thin film deposition on geometrically complicated substrates

In this paper we report a study on the elastic scattering of electrons by lithium and sodium atoms in the presence of circularly polarized resonant laser field within the framework of the two-state rotating wave approximation. The effect of laser on projectile electrons is described by Volkov states. The frequency of the laser field is chosen to match with the 2s–3p (3s–3p) transition frequency in lithium (sodium) atoms. The total and differential elastic cross sections with single photon exchange are calculated for intermediate energies (50–150 eV) and laser intensity (10⁷–10¹¹ W cm^-2). An erratum to this article can be found online at http://dx.doi.org/. An erratum to this article can be found at     

Direct photometric determination of cobalt(II) with N-methylaminothioformyl-N'-phenylhydroxylamine

N-Methylaminothioformyl-N'-phenylhydroxylamine forms a 1:2 (metal:ligand) greenish yellow complex with cobalt(II). This complex has maximum absorption at 470 nm with a molar absorptivity of 1.65 x 10(4) 1.mole(-1).cm(-1). Beer's law is obeyed over the concentration range 6 x 10(-6)-6 x 10(-5)M. The effect of diverse ions is described.     

STUDIES ON THE EXTRACTION OF SELENIUM AND TELLURIUM FROM COPPER ELECTROLYTIC SLIMES BY SUBLIMATION IN VACUUM

Abstract

Anode slimes obtained from the electrolytic refining of copper contain selenium and tellurium in the form of selenides and tellurides of metals, e.g., copper and silver. The slimes were treated with sulfur under vacuum; selenides and tellurides decomposed to give selenium and tellurium in metallic form which condensed on a cooler zone. Various parameters studied were temperature, time, sulfur addition, briquetting pressure, and fineness of sulfur added. The X-ray diffraction studies carried out on treated and then on untreated slime proved the reaction of sulfur with selenide and telluride of copper to give copper sulfide, selenium, and tellurium. Sulfurization at around 475°C for 60 min gives optimum recoveries.     

High-Throughput GC-FID Method for the Determination of Residual Solvents in Early-Phase Drug Discovery Samples

Chromatographia - In drug discovery environment, determination of residual solvents is indispensable and requires rapid analysis covering a maximum number of commonly used solvents especially with...     

Synthesis and structural characterisation of a novel tris-methylene bridged compound (NO) 4Fe2 Se(μ-CH2)3

The tris-methylene bridged compound (NO)₄Fe₂Se(μ-CH₂)₃ has been isolated. It has been characterised by IR and ¹H, ¹³C, and ⁷⁷Se NMR spectroscopy. Its structure has been determined by single-crystal X-ray diffraction methods. The structure consists of a heavy atom triangle consisting of one Se and two Fe atoms. The Fe-Fe and the two Fe-Se edges are bridged by methylene groups.     

Adsorptive stripping voltammetric determination of chromium in gallium

The electroanalytical chemistry of trace metals has progressed strongly with the development of cathodic stripping voltammetry (CSV) preceded by adsorption collection of organic metal complexes. A sensitive method for the determination of trace amount of chromium in gallium is described. Gallium is dissolved in sodium hydroxide containing hydrogen peroxide. The method is based on the catalytic activity of nitrate ions on the reduction of Cr(III)TTHA (triethylene tetramine-N,N,N',N',N',N'-hexaacetic acid) complex. The sensitivity of this method is further improved by adsorption preconcentration of Cr(III)TTHA complex at a hanging mercury drop electrode (HMDE). The Cr(III) formed at the electrode surface by the reduction of Cr(VI), which is present in the bulk solution, is immediately complexed by TTHA. The adsorbed complex is then reduced at a peak potential of - 1.26 V, and the peak height of Cr(III) reduction is measured. The determination limit was restricted by the amount of chromium present in the reagent blank solution. The method is suitable for the determination of chromium at level as low as 0.2 mug g(-1) (with about 50 mg of sample) and a relative standard deviation of 15%.