Effect of nuclear structure on the single particle β− transitions in deformed nuclei

In the framework of the Nilsson model the calculations of the so called shape factor for the first forbidden ^– transitions 5/2^{+ 241}Pu 5/2^{– 241}Am and 7/2^{+ 177}Lu 7/2^{– 177}Hf are carried out. The dependence on the Nilsson potential parameters is studied. It turns out that for the transitions considered the calculated shape factor depends linearly on the electron energy and its slope is 10^–3 per 20 keV. This can affect the analysis of electron spectra if the endpoint energy is sufficiently large.     

Nuclear structure effect in internal conversion of the 166 kev hinderedM1 transition in139La

The internal conversion coefficients were calculated for the 165.853 keV 5/2⁺7/2⁺ hindered transition in ₅₇ ¹³⁹ La using the new computer program NICC for conversion coefficients of all atomic shells. The algorithm employed in this code is described. The analysis of precise experimental data yielded the nuclear penetration parameter=4.2±0.8. This value was found to be in accord with theoretical estimates and to correspond to the Nilsson deformation parameter=–0.056±0004 of the¹³⁹La nucleus. Using the Nilsson wave functions for above the mixing ratio ² = N(E2)/N(M1) was determined to be less than 8.10^–5, which supports the assumption of a pureM1 multipolarity of this transition.Presented at the 26th All-Union Conference on Nuclear Spectroscopy and Nuclear Structure (February 1976, Baku, USSR).We are obliged to Dr. B. N.Subba Rao for the communication of his value for the investigated transition.     

Nuclear structure and chemical effects in internal conversion of the 35 keVM1+E2 transition in125Te

The relative conversion line intensities of the 35 keV transition in¹²⁵Te were measured using the 50 cm π√2 iron-yoke magnetic spectrometer. The transition was proved to be ofM1+(8.7±1.5)×10^?4 E2 multipolarity, the magnetic component being affected by the nuclear structure with λ=2.4±1.4. The conversion intensity ratio,0/N ₁ , was determined to be 0.115+0.005 for both Ag¹²⁵ I and Cu¹²⁵ I sources. It is in accordance with previous measurements for the Zn^125m Te and Pb^125m Te sources and differs from those for the^125mTeO₂ and Na₂H ₄ ^125m TeO₆ ones. The conversion coefficients were calculated for 32 configurations of the valence shell of free tellurium atom and ions and were compared with the experimental results.     

Offline and online capillary electrophoresis enzyme assays of β-N-acetylhexosaminidase

Enzyme assays of β-N-acetylhexosaminidase from Aspergillus oryzae using capillary electrophoresis in the offline and online setup have been developed. The pH value and concentration of the borate-based background electrolyte were optimized in order to achieve baseline separation of N,N′,N″-triacetylchitotriose, N,N′-diacetylchitobiose, and N-acetyl-d-glucosamine. The optimized method using 25 mM tetraborate buffer, pH 10.0, was evaluated in terms of repeatability, limits of detection, quantification, and linearity. The method was successfully applied to the offline enzyme assay of β-N-acetylhexosaminidase, which was demonstrated by monitoring the hydrolysis of N,N′,N″-triacetylchitotriose. The presented method was also utilized to study the pH dependence of enzyme activity. An online assay with N,N′-diacetylchitobiose as a substrate was developed using the Transverse Diffusion of Laminar Flow Profiles model to optimize the injection sequence and in-capillary mixing of substrate and enzyme plugs. The experimental results were in good agreement with predictions of the model. The online assay was successfully used to observe the inhibition effect of N,N′-dimethylformamide on the activity of β-N-acetylhexosaminidase with nanoliter volumes of reagents used per run and a high degree of automation. After adjustment of background electrolyte pH, an online assay with N,N′,N″-triacetylchitotriose as a substrate was also performed.

Improved energies for the 5.2 keV M1 and 42.0 keV M2 nuclear transitions in 83Rb

The European Physical Journal A - The low-energy electron spectrum following the decay of 83Sr was analysed at high instrumental resolution by an electrostatic spectrometer. Significantly improved...     

Determination of acid volatile sulphur in river sediments by ICP-OES coupled with purge and trap method

The developed and tested method is based on the acid volatile sulphur (AVS) releasing from a sample of sediment by acidification with hydrochloric acid and sequential absorption of released hydrogen sulphide into the absorption solution of sodium hydroxide. Total sulphur absorbed in the absorption solution is subsequently determined by inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The method was tested using both model and real samples of the river sediment. Obtained results were compared with the results of iodometric determination as the method routinely used for the AVS determination. In case of using ICP-OES with purge and trap, there is no spectral interference of calcium; therefore for the determination of sulphur, it is possible to use atomic emission line of sulphur S I 180.7 nm. The tested method provides the results comparable with the iodometric method within the range of tested concentrations. The detection limit (LOD) of this method is 0.09 mg· S^2? ? L^?1 in the absorption solution which corresponds to 0.23 mg S^2?·kg^?1 in a sediment. Value of LOD is comparable with the iodometric determination.     

Linear polystyrene-stabilized PdO nanoparticle-catalyzed Mizoroki-Heck reactions in water

Linear polystyrene-stabilized PdO nanoparticles (PS-PdONPs) were prepared by thermal decomposition of Pd(OAc)(2) in the presence of polystyrene. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated the production of PdO nanoparticles. The loading of palladium was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). PS-PdONPs exhibited high catalytic activity for Mizoroki-Heck reactions under air in water and could be recycled without loss of activity.     

Qualitative calorimetry of some sulphur rich glasses

By DS calorimetry of Ge₃₀S₇₀(a), Ge₂₀S₈₀(b), Ge₂₀Sb_2.5S_77.5(c) and Ge₂₀Bi₅S₇₅(d) crystalline sulphur was identified in (b), (c) and (d) glasses, respectively. It means that these compositions are heterogeneous. Thus the application of the Phillips topological model for estimation of the “ideal” glassy composition in Ge_xS_1?x system seems to be open.