Study of short-lived silver isotopes with a laser ion source

The continuum part of the⁶Li (a,a)⁶Li (1.47–2.47 MeV) scattering data at E_a=50 MeV are extracted in two discretized bins. Coupled-channel calculations are carried out coupling the 1⁺ ground state of⁶Li with both the resonant, 3⁺ ₁ state, and two non-resonant continuum states. The discretized continuum of the⁶Li (p,p)⁶Li (1.75–3.25 MeV) scattering data at E_p=65 MeV are also analysed on the same footing. In both the cases the effect of coupling is found to be minimal.     

Effect of epitaxial growth on the formation of the cobalt catalysts of the Fischer-Tropsch synthesis

Mixed oxides Co_xAl_yO₄ with different Al/Co ratios applied as supports for the catalysts of the Fischer-Tropsch synthesis were prepared using the solid-state chemical reaction. The Co_xAl_yO₄ supports were prepared by modifying gibbsite with various cobalt salts (acetate, nitrate, and basic carbonate). The use of basic cobalt carbonate gives the Co(20%)/Co_xAl_yO₄ catalyst, which provides an increased yield of hydrocarbons C₅₊ and a decreased methane content compared to the impregnation catalyst Co(30%)/Al₂O₃. The introduction of small amounts of rhenium additives makes it possible to enhance the yield of hydrocarbons C₅₊ (179 g m⁻³) and also to increase the selectivity with respect to the C₅–C₁₈ fraction. The introduction of basic cobalt carbonate into the support, most likely, creates favorable conditions for the epitaxial growth of the precursor of the active phase. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1856–1860, September, 2007.     

Studying the Dynamics of Hybrid X-Pinches

Since the first experiments with hybrid X-pinches (HXP), it has been shown that a short wire between two conical tungsten electrodes produces the same radiation as a standard X-pinch. Since HXP has a simple construction, it is commonly used in many laboratories instead of standard pinches. Although details of the HXP dynamics remain poorly studied, the main factors governing HXP formation are investigated experimentally in this work. It is shown that the process of the electrode plasma formation is one of the main factors that lead to single hot spot bursts. Experimental results allow the fitting of HXP parameters and determination of the size of the source of X-ray radiation. It is also shown the radiation of HXP can be used as a source for point projection radiography in the wavelength range of soft to hard X-rays. Such sources can be also used for absorption spectroscopy and even electron beams.     

INVESTIGATION OF ELASTIC PROPERTIES OF A MATERIAL OBTAINED BY MEANS OF COLD GAS DYNAMIC SPRAYING WITH LASER PROCESSING

Journal of Applied Mechanics and Technical Physics - A heterogeneous material obtained by means of cold gas dynamic spraying with subsequent laser processing is studied. The reasons for reduction...     

Relationships of the synthesis of silicon dioxide nanoparticles in low-temperature plasma created in helium and argon at atmospheric pressure

Low-temperature plasma-chemical synthesis of silicon dioxide nanoparticles from tetraethoxysilane, performed at atmospheric pressure in a reactor with flat perforated electrodes coated with an insulating layer, was studied. The use of such electrodes allows reaching stable sustaining of RF discharge (α-mode) with helium and argon used as plasma-forming gases. The relationships of the synthesis of silicon dioxide nanoparticles from tetraethoxysilane in helium and argon plasma differ insignificantly. Most probably, nanoparticles with the size in the interval 100–150 nm are formed in the zone of the discharge sustaining, but, as the particles are transported with the gas flow beyond the plasma zone, they undergo agglomeration. An increase in the nanoparticle size to 100–150 nm, observed when using perforated electrodes with an insulating coating, is most probably due to an increase in the residence time of the reaction gas medium in the zone of the discharge sustaining.