Neodymium-calcium cobaltates: Features of synthesis,phase composition,activity and selectivity in partial methane oxidation

Nd_{2 ? x} Ca _x CoO_{4 ± δ}-based materials demonstrated high effectiveness in partial methane oxidation into synthesis gas with almost 100% selectivity. It has been determined that Nd_{2 ? x} Ca _x CoO_{4 ± δ} materials synthesized via the solid-state or cryochemical methods are single-phase in the range of 0.6 ≤ x ≤ 1 at a synthesis temperatures of 1100–1200°C. Synthesis at t ≤ 1100°C allows to prepare solid solutions in the range of 0.9 < x < 1.05.     

Kinetic description of rapeseed oil conversion into aromatic hydrocarbons on promoted MFI zeolite

An approach to the construction of a kinetic model for the reactions of rapeseed oil hydroconversion to aromatic hydrocarbons has been proposed, which is based on analysis of experimental data obtained using a MFI zeolite promoted with zinc and chromium ions. An empirical mathematical model describing the dynamic behavior of the main products of the decomposition reaction of rapeseed oil as a model feedstock has been developed. It has been shown that an increase in the space time and temperature in the examined range of reaction conditions increase the yield of aromatic hydrocarbons. The influence of hydrogen pressure on the yield of aromatics is nonmonotonic in character, passing through a maximum, with the optimum yield being in the middle of the hydrogen pressure range of 10–20 atm.     

Dynamic contact of a spherical indenter and a prestressed orthotropic Uflyand�CMindlin plate

In this paper, the dynamic contact of a spherical indenter and an orthotropic plate is investigated. The plate possesses curvilinear anisotropy and is subject to a prestressing longitudinal force together with two moments. The dynamic behavior of the target is described by wave equations that take into account the transverse shear and rotary inertia of the cross sections and allow for modeling the process of propagation of elastic waves after the impact. The asymptotic method of the series expansion of unknown quantities in terms of a Legendre polynomial and Laurent series nearby the desirable point is used as a method of solution. In this work, the dynamic characteristics of the interaction are determined, and the influence of the preloaded target on these dynamic characteristics is investigated. The results of the analysis are represented in form of analytical expressions and graphical dependencies. The influence of the prestressed plate on the dynamic buckling and the contact force at the interaction point is studied.     

Effect of pressure on the phase composition of Li(Na)/W/Mn/SiO2 composites and their catalytic activity for oxidative coupling of methane

The phase state of Li/W/Mn/SiO₂ and Na/W/Mn/SiO₂ composites after exposure to high pressures (2.5 GPa at 500°C) and subsequent exploitation in oxidative coupling of methane (OCM) was studied. Comparison of the catalytic activity of the composites before and after exposure to high pressures indicates that the formation of Li(Na)/W/Mn/SiO₂ composites catalytically active for OCM is significantly influenced by high pressures.     

Partial oxidation of methane to synthesis gas: Novel catalysts based on neodymium–calcium cobaltate–nickelate complex oxides

Novel catalysts based on neodymium–calcium cobaltate–nickelate complex oxides for the partial oxidation of methane to synthesis gas have been synthesized and studied using catalyst precursors with the general formula NdCaCo_1–xNi _x O _n (x = 0, 0.2, 0.4, 0.6, 0.8, 1) prepared by the solid state synthesis method. It has been shown that the synthesized samples form a series of solid solutions with a K₂NiF₄ structure at x ≤ 0.8 or a rhombically distorted K₂NiF₄ structure at x = 1. The products of conversion of the resulting precursors in a methane–oxygen mixture at high temperatures have shown high methane conversions and synthesis gas yields. The highest values of these parameters have been achieved in the presence of catalysts synthesized by the reduction of NdCaCo_0.4Ni_0.6O _n and NdCaNiO _n precursors. The complete replacement of cobalt with nickel has led to an increase in the synthesis gas yield; however, it has been found that the resulting catalyst is prone to carbonization. It has been determined that an optimum nickel to cobalt ratio in the catalyst composition provides the formation of a carbonization-resistant catalyst.     

Clever Nuclear Fuel Technology

The purpose of given article-consideration of the basic features of modern manufacturing of nuclear fuel which would confirm fact, that the manufacturer does everything that its production would respond not only to requirements of the consumer, but also to its expected inquiries, and would correspond to intended purposes of fuel. It was defined main tendencies and features of modern technology, especially in nuclear fuel production, on base of meeting discussions, themes of journal articles on nuclear subject. They are correspond with practice of JSC NCCP （Novosibirsk Chemical Concentrates Plant） and listed in the paper. In result of it number of base features of any advanced technology, not only nuclear, described here with examples from NCCP＇s practice. Of course, there is no certain list of all attributes of modern manufacturing as there is no limit to its perfection. These categories are forming by current needs of the market, but listed ones must be.     

On The Theory of Isotope-effect in the d-wave Superconductors

The isotope-effect in a two-dimensional model of the d-wave phonon-exchange superconductor is studied. It is shown that the mean-field critical temperature, the Berezinskii–Kosterlitz–Thouless critical temperature and the superconducting gap strongly depend on the phonon frequency only in some range of the model parameters. These dependencies have different from the BCS theory forms. A qualitative comparison of the results with experimental data on some high-temperature superconductors is made. In particular, it is shown that the isotope-effect is significant in the case of strong electron–phonon coupling, when the phonon frequency is small compared to the free electron bandwidth.     

Recombinant vaccinia virus expressing Japanese encephalitis virus protein E

Contrasts are drawn between dental care based on fee-for-service and managed care financial arrangements. The advantages of fee-for-service include (for the profession) slow acceptance of managed care in dentistry compared to medicine; (for society and the patient) more community service, higher technical quality of work, and stimulation of innovations; and (for the individual dentist) the strong dentist-patient bond as well as professionalism.