IR spectra of certain methyl -d-glucopyranoside nitrates

Conclusions A study has been made of the IR spectra of methyl--D-glucopyranoside 2-and 3-nitrates, methyl--D-glucopyranoside 6-nitrate, and methyl-4-O-methyl--D-glucopyranoside 2,3-and 3,6-dinitrates and 2,3,6-trinitrate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1763–1765, August, 1987.     

High-order accurate bicompact schemes for solving the multidimensional inhomogeneous transport equation and their efficient parallel implementation

The method of lines is used to obtain semidiscrete equations for a bicompact scheme in operator form for the inhomogeneous linear transport equation in two and three dimensions. In each spatial direction, the scheme has a two-point stencil, on which the spatial derivatives are approximated to fourth-order accuracy due to expanding the list of unknown grid functions. This order of accuracy is preserved on an arbitrary nonuniform grid. The equations of the method of lines are integrated in time using diagonally implicit multistage Runge–Kutta methods of the third up fifth orders of accuracy. Test computations on refined meshes are presented. It is shown that the high-order accurate bicompact schemes can be efficiently parallelized on multicore and multiprocessor computers.     

A study of 192Ir production conditions at an electron accelerator

This communication deals with the conditions of ¹⁹²Ir isotope production under a nonreactor technology via the ¹⁹³Ir(γ, n)¹⁹²Ir reaction. It can be carried out by irradiation of a target from natural iridium with the high-energy X-ray of an electron accelerator. The possibility of increasing the photonuclear yield of the target isotope by addition of the ¹⁹¹Ir(n, γ)¹⁹²Ir reaction induced by moderated photoneutrons has been shown. For this, an X-ray converter and a target were placed inside a neutron moderator. Data on the ¹⁹²Ir and admixture yields for the techniques using the moderator and without it have been obtained by computer simulation and experimentally.     

The features of electron dose distributions in circular objects: Comparison of Monte Carlo calculation predictions with dosimetry

The features of electron dose field formation in the multi-layer circular objects are related with its surface irregularity such as convexity, concavity and roundness of inner and outer layers. The simulation of dose distributions in multi-layer tubes irradiated with a scanned electron beam (EB) was carried out by Monte Carlo (MC) method with utilization of the software ModeCEB. The effects of mutual influence on dose field formation in contacting multi-layers tubes irradiated with EB were MC simulated and measured with a film dosimetry. An experimental validation of the obtained simulation predictions for dose distributions in multi-layer tubes irradiated with 10 MeV electrons was performed on radiation facility with linear electron accelerator LAE 13/9, INCT, Warsaw. Comparison of MC simulation results with a film dosimetry is discussed in the report.     

Theoretical Optimization of Neutron and Physical Characteristics of a Multiplying Pulsed Neutron Source Based on a Proton Accelerator

Physics of Particles and Nuclei Letters - The neutron source operating at the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research (JINR, Dubna, Russia), based on an IBR-2M...     

Selective oxidation of hydrocarbons into synthesis gas at short contact times: Design of monolith catalysts and main process parameters

This review summarizes the main achievements of the Boreskov Institute of Catalysis (Siberian Division, Russian Academy of Sciences) in the development of efficient and stable monolith catalysts for selective oxidation of hydrocarbons into synthesis gas at short contact times. Research in this field has included (1) design of new types of active component based on metal oxides, (2) design of new types of monolith support and development of supporting procedures for active components, and (3) optimization of process parameters for different types of fuel (natural gas, isooctane, and gasoline) and oxidant (air oxygen, including its mixtures with water and carbon dioxide), including the start-up regime. Design of active components (platinum, nickel, or their combination) supported on fluorite-like solid solutions based on cerium dioxide and rare-earth (samarium, gadolinium, and praseodymium) or zirconium cations has been aimed at separating hydrocarbon activation (on metal sites) and oxidation (on the support) and conjugating the separated steps of hydrocarbon oxidation at the metal-oxide interface. Optimization of oxygen mobility in the support lattice by varying the nature and concentration of doping cation along with optimization of hydrocarbon activation on supported metal clusters allow hydrocarbons to be completely converted into synthesis gas by selective oxidation or dry or steam reforming at contact times of a few milliseconds, ruling out undesirable carbon build-up on the catalyst surface. The development of new types of monolith support has targeted the enhancement of thermal shock resistance, including testing of supports based on thermally stable metal foils and composites (cermets). The main steps of the production of these supports have been refined, including unique technologies of blast dusting and hydrothermal treatment. The electric conductivity of these systems allows a quick startup of selective oxidation to be performed by passing electric current, and their thermal conductivity minimizes the temperature gradient arising from heat transfer in the bed. Procedures for loading monolith supports with active components have been developed, including impregnation, washcoating, or encapsulation in cermet matrices. The catalysts produced show a high efficiency and an operational stability adequate to the above tasks in the selective oxidation and steam-air autothermal reforming of natural gas (including processes under pressure), isooctane, and gasoline into synthesis gas.__________Translated from Kinetika i Kataliz, Vol. 46, No. 2, 2005, pp. 243–268.Original Russian Text Copyright © 2005 by Sadykov, Pavlova, Bunina, Alikina, Tikhov, Kuznetsova, Frolova, Lukashevich, Snegurenko, Sazonova, Kazantseva, Dyatlova, Usoltsev, Zolotarskii, Bobrova, Kuzmin, Gogin, Vostrikov, Potapova, Muzykantov, Paukshtis, Burgina, Rogov, Sobyanin, Parmon.     

Determination of diffusion and activity coefficients in the gallium-indium system by the contact-melting method

The concentration profile in the liquid layer and the rate of contact melting are derived. These characteristics are found as functions of the self-diffusion coefficients D_A and D_B of the components and of the activity coefficients in the regular-solution approximation. Comparison of these equations with the experimental concentration profile and with the experimental contact-melting rate allows calculation of D_A, D_B, and the factork in the expression for Inf in the Ga-In system.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 53–57, April, 1971.