Experimental study of injector based on the spark source with titanium cathode saturated with hydrogen

The results of experimental study of short-pulse proton injector for various variants of construction of pulse spark ion source are considered. The experimental results of study of regimes of both ignition and discharge support within the source with stabilized pulse feeding (~10 μs, 5 Hz). Of special concern the increasing of the cathode electrode lifetime. The results ofmeasurements ofboth absolute and partial (in spices) density ofion beam are presented.Представлені результати іспитів короткоімпульсного інжектора протонів для різних варіантів виконання конструкції імпульсного іскрового джерела. Приводяться експериментальні результати відпрацьовування оптимальних режимів порушення і підтримки розряду в джерелі зі стабілізованим імпульсним живлення (~ 10 мкс, 5 Гц).Представлены результаты испытаний короткоимпульсного инжектора протонов для различных вариантов выполне- ния конструкции импульсного искрового источника. Приводятся экспериментальные результаты отработки оптимальных режимов возбуждения и поддержания разряда в источнике со стабилизированным импульсным питанием (~ 10 мкс, 5 Гц)

Mechanical properties of microwave sintered Si3N4-based ceramics

The mechanical properties and microstructure formation processes in Si3N4+3% AI2O3+5% Y2O3(Yb2O3) ceramic compacts sintered under microwave heating (MWH) and under traditional heating (TH) were investigated. The initial ceramic materials were powder blends of silicon nitride with oxides. The mean powder particle sizes were 0.5-1.0 mim. The content of alfa-phase in the Si3N4 powder was more than 95 %. The samples were sintered at 1800BC in nitrogen at normal pressure, the heating rate in all experiments was 60BC/min. The Vickers hardness (HV), fracture toughness (K1C) and bending strength (on) were determined. The microstructures of fracture surfaces of samples were studied by SEM. Quantitative microstructure analysis was carried out. It was shown that the values of HV and Kic of ceramic samples sintered under MWH at 1800BC rose steadily with the sintering time. This caused an increase in density, which reached maximum as fast as after 30 min of the MWH sintering; the mass loss at that time amounted to 3-4 %. The porosity of sintered samples with an addition of yttria was less than 1 %, that of ytterbia was greater, 2.4 %. For similar values of relative density, the hardness and fracture toughness of ceramic samples produced under MWH were higher as compared with those of samples sintered under TH. The microstructure of samples had the form of elongated grains in a matrix of polyhedral grains of the beta-Si3N4 phase. Measurements showed the mean size of grains in samples produced by MWH to be greater that in samples produced by TH. A larger number of elongated grains were formed. It was concluded that for sintering under MWH of Si3N4-based ceramics the growth of elongated beta-Si3N4 grains and formation of a "reinforced" microstructure were promoted and thereby improved the mechanical properties of such ceramics

Information model of the structure of the heat and power system of pulp and paper production and a systematic approach to its improvement

The stages of the system analysis of an industrial energy system with a complex structure are considered by the example of pulp and paper production. The software of the structural and thermodynamic stages of the analysis is presented. The results of thermodynamic calculations of the elements of the energy system by the optimal sequence are given. A variant of the system modernization using a heat pump is presented

Anisotropic cosmological models in terms of Raychaudhuri and Wheeler-DeWitt equations

Classical anisotropic cosmological models are described in terms of the Raychaudhuri equation for a perfect fluid. Quantum ones are considered using the Wheeler-DeWitt equation. The Universe birth probability has been calculated for a flat model with dust and de Sitter vacuum. © 2009 Pleiades Publishing, Ltd

Anisotropic cosmological models in terms of Raychaudhuri and Wheeler-DeWitt equations

Classical anisotropic cosmological models are described in terms of the Raychaudhuri equation for a perfect fluid. Quantum ones are considered using the Wheeler-DeWitt equation. The Universe birth probability has been calculated for a flat model with dust and de Sitter vacuum. © 2009 Pleiades Publishing, Ltd