Generation of low-temperature plasma by low-pressure arcs for synthesis of nitride coatings

Experiments were performed to study gas, metal, and mixed metal-gas plasmas. The plasmas were generated with the use of an arc evaporator and a gas-plasma source with a hot filament and hollow cathode that were operated independently or simultaneously. It has been revealed that the arc current of gas-plasma source affects the parameters of the metal-gas plasma and the element concentrations in the coatings. It has been demonstrated that the characteristics of the nitride coatings produced by plasma-assisted vacuum-arc deposition can be controlled by varying the parameters of the arc in the gas-plasma source

Synthesis and Hydrothermal Study of (Na,K)M2(PO4)3 (M = Ti, Zr, Hf) Solid Solutions

(Na,K)M2(PO4)3 (M = Ti, Zr, Hf) continuous solid solutions were synthesized by sol-gel and solidstate methods. Cation-exchange reactions in the NaM2(PO4)3–KM2(PO4)3–NaCl–KCl–H2O systems were studied at T = 723 – 973 K and p = 100–200 MPa. The concentration dependences of unit cell parameters of the studied phosphates were found. The sodium/potassium distribution coefficients in the phosphate-fluid systems were functions of the solid solution compositions, that is, the systems behave nonideally. The excess volumes and excess Gibbs functions of solid solutions mixing were fitted to thirdorder polynomials and described in terms of the Margules model. From the comparison of the results obtained Ti-, Zr-, and Hf-systems, we made the conclusion that the titanium phosphates show greater nonideality than zirconium and hafnium phosphates and lower thermodynamic stability to decomposition to double phosphates at high pressures and temperatures

МОДЕЛИРОВАНИЕ ПРИВОДА РАМЫ ПМА-1

The article describes the features and methods of mathematical simulation of hydraulic displacement gear of lengthwise cyclic displacement of the movable frame of straightening and tamping machine PMA-1 with the use as displacement of twin rods hydraulic cylinder device. The authors describe the main results of simulation and analyze them. They also put forward some recommendations concerning tuning of control system of the driving gear. The general conclusion is that twin rods cylinder simplifies the controlled hydraulic processes as compared to other existing systems and removes the problem of additional feedback.Авторами отражены основные  особенности и методика  имитационного математического  моделирования гидрообъемного  привода продольного циклического  перемещения подвижной рамы выправочно-подбивочной машины ПМА-1 с использованием в качестве  рабочего органа перемещения двухштокового гидравлического цилиндра. Приведены основные  результаты моделирования, проведен их анализ, а также даны рекомендации по настройке  системы управления приводом. Общий вывод при этом сводится к тому, что по сравнению  с существующими конструкциями  применение двухштокового цилиндра  заметно упрощает регулируемые гидравлические процессы, снимает проблему введения дополнительных  обратных связей

Пневмонии и их диагностика в стационарах Санкт-Петербурга по данным аутопсий

15 633 records of postmortem examinations of the St.-Petersburg municipal bureaus were analyzed for 1993— 1995. All kinds of pneumonia were revealed in 38% of cases. The frequency of primary and secondary pneumonia including pneumonia as a manifestation of chronic bronchitis exacerbation, was analyzed. The low quality of pneumonia diagnosis in non-specialized hospitals as well as its reasons are shown.Проанализированы 15 633 протокола патологоанатомических вскрытий городского бюро Санкт-Петербурга за 1993—1995 гг. Выявлено, что все виды пневмоний обнаружены в 38% наблюдений. Проанализирована частота первичных и вторичных пневмоний, а также пневмоний, явившихся проявлением обострения хронического бронхита. Показан низкий уровень диагностики пневмоний в стационарах общего профиля и его причины

Gold-plated Mode of CP-Violation in Decays of B_c Meson from QCD Sum Rules

The model-independent method based on the triangle ideology is implemented to extract the CKM-matrix angle gamma in the decays of doubly heavy long-lived meson B_c. We analyze a color structure of diagrams and conditions to reconstruct two reference-triangles by tagging the flavor and CP eigenstates of D^0 meson in the fixed exclusive channels. The characteristic branching ratios are evaluated in the framework of QCD sum rules.Comment: 11 pages, RevTeX4 file, 4 eps-figure

Research results of makeup influence on semi-synthetic motor oils thermal oxidation stability

During the running motor oil quality determination oil makeup has a big influence on thermal oxidation mechanism, however there is a problem of insufficient examination of makeup influence on motor oil conditions. Main goal of these researches is to determine how makeup effects on motor oil’s thermal oxidation stability. For the research Lube oil Lukoil Super 10W-40 SG/CD has been chosen. Thermal oxidation stability results assessment was conducted basing on obtained values of: light stream absorption criteria, volatility and thermal oxidation stability criteria in cases of research with makeup and without it. There was offered a criteria of makeup influence on thermal oxidation stability values, which identified as change of light stream absorption rate proportion and thermal oxidation stability criteria in case of research with and without makeup. Research methodology involved motor oil test on thermostating device consequently under temperatures 180, 170 and 160 °С with makeup and without it in condition when quantity of makeup oil corresponded to vaporized oil quantity. Research results demonstrated that oil makeup decrease thermal oxidation intensity on the whole temperature test rate