Catalytic properties of composite amorphous carbon-platinum layers in fuel cells

Catalytic properties of composite amorphous carbon-platinum layers produced by magnetron cosputtering have been studied. The layers were characterized by electron microscopy, IR spectroscopy, ellipsometry, gravimetry, and spectrophotometric chemical analysis. The catalytic activity of the layers was studied in an air-hydrogen fuel cell by measuring its load and power characteristics.     

Testing procedure and results of tests performed on a VVÉR-1000 fuel assembly fragment in a MIR channel for a maximum anticipated accident

The testing procedure and the results of tests performed on a 19-element fragment of a VVéR-1000 fuel assembly in the channel of a MIR reactor under conditions of the second and third stage of a maximum anticipated accident are presented. The state arising in the reactor core with an uncompensated leak arising in the first cooling loop when a pipeline with the maximum diameter bursts (large leak) is studied in the experiment. In each case study, superheated steam cools the top part of the fuel elements. The main goal of the tests is to obtain data on the distortion of fuel-element cladding under tensile stresses. __________ Translated from Atomnaya énergiya, Vol. 103, No. 5, pp. 286–291, November, 2007.     

Low-temperature nonequilibrium-ionization inert-gas plasma and MHD-generators

The main results of theoretical and experimental studies of low-temperature magnetized (>1) nonequilibrium-ionization plasma properties are reported. Such plasma is found to be more stable as compared to the equilibrium-ionization one. Development of ionization instability in such plasma results in the formation of striae oriented perpendicularly to the plasma velocity and not decreasing its effective electric conductivity. Thus, the possibility exists of designing an effective MHD-generator operating with the inert-gas plasma without admixtures in closed-cycle installations.Reported at the VIIIth All-Union Conference on Physics of Low-Temperature Plasma (Minsk, September 1991).St. Petersburg Branch of the All-Union Research Institute for Electromechanical Engineering. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 63, No. 2, pp. 161–164, August, 1992.     

Free-standing luminescent layers of porous silicon

Free-standing layers of porous silicon with a thickness ranging from 50 to 200 μm have been fabricated using an electrolyte composed of HF and acetic acid. Chemical aspects of the etching process associated with the evolution of gases that favor detachment of layers from substrates are considered. The layers exhibit stable photoluminescence in the visible spectral region observed from both of their sides.     

A piezoelectric sensor for pressure measurements behind a shock front

The construction and measuring circuit of a pressure pickup designed for measurements in ionized gases behind a shock front are described. Calibration results are given, along with oscillograms of the pressure up to the arrival of the rarefaction wave.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 21, No. 1, pp. 168–171, July, 1971.     

Investigation of the Serviceability of the Heat Shield of the Orbital Aircraft “Buran” under the Conditions of Radiant Heating on Solar Plants

We have investigated the serviceability of the heatinsulating tiles of the orbital aircraft Buran under radiant heating on an SGU7 solar plant with a mirror concentrator 5 m in diameter. Cycles of aerodynamic heating with a duration of 20 min were simulated. For the total number of cycles for different materials from 20 to 85, the efficiency and serviceability of TZMKtype materials with different coats have been corroborated. The results obtained agree with the test data obtained on gasdynamic (power consumption 1 MW) and radiation (250 kW) test beds, which enables such tests to be recommended for use at preliminary stages in powersaving and ecologically harmless solar furnaces.     

Catalytic properties of chemically deposited platinum in fuel cells

A new method for depositing platinum onto a macroporous silicon electrode is described that allows the catalytic properties of platinum in fuel cells to be significantly improved. This effect is achieved by means of the chemical deposition of platinum on silicon at reduced temperatures.