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A method for calculating the nonstationary thermal interaction between a viscous gas flow and a solid body is presented. The method consists in direct joint integration over time of the equations of gas dynamics of a multicomponent mixture and the heat equation in a solid on multi-block unstructured meshes. To calculate one time step, the system of governing equations is split into hyperbolic and parabolic subsystems. The numerical method provides approximation of the matching condition (continuity of temperature and the normal component of the heat flux) at the interface between gas and solid and is efficient for nonstationary calculations. The comparison with the analytical solution of the model problem of the interaction of a high-speed flow and a heated plate confirm the efficiency of the method. [ABSTRACT FROM AUTHOR]

An approach to numerical simulation of three-dimensional electrical and thermal fields in high-temperature superconductors is described. In such a semiconductor, the phenomena of superconductivity are observed at high temperatures above the temperature of liquid nitrogen. The absence of a generally accepted theory of superconductivity leads to the need to study physical processes in semiconductor structures using mathematical simulations. The main attention is paid to the calculation of temperature and electric current distributions in large-size mesas with a self-heating effect. An efficient algorithm for solving the equations describing these distributions is constructed. The basis of the algorithm is an adaptive multigrid method on structured Cartesian grids. The adaptability is based on the Chebyshev iterative method for constructing the smoothing procedures at each grid level and for solving the coarsest grid equations. The adaptive technique allows us to realistically simulate the anisotropic phenomena. The functionality of the algorithm is demonstrated along with an example of solving an anisotropic model problem with discontinuous coefficients. [ABSTRACT FROM AUTHOR]

The article describes a robust technology for numerical simulation of multicomponent flows in the presence of strong shock waves, for example, in the flight of a high-speed vehicle with a ramjet/scramjet engine. This takes into account the phenomena of turbulence, multicomponent diffusion and heat transfer. High-temperature phenomena that occur when moving at a high supersonic speed and are associated with dissociation and ionization of the gas environment are not considered, although they fit well into the framework of the general model of a multicomponent reacting gas. The advantage of the algorithm proposed in this article is its adaptability to both the simulation of strong shock waves and to the simulations on small scales, as well as a high potential for parallelization. Illustrative examples of simulations based on the developed method are given. [ABSTRACT FROM AUTHOR]

The effort was made to assess the feasibility to remove microorganisms from surface of materials with the help of high-intensity ultrasound generator <> and further air decontamination using unit <>. The test data guided construction of a system capable to eliminate completely a mature association of microorganisms from aluminum surfaces. The combined use of 2 units resulted in total decontamination of atmosphere.

The salad machine experiment was aimed to fulfill performance testing of a prototype of space conveyor-type cylindrical greenhouse PHYTOCYCLE-SL, to study growth and development of plants, and to evaluate microbial contamination of equipment in the closed manned environment. Crops of leaf cabbage Brassica chinensis L., cultivar Vesnianka were raised in the time interval between MARS-500 days 417 and 515. The greenhouse proved it serviceability demanding 17 min/(man x d) in the normal mode. Most likely that the slow growth rate and deviations in plant morphology were caused by the presence of volatile pollutants in the greenhouse compartment Accumulation of micromycetes was observed at the sites of humid surfaces contact with ambient air; reduction of the artificial soil area contacting with air decreased population of micromycetes in 40 times. Cabbage leafs were free of pathogenic microflora. These results of the experiment helped develop recommendations on how to work out some units and systems in projectable greenhouse VITACYCLE-T

The necessity of microbial studying the soil from Phobos and terrestrial biological objects, which were for a long time in deep space and may represent a biological hazard has been shown. Developed medical and technical requirements for laboratories comply with Russian regulations and recommendations of international instruments for the ensuring of biosafety on the basis of process (continuous) biorisk management.

The work was performed in order to evaluate possible negative effect of high temperatures on biological properties of seeds in space experiment BIORISK-MSN-2. Laboratory experiments showed that seeds possess high enough resistance to extended exposure to high temperatures. Results of studying effects of positive temperatures in the region of 40 to 100 degrees C on biological properties of seeds of 19 species and varieties of higher plants belonging to three different families lead to the conclusion that heat stability of seeds depends on temperature value, period of exposure, species, variety and individual peculiarities of plants. These data can be useful in future interpretation of results of experiment BIORISK-MSN-2.

Subject of the test was a procedure of electron sterilization of Mars descent module units. As a result, data on distribution of absorbed dose field across the surface and by the entire volume of the mockup of a miniature meteorological station (MMS) were obtained In addition, electron sterilization technology was developed and the range of absorbed dose from electron radiation that will sterilize reliably packaged MMS hardware were defined in the interval from 30 to 40 kGy.

Purpose of the work was to study usability and efficiency of UV decontamination units aboard space station. UV-radiators were high-intensity xenon flashbulbs, as well as standard mercury and amalgam lamps; subjects were reference strains and test-microorganisms isolated from the ISS environment. Quantities of viable airborne and superficial microorganisms were determined before and after UV irradiation. The sanitary-microbiological assessment involved visual and microscopic counting of colony-forming units on material samples (CFU/100 cm2) and Petri dishes after air sampling (CFU/m3 of air). Continuous spectrum of high-intensity pulsed UV was demonstrated to be effective against contamination both by vegetative and high-resistant bacterial spores and molds.

Analysis of species diversity of the micro-fungi typically detected at the sites of biodamage of synthetic polymers on space vehicles exhibited the presence of a broad variety of opportunistic pathogens and toxic species. Thus, 78 species of micromycetes of 300 polymer destructing fungi are associated with biological risk levels BSL-1 and BSL-2 (low and moderate levels, respectively). As many as 56 species are able to produce toxic compounds.

Purpose of the experiment was to define the hypothesized margins of phenotype adaptation and genotype modifications of bacteria-fungi associations that form the typical microbiota on space vehicle materials. The fundamental questions to answer were whether the selected test-cultures would remain vital after extended (comparable to the Mars mission duration) exposure in open space as part of microbesstructural material model systems, and how the space factors would affect microorganisms in the context of eco-safety of space vehicles and planetary quarantine precautions. The first extended (1.5 years) exposure of the model systems outside of the International space station proved survivability of bacterial and microfungal spores in open space. Ultrastructures of eukaryotic and prokaryotic organisms were found altered, and so were their biological properties.

To get better appreciation of the margins of phenotypic adaptation and genotypic changes in bacteria-fungi associations within the typical microbiota residing on structural materials of space-flown equipment, developed were a program and hardware for a series of experiments under the general name BIORISK. Protocol of each experimental cycle is based on the well-proven method of exposure of "passive" samples of materials (Biorisk-KM), microorganisms-materials systems inside the ISS service module (Biorisk-MSV), and microorganisms-materials systems on the outside of the ISS SM (Biorisk-MSN). Each six months the samples are returned to the laboratory in conjunction with crew rotation. Already the first in-hand data from the experiment point to the dramatic effect of space flight on growth, reproduction, and biological properties of test microbes and fungi. Thus, the activity of enzymes that characterize the pathogenic potential (RNA-ase and DNA-ase), and resistance of microorganisms to aseptic agents were found increased.