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At least 73 records · Page 4

All sources NASA NTRS DOE OSTI

NASA NTRS1973

Methods for study of cardiovascular adaptation of small laboratory animals during exposure to altered gravity

Several new techniques are reported for studying cardiovascular circulation in small laboratory animals kept in metabolic chambers. Chronical cannulation, miniaturized membrane type heart-lung machines, a prototype walking chamber, and a fluorocarbon immersion method to simulate weightlessness are outlined. Differential hypothermia work on rat cancers provides localized embedding of radionuclides and other chemotherapeutical agents in tumors and increases at the same time blood circulation through the warmed tumor as compared to the rest of the cold body. Some successful clinical applications of combined chemotherapy and differential hypothermia in skin cancer, mammary tumors, and brain gliomas are described.

Popovic, V.↗

NASA NTRS1974

Development and creation of conditions for the radiation of biological objects with high energy protons

Depth distribution of an absorbed proton radiation dose was studied by both calculation and experimental methods on a cylindrical, homogeneous plexiglass phantom that represented the geometric form of a dog. The basis of the heterogeneous phantom was the natural skeleton of a dog, muscle tissue was simulated by a mixture of paraffin and silica filler, and lung tissue by gelatine capsules.

Popov, V. P.↗

NASA NTRS1974

Physical conditions for conducting radiobiological experiments in beams of accelerated particles with high linear energy transfer

The design and construction of an accelerator to conduct radiobiological experiments is reported that uses aluminum filters to control the accelerated ion beam while preserving its stability, and a vacuum chamber to conduct the ion beam with the help of a collector through a lavsan exit port to the target. Depth distribution of the absorbed dose from a monodirectional ion beam is practically completely represented by the change in the energy spectrum of the biological object.

Kudryashov, Y. I.↗

NASA NTRS1974

Methodological questions of creating tissue-equivalent phantoms

On the basis of analysis and generalization of literature data, the composition of tissue equivalent plastic was justified, parameters of a standard man were determined, plaster and metal forms were created for casting dummies, and an experimental model was produced from tissue equivalent material.

Kolodkin, A. V.↗

NASA NTRS1975

Vestibular reactions of astronauts during flight in Voskhod spacecraft

It is shown that differing human vestibular resistances to weightlessness stress are connected with the nonuniform initial sensitivity of the vestibular apparatus, as well as with different lengths of vestibular training. However, intensive vestibular training of persons with a moderate degree of sensitivity of the vestibular analyzer does not ensure vestibular stability under weightlessness conditions.

Yuganov, Y. M.↗

NASA NTRS1975

Some results of medical studies of Voskhod 2 spacecraft crew members

Clinical and psychological examinations of the astronauts before, during and after space flight established fluctuations in heart rate, blood circulation, metabolism and sensorimotor reactions that disappeared completely one month after flight.

Kasyan, I. I.↗

NASA NTRS1975

Condition of cardiovascular systems of astronauts during flight of Soyuz orbital station

Extensive studies of blood circulation functions during manned space flight demonstrated a pronounced tendency toward an increase in minute volume of the blood and a decrease in pulse wave propagation rate. Individual blood circulation indices had large amplitude fluctuations. Physical work loads caused slow recovery of heart rate, arterial pressure and minute blood volume.

Degtyarev, V. A.↗

NASA NTRS1975

Astronaut activity in weightlessness and unsupported space

For the purpose of study of the performance ability of a human operator in prolonged weightless conditions was studied by the following methods: (1) psychophysiological analysis of certain operations; (2) the dynamic characteristics of a man, included in a model control system, with direct and delayed feedback; (3) evaluation of the singularities of analysis and quality of the working memory, in working with outlines of patterned and random lines; and (4) biomechanical analysis of spatial orientation and motor activity in unsupported space.

Ivanov, Y. A.↗

NASA NTRS1975

Food and water supply

Supplying astronauts with adequate food and water on short and long-term space flights is discussed based on experiences gained in space flight. Food consumption, energy requirements, and suitability of the foodstuffs for space flight are among the factors considered. Physicochemical and biological methods of food production and regeneration of water from astronaut metabolic wastes, as well as wastes produced in a closed ecological system, or as a result of technical processes taking place in various spacecraft systems are suggested for long-term space flights.

Popov, I. G.↗

NASA NTRS1980

Comparative assessment of prognosis of the stop stimulus and trapezoidal rotation programs

For prognosis of the diagnostic possibilities of the stop stimulus and trapezoidal rotation programs with respect to the nystagmus response, 24 healthy young persons with normal auditory and vestibular analysers were studied experimentally. The trapezoidal program more accurately reflects the function and tone balance of the vestibular system than the stop stimulus program and causes the subject no unpleasant sensations during the study. Some optimum couples, acceleration and armchair rotation rate, necessary for effective deviation of the cupuloendolymphatic system were determined. The maximum angular velocity of the slow nystagmus component was more informative than nystagmus duration. The trapezoidal program is recommended for otoneurological practice and the maximum angular velocity of the slow nystagmus component as the basic index.

Grigorova, V. K.↗

NASA NTRS1980

Linking of the BENSON graph-plotter with the Elektronika-1001 computer

A device, developed by the Institute of Space Research of the Academy of Sciences of the USSR, for linking the Elektronika-100I computer with the BENSON graph-plotter is described. Programs are compiled which provide display of graphic and alphanumeric information. Instructions for their utilization are given.

Valtts, I. Y.↗

NASA NTRS1982

Antiorthostatic hypokinesia and circulation in the rat

Circulatory mechanisms that occur during exposure to head-down hypokinesia as well as during readaptation to control conditions were studied on unanesthetized unrestrained Sprague-Dawley rats exposed to hypokinesia for seven days. The heart rate was slightly elevated, and the right atrial pressure increased to 4 mm Hg, but returned to 0 mm Hg after three days of exposure. Mean arterial blood pressure decreased from 118 to 100 mm Hg during early exposure to antiorthostatic hypokinesia. Cardiac output and stroke volume of resting rats increased during early exposure to hypokinesia but decreased continuously during the next seven days. The results indicate that antiorthostatic hypokinesia induces circulatory changes similar to those seen in astronauts after several days of exposure to 0 g forces.

Popovic, V.↗

NASA NTRS1982

Cardiovascular adaptations during long-term altered gravity

Cardiovascular studies were performed on unrestrained, unanesthetized rats and on the same animals in head-down hypokinetic conditions as well as during readaptation of the same animals to free activity. Possible circulatory mechanisms that evolved in mammals during long-lasting gravity exposure are considered. These mechanisms are likely to be affected during exposure to 0-g forces.

Popovic, V. P.↗

NASA NTRS1985

Descent vehicles

The creation of descent vehicles marked a new stage in the development of cosmonautics, involving the beginning of manned space flight and substantial progress in space research on the distant bodies of the Solar System. This booklet describes these vehicles and their structures, systems, and purposes. It is intended for the general public interested in modern problems of space technology.

Popov, Y. I.↗

NASA NTRS1986

Organization of the channel-switching process in parallel computer systems based on a matrix optical switch

After a classification and analysis of electronic and optoelectronic switching devices, the design principles and structure of a matrix optical switch is described. The switching and pair-exclusion operations in this type of switch are examined, and a method for the optical switching of communication channels is elaborated. Finally, attention is given to the structural organization of a parallel computer system with a matrix optical switch.

Golomidov, Y. V.↗

NASA NTRS1986

The influence of scattering particles morphology on the characteristics of lidar signals

The characteristics of light scattering by a separate spherical particle are used as a priori information when interpreting the data on laser sounding of atmospheric aerosols. Analogously, it is necessary to have a priori information on the characteristics of light scattering by a single crystals in order to restitute the microstructure of crystal formation in the atmosphere. In contrast to the aerosol particles the crystals are of different shapes. On the one hand, this complicates the solution of electrodynamic problems on light scattering by such crystals. On the other hand, if obtaining such a solution is possible, one can determine the morphology of scattering particles accoring to the sounding data and this enables additonal information to be obtained on such meteorological parameters as temperature, pressure, and humidity. Using the geometric-wave approach the problem of scattering of plane electromagnetic wave on convex polyhedrons of arbitrary form was solved. As a result, the expressions were obtained for electric field components of perpendicular and parallel polarizations scattered in any given direction.

Zuev, V. E.↗

NASA NTRS1987

Automatic processing system for shadowgraph and interference patterns

The design and operation of an automatic system for the processing of shadowgraph and interference images are described. The system includes a two-coordinate processing table with an optical system for the projection of transparent images onto the photodetector, an image filter in the photodetector field, and a device for controlling the movement of the table and transmitting information to the minicomputer.

Vereninov, I. A.↗

NASA NTRS1986

Influence of convection of spiral structures in lead-tin eutectic

Convection was generated during directional solidification by the accelerated crucible rotation technique (spin up/spin down). This stirring increased the rotation rate of the microstructure and reduced the length solidifying cooperatively, but had no influence on the lamellar spacing.

Popov, Dimitar↗