Micromechanical gyros & accelerometers for digital navigation & control systems

There is no general consensus of opinion about the future of micromechanical gyroscopes and accelerometers. According to the pessimistic estimation, micromechanical gyroscopes and accelerometers have attained the limit of their accuracy. However, optimists believe that micromechamical gyroscopes will soon occupy the niche of fiber-optical gyroscopes and the latter will press laser gyroscopes. The present-day development of micromechanical gyroscopes and accelerometers is aimed at improving the basic and minor parameters: sensitivity, bias, offset, drift, resolution, scale factor, and its non-linearity. High level of performance is provided by application of high technology. This is devoted to the development and manufacturing of "silicon-glass" micromechanical sensors of encapsulated-type with digital output processing. The key technological processes allowing production of micromechanical encapsulated sensors with vacuum insides are considered and the features of their design are described. The methods for maintaining high reliability of encapsulated micromechanical gyroscopes with inner getter structure are discussed. ASIC designs for control and processing of micromechanical sensor outputs allow their accuracy, which is part of modern integrated systems, to be considerably improved. Also considered are various assemblies and packaging of the ASIC and micromechanical sensor as a single product.     

Energetic metabolism response in algae and higher plant species from simulation experiments with the clinostat.

Adenylate state is acknowledged to be among the most convenient approaches in the study of physiological changes in plant cells under simulation of altered gravity condition with the clinostat. Adenylate levels and the ATP/ADP ratio in cytoplasmic and mitochondrial extracts of cultivated cells of Haplopappus gracilis and algae cells of Chlorella vulgaris under initial stages of the fast-rotating and slow-rotating clinorotation, as well as the long-term clinorotation, have been investigated. For analysis of ATP and ADP levels in the plant cells under the clinorotation, we applied a high-sensitive bioluminescence method using the luciferase and piruvate kinase enzyme systems. It has been shown that the adenylate ratio is already increased during at the start of clinorotation with the different speed of rotation in the biological material tested. The considerable changes in mitochondrial ultrastructure of Chlorella cells, as well as the rising ATP level and dropping of the ATP/ADP ratio appear after long-duration clinorotation if compared to control material. It is probably connected with the distinctions in ATP-synthetase functioning in mitochondria of the cells under the clinorotation conditions.     

Peculiarities of ultrastructure of Chlorella cells growing aboard the Bion-10 during 12 days.

The ultrastructure of Chlorella cells grown in darkness on a solid agar medium with organic additions aboard the Bion-10 biosatellite was studied. Certain differences in submicroscopic organization of organelles in the experimental cells were revealed compared to the Earth control. The changes are registered mainly in ultrastructure of energetic organelles--mitochondria and plastids of the experimental cells, in particular, an increase of mitochondria and their cristae size, as well as an increase of the total volume of mitochondrion per cell were established. The decrease of the starch amount in the plastid stroma and the electron density of the latter was also observed. In many experimental cells, the increase of condensed chromatin in the nuclei has been noted. Ultrastructural rearrangements in cells after laboratory experiment realized according to the thermogram registered aboard the Bion-10 were insignificant compared to the flight experiment. Data obtained are compared to results of space flight experiments carried out aboard the Bion-9 (polycomponent aquatic system) and the orbital station Mir (solid agar medium).     

Plasma and urine catecholamine levels in cosmonauts during long-term stay on Space Station Salyut-7.

The activity of the sympathetic adrenal system in cosmonauts exposed to a stay in space lasting for about half a year has so far been studied only by measuring catecholamine levels in plasma and urine samples taken before space flight and after landing. The device "Plasma 01", specially designed for collecting and processing venous blood from subjects during space flight on board the station Salyut-7 rendered it possible for the first time to collect and freeze samples of blood from cosmonauts in the course of a long-term 237-day space flight. A physician-cosmonaut collected samples of blood and urine from two cosmonauts over the period of days 217-219 of their stay in space. The samples were transported to Earth frozen. As indicators of the sympathetic adrenal system activity, plasma and urine concentrations of epinephrine and norepinephrine as well as urine levels of the catecholamine metabolites metanephrine, normetanephrine, and vanillylmandelic acid were determined before, during and after space flight. On days 217-219 of space flight plasma epinephrine and norepinephrine levels were slightly increased, yet not substantially different from normal. During stress situations plasma norepinephrine and epinephrine levels usually exhibit a manifold increase. On days 217-219 of space flight norepinephrine and epinephrine levels in urine were comparable with pre-flight values and the levels of their metabolites were even significantly decreased. All the parameters studied, particularly plasma norepinephrine as well as urine norepinephrine, normetanephrine, and vanillylmandelic acid, reached the highest values 8 days after landing. The results obtained suggest that, in the period of days 217-219 of the cosmonauts stay in space in the state of weightlessness, the sympathetic adrenal system is either not activated at all or there is but a slight activation induced by specific activities of the cosmonauts, whereas in the process of re-adaptation after space flight on Earth this system is considerably more markedly activated.     

Population dynamics of transgenic strain Escherichia coli Z905/pPHL7 in freshwater and saline lake water microcosms with differing microbial community structures.

Populations of Escherichia coli Z905/pPHL7, a transgenic microorganism, were heterogenic in the expression of plasmid genes when adapting to the conditions of water microcosms of various mineralization levels and structure of microbial community. This TM has formed two subpopulations (ampicillin-resistant and ampicillin-sensitive) in every microcosm. Irrespective of mineralization level of a microcosm, when E. coli Z905/pPHL7 alone was introduced, the ampicillin-resistant subpopulation prevailed, while introduction of the TM together with indigenous bacteria led to the dominance of the ampicillin-sensitive subpopulation. A high level of lux gene expression maintained longer in the freshwater microcosms than in sterile saline lake water microcosms. A horizontal gene transfer has been revealed between the jointly introduced TM and Micrococcus sp. 9/pSH1 in microcosms with the Lake Shira sterile water.     

Expression of lux-genes as an indicator of metabolic activity of cells in model ecosystem studies.

Quick response to different impacts and easy measurement make the luminescent systems of luminous bacteria an object convenient for application in various fields. Cloning of gene luminescence in different organisms is currently used to study both the survival of microbial cells and the effect of different factors on their metabolic activity, including the environment. A primary test-object in estimating bacteriological contamination of water bodies, Escherichia coli, can be conveniently used as an indicator of bactericidal properties of aquatic ecosystems. The application of Escherichia coli Z905/pPHL7 (lux+) as a marker microorganism can facilitate monitoring the microbiological status of closed biocenoses, including systems with higher organisms. The investigation of various parameters of microecosystems (carbon nutrition type, concentrations of inorganic ions and toxic compounds) shows that the recombinant strain E. coli Z905/pPHL7 can be effectively used as a marker.     

Prospects of autotrophic link functioning in biological life-support systems based on cell biology studies

On the basis of using of modern methods of cytological analysis the cell growth peculiarities, reproduction and structure of plant cells of different level organisation (unicellular algae, mosses, angiosperms, cell cultures of higher factors--weightlessness, hypogravity, magnetic fields of various intensity, vibration and acceleration were cleared. It is shown that many discovered biological effects of space flight are connected with the degree of complexity of the object organisation and intensified with the increasing duration of influence.     

New data on the variability of X-ray source KR Aurigae

The results from the photometric observations of the x-ray source KR Aur for the period Oct. 1979 – Mai 1983 obtained at the National Astronomical Observatory, Bulgarian Acedemy of Sciences, are presented. The 1981 – 1982 minimum of the light curve is discussed.     

Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight.

The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.     

Peculiarities of the submicroscopic organization of Chlorella cells cultivated on a solid medium in microgravity.

The submicroscopic organization of Chlorella vulgaris cells (strain LARG-1) growing over 30 days on a solid agarized medium aboard the orbital station "Mir" was studied. A number of differences in the ultrastructure of cells of the experimental population compared to the control has been revealed. Thus, changes in the membrane system of plastids, in particular, appearance of numerous vesicles of different diameter and outgrowths of the plastids and their contact with the plasmalemma as well as a considerable decrease of reserve polysaccharide number in the plastids. Moreover, an increase in the size of mitochondria, their cristae and lipid drops in cytoplasm, the formation of more complicated configuration folding of plasmalemma and appearance of small-granular material of mean electron density in the periplasmic space of Chlorella cells grown during space flight, are demonstrated. Comparative cytological analysis has revealed general regularities of rearrangements of the submicroscopic organization in Chlorella cells cultivated on both solid and semiliquid agarized nutrient media.