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A concept and strategy of the monitoring of chemical composition of the atmosphere in manned spacecrafts applicable during long-term and interplanetary flights are considered. The suggested concept and strategy are applicable for the life support system in spacecraft, which includes a system of gas composition support, a water supply system, a system of sanitary and hygienic support, a food supply system and a thermal control system. Major risk factors related with changes of the atmosphere composition during interplanetary space missions are evaluated. An advanced design of the analytical complex is described for the control of air quality in manned spacecraft's taking into account these risk factors. The simultaneous use of several methods of gas analysis is proposed together with partial overlapping of the set of substances to be detected with regard to the substances of particular (critical) importance. Application of such gas control system will provide a tool for the analyzing of a wide range of substances and will ensure the analysis of the atmosphere even in case of the failure of some of its parts. • Major risk factors the atmosphere composition during space missions are set forth. • Concept of monitoring the chemical composition of atmosphere is substantiated. • Mean-IR range laser gas analyzer to detect of heavy trace impurities is proposed. • Near-IR range laser gas analyzer to detect of light trace impurities is proposed. • Chemical sensory analyzers are used in a regular situation and emergency situations. [ABSTRACT FROM AUTHOR]

Advanced approaches to the development of analytical modules for water quality on-line monitoring during long-time orbital piloted missions are discussed. The first module is intended for an analysis of water ionic composition and its microbiological toxicity with individual selective sensors. The second module operating with the use of an oxythermographic method ensures recirculating water monitoring for the content of total carbon and specific hydrocarbons, e.g., ethanol. Both modules represent subsystems of an integrated analytical complex for an on-line control of air and water quality onboard spacecrafts. • Oxythermography and electronic tongue – new instruments of water quality control in space ships. • Multivariable data are processed with the use of chemometrical methods. • Possibility to measure of total carbon in water using oxythermography. [ABSTRACT FROM AUTHOR]

Traditional methods of synthesis of metal-oxide gas sensing materials for semiconductor sensors are based on wet sol-gel processes. However, these processes lead to the formation of hydroxyl groups on the surface of oxide particles being responsible for the strong response of a sensing material to humidity. In this work, we investigated the possibility to synthesize metal-oxide materials with reduced sensitivity to water vapors. Dry synthesis of SnO 2 nanoparticles was implemented in the gas phase by spark discharge, which allowed us to produce powder with specific surface area of about 40 m 2 /g after additional annealing at 610 °C. The drop of sensor resistance does not exceed 20%, when air humidity increases from 40 to 100%, whereas the response to 100 ppm of hydrogen is of a factor of 8 with very short response time of about 1 s. [ABSTRACT FROM AUTHOR]

Abstract: We present the first results on CO2 gas detection with the help of sensors based on metal-polymer electrolyte-isolator-semiconductor structure with additional layer of proton conducting solid electrolyte – ether of phenylsulphonic acid and polyvinyl alcohol. The sensor operates at room temperature. The detection limit is shown to be of about 100ppm of CO2 in air. [Copyright &y& Elsevier]

In order to study the mechanism behind the phase separation scenario in the Sm0.15Ca0.85MnO3 compound, magnetization and resistivity measurements have been carried out in pulsed magnetic fields up to 50 T at temperatures 4.2 K(P21/m) phase resulting in field-induced insulator–metal transition, which is irreversible below T1=75 K. In zero field the content of a G-type phase in the mixed C–G state can vary from 10 to 17% at T=10 K. A set of metastable states with different volume ratios of G-type to C-type phases is observed below T1 depending on the history of the sample. The obtained results indicate that the phase separation plays a dominant role for the electric and the magnetic properties of this material. [Copyright &y& Elsevier]

A fairly reliable method of fire detection at an early stage is suggested and proved. The method is based on the monitoring of the air chemical composition, which changes strongly due to thermal decomposition (pyrolysis) of overheated combustible materials that are starting to smolder. It is at this stage of incipient fire that adequate measures can be taken for fire extinction with simple tools or, in the case of overheating of electrical equipment, for switching off this equipment automatically using a signal from the fire protection system thereby eliminating the fire hazardous situation. Fire detectors and microcontrollers are designed. These gas fire detectors are particularly suitable at the objects with active ventilation, fоr example, at space vehicles. [ABSTRACT FROM AUTHOR]