Performance characteristics of lithium ion cells at low temperatures

The low temperature charge and discharge characteristics of experimental MCMB-Li/sub x/Ni/sub y/Co/sub 1-y/O/sub 2/ cells containing different electrolytes were investigated. The use of low ethylene carbonate (EC)-content electrolyte formulations has resulted in good discharge performance to temperatures as low as -40/spl deg/C. The effect of charge voltage and charge current upon the individual electrode potentials at low temperature was investigated using the three electrode cells (containing lithium reference electrodes). In some cases, lithium plating was observed to occur upon low temperature charge, and found to be facilitated by high charge voltages, high charge currents, and poor anode kinetics. Electrochemical characterization of the cells has helped to establish the conditions under which lithium plating can occur by providing information regarding the polarization effects present at each electrode.     

An experimental and empirical model of electron temperature for altitudes of 500 to 1000 km and for a high solar activity period

On the basis of systematic electron temperature measurements onboard the Interkosmos-19 satellite, an experimental global model of electron temperature T_e has been constructed; namely, a set of samples representing 10 intervals of measured T_e, accompanied by values of the geographic longitude, solar zenith angle, season of the year, Covington index, Dst and Kp, grouped according to the invariant latitude, geomagnetic time and altitude. On the basis of the experimental model, the coefficients of the empirical models for the summer and winter seasons, for geophysically quiet conditions, and for heights of 520, 600, 920 and 1000 km are calculated. For heights of 680, 760 and 840 km with fewer data available, the coefficients are provisional.     

Interaction of artificially injected plasma flows with ionospheric plasma

Results of rocket experiments on study of plasma flows (PF) artificially injected by sources separated from vehicles and their effect on medium parameters in ionosphere at altitudes 160:230 km are presented.PF were injected comprising lithium ions with velocities 1,2 x 10⁴ m/sec. and cesium-potassium ions with velocities (1,4–1,5)x10³ m/sec. Mass flow rate in case of lithium PS is 2 mg/sec, and in case of cesium-potassium PS is 0,2 g/sec. During experiments mass-spectrometer measurements of ion medium content in ranges of different ion masses were held, disturbancies of electric fields with frequencies up to 20 kHz and electron flows with energies 0,7keV, 4,6keV and over 40 keV were controlled at distancies from 150m to (500–600)m between plasma source and scientific equipment.     

Functional state of chromatin and proliferative activity of meristematic cells in pea seedlings under various clinostatic conditions.

Data from a complex cytochemical analysis show that the functional state of chromatin and the level of the cell proliferative activity may be reliable cytological criteria for primary structural and functional changes that result in disturbances of plant growth and development. Autoradiographic and cytophotonetric studies made it possible to establish certain differences, induced by fast rotation (50 rev/min) on the clinostat, in the chromatin state and cell reproduction of the pea seedling root meristem for the initial stages of plant development. There were no essential differences for the given parameters under slow (2 rev/min) clinostatic conditions.     

On ionospheric aerodynamics

This paper presents theoretical methods to determine the gas dynamic and the electrostatic effects due to the interaction caused by a rapidly moving body in the ionosphere. The principles of the methods are derived from the kinetic theory of collision-free plasma. It is shown that the collective behavior of the collision-free plasma makes it possible to use the fluid approach to treat the problems of ionospheric aerodynamics. Various solutions to the system of fluid and field equations that have direct bearing on the ionospheric aerodynamics are presented and discussed. Physical significances of the mathematical results are stressed. Some outstanding unsolved problems in ionospheric aerodynamics are elaborated and discussed.     

Thermoluminescent dose measurements on-board Salyut type orbital stations.

A small, vibration- and shock-resistant thermoluminescent dosemeter /TLD/ system--named PILLE--was developed at the Health Physics Department of the Central Research Institute for Physics, Budapest, to measure the cosmic radiation dose on board orbital stations. The first on-board measurements with this system were performed /by B. Farkas, the Hungarian astronaut/, on the Salyut-6 space station in 1980. The same instrument was used by other crews in the following years. Doses measured at different sites in Salyut-6 are presented. The dose rates varied from 0.07 to 0.11 mGy.day-1. After the first cosmic measurements, the system was further developed. The minimum detectable dose of the new TLD system is 1 microGy, i.e. less by on order of magnitude than that of the former system. The self-irradiation dose rate of the TLD bulbs is also reduced--by more than one order of magnitude--to 10 nGy.h-1, by the use of potassium-free glass for the bulb envelope. This new type of PILLE TLD system is currently on-board Salyut-7. The dose rates /0.12-0.23 mGy.day-1/ measured in 1983 are presented in detail.     

Potential defense applications of expert systems

The authors provide an overview of expert systems and how they may effect the development of future defense applications. Military uses of computers are outlined, and expert-systems fundamentals are described. Artificial research and development efforts by the military are examined, and potential military applications are discussed. Expert systems efforts at NASA, by the US Air Force, and for the Strategic Defence Initiative are considered     

Preliminary data of the thermal regime and circulation in the upper mesosphere and mesopause

Circulation and thermal structure for the 90–95 km region is described on the basis of the joint analysis of direct and indirect sounding data. Mean season charts of the 0.001 mb surface were compiled using data from meteor trials, ionospheric drifts, rocket launchings and data of the rotational temperature of hydroxyl emission.     

Some aspects of the application of the bunch of MPD engines

In the present work, the asymptotic dependence of the reservation multiplicity on the failure danger diminution coefficient in both cases of reservation replacement and continually acting reserver is investigated. The comparison of the method of reservation for different multiplicities with the method of diminution of the failure intensity, related to the mean performance time shows that the decrease of the failure intensity of the plazma engine is the most rational. Nevertheless, there is a value of the time flight for which even a simple duplication is better than arbitrarily large, though finite, failure intensity decrease of the engine. The reliability of coupled MOD-thrusters is verified experimentally. The specific character of the thruster V-I curves and, in particular, their increase in the pubricrcrisis region, yield normally working couples, conformly to many types of feed sources with weakly decreasing of constant V-I characteristics. The parallel connection of a second thruster is shown to double the customed current and, as a consequence the thruster intermediary regimes of the thruster and the dynamics of switching on and by breaking the electric line and stopping the propellant rate flow are investigated.     

A noise insensitive solution to an ambiguity problem in spectralestimation

The instantaneous frequency measurement (IFM) receiver is capable of measuring the center frequency of single frequency pulses over a wide range (bandwidth) of center frequencies. Because of various constraints, the frequency resolution requirement results in long correlator delay times that reduce the single correlator bandwidth. A large bandwidth can be achieved only if two or more correlators are used. The problem of estimating frequency is then reduced to the simultaneous congruence problem of number theory. A design procedure is presented for solving the congruence problem for a given amount of noise protection, a stated frequency resolution, a minimum bandwidth, and a fixed level of precision (bits) in the IFM receiver