Human adaptation to simulated gravitational fields

We present the resuIts of manned studies in which test subjects were exposed to simulated zero g (water immersion or head-down tilt at -6 degrees) and head-to-feet acceleration. The findings give evidence that humans have different individual tolerances to an acceleration of +3 Gz after exposure to zero g, whether simulated by immersion or by head-down tilt. The paper discusses the role of functional relationship between water balance and cardiac output in the establishment of adaptive reactions to simulated zero g.     

Otorhinolaryngological problems in medical support of space flights

At present the main trends among the most important problems of otorhinolaryngology in space medicine have become defined as vestibulology, audiology and clinical aspects (prophylaxis, diagnosis and treatment of ENT diseases in flight). The principal result of recent vestibular studies has probably been the establishment of an apparent relationship between the resistance of the vestibular system to adequate ground-based stimulation and tolerance to space flight. The findings of the studies formed the basis for the development of a new system of vestibular selection, as well as demonstrated the usefulness of special vestibular training of astronauts by active and passive methods. In audiology certain urgency is acquired by the problem of noise limitation in space cabins and auditory system reliability prediction for preserving a high work capability in crew members. The hemodynamic changes in weightlessness, as well as the possibility for allergic lesions, create conditions for distorted course of the ENT diseases and vaso-motor disorders. The prophylaxis of aspirations also deserves close attention since the possibilities of their onset increase in weightlessness. The rendering of immediate, timely aid will depend not only on the presence of the necessary medical equipment but also on the ability of the crew members to render the appropriate otorhinolaryngological aid.     

Soviet-Indian research of cosmic radiation by high altitude balloons

The report presents some results on the cosmic radiation intensity research carried out with the high-altitude balloons for the period of 1977–1979. The intensity of gamma-radiation with the energy above 40 MeV was measured in two balloon flights at an altitude of 4–7 g/cm² of residual atmosphere in the vicinity of the geomagnetic equator. A temporal analysis of the intensity to discover fluctuations with periods in the range of 4–60 min was made. Quasi-periodic fluctuations of gamma-radiation intensity with 5 min periods, amplitude ～20% and duration of several hours were discovered. Possible mechanisms of such fluctuation appearance are discussed.The report gives the results of measuring downward, upward and horizontal electron fluxes in the vicinity of the equator. The obtained data and the data provided by satellites are compared. The report discusses the prospects of further joint Soviet-Indian research of cosmic gamma-radiation.     

Shock waves in water foams

Propagation of shock waves in tubes filled with water foams is studied using pressure gauges. Low amplitude shock waves consist of a precursor which propagates at a velocity slightly less than the acoustic velocity in the gas, and of a main compression wave which propagates slower than the precursor. Stronger shock waves have a single front. Maximum pressure rise in the incident and reflected shock waves cannot be calculated using one-dimensional conservation equations at the shock front. It is suggested that the flow of the liquid in foam cells has to be taken into account in order to predict the behavior of shock waves in foams. The nature of the gas which fills the cells is shown to have a strong effect on the quenching of blast waves in foams.     

A retarding potential analyzer for rocket experiments

A Retarding Potential Analyzer (RPA) is designed using a micro-channel plate in front of the collector as a flow amplifier, which makes it possible to detect ion species with very low concentration (<0,5 cm.^?3). A technique is described for using the micro-channel plate at abnormally high pressure (>0.01 N/m²). This allows the precise determination of the mass composition of the low ionosphere. An adaptive retarding potential consisting of 2048 steps is used to increase the sensitivity. This retarding potential is applied in the range where dI/dU ≠ 0. The sensor is hermetically sealed and opens on command.     

Pseudotransfer Function to Characterize a Hard Limiter

Results are reported on the attempt to define a pseudotransfer funtion of a circuit composed of a 2-pulse canceler and hard limiter.     

Effect of Envelope Limiting in Adaptive Array Control Loops

The properties of an adaptive array antenna, including transient response rate and control loop noise, depend on the intensity of the external noise field. This dependence can be reduced by envelope hard limiting in the control loops, without degrading the performance of the adaptive array.     

A Minimax Filter for Systems with Large Plant Uncertainties Using Measurements Corrupted by Colored Noise

A minimax filter is derived to estimate the state of a system, using observations corrupted by colored noise, when large uncertainties in the plant dynamics and process noise are present.     

Multiple Target Effects on Monopulse Signal Processing

Analysis of a typical amplitude-comparison monopulse angle-tracking radar shows that gain variation and bias in the radar error signal can occur under certain conditions involving multiple targets. The general behavior depends on the Doppler separation of the targets relative to system bandwidths; for a specific situation, the gain variation and bias are functions of the relative strengths of the targs. The analysis is shown to be consistent with experimental observations.