Biological studies of martian soil analogues

Results of the study of the influence of Martian soil analogues, both as described by American scientists and as prepared by us, and of hydrogen peroxide on the viability of microorganisms are presented. The experiments were carried out using mixtures of soil analogues with desert soil and black earth (chernozem) samples, and pure cultures of microorganism. Microorganisms capable of withstanding a concentration of hydrogen peroxide in the medium as high as 1.5–2.0% were isolated. None of the 40 strains of microorganisms studied, all belonging to different systematic and physiological groups, exhibited growth inhibition on solid media in the presence of Martian soil analogues. In view of the fact that Martian soil cannot contain microorganisms in great quantities, we suggest using electroadsorption for their concentration, to make detection reliable. A device was designed for this purpose, using the principle of electroadsorption on a polarisable carrier (sterile cotton wool or cheesecloth). The concentrated suspension of microorganisms thus obtained was then characterized by various physicochemical methods.     

Experiments with injection of powerful plasma jet into the ionosphere

This paper describes two rocket experiments “Aelita” with high power lithium plasma injection. The results of onboard magnetometer, massspectrometer, photometer, plasma, corpuscular and ground radar measurements are given. Dynamics and structure of plasma formation are discussed.     

The dynamics of the atmospheres of the major planets

The literature on the dynamics of Jupiter's atmosphere is reviewed and used as a basis for suggesting what observations would yield useful information about Jovian Dynamics. The atmospheres of Saturn, Uranus and Neptune are discussed from the same point of view.This is one of the publications by the Science Advisory Group.     

Determination of Bounds on Performance Measure and Min-Max Controllers in Time-Lag Systems

The effect of bounded deterministic disturbances (external and/or internal) on a chosen performance index (PI) is investigated. Upper and lower bounds of the PI about a nominal value are determined by the application of the optimum control theory. A computational procedure is also proposed to determine an approximately optimal feedback controller for time-lag systems. Such a controller is designed here on the basis of min-max criteria. Numerical examples illustrate the proposed approach.     

Landsat satellite imagery of the Qattara Depression area,Egypt

The Qattara Depression lies in the northern part of the Western Desert of Egypt at a distance of some tens of kilometers to the south of the Mediterranean Sea Coast. The depression in question is the largest one in the great Sahara extending across North Africa. It covers an area of some 19,000 km² at ? 60 m level and the absolute level of its lowest point is about ? 134 m. The depression extends for about 300 km in a roughly ENE-WSW direction, while its width is variable reaching to a maximum of about 145 km. Feasibility studies are currently carried out for the Qattara solar-hydro-electric project which aims at generating hydro-electric power by the drop of the Mediterranean Sea water into the depression after passing through a canal/tunnel system. Peak load electric power may be also generated by raising the water to the small hollow of Deir Kirayim, situated at a higher level near the depression, and allowing it to drop to a low level.For the purpose of assessing the regional criteria involved in the implementation of the project and the environmental impact of such implementation, the Qattara Depression and the surrounding area has been studied on a regional scale by the utilization of LANDSAT satellite imagery. The maps produced by the interpretation of the images in question include those of the geological and environmental units, structural lineations, drainage and vegetation cover. Lineation density and drainage density maps are derived by the computation of the structural lineation and drainage maps respectively. A map of groundwater conditions is worked out on the basis of the image interpretation, and the observations previously carried out on the groundwater aquifers in the Qattara Depression and the surrounding area. LANDSAT satellite image interpretation and computation are supported by intensive observations carried out in the field as well as chemical, petrological and mineralogical analyses of the samples collected.The LANDSAT satellite images proved to be of great importance in mapping the Qattara Depression floor which is hardly accessible to classical mapping, and especially in view of the large area which could be covered by imagery mapping in a reasonably short time compatible with the duration of the feasibility study. The special characters of the spaceborne multispectral imagery have been paramount in deciphering the major regional features of the investigated area.The overall synoptic picture of the regional setting of the geological and environmental units, faults, fractures and folds, drainage lines and plant cover in the large area studied has been clarified for the first time. It has been demonstrated that the Qattara Depression is actually constituted of several small depressions. The environmental impact of the project implementation has been visualized especially regarding the possible influence of the saline water on the fresh groundwater sources. The thick salt accumulation in the depression has been found to be of such extension as to increase the salinity of the Mediterranean Sea water stored in the depression following the implementation of the project. The lineation density map has been particularly of great help in the localization of sites subjected to intense crustal deformation, greater slope instability and run off surface water flooding.     

Radar Doppler Spectra of Turbulent Ionized Wakes

The evaluation of the double convolution integrat involved in the expression of the radar response to scattering from a turbulent ionized wake is simplified by the approximation technique presented here, so that the Doppler spectrum parameters can be explicitly expressed in terms of the wake characteristics.     

Doppler Spectral Moments of Radar Scattering from Turbulent Ionized Wakes

The Doppler frequency shift, and spectral spread, of the radar scattering return from turbulent underdense ionized wakes are explicitly related here to the wake mean velocity, and to the wake turbulent velocity fluctuations and mean velocity gradients, respectively, via spectral moments of the matched-filter receiver response.     

Cross Polarization in Radomes: A Program for Its Computation

A study is made of transmission by radomes, with particular reference to cross polarization, and of the consequent radiation patterns of the radome with its aerial for both linear and circular polarizations. The work is embodied in a computer program which considers a scanner of specifiable size, position, and power distribution at different orientations inside a multilayer radome of given dimensions, class of shape, and construction in terms of the number and properties of its layers. Initially, rays are traced from points on the scanner, and details of their paths and propagation are presented in tables of preliminary results; later, diffraction theory is used. Polar diagrams of cross polarization, of main beam, etc., are presented in final tables for the system. Nearly all the parameters are specifiable, and so the program has reasonably general applicability, and it can also assess the effects of bandwidth, tapering of layer thickness, complex permittivity, and other parameters of the system.     

Performance Degradation Due to Specular Multipath Intersymbol Interference

Plots of performance degradation are used to compare the effects of fading and intersymbol interference in a two- component specular multipath digital communications channel. Similar plots are then used to compare two practical receivers designed to combat the interference. Degradation plots are shown to allow easy identification of each receiver's range of usefulness, as well as identification of variance bounds demanded of channel parameter estimates which the receivers require.