Microwave spectrum analysis as solar energy release diagnostics

The possibilities of using spectrographic observations of microwave radio emission as a solar flare plasma diagnostic are discussed. The spectral fine structure of the emission is interpreted in the context of plasma emission mechanisms. The balance equations for particles and plasma turbulence together with the transfer equations for electromagnetic waves in a plasma are solved for a model containing a diverging magnetic loop. As a result of the analysis of the blip-type spectral feature, the structure of energy release region and the unperturbed plasma concentration in the preflare loop are evaluated. The number of accelerated electrons and the intensity of the plasma turbulence in the source region are estimated using the properties of the weak continuum emission following the blip. Based on the degree of circular polarization of both the narrow band and the continuum emission, estimates for the external magnetic field strength and the angular width of the radiating plasma turbulence have been obtained.     

Assessment of Space Station design and operation through Bioastronautics.

The paper reviews the main elements and major issues affecting human productivity and discusses some selected factors which might not be sufficiently identified and/or considered from the Bioastronautics point of view at the present stage of planning Space Station design and operation.     

Observed and model N(h) profiles for the Bulgarian region

In this paper, combined bottom- and topside ionospheric N(h)-profiles are presented for the Bulgarian region. The profiles were constructed using ground (ionospheric observatories Sofia and Michurin) and satellite (Interkosmos-19) observations /1/.The observatories make quarter-hourly observations; in order to connect bottom and upper parts of the N(h) profile, we selected satellite orbits passing rather near to the observatory (zenith distance lsss than 100 km). Thus the time difference between ground station and satellite measurement was never more than 7.5 min.     

Time-dependent dynamical behavior of surface tension on rotating fluids under microgravity environment

Time dependent evolutions of the profile of free surface (bubble shapes) for a cylindrical container partially filled with a Newtonian fluid of constant density, rotating about its axis of symmetry, have been studied. Numerical computations of the dynamics of bubble shapes have been carried out with the following situations: (1) linear functions of spin-up and spin-down in low and microgravity environments, (2) step functions of spin-up and spin-down in a low gravity environment, and (3) sinusoidal function oscillation of gravity environment in high and low rotating cylinder speeds. The initial condition of bubble profiles was adopted from the steady-state formulations in which the computer algorithms have been developed by Hung and Leslie/1/, and Hung et al./2/     

Eutectic solidification of Al-Cu alloys influenced by convection

Directional solidification of eutectic Al-Cu alloys has been studied to demonstrate the influence of both impurity concentration and convective conditions. The λ/R relations show that higher iron concentration and intensive stirring coarsen the microstructure. The formation and growth of new iron-containing phases at the solidification front restrict impurity influence. Kinetic data follow a dependence λ.Rⁿ=const with n-value close to 0,5.     

Sporadic emission of ultra high energy gamma rays from crab pulsar

In a further study of sporadic emission from pulsars we find evidence for short lived intense emission from the Crab pulsar.     

Properties of electrophoretic fractions of human embryonic kidney cells separated on Space Shuttle flight STS-8.

Suspensions of cultured primary human embryonic kidney cells were subjected to continuous flow electrophoresis on Space Shuttle flight STS-8. The objectives of the experiments were to obtain electrophoretically separated fractions of the original cell populations and to test these fractions for the amount and kind of urokinase (a kidney plasminogen activator that is used medically for digesting blood clots), the morphologies of cells in the individual fractions, and their cellular electrophoretic mobilities after separation and subsequent proliferation. Individual fractions were successfully cultured after return from orbit, and they were found to differ substantially from one another and from the starting sample with respect to all of these properties.     

Airborne hyperspectral sensor systems

This paper presents brief profiles of 19 airborne hyperspectral sensor systems currently or nearly available for data acquisition. These systems represent various design concepts and innovations in hyperspectral information collection technology. A number of companies now have the ability to acquire data from these systems. As the scientific and commercial communities become aware of hyperspectral imaging data acquisition opportunities, more applications for this type of data will be investigated and implemented     

Initial results from the repaired solar maximum mission and future prospects

Goals of the recently repaired Solar Maximum Mission Observatory are outlined, including continued emphasis on diagnosing impulsive phase of flares, studies of prominence and coronal plasmas, solar cycle variations of flares, the corona and solar irradiance, and comets. Some preliminary observations taken after the repair are shown, particularly of the X13 flare of April 1984.     

Progress in the study of homologous flares on the sun — Part II

Studies of groups of homologous flares in active regions in 1980 have been made using a variety of space and ground based instruments. Detailed properties of three of these groups have been studied, and are combined to form a possible sequence of events.