Scalar-tensor bimetric theory of gravitation. II. Energy-momentum tensor of the gravitational field

Institute of Applied Physics Problems, Armenian Academy of Sciences. Translated from Astrofizika, Vol. 33, No. 1, pp. 107–112, July–August, 1990.     

Spectral Observations of the Flare Star HU Del

Results are presented from a study of 27 spectra of the flare star HU Del obtained during 2000–2002 on the 2.6 meter telescope at the Byurakan Observatory. Two flares were detected, along with a weak correlation between the equivalent widths of the Hα and Hβ emission lines. At the time of the photometric maximum of a flare the equivalent widths of both these lines are minimal and reach their maximum only significantly afterward. A strong increase in the Hβ line intensity is observed which appears to be the consequence of a photometrically undetected, short-duration flare. A possible relationship between the binary (multiple) character and the physical activity of this star is examined briefly in terms of current theoretical models.__________Translated from Astrofizika, Vol. 48, No. 3, pp. 335–348 (August 2005).     

The state equation of superdense degenerate plasma

On the basis of general requirements, the parameters of the hadronic plasma and the state equation of degenerate superdense matter in the whole range of pressures are improved and corrected.     

Lithostratigraphic Characteristic and Lithology of Triassic–Paleozoic Rocks of Southern Mangyshlak

The paper considers principles of the subdivision and correlation and a new petrographic model of Triassic–Paleozoic rocks based on their lithogenetic features. The structure of the folded basement and quasi-platform complex of southern Mangyshlak, as well as petrological–mineralogical features of Variscan granites and products of their hypergene weathering, are analyzed.     

Evolution of double diffusion convection in a felsic magma chamber

The onset of double diffusion convection (DDC) is modeled in a two-dimensional case in respect to magma chambers. The viscosity model for the melt takes into account the effects of temperature and concentration of the dissolved component (H₂O). The upper boundary of the convecting magma chamber is assumed to be anhydrous and at constant temperature, whereas the lower boundary is treated as being hydrous permeable with a temperature greater than that within the upper boundary. The case of positive compositional and thermal buoyancy of melt is studied assuming a H₂O diffusion coefficient small in comparison with thermal diffusivity. The DDC has been modeled using a system of equations solved by the finite difference method on a square grid. The convective pattern evolution has been studied for fixed boundary conditions as well as for cooling and degassing. Due to the higher viscosity in the upper zone, the upper boundary layer is thicker than the lower one. The variation of water concentration in this zone of the convective cell can be significant. In nature, the high gradient of water concentration can be responsible for the observed variations of water content in minerals crystallized from a granite melt (e.g., biotite). Because of a high Lewis number (= 100), temperature variations in the magma chamber decay much faster than the water concentration. In this case the intensive convection can continue at a constant temperature due to the non-zero water content in the chamber. In principle, the effect can be applied to the formation of magmatic bodies. If the cooling and degassing system reaches a uniform temperature distribution prior to the crystallization temperature, water content throughout the body may still remain variable.     

The Uzbekistan Loess,genesis and distribution

The distribution and genesis of Uzbekistan loess rocks, their composition, properties and conditions are naturally changing from mountains to the piedmont plains. For the piedmont plains and intermontane depressions the occurrence of alluvial and deluvial loess types is typical, and in the high mountains eluvial, deluvial, eluvial-deluvial and fluvioglacial ones. This can be explained by the difference of tectonic activity as well as by climatic humidity. The study and analyss of the accumulated data of loess of various genetic type, composition and properties show that the initial material of loess formation comes from the mountainous and alpine areas. The primariy sources of the parent rocks are ancient sediments above the limit of loess occurrence. As a result of intensive developments and irrigation in the territory of the republic, loess areas are decreasing, losing their properties, while they are transforming into the loess-like rocks. It was also determined that their structural and textural properties such as porosity, density, salt composition and filtration coefficient are changing simultaneously. The same changes are also noted in the mineralogical and granulometric composition.