Bottom sediments of the oldest reservoir in Moscow region

The methodological features and results of two soil surveys of the Senezh Reservoir carried out in 1992 and 2006 as a part of multidisciplinary limnological studies of this large recreation water body with the aim to monitor its ecological state and prepare recommendations for water protection measures are analyzed     

Investigation of dynamic response of masonry minaret structures

Almost all historical minarets in Turkey were constructed using cut stone, masonry blocks or combination of these two materials. The structural and geometrical properties of each masonry minaret, or slender tower structure, depend on many factors including the structural knowledge and applications at the time of construction, experience of the architect or engineer, seismicity of the region, and availability of construction materials in that area. Recent earthquakes in Turkey have shown that most masonry minarets in high seismic regions are vulnerable to structural damage and collapse. In this study, in order to investigate the dynamic behavior of historical unreinforced masonry minarets, three representative minarets with 20, 25, and 30 m height were modeled and analyzed using two ground motions recorded during the 1999 Kocaeli and Duzce, Turkey earthquakes. The modal analyses of the models have shown that the structural periods and the overall structural response are influenced by the minaret height and spectral characteristics of the input motion. The dynamic displacement and axial stress time histories are computed at the critical points on the minarets. During recent earthquakes, most minaret failures occurred above the base of the structure. Consistent with the observed response, the largest stresses were calculated at the same location.     

Multifunctional broad-band seismic assemblage SEP-1

Results of research and development of three velocimeter components in the form of an assemblage of mechanical seismic detector and boards of electronics, realizing stabilization of inertial mass zero point and formation of amplitude-frequency characteristic, are presented. Original electromagnetic system of mass suspension for the vertical variant is applied in the seismic detector; it gives a possibility of mass reduction to the variant of horizontal seismic detector without change of the general design. The suspension system consists of two cylindrical magnets and a ferromagnetic shunt. On the basis of the developed seismic detectors, design of the multifunctional seismic assemblage SEP-1 is realized allowing its application for solution of a wide variety of seismologic problems at measurements both in base variant and in wellholes.     

The geology, hydrodynamics, and the oil and gas potential of the Kosheleva steam-water field in Kamchatka

This paper considers the geology, hydrodynamics, and oil and gas occurrences in the Kosheleva vapor-dominated field related to the activity of the Kosheleva Volcano. The hydrodynamic peculiarities of this field allow the upper boundary of the vapor zone to be outlined. One notes an intimate connection between vapor-dominated hydrothermal occurrences and the occurrences of oil and gas containing heavy hydrocarbons, including even C₇H₁₂, as well as methane.     

Solar corona top heating

The solar magnetic field fragmentation into thin magnetic tubes above the photosphere makes it possible to transform and factorize MHD equations analytically and to obtain explicit expressions for Alfvén and magnetosonic fields. A physical model that enables an explanation of the effect of strong heating of the solar chromosphere and corona has been proposed. This model makes it possible to estimate analytically a powerful Alfvén disturbance entering the chromosphere due to convective motions of the photosphere and a thermal release due to a three-wave interaction within the chromosphere.