Instrumentation complex for comprehensive study of atmospheric parameters

A unique instrumentation complex of the Institute of Atmospheric Optics SB RAS is presented. The complex has no analogues anywhere in the world, and makes possible simultaneous measurements of a great number of optical, meteorological, and radiative parameters of the atmosphere, as well as characteristics of aerosol and gas composition. The instrumentation complex is based on permanent stations recording numerous parameters of the atmosphere, namely, TOR (Tropospheric Ozone Research) station, Aerosol Monitoring Station, BEC (Basic Experimental Complex), Fonovaya (Background) Station, and stations for receiving satellite images (NOAA, MODIS/TERRA, MODIS/AQUA). An important part of the complex is the Tu-134 aircraft laboratory enabling measurement of atmospheric parameters in the altitude range up to 7 km. In addition, the following instruments are used in experiments: weather balloons, lidars, sodars, sun photometers, Fourier spectrometers, and others. Satellite data are also used for interpretation of data. The article presents an example of complex operation on one measurement day – 22 May 2012.     

Dynamics and wear of fragments of a lower part of a fuel assembly with free fuel elements

A procedure and findings of investigations of the dynamic characteristics and the wear of fuel elements in the framework of the development of a perspective design of fuel elements without fastening in a lower support grid are presented. At the first phase of the work, natural vibration frequencies and the dynamic rigidity of fuel elements are determined in various design variants of lower spans. Resonance frequencies of spans of fuel elements are revealed by minimums of the dynamic rigidity. At the second phase, investigations of vibrational wear within contact of fuel elements with cells of spacer grids are performed on models of a lower part of a fuel assembly. Four embodiments of the lower part of the fuel assembly are investigated. As a result of the application of high vibrational loads, the wear of fuel element cans and grid cells is observed in more than a half of contact assembles of fuel elements with spacer grids. The most and least wear-resistant designs of the lower part of the fuel assembly are determined by results of tests.     

Two approaches to taking nonsingular <Emphasis Type="Italic">T</Emphasis>-stresses into account in the criteria of fracture mechanics for bodies with notches

Two possible models and criterion equations of fracture mechanics for bodies with notches taking into account nonsingular expansion terms of stresses at the notch (crack) apex based on crack-growth resistance diagrams and a master curve are considered. A criterion equation of a generalized crack-growth resistance diagram admissible for a body with a crack and a notch and taking into account the changes in the degree of strain constraint at the notch apex due to finiteness of its apex radius rounding and a nonsingular stress component (T-stresses) is given. The notion of effective T-stresses determined using averaging of T-stresses in front of the notch apex in the pre-fracture zone characterized by effective scattering in introduced. A basic dependence of fracturing viscosity in the function of effective T-stresses (a master curve) of pipe steel is constructed for the given notch geometry.     

Effect of Photoperiod on Linum usitatissimum L. Characters

ABSTRACT

The review summarizes diverse knowledge about the problem of Linum usitatissimum L. response on photoperiod. Within this species, high genetic variability of the photosensitivity degree and influence of photoperiod on different plants characters were discovered. It was shown that in flax, earliness of flowering in long daylight is not strictly related to the low photosensitivity, and late genotypes with low photosensitivity can be found. In short daylight, various plant characters of different genotypes can be stable or display different reactions: increase or decrease their values. Also, the degree of photosensitivity does not have stable correlations with agronomic characters.