Radial Strains of Double-layer Cylinders in Hydraulic Props of Powered Supports

At present a lot of efforts are made to use double-layer power cylinders in hydraulic props of powered supports. To study the response of these cylinders to loads a special finite-element model has been developed and used for investigations into tension effect and double-layer cylinder thickness – radial strain relation under pressure of hydraulic liquid 50 MPa. It has been revealed that double-layer cylinders are distinguished by much lower radial strains in the zone of cup-like sealing elements as if compared with one-layer cylinders, as well as equivalent stresses are lower, and safety factor is higher. The data of the study can be recommended to calculate appropriate geometrical parameters of hydraulic props with respect to lower radial strains of a hydraulic cylinder, which improve its leak-tightness and functioning of cup-like sealing elements. The obtained results can be useful for design and construction of powered supports

Multifrequency dial sensing of the atmospheric gaseous constituents using the first and second harmonics of a tunable CO2 laser radiation

The results of field measurements of concentration of some gaseous components of the atmosphere along the paths, in Sofia, Bulgaria, using a gas analyzer based on the use of a CO2 laser radiation frequency-doubled with ZnGeP2 monocrystals are presented. The gas analyzer is a traditional long path absorption meter. Radiation from the tunable CO2 laser of low pressure and from an additional He-Ne laser is directed to a colliminating hundredfold Gregori telescope with a 300 mm diameter of the principal mirror. The dimensions of the mirrors of a retroreflector 500 x 500 mm and a receiving telescope allow one to totally intercept the beam passed through the atmospheric layer under study and back

MICROBIOCENOSIS, IMMUNE SYSTEM AND HEREDITY

The formation of pro-/eukaryotic systems is the general biological mechanism of formation and variability of the phenotype of plants, animals, human beings under the influence of external Wednesday, i.e. formation of adaptive potency conditions to external Wednesday that increases the «biological status» prokaryotic structures in sustaining body health. Prominent role in the formation of the phenotype of micro media, immunological tolerance (immunological programming), as a basis for the formation of individual pro-/eukaryotic interactions in perinatal age, the dominant role of maternal influence in this process on the one hand, micro-variability due to external stress impact on the other, makes it possible to consider pro-/eukaryotic interaction as a possible mechanism of perinatal programming and epigenetics inheritance and therefore, as one possible approach for correction of chronic and congenital pathology. This points to the need to improve monitoring ofthe formation microbiocenosis of children, improve the methods of assessment and correction