Stress State of Multilayer Thin-Walled Elements with Interfacial Defects of Structure

Based on the discrete-structural theory of thin plates and shells, a calculation model for thin-walled elements consisting of a number of rigid anisotropic layers is put forward. It is assumed that the transverse shear and compression stresses are equal on the interfaces. Elastic slippage is allowed over the interfaces between adjacent layers. The solution to the problem is obtained in a geometrically nonlinear statement with account of the influence of transverse shear and compression strains. The stress-strain state of circular two-layer transversely isotropic plates, both without defects and with a local area of adhesion failure at their center, is investigated numerically and experimentally. It is found that the kinematic and static contact conditions on the interfaces of layered thin-walled structural members greatly affect the magnitude of stresses and strains. With the use of three variants of calculation models, in the cases of perfect and weakened contact conditions between layers, the calculation results for circular plates are compared. It is revealed that the variant suggested in this paper adequately reflects the behavior of layered thin-walled structural elements under large deformations. __________ Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 6, pp. 761–772, November–December, 2005.     

Mechanism of the thermal decomposition of nitrates from graphite furnace mass spectrometry studies

A basically new mechanism of the thermal decomposition of solids is proposed to explain the mass spectral observations of gaseous molecules of CoO, CuO, Cu₂O, NiO, PbO and Mg(OH)₂ during the low-temperature decomposition of the anhydrous and hydrated nitrates of these metals. The mechanism consists of two stages: congruent gasification of all reaction products irrespective of their saturated vapor pressure and subsequent condensation of the low-volatility species (oxides and hydroxides). The partial pressures of these species at the appearance temperatures calculated from this theory for the first stage of the process (1–50 mPa) are in agreement with the detection limits of the quadrupole mass spectrometers used in these experiments. The proposed mechanism is supported by other available data obtained by thermal analysis.     

Vasoactive peptides from venom of the wasp Polistes gallicus. Isolation and physicochemical and functional properties

Six vasoactive peptides have been isolated in the homogeneous form from the venom of the waspPolistes gallicus. Their physicochemical characteristics have been investigated. The wasp kinins exhibit myotropic and hypotensive effects. One of the kinins shows a prolonged hypotensive action.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 564–568, July–August, 1989.     

Resistance of vasoactive peptides from venom of Vespa orientalis to action of proteolytic enzymes

The kinetics of the hydrolysis by proteolytic enzymes of vasoactive peptides isolated from the venom of the hornetVespa orientalis has been investigated. It has been found that the half-period of decomposition of the peptides exceeds that of bradykinin. These facts are in harmony with in vivo results on the prolonged hypotensive action of the peptides.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 658–661, September–October, 1988.     

Vasoactive peptides from venom of the hornet Vespa orientalis physiochemical and functional characterization

Two peptides having kinin activity have been isolated from hornet venom. The peptides isolated exhibit hypotensive action and a myotropic effect, and they also liberate histamine from mast cells. One of the peptides is a close structural analog of bradykinin while the other differs considerably from it.Institute of Bioorganic Chemistry of the Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 255–258, March–April, 1988.     

Spectral characteristics of high-frequency discharges in hollow-electrode lamps

In order to increase the emission intensity of metal resonance lines in hollow-cathode lamps, the possibility of supplying the lamps with a high-frequency current was investigated. It was established that, compared with direct current glow discharges, high-frequency discharges provide an intensity increase by two orders of magnitude at the same line self-absorption level. The reasons for this difference are discussed. A simplified highfrequency lamp design is outlined.Presented at the 14th Conference on Spectroscopy, Moscow, 28 January–2 February 1965.