Calculation of shrinkage stresses in fibrous composites with regular structure

The effect of the chemical and thermal shrinkage of the epoxy matrix on the structural residual stresses in plastics reinforced with anisotropic fibers has been investigated. The process of residual stress formation in all stages of a given curing regime is examined with reference to a regular triangular fiber distribution. The model of a hardening hypoviscoelastic medium [8] is used to describe the variation of the rheological properties of the matrix. The effect of the cooling rate on the residual stresses is investigated with reference to a single inclusion.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, No. 3, pp. 409–415, May–June, 1976.     

Pentagonal two-loop ring interferometer

Results of work on the assembly and adjustment of an original pentagonal, two-loop interferometer are reported; the interferometer is a passive version of a compact laser gravitational wave detector. It is shown that the correlative automatic noise-compensation system developed for the project is capable of lowering the phase noise level in the resultant signal channel of the detector by two orders of magnitude. Zh. Tekh. Fiz. 68, 121–125 (May 1998)     

Stabilization of the different frequency of reference and signal resonators in the Dulkyn gravitational-wave detector

It is shown that stabilization of the different frequency of optical radiations generated in the reference and signal resonators of the Dulkyn laser-interferometric gravitational-wave detector results in an efficient reevaluation of basic parameters describing the line widths of the laser radiation and the passive resonator, as well as the minimal laser power required to separate the valid signal from noises caused by natural fluctuations.     

Temperature - time analogy for thermorheologically complex polymeric materials

Conclusions 1. The viscoelastic properties of mixtures of crystalline polymers with elastomers have been studied as functions of temperature. It is shown that, for mixtures of PP with PIB and TEP, the concept of thermorheologically simple behavior is applicable only within a narrow interval of temperature.2. Parameters of the temperature—time analogy for thermorheologically complex materials have been calculated. It is established that, at temperatures above a characteristic temperature T*, a strong dependence of the correction coefficient on time and a strong dependence of the relaxation function on the ratio of components exist.3. It is shown that use of the concept of thermorheologically complex behavior for prediction of the long-term deformability allows analysis of the contributions of specific components to the viscoelastic behavior of the mixture in different temperature intervals.Paper presented at the Third All-Union Conference on Polymer Mechanics, Riga, November 10–12, 1976.Okhtinsk Scientific-Industrial Association "Plastpolimer," Leningrad. Translated from Mekhanika Polimerov, No. 4, pp. 614–620, July–August, 1977.     

Parametric method for selecting an infralow-frequency signal in the Dulkyn gravitational-wave detector

A parametric method for selecting a response signal in the Dulkyn laser gravitational-wave detector is considered that allows the observation time required for detecting low-frequency periodic gravitational radiation from double relativistic astrophysical sources to be reduced to several periods of detectable signal. Dulkyn Scientific, Center of Gravitational-Wave Research. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 62–67, November, 1999.     

The possibility of checking the equivalence principle in a null gravitational redshift experiment by a two-resonator laser system

A scheme of an optical detector is proposed for checking Einstein’s equivalence principle (EEP) in a null gravitational redshift experiment and for testing methods for calculating the length of a resonator in a weak variable gravitational field by recording the variations of the difference frequency of resonators caused by lunisolar variations of the geopotential in a double or a two-resonator laser system.     

Generation of Optically Addressable Spin Centers in Hexagonal Boron Nitride by Proton Irradiation

Physics of the Solid State - The possibility of creating defects with spin-dependent fluorescence in a van der Waals material, namely, hexagonal boron nitride (hBN), by irradiating the latter with...