Size Effects in Climatic Aging of Epoxy Basalt Fiber Reinforcement Bar.

The purpose of this study was to obtain information on the influence of the size factor on the climatic aging of circular fiber plastics produced by pultrusion. The kinetics of moisture transfer was obtained in humidification and drying modes at 60 °C in samples of epoxy basalt fiber reinforcement bars: after 28 months of exposure in the extremely cold climate of Yakutsk and 30 months of exposure in the moderately warm climate of Gelendzhik. It was shown that the 2D Langmuir model adequately describes the kinetics.

The Initial Stage of Climatic Aging of Basalt-Reinforced and Glass-Reinforced Plastics in Extremely Cold Climates: Regularities.

Detailed analyses of the reasons for changes in the mechanical parameters of fiberglass exposed to different climatic zones have been made available in the literature; however, such detailed studies of basalt plastic do not yet exist. It is possible to make reasonable conclusions on the climatic resistance of reinforced plastics by monitoring the deformation-strength characteristics in combination with fractographic and DMA analyses of the solar- and shadow-exposed parts of the plastics; additionally, one can conduct analyses of the IR spectrum and the moisture sorbtion kinetics. As a starting point for the climatic aging of polymer composite materials, it is necessary to accept the time of exposure in which the maximum values of the elastic strength properties of polymeric materials are achieved.

Contributing Factors of Uneven Climatic Aging for Polymeric Composite Materials: Methods and Modelling.

Regarding a wide variety of PCMs, the materials' strength properties which decrease no more than 20% after 30 years of operation are of special interest. One of the important regularities of the climatic aging of PCMs is the formation of gradients of mechanical parameters across the thickness of the plates. The occurrence of gradients must be taken into account when modeling the strength of PCMs for long periods of operation.

[To the question of genetic predisposition to the development of professional sensorineural hearing loss].

Unlabelled: Objective was to study single-nucleotide polymorphisms (SNP) in CAT, NCL, HSPA1L, PCDH15, and PON2 genes and their associations with hearing impairment among the people working among noise-exposed workers of the mashine-building plant (JSC «Krasmash», Krasnoyarsk, Eastern Siberia, Russia).

Materials And Methods: The 443 employees of Krasmash JSC, who have been working under conditions of increased noise for at least 1 year, were surveyed and examined. A hearing study was performed by speech and tonal audiometry.