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The main electrophysical properties of polyvinylidene fluoride (PVDF) films produced by two technologies: the solution casting method and the method of hot pressing from the melt are investigated. To analyze the PVDF films, methods of dielectric spectroscopy (DS), IR spectroscopy, TGA/DSC analysis, and x-ray diffraction (XRD) are used. It is demonstrated that the IR spectra of both PVDF films change weakly in comparison with the virgin PVDF film. The absorption bands characteristic for α-, β-, and γ-phases are observed for the virgin and both types of PVDF films. This testifies to the fact that the molecular structure of film samples is practically independent of their processing method. The only difference is that the new absorption band at 1723 cm -1 arises in the IR spectra of the films produced by the method of hot pressing from the melt. The TGA/DSC analysis demonstrates that the beginning melting temperature, melting temperature, beginning decomposition temperature, and decomposition temperature for the film samples produced by the method of hot pressing from the melt decrease by 8, 2, 10, and 12°C, respectively, compared to the film samples produced by the solution casting method.

Vegetation cover has a noticeable effect on surface reflectivity and local microclimate in arid areas of Mongolian Gobi. Over the past decades, various shrub species (Haloxylon ammodendron and Calligonum mongolicum) have appeared on the previously unvegetated hamada. The climatic consequences of bush encroachment are still poorly understood. Using the experimental data, this article estimates the reflectance of plants dominating in Mongolia’s dry steppe, desert-steppe, and desert ecosystems. The average values of the total reflection coefficient at visible and infrared wavelengths range from 19.7% ± 1.4% to 20.1% ± 1.7% in plants growing in desert-steppe ecosystems, and from 25.0% ± 0.9% to 24.8% ± 1.5% on the bare surface. The difference between the reflectance of vegetated and unvegetated surfaces reaches 5%. Therefore, in daylight hours, the vegetated day surface loses less solar energy than the non-vegetated surface does. This phenomenon may be defined as a quasi- or secondary greenhouse effect – in daylight hours, solar energy is retained on the surface by vegetation and this contributes to the temperature increase. Such an impulse, which seems to be insignificantly small at first glance, triggers a series of climatic variations leading to a change in the structure of the radiation and heat balance as well as the climate not only in the desert-steppe and desert ecosystems but also in Central Asia as a whole. All this may explain the 1.2-2.3°C increase in air temperatures in the Gobi observed over the last 25 years.

This article presents the results of a study into the influence of the diet, air temperature and relative air humidity, and soil temperature on the average weight of Helix pomatia in captivity. It was shown that vegetables included in the mixed leaf-vegetable diet mitigated the effect of a high air temperature and a low relative humidity. It was established that the air temperature and relative humidity had opposite effects on weight gain in Helix pomatia. The increase in temperature predetermined the weight loss. Despite the high temperature, a humidity of over 75% caused all the molluscs gain weight regardless of their diet.

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