Mechanism of Multi-Stage Degradation in Hot Bitumen of Micronized Powder Elastomeric Modifiers from Worn-Out Tire's Rubber.

For the first time, by atomic force microscopy (AFM) methods, micro- and nanofragments of micronized powder elastomeric modifier (PEM) formed at the short-term (3 min at 160 °C) interaction of PEM with hot bitumen have been demonstrated. It is the technology of high-temperature shear-induced grinding of a worn-out tire's crumb rubber or its co-grinding with styrene-butadiene-styrene (SBS) block copolymer which provides the creation of the PEM structure inclined to rapid degradation in hot bitumen. The formation just after the preparation process of a new structure of a modified binder, more resistant to external effects, is supported by the data of rheological tests.

Ultra-Dispersed Powders Produced by High-Temperature Shear-Induced Grinding of Worn-Out Tire and Products of Their Interaction with Hot Bitumen.

Structural features of crumb rubber (CR) particles obtained by grinding on rollers and ultra-disperse powder elastomeric modifiers (PEM) obtained by high-temperature shear-induced grinding (HTSG) of CR or co-grinding with butadiene styrene thermoplastic elastomer (SBS) have been studied by electron and optical microscopy methods. Samples of modified bitumen were obtained at different mixing times (1-40 min) in a wide temperature range (120-180 °C). The products of interaction of PEM with hot bitumen precipitated on filters when washed with solvent from modified bitumen (MB) were studied by scanning electron microscopy (SEM).

[Chronic pain syndrome in diseases of periarticular tissues].

The search for an effective method of treating diseases of the musculoskeletal system is a rather actual problem for a practicing physician nowadays in connection with the modern lifestyle of most people. A prolonged stay in the same position, as a rule, leads to overstrain of the capsule-joint complexes, and, as a consequence, to the development of degenerative changes in the joints and periarticular tissues. These changes can manifest themselves clinically in the form of a chronic or acute pain syndrome.

[Experience of functioning of the psychological- medical- and pedagogical commission at psychiatric hospital].

Psychological- medical- and pedagogical commissions (PMPC) are most often established at educational institutions. However, children cannot be thoroughly examined in educational settings in certain cases; therefore, the physicians fail to diagnose mental deficiency in children due to insufficiently careful examinations. Correspondingly, PMDCs, when established at patient-care and preventive facilities, ensure a more accurate diagnosis and determination of an intellectual-deficiency degree in children or teenager; they also provide for elaborating a set of psychological- medical- and pedagogical measures.

[Seasonal changes in the resistance of a Drosophila population to low temperatures and their association with fertility].

Significant genetic variation in resistance to cold was detected in samples collected from a natural Drosophila population in spring, summer, and autumn. In the summer sample, phenotypic variation was determined by genetic factors; in the summer and autumn samples, exclusively by environmental factors. Flies collected in spring had the highest longevity at low temperatures.