The influence of sodium oleate additives on processing and morphology of polypropylene ‐ co‐polyamide (PP/CPA) mixture melts has been investigated. It is shown that sodium oleate is located in the interphase of the components and acts at small additives (up to 3 wt%) as an interfacial tension agent, improving miscibility of polymers, and increasing the kinetic stability of mixtures and the degree of PP dispersion in the co‐polyamide matrix. The plasticizing effect on mixture melt was observed at 7 wt% sodium oleate as a reduction of mixture viscosity. The ultrathin PP fibers (microfibers) strictly oriented in the direction of extrusion are the main type of structure produced during extrusion of a PP/CPA mixture. Addition of sodium oleate changed the PP fiber‐formation in the CPA matrix: the total number of fibers increased, their diameter and diameter distribution decreased.

The influence of the compatibilizers of an ethylene-vinyl acetate copolymer and sodium oleate on the processes of melting and crystallization and the supermolecular structure of polypropylene/copolyamide blends of composition 20/80, 40/60, and 50/50 wt.% has been investigated. It has been shown that a specific fiberization is clearly realized in the compatibilized blends even for compositions corresponding to the region of phase change. Two to three peaks of crystallization of polypropylene in the blends containing an ethylenevinyl acetate copolymer or sodium oleate have been revealed, which is attributed to the increase in the degree of dispersion of polypropylene as a result of the improvement in the specific fiberization and to the growth in the fraction of polypropylene in the interphase transition layer.It is well known [1] that polymer blends are being used in a modern, simple, and efficient method of modifying them and obtaining products with completely new properties. Thus, for example, processing of polymer blends opens up a completely new avenue for production of ultrafine synthetic fibers (microfibers). We are dealing with the so-called phenomenon of specific fiberization [2], where one (fiberizing) component forms numerous microfibers strictly oriented in the direction of extrusion in the mass of another (matrix) component in the case of flow of a molten blend. The morphology of a polymer blend is determined not only by the microrheological processes (deformation of droplets to liquid jets, disintegration of the latter into droplets, and migration on the radius of the extruder-die orifice) at the stage of processing but also to a large extent by the capacity of the blended polymers for crystallization and by the conditions under which it occurs. Realization of specific fiberization substantially depends on the degree of compatibility of the components of the blend and the possibility of forming a transition layer transferring the deforming force from the matrix polymer to the fiberizing polymer. Commercially produced polymers are thermodynamically incompatible, as a rule. Therefore, in processing their blends, one adds special substances improving their compatibility; they are called compatibilizers [3]. Physicochemical processes in compatibilized polymer blends were investigated in [4,5] in detail, but no consideration was given to phase transitions.This work seeks to study the processes of melting and crystallization in ternary compatibilized polymer blends.Objects and Methods of Investigation. Blends of polypropylene (PP) and copolyamide (CPA) with a ratio of the components of 20/80, 40/60, and 50/50 were used as the objects of investigation. Copolyamide represented a caprolactam-AH (adipic acid and hexamethylene diamine) salt copolymer of composition 50/50. The characteristics of the starting polymers have been given in [4,5]. As the compatibilizers we used an ethylene-vinyl acetate copolymer (EVAC) and sodium oleate. We added EVAC in an amount of 5, 10, 20, and 25% of the PP mass. The amount of ...

The accident in the second power-generating unit of the Chernobyl nuclear power plant on October 11, 1991 was the result of unauthorized connection of the TG-4 turbogenerator, which was shut down for repairs, into the grid (in the off-design asynchronous engine mode), and this resulted in a serious fire in the machine room and subsequent failure of systems which are important for safety and which ensure the design mode of reactor cooling: These were primarily failures of the feed and emergency feed pumps and failure of the BRU-B control valve, which regulates steam release during cooling.In accordance with the INES international scale of nuclear events, this event was a level 2 incident, and according to the category of disruptions of operation (AS-PNA]~ G-12-005-9t) -a "PO5 event" with insignificant radiation consequences [I]. It was determined to be a malfunction in the electrical part of the unit, which resulted in a fire in the No. 4 electric generator followed by disruption of the conditions for safe operation.The emission of radioactive aerosols into the atmosphere was due to the combustion of elements of the roof with traces of contamination from the accident in the fourth power-generating unit of April 26, 1986 and constituted 3.6.10 -5 Ci. The total emission during the event was equal to 1.4.10 -3 Ci and did not exceed the admissible daily emission into the atmosphere. The personnel were not exposed to radiation above admissible control levels. The participants in putting out the fire, 63 individuals from the operating personnel, and firemen received doses from 0.02 up to 0.17 rem, which does not exceed the admissible two-weak dose. A statistically significant increase in the concentration of aerosols in a 30-km zone around the nuclear power plant was not recorded [I].During the fire the surfaces of the technological enclosures were contaminated with radioactive substances from 20-100 up to 30-400 /3-particles/cm2-min, which did not exceed the admissible level for normal operation 2000 /3-particles/cm2.min. No additional contamination of the territory inside or outside the plant confines was observed within the limits of sensitivity of the modem dosimetric and 3,-spectrometric apparatus employed [1].The sequence of events in the incident was as follows. The power-generating unit was being put into an established power level after preventive maintenance, lasting for two months. The thermal power was equal to 1570 MW (50% of the thermal power of the reactor). One 425 MW turbogenerator (TG-3) in the power-generating unit was in operation. The second turbogenerator (TG-4) of the power-generating unit was shut down for repairs to the separator-steam superheater (SPP-44).

Although more than 2 years have passed since the beginning of the pandemic of the new coronavirus infection, treatment and prediction of the course of SARS-CoV-2 infection remain pressing global problems. In this regard, the search for additional links in the pathogenesis of SARS-CoV-2 is currently one of the most important tasks. The Aim. To assess the level of lipopolysaccharide-binding protein (LBP) and presepsin (sCD14-ST) in patients with SARS-CoV-2 viral lung disease in Crimea.Methods. We examined 121 patients with a positive PCR result for SARS-CoV-2 in the age group of 45 – 75 years who were hospitalized in the Department of Infectious Diseases, State Budgetary Healthcare Institution of the Republic of Crimea “N.A.Semashko Republican Clinical Hospital”. Patients were divided into 3 clinical groups according to the severity of SARS-CoV-2 infection: Group 1 – patients with moderate disease, Group 2 – patients with severe disease, and Group 3 – patients with fatal outcome. Peripheral blood levels of LBP, presepsin, ferritin, and C-reactive protein were determined upon admission to the infectious disease hospital.Results. A significant increase in all studied parameters was observed in the 1st, 2nd and 3rd clinical groups of patients with coronavirus infection. This finding corresponds to the state of lipopolysaccharide-binding systems and systemic infection in patients with SARS-CoV-2 viral lung disease. The highest levels of LBP, sCD14-ST, and ferritin were registered in the 3rd clinical group. We found a direct correlation between LBP and sCD14-ST levels in the 2nd group (r = 0.523, p < 0.05) and the 3rd group (r = 0.748, p < 0.05).Conclusion. Patients with SARS-CoV-2 lung disease were found to have an increased blood levels of LBP and presepsin upon admission. The highest values were observed in patients with fatal outcome. Severe SARSCoV-2 lung damage was associated with a direct correlation between levels of LBP and sCD14-ST. Presepsin, LBP, and ferritin are important prognostic markers for severe SARS-CoV-2 lung damage and risk of death in the early stages of hospital treatment.

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