Institute of Hydrocarbon Processing

Abstract Medium to extra‐high voltage electrical cables typically comprise a semiconductive polymer composite layer to homogenize the electromagnetic field through the cables. The semiconductive layers usually contain a high content of carbon black (CB) for reduced electrical resistivity. In this study, we found that both the morphology and resistivity of a ternary polymer composite of CB/low density polyethylene (LDPE)/ethylene‐vinyl acetate (EVA) depend on CBs used and the order of addition. Three types of CB were investigated. CB‐A, which has the lowest surface energy and the most uniform surface energy profile, exhibits a strong affinity to LDPE and always segregates in the LDPE phase whether it is first added in the LDPE phase or the EVA phase. CB‐B and CB‐C, which have higher and less homogeneous surface energies, distribute differently with different orders of addition. We observe a significant reduction in the percolation threshold of CB‐A in the CB/LDPE/EVA composite, but not with CB‐B or CB‐C. Adding CB‐A in the LDPE phase first results in substantially lower resistivity than adding it in the EVA phase first, whereas adding CB‐B or CB‐C in the LDPE phase first results in higher resistivity than adding them in the EVA phase first.

To improve the management of patients with chronic endometritis (CE) by using a molded sorbent-modified by polyvinylpyrrolidone (FSMP). This prospective study included 70 patients with CE divided into two groups: group 1 (n=23) received traditional antibiotic therapy (from days 3 to 10 of the menstrual cycle); group 2 (n=47), received antibiotics and FSMP was inserted from days 5 to 10. At the end of therapy, group 1 had massive growth of pathogenic microflora in 21.7%, moderate growth in 69.6%, and no growth in 8.7% of cases. In group 2, after combined therapy, massive growth was observed in 4.3%, moderate growth in 44.7%, and no growth in 51.0%. In group 2 after 5days, serum levels of interleukin-1β (IL-1β) were 1.9 times, of IL-6 were 7.0 times, and of IL-8 and IL-1 receptor antagonist were 1.3 times lower than in group 1. In uterine cavity aspirates, IL-1β decreased around 4.8 times, IL-6 by 11.8 times, IL-8 by 3.2 times, tumor necrosis factor-α by 3.9 times, and IL-1 receptor antagonist by 2.1 times in comparison to group 1. Combined therapy of FSMP with antibiotics is more effective in treating CE, because it contributes to the almost complete elimination of pathogens and toxins from the uterine cavity, blocking the local pro-inflammatory cascade.

Catalytic properties of Pd/Al2O3 and Pd-Ga/Al2O3 in selective liquid-phase hydrogenation of acetylene in a flow under pressure and the effect exerted on them by introduction of CO into the feed were studied. The presence of CO in the reaction mixture ensures the reaction with the predominant formation of ethylene. Introduction of gallium into the catalyst formulation prevents the catalyst deactivation. Simultaneous action of these factors allows reaching high yield of the target product in combination with long operation life of the catalyst.

The studies were focused on the influence of key parameters (temperature, pressure, dilution of the reaction medium with an inert gas) of catalytic processes (cracking of vacuum gasoil, hydrogen-free upgrading and cracking of gasoline fractions) on the ratio of selectivities to cracking and intermolecular hydrogen transfer. Controlling the ratio of these reactions allows the required products to be obtained on the feedstock processing. Lengthening of the feedstock-catalyst contact time, a decrease in the proportion of the diluting inert gas, and the pressure rise provides an increase in the selectivity to hydrogen transfer. Fixed and circulating catalyst bed setups were used for the experiments. Transformations of the feedstock containing deuterated compounds were studied.

Carbon sorbents modified with poly(N-vinylpyrrolidone), betulin, and poly(N-vinylpyrrolidone) together with betulin have been synthesized. The synthesized samples have been studied by a complex of physicochemical methods (low-temperature nitrogen adsorption, thermal analysis, elemental analysis). Under model conditions, the antioxidant properties of the modified sorbents with respect to their ability to deactivate hydrogen peroxide have been studied. The effect of the carbon sorbents on the hydrogen peroxide decomposition rate has been determined by the gasometric method; the reaction rate constants have been calculated. Dependences of the hydrogen peroxide concentration on the time of contact with the test sorbents have been studied by the optical method using an LIR-2 interferometer.

The influence of temperature on the conversion of ethanol-lignin in supercritical ethanol and on the yield and composition of the products formed was studied. In the absence of catalysts, the highest yield (60 wt.%) of liquid products of thermal conversion of ethanol-lignin was obtained at the temperature of 300 C. According to GC-MS data, the ethanol-soluble products mainly consist of phenols, methoxyphenols and ethyl esters of carboxylic acids. The increase of the temperature of ethanol-lignin conversion to 400 C intensifies the transformation of liquid ethanol-soluble products into solid and gaseous substances and leads to a decrease in ethanol-soluble products the content of methoxyphenols by 3 times and of carboxylic acid esters by 2 times. The use of catalysts, based on borate-containing alumina in the process of ethanol-lignin conversion in a supercritical ethanol at the temperature 300 C increases the yield of products, boiling up to 180 C by 3,4-3,6 times and rises the yield of methoxyphenols by 1,4-1,7 times in comparison with a non-catalytic process.