The composition of carboxymethylcellulose–dioxydine was obtained and its structural, morphological and rheological characteristics in the processes of heat treatment and chemical hydrolysis were studied. Using IR spectroscopy, scanning electron microscopy, and viscometry, it has been established that the introduction of dioxidine into a solution of carboxymethylcellulose sodium salt with different molecular weights leads to partial disordering of hydrogen bonds between macromolecules, promotes thermal destruction of the polysaccharide and a decrease in the dynamic viscosity of solutions. Experimental kinetic curves of carboxymethylcellulose hydrolysis in the presence and absence of dioxidine were obtained, and it was shown that they could be described using a first-order equation. The hydrolysis rate coefficients were calculated, and it was shown that, as a result of heat treatment, as well as in the presence of an active substance, the rate of carboxymethylcellulose hydrolysis increased. The change in the rheological properties of carboxymethylcellulose sodium salt solutions with different degrees of polymerization in the presence of an antimicrobial substance should be taken into account when choosing the composition of viscous prolonged forms of biologically active substances.

Dependencies of the viscoelastic and thermodynamic properties of high-viscosity oil from the oil-gathering reservoir of the N-Korenevskoye and Denisovskoye fields on the degree of water cut and temperature have been established. Under the conditions of shear deformations and at comparable temperatures, the nature of the processes of structure formation of oil at a low degree of water cut is due to phase transitions of paraffins, which is consistent with the experimental data described in the literature for non-watered oils, indicating the identity of the nature of intermolecular interactions between non-watered oil and oil with a low degree of water cut. The maximum effect of the thermal method for reducing the viscosity of oil with a low degree of water cut can be achieved when it is heated to the paraffin melting point T_m*, determined using the ln(η) = f (1/T) dependence. The peculiarity of the rheological behavior of high-water-cut oil is due to an increase in the energy of intermolecular interaction, which in the entire temperature range is practically comparable to E_act1 of low-water cut oil at T <T_m*, which is associated with the formationn of invert emulsions stabilized by interphase layers of asphaltene molecules. It is shown that an increase in temperature and shear deformations contribute to a decrease in the values of the effective viscosity of low and high water cut oil; however, the destruction of their colloidal structure does not occur in the entire range investigated. The loss of aggregate and kinetic stability of high-viscosity watered oil is achieved in the presence of a surfactant composition based on Sorbital C-20 and a sodium salt of alkylbenzenesulfonic acid, which causes the desorption of “natural stabilizers” from the oil-water interface and, as a consequence, the coalescence of water droplets.

The state of the steel substrate (steel 3) was studied before the application of composite copper coatings from citrate copper-plating electrolyte. The properties of steel base in the investigated copper-plating electrolyte with the addition of ultradispersed diamonds (UDD) have been studied. A component-by-component analysis of the citrate copper-plating electrolyte was carried out, and the effect of each component on the properties of the steel electrode was evaluated. The possibility of using the considered electrolyte for coating directly on steel is shown, which significantly distinguishes it from currently used ethylenediamine, pyrophosphate, acid and other electrolytes. Electrochemical impedance spectroscopy and cathodic polarization were used as research methods. It was found that the lowest resistance of the steel surface (about 15 Ω) corresponded to the sample immersed in citrate copper-plating electrolyte with the addition of 1.0 g/l of UDD. Diffusion current density for suspensions with 1.0 g/l UDD in citrate copper-plating electrolyte was 2.6 A/dm². Ultradispersed diamonds in citrate copper-plating electrolyte shielded the surface of the steel sample, while reducing the total resistance of the passive layer of steel 3. Equivalent electrical circuits of the surface of steel samples immersed in citrate copper-plating electrolyte and its components are also presented.

Ni₉₃Cu and Ni₈₂Cu (at%) alloys were synthesized by the method of combined chemical reduction of Ni(II) and Cu(II) with hydrazine hydrate. These alloys consist of crystalline phases of nickel, solid solution of copper in nickel. Determination by the “capacitive method” of the electrochemically active surface area of working graphite electrodes with “catalytic inks” containing Ni₉₃Cu and Ni8₂Cu powders showed that it is 4 and 20 % larger than for nickel powder, respectively. It was found that powder alloys Ni₉₃Cu and Ni₈₂Cu are applicable as catalysts for the electrochemical process of hydrogen evolution in alkaline solutions and alkaline ethanol solution. It was determined that the catalytic activity of Ni82Cu powder alloy in the process of hydrogen evolution in the alkaline ethanol solution is higher than for nickel and Ni₉₃Cu powders. The catalytic ability of the Ni₈₂Cu powder alloy during cycling for 25 cycles practically does not change, in contrast to Ni and Ni₉₃Cu.

A research on the process of enrichment of potash ore using a collective mixture based on higher aliphatic amines, pine oil, and polyethylene glycol (PEG-400) has been carried out. Comparative flotation studies using pine oil and PEG-400 have shown the effectiveness of combined use of these reagents. The effect of adding foaming agents on the micellar structure of amine solutions and the adsorption of amine on the surface of potassium chloride was proved by colloidalchemical methods. It was shown that the introduction of a combination of pine oil and PEG-400 makes it possible to extract 90.3% of potassium chloride into a concentrate at content 87.0 % of potassium chloride. Recovery rates when using a combination of foaming agents are higher than those for adding only one of the foaming agents to the collective mixture. Thus, the best performance was achieved by using a combination of foaming agents. The optimal consumption in laboratory conditions for pine oil and PEG-400 was 10 g/t of ore.

Determination of the composition of pyrolysis products of organic compounds is a very difficult task due to their multicomponent nature [1–3]. Pyrolysis oils formed from rubber products and organic polymer wastes contain various classes of organic compounds with a huge spread in molecular weight and polarity: hydrocarbons, amides, phenols, amines, organosulfur compounds, etc. [1]. At the same time, the results of qualitative and quantitative chromatographic analysis of pyrolysis oils are often ambiguous: there are problems of overlapping peaks and misinterpretation of the data obtained due to the complexity of the matrix and the multicomponent composition [2–5]. Pyrolysis products can be used as valuable hydrocarbons or additives to hydrocarbon fuels. Therefore, the analysis of the chemical composition of pyrolysis oils is important both for assessing the degree of their toxicity and for finding an effective method for their purification.

Two new fluorescent NBD-piperazine derivatives with lipophilic substituents of formylcholesterol and hexanoic acid (compounds 2 and 3, respectively) were synthesized. Using in silico calculations, their abilities to permeate through lipid bilayer and to be bound affinely with some cytochromes P450 of human (2 with lanosterol 14α-demethylase CYP51, 3 with drug-metabolizing CYP1A1, CYP2D6, CYP3A4; energy of binding E_bind from –14.4 to –10 kcal/mol) and of mycobacteria (2 with sterol 27-hydroxylase CYP125, 3 with “orphan” CYP164; E_bind from –13.3 to –9.1 kcal/mol) were demonstrated. The synthesized compounds and calculated computational data will contribute to prioritization of in vitro investigations aiming to revealing properties of the proteins.

Hedyotis corymbosa from the Rubiaceae family, widely distributed in tropical regions of Asia. Based on the traditional uses, researchers provided substantial scientific evidence revealing the beneficial impact of this plant highlighting its anticancer, hepatoprotective, antiulcer, antioxidant, anti-malarial, antibacterial and antifungal activities. This study aims to screen and identify anthraquinone from the methanol extract of whole plant H. corymbosa. The Anthraquinone was further fractionated and isolated using chromatographic techniques to obtain the purity of compounds. The anthraquinone structure was determined using spectroscopic analysis especially the Nuclear Magnetic Resonance (NMR) and Mass Spectrum (MS).

Studies on the flotation enrichment of polyhalite-halite ore have been carried out. It was determined that the maximum degree of disclosure of polyhalite-halite ore to the components during grinding falls on the fraction (–0.5 mm). It was established that the enrichment of polyhalite-halite ore is possible by the method of reverse flotation using alkylmorpholine as a collector. It was established that high levels of enrichment of polyhalite-halite ore (recovery of halite 95.41 %) are achieved at high dosage of the collector (1600 g/t).

The features of the structure formation processes of potassium sulfate and chloride dispersions in the presence of various binding additives have been studied. It has been shown that the process of structure formation proceeds most effectively in the presence of a complex additive containing a finely dispersed clay component and a high molecular weight polymer. Mechanism of structure formation and the optimized process of additive introduction into the dispersed system is discussed.

The feasibility of separation of activated prothrombin complex (APC) solution via ultrafiltration was investigated. To separate thrombin from high molecular weight impurities, polyethersulfone hollow fiber ultrafiltration membrane PES-HF-100 (manufactured by Institute of Physical Organic Chemistry of the National Academy of Sciences of Belarus) was used, further concentration of the target filtrate of PES-HF-100 was carried out using polysulfone membrane PS-PV-20. It was found that ultrafiltration methods are suitable for isolation of thrombin from APC. Comparative analysis of prepared samples with commercial analogs of the coagulation reagent “Thrombin” established that thrombin isolated via ultrafiltration is not inferior in purity to thrombin isolated by chromatography.

The aim of the study is to develop an environmentally friendly chromium-free passivation technology for galvanized steel. Passivation of zinc coatings was carried out by deposition of conversion coatings from solutions containing ZrO(NO₃)₂, Na₂SiF₆ and oxidizer H₂O₂ or K₂S₂O₈. The effect of the solution pH, the concentration of Na₂SiF₆ and the type of oxidizer on the protective properties of coatings was studied by the drop method and electrochemical method of linear voltammetry in 3 % NaCl using the full factor experiment 23 . The main effects and effects of the interaction of the studied factors for the darkening time of the droplet and the dissolution potential of zinc are calculated. The solution pH in the presence of the oxidizing agent K₂S₂O₈ influences the both parameters in the most extent. Concentration of Na₂SiF₆ has a significant effect on the dissolution potential of zinc and the least effect on the darkening time of the droplet. An increase in the solution pH and the concentration of Na₂SiF₆ increases the protective properties of the coatings. Measurements of the mass loss and open circuit potential during the resource testing of conversion coatings in 3% NaCl showed an increase in the corrosion rate over time.

A review of the results of studying the relationship in the system “nucleosides–phospholipase A₂”, which plays a decisive role in the metabolism of phospholipids and their derivatives – prostaglandins, thromboxanes and leukotrienes as the most important intracellular messengers, is presented. The review considers the effect of nucleosides on the activity of secretory PLA₂ and the metabolism of liponucleosides, which are of interest as specific delivery vehicles for nucleoside drugs. The results of these studies are considered from the point of view of the pharmacological potential of liponucleosides as new forms of known drugs.