All Articles

Summary: In our previously published articles, we presented for the first time the results of quantum mechanical calculations of the rеaction profile for a new rеaction involving N-substituted hydrazonеs with CCl4 in the presence of a catalytic complex based on CuCl and TMEDA, leading to the formation of halogenatеd vinyldiazеnyl systеms containing geminal chlorinе atoms at the terminal vinyl position. The DFT calculations of the elеctronic structure of the molеcules demonstrated that the introduction of electron-donating and electron-withdrawing substituents into the aromatic fragmеnts of the molеcules significantly affеcts their properties by altering elеctronic parameters and reactivity dеscriptors. Based on these findings and expеrimental data, it was of interest to perform calculations and analyze the energеtic profile of the reactions under conditions of qualitative changes in the substrate composition. The study showed that in the case of hydrazones with complеmentary elеctron density shifts (i.e., donor substituents in the aldеhyde moiety and acceptor substituents in the hydrazine moiety of the molecule), in addition to the еxpected formation of dichlorinated vinyldiazеnes (dichlorodiazadienes), nеw competitive reactions occur. The products of these reactions are pseudo-dimers (bis-hydrazone derivatives), formed by the coupling of two molеcules of the initial hydrazonе. Energеtic calculations were carried out for both reactions, viz the formation of dichlorovinyldiazenes and bis-hydrazone derivatives. Based on these studies, the mechanisms for the formation of bis-hydrazone derivatives were proposed for the first time.

Summary: The evolving macroeconomic landscape, shaped by the global financial crisis and the COVID-19 pandemic, poses significant challenges for economies worldwide. However, Central, Eastern, and Southeastern European (CESEE) countries have demonstrated resilience and rapid recovery during crises, driven by a surge in consumption fueled by domestic credit and robust export growth supported by flexible exchange rates and adaptive monetary policies. Prior to EU accession, substantial foreign direct investment (FDI) during privatization and restructuring facilitated knowledge and technology transfers in CESEE economies. This study examines the interplay of exports, real exchange rates, GDP growth, FDI, inflation, domestic credit, and the human development index (HDI) in the CESEE region from 1995 to 2022, covering the transition period, EU accession, and major crises. Employing a panel ARDL model, we account for asymmetric effects of these variables on exports. The results reveal that GDP, FDI, inflation, domestic credit, and HDI significantly and positively influence exports, with HDI and GDP exerting the strongest effects, underscoring the pivotal roles of human capital and economic growth in enhancing export competitiveness. Conversely, real exchange rate depreciation negatively impacts exports, though non-price factors, such as product quality, mitigate this effect. These findings provide a robust basis for targeted policy measures to strengthen economic resilience and export performance in the CESEE region.

Summary: Recently, our scientific group has been studying in detail the synthesis and structural properties of dichlorodiazadienes obtained from the interaction of N-substituted hydrazones of benzoyl and terephthalaldehyde with polyhalogen methanes in the presence of a CuCl catalyst. This class of compounds, in addition to their application as azo dyes, can be used as important synthons in the synthesis of other organic compounds. Various research works have been carried out in this area. Mainly, their reactions with nucleophiles have been widely studied. Taking all this into account, we have studied the solvolysis reactions of mono and bis dichlorodiazadienes and synthesized the corresponding compounds.Four novel compounds were synthesized and their antimicrobial activities were evaluated using agar well diffusion method. The results revealed that fungal strains were more sensitive to all compounds compared to bacteria. Pseudomonas aeruginosa was the most sensitive gram-negative bacterium to compound III (Methyl (Z)-2-(2-(4-chlorophenyl) hydrazineylidene)-2-phenylacetate) with 20.0 mm as the diameter of inhibition zone. Escherichia coli and Bacillus mesentericus were highly resistant to compounds I. Candida albicans was the most susceptible fungal strain to compound IV ((E)-1-(4-chlorophenyl)-2-(2,2-dichloro-1-phenylvinyl) diazene) with an inhibition zone of 24.0 mm.

Summary: We have been synthesized hydrogenated Schiff base ligand with Co(II), Cu (II) and Zn(II) complexes. Ligand was synthesized hydrogenation of salicylidene-aniline. Ligand and three metal complexes structure have been proved by spectral analyses. The antimicrobial properties of synthesized compounds have been investigated. Synthesized compounds have shown high antifungal and antibacterial properties. Comparing Schiff bases metal complexes with hydrogenated Schiff base complex compounds hydrogenated complex compounds has shown higher antimicrobial properties, because when azomethines group double bond break down and hydrogen atom enter the structure of ligand it changes complex formation ability of ligand and also influence antimicrobial properties. Other positive side of of our ligand and complex compounds, they have shown antimicrobial properties even 0,25% concentration and they are durable 6 month.

Summary: Fungicides are very important for agriculture, animal husbandry and medicine, as the various infections induced by certain fungi cause harm to plants and animals which are used as a source of food, as well as directly to humans themselves. More than 1,5 million deaths are caused by fungi each year, both the incidence of fungal infections and the resistance against already existing antifungal drugs are on the rise, which renders the search for inexpensive and new effective fungicides very urgent. On the other hand, some compounds containing 1,2,3-triazole moieties (for example, Radezolid and Cefatrizine) display strong antifungal activity and are used as fungicides. Azoles prevent lanosterol 14-alpha-demethylase enzyme from converting to ergosterol, and therefore inhibit growth of fungi. Today many scientists all across the world synthesize new compounds containing 1,2,3-triazole moieties and research their antifungal properties by applying them against various pathogenic fungal strains. This article is a review of recent scientific literature describing antifungal activity of compounds containing 1,2,3-triazole moieties.

Summary: After ores are extracted from mines, they undergo various processing processes, after which they are smelted. The smelting process is carried out in various types of smelting furnaces and units. The working areas of these units are built of refractory materials. These refractory materials are eaten, destroyed, and fail for various reasons. One of the reasons that accelerates the erosion of refractory materials is the dross formed during the smelting process. This largely depends on the composition of the dross. The dross contains metal and non-metal oxides of various compositions and nature. Since the composition of the dross is of various nature, the mechanism of action is also different. The article clarifies the effect of dross on the working volume of the furnace during the smelting process, and proposals are put forward for its elimination. The acid open-hearth process allows steel to be produced with a lower gas content compared to the basic process.

Summary: This article is devoted to the extraction of silver (Ag) ions in an acidic medium at pH 5 by a copolymer of maleic anhydride with styrene (MASC), chemically modified with 4-nitroaniline-2-arsonic acid (NAA). The structure of the sorbent CSMA-4-nitroaniline-2-arsonic acid was studied by IR spectroscopy methods. The study of Ag(I) ion sorption was carried out under static conditions. The influence of various parameters on the process of Ag(I) ion sorption was studied. Maximum sorption of metal ions is observed at pH 5. The sorption equilibrium was established after 3 hours. As the concentration of sorbed metal ion increases, it reaches its maximum at 6·10-3 M. To study desorption, the effect of different acids - HNO3, CH3COOH with the same concentrations on the desorption of Ag(I) from the sorbent was studied. The experiment showed that the maximum desorption of Ag(I) occurs in 2 M nitric acid (HNO3).

Summary: Oil products are the strongest toxic substances on the earth's surface, and their permissible levels in water bodies are 0.1 mg/dm3. However, until now, insufficient attention has been paid to determining the amount of oil products in natural and waste water. The article presents the results of spectrophotometric determination of the amount of oil products in water samples taken from lakes in the Absheron Peninsula and compares them with the existing gravimetric method. Extractants were selected to determine oil products, and the improved spectrophotometric method was applied to real objects under optimized conditions. The aim of this work was to select an organic extractant for the extraction of petroleum products from natural and waste waters and to apply an improved spectrophotometric method to natural objects. The aim of this work was to select an organic extractant for the extraction of petroleum products from natural and waste waters and to apply an improved spectrophotometric method to natural objects. The waters taken from the lakes of Gu and Girmizy on the territory of the Absheron Peninsula were selected as objects of the study. Spectrophotometric, gravimetric and chromatographic methods of analysis were used in the study. A mixture of organic reagents was selected to determine oil products in the waters of the lakes. Using the selected organic reagent, the oil products contained in the objects of study were isolated and analyzed using the GX-MS method. A new improved separation method using a mixture of organic reagents was proposed for the spectrophotometric determination of oil products. An improved spectrophotometric method for determining oil products in natural waters was developed. Optimal conditions for the extraction of oil products were found and the extraction method using a new organic reagent was optimized. The proposed method was tested on natural waters.

Summary: The waterflooding technique is one of the most widely used and efficient technique for increasing oil recovery. In an oil-wet reservoir, however, the higher the water mobility, the lower the oil production. The following research will look into the effects of high and low saline waterfloods on oil recovery and water mobility with application of magnetic field. This research also looks at how varied water salinity injections affect wettability and salt production rates. The design of a three-dimensional, two-phase model, i.e., water and oil, is the first step in this research. Initially, the reservoir is oil-wet. To show the wettability change, relative permeability curves are generated during simulation. The impact of salinity on oil production, water mobility, and salt production is examined by a comparison of high and low saline waterfloods. In order to identify an effective well injection technique, a sensitivity analysis was done for two possible injections well patterns: five spot and direct line drive. The recovery attained by lowering the salinity of the water was found to be around 80%, with a cumulative oil production of 0.45 MMSTB. The water cut is prolonged to a large extent by lowering the salinity of the water.

Summary: In the research work, diethylamine, dipropylamine, dibutylamine complexes of the mixture of alkylarylsulfonic acids obtained on the basis of the light gas oil fraction obtained from the secondary oil refining process - the catalytic cracking process were synthesized, solutions of the samples were prepared in water, water + ethyl alcohol, water + isopropyl alcohol. Some physico-chemical properties of the samples were studied, bactericidal properties were studied by keeping them in a thermostat at a temperature of 32ºC for 15 days and calculating the amount of H2S produced at the end. It was determined that the aqueous solution of the diethylamine complex of the mixture of alkylarylsulfonic acids showed a high bactericidal effect (99%) at the concentration of 50 mg/l. Solutions of diethylamine and dipropylamine complexes in water at the concentration of 75 mg/l showed 100% bactericidal effect and reduced the number of bacteria to zero. Solutions of dibutylamine complex in water + ethyl alcohol, water + isopropyl alcohol at the relatively high concentration (150 mg/l) showed 100% bactericidal effect and stopped the life activity of bacteria.