Home – Home – Jornals – Advanced Search

Extraction processing of pine needles ( Pinus sylvestris Ledeb.) allows obtaining the products that are used to manufacture the goods in medical, food, perfumery and cosmetics, and other branches of industry. At the same time, the post-extraction residue of needles (PERN), being a specific lignocellulose raw material, has not yet found proper (effective) use for obtaining innovative products. Using the method of thermogravimetry in a nitrogen atmosphere (TG/DTG), a number of thermal decomposition patterns of PERN have been established. Based on the results of TG/DTG, the kinetics of PERN pyrolysis was analyzed, the thermodynamic parameters Δ H , Δ G and Δ S were calculated. The average values of Δ H , Δ G and Δ S are 246.3, 160.3 kJ/mol and 135.7 J/(mol · K), respectively. According to the method of the fourth derivative of DTG contour proposed by us, a detailed “fractionality” of mass loss during heating of PERN under the conditions of thermogravimetric test has been established. The values of the apparent rate constant are calculated, indicating the multistage (I-V) process of thermal decomposition. By means of analytical flash pyrolysis of PERN, 66 pyrolysis products were identified. Among them, 35 compounds were identified that are not found in pine bark and wood pyrolyzates and can be in demand in organic synthesis, in the production of technical and food products, perfumes, medical products, etc . The obtained results are basic for designing the manufacture of technical products with increased added value and scaling of heat treatment technologies and pyrolysis of similar plant raw materials.

The production of many important carbon materials is currently based on the use of aromatic fractions of coal tar - a minor by-product in the production of metallurgical coke for the needs of ferrous metallurgy. Innovations to reduce the consumption of expensive metallurgical coke in blast furnace smelting and the priority development of the coke-free methods of steel production lead to a reduction in the output of coke-chemical products, which destabilizes the prospects for the production of important carbon materials, including those necessary for ferrous and non-ferrous metallurgy. The relevance of creating alternative methods for obtaining aromatic feedstock is substantiated. The potential of low-temperature coal processing by its thermosolvolysis with the production of concentrates of aromatic substances is shown. The possibility of their use as the raw material in the production of carbon anodes for the process of aluminum electrolysis is demonstrated.

To develop recommendations for the optimal consumption of food items considering the features of the Far North regions and the regional specificity of mineral composition, the content of 25 chemical elements was analyzed in the food items of local origin and those transported to the territory of the Magadan Region. It is determined that a portion of beef from cows grown in Magadan contains substantially higher amounts of calcium, sodium and phosphorus than beef samples brought from other regions. Locally produced beef liver contains higher concentrations of iron, iodine, manganese, and zinc. Locally produced pork contains significantly higher amounts of copper ( p = 0.01) and iron ( p = 0.1) in comparison with pork transported from other regions. Evaluation of microelement concentrations in vegetables in comparison with imported samples shows that local carrots contain higher selenium concentration, local cucumbers - higher potassium, copper, and manganese, beetroot is richer in selenium and zinc, with its portion being able to meet fully the daily demand for manganese. In all the analyzed vegetable samples imported from China, nickel content is higher than in local products. In addition, Chinese carrots contain reliably higher concentrations of boron and cobalt, tomatoes and cucumbers contain higher levels of chromium and vanadium, while silicon content is higher in vegetables from the Magadan Region. At the same time, neither of the examined samples exceeds the permissible levels of toxic elements.

Prediction of the physical-mechanical properties of metallurgical coke is an essential task from the viewpoint of its efficient application in the blast furnace process, in chemical industry, and also as fuel. The development of this task is the physical substantiation of the formation of coke piece strength. A method based on gasification is proposed to evaluate the size distribution of molecular oriented domains L_с(lamella height) and L_a(lamella length) indexes. It has been established through the analysis of the structure of large and small domains that large domains are less reactive in comparison with the small ones. For this reason, it is possible to use gasification with carbon dioxide to remove small domains leaving the large domains within the coke pieces. Results of the experiments provide evidence that mainly large domains remain in coke pieces after gasification. The indexes L_с and L_a were determined to increase approximately by a factor of 1.5 after gasification.

A systematic study of the relationship between the composition and structure of skeletal-dendritic ferrospheres isolated from fly ash formed in the combustion of Ekibastuz coal, carried out by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), allowed us to establish the general routes of their formation and the peculiarities of the influence of mineral precursors on their structure. The groups of globules were distinguished exhibiting a linear correlation between the content of silicon, iron and aluminium oxides in the gross composition of the polished sections. It is shown that the investigated ferrospheres are formed from the melt droplets of the general FeO-SiO₂-Al₂O₃-CaO system during their cooling and crystallization of individual phases. The formation of melt droplets occurs due to the sequential transformation of dispersed products from thermal conversion of mineral precursor associates, such as siderite, quartz, calcite and aluminosilicate components in the carbon matrix. The aluminosilicate precursor determining the structure of globules is hydromica of illite group. The crystallization of the ferrospinel of skeletal-dendritic globules occurs due to the “seed” of Al,Mg-ferrospinel, which is formed as a result of the thermochemical transformation of the illite of the initial coals. The observed general trend to changes in the structure of ferrospheres from coarse-grained crystalline skeletal type to fine-crystalline skeletal-dendritic globules is explained by a decrease in the content of the main spinel-forming oxides FeO, Al₂O₃ and MgO in the melt microdroplets.

Based on the results of adsorption studies, a procedure for modifying the porous carbon sorbent with tributyrin has been developed. The synthesis of tributyrin and the procedure of its quantitative determination in ethanol solutions by means of spectrophotometry are described. Carbon sorbent samples modified with tributyrin were obtained. Their properties have been studied using a complex of physicochemical methods. The possibility of using the modified sorbent as a drug of prolonged action is studied: tributyrin desorption from the carbon sorbent under model conditions in contact with 0.9 % NaCl (physiological solution) and in ethanol is investigated. It is established that in contact with the test solutions, the modifier deposited on the carbon carrier is desorbed within 6 h.

The dispersed fractions of industrial high-calcium fly ash (HCFA), selectively collected in the form of fractions 1-4 (Fr1-Fr4) on fields 1-4 of the electrostatic precipitators of the ash collecting unit at the Krasnoyarsk TPP-2, are systematically characterized. The fluidity parameters of ash mortars prepared from 100 % of each of the fractions at a ratio of water/binder = 0.5 were determined. It has been established that the value of fluidity decreases with an increase in the specific surface area of the fractions from Fr1 to Fr4. The parameters of cement-ash mortars with the replacement of cement by 50 and 20 % of each of the four fractions were determined. It has been established that at a 20 % HCFA content, the fluidity of cement-ash mortars of all fractions meets the requirements of GOST 1581-2019 for oil well cements. The samples based on finely dispersed fractions Fr3 and Fr4 meet the requirements for compressive strength on the second day of hardening. The specimens of ash-cement composites with high strength, more than 50 MPa for the 28th day of hardening, were prepared on the basis of the Fr4 fraction. In particular, high compressive strength (62-90 MPa) has been achieved for composite cements containing 80 and 90 % of the Fr4 fraction of HCFA in the presence of the superplasticizer Melflux 5581 F, which promotes efficient dispersion of finely dispersed HCFA in the liquid phase, faster and more complete interaction of active components with the formation of hardening hydrated phases. The addition of 5 % microsilica, which promotes the formation of an additional amount of calcium hydrosilicates, made it possible to achieve an increase in strength up to 108 MPa. The results obtained show that finely dispersed HCFA can be used as the components of oil well cements to improve the flowability of cement-ash slurries and improve the strength properties of highly filled ash-cement composite materials.

It is shown that the yield of humic acids increases by 20-30 % during the mechanical treatment of coals with a complex of oxidative-alkaline reagents. Upon the mechanochemical oxidation of the organic matter of brown coals, the molecular weight of humic acids and the percentage of aliphatic fragments in their structure decrease, while the content of phenolic and carboxyl groups increases. Ion exchange processes during the mechanical treatment of coals with mineral salts are accompanied by a decrease in the content of Na⁺ cations and an increase in Ca²⁺, Mg²⁺ cations in the composition of water-soluble humic substances. The concentration of SO₄^2- ions increases in samples of humic substances obtained from coals after mechanical treatment with ammonium sulphate.

The effect of leuzea (Rhaponticum carthamoides) and cranberry (Vaccinium oxycoccus) meal extracts composition at a dose of (70 + 500) mg/kg, as well as individual active substances (ecdisten and ursolic acid) in equivalent doses, on the biochemical parameters of physical endurance (lactate, glucose) in the forced swim test on CD-1 male mice is investigated. It has been established that the developed composition exhibits pharmacological effects similar to those of the individual active substances promoting a decrease in the concentration of glucose (in blood) and lactate (in blood and in muscles).

Copolymer of 2-(4-acryloylpiperazin-1-yl)methyl)-9H-thioxanthen-9-one and methyl methacrylate was synthesized by radical polymerization. This copolymer has high molecular weight characteristics and is capable of forming long-lived anion radical states of the pendant thioxanthenone groups during electrochemical reduction. Using a combination of electrochemical and optical methods, it has been shown that the electronic states of the pendant groups are located within the band gap of methyl methacrylate and may promote the Frenkel mechanism of conductivity in dielectric thin films used in resistive memory devices.