Ukhta State Technical University

Granites recovered by boreholes 1-Yuzhnaya Bolotnaya and 1-Sosyanskaya in the Izhma zone of the Timan megablock of the Pechora basin basement are most similar in their mineral and chemical composition to S-type granites. U-Pb (SIMS SHRIMP-IIe and SHRIMP-RG) zircon studies of these granitoids have not allowed for a correct determination of the rock formation time, as the zircons are either inherited or highly discordant. The granite age has been revised by the 40Ar-39Ar dating of muscovite from the same samples. The 40Ar-39Ar age of muscovite in granites of the 1-Yuzhnaya Bolotnaya borehole is 548 ± 7 Ma and in the 1-Sosyanskaya borehole is 565 ± 7 Ma. These data correlate with U-Pb (SIMS SHRIMP-IIe and SHRIMP-RG) ages on zircons from granites of other zones of Pechora basin basement and confirms the large-scale intrusion of granitoids in the Late Vendian during collision processes at the final stage of Timanian tectogenesis.

Depolarization currents in submicron polymethylmethacrylate (PMMA) films were measured using the thermally stimulated depolarization (TSD) method in the range from 170 to 450 K. The concentration of the solution was 0,5; 1,0; 2,0; 3,0; 5,0; 7,5 and 10.0 wt.%. The value of the polarizing electric field strength was 1.7·105 V/cm. The rate of temperature change was 5 K/min. Based on experimental data, the values of the released charge and the activation energy of relaxation processes depending on the thickness of the polymer film are shown.

For the study, researchers selected reinforcing material, along with effective strengthening methods for the knives. These knives were intended to replace similar imported parts from MWS (Germany) on combines produced by Rostselmash plant LLC. During the study, the causes of the dispersion of blanks, wear in real operating conditions were determined, methods for optimizing charge materials for obtaining hardening coatings were described, material science studies of coatings containing wear resistance modifiers (B4C, WC). As an import-substituting material for strengthening coatings, completely similar in properties to the German one, a mechanical mixture of powders from nickel-based alloys of the PG-CP2, 3, 4 type with grinding powders of normal electrocorundum grades 14A, 13A with a grain size of 40-160 microns can be used. Induction surfacing of hard alloys (charges), at high frequencies (40-100, 150-220 kHz), using transistor inverter generators with a power of 100 kW and above, was used as a modern method of hardening knives, and laser surfacing (for blanks made of 65G steel) or laser thermal hardening (for blanks made of steel 6HV2S). The data demonstrating the effectiveness of induction surfacing to reduce knife wear are presented.

The aim of the study is to develop an algorithm for constructing a network of polygons for storing, recycling and neutralizing industrial and consumer waste in a certain region, taking into account the generated mass of solid communal waste and the existing transport network, allowing one to come to an economically optimal solution. The mathematical methods presented in the scientific literature are aimed at solving problems of determining the optimal location of logistics infrastructure objects, namely a manufacturing plant, a warehouse, a distribution centre, a retail outlet. The paper formulates and implements an algorithm for constructing an optimal network of polygons, which would minimize economic costs for logistics, construction, and operation of the polygons. The main factors taken into account are the mass of generated solid communal waste, the transportation cost from the temporary accumulation site to the solid communal waste polygon, the distance between administrative centres. The basic principle of searching for the logistics extremum is based on determining the main node, that is the one with the largest mass of solid communal waste along all available road junctions and choosing the polygon location based on the condition of the maximum difference in annual logistics costs. Using the proposed algorithm, the paper solves the problem of determining the number and location of solid communal waste polygons for the southern part of the Komi Republic.

Biomethane energy, which has the status of renewable energies, has the potential to be produced from all kinds of organic wastes, as well as from lignocellulosic materials, which are the most common in nature. In this study, hazelnut shells (HS), one of the hazelnut by-products, were used for biomethane production. In order to obtain higher yields from HS, thermal pre-treatments were applied at temperatures of 60°C, 80°C and 100°C. Pretreatment effects were controlled by lignocellulosic substance amount determinations. As a result of thermal pretreatment at 100°C for 2 h, cellulose and lignin removals occurred approximately 15% and 30%, respectively. While the cumulative biomethane yield of raw HS was 32.3 mL•g total solids (TS)‒1, the cumulative biomethane yields of 100°C pretreated HS were measured as 132.3 mL•gTS‒1. As a result of different pretreatment temperatures, different cumulative biomethane yield curves were successfully simulated with the Modified Gompertz equation and R2 values were found to be between 0.9962 - 0.9985.

Currently, a promising direction of study is the use of biologically active coordination compounds in the pharmacopoeia and the creation of effective bactericidal drugs, biomaterials, and enzyme modulators on that basis. The paper considers a coordination germanium compound with 2-amino-3-hydroxybutanoic acid. The prospects for the use of the compound in medicine are outlined. This work is aimed at solving the problems regarding the synthesis of biologically active compounds with a wide spectrum of actions. The structure and composition of the coordination compound have been established through calculation and experimental methods. The biocidal (bactericidal and fungicidal) activity of germanium-containing compounds against a number of bacteria and microscopic fungi has been studied. Using the quantum-chemical method with density functional theory (DFT, B3LYP/6–311++G(2d,2p)), the theoretical IR spectrum of the compound was calculated. The structure of the coordination compound and the structure of the intermediates at all stages of the synthesis process were established by calculation.

The article is devoted to the consideration of the current problem of low-rise development of settlements in rural areas. The presence of federal and regional legislative initiatives at the strategic level of planning is noted. The purpose of the study is related to the development of methods and algorithms for the current planning of low-rise buildings. The stated task is considered as a multi-project planning problem. The problem was formulated and formalized using scheduling schemes and priority rules. For numerical experimentation, a model of a multi-project planning program and a test task were developed, including 27 projects of various buildings with household buildings. The task contains 504 requests for the implementation of project work, as well as the work requirements for workers of various specialties, construction mechanisms and funding levels. The developed program layout, in addition to carrying out calculations using the presented algorithms, visualizes the results of numerical experimentation in the form of Gantt charts and resource consumption diagrams. The performance of the developed methods and algorithms has been confirmed. Conclusions and discussion of the study results are presented.

The Pechora Basin is the largest tectonic structure of the Pechora Plate. It is located between the Timan and the Cis-Ural Foredeep. The Upper Precambrian sedimentary-metamorphic and igneous rocks of the basement are completely overlain by a sedimentary cover, therefore, the geological structure of the basement is known only on the basis of geophysical data and core samples from boreholes up to 5 km deep. The basement has a heterogeneous structure. It includes complexes of the Late Precambrian passive margin of the East European continent, which compose the Timan megablock (Izhma zone with Timan adjoining from the southwest) and formations formed in an active margin geodynamic setting combined into the Bolshezemel megablock (Pechora and Bolshezemel zones). The boundary between megablocks is the Pripechora fault (suture) zone. The age of igneous rocks of the basement is debatable; therefore, U-Pb (SIMS) studies of single zircon grains are undertaken to specify it. The article presents petrogeochemical data and U-Pb (SIMS, SHRIMP-RG) ages of zircon grains from plutonic rocks of the Pechora zone belonging to the Bolshezemel megablock drilled by two boreholes at depths of ~ 4.5 km. The obtained results indicated two episodes of island-arc magmatism. The first took place at the end of the Riphean, and the second was confined to the Early–Late Vendian boundary. The age of gabbrodiorites from the 1-Severny Savinobor borehole, interpreted as early island-arc rocks, is 673 ± 7 Ma. Late island-arc plagiogranites from the 1-Novaya borehole yield the age of 564 ± 5 Ma and precede the orogenic granitoids of the Pripechora fault zone which are dated (U-Pb) to 555—544 Ma.

The article describes cases of diagnosis of an additional spleen in the pelvis and splenosis of the pelvis in women, detected by ultrasound, confirmed by MRI. The relevance of the publication of the presented observations is determined by the rarity of such localization of the spleen and splenosis in the pelvis and the low awareness of obstetricians and gynecologists, most often conducting ultrasound examination of pelvic organs, about this pathology. Cases of an accessory spleen and splenosis in the abdomen are known and written in the literature, while similar findings in the pelvis are, firstly, a rare find, and secondly, ultrasound examination in gynecology is carried out by obstetricians-gynecologists, who rarely meet with surgical pathology, thirdly, the echographic picture requires differential diagnosis with endometrioma, hemangioma, primary and metastatic cancer, and splenosis and accessory spleen should also be differentiated from each other. The article presents two of our own clinical cases of splenosis and accessory spleen with US and MRI data, discusses the reasons for difficulties in diagnosis and key criteria for differential diagnosis, and also includes a review of the literature on this topic. Based on all of the above, it was concluded that should not forget about such a rare but possible diagnosis as pelvic splenosis, and also remember about a possible congenital condition – accessory spleen.