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The article considers the control system of a parallel structure mechatronic device for space application such as a hexapod (Stewart platform). The solution of the inverse problem of kinematics is described and the necessity of solving the direct problem of kinematics by numerical methods is substantiated. During the research, it was revealed that the main source of positioning errors of the hexapod without the main feedback is its linear drives, which have systematic errors in the mechanical part of the linear transmission, gearbox, in the location of the motor windings; temperature errors due to changes in the dimensions of parts due to heating or cooling; errors caused by elastic deformations under load. To improve the static accuracy of the hexapod, a number of both design and software solutions are proposed: mechanical transmission preload, individual calibration of each drive, compensation for thermal expansion, etc. To improve the dynamic accuracy, it is proposed to use the method of controlling linear drives in the servo mode along with ensuring the trajectory of the platform with the limitation of the speed of its movement and derivatives of the speed. The use of these methods makes it possible to significantly improve the accuracy of the operation of the mechanisms of a parallel structure and, thereby, to approach the achievement of the limiting qualitative properties of onboard optical-electronic and information systems of spacecraft and stations.

A fir-spruce-linden herbs forest and fir-spruce tall herbs forest on brown mountain soil in the Visimsky State Natural Biosphere Reserve were studied. In each type of forest, the biodiversity and variability of the chemical composition of ground cover and litter plants in different seasons were studied, and the relationship between the chemical composition of plants and the chemical composition of soils was assessed. Found that in spring the content of Fe, Cr, Rb, Ti, Zn, Ni, Al, S and P in the ground cover is higher, and by the end of the growing season the content of Mn, Sr, Ca, K, Mg and Cl increases. Ground cover plants of the studied forests contribute to the accumulation of Fe, Al, Mg, Ba, Ti, Mn, Ni, Cr and Zn in the soil due to their concentration in roots. In the chemical composition of the litter of the fir-spruce-linden herbs forest, the content of Ca, S, Sr, Ba, Mg, Fe, Ba, and Ti is higher than that of the fir-spruce tall herbs forest, which is reflected in the increase in the content of these elements in the organic horizon of the studied soils.

Quantum computing can become scalable through error correction, but logical error rates only decrease with system size when physical errors are sufficiently uncorrelated. During computation, unused high energy levels of the qubits can become excited, creating leakage states that are long-lived and mobile. Particularly for superconducting transmon qubits, this leakage opens a path to errors that are correlated in space and time. Here, we report a reset protocol that returns a qubit to the ground state from all relevant higher level states. We test its performance with the bit-flip stabilizer code, a simplified version of the surface code for quantum error correction. We investigate the accumulation and dynamics of leakage during error correction. Using this protocol, we find lower rates of logical errors and an improved scaling and stability of error suppression with increasing qubit number. This demonstration provides a key step on the path towards scalable quantum computing.

The combined value of any product design method depends on the design benefits and costs of use, determining the need to put the method into practice. In this study, a virtual reality design system was constructed to support the widely adopted user interview method for the usability improvement design of an existing product, using an industrial remote control as example. The combined value of the method was verified to be superior to the use of user interviews alone, in terms of the number and importance of usability questions mined by users, the level of styling of improved design solutions guided by usability questions, and the willingness of designers to use the method. It provides a useful reference for the promotion of immersive technology in the field of product design and the search for new focus points.

A clinical case of a patient with pharmacoresistant epilepsy due to focal cortical dysplasia (PCD) directly adjacent to the speech zone in the left temporal region is presented. The diagnostic search and transition from MRI-negative form to structural focal epilepsy progressed for more than 6 years. It was accounted for by the fact that type IIa vs. IIb FCD is visualized much worse, magnetic resonance imaging (MRI) signs of type IIa FCD are not so prominent, so that this type of dysplasia is often omitted. Functional research methods in epileptology, such as video-electroencephalography monitoring, brain positron emission tomography with 18F-fluorodeoxyglucose, functional MRI of speech zones, allow to more accurately verify the form of epilepsy and determine a scope of surgical treatment. Surgical intervention in carefully selected patients may contribute to favorable outcome of epilepsy (Engel 1, 51-months follow-up), which will lead to improved quality of life.

The article presents a clinical case of perineal defect reconstruction using a VRAM flap in a patient with vulvar cancer. Stepwise surgical treatment method is described. A multidisciplinary meeting allows to realize a plan of surgical help for such patients with the goal of treating oncological process and its complications.We have proposed a variant of perineal defect reconstruction through transfer of a vertical rectus abdominis musculocutaneous flap with a vascular pedicle.

Zr57Cu15Ni10Nb5 (more known as Vit-106) is a promising zirconium-based alloy with a high glass-forming ability, and belongs to the so-called bulk metallic glasses (BMG). Workpieces with a size of around one centimeter in all three dimensions can be obtained from a BMG alloy by casting. However, further increasing the cast size decreases the cooling rate and thus induces crystallization. Selective laser melting (SLM) is a well-known technique to overcome size limitations for BMGs because a workpiece is built by the addition of multiple melt portions in which the cooling rate is kept above the critical one. Currently, BMG parts obtained by SLM suffer from partial crystallization. The present work studies the influence of SLM process parameters on the partial crystallization of Vit-106 by metallography and the influence of the microstructure on mechanical properties by microhardness and wear resistance testing. Submicron crystalline inclusions are observed in an amorphous matrix of a Vit-106 alloy obtained by SLM. The size and the concentration of the inclusions can be controlled by varying the laser scanning speed. It is shown that submicron crystalline inclusions formed in the amorphous matrix during SLM can favorably affect microhardness and wear resistance.

An analysis of the influence of common modifiers on the kinetics of the curing process of epoxy-anhydride vitrimers was carried out. As common modifiers to enhance the “vitrimeric” nature of the material, zinc acetylacetonate as a transesterification catalyst and glycerol as a modifier of hydroxyl group content were chosen. The curing process of all obtained compositions was studied by differential scanning calorimetry (DSC) followed by the application of the isoconversional approach. It was shown that additives significantly affect the curing process. The resulting cured polymers were shown to be chemically recyclable by dissolution in the mixture of ethylene glycol and N-methylpirrolidone in a volume ratio of nine to one. The introduction of both zinc acethylacetonate and glycerol to the neat formulation led to a decrease in the dissolution time by 85.7% (from 35 h for the neat epoxy-anhydride formulation to 5 h for the modified formulation). In order to show the opportunity of the secondary use of recyclates, the mixtures based on the basic composition containing 10 wt. % of secondary polymers were also studied. The introduction of a recycled material to neat composition led to the same curing behavior as glycerol-containing systems.

Link for citation: Korotkov R.N., Konovalov A.A., Ovcharenko D.M., Erofeev V.I. Binary mixture technology as a modern complex method of increasing oil recovery for the development of hard-to-recover reserves in the fields of Western Siberia. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 146-153. In Rus. The relevance of the study is caused by the current situation, when subsoil users are trying to extract the maximum amount of oil in a short time, as a result of which the development system is mainly compiled incorrectly, the share of hard-to-recover reserves is growing every year. Therefore, there is an urgent need to develop residual reserves from the subsoil, which are often difficult to recover. One of the complex reservoir stimulation is thermal-gas-chemical stimulation, which is a method of extensive reservoir stimulation and describes a promising technology among other existing methods for enhanced oil recovery. Binary mixtures, in their turn, will increase oil recovery by an average of 5–10 %. Purpose: to study the effectiveness of the application of binary systems technology in order to increase oil recovery from reservoirs containing hard-to-recover hydrocarbon reserves. Methods: systematization of classification approaches in terms of hard-to-recover reserves, selection of the most relevant methods of enhanced oil recovery according to the efficiency criterion, analysis of Russian and foreign experience in the use of thermal-gas-chemical treatment, assessment of the technological and economic feasibility of using binary mixtures in analogous fields. Results. The use of binary mixtures makes it possible to increase oil recovery by 5–10 % on average. The principles of oil displacement using ammonium nitrate and the decomposition reaction product were studied, an analysis of pilot industrial tests both in Russia and abroad was reproduced, and current issues were studied. Various fields are also considered, which have already proved the positive dynamics of the development potential when using this technology. A preliminary assessment of the economic efficiency of thermal-gas-chemical treatment in the current state of the gas and oil industry in comparison with other methods of enhanced oil recovery is presented.

D.F. Belov1, V.G. Korotkov1, P.A. Nikitin2, I.V. Terekhova1, Ya.S. Konenkova1 1City Multidisciplinary Hospital No. 2, St. Petersburg, Russian Federation 2Scientific and Clinical Center No. 2 of the Academician B.V. Petrovskiy Russian Scientific Center of Surgery, Moscow, Russian Federation Endogenous endophthalmitis (EE) is a severe inflammatory disease resulting from hematogenous dissemination of pathogenic agents (bacteria, fungi) from the primary focus into the choroid due to impaired permeability of blood-ocular barrier. Retina, vitreous body, and anterior chamber are further involved. This paper describes a 61-year-old woman with EE associated with autoimmune hepatitis (AIH). Ocular inflammation was preceded by bacteremia. Clinical signs of EE included vitreitis, choroidal effusion, and exudative retinal detachment followed by amaurosis and phthisis bulbi. In 2008, the woman was diagnosed with AIH of unknown origin. Insulin-dependent diabetes developed secondary to treatment with prednisolone. After canceling steroids, AIH progressed to cirrhosis. Here, the development of EE was probably associated with secondary immunodeficiency in the setting of AIH. The timely diagnosis of EE is important for selecting an effective treatment strategy that involves intravitreal antibiotics and vitrectomy. Ophthalmologists should be aware of previous fever or flu-like disorder, severe ocular inflammation (hypopion, vitreitis, choroidal effusion, retinal detachment), no red reflex, and severe vision loss. Keywords: endogenous endophthalmitis, autoimmune hepatitis, vitrectomy, intravitreal injections, and phthisis bulbi, hypopyon, choroid, bacteremia, cirrhosis, retinal detachment. For citation: Belov D.F., Korotkov V.G., Nikitin P.A., Terekhova I.V., Konenkova Ya.S. Endogenous endophthalmitis associated with autoimmune hepatitis: case report. Russian Journal of Clinical Ophthalmology. 2023;23(3):164–169 (in Russ.). DOI: 10.32364/2311-7729-2023-23-3-9.

We analyze the continuous operation of the nine-qubit error-correcting Bacon-Shor code with all noncommuting gauge operators measured at the same time. The error syndromes are continuously monitored using cross correlations of sets of three measurement signals. We calculate the logical error rates due to X, Y, and Z errors in the physical qubits and compare the continuous implementation with the discrete operation of the code. We find that both modes of operation exhibit similar performances when the measurement strength from continuous measurements is sufficiently strong. We also estimate the value of the crossover error rate of the physical qubits, below which continuous error correction gives smaller logical error rates. Continuous operation has the advantage of passive monitoring of errors and avoids the need for additional circuits involving ancilla qubits.

Professor Olga V. Smirnova, Doctor of Biological Sciences, is a prominent scientist in the field of plant demography, population biology, and forest ecosystem ecology. Professor Olga V. Smirnova’s edifice is based on ideas about the leading role of plant and animal populations in the organization of the biogeocenotic cover. In this case, it is implied that a continuous generational turnover in edificator (keystone species) populations is necessary to maintain the species and structural diversity in communities and ensure their sustainability. This system of views was influenced by Professor Alexey A. Uranov. The development of these ideas was consistent and gradual. First, Professor Olga V. Smirnova studied the biology of different plant species life forms. Examining their individual development, with identification of ontogenetic stages, is necessary for demographic research. She then developed the theory of coenopopulations as supraorganismal systems, which can self-sustain under different conditions. Finally, she developed the doctrine of biogeocenosis as a system of interacting populations and created the concept of anthropogenic transformation of the forest cover in the Holocene. Her contributions helped researchers to understand the mechanisms of the formation of modern zonality that are due to human activity.

The influence of the ultrasonic field on lead dioxide electrodeposition from nitrate electrolyte was studied. The adsorption of electroactive particles and the amount of nucleation on the electrode surface were found to have increased as well as the formation of OH-radicals accelerated under the influence of the ultrasonic field. Fine-crystalline deposits of lead dioxide were formed, which contributed to obtaining high current yield of lead dioxide, coefficient increasing of the electrode active mass and increasing of the discharge capacity of the emergency current generator cell layout. It was shown that the application of ultrasound in producing a lead dioxide electrode made it possible to reduce the time of the technological procedure.

Determination of 137Cs, 40K and 210Po in water, bottom sediments and suspended matter of river systems of the Can Gio Biosphere Reserve, Vietnam was carried out. The average activity concentration of 137Cs in waters of Ca Gau and Long Tau was 0.89 ± 0.14 and 1.08 ± 0.15 Bq m−3 and was comparable to the levels of this radioisotope in waters of the East Sea. The activity concentration of 137Cs in bottom sediments was 2.23 ± 0.81 and 3.63 ± 1.24 Bq kg−1. The activity concentration of 137Cs in water and bottom sediments could be characterized as low. So, the water areas of the Ca Gau and Long Tau rivers could be attributed to areas with insignificant pollution by technogenic radionuclides. The 210Ро activity concentration in bottom sediments of the Ca Gau and Long Tau rivers ranged from 9.2 ± 1.2 to 25.5 ± 2.1 Bq kg−1, which is typical for river bottom sediments. Such values indicate the absence of anthropogenic enhancement of the entry of this radionuclide into the Can Gio river systems. The 40K activity concentration varied within 467 ± 42–651 ± 39 Bq kg−1 and represented typical values of potassium content in the bottom sediments of coastal water bodies, subject to a significant influence of the lithogenic component of suspended matter.

Chemoradiotherapy anal cancer is the main one at stages I–II. In some patients after radiation therapy, late radiation damage to soft tissues occurs. The article presents a clinical case of successful surgical treatment of extensive radionecrosis of the perianal region.