bluuebunny/crossref_metadata_2025 huggingface dataset:
Live birth using autologous sperm cryopreserved for 26 years
Authors: Sleiman Sue , Bacha Feyrous , Handelsman David J
Published: April 2023

We report the successful delivery of a healthy baby after intracytoplasmic sperm injection (ICSI) with frozen-thawed autologous sperm, cryostored for 26 years, the longest successful autologous sperm cryostorage reported. Sperm was cryostored for a 15-year-old boy at the time of his cancer diagnosis. Semen samples were frozen with cryoprotectant, using a graduated vapour-phase nitrogen protocol. Straws were stored in a large vapour-phase nitrogen tank until transfer for use. The couple underwent a single ICSI–in vitro fertilisation procedure using the frozen-thawed sperm with a transfer of five fertilised embryos, resulting in the live birth of a healthy baby boy. This reinforces the importance of offering sperm cryopreservation to men who have not completed their family prior to gonadotoxic treatment for cancer or other diseases. As practical, low-cost fertility insurance, it should be offered to any young man who can collect semen and it provides essentially unlimited duration of fertility preservation.

Learning points

Gonadotoxic chemo or radiotherapy treatment for cancer or other diseases usually causes temporary or permanent male infertility.

Sperm cryostorage serves as a practical, low-cost insurance to facilitate future paternity.

All men who have not completed their families and are scheduled for gonadotoxic treatments should be offered sperm cryostorage.

There is no lower age limit for young men who can collect semen.

Sperm cryostorage offers essentially indefinite duration for the preservation of male fertility.
Association of Lower Urinary Tract Symptoms and Benign Prostatic Enlargement in Patients with Hypertension
Authors: Stefanus Dicky , Siregar Safendra
Published: April 2023

Development of hyperplastic nodules in the transition zone of the prostate is the characteristic of Benign prostatic enlargement (BPE). Men with hypertension have a high risk of severe lower urinary tract syndrome (LUTS). This restrospective cohort analytic study investigated the association between LUTS and BPE in hypertension patients. Subjects were BPE patients with primary hypertension who visited the urology clinic of Dr. Hasan Sadikin General Hospital Bandung that were sampled consecutively from 2017 to 2020. Three hundred and twenty-four patients from the urology department participated in the study. These patients were categorized into  mild LUTS (IPSS 1-7)  (n=37, 11.4%), moderate LUTS (IPSS 8-19) (n=169, 52.2%), and severe LUTS (IPSS 20-35) (n=118, 36.4%). A positive correlation (r = 0.761, p = 0.000) and weak positive correlation (r = 0.152, p = 0.006) were found between systolic blood pressure and prostate volume and between LUTS and systolic blood pressure, respectively. In addition, there was also a weak positive correlation between diastolic blood pressure and prostate volume (r = 0.065, p = 0.245) and LUTS (r = 0.015, p = 0.784). Thus, there is an association between hypertension and prostate enlargement and the severity of lower urinary tract symptoms
Application of random forest-based decision tree approach for modeling fully developed turbulent flow in rough pipes
Authors: Yetilmezsoy Kaan
Published: April 2023

A random forest (RF) -based decision tree programming methodology was aimed for modeling fully developed turbulent flow conditions in rough pipes. In the present computational study, a flexible RF-based soft-computing strategy was applied for the estimation of the required pipe diameter (D) and Darcy–Weisbach friction factor (λ or f) obtained from the iterative solution of the implicit Colebrook–White equation for five basic pipeline design variables considered in sizing problems (Type 3) of pipe distribution systems. The prediction performance of the implemented RF-based model was assessed more than 15 different statistical goodness-of-fit parameters and useful mathematical diagrams such as box-and-whisker-plots and spread plots. The statistical metrics corroborated the superiority of the RF-based approach in predicting both the required pipe diameter (R2 = 0.9793, MAE = 0.0287 m, RMSE = 0.03833 m, SEE = 0.0326 m, IA or WI = 0.9933, CV(RMSE) or SI = 0.0595, NSE = 0.9753, LMI = 0.8482, and AIC = -1954.6438 for the testing dataset) and friction factor (R2 = 0.9576, MAE = 0.0011, RMSE = 0.0023, SEE = 0.0018, IA or WI = 0.9851, CV(RMSE) or SI = 0.0660, NSE = 0.9478, LMI = 0.8500, and AIC = -3646.7124 for the testing dataset). The descriptive statics suggested that the 25% percentile values (Q1), median values (Q2), and 75% percentile values (Q3) of RF-predicted values of D and λ and the corresponding actual values of these responses were found to be very close. The proposed RF-based model was also tested against additional some dataset obtained from the relevant literature. The validation results indicated that the applied decision tree-based method produced realistic estimations and acceptable statistics (i.e., R2 = 0.9624, MAE = 0.0598 m, and RMSE = 0.0708 m for D values, and R2 = 0.9130, MAE = 0.0043, RMSE = 0.0052 for λ values) even at extreme L values greater than 2000 m. This study demonstrated the importance and ability of the applied soft-computing strategy to accurately predict D and λ values and eliminated error-prone steps of the traditional iterative approach.
Machine Learning and the Conundrum of Stroke Risk Prediction
Authors: Chahine Yaacoub , Magoon Matthew J , Maidu Bahetihazi , del Álamo Juan C , Boyle Patrick M , Akoum Nazem
Published: April 2023

Stroke is a leading cause of death worldwide. With escalating healthcare costs, early non-invasive stroke risk stratification is vital. The current paradigm of stroke risk assessment and mitigation is focused on clinical risk factors and comorbidities. Standard algorithms predict risk using regression-based statistical associations, which, while useful and easy to use, have moderate predictive accuracy. This review summarises recent efforts to deploy machine learning (ML) to predict stroke risk and enrich the understanding of the mechanisms underlying stroke. The surveyed body of literature includes studies comparing ML algorithms with conventional statistical models for predicting cardiovascular disease and, in particular, different stroke subtypes. Another avenue of research explored is ML as a means of enriching multiscale computational modelling, which holds great promise for revealing thrombogenesis mechanisms. Overall, ML offers a new approach to stroke risk stratification that accounts for subtle physiologic variants between patients, potentially leading to more reliable and personalised predictions than standard regression-based statistical associations.
Plant “Geophysics” in the 1920s – 1930s in the Context of Soviet Industrial Modernization
Authors: Sludnyh Anatoly V.
Published: April 2023

Introduction. The relevance of the topic is due to the importance of studying the mechanisms of industrial modernization in the 1920s – 1930s in comparison with the modern period of modernization taking place in the conditions of the information society. The experience of early Soviet industrial modernization can be useful in today’s difficult geopolitical conditions in which the next technological transition takes place.

Materials and Methods. The study is based on the theory of modernization, taking into account the development of the economy, technology and the socio-cultural sphere. The formation of one of the enterprises of the optical-mechanical industry of the USSR is considered in the context of industrialization in the optical industry. The combination of macro- and micro-historical perspective of the study made it possible to study the phenomenon of industrial modernization at different levels.

Results. In the development of the plant “Geophysics” in the 1920s – 1930s the processes of industrial recovery during the years of the NEP and the features of the Soviet industrialization were reflected. The dynamics of the plant’s development during the first five-year plans is impressive. In terms of technology, the plant moved to the third technological order. The plant began production of sophisticated optical instruments for defense purposes. The mechanisms of the planned economy harmoniously combined with the process of industrial modernization.

Discussion and Conclusions. The features of “Stalin’s industrialization” were: a forced character; borrowing imported technologies with adaptation to domestic production; military sector priority. The problems of the first five-year plans (increased planned commitments, limited capital investment, overtime work, shortage of materials, interruptions in the supply of imported equipment, shortage of qualified personnel) were solved with the help of administrative resources, the reliance of the enterprise on internal reserves, the enthusiasm of workers and non-economic incentives, socialist competition, advanced training and a progressive bonus system of remuneration.
Modernization of the Coal Industry of the Far East during the First Five-Year Plan (1928–1932)
Authors: Pavlenko Oleg K.
Published: April 2023

Introduction. The coal industry of the Far East, which was the main fuel base of the region, was in a state of severe crisis by 1928. The enterprises of the industry did not have the necessary working capital, were equipped with obsolete equipment, experienced an acute shortage of qualified personnel. The solution of these problems became possible with the beginning of industrialization in the USSR and the provision of assistance to the region by the center.

Materials and Methods. The source basis of the research is unpublished documents identified in the funds of federal and regional archives. In the course of the work, the author used a set of general scientific and special historical methods.

Results and Discussion. During the implementation of the first five-year plan, the financing of coal mining in the Far East has sharply increased. At the mines of the region, the active introduction of the latest technology began, which made it possible to begin mechanization of production processes, increase the level of electrification and mechanization. The foundations of the personnel training system were also laid, significant labor resources from the central regions were attracted. However, despite the successes achieved: an increase in labor productivity, an increase in total production, the final results turned out to be more modest than expected. Basically, the changes covered the enterprises of Primorye, on Sakhalin and in the Amur region, reconstruction was carried out much slower.

Conclusion. The reasons that caused the divergence of plans and the results obtained in practice were the periphery of the region, which led to its supply on a residual basis and ignoring its interests in favor of more industrialized areas. As well as underestimating the production capabilities of the enterprises themselves, the geological conditions of their operation. In 1928–1932, it was not possible to create a stable supply system for equipment and machinery, low qualifications and high turnover of labor remained.
The Functioning of the Tram Infrastructure in the Cities of the Chelyabinsk Region in 1941–1945
Authors: Kozhushko Julia N.
Published: April 2023

Introduction. During the Great Patriotic War, the main function most characteristic of the tram infrastructure of the Union was most pronounced – the connection between workers and industrial enterprises. The historical experience of overcoming the total shortage of material and human resources in the context of the reorientation of the country’s economy towards defense needs is relevant today to identify the main elements of a sustainable urban life support system. Analysis of the historiography of the tram demonstrates a paradox: on the one hand, the period 1941–1945 affected in most local studies of the tram, on the other hand, researchers paid attention to individual components of the tram infrastructure. The purpose of the study is based on the characteristics of the tram infrastructure in the cities of the Chelyabinsk region in 1941–1945 identify the factors that had the greatest impact on it and show management decisions taken in connection with the problems that arose.

Materials and Methods. The study was carried out on the basis of an analysis of unpublished sources found in the funds of federal and regional archives, materials of local periodicals. The methodological framework of the study is the anthropology of infrastructure and model of mobilization development, the main method is case-study.

Results. Tram infrastructure in most cities of the RSFSR in 1941–1945 did not meet the growing needs of society. In many cities that had trams, the depots were not fully staffed, tram tracks and electrical facilities needed repairs.

Discussion and Conclusion. Analyzing the state of tram tracks, electrical facilities, stops, depots in Chelyabinsk, Zlatoust, Magnitogorsk, the author reveals the reasons for the plight of the tram in these cities, referring to the situation in the RSFSR, the state of infrastructure at the stage of its construction and launch in the first half of the 1930s.
The Agrarian Question in the Views of N. Kh. Bunge (to the 200th Anniversary of his Birthday)
Authors: Stozhko Dmitrii K. , Stozhko Konstantin P.
Published: April 2023

Introduction. 2023 marks the 200th anniversary of the birth of N. Kh. Bunge, an outstanding Russian scientist, economist, public figure and statesman. His views, especially on the agrarian question, are still poorly understood. The aim of the study is to analyze and evaluate the views of N. Kh. Bunge on the agrarian issue and to reveal their humanistic nature.

Materials and Methods. The study used methods of analysis, synthesis, generalizations and axiology, as well as historical-retrospective, historical-genetic and hermeneutical, program-targeted and structural-functional methods for studying problematic issues in the history of economic science. The study is based on primary sources: the writings of N. Kh. Bunge himself and the works of his contemporaries.

Results. Among the most significant ideas in the field of posing and solving the agrarian issue of N. Kh. Bunge, his approaches to the issues of land ownership and land use, migration (settlement) processes, the development of peasant self-government, the development of rental, tax and financial-credit relations are identified and disclosed. The multidimensional and at the same time contradictory nature of the views of N. Kh. Bunge in matters of domestic economic policy were revealed. The conclusion is made about the humanistic orientation of the scientific heritage of the scientist and the need for its further more detailed study in the context of a new social reality.

Discussion and Conclusion. Specific approaches of Russian historiography to the study of the works of N. Kh. Bunge in the pre-revolutionary period (A. N. Zak, I. I. Levin, A. A. Mikulin, M. N. Sobolev, M. I. Tugan-Baranovsky and others) and the growing interest in his political and economic views in the 21st century. An assessment is given to the debatable thesis about the characterization of the views of N. Kh. Bunge as being “between historicism and liberalism” (J. Zweinert).
ECONOMY OF THE FUTURE – FOR THE BENEFIT OF SOCIETY THE REVIEW ON THE MONOGRAPH Tirole J. Economics for the common good
Authors: Somkin Aleksandr A.
Published: April 2023

Tirole J. Economics for the common good / Transl. from French by I. Sheveleva; Ed. of the translation M. Levin. Moscow, Publishing House of Gaidar Institute, 2020, 696 p.
Finite Element Model Updating Method of Dynamic Systems
Authors: Krasnorutskiy D. A , Lakiza P. A , Berns V. A , Zhukov E. P
Published: April 2023

The finite element model updating method of dynamical systems based on results of modal tests is proposed. The purpose of updating is to change eigenspectrum. The method alters a stiffness matrix by adding an updating finite element model created on the nodes of the intial one with respect to the existing links between the linear degrees of freedom. The stiffnesses of the updating elements are utilized as the updating parameters to be defined. The objective function equals to the least square weighted sum of residuals between the target, which were determined experimentally, and current values of modal stiffnesses. The iterative solution process is carried out. At each iteration step the conjugate gradient method is applied to solve the unconstrained minimization problem. The modeshapes, which were calculated as the result of solving the generalized eigenvalue problem at the previous iteration step, are employed to calculate the current modal stiffnesses. The method does not have a limit to a size of matrices and keeps their sparsity and symmetry. It provides the model updating of selected regions of a structure and step-by-step model updating of predefined groups of eigenfrequencies. Moreover, geometrical features of a structure, such as the presence of the symmetry planes and structurally identical elements, may be taken into account. The method is implemented into a program and verified by the example of the free dynamically-scaled model of Tu-204. In order to perform the ground vibration testing, the model was suspended with a low-rigidity flexible support. The finite element model made of solid elements has been updated on the basis of the six experimentally determined sets of eigenfrequencies. The target frequencies from each set have been achieved with a high level of accuracy.
Influence of the stress-strain state on the jerky flow effects and kinetics of the strain bands nucleation in Al-Mg alloy (A 95456)
Authors: Tretyakova T. V , Tretyakov M. P , Lunegova E. M
Published: April 2023

The aim of the work is to develop a technique on the experimental study of inelastic deformation of structural metal materials in various types of stress-strain state. A technique is proposed based on the use of original samples of specialized complicated geometry, in the working zone of which a controlled biaxial stress state is realized, and the use of a contactless 3D digital image correlation measurement system Vic-3D for recording displacement and deformation fields. The authors proposed the use of original samples of variable thickness in the form of plates located inside a rigid circular rim and a rim of reverse curvature. Under uniaxial tension of these samples in the central area of the plate (working part of the sample), the plane stress state is realized with principal stresses of different signs, depending on the shape and rigidity of the rim. In the working part of the plate with a ring-shaped rim, tensile forces in the longitudinal direction and compressive forces in the transverse direction are realized due to the curvature of the circular rim and its narrowing in the transverse direction. In a plate with a rigid rim of reverse curvature, biaxial tension is realized in the working section. High efficiency of the proposed experimental technique has been shown to solve problems in the mechanics of solids, in particular, to study the processes of macroscopic localization of plastic flow in Al-Mg alloys (AlMg6) under the conditions of the Portevin - Le Chatelier effect. Using a video system, experimental data of the realized ratio of the deformation components (longitudinal and transverse deformations) in the working zone of the samples were obtained. The analysis of the kinetics of band formation and discontinuous yield strain occurring under conditions of a plane stress state has been carried out. The use of the Vallen Amsy-6 system made it possible to obtain data on the occurrence of acoustic emission signals accompanying the observed processes of inelastic deformation of the material. The graphs of the dependence of the energy parameter and frequency characteristics of acoustic emission signals on time have been constructed and analyzed.
Analysis of stress fields at the crack tip and fracture resistance parameters under conditions of gradient plasticity
Authors: Khamidullin R. M , Fedotova D. V
Published: April 2023

This paper presents a numerical analysis based on previously obtained experimental data on crack growth for P2M and 34X steels, aluminum 7050 and titanium alloy Ti-6Al-4V compact samples (CTS) with a one-sided lateral incision, within the framework of the conventional theory of strain gradient plasticity (CMSG), based on the Taylor dislocation model. In this study, the initial points of the curved crack trajectory were considered for two classical states: plane strain and plane stress with normal separation and pure shear. The constitutional equations of material behavior for CMSGP theories were introduced into the finite element computational complex and new fields of stress-strain state parameters for the conditions of strain gradient plasticity were obtained. The results of FE calculations show a significant increase in the magnitude of the true stress fields at the crack tip, taking into account the plastic deformation gradients and the internal characteristic length of the material. The numerical results also show that the singularity in the crack tip region is different for the model of gradient plasticity of deformations and depends on the mode I/II. An important conclusion regarding the numerical results regarding the parameters of the material's fracture resistance is that the new plastic stress intensity coefficients for gradient plasticity differ for plane strain and plane stress, and also show significant sensitivity to the plastic properties of the material and to the scale parameter of the intrinsic material length, which is attractive from the point of view of practical application and further fundamental research.
Contour integrals in nonlinear fracture mechanics for mixed forms of deformation
Authors: Tartygasheva A. M
Published: April 2023

Modern knowledge in the field of fracture mechanics is the first key knowledge in solving the problems of safety and strength of the objects with crack-like damages of the various origins. Nonlinear fracture mechanics in the analysis of the stress-strain state in the crack tip region is based on the one- and two-parameter approaches. The classical one-parameter studies involve the study of singular quantities, including a contour J -integral, independent of the path of integration, a stress intensity factor (SIF), etc. The values of the SIF and J -integral are interdependent. Combined methods are very popular, based on the union of numerical, experimental and analytical calculations, which make it possible to obtain the most clear description of the parameters of fracture mechanics. Calculation of the J -integral in finite element models, by the method of reactions or stresses, is very effective, but this requires sufficiently accurate analytical representations of the contour J -integral. There are certain limiting conditions when obtaining such formulas. In the numerous scientific works, it has been proved that J is an integral in the most cases does not depend on the path of integration, but is highly dependent on the methods of describing the parameters of the stress-strain state, as well as their derivatives, on the dimension of the problem and on the degree of distance of the contour of integration from the crack tip. In this paper, we review and present the author's conclusions of the contour integrals in nonlinear fracture mechanics for three cases: the classical Hutchinson - Rosengren - Rice solution (HRR), contour integrals in the gradient theory of plasticity, and the calculation of the J -integral for a general case when the components of stresses and displacements are the functions of three Cartesian coordinates. A generalized J- integral is derived and used to characterize a nonlinear amplitude fac.
Contact problems for a transversely isotropic layer
Authors: Pozharskii D. A , Zolotov N. B
Published: April 2023

Two spatial, one axisymmetric and two plane contact problems are considered for a transversely isotropic elastic layer with one face subjected to sliding support. In the spatial and plane contact problems, the planes of isotropy may be either parallel or perpendicular to the layer faces. In the case of axial symmetry, the planes of isotropy are parallel to the layer faces. By using Fourier integral transforms, the contact problems are reduced to integral equations with respect to the contact pressure, the limiting cases of which are the well-known equations of the corresponding problems for an isotropic layer. For solving the spatial problems with unknown contact domains, the nonlinear boundary integral equations method is used, which make it possible to determine the contact pressure and the contact domain simultaneously. To extract the kernel principal part of the spatial problem integral equation when the isotropy planes are perpendicular to the layer faces, it is used the kernel of the integral equation of the corresponding contact problem for a transversely isotropic half-space obtained earlier without quadratures. The integral equation of the axially symmetric problem is reduced to a Fredholm integral equation of the second kind with the help of the method of pair equations, and the method of mechanical quadratures is used for numerical solutions. Plane problems are solved in a closed form based on special approximations of the kernel symbols. The approximations accuracy grows as anisotropy increases. Here, the anisotropy level can be characterized by the difference between ratio of a characteristic equation roots and unit because the unit value corresponds to the isotropic case. Mechanical characteristics as well as errors of the approximations are calculated for well-known transversely isotropic materials.
EFFECT OF SYNCHRONIZATION OF CONTINUOUS ACOUSTIC EMISSION STATISTICAL PROPERTIES DURING STRUCTURALLY HETEROGENEOUS MATERIALS DEFORMATION
Authors: Panteleev I. A , Bayandin Yu. V , Plekhov O. A
Published: April 2023

In this paper, a correlation analysis of the statistical properties of continuous acoustic emission recorded in various parts of marble and glass fiber laminate samples during their quasi-static deformation is carried out. The spectral measure of coherence, which is a generalization of the square modulus of the coherence spectrum to the case of multidimensional series, is chosen as a correlation measure. The measure of coherence was estimated for the width of the multifractal spectrum and the spectrum carrier realizing its maximum, calculated in a sliding time window for acoustic emission signals. It is shown that the preparation of a macrofracture site is accompanied by synchronization of the statistical properties of acoustic emission in the selected frequency intervals. Based on the analysis of changes in the frequency-averaged measure of coherence for both types of materials, four characteristic stages are distinguished, the boundaries of which are individual for each of the materials. The onset of the fourth stage, which is characterized by a monotonic increase in the average measure of the coherence of the statistical properties of the AE, can be chosen as a possible criterion for the transition of the material to the limiting state.
Cycle life prediction under low cycle fatigue using nonlinear Marco - Starkey model
Authors: Lykova A. V , Ilinykh A. V , Wildemann V. E
Published: April 2023

The process of deformation and fracture of structural alloys under low-cycle fatigue in conditions of uniaxial loading with axial strain control under complex cycle shape and block loading has been studied. The obtained results of experimental studies of structural alloys were used to assess the possibility of using the nonlinear Marco - Starkey damage accumulation model. The processing of the nickel alloy cyclic tests results with a simple and complex form of the cycle has been carried out. A combination of exponents included in the non-linear Marco - Starkey model was selected which for the case of low-cycle fatigue with a complex M-shaped cycle made it possible to predict durability which is in good agreement with experimental test data. The main problem of using the nonlinear Marco - Starkey model for predicting cyclic durability with an M-shaped cycle is the presence of many combinations of exponents that allow predicting cyclic durability with the same accuracy. To determine the uniqueness of the solution it is proposed to carry out a set of tests under simple and block loading. Experimental results have been obtained on the processes of deformation, fracture of D16T aluminum alloy under low-cycle fatigue conditions under simple cycle forms with constant parameters, and block loading with variable cycle parameters in tests for uniaxial loading with axial strain control. Based on the obtained experimental results according to the new method combinations of the m degrees coefficients were selected, which was carried out in the range of exponents from 0.2 to 10 with a step of 0.2. Comparison of the forecasting results for blocks consisting of three groups made it possible to find several combinations of general exponents m for two groups that are present in all blocks. The final choice of a pair of coefficients was carried out on the condition that the predicted damage is close to unity in the first (test) block. The selected values of the coefficients made it possible to predict the durability under block low-cycle loading using the nonlinear Marco - Starkey model.
INFLUENCE OF GEOMETRIC, KINEMATIC, GAS-DYNAMIC PARAMETERS ON ROTOR DYNAMIC STATE TAKING INTO ACCOUNT GAS DYNAMIC FLOW IN LABYRINTH SEALS CLEARANCES
Authors: Modorskii V. Ya. , Cherepanov I. E. , Babushkina A. V.
Published: April 2023

The present work details a new approach to the study of GTU rotor vibrations, based on the solution of a related dynamic problem for the «gas – dynamic flow – deformable structure» sys-tem. The modern tendency to increase an aggregates power with a simultaneous decrease stiffness results in new phenomenons that affected a rotor vibration state. The compressor rotor model with a labyrinth seal is considered. ANSYS software product is used. The calculations were carried out on a high-performance computer complex PNRPU. The performed calculations showed a qualitative and quantitative effect of a gas-dynamic gap on the rotor dynamics. A 2FSI calculations series was performed to study the influence of geometric, kinematic and gas-dynamic parameters on the rotor dynamic state. A pressure fluctuations spectral analysis in the gas-dynamic gap and displacements has been carried out. The obtained spectrograms pro-cessing it possible to plot amplitudes and frequencies dependences of resonant pressure oscil-lations over an initial pressure in the gas-dynamic gap. It was found that the initial pressure in a gas-dynamic gap has the greatest influence. A rotor and gas oscillations resonant frequency was found, which corresponds to a change in the shaft axis spatial position. The «gas – struc-ture» system resonant frequencies were obtained for models differing in mass and stiffness. A decrease in an elasticity modulus of the structure led to a decrease in the maximum pressure fluctuations amplitude, while a decrease in mass led to its increase. For the base model and the model with lower rigidity, the resonant pressure oscillations frequency depends on the initial pressure value according to a law close to linear, while for the model with a lower mass, the dependence has a pronounced non-linear character.
SIMULATION OF VIBRATORY PLATE INTERACTION WITH THE GROUND SURFACE
Authors: Tyuremnov I. S. , Efimov S. S.
Published: April 2023

The paper presents a three-mass rheological model of the system "soil – vibration plate base – vibration plate frame". The rheological model makes it possible to reproduce different modes of interaction between the vibratory plate base and soil: with different types of plate decoupling and without decoupling. We verify this model by comparing the experimental values of the vertical oscillation span of the base and frame of the Zitrek CNP 20 vibrating plate with the previously calculated values. As a whole, the calculated values of the span of vertical oscillations of the base and frame of the Zitrek CNP 20 vibrating plate correlate with the experimental data in the range of the dynamic modulus of soil deformation of 13…30 MPa. During the experiment we used the rheological model and obtained results are as follows: the mass of the vibrating plate (50; 150; 250; 350; 450; 550; 650; 750 kg), the coefficient of the elastic resistance of soil (30; 60; 90; 120 MN / m), and the coefficient of viscous resistance of soil (100; 200; 300 kN • s / m). The total number of combinations of parameters was 96. The processed results of the computational experiment provide the regression dependences for calculating the maximum soil reaction force, the time of soil loading (increasing the values of the reaction force of soil) t1, and the time of soil unloading (decrease the values of the reaction force of soil) t2. The simulation results show that, within one exposure cycle, the soil loading time t1 is less than the soil unloading time t2. The ratio t1/t2 is influenced by the weight of the vibratory plate, as well as the factors of elastic and viscous resistance of soil. This feature (t1/ t2  1) is typical for both vibratory rollers and rammers, which is confirmed by the results of the relevant experimental studies. The obtained regression dependences of parameters Fs, t1, and t2 on the vibratory plate mass and the factors of elastic and viscous resistance of soil are important for calculating the distribution of stresses and strains on the depth of the compacted soil.
MODELING OF CREEP PROCESSES OF SINGLE-CRYSTAL ALLOYS WITH TAKING INTO ACCOUNT OF RAFTING
Authors: Grishchenko A. I. , Semenov A. S.
Published: April 2023

The research is devoted to the development and verification of a two-level micromechani-cally motivated model of viscoelastic deformation of two-phase nickel-based single-crystal al-loys, predicting behavior under high thermomechanical loading with taking into account the presence of γ and γ' phases. The model is relevant for computations of the stress-strain state of cooled single crystal blades of gas turbine units. The formulation of the constitutive equations for each of the phases considered the anisot-ropy of elastic and viscous properties, the presence of octahedral slip systems, the features of the cubic system, and the presence of viscous properties both below and above the yield stress. Model parameters for γ and γ' phases were identified based on known creep curves for each phase. The effective properties of a single-crystal alloy, considering the presence of γ and γ' phas-es, were determined both based on finite element homogenization for a representative volume and using the simplest rheological (structural) models of the material, considering the series and parallel connection of phases. Based on multivariant computational experiments and analytical estimates, the dependences of the viscoelastic properties of nickel-based single-crystal alloys on the volume fraction of the γ' phase are determined. Phenomenological creep models that take into account the change in the volume fraction and the morphology of γ' inclusions have been proposed. The simulation results using the proposed two-level microstructural model of the material demonstrate a good agreement with the experimental data for the ZhS32 single-crystal heat-resistant alloy.
DETERMINATION OF THE CONTACT AREA UNDER CYCLIC LOADING OF CONTACT PAIRS OF ISOTROPIC MATERIALS ON THE BASIS OF 3D SURFACE MICRORELIEF MODELLING
Authors: Ezhov A. D. , Bykov L. V. , Krylova Yu. A.
Published: April 2023

The parameters of the surface microrelief are paramount in the problems of frictional interaction of parts, the flow of liquid and gas in channels, ensuring the required thermal conditions and the stress-strain state of the structure. The solution of the problem of ensuring the optimal thermal regime for a significant range of technical products often becomes decisive in the design of products operating under conditions of high-intensity heat flows. Transit heat fluxes flowing through the product, as well as heat fluxes from own heat sources, must be either accumulated or removed to the external space. In this case, the directions of the heat flux vectors are determined by the design features of the products, including through various contact connections. Obviously, a reliable determination of the parameters of the contact interaction of product parts is the basis for a reliable analysis of the stress-strain and thermal state of a wide range of structures operating under conditions of high-intensity heat flows. The operational characteristics of the contacting parts of the structure are directly determined by the properties of the contact of the mating surfaces. When solving many problems of thermal, mechanical and electrical contact interaction, surface roughness is a major factor. The processes of friction and wear occur precisely on the actual contact area and depend not only on the properties of the material, but also on the intercontact pressure on this area, since the magnitude of the actual pressure determines the destruction of surface films and the appearance of adhesive bonds in the contact. In the presented work, the change in the actual contact area under cyclic loading of contact pairs of materials based on digital twins of contact surfaces in a wide range of compressive pressures is considered.
ANALYSIS OF THE FORM AND EVOLUTION OF THE SOLID PHASE DURING DIRECTIONAL CRYSTALLIZATION OF NON-FERROUS METALS WITH ELECTROMAGNETIC INFLUENCE BY ULTRASONIC AND TEMPERATURE METHODS
Authors: Losev G. L. , Mamykin A. D.
Published: April 2023

The paper is devoted to the experimental study of new mechanisms of controlling the process of directional crystallization of non-ferrous metals. The focus of the study is on the development and testing of measuring techniques applicable both to laboratory modeling and to processes under real operating conditions. The mechanism of controlling the rate and homogeneity of crystallization of a metal melt by changing the phase angles between the supply currents of a traveling magnetic field induction stirrer is proposed. This makes it possible to generate vortex flows of various topologies in the liquid metal, in particular, to change the number of large-scale vortices or to suppress the large-scale flow. It is shown that the hydrodynamic flows have an impact on the crystallization front shape, which allows one to control the homogeneity of metal solidification by changing the characteristics of the power supply of the inductor. It is important to note that a change in the phase angles of the currents while maintaining the supply amplitude does not significantly affect the crystallization rate, which opens up wide possibilities for controlling processes by changing both the current strength and the phase angles. The temperature method for determining the position of the crystallization front was successfully applied and verified by ultrasonic velocimetry measurements. It has been found that, in the presence of developed flows in a liquid medium, thermocouple measurements provide good agreement (up to a few percent) of the measured position and geometric shape of the crystallization front with the ultrasonic measurement data. In the absence of liquid phase stirring, the difference between the thermocouple and ultrasonic measurements increases slightly. Nevertheless, even in this case, the thermocouple method can be used to correctly determine the position and velocity of the crystallization front.
ELECTROMAGNETIC COUPLING OF PIEZOELECTRIC/FERRITE COMPOSITE WITH INITIAL STRESS STATE
Authors: Pan’kov A. A.
Published: April 2023

A mathematical model of electromagnetic thermoelasticity for an initial-stressed transversal-isotropic composite with piezoelectric magnetostrictive phases has been developed. To solve the related boundary value problem of electromagnetic thermoe-lasticity, the Green function method was used as part of a generalized singular approximation of the statistical mechanics of composites, taking into account the initial stress state of the representative domain of the composite at micro- and macro-levels. The solution of the problem of "effective module" for tensors of effective elastic, piezomechanical, magnetostrictive properties, dielectric permittivity and magnetic permit-tivity, temperature, pyroelectric, pyromagnetic coefficients and (which appeared only at the macro level) electromagnetic and magnetoelectric couplings of a quasi-periodic composite with an initial electromagnetic elastic state was obtained. The solutions for the desired tensors of effective properties of the quasi-periodic composite are presented in the form of analytical formulas of simple linear decompositions by solutions for tensors of effective properties of the periodic structure and statistical mixture, decomposition coefficients are the coefficient of "periodicity" (correlation of quasi-periodic and periodic structures) p and "disordering" 1-p, respectively. Results of calculation of all independent components of tensors of effective coefficients of electromagnetic and magnetoelectric couplings of different structures (periodic, quasi-periodic and statistical mixture) are presented in unidirectional direction of fibrous composite "PZT-4/ferrite" with axisymmet-ric tensor of initial macrostrain of composite. For a quasi-periodic composite (with initial macrostrain), the significantly non-monotonic nature of the dependencies of relative (to values in the absence of an initial stress state) values of effective coefficients of electromagnetic and magnetoelectric couplings from the volume fraction of ferrite fibers was revealed. It was revealed that we have an increase in the absolute values of the electromagnetic and magnetoelectric coupling coefficients of composite at negative values of its initial axisymmetric axial macrostrains. The most significant effect is the initial comprehensive macrostrain in the transversal plane on the coefficients of the transversal magnetoelectric coupling of the composite.
A NÃO HABILITAÇÃO DO CRÉDITO NO PLANO DE RECUPERAÇÃO JUDICIAL E AS CONSEQUÊNCIAS PARA O CREDOR SOB A ANÁLISE DA TEORIA DO FATO GERADOR
Authors: Jardim Priscila , Argiles André Vatimo
Published: April 2023

A Lei 11.101/2005 objetiva a recuperação de uma empresa em crise, viabilizando meios de parcelar e quitar dívidas, mediante aprovação dos detentores dos créditos, quais sejam, os credores. Todavia, muito embora as definições da referida Lei, ainda há alguns credores que não se habilitam no momento oportuno, seja por esquecimento ou vontade, visando vantagem perante os outros credores. Tal situação será analisada por intermédio da aplicação da Teoria do Fato Gerador, que desmistifica o termo de “crédito não vencido” previsto no artigo 49 da lei estudada, tudo para trazer segurança jurídica à empresa recuperanda, bem como igualdade e isonomia entre os credores.
CONTRATO DE NAMORO: suas proteções e a quarentena
Authors: Danzmann Filippi , Crippa Anelise
Published: April 2023

O artigo tem como objetivo analisar a validade jurídica do contrato de namoro e sua efetividade no que tange em afastar os deveres civis concorrentes da união estável e propor o debate sobre o atual ambiente que o isolamento social causado pela pandemia do COVID-19, domiciliando os relacionamentos em nossa sociedade. Essa nova modalidade de contrato vem sendo utilizado para declarar que os contratantes possuem na atual situação uma relação de simples namoro, que não querem arcar com as concorrências jurídicas além das devidas e requeridas. A importância da presente pesquisa fica apontada pela crescente utilização do instrumento contratual em apreço pela sociedade, pois cada vez mais cotidiano que os indivíduos utilizem da maneira contratual para regular suas relações pessoais. Com isso, a metodologia da pesquisa é de natureza bibliográfica, buscando como fontes o uso de doutrinas, teses publicadas, dissertações e jurisprudências.
A (IN)SUFICIÊNCIA DO SISTEMA DE CONTROLE DE CONSTITUCIONALIDADE CHILENO DIANTE DO LEGADO LEGISLATIVO DO REGIME PINOCHET: O CASO DO ARTIGO 116 DO CÓDIGO TRIBUTÁRIO
Authors: Carpenedo Alexandre De Freitas , Aveline Ricardo Strauch
Published: April 2023

Entre os anos de 1973 e 1990, o Chile foi governado por um regime militar ditatorial, comandado por Augusto Pinochet. Durante o regime foram editados inúmeros Decretos-Lei e foi promulgada a Constituição de 1980, a qual passou por importantes reformas em 2005. Dentre os Decretos-Lei editados, encontra-se o Código Tributário de 1974, o qual prevê em seu artigo 116 a possibilidade de delegação de competência jurisdicional de casos tributários. O artigo pretende analisar a posição do Tribunal Constitucional em três casos em que se questiona a constitucionalidade do referido artigo 116 do Código Tributário e, a partir dos julgados, busca analisar o nível de suficiência/eficiência do sistema de controle constitucional chileno. Para tanto, utilizou-se de delineamento de pesquisa na forma de estudos de casos, os quais foram analisados à luz do método de abordagem da sociologia histórica. Concluiu-se que o sistema de controle de constitucionalidade chileno possui características que o tornam “engessado” e com reduzida eficiência para lidar com o desafio do legado legislativo do regime Pinochet.
OS IMPACTOS DO ESTATUTO DA PESSOA COM DEFICIÊNCIA NA LEGISLAÇÃO CIVIL E PROCESSUAL CIVIL E O CONFLITO ENTRE NORMAS
Authors: Lima Karine Lamberch Maciel de , Crippa Anelise
Published: April 2023

O presente artigo tem como tema os impactos do Estatuto da Pessoa com Deficiência (EPD) na legislação civil e processual civil e o conflito entre essas normas. A Lei nº 13.146/2015 surgiu para regulamentar os termos da Convenção interamericana sobre os Direitos das Pessoas com Deficiência, e, assim, acarretou transformações em institutos do direito civil: teoria das incapacidades, curatela, negócios jurídicos, entre outros. Desse modo, o objetivo do presente trabalho é analisar as principais consequências promovidas pelo referido Estatuto e abordar a antinomia jurídica na aplicação de normas conflitantes. Propõe-se, assim, apresentar o trabalho, na forma de artigo científico. Para o desenvolvimento, foi utilizada uma metodologia bibliográfica e documental, com análise dos entendimentos doutrinários. Sob essa ótica, observa-se que existem alterações que trouxeram benefícios e outras, que embora sejam bem-intencionadas, causaram prejuízos à segurança e à igualdade que buscava a Lei nº 13.146/2015.
DA HOSPITALIDADE TEMPORÁRIA AO PERTENCIMENTO: UMA ANÁLISE DO “DIREITO DOS REFUGIADOS” FRENTE AO BINÔMIO SOBERANIA-DIREITOS HUMANOS
Authors: Aveline Ricardo Strauch
Published: April 2023

Os pressupostos cosmopolitas introduzidos por Kant na obra “À Paz Perpétua” inspiraram a Convenção de Genebra sobre o Estatuto dos Refugiados de 1951, estando na base do princípio do non refoulement, segundo o qual um refugiado não pode ser enviado de volta ao país de origem se isso representar risco para a sua vida. Mas o princípio do non refoulement, em si, não garante direitos e nem pertencimento no novo país, fato constatado por Hannah Arendt ao reconhecer o “direito a ter direitos” no país de acolhimento. Para efetivação desses direitos, entretanto, Benhabib afirma ser necessária uma reconfiguração do conceito de soberania e do papel do Estado-Nação.Objetivo: O artigo procura analisar a evolução do pensamento cosmopolita em Kant, Arendt e Benhabib e suas contribuições para a compreensão da temática da proteção internacional dos refugiados.Metodologia: A pesquisa adota uma abordagem indutiva e utiliza a técnica de pesquisa bibliográfica e de análise de casos com objetivos exploratório e propositivo.Resultados esperados: Identificar os óbices que impedem a efetivação dos direitos humanos e do pertencimento de refugiados nos países de acolhimento.Conclusões: Conclui-se que, se por um lado, os motivos encontram-se na necessidade de um novo equilíbrio no binômio soberania-direitos humanos, por outro lado, a visão popular sobre o estrangeiro não mudou muito desde o período descrito por Arendt em sua obra Origens do Totalitarismo, permanecendo o medo, a xenofobia e o racismo como importantes óbices ao direito de pertencimento.