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When it comes to hydropower dam safety, continuous and comprehensive monitoring is increasingly important. Especially for aging dams, this can pose a difficult challenge that benefits from a multimethod analysis. Here, we present the use and suitability of a geophysical method, Ground Penetrating Radar (GPR), for the non-invasive assessment of two distinct types of hydropower dams in Romania: Herculane (a concrete arch dam) and Gura Apelor (an embankment dam with a rockfill and clay core). Unlike traditional monitoring methods for dam safety in Romania, which might provide an incomplete overview, GPR offers a broader, non-destructive approach to evaluating some elements of dam integrity. Here, we present the results of surveys carried out with a 200 MHz antenna on the crests of both dams. The aim was to conduct a rapid assessment of the crest condition and identify the potential damage to the crest that may elude standard monitoring techniques. The surveys provide an imaging indicative of the structural integrity, although this is more challenging in the embankment dam, and additionally we provide significant information regarding the deformations in the upper layers. This complements data from routine topo-geodetical surveys, offering a potential explanation for the vertical displacements observed therein. We highlight several areas of potential deformation as well as degradation in subsurface structures such as rebars. The results underscore the value of GPR in supplementing established dam monitoring methods, highlighting its effectiveness in different contexts and dam types, as well as its potential in shaping future standards for dam safety management in Romania. [ABSTRACT FROM AUTHOR]

The notion of pre-Leibniz algebras was recently introduced in the study of Rota-Baxter operators on Leibniz algebras. In this paper, we first construct a graded Lie algebra whose Maurer-Cartan elements are pre-Leibniz algebras. Using this characterization, we define the cohomology of a pre-Leibniz algebra with coefficients in a representation. This cohomology is shown to split the Loday-Pirashvili cohomology of Leibniz algebras. As applications of our cohomology, we study formal and finite order deformations of a pre-Leibniz algebra. Finally, we define homotopy pre-Leibniz algebras and classify some special types of homotopy pre-Leibniz algebras. [ABSTRACT FROM AUTHOR]

Tunnel accidents caused by water leakage are closely related to the segmental joints, and it is therefore significant to control joint deformation. The traditional segmental joints cannot provide sufficient stiffness and strength in complex geological conditions. To solve these problems, in this study, a type of plug-in joint (composed of a sleeve and a pin) was added to the traditional segmental joints and worked in conjunction with the bolts to form a new type of combined splicing joint. The combined splicing joint was tested under four-point bending conditions. Results show that the combined splicing joint can improve the bending stiffness and load capacity of the structure. The number and position of the plug-in joints clearly affect the load capacity of the segmental joint. This study then develops an analytical method to predict the load capacity and bending stiffness of the combined splicing joints. The new combined splicing joint can effectively reduce the deformation of the segmental joints. [ABSTRACT FROM AUTHOR]

The aim of the article is to present the method of modeling the frequency response of the transformer windings with axial displacements. Frequency response analysis (often referred to as FRA or SFRA) is a powerful and sensitive method for testing the mechanical integrity of transformer cores, windings, and press frames in power transformers. The proper interpretation of FRA results is crucial in assessing winding faults. Computer modeling of transformer active part deformations is one way to expand knowledge about the impact of mechanical faults on the shape of the frequency response (FR) curve. The data collected from these models can be used as training data sets for artificial intelligence tools. An automatic tool developed from this approach would significantly improve the accuracy of the FRA method and simplify the interpretation and evaluation of results. The described study utilizes new types of lumped parameter models with input data obtained from the FEM analysis. The research conducted shows the influence of the winding axial deformation on the frequency response curve and provides information on the sensitivity of the FR curve's shape to this type of deformation. A series of tests, which involved measuring and simulating typical axial damages, were conducted to evaluate the effectiveness of the presented algorithms. [ABSTRACT FROM AUTHOR]

We consider quantum (skew) polynomial rings and observe that their graded automorphisms coincide with those of quantum exterior algebras. This allows us to define a quantum determinant that gives a homomorphism of groups acting on quantum polynomial rings. We use quantum subdeterminants to classify the resulting Drinfeld Hecke algebras for the symmetric group, other infinite families of Coxeter and complex reflection groups, and mystic reflection groups (which satisfy a version of the Shephard–Todd–Chevalley theorem). This direct combinatorial approach replaces the technology of Hochschild cohomology used by Naidu and Witherspoon over fields of characteristic zero and allows us to extend some of their results to fields of arbitrary characteristic and also locate new deformations of skew group algebras. [ABSTRACT FROM AUTHOR]

Introduction. When designing metal structures, many factors are taken into account, including the suppleness of joints, which affects the results of stress-strain calculations of structural elements. In the design of high-rise buildings, outriggers are provided to distribute wind loads between the core and perimeter columns, reducing horizontal displacements. Considering the suppleness in the joints of the outrigger affects the distribution of forces in the building structure elements, as well as on the building deformations. This paper presents an analysis of the influence of considering the suppleness of outrigger joints on the stress-strain state of structural elements of a steel high-rise building.Materials and methods. The research focuses on a structural model of a 60-story building with an outrigger, modelled using the ETABS software. The suppleness of the joints of the outrigger structures was determined using the IDEA StatiCa software.Results. According to the results of static calculations considering the suppleness of the outrigger joints, when placing one outrigger on the 54th floor, the maximum horizontal displacement at the top of the building increased by 2.9 % compared to calculations without considering suppleness. Placing two outriggers increased it by 4.7 %. The maximum axial force value in the outrigger brace decreased by 23 % compared to calculations without considering suppleness, while the maximum bending moment increased by 10 %.Conclusions. When calculating a high-rise building taking into account suppleness, the values of horizontal displacement at the building’s top increase within 5 %. If it is necessary to limit horizontal displacements, calculations should consider the suppleness of the joints in steel outrigger structures. Additionally, considering suppleness in calculations allows reducing the material intensity of the designed outrigger braces, as the determining force is the axial force, which decreases by about 25 % when calculated considering suppleness.

For any complete C -algebraic variety X and its associated compact C -analytic space X , it follows from the well known GAGA principle that the algebraic Picard group P i c (X) and the analytic Picard group P i c (X) are isomorphic. Our main purpose here is to investigate an analogous situation for non complete situation, namely C -algebraic affine hypersurfaces. [ABSTRACT FROM AUTHOR]

We introduce the concept of Hom-associative algebra structures in Loday–Pirashvili category. The cohomology theory of Hom-associative algebras in this category is studied. Some applications on deformation and abelian extension theory are given. We also introduce the notion of Nijenhuis operators to describe trivial deformations. It is proved that equivalent classes of abelian extensions are one-to-one correspondence to the elements of the second cohomology groups. [ABSTRACT FROM AUTHOR]

Abstract Magnetic skyrmions are quasi-particles with a swirling spin texture that form two-dimensional lattices. Skyrmion lattices can exhibit defects in response to geometric constraints, variations of temperature or applied magnetic fields. Measuring deformations in skyrmion lattices is important to understand the interplay between the lattice structure and external influences. Geometric phase analysis (GPA) is a Fourier-based image processing method that is used to measure deformation fields in high resolution transmission electron microscopy (TEM) images of crystalline materials. Here, we show that GPA can be applied quantitatively to Lorentz TEM images of two-dimensional skyrmion lattices obtained from a chiral magnet of FeGe. First, GPA is used to map deformation fields around a 5–7 dislocation and the results are compared with the linear theory of elasticity. Second, rotation angles between skyrmion crystal grains are measured and compared with angles calculated from the density of dislocations. Third, an orientational order parameter and the corresponding correlation function are calculated to describe the evolution of the disorder as a function of applied magnetic field. The influence of sources of artifacts such as geometric distortions and large defoci are also discussed.

Introduction. In connection with the constantly existing threats of deliberate damage to the infrastructure of critical facilities using vehicles, the task of development and research of protective structures aimed at preventing this kind of damage becomes relevant and of practical interest. The application of steel ropes as the main load-bearing elements of such structures is substantiated.Materials and methods. The proposed numerical algorithm was used to determine the minimum permissible cross-sectional area of steel ropes based on the requirements for a protective structure in terms of resistance to impact caused by the collision of a car with a given mass and speed. The developed method is based on mathematical modelling of the conditional optimization problem. The objective function was the function of the longitudinal force arising in the steel ropes. At the same time, requirements were made to comply with the conditions of energy conservation and continuity of deformations, as well as strength limitations. A verification calculation of the designed protective structure was carried out in a commercial software package implemented on the generally recognized finite element method. The methodology of the full-scale experiment is presented. A full-scale experiment was carried out in order to determine the true distribution of deformations over the structural elements of the test object under impact.Results. The results of the experimental study are presented. A comparative analysis of the data obtained in the process of numerical and computer simulation, as well as in the course of a full-scale test, was carried out. A slight discrepancy in the values of the controlled parameters obtained by different methods was found.Conclusions. The proposed numerical algorithm for searching the minimum permissible cross-sectional area of steel ropes, based on the requirement of a given strength, confirmed its reliability, and the adopted design solutions of the developed protective structure proved their validity. The results of the research can be used in the design of such engineering structures designed for the physical protection of critical facilities.

Significance: The accurate correlation between optical measurements and pathology relies on precise image registration, often hindered by deformations in histology images. We investigate an automated multi-modal image registration method using deep learning to align breast specimen images with corresponding histology images. Aim: We aim to explore the effectiveness of an automated image registration technique based on deep learning principles for aligning breast specimen images with histology images acquired through different modalities, addressing challenges posed by intensity variations and structural differences. Approach: Unsupervised and supervised learning approaches, employing the VoxelMorph model, were examined using a dataset featuring manually registered images as ground truth. Results: Evaluation metrics, including Dice scores and mutual information, demonstrate that the unsupervised model exceeds the supervised (and manual) approaches significantly, achieving superior image alignment. The findings highlight the efficacy of automated registration in enhancing the validation of optical technologies by reducing human errors associated with manual registration processes. Conclusions: This automated registration technique offers promising potential to enhance the validation of optical technologies by minimizing human-induced errors and inconsistencies associated with manual image registration processes, thereby improving the accuracy of correlating optical measurements with pathology labels. [ABSTRACT FROM AUTHOR]

A technological process for hot forging of two-layer forgings with deep cavities and an inverted cone has been developed. A hot forging process flow chart has been analyzed. Digital simulation using QForm software was employed to study the effect of the process parameters on the force characteristics of the metal-forming process, stress-strain condition, and temperature fields of the forging and tooling after each pass. A new design of the die tooling has been proposed. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the formation of the structure and stress–strain state in the joints of AISI 304 stainless steel with a thickness of 2 mm and produced by welding with laser and plasma energy sources. It is established that the microhardness and parameters of the grain and subgrain structures of the welded joint material differ with respect to the dimensions of crystallites, grains, and subgrains according to the welding process. It is shown that, in terms of structure formation, including substructural features, the most favorable structures of 2 mm AISI 304 welded joints are formed by laser–plasma welding. It is predicted that the residual stressed state is less localized with the application of laser–plasma welding than laser welding, and it is characterized by a lower level of residual stresses compared to plasma welding. In all the cases, the maximal stress values are concentrated in the HAZ, and the value obtained using laser–plasma welding is in an intermediate position (431.7 MPa) between those of the laser (443 MPa) and plasma (413.7 MPa) processes. With laser–plasma and laser welding, displacements (deformations) are minimal and close to 0.2 mm. The method of electron speckle interferometry was used, and the results reveal that the error between the calculated and experimental values of equivalent stresses is no more than 6%, which is acceptable. The results of mechanical testing show that, under uniaxial tension, the strength of the welded joints made of AISI 304 steel using laser–plasma and laser welding is the highest and equal to 97% of that of the base metal. [ABSTRACT FROM AUTHOR]

Camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP) is a rare hereditary disease of childhood, characterized by camptodactyly, non-inflammatory arthropathy, progressive coxa vara deformity and non-inflammatory sterile pericarditis. Due to the predominant joint involvement in childhood, CACP is often misdiagnosed as juvenile idiopathic arthritis (JIA), leading to delayed diagnosis and unwarranted treatment with antirheumatic drugs. Delayed diagnosis can lead to serious complications such as joint deformities and cardiovascular dysfunction. This case report illustrates once again the diagnostic difficulties associated with this rare syndrome. [ABSTRACT FROM AUTHOR]

In this research, by using the finite element method, the effect of five parameters (density of a liquid mineral fertilizer (ρ), its temperature (T), tank wall thickness (L), spacing of stiffeners (K) and stiffeners height (h)) on the strength of standard polyethylene rotomolded tanks used for storage of liquid mineral fertilizers (LMF) was studied. Using the Taguchi method, it was found that these parameters are ranked according to the degree of their influence (in decreasing order) on: maximum stresses (ρ>L>h>T>K), maximum stresses in the tank walls (ρ>L>K>T>h) and deformations of the tank ( for DX/DY: ρ>L>h>T>K and for DZ: ρ>L>h>K>T). Validation of the FEM strength calculations was carried out, which showed satisfactory convergence of the calculated and experimental values. Generalized equations are derived that describe the effect of all five studied parameters on P, PW and tank deformations (along the X, Y and Z axes). On the basis of the derived equations, a nomogram has been constructed, which makes it possible to choose the optimal wall thickness that will correspond to the LMF density and storage temperature. Applying the optimal wall thickness ensures a guaranteed service life of at least 50 years, minimizing the risk of environmental accidents caused by tank failure and the release of LMF and associated toxic substances into groundwater. This research offers valuable insights for designing safer and more durable storage tanks for liquid mineral fertilizers. As an optimal design of the tank for storing the most common fertilizer UAN-32 (Urea Ammonium Nitrate, 32 % nitrogen), with a density of 1.32 g/cm³ and at storage temperatures up to 40 °C, the following values of structural parameters are recommended: L=10 mm, K=38 mm, and h=4 mm. [ABSTRACT FROM AUTHOR]

Rota–Baxter algebras are important in probability, combinatorics, associative Yang–Baxter equation and splitting of algebras. This paper studies the formal deformations of Rota–Baxter algebra morphisms. As a consequence, we develop a cohomology theory of Rota–Baxter algebra morphisms to interpret the lower degree cohomology groups as formal deformations. Finally, we prove the cohomology comparison theorem of Rota–Baxter algebra morphisms, i.e. the cohomology of a morphism of Rota–Baxter algebras is isomorphic to the cohomology of an auxiliary Rota–Baxter algebra. [ABSTRACT FROM AUTHOR]

The paper presents the results of computational analysis of the stress-strain state of reinforced concrete spans of the railway (single-track railway line) overpass over the highway, under specified loads using spatial finite element models. The static load consists of a cohesion of three TEM-18 diesel locomotives and two loaded gondola cars (up to 25 tons per axle). The purpose of this study was to ensure reliable and safe operation of artificial structures on the railroads, as there is a constant increase in transit freight trains from China through the territory of Kazakhstan to near and far abroad, and often the load on the axle reaches 25 tons, and sometimes larger values – up to 27 tons per axle. The results of the study are recommended to be used for inspections and tests of typical girder bridge spans, as well as in the case of monitoring their technical condition with increasing operational loads. [ABSTRACT FROM AUTHOR]

The most important issue regarding the safety and performance of concrete face rockfill dams (CFRDs) is to determine stresses and deformations. However, predictions of crest settlements of CFRDs are usually performed using empirical relationships. In recent years, CFRDs have been constructed much higher and at more complicated topographical and geological dam sites, so numerical analysis is required to evaluate the stress and deformations in the entire dam body. Also, assessing long-term rockfill behaviour and the concrete face membrane crack potential are important for post-construction dam safety. This study evaluates post-construction deformations and crest settlements of a high CFRD under two different loading cases, considering the non-linear elasto-plastic behaviour of the rockfill structure. As a constitutive model, the Duncan–Chang hyperbolic stress–strain model was applied in finite-element simulations considering the failure criterion is isotropic and hardening. Calibration of the rockfill's hyperbolic parameters was performed by comparing the calculated displacements with actual settlement measurements. Computed crest settlements were also compared with those of some CFRDs given in the literature. Calculated crest settlement and other deformations are in good agreement with the rockfill settlement measurements and in acceptable ranges, and do not threaten the dam's safety. [ABSTRACT FROM AUTHOR]

This paper focuses on investigating the stability of a deep foundation pit with hard surrounding rocks at different excavation stages with different supporting schemes by means of numerical calculations. The supporting schemes in question were combinations of one fixed vertical support and four varied transverse supports. Drilled grouting piles were used as vertical supports, and the commonly used steel bracings and prestressed anchorages served as transverse supports. The parameters used to evaluate the stability of the foundation pit at different excavation stages included the lateral displacements of the surrounding rocks, the settlement of the surrounding ground, the axial forces of steel bracings, and displacements at the tops of the drilled grouting piles. Simulation results showed that when a transverse supporting scheme consisting of one-layer steel bracings and prestressed anchorages set at 9 m and 22.5 m underground, respectively, was adopted, the lateral displacements of the surrounding rocks and settlement of the surrounding ground at different excavation stages were the largest compared to those under the other three transverse supporting schemes, while the corresponding values were lower compared to those allowed in Chinese standard GB50007-2011, demonstrating that this kind of supporting scheme is effective in terms of ensuring the safety of the foundation pit at different excavation stages. Moreover, the setting techniques for this kind of supporting scheme were relatively simple, and the corresponding influences of supporting element arrangements on excavation techniques were the lowest. Therefore, one-layer steel bracings and one-layer prestressed anchorages constituted the most suitable transverse supporting scheme for excavating a deep foundation pit with hard surrounding rocks. [ABSTRACT FROM AUTHOR]

In the context of the continuous development of armoured vehicles and the increasing requirements for the strength and efficiency of armoured vehicles, the study and improvement of torsion shafts becomes relevant to ensure high service life and optimal functioning. The aim of this study is to analyse the torsion shafts of light armoured vehicles to identify possible areas of optimization to increase the strength and durability of these vehicle elements. The methods used include the analytical method, classification method, functional method, statistical method, synthesis method, and others. As a result of the study, a comprehensive analysis and optimization of torsion shafts for light armoured vehicles was carried out to increase their strength and durability. The choice of high-strength material and weight consideration helped to reduce the weight of the vehicle, increasing its efficiency. Geometric design included the use of advanced techniques to optimize the shaft shape, and stress and strain analysis helped determine the optimum parameters. The use of computer modelling and simulation simplified the analysis of the shaft’s behaviour under load. The use of safety factors and consideration of impact loads during operation helped to improve the reliability and durability of the structure. The use of the latest materials and manufacturing technologies allowed achieving the optimum parameters of the transmission element. Testing of the prototypes in real conditions confirmed their efficiency and durability. The optimization of weight and weight distribution was aimed at improving the stability of the armoured vehicle, taking into account the requirements of a particular application and manufacturer. The results indicate the potential for improving the design of torsion shafts to increase the performance and stability of light armoured vehicles. This study makes an important contribution to science, as the identified optimizations and improvements in the design of torsion shafts of light armoured vehicles contribute not only to increasing their strength and durability, but also to the rational use of resources and increasing the overall performance of the vehicle

Uchino initiated the investigation of twisted Rota-Baxter operators on associative algebras. Relevant studies have been extensive in recent times. In this paper, we introduce the notion of a twisted Rota-Baxter operator on a Hom-Lie algebra. By utilizing higher derived brackets, we establish an explicit $ L_{\infty} $-algebra whose Maurer-Cartan elements are precisely twisted Rota-Baxter operators on Hom-Lie algebra s. Additionally, we employ Getzler's technique of twisting $ L_\infty $-algebras to establish the cohomology of twisted Rota-Baxter operators. We demonstrate that this cohomology can be regarded as the Chevalley-Eilenberg cohomology of a specific Hom-Lie algebra with coefficients in an appropriate representation. Finally, we study the linear and formal deformations of twisted Rota-Baxter operators by using the cohomology defined above. We also show that the rigidity of a twisted Rota-Baxter operator can be derived from Nijenhuis elements associated with a Hom-Lie algebra.

Slope instability problems due to widening of roads are very common in mountainous terrains particularly in Indian Himalayan region. Slope instability may occur due to action of different natural as well as anthropogenic activities or through combined action of both. The present paper deals with the slope stability assessment of natural and cut slopes along the Imphal–Moreh section of NH-39 in Manipur state, India. The factor of safety (FoS) for pre- and post-excavations is evaluated, and the FoS with the mitigation measures is examined using limit equilibrium and finite element method. Construction sequences are modeled, and the stability and deformation patterns are evaluated for each construction stage. It is found that about 78% of the slopes is having an angle more than 45° after cutting. The present study suggests that a FoS greater than 1.25 can be achieved by installing a 5.5 m anchor at 18° with the horizontal at a spacing of 1 m. Confirmatory field tests on the anchor are also conducted to ensure the accuracy of the adopted design parameters. This study provides useful informations to researchers and practitioner about the stability assessment of slopes and potential mitigative measures. Similar schemes of mitigative measures are effective for the same/similar geologic conditions in the Indian Himalayan terrain. [ABSTRACT FROM AUTHOR]

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The 40Ar–39Ar isotope dating of newly formed micas and chlorites from thrust zones made it possible to establish that they were formed in the Tithonian (150 Ma). Sedimentary rocks from the Devonian to Triassic were involved in thrusts. An older stage of deformations of 257 Ma was established in the Silurian rocks composing the Dream-Head Mountains of Wrangel Island. This age corresponds to the Late Permian stratigraphic interval and indicates the existence of deformations after the Ellesmerian orogeny in the Early Carboniferous. The formation of thrusts was accompanied by the heating of sedimentary sequences up to temperatures of 250–380°C, while the temperature regime in the thrust zone almost did not change. The temperature difference between the thrust zone and under the thrust is not more than 20°C. [ABSTRACT FROM AUTHOR]

It is well-known that the deformation problem of a compact coisotropic submanifold C in a symplectic manifold is obstructed in general. We show that it becomes unobstructed if one only allows coisotropic deformations whose characteristic foliation is diffeomorphic to that of C. This extends an unobstructedness result in the setting of integral coisotropic submanifolds due to Ruan. [ABSTRACT FROM AUTHOR]

In this paper, we define and study (co)homology theories of a compatible associative algebra. At first, we construct a new graded Lie algebra whose Maurer-Cartan elements are given by compatible associative structures on a vector space. Then we define the cohomology of a compatible associative algebra A and as applications, we study extensions, deformations and extensibility of finite order deformations of A. We end this paper by considering compatible presimplicial vector spaces and the homology of compatible associative algebras. [ABSTRACT FROM AUTHOR]

Using Hodge theory and Banach fixed point theorem, Liu and Zhu developed a global method to deal with various problems in deformation theory. In this note, the authors generalize Liu-Zhu's method to treat two deformation problems for non-Kähler manifolds. They apply the -Hodge theory to construct a deformation formula for (p, q)-forms of compact complex manifold under deformations, which can be used to study the Hodge number of complex manifold under deformations. In the second part of this note, by using the -Hodge theory, they provide a simple proof of the unobstructed deformation theorem for the non-Kähler Calabi-Yau -manifolds. [ABSTRACT FROM AUTHOR]

In the context of the continuous development of armoured vehicles and the increasing requirements for the strength and efficiency of armoured vehicles, the study and improvement of torsion shafts becomes relevant to ensure high service life and optimal functioning. The aim of this study is to analyse the torsion shafts of light armoured vehicles to identify possible areas of optimization to increase the strength and durability of these vehicle elements. The methods used include the analytical method, classification method, functional method, statistical method, synthesis method, and others. As a result of the study, a comprehensive analysis and optimization of torsion shafts for light armoured vehicles was carried out to increase their strength and durability. The choice of high-strength material and weight consideration helped to reduce the weight of the vehicle, increasing its efficiency. Geometric design included the use of advanced techniques to optimize the shaft shape, and stress and strain analysis helped determine the optimum parameters. The use of computer modelling and simulation simplified the analysis of the shaft's behaviour under load. The use of safety factors and consideration of impact loads during operation helped to improve the reliability and durability of the structure. The use of the latest materials and manufacturing technologies allowed achieving the optimum parameters of the transmission element. Testing of the prototypes in real conditions confirmed their efficiency and durability. The optimization of weight and weight distribution was aimed at improving the stability of the armoured vehicle, taking into account the requirements of a particular application and manufacturer. The results indicate the potential for improving the design of torsion shafts to increase the performance and stability of light armoured vehicles. This study makes an important contribution to science, as the identified optimizations and improvements in the design of torsion shafts of light armoured vehicles contribute not only to increasing their strength and durability, but also to the rational use of resources and increasing the overall performance of the vehicle. [ABSTRACT FROM AUTHOR]

This study systematically examines the behavior of cantilever and anchorage sheet piles influenced by a range of variables, namely dredge level, water table level, anchor interanchor distance, anchors’ number, and the distance from the ground surface. Utilizing a single sheet pile material, the investigation highlights the deformations resulting from these variables, in addition to assessing the effects of different soil types and degrees of saturation. The primary objective centers on the computation of bending moments arising from these factor variations under a constant load, using the finite element theory-based software, Plaxis 2D Connect Edition V20. Sheet pile behavior could be evaluated using this tool by investigating driven depth, maximum bending moments, and horizontal displacements in both anchorage and cantilever sheet piles. To enhance the reliability and realism of findings, outcomes are compared with results from the Pro Sheet program. This comprehensive evaluation furnishes valuable insights into sheet pile deformations under diverse conditions, contributing to the existing body of knowledge and facilitating more robust engineering practices. [ABSTRACT FROM AUTHOR]

Sliding bearings with curved internal cylindrical surfaces have great potential and can play an important role in the repair and restoration of mechanisms of the agro-industrial complex. Since their use is becoming more and more common, there is a need to improve the design of such bearings to ensure their quality use and avoid errors in research on this issue, in addition, achieving better results in this area require significant financial investments to improve the efficiency of such mechanisms. The main goal of this work is to provide recommendations aimed at eliminating errors in the processes of improving and improving the quality of sliding bearings, as well as analyzing the functioning of machines used in the agro-industrial complex. An analytical method, a classification method, a functional method, a statistical method, and a synthesis method were used. In the course of the research, the peculiarities and differences of sliding bearings with curvilinear generators of the internal cylindrical surface were noted, errors and their causes, which are allowed during the improvement of agro-industrial mechanisms that ensure the development of the agricultural industry, were analyzed. It is important to analyze the functioning of these mechanisms in order to assess their effectiveness, development and complexity of work during the production of agricultural products. The issue of evaluating the performance of sliding bearings of this type, the expediency of using this element, their limitations during the process, the impact of limitations on the result was considered, and recommendations were proposed that would contribute to an effective mechanism for regulating the issue. It was determined that the use of sliding bearings of this type, in the process of restoring agro-industrial mechanisms, will ensure a significant increase in the productivity of these machines. The practical value of this work lies in the possibility of applying the obtained results to eliminate errors in the development and improvement of the mechanisms of the agro-industrial complex, studying the reliability of the use of sliding bearings in general, taking into account various factors, will provide a basis for recommendations on the appropriate use of these bearings

The algorithm presented in this paper concerns the processing of data in the form of coordinates of measurement points located around the structure periphery, obtained from the geodetic measurements. The geometric parameter used here to study the deformation of the steel shell is the change of curvature. It is used to estimate the bending moment and hence the normal stress in the corrugated steel shell. The results given in the examples of calculations of the analyzed structure show the possibility of determining places with extreme values. For this purpose, a dense layout of measuring points and use the precision geodesy technique is necessary. Of significant importance in stress estimation is the correction of the geodetic measurement base. This is due to the fact that the points in the initial measurement do not lie on a section of the circle as a reference curve, used to determine the deformation of the shell.

When it comes to hydropower dam safety, continuous and comprehensive monitoring is increasingly important. Especially for aging dams, this can pose a difficult challenge that benefits from a multimethod analysis. Here, we present the use and suitability of a geophysical method, Ground Penetrating Radar (GPR), for the non-invasive assessment of two distinct types of hydropower dams in Romania: Herculane (a concrete arch dam) and Gura Apelor (an embankment dam with a rockfill and clay core). Unlike traditional monitoring methods for dam safety in Romania, which might provide an incomplete overview, GPR offers a broader, non-destructive approach to evaluating some elements of dam integrity. Here, we present the results of surveys carried out with a 200 MHz antenna on the crests of both dams. The aim was to conduct a rapid assessment of the crest condition and identify the potential damage to the crest that may elude standard monitoring techniques. The surveys provide an imaging indicative of the structural integrity, although this is more challenging in the embankment dam, and additionally we provide significant information regarding the deformations in the upper layers. This complements data from routine topo-geodetical surveys, offering a potential explanation for the vertical displacements observed therein. We highlight several areas of potential deformation as well as degradation in subsurface structures such as rebars. The results underscore the value of GPR in supplementing established dam monitoring methods, highlighting its effectiveness in different contexts and dam types, as well as its potential in shaping future standards for dam safety management in Romania.

The aim of the article is to present the method of modeling the frequency response of the transformer windings with axial displacements. Frequency response analysis (often referred to as FRA or SFRA) is a powerful and sensitive method for testing the mechanical integrity of transformer cores, windings, and press frames in power transformers. The proper interpretation of FRA results is crucial in assessing winding faults. Computer modeling of transformer active part deformations is one way to expand knowledge about the impact of mechanical faults on the shape of the frequency response (FR) curve. The data collected from these models can be used as training data sets for artificial intelligence tools. An automatic tool developed from this approach would significantly improve the accuracy of the FRA method and simplify the interpretation and evaluation of results. The described study utilizes new types of lumped parameter models with input data obtained from the FEM analysis. The research conducted shows the influence of the winding axial deformation on the frequency response curve and provides information on the sensitivity of the FR curve’s shape to this type of deformation. A series of tests, which involved measuring and simulating typical axial damages, were conducted to evaluate the effectiveness of the presented algorithms.

This article presents the results of a study on reducing deformations resulting from high-temperature vacuum carburizing and post-carburizing heat treatment. The idea was to increase the strength of steel at elevated temperatures by pre-carburizing at heat-up to the process temperature (SC—stage carburizing). It has been shown that the use of carburizing in stages from a lower temperature to the target temperature, compared to traditional vacuum carburizing at a constant temperature (Constant-Temperature Carburizing—CTC), has a significant impact on the chemical and phase composition of the technological layer, surface after the process and, consequently, on its mechanical properties. It was shown that the retained austenite content after stage carburizing was reduced by approximately 45%, as was the thickness of the gear teeth measured at the pitch diameter. Additionally, uniform stress distribution was demonstrated for the SC process. Carbon saturation of austenite increases the yield strength, and therefore the dimensional stability of steel heat-treated at elevated temperatures also improves, which effectively permits high-temperature treatment of critical steel parts such as, for example, gear wheels, for which high dimensional accuracy is required. [ABSTRACT FROM AUTHOR]

The paper presents findings of tectonic-stress field reconstruction in the central part of Sakhalin Island as a result of field tectonophysical studies between 2020 and 2022. The measurements made it possible to determine the predominant orientation of the main slickenside systems with different kinematics. The territory of Central Sakhalin is characterized by mainly subvertical orientation of the axis of maximum compression and by the subhorizontal and mostly submeridionally directed axis of minimum compression/extension. The main detected feature of Central Sakhalin is the predominance of horizontal extension as the stress state type for the entire area. Horizontal shear and compression settings are significant in its western part. The number of horizontal extension settings increases in the near-axial and eastern part of Central Sakhalin towards the Sea of Okhotsk. We found a cardinal difference between the stress field reconstruction data obtained there and the results of similar studies in other geodynamically active regions of Russia. [ABSTRACT FROM AUTHOR]

The wavelet scattering transform introduced by Stéphane Mallat is a unique example of how the ideas of harmonic and multiscale analysis can be ingeniously exploited to build a signal representation with provable geometric stability properties, such as the Lipschitz continuity to the action of small C 2 diffeomorphisms – a remarkable result for both theoretical and practical purposes, inherently depending on the choice of the filters and their arrangement into a hierarchical architecture. In this note, we further investigate the intimate relationship between the scattering structure and the regularity of the deformation in the Hölder regularity scale C α , α > 0. We are able to precisely identify the stability threshold, proving that stability is still achievable for deformations of class C α , α > 1 , whereas instability phenomena can occur at lower regularity levels modeled by C α , 0 ≤ α < 1. While the analysis at the threshold given by Lipschitz (or even C 1) regularity remains beyond reach, we are able to prove a stability bound in that case, up to ε losses. [ABSTRACT FROM AUTHOR]

The deformations of an ice cover on the surface of an ideal incompressible fluid of finite depth under the action of a pressure domain that moves rectilinearly at a constant velocity in the presence of a current with velocity shift, as well as the wave forces exerted on a moving body, are studied. Fluid flow is not potential. The ice cover is modeled by a thin elastic plate with account for uniform compression. The motion of the load can occur at an arbitrary angle to the direction of current. It is assumed that the ice deflection is steady in the coordinate system moving with the load. The Fourier transform method is used within the framework of the linear wave theory. The maximum deformations of ice cover and the wave forces are studied depending on the current velocity gradient, the direction of motion, and the compression ratio. [ABSTRACT FROM AUTHOR]

A Lie algebra morphism triple is a triple (g , h , ϕ) consisting of two Lie algebras g , h and a Lie algebra homomorphism ϕ : g → h . We define representations and cohomology of Lie algebra morphism triples. As applications of our cohomology, we study some aspects of deformations, abelian extensions of Lie algebra morphism triples and classify skeletal sh Lie algebra morphism triples. Finally, we consider the cohomology of Lie group morphism triples and find a relation with the cohomology of Lie algebra morphism triples. [ABSTRACT FROM AUTHOR]

The Bianchi groups Bi (d) = PSL (2 , O d) < PSL (2 , C) (where O d denotes the ring of integers of Q (i d) , with d ⩾ 1 squarefree) can be viewed as subgroups of SO (3 , 1) under the isomorphism PSL (2 , C) ≃ SO 0 (3 , 1) . We study the deformations of these groups into the larger Lie groups SU (3 , 1) and SL (4 , R) for small values of d. In particular we show that Bi (3) , which is rigid in SO (3 , 1) , admits a 1-dimensional deformation space into SU (3 , 1) and SL (4 , R) , whereas any deformation of Bi (1) into SU (3 , 1) or SL (4 , R) is conjugate to one inside SO (3 , 1) . We also show that none of the deformations into SU (3 , 1) are both discrete and faithful. [ABSTRACT FROM AUTHOR]

The main dependences that make it possible to determine and evaluate the dynamic components of stresses and displacements in main gas pipelines under the action of a moving concentrated force are considered. The solution of the problem is given for single-span, two-span, and three-span beam transitions. According to the requirements of industry documents, decisions were made on the further operation of crossings or the need for their reconstruction. [ABSTRACT FROM AUTHOR]

A problem of the longitudinal impact of a ram with a punch on a forging for an impact press is solved using the finite difference method. An algorithm is presented for calculating the maximum deformations and stresses of an elastic polyurethane liner when a self-resetting force fuse is triggered for a KD2124 crank press with a force of 250 kN. The solution can be used to develop a concept for constructing a means of protecting impact crank presses from technological overloads. [ABSTRACT FROM AUTHOR]