Individual Structural Elements Research Articles

Role of individual structural and functional elements of myelin in Parkinson’s disease

Role of individual structural and functional elements of myelin in Parkinson’s disease

Evaluation of blast-induced progressive collapse in steel structures with conventional braces, moment-resisting braces, and buckling-restrained braces using LS-DYNA software

Today, considering the increased cases of terroristic operations, structural design engineers are starting to acknowledge blast-induced loads alongside other design parameters. Since a blast-induced load exhibits a much shorter period than the natural period of the structure, it is unlikely to induce general damages or stimulate the entire structure immediately after the loading, but rather local damages in individual structural elements are the common form of damage. These local damages, however, can set the scene for the gradual failure of the structure. The present study on structures with moment-resisting frames, buckling-restrained braces (BRBs), and conventional steel braces was conducted through an alternative load path (ALP, also known as column elimination) and exact modeling of the blast on the steel frames was undertaken using LS-DYNA software. In this work, the behavior of three five-story steel frames under a blast-induced load of 100 kg TNT equivalent at a distance of 10 m from the structural columns for a period of 100 ms was investigated. Results of analyzing the blast-induced effect on the frames showed that the frame equipped with buckling-restrained braces (BRB) exhibited improved overall peak displacement across the entire frame, peak induced velocity, and peak induced acceleration by 30%, 30%, and 46%, respectively, as compared to other steel frames exposed to blast loads.

The endoplasmic reticulum as an active liquid network

The peripheral endoplasmic reticulum (ER) forms a dense, interconnected, and constantly evolving network of membrane-bound tubules in eukaryotic cells. While individual structural elements and the morphogens that stabilize them have been described, a quantitative understanding of the dynamic large-scale network topology remains elusive. We develop a physical model of the ER as an active liquid network, governed by a balance of tension-driven shrinking and new tubule growth. This minimalist model gives rise to steady-state network structures with density and rearrangement timescales predicted from the junction mobility and tubule spawning rate. Several parameter-independent geometric features of the liquid network model are shown to be representative of ER architecture in live mammalian cells. The liquid network model connects the timescales of distinct dynamic features such as ring closure and new tubule growth in the ER. Furthermore, it demonstrates how the steady-state network morphology on a cellular scale arises from the balance of microscopic dynamic rearrangements.

Переходные участки бесстыкового пути, примыкающие к стрелочным переводам

Purpose: consider the problem of interaction between turnouts and adjacent sections of a seamless railway track. Methods: statistical data analysis. Results: an analysis of the results of domestic and foreign studies has been carried out, which show that in such areas there is a jump with subsequent extrusion of material of less rigidity and an increase in the slope of the elastic unevenness, i. e., an undesirable phenomenon occurs — a shock wave. The impact force depends on the mass of the rolling stock and the speed of movement, the geometric evenness of the rail track and the chosen approaches to designing the transition zone as a whole. Jump and mainly occurs due to compression and pushing out of structural layers and materials of lower rigidity in the under-rail area. The impact force depends on the mass of the rolling stock and the speed of movement, the geometric evenness of the rail track and the chosen approaches to designing the transition zone as a whole. Jump and mainly occurs due to compression and pushing out of structural layers and materials of lower rigidity in the under-rail area. Shock waves caused by uneven rigidity of sections have negative consequences (the appearance of deviations in level, subsidence, distortions, increased intensity of rail wear, the appearance of rail defects), which increase the cost of maintenance of the railway track. An analysis of the accumulation of residual deformations has been carried out, which shows the systematic formation of geometric irregularities in adjacent areas in the turnout area. Practical importance: from the point of view of the design of the transition zone, the expected advantage will be the differentiation of structural materials and elements and their influence on achieving the optimal gradation of railway track rigidity in the vertical and horizontal (transverse, longitudinal directions), selection of the optimal ratio of the mechanical properties of individual elements of the superstructure structure. It should also be noted that it is necessary to conduct an additional feasibility study of the feasibility of constructing transition sections in the area where the track and switches meet, taking into account the operational features of individual railway lines.

Prediction of Failure Due to Fatigue of Wire Arc Additive Manufacturing-Manufactured Product

Currently, the focus of production is shifting towards the use of innovative manufacturing techniques and away from traditional methods. Additive manufacturing technologies hold great promise for creating industrial products. The industry aims to enhance the reliability of individual components and structural elements, as well as the ability to accurately anticipate component failure, particularly due to fatigue. This paper explores the possibility of predicting component failure in parts produced using the WAAM (wire arc additive manufacturing) method by employing fractal dimension analysis. Additionally, the impact of manufacturing imperfections and various heat treatment processes on the fatigue resistance of 30CrMnSi steel has been investigated. Fatigue testing of samples and actual components fabricated via the WAAM process was conducted in this study. The destruction of the examined specimens and products was predicted by evaluating the fractal dimensions of micrographs acquired at different stages of fatigue testing. It has been established that technological defects are more dangerous in terms of fatigue failure than microstructural ones. The correctly selected mode of heat treatment for metal after electric arc welding allows for a more homogeneous microstructure with a near-complete absence of microstructural defects. A comparison of the fractal dimension method with other damage assessment methods shows that it has high accuracy in predicting part failure and is less labor-intensive than other methods.

Forest structural heterogeneity positively affects bird richness and acoustic diversity in a temperate, central European forest

IntroductionForests managed for timber production can also be managed for biodiversity conservation by retaining structures typical of old-growth forests, which provide heterogenous structures for forest-dwelling species, including birds. Ecoacoustic monitoring of forest birds is now a well-studied field, however the extent to which acoustic indices can reflect bird assemblage responses to stands of lower or higher structural heterogeneity is disputed. MethodIn this study, we acoustically surveyed 75 plots over two years in mature, previously managed forests and computed acoustic indices from the recordings. We first identified an acoustic index that significantly correlated with bird richness over more than one spring season. Next, we tested the response of bird richness to individual forest structural elements using linear regressions. We then repeated this analysis but combined the individual structural elements into one structural composition variable using an NMDS and gam smooth overlay, to compare the effect of individual forest structures versus overall forest heterogeneity on bird richness. We then repeated this analysis using our selected acoustic index, the Normalized Difference Soundscape Index (NDSI), to see if it followed the same patterns as bird richness in response to individual and collective forest structural elements.ResultsOur results showed that plots with high bird richness were also associated with high NDSI values, and high values of both variables occurred in plots with high structural heterogeneity (tree species richness, tree size variability, and snag height variability) and low amounts of standing and lying deadwood. DiscussionOur findings suggest that once an acoustic index can be identified as a robust correlate of bird richness, it can serve as a proxy for the response of birds to differences in forest structural heterogeneity within a managed forest context. It is therefore possible for forest managers interested in conserving or increasing bird richness in their production forests to identify a robust acoustic index to track the response of bird richness to management decisions over time.

Methodological approaches to the study of household financial sustainability

Introduction. The implementation of theoretical achievements of scientists in the study of household finances is preceded by the development of appropriate methodological approaches for conducting such research. However, a review of the literature has shown that scholars study mainly the methodology of household finances or their material embodiment - financial resources through the prism of using individual methods, without giving a general definition of the concept of methodology. Today, there is no consensus on the interpretation of the methodology of household finance research. This affects the overall development of this area of the financial system. This determines the relevance of developing methodological approaches to scientific knowledge of household financial sustainability The purpose of the paper is to continue existing research and develop proposals on methodological approaches to understanding the financial sustainability of households. During the study, analysis and synthesis were used as theoretical cognition of ensuring households’ financial sustainability. Results. The paper proposes dialectical, cognitive and institutional methodological approaches to the study of household financial sustainability. It is substantiated that the combination of such methodological approaches makes it possible to deepen the understanding of the concept of financial stability of households as a single whole, which is characterized by the interaction of external and internal. The process of external interaction takes place with the real economic and financial environment in which the household operates. As for the internal interaction, its essence is manifested through the peculiarities of the structure of the sustainability system, its composition and the interrelationships between the individual structural elements of the households’ financial activity. Conclusion. The proposed approaches make it possible to deepen the content of the concept of financial sustainability of households as a single whole, which is characterized by the interaction of external and internal. Taken together, the dialectical, cognitive, and institutional approaches discussed form the methodological basis for theoretical and practical research on the processes of ensuring household financial sustainability.

Full-scale hybrid fire test in real-time with multiple degree of freedom

To experimentally assess the fire resistance of civil structures, testing whole structures is very costly but the standard tests on individual structural elements can sometimes be too simplistic, regarding their boundary conditions. Hybrid fire testing offers a promising solution to these limitations, but performing such tests is technically challenging and few full-scale tests have been conducted. Current approaches rely on high-performance sensors and actuator systems, as well as assumptions about the stiffness of the tested element. This paper presents the detailed methodology and results of a full-scale, real-time test with 3 degrees of freedom on a concrete beam. The use of an adaptive controller allowed for maintaining stability and achieving reasonable precision despite the use of relatively low-precision sensors, regular hydraulic actuators, and no assumptions about the tested element’s stiffness. The comparison with the same element tested using a standard fire resistance test demonstrates the usefulness of this technique in achieving a more accurate representation of the performance of the tested element in realistic conditions.

Impact of Digital Technologies on Implementing Individual Elements of the Tax Structure

Impact of Digital Technologies on Implementing Individual Elements of the Tax Structure

Steel ribbed dome structural performance with different node connections and bracing system

The conventional design of steel structure objects relies on a first-order elastic analysis, where the entire object is treated as a set of individual structural elements requiring time-consuming, semi-empirical design calculations. Such an approach leads to inefficient design time and excessive material consumption and may additionally result in designing on the verge of structural safety. The AEC sector's technological and digitization advancement process forces designers to use advanced design methods. Hence, it is necessary to indicate the benefits of using effective optimization. The paper presents a comparative analysis of steel domes using two design approaches: traditional first-order analysis and an advanced second-order analysis. The latter method considers the influence of structural deformation on the magnitude of internal forces. Eight models were developed, varying in terms of the connection's stiffness. The work results identify the differences between the two selected design approaches and present opportunities for further structural performance of steel structures.

MODELING OF A LIGHTWEIGHT FLAT FLOOR WITH VOIDS MADE OF PLASTIC BALLS

Formulation of the problem. Prefabricated monolithic construction in domestic and global practice in recent years has occupied a small share in the field of construction. A fairly large number of designs of prefabricated monolithic lightweight floors, as well as its individual structural elements, have been proposed. The use of lightweight floors in the construction of residential and public buildings can significantly reduce the consumption of materials and the dead weight of structures and increase the size of live loads and overlapping spans. Despite this, it cannot be said that effective design solutions have been found that can maximally satisfy the requirements of consumers, architects and builders. Based on this, a constructive solution for a lightweight prefabricated monolithic floor with voids made of plastic balls, quite effective from the point of view of construction and subsequent operation, was proposed and investigated. The proposed design solution for a lightweight prefabricated monolithic flat floor with voids made of plastic balls has less mass than solid floors and optimal use of material resources, namely the consumption of concrete and reinforcement. Therefore, research to determine the optimal design parameters of a flat lightweight floor with void formers made of plastic balls is relevant. The purpose of the article is to conduct numerous studies of the stress-strain state of the proposed design of a prefabricated monolithic floor with voids made of plastic balls. Conclusion. As a result of the research, it was established that it is rational to use hollow balls made from recycled materials as a material for making voids from balls in flat floors. Moreover, all studied floor options with spans of 6 m, 7 m, 8 m and void sizes made of balls with diameters of 180 mm, 315 mm and 500 mm meet the requirements of the first and second groups of limit states.

Development prospects for production of filtration equipment in the Russian Federation at the present stage

The article examines the challenges caused by changes in the global situation that the production of filtration equipment faced. The equipment is used for the petrochemical complex. The article assesses prospects for technological independence in the petrochemical complex, including the auxiliary market of filtration and separation equipment. The article provides a statistical analysis of the indicators of the Russian filtration sector and analyses the applied filtration and separation methods in a comparative manner. To determine the prospects of companies producing the corresponding equipment and its individual structural elements, the method of situational analysis was used, with the help of which the features of products manufactured at the present stage that influence the development of business in this economic segment are identified. With the method of economic forecasting, the perspective position of domestic manufacturers in the filtration market was determined. With consideration to the modern developments in the field of industry management and to the given basic concepts used in the management of western companies, the possible ways of introduction of advanced managerial decisions were proposed. It is done in order to improve the position of domestic producers, to develop business and to switch to a new level of product improvement, process optimisation, continuous development of companies’ approaches, and thus respond quickly to the emerging challenges.

Studies of Fractal Microstructure in Nanocarbon Polymer Composites.

The in situ study of fractal microstructure in nanocarbon polymers is an actual task for their application and for the improvement in their functional properties. This article presents a visualization of the bulk structural features of the composites using pulsed acoustic microscopy and synchrotron X-ray microtomography. This article presents details of fractal structure formation using carbon particles of different sizes and shapes-exfoliated graphite, carbon platelets and nanotubes. Individual structural elements of the composite, i.e., conglomerations of the particles in the air capsule as well as their distribution in the composite volume, were observed at the micro- and nanoscale. We have considered the influence of particle architecture on the fractal formation and elastic properties of the composite. Acoustic and X-ray imaging results were compared to validate the carbon agglomeration.

Иерархическая модель оптимизации технологических параметров комплекса рабочих переходов для процесса механической обработки

Optimization of the parameters of the product manufacturing process is one of the key tasks of technological preparation of production. The technological process of mechanical processing has a complex hierarchical struc-ture. The effectiveness of optimizing the manufacturing process of a product directly depends on the level of its detail and the optimal choice of targets and control parameters. In this case, the technological process of mechanical processing, as an object of control, can be described in the form of a hierarchical model. Thus, the task of optimizing the technological process of mechanical processing is to determine the optimal values of control parameters for each structural element (intermediate state of the control object) of the hierarchical control model. The aim of the work is to develop a hierarchical model for optimizing the parameters of a complex of working transitions for machining operations. The structure of the hierarchical model of the product manufacturing process on metal-cutting machines is described. Within the framework of the developed model, five control levels are identified, control parameters for individual structural elements of the model are defined, as well as the relationship between them. For the intermediate states of the control object (structural elements), a description of single and vector optimization criteria is presented. The practical implementation of the developed control model is presented using the example of optimizing the technological parameters for the “Bushing” part. The application of the developed control model will increase the efficiency of the technological process of manufacturing products on metal-cutting machines by optimizing technological parameters based on a multi-criteria analysis at the stage of technological preparation of production.

Improving the survivability of a railway bridge with damage to a truss members

In the modern era, accidents and damage to individual structural elements of bridges are frequently recorded, so the issue of bridges survivability, as the ability to pass the transport load with damaged elements, is becoming more and more relevant. The timeliness is confirmed by the inclusion of new requirements for survivability testing in modern bridge design standards. The article gives a publications review in the field of survivability theory development, identifies the methods of its increase in relation to transport structures and conducts research on increasing the railway bridges survivability. The research review in the field of assessment and increase of structures survivability as applied to transport structures allowed to single out the methods of survivability increase by providing bearing capacity of structures key elements, optimisation of spatial performance of a building structure and development of special organisational measures of emergency situation exclusion. With regard to the superstructure with through main trusses of a railway bridge with a design length of 66 m, numerical methods have been used to investigate the possibilities of increasing the reliability by increasing the bearing capacity of key elements. It has been established that the positive effect of increasing the survivability by excluding the bottom chord member and struts from operation gives an increase in the bearing capacity of the bottom lateral bracing and struts, respectively. It is revealed that the most dangerous is the exclusion from operation of the upper chord truss members, and the bearing capacity increase of the key lateral bracing elements, as well as the increase of the degree of static indeterminacy of the lattice of links is ineffective. Organisational measures in case of damage and failure of the span truss element are proposed.

The influence of individual elements of agricultural technology on the productivity of durum wheat in the southern forest-steppe of the Omsk region

Relevance. For the manufacture of high-quality pasta, durum wheat grain is used. Improving the productivity of hard spring wheat is an urgent task. The formation of a powerful root system is the key to the full supply of nutrients and plastic substances to the plant. Increased productivity, the number of spikebearing shoots. Plants become more resistant to adverse environmental factors, which is important for spring durum wheat, which is more demanding than spring soft wheat. The timing of sowing and especially the application of mineral fertilizers are a significant factor affecting not only the formation of individual elements of the crop structure, which subsequently form the productivity of plants, but also the formation of the root system. To do this, it is necessary to choose the optimal sowing time, at which the critical phases of plant development fall under the most favorable agrometeorological conditions and the formation of the most powerful root system.Results. The conducted studies allow us to recommend the most optimal terms of sowing and the use of fertilizers to ensure the efficiency of growing durum spring wheat. In dry conditions, when sowing crops without applying fertilizers, sowing in the second ten days of May is most effective. If it is possible to apply nitrogen fertilizers and nitrogen-phosphorus fertilizers, it is better to sow durum spring wheat in the second and third decades of May.

ANTI-CRISIS MANAGEMENT STRATEGIES IN THE CONDITIONS OF ECONOMIC AND SOCIAL TURBULENCE

The relevance of the research on anti-crisis management is determined by the rapid changes in the global economic and social context. In this context, the development and implementation of effective anti-crisis strategies are extremely relevant for organizations of various levels and activities. The purpose of the present research is to provide an in-depth analysis of various anti-crisis management strategies used by modern organizations to effectively respond to a wide range of crisis situations. Particular emphasis is placed on the analysis of the impact of technological innovations, leadership styles and organizational culture on anti-crisis management processes. A structural-functional analysis and a systemic analysis formed the methodological basis of the research. These methods made it possible to comprehensively assess the interrelationship between internal organizational processes and the external environment, as well as the impact of individual elements of the organizational structure on the company’s ability to respond effectively to crisis challenges. The obtained results indicate the importance of implementing modern technological solutions to increase efficiency and flexibility in crisis management. The analysis showed that effective leadership, able to quickly adapt to changing conditions and motivate the team to innovate, is crucial in creating a sustainable and flexible organizational structure. Special attention is paid to the role of organizational culture, which should promote openness, collaboration and readiness for change. It has been revealed that the need for adaptation and a flexible approach to management becomes of particular importance in the context of uncertainty caused by factors such as global financial crises, political conflicts and pandemics. These findings are of significant practical importance since they provide organizational leaders with the tools and insights to develop and implement effective crisis management strategies.

Influence of fungicides on changes in individual productivity and elements of soybean yield structure

Influence of fungicides on changes in individual productivity and elements of soybean yield structure

Monitoring of the technical condition of structures and building materials of an elevator silo housing

The results of assessing the technical condition of the elevator silo housing, obtained on the basis of a visual instrumental examination using the non-destructive testing method, are considered. Existing defects and damages in the building materials and structures of the building, which adversely affect its performance, were identified. An assessment was made of the state of foundations, walls, floors of the silo and columns installed at the corners of the silo at the height of the silo. The results of the assessment of individual results of the performed instrumental studies of structures and building materials at the object under study are presented. The technical condition of the building as a whole is assessed as a limited operational technical condition. The phase of the period of operation of the building was determined. Recommendations have been developed to ensure the safe operation of the building under study. It has been established that it is necessary to strengthen the structural elements of the building for further safety during the operation of the elevator. It is proposed to introduce the necessary measures to improve the reliability and strength properties of individual structural elements after a period of their long-term operation.

Use of Technological Normals in the Development of a Building Information Model

At each stage of the life cycle, the digital model is characterized by a specific level of elaboration and respective attribute data of elements. At the stage of construction, the model is used for planning and organization of construction operations, progress control. It should contain elements providing fulfillment of the adopted organizational and technological solutions. For the formation of a building model, it is suggested to utilize technological normals of building processes. Technological normals contain basic requirements, parameters and factors for performance of particular types of construction and erection works, also special works; they also include the characteristics of required machines and mechanisms, tools, equipment and materials, labor inputs, staff qualifications and numbers, as well as the main technological solutions for execution of works. Normals can be made both for unit scopes of works and for individual structural elements, sections, assembly units. It would be useful to use normals as a catalog of standard elements for designing organizational and technological solutions in creating a building model. The structuring and standardization of catalogs (sets) of technological normals, their correlation with catalogs of building machines, structures and materials, will allow finding the most rational engineering and economic options during construction.