Analysis and numerical solution of dynamic Jiles–Atherton model applied to hysteresis modeling for giant magnetostrictive materials

PurposeOwing to the excellent performance, giant magnetostrictive materials (GMMs) are widely used in many engineering fields. The dynamic Jiles–Atherton (J-A) model, derived from physical mechanism, is often used to describe the hysteresis characteristics of GMM. However, this model, despite cited by many different literature studies, seems not to possess unique expressions, which may cause great trouble to the subsequent application. This paper aims to provide the rational expressions of the dynamic J-A model and propose a numerical computation scheme to obtain the model results with high accuracy and fast speed.Design/methodology/approachThis paper analyzes different published papers and provides a reasonable form of the dynamic J-A model based on functional properties and physical explanations. Then, a numerical computation scheme, combining the Newton method and the explicit Adams method, is designed to solve the modified model. In addition, the error source and transmission path of the numerical solution are investigated, and the influence of model parameters on the calculation error is explored. Finally, some attempts are made to study the influence of numerical scheme parameters on the accuracy and time of the computation process. Subsequently, an optimization procedure is proposed.FindingsA rational form of the dynamic J-A model is concluded in this paper. Using the proposed numerical calculation scheme, the maximum calculation error, while computing the modified model, can remain below 2 A/m under different model parameter combinations, and the computation time is always less than 0.5 s. After optimization, the calculation speed can be enhanced with the computation accuracy guaranteed.Originality/valueTo the best of the authors’ knowledge, this paper is the first one trying to provide a rational form of the dynamic J-A model among different citations. No other research studies focus on designing a detailed computation scheme targeting the fast and accurate calculation of this model as well. And the performance of the proposed calculation method is validated in different conditions.

Extension of the kinematic approximations to the multilayered elastic orthorhombic medium

Understanding the kinematics of horizontally-layered reservoir rocks is important to their proper characterization and to accomplish this it is necessary to specify the explicit model for these kinematic properties. The accurate approximations for traveltime and relative geometrical spreading in an elastic homogeneous orthorhombic (ORT) have been investigated with different forms: Shifted Hyperbola Form (SHF), Taylor Series (TS) and the Rational Form (RF). This paper extends these approximations to the multi-layered ORT model by adopting composite coefficients and effective model parameters. The multi-layered model is characterized without and with the azimuthal variation among layers. There is an overdetermined problem when the azimuthal variation exists; and to address that case, the Least Squares Method (LSM) is adopted. To check the feasibility of the expansion, we select the SHF (Shifted Hyperbola Form) approximation specified in the homogeneous elastic ORT model for the calculation in the numerical example. Four groups of examples are analyzed to investigate the influence on the accuracy of the approximation with the change in rotation angle, degree of anisotropy, and the direction of the orientation. The results indicate that, for the multi-layer, the accuracy of the approximation is proportional to the degree of anisotropy and the value of the angle of rotation. The relative errors in travel time and relative geometrical spreading in this multi-layered extension are very small and can be implemented in practical applications

DETERMINATION OF THE MODE OF FUNCTIONING OF THE CENTRIFUGAL-GRAVITATIONAL SEPARATOR OF THE GRINDING DEVICE

The peculiarity of harvesting legumes is the need to process their heap on grater devices with subsequent separation. To improve the technical and economic performance of seed heap processing equipment, it is advisable to combine wiping and separation operations by combining a grater working body and a separating rotating sieve of cylindrical or conical shape. The analysis of influence of geometry of rotary sieve drums allows to define the rational form and parameters of work of the separating device which will provide the necessary quality of seed material. Analysis of the literature on the processes of sieve separation of grain and seed mixtures showed the advantages of centrifugal separators with a rotating sieve surface. Improving the efficiency of separation of mixtures by rotary sieves is achieved by the simultaneous use of centrifugal, Coriolis and gravitational forces. The aim of the study is to increase the efficiency of separation of seed heaps of legumes after treatment with a grater device by determining the trajectory of the seeds along the rotational surfaces. Earlier, the authors developed a grater-separating unit in which a cylindrical perforated drum is used to remove unworn seeds. This design does not use the surface of the sieve effectively enough. To increase the uniformity of the load on the steaming surface of the rotary drum, it is advisable to reduce its area in the direction of seed movement. To do this, use a conical separating surface to reduce the radius of the cone in the direction of movement of the material. When considering the movement of a particle, it is represented as a material point with mass m moving along a conical surface that rotates around a vertical axis. As a result of theoretical researches the dependence which defines time of stay of a particle on a sieve depending on a coordinate (length of a generating cone) is received. A graphical interpretation of this dependence for certain values of design parameters is also presented. As a result of research, it was found that increasing the residence time of the material on the sieve due to the use of a conical surface increases the yield of pure seeds, and also contributes to the uniform loading of the sieve surface, which improves the quality of the source material.

The Development of Agglomerations is a Key Direction of the Social and Economic Development Strategy of the Republic of Tatarstan

The current economic situation makes the issue of the urban agglomerations appearance and development crucial. Global experience shows that urban agglomeration is a rational form of territorial use. Through this process the creation of a unified social, economic and investment space takes place. The goal of agglomeration in the 21st century is to establish the basis for the development of large cities as the best form of people settlement. The development of a locality within an urban agglomeration should give it significant advantages. In most cases, the agglomeration process can produce a significant social and economic effect, as well as provide an opportunity to improve the quality and standard of living of the population. In world practice, agglomeration processes have an extensive system of support from the state, and currently there are trends towards the consolidation of individual agglomerations into superagglomerations or megacities. A distinctive feature of agglomeration is the presence of economic interaction between its system-forming elements, characterized by their interconnectedness and features, such as the presence of a large city, which is the center of agglomeration (center of attraction), intensive travel within the agglomeration, as well as industrial and technological cooperation within the agglomeration. In the Republic of Tatarstan the importance of agglomeration development is well understood: the key direction of the implementation of the Strategy of social and economic development of the Republic of Tatarstan up to 2030, approved in 2015, is the development of agglomerations (Kazan, Kama and Almetyevsk). The lack of unified approaches to the management of agglomeration processes is a limiting factor in the integrated development of territories, which leads to an imbalance in plans for housing construction, job supply and provision of transport and social infrastructure facilities. The purpose of this article is to identify these approaches.

Balancing, Constitutional Review, and Representation

Balancing is one of the main issues in current debates on the interpretation of constitutional rights. Numerous authors have raised the objection that balancing is both irrational and subjective. It is argued that this objection is unjustified. To show this, balancing is embedded in a theory of discursive constitutionalism that connects the concept of balancing with the concepts of constitutional rights, discourse, constitutional review, and representation. The main theses are these: first, balancing is based on a rational form of argument that can be made explicit by means of the Weight Formula, and second, constitutional review comports with the requirements of democratic legitimation to the extent that it succeeds in becoming an argumentative representation of the people.

Revelation in the Jewish Tradition

This chapter opens with a note on the naive concept of revelation as it appears in the Hebrew Scriptures. An account of the accommodation of Jewish thought to Hellenistic models by Philo leads to a remark on Talmud and early Jewish mysticism. Medieval philosophers such as Saadia and Maimonides attempted not only to present Jewish belief and practice in rational form but to justify its claim to possession of the only authentic revelation; the kabbalistic or mystical reaction is described. The moral, historical, and scientific concerns brought into focus by Spinoza, who appealed to reason as the criterion of what constituted revelation, are then outlined; Jewish responses to issues he raised are discussed. The chapter shows how Jewish responses to the Enlightenment generated different interpretations of revelation, leading to the formation of Reform, Conservative, and Orthodox denominations of Judaism. Moving rapidly through the twentieth and twenty-first centuries, we survey interpretations of revelation by Jewish thinkers including Hermann Cohen (‘progressive’ revelation), Martin Buber (revelation as ‘encounter’), J. D. Soloveitchik (halakha as a priori system), Abraham J. Heschel (between immanence and transcendence), Emil Fackenheim (Holocaust theology), and Tamar Ross (feminism, ‘cumulative’ revelation), concluding with a selection of contemporary thinkers who reinterpret the language of revelation in non-dogmatic terms.

Logistical support for sustainable development of the region

The purpose of the study is to develop recommendations for sustainable development of infrastructure in the region. The article considers the role of logistical support for sustainable development of the region. The object of the study is the process of logistical support for sustainable development of the region through investment, as a system of public-private relations for the development of sustainable infrastructure. Public-private relations will promote global demand and activity in the short term, lay the foundations for sustainable long-term growth. The research methods are: comparative economic analysis - to study the current situation in Ukraine, assess the contribution of different companies to the sustainable development of infrastructure and support it in the regions where they are based, to summarize the advantages and disadvantages; cartographic analysis - to clearly illustrate current trends in the functioning of international transport corridors that pass through the territory of Ukraine. The strengths and weaknesses of Ukraine's sustainable development have been identified. Substantiated legal and organizational procedures of public-private relations in the region. The key advantages and risks of the state and enterprises during public-private relations are identified. The main tasks of logistical support and sustainable development of the region are revealed, the logistic infrastructure of the regions is assessed. The potential development of transport infrastructure as one of the main factors of formation of sustainable development of the region is substantiated. National goals for creating sustainable development of regions are highlighted. The scientific novelty of the obtained results is to determine a rational form of interaction between companies and local authorities to create conditions for sustainable infrastructure development in the regions.

BUROCRACIA COM DEMOCRACIA: A ADMINISTRAÇÃO BUROCRÁTICA-COLEGIADA-PARTILHADA COM SISTEMA DE REPRESENTAÇÃO-LIVRE SEGUNDO MAX WEBER BUREAUCRACY WITH DEMOCRACY: THE BUREAUCRATIC-COLLEGIATE ADMINISTRATION WITH FREE-REPRESENTATION SYSTEM ACCORDING TO MAX WEBER

O artigo analisa os dois tipos ideais de burocracia em Max Weber, a “administração burocrática monocrática” e a “administração burocrática colegiada com representação livre”. Ambos os tipos são apresentados por Max Weber em lugares separados do capítulo sobre a dominação, redigido na fase tardia de Economia e Sociedade. A análise comparativo-sistemática dessas duas variantes da administração burocrática demonstra que, do ponto de vista histórico-exegético, Max Weber buscava integrar analiticamente o tema da democracia no contexto de sua sociologia da dominação. A partir de tal constatação sugere-se uma leitura diferenciada de sua teoria política que explora, além das tensões e contradições, também os nexos estruturais existentes entre a forma racional de dominação e a democracia.ABSTRACTThe article analyzes the two ideal types of bureaucracy in Max Weber, the “monocratic bureaucratic administration” and the “collegiate bureaucratic administration with free representation. Both types are presented by Max Weber in separate places from the chapter on domination written in the late phase of Economics and Society. The comparative-systematic analysis of these two variants of bureaucratic administration demonstrates that, from a historical-exegetical point of view, Max Weber sought to analytically integrate the theme of democracy into the context of hissociology of domination. Based on this observation, a differentiated reading of his political theory is suggested, which explores, in addition to the tensions and contradictions, also the existing structural links between the rational form of domination and the democracy.

Philip Pullman’s Jesus and ‘Christ’ - and God?

A story which dramatizes the distinction between the historical reality of Jesus and the ‘Christ of faith’ has given new life to a once powerful critique of Christian doctrine. Pullman’s alternative version of the gospel story can be countered by historical scholarship which shares his non-supernaturalist assumptions, but a theological response which communicates the Christian message of the gospels is also needed. The allegorical interpretation that Pullman’s fable invites allows a reading that is compatible with a rational form of traditional Christianity.