Journal articles on the topic 'Field’s elements and forces'
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1
Potachits, Ya V. "A Study of the Occurrence of Resonance under the Influence of Dynamic Forces on the Structural Elements of Electrical Installations." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 64, no. 3 (June 4, 2021): 228–38. http://dx.doi.org/10.21122/1029-7448-2021-64-3-228-238.
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The increase in the levels of short-circuit currents in the power system of the Republic of Belarus requires the study of the parameters of the electrodynamic stability of the main structural elements of electrical installations with flexible conductors. In case of a short circuit in the network, currents tenfold exceeding the rated one hundreds of times can flow through the current-carrying part of the device. When the magnetic fields formed by these currents interact, significant electromagnetic forces arise, which have a destructive effect both on the current-carrying parts themselves and on the structural elements of electrical installations, viz. support insulators, switching devices, measuring equipment. The movement of the wires in a short-circuit mode leads to the appearance of significant dynamic loads in them, which, in turn, are transmitted to the portals, support insulators and electrical devices. A topical problem is the occurrence of unacceptable mechanical forces in the main structural elements that can cause their destruction. Thus, the analysis of the physical and mechanical parameters and geometric dimensions of the flexible busbar of switchgear shows that a violation of the condition of electrodynamic resistance to tension is unlikely due to the high mechanical strength of the large-section steel-aluminum wires used. At the same time, span-limiting portals, support insulators and other electrical devices have significantly lower permissible bending loads. When exposed to dynamic forces, the conductors bend and transfer the load to the structural elements which have certain elasticity. Thus, a reliable determination of dynamic loads, taking into account the current-carrying parts acting on the supporting structures, is possible only if a dynamic task is set. The article describes the methods of mathematical modeling and computational experiment for analyzing the parameters of the electro-dynamic stability of the main structural elements which are determined using coefficients that depend on the natural frequencies of oscillations and the nature of changes in dynamic forces over time. To solve these problems, mathematical models are compiled and boundary value problems are formulated for calculating the electrodynamic stability of structural elements, taking into account the possible coincidence of the frequencies of natural and forced oscillations of structural elements taking into account the probable coincidence of the frequencies of forced and natural vibrations of structural elements.
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Anischenko, Galyna, and Denys Lavinskyi. "Non-stationary phenomena in technological systems of electromagnetic processing of materials." Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines, no. 2 (December 31, 2022): 39–42. http://dx.doi.org/10.20998/2078-9130.2022.2.270863.
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A large number of technical and technological facilities work under the action of electromagnetic fields. In electroconductive bodies have significant largest electromagnetic forces that can cause movement or deformation of structural elements. The creation of effective methods of analysis of the distribution of the electromagnetic field and coupled nonstationary deformation of structural elements is topical at present time. The article contains a mathematical formulation of the problem of nonstationary deformation of structural elements under the action of electromagnetic fields. Coupling of electromagnetic field and mechanical field is carried out with the help of local electromagnetic forces. Further made the transition to a variational formulation on the basis of the task of finding the minimum of the total energy of the system, which includes the energy of the electromagnetic field. For the numerical solution the finite element method is used. Nodal unknowns in this case are the magnetic vector potential and displacements. The proposed method is applied to non-stationary deformation of the "inductor-billet" technological operation of magnetic-pulse processing of metals. Some results of the deformation are presented.
A large number of technical and technological facilities work under the action of electromagnetic fields. In electroconductive bodies have significant largest electromagnetic forces that can cause movement or deformation of structural elements. The creation of effective methods of analysis of the distribution of the electromagnetic field and coupled nonstationary deformation of structural elements is topical at present time. The article contains a mathematical formulation of the problem of nonstationary deformation of structural elements under the action of electromagnetic fields. Coupling of electromagnetic field and mechanical field is carried out with the help of local electromagnetic forces. Further made the transition to a variational formulation on the basis of the task of finding the minimum of the total energy of the system, which includes the energy of the electromagnetic field. For the numerical solution the finite element method is used. Nodal unknowns in this case are the magnetic vector potential and displacements. The proposed method is applied to non-stationary deformation of the "inductor-billet" technological operation of magnetic-pulse processing of metals. Some results of the deformation are presented.
A large number of technical and technological facilities work under the action of electromagnetic fields. In electroconductive bodies have significant largest electromagnetic forces that can cause movement or deformation of structural elements. The creation of effective methods of analysis of the distribution of the electromagnetic field and coupled nonstationary deformation of structural elements is topical at present time. The article contains a mathematical formulation of the problem of nonstationary deformation of structural elements under the action of electromagnetic fields. Coupling of electromagnetic field and mechanical field is carried out with the help of local electromagnetic forces. Further made the transition to a variational formulation on the basis of the task of finding the minimum of the total energy of the system, which includes the energy of the electromagnetic field. For the numerical solution the finite element method is used. Nodal unknowns in this case are the magnetic vector potential and displacements. The proposed method is applied to non-stationary deformation of the "inductor-billet" technological operation of magnetic-pulse processing of metals. Some results of the deformation are presented.
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Di Barba, P., A. Savini, and I. Perugia. "Mixed finite elements for the simulation of fields and forces in electromagnetic devices." IEEE Transactions on Magnetics 34, no. 5 (1998): 3572–75. http://dx.doi.org/10.1109/20.717843.
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Kupferman, Raz, Elihu Olami, and Reuven Segev. "Stress theory for classical fields." Mathematics and Mechanics of Solids 25, no. 7 (August 8, 2017): 1472–503. http://dx.doi.org/10.1177/1081286517723697.
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Classical field theories, together with the Lagrangian and Eulerian approaches to continuum mechanics, are embraced under a geometric setting of a fiber bundle. The base manifold can be either the body manifold of continuum mechanics, the space manifold, or space–time. Differentiable sections of the fiber bundle represent configurations of the system and the configuration space containing them is given the structure of an infinite-dimensional manifold. Elements of the cotangent bundle of the configuration space are interpreted as generalized forces and a representation theorem implies that there exists a stress object representing forces, non-uniquely. The properties of stresses are studied, as well as the role of constitutive relations in this general setting.
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Metelkin, Sergey, and Vladimir Paramonov. "The effect of negative temperatures on the retaining walls of deep pits." E3S Web of Conferences 371 (2023): 02006. http://dx.doi.org/10.1051/e3sconf/202337102006.
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In countries with negative winter temperatures, pits and walls of underground structures are subjected to additional forces caused by frost heaving forces. In Russian construction practice, cases of the impact of such forces on the struts and anchors of construction walls are known, which led to the loss of stability of the struts and the failure of the anchors. Obviously, the design of retaining walls in winter should take into account the effect of additional forces caused by frost heaving and their evolution over time. The solution of test problems for an open pit shows that under certain conditions, the forces in the struts can exceed their values by an order of magnitude, determined when taking into account only the active pressure of the soil. Experimental studies were carried out to assess the processes of development of forces in the elements of the retaining walls in winter. The calculated assessment of the temperature fields and the stress-strain state in the excavation walls was performed using the Termoground program. The comparison of results of experimental and calculated data are shown in the article. The comparison of results of experimental and calculated data is shown in the article.
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Moyseychik, Е. А. "PASSIVE METHOD OF THERMAL NON-DESTRUCTIVE TESTING OF STEEL ELEMENTS AND PRODUCTS ON THE BASIS OF THE MECHANISM OF DEFORMATION HEAT GENERATION." Kontrol'. Diagnostika, no. 252 (2019): 50–57. http://dx.doi.org/10.14489/td.2019.06.pp.050-057.
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The features of heat generation and the basic capabilities of the passive method of thermal non-destructive testing of steel elements and products are considered. The mechanism of heat generation in steel is presented and the structure of the formula for changing its temperature during deformation is substantiated. It is shown that the diagnosis of steel elements in the passive mode should be carried out with the operation of heat sources in them, resulting from the force effects on the structure. The features of determining the stress in steel elements by the passive thermal method are considered. It is shown that the passive method of thermal non-destructive testing of steel structures loaded with forces continuously changing in time, under the action of which internal deformation sources of heat and surface temperature fields operate in potentially dangerous areas of the elements, allows the kinetics and anomalies of temperature fields to exercise health -plastic stages of steel, with the birth and development of destruction.
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Darnell, I., R. Mousseau, and G. Hulbert. "Analysis of Tire Force and Moment Response During Side Slip Using an Efficient Finite Element Model." Tire Science and Technology 30, no. 2 (April 1, 2002): 66–82. http://dx.doi.org/10.2346/1.2135250.
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Abstract This paper describes the application of a new type of non-linear 3D finite element tire model for simulating tire spindle force and moment response during side slip. The simulation model, briefly described in the paper, is composed of shell elements, which model the tread deformation, coupled to special purpose finite elements that model the deformation of the sidewall and contact between the tread and the ground. The sidewall special purpose element uses a pre-computed look-up table to efficiently calculate the sidewall shape and the forces acting on the tread. The model is designed to predict the forces at the spindle and ground and the overall tire shape, as opposed to the internal stress fields. This paper considers the following deformation scenarios: 1) a vertically loaded tire deforming laterally on a flat surface and 2) a tire rolling straight ahead under a prescribed sideslip angle. Experimental data is also presented to verify the force predictions.
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Safarov, Q. A., G. Vagif gizi, and S. V. Galkin. "Application of statistical dependencies to evaluate economic indicators of production efficiency by the example of oil fields in Azerbaijan." IOP Conference Series: Earth and Environmental Science 1021, no. 1 (May 1, 2022): 012003. http://dx.doi.org/10.1088/1755-1315/1021/1/012003.
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Abstract Improving the use of basic funds and production capacity in oil and gas recovery is not only the introduction of new techniques and technology, but also the improvement of labor, management and organization of work. The process of renewal of the fixed capital and production forces is considered intensive at the time when the vast majority of the newly incorporated basic funds and forces are aimed at replacement of morally obsolete and physically worn out parts. This time, their compliance with the economically justified life expectancy is of interest. All these are elements of recycling. Oil and gas wells are important elements of the active part of the main production funds and they determine the future development of oil and gas recovery. Productive use of production wells for oil and gas recovery is considered as a source of improvement of production efficiency in terms of production-resource potential (PRP). In order to increase the efficient use of oil and gas wells as an active element of the main production funds, special attention is paid to both extensive and intensive factors at oil and gas production enterprises.
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Moffatt, H. K. "Helicity and celestial magnetism." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2190 (June 2016): 20160183. http://dx.doi.org/10.1098/rspa.2016.0183.
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This informal article discusses the central role of magnetic and kinetic helicity in relation to the evolution of magnetic fields in geophysical and astrophysical contexts. It is argued that the very existence of magnetic fields of the intensity and scale observed is attributable in large part to the chirality of the background turbulence or random-wave field of flow, the simplest measure of this chirality being non-vanishing helicity. Such flows are responsible for the generation of large-scale magnetic fields which themselves exhibit magnetic helicity. In the geophysical context, the turbulence has a ‘magnetostrophic’ character in which the force balance is primarily that between buoyancy forces, Coriolis forces and Lorentz forces associated with the dynamo-generated magnetic field; the dominant nonlinearity here arises from the convective transport of buoyant elements erupting from the ‘mushy zone’ at the inner core boundary. At the opposite extreme, in a highly conducting low-density plasma, the near-invariance of magnetic field topology (and of associated helicity) presents the challenging problem of ‘magnetic relaxation under topological constraints’, of central importance both in astrophysical contexts and in controlled-fusion plasma dynamics. These problems are reviewed and open issues, particularly concerning saturation mechanisms, are reconsidered.
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Vaskovskiy, Yuriy, Alexandr Geraskin, and Konstantin Tatarinov. "Research of dampher system damage physical processes of synchronous machines rotor." Bulletin of NTU "KhPI". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice, no. 2 (6) (December 9, 2021): 19–24. http://dx.doi.org/10.20998/2079-3944.2021.2.04.
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The physical processes in the damper system of the rotor with the appearance of a static eccentricity of the rotor for two types of salient-pole synchronous machines - a capsule hydrogenator SGK 538/160-70M with a capacity of 22 MW and a synchronous generator with a capacity of 500 kW were investigated by means of mathematical modeling. A field mathematical model has been developed that takes into account the combined action of three physical fields of different nature: electromagnetic, temperature and field of thermomechanical stresses, and makes it possible to evaluate the heating and three-dimensional distribution of thermomechanical stresses in the structural elements of the rotor damper system of a salient-pole synchronous machine. These physical processes cause gradual destruction of the structure of the rotor damper system. It is proved that the primary cause of degradation and damage of the damping system of the rotor of an open-pole synchronous machine is the uneven distribution of induced currents in the rods at the poles of the rotor, which occurs when the machine works asynchronously or with the appearance of rotor static eccentricity. The largest induced currents and heat occur in the rods located at the edges of the pole pieces, while the central rods at the pole are heated significantly less. This asymmetric heating of the damping system of the rotor leads to significant thermomechanical stresses in the elements of the damping system of the rotor, which significantly depend on the magnitude of the eccentricity and slippery of the rotor in asynchronous mode. The magnitude of the total thermomechanical stresses in the rods is influenced not only by axially directed forces but also by transverse forces in the end short-circuiting elements. At considerable slippery and eccentricities there are inadmissibly big breaking forces which break cores and face short-circuiting elements of a damping system of a rotor. According to the results of the analysis, the heating and thermomechanical stresses of the structural elements were determined and recommendations for its structural improvement were given.
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Yakovlev, P. V., V. A. Lebedev, and V. M. Piskunov. "Thermal conditions of load-bearing elements of radioactive waste storage facilities." E3S Web of Conferences 220 (2020): 01079. http://dx.doi.org/10.1051/e3sconf/202022001079.
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Facilities for storing radioactive waste with residual heat differ from other facilities in high safety standards in all operating conditions. A feature of these structures is the presence of biological protection in the form of walls and ceilings made of reinforced concrete with a large thickness. The combination of heat dissipation and the large thickness of walls and floors create conditions for the appearance of significant thermal stresses. This feature should be taken into account in the strength calculations of these buildings, taking into account the summation of seismic effects, gravitational forces and thermal stresses caused by uneven temperature fields in concrete. The paper presents the results of calculations of the combined effects of thermal stresses and earthquakes on a building. The data obtained made it possible to determine the features of the deformation of concrete structures with a combination of loads.
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Suryo, Sumar Hadi, Athanasius Priharyoto Bayuseno, J. Jamari, and Gilang Ramadhan. "Simulation of Excavator Bucket Pressuring Through Finite Element Method." Civil Engineering Journal 4, no. 3 (April 7, 2018): 478. http://dx.doi.org/10.28991/cej-0309107.
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Excavator bucket tool is one of the most important parts of an excavator. It is made of steel mixture. It is commonly equipped with protruding teeth on its cutting side to breakdown hard materials and also to prevent dryness and damage of the bucket. Excavator bucket tooth must have supporting geometrical shape to penetrate and to endure the digging process on the ground, gravels, stones, or any other abrasive field. It is because of the field’s natural characteristic when the bucket tool grinds the material. Mixed iron is common to be used as excavator bucket tool’s material because it is easy to get and economic. High hardness value is also needed on the surface that transports hard material such as mining equipment. Therefore, an accurate analysis should be done to determine the suitable material on this field. Design and analysis were done by using Computer-Aided Engineering (CAE) Abaqus 6.10 application to get the maximum tension as the result of loading. Analysis process to get the tension was done by adding 8285.06 N weight forces in static condition with the angle of 32o to the horizon. From the analysis it could be known that maximum tension experienced by excavator bucket tooth is 209.3 MPa, and it is still below the Maximum Equivalent von Mises stress so the design could be categorized as safe.
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Imai, K., Y. Riho, T. Matsumoto, T. Takahashi, and K. Bando. "Wave Force Analysis by the Finite Element Method." Journal of Offshore Mechanics and Arctic Engineering 109, no. 4 (November 1, 1987): 320–26. http://dx.doi.org/10.1115/1.3257027.
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The finite element method is applied to determine the wave forces and wave fields for various coastal and ocean structures. Wave diffraction and radiation problems are solved by the method. A special infinite element is implemented in a computer program to model an outer infinite sea area. The employed numerical examples are for a vertical breakwater, a gravity-type ocean platform and a floating rectangular caisson. All computed results are compared with ones from experiments and other numerical methods. As a result, it is concluded that the finite element method using infinite elements can give sufficient accuracy to be applicable to most practical structures in the ocean.
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Wang, Qiang, Xue Jun Pang, Chun Jiang Wang, Tie Liu, Dong Gang Li, and Ji Cheng He. "Control of the Alloying Element Distribution in Al-Alloys by High Magnetic Fields." Materials Science Forum 539-543 (March 2007): 457–62. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.457.
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The distribution and solidified structure of alloying elements are important for the quality and the properties of alloys. In the present study, the solidification behavior of aluminum-rich alloys is studied under various high magnetic field conditions, and the influences of uniform and gradient magnetic fields with different intensity and direction on the distribution and the morphology of solute elements of Al-Cu and Al-Mg alloys are investigated. It is found that because of the differences of the electromagnetic force (Lorentz and magnetization forces) acting on Cu element and Mg element with different physical properties in the matrix, the regularities of distribution for Cu element and Mg element are opposite just in the intracrystalline and intergranular under high uniform magnetic field condition, and not only the content but the distributions of Cu and Mg elements are obviously different under high gradient magnetic field conditions as well. It can be concluded that high magnetic field has different effect on the solute distribution in alloys with different physical properties such as density, susceptibility, conductivity, etc. And the experimental results indicate that it is possible to control the terminal solubility and morphology of the solute elements in alloys by high magnetic fields.
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Rehbein Sathler Guimarães, André, and Valdemir Pires. "ELECTORAL ARENA: ELEMENTS FOR A STRATEGIC MODEL OF PARTY BEHAVIOR AND ELECTORAL PERFORMANCE." Revista Política y Estrategia, no. 140 (January 13, 2023): 15–33. http://dx.doi.org/10.26797/rpye.vi140.978.
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This paper outlines a theoretical perspective informed by the field of public choice, using empirical elements as examples. The field of public choice has been shaped by many thinkers and strives to understand and explain political behavior from economic motivations such as voters, candidates, parties, and bureaucrats. This approach is aligned with methodological individualism and was created as a reaction to the notion that governments act for the benefit of the common good. In this paper, we propose elements to build a model to analyze partisan competition by transposing elements from Porter’s Five Forces Model. This model has been applied for decades to competitive analysis among firms in the fields of economics and management. Economics, through Public Choice theory, postulates an “electoral market”; in this arena, parties and candidates compete for ballots (“preferences revealed,” like prices). In management, there is discussion about strategies and strategic management in the competition among firms.
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Gerhardt, Claus. "A Unified Quantization of Gravity and Other Fundamental Forces of Nature." Universe 8, no. 8 (August 1, 2022): 404. http://dx.doi.org/10.3390/universe8080404.
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We quantized the interaction of gravity with Yang–Mills and spinor fields; hence, offering a quantum theory incorporating all four fundamental forces of nature. Let us abbreviate the spatial Hamilton functions of the standard model by HSM and the Hamilton function of gravity by HG. Working in a fiber bundle E with base space S0=Rn, where the fiber elements are Riemannian metrics, we can express the Hamilton functions in the form HG+HSM=HG+t−23H˜SM, if n=3, where H˜SM depends on metrics σij satisfying detσij=1. In the quantization process, we quantize HG for general σij but H˜SM only for σij=δij by the usual methods of QFT. Let v resp. ψ be the spatial eigendistributions of the respective Hamilton operators, then, the solutions u of the Wheeler–DeWitt equation are given by u=wvψ, where w satisfies an ODE and u is evaluated at (t,δij) in the fibers.
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Ahuett-Garza, Horacio, Juan I. Melecio, and Pedro Orta. "Modal Analysis of a New Thermosensitive Actuator Design for Circuit Breakers Based on Mesoscale U-Shaped Compliant Mechanisms." Mathematical Problems in Engineering 2018 (July 16, 2018): 1–10. http://dx.doi.org/10.1155/2018/2850309.
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A new mesoscale thermosensitive actuator design for circuit breakers based on a U-shaped compliant mechanism was introduced as a potential replacement for bimetal strips in miniature circuit breakers. In a previous study, the response of this design to the thermal fields produced by a steady current flow was analyzed. This article presents a modal analysis of the compliant mechanism. The goal of the analysis is to compare the natural frequencies of the mechanism with the frequency of the magnetic loads caused by the flow of the alternating currents. Simulations with simple beam elements and 3D elements are presented and results are compared with experimental measurements. The study finds that the natural frequency of the mechanism differs by a factor of about 8 with the AC frequency. The conclusion is that the proposed compliant mechanism design’s performance as a thermal actuator will not be affected by the cyclic loads generated by the forces induced by the AC magnetic fields.
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Copeland, Edmund J., Peter Millington, and Sergio Sevillano Muñoz. "Fifth forces and broken scale symmetries in the Jordan frame." Journal of Cosmology and Astroparticle Physics 2022, no. 02 (February 1, 2022): 016. http://dx.doi.org/10.1088/1475-7516/2022/02/016.
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Abstract We study the origin of fifth forces in scalar-tensor theories of gravity in the so-called Jordan frame, where the modifications to the gravitational sector are manifest. We focus on theories of Brans-Dicke type in which an additional scalar field is coupled directly to the Ricci scalar of General Relativity. We describe how the necessary diffeomorphism invariance of the modified gravitational sector leads to a modification of the usual gauge fixing term (for the harmonic gauge), as compared to Einstein gravity. This allows us to perform a consistent linearization of the gravitational sector in the weak-field limit, which gives rise to a kinetic mixing between the non-minimally coupled scalar field and the graviton. It is through this mixing that a fifth force can arise between matter fields. We are then able to compute the matrix elements for fifth-force exchanges directly in the Jordan frame, without the need to perform a conformal transformation to the so-called Einstein frame, wherein the gravitational sector is of Einstein-Hilbert form. We obtain results that are in agreement with the equivalent Einstein-frame calculations and illustrate, still in the Jordan frame, the pivotal role that sources of explicit scale symmetry breaking in the matter sector play in admitting fifth-force couplings.
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Geshev, P. I. "Calculation of evaporation length of a liquid bridge flowing between inclined hot tubes." Journal of Physics: Conference Series 2119, no. 1 (December 1, 2021): 012056. http://dx.doi.org/10.1088/1742-6596/2119/1/012056.
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Abstract The bridge consists of liquid held by surface tension forces between two inclined tubes in an LNG heat exchanger. The shape of the bridge is calculated by the hydrostatic equation, which is reduced to a nonlinear integral equation and resolved by the Newton method. The velocity and temperature fields in the bridge are described by the Navier-Stokes and energy equations, respectively. They are reduced to the boundary integral equations and calculated by the method of boundary elements. Heat transfer coefficient is calculated for evaporating bridge and the length of total bridge evaporation is estimated.
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Bongaerts, Maud, Koceila Aizel, Emilie Secret, Audric Jan, Tasmin Nahar, Fabian Raudzus, Sebastian Neumann, et al. "Parallelized Manipulation of Adherent Living Cells by Magnetic Nanoparticles-Mediated Forces." International Journal of Molecular Sciences 21, no. 18 (September 8, 2020): 6560. http://dx.doi.org/10.3390/ijms21186560.
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The remote actuation of cellular processes such as migration or neuronal outgrowth is a challenge for future therapeutic applications in regenerative medicine. Among the different methods that have been proposed, the use of magnetic nanoparticles appears to be promising, since magnetic fields can act at a distance without interactions with the surrounding biological system. To control biological processes at a subcellular spatial resolution, magnetic nanoparticles can be used either to induce biochemical reactions locally or to apply forces on different elements of the cell. Here, we show that cell migration and neurite outgrowth can be directed by the forces produced by a switchable parallelized array of micro-magnetic pillars, following the passive uptake of nanoparticles. Using live cell imaging, we first demonstrate that adherent cell migration can be biased toward magnetic pillars and that cells can be reversibly trapped onto these pillars. Second, using differentiated neuronal cells we were able to induce events of neurite outgrowth in the direction of the pillars without impending cell viability. Our results show that the range of forces applied needs to be adapted precisely to the cellular process under consideration. We propose that cellular actuation is the result of the force on the plasma membrane caused by magnetically filled endo-compartments, which exert a pulling force on the cell periphery.
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Hopf, Barbara, Bennet Fischer, Thomas Bosselmann, Alexander W. Koch, and Johannes Roths. "Strain-Independent Temperature Measurements with Surface-Glued Polarization-Maintaining Fiber Bragg Grating Sensor Elements." Sensors 19, no. 1 (January 3, 2019): 144. http://dx.doi.org/10.3390/s19010144.
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A novel technique for strain and temperature decoupling with surface-glued fiber Bragg gratings (FBGs) is presented and applied for strain-independent temperature measurements in a temperature range between −30 °C and 110 °C with uncertainties below 4 °C over the entire measurement range. The influence of temperature-dependent glue-induced transversal forces on the fiber sensor could be eliminated with a sensor element consisting of two FBGs in identical polarization-maintaining fibers that were spliced perpendicular to each other. After aligning and gluing the sensor element with its optical axes parallel and perpendicular to the specimen, the averaged Bragg wavelength shifts of both FBGs were proven to be independent of the glue’s influence and therefore independent of any change in the material characteristics of the glue, such as aging or creeping behavior. For the first time, this methodology enables temperature measurements with surface-attached bare FBGs independently of arbitrary longitudinal and glue-induced strains. This is of great value for all applications that rely on a fully glued sensor design, e.g., in applications with high electromagnetic fields, on rotating parts, or in vacuum for space applications.
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Sinopoli, A., and V. Sepe. "Coupled Motion in the Dynamic Analysis of a Three Block Structure." Applied Mechanics Reviews 46, no. 11S (November 1, 1993): S185—S197. http://dx.doi.org/10.1115/1.3122636.
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A mathematical model is presented for the in-plane dynamic analysis of a structure composed of three rigid blocks, simply supported on each other, in presence of dry friction. In order to investigate the dynamics excited by a given ground motion, a Lagrangian formulation is proposed, with displacements, velocities and reactive forces restricted in bounded fields, due to the incompenetrability of the elements. Special attention is devoted to the modelling of the impacts, and to the role of Coulomb friction during the smooth dynamics. Different failure modes are obtained, characterized by a different participation factor of the degrees of freedom. Regions of coupling between rocking and sliding-displacements can be identified, as a function of the features of the excitation and of the friction coefficients. Survival domains decreasing with time can be obtained. They seem to indicate that, in presence of an earthquake, excessive relative displacements in the contact surfaces between the elements would be the most probable cause of failure of such a structure.
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Smith, Ray T., Fred P. M. Jjunju, Iain S. Young, Stephen Taylor, and Simon Maher. "A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2191 (July 2016): 20160338. http://dx.doi.org/10.1098/rspa.2016.0338.
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A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting’s theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond.
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Gheorghe, Gabriel, Daniel Lates, Catalin Persu, and Marinela Mateescu. "Static and modal analysis of a deep soil loosening machine." E3S Web of Conferences 180 (2020): 03019. http://dx.doi.org/10.1051/e3sconf/202018003019.
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The article will present a static analysis of the equipment in order to calculate the vector field distribution of the relative resulting displacement in the structure, the Cauchy stress tensor and tensor fields distribution of the specific deformation in the same structure. This is done in order to improve the structure and highlight the most vulnerable points within an equipment depending on the way of working. After performing the static analysis, tensometric marks were mounted in the most vulnerable points to calculate the displacement of the material and to calculate the major forces that appeared in the structure during the field experiments. At the same time, the idea of the equipment prototype was to improve the equipment with vibrating elements on the working bodies of the body type in order to increase the degree of crushing and to reduce the advancing forces, respectively to reduce the fuel consumption. Therefore, a modal analysis was performed to calculate the vibrations that appeared in the structure in order not to resonate with the frequency of the motor mounted on the working member.
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Ivanychev, D. A., and E. Yu Levina. "The Solution of Boundary Value Problems of Various Types with Consideration of Volume Forces for Anisotropic Bodies of Revolution." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 4 (97) (August 2021): 57–70. http://dx.doi.org/10.18698/1812-3368-2021-4-57-70.
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In this work, we studied the axisymmetric elastic equilibrium of transversely isotropic bodies of revolution, which are simultaneously under the influence of surface and volume forces. The construction of the stress-strain state is carried out by means of the boundary state method. The method is based on the concepts of internal and boundary states conjugated by an isomorphism. The bases of state spaces are formed, orthonormalized, and the desired state is expanded in a series of elements of the orthonormal basis. The Fourier coefficients, which are quadratures, are calculated. In this work, we propose a method for forming bases of spaces of internal and boundary states, assigning a scalar product and forming a system of equations that allows one to determine the elastic state of anisotropic bodies. The peculiarity of the solution is that the obtained stresses simultaneously satisfy the conditions both on the boundary of the body and inside the region (volume forces), and they are not a simple superposition of elastic fields. Methods are presented for solving the first and second main problems of mechanics, the contact problem without friction and the main mixed problem of the elasticity theory for transversely isotropic finite solids of revolution that are simultaneously under the influence of volume forces. The given forces are distributed axisymmetrically with respect to the geometric axis of rotation. The solution of the first main problem for a non-canonical body of revolution is given, an analysis of accuracy is carried out and a graphic illustration of the result is given
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HUMPHRIES, STANLEY, and JOHN PETILLO. "Self-magnetic field calculations in ray-tracing codes." Laser and Particle Beams 18, no. 4 (October 2000): 601–10. http://dx.doi.org/10.1017/s0263034600184046.
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Beam-generated magnetic fields strongly influence the behavior of relativistic electron guns. Existing methods used in ray-tracing codes have limited accuracy and may not correctly represent nonlaminar beams. We describe a technique for the magnetic field calculation in a two-dimensional code based on the assignment of particle currents to the faces of elements in the mesh used for the electrostatic calculation. The balanced calculation of electric and magnetic forces in the same iteration cycle reduces the possibility of numerical filamentation instabilities. With simple rules of assignment on boundary faces, the method also handles field contributions of electrode currents. Several benchmark calculations performed on conformal meshes illustrate the versatility of the technique.
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Barkallah, M., A. Bouaziz, S. Bouaziz, J. Y. Choley, and M. Haddar. "Modeling and Analysis of Spindle with Active Magnetic Bearings for High-Speed Milling Process." Journal of Mechanics 32, no. 2 (December 14, 2015): 131–41. http://dx.doi.org/10.1017/jmech.2015.96.
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AbstractThe high speed milling represents the most important process to produce parts in different fields such as aeronautics, automotive and mould. It allows obtaining parts with complex form and with the best surface quality. So, it remains essential to understand the impact of both the cutting force model and its parameters on the tool tip response. Consequently, the mastering of chatter vibration in milling and surface properties of the work piece is essential. In this paper, the simulation of machining is applied to determine the cutting forces distribution. A spindle system modeling is presented using a new approach: Both rigid and flexible modes of the spindle's shaft are taken into account. The shaft is discretized with the Timoshenko beam finite elements with different circular sections. Nonlinear electromagnetic loads exerted by AMBs are computed in terms of the nominal air gap between bearings and spindle, the control current and the displacement of each node. A parametric study is performed to determine the influence of some parameters, such as the feed rate, the tangential cutting coefficient, the spindle speed and the axial depth of the cut on the cutting forces and the chatter vibrations in milling.
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Cicciù, Marco. "Bioengineering Methods of Analysis and Medical Devices: A Current Trends and State of the Art." Materials 13, no. 3 (February 10, 2020): 797. http://dx.doi.org/10.3390/ma13030797.
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Implantology, prosthodontics, and orthodontics in all their variants, are medical and rehabilitative medical fields that have greatly benefited from bioengineering devices of investigation to improve the predictability of clinical rehabilitations. The finite element method involves the simulation of mechanical forces from an environment with infinite elements, to a simulation with finite elements. This editorial aims to point out all the progress made in the field of bioengineering and medicine. Instrumental investigations, such as finite element method (FEM), are an excellent tool that allows the evaluation of anatomical structures and any facilities for rehabilitation before moving on to experimentation on animals, so as to have mechanical characteristics and satisfactory load cycle testing. FEM analysis contributes substantially to the development of new technologies and new materials in the biomedical field. Thanks to the 3D technology and to the reconstructions of both the anatomical structures and eventually the alloplastic structures used in the rehabilitations it is possible to consider all the mechanical characteristics, so that they could be analyzed in detail and improved where necessary.
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Kłonkowska, Anna Maria, and Stephanie Bonvissuto. "PERSONAL AND COLLECTIVE TRANS-MYTHOLOGIES: CREATIVE ATTITUDES TO GENDER INCONGRUENCE AMONG TRANSGENDER INDIVIDUALS." Creativity Studies 12, no. 1 (March 26, 2019): 61–74. http://dx.doi.org/10.3846/cs.2019.5823.
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Embedded within the biographies of some transgender people are narratives elements more frequently found in culturally-specific legends settings and the interplay of mythological figures. Individuals who specifically identify as transsexuals (unlike other, non-binary or gender-queer transgender people) sometimes report the wish, the dream, and/or the desire to understand or alleviate their experienced gender incongruence in a surprisingly creative way: through some type of magical transformation. Calling upon recently collected interviews, this study examines those narratives and their use of such elements, noting their reliance on binary gender formations. Through philosophical and cultural-anthropological analyses, we suggest that these fields grant powerful and imaginative personal allowances, opportunities and perceptions to transsexual identifying transgender individuals – magical transformations and justified transpositions to alleviate dysphoria, a surrender of personal responsibility to unseen universal forces, and especially an inherent wisdom gifted during transitional liminality – that neither scientific nor academic evaluations of gender transition can. While these creative allowances are fictive, fantastical, and temporary, they nevertheless articulate a need if not an imperative for understanding, expression and ultimately action on behalf of the transitioning individual.
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Neri, Luis, Víctor Robledo-Rella, Rosa María Guadalupe García-Castelán, Andres Gonzalez-Nucamendi, David Escobar-Castillejos, and Julieta Noguez. "Visuo-Haptic Simulations to Understand the Dependence of Electric Forces on Distance." Applied Sciences 10, no. 20 (October 15, 2020): 7190. http://dx.doi.org/10.3390/app10207190.
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In this paper, the potential of visuo-haptic simulators to help engineering students to understand the nature of electric forces between different electric charge distributions is addressed. Three visuo-haptic simulators were designed to perceive the attractive–repulsive behavior as well as the dependence on distance of electrical forces for: (a) point charge, (b) line charge, and (c) plane charge. Design elements were incorporated to improve the 3D perception of the simulators. A sample of N = 111 engineering students practiced with the simulators: 87 enrolled in an Electricity and Magnetism course and 24 enrolled in a more advanced Electromagnetic Fields course. Pre-test and Post-test were applied before and after working with the simulators and average learning gains were obtained. t-tests were performed to determine the statistical significance of the results. Significant learning gains were obtained for the comprehension of the force dependence in the case of line charge and plane charge, but not for the point charge, due to the fact that most students started with very high Pre-test scores in this last case. These results suggest that the use of visuo-haptic simulators may help students to better identify the dependence of electric forces on distance. It was also observed that the potential effect of improving the recognition of electric interactions was higher among students with lower previous familiarity with these topics, as compared to more advanced students. Through exit surveys, it was found that the students liked very much the haptic activity and that it sparked their interest in learning new physical concepts.
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Zalavadiya, Sweta, Anwarulhaq Anwarulhaq, and Payal Makavana. "Biodynamic Preparations: A Dilemma To Use." International Review of Business and Economics 4, no. 2 (2020): 43–51. http://dx.doi.org/10.56902/irbe.2020.4.2.45.
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Biodynamics is an agricultural management system based on degradation of food produced through farming practices that increasingly relied on additions of inorganic fertilizers and pesticides. Biodynamics were thought to be one of the first alternative approaches to modern agriculture as one of three alternative or ‘‘organic’’ agricultural methodologies. Biodynamic preparations influences organic life on earth through cosmic and terrestrial forces that would stimulate vitalizing and harmonizing processes in the soil. Some preparations are made by packing cow manure or silica, respectively, into cow horns and burying them for a number of months before use. It was believed that cow horns, by virtue of their shape, functioned as antennae for receiving and focusing cosmic forces, transferring them to the materials inside. The contents are then diluted with an unspecified amount of water to create a homeopathic solution and applied to soil or crops to influenced root or leaf growth. Other compounds are extracts of various plants packed into either the skulls or organs of animals or peat or manure. The chemical elements contained in these preparations were carriers (it was thought) of terrestrial and cosmic forces and would impart these forces to crops and thus to the humans that consume them. In general organically grown crops and biodynamic preparations have been uniformly ineffective. Compared with organically managed systems, additions of biodynamic preparations did not affect yields of cover crops, forage grasses, lentil Lens culinaris, rice, sunflower and wheat. A similar lack of efficacy can be found in wheat seedling root and shoot growth, lettuce and soybeans. A rice and cabbage found superior in cost-effectiveness and consumer preference than organic treatments with additional biodynamic preparations. Organically raised mangoes had significantly greater phenolics, flavonoids, and antioxidant activity than those from biodynamic fields. So, biodynamic preparations to be of questionable scientific quality and efficacy.
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Pokonieczny, Krzysztof. "Use of a Multilayer Perceptron to Automate Terrain Assessment for the Needs of the Armed Forces." ISPRS International Journal of Geo-Information 7, no. 11 (November 6, 2018): 430. http://dx.doi.org/10.3390/ijgi7110430.
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The classification of terrain in terms of passability plays a significant role in the process of military terrain assessment. It involves classifying selected terrain to specific classes (GO, SLOW-GO, NO-GO). In this article, the problem of terrain classification to the respective category of passability was solved by applying artificial neural networks (multilayer perceptron) to generate a continuous Index of Passability (IOP). The neural networks defined this factor for primary fields in two sizes (1000 × 1000 m and 100 × 100 m) based on the land cover elements obtained from Vector Smart Map (VMap) Level 2 and Shuttle Radar Topography Mission (SRTM). The work used a feedforward neural network consisting of three layers. The paper presents a comprehensive analysis of the reliability of the neural network parameters, taking into account the number of neurons, learning algorithm, activation functions and input data configuration. The studies and tests carried out have shown that a well-trained neural network can automate the process of terrain classification in terms of passability conditions.
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Vlemmings, W. H. T. "Magnetic fields around AGB stars and Planetary Nebulae." Proceedings of the International Astronomical Union 9, S302 (August 2013): 389–97. http://dx.doi.org/10.1017/s1743921314002580.
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AbstractStars with a mass up to a few solar masses are one of the main contributors to the enrichment of the interstellar medium in dust and heavy elements. However, while significant progress has been made, the process of the mass-loss responsible for this enrichment is still not exactly known and forces beyond radiation pressure might be required. Often, the mass lost in the last phases of the stars life will become a spectacular planetary nebula. The shaping process of often strongly a-spherical PNe is equally elusive. Both binaries and magnetic fields have been suggested to be possible agents although a combination of both might also be a natural explanation.Here I review the current evidence for magnetic fields around AGB and post-AGB stars pre-Planetary Nebulae and PNe themselves. Magnetic fields appear to be ubiquitous in the envelopes of apparently single stars, challenging current ideas on its origin, although we have found that binary companions could easily be hidden from view. There are also strong indications of magnetically collimated outflows from post-AGB/pre-PNe objects supporting a significant role in shaping the circumstellar envelope.
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Sun, Jian, Hua Zou, Shuo Zhang, and Hao Qin. "Gravitational Agglomeration of Local Synchronization Data Set in Innovation Ecosystem: A Game between Innovation and Institutional Governance." Mathematical Problems in Engineering 2022 (March 21, 2022): 1–17. http://dx.doi.org/10.1155/2022/9620979.
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Innovation and governance have become new driving forces for the high-quality development of the innovation ecosystem under the new normal. This study is inspired by the universal gravitation model. The model of element agglomeration is constructed in the innovation ecosystem, which deals with the local synchronization problem of innovation and institutional governance’s data set. Based on the perspective of fluctuation, the agglomeration of elements produces fields in the innovation ecosystem. The relationship between innovation and governance is simulated and analyzed to game theory in the innovation ecosystem. In addition, the effects of different parameter conditions on synchronous clustering of data set are explored. The empirical results show the following: (1) The government’s investment in innovation elements and institutional governance elements is directly proportional to the obtained benefits. The government’s high-intensity support is greater than the benefits obtained from low-intensity support. (2) The emergence of enterprise synchronization is in line with the principle of moderation. The threshold is approximately 0.5, which can realize the accumulation and superposition of the effectiveness of innovation field and institutional governance field. Besides, neither high probability nor low probability synchronization of innovation and institutional governance’s data set can reach the optimal solution. (3) It indicates the higher the coupling investment of university and scientific research institute, the higher the income. Meanwhile, increasing the coupling investment can help universities and research institutions save the cost of research time. Finally, energy superposition can be realized through simultaneous gathering of innovation elements and institutional governance elements to achieve the aim of promoting high-quality development in innovation ecosystem. Moreover, it provides reference for deepening the development of innovation ecosystem.
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Drucker, E., and G. Lauder. "Wake dynamics and fluid forces of turning maneuvers in sunfish." Journal of Experimental Biology 204, no. 3 (February 1, 2001): 431–42. http://dx.doi.org/10.1242/jeb.204.3.431.
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While experimental analyses of steady rectilinear locomotion in fishes are common, unsteady movement involving time-dependent variation in heading, speed and acceleration probably accounts for the greatest portion of the locomotor time budget. Turning maneuvers, in particular, are key elements of the unsteady locomotor repertoire of fishes and, by many species, are accomplished by generating asymmetrical forces with the pectoral fins. The development of such left-right asymmetries in force production is a critical and as yet unstudied aspect of aquatic locomotor dynamics. In this paper, we measure the fluid forces exerted by the left and right pectoral fins of bluegill sunfish (Lepomis macrochirus) during turning using digital particle image velocimetry (DPIV). DPIV allowed quantification of water velocity fields, and hence momentum, in the wake of the pectoral fins as sunfish executed turns; forces exerted during turning were compared with those generated by the immediately preceding fin beats during steady swimming. Sunfish generate the forces required for turning by modulating two variables: wake momentum and pectoral fin stroke timing. Fins on opposite sides of the fish play functionally distinct roles during turning maneuvers. The fin nearer the stimulus inducing the turn (i.e. the strong side fin) generates a laterally oriented vortex ring with a strong central jet whose associated lateral force is four times greater than that produced during steady swimming. Little posterior (thrust) force is generated by the strong-side fin, and this fin therefore acts to rotate the body away from the source of the stimulus. The contralateral (weak-side) fin generates a posteriorly oriented vortex ring with a thrust force nine times that produced by the fin during steady swimming. Minimal lateral force is exerted by the weak-side fin, and this fin therefore acts primarily to translate the body linearly away from the stimulus. Turning with the paired fins is not simply steady swimming performed unilaterally. Instead, turning involves asymmetrical fin movements and fluid forces that are distinct in both direction and magnitude from those used to swim forward at constant speed. These data reflect the plasticity of the teleost pectoral fin in performing a wide range of steady and unsteady locomotor tasks.
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Ulbrich, Heinz. "Comparison of Different Actuator Concepts for Applications in Rotating Machinery." International Journal of Rotating Machinery 1, no. 1 (1994): 61–71. http://dx.doi.org/10.1155/s1023621x94000060.
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Considerable improvements of machines can be expected in the near future through the use ofelectronics in combination with control techniques. A key position will be held by the actuator systems that finally have to accomplish the controlled energy transfer according to the objectives. For rotating machine parts this is usually done via the bearings. Basically, there are two possibilities to transmit the controlled forces; contact free via magnetic fields (magnetic bearings) or the traditional way via conventional bearings. To realize the regulating actions multiple physical effects can be employed. In this paper some of the promising types of actuators and their advantages and disadvantages will be discussed, as well as how effectively to use these active elements under different objectives. Questions concerning the practical realizations will be given high priority.
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Riedel, Eberhard. "Collective Trauma." International Journal of Jungian Studies 12, no. 1 (February 3, 2020): 60–87. http://dx.doi.org/10.1163/19409060-01201002.
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Abstract Humanizing the devastating emotional forces released by the worldwide plague of collective violence and trauma demands developing integral awareness. This article develops an ecological perspective that views human communities as ecosystems and individuals as embedded in these environments. This perspective offers a space large enough to generate fresh ideas. The process evolved under the press of fieldwork in crisis areas in the eastern Democratic Republic of Congo. To explore psychosocial and political characteristics of human ecosystems Riedel employs a biaxial map, the Mandala of the Five Worlds. The map brings into purview in dynamic mandala format the Familial and Societal Worlds on the horizontal axis, the worlds of Nature and Mind on the vertical axis, and the Rhizome World at the core. Riedel views the rhizome world as a container and co-created field of human inheritances and codes, natural-physical and socio-cultural. The rhizome plays a central role in the resonance and synergistic phenomena interrelating elements of the five spheres. Community self-states are collective aggregates that involve elements from all five spheres of the mandala. Riedel explores patterns of dynamic forces of aggregation and evolution that determine a group’s connectivity and tendencies. For example, in community states of collective violence and trauma at extreme levels of severity, the socio-cultural and nature-mind dimensions of the map are “unhinged,” resulting in nature-nurture and humane-ethical considerations being split off from social behaviour with fractionizing fields dominating. Via emotional resonance, purposeful action interventions seek to loosen adhesion to the collectivity of suffering through which people are connected to the social traumas of their groups, past and present. Thus the rhizomic systems approach raises awareness about the dynamic of cultural seizures as major sources of sociocultural difficulties.
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Payne, Elizabeth. "Moving the Material Me: A Visual Autoethnography." Journal for Undergraduate Ethnography 12, no. 2 (July 6, 2022): 36–54. http://dx.doi.org/10.15273/jue.v12i2.11409.
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This visual autoethnography aims to understand how the significant event of moving house forces us to consider the materiality of our lives and the intimate relationships we have with our belongings. Situated at the intersection of anthropological studies on the home and materiality, this study looks at the ways these fields interact to reveal new conceptions of responsibility over the social life of things. Using autoethnographic methods, this research is embedded in my personal embodied experience of moving house, with particular emphasis on the sensory and subjective elements of this process, as highlighted through photographs and descriptive vignettes. This study delves into the decisions behind whether we keep, throw away, or pass on our things, interwoven with discussions around our moral obligations to the material lifeworlds of our stuff. It explores how our possessions reflect our relationships, our heritage, and ourselves.
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Beck, Tilmann, Karl-Heinz Lang, Otmar Vöhringer, and Detlef Löhe. "Experimental Analysis of the Interaction of “Hot” and “Cold” Volume Elements during Thermal Fatigue of a Cooled Component Made from AISI 3161 Steel." International Journal of Materials Research 92, no. 8 (August 1, 2001): 875–81. http://dx.doi.org/10.1515/ijmr-2001-0160.
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Abstract Start-stop and load change procedures of combustion engines result in inhomogenous and instationary temperature fields, which induce cyclic mechanical loadings, e. g., in solid and cooled turbine blades and vanes. The present study shows results of so-called “complex thermal-mechanical fatigue” (CTMF) tests carried out with a two specimen testing system in order to simulate the interaction of the “hot” outer and the “cold” inner side of a cooled turbine blade. The test samples were made from the austenitic steel AISI 316 L. Specimen 1 represents the “hot” and specimen 2 the “cold” side of the blade, respectively. Both specimens were loaded by individual thermal cycles with closed loop control of the temperature. The mechanical interaction of the “hot” and the “cold” side was simulated by keeping the total strains of both specimes at identical values and keeping the sum of the forces at a value of zero at every moment throughout the tests. The results are discussed on the background of the microstructures resulting from the individual loadings of specimen 1 and 2.
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Cieśla, Antoni, Wojciech Kraszewski, Mikołaj Skowron, Agnieszka Surowiak, and Przemysław Syrek. "Application of electrodynamic drum separator to electronic wastes separation." Gospodarka Surowcami Mineralnymi 32, no. 1 (March 1, 2016): 155–74. http://dx.doi.org/10.1515/gospo-2016-0007.
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AbstractStatic electric fields are used, among others, in technological processes such as electric separation. Electrodynamic separation is a process of separating two or more solid phases of various physical properties by electric field forces. The advantage of electrodynamic separation is possibility of obtaining separation of individual components in dry conditions. This eliminates many operations such as thickening, dewatering, hydrotransportation, additional drying which cause higher energy consumption and higher separation process costs. Efficiency of beneficiation depends on many factors such as: electric properties of feed components, feed particle size distribution, drum rotary speed, electric field intensity in working space of separator, configuration of electrodes or surrounding conditions.The paper presents the working of high-voltage drum separator. The analysis of electric field distribution in separator working space was done. Additionally, distribution of forces acting on particles of dielectric and conductive properties was examined, trajectories of charged particles movement were presented too. The laboratory investigations of electronic wastes were performed in two particle fractions: 0.25–0.5 mm and 0–0.25 mm. It was observed that as a result of selective charging of particles they separate according to surface ability to electrifying what allows to obtain selective separation of components being so-called electronic wastes. The application of electrodynamic drum separator allows to separate such elements as Ti, Cu, Fe, Pb, Sn from plastics occurring in electronic wastes.
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Claar, Simone. "Green colonialism in the European Green Deal: Continuities of dependency and the relationship of forces between Europe and Africa." Culture, Practice & Europeanization 7, no. 2 (2022): 262–74. http://dx.doi.org/10.5771/2566-7742-2022-2-262.
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In 2019, the European Union set a new course for a sustainable Europe with the European Green Deal (EGD), which included not only energy strategies but also mobility or clean water for a green Europe. The European Green Deal policies have implications and global effects on other world regions, e.g., the African continent. As I would argue, the EGD has a new EU-Africa strategy, which is marked by a continuity of dependency and might be an enabler of green colonialism. Existing patterns of dependency between Africa and Europe are reproduced, but new demands are made vis-à-vis African states which are supposed to implement European ecological transformation plans. This article discusses two fields of the EU-Africa strategy in the EGD: hydrogen and biodiversity. It shows that the EGD preserves the existing asymmetric relationship between Africa and the EU by highlighting the elements of green capitalism and green colonialism. Furthermore, it discusses alternative socio-ecological transformation methods in Africa, e.g., the South African Climate Justice Charter.
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Țîțu, Mihail, Constantin Oprean, Claudiu Pîrnau, and Ștefan Țîțu. "Using the Modelling and Simulation Techniques to Improve the Management of SMEs Belonging to Regional Clusters." Management of Sustainable Development 7, no. 2 (December 1, 2015): 17–21. http://dx.doi.org/10.1515/msd-2015-0025.
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Abstract The efficiency of exploiting the software takes on new dimensions under the conditions of integrated exploitation at the level of process and structural organization of SMEs found within the regional strategic alliances. The modeling and simulation of the leadership and regulation processes of the supply, sales and production flows imply a complex display of forces between the different partners of the logistic chain which can be supported by the existence of some data bases developed based on information partnership whose purpose is to counterattack the communication barriers and to ensure a flow and flexibility of the entire logistic flow. The modeling and simulation of the non-industrial processes can lead to the increase of the efficient development of the rural areas and small urban areas through agro-tourism, combining elements that are specific to some fields such as agriculture, ecology, merchandise/people transportation and tourism.
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Browne, P. F. "A New Model for Stellar Magnetism." International Astronomical Union Colloquium 138 (1993): 284–90. http://dx.doi.org/10.1017/s0252921100020625.
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AbstractDifferent drift velocities of electrons and ions in response to viscous forces exerted by neutral atoms generate current density j and magnetic field B, where B is proportional to vorticity ω of the fluid. Magnetic vortex tubes (MVTs) form arrays on a hierarchy of scales. MVTs are basic to the magnetism of all astrophysical systems, conferring a structure of aligned filaments. In the Sun a torsional oscillation generates oscillatory vorticity, and hence an oscillatory magnetic field. The same mechanism is proposed for the Ap stars, but with “pole-on” viewing. Resonance-line radiation pressure segregates elements within MVTs of Ap stars, where the anomalous concentrations are preserved. However, variation of the 30 MG magnetic fields of AM Her white dwarfs may be due to precession of an MVT. There is reason to attribute common magnetic flux to the Sun, Ap stars, white dwarfs and neutron stars
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Boris, Dieter, and Ingo Malcher. "Argentinien nach dem Zusammenbruch des neoliberalen Modells." PROKLA. Zeitschrift für kritische Sozialwissenschaft 35, no. 138 (January 1, 2005): 131–48. http://dx.doi.org/10.32387/prokla.v35i138.48.
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Starting from the deep financial and economic crisis, which took place in Argentina towards the end of 2001, the political, economical and societal reconstruction phases up to early 2005 are briefly summarized. Especially the government of Kirchner - in office since May 2003 - set new priorities in several fields of politics, e.g. human rights, the attitude towards the IMF and the foreign creditors, as well as foreign policy. Many structural elements and legacies of the neoliberal era, however, are still very present even three years after the collapse. In spite of the high growth rates in the last two years the reconstruction process has to be qualified as fragile and reversible. Compared to 2002 the social movements appear mainly weakened today. Whether the Kirchner government will succeed in establishing a more social and law abiding type of capitalism, remains to be seen, since a durable change of power relations in favour of progressive forces has not been realized.
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Huq, Jo-Louise. "Conditioning a Professional Exchange Field for Social Innovation." Business & Society 58, no. 5 (February 26, 2018): 1047–82. http://dx.doi.org/10.1177/0007650318758321.
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Social innovation is about solving important problems in new ways. In professional exchange fields, however, structuring and constraining forces make introducing new solutions exceedingly difficult, and known pathways that introduce new solutions are unlikely to be successful. In this article, I examine how social innovation can be encouraged in a professional exchange field. I identify three kinds of disrupting action (entwining problems, reconfiguring arrangements, and actively waiting) that can be used to encourage social innovation. These actions interrupt and expand essential elements of professionals’ work and they condition parts of the field to be supportive of and susceptible to social innovation. This research contributes to literature in three ways. First, it examines social innovation in a setting that has not been explored, uncovering an amalgamation of pathways that encourage social innovation. Second, it describes three types of disrupting action that set pathways in motion. Third, it conceptually links disrupting action to social innovation.
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Burton, Lindsay. "The Posthumanist Child: Pharmakon and Collodi's Pinocchio." Oxford Literary Review 41, no. 2 (December 2019): 202–18. http://dx.doi.org/10.3366/olr.2019.0279.
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The childlike elements of deconstruction—deconstruction's suggestion of play—require an interdisciplinary attention that they have previously not been afforded in scholarly discourse on Derrida. The power of the child in children's literature scholarship has similarly been immune to binary-disrupting forces common in adjacent literary fields; such immunity has been granted under the banner of ‘aetonormativity,’ which norms adult power while subverting that of the child. In light of the posthumanist turn in critical thinking, which demands a dissolution of binaries in favour of heterogeneity, deconstruction offers a novel approach to analysing the child in children's literature. In this paper, I draw upon Donna Haraway's diffractive approach to textual analysis to read Derrida's discussion of pharmakon through Maria Nikolajeva's conceptualization of aetonormativity. The resulting shift in understanding of both concepts allows for a reading of Carlo Collodi's The Adventures of Pinocchio that explores a figure I term the posthumanist child, whose undecidable embodiment works to disrupt the aetonormative binary.
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Liu, Jianbin, and Shinji Muraishi. "Dislocation Dynamics Simulations of Dislocation-Particle Bypass Mechanisms." Materials Science Forum 985 (April 2020): 35–41. http://dx.doi.org/10.4028/www.scientific.net/msf.985.35.
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Effect of precipitation strengthening on metal is generally attributed to the dislocation interaction with the precipitate which acts as the barrier to the dislocation motion on the slip plane. In order to achieve better understanding of critical events of dislocation motion and evolution of dislocation microstructure, we have developed numerical simulation method of dislocation-dislocation and dislocation-particle interactions by means of discrete dislocation dynamics at mesoscopic scale. In this work, Green’s function method is utilized for the computation of the stress fields of dislocation and misfitting particle, and the interaction forces acting on the dislocation. We also proposed the efficient algorithm of the connectivity vector for the dislocation line elements, linked-list data structure, to deal with the flexible interaction of dislocation line elements. The geometrical effect of dislocation slip planes on the dislocation bypassing behaviors is tested by changing the relative height of dislocation slip plane against the center plane of spherical particle, where cross slip event is also taken into account for the dislocation motion. Simulation results show a wide variety of topological changes of dislocation during motion on the slip planes around the particle, which results from the stress field of the particle varied with the relative height between the dislocation slip plane and center plane of particle. The full analysis of the mechanisms of dislocation line bypassing misfitting particle has been explained in this study.
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Chernykh, J., and O. Chernykh. "OFFICER TRAINING SYSTEM IN THE ARMED FORCES OF THE REPUBLIC OF BELARUS." Collection of scientific works of the Military Institute of Kyiv National Taras Shevchenko University, no. 66 (2019): 105–16. http://dx.doi.org/10.17721/2519-481x/2020/66-10.
Full textAbstract:
Analysis of the foreign experience of the organisation and reformation of the armed forces in other countries, with the respective systems of military education being an integral part, reveals the specific national aspect of such activities in each country. In the meantime, there are some general methodological approaches used in military pedagogic practice across different countries of the world to be practicably considered and applied. The article examines the experience of officers’ training for the armed forces of the Republic of Belarus. The article provides information on the existing network of military educational institutions for the officer training of tactical, operational-tactical and operational-strategic level of military command. Requirements for admission to military educational institutions for the officer training of different levels of training has been given. The terms of military specialists’ training on tactical, operational-tactical and operational-strategic level have been defined. The analysis of the content of officer training for different armed services of the armed forces and different levels of military administration has been conducted. We used the system of the general scientific methods of theoretical and empirical research, in particular, the theoretical-methodological analysis of the problem and the relevant scholarly resources, systematization and generalization of the scientific information pertaining to the essence and content of the set objectives, monitoring of the existing system of military specialists training in the Armed Forces of the republic of Belarus, scientific generalisation, the general scientific methods of logical and comparative analysis, systems approach, peer review, analysis and interpretation of the obtained theoretical and empirical data. An analysis of the concept, structure, goals, content and technologies of officers’ training inthe armed forces of the Republic of Belarus shows that the military education system reflects the current stage of development of the armed forces, as well as the national cultural specificity of the country. Education and training of officers is carried out on the basis of national cultural and military traditions, taking into account the mentality of the Belarusian people. The main direction of officers’ training is their fundamental military and professional training in both the military and civilian fields. First of all, the training of the citizen – patriot of his homeland is carried out. The content of the officers’ training is based on two military education levels. Each level of military education ends with a certain level of qualification. It is possible to distinguish the general tendencies of development of the higher Belarusian military school: improvement of the quality of applicants’ selection, individualization of training of cadets and trainees, stabilization of their number at the present level; further informatization of the educational process, introduction of multimedia learning tools. The reform of higher military education in Belarus continues in line with pan-European development. However, it does not embark on the path of simply copying military educational models of other countries, but takes into account the experience, traditions of the military school, national peculiarities of formation and development of national armed forces. Certainly, the positive elements of the experience of the Belarusian army can be used in the training of officers in the Ukrainian Armed Forces under the conditions of gradual transition to the recruitment on a contract basis.
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Chernykh, J., and O. Chernykh. "OFFICER TRAINING SYSTEM IN THE REPUBLIC OF HUNGARY." Collection of scientific works of the Military Institute of Kyiv National Taras Shevchenko University, no. 68 (2020): 119–27. http://dx.doi.org/10.17721/2519-481x/2020/68-13.
Full textAbstract:
Analysis of the foreign experience of the organisation and reformation of the armed forces in other countries, with the respective systems of military education being an integral part, reveals the specific national aspect of such activities in each country. In the meantime, there are some general methodological approaches used in military pedagogic practice across different countries of the world to be practicably considered and applied. The article examines the experience of officers’ training for the armed forces of the Republic of Hungary. The article provides information on the existing network of military educational institutions for the officer training of tactical, operational and strategic level of military command. Requirements for admission to military educational institutions for the officer training of different levels of training has been given. The terms of military specialists’ training on tactical, operational and strategic level have been defined. The analysis of the content of officer training for different armed services of the armed forces and different levels of military administration has been conducted. We used the system of the general scientific methods of theoretical and empirical research, in particular, the theoretical-methodological analysis of the problem and the relevant scholarly resources, systematization and generalization of the scientific information pertaining to the essence and content of the set objectives, monitoring of the existing system of military specialists training in the Armed Forces of the republic of Hungary, scientific generalisation, the general scientific methods of logical and comparative analysis, systems approach, peer review, analysis and interpretation of the obtained theoretical and empirical data. The general structure of the National University of Public Administration, the Faculty of Military Sciences and the training of officers is shown, as well as the main tasks that are solved by the institutes and training centers that are part of it are identified. An analysis of the concept, structure, goals, content and technologies of officers’ training in the armed forces of the Republic of Hungary shows that the military education system reflects the current stage of development of the armed forces, as well as the national cultural specificity of the country. Education and training of officers is carried out on the basis of national cultural and military tradition. The main direction of officers’ training is their fundamental military and professional training in both the military and civilian fields. The content of the officers’ training is based on two military education levels. Each level of military education ends with a certain level of qualification. It is possible to distinguish the general tendencies of development of the higher Hungarian military school: improvement of the quality of applicants’ selection, individualization of training of cadets and trainees, stabilization of their number at the present level; further informatization of the educational process, introduction of multimedia learning tools. Certainly, the positive elements of the experience of the Hungarian army can be used in the training of officers in the Ukrainian Armed Forces under the conditions of gradual transition to the recruitment on a contract basis.
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Shi, Yongjun, Xiaoyu Zhou, Xiaogang Wang, Xingteng Feng, and Laida Peng. "Effects of Electromagnetic Fields on the Microstructure of Laser Cladding." Materials 15, no. 12 (June 13, 2022): 4198. http://dx.doi.org/10.3390/ma15124198.
Full textAbstract:
The fast heating and quenching of laser cladding increase the internal stresses in the cladding layer. Moreover, the quick condensation of the molten pool leads to an uneven distribution of the internal elements and coarse grains of the structure. To address the above defects and increase the molding quality of laser cladding, an electromagnetic field was introduced into the laser cladding technique, and the effects of the external assisted electromagnetic field on the mixed metal fluid in the molten pool were explored. On this basis, the action of the electromagnetic field on the flow states of the molten pool was further analyzed. The results demonstrate that after introducing electromagnetic assistance, the material flow in the molten pool accelerated as a response to the periodic changes in electromagnetic forces and the influences of the electromagnetic field on crystallization, thus refining the grains and improving the grain distribution uniformity in the cladding layer. The dendritic crystals in the cladding layer decreased, while the isometric crystals and the cellular-like dendrites increased. The element distribution in the cladding layer increased in uniformity. Additionally, this method can decrease the dilution rate of the cladding layer and improve its overall hardness. A laser-cladding test of the Ni-based powder was carried out on the AISI 1045 steel surface under the coaxial powder-feeding mode. Moreover, the influences of the electromagnetic field on the microstructure of the laser-cladding layer were compared, and the causes of the changes were disclosed.