Comparison of Radial Forces between Double-Rotor Planetary and Coaxial Magnetic Gears

2021 ◽  
Author(s):  
Oleg Molokanov ◽  
Elizaveta Konyushenko ◽  
Eugene Zenko ◽  
Ekaterina Kurbatova ◽  
Nikolay Sabaykin ◽  
...  
Keyword(s):  
Radial Forces

scholarly journals High Throughput Centrifugal Electrospinning of Polyacrylonitrile Nanofibers for Carbon Fiber Nonwovens

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1313
Author(s):  
Andreas Hoffmann ◽  
Alexander J. C. Kuehne
Keyword(s):  
High Throughput ◽  
Carbon Nanofiber ◽  
Fiber Diameter ◽  
Carbon Precursor ◽  
Production Methods ◽  
High Throughput Method ◽  
Radial Forces ◽  
Fiber Deposition ◽  
The Impact ◽  
Pan Fibers

Carbon nanofiber nonwovens are promising materials for electrode or filtration applications; however, their utilization is obviated by a lack of high throughput production methods. In this study, we utilize a highly effective high-throughput method for the fabrication of polyacrylonitrile (PAN) nanofibers as a nonwoven on a dedicated substrate. The method employs rotational-, air pressure- and electrostatic forces to produce fibers from the inner edge of a rotating bell towards a flat collector. We investigate the impact of all above-mentioned forces on the fiber diameter, morphology, and bundling of the carbon-precursor PAN fibers. The interplay of radial forces with collector-facing forces has an influence on the uniformity of fiber deposition. Finally, the obtained PAN nanofibers are converted to carbon nonwovens by thermal treatment.

scholarly journals Magneto-Thermo-Structural Analysis of Power Transformers under Inrush and Short Circuit Conditions

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3266
Author(s):  
Antonio Roniel Marques de Sousa ◽  
Marcus Vinicius Alves Nunes ◽  
Wellington da Silva Fonseca ◽  
Ramon Cristian Fernandes Araujo ◽  
Diorge de Souza Lima
Keyword(s):  
Structural Analysis ◽  
Electric Power ◽  
Short Circuit ◽  
Real Data ◽  
Short Circuit Current ◽  
Power Transformers ◽  
Inrush Current ◽  
Electric Power Supply ◽  
Axial Forces ◽  
Radial Forces

The main equipment responsible for connection and transmission of electric power from generating centers to consumers are power transformers. This type of equipment is subject to various types of faults that can affect its components, in some cases also compromising its operation and, consequently, the electric power supply. Thus, in this paper, electromagnetic, thermal, and structural analysis of power transformers was carried out with the objective of providing the operator with information on the ideal moment for performing predictive maintenance, avoiding unplanned shutdowns. For this, computational simulations were performed using the finite element method (FEM) and, from that, the different transformer operation ways, nominal currents, inrush current, and short-circuit current were analyzed. In this perspective, analyses of the effects that thermal expansion, axial forces, and radial forces exerted were carried out, contributing to possible defects in this type of equipment. As a study object, simulations were carried out on a 50 MVA single-phase transformer. It is important to emphasize that the simulations were validated with real data of measurements and with results presented in the current literature.

Analytical estimation of short circuit axial and radial forces on power transformers windings

2014 ◽  
Vol 8 (2) ◽  
pp. 250-260 ◽  
Author(s):  
Bashir Mahdi Ebrahimi ◽  
Saeed Saffari ◽  
Jawad Faiz ◽  
Alireza Fereidunian
Keyword(s):  
Short Circuit ◽  
Power Transformers ◽  
Analytical Estimation ◽  
Radial Forces

scholarly journals ‘Pave-and-crack’ technique for the recanalization of severely calcified occlusive aorto-ilio-femoral disease in type-III Leriche syndrome: a case report

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Sorin Giusca ◽  
Andrej Schmidt ◽  
Grigorios Korosoglou
Keyword(s):  
External Iliac Artery ◽  
Covered Stent ◽  
Radial Force ◽  
Covered Stents ◽  
Leriche Syndrome ◽  
Step Procedure ◽  
Technical Advances ◽  
Radial Forces ◽  
Endovascular Approach ◽  
The Right

Abstract Background  Leriche syndrome is the result of the atherosclerotic occlusion of the distal aorta that may also involve pelvic arteries. The standard treatment for this condition is considered surgical with various techniques available for establishing appropriate flow to both limbs. However, due to the technical advances in the last decades, endovascular approaches are now also capable to tackle such lesions. The ‘pave-and-crack’ technique enables the treatment of severely calcified lesions. This two-step procedure consists of firstly placing a covered stent prothesis (VIABAHN) into the severely calcified segment, which is afterwards aggressively dilated with high-pressure balloons. Subsequently, an interwoven nitinol SUPERA stent with high radial forces is placed within the prothesis. Case summary  Herein, we describe the case of an 81-year-old male patient, who presented with critical limb-threatening ischaemia of his right leg. Doppler ultrasound revealed a long occlusion of the right external iliac artery, common femoral, superficial femoral, and deep femoral artery. The lesion was successfully tackled using antegrade and retrograde punctures and the ‘pave-and-crack’ technique. Discussion  The ‘pave-and-crack’ technique is an endovascular approach for the treatment of severe circumferential calcified lesions. Based on this technique covered stents are initially placed to prevent vessel rupture, which might occur during the aggressive balloon dilatation. Subsequently, the covered stents are relined by interwoven Supera stents, which provide high radial force preventing recoil and restenosis.

scholarly journals On the stresses induced by flexure in a deep rectangular beam

1934 ◽  
Vol 143 (849) ◽  
pp. 271-284 ◽  
Keyword(s):  
Stress Distribution ◽  
Practical Importance ◽  
Sufficient Accuracy ◽  
Elastic Instability ◽  
Theoretical Interest ◽  
Close Approximation ◽  
Rectangular Section ◽  
Apparent Paradox ◽  
State Of Stress ◽  
Radial Forces

1. When a straight cylindrical rod is bent into a circle by couples applied at its ends, the resulting state of stress is given, with sufficient accuracy for practical purposes, by the well-known theory of St. Venant. In that theory qunatities of the second and higher orders in therms of strain are neglected, and the resulting solution asserts that the stress is purely longitudinal, so that the rod may be thought of as an assembly of cylindrical fibres, each of which behaves independently of its neighbours. It is evident that this description cannot be exact; for a fibre bent into a circle cannot be kept in tension unless radial forces operate to maintain equilibrium, and in the case considered such forces can come only from actions between adjacent fibres. The apparent paradox is explained by the consideration that those action are of the second order in terms of the curvature, and accordingly are neglected in St. Venant's theory. In connection with a certain problem of elastic instability it was thought desirable to attempt a more accurate description for a particular case, namely, a rod of deep and thin rectangular section. It was found that the equations of equilibrium can be integrated independently of any simplifying assumption, and the stress-distribution determined for curvature of any magnitude. The results have no great practical importance, sice they show that St. Venant's theory gives a close approximation to the facts within that range of strains which actual materials can sustain elastically; but they have some theoretical interest, and accordingly are presented in this paper.

The Filament Lattice of Striated Muscle

1998 ◽  
Vol 78 (2) ◽  
pp. 359-391 ◽  
Author(s):  
BARRY M. MILLMAN
Keyword(s):  
Muscle Contraction ◽  
Structural Changes ◽  
Striated Muscle ◽  
Muscle Fibers ◽  
Lattice Stability ◽  
X Ray Diffraction ◽  
Thin Filaments ◽  
Intact Muscle ◽  
Radial Forces ◽  
Speed Of Shortening

Millman, Barry M. The Filament Lattice of Striated Muscle. Physiol. Rev. 78: 359–391, 1998. — The filament lattice of striated muscle is an overlapping hexagonal array of thick and thin filaments within which muscle contraction takes place. Its structure can be studied by electron microscopy or X-ray diffraction. With the latter technique, structural changes can be monitored during contraction and other physiological conditions. The lattice of intact muscle fibers can change size through osmotic swelling or shrinking or by changing the sarcomere length of the muscle. Similarly, muscle fibers that have been chemically or mechanically skinned can be compressed with bathing solutions containing very large inert polymeric molecules. The effects of lattice change on muscle contraction in vertebrate skeletal and cardiac muscle and in invertebrate striated muscle are reviewed. The force developed, the speed of shortening, and stiffness are compared with structural changes occurring within the lattice. Radial forces between the filaments in the lattice, which can include electrostatic, Van der Waals, entropic, structural, and cross bridge, are assessed for their contributions to lattice stability and to the contraction process.

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