The Experts below are selected from a list of 20832 Experts worldwide ranked by ideXlab platform
Mikhail Kostylev - One of the best experts on this subject based on the ideXlab platform.
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microwave eddy current Shielding Effect in metallic films and periodic nanostructures of sub skin depth thicknesses and its impact on stripline ferromagnetic resonance spectroscopy
Journal of Applied Physics, 2014Co-Authors: Ivan S Maksymov, Mikhail KostylevAbstract:A strong microwave Shielding Effect due to the excitation of microwave eddy-currents exists for metallic films of sub-skin-depth thickness (10–100 nm). If the film is ferromagnetic, this Effect strongly influences results of the broadband stripline ferromagnetic resonance (FMR) spectroscopy. It also potentially hampers the development of magnetically tuneable metamaterials. By means of rigorous numerical simulations, we address an important problem of the dependence of the eddy current Effect on the width of the stripline used for driving magnetisation dynamics in the broadband FMR spectroscopy. We study theoretically electrodynamics of realistic striplines and also extend the main result from the case of continuous conductive films to periodic conductive nanostructures—magnonic crystals. Based on these findings, we also give recommendations on improving performance of magnetically tuneable metamaterials, which are based on conductive ferromagnetic films and nanostructures. In our simulations, we consider...
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microwave eddy current Shielding Effect in metallic films and periodic nanostructures of sub skin depth thicknesses and its impact on stripline ferromagnetic resonance spectroscopy
Journal of Applied Physics, 2014Co-Authors: Ivan S Maksymov, Mikhail KostylevAbstract:A strong microwave Shielding Effect due to the excitation of microwave eddy-currents exists for metallic films of sub-skin-depth thickness (10–100 nm). If the film is ferromagnetic, this Effect strongly influences results of the broadband stripline ferromagnetic resonance (FMR) spectroscopy. It also potentially hampers the development of magnetically tuneable metamaterials. By means of rigorous numerical simulations, we address an important problem of the dependence of the eddy current Effect on the width of the stripline used for driving magnetisation dynamics in the broadband FMR spectroscopy. We study theoretically electrodynamics of realistic striplines and also extend the main result from the case of continuous conductive films to periodic conductive nanostructures—magnonic crystals. Based on these findings, we also give recommendations on improving performance of magnetically tuneable metamaterials, which are based on conductive ferromagnetic films and nanostructures. In our simulations, we consider examples of microstrip lines which are 5 μm to 1.5 mm wide. However, the simulation results should be equally applicable to coplanar waveguides with the same width of the signal line.
Ivan S Maksymov - One of the best experts on this subject based on the ideXlab platform.
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microwave eddy current Shielding Effect in metallic films and periodic nanostructures of sub skin depth thicknesses and its impact on stripline ferromagnetic resonance spectroscopy
Journal of Applied Physics, 2014Co-Authors: Ivan S Maksymov, Mikhail KostylevAbstract:A strong microwave Shielding Effect due to the excitation of microwave eddy-currents exists for metallic films of sub-skin-depth thickness (10–100 nm). If the film is ferromagnetic, this Effect strongly influences results of the broadband stripline ferromagnetic resonance (FMR) spectroscopy. It also potentially hampers the development of magnetically tuneable metamaterials. By means of rigorous numerical simulations, we address an important problem of the dependence of the eddy current Effect on the width of the stripline used for driving magnetisation dynamics in the broadband FMR spectroscopy. We study theoretically electrodynamics of realistic striplines and also extend the main result from the case of continuous conductive films to periodic conductive nanostructures—magnonic crystals. Based on these findings, we also give recommendations on improving performance of magnetically tuneable metamaterials, which are based on conductive ferromagnetic films and nanostructures. In our simulations, we consider...
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microwave eddy current Shielding Effect in metallic films and periodic nanostructures of sub skin depth thicknesses and its impact on stripline ferromagnetic resonance spectroscopy
Journal of Applied Physics, 2014Co-Authors: Ivan S Maksymov, Mikhail KostylevAbstract:A strong microwave Shielding Effect due to the excitation of microwave eddy-currents exists for metallic films of sub-skin-depth thickness (10–100 nm). If the film is ferromagnetic, this Effect strongly influences results of the broadband stripline ferromagnetic resonance (FMR) spectroscopy. It also potentially hampers the development of magnetically tuneable metamaterials. By means of rigorous numerical simulations, we address an important problem of the dependence of the eddy current Effect on the width of the stripline used for driving magnetisation dynamics in the broadband FMR spectroscopy. We study theoretically electrodynamics of realistic striplines and also extend the main result from the case of continuous conductive films to periodic conductive nanostructures—magnonic crystals. Based on these findings, we also give recommendations on improving performance of magnetically tuneable metamaterials, which are based on conductive ferromagnetic films and nanostructures. In our simulations, we consider examples of microstrip lines which are 5 μm to 1.5 mm wide. However, the simulation results should be equally applicable to coplanar waveguides with the same width of the signal line.
Alex Hansen - One of the best experts on this subject based on the ideXlab platform.
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can local stress enhancement induce stability in fracture processes part ii the Shielding Effect
Frontiers in Physics, 2019Co-Authors: Jonas T. Kjellstadli, Srutarshi Pradhan, Eivind Bering, Alex HansenAbstract:We use the local load sharing fiber bundle model to demonstrate a Shielding Effect where strong fibers protect weaker ones. This Effect exists due to the local stress enhancement around broken fibers in the local load sharing model, and it is therefore not present in the equal load sharing model. The Shielding Effect is prominent only after the initial disorder-driven part of the fracture process has finished, and if the fiber bundle has not reached catastrophic failure by this point, then the Shielding increases the critical damage of the system, compared to equal load sharing. In this sense, the local stress enhancement may make the fracture process more stable, but at the cost of reduced critical force.
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can local stress enhancement induce stability in fracture processes part ii the Shielding Effect
arXiv: Disordered Systems and Neural Networks, 2019Co-Authors: Jonas T. Kjellstadli, Srutarshi Pradhan, Eivind Bering, Alex HansenAbstract:We use the fiber bundle model to demonstrate a Shielding Effect where strong elements protect weaker ones when the force distribution scheme is localized in space. This Shielding does not exist with equal force distribution, and it has two major Effects. Firstly, the damage at which catastrophic failure sets in is delayed by the localization of the forces, and secondly, that more weak fibers survive until catastrophic failure than with equal force distribution. However, the localized force distribution scheme also results in a lower strength of the fiber bundle. The Shielding Effect is expected to be relevant for the class of threshold distributions where catastrophic failure happens at sufficiently high damage, depending on the geometry of the lattice used in the model.
Tong Deng - One of the best experts on this subject based on the ideXlab platform.
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influence of particle size density particle concentration on bend erosive wear in pneumatic conveyors
Wear, 2013Co-Authors: R Macchini, M S A Bradley, Tong DengAbstract:Abstract Particle concentration is a principal factor that affects erosion rate of solid surfaces under particle impact, such as pipe bends in pneumatic conveyors; it is well known that a reduction in the specific erosion rate occurs under high particle concentrations, a phenomenon referred to as the “Shielding Effect”. The cause of Shielding is believed to be increased likelihood of inter-particulate collisions, the high collision probability between incoming and rebounding particles reducing the frequency and the severity of particle impacts on the target surface. In this study, the Effects of particle concentration on erosion of a mild steel bend surface have been investigated in detail using three different particulate materials on an industrial scale pneumatic conveying test rig. The materials were studied so that two had the same particle density but very different particle size, whereas two had very similar particle size but very different particle density. Experimental results confirm the Shielding Effect due to high particle concentration and show that the particle density has a far more significant influence than the particle size, on the magnitude of the Shielding Effect. A new method of correcting for change in erosiveness of the particles in repeated handling, to take this factor out of the data, has been established, and appears to be successful. Moreover, a novel empirical model of the Shielding Effects has been used, in term of erosion resistance which appears to decrease linearly when the particle concentration decreases. With the model it is possible to find the specific erosion rate when the particle concentration tends to zero, and conversely predict how the specific erosion rate changes at finite values of particle concentration; this is critical to enable component life to be predicted from erosion tester results, as the variation of the Shielding Effect with concentration is different in these two scenarios. In addition a previously unreported phenomenon has been recorded, of a particulate material whose erosiveness has steadily increased during repeated impacts.
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Effect of particle concentration on erosion rate of mild steel bends in a pneumatic conveyor
Wear, 2004Co-Authors: Tong Deng, A.r. Chaudhry, Mayur Patel, Ian M. Hutchings, M S A BradleyAbstract:Particle concentration is known as a main factor that affects erosion rate of pipe bends in pneumatic conveyors. With consideration of different bend radii, the Effect of particle concentration on weight loss of mild steel bends has been investigated in an industrial scale test rig. Experimental results show that there was a significant reduction of the specific erosion rate for high particle concentrations. This reduction was considered to be as a result of the Shielding Effect during the particle impacts. An empirical model is given. Also a theoretical study of scaling on the Shielding Effect, and comparisons with some existing models, are presented. It is found that the reduction in specific erosion rate (relative to particle concentration) has a stronger relationship in conveying pipelines than has been found in the erosion tester.
Jonas T. Kjellstadli - One of the best experts on this subject based on the ideXlab platform.
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can local stress enhancement induce stability in fracture processes part ii the Shielding Effect
Frontiers in Physics, 2019Co-Authors: Jonas T. Kjellstadli, Srutarshi Pradhan, Eivind Bering, Alex HansenAbstract:We use the local load sharing fiber bundle model to demonstrate a Shielding Effect where strong fibers protect weaker ones. This Effect exists due to the local stress enhancement around broken fibers in the local load sharing model, and it is therefore not present in the equal load sharing model. The Shielding Effect is prominent only after the initial disorder-driven part of the fracture process has finished, and if the fiber bundle has not reached catastrophic failure by this point, then the Shielding increases the critical damage of the system, compared to equal load sharing. In this sense, the local stress enhancement may make the fracture process more stable, but at the cost of reduced critical force.
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can local stress enhancement induce stability in fracture processes part ii the Shielding Effect
arXiv: Disordered Systems and Neural Networks, 2019Co-Authors: Jonas T. Kjellstadli, Srutarshi Pradhan, Eivind Bering, Alex HansenAbstract:We use the fiber bundle model to demonstrate a Shielding Effect where strong elements protect weaker ones when the force distribution scheme is localized in space. This Shielding does not exist with equal force distribution, and it has two major Effects. Firstly, the damage at which catastrophic failure sets in is delayed by the localization of the forces, and secondly, that more weak fibers survive until catastrophic failure than with equal force distribution. However, the localized force distribution scheme also results in a lower strength of the fiber bundle. The Shielding Effect is expected to be relevant for the class of threshold distributions where catastrophic failure happens at sufficiently high damage, depending on the geometry of the lattice used in the model.
