Plasma behavior in an externally applied magnetic field reversal is numerically explored in order to demonstrate the existence of a self-consistent drift caused by the kinetic interaction of ions with the magnetic nul...
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ISBN:
(纸本)9781624102226
Plasma behavior in an externally applied magnetic field reversal is numerically explored in order to demonstrate the existence of a self-consistent drift caused by the kinetic interaction of ions with the magnetic null. Single-particle analysis of ion trajectories is performed in the magnetic topology to predict expected ion particle and momentum fluxes out of the system. A particle-in-cell (PIC) code is used to simulate the actual fluxes out of the system for a set of magnetic field strengths from 0 to 800 G. The results of the simulations upheld the concept's presumed ability to accelerate plasma in a desired direction and demonstrated that single-particle analysis does not predict the exact particle and momentum fluxes out of the system but does predict the optimum magnetic field for our limited parameter space.
The paper aims to compare the hardness and corrosion behavior of carburized and borided Iron-Based Austenitic Steels (IBAS) which were treated at the same temperature and time under vacuum conditions. Boronizing was p...
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In this research, efforts were made to study the modification of microstructure of pure Ni matrices. Modification was attempted using glucose as carburizing medium under a control of heat treatment conditions. Nickel ...
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作者：
G YangY T GuanF Y JianM D WagnerH MeiG J WangS M HowardD M MeiA NelsonJ MarshalK FitzgeraldC TenzinX MaDepartment of Physics
The University of South Dakota Vermillion SD 57069 USA Department of Materials and Metallurgical Engineering
South Dakota School of Mines and Technology Rapid City SD 57701 USA Metallurgical Engineer
North American Stainless Ghent KY formerly Research Assistant and MS Candidate Department of Materials and Metallurgical Engineering South Dakota School of Mines and Technology Rapid City SD 57701 USA Mechanical Engineer
Applied Controls Equipment Denver CO formerly Research Assistant and BS Candidate Department of Materials and Metallurgical Engineering South Dakota School of Mines and Technology Rapid City SD 57701 USA Metallurgical Engineer
Logan Aluminum Lewisburg KY formerly Research Assistant and MS Candidate Department of Materials and Metallurgical Engineering South Dakota School of Mines and Technology Rapid City SD 57701 USA Technical Consultant
Wenatchee WA formerly Research Assistant and MS Candidate Department of Materials and Metallurgical Engineering South Dakota School of Mines and Technology Rapid City SD 57701 USA
Purification of commercial germanium with an impurity level of ~1013-14 cm-3 was successfully conducted in two-step zone refining process under an undiluted high-purity hydrogen gas atmosphere. Results for the first s...
Purification of commercial germanium with an impurity level of ~1013-14 cm-3 was successfully conducted in two-step zone refining process under an undiluted high-purity hydrogen gas atmosphere. Results for the first step conducted in graphite boats yielded ingots with an impurity level of ~1012 cm-3 near the center of the 60 cm long ingots. These center portions were collected and subsequently zone refined in a high purity quartz boat to reach a purity level of ~1011 cm-3. The best material achieved in a one step process employing a carbon-coated quartz boat yielded material of purity 8×1011 cm-3.
Electron-holes, phonons, and plasmons come in close proximity to each other in the low-energy range of the excitation spectrum of two-dimensional (2D) crystals, breaking the validity of the weakly interacting-quasipar...
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Electron-holes, phonons, and plasmons come in close proximity to each other in the low-energy range of the excitation spectrum of two-dimensional (2D) crystals, breaking the validity of the weakly interacting-quasiparticles picture. By including the lattice oscillations into the scheme of time-dependent density-functional theory, we open a pathway to the ab initio treatment of the coupled low-energy excitations in 2D crystals. With the use of graphene as an important test system, we find the strong coupling of the elementary excitations, giving rise to new hybrid collective modes. The total (including both the electronic and ionic response) dielectric function ɛtot(ω) is constructed and the picture of the low-energy excitation spectrum of graphene is redrawn.
The influence of Co and Cu doping on Ni-Mn-Ga Heusler alloy is investigated using the first-principles exact muffin-tin orbital method in combination with the coherent-potential approximation. Single-element doping an...
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The influence of Co and Cu doping on Ni-Mn-Ga Heusler alloy is investigated using the first-principles exact muffin-tin orbital method in combination with the coherent-potential approximation. Single-element doping and simultaneous doping by both elements are investigated in Ni50−xCoxMn25−yGa25−zCuy+z alloys, with dopant concentrations x,y, and z up to 7.5 at. %. Doping with Co in the Ni sublattice decreases the (c/a)NM ratio of the nonmodulated (NM) martensite, but it simultaneously increases the cubic phase stability with respect to the NM phase. Doping with Cu in the Mn or in Ga sublattices does not change the (c/a)NM ratio significantly and it decreases the cubic phase stability. For simultaneous doping by Co in the Ni sublattice and Cu in the Mn or Ga sublattices, the effects of the individual dopants are independent and about the same as for the single-element doping. Thus, the (c/a)NM ratio can be adjusted by Co doping while the phase stability can be balanced by Cu doping, resulting in stable martensite with a reduced (c/a)NM. The local stability of the cubic phase with respect to the tetragonal deformation can be understood on the basis of a density-of-states analysis.
In recent years wind energy is the fastest growing branch of the power generation industry. The largest cost for the wind turbine is its maintenance. A common technique to decrease this cost is a remote monitoring bas...
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In recent years wind energy is the fastest growing branch of the power generation industry. The largest cost for the wind turbine is its maintenance. A common technique to decrease this cost is a remote monitoring based on vibration analysis. Growing number of monitored turbines requires an automated way of support for diagnostic experts. As full fault detection and identification is still a very challenging task, it is necessary to prepare an early-warning tool, which would focus the attention on cases which are potentially dangerous. There were several attempts to develop such tools, in most cases based on various classification methods. The techniques that have been used so far are based on the vibration signals analysis in which the signals are considered as time series. However such approach has crucial limitations. Therefore, new approaches for wind turbines intelligent monitoring are worked out. Artificial intelligence systems are ones of promising. In this paper such approach is proposed - a vibration signal spectrum is considered as a pixel matrix which is processed using deterministic cellular automaton (DCA). It turns out that such processing allows us to detect pre-failure states.
The kinetics of ignition in lean and stoichiometric C2H2:O2:Ar mixtures has been studied experimentally and numerically after a high-voltage nanosecond discharge. The ignition delay time behind a reflected shock wave ...
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