Relevant bibliographies by topics / Electric Arc Plasma

Academic literature on the topic 'Electric Arc Plasma'

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Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Electric Arc Plasma"

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Ramakrishnan, S. "Technological Challenges in Thermal Plasma Production." Australian Journal of Physics 48, no. 3 (1995): 377. http://dx.doi.org/10.1071/ph950377.

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Thermal plasmas, generated by electric arc discharges, are used in a variety of industrial applications. The electric arc is a constricted electrical discharge with a high temperature in the range 6000-25,000 K. These characteristics are useful in plasma cutting, spraying, welding and specific areas of material processing. The thermal plasma technology is an enabling process technology and its status in the market depends upon its advantages over competing technologies. A few technological challenges to enhance the status of plasma technology are to improve the utilisation of the unique characteristics of the electric arc and to provide enhanced control of the process. In particular, new solutions are required for increasing the plasma-material interaction, controlling the electrode roots and controlling the thermal power generated by the arcing process.
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Anshakov, A. S., E. K. Urbakh, S. I. Radko, A. E. Urbakh, and V. A. Faleev. "Electric-arc steam plasma generator." Thermophysics and Aeromechanics 22, no. 1 (January 2015): 95–104. http://dx.doi.org/10.1134/s0869864314010096.

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Kruchinin, A. M., M. Ya Pogrebissky, E. S. Ryazanova, and A. Yu Chursin. "Thermal characteristics of an arc column in the stabilization zone of an air-operated laminar plasma torch." Physics and Chemistry of Materials Treatment 6 (2020): 56–61. http://dx.doi.org/10.30791/0015-3214-2020-6-56-61.

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The method of universal characteristics of an electric arc is described as a mathematical basis for the heat exchange model of an electric arc in the processes of electric arc heating in electrical engineering. Application of this method for calculation of the temperature characteristics of an arc column compressed by the walls of the discharge channel in the stabilization zone of a laminar plasma torch operating in air is considered. An example of the temperature profile calculation of a wall-stabilized arc for a plasma generator with a discharge channel diameter of 5 mm operating in air at an arc current of 60 A is presented. Calculated results are compared with the results of experimental studies of this plasma generator.
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Tazmeev, K. K., R. N. Tazmeeva, and B. K. Tazmeev. "Low-current arc in plasma flow from discharge with liquid electrolyte cathode." Journal of Physics: Conference Series 2270, no. 1 (May 1, 2022): 012028. http://dx.doi.org/10.1088/1742-6596/2270/1/012028.

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Abstract The effect of plasma flow from a discharge with a solution cathode on the properties of a low-current electric arc has been experimentally studied. Electric power was supplied to the arc from a GORN-type inverter source. A rectifier served as a power source for the discharge with a solution cathode. The output voltage was 1700 V. Aqueous solutions of table salt were used in the experiments. The specific electrical conductivity of the solutions was in the range of 10–15 mS/cm. The electric arc was ignited between horizontally oriented rod electrodes. The interelectrode distance varied within 2–15 mm. The discharge current with a water cathode was established within 8–15 A. The arc burned in the current range of 1–8 A. The conditions under which stable burning of the electric arc is ensured are revealed.
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Et. al., Evseev Alexei Mikhailovich,. "Rectifilter for electric arc plasma plant." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 2 (April 10, 2021): 3130–36. http://dx.doi.org/10.17762/turcomat.v12i2.2358.

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This article presents the results of the development and research of a new type of AC-DC converter - a filter-rectifier (or rectifilter). The object of application of the proposed device is an industrial plant of electric arc plasma processing, the operation of which requires maintaining a constant value of the arc current and is accompanied by a high level of harmonic distortion and consumed reactive energy. From the point of view of the reactive power compensation and harmonic filtering strategy, the rectifilter can be attributed to active electric power filters and FACTS, however, from the position of the main function performed, it is a direct current source, an AC to DC converter, an active rectifier. This work describes in detail the principles of operation of the control system and the hardware architecture of the device. Mathematical modeling of the rectifilter and analysis of the graphs of the consumed alternating current, rectified current, analysis of the harmonic composition and power factor in comparison with the thyristor rectifier of an electric arc plasmatron were carried out.
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Sawicki, Antoni. "Selected Properties of High-Frequency Electric Arc Initiators and Stabilisation Oscillators. Part 2. Devices with Compressed Electric Arc." Biuletyn Instytutu Spawalnictwa, no. 3 (June 2021): 49–60. http://dx.doi.org/10.17729/ebis.2021.3/5.

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The second part of the overview article discusses general features of the design and operation of selected industrial arc plasma torches. Because of their structural and operating differences, plasma torch power supply systems with internal and partly external arc are discussed separately. Particular attention was paid to the design of electric systems used for the initiation of arc discharges. Because of the fact that the operation of plasma torches with partly external arc is often accompanied by the formation of double arc, the article also presents measures and methods enabling the prevention of the aforesaid unfavourable phenomenon. In addition, the article discusses selected technological properties of plasma torches and micro-plasma torches used for joining, cutting, surfacing and hardening.
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Tazmeev, K. K., and A. K. Tazmeev. "Features of a burning electric arc superimposed on gas discharge with liquid electrolyte cathode." Journal of Physics: Conference Series 2270, no. 1 (May 1, 2022): 012021. http://dx.doi.org/10.1088/1742-6596/2270/1/012021.

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Abstract The conditions for burning an electric arc in a discharge plasma with a solution cathode have been studied. Both discharges were connected to the same metal anode. The electric arc burned in the current range of 5–10 A. The discharge current with a solution cathode varied within 8-15 A. In the experiments, aqueous solutions of common salt were used. The specific electrical conductivity of the solutions was 10–15 mS/cm. Spectral investigations of arc plasma radiation and discharge with a solution cathode have been carried out. Calculations of the parameters of the electron gas in the plasma column have been performed.
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Veklich, A., S. Fesenko, and V. Boretskij. "Plasma Peculiarities of Arc Discharge Between Carbon-Copper Electrodes." PLASMA PHYSICS AND TECHNOLOGY 6, no. 2 (2019): 152–55. http://dx.doi.org/10.14311/ppt.2019.2.152.

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Composite materials on carbon-copper base have advanced electric and exploitation characteristics. They usually used as materials for sliding contacts for high-speed railway. Arc discharges appear during pantograph lowering process in pantograph-catenary system, so injection of contact material into discharge gap has place. Therefore, investigations of electric arc plasma between such composite electrodes can be useful for further optimization of materials. It would be very useful as well to examine the peculiarities of electric arc plasma and contacts’ working surface interaction. So, the aim of this work is spectroscopy investigations of electric arc discharge plasma between C-Cu composite electrodes. The mutual correlation of plasma properties and composition of contacts’ was found.
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Kruchinin, A. M., M. Ya Pogrebisskiy, E. S. Ryazanova, and A. Yu Chursin. "Calculation of rational modes of plasma torches for plasma arc furnaces." Physics and Chemistry of Materials Treatment 2 (2022): 13–22. http://dx.doi.org/10.30791/0015-3214-2022-2-13-22.

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The method of universal arc characteristics developed for calculating the electrical and thermal characteristics of the cylindrical part of the Mecker model column allows simple algebraic methods to calculate the characteristics of the arc column at a distance from the cathode and, thereby, to concretize the mathematical model of Mecker. The proven conservativeness of the arc as a result of the formation of a spatial layer with increased volumetric viscosity on the surface of the column allows, in accordance with the provisions of the boundary layer theory, to apply a boundary condition of the third kind to the surface of the cylindrical part of the arc column. The method of universal arc characteristics also helps to link the boundary value of the linear heat flux density on the surface of the cylindrical part of the column with the temperature profile of the column and, thereby, to specify the dependence of the electrical, geometric and thermal characteristics of the column plasma on the conditions of arc heat exchange in the working space of the installation with electric arc heating. The proposed method makes it possible, based only on the external voltage characteristics of the arc, to identify the Mecker heat exchange model and calculate by a simple algebraic method the structure and values of the heat fluxes generated by the arc during heat exchange with the plasma torch gas jet in the melting space of the plasma arc furnace. Examples of arc characteristics are given when working on different gases for different stages of melting — at the beginning of melting and during the melting of the charge.
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Rutberg, Ph G., A. A. Safronov, S. D. Popov, A. V. Surov, and G. V. Nakonechnyi. "Multiphase electric-arc ac plasma generators for plasma technologies." High Temperature 44, no. 2 (March 2006): 199–205. http://dx.doi.org/10.1007/s10740-006-0024-0.

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Dissertations / Theses on the topic "Electric Arc Plasma"

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Javidi, Shirvan Alireza. "Modelling of Electric Arc Welding : arc-electrode coupling." Licentiate thesis, Högskolan Väst, Avd för maskinteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-5826.

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Arc welding still requires deeper process understanding and more accurateprediction of the heat transferred to the base metal. This can be provided by CFD modelling.Most works done to model arc discharge using CFD consider the arc corealone. Arc core simulation requires applying extrapolated experimental data asboundary conditions on the electrodes. This limits the applicability. To become independent of experimental input the electrodes need to be included in the arcmodel. The most critical part is then the interface layer between the electrodesand the arc core. This interface is complex and non-uniform, with specific physicalphenomena.The present work reviews the concepts of plasma and arc discharges that areuseful for this problem. The main sub-regions of the model are described, andtheir dominant physical roles are discussed.The coupled arc-electrode model is developed in different steps. First couplingsolid and fluid regions for a simpler problem without complex couplinginterface. This is applied to a laser welding problem using the CFD softwareOpenFOAM. The second step is the modelling of the interface layer betweencathode and arc, or cathode layer. Different modelling approaches available inthe literature are studied to determine their advantages and drawbacks. One ofthem developed by Cayla is used and further improved so as to satisfy the basicprinciples of charge and energy conservation in the different regions of thecathode layer. A numerical procedure is presented. The model, implementedin MATLAB, is tested for different arc core and cathode conditions. The maincharacteristics calculated with the interface layer model are in good agreementwith the reference literature. The future step will be the implementation of theinterface layer model in OpenFOAM.
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Aula, M. (Matti). "Optical emission from electric arc furnaces." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526210926.

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Abstract The main cause of temperature and composition fluctuations in the electric arc furnace (EAF) process is the scrap used as a raw material. Process conditions in EAF can vary significantly from heat to heat because there is no accurate information of scrap composition. Due to harsh process conditions, there are currently few sensors available for direct on-line measurement of the EAF process. In this work new information about stainless steelmaking EAF process conditions is sought with optical emission spectrum measurement. The measurement system relies on transportation of the light emitted from the measured furnace to a remotely situated spectrometer. Analysing the slag composition from the arc emission spectrum was tested in the laboratory and on a pilot scale. The laboratory measurements indicate that changes in the amount of CrOx and MnO in the slag have the highest impact on optical emission spectra. The pilot scale measurements show that the Cr2O3 content of the slag can be measured from the arc emission spectrum using suitable reference lines with an average absolute error of 0.62 %-points and a standard deviation of 0.49 %-points. The results from measurements at Outokumpu Stainless Oy, Tornio Works, indicate that measurement of the optical emission spectrum from industrial EAF is feasible in a practical sense, and can be used in analysing of EAF atmosphere, scrap melting and slag surface. Furthermore, the results of industrial measurements indicate that the atoms in the arc plasma mainly originate from the slag. The measurement of scrap melting could be potentially used in EAF control in optimization of arc voltages and second scrap bucket charging. The potential use of slag CrOx measurements is in optimization of reductant additions as well as defining the further processing of EAF slag
Tiivistelmä Valokaariuunien ohjaus on perinteisesti ollut uunioperaattorin käsissä. Valokaaariuuniprosessin on-line mittaukseen on olevassa vähän menetelmiä johtuen uunin hyvin haastavaista olosuhteista. Tässä työssä on tutkittu optiseen emissiospektroskopiaan perustuvaa menetelmää uuden jatkuva-aikaisen tiedon tuottamisessa valokaariuuniprosessista. Mittausjärjestelmä perustuu valon keräämiseen mitattavasta uunista valokuidun avulla, joka johtaa valon analysoitavaksi etäälle prosessista sijoitettuun spektrometriin. Mittauksia suoritettiin laboratorio-, pilot- ja tehdas-mittakaavassa. Valokaariuunin kuonan koostumuksen analysointia testattiin laboratorio- ja pilot-mittakaavan uuneilla. Laboratoriomittaukset osoittivat että kuonan komponenteista CrOx ja MnO ja vaikuttavat eniten mitattuun emissiospektriin. Pilot-mittakaavan kokeissa havaittiin, että kuonan Cr2O3-pitoisuutta voidaan mitata valokaaren emissiospektristä 0,62 %-yksikön keskimääräisellä absoluuttisella virheellä ja 0,49 %-yksikkön hajonnalla. Teollisella valokaariuunilla suoritetuista mittauksista havaittiin että optisen emissiospektrin mittaus voidaan suorittaa ilman ylitsepääsemättömiä teknisiä esteitä. Mittauksen tuloksia voidaan puolestaan käyttää kaasufaasin reaktioiden, romun sulamisen ja kuonapinnan ominaisuuksien arvioinnissa. Valokaaren emissiospektrin analyysi osoitti, että valokaaren plasman komponentit ovat pääosin peräisin kuonasta, joka mahdollistaa kuonan koostumuksen arvioinnin valokaaren emissiospektrin perusteella. Romun sulamisen mittausta voidaan prosessinohjauksessa käyttää jänniteportaiden ja toisen korin panostuksen optimointiin. Kuonan kromipitoisuuden mittaamista voidaan puolestaan käyttää pelkistinaineiden lisäyksen optimointiin ja kuonan jatkokäsittelyn valintaan
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Lisnyak, Marina. "Theoretical, numerical and experimental study of DC and AC electric arcs." Thesis, Orléans, 2018. http://www.theses.fr/2018ORLE2013/document.

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L’apparition accidentelle d’un arc électrique dans le système de distribution électrique d’un aéronef peut compromettre la sécurité du vol. Il existe peu de travaux liés à cette problématique.Le but de ce travail est donc d’étudier le comportement d’un arc électrique, en conditions aéronautiques,par des approches théorique, numérique, et expérimentale. Dans ce travail, un modèle MHD de la colonne d’arc à l’ETL a été utilisé, et résolu à l’aide du logiciel commercial comsolMultiphysics. Afin de décrire l’interaction plasma-électrodes, le modèle a dû étendu pour inclure les écarts à l’équilibre près des électrodes. Ces zones ont été prises en compte en considérant la conservation du courant et de l’énergie dans la zone hors-équilibre. L’approche choisie et le développement du modèle ont été détaillés. La validation du modèle dans le cas d’un arc libre a montré un excellent accord avec les résultats numériques et expérimentaux de la littérature.Ce modèle d’arc libre a été étendu au cas de l’arc se propageant entre des électrodes en configuration rails et en géométrie 3D. Une description auto-cohérente du déplacement de l’arc entre les électrodes a été réalisée. La simulation numérique a été faite pour des arcs en régimes DC, pulsé et AC à des pressions atmosphériques et inférieures. Les principales caractéristiques de l’arc ont été analysées et discutées. Les résultats obtenus ont été comparés avec les résultats expérimentaux et ont montré un bon accord.Ce modèle d’arc électrique est capable de prédire le comportement d’un arc de défaut dans des conditions aéronautiques. Des améliorations du modèle sont discutées comme perspectives de ce travail
The ignition of an electric arc in the electric distribution system of an aircraft can be a serious problem for flight safety. The amount of information on this topic is limited, however. Therefore,the aim of this work is to investigate the electric arc behavior by means of experiment and numerical simulations.The MHD model of the LTE arc column was used and resolved numerically using the commercial software comsol Multiphysics. In order to describe plasma-electride interaction, the model had to be extended to include non-equilibrium effects near the electrodes. These zones were taken into account by means of current and energy conservation in the non-equilibrium layer. The correct matching conditions were developed and are described in the work. Validation of the model in the case of a free burning arc showed excellent agreement between comprehensive models and the experiment.This model was then extended to the case of the electric arc between rail electrodes in a 3D geometry. Due to electromagnetic forces the electric arc displaces along the electrodes. A self-consistent description of this phenomenon was established. The calculation was performed for DC, pulsed and AC current conditions at atmospheric and lower pressures. The main characteristics of the arc were analyzed and discussed. The results obtained were compared with the experimental measurements and showed good agreement.The model of electric arcs between busbar electrodes is able to predict the behavior of a fault arc in aeronautical conditions. Further improvements of the model are discussed as an outlook of the research
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Coulombe, S. (Sylvain). "A model of the electric arc attachment on non-refractory (cold) cathodes /." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34710.

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In this work, a physical model describing the electric arc attachment on electron emitting non-refractory (cold) cathodes is developed and applied to Cu, Fe and Ti cathodes. The model considers the possibility of a pressure build up in the cathode region due to the strong vaporization of the cathode, the formation of a cathode sheath according to the Bohm's model, and the ion-enhanced thermo-field emission of electrons by the cathode surface. The self-sustaining operating conditions of the discharge are defined by two simple criteria based on particle and energy balance considerations. Results clearly show the necessity of having high local metallic vapor pressures in the cathode region of non-refractory cathodes in order to have a self-sustaining arc attachment. A minimum pressure of at least 19 atm is needed for a Cu cathode. This minimum pressure is shown to decrease as the cathode material boiling temperature increases according to an exponential decay law. Current densities of the order of 1010 A m--2 are maintained at the surface of a Cu cathode mainly by the emitted electrons. A comparison of the three different models for the electron emission current found in the literature allowed to define the limits of validity of each model for two typical arc-cathode interaction systems, and to evaluate the underestimation made on the emission current density when a less appropriate model is used. This underestimation is shown to cause an overestimation of important parameters such as the cathode surface temperature and metallic vapor pressure in the cathode region. An analysis of the mechanisms of heat transfer to the cathode surface allowed to show that the confinement of the cathode spot plasma forming the arc attachment could favor the production of vapors to the detriment of liquids. Such a phenomenon is of importance in Arc Ion Plating for instance. Heat losses by conduction in the cathode bulk larger than 1010 W m--2 are shown to favor the formation of liquid
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Krolak, Matthew Joseph. "Optimization of a magnetoplasmadynamic arc thruster." Link to electronic thesis, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-042607-155701/.

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Sousa, martins Rafael Alexandre. "Etude expérimentale et théorique d'un arc de foudre et son interaction avec un matériau aéronautique." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC080/document.

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Aujourd’hui, l’étude des effets directs de la foudre sur les structures aéronautiques pourrait s’appuyer, au moins en partie, sur des outils de simulation. Néanmoins, le manque de données expérimentales sur la phase d’arc impulsionnelle ne permet pas de justifier le caractère prédictif des outils de simulation.L’objectif de cette thèse est de réaliser une base de données expérimentale en s’appuyant sur la caractérisation des arcs de foudre dans des situations standardisées. Ces données peuvent être utilisées à la fois pour la compréhension des phénomènes observés lors des essais, mais surtout comme référence comparable aux outils de simulation.Dans un premier temps, on s’intéresse à la colonne d'arc libre dans l’air, hors interaction avec les électrodes. Par ailleurs, les profils spatio-temporels de température et de pression sont évalués par spectroscopie d'émission. On montre ainsi que, pour un arc de 100 kA, la température maximale atteint 37400 K sur l'axe de la colonne à 2 μs après l’amorçage, avec une pression de l’ordre de 45 bars.Dans un second temps, on s’intéresse à l'interaction de l'arc foudre avec des matériaux aéronautiques. La dynamique du pied d'arc ainsi que les caractéristiques de l’onde de choc sont analysées sur différents matériaux aéronautiques tels que l’aluminium ou des composites à fibres de carbone. Les contraintes thermomécaniques subies par le matériau sont étudiées par thermographie infrarouge, et par des mesures de déflexion rapide au centre du matériau, conduisant à une évaluation de la pression exercée par l’arc au point d’impact
Nowadays, the study of the direct effects of lightning on aeronautical structures could be based, at least in part, on simulation tools. Nevertheless, the lack of experimental data on the transient phase of the lightning arc does not allow us to justify the predictive nature of the simulation tools. The objective of this thesis is to produce an experimental database based on the characterization of lightning arcs in standardized situations. These data can be used both for the understanding of the phenomena observed during the tests, but especially as a reference comparable to the simulation tools.First, we are interested in the free arc column in air, without interaction with the electrodes. Furthermore, time- and space-resolved profilesof temperature and pressure are evaluated by emission spectroscopy. For a 100 kA arc, it is shown that the temperature reaches 37400 K in the arc axis at 2 μs after arc ignition, with a corresponding pressure of 45 bar.Second, we are interested in the interaction of the lightning arc with aeronautical materials. The dynamics of the arc roots and the characteristics of the shock wave are analyzed for different aeronautical materials such as aluminum or carbon fiber composites. The thermo-mechanical constraints applied on the material are studied by infrared thermography and by rapid deflection measurements at the center of panel, leading to an evaluation of the pressure exercised by the arc at the attachment point
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Hameurlaine, Kheira. "Contribution à l'étude d'un arc électrique de faible puissance." Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00821030.

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L'étude présentée ici entre dans la problématique générale des arcs électriques intervenant dans des applications industrielles telles que le soudage, le découpage, le traitement des déchets. Ce travail constitue une première phase de modélisation de cette étude générale. Le plasma est décrit par un ensemble d'équations de conservation de fluide et de l'électromagnétisme, complétés par des propriétés thermodynamiques et des coefficients de transport appropriés, en formant un système d'équations non linéaires fortement couplées. Ces équations sont écrites en supposant l'équilibre thermodynamique local, une symétrie cylindrique et un écoulement laminaire stationnaire. Ce système d'équations est résolu à l'aide du logiciel commercial FLUENT de type CFD fondé sur l'approche des volumes finis. Pour pouvoir utiliser la partie solveur nous avons résolu notre modèle en utilisant les routines UDF Users-Defined-Function. Dans une première partie, nous présentons la validation du modèle à deux dimensions et à 100 A dans l'argon par des résultats de la littérature. Cette comparaison laisse apparaître un accord satisfaisant sur les profils de température dans la colonne de plasma et des différences dans les zones proches des électrodes dues aux conditions aux limites. Dans une deuxième partie, nous présentons une étude expérimentale, à l'issue de laquelle on constate que les profils de température expérimentaux sont en accord avec ceux du modèle dans la zone de colonne positive.
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Trenty, Laurent. "Modélisation du chauffage de bains métalliques par un plasma d'arc transféré." Châtenay-Malabry, Ecole centrale de Paris, 1997. http://www.theses.fr/1997ECAP0510.

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L'objet de la thèse est le développement d'un modèle numérique bidimensionnel de simulation du chauffage d'un bain métallique anodique par un plasma d'arc transféré. La configuration retenue est proche de celle du four à arc transféré de petite capacité (200kw - 2000a, 40 litres) développé au laboratoire plasma d'EDF-der aux renardières pour étudier les transferts thermiques dans ce type de chauffage. Le modèle permet le calcul des différents champs (vitesse, température, turbulence, électromagnétique) dans la région de l'arc électrique, dans le bain et dans l'électrode de sole. Les équations de Navier-Stokes couplées aux équations de l'électromagnétisme sont résolues dans chaque domaine par une méthode numérique aux différences finies ou volumes finis à pas fractionnaires. Pour le calcul de l'arc, les transferts radiatifs sont également calcules ainsi que le transport des vapeurs métalliques et leurs effets sur les propriétés du plasma. Un modèle monodimensionnel spécifique est utilise pour la modélisation de la couche limite anodique au-dessus du bain. Le couplage du calcul arc avec le calcul du bain est assure par des conditions aux limites a l'interface. Deux cas de longueur d'arc, 0,15m et 0,25m, ont été traites. Les résultats seront présentés et comparés avec des mesures de flux effectuées sur le four dans des conditions similaires.
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Fleury, Emmanuel. "Etude d'un plasma de méthane en atmosphère non oxydante." Rouen, 1988. http://www.theses.fr/1988ROUES004.

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Analyse spectrale de l'arc de 1 à 10 µm. Une étude en chromatographie en phase gazeuse a permis de mesurer la concentration des espèces stables générées par le plasma. L'étude du spectre visible permet une estimation de l'état d'excitation du plasma en particulier par l'étude des bandes de Swann de C2
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Lu, Jingjing. "Caractérisation du comportement du plasma dans un disjoncteur basse tension par le développement d'un outil numérique et d'expériences associées." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30154.

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Les processus liés à la segmentation de l'arc et à la quantification des chutes de tension additionnelles sont les phénomènes prépondérants à la compréhension et à l'optimisation des Disjoncteurs Basse Tension (DBT). Le but de nos travaux est d'appréhender leurs comportements par l'expérience et leurs représentations par l'outil numérique. Pour cela une modélisation magnétohydrodynamique tridimensionnelle (3D) est réalisée sur une géométrie simplifiée de DBT. Les développements sont basés sur le code commercial Ansys @Fluent agrémenté d'UDF (User Define Functions). Afin d'étudier et d'isoler les mécanismes, les travaux expérimentaux et numériques sont réalisés sur une maquette simplifiée constituée de deux électrodes en parallèle et de la présence optionnelle de séparateurs. Numériquement la tension additionnelle, provenant de la présence des gaines aux interfaces plasma/matériau, est prise en compte par une méthode approchée basée sur la caractéristique théorique d'une variation de la tension en fonction de la densité de courant. Cette résistivité additionnelle permet une représentation du passage du courant vers les matériaux et du retard à la commutation sur le séparateur en fonction de la chute de tension. Les travaux ont été menés entre deux rails en utilisant un et deux séparateurs. Côté expérimental, le comportement de l'arc est caractérisé par des mesures électriques (Tension, courant) et par des acquisitions de la caméra rapide. L'amorçage de l'arc est initié par un fil fusible en cuivre de 0.1 mm. La géométrie étudiée peut être plus ou moins fermée à ses extrémités afin de mettre en évidence les effets des forces de pression et/ou des forces de Lorentz. Une bonne analogie de la description du comportement de l'arc est retrouvée entre les résultats du modèle et les résultats expérimentaux. Cependant les conditions initiales du modèle s'avèrent prépondérantes et dans les mêmes temps délicats à déterminer
The arc splitting process and the quantification of additional voltage drops are the major phenomena to understand and to optimize the Low Voltage Circuit Breaker (LVCB). The aim of our work is to understand their behavior through experiments and then their representation by our model. Therefore, a three-dimensional (3D) magnetohydrodynamic modeling is carried out on a simplified LVCB geometry. The developments are based on the commercial code Ansys @Fluent with UDF (User Define Functions). The plasma is described by fluid equations and a finite volume method. To study and isolate the mechanisms, the experimental and numerical work were realized on a simplified geometry, composed by two parallel electrodes with or without splitter plates. Numerically, the additional voltage resulting from the sheaths at the plasma/material interfaces, is considered by an approximate method based on the theoretical characteristic of voltage variation, as the function of current density. This additional resistivity allows to present the current flow in the materials and create some delay at the switching during the splitting process. Further to the experiments, the arc behavior is characterized by electrical measurements (Voltage, current) and by high-speed camera. The arc ignition is realized by a copper fuse of 0.1 mm. The geometry can be more or less closed at its both extremities in order to highlight the effects of pressure force and/or Lorentz force. The description of arc behavior was found similar between the simulation and experiments results. However, the initial conditions of our model proved to be preponderate while at the same time, the conditions remained delicate to determine
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Books on the topic "Electric Arc Plasma"

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Aubrecht, V. Spectral and equidensitometry diagnostics of electric arc plasma. Tomsk: Tomsk Polytechnical Univ., 1999.

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Krouchinin, Anatoli M. Modelling of the constricted arc in plasma generators. Częstochowa: Publishing Office of Czestochowa University of Technology, 2005.

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Aubrecht, V. Radiative transport of energy in SF₆ arc plasma. Tomsk: [s.n], 2000.

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Zhukov, M. F., and I. M. Zasypkin. Ėlektrodugovye generatory termicheskoĭ plazmy. Novosibirsk: "Nauka", 1999.

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Montgomery, R. W. The use of plasma torches for auxiliary heating in an electric arc furnace. Luxembourg: Commission of the European Communities, 1985.

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M, Oks E., and Brown Ian G, eds. Emerging applications of vacuum-arc-produced plasma, ion, and electron beams. Dordrecht: Kluwer Academic Publishers, 2003.

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International Power Beam Conference (1988 San Diego, Calif.). Power beam processing: Electron, laser, plasma-arc : proceedings of the International Power Beam Conference, 2-4 May 1988, San Diego, California, USA. [Metals Park, Ohio]: ASM International, 1988.

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Cyclic plasticity and low cycle fatigue life of metals. Amsterdam: Elsevier, 1991.

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NCCER. 29103-09 Plasma Arc Cutting. Pearson Education, Limited, 2014.

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NCCER. 29205-03 Plasma Arc Cutting (PAC) IG. Pearson Education, Limited, 2003.

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Book chapters on the topic "Electric Arc Plasma"

1

Younian, Wang, and Ma Tengcai. "Investigation of Electric Conductivity of Plasma in Magnetic Rotating Arc." In Plasma Jets in the Development of New Materials Technology, 27–32. London: CRC Press, 2023. http://dx.doi.org/10.1201/9780429070938-4.

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Yasko, O. I., L. I. Sharakhovsky, and L. P. Podenok. "Heat Treatment of a Surface with a Vortex – Stabilized Electric ARC." In Plasma Jets in the Development of New Materials Technology, 539–41. London: CRC Press, 2023. http://dx.doi.org/10.1201/9780429070938-51.

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Dong, Qipeng, and Jiongming Zhang. "Simulation of Fluid Flow and Heat Transfer in Plasma ARC Region of AC Electric ARC Furnace." In CFD Modeling and Simulation in Materials Processing 2016, 35–42. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119274681.ch5.

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Dong, Qipeng, and Jiongming Zhang. "Simulation of Fluid Flow and Heat Transfer in Plasma Arc Region of AC Electric Arc Furnace." In The Minerals, Metals & Materials Series, 35–42. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-65133-0_5.

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Wescott, E. M. "The Electric Field Structure of Auroral Arcs as Determined from Barium Plasma Injection Experiments." In Physics of Auroral Arc Formation, 175–84. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm025p0175.

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Jainakov, A., J. O. Usenkanov, T. R. Dzhumaliev, and S. Kydyraliev. "Study of Electric Arc Plasma Flow in Transition Region from Laminar to Turbulent Current." In Plasma Jets in the Development of New Materials Technology, 17–25. London: CRC Press, 2023. http://dx.doi.org/10.1201/9780429070938-3.

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Desyatkov, G. A., V. S. Engelsht, V. Ts Gurovich, N. U. Musin, G. M. Okopnik, A. N. Saichenko, and V. L. Spektorov. "High-Voltage Electric Arc as the Source for Ignition of Air-Dispersed Fuel Flows." In Plasma Jets in the Development of New Materials Technology, 499–509. London: CRC Press, 2023. http://dx.doi.org/10.1201/9780429070938-47.

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Beilis, Isak. "Vacuum Arc Ignition. Electrical Breakdown." In Plasma and Spot Phenomena in Electrical Arcs, 143–64. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44747-2_6.

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Beilis, Isak. "Vacuum Arc Plasma Sources. Thin Film Deposition." In Plasma and Spot Phenomena in Electrical Arcs, 933–1001. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44747-2_22.

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Galonska, M., F. Heymach, R. Hollinger, and P. Spädtke. "Vacuum Arc Ion Sources: Charge State Enhancement and Arc Voltage." In Emerging Applications of Vacuum-Arc-Produced Plasma, Ion and Electron Beams, 123–30. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0277-6_12.

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Conference papers on the topic "Electric Arc Plasma"

1

Karpov, Dmitriy A., and S. N. Nazikov. "Multicomponent electric-arc source of metallic plasma." In Shanghai - DL tentative, edited by Shixun Zhou and Yongling Wang. SPIE, 1991. http://dx.doi.org/10.1117/12.47293.

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SHEPARD, CHARLES, FRANK MILOS, and JASWINDER TAUNK. "A sonic flow equation for electric arc jets." In 24th Plasma Dynamics, and Lasers Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1993. http://dx.doi.org/10.2514/6.1993-3183.

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Roychoudhury, Subhasish. "Simulation of plasma-dynamic processes in electric arc." In 38th Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2000. http://dx.doi.org/10.2514/6.2000-1070.

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Raniszewski, G., Z. Kolacinski, and L. Szymanski. "Influence of mineral components on electric arc plasma parameters." In 2009 IEEE 36th International Conference on Plasma Science (ICOPS). IEEE, 2009. http://dx.doi.org/10.1109/plasma.2009.5227623.

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Meshcheryakov, V. N., V. V. Pikalov, A. M. Evseev, O. V. Danilova, and S. K. Ambrosimov. "Electric Arc Plasma Installation with Control Information-Measuring System." In 2019 1st International Conference on Control Systems, Mathematical Modelling, Automation and Energy Efficiency (SUMMA). IEEE, 2019. http://dx.doi.org/10.1109/summa48161.2019.8947588.

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Bussiere, William, David Rochette, Pascal Andre, Gerard Velleaud, and Steeve Memiaghe. "Study of the SIO2 plasma radiation. application to the fuse arc plasma." In 2007 8th International Conference on Electric Fuses and their Applications. IEEE, 2007. http://dx.doi.org/10.1109/icefa.2007.4419975.

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An, L. T., and Y. Gao. "Electric Characteristics of Plasma Arc Produced by Bi-Anode Torch." In ITSC2009, edited by B. R. Marple, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and G. Montavon. ASM International, 2009. http://dx.doi.org/10.31399/asm.cp.itsc2009p1122.

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Abstract This paper discusses the double-arc phenomenon that occurs in plasma arc spraying and its prevention through the use of a bi-anode torch. It also presents the results of a study that compares voltage-current characteristics of the arc for different plasma gases and arc root attachment points. It is shown that the arc has different electrical characteristics when changing from the first to the second anode, which is explained using a simplified arc model.
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Deblauw, Bradley, Eli Lazar, Nachiket Kale, Nick Glumac, Craig Dutton, and Greg Elliott. "Flow and Thermal Properties Induced by Electric Arc Plasma Actuators." In 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2011. http://dx.doi.org/10.2514/6.2011-734.

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Burkat, D., F. Aristizabal, and S. Coulombe. "High-speed imaging and electrical diagnostics of interacting arcs in dual-cathode electric arc furnace." In 2016 IEEE International Conference on Plasma Science (ICOPS). IEEE, 2016. http://dx.doi.org/10.1109/plasma.2016.7534013.

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Peng Sun and Ruxv Xie. "Numerical simulation of large-current vacuum arc plasma." In 2011 1st International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST). IEEE, 2011. http://dx.doi.org/10.1109/icepe-st.2011.6123043.

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Reports on the topic "Electric Arc Plasma"

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Yermiyahu, Uri, Thomas Kinraide, and Uri Mingelgrin. Role of Binding to the Root Surface and Electrostatic Attraction in the Uptake of Heavy Metal by Plants. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7586482.bard.

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The principal accomplishment of the research supported by BARD was progress toward a comprehensive view of cell-surface electrical effects (both in cell walls [CWs] and at plasma membrane [PM] surfaces) upon ion uptake, intoxication, and amelioration. The research confirmed that electrostatic models (e.g., Gouy-Chapman-Stern [G-C-S]), with parameter values contributed by us, successfully predict ion behavior at cell surfaces. Specific research objectives 1. To characterize the sorption of selected heavy metals (Cu, Zn, Pb, Cd) to the root PM in the presence of other cations and organic ligands (citric and humic acids). 2. To compute the parameters of a G-C-S model for heavy-metal sorption to the root PM. 3. To characterize the accumulation of selected heavy metals in various plant parts. 4. To determine whether model-computed ion binding or ion activities at root PM surfaces predict heavy-metal accumulation in whole roots, root tips, or plant shoots. 5. To determine whether measured ion binding by protoplast-free roots (i.e., root CWs) predicts heavy-metal accumulation in whole roots, root tips, or plant shoots. 6. To correlate growth inhibition, and other toxic responses, with the measured and computed factors mentioned above. 7. To determine whether genotypic differences in heavy-metal accumulation and toxic responses correlate with genotypic differences in parameters of the G-C-S model. Of the original objectives, all except for objective 7 were met. Work performed to meet the other objectives, and necessitated on the basis of experimental findings, took the time that would have been required to meet objective 7. In addition, work with Pb was unsuccessful due to experimental complications and work on Cd is still in progress. On the other hand, the uptake and toxicity of the anion, selenate was characterized with respect to electrostatic effects and the influences of metal cations. In addition, the project included more theoretical work, supported by experimentation, than was originally planned. This included transmembrane ion fluxes considered in terms of PM-surface electrical potentials and the influence of CWs upon ion concentrations at PM surfaces. A important feature of the biogeochemistry of trace elements in the rhizosphere is the interaction between plant-root surfaces and the ions present in the soil solution. The ions, especially the cations, of the soil solution may be accumulated in the aqueous phases of cell surfaces external to the PMs, sometimes referred to as the "water free space" and the "Donnan free space". In addition, ions may bind to the CW components or to the PM surface with variable binding strength. Accumulation at the cell surface often leads to accumulation in other plant parts with implications for the safety and quality of foods. A G-C-S model for PMs and a Donnan-plus-binding model for CWs were used successfully to compute electrical potentials, ion binding, and ion concentration at root-cell surfaces. With these electrical potentials, corresponding values for ion activities may be computed that are at least proportional to actual values also. The computed cell-surface ion activities predict and explain ion uptake, intoxication, and amelioration of intoxication much more accurately than ion activities in the bulk-phase rooting medium.
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Elbaum, Michael, and Peter J. Christie. Type IV Secretion System of Agrobacterium tumefaciens: Components and Structures. United States Department of Agriculture, March 2013. http://dx.doi.org/10.32747/2013.7699848.bard.

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Objectives: The overall goal of the project was to build an ultrastructural model of the Agrobacterium tumefaciens type IV secretion system (T4SS) based on electron microscopy, genetics, and immunolocalization of its components. There were four original aims: Aim 1: Define the contributions of contact-dependent and -independent plant signals to formation of novel morphological changes at the A. tumefaciens polar membrane. Aim 2: Genetic basis for morphological changes at the A. tumefaciens polar membrane. Aim 3: Immuno-localization of VirB proteins Aim 4: Structural definition of the substrate translocation route. There were no major revisions to the aims, and the work focused on the above questions. Background: Agrobacterium presents a unique example of inter-kingdom gene transfer. The process involves cell to cell transfer of both protein and DNA substrates via a contact-dependent mechanism akin to bacterial conjugation. Transfer is mediated by a T4SS. Intensive study of the Agrobacterium T4SS has made it an archetypal model for the genetics and biochemistry. The channel is assembled from eleven protein components encoded on the B operon in the virulence region of the tumor-inducing plasmid, plus an additional coupling protein, VirD4. During the course of our project two structural studies were published presenting X-ray crystallography and three-dimensional reconstruction from electron microscopy of a core complex of the channel assembled in vitro from homologous proteins of E. coli, representing VirB7, VirB9, and VirB10. Another study was published claiming that the secretion channels in Agrobacterium appear on helical arrays around the membrane perimeter and along the entire length of the bacterium. Helical arrangements in bacterial membranes have since fallen from favor however, and that finding was partially retracted in a second publication. Overall, the localization of the T4SS within the bacterial membranes remains enigmatic in the literature, and we believe that our results from this project make a significant advance. Summary of achievements : We found that polar inflations and other membrane disturbances relate to the activation conditions rather than to virulence protein expression. Activation requires low pH and nutrient-poor medium. These stress conditions are also reflected in DNA condensation to varying degrees. Nonetheless, they must be considered in modeling the T4SS as they represent the relevant conditions for its expression and activity. We identified the T4SS core component VirB7 at native expression levels using state of the art super-resolution light microscopy. This marker of the secretion system was found almost exclusively at the cell poles, and typically one pole. Immuno-electron microscopy identified the protein at the inner membrane, rather than at bridges across the inner and outer membranes. This suggests a rare or transient assembly of the secretion-competent channel, or alternatively a two-step secretion involving an intermediate step in the periplasmic space. We followed the expression of the major secreted effector, VirE2. This is a single-stranded DNA binding protein that forms a capsid around the transferred oligonucleotide, adapting the bacterial conjugation to the eukaryotic host. We found that over-expressed VirE2 forms filamentous complexes in the bacterial cytoplasm that could be observed both by conventional fluorescence microscopy and by correlative electron cryo-tomography. Using a non-retentive mutant we observed secretion of VirE2 from bacterial poles. We labeled the secreted substrates in vivo in order detect their secretion and appearance in the plant cells. However the low transfer efficiency and significant background signal have so far hampered this approach.
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Van Rijn, Jaap, Harold Schreier, and Yossi Tal. Anaerobic ammonia oxidation as a novel approach for water treatment in marine and freshwater aquaculture recirculating systems. United States Department of Agriculture, December 2006. http://dx.doi.org/10.32747/2006.7696511.bard.

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Ammonia waste removal in recirculating aquaculture systems is typically accomplished via the action of nitrifying bacteria in specially designed biofilters that oxidize ammonia to produce nitrate. In the majority of these systems nitrate is discharged to the environment through frequent water exchanges. As environmental considerations have made it necessary to eliminate nitrate release, new strategies for nitrate consumption are being developed. In the funding period we showed that ammonia removal from wastewater could take place by an anaerobic ammonia oxidation process carried out by bacterial Planctomycetessp. Referred to as “anammox”, this process occurs in the absence of an organic source and in the presence of nitrite (or nitrate) as an electron acceptor as follows: NH₃ + HNO₂ -> N₂ + 2H₂O. Annamox has been estimated to result in savings of up to 90% of the costs associated with was wastewater treatment plants. Our objective was to study the applicability of the anammox process in a variety of recirculating aquaculture systems to determine optimal conditions necessary for efficient ammonia waste removal. Both seawater and freshwater systems operated with either conventional aerobic treatment of ammonia to nitrate (USA) or, in addition, denitrifying biofilters as well as anaerobic digestion of sludge (Israel) were tested. Molecular tools were used to screen and monitor different treatment compartments for the presence of Planctomycetes. Optimal conditions for the enrichment of the anammox bacteria were tested using laboratory scale biofilters as well as a semi-commercial system. Enrichment studies resulted in the isolation of some unique heterotrophic bacteria capable of plasmid-mediated autotrophic growth in the presence of ammonia and nitrite. Our studies have not only demonstrated the presence and viability of Planctomycetes spp. in recirculating marine and freshwater systems biofilter units but also demonstrated the applicability of the anammox process in these systems. Using our results we have developed treatment schemes that have allowed for optimizing the anammox process and applying it to recirculating systems.
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Ohad, Itzhak, and Himadri Pakrasi. Role of Cytochrome B559 in Photoinhibition. United States Department of Agriculture, December 1995. http://dx.doi.org/10.32747/1995.7613031.bard.

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The aim of this research project was to obtain information on the role of the cytochrome b559 in the function of Photosystem-II (PSII) with special emphasis on the light induced photo inactivation of PSII and turnover of the photochemical reaction center II protein subunit RCII-D1. The major goals of this project were: 1) Isolation and sequencing of the Chlamydomonas chloroplast psbE and psbF genes encoding the cytochrome b559 a and b subunits respectively; 2) Generation of site directed mutants and testing the effect of such mutation on the function of PSII under various light conditions; 3) To obtain further information on the mechanism of the light induced degradation and replacement of the PSII core proteins. This information shall serve as a basis for the understanding of the role of the cytochrome b559 in the process of photoinhibition and recovery of photosynthetic activity as well as during low light induced turnover of the D1 protein. Unlike in other organisms in which the psbE and psbF genes encoding the a and b subunits of cytochrome b559, are part of an operon which also includes the psbL and psbJ genes, in Chlamydomonas these genes are transcribed from different regions of the chloroplast chromosome. The charge distribution of the derived amino-acid sequences of psbE and psbF gene products differs from that of the corresponding genes in other organisms as far as the rule of "positive charge in" is concerned relative to the process of the polypeptide insertion in the thylakoid membrane. However, the sum of the charges of both subunits corresponds to the above rule possibly indicating co-insertion of both subunits in the process of cytochrome b559 assembly. A plasmid designed for the introduction of site-specific mutations into the psbF gene of C. reinhardtii. was constructed. The vector consists of a DNA fragment from the chromosome of C. reinhardtii which spans the region of the psbF gene, upstream of which the spectinomycin-resistance-conferring aadA cassette was inserted. This vector was successfully used to transform wild type C. reinhardtii cells. The spectinomycin resistant strain thus obtained can grow autotrophically and does not show significant changes as compared to the wild-type strain in PSII activity. The following mutations have been introduced in the psbF gene: H23M; H23Y; W19L and W19. The replacement of H23 involved in the heme binding to M and Y was meant to permit heme binding but eventually alter some or all of the electron transport properties of the mutated cytochrome. Tryptophane W19, a strictly conserved residue, is proximal to the heme and may interact with the tetrapyrole ring. Therefore its replacement may effect the heme properties. A change to tyrosine may have a lesser affect on the potential or electron transfer rate while a replacement of W19 by leucine is meant to introduce a more prominent disturbance in these parameters. Two of the mutants, FW19L and FH23M have segregated already and are homoplasmic. The rest are still grown under selection conditions until complete segregation will be obtained. All mutants contain assembled and functional PSII exhibiting an increased sensitivity of PSII to the light. Work is still in progress for the detailed characterization of the mutants PSII properties. A tobacco mutant, S6, obtained by Maliga and coworkers harboring the F26S mutation in the b subunit was made available to us and was characterized. Measurements of PSII charge separation and recombination, polypeptide content and electron flow indicates that this mutation indeed results in light sensitivity. Presently further work is in progress in the detailed characterization of the properties of all the above mutants. Information was obtained demonstrating that photoinactivation of PSII in vivo initiates a series of progressive changes in the properties of RCII which result in an irreversible modification of the RCII-D1 protein leading to its degradation and replacement. The cleavage process of the modified RCII-D1 protein is regulated by the occupancy of the QB site of RCII by plastoquinone. Newly synthesized D1 protein is not accumulated in a stable form unless integrated in reassembled RCII. Thus the degradation of the irreversibly modified RCII-D1 protein is essential for the recovery process. The light induced degradation of the RCII-D1 protein is rapid in mutants lacking the pD1 processing protease such as in the LF-1 mutant of the unicellular alga Scenedesmus obliquus. In this case the Mn binding site of PSII is abolished, the water oxidation process is inhibited and harmful cation radicals are formed following light induced electron flow in PSII. In such mutants photo-inactivation of PSII is rapid, it is not protected by ligands binding at the QB site and the degradation of the inactivated RCII-D1 occurs rapidly also in the dark. Furthermore the degraded D1 protein can be replaced in the dark in absence of light driven redox controlled reactions. The replacement of the RCII-D1 protein involves the de novo synthesis of the precursor protein, pD1, and its processing at the C-terminus end by an unknown processing protease. In the frame of this work, a gene previously isolated and sequenced by Dr. Pakrasi's group has been identified as encoding the RCII-pD1 C-terminus processing protease in the cyanobacterium Synechocystis sp. PCC 6803. The deduced sequence of the ctpA protein shows significant similarity to the bovine, human and insect interphotoreceptor retinoid-binding proteins. Results obtained using C. reinhardtii cells exposes to low light or series of single turnover light flashes have been also obtained indicating that the process of RCII-D1 protein turnover under non-photoinactivating conditions (low light) may be related to charge recombination in RCII due to back electron flow from the semiquinone QB- to the oxidised S2,3 states of the Mn cluster involved in the water oxidation process.
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