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ABB Ltd

CompanyZurich, Switzerland
About: ABB Ltd is a company organization based out in Zurich, Switzerland. It is known for research contribution in the topics: Fault (power engineering) & Voltage. The organization has 6222 authors who have published 6852 publications receiving 83994 citations.


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Journal ArticleDOI
TL;DR: The Ginzburg number as discussed by the authors was introduced to account for thermal and quantum fluctuations and quenched disorder in high-temperature superconductors, leading to interesting effects such as melting of the vortex lattice, the creation of new vortex-liquid phases, and the appearance of macroscopic quantum phenomena.
Abstract: With the high-temperature superconductors a qualitatively new regime in the phenomenology of type-II superconductivity can be accessed. The key elements governing the statistical mechanics and the dynamics of the vortex system are (dynamic) thermal and quantum fluctuations and (static) quenched disorder. The importance of these three sources of disorder can be quantified by the Ginzburg number $Gi=\frac{{(\frac{{T}_{c}}{{H}_{c}^{2}}\ensuremath{\varepsilon}{\ensuremath{\xi}}^{3})}^{2}}{2}$, the quantum resistance $Qu=(\frac{{e}^{2}}{\ensuremath{\hbar}})(\frac{{\ensuremath{\rho}}_{n}}{\ensuremath{\varepsilon}\ensuremath{\xi}})$, and the critical current-density ratio $\frac{{j}_{c}}{{j}_{o}}$, with ${j}_{c}$ and ${j}_{o}$ denoting the depinning and depairing current densities, respectively (${\ensuremath{\rho}}_{n}$ is the normal-state resistivity and ${\ensuremath{\varepsilon}}^{2}=\frac{m}{M}l1$ denotes the anisotropy parameter). The material parameters of the oxides conspire to produce a large Ginzburg number $\mathrm{Gi}\ensuremath{\sim}{10}^{\ensuremath{-}2}$ and a large quantum resistance $\mathrm{Qu}\ensuremath{\sim}{10}^{\ensuremath{-}1}$, values which are by orders of magnitude larger than in conventional superconductors, leading to interesting effects such as the melting of the vortex lattice, the creation of new vortex-liquid phases, and the appearance of macroscopic quantum phenomena. Introducing quenched disorder into the system turns the Abrikosov lattice into a vortex glass, whereas the vortex liquid remains a liquid. The terms "glass" and "liquid" are defined in a dynamic sense, with a sublinear response $\ensuremath{\rho}={\frac{\ensuremath{\partial}E}{\ensuremath{\partial}j}|}_{j\ensuremath{\rightarrow}0}$ characterizing the truly superconducting vortex glass and a finite resistivity $\ensuremath{\rho}(j\ensuremath{\rightarrow}0)g0$ being the signature of the liquid phase. The smallness of $\frac{{j}_{c}}{{j}_{o}}$ allows one to discuss the influence of quenched disorder in terms of the weak collective pinning theory. Supplementing the traditional theory of weak collective pinning to take into account thermal and quantum fluctuations, as well as the new scaling concepts for elastic media subject to a random potential, this modern version of the weak collective pinning theory consistently accounts for a large number of novel phenomena, such as the broad resistive transition, thermally assisted flux flow, giant and quantum creep, and the glassiness of the solid state. The strong layering of the oxides introduces additional new features into the thermodynamic phase diagram, such as a layer decoupling transition, and modifies the mechanism of pinning and creep in various ways. The presence of strong (correlated) disorder in the form of twin boundaries or columnar defects not only is technologically relevant but also provides the framework for the physical realization of novel thermodynamic phases such as the Bose glass. On a macroscopic scale the vortex system exhibits self-organized criticality, with both the spatial and the temporal scale accessible to experimental investigations.

4,502 citations

Journal ArticleDOI
TL;DR: In this paper, the nature of the silent discharge (dielectric barrier discharge) is reviewed and theoretical models for describing its discharge physics and ensuing plasma chemistry are presented, and the phenomena leading to gas breakdown in such electrode configurations at about atmospheric pressure are discussed.
Abstract: The nature of the silent discharge (dielectric barrier discharge) is reviewed. Theoretical models for describing its discharge physics and ensuing plasma chemistry are presented. The phenomena leading to gas breakdown in such electrode configurations at about atmospheric pressure are discussed. The current transport takes place within a large numer of short-lived microdischarges, the plasma conditions of which are investigated. The theoretical predictions are compared to measurements. Two entirely different applications of silent discharges are treated: industrial ozone production and the formation of excimers to generate ultraviolet radiation. The special capability of the silent discharge for large-scale industrial processing is demonstrated. >

813 citations

Journal ArticleDOI
TL;DR: In this paper, a review of plasma chemical processes occurring in the volume part of electrical nonequilibrium discharges is presented, where the role of energetic electrons as initiators of chemical reactions in a cold background gas is discussed.
Abstract: A review is presented of plasma chemical processes occurring in the volume part of electrical nonequilibrium discharges. The role of energetic electrons as initiators of chemical reactions in a cold background gas is discussed. Different discharge types of (glow, corona, silent, RF, and microwave discharges) are investigated with respect to their suitability for plasma processing. Emphasis is placed on the requirements of initiating and maintaining the discharge and, at the same time, optimizing plasma parameters for the desired chemical process. Using large-scale industrial ozone production as an example, the detailed process of discharge optimization is described. Other applications of volume plasma processing include other plasma chemical syntheses as well as decomposition processes such as flue gas treatment and hazardous waste disposal. The author only deals with plasmas which are not in equilibrium. >

771 citations

Journal ArticleDOI
TL;DR: An overview of high voltage direct current systems and applications is presented in this paper, where the favorable economics of long-distance bulk-power transmission with HVDC together with its controllability make it an interesting alternative or complement to AC transmission.
Abstract: An overview of high voltage direct current systems and applications is presented in this paper. The favorable economics of long-distance bulk-power transmission with HVDC together with its controllability make it an interesting alternative or complement to AC transmission. The higher voltage levels, mature technology, and new converter designs have significantly increased the interest in HVDC transmission and expanded the range of applications

705 citations

Journal ArticleDOI
TL;DR: The two main advantages of catalytic combustors over flame combustors apply to these goals: Catalytic combustion can be carried out over a wide range of fuel concentrations in air and at low temperatures as mentioned in this paper.
Abstract: Catalytic combustion, as an alternative to conventional thermal combustion, has received considerable attention during the past decade. Research efforts have been promoted by the need to meet governmental demands concerning pollution and the wish to use energy sources more efficiently. The two main advantages offered by catalytic combustors over flame combustors apply to these goals: Catalytic combustion can be carried out over a wide range of fuel concentrations in air and at low temperatures. These low temperatures result in attaining NO, emission levels substantially lower than possible with conventional combustors.

626 citations


Authors

Showing all 6228 results

NameH-indexPapersCitations
Johann W. Kolar9796536902
Stefan Karlsson7029219180
Rüdiger Kötz6319517364
Erik Janzén5868214357
Peter J. Uggowitzer5733811393
Rolando Burgos5547113606
Fangxing Li5540211226
Ming Li485918784
Gianni Blatter4627712191
A. I. Larkin4622117156
Vladimir Terzija453578170
Mats Leijon412957355
Wolfgang Polifke403365746
Thomas Sattelmayer404866387
Thierry Meynard402469625
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20231
202211
202158
202057
201969
201898