897 research outputs found

    Tungsten divertor sources in WEST related to impurity inventory and local plasma conditions

    Get PDF
    A dedicated series of L-mode deuterium discharges were performed in WEST in which a broad parameter space in terms of divertor plasma temperature (inner divertor at &lt;10 eV, outer divertor up to 50 eV) and impurity flux density was achieved by variation of X point elevation, upstream plasma density and fuelling position and rate. Density steps provided stable reference plasma conditions whilst density scans up to the point of detachment revealed the sputtering threshold behaviour of the dominant sputtering species. Tungsten gross erosion was quantified via the common WI 400.9 nm line and correlated with the residual gas content.</p

    Efficient generation of energetic ions in multi-ion plasmas by radio-frequency heating

    Get PDF
    We describe a new technique for the efficient generation of high-energy ions with electromagnetic ion cyclotron waves in multi-ion plasmas. The discussed ‘three-ion’ scenarios are especially suited for strong wave absorption by a very low number of resonant ions. To observe this effect, the plasma composition has to be properly adjusted, as prescribed by theory. We demonstrate the potential of the method on the world-largest plasma magnetic confinement device, JET (Joint European Torus, Culham, UK), and the high-magnetic-field tokamak Alcator C-Mod (Cambridge, USA). The obtained results demonstrate efficient acceleration of 3He ions to high energies in dedicated hydrogen–deuterium mixtures. Simultaneously, effective plasma heating is observed, as a result of the slowing-down of the fast 3He ions. The developed technique is not only limited to laboratory plasmas, but can also be applied to explain observations of energetic ions in space-plasma environments, in particular, 3He-rich solar flares.This paper is dedicated to the late P. E. M. Vandenplas, founder and first director of LPP-ERM/KMS, in recognition of his lifelong outstanding commitment to fusion research, in particular to ICRH. The support from the JET and Alcator C-Mod Teams is warmly acknowledged. We are grateful to A. Cardinali, C. Castaldo, R. Dumont, J. Eriksson, T. FĂŒlöp, C. Giroud, C. Hellesen, S. Menmuir and M. Schneider for fruitful discussions. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement no. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work was also supported by the US DoE, Office of Science, Office of Fusion Energy Sciences, SciDAC Center for Simulation of Wave Plasma Interactions under DE-FC02-01ER54648 and the User Facility Alcator C-Mod under DE-FC02-99ER54512. The Alcator C-Mod Team author list is reproduced from ref. 12. The JET Contributors author list is reproduced from ref. 33.Peer ReviewedPostprint (author's final draft

    Über den Zusammenhang von Kommunikation und Lernen im schulischen Kontext. Ein Modell Kommunikationsorientierter Schulsozialarbeit auf der Grundlage der Gewaltfreien Kommunikation von Marshall B. Rosenberg

    Full text link
    Zum ersten geht es um die Leitfrage, wie Schulsozialarbeit dazu beitragen kann, dass Schulbildung nicht nur fĂŒr einen anpassungsbereiten Teil der SchĂŒler/innen Teilhabe befördert, sondern auch diejenigen erreicht, die dazu neigen, sich von ihr abzuwenden. HierfĂŒr wird im ersten Teil der Arbeit zunĂ€chst untersucht, wie Lernen aus neurobiologischer, pĂ€dagogischer und psychologischer Perspektive verstanden werden kann, welche Faktoren Lernprozesse begĂŒnstigen bzw. hemmen und wie die subjektive TĂ€tigkeit des Lernens auf schulisch-gesellschaftlicher Ebene in einen Kanon des Lernens einfließt. In den beiden darauffolgenden Kapiteln werden zunĂ€chst wesentliche Aspekte der zwischenmenschlichen Kommunikation mit Bezug auf psychologisch-soziologische Kommunikationstheorien umrissen und anschließend zu dem Sachverhalt ĂŒbergeleitet, dass jedes Lernen immer auch eine komplexe Kommunikationsleistung ist. Neben der Relevanz, Kommunikation in der Schule zu thematisieren, wird darin ebenso aufgezeigt, an welcher Stelle der Kommunikationsbegriff in der Schul- und SozialpĂ€dagogik an eine Grenze gelangt. Innerhalb der zweiten Kernfrage wird betrachtet, wie eine Kooperation von Schule und Jugendhilfe idealer Weise aussehen könnte, in der die wissenschaftlichen Erkenntnissen zu LernverlĂ€ufen offensiv einbezogen werden. Dem liegt eine Analyse des deutschen allgemeinbildenden Schulwesens zu Grunde. Hierin wird die Schulpflicht und auch die SelektivitĂ€t, welche mit der EinfĂŒhrung verschiedener Schulformen einhergeht, in deren historischen Wurzeln betrachtet, worin einzelne Wellen der Bildungsreformen ersichtlich werden. Vertiefend dazu wird aufgezeigt, welche Faktoren Bildungsreformen begĂŒnstigten bzw. hervorriefen und welche KrĂ€fte dem horizontalen Schulwesen in Deutschland und damit der Verringerung des selektiven Gehalts von Schule, entgegen wirkten. Denn Inklusionsleistungen, zu denen Schulsozialarbeit unter anderem berufen ist, finden keinen Bedarf, wenn nicht vorher eine Exklusion stattfand. Welche Möglichkeiten Schulsozialarbeit fĂŒr allgemeinbildende Schulen dahingehend eröffnen kann, sich inhaltlich und methodisch anzureichern, weiterzuentwickeln, zu öffnen und zu vernetzen, sowie ein Blick auf die Herausforderungen fĂŒr eine gegenseitig integrierende Kooperation, wird im darauffolgenden Teil, im Hinblick auf eine Charakterisierung von Schulsozialarbeit aufgezeigt. Dem folgt ein Einblick in das Konzept der Gewaltfreien Kommunikation, und daran anschließend ein Rahmenkonzept Kommunikationsorientierter Schulsozialarbeit. Dieses verbindet wissenschaftliche Erkenntnisse zu LernverlĂ€ufen und das Konzept der Gewaltfreien Kommunikation mit den ermittelten Schwachstellen von Schule, was schließlich einen ideellen Ausblick ĂŒber sozialpĂ€dagogische Handlungsfelder in der Schule gibt. Und letztendlich schließt die Arbeit mit einer schlussfolgernden Zusammenfassung ab.The first central question is about, what schoolsocialwork could contribute to the actual school-situation, that not only adaptionable pupils getting reached, but also those ones, whose are tended to anticipate themselves from school. Therefore in the first part of the work gets analyzed, how learning out of the perspective of neurobiology, education and psychology can be understood, which factors are suppporting respectively blocking learning-processes and how the subjective learning-activity is connected to the school-societal-level. In the both following chapters initially it gets outlined main aspects of the interpersonal communication related to psychologic-sociological communication-theories, bridging to the point where every learning also is a complex communication-activity. Next to the relevance to broach the issue of communication in school, it also gets illustrated on which point the communication-term is coming to a border within the school- and social pedagogy. Inside the second central question gets considered how an ideal cooperation of school and youth welfare can look like, wherein the scientific knowledge to learning-processes offensive getting included. The analysis of the german, general-education-system is the first base therefor. Herein gets regarded the historical roots of the school-obligation and also the selectivity, which results automatically out of different kindes of schools. This showes single waves of education-reformes. Deepening to that it gets demonstrated which factors were supporting respectively effecting education-reformes and which power was working against the horizontal school-system in Germany, and therein working against the reduction of the selective content of school. Because inclusion-activities, to which schoolsocialwork is appointed, does not have a necessity, if not before happened an exclusion. Which possibilities schoolsocialwork can develop for general-education-schools, to get with regard to contents and methodes enriched, advanced, opened up and linked, as well as building up a mutual integrative cooperation, gets brought out in the following part within a characterisation of schoolsocialwork. Thereafter it is about to gain inside the concept of nonviolent communiation which followes a frame-concept of communication-oriented schoolsocialwork. These connects scientific findings of learning processes and the concept of the nonviolent communication with the determined weak points of school, which gives finally an forecast about social pedagogic spheres of activity in schools. And eventual the work is closing with a deductive abstraction

    Representing 3D Space in Working Memory: Spatial Images from Vision, Hearing, Touch, and Language

    Get PDF
    The chapter deals with a form of transient spatial representation referred to as a spatial image. Like a percept, it is externalized, scaled to the environment, and can appear in any direction about the observer. It transcends the concept of modality, as it can be based on inputs from the three spatial senses, from language, and from long-term memory. Evidence is presented that supports each of the claimed properties of the spatial image, showing that it is quite different from a visual image. Much of the evidence presented is based on spatial updating. A major concern is whether spatial images from different input modalities are functionally equivalent— that once instantiated in working memory, the spatial images from different modalities have the same functional characteristics with respect to subsequent processing, such as that involved in spatial updating. Going further, the research provides some evidence that spatial images are amodal (i.e., do not retain modality-specific features)
    • 

    corecore