2,121 research outputs found
The Dynamo Effects in Laboratory Plasmas
A concise review of observations of the dynamo effect in laboratory
plasmas is given. Unlike many astrophysical systems, the laboratory pinch
plasmas are driven magnetically. When the system is overdriven, the resultant
instabilities cause magnetic and flow fields to fluctuate, and their
correlation induces electromotive forces along the mean magnetic field. This
-effect drives mean parallel electric current, which, in turn, modifies
the initial background mean magnetic structure towards the stable regime. This
drive-and-relax cycle, or the so-called self-organization process, happens in
magnetized plasmas in a time scale much shorter than resistive diffusion time,
thus it is a fast and unquenched dynamo process. The observed -effect
redistributes magnetic helicity (a measure of twistedness and knottedness of
magnetic field lines) but conserves its total value. It can be shown that fast
and unquenched dynamos are natural consequences of a driven system where
fluctuations are statistically either not stationary in time or not homogeneous
in space, or both. Implications to astrophysical phenomena will be discussed.Comment: 21 pages, 15 figures, submitted to Magnetohydrodynamic
Space shuttle orbiter heat pipe applications. Volume 2: Final report
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Management of Dravet syndrome and emerging therapy options
Introduction: Dravet syndrome is an early onset epileptic and genetic encephalopathy. Although a well-recognised electroclinical picture is key to diagnosis, a mutation in the SCN1A gene is found in excess of 80%. In general prognosis is poor overall for seizure control and neurodevelopment. With careful phenotyping of the condition and review of treatment response we have become aware of the antiepileptic drugs that are most likely to help, but more importantly drugs that may lead to deterioration and consequently to avoid. Despite this, a significant number of children continue to have seizures and there is little evidence to suggest that we have substantially changed the prognosis in these patients.
Areas covered: This review explores current views on the diagnosis and treatment of Dravet syndrome. Consideration is given to the underlying genetics, as well as agents proving to be useful in the management of seizures, including those currently under trial. This has been prepared utilising a review of current literature, as well as expert opinion.
Expert opinion: Considerable experience in the field has led to a knowledge of optimised treatment in this condition. This involves both acute and maintenance treatment. Despite this, there has been little impact on overall outcomes. Newer treatments now provide promise with regard to seizure control; whether this will have an impact on overall outcome remains to be seen
De Novo Genome Sequence of "Candidatus Liberibacter solanacearum" from a Single Potato Psyllid in California.
The draft genome sequence of "Candidatus Liberibacter solanacearum" strain RSTM from a potato psyllid (Bactericera cockerelli) in California is reported here. The RSTM strain has a genome size of 1,286,787Â bp, a G+C content of 35.1%, 1,211 predicted open reading frames (ORFs), and 43 RNA genes
Risk Analyses and Risk Management - Slope Instabilities in Alpine Environments
Two prominent deep-seated gravitational slope deformations in the Eastern Alps (Tyrol, Austria) have been activated in the last seven years and pose serious threats to the densely populated valleys. Based on multidisciplinary field investigations, different hazard scenarios of slope failures have been evaluated for risk management processes. These event scenarios, which are characterised by strongly varying volumes of the failing slide masses as well as by different probabilities of occurrence, and varying disintegration factors control different accumulation and damage scenarios. Finally, these evaluations and risk analyses aimed to define “design events”, i.e. which scenarios are relevant for the dimensioning of mitigation measures. The main aim is to sustainably enable further land use, in comparison to the overall geohazard risks that are also present at several other sites in Tyrol (Austria)
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Flexible Transparent Barrier Applications of Oxide Thin Films Prepared by Photochemical Conversion at Low Temperature and Ambient Pressure
Photoconversion of metal-organic precursors to thin film metal oxides using ultraviolet (UV) radiation in oxidative atmosphere is an attractive technology because it can be applied at temperatures <80°C and at ambient pressure. Thus, it enables preparing this class of thin films in a cost-efficient manner on temperature sensitive substrates such as polymer films. In this article, various aspects of research and development in the field of photochemical thin-film fabrication, with particular focus to the application of the produced films as gas permeation barriers for the encapsulation of optoelectronic devices are reviewed. Thereby, it covers investigations on fundamental photochemically initiated reactions for precursor classes containing metal-oxygen and metal-nitrogen bonds, and emphazises the relevance of that understanding for applicative considerations like integration of the single-layer barrier films into relevant encapsulation films. Further perspectives are given concerning integration of additional functionalities like electrical conductivity to the flexible and transparent barrier films. © Copyright © 2020 With, Helmstedt and Prager
Cultural differences in intimacy: The influence of gender-role ideology and individualism-collectivism
Two studies examined emotional intimacy in European Canadian and Chinese Canadian dating relationships. Cultural differences in gender-role ideology and individualism–collectivism
were hypothesized to differentially contribute to selfdisclosure and responsiveness, and in turn, intimacy. Study 1 revealed that Chinese Canadians’ lower intimacy relative to European Canadians was mediated by their greater gender-role traditionalism but not by their individualism or collectivism. Study 2 further linked greater gender-role traditionalism to
lower self-disclosure, and in turn, lower intimacy. Results also revealed that Chinese Canadians’ lower intimacy mediated their lower relationship satisfaction and higher rate of relationship termination in Study 1, but that Chinese Canadians were not any more likely to terminate their relationships in Study 2
Saturation of Magnetorotational Instability through Magnetic Field Generation
The saturation mechanism of Magneto-Rotational Instability (MRI) is examined
through analytical quasilinear theory and through nonlinear computation of a
single mode in a rotating disk. We find that large-scale magnetic field is
generated through the alpha effect (the correlated product of velocity and
magnetic field fluctuations) and causes the MRI mode to saturate. If the
large-scale plasma flow is allowed to evolve, the mode can also saturate
through its flow relaxation. In astrophysical plasmas, for which the flow
cannot relax because of gravitational constraints, the mode saturates through
field generation only.Comment: 9 pages, 10 figures to appear in ApJ, Jun 2009, 10 v69
Methyl group dynamics in a confined glass
We present a neutron scattering investigation on methyl group dynamics in
glassy toluene confined in mesoporous silicates of different pore sizes. The
experimental results have been analysed in terms of a barrier distribution
model, such a distribution following from the structural disorder in the glassy
state. Confinement results in a strong decreasing of the average rotational
barrier in comparison to the bulk state. We have roughly separated the
distribution for the confined state in a bulk-like and a surface-like
contribution, corresponding to rotors at a distance from the pore wall
respectively larger and smaller than the spatial range of the interactions
which contribute to the rotational potential for the methyl groups. We have
estimated a distance of 7 Amstrong as a lower limit of the interaction range,
beyond the typical nearest-neighbour distance between centers-of-mass (4.7
Amstrong).Comment: 5 pages, 3 figures. To be published in European Physical Journal E
Direct. Proceedings of the 2nd International Workshop on Dynamics in
Confinemen
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