1,913 research outputs found
Scaling of spontaneous rotation with temperature and plasma current in tokamaks
Using theoretical arguments, a simple scaling law for the size of the
intrinsic rotation observed in tokamaks in the absence of momentum injection is
found: the velocity generated in the core of a tokamak must be proportional to
the ion temperature difference in the core divided by the plasma current,
independent of the size of the device. The constant of proportionality is of
the order of . When the
intrinsic rotation profile is hollow, i.e. it is counter-current in the core of
the tokamak and co-current in the edge, the scaling law presented in this
Letter fits the data remarkably well for several tokamaks of vastly different
size and heated by different mechanisms.Comment: 5 pages, 3 figure
Quality of Life of Adults with Pervasive Developmental Disorders and Intellectual Disabilities
The purpose of this study was to observe quality of life (QoL) and global evolution of persons with Pervasive Developmental Disorders (PDD) in three different groups. Individualized programs for PDD were compared to traditional programs for intellectual disabilities. Behavioural disorders were repeatedly evaluated using the Aberrant Behaviour Checklist (ABC) and QoL once a year. Little research has investigated this domain due to methodological problems with a non-verbal population. Two preliminary studies of individualized programs showed a significant reduction in behaviour disorders over the course of the study. The recent inclusion of a control group indicates that a traditional program reduces lethargy/social withdrawal (ABC factor 2). A good QoL was measured for the three group
Nouveaux résultats concernant les réactions sérologiques vis-à -vis d’éléments néo-rickettsiens, situés à côté du groupe de la psittacose, chez des animaux du département de l’Aveyron
Giroud Paul, Gibert P., Roger F. Nouveaux résultats concernant les réactions sérologiques vis-à -vis d’éléments néo-rickettsiens, situés à côté du groupe de la psittacose, chez des animaux du département de l’Aveyron. In: Bulletin de l'Académie Vétérinaire de France tome 108 n°9, 1955. pp. 447-449
La recherche de la Fièvre Q dans le département de l’Aveyron nous amène à authentifier des affections du groupe de la psittacose chez les Ovins et les Bovins
Giroud Paul, Gibert P., Roger F. La recherche de la Fièvre Q dans le département de l’Aveyron nous amène à authentifier des affections du groupe de la psittacose chez les Ovins et les Bovins. In: Bulletin de l'Académie Vétérinaire de France tome 108 n°3, 1955. pp. 81-85
Gyrokinetic analysis and simulation of pedestals, to identify the culprits for energy losses using fingerprints
Fusion performance in tokamaks hinges critically on the efficacy of the Edge
Transport Barrier (ETB) at suppressing energy losses. The new concept of
fingerprints is introduced to identify the instabilities that cause the
transport losses in the ETB of many of today's experiments, from widely posited
candidates. Analysis of the Gyrokinetic-Maxwell equations, and gyrokinetic
simulations of experiments, find that each mode type produces characteristic
ratios of transport in the various channels: density, heat and impurities.
This, together with experimental observations of transport in some channel, or,
of the relative size of the driving sources of channels, can identify or
determine the dominant modes causing energy transport. In multiple ELMy H-mode
cases that are examined, these fingerprints indicate that MHD-like modes are
apparently not the dominant agent of energy transport; rather, this role is
played by Micro-Tearing Modes (MTM) and Electron Temperature Gradient (ETG)
modes, and in addition, possibly Ion Temperature Gradient (ITG)/Trapped
Electron Modes (ITG/TEM) on JET. MHD-like modes may dominate the electron
particle losses. Fluctuation frequency can also be an important means of
identification, and is often closely related to the transport fingerprint. The
analytical arguments unify and explain previously disparate experimental
observations on multiple devices, including DIII-D, JET and ASDEX-U, and
detailed simulations of two DIII-D ETBs also demonstrate and corroborate this
2C-B: A New Psychoactive Phenylethylamine Recently Discovered in Ecstasy Tablets Sold on the Swiss Black Market
This study sought to identify, by means of several analytical methods (GC-MS, HPLC-DAD, CE-DAD, FTIR, and NMR), 4-bromo-2,5-dimethoxyphenethylamine (2C-B), which was found in two sets of tablets obtained from the Swiss black market. Unequivocal identification of 2C-B was only achieved by a combination of mass spectrometric and NMR analysis. Quantitation of 2C-B was performed by HPLC-DAD and CE-DAD. The amounts of 2C-B found in the tablets (3-8 mg) were in the range of the minimum quantity required to induce the effects characteristic of this dru
Superconducting proximity effect in a mesoscopic ferromagnetic wire
We present an experimental study of the transport properties of a
ferromagnetic metallic wire (Co) in metallic contact with a superconductor
(Al). As the temperature is decreased below the Al superconducting transition,
the Co resistance exhibits a significant dependence on both temperature and
voltage. The differential resistance data show that the decay length for the
proximity effect is much larger than we would simply expect from the exchange
field of the ferromagnet.Comment: 4 pages, 6 included epsf figures, published version with small
change
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