3,698 research outputs found
Abilities of development support in children with genetic syndromes. Experiences from annual integrational meetings
Evidence of convective rolls in a sunspot penumbra
aims: We study the recently discovered twisting motion of bright penumbral
filaments with the aim of constraining their geometry and the associated
magnetic field. methods: A large sunspot located 40\degr from disk center was
observed at high resolution with the 1-m Swedish Solar Telescope. Inversions of
multi-wavelength polarimetric data and speckle reconstructed time series of
continuum images were used to determine proper motions, as well as the velocity
and magnetic structure in penumbral filaments. results: The continuum movie
reveals apparent lateral motions of bright and dark structures inside bright
filaments oriented parallel to the limb, confirming recent Hinode results. In
these filaments we measure upflows of on their
limbward side and weak downflows on their centerward side. The magnetic field
in them is significantly weaker and more horizontal than in the adjacent dark
filaments. conclusions: The data indicate the presence of vigorous convective
rolls in filaments with a nearly horizontal magnetic field. These are separated
by filaments harbouring stronger, more vertical fields. Because of reduced gas
pressure, we see deeper into the latter. When observed near the limb, the
disk-centerward side of the horizontal-field filaments appear bright due to the
\textit{hot wall} effect known from faculae. We estimate that the convective
rolls transport most of the energy needed to explain the penumbral radiative
flux.Comment: 4 pages, 4 figures, letter to Astronomy & Astrophysic
Mikrokurse
In den Lehrplänen einiger Bundesländer gibt es noch keinen eigenständigen Themenbereich Teilchenphysik. Für diesen Fall sind die hier vorgestellten Mikrokurse zusammengestellt worden. Alle Kurse schlagen auf originelle Weise eine Brücke von klassischen Lehrplanthemen zu aktuellen Forschungsgegenständen. Denn viele der im Physikunterricht behandelten Themen lassen sich leicht um einen Bezug zur modernen Physik und insbesondere der Teilchenphysik ergänzen. Der zeitliche Bedarf für die Behandlung eines Kurses beträgt ca. ein bis zwei Unterrichtsstunden. Vorkenntnisse zur Teilchenphysik sind kaum notwendig. Die Mikrokurse können und sollen deshalb auch gerade dort eingesetzt werden, wo nur wenig Zeit zur Verfügung steht oder das Thema Teilchenphysik nicht im Lehrplan verankert ist. Zu jedem Kurs werden Einsatzmöglichkeiten und wünschenswerte Vorkenntnisse der Schüler:innen angegeben. Auf mögliche Erweiterungen und Vertiefungen wird hingewiesen
Two-Fermion Production in Electron-Positron Collisions
This report summarizes the results of the two-fermion working group of the
LEP2-MC workshop, held at CERN from 1999 to 2000. Recent developments in the
theoretical calculations of the two fermion production process in the
electron-positron collision at LEP2 center of the mass energies are reported.
The Bhabha process and the production of muon, tau, neutrino and quark pairs is
covered. On the basis of comparison of various calculations, theoretical
uncertainties are estimated and compared with those needed for the final LEP2
data analysis. The subjects for the further studies are identified.Comment: 2-fermion working group report of the LEP2 Monte Carlo Workshop
1999/2000, 113 pages, 24 figures, 35 table
P53 IMMUNOHISTOCHEMISTRY AS A SURROGATE FOR TP53 MUTATIONAL ANALYSIS IN ENDOMETRIAL CANCER BIOPSIES
Meeting abstract from 17th Biennial Meeting of the International Gynecologic Cancer Society Kyoto, Japan September 14-16, 201
High-resolution spectro-polarimetry of a flaring sunspot penumbra
We present simultaneous photospheric and chromospheric observations of the
trailing sunspot in NOAA 10904 during a weak flare eruption (GOES magnitude
B7.8), obtained with the Swedish Solar Telescope (SST) in La Palma, Canary
Islands. High-resolution \ion{Ca}{ii} images show a typical two-ribbon
structure that has been hitherto only known for larger flares, and the flare
appears in a confined region that is discernible by a bright border. The
underlying photosphere shows a disturbed penumbral structure with intersecting
branches of penumbral filaments. High-resolution Doppler- and
vector-magnetograms exhibit oppositely directed Evershed flows and magnetic
field vectors in the individual penumbral branches, resulting in several
regions of magnetic azimuth discontinuity and several islands where the
vertical magnetic field is reversed. The discontinuity regions are co-spatial
with the locations of the onset of the flare ribbons. From the results, we
conclude that the confined flare region is detached from the global magnetic
field structure by a separatrix marked by the bright border visible in
\ion{Ca}{ii} . We further conclude that the islands of reversed vertical
field appear because of flux emergence and that the strong magnetic shear
appearing in the regions of magnetic azimuth discontinuity triggers the flare.Comment: 20 pages + 1 online Figure for A&
Universal Interface of TAUOLA Technical and Physics Documentation
Because of their narrow width, tau decays can be well separated from their
production process. Only spin degrees of freedom connect these two parts of the
physics process of interest for high energy collision experiments. In the
following, we present a Monte Carlo algorithm which is based on that property.
The interface supplements events generated by other programs, with tau decays.
Effects of spin, genuine weak corrections or of new physics may be taken into
account at the time when a tau decay is generated and written into an event
record.Comment: 1+44 pages, 17 eps figure
Predictions for Fermion Pair Production at e+e- Colliders
We discuss the status and some ongoing upgrades of the ZFITTER program for
applications at e+e- colliders LEP1/SLC, LEP2, GigaZ, and TESLA. The inclusion
of top quark pair production is under work.Comment: 10 pages, 1 table, 2 figures, uses npb.sty, to appear in the
proceedings of Zeuthen Workshop: Loops and Legs in Quantum Field Theory, 9-14
April, Bastei, German
Micro-fabrication of Carbon Structures by Pattern Miniaturization in Resorcinol-Formaldehyde Gel
A simple and novel method to fabricate and miniaturize surface and
sub-surface micro-structures and micro-patterns in glassy carbon is proposed
and demonstrated. An aqueous resorcinol-formaldehyde (RF) sol is employed for
micro-molding of the master-pattern to be replicated, followed by controlled
drying and pyrolysis of the gel to reproduce an isotropically shrunk replica in
carbon. The miniaturized version of the master-pattern thus replicated in
carbon is about one order of magnitude smaller than original master by
repeating three times the above cycle of molding and drying. The
micro-fabrication method proposed will greatly enhance the toolbox for a facile
fabrication of a variety of Carbon-MEMS and C-microfluidic devices.Comment: 16 pages, 5 figure
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