4,017 research outputs found
Existence theorems in the geometrically non-linear 6-parametric theory of elastic plates
In this paper we show the existence of global minimizers for the
geometrically exact, non-linear equations of elastic plates, in the framework
of the general 6-parametric shell theory. A characteristic feature of this
model for shells is the appearance of two independent kinematic fields: the
translation vector field and the rotation tensor field (representing in total 6
independent scalar kinematic variables). For isotropic plates, we prove the
existence theorem by applying the direct methods of the calculus of variations.
Then, we generalize our existence result to the case of anisotropic plates. We
also present a detailed comparison with a previously established Cosserat plate
model.Comment: 19 pages, 1 figur
On Chromospheric Variations Modeling for Main-Sequence Stars of G and K Spectral Classes
We present a method of chromospheric flux simulation for 13 late-type
main-sequence stars. These Sun-like stars have well-determined cyclic flux
variations similar to 11 yr solar activity cycle. Our flux prediction is based
on chromospheric HK emission time series measurements from Mount Wilson
Observatory and comparable solar data. We show that solar three - component
modeling explains well the stellar observations. We find that the 10 - 20% of K
- stars disc surfaces are occupied by bright active regions.Comment: 8 pages, 2 figure
Simulation and Analysis Chain for Acoustic Ultra-high Energy Neutrino Detectors in Water
Acousticneutrinodetectionisapromisingapproachforlarge-scaleultra-highenergyneutrinodetectorsinwater.In
this article, a Monte Carlo simulation chain for acoustic neutrino detection
devices in water will be presented. The simulation chain covers the generation
of the acoustic pulse produced by a neutrino interaction and its propagation to
the sensors within the detector. Currently, ambient and transient noise models
for the Mediterranean Sea and simulations of the data acquisition hardware,
equivalent to the one used in ANTARES/AMADEUS, are implemented. A pre-selection
scheme for neutrino-like signals based on matched filtering is employed, as it
is used for on-line filtering. To simulate the whole processing chain for
experimental data, signal classification and acoustic source reconstruction
algorithms are integrated in an analysis chain. An overview of design and
capabilities of the simulation and analysis chain will be presented and
preliminary studies will be discussed.Comment: 6 pages, 5 figures, ARENA 2012. arXiv admin note: substantial text
overlap with arXiv:1304.057
transition form factors in Quenched and QCD
Calculations of the magnetic dipole, electric quadrupole and Coulomb
quadrupole amplitudes for the transition are presented
both in quenched QCD and with two flavours of degenerate dynamical quarks.Comment: Lattice2003(Matrix), 3 page
Calculation of the N to Delta electromagnetic transition matrix element
We present results on the ratio of electric quadrupole to magnetic dipole
amplitudes, , for the transition from lattice QCD. We consider both the quenched and the 2-flavor
theory.Comment: 3 pages, 4 figures, talk presented at Lattice2002(matrixel); Layout
of figures adjuste
Development of Combined Opto-Acoustical Sensor Modules
The faint fluxes of cosmic neutrinos expected at very high energies require
large instrumented detector volumes. The necessary volumes in combination with
a sufficient shielding against background constitute forbidding and complex
environments (e.g. the deep sea) as sites for neutrino telescopes. To withstand
these environments and to assure the data quality, the sensors have to be
reliable and their operation has to be as simple as possible. A compact sensor
module design including all necessary components for data acquisition and
module calibration would simplify the detector mechanics and ensures the long
term operability of the detector. The compact design discussed here combines
optical and acoustical sensors inside one module, therefore reducing
electronics and additional external instruments for calibration purposes. In
this design the acoustical sensor is primary used for acoustic positioning of
the module. The module may also be used for acoustic particle detection and
marine science if an appropriate acoustical sensor is chosen.
First tests of this design are promising concerning the task of calibration.
To expand the field of application also towards acoustic particle detection
further improvements concerning electromagnetic shielding and adaptation of the
single components are necessary.Comment: 4 pages, 2 figures, ARENA2010 proceeding
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