18,984 research outputs found
Microstrip resonator for microwaves with controllable polarization
In this work the authors implemented a resonator based upon microstrip
cavities that permits the generation of microwaves with arbitrary polarization.
Design, simulation, and implementation of the resonators were performed using
standard printed circuit boards. The electric field distribution was mapped
using a scanning probe cavity perturbation technique. Electron spin resonance
using a standard marker was carried out in order to verify the polarization
control from linear to circular.Comment: 3 pages, 3 figures, submitted to Appl. Phys. Let
Analysis of the temperature influence on Langmuir probe measurements on the basis of gyrofluid simulations
The influence of the temperature and its fluctuations on the ion saturation
current and the floating potential, which are typical quantities measured by
Langmuir probes in the turbulent edge region of fusion plasmas, is analysed by
global nonlinear gyrofluid simulations for two exemplary parameter regimes. The
numerical simulation facilitates a direct access to densities, temperatures and
the plasma potential at different radial positions around the separatrix. This
allows a comparison between raw data and the calculated ion saturation current
and floating potential within the simulation. Calculations of the
fluctuation-induced radial particle flux and its statistical properties reveal
significant differences to the actual values at all radial positions of the
simulation domain, if the floating potential and the temperature averaged
density inferred from the ion saturation current is used.Comment: Submitted to Plasma Physics and Controlled Fusio
Magnon Heat Conductivity and Mean Free Paths in Two-Leg Spin Ladders: A Model-Independent Determination
The magnon thermal conductivity of the spin ladders
in has been investigated at low doping levels
, 0.125, 0.25, 0.5 and 0.75. The Zn-impurities generate nonmagnetic
defects which define an upper limit for and therefore allow
a clear-cut relation between and to
be established independently of any model. Over a large temperature range we
observe a progressive suppression of with increasing
Zn-content and find in particular that with respect to pure is strongly suppressed even in
the case of tiny impurity densities where ~{\AA}.
This shows unambiguously that large ~{\AA} which
have been reported for and on basis of a kinetic model are in the correct order
of magnitude
Irrigação do cajueiro-anão-precoce na região de Teresina.
bitstream/CPAMN-2009-09/20953/1/CT186.pd
The motion of two masses coupled to a massive spring
We discuss the classical motion of a spring of arbitrary mass coupled to two
arbitrary massive blocks attached at its ends. A general approach to the
problem is presented and some general results are obtained. Examples for which
a simple elastic function can be inferred are discussed and the normal modes
and normal frequencies obtained. An approximation procedure to the evaluation
of the normel frequencies in the case of uniform elastic function and mass
density is also discussed.Comment: Standard Latex file plus three eps figure
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