876 research outputs found
The classical multicomponent nucleation theory for cavitation in water with dissolved gases
The Classical Nucleation Theory (CNT) in its multicomponent form is presented as a reliable tool for the investigation of homogeneous nucleation in cavitation processes in aqueous systems. Several cases are considered, starting form the most simple case of a void cavity emerging at negative pressure, then treating the case of a bubble composed of water vapor only, and finally investigating the influence of various gases dissolved in water on the nucleation rate and the composition of the critical cluster. Aqueous systems related to cavitation in hydraulic machinery and to cavitation in carbonated beverages are discussed.http://deepblue.lib.umich.edu/bitstream/2027.42/84298/1/CAV2009-final120.pd
Coherent control of magnetization precession in ferromagnetic semiconductor (Ga,Mn)As
We report single-color, time resolved magneto-optical measurements in
ferromagnetic semiconductor (Ga,Mn)As. We demonstrate coherent optical control
of the magnetization precession by applying two successive ultrashort laser
pulses. The magnetic field and temperature dependent experiments reveal the
collective Mn-moment nature of the oscillatory part of the time-dependent Kerr
rotation, as well as contributions to the magneto-optical signal that are not
connected with the magnetization dynamics.Comment: 6 pages, 3 figures, accepted in Applied Physics Letter
Laser-induced Precession of Magnetization in GaMnAs
We report on the photo-induced precession of the ferromagnetically coupled Mn
spins in (Ga,Mn)As, which is observed even with no external magnetic field
applied. We concentrate on various experimental aspects of the time-resolved
magneto-optical Kerr effect (TR-MOKE) technique that can be used to clarify the
origin of the detected signals. We show that the measured data typically
consist of several different contributions, among which only the oscillatory
signal is directly connected with the ferromagnetic order in the sample.Comment: 4 pages, 5 figure
Cavitation processes in binary systems – the effect of a dissolved gas on the nucleation rate described by the classical nucleation theory
Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.The Classical Nucleation Theory (CNT) is applied to nucleation
in cavitation processes in binary mixtures of a liquid component
and a dissolved gas component. The multi-component form of
the CNT allows to study the influence of the dissolved gas concentration
on the resulting nucleation rate. Four binary mixtures
are studied, diethylether – nitrogen, propane – carbon dioxide,
isobutane – carbon dioxide, and chlorodifluoromethane – carbon
dioxide, whose experimental nucleation rates are available in
the literature. The nucleation rates and their dependence on
concentration of the dissolved gas calculated according to the
CNT show good agreement with the experimental data.pm201
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