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