261 research outputs found
Thermodynamics of strongly-coupled Yukawa systems near the one-component-plasma limit. II. Molecular dynamics simulations
R. T. Farouki and S. Hamaguchi, J. Chem. Phys. 101, 9885 (1994) https://doi.org/10.1063/1.46795
Polarization force on a charged particulate in a nonuniform plasma
S. Hamaguchi and R. T. Farouki, Phys. Rev. E 49, 4430, 199
Phase transitions of dense systems of charged "dust" grains in plasmas
R. T. Farouki and S. Hamaguchi, Appl. Phys. Lett. 61, 2973 (1992) https://doi.org/10.1063/1.10803
Ion energetics in collisionless sheaths of rf process plasmas
S. Hamaguchi, Physics of Fluids B: Plasma Physics 4, 2362 (1992) https://doi.org/10.1063/1.86020
Construction of planar quintic Pythagorean-hodograph curves by control-polygon constraints
In the construction and analysis of a planar Pythagoreanâhodograph (PH) quintic curve r(t), tâ[0,1] using the complex representation, it is convenient to invoke a translation/rotation/scaling transformation so r(t) is in canonical form with r(0)=0, r(1)=1 and possesses just two complex degrees of freedom. By choosing two of the five controlâpolygon legs of a quintic PH curve as these free complex parameters, the remaining three controlâpolygon legs can be expressed in terms of them and the roots of a quadratic or quartic equation. Consequently, depending on the chosen two controlâpolygon legs, there exist either two or four distinct quintic PH curves that are consistent with them. A comprehensive analysis of all possible pairs of chosen control polygon legs is developed, and examples are provided to illustrate this controlâpolygon paradigm for the construction of planar quintic PH curves
Ponderomotive force and ion energy distributions in an rf sheath
The incident-ion energy distribution in a collisionless radio-frequency (rf) sheath is derived analytically for a general electric-field configuration in the high-frequency regime. The analysis is based on a two-time-scale asymptotic expansion of the ion equation of motion, where the ratio of the ion transit frequency tr to the rf frequency is assumed to be small. It is shown that the ponderomotive force due to the rf modulation of the electric field exerts a retarding effect on the ion motion, counteracting the dc-bias field. The results obtained here are applicable to rf-discharge-based process tools used in microelectronics fabrication, where the conditions of low collisionality and high rf frequency are usually satisfied. © 1992 The American Physical Society.S. Hamaguchi, R. T. Farouki, and M. Dalvie, Phys. Rev. Lett. 68, 44, 199
Phase diagram of Yukawa systems near the oneâcomponentâplasma limit revisited
Transition inverse temperatures (or Î values) at the fluidâsolid phase boundary of Yukawa systems near the oneâcomponentâplasma (OCP) limit have been evaluated by molecular dynamics simulations. These values are systematically smaller than those obtained in an earlier study by Farouki and Hamaguchi [J. Chem. Phys. 101, 9885 (1994)]. The discrepancy is attributed to the fact that, in the earlier study, the harmonic entropy constants were approximated by that of the OCP, whereas the new results are based on more accurate harmonic entropy constants obtained from latticeâdynamics calculations. The new molecular dynamics simulations also confirm that the bccâfcc phase transition curve is in good agreement with that of the quasiharmonic theory in the regime Îșâ€1.4, where Îș is the ratio of the WignerâSeitz radius to the Debye length. Examples of Yukawa systems include dusty plasmas and colloidal suspensions. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69874/2/JCPSA6-105-17-7641-1.pd
Spectroscopic evolution of dusty starburst galaxies
By using a one-zone chemical and spectrophotometric evolution model of a disk
galaxy undergoing a dusty starburst, we investigate, numerically, the optical
spectroscopic properties in order to explore galaxy evolution in distant
clusters. We adopt an assumption that the degree of dust extinction
(represented by ) depends on the ages of starburst populations in such a
way that younger stars have larger (originally referred to as selective
dust extinction by Poggianti & Wu 2000). In particular, we investigate how the
time evolution of the equivalent widths of [OII]3727 and H is
controlled by the adopted age dependence. This leads to three main results: (1)
If a young stellar population (with the age of yr) is more
heavily obscured by dust than an old one ( yr), the galaxy can show
an ``e(a)'' spectrum characterized by strong H absorption and
relatively modest [OII] emission. (2) A dusty starburst galaxy with an e(a)
spectrum can evolve into a poststarburst galaxy with an a+k (or k+a) spectrum
0.2 Gyr after the starburst and then into a passive one with a k-type spectrum
1 Gyr after the starburst. This result clearly demonstrates an evolutionary
link between galaxies with different spectral classes (i.e., e(b), e(a), a+k,
k+a, and k). (3) A dusty starburst galaxy can show an a+k or k+a spectrum even
in the dusty starburst phase if the age-dependence of dust extinction is rather
weak, i.e., if young starburst populations with different ages (
yr) are uniformly obscured by dust.Comment: 27 pages 12 figures,2001,ApJ,in pres
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