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The creeping motion of a spherical particle normal to a deformable interface
Numerical results are presented for the approach of a rigid sphere normal to a deformable fluid-fluid interface in the velocity range for which inertial effects may be neglected. Both the case of a sphere moving with constant velocity, and that of a sphere moving under the action of a constant non-hydrodynamic body force are considered for several values of the viscosity ratio, density difference and interfacial tension between the two fluids. Two distinct modes of interface deformation are demonstrated: a film drainage mode in which fluid drains away in front of the sphere leaving an ever-thinning film, and a tailing mode where the sphere passes several radii beyond the plane of the initially undeformed interface, while remaining encapsulated by the original surrounding fluid which is connected with its main body by a thin thread-like tail behind the sphere. We consider the influence of the viscosity ratio, density difference, interfacial tension and starting position of the sphere in deter-mining which of these two modes of deformation will occur
Corrections to the energy levels of a spin-zero particle bound in a strong field
Formulas for the corrections to the energy levels and wave functions of a
spin-zero particle bound in a strong field are derived. General case of the sum
of a Lorentz-scalar potential and zero component of a Lorentz-vector potential
is considered. The forms of the corrections differ essentially from those for
spin-1/2 particles. As an example of application of our results, we evaluated
the electric polarizability of a ground state of a spin-zero particle bound in
a strong Coulomb field.Comment: 7 pages, 1 figur
How specific is synchronous neuronal firing? : Poster presentation
Background Synchronous neuronal firing has been discussed as a potential neuronal code. For testing first, if synchronous firing exists, second if it is modulated by the behaviour, and third if it is not by chance, a large set of tools has been developed. However, to test whether synchronous neuronal firing is really involved in information processing one needs a direct comparison of the amount of synchronous firing for different factors like experimental or behavioural conditions. To this end we present an extended version of a previously published method NeuroXidence [1], which tests, based on a bi- and multivariate test design, whether the amount of synchronous firing above the chance level is different for different factors
Effect of Plasma Irradiation on films
The effect of plasma irradiation is studied systematically on a 4H polytype
(002) oriented stoichiometric film having compressive residual
stress. Plasma irradiation was found to change the orientation to (110) of the
film at certain moderate irradiation distances. A linear decrease in grain size
and residual stress was observed with decreasing irradiation distance (or
increasing ion energy) consistent with both structural and morphological
observations. The direct optical energy gap was found to increase
linearly at the rate with the compressive stress. The
combined data of present compressive stress and from earlier reported tensile
stress show a consistent trend of change with stress. The
iodine-iodine distance in the unit cell could be responsible for the observed
change in with stress.Comment: 13 pages and 10 fi
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Surface mineral crusts: A priority target in search for life on Mars
Mineral crusts are strong candidates in the search for evidence of life during planetary exploration, and should be an important target for examination in impact craters. Crusts in the Haughton crater readily yield a biological signature
Nanogaps with very large aspect ratios for electrical measurements
For nanoscale electrical characterization and device fabrication it is often
desirable to fabricate planar metal electrodes separated by large aspect ratio
gaps with interelectrode distances well below 100 nm. We demonstrate a
self-aligned process to accomplish this goal using a thin Cr film as a
sacrificial etch layer. The resulting gaps can be as small as 10 nm and have
aspect ratios exceeding 1000, with excellent interelectrode isolation. Such
Ti/Au electrodes are demonstrated on Si substrates and are used to examine a
voltage-driven transition in magnetite nanostructures. This shows the utility
of this fabrication approach even with relatively reactive substrates.Comment: 4 pages, 4 figure
Self-Dual Chern-Simons Solitons in (2+1)-Dimensional Einstein Gravity
We consider here a generalization of the Abelian Higgs model in curved space,
by adding a Chern--Simons term. The static equations are self-dual provided we
choose a suitable potential. The solutions give a self-dual
Maxwell--Chern--Simons soliton that possesses a mass and a spin
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