Persistent Superfluid Flow Arising from the He-McKellar-Wilkens Effect in Molecular Dipolar Condensates.

We show that the He-McKellar-Wilkens effect can induce a persistent flow in a Bose-Einstein condensate of polar molecules confined in a toroidal trap, with the dipolar interaction mediated via an electric dipole moment. For Bose-Einstein condensates of atoms with a magnetic dipole moment, we show that although it is theoretically possible to induce persistent flow via the Aharonov-Casher effect, the strength of the electric field required is prohibitive. We also outline an experimental geometry tailored specifically for observing the He-McKellar-Wilkens effect in toroidally trapped condensates.

What property of a haze is determined by light scattering? 2: Nonuniform particles of arbitrary shape.

We generalize our earlier result on forward scattering of light by polydisperse hazes of uniform spheres to include nonuniform particles of arbitrary shape. The forward scattering determines a (polarizability)(2) weighted mean mean-square radius of the haze.

Relationship between two analytic inversion formulae for multispectral extinction data.

Recently Box and McKellar and Fymat have presented analytic inversion formulae for multispectral extinction data in the anomalous diffraction approximation. In this paper, we shall examine the relationship between these two formulae, and in the process we shall derive both the power series expansion and the asymptotic expansion for the extinction in this approximation.

Modulation transfer function of photographic emulsion: the small-angle approximation in radiative transfer theory.

The modulation transfer function (MTF) of photographic emulsion can be conveniently represented by an expression derived from the theory of radiative transfer. Small-angle scattering is assumed to simplify the transfer equation and a Gaussian model is used to represent the forward lobe of the scattering phase function. The MTF depends on such variables as emulsion thickness, crystal size and concentration, relative refractive index, and the wavelength of incident light. The experimental results show that the Gaussian model adequately represents the phase function and also that useful MTF predictions are possible in the spatial frequency bandwidth 0-40 cycles/mm for AgBr crystals in a gelatin matrix.

Atmospheric turbidity and the circumsolar radiation.

We investigate the possibility of determining the turbidity from the intensity of the circumsolar radiation and find that such a connection can be made only when the size distribution of the aerosol particles is known. However, measurements of both the turbidity and the aureole intensity can give useful information about the size distribution.