The opacity of spiral galaxy disks, from counts of distant galaxies, is compared to HI column densities. The opacity measurements are calibrated using the “Synthetic Field Method” from González et al. (1998); Holwerda et al. (2005a). When compared for individual disks, the HI column density and dust opacity do not seem to be correlated as HI and opacity follow different radial profiles. To impr...

Equipartition magnetic fields can dramatically affect the polarization of radiation emerging from accretion disk atmospheres in active galactic nuclei. We extend our previous work on this subject by exploring the interaction between Faraday rotation and absorption opacity in local, plane-parallel atmospheres with parameters appropriate for accretion discs. Faraday rotation in pure scattering at...

Opacity is an information flow property that captures the notion of plausible deniability in dynamic systems, whether intruder can deduce "secret" behavior has occurred. In this paper we provide a general framework opacity to unify many existing notions exist for discrete event systems. We use discuss language-based and state-based over automata. present several methods verification, approach t...

The possibility of unaccounted for opacity sources in the UV for late-type stars has often been invoked to explain discrepancies between predicted and observed flux distributions and spectral line strengths. Such missing UV-opacity could among other things have a significant impact on abundance determination for elements whose only relevant spectral features are accessible in this wavelength re...

This work studies ethnic and geographical differences in the age-related straylight increase by means of a stochastic model and unpublished lens opacity data of 559 residents of Villa Maria (Argentina), as well as data of 912 Indonesian subjects published previously by Husain et al. For both cohorts the prevalence of each type and grade of lens opacity was determined as a function of age, from ...

Three Staphylococcus epidermidis strains produced a factor giving rise to opacity in different sera but not in albumin. Serum opacity factor was resistant to age and heat and active in acidic media.

The observed extragalactic background light (EBL) is affected by light attenuation due to absorption of light by galactic and intergalactic dust in the Universe. Even galactic opacity of 10-20 percent and minute universe intergalactic opacity of 0.01 mag h Gpc ́1 at the local Universe have a significant impact on the EBL because obscuration of galaxies and density of intergalactic dust increase ...

A security property called process environment opacity is formalized and studied. Properties of process’s inputs (environments) are expressed by predicate and it is required that an intruder cannot learn their validity by observing process’s behavior. This basic idea can be formulated in various ways. The resulting security properties are compared.

A backbone of a boolean formula F is a collection S of its variables for which there is a unique partial assignment aS such that F [aS ] is satisfiable [MZK 99,WGS03]. This paper studies the nontransparency of backbones. We show that, under the widely believed assumption that integer factoring is hard, there exist sets of boolean formulas that have obvious, nontrivial backbones yet finding the ...

We investigate the importance of the pseudo-continuum bound-free opacity from hydrogen atoms in the atmospheres of cool white dwarfs. This source of absorption, when calculated by the occupation probability formalism applied in the modeling of white dwarf atmospheres with Teff < 17000K, dominates all other sources of opacity at optical wavelengths. This is unrealistic and not observed. On the o...