Radiological findings were evaluated on a mass survey (70 mm films) in four villages where mining and processing of sepiolite have occurred for more than 100 yr, together with a clinical and radiological study in 63 sepiolite trimming workers in Eskisehir, Turkey. Mineral fiber-related pleural diseases were not detected in those people who were exposed to sepiolite dust. Although pulmonary fibr...

Instability of high frequency wave, such as, Langmuir wave (LW) is studied using fluid model in collisional and streaming dusty plasma with dust charge fluctuation. In irradiated dusty plasma, dust charge fluctuation is considered to be due to the combined effect of LW perturbation and photoelectron emission. The piled up electrons on a dust grain due to LW perturbation can be swept out by phot...

The shear viscosity of a two-dimensional (2D) liquid was calculated using equilibrium molecular dynamics simulations with a Yukawa potential. The shear viscosity has a minimum, at a Coulomb coupling parameter Γ of about 17, arising from the temperature dependence of the kinetic and potential contributions. Previous calculations of 2D viscosity were less extensive, and for a different potential....

We describe planetesimal accretion calculations for the dusty ring observed in the nearby A0 star HR 4796A. Models with initial masses of 10–20 times the minimum mass solar nebula produce a ring of width 7–15 AU and height 0.3–0.6 AU at 70 AU in ∼ 10 Myr. The ring has a radial optical depth ∼ 1. These results agree with limits derived from infrared images and from the excess infrared luminosity...

The shear viscosity of a two-dimensional (2D) liquid was calculated using molecular dynamics simulations with a Yukawa potential. The viscosity has a minimum at a Coulomb coupling parameter Gamma of about 17, arising from the temperature dependence of the kinetic and potential contributions. Previous calculations of 2D viscosity were less extensive as well as for a different potential. The stre...

Using Korteweg-de Vries (KdV) equation, solitons are investigated in a dusty plasma consisting of positive ion, negatively charged dust grain and Boltzmann distributed electron. Both compressive and rarefactive solitons are found to exist in the dusty plasma for fast and slow modes. Greater d Z ( d Z is the number of elementary charges residing on the dust grain) is found to yield higher amplit...

Unified schemes of active galactic nuclei (AGN) require an obscuring dusty torus around the central engine. Torus sizes of hundreds of parsecs were deduced from early theoretical modeling efforts, but high-resolution IR observations now show that the torus size is no more than a few parsecs. This conflict is resolved when the clumpy nature of the torus is taken into account. The compact torus m...

In this article, we develop a set of partial differential equations describing the flow of a dusty fluid in variable porosity media. The developed equations take into account the effect of the porous microstructure on the flowing phases. We presented and overview of the equations governing the flow of a dusty gas in various type media, including that in naturally occurring porous media. Numeric...

Thermodynamic quantities of a two-dimensional Yukawa system, a model for various systems including single-layered dust particles observed in dusty plasmas, are obtained and expressed by simple interpolation formulas. In the domain of weak coupling, the analytical method based on the cluster expansion is applied and, in the domain of intermediate and strong coupling, numerical simulations are pe...