OBJECTIVES Determine whether surface dust grab samples taken from a large military base in Iraq are toxic and respirable. METHODS X-ray diffraction for mineral content, x-ray fluorescence for elemental content, in vivo mouse dust challenges for assessment of histological changes, bronchoalveolar lavage for cytokines, polarizing light microscopy for crystals in lung tissue, and Fluorescence Ac...

Aims. The aim of this paper is to study the vertical profile of small dust particles in protoplanetary discs in which angular momentum transport is due to MHD turbulence driven by the magnetorotational instability. We consider particle sizes that range from approximately 1 micron up to a few millimeters. Methods. We use a grid–based MHD code to perform global two-fluid simulations of turbulent ...

BACKGROUND Surfactant-containing water sprays are commonly used in coal mines to collect dust. This study investigates the dust collection performance of different surfactant types for a range of coal dust particle sizes and charges. METHODS Bituminous coal dust aerosol was generated in a wind tunnel. The charge of the aerosol was either left unaltered, charge-neutralized with a neutralizer, ...

We observed comet 2P/Encke with the Infrared Space Observatory ISOCAM on July 14, 1997 from a particularly favorable viewing geometry above the comet’s orbital plane and at a distance of 0.25 AU. A structured coma was observed, along with a long, straight dust trail. For the first time, we are able to observe the path of particles as they evolve from the nucleus to the trail. The particles that...

It is believed that planets are formed by aggregation of dust particles suspended in the turbulent gas forming accretion disks around developing stars. We describe a mechanism, termed 'Stokes trapping', which limits the growth of aggregates of dust particles, so that their Stokes number, a dimensionless measure of the damping of their motion relative to the gas, remains close to unity. We discu...

Charging mechanism of dust particles in a nonuniform discharge plasma under cryogenic environment is studied theoretically. The plasma density and temperature effects on dust grain charging are investigated with characteristic time scales of density variation and temperature relaxation in consideration. The charge of a dust grain, initially placed in a discharge plasma and cooled to cryogenic t...

AIMS To assess hazards associated with exposure to dust in the London Underground railway and to provide an informed opinion on the risks to workers and the travelling public of exposure to tunnel dust. METHODS Concentrations of dust, as mass (PM2.5) and particle number, were measured at different underground stations and in train cabs; its size and composition were analysed; likely maximal e...

The Cosmic Dust Analyzer aboard the Cassini spacecraft consists of a several targets as well as a photomultiplier tube which provide information upon collision with ambient dust particles in Saturn’s magnetosphere. Information includes particle mass, velocity, chemical composition, and charge. The focus of this report is the charge of the dust particles; specifically, the processes by which the...

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles...