A Spitzer IRAC survey of 17 nearby metal-rich white dwarfs, nominally DAZ stars, reveals excess emission from only 3 targets: G29-38, GD 362 and G167-8. Observations of GD 362 with all three Spitzer instruments reveals a warm (≈ 1000 K) dust continuum, very strong silicate emission, and the likely presence of cooler (≈ 500 K) dust. While there is a general similarity between the mid-infrared sp...

Estimates of the total metal production rate (ρ̇Z) and star formation rate at z > 2 are based on Lyman break systems observed in the rest-frame ultraviolet (UV). These observations are very sensitive to dust obscuration. Here I elucidate and refine the Meurer et al. (1997) method for calculating UV obscuration, presenting new relationships which accurately model the dust reprocessing of radiatio...

A plasmonic metal film with a subwavelength hole array (a mesh) is used to capture an individual subwavelength particle, like a single yeast cell or airborne dust particle, and an imaging infrared (IR) microscope, records a scatterfree, IR absorption spectrum of the particle. Individual spectra of wavelength scale particles usually suffer from large scattering effects. This paper starts by demo...

background: incense and joss stick are generally used in the world. most products were made in small household factories. there are many environmental and occupational hazards in these factories. objective: to evaluate the workplace environmental and occupational hazards in small household incense and joss stick factories in roi-et, thailand. methods: nine small household factories in rural are...

the potential of six economically cheap agricultural waste materials, viz. rice husk, betel nutpeels, sugarcane molasses, tea waste, mustard oil cake and saw dust, was investigated for copper and leadremoval from aqueous solutions under batch and continuous conditions. the effect of ph, contact time,sorbent dose and initial metal ion concentration on the uptake of copper and lead was first exam...

This study compared respirable dust and nanoparticle concentrations measured by different sampling devices at a titanium dioxide pigment factory. Respirable particle mass concentrations, nanoparticle concentrations, particle size distribution and particle metallic content were measured at different sampling locations. The sampling results of the Multi-orifice Uniform Deposit Impactor (MOUDI) sh...

Oral bioaccessibility estimates for six metals which are prevalent as contaminants in Canada (zinc, lead, cadmium, copper, nickel, and chromium) are investigated for house dust using the simple gastric phase versus the two-phase physiologically-based extraction technique (PBET). The purpose is to determine whether a complete gastrointestinal (GI) assay yields a more conservative (i.e., higher) ...

The purpose of the Enhanced Particulate Matter Surveillance Program was to provide scientifically founded information on the chemical and physical properties of dust collected over a period of approximately 1 year in Djibouti, Afghanistan (Bagram, Khowst), Qatar, United Arab Emirates, Iraq (Balad, Baghdad, Tallil, Tikrit, Taji, Al Asad), and Kuwait (northern, central, coastal, and southern regi...

A key component of the baryon cycle in galaxies is depletion metals from gas to dust phase neutral ISM. The METAL (Metal Evolution, Transport and Abundance Large Magellanic Cloud) program on Hubble Space Telescope acquired UV spectra toward 32 sightlines half-solar metallicity LMC, which we derive interstellar depletions (gas-phase fractions) Mg, Si, Fe, Ni, S, Zn, Cr, Cu. different elements ar...

We hypothesized that the reduction in hospital respiratory admissions in the Utah Valley during closure of a local steel mill in 1986-1987 was attributable in part to decreased toxicity of ambient air particles. Sampling filters for particulate matter < 10 μm (PM10) were obtained from a Utah Valley monitoring station for the year before ( year 1), during ( year 2), and after ( year 3) the steel...