We discuss our present knowledge about the brightness of the solar F-corona in the wavelength range from the visible to the middle infrared. From the general trend of the observational data, the F-corona is regarded as the continuous extension of the zodiacal light at smaller elongation of the line of sight. A contribution of thermal emission from dust is indicated by the increasing F-coronal b...

We present an analysis of the effects of luminosity on the shape of the mid-infrared spectral energy distributions (SEDs) of 234 radio-quiet quasars originally presented by Richards et al. In quasars without evident dust extinction, the spectrally integrated optical and infrared luminosities are linearly correlated over nearly three decades in luminosity. We find a significant (& 99.99% confide...

It is well established in the local Universe that regions of high star-formation rate are dusty. As a result of this physical causal link, galaxies of increasing current star formation activity emit a larger proportion of their bolometric luminosity via dust absorption and re-radiation in the thermal midto far-infrared. Several new observations indicate that this trend continues back to earlier...

An intriguing fact about cosmic gas clouds is that they all appear to have neutral (atomic) hydrogen column densities smaller than 1022 cm−2. Observations of damped Lyα (DLA) absorption systems further indicate that the maximum NHI decreases with increasing metallicity. It is generally assumed that this trend is due to a dust-induced selection bias: DLA systems with high NHI and high metallicit...

OBJECTIVES Sino-nasal cancer has been consistently associated with exposure to wood dust, leather dust, nickel and chromium compounds; for other occupational hazards, the findings are somewhat mixed. The aim of this study was to investigate the risk of sino-nasal epithelial cancer (SNEC) by histological type with prior exposure to suspected occupational risk factors and, in particular, those in...

climate change is defined as long term and irreversible changes in the climatic behaviorof a region. many studies have been conducted in different regions of the world on climatechange. the results of these studies show considerable changes in climatic factors especiallyin precipitation and temperature. in this research, the trend of changes in annual and seasonalrainfall and temperature in 24 ...

1. introduction dust storm is an important atmospheric phenomenon. it has important environment, health, economic and social activities due to penetration of suspended particles of dust to the atmosphere. measurements resulting from earth and satellite stations show the fact that particles of dust in storms, remain in the nature for a long time. they can get far away by wind, hundreds of kilome...

Background & Aims of the Study: According to statistics reported by the international organization, 500,000 people annually due to airborne particulate matter exposure of the air are dying prematurely. Studies show the dust storm is responsible for the 7.1 % increase of fatality. Control of particulate matter is one of the most important methods of direct and indirect effects of par...

The Lake Maggiore catchment is the area of Italy most affected by acid deposition. Trend analysis was performed on long-term (15-30 years) series of chemical analyses of atmospheric deposition, four small rivers draining forested catchments and four high mountain lakes. An improvement in the quality of atmospheric deposition was detected, due to decreasing sulphate concentration and increasing ...