Heavy metal pollutionis one of the largest problems in the Environment and human being. In industrial and urban areas trees can give better quantifications for pollutant concentrations and atmospheric deposition than non-biological samples. In order to know ability of Fraxinus excelsior­ (Ash tree) to reduce the concentrations of heavy metals and compared with the concentration of thes...

Spitzer Space Observatory IRAC and MIPS photometric observations are presented for 20 white dwarfs with Teff . 20, 000 K and metal-contaminated photospheres. A warm circumstellar disk is detected at GD 16 and likely at PG 1457−086, while the remaining targets fail to reveal mid-infrared excess typical of dust disks, including a number of heavily polluted stars. Extending previous studies, over ...

The presence of metals in hot cluster gas and in Lyα absorbers, as well as the mass-metallicity relation of observed galaxies, suggest that galaxies lose a significant fraction of their metals to the intergalactic medium (IGM). Theoretical studies of this process have concentrated on metal removal by dynamical processes or supernova-driven winds. Here, we investigate the enrichment of the IGM b...

Using a high-resolution cosmological hydrodynamic simulation, we present a method to constrain extinction due to intergalactic gray dust based on the observed magnitudes of distant Type Ia supernovae. We apply several simple prescriptions to relate the intergalactic dust density to the gas density in the simulation, thereby obtaining dust extinctions that may be directly compared with the obser...

[1] Dusty regolith particles accumulate charge through grain-grain contact and contact with various surfaces. These processes affect vertical and horizontal transport and may cause electrical discharges in dust storms. We report the results of a simple experimental setup used to investigate the contact charging properties of two planetary analog dust samples: lunar (JSC-1) and Martian (JSC-Mars...

Sawdust is obtained from naturally and easily available which is biodegradable. The bio sorption capacity of the sawdust for hexavalent chromium was studied at different solution pH values (1.5-6), initial metal concentration (50450 mg/L), adsorbent dose (1-7 g/L). The maximum adsorption of Cr (VI) is obtained at pH 1.5, initial concentration 50 ppm and adsorbent dose 5 g/l. The adsorption of c...

Workers at metal machining workstations are exposed to airborne dust particles containing metals and their compounds. Their harmful impact on the workers' health depends on both their chemical composition and their distribution. The aim of this study was to determine the content of metals in dust fractions emitted in the process of mechanical machining of products made of brass, steel and cast ...

According to Pei, Fall & Hauser (1999), the global metallicity evolution of the Universe can be represented by the ratio of the total metal content to the total gas content measured in Damped Lyman–α (DLA) systems (the “column density weighted metallicity” à la Pettini). To minimize dust obscuration effects, a DLA sample with negligible dust content is considered, namely, 50 DLAs with logNHI < ...