We use a sample of 332 Hubble Space Telescope spectra of 184 QSOs with z > 0.33 to study the typical ultraviolet spectral properties of QSOs, with emphasis on the ionizing continuum. Our sample is nearly twice as large as that of Zheng et al. (1997) and provides much better spectral coverage in the extreme ultraviolet (EUV). The overall composite continuum can be described by a power law with i...

The Quantitative Assessment of Solar UV [ultraviolet] Exposure for Vitamin D Synthesis in Australian Adults (AusD) Study aimed to better define the relationship between sun exposure and serum 25-hydroxyvitamin D (25(OH)D) concentration. Cross-sectional data were collected between May 2009 and December 2010 from 1,002 participants aged 18-75 years in 4 Australian sites spanning 24° of latitude. ...

background: organophosphorus pesticides are one of the most consumable poisons. such poisons can enter water sources by different routes. since consuming some drinking water containing an amount of poison higher than the standard level, causes undesirable effects on human health. this research aimed to study the effectiveness of elimi­nating malathion from water by ultraviolet irradiation (uv) ...

background: carbaryl (1-naphthyl-n-methyl carbamate) is a chemical in the carbamate family used chiefly as an insecticide. it is a cholinesterase inhibitor and is toxic to humans and classified as a likely human carcinogen. in the present study, the degradation of the carbaryl pesticide was investigated in the laboratory synthetic samples of tap water, in the effect of sonolysis and photolysis ...

background: benzene is one of the most widely used volatile organic compounds showing severely adverse effects on human health. removing benzene from the airflow or controlling its amounts, is one of the issues put to discussion in the field of environmental engineering. the objective of this study was to examine the efficacy of the ultraviolet-c (uv-c) radiations on removing benzene from the a...

We present ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) of 12 early B-type stars in the Small Magellanic Cloud (SMC), comprising 9 supergiants and 3 giants. A morphological comparison with Galactic analogues is made using archival data from the International Ultraviolet Explorer (IUE). In general, the intensity of the P Cygni emission in the UV resonance lines is gre...

The ultraviolet radiation present in sunlight is immune suppressive. Recently we showed that solar-simulated ultraviolet radiation (ultraviolet A + B; 295-400 nm), applied after immunization, suppressed immunologic memory and the elicitation of delayed-type hypersensitivity to the common opportunistic pathogen, Candida albicans. Further, we found that wavelengths in the ultraviolet A region of ...