UNLABELLED • PREMISE OF THE STUDY Although ultraviolet radiation (UV) is known to have negative effects on plant growth, there has been no direct evidence that plants growing at higher elevations are more severely affected by ultraviolet-B (UV-B) radiation, which is known to increase with elevation. We examined damage to DNA, a primary target of UV-B, in the widespread species Polygonum sacha...

Plants use sunlight for photosynthesis and, as a consequence, are exposed to the ultraviolet (UV) radiation that is present in sunlight. UV radiation is generally divided into three classes: UV-C, UV-6, and UV-A. The UV-C region of the UV spectrum includes wavelengths below 280 nm; these highly energetic wavelengths are effectively absorbed by ozone in the stratosphere and, thus, are not presen...

ultraviolet radiation (uvr) has been accepted as an attractive alternative to chlorination for the disinfection of wastewater. in this study the effluent from sahebgaranieh treatment plant was subjected to changes in uv transmission and turbidity in order to correlate these commonly measured parameters with the performance of a submerged -uv- reactor employed in disinfecting the effluent. studi...

background and purpose: highly consumption of antibiotics and their entrance into the environment has increased concerns all over the world. these compounds enter to the environment through an incomplete metabolism and a considerable amount of them cannot be removed using usual waste filtration systems. therefore, the present study aimed to investigate the feasibility of using ultraviolet radia...

This work addresses the issue as to whether ultraviolet radiation of wavelengths longer than 200 nm can break Si-CH3 bonds in porous low-k dielectrics. To resolve this issue, porous SiCOH films (k = 2.3) were exposed to 4.9 eV (254 nm) ultraviolet (UV) radiation in both air and vacuum for 1 hour. Using Fourier Transform Infrared (FTIR) spectroscopy, the chemical structures of the dielectric fil...

Increases in the terrestrial levels of ultraviolet-B (UV-B) radiation (280 to 320 nm) due to diminished stratospheric ozone have prompted an investigation of the protective mechanisms that contribute to UV-B tolerance in plants. In response to UV-B stress, flowering plants produce a variety of UV-absorptive secondary products derived from phenylalanine. Arabidopsis mutants with defects in the s...

The present study was focused to examine the combined effects of climate and ultraviolet-B radiation on conifer tree-ring density. Statistical methods were employed to extract tree responses in annual ring density and to identify functional relationship in trees when the level of ultraviolet-B radiation changes regardless of climate variations. In this study, the consideration was given to the ...

The effects of ultraviolet (UV) radiation on ionizing radiation biodosimetry were studied in human tooth enamel samples using the technique of electron paramagnetic resonance (EPR) in X-band. For samples in the form of grains, UV-specific EPR spectra were spectrally distinct from those produced by exposure to gamma radiation. From larger enamel samples, the UV penetration depth was determined t...