The data on the far-ultraviolet extinction of starlight in our galaxy and in external galaxies is interpreted in terms of the widespread occurrence of organic particles of optical refractive index 1.4 and radii less than or equal to 20 nm. Such particles are candidates for nanobacteria such as recently been found in abundance on the Earth.

ultraviolet waves, because of their short wavelength, have a high energy and considerable damaging effects on surfaces. protection against ultraviolet radiations is one of the finishing treatments done on surfaces exposed to sunlight. the importance of this issue in relation to human health, due to complications such as skin burns and cancer, is doubled. up to now, different materials such as z...

Ultraviolet (UV) exposure significantly contributes to non-melanoma skin cancer. In the context of health, UV is product time and Index (UVI), a weighted sum irradiance I(λ) over all wavelengths from λ = 250 400 nm. our analysis United States Environmental Protection Agency’s UV-Net database 400,000 spectral measurements taken several years, we found that UVI well estimated by 77 I310. To furth...

We investigate ultraviolet fixed points in the real-time evolution of non-Abelian gauge fields. Classical-statistical lattice simulations reveal equal-time correlation functions with a spectral index κ = 1.5. Analytical understanding of this result is achieved by employing a 2PIloop expansion for the quantum theory.

We demonstrate spectrally resolved transient grating (TG) spectroscopy in the extreme ultraviolet (EUV) near the M-edge of vanadium dioxide. Timedependent and broadband EUV-TG measurements separate the index of refraction change due to the insulator to metal transition from purely acoustic effects.

chemical methods ( actinometry ) depend on the measurement of the extent to which a chemical reaction occurs under the influence of uv light. two chemical actinometers have been used in this research. in one method, the mixtures of potassium peroxidisuiphate butanol solutions were irradiated for various time intervals, and ph-changes were determined. a linear relationship was observed between t...

drought, ultraviolet radiation and atmospheric co2 are some three environmental factors that seriously affect future food security. the objective followed in the present research was to study the effect of two levels of carbon dioxide (400 and 900 ppm), ultraviolet radiation (uv a, b and c with intensities of 18, 25 and 40 microw.cm-2 respectively) and water deficit (%100 and %60 of field capac...