A system to record the ultraviolet (UV) spectra of atmospheric global irradiance with the miniature fiber optic spectrometer AvaSpec-256 was developed for continuous computer-aided spectrometry at Tartu Observatory in 2005. As a result, the database of spectra recorded with 15-min-interval round 24h over 300–400nm, has been de5 veloped. The quantities retrieved from the spectra have been compar...

A combined theoretical and experimental study on the structure, infrared, UV-Vis and 1H NMR data of trans-2-(m-cyanostyryl)pyridine, trans-2-[3-methyl-(m-cyanostyryl)]pyridine and trans-4-(m-cyanostyryl)pyridine is presented. The synthesis was carried out with an efficient Knoevenagel condensation using green chemistry conditions. Theoretical geometry optimizations and their IR spectra were ca...

FOS spectra and FOC photometry of two centrally located, UV-bright spikes in the elliptical galaxy NGC 4552 and the bulge-dominated early spiral NGC 2681, are presented. These spectra reveal that such point-like UV sources detected by means of HST within a relatively large fraction (∼ 15%) of bulges can be related to radically different phenomena. While the UV unresolved emission in NGC 4552 re...

Using five high-resolution (λ/∆λ ≈ 3000) FUV (λλ = 910–1210 Å) spectra acquired in 1996 December during the flight of the ORFEUS-SPAS II mission, 47 archival IUE short-wavelength UV (λλ = 1150–1950 Å) spectra, and archival EUVE deep survey photometry (λλ ≈ 70–200 Å), we present a detailed picture of the behavior of the magnetic cataclysmic variable EX Hydrae in the vacuum ultraviolet. Like HUT ...

three antituberculosis medications are investigated in this work consist of rifampicin, isoniazid and pyrazinamide. the ultra violet (uv) spectra of these compounds are overlapped, thus use of suitable chemometric methods are helpful for simultaneous spectrophotometric determination of them. a generalized version of net analyte signal standard addition method (gnassam) was used for determinatio...

Urocanic acid (UCA) is a major UV chromophore in the upper layers of the skin where it is found predominantly as the trans isomer. UV irradiation induces photoisomerisation of trans-UCA to cis-UCA which has been shown to mimic some of the immunosuppressive properties of UV exposure. We examined the wavelength dependence for trans-UCA to cis-UCA photoisomerisation in vitro and in mouse skin in v...

UV-vis optical absorption spectra of the antitrypanocidal drug benznidazole solvated in water were measured for various concentrations. The spectra show a prominent peak around 3.80 eV, while deconvolution of the UV-vis optical absorption spectra revealed six bands centered at 3.60, 3.83, 4.15, 4.99, 5.60, and 5.76 eV. Benznidazole electronic transitions were obtained after density functional t...

Using an automated simulated annealing (SA) procedure, spectrum decomposition on angular measurements of tooth enamel fragments shows that UV irrad iation of modern human and fossil bovid samples results in distinctively different ESR spectra. In the fossil sample, UV irradiation generates qualitatively identical spectra to natural. The amounts of non-oriented CO2 radicals in the modern and fos...