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...

Bailey, Glen F. (Western Regional Research Laboratory, Albany, Calif.), Saima Karp, and L. E. Sacks. Ultraviolet-absorption spectra of dry bacterial spores. J. Bacteriol. 89:984-987. 1965.-The possibility of obtaining reasonably satisfactory ultraviolet-absorption spectra of dry spores embedded in KBr has been demonstrated. Such spectra show the three peaks characteristic of calcium dipicolinat...

Two approaches for the determination of the background absorption (p0 ) in the extended xray-absorption fine structure (EXAFS) are presented. Both methods, experimental and computational, take advantage of the damping of the EXAFS amplitude resulting from the convolution with Gaussian functions of different widths. In the experimental method two or more spectra are collected with the use of dif...

We consider fundamental structures in x-ray absorption spectra over a wide energy range. We formulate the elastic scattering in addition to the photoelectric absorption in recently reported photon interference x-ray absorption fine structure (pXAFS). The simulations show excellent agreement with experimental x-ray absorption spectra for platinum and tungsten powders far above and below the L ab...

We present density-functional theory calculations of the optical absorption spectra of silica glass for temperatures up to 2400 K. The calculated spectra exhibit exponential tails near the fundamental absorption edge that follow the Urbach rule in good agreement with experiments. We discuss the accuracy of our results by comparing to hybrid exchange correlation functionals. We show that the Urb...

Owing to its element specific and short-range nature, core-level X-ray absorption spectroscopy (XAS) is now routinely used to elucidate the local structural, vibrational, and other physical properties of complex, aperiodic materials. XAS encompasses both extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge spectra (XANES) [1, 2], where the terms refer, respectively, t...

Detailed examination of the absorption spectra from dark ocean samples allowed us to identify and deconvolve two distinct chromophores centered at 302 nm (UV) and 415 nm (visible) from the exponential decay curve characteristic of humic substances. The UV chromophore was ubiquitous in intermediate and deep waters, and it has been proposed as the secondary absorption peak of nitrate. The visible...

Although the ultraviolet absorption spectra of most of the amino acids have been reported many times, in nearly all instances the spectra were limited to the region above approximately 220 rnp. Below this wavelength the absorption curves rise steeply into what has been considered a region of general, or continuous, or end-absorption. Most investigators have failedto examine this region closely....

The emergence of hyperspectral optical satellite sensors for ocean observation provides potential for more detailed information from aquatic ecosystems. The German hyperspectral satellite mission EnMAP (enmap.org) currently in the production phase is supported by a project to explore the capability of using EnMAP data and other future hyperspectral data from space. One task is to identify phyto...