In ray tracing, it is standard practice to consider solely the real part of any medium’s refractive index for determining the changes in a ray’s direction at the interface between two media. Any absorption is accounted for by reducing the intensity or weight of the ray in accordance with its propagation distance. This practice is adequate at optical wavelengths where absorption is generally ver...

Balloon expandable stents can be used to treat coronary stenosis. During stent implantation, X-ray imaging is used. In order to assist the doctors, it was decided to improve the cardiovascular stents’ X-ray absorption ability by placing a unique marker in the stent strut. Tantalum powder, with 98% purity and 3-10 μm grains diameter, was used as the stent integrated marker. The stents were laser...

Light-driven oxidation of water to dioxygen in plants, algae, and cyanobacteria is catalyzed within photosystem II (PS II) by a Mn 4Ca cluster. Although the cluster has been studied by many different methods, its structure and mechanism have remained elusive. X-ray absorption and emission spectroscopy and extended X-ray absorption fine structure studies have been particularly useful in probing ...

Abstract The existing setup for time-resolved quick-scanning X-ray absorption spectroscopy (QEXAFS) at beamline P64 the PETRA III storage ring is complemented by new infrastructure suited collection of diffraction data simultaneously to QEXAFS experiment. In particular, sinusoidal periodic movements quick-EXAFS mono-chromator are modified in such a way, that an energy plateau with approximately...

PURPOSE Strontium has chemical similarity to calcium, which enables the replacement of calcium by strontium in biomineralization processes. Incorporating strontium into human bone and teeth has been studied extensively but little research has been performed of the incorporation of strontium into urinary calculi. We used synchrotron based x-ray fluorescence and x-ray absorption techniques to exa...

We have surveyed the optical linear polarization of a completely identified sample of 43 bright soft-X-ray-selected ROSAT AGN. Most (40) of these AGN show low polarization (∼<1%), and no clear optical reddening. This supports the suggestion from rapid X-ray variability, disk-like spectral energy distributions, and lack of cold X-ray absorption, that we are viewing a bare AGN disk. IRAS F12397+3...

A number of emission and absorption features are expected to be visible in high energy resolution X-ray spectra of type 1 AGN with ionized gas along the line of sight (so called " warm absorbers "). Emission strongly depends on the geometrical configuration of the gas, while absorption along the line of sight does not. Absorption features include photoelectric absorption K and L edges along wit...