[en] Full text of publication follows. Fluorescence detection is often used to measure XAFS spectra of diluted or thick samples that cannot be measured in the normal transmission mode. For the last two decades mostly energy-dispersive semi-conductor detectors were used for this task. Because of the limited energy resolution of these detectors, nowadays also secondary monochromator systems are used to gain more energy resolution. The usage of this systems is limited because the number of beamlines for RIXS and similar techniques is restricted to a view insertion devise beamlines on mainly third generation sources and the needed intensity is so high that it could cause changes in the speciation of the sample. But even for the usage of semi-conductor detectors is nevertheless of utmost importance to separate the interesting fluorescence line as good as possible from neighbouring emission lines and from the peak caused by elastically scattered photons. Especially the scattering line can cause sever problems, because it changes it's position depending on the excitation energy. Modern fluorescence detector electronics therefore allow the user to store the complete fluorescence spectra for each energy of the monochromator during a XAFS scan. This enables to perform an elaborate peak fitting procedure and thus minimizes the background contribution to the fluorescence yield-XAFS (fl-XAFS) spectra. To enable the post processing of the acquired data a set of procedures in IgorPro 5 was developed. For a 3-dimensional graphical display of data the OpenGL-plotter of IgorPro is used. Additional to the fitting procedures it is also possible to set new SCA-windows. The fitting procedure uses a multiple Gauss peaks to a sub range of a set of spectra. Especially very diluted systems induces a lot of problems to the background subtraction in a standard data EXAFS data evaluation, because of a steadily decreasing overlap of the peak of interest with the elastic and inelastic scattering peaks. The two main advantages is the reduction of the background before the absorption edge and the correction a complex slope after the absorption edge. (author)

[en] Knowledge on the behavior of sulfur in the environment requires investigation on a molecular level. With that, chemical states of sulfur can be determined and can be used to track, e.g., microbially catalyzed remediation measurements of acidic mine waters and mineral bacteria interactions. ANKA provides an X-ray absorption beamline that is optimum for measurements at the sulfur K edge. Basics, experimental set-up, applications, and future upgrades are presented. (orig.)

[en] Zirconolite-based (nominally CaZrTi₂O₇) glass-ceramics belonging to the SiO₂Al₂O₃-CaO- ZrO₃-TiO₂ system are good waste forms for the specific immobilisation of actinides. The understanding of their crystallisation processes implies to investigate the structure of the glass. Thus, the environment around Ti, Zr (nucleating agents) and Nd (trivalent actinides surrogate) was characterised in parent glasses. Electron spin resonance (ESR) study of the small amount of Ti³⁺ occurring in the glass enabled to identify two types of sites for titanium: the main one is of C_4v or D_4h symmetry. EXAFS showed that Zr occupied a quite well defined 6-7-fold coordinated site with second neighbours which could correspond to Ca/Ti and Zr. Nd environment was probed by optical spectroscopies (absorption, fluorescence), ESR and EXAFS. All these techniques demonstrated that the environment around Nd was very constrained by the glassy network. Notably, Nd occupies a highly distorted 8-9-fold coordinated site in the parent glass. (authors)

[en] X-ray absorption spectroscopy has been applied to the study of the Belousov-Zhabotinsky reaction. Ultraviolet-visible spectroscopy has been used as the reference spectroscopic technique. The extent of the reaction has been followed continuously by acquiring the X-ray absorption at specific photon energies during the process. Oxidation states as well as local structural data of the cerium catalyst and the bromine reactant species during self sustained chemical oscillations have been determined.

[en] Different methods have been proposed to calculate the vertical position of the photon beam centroid from the four blade currents of staggered pair X-ray beam position monitors (XBPMs) at bending magnet beamlines since they emerged about 15 years ago. The original difference-over-sum method introduced by Peatman and Holldack is still widely used, even though it has been proven to be rather inaccurate at large beam displacements. By systematically generating bumps in the electron orbit of the ANKA storage ring and comparing synchronized data from electron BPMs and XBPM blade currents, we have been able to show that the log-ratio method by S. F. Lin, B.G. Sun et al. is superior (meaning the characteristic being closer to linear) to the ratio method, which in turn is superior to the difference over sum method. These findings are supported by simulations of the XBPM response to changes of the beam centroid. The heuristic basis for each of the methods is investigated. The implications on using XBPM readings for orbit correction are discussed

[en] Besides ischemic heart disease cardiomyopathies are common causes of heart failure and sudden cardiac death. The diagnostic spectrum in cardiomyopathies comprises non-invasive and invasive examination techniques. The exact verification of certain cardiomyopathies necessitates knowledge of the latest classification of cardiomyopathies as well as dedicated examination protocols. Modern imaging modalities, such as echocardiography and cardiac magnetic resonance imaging (MRI) have emerged as useful imaging tools in the investigation of patients suspected of having many different types of cardiomyopathies. Based on a better understanding of the underlying pathophysiology several diagnostic criteria have been defined using cardiac MRI. In particular there is an increasing importance of cardiac MRI in the description of patients with restrictive and unclassified cardiomyopathies. Echocardiography still remains the modality of choice in the diagnostics of unclear left ventricular heart failure. Further diagnostic work-up should include cardiac MRI in case of any lack of clarity. (orig.)

[en] The purpose of this study is to better understand redox transitions associated with the adsorption of Cr(VI) on soil components and their synthetic mixtures. Previous surface complexation modeling results (SCM) confirmed, that Cr(VI) adsorption in the mixtures is controlled by iron oxides and (oxy)hydroxides. In addition, a coupled spectroscopic and isotope approach has been used in order to obtain a more detailed insight into the accompanied redox processes. Developing an isotopic tool to assess redox and adsorption processes in mixtures of different soil components is important in order to enable its further application and verification on natural soils. (authors)

[en] Purpose: To evaluate a novel monoenergetic post-processing algorithm (MEI+) in patients with poor intrahepatic contrast enhancement. Materials and Methods: 25 patients were retrospectively included in this study. Late-phase imaging of the upper abdomen, which was acquired in dual-energy mode (100/140 kV), was used as a model for poor intrahepatic contrast enhancement. Traditional monoenergetic images (MEI), linearly weighted mixed images with different mixing ratios (MI), sole 100 and 140 kV and MEI+ images were calculated. MEI+ is a novel technique which applies frequency-based mixing of the low keV images and an image of optimal keV from a noise perspective to combine the benefits of both image stacks. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the intrahepatic vasculature (IHV) and liver parenchyma (LP) were objectively measured and depiction of IHV was subjectively rated and correlated with portal venous imaging by two readers in consensus. Results: MEI+ was able to increase the SNR of the IHV (5.7 ± 0.4 at 40 keV) and LP (4.9 ± 1.0 at 90 keV) and CNR (2.1 ± 0.6 at 40 keV) greatly compared to MEI (5.1 ± 1.1 at 80 keV, 4.7 ± 1.0 at 80 keV, 1.0 ± 0.4 at 70 keV), MI (5.2 ± 1.1 M5:5, 4.8 ± 1.0 M5:5, 1.0 ± 3.5 M9:1), sole 100 kV images (4.4 ± 1.0, 3.7 ± 0.8, 1.0 ± 0.3) and 140 kV images (2.8 ± 0.5, 3.1 ± 0.6, 0.1 ± 0.2). Subjective assessment rated MEI+ of virtual 40 keV superior to all other images. Conclusion: MEI+ is a very promising algorithm for monoenergetic extrapolation which is able to overcome noise limitations associated with traditional monoenergetic techniques at low virtual keV levels and consequently does not suffer from a decline of SNR and CNR at low keV values. This algorithm allows an improvement of IHV depiction in the presence of poor contrast. (orig.)

[en] Full text: Soil samples collected inside and outside an industrial polluted area of national environmental interest located in 'Val Basento' (Basilicata, Italy) have been studied by a combination of different advanced analytical techniques exploiting high intensity synchrotron generated x-rays. Mercury (Hg) concentration in the soil ranged from 1 up to 250 μg/g. Bulk EXAFS (Extended x-ray Absorption Fine Structure spectroscopy) and XANES (x-ray Absorption Near Edge Structure spectroscopy) were performed on soil samples sieved at 2 mm and on the clay fraction (< 2 μm), where the highest amount of Hg was concentrated. In addition to bulk XAS investigations, microanalyses on soil thin sections by combined μ-XRF/μ-XRD (micro x-ray fluorescence / micro x-ray diffraction) and μ- XANES, with a resolution from 10 to 20 μm, were also performed. μ-XRF maps were collected in order to localize microscopic Hg containing particles in areas of ca. 1 mm². Simultaneous to μ-XRF spectra, microdiffraction patterns were collected in each point of the maps, in order to identify any correlation between Hg and its mineralogical forms. Once points of interest were localized, μ-XANES spectra were collected and compared with the spectra of known Hg standard compounds. The combination of bulk XAS and microbeam measurements not only provide a detailed Hg speciation at the microscale level, enables better interpretation of the higher length bulk scale XAS spectra in the light of the more easily manageable information obtained from microanalyses. From this combined synchrotron x-ray spectroscopic investigation, we find that Hg was mainly speciated as HgS (cinnabar) and Hg(0) in the samples collected inside the industrial site and as Hg₂Cl₂, HgCl₂ and Hg bound to organic matter in the samples collected in the areas surrounding the industrial site. Quantification of the percentage of the various Hg forms in the soil samples was also obtained. This type of pollution is typical of industrial areas where chlor-alkali plants have been operating in the past. The detailed Hg speciation will allow for a better assessment of the environmental and human risk connected to Hg contamination of these soils, as well as to develop more effective remediation strategies for an environmental restoration of the area. (author)

[en] We report on the structure and arrangement of particles created in the Fe_2O_3/TiO_2 + SiO_2 multilayers. X-ray diffraction and extended X-ray absorption fine structure spectroscopy reveal the presence of crystalline rutile-TiO_2 while the iron oxide remains either amorphous or forms very small clusters of Fe_2O_3. The Fe"3"+ oxidation state of iron atoms has been confirmed by Mössbauer and X-ray spectroscopy. The degree of the particle ordering has been studied by grazing-incidence small-angle X-ray scattering. It was demonstrated that with increasing temperature partially ordered nanoparticles are created and grow up to a critical temperature when the ordering is destroyed. Both particle sizes and inter-particle distances depend strongly on the thickness of the Ti/Fe containing layer. - Highlights: • Titanium oxide forms ordered rutile nanoparticles after annealing. • Iron (Fe"3"+) oxide remains in amorphous-like state up to 1000 °C. • Particle sizes and inter-particle distances depend strongly on the layer thickness