A5042891418- Geological and Geochemical Analysis
- Radioactive element chemistry and processing
- High-pressure geophysics and materials
- Geochemistry and Geologic Mapping
- Iron oxide chemistry and applications
- X-ray Spectroscopy and Fluorescence Analysis
- Glass properties and applications
- Advanced X-ray Imaging Techniques
- Diamond and Carbon-based Materials Research
- Advanced Materials Characterization Techniques
- Nuclear Materials and Properties
- Extraction and Separation Processes
- Hydrocarbon exploration and reservoir analysis
- Clay minerals and soil interactions
- Freezing and Crystallization Processes
- Minerals Flotation and Separation Techniques
- Heavy metals in environment
- Inorganic Fluorides and Related Compounds
- Mineral Processing and Grinding
- Chemical Synthesis and Characterization
- Soil and Unsaturated Flow
- Cardiac Valve Diseases and Treatments
- Mine drainage and remediation techniques
- Corrosion Behavior and Inhibition
- Mineralogy and Gemology Studies
Deutsches Elektronen-Synchrotron DESY
2010-2023
University of Münster
2022-2023
Dioxide Materials (United States)
2012
Beijing Research Institute of Uranium Geology
2012
University of Potsdam
2008-2010
GFZ Helmholtz Centre for Geosciences
2010
Philips (Netherlands)
1990
Zirconium and hafnium behave nearly identically in most geological processes due to their identical nominal ionic charge similar radius. Some of the pronounced exceptions from this rule are observed fluoride-rich aqueous systems, suggesting that fluoride complexation may be involved Zr/Hf fractionation. To understand mechanisms causing phenomenon, we investigated Zr4+ Hf4+ (1.0 mol/kg HF) solutions at 40 MPa 100 - 400 °C, using synchrotron X-ray absorption spectroscopy (X-ray near edge...
Abstract. Tungsten (W) concentrations in fluids equilibrium with crystalline tungsten oxide are used to determine thermodynamic parameters for W solubility and species hydrothermal fluids. The data were measured situ at high pressures temperatures using X-ray absorption. spectroscopic – absorption near-edge structure (XANES) extended fine (EXAFS) applied characterize the symmetry type of atoms first coordination shell aqueous complexes present fluid given pressures. Experiments performed up...
A confocal set-up is presented that improves micro-XRF and XAFS experiments with high-pressure diamond-anvil cells (DACs). In this experiment a probing volume defined by the focus of incoming synchrotron radiation beam polycapillary X-ray half-lens very long working distance, which placed in front fluorescence detector. This enhances quality spectra, thus sensitivity for detecting elements at low concentrations. It efficiently suppresses signal from outside sample chamber, stems elastic...
Data on partitioning behavior of elements between different phases at in situ conditions are crucial for the understanding element mobility especially geochemical studies. Here, we present results trace (Zr, Pd, and Ru) silicate iron melts, up to 50 GPa 4200 K, using a modified laser heated diamond anvil cell (DAC). This new experimental set allows simultaneous collection x-ray fluorescence (XRF) diffraction (XRD) data as function time high pressure beamline ID27 (ESRF, France). The...
High-field-strength elements such as Zr and Hf are important geochemical indicators for processes in the deep Earth. Aqueous fluids play a significant role transport of heat matter these systems. However, concentrations complexation at high pressure (P) temperature (T) conditions largely unknown. Zr/Hf contents were determined in-situ P T aqueous containing NaOH, HCl or Na-Al silicate components equilibrium with zircon baddeleyite. Concentrations strongly enhanced comparison to pure H2O. The...
We present a new autoclave that enables in situ characterization of hydrothermal fluids at high pressures and temperatures synchrotron x-ray radiation sources. The has been specifically designed to enable absorption spectroscopy with applications mineral solubility element speciation analysis complex compositions. However, other applications, such as Raman spectroscopy, high-pressure are also possible the autoclave. First experiments were run between 100 600 bars 25 °C 550 °C, preliminary...
X-ray absorption near edge structure (XANES) is recorded for nano- and micro-particles formed in Mo doped UO2 thin films (TFs) prepared by situ sputter co-deposition 1000°C tempering. These UO2/Mo TFs are intended to serve as synthetic models -particles spent nuclear fuel. We find that when Si used substrate, nano-sized zero-valent particles form desired. However, these embedded USi3, which forms at the high temper temperatures. Micron-sized Mo-particles SiO2 substrate. Using focussed beams...
Synchrotron-based X-ray microfluorescence (µSXRF) is an analytical method suitable for in situ investigation of the distribution micronutrient and macronutrient elements several-micrometres-thick unstained biological samples, e.g. single cells tissues. Elements are mapped quantified at sub-p.p.m. concentrations. In this study quantity, grouping/co-localization various have been identified straight twisted internodes stems monocotyledonous climber D. balcanica Košanin. Three different...
The German Guidelines for stainless steel in buildings (Z.30.3-6) issued by the Institute Building Technology (DIBt) categorizevarious grades into five corrosion resistance classes (CRCs). Only 21 frequently used are approved and assigned to these CRCs. To assign new or less commonly materials, a large program of outdoor exposure tests laboratory is required. present paper shows theresults stress cracking (SCC) that can distinguish between different Slow strain rate (SSRT) were performedin...
Lithographically generated well-defined surface topography of submicron dimensions has been etched into silicon (100) previously implanted with 25 keV 11B to a fluence 2×1014 atoms/cm2. The thus-obtained samples were depth profiled via secondary-ion mass spectrometry (SIMS). boron concentration distributions measured contrasted against those found on undisturbed flat parts the target. From this intercomparison otherwise trivial observation that causes profile distortion becomes suddenly...
Microsymposia C168they are related to the network structure formed by hydrogen bonds between water molecules.Due directional bonds, coordination number of molecules at ambient conditions is much smaller than that simple liquid such as metals and rare gases.We have measured x-ray diffraction under high-pressure high-temperature just above melting line up 9 GPa 690 K using a cubic-type multi-anvil press BL14B1 17 850K Kawai-type BL04B1 in SPring-8 [1].The increased rapidly 4 while maintaining...