A. Herring, OSU, uses tomography at 13 BMD to quantify pore scale trapping and to analyze how mechanisms affect the efficiency of capillary trapping of CO2 in saline aquifers.

Tomography at 13 BMD

A Best-Yet Cell Culture System for Age-Related Macular Degeneration

An international team utilizing 13-ID-E has developed a cell culture model that could help to develop earlier treatment strategies for age-related macular degeneration (AMD). Details in ANL Science Highlights based on press release from the University of Alabama at Birmingham.

A Best-Yet Cell Culture System for Age-Related Macular Degeneration

X-ray diffraction patterns from a diamond anvil cell (DAC).

X-ray diffraction is the most powerful technique for crystal structure determination. From left to right, patterns from a single crystal, polychrystalline, nano-cyrstalline and amorphous crystals.

X-ray diffraction patterns from a diamond anvil cell.

High pressure x-ray tomographic microscopy module

The HPXTM module helps researchers study the texture change of their sample under extreme pressure and temperature conditions by collecting in-situ HP/HT 3D x-ray tomographic images.

High Pressure X-ray Tomographic Microscopy Module sitting outside of the 250 ton press in 13 BMD.

GSECARS hosts experiments at 13 IDE for high school students in the Exemplary Student Research Program (ESRP) representing local area high schools. GSECARS Outreach

GSECARS Outreach

GSECARS is a national user facility
for frontier research in the earth sciences using synchrotron radiation at the
Advanced Photon Source, Argonne National Laboratory.

GSECARS provides earth scientists with access to the high-brilliance hard x-rays from this third-generation synchrotron light source. All principal synchrotron-based analytical techniques in demand by earth scientists are being brought to bear on earth science problems:

  • High-pressure/high-temperature crystallography and spectroscopy using the diamond anvil cell
  • High-pressure/high-temperature crystallography and imaging using the large-volume press
  • Powder, single crystal and interface diffraction
  • Inelastic x-ray scattering
  • X-ray absorption fine structure spectroscopy
  • X-ray fluorescence microprobe analysis
  • Microtomography

► ANL Introduce a Girl to Engineering Day 2017

GroupShot_March2017sm.jpg

GSECARS beamline scientists, Dr. Joanne Stubbs and Dr. Margaret Koker, volunteered with the ANL Introduce a Girl to Engineering Day event. This outreach program for middle school aged girls provided an opportunity for the young students to learn about STEM careers with presentations, tours and hands-on activities. 
                             Event Web Site ♦  Group Photo


Science Highlights

Titanium, vanadium and chromium valences in silicates of ungrouped achondrite NWA 7325 and ureilite Y-791538 record highly-reduced origins.

Fig2_75.jpg

Backscattered electron image of the Y-791538 thin section showing the locations of olivine (yellow labels) and pyroxene (white labels; PIG = pigeonite, OPX = orthopyroxene) grains for XANES analysis. The bright veins are metal or terrestrial iron oxides.

                                                       Abstract

Titanium, Cr, and V valences were determined by applying micro-X-ray Absorption Near Edge Structure (micro-XANES) spectroscopy methods to individual grains of olivine and pyroxene in the ungrouped achondrite NWA 7325 and ureilite Y-791538, as well as to plagioclase in NWA 7325. The advantages of applying multiple, multivalent-element-based oxybarometers to individual grains are (1) the ability to cover the entire oxygen fugacity (fO2) range encountered in nature, and (2) the increased reliability from consistent results for semi-independent fO2 proxies. fO2 values were inferred from each mineral valence determination after correcting with available laboratory-experiment-derived, valence-specific partition coefficients to obtain melt valences and then calibrating with the fO2 values of the relevant equal species proportions points suggested for igneous (primarily basaltic) systems.

The resulting olivine and pyroxene valences are highly reduced and similar in the two meteorites with substantial fractions of Cr2+, Ti3+ and V2+. The exception is Cr in NWA 7325 pyroxene which is much more oxidized than the Cr in its olivine. Chromium and Ti in plagioclase in NWA 7325 is relatively oxidized (V valence not determined). The anomalously oxidized Cr in NWA 7325 pyroxene may be due to a secondary reheating event that oxidized Cr in the pyroxene without similarly oxidizing Ti and V. Such a separation of the redox couples may be an effect of re-equilibration kinetics, where the valence of Cr would be more rapidly modified. These valences yielded similar mean fO2s for the two meteorites; IW-3.1 ± 0.2 for NWA 7325 and IW-2.8 ± 0.2 for Y-791538, consistent with an origin of NWA 7325 in either Mercury or an asteroid that experienced redox conditions similar to those on the ureilite parent body.

S.R. Sutton, C.A. Goodrich, S. Wirick, "Titanium, vanadium and chromium valences in silicates of ungrouped achondrite NWA 7325 and ureilite Y-791538 record highly-reduced origins," Geochim. Cosmochim. Acta 204, 313-330 (2017). DOI: 10.1016/j.gca.2017.01.036