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Ultrasonic interferometry was utilized in conjunction with synchrotron-based X-ray diffraction and X-radiographic imaging to determine the compressional and shear wave velocities and unlt-cdl volumes of pyrite （FeS2） at room temperature and pressures up to 9.6 GPa. Fitting all of the experimental volume and velocity data to third-order finite-strain equations yielded the adiabatic zero-pressure bulk and shear moduli and their first pressure derivatives： Ks0=138.9（7） GPa, Go=U2.3（3） GPa, （δKS0/δP）T=KS0＇=6.0（1）, （δG0/δP）T=G0＇=3.0（〈1）, where the numbers in parentheses represent the 1δ uncertainty in the last significant digit. These results are in good agreement with several previous static compression studies on this material but differ quite strongly from the results obtained via first principles calculations. This study presents the first direct measurement of the bulk shear properties of this material.

Ellis Reinherz and I were riding in a luxury Boston Coach to Long Island in New York State driven by a professional driver. This was not a vacation trip to one of the best leisure places in the United States. We were heading toward the National Laboratory at Brookhaven, where a powerful X-ray source is available in a facility called a synchrotron. The aim of our trip was to use a strong X-ray to shoot the crystals of the T cell receptor （TCR） we had just managed to grow after considerable effort for three-dimensional structure determination. In 1996, this was one of the hottest projects in structural biology as well as in immunology.

In order to improve the knowledge of the precipitation mechanism in martensitic steels containing carbon,XRD synchrotron experiments were performed. Firstly, the influence of Ni,Co and Al were studied and it was found that the precipitation of iron carbides occurs in same way as in Fe-C steel. However, with the addition of molybdenum and chromium in same steels, XRD synchrotron investigations clearly showed alloyed carbides directly precipitate, thereby preventing the iron carbides formation.

The CAS phase is a major constituent phase for the continental crust and basaltic compositions at the P-T conditions of the Earth＇s mantle, and potentially plays an important role in the geodynamic processes related to slab subduction. Its equation of state has been investigated here at ambient temperature up to about 25 GPa by using a diamond-anvil cell and synchrotron Xray radiation. Its P-V data, fitted to the third-order Birch-Murnaghan equation, yield an isothermal bulk modulus （KT） of 185 （9） GPa and first pressure derivative （ KT^t ） of 7.2 （12）. If KT^t is fixed at 4, file derived Kr is 212 （4） GPa. Additionally, the CAS phase is strongly elastically anisotropic, with its a-axis direction much less compressible than c-axis direction： Kr-a ： Kr-c = 2.19.

High concentrations of As in windblown and vehicle-raised dust from historical gold mine tailings in Nova Scotia, Canada pose a potential health risk for residents who use these areas for recreational activities. Routes of exposure may include inhalation of dust, as well as oral ingestion of particles. It is important to understand the particle size, chemical composition, and speciation of As in the tailings-derived dust to evaluate the human health risk, and the need for management actions. In this study, electron microprobe, conventional and synchrotron-based X-ray diffraction, X-ray absorption near edge structure, and sequential extraction methods were applied to near-surface tailings samples from three sites. Primary minerals in the tailings consist mainly of quartz, muscovite, clinochlore, and albite. Arsenic concentrations vary from 400×10^-6 to 28600×10^-6 in the bulk samples, and from 3000×10^-6 to 105000×10^-6 in the 〈38 μm fraction. These concentrations significantly exceed 12×10^-6 As, the Canadian Soil Quality Guideline. Arsenic in the tailings was originally in the form of arsenopyrite, but weathering reactions have oxidized most of the sulfide in near-surface samples. Scorodite （FeAsO4 · 2H2O） was found to be the dominant secondary phase in some samples. On a microscopic scale, scorodite cements silicate grains; in the field, it forms hardpans which have been pulverized by vehicle activity at some sites. Arsenic is also hosted in amorphous Fe arsenates, Ca-Fe arsenates, and Fe oxyhydroxides containing up to 30 wt% As2O5. To evaluate how much of this As is potentially bioaccessible, the samples were subjected to an in-vitro two-part extraction method designed to mimic the human digestive system. The results indicate that the percent of bioaccessible As is significantly higher in samples where As is hosted by Fe oxyhydroxides and Ca-Fe arsenates, as compared to the scorodite-rich samples.

The traditional XRF analysis with high limits of detection is limited in application for geochemical research. Use of synchrotron radiation considerably expands its opportunities. Since 1985 in BINP analytical work with syncrotron radiation from storage ring VEPP-3 has been carried out. A plenty of methodical and research work with geochemical samples has been executed. The range of energy excitation 15-50 keV is now accessible, which allows to determine the following elements in geological or biological samples weight from 1mg： P, S, Cl, K, Ca, Ti （LD=50× 10^-6, St.dev. =5× 10^-6）; V, Cr, Mn, Fe, Co, Ni （LD=5× 10^-6, St.dev. =0.5× 10^-6）; Cu, Zn, Ga, Ge, As, Se （LD=0.5× 10^-6, St.dev. =0.1× 10^-6）; Br, Rb, Sr, Y, Zr, Nb, Mo （LD=0.1× 10^-6, St.dev. =0.03× 10^-6）; Ru, Rh, Pd, Ag （LD=0.05× 10^-6, St.dev. =0.01× 10^-6）; Cd, In, Sn, Sb, Te, I （LD=0.1× 10^-6, St.dev. =0.03× 10^-6）; Ba, La, Ce, Nd, Sm （LD=1.0× 10^-6, St.dev.=0.15× 10^-6）; Pb, Bi, Th, U （LD=3 × 10^-6, St.dev.= 1 × 10^-6）. The analysis was carried out in some stages with various energies of excitation （usually-15, 25 and 45 keV）. Unique opportunities of XRF SR allow to carry out scanning microanalysis with spatial resolution 100 micron. The set of analyzed elements and range of concentrations are determined by selection of energy of excitation and time of measurement at a point.