There is a fairly old apocryphal quotation stating : “Everything that can be invented has been invented.” [1] attributed at one time to Charles H. Duell of the US Patent office in 1899. We all realize this is an absurd statement, and it is well documented that Duell actually said something quite different and urged the US Congress to encourage the advancement of science as well as to improve th...

Large amounts of calcium and phosphorus have been found by electron-microprobe analysis in the dense bodies of frozen-dried, human platelets. The calcium and phosphorus occurred in a fixed ratio that was similar to that in dicalcium ATP. No other elements were detectable except chlorine. Minute, electron-dense disks were found in the surface membranes of glutaraldehyde-fixed platelets, and are ...

Details are given of the techniques used in the analysis of asbestiform fibers in the water systems of Duluth, Minnesota and other cities. Photographic electron diffraction and electron microprobe analyses indicated that the concentration of verified amphibole mineral fibers ranged from 20 x 10(6) to 75 x 10(6) fibers/l. Approximately 50-60% of the fibers were in the cummingtonite-grunerite ser...

Natural peridotite samples containing olivine, orthopyroxene, and spinel can be used to assess the oxygen fugacity ( fO2) of the upper mantle. The calculation requires accurate and precise quantification of spinel Fe3+/SFe ratios. Wood and Virgo (1989) presented a correction procedure for electron microprobe (EPMA) measurements of spinel Fe3+/SFe ratios that relies on a reported correlation bet...

The purpose of the present study was to investigate whether fluoride (F) ions are really capable of the repair (remineralization) of damaged crystals and useful for reinforcing the quality (i.e. modify the crystal structure) of tooth enamel using transmission electron microscopy and Raman microprobe analysis. Additionally, carbonic anhydrase activity was measured in immature enamel tissue to co...

Introduction: The progress in the development of the AEXS is described. The AEXS is a surface analysis tool based on excitation of characteristic x-ray fluorescence (XRF) spectra from samples in ambient atmospheres using a focused electron beam. Operation in ambient atmospheres with moderate-tohigh spatial resolution in comparison to similar instruments is obtained through the use of a thin ele...

The analytical characteristics of a W/Si multilayer dispersion element (MLDE) with a nominal 2d spacing of 60,~ are assessed and compared with those of a conventional thallium acid phthalate (TAP) crystal for the determination of fluorine in silicate and phosphate minerals by electron microprobe. Measured count rates for fluorine were found to be up to fourteen times higher using the MLDE compa...

The two-color soft x-ray (SXR) tomography diagnostic on the Madison Symmetric Torus is capable of making electron temperature measurements via the double-filter technique; however, there has been a 15% systematic discrepancy between the SXR double-filter (SXRDF) temperature and Thomson scattering (TS) temperature. Here we discuss calibration of the Be filters used in the SXRDF measurement using...