studies of three selected sulfide-silicate assemblages from ore samples from the sar cheshmeh porphyry copper deposit led to some ore genetic conclusions. the presence of chalcopyrite blebs in the groundmass orthoclase and quartz from the stock suggests liquid immiscibility in a cooling late-magmatic melt. this is in favor of the orthomagmatic model proposed for porphyry copper deposits. the pr...

X-ray microanalyses of sub-micrometer features require that a lower accelerating voltage be used. This reduction in the accelerating voltage reduces the penetrating distance of the beam electrons and thereby reduces the analytical volume. Two general strategies have been proposed for achieving the smallest analytical volume. The first approach involves significantly reducing the accelerating vo...

Aqueous humor is secreted by the bilayered ciliary epithelium. Solutes and water enter the pigmented ciliary epithelial (PE) cell layer, cross gap junctions into the nonpigmented ciliary epithelial (NPE) cell layer, and are released into the aqueous humor. Electrical measurements suggest that heptanol reduces transepithelial ion movement by interrupting PE-NPE communication and that gap junctio...

The calcium content and distribution across the abscission zones of (2-chloroethyl) phosphonic acid-treated bean (Phaseolus vulgaris L. var. Contender) leaves were lower and not uniformly distributed as compared to the control. Calcium chloride-treated bean leaves had a higher calcium content, with more calcium localized in the potential abscission layer. Ethephon treatment promoted abscission ...

It is shown by x-ray microanalysis that a gradient of total intracellular Ca concentration exists from the outer oral ectoderm to the inner skeletogenic calicoblastic ectoderm in the coral Galaxea fascicularis. This suggests an increase in intracellular Ca stores in relation to calcification. Furthermore, Ca concentration in the fluid-filled space of the extrathecal coelenteron is approximately...

Unquestionably, since their introduction one decade ago, field emission (FE) electron microprobes have pushed the boundaries of electron probe microanalysis (EPMA) by offering new possibilities to characterize smaller features. As with conventional microprobes, the proper selection of the analytical conditions (beam energy, beam current, acquisition time, x-ray line) is essential to obtain an a...

The electron microprobe was used to study tooth discoloration caused by old silver amalgam fillings. Oscilloscopic displays were obtained for the distribution of tin, silver, and mercury. In addition, a linear graphic display technic on the Enhancitron was used. The oscilloscopic displays showed the migration of tin from the amalgam into the enamel and dentin as opposed to silver or mercury, or...

Five patients with respiratory disorders associated with hard metal exposure are described. In four patients electron microprobe analysis of bronchoalveolar lavage cells or lung tissue was used to show tungsten and other hard-metal components. Three patients had interstitial pneumonia and fibrosis with unusual multinucleate giant cells. Electron microscopy showed that the giant cells comprised ...

Solubility limits and constitutional defects in Laves phase intermetallics are investigated with the C15 HfCo2 system. Several binary alloy compositions based on HfCo2 are characterized by optical and scanning electron microscopy (SEM), electron microprobe analysis (EPMA), X-ray diffraction (XRD), and density measurements. Rietveld refinements of XRD scans are used to determine lattice constant...