A space-charge-limited beam with current densities (J) exceeding 1 mA/cm(2) have been measured from lithium alumino-silicate ion sources at a temperature of ∼1275 °C. At higher extraction voltages, the source appears to become emission limited with J ≥ 1.5 mA/cm(2), and J increases weakly with the applied voltage.
View Article and Find Full Text PDFWe report results on lithium alumino-silicate ion source development in preparation for warm dense matter heating experiments on the new neutralized drift compression experiment II. The practical limit to the current density for a lithium alumino-silicate source is determined by the maximum operating temperature that the ion source can withstand before running into problems of heat transfer, melting of the alumino-silicate material, and emission lifetime. Using small prototype emitters, at a temperature of ≈1275 °C, a space-charge limited Li(+) beam current density of J ≈1 mA/cm(2) was obtained.
View Article and Find Full Text PDFComp Biochem Physiol B Biochem Mol Biol
October 2007
Vitamin K has been known to regulate bone formation through osteocalcin synthesis by osteoblasts, which is important for mineralization and bone structure. The mechanism underlying the relationship of vitamin K with the changes of microanatomy is not fully understood, and our goal is to test whether bone deformities develop in association with vitamin K deficiency. Fish were fed a semi-purified diet containing either devoid (0.
View Article and Find Full Text PDFOxynticopeptic cells of fish stomach are thought to secrete less acid than the specialized parietal cells of mammalian stomach. Gastric acidity, however, has not been directly compared between fish and mammals. We therefore fed rainbow trout and rats the same meal, and found that the lowest postprandial pH of trout stomach was 2.
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