著者

Kenji Shimizu Takayuki Ushikubo Takeshi Kuritani Naoto Hirano Shigeru Yamashita

出版者

GEOCHEMICAL SOCIETY OF JAPAN

雑誌

GEOCHEMICAL JOURNAL (ISSN:00167002)

巻号頁・発行日

pp.GJ22019, (Released:2022-11-22)

被引用文献数

1

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Analyses of elemental abundances by secondary ion mass spectrometry (SIMS) require matrix-matched standard samples to account for the matrix effect on correction factors. This requirement makes it difficult to obtain accurate results for geological samples of variable chemistry. In this study, we prepared 39 volcanic glasses of foiditic, basaltic, basaltic andesitic, rhyolitic and pure SiO2 compositions, including synthetic samples and natural samples collected from the deep seafloor. The measured H2O contents of these samples were in the range 0.02–4.8 wt%. We showed that calibration curves (H2O content vs. 16OH−/30Si−SIMS ratio) differed according to the composition of the volcanic glasses. Our results demonstrated that for a particular 16OH/30SiSIMS ratio, water content could differ by up to a factor of five, depending on the composition of the volcanic glass. Although the correction factor (the slope of the calibration curve for water [H2O/(16OH−/30Si−)SIMS]) was weakly correlated with SiO2 content, we identified a stronger correlation with the molar weight (g mol−1, on a one-oxygen mole basis) of the silicate glasses. Our results suggest that modification of the correction factor for the matrix effect on SIMS-based H2O content of volcanic glasses according to their molar weights provides more accurate water contents of silicate glasses, regardless of their chemical composition and water content and without the need for a series of standard glasses of known water contents.

著者

Yifang BAO Shigeru YAMASHITA Bing LI Tsung-Yi HO

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E105-A, no.10, pp.1385-1391, 2022-10-01

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When we use a Programmable Microfluidic Device (PMD), we need to wash some contaminated area to use the chip for further experiments. Recently, a novel washing technique called Block-Flushing has been proposed. Block-Flushing washes contaminated area in PMDs by using buffer flows. In Block-Flushing, we need to keep a buffer flow from an input port to an output port of a PMD for a long period to dissolve residual contaminants. Thus, we may need a lot of buffer fluids and washing time even if the contaminated area is small. Another disadvantage of the washing method by Block-Flushing is such that we may not able to clean residual contaminants at valves completely by only buffer flows. To address the above-mentioned issues, this paper proposes a totally new idea to wash PMDs; our method does not use buffer flows, but washes contaminated area by using mixers. By using a mixer, we can dissolve residual contaminants at valves in the area of the mixer very efficiently. In this paper, we propose two methods to wash PMDs by using mixers. The first method can wash the whole chip area by using only four times of a single 2x2-mixer time. We also propose the second method which is a heuristic to reduce the number of moving valves because valves may wear down if they are used many times. We also show some experimental results to confirm that the second method can indeed decrease the number of used valves.