Partition coefficients of water/air, blood/air, oil/air, and oil/water for twenty chlorianted hydrocarbons, which were determined by means of a vial-equilibration method, were examined in relation to their chemical structures and threshold limit values (TLVs) recommended by the American Conference of Governmental Industrial Hygienists. The TLV was correlated closely with the blood/air partition coefficient and with the product of the water/air and the oil/air partition coefficient except for carbon tetrachloride and o-dichlorobenzene. A relation between partition coefficients and toxicity of these hydrocarbons is also described.

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In this work, we examine how deuterium becomes trapped in plasma-exposed tungsten and forms near-surface platelet-shaped precipitates. How these bubbles nucleate and grow, as well as the amount of deuterium trapped within, is crucial for interpreting the experimental database. Here, we use a combined experimental/theoretical approach to provide further insight into the underlying physics. With the Tritium Plasma Experiment, we exposed a series of ITER-grade tungsten samples to high flux D plasmas (up to 1.5 × 1022 m−2 s−1) at temperatures ranging between 103 and 554 °C. Retention of deuterium trapped in the bulk, assessed through thermal desorption spectrometry, reached a maximum at 230 °C and diminished rapidly thereafter for T > 300 °C. Post-mortem examination of the surfaces revealed non-uniform growth of bubbles ranging in diameter between 1 and 10 μm over the surface with a clear correlation with grain boundaries. Electron back-scattering diffraction maps over a large area of the surface confirmed this dependence; grains containing bubbles were aligned with a preferred slip vector along the ⟨111⟩ directions. Focused ion beam profiles suggest that these bubbles nucleated as platelets at depths of 200 nm–1 μm beneath the surface and grew as a result of expansion of sub-surface cracks. To estimate the amount of deuterium trapped in these defects relative to other sites within the material, we applied a continuum-scale treatment of hydrogen isotope precipitation. In addition, we propose a straightforward model of near-surface platelet expansion that reproduces bubble sizes consistent with our measurements. For the tungsten microstructure considered here, we find that bubbles would only weakly affect migration of D into the material, perhaps explaining why deep trapping was observed in prior studies with plasma-exposed neutron-irradiated specimens. We foresee no insurmountable issues that would prevent the theoretical framework developed here from being extended to a broader range of systems where precipitation of insoluble gases in ion beam or plasma-exposed metals is of interest.

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The generation mechanism of the microloading effect in magnetron enhanced reactive ion etching (MERIE) and its suppression have been investigated. The suppression of damage to the substrate was achieved with fluorocarbon gases of high molecular weight in MERIE, however, strong microloading effect generation was observed. In this study, it was found that low-temperature etching is the most effective technique for reducing the microloading effect.

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