Dissolution Reagent Research Articles

Transmission electron microscopy of thin oxide layers recovered from the surface of metals

It is demonstrated in this study that transmission electron microscopy can make an extremely valuable contribution towards the characterization of surface films and coatings. It is also shown that heterochemical layers which develop beneath the surface of the native scale on alloys can be extracted for examination by a suitable combination of dissolution reagents. Thin layers of native oxide are shown to be generated at the surfaces of nickel and Fecralloy steel when ceria sol coatings are applied to them.

12. 強リン酸十硫酸分解法によるチッ化ウラン中のチッ素の定量

Kjeldahl procedures were applied to the determination of nitrogen in uranium nitrides. There have been reported various dissolution reagents such as mixtures of hydrochloric, hydrofluoric, and sulfuric acids, sulfuric and perchloric acids, sulfuric acid and copper selenate. Preliminary dissolution tests, however, have shown that none of the dissolution reagents mentioned above are strong enough to dissolve the uranium nitride, even at high temperatures. The best result was obtained with a mixture of strong phosphoric and sulfuric acids. Compared with the other reported dissolution reagents, mentioned above, the proposed reagent gave excellent results with all the samples examined. Nitrogen recovery proved to be 100±0.50%.