Effect of Zr and Ti Addition and Aging Treatment on the Microstructure and Tensile Properties of Al-2%Cu-Based Alloys

The present work investigated the effect of aging treatment on the microstructure and tensile properties of an Al-2%Cu base alloy containing various additions of Zr and other alloying elements. Aging was carried out at temperatures of 180–300 °C for different aging times at each temperature. The tensile properties indicated that Zr additions improved the strength of the base alloy, especially at high Zr levels at 180 °C. At the 220 °C aging temperature, however, while Zr addition did not have a beneficial effect on the alloy strength, the ductility was found to improve. Zr-Ti combined additions had a significant effect on the microstructure of the base alloy, as the morphology of the α-Al grains transformed into a non-dendritic morphology, and the grain size decreased sharply. These effects were at their maximum at 180 °C and 0.5 wt% Zr addition. Moreover, the Zr-containing alloys aged at higher temperatures, such as 220 °C and 240 °C, maintained a noticeably higher level of strength over the base alloy aged at the same temperatures. Quality index charts based on the tensile test data also reflected an improvement in alloy quality and strength with Zr-Ti combined additions.     

Über eine isolierte aplastische Anämie mit vollständigem Fehlen der Erythroblasten (Erythroblastophthise)

Journal of Molecular Medicine - Es wird über einen 59jährigen Landwirt berichtet, der seit 4 Jahren wegen einer isolierten aplastischen Anämie in Behandlung ist. Während dieser...     

Nervenaktionsströme bei Wechselstromreizung

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THE HYPOPHYSEAL SUBSTANCE GIVING INCREASED GONADOTROPIC EFFECTS WHEN COMBINED WITH PROLAN

The increased gonadotropic effect obtained by combining prolan with hypophyseal extracts can be secured equally well by the use of preparations which contain high amounts of the growth or of the gonad-stimulating hormone. In hypophyseal extracts containing the growth hormone, the synergistic effects do not parallel the content of growth-promoting substance. Similarly, in hypophyseal extracts containing the gonad-stimulating hormone, the synergistic effects do not parallel the content in the gonadotropic factor. The hypophyseal substance involved has been prepared sufficiently free of the growth and gonad-stimulating hormones to make it inadmissible to consider either of these substances as responsible for the reaction.     

THE SOLVENT ACTION OF ANTISEPTICS ON NECROTIC TISSUE

1. Dakin''s hypochlorite solution has the power of dissolving necrotic tissue, pus, and plasma clot in the concentration and reaction used clinically. 2. Chloramine-T and dichloramine-T do not exhibit this action. 3. The solvent action of Dakin''s hypochlorite solution of the degree of alkalinity used clinically is due primarily to its hypochlorite content, but its slight alkalinity, while in itself without solvent action, enhances the effectiveness of the hypochlorite. 4. In the degree of alkalinity used clinically, the solvent action of hypochlorite is absent below about 0.2 per cent sodium hypochlorite concentration. 5. The hypochlorite concentration at which the solvent action ceases is lower the more alkaline the solution, and vice versa. 6. None of the antiseptics studied had demonstrable solvent action on blood clot.