Synthesis of aluminum nitride nanolayers

The interaction between the surface of polycrystalline aluminum and nitrogen at a slow heating to a temperature of 623°C and a pressure of 1.25 atm is studied by ellipsometry. It is shown that the formation of a continuous nanolayer of aluminum nitride occurs in a temperature range of 520–580°C and above. The maximum thickness of the synthesized aluminum nitride nanolayer is 32 nm. The formation of nitride on the surface of aluminum is confirmed by IR spectroscopy of powders with a specific surface area of 6.4 m²/g.     

A Study of the Cooling Capacity of Quenching Media with the Help of Gradient Probes

Metal Science and Heat Treatment -     

Synthesis of Pro-Pro-Ile,a corticoliberin fragment,labeled with tritium in proline unit

Boc-Δ³Pro-Pro-Ile-OBzl and Boc-Pro-Δ³Pro-Ile-OBzl were synthesized. Tritium-labeled Pro-Pro-Ile was prepared by their hydrogenation in a tritium atmosphere in the presence of a catalyst. In the reduction of Boc-Δ³Pro-Pro-Ile-OBzl and Boc-Pro-Δ³Pro-Ile-OBzl, elimination of the Bzl protective group occurs faster than hydrogenation of the 3,4-dehydroproline residue (benzene and dioxane were used as solvents). The resulting Boc-Δ³Pro-Pro-Ile-OH and Boc-Pro-Δ³Pro-Ile-OH are poorly soluble in aprotic solvents, which accounts for the low yield of the desired tritium-labeled peptides.     

Spatial localization of the sources of a polarized electromagnetic field

Different approaches to the problem of estimation of the direction of arrival of the incident wave with an unknown polarization are considered. It is found that the obtained solutions can be used to increase the accuracy and reliability of direction finding due to elimination of polarization errors and to determine the polarization parameters as an additional information parameter. Analysis of the results obtained for a particular configuration of the antenna array is performed. It is shown that the proposed method is more efficient for determination of the direction to the source of an arbitrarily polarized electromagnetic field than the approaches oriented to processing of the field with a predetermined polarization. The results of a numerical simulation confirming these conclusions are presented.     

Zak-PG polymer quenching medium

The present work is devoted to the properties of new fireproof polymer quenching medium ZAK-PG with reversible solubility based on PG-40 polymer. The developed medium makes it possible to use various cooling regimes with various contents of the polymer in the solution. A composition in which the polymer content remains unchanged during use is suggested. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 7–8, February, 1999.     

Primary structure and strand specificity of BstF5I-1 DNA methyltransferase which recognizes 5''-GGATG-3''

1. Ovomucoids were purified from Muscovy duck, domestic duck and domestic goose. 2. Peptide maps of cyanogen bromide-cleaved ovomucoids from Muscovy duck and domestic duck were very similar to one another, but differed from that of goose. 3. Muscovy duck ovomucoid showed the same protease inhibitory pattern as ovomucoid from domestic duck, inhibiting trypsin in the molar ratio of 1:2 and chymotrypsin 1:1. 4. Inhibitory complexes could be detected between chymotrypsin and ovomucoid from both Muscovy and domestic duck, but not from goose, by using non-denaturing gels. 5. No complexes could be detected between DFP-inactivated chymotrypsin and any of the ovomucoids. 6. The results show that of ovomucoid from Muscovy duck more closely resembles that from domestic duck than goose.     

Making the Lining of Steelmaking Furnaces More Durable by Guniting

This article describes the main operations performed in guniting open-hearth furnaces, the equipment that is used, and the composition of the mixtures employed for guniting.