Corrosion of dental amalgams: electrochemical study of Ag-Hg, Ag-Sn and Sn-Hg phases

Dental amalgams, formed by reaction of mercury with a powder alloy containing mainly Ag, Sn, Cu and Zn, have a complex metallurgical structure which can contain up to six phases. Their observed corrosion is thus a complex process, which involves contributions from each of the phases present as well as intergranular corrosion. It is thus of interest to investigate the corrosion of individual phases present in dental amalgams. In this work the corrosion behaviour in 0.9% NaCl solution of Ag-Hg, Ag-Sn and Sn-Hg phase components of dental amalgams was investigated by electrochemical methods. The corrosion resistance was found to decrease in the order gamma (1)-Ag2\Hg3, gamma -Ag3Sn and gamma (2)-Sn7Hg. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Investigação de propriedades de filmes finos de Sn'O IND. 2' e 'Al IND. 2''O IND. 3' para aplicação em dispositivos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

No surviving evolved companions of the progenitor of SN 1006

Type Ia supernovae are thought to occur when a white dwarf made of carbon and oxygen accretes sufficient mass to trigger a thermonuclear explosion(1). The accretion could be slow, from an unevolved (main-sequence) or evolved (subgiant or giant) star(2,3) (the single-degenerate channel), or rapid, as the primary star breaks up a smaller orbiting white dwarf(3,4) (the double-degenerate channel). A companion star will survive the explosion only in the single-degenerate channel(5). Both channels might contribute to the production of type Ia supernovae(6,7), but the relative proportions of their contributions remain a fundamental puzzle in astronomy. Previous searches for remnant companions have revealed one possible case for SN 1572 (refs 8, 9), although that has been questioned(10). More recently, observations have restricted surviving companions to be small, main-sequence stars(11-13), ruling out giant companions but still allowing the single-degenerate channel. Here we report the results of a search for surviving companions of the progenitor of SN 1006 (ref. 14). None of the stars within 4 arc minutes of the apparent site of the explosion is associated with the supernova remnant, and we can firmly exclude all giant and subgiant stars from being companions of the progenitor. In combination with previous results, our findings indicate that fewer than 20 per cent of type Ia supernovae occur through the single-degenerate channel.

Used car safety standards (vehicle safety status). Final report. Volume IIA (SN 11 A).

National Highway Safety Bureau, Washington, D.C.

Un combate singular, o, Infancia de Sn. José de Calasanz : juguete lírico en un acto y en verso /

Spanish words.

Factum pour maistre Nicolas de Blegny conseiller, chirugien ordinaire du corps de Monsieur, et préposé sous l'aueu du Roy par le sieur Premier Medicin de sa Majesté, à la recherche [et] verification des nouvelles découvertes de médecine : Appelant de la permision d'informer, information decret décerné par le Sieur Lieutenant de Police, [et] de tout ce qui sén est ensuivy ; contre les Doyen [et] Docteurs de la Faculté de Médecine, en l'Université de Paris ...

Mode of access: Internet.

Viage [sic] pintoresco por los rios Paraná, Paraguay, Sn Lorenzo, Cuyabá y el Arino tributario del grande Amazonas : con la descripción de la provincia de Mato Grosso bajo su aspecto físico, geográfico, mineralójico [sic] y sus producciones naturales /

Sabin,

Compendio de la vida, virtudes, y milagros de Sn. Camilo de Lelis, fundador de la sagrada religion de Padres Clerigos Regulares Ministros de los Enfermos agonizantes /

Mode of access: Internet.

Pi︠e︡snʹ o Gaĭavati︠e︡ /

Mode of access: Internet.

Traité des maladies les plus frequentes et des remèdes propres a les guerir avec la methode de sén servir ... /

Mode of access: Internet.

Pi︠e︡snʹ o vi︠e︡shchem Olegi︠e︡. Tochnai︠a︡ kopīi︠a︡ rukopisi poėta.

Part of Rimsky-Korsakov's music to Pi︠e︡snʹ o vi︠e︡shchem Olegi︠e︡: p. [127-128].

Jednání sněmů Mpravských v letech 1792-1835 /

Mode of access: Internet.

Collecter, Epistler og Evangelier paa Søn - og Helligdagene i det ganske Aar of vor Herres Jesu Christi Lidelses-Historie, dernæst Bønner for og efter Gudstienesten og aarlige Kirke-Bønner, samt Morgen - og Aftenbønner.

In Evangelisk-Kristelig Psalmebog til Brug ved Kirke - og Huus-Undagt. Kiøbenhavn, 1824, pp. 224 at end.

Organizational maintenance manual for combat vehicle, anti-tank, improved tow vehicle, M901, SN 2350-01-045-1123.

"June 1979."

Direct support and general support maintenance repair parts and special tools lists ... for synchronizer, electrical, SN-421-TPX-50 (NSN 5895-00-130-5814).

"October 1977."