Thermal stability of ferritic alloys for fossil-fuel processing systems. Final technical report, September 1, 1978-August 31, 1981. [at 475/sup 0/C]

This research program has investigated the thermal stability of several ferritic stainless steels containing 15 to 18 weight percent chromium over the temperature range 400/sup 0/C to 550/sup 0/C where the 475/sup 0/C embrittlement reaction is of concern. A major part of the experimental work was concerned with the effect of ternary additions of up to 6 weight percent; aluminum on the kinetics and the magnitude of the embrittlement reaction. The work also included a binary Fe-18Cr alloy, a ternary Fe-18Cr-2Mo, and two commercial alloys, Armco type 430 and type 18SR. Resistometric studies of the kinetics of microstructural instability indicated that aluminum additions promote the tendency of chromium atoms to cluster at temperatures in the vicinity of 475/sup 0/C. The magnitude of embrittling reaction is intensified by the aluminum additions which are expected to restrict dislocation cross slip and increase the coherency strains associated with the alpha prime precipitates. Activation energy determinations for the decomposition reaction indicate that the rate controlling process is most likely determined by the diffusion of chromium, and the tendency of aluminum to enhance the clustering of chromium atoms is similar to the effect reported for molybdenum additions by previous workers

Electric telegraphy in the pages of “O Instituto”, Journal of Coimbra’s Academy

Analisamos os avanços da telegrafia eléctrica e da telegrafia sem fios no mundo e, em particular, em Portugal, com base em artigos da revista O Instituto, publicada pelo Instituto de Coimbra, uma sociedade científica, fundada em 1852, que reuniu um vasto leque de personalidades das ciências e artes nacionais. Passamos em revista os principais artigos sobre a telegrafia: o artigo de José Maria de Abreu de 1855, publicado menos de um mês depois da adjudicação das primeiras linhas telegráficas em Portugal; o parecer da Faculdade de Filosofia da Universidade de Coimbra sobre as deliberações do Congresso e Conferências de Paris para determinação das unidades eléctricas, onde esteve Santos Viegas, Presidente do Instituto; e o artigo de Álvaro Silva Basto de 1903 sobre a telegrafia sem fios. Uma menção especial é feita ao artigo de Adriano Paiva Brandão de 1878 sobre telescopiaWe analyze the advances of electric telegraphy and of wireless telegraphy in the world and, in particular, in Portugal, based on articles of the periodical O Instituto, published by the Instituto de Coimbra, a scientific society, founded in 1852, that gathered many Portuguese personalities of science and arts. We review the main articles on telegraphy: the paper by José Maria de Abreu in 1855, less than a month after the adjudication of the first telegraphic lines in Portugal; the assessment by the Philosophical Faculty of the University of Coimbra on the deliberations of the Congress and Conferences of Paris for the unification of electric units, where Santos Viegas, the President of the Coimbra's Institute was present; and the paper of Álvaro Silva Basto in 1903 on wireless telegraphy. Special mention is made to the article by Adriano Paiva Brandão in 1978 on telescop

Two Distinctly Localized P-Type ATPases Collaborate to Maintain Organelle Homeostasis Required for Glycoprotein Processing and Quality Control

Membrane transporter proteins are essential for the maintenance of cellular ion homeostasis. In the secretory pathway, the P-type ATPase family of transporters is found in every compartment and the plasma membrane. Here, we report the identification of COD1/SPF1 (control of HMG-CoA reductase degradation/SPF1) through genetic strategies intended to uncover genes involved in protein maturation and endoplasmic reticulum (ER)-associated degradation (ERAD), a quality control pathway that rids misfolded proteins. Cod1p is a putative ER P-type ATPase whose expression is regulated by the unfolded protein response, a stress-inducible pathway used to monitor and maintain ER homeostasis. COD1 mutants activate the unfolded protein response and are defective in a variety of functions apart from ERAD, which further support a homeostatic role. COD1 mutants display phenotypes similar to strains lacking Pmr1p, a Ca(2+)/Mn(2+) pump that resides in the medial-Golgi. Because of its localization, the previously reported role of PMR1 in ERAD was somewhat enigmatic. A clue to their respective roles came from observations that the two genes are not generally required for ERAD. We show that the specificity is rooted in a requirement for both genes in protein-linked oligosaccharide trimming, a requisite ER modification in the degradation of some misfolded glycoproteins. Furthermore, Cod1p, like Pmr1p, is also needed for the outer chain modification of carbohydrates in the Golgi apparatus despite its ER localization. In strains deleted of both genes, these activities are nearly abolished. The presence of either protein alone, however, can support partial function for both compartments. Taken together, our results reveal an interdependent relationship between two P-type ATPases to maintain homeostasis of the organelles where they reside