Morphological analysis of pitting corrosion in AISI 310S austenitic stainless steel after salt spray exposition

This paper aims to study evolution of increase, distribution and classification of pits in 310S austenitic stainless steels obtained in the state as-received and heat-treated under different exposure times in saline. This work applicability has been based on a technique development for morphologic characterization of localized corrosion associated with description aspects of shapes, size and population-specific parameters. Methodology has been consisted in the following steps: specimens preparation, corrosion tests via salt spray in different conditions, microstructural analysis, pits profiles analysis and images analysis, digital processing and image analysis in order to characterize the pits distribution, morphology and size. Results obtained in digital processing and profiles image analysis have been subjected to statistical analysis using median as parameter in the alloy as received and treated. The alloy as received displays the following morphology: hemispheric pits> transition region A> transition region B> irregular> conic. The pits amount in the treated alloy at each exposure time is: transition region B> hemispherical> transition region A> conic> irregular.

Histological alterations in liver and testis of Astyanax aff. bimaculatus caused by acute exposition to zinc

This study investigated the effect of acute exposition to zinc (Zn) on histology of the liver and testes of yellow tail lambari (Astyanax aff. bimaculatus). The exposure consisted of six concentrations of Zn (0, 3, 5, 10, 15, and 20 mg/L) for 96 hours of exposure. Fragments of liver and testis were routinely processed and embedded in plastic resin based on glycol methacrylate. Fragments of bones, muscles, liver and testis were dehydrated and digested to quantify the absorption levels of Zn in the tissue. Acute exposure to concentrations above 10mg/L has produced structural changes in the liver and gonads. The changes found in the liver were vascular congestion; decrease of cellular volume; displacement of the hepatocyte nucleus; necrosis; disarrangement of cordon structure; leukocyte infiltrate and vacuolization. The changes found in the gonads were ruptured cyst, delayed development of germ cells, pyknotic nucleus, cell cluster, displacement of cyst wall and vacuolization. The histological changes observed were compatible with the increasing concentration of zinc in environment, compromising liver and reproductive functions, because there was an increase in relative frequency of hepatocytes and reduced sperm production

Recensão: Fukuko Ando et "Amaterasu". Exposition – performance

Recensão de: Fukuko Ando, "Amaterasu". Exposition – performance

Darwin and after Darwin. An exposition of the Darwinian theory and a discussion of post-Darwinian questions, by George John Romanes ...

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Darwin and after Darwin. An exposition of the Darwinian theory and a discussion of post-Darwinian questions, by George John Romanes ...

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Darwin and after Darwin. An exposition of the Darwinian theory and a discussion of post-Darwinian questions, by George John Romanes ...

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Congress of arts and science, Universal exposition, St. Louis, 1904; ed. by Howard J. Rogers.

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Congress of arts and science, Universal exposition, St. Louis, 1904; ed. by Howard J. Rogers.

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Congress of arts and science, Universal exposition, St. Louis, 1904; ed. by Howard J. Rogers.

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Congress of arts and science, Universal exposition, St. Louis, 1904; ed. by Howard J. Rogers.

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Congress of arts and science, Universal exposition, St. Louis, 1904; ed. by Howard J. Rogers.

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Histoire naturelle des animaux sans vertèbres : présentant les caractères généraux et particuliers de ces animaux, leur distribution, leurs classes, leurs familles, leurs genres, et la citation des principales espèces qui s'y rapportent : précédée d'une introduction offrant la détermination des caractères essentiels de l'animal, sa distinction du végétal et des autres corps naturels, enfin, l'exposition des principes fondamentaux de la zoologie /

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