Sulfate Attack
Mostrando 1-12 de 47 artigos, teses e dissertações.
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1. Mechanical behavior and durability of mortars with quartzite and Portland cement after sulfate attack
RESUMO Os resíduos de rochas ornamentais, especialmente quartzito, causam grande impacto ambiental. Mais impulso tem sido dado à pesquisa sobre a reciclagem desses resíduos nos últimos anos, particularmente para uso como agregados em concreto e argamassa. No entanto, os estudos realizados até o momento não mencionam o comportamento da argamassa mistura
Matéria (Rio J.). Publicado em: 25/11/2019
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2. Corrosão em estacas metálicas de torres de energia elétrica
RESUMO Para se manter a qualidade e continuidade do fornecimento de energia é essencial monitorar a integridade da estrutura das torres de transmissão usualmente executadas em aço. Por isso, avaliou-se a corrosividade do solo na região amazônica no trecho Vila do Conde-Tucuruí́, no estado do Pará. Foi analisado a resistividade, potencial estrutura-so
Matéria (Rio J.). Publicado em: 20/05/2019
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3. Purification of trypsin inhibitor from seeds of Cicer arietinum (L.) and its insecticidal potential against Helicoverpa armigera (Hübner)
Trypsin inhibitors (TI) have crucial functions in plant defense against pests, and recent studies reveal their diversity in stress response. Disease and herbivore infestations are harmful to plant growth, but the response of TI in Cicer arietinum (L.) in Central India has been less studied. In the present study, we partially characterized the TI from Cicer a
Theor. Exp. Plant Physiol.. Publicado em: 2013
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4. Estudos das características técnicas e operacionais das galerias de águas pluviais como subsídios para gestão patrimonial e estabelecimento de diretrizes para projetos de sistemas de drenagem urbana
The purpose of this work is to study the emergence and evolution of pathological manifestations in urban stormwater channels and relate them to technical and operational characteristics of concrete structures so that plans for urban drainage systems management are developed, as well as new concepts for stormwater channel projects. The main reference is the D
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/04/2012
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5. Cement mixtures containing copper tailings as an additive: durability properties
The effects of copper tailings as an additive, on some durability properties of cement mixtures were investigated. In each mixture, copper tailings addition levels by mass were 0%, 5% and 10%. Compared to the control samples, copper tailings blended pastes showed superior performance against autoclave expansion while insignificant decreases in sulfate resist
Mat. Res.. Publicado em: 09/10/2012
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6. DESEMPENHO DO CIMENTO PORTLAND BRANCO COM ESCÓRIA DE ALTO-FORNO E ATIVADOR QUÍMICO FRENTE AO ATAQUE POR SULFATO DE SÓDIO / PERFORMANCE OF A WHITE PORTLAND CEMENT WITH SLAG AND CHEMICAL ACTIVATOR AGAINST SODIUM SULFATE ATTACK
Os íons sulfato, encontrados na água do mar, em águas subterrâneas e em águas residuárias são agentes agressivos que podem levar a uma severa degradação do concreto. Ao reagirem com os produtos de hidratação do cimento, dependendo do tipo de cátion a que estão associados (magnésio, cálcio, potássio, sódio, amônio, etc.), da concentração e
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/08/2011
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7. Comportamiento de presas de gravedad de hormigón con problemas de ataque interno por sulfatos
Herein is described a methodology developed to evaluate concrete expansion and consequent abnormal behavior in gravity dams suffering from internal sulfate attack. The work presented here encompasses the analysis, in different phases, of three Spanish dams plagued by sulfate reactions. The aggregate and concrete of the Torán dam were characterized at a micr
Rev. IBRACON Estrut. Mater.. Publicado em: 2008-03
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8. Susceptibility of cement pastes to sulfate attack - accelerated test method. / Suscetibilidade de pastas de cimento ao ataque por sulfatos - método de ensaio acelerado.
O presente trabalho tem por objetivo investigar e propor uma metodologia rápida e eficaz de avaliação da reatividade do cimento Portland frente ao ataque por sulfatos. O método consiste na utilização de amostras de pasta de cimento hidratada em pó, colocadas em contato direto com soluções concentradas de Na2SO4 e MgSO4, em temperatura elevada (65ºC
Publicado em: 2006
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9. Effects of Dextran Sulfate 500 on Cell-Mediated Resistance to Infection with Listeria monocytogenes in Mice
Injection of dextran sulfate 500 caused loss of antibacterial resistance. Mice became more susceptible to an infection with Listeria monocytogenes and were unable to develop antilisterial immunity after both active and passive immunization with passively administered spleen cells from Listeria-immune donors. Indirect evidence suggests that the phagocytic com
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10. Translocation of an outer membrane protein into prey cytoplasmic membranes by bdellovibrios.
Within minutes of Bdellovibrio bacteriovorus attack on prey cells, such as Escherichia coli, the cytoplasmic membrane of the prey is altered. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified invaded prey cell (bdelloplast) membranes revealed the appearance of a noncytoplasmic membrane protein. This protein is not observed in preparations
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11. Interaction between the third complement protein and cell surface macromolecules.
The activated form of the third complement protein, C3b, forms a stable complex with components of plasma membranes and particulate entities such as zymosan. The complex resists the action of detergents and protein denaturants as well as extremes of temperature, salt concentration, and pH. It can, however, be broken by exposure to hydroxylamine or by ammonol
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12. PROTEOLYTIC ATTACK OF THE CHROMOPROTEINS OF PORPHYRA BY MARINE BACTERIAL ENZYMES1
Merkel, Joseph R. (College of Charleston, Charleston, S.C.), Gordon D. Braithwaite, and Henry Kritzler. Proteolytic attack of the chromoproteins of Porphyra by marine bacterial enzymes. J. Bacteriol. 88:974–980. 1964.—Three chromoproteins were isolated from the marine red alga, Porphyra leucosticta (Thuret), and were purified by adsorption chromatography