Quick Cooling
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Grain refinement of AZ91D magnesium alloy by MgCO3
The grain refining technique of AZ91D magnesium alloy by MgCO3 has been investigated. The refining mechanism and tensile properties of the resulting alloy have also been discussed. The results indicate that MgCO3 can decrease its grain size from 311 to 53µm. Correspondingly, the tensile properties are obviously improved. The higher the cooling rate from add
Materials Research. Publicado em: 01/04/2011
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2. Estudo das transformaÃÃes de fase em Pseudo â ZTAs para aÃo API 5L X-70 visando desenvolvimento de dispositivo substrato
The microstructure transformation of structural steel has been studied from continuous cooling in metallic means to simulate the microestrutural transformations in different places in a HAZ (Heat Affected Zone). The studied material is Steel API 5L X70, largely used in piping in the Petrochemical Industries for its hight mechanical resistance and low weight,
Publicado em: 2008
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3. Influencia do tipo de agregado nas propriedades mecanicas do concreto submetido ao fogo / Aggregate types influence in mechanical properties of the concrete submitted to fire
This work deals with aggregate types influence in mechanical properties of the concrete submitted to high temperatures, evaluating the probable alterations to compression and tension resistances and elasticity module. An experimental study of the three chosen aggregates influence is presented, expanded clay, basalt and limestone in the concrete behavior subm
Publicado em: 2005
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4. Solução analitica para distribuição de temperatura no processo de soldagem MIG com multiplos passes
Although heat transfer in welding is a fairly well studied topic, there is not much literature about multipass process, necessary for the welding of thick plates, which are generally used as primary components of weldments. During multipass welding process, the material undergoes quick cycles of heating and cooling, and the heat affected zone ( HAZ ) suffers
Publicado em: 1997
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5. Pathway-dependent refolding of E. coli 5S RNA.
The refolding of 5S RNA into its two conformational states has been examined as a function of solvent composition and annealing conditions. The results show that the product distribution depends on the folding pathway. Quick cooling from high temperature produces roughly equal amounts of the two forms, even in the presence of 1 mm Mg++. However annealing by
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6. Genome of Sindbis Virus
32P-labeled ribonucleic acid (RNA) from purified Sindbis virus was examined for the presence of hidden breaks. Viral RNA was treated with acid at pH 2.9 or with formaldehyde and was analyzed on sucrose gradients or by polyacrylamide gel electrophoresis. The sedimentation pattern and mobility on polyacrylamide gels of the 42S RNA was unaffected by heating and
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7. Measuring Osmotic Pressure of Sap within Live Cells by Means of a Visual Melting Point Apparatus 1
A freezing slide apparatus is described for visual observation of freezing water and melting ice within plant cells. The slide consists of an ordinary microscope slide glued into a Plexiglass jacket, through which cold 90% ethyl alcohol is pumped at varying rates for temperature control. Temperature is recorded by means of an iron-constantan thermocouple wir
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8. The minute virus of mice capsid specifically recognizes the 3' hairpin structure of the viral replicative-form DNA: mapping of the binding site by hydroxyl radical footprinting.
The terminal hairpin structures of the DNA of minute virus of mice (MVM) are essential for viral replication. Here we show that the hairpin 3' terminus of MVM replicative-form DNA binds specifically to empty MVM capsids. Binding of the same terminal DNA sequence in its linear double-stranded (extended) conformation was not observed. After heat denaturation a
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9. Generation of viroid conformational isomers that are stable to incubation with magnesium ions and in a nuclear extract from tomato plants.
We identified conditions for heating and quick cooling viroid RNAs in the presence of salt which lead to the production of conformational isomers stable to incubation for at least 45 minutes at 30 degrees in the presence of magnesium ions. Elution in 0.3 M NaCl allowed the purification of an electrophoretically slow form of an in vitro transcript carrying a