52 research outputs found
In situ observation of calcium oxide treatment of inclusions in molten steel by confocal microscopy
Calcium treatment of aluminum killed steel was observed in situ using high-temperature confocal scanning laser microscope (HT-CSLM). This technique along with a novel experimental design enables continuous observation of clustering behavior of inclusions before and after the calcium treatment. Results show that the increase in average inclusion size in non-calcium-treated condition was much faster compared to calcium-treated condition. Results also show that the magnitude of attractive capillary force between inclusion particles in non-treated condition was about 10â15 N for larger particles (10 ”m) and 10â16 N for smaller particles (5 ”m) and acting length of force was about 30 ”m. In the case of calcium-treated condition, the magnitude and acting length of force was reduced to 10â16 N and 10 ”m, respectively, for particles of all sizes. This change in attractive capillary attractive force is due to change in inclusion morphology from solid alumina disks to liquid lens particles during calcium treatment
Investigation into the cause of spontaneous emulsification of a free steel droplet : validation of the chemical exchange pathway
Small Fe-based droplets have been heated to a molten phase suspended within a slag medium to replicate a partial environment within the basic oxygen furnace (BOF). The confocal scanning laser microscope (CSLM) has been used as a heating platform to interrogate the effect of impurities and their transfer across the metal/slag interface, on the emulsification of the droplet into the slag medium. The samples were then examined through X-ray computer tomography (XCT) giving the mapping of emulsion dispersion in 3D space, calculating the changing of interfacial area between the two materials, and changes of material volume due to material transfer between metal and slag. Null experiments to rule out thermal gradients being the cause of emulsification have been conducted as well as replication of the previously reported study by Assis et al.[1] which has given insights into the mechanism of emulsification. Finally chemical analysis was conducted to discover the transfer of oxygen to be the cause of emulsification, leading to a new study of a system with undergoing oxygen equilibration
Estudos sobre a nutrição mineral do sorgo granĂfero: VII absorção de sulfato marcado por raizes destacadas
Some aspects of SO4ÂČ absorption by excised roots of "Sorghum bicolor (L.) Moench" namely, inibition effects of NaF, KCN, 2,4- DNP and factors such as aeration, solution pH and temperature on the rate of absorption were studied. The excised roots showed multiphasic mecanism of SO4ÂČ- absorption. The relative absorption rates, presented by three varieties, were in decreasing order: Tey-101, Contibrasil-101 and Dekalb-E-57. Inhibition effects on the absorption of SO4ÂČ- by excised roots were shown in the case of the three ihibitors studied hereof-. Aeration and solution temperature are important factors on SO4ÂČ- absorption. At the external solutio n concentration of Na,2SO(4)10-ÂłM the best fitted equation to the experimental values was shown to be: umoles/g dry matter = 1,639- 1,585 exp. (-0,006618t)Um estudo da absorção de sulfato por raizes destacadas de sorgo granĂfero mostrou: mecanismo (ou sĂtios) mĂșltiplo para absorção; o tamanho do espaço livre aparente; a influĂȘncia da temperatura, pH; a dependĂȘncia da atividade metabĂłlica
Penetration resistance according to penetration rate, cone base size and different soil conditions
DiagnĂłstico do complexo tenĂase-cisticercose bovina em SĂŁo JoĂŁo Evangelista, Minas Gerais, Brasil
INFLUĂNCIA DE IMPLEMENTOS DE PREPARO E DE NĂVEIS DE COMPACTAĂĂO SOBRE ATRIBUTOS FĂSICOS DO SOLO E ASPECTOS AGRONĂMICOS DA CULTURA DO MILHO
Avaliação da resistĂȘncia do solo Ă penetração em diferentes solos com a variação do teor de ĂĄgua
Agregação de ume nitossolo vermelho distroférrico sob sistemas de plantio direto, preparo convencional e mata nativa
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans â anteaters, sloths, and armadillos â have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
Degradabilidade in situ e observaçÔes microscĂłpicas de volumosos em bovinos suplementados com enzimas fibrolĂticas exĂłgenas
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