Engenharia de microestrutura em varistor à base de ZnO: evidências de homogeneidade e correlação com reações químicas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological analysis of the corneal endothelium in eyes of dogs using specular microscopy

Foram estudados 20 olhos de 10 cães sem raça definida, machos e fêmeas com 6 anos de idade. A morfologia das células do endotélio da córnea foi analisada utilizando-se microscópio especular de contato. Foram estudadas as regiões central e periférica da córnea. de cada região da córnea foram realizadas três micrografias. de cada micrografia foram analisadas no mínimo 100 células endoteliais. Foram obtidos os valores do polimegatismo e pleomorfismo. O endotélio corneano de cães caracterizou-se por uma monocamada de células poligonais uniformes em tamanho e forma. A forma predominante das células endoteliais foi hexagonal. O índice de polimegatismo foi 0.22. Este estudo demonstrou que a morfologia das células do endotélio da córnea de cães é semelhante à observada em humanos.

Utilização de processos oxidativos avançados baseados em ozônio como pré-tratamento para bagaço de cana-de-açúcar, e hidrólise do bagaço pré-tratado com combinado enzimático dos fungos Penicillium viridicatum RFC3 e Trichoderma reesei QM9414

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência dos elementos de liga nos parâmetros de processo de fundição de ferros fundidos especiais

Pós-graduação em Engenharia Mecânica - FEG

Caracterização de Bacteriófagos Infectando Isolados Clínicos de Pseudomonas aeruginosa Armazenados em uma Coleção de Cultura

To isolate, to concentrate and to purify bacteriophages from isolates of P. aeruginosa; To observe the capacity of bacteriophages to infect isolates of P. aeruginosa susceptible and multiresitant to antimicrobial; To caractherize bacteriphages by electronic microscopy techniques. 10 isolates of Pseudomonas aeruginosa from LEMC culture collection were submitted to the experiments of ideal temperature for the lyse region appearance in the MaConkey culture plate and 2 extraction methods for the concentration of the phages, clorophorm (Silankorva) and filtration plus centrifugation (Bergan). Three infected clinical isolates of multiresistant P. aeruginosa an one susceptible isolate ( PA01) were evaluated by 3 transmission electron microscopy techniques to caractherize phages morphologically (“on grid”, “on drop” and direct extraction from the lyse region of the culture plate). The ideal temperature to obtain lyses region was 37°C. The stock solutions, obtained through the methodologies of Sillankorva and Bergan, had satisfactory results in infecting the multiresistant isolate and the negative control. Among the 3 techniques of electronic microscopy tested the direct from the lyse plate was the best to obtain the micrography of the phages

Efeito do Estrôncio (Sr) no tratamento de modificação do eutético da liga Al-1%Si

This study aimed to analyze the cooling curves, micro and macrograph alloy Al-1 %Si without the addition of strontium modifier and with the addition of the same. One of the ways of improving mechanical properties of alloy Al -Si is through the modification process. For the experiments two billets of the alloy Al-1%Si cast iron mold in a billet with addition of 0.02% strontium by weight, and the other billet without the addition of modifier were fused. In the solidification process of billet temperature was monitored and recorded every second for later plotting in Origin 8 program and analyzes the cooling curves obtained. The billets were cut and passed by grinding and polishing to perform the macrograph and micrographs. The results concerning the macrograph indicated that billet without the addition of Strontium particle size obtained was more refined than the billet where the strontium modifier was added. Regarding the micrograph, photos stemmed from the optical microscope didn´t show the expected modification effect by the addition of Strontium. This suggests that the low amount of silicon (1 %) present in the alloy used in this study interfered in the change process, because according to the literature review, Strontium 0.022 % by weight is sufficient to fully modify an alloy with 7% Silicon. The results from the cooling curve showed that both the eutectic temperature and the solidification time remained unchanged with the addition of strontium

Análise macro e micrográfica da liga AA-356 conforme a taxa de resfriamento

The present work aims to study the characteristics of the alloy Al - 7 % Si - 0 , 3Mg ( AA356 ) , more specifically characterize the macrostructure and microstructure and mechanical properties of the alloy ingots AA356 obtained in metal molds and sand molds for power studying the structures through the difference of cooling rates . This alloy is explained by the fact of referring league has excellent combination of properties such as low solidification shrinkage and good fluidity, good weldability , high wear resistance , high strength to weight ratio, has wide application in general engineering , and particularly in the automotive and aerospace engineering . In this work we will verify this difference in properties through two different cooling rates . We monitor the solid solidification temperatures by thermocouples building with them the cooling curve as a tool that will aid us to evaluate the effectiveness of the grain refining because it achieved with some important properties of the alloy as the latent heat of solidification fraction the liquid and solid temperatures, the total solidification time, and identify the presence of inoculants for grain refinement. Thermal analysis will be supported by the study of graphic software “Origin “will be achieved where the cooling curve and its first derivative that is the cooling rate. Made thermal analysis, analysis will be made in macrographs ingots obtained for observation of macrostructures obtained in both types of ingots and also analysis of micrographs where sampling will occur in strategic positions ingots to correlate with the microstructure. Finally will be collecting data from Brinell hardness of ingots and so then correlating the properties of their respective ingots with cooling rate. We found that obtained with cast metal ingots showed superior properties to the ingots obtained with sand mold

Caracterização estrutural da Liga Al-1% Si

The aim of this study is to characterize the macrostructure and microstructure of Al - 1%Si alloy obtained in sand and metallic molds. Aluminium has good mechanical properties, but adding silicon, even in small quantities, can change the microstructure and improves mechanical behavior. Workpieces were castings in metallic and sand molds and one can see a difference in their cooling curve, macroscopic and microscopic structures. The sand mold casting has lower cooling rate and so its grains are larger. Due to the lower concentration of grain boundary, the hardness is lower compared to that found in metallic molds, which has smaller grains and a higher hardness. Therefore, it can be concluded that the cooling rate and alloying elements affect the final microstructure of the workpiece