Determinação de enantiômeros em extratos vegetais por cromatografia quiral e dicroísmo circular

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos da vibração simultânea nas propriedades mecânicas de juntas de aço ASTM A131 soldadas pelo processo arame tubular (FCAW)

Pós-graduação em Engenharia Mecânica - FEG

Caracterização mecânica e microestrutural do aço MARAGING 300, soldado a plasma e submetidas a reparos

Pós-graduação em Engenharia Mecânica - FEG

Caracterização microestrutural e mecânica de trilhos ferroviários soldados de topo por caldeamento

Pós-graduação em Engenharia Mecânica - FEIS

Adhesion of substrate-adherent combinations for early composite repairs: Effect of intermediate adhesive resin application

This study evaluated the effect of intermediate adhesive resin application (IAR) on tensile bond strength (TBS) for early composite repairs in situations where substrate and repair composite bonded together were once of the same kind with the substrate (similar) and once other than the substrate material (dissimilar). Specimens from three types of composites (TPH Spectrum (TPH), Charisma (CHA) and Filtek Z250 (Z250)) were fabricated. The specimens in each composite group (n=72) were randomly divided into six subgroups (n=12). In each composite group, the similar and two dissimilar composites were bonded onto the substrates once using an IAR (Adper Single Bond Plus) and once without. After water storage for I week at 37 degrees C, substrate-adherent combinations were submitted to tensile test. Data were analyzed with three-way ANOVA and Tukey's tests (alpha=0.05). The substrate-adherent combination (p=0.0001), adherent (repair) composite (p=0.0001), and application of IAR (p=0.0001) significantly affected the results. Utilization of IAR improved the repair bond strength for all composite combinations. (C) 2013 Elsevier Ltd. All rights reserved.

Análise histopatológica do comportamento pulpar, pós cimentação de coroas totais metálicas com cimentos de ionômero vítreo e fosfato de zinco

Pós-graduação em Odontologia Restauradora - ICT

Determinação da resistência à flexão de ligas odontológicas, utilizadas em prótese parcial fixa e prótese sobre implante, soldadas por brasagem e a laser

Pós-graduação em Odontologia Restauradora - ICT

Aplicação de cavacos de titânio para produção de revestimentos resistentes ao desgaste

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

Avaliação da integridade estrutural em um tubo de aço API 5L X70 através da propagação de trincas por fadiga

Pós-graduação em Engenharia Mecânica - FEG

A mathematical approach to simulate spatio-temporal patterns of an insect-pest, the corn rootworm Diabrotica speciosa (Coleoptera: Chrysomelidae) in intercropping systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da tenacidade CHARPY-V de um tubo de aço API 5L X70 soldado com arco submerso

This research project focused primarily on assessing the impact toughness of the weld and the base material of a steel pipe API 5L X70 submerged arc welded, used to conduct remote oil and gas (linepipes). The analysis followed strictly the Specification for Line Pipe - API 5L Standard, regarding the removal of the specimens of regions-of-proof-long section of the pipe, at 90o and 180o from the welded joint, and mechanical properties of toughness and Charpy-V, both the joint welded as the base material. Specimens of steel tube supplied by Tenaris Confab-SA were sized for tensile and Charpy-V, according to ASTM E 8M and ASTM E23, respectively. The result obtained showed that the API X70 steel tube has high Charpy-V toughness, near to each other at both 90o and 180o from the welded joint of the tube, and both higher than the weld metal. Microstructural and microhardness analysis complemented the present study

Determinação experimental da tenacidade à fratura em baixas temperaturas de tubos de aço API 5L X70

Because of the great metallurgical advances, the welded tubes by HF / ERW (High Frequency / Electrical Resistance Welding) have played a more active role in the oil and gas, gradually replacing tubes produced by other processes (UOE, SAW, and others) to deep water applications, in high and extremely low temperatures, highpressure conditions and in highly corrosive environments. However, studies have revealed that defects in the welded joints are in one of main causes of failures in pipelines. Associated with damage external and the stringent requirements of this sector, the welded joints become particularly critical for his toughness and the determination of this particular property is fundamental. This study aims to evaluate the toughness of the HF / ERW pipes in HSLA steel API X70 class, used in pipelines transport systems of gas and oil from data obtained with CTOD tests (Crack Tip Opening Displacement). The main objectives of this project are: mechanical and microstructural characterization of steels API X70 manufactured in Brazil; and evaluation of the toughness of weld process by HF / ERW steel API X70 national. After having the tests done, mechanical, chemical and metallurgical, we have the conclusion that those pipe are in agreement to API 5L 42ª edition for X70MO and the toughness behaves like the expected

Investigação experimental da tenacidade em tubos de aço API 5L X70 soldados pelo processo HF/ERW

Studies about structural integrity are very important when it desires to prevent disasters associated with flaws inherent in materials used in structural components. The welded joints in steel pipes used to conduction and distribution of oil and gas correspond to the regions most susceptible to flaw. Aiming to contribute to this research line, the present study was designed to assess experimentally the structural integrity of welded joints in steel pipes API 5L X70 used in pipeline systems. This assessment is given from tests of CTOD, whose aim is simulate in laboratory the real behaviour of crack from of his propagation on the welded joint obtained by high frequency electric resistance welding. In this case, the analyses are performed from specimens SE(B) obtained directly of steel pipe API 5L X70. The proposed methodology involves tests of CTOD at lower temperature, in order to assess the toughness of material in critical operation conditions. From performance of CTOD tests, was possible assess the toughness of welded joints in terms of quantity through CTOD parameter and in terms of quality from behaviour of curve load versus CMOD. In this study, also, sought to compare CTOD’s results obtained through rules ASTM E1820 (2008) and BS 7448 (1991). Although the two standards cited previously have adopted different parameters to calculated the value of CTOD, concluded that the values of CTOD tend to converge for a common value

Análise microestrutural de tubos API P110, para prospecção de petróleo e gás, soldados pelo processo HF/ERW

On the grounds of the great advances achieved over recent years, the process HF/ERW (High-Frequency/Electric Resistance Welding)welded pipe have played an active role in the oil and gas industry for deep water applications, at high and extremely low temperatures, under high pressure and in highly corrosive environments, gradually replacing manufactured pipes by other processes. However, studies have shown that defects in the welded joints are a the leading causes of pipelines failures, which has required the determination of toughness values in this region, in compliance with the strict recommendations of the codes and standards with manufacturers and construction companies, on the oil and gas sector. As part of the validation process required toughness values, this research project focuses on a microstructural analysis in HF / ERW tubes microalloyed, steel grade API 5CT P110, designed to explore oil and gas in deep waters, the subject of strategic relevance to the country because of the recent discoveries in the Santos mega fields: Tupi and Libra (pre-salt). In this scientific work will be presented and discussed the results of mechanical tensile and Charpy, a few CTOD tests curves (showing the trend of toughness values to be obtained), and the microstructures of the base material obtained by optical microscopy, with special emphasis on the formation of nonmetallic inclusions in the welded joint

Identificação de causas especiais no processo que aumentam a ocorrência de poro na solda de tubos de aço: aplicação etapas definir, medir e analisar do DMAIC

This work covers the methodology Six Sigma with the application of the steps Define, Measure and Analyze a company of steel tubes, with the objective of identify special causes in the process that drives the creation of the pore defect in the solder. It is highlighted the fact that this work is the base of an continuous upgrade project that aims in eliminating the occurrence of this defect. The motivation is given to the necessity of improving the productivity of the factory, considering that the defect occurs at random and your causes are unknown. This way, it was defined that the problem to analyze, measured the capability of the process in DPMO and analyzed with the aid of graph by attribute P. The results show the process that present special cases, as well as the process considered ideal, This way it was stated that in this work, the processes destabilized and the controlled, allowing a comparison of the characteristics for the elaboration of concise action plans to eliminate the defect. The project must follow the steps Upgrade and control the methodology Six Sigma, in order to ensure success in his execution, aiming to amplify the competitive edge of the business