Study of corrosion resistance of laser welded Au-Pd-Ag-In alloy using electrochemical.

The aim of this work was to evaluate the corrosion resistance of AuPdAgIn alloy, submitted to laser beam welding, in 0.9% NaCl solution, using electrochemical techniques. Measures of the open circuit potential (OCP) versus time were applied to electrochemical experiments, as well as potentiodynamic direct scanning (PDS) and electrochemical impedance spectroscopy (EIS) on AuPdAgIn alloy, submitted to laser beam welding in 0.9% NaCl solution. Some differences observed in the microstructure can explain the results obtained for corrosion potential, Ecorr, and corrosion resistance, Rp. EIS spectra have been characterized by distorted capacitive components, presenting linear impedance at low frequencies, including a non-uniform diffusion. The area of the laser weld presented corrosion potential slightly superior when compared to the one of the base metal. The impedance results suggest the best resistant corrosion behavior for laser weld than base metal region. This welding process is a promising alternative to dental prostheses casting.

Lisina e metionina+cistina digestíveis sobre o desempenho, rendimento, qualidade e morfometria do músculo peitoral (Pectoralis major) de frangos de corte

Pós-graduação em Zootecnia - FCAV

Estudo do comportamento em fadiga de um tubo de aço microligado, grau API 5L X70

This work focuses on a study on the fatigue behavior of a microalloyed steel API 5L X70, used in pipes lines to transport oil and gas. These types of steels have excellent mechanical resistance values and ductility and therefore increased their study driven by increased demand for oil and especially natural gas, which consequently raises the need to build new pipelines to transport these products. The oil extraction units, composed of the risers (pipelines connecting the oil well to the ship), are dimensioned to remain installed for periods of 20 to 30 years in the marine environment, a hostile environment for high pressure, corrosion, low temperatures and the stresses caused by the movement of water and tides. For analysis, the S-N (stress versus number of cycles) curves were obtained from data collected from bodies-of-proof cylindrical longitudinal, transverse and that one removed from the weld area of the pipe, tested in accordance with ASTM E466. Tensile tests were performed for characterizing the mechanical properties of the samples and welded joints, concluded that the values meet the specifications of the standard API 5L. To characterize microstructural material, also metallographic analysis was made of regions of the base metal and the HAZ. The results of fatigue tests demonstrated a higher life for the specimens removed from the longitudinal direction the pipe, followed by those in the transverse direction and, finally, the welded joint. The origins of the fatigue cracks were determined by scanning electron microscopy (SEM)

Análise metalográfica do titânio puro submetido à soldagem laser Nd: YAG e TIG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reciclagem de cavacos para a formação de carbonetos de titânio no metal de solda produzido por soldagem GTAW em aço-carbono

Pós-graduação em Engenharia Mecânica - FEIS

Processing yield and chemical composition of rainbow trout (Oncorhynchus mykiss) with regard to body weight

The influence of weight (W) category of the rainbow trout on processing yield and chemical composition of the entire eviscerated fish and fish fillet was analyzed. A completely randomized design was employed for processing variables (W1 = 300 to 370 g and W2 = 371 to 440) coupled to a 2 x 2 factorial scheme for the chemical composition (W1 and W2 and forms of presentation: fillet and whole eviscerated fish). W1 showed higher yield for entire eviscerated fish (83.00%) and head (13.27%), but a lower yield for the viscera (17.00%), when compared to W2. We did not affect abdominal muscle yield, fillet with or without skin, skin percentage and residues. There were significant differences between W for moisture (W1 = 72.30% and W2 = 71.15%) and lipids (CP1 = 7.96% and CP2 = 9.04%) rates. Fillet moisture contents (73.74%) and crude protein (19.05%) were higher (p < 0.01) than for entire eviscerated fish (69.71% and 17.81%, respectively). Ash (2.15%) and lipid (10.48%) rates were higher (p < 0.01) for entire fish when compared to those of fillets (1.16% and 6.52%, respectively). The slaughter of fish weighing between 300 and 370 g and their fillets are more adequate for the market.

Mechanical and microstructural characterization of laser-welded joints of 6013-T4 aluminum alloy

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

Avaliação econômica da alimentação de tilápias em tanques-rede com níveis de proteína e energia digestíveis

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

Genetic and phenotypic parameters of carcass and organ traits of broiler chickens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do desbalanceamento da onda retangular na liga de alumínio 6063-T6 soldada pelo processo TIG-CA

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Análise de falhas por fadiga num rotor de hidrogerador vertical via método dos elementos finitos

Pós-graduação em Engenharia Mecânica - FEG

Caracterização de juntas soldadas em PAW e GTAW de chapas finas em aço maraging 300 submetidas a vários reparos

Pós-graduação em Engenharia Mecânica - FEG

Qualidade microbiológica e perfil de sensibilidade antimicrobiana dos isolados de tilápias (Oreochromis spp.) de pesque-pague da microrregião do Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do aporte térmico da soldagem GTAW no balanço de fases Ferrita/Austenita do Aço Inoxidável Duplex UNS S32205

Pós-graduação em Engenharia Mecânica - FEIS

Gamma irradiation can control the number of psychotrophic bacteria in Agaricus bisporus during storage

We evaluated the effect of gamma irradiation doses (0, 125, 250, and 500 Gy) in control of psychrotrophic bacteria in different strains of Agaricus bisporus (ABI-07/06, ABI-05/03, and PB-1) during storage, cultivated in composts based on oat straw (Avena sativa) and Brachiaria spp. The experimental design was completely randomized in a factorial scheme 4  2  3 (irradiation doses  composts  strains), with 24 treatments, each consisting of 2 replicates, totaling 48 experimental units (samples of mushrooms). The mushrooms collected from all culture conditions were packaged in plastic polypropylene with 200 g each and subjected to Cobalt-60 irradiator, type Gammacell 220, and dose rate 0.740 kGy h–1 , according to the treatments. Subsequently, the control (nonirradiated) and other treatments were maintained at 4 ± 1°C and 90% relative humidity (RH) in a climatic chamber to perform the microbiological analysis of mushrooms on the 1st and 14th day of storage. According to the results, it was found that the highest mean colony psychotrophic count, after 14 days of storage, was observed in strain ABI-07/06 1.30 × 108 g -1 most probable number (MPN) in nonirradiated mushrooms, coming from Brachiaria grass-based compost, and this same strain under the same storage conditions, coming from the same type of compost that underwent a dose of 500 Gy, obtained a significant reduction in mean colonies of psychrotrophic bacteria (2.25 × 104 g –1 MPN). Thus, the irradiation doses tested favored reducing the number of colonies of psychrotrophic bacteria, regardless of the type of compound and strain of A. bisporus.