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Hafle O.M.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba | Ramos J.D.,Federal University of Lavras | Mendonca V.,Federal Rural University of the Semiarid Region | Rufini J.C.,Federal University of Säo João del Rei | Santos V.M.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba
Revista Brasileirade Ciencias Agrarias | Year: 2012

The objective of this work was to evaluate the production and productivity of yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg.) subjected to different pruning for renewal. The experiment was conducted in commercial orchard in Lavras, MG (21°14'S; 45°58'W; altitude de 910 m), from July/2006 to June/2008. The seedlings originated from seeds planted in 4×3 m spacing, conducted in a vertical trellis wire. The experimental design was randomized blocks in factorial scheme of 5×3: number of tertiary branches per plant (40, 30, 24, 20 and 14) and length of pruning branches (40, 80 and 120 cm) with four replications of three plants. The following characteristics were evaluated: number of fruits per plant, mean weight of fruit, fruit and juice yield. The renewal pruning affected the amount and size of the yellow passion fruit. Plants that have suffered more severe pruning, leaving 14 and 20 stems and tertiary pruned to 40 cm in length, had lower productivity in the first season after renewal pruning.


Goncalves Costa Junior A.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba | Antonio Riul J.,Federal University of Paraiba | Henrique Miranda Montenegro P.,Federal University of Paraiba
IEEE Latin America Transactions | Year: 2016

This paper presents results for the application of the Subspace Identification Method using N4SID technique in its deterministic case. The goal is to obtain a state-space mathematical model for a robotic manipulator with five degrees of freedom. This study aims to present alternatives to the Prediction Error identification techniques in multivariable systems with high complexity and elevated computational efforts. Results indicate that the applied subspace identification leads to a successful state-space mathematical model which makes it an efficient alternative method to mathematical modeling in future projects. © 2016 IEEE.


de Macedo Silva E.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba | Leite J.P.,Federal University of Paraiba | Leite J.P.,Federal University of Campina Grande | Fialho W.M.L.,Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba | And 2 more authors.
Journal of Nondestructive Evaluation | Year: 2016

Sigma phases are formed due to heat treatments and/or welding processes during the solidification stage, and they are responsible for embrittlement of duplex stainless steels. Only a small amount of this phase promotes unfavorable mechanical properties and liability to corrosion. In this work, a new affordable approach to detect and follow-up the kinetics of the sigma phase transformation is evaluated. The measurements are based on an induced magnetic field generated through the interaction between an external magnetic field and the microstructure under study. To validate this approach, the induced magnetic field values are compared with the values of the Charpy impact energy, and the sigma phase is assessed by optical microscopy. Moreover, surface fractures are analyzed by scanning electron microscopy and X-ray diffraction. The results from the 2205 duplex stainless steel used show that there is a direct relation among the impact energy, fracture mechanism and induced magnetic field. The method proved to be able to follow up the embrittlement of the DSS successfully. Moreover, the results confirm that the presence of a sigma phase can be studied based on an induced magnetic field, even when in low amounts, and that a critical threshold value can be defined to monitor structures in service. © 2016, Springer Science+Business Media New York.


Melo M.A.M.F.,Federal University of Paraiba | De Melo M.A.R.,Federal University of Paraiba | Pontes A.S.G.C.,Federal University of Paraiba | Farias A.F.F.,Federal University of Paraiba | And 4 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2014

Vegetable oils with variable proportions of oleic, linoleic, and linolenic acids are more susceptible to oxidative processes. In this subject, this study evaluates the physical chemical properties and oxidative stability of nonconventional oils such as andiroba, babassu, sesame, oiticica, jatropha, and grape through accelerated oxidation techniques (pressurized differential scanning calorimetry, Rancimat and PetroOxy). It was verified that babassu and andiroba oil do not showed detectable induction period presenting high oxidative stability; moreover, it was observed that the enthalpic events occurred in 1.19,>10, 0.53, 0.49, 0.49, and 0.60 h for the andiroba oil, babassu oil, sesame seeds, jatropha, oiticica oils, and grapes, respectively, stimulating the conclusion of greater stability for the babassu oil. © Akadémiai Kiadó, Budapest, Hungary 2014.


PubMed | University of Amazon, Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba and Secretaria de Estado de Educacao
Type: Journal Article | Journal: Brazilian journal of biology = Revista brasleira de biologia | Year: 2015

A zooplankton checklist is presented for the Middle Xingu River, based on surveys conducted at four sites in the main channel and two fluvial lakes. A total of 175 taxa are listed, including 141 rotifers, 20 cladocerans, and five copepods. Rapids presented the greatest species richness, with up to 124 taxa, while Ilha Grande lake had 70 taxa, the lowest number. Non-planktonic benthic larvae were recorded frequently in the samples.


PubMed | Federal University of Pará and Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba
Type: Journal Article | Journal: Brazilian journal of biology = Revista brasleira de biologia | Year: 2015

This study estimates the main biological parameters, including growth rates, asymptotic length, mortality, consumption by biomass, biological yield, and biomass, for the most abundant fish species found on the middle Xingu River, prior to the construction of the Belo Monte Dam. The specimens collected in experimental catches were analysed with empirical equations and length-based FISAT methods. For the 63 fish species studied, high growth rates (K) and high natural mortality (M) were related to early sexual maturation and low longevity. The predominance of species with short life cycles and a reduced number of age classes, determines high rates of stock turnover, which indicates high productivity for fisheries, and a low risk of overfishing.


PubMed | Federal University of Pará and Instituto Federal Of Educacao Ciencia E Tecnologia Da Paraiba
Type: Journal Article | Journal: Brazilian journal of biology = Revista brasleira de biologia | Year: 2015

The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperana and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

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