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De Souza Belo J.,Federal University of Ceara | Pinheiro V.M.,Federal University of Ceara | Guimaraes R.F.,Instituto Federal Of Educacao Ciencia | Da Silva M.J.G.,Federal University of Ceara | Abreu H.F.G.,Federal University of Ceara
65th ABM International Congress, 18th IFHTSE Congress and 1st TMS/ABM International Materials Congress 2010 | Year: 2010

The objective of this study is to determine the main mechanical properties and combination of these properties with the microstructural characteristics of new alloys with 9% Cr and Mo, 5% and 9% after the solubilizing. The performance of mechanical tests aimed at determining the mechanical properties of alloys by testing the hardness, tensile and impact. Measurements of hardness, based on the NBR NM 188, were made in samples subjected to microstructural analysis by scanning electron microscopy. Specimens were machined to perform tensile tests at room temperature, according to NBR 6152. Also were prepared specimens for testing of impact Charpy-V low, the temperature, according to NBR 6157 and ASTM E 23-96. The alloy with higher content of molybdenum had a higher mechanical strength than that of lower content of molybdenum. Source


Silva L.O.C.,Instituto Federal Of Educacao Ciencia | Silva A.A.,Federal University of Vicosa | Queiroz M.E.L.R.,Federal University of Vicosa | Lima C.F.,Federal University of Vicosa | And 2 more authors.
Planta Daninha | Year: 2012

The evolution of chemical weed control methods has been fundamental to cultivation of large areas where production costs are compatible with national and international markets. Currently, herbicides account for approximately 45.0% of all pesticides used in Brazil. Most of these compounds present long persistence in the environment, contaminating soil, hindering new crops as well as surface water and groundwater, thus leading to environmental problems. The objective of this work was to quantify, using the chromatographic technique, the efficacy of the species E. coracana in reducing picloram persistence in two soils, a Red Yellow Ultisol and a Red Yellow Latosol, treated with this herbicide, and widely cultivated for pastures and crops in Brazil. It was concluded that the species E. coracana is effective in the remediation of soils contaminated by this herbicide, indicating its potential use in programs of phytoremediation of contaminated areas to reduce the risk of environmental impact. Picloram half-life values of the soils evaluated differed for the same weather conditions, probably differing even more under field conditions. Source


Freitas F.C.L.,Rural University | Silva A.A.,Federal University of Vicosa | Silva L.O.C.,Instituto Federal Of Educacao Ciencia | Rocha P.R.R.,PNPD UFERSA | And 3 more authors.
Planta Daninha | Year: 2012

This work aimed to evaluate ametryn mobility in four types of soils, three from the semiarid region of the state of Rio Grande do Norte (Cambisol; Fluvic Neosol; Latosolic Dystrophic Red-Yellow Argisol) and one from the state of Minas Gerais (Red-Yellow Latosol). Ametryn mobility was evaluated using PVC columns of 10 cm in diameter and 50 cm long. The experiment was conducted in a split-plot in a completely randomized design with four replications. The plots were composed by the columns, filled with the four types of soils and the subplots by 10 depths at intervals of 5 cm (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45 and 45-50 cm). Ametryn was applied on top of the columns (4 kg ha-1) and, 12 hours later, rainfall was simulated at the intensity of 60 mm. After 72 hours of simulated rain, the columns were placed in a horizontal position and opened longitudinally, divided into sections of 5.0 cm. At the center of each section, soil samples were collected for subsequent herbicide extraction and quantification through analysis by liquid chromatography (HPLC). Five seeds of cucumber (Cucumis sativus) were sown as bio-indicators of the presence of the herbicide. Ametryn mobility at the columns was influenced by the physical and chemical characteristics of the soil,(soil texture, organic matter, and pH). The Rio Grande do Norte semiarid region soils had higher ametryn mobility potential, being detected at up to 25, 20, and 15 cm depth in Latosolic Dystrophic Red- Yellow Argisol, Cambisol, and Fluvic Neosol, respectively. Ametryn mobility was restricted to 5 cm depth in the Red Yellow Latosol, with higher organic matter content and pH 4.7. The bioassay method was more efficient to confirm ametryn leaching than liquid chromatography. Source


Filho F.D.C.C.,Federal University of Piaui | Calvet R.M.,Instituto Federal Of Educacao Ciencia | Da Rocha Rosa C.A.,Federal Rural University of Rio de Janeiro | Pereira M.M.G.,Federal University of Piaui | And 2 more authors.
Ciencia Animal Brasileira | Year: 2013

The aim of this study was to determine the occurrence of fungi and aflatoxins in fish feeds. We analyzed 36 samples of feed for fish, with two protein compositions (juvenile/fattening) and two forms of use (sealed/open). Aspergillus and Penicillium species were counted, isolated and identified, the toxic capacity of Flavi strains was measured and aflatoxins in the feed were researched. The mean fungal counts ranged from 2.96 to 4.00 log10 CFU/g and there was no significant difference between treatments. The most isolated species were Aspergillus flavus, Eurotion spp. and Penicillium implicatum. We concluded that the feeds studied had high fungal counts; the isolated Aspergillus flavus strains were not producers of aflatoxin; and aflatoxin was not detected in the feed samples analyzed. Source


Do Valle Junior R.F.,Instituto Federal Of Educacao Ciencia | Galbiatti J.A.,Sao Paulo State University | Filho M.V.M.,Sao Paulo State University | Pissarra C.T.,Sao Paulo State University
Engenharia Agricola | Year: 2010

This work aimed to identify qualitatively the areas susceptive to laminar erosion in Uberaba river watershed, located in Uberaba-MG, Brazil, based on the mathematical model of the Universal Soil Loss Equation (USLE). The following maps had been used: soil, land use, drainage net, slope and rainfall data, using a Geographic Information System (GIS - IDRISI) to analyze and manage the data that are linked to the location. The spatiality of the potential of erosion was possible from the estimative of the tolerance to laminar losses for each kind of soil in the watershed and soil depth, to understand that the losses are more significant in flatter soil than in very deep ones. In the analysis of the results, it was verified that 37% of the total area of the watershed of the Uberaba river (905,24 km2) showed losses above the tolerance limit, being 12% in deep soil and 25% in very deeply ones, and the spatiality of this event, regards to effective the actions due to soil conservation of the watershed. Source

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