Instituto Federal Of Educacao Ciencia

Uberaba, Brazil

Instituto Federal Of Educacao Ciencia

Uberaba, Brazil
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Martins R.S.,Brazilian Center for Research in Physics (CBPF) | Martins R.S.,Instituto Federal Of Educacao Ciencia | Konstantinova E.,Federal University of Juiz de fora | Belich H.,Federal University of Espirito Santo | Helayel-Neto J.A.,Brazilian Center for Research in Physics (CBPF)
Journal of Magnetism and Magnetic Materials | Year: 2017

Magnetic and thermodynamical properties of a system of spins in a honeycomb lattice, such as magnetization, magnetic susceptibility and specific heat, in a low-temperature regime are investigated by considering the effects of a Kekulé scalar exchange and QED vacuum polarization corrections to the interparticle potential. The spin lattice calculations are carried out by means of Monte Carlo simulations. We present a number of comparative plots of all the physical quantities we have considered and a detailed analysis is presented to illustrate the main features and the variation profiles of the properties with the applied external magnetic field and temperature. © 2017 Elsevier B.V.

Charlo H.C.O.,Instituto Federal Of Educacao Ciencia | Ferreira A.F.,Instituto Federal Of Educacao Ciencia
Acta Horticulturae | Year: 2012

The objective of this study was to evaluate the chemical alterations of the substrate in the cultivation of peppers grown in coconut husk fiber, in a protected environment. Initially, 160 pepper plants ('Eppo') were divided into four blocks, where two pots per block were analyzed every 21 days after transplanting. The cultivation of pepper was carried out in plastic pots of 13 L, containing coconut husk fiber, and placed in double rows with a spacing of 0.5×0.8 m between single rows and 1.10 m between double rows. After removal of the plants from the pots, individual samples of substrate (approximately 1 L) were collected from each pot and dried at ambient temperature. The levels of Ca, Mg, S, Cl, Na, B, Fe, Mn, Cu and Zn were determined for all periods of the cultivation. These analyses were performed using the method of extraction 1:1.5 v/v. There was an increase in the levels of all the nutrients evaluated. Further studies should be conducted to develop a better nutrient solution.

Silva L.O.C.,Instituto Federal Of Educacao Ciencia | Silva A.A.,Federal University of Viçosa | Queiroz M.E.L.R.,Federal University of Viçosa | Lima C.F.,Federal University of Viçosa | 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.

Freitas F.C.L.,Rural University | Silva A.A.,Federal University of Viçosa | 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.

Coelho M.E.H.,Instituto Federal Of Educacao Ciencia | de Freitas F.C.L.,Rural University | Cunha J.L.X.L.,University Federal Of Alogoas | Dallabona Dombroski J.L.,Rural University | Oliveira de Santana F.A.,Rural University
Revista Caatinga | Year: 2013

Aiming at assessing the growth of sweet peppers (Capsicum annum L.), submitted to different controlling strategies of weeds in the no-trillage and conventional planting systems, an experiment was carried out in UFERSA's experimental orchard in Mossoró-RN. The split-plot scheme was used, which was distributed within the experimental design, in randomized blocks with four replications. The planting systems (no-trillage and conventional) were assessed in the plots, and three weed handling strategies (soil covering with polyethylene film, with hoeing, and without hoeing) were assessed in the subplots. Within each subplot, assessments were made on 0, 21, 42, 63, 84, 105, 126, and 147 days after transplanting (DAT) for the purpose of determining the following features of the sweet pepper: leaf area, leaf area index, dry mass of leaves, of stem, of fruits, and the total dry mass per plant, leaf area ratio, leaf weight ratio as well as the rates of absolute and relative growth and of net assimilation. On the 30th and 90th DAT, the weeds' density was assessed in the treatments without hoeing. It was found that the no-trillage system displayed a decrease in the incidence of weeds as compared to the conventional planting system. The no-trillage system decreased the incidence of weeds compared to the conventional planting systems. The weed interference in treatments without hoeing reduced the growth of pepper in both systems and the no-trillage with hoeing system showed higher indices than the other management strategies of plants in both planting systems.

Filho F.D.C.C.,Federal University of Piauí | 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 Piauí | 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.

De Souza Belo J.,Federal University of Ceará | Pinheiro V.M.,Federal University of Ceará | Guimaraes R.F.,Instituto Federal Of Educacao Ciencia | Da Silva M.J.G.,Federal University of Ceará | Abreu H.F.G.,Federal University of Ceará
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.

Do Valle Junior R.F.,Instituto Federal Of Educacao Ciencia | Galbiatti J.A.,São Paulo State University | Filho M.V.M.,São Paulo State University | Pissarra C.T.,São 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.

de Magalhaes Arantes A.,Instituto Federal Of Educacao Ciencia | Donato S.L.R.,Instituto Federal Of Educacao Ciencia | de Oliveira e Silva S.,Embrapa Mandioca e Fruticultura Tropical
Pesquisa Agropecuaria Brasileira | Year: 2010

The objective of this work was to assess the magnitude and significance of associations between morphological traits and yield of plantains. Five genotypes were evaluated: Terra, Terra-maranhão, Terrinha, and D'Angola (AAB), besides the hybrid Fhia-21 (AAAB). The associations of bunch weight (BW) with plant characters were not significant, for most of the genotypes. When all genotypes were analyzed simultaneously, most of the evaluated traits showed significant correlations between themselves. In this case, BW was significantly correlated to all traits except fruit-skin thickness.

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