University Federal do Espi rito Santo
University Federal do Espi rito Santo
Soares C.C.V.,University Federal do Espi rito Santo |
Soares C.C.V.,Federal University of Ouro Preto |
Varajao A.F.D.C.,Federal University of Ouro Preto |
Varajao C.A.C.,Federal University of Ouro Preto |
Boulange B.,Retired By Ird Institute Of Recherche Pour Le Of Veloppement
Journal of South American Earth Sciences | Year: 2014
X-ray diffraction (XRD), X-ray Fluorescence (XRF), optical microscopy, Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry (SEM-EDS) and Electron Probe micro-analyser (EPMA) and Wavelength-Dispersive Spectroscopy (WDS) were conducted on charnockite from the Caparao´ Suite and its alteration cortex to determine the mineralogical, micromorphological and geochemical transformations resulting from the weathering process. The hydrolysis of the charnockite occurred in different stages, in accordance with the order of stability of the minerals with respect to weathering: andesine/orthopyroxene, pargasite and alkali feldspar. The rock modifications had begun with the formation of a layer of incipient alteration due to the percolation of weathering solutions first in the pressure relief fractures and then in cleavage and mineral edges. The iron exuded from ferromagnesian minerals precipitated in the intermineral and intramineral discontinuities. The layer of incipient alteration evolves into an inner cortex where the plagioclase changes into gibbsite by direct alitisation, the ferromagnesian minerals initiate the formation of goethitic boxworks with kaolinitic cores, and the alkali feldspar initiates indirect transformation into gibbsite, forming an intermediate phase of illite and kaolinite. In the outer cortex, mostly traces of alkali feldspar remain, and they are surrounded by goethite and gibbsite as alteromorphics, characterising the formation of the isalteritic horizon that occurs along the slope and explains the bauxitization process at the Caparao´ Range, SE Brazil. © 2014 Elsevier Ltd.
Paes J.B.,University of Madeira |
Lopes D.J.V.,University Federal do Espi rito Santo |
Brito F.M.S.,University Federal do Espi rito Santo |
Lombardi L.R.,University of Vic
Floresta e Ambiente | Year: 2014
The aim of this study was to verify the influence of concentration on ascension of preservative solutions in the treatment time of Eucalyptus urophylla x Eucalyptus grandis fence posts. The solutions were prepared with four concentrations of chromated copper borate - CCB, with 0.5; 1.0; 2.0; and 3.0% active ingredients. The sap displacement method by radial transpiration was employed, and five fence posts were treated for each concentration. The ascension times of the respective concentrations were of 8, 7, 5, and 3 days. Penetration was analyzed at four positions on fence posts and retention was analyzed at the position corresponding to the ground zone of installed fence posts. Boron and copper penetrations were satisfactory for the fence posts treated with 3.0% solution, and fence posts treated with 2.0% solution reached values close to those recommended by the Brazilian legislation. Retention in the samples of external disks reached the recommended values, except for the fence posts treated with 0.5% solution. Increased solution concentration caused a reduction in the treatment time of fence posts.
Rodrigues W.N.,University Federal do Espi rito Santo |
Tomaz M.A.,University Federal do Espi rito Santo |
do Amaral J.F.T.,University Federal do Espi rito Santo |
Ferra&tild;o M.A.G.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária |
And 2 more authors.
Australian Journal of Crop Science | Year: 2014
The great demand for improvements in productivity lead to the search of new information regarding the behaviour of new cultivars of arabica coffee. Improved genotypes need be studied in specific regions to evaluate their potential, such as the exploration on mountains, aiming to define variables that can be exploited for the study and selection of genotypes in those conditions. This study aimed to evaluate the genetic diversity of genotypes of Coffea arabica L. with the potential for cultivation in increased-density systems in the region of Caparao´ (state of Espi´rito Santo, Brazil), based on the characteristics of plagiotropic branches in production, to evaluate the existence of correlations and to estimate the relative contributions of each of the aforementioned characteristics to the diversity. To this end, 25 characteristics were determined in 16 genotypes of arabica coffee cultivated under competition of density (evaluated in 2013, with the stabilisation of their reproductive phenological cycle). These genotypes presented considerable diversity for almost all of the traits, being possible to separate seven groups of genotypes. Among the genotypes cultivated with high plant density, IAPAR 59 and Catigua´ MG2 presented a greater degree of dissimilarity. Of the 25 traits, the number of fruits per branch and the biomass contributed more to the variability among the genotypes (over 95% of accumulated contribution). A total of 111 significant correlations were observed, with values over |0.60| in 78% of cases. Strong positive and negative correlations are observed between the various characteristics, revealing the possibility of the simultaneous selection of correlated traits.