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Search Results: 1 - 10 of 136071 matches for " José Wagner da Silva;Domingos "
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Biologia do ácaro predador Euseius alatus DeLeon (Acari: Phytoseiidae) em diferentes temperaturas = Biology of predator mite Euseius alatus DeLeon (Acari: Phytoseiidae) under different temperatures
José Wagner da Silva Melo,Cleiton Araújo Domingos,Andreia Serra Galv?o,Manoel Guedes Corrêa Gondim Junior
Acta Scientiarum : Agronomy , 2009,
Abstract: Euseius alatus DeLeon (Acari: Phytoseiidae) é um dos predadores mais comuns em fruteiras no Brasil, alimentando-se de pólen, ácaros e outros pequenos artrópodes. Este predador apresenta ampla distribui o, ocorrendo desde o Rio Grande do Sul até o Ceará. O presente trabalho teve como objetivo avaliar o efeito da temperatura no desenvolvimento e na reprodu o de E. alatus e determinar suas exigências térmicas. O estudo foi conduzido a 18, 21, 24, 27, 30 e33°C, umidade relativa de 70 ± 5% e fotofase de 12h. Nessas temperaturas, o período de ovoadulto durou 14,0; 8,1; 5,5; 4,9; 3,8 e 3,1 dias, respectivamente. Os estágios de ovo, larva, protoninfa, deutoninfa e período de ovo-adulto apresentaram limiares térmicos de 12,52; 13,85; 14,86; 14,86 e 13,31oC e constantes térmicas de 22,32; 14,23; 16,23; 17,3 e 70,16 graus dias. Os valores para os parametros da tabela de vida de fertilidade, analisados em conjunto com os valores das diferentes variáveis de desenvolvimento em diferentes temperaturas, permitiram concluir que a temperatura de 30°C mostrou-se mais adequada ao desenvolvimento e reprodu o de E. alatusem laboratório. Logo, tudo indica que E. alatus encontra melhores condi es de temperatura para se desenvolver em regi es mais quentes do Brasil, como as preponderantes no Nordeste brasileiro. Euseius alatus DeLeon (Acari: Phytoseiidae) is one of the mostcommon predators of tropical fruit trees in Brazil, feeding of pollen, mites and other small arthropods. This predator presents wide distribution, occurring from Rio Grande do Sul to Ceará. This work had as objective to evaluate the effect of temperature on the development and reproduction of E. alatus, in addition to determining their thermal requirements. The study was accomplished at temperatures of 18, 21, 24, 27, 30 and 33°C; relative humidity of 70 ± 5%; and 12-h photophase. At these temperatures, the egg-adult period lasted 14.0; 8.1; 5.5; 4.9; 3.8 and 3.1 days, respectively. The egg, larva, protonymph and deutonymph stages and the egg-adult period presented thermal thresholds of 12.52; 13.85; 14.86; 14.86 and 13.31oC, and thermal constants of 22.32; 14.23; 16.23; 17.3 and 70.16 degrees days. The values for the parameters of the fertility lifetable, analyzed in conjunction with the values of the different variables of development at different temperatures, showed that the temperature of 30oC is the most suitable for development and reproduction of E. alatus in the laboratory. Therefore, is it apparent that the best temperature conditions for the development of E. alatus are found in the warmer regi
Biologia do ácaro predador Euseius alatus DeLeon (Acari: Phytoseiidae) em diferentes temperaturas
Melo, José Wagner da Silva;Domingos, Cleiton Araújo;Galv?o, Andreia Serra;Gondim Junior, Manoel Guedes Corrêa;Moraes, Gilberto José de;
Acta Scientiarum. Agronomy , 2009, DOI: 10.4025/actasciagron.v31i3.466
Abstract: euseius alatus deleon (acari: phytoseiidae) is one of the most common predators of tropical fruit trees in brazil, feeding of pollen, mites and other small arthropods. this predator presents wide distribution, occurring from rio grande do sul to ceará. this work had as objective to evaluate the effect of temperature on the development and reproduction of e. alatus, in addition to determining their thermal requirements. the study was accomplished at temperatures of 18, 21, 24, 27, 30 and 33oc; relative humidity of 70 ± 5%; and 12-h photophase. at these temperatures, the egg-adult period lasted 14.0; 8.1; 5.5; 4.9; 3.8 and 3.1 days, respectively. the egg, larva, protonymph and deutonymph stages and the egg-adult period presented thermal thresholds of 12.52; 13.85; 14.86; 14.86 and 13.31oc, and thermal constants of 22.32; 14.23; 16.23; 17.3 and 70.16 degrees days. the values for the parameters of the fertility life table, analyzed in conjunction with the values of the different variables of development at different temperatures, showed that the temperature of 30oc is the most suitable for development and reproduction of e. alatus in the laboratory. therefore, is it apparent that the best temperature conditions for the development of e. alatus are found in the warmer regions of brazil, such as those observed in northeastern brazil.
Preparation and characterization of Nickel-and cobalt-doped magnetites
Lelis, Maria de Fátima Fontes;Fabris, José Domingos;Mussel, Wagner da Nova;Takeuchi, Armando Yoshihaki;
Materials Research , 2003, DOI: 10.1590/S1516-14392003000200006
Abstract: nickel- and cobalt-doped magnetites were prepared by a co-precipitation method and studied in some detail, in an effort to identify some effects of the doping cations on the magnetic, crystallographic and morphological properties of the resulting spinel. the synthetic samples were characterized by conventional chemical analysis, powder x-ray diffractometry, m?ssbauer spectroscopy, saturation magnetization and scanning electron microscopy. from chemical analysis, the continuous increase of ni2+ or co2+ is accompanied by a simultaneous decrease of the fe2+ contents, in the spinel structure. the magnetization values also decrease continuously with increasing doping cation contents. m?ssbauer parameters are characteristic of substituted magnetites and indicate the presence of a single phase only. based on the inverted intensities of the lines 1 (leftmost, on the negative doppler velocity scale) and 2 of m?ssbauer spectra of doped samples, relatively to the pure magnetite, it was assumed that the isomorphical substitution occurs preferentially on octahedral coordination sites of the spinel structure. the coercive field of these ferrites decrease steadily with ni2+ but increases with co2+ contents, reaching a maximum at x = 0.38, in the general formula coxfe3-xo4 .
Preparation and characterization of Nickel-and cobalt-doped magnetites
Lelis Maria de Fátima Fontes,Fabris José Domingos,Mussel Wagner da Nova,Takeuchi Armando Yoshihaki
Materials Research , 2003,
Abstract: Nickel- and cobalt-doped magnetites were prepared by a co-precipitation method and studied in some detail, in an effort to identify some effects of the doping cations on the magnetic, crystallographic and morphological properties of the resulting spinel. The synthetic samples were characterized by conventional chemical analysis, powder X-ray diffractometry, M ssbauer spectroscopy, saturation magnetization and scanning electron microscopy. From chemical analysis, the continuous increase of Ni2+ or Co2+ is accompanied by a simultaneous decrease of the Fe2+ contents, in the spinel structure. The magnetization values also decrease continuously with increasing doping cation contents. M ssbauer parameters are characteristic of substituted magnetites and indicate the presence of a single phase only. Based on the inverted intensities of the lines 1 (leftmost, on the negative Doppler velocity scale) and 2 of M ssbauer spectra of doped samples, relatively to the pure magnetite, it was assumed that the isomorphical substitution occurs preferentially on octahedral coordination sites of the spinel structure. The coercive field of these ferrites decrease steadily with Ni2+ but increases with Co2+ contents, reaching a maximum at x = 0.38, in the general formula Co xFe3-xO4 .
Mechanical characterisation of porous glass reinforced hydroxyapatite ceramics: Bonelike?
Silva, Marcelo Henrique Prado da;Lemos, Alexandra Fernandes;Ferreira, José Maria da Fonte;Santos, José Domingos;
Materials Research , 2003, DOI: 10.1590/S1516-14392003000300004
Abstract: in the present study, mechanical properties of porous glass reinforced hydroxyapatite bioceramics were assessed by microhardness, bending and compression tests and fracture toughness determination. porous discs were produced by a dry method using wax spheres as pore formers. green bodies were sintered and the final microstructure of the composites consists of hydroxyapatite, alpha and beta tricalcium phosphate (a and b-ca3(po4)2)due to the reaction between the glassy phase and the hydroxyapatite matrix. the results of the mechanical tests showed that the glassy phase yielded higher fracture toughness and bending strength when comparing with literature data for single hydroxyapatite. there is a compromise between mechanical properties and the porosity level for bioceramics: for example, according to weibull statistics for composites with 65% porosity the maximum bending stress level is 0.2 mpa for 100% survival probability whereas this stress level increases to 2.5 mpa for composites with 40%. however, only the 65% porosity composite samples seem to have the complete adequate morphology for bone ingrowth.
Mechanical characterisation of porous glass reinforced hydroxyapatite ceramics: Bonelike
Silva Marcelo Henrique Prado da,Lemos Alexandra Fernandes,Ferreira José Maria da Fonte,Santos José Domingos
Materials Research , 2003,
Abstract: In the present study, mechanical properties of porous glass reinforced hydroxyapatite bioceramics were assessed by microhardness, bending and compression tests and fracture toughness determination. Porous discs were produced by a dry method using wax spheres as pore formers. Green bodies were sintered and the final microstructure of the composites consists of hydroxyapatite, alpha and beta tricalcium phosphate (alpha and b-Ca3(PO4)2)due to the reaction between the glassy phase and the hydroxyapatite matrix. The results of the mechanical tests showed that the glassy phase yielded higher fracture toughness and bending strength when comparing with literature data for single hydroxyapatite. There is a compromise between mechanical properties and the porosity level for bioceramics: for example, according to Weibull statistics for composites with 65% porosity the maximum bending stress level is 0.2 MPa for 100% survival probability whereas this stress level increases to 2.5 MPa for composites with 40%. However, only the 65% porosity composite samples seem to have the complete adequate morphology for bone ingrowth.
Airborne geophysical and tectonics of the Ceará central domain, eastern region of the Santa Quitéria magmatic ARC, Borborema Province, NE Brazil
Amaral, Wagner da Silva;Santos, Ticiano José Saraiva dos;
Revista Brasileira de Geofísica , 2008, DOI: 10.1590/S0102-261X2008000400012
Abstract: the airborne geophysical data gamma-spectrometric and magnetic from itatira project (1977) was carried out, in the central region of the state of the ceará, brazil. their processing produced products useful to indirectly identify regional geologic features. the verification and applicability of this approach was tested in a pilot-area whose limits are within the umirim and canindé topographic sheets, at 1:100,000 scale. the integration between the airborne geophysical and the geologic field data supported to the geologic mapping at the same cited scale. two main units were recognized: the santa quitéria magmatic arc and the supracrustal sequences that surround the arc. the rocks fram santa quitéria magmatic arc are characterized by high counting on the k-channel in its almost entire region and intermediate and low counting of eth and eu. generally, the supracrustal sequences are characterized by high values on the eu-and-eth-channels and low on k-channel. the subunit metaultramafics and, mafics granulites, are remarkable by the occurrence retrograde eclogites bands and mafic granulites as lenses within gneisses and migmatites. these subunits present strong negative anomalies, with low counting on the three k, eth and eu channels. that area also has positive magnetic anomalies, and may reflect high values of magnetic susceptibility.
Mecanismos químicos e mineralógicos de transforma??o da magnesioferrita de solo derivado de tufito, da regi?o do Alto Paranaíba, MG
Silva, Fernando Dias da;Goulart, Antonio Taranto;Couceiro, Paulo Rogério da Costa;Fabris, José Domingos;
Química Nova , 2009, DOI: 10.1590/S0100-40422009000700031
Abstract: magnetic soils forming on tuffite of the region of alto paranaíba, minas gerais, brazil, usually contain iron-rich spinels exceptionally rich in magnesium and titanium. in this work, samples of the magnetically separated portion from the sand fraction of a brunizém (chernossolo) and from its mother-rock material were analyzed with synchrotron x-ray diffraction and 57fe-m?ssbauer spectroscopy. magnesioferite (mgfe2o4) and maghemite (its pure non-stoichiometric spinel structure, fe8/3 ⊕ 1/3 o4, where ⊕ = cation vacancy, corresponds to γfe2o3) were the magnetic iron oxides so identified. basing on these data, a consistent chemical-mineralogical model is proposed for the main transformation steps involving these iron oxides in the pedosystem, starting on magnesioferrite to finally render hematite (αfe2o3), passing through maghemite as an intermediate specie.
Composi??o química e digestibilidade in vitro de laminas foliares e colmos de gramíneas forrageiras, em fun??o do nível de inser??o no perfilho, da idade e da esta??o de crescimento
Paciullo, Domingos Sávio Campos;Gomide, José Alberto;Queiroz, Domingos Sávio;Silva, Eldo Ant?nio Monteiro da;
Revista Brasileira de Zootecnia , 2001, DOI: 10.1590/S1516-35982001000400009
Abstract: chemical composition and the in vitro dry matter digestibility were evaluated in blades and stems at two stages of development and two insertion levels on tillers of signalgrass (brachiaria decumbens), molassesgrass (melinis minutiflora) and tifton 85 bermudagrass (cynodon sp), in two seasons of the year (summer and autumn). lower and upper leaf blades were sampled from the tillers, on the day of ligule exposure and 20 days thereafter, and stems segments located below of the upper leaf blade. the crude protein contents of leaf blades showed little differences among the species, but decreased with development from 18.8 to 14.6% and level of insertion from 18.9 to 14.5% from lower to upper position. leaf blades of higher insertion level had a greater neutral detergent fiber and lignin concentrations. the ivdmd decreased as leaf aged and exhibited greater values when situated at lower insertion level and sampled in the autumn. the ivdmd of old leaf blades were higher to tifton 85 bermudagrass and lower to signalgrass. the average values of ivdmd of stems varied from 56.7 to 62.7%, according to stage of development and season of growth. the values were 56.9, 59.6 and 60.5% for the signalgrass, bermudagrass and molassesgrass, respectively.
Correla??es entre componentes anat?micos, químicos e digestibilidade in vitro da matéria seca de gramíneas forrageiras
Paciullo, Domingos Sávio Campos;Gomide, José Alberto;Queiroz, Domingos Sávio;Silva, Eldo Ant?nio Monteiro da;
Revista Brasileira de Zootecnia , 2001, DOI: 10.1590/S1516-35982001000400008
Abstract: leaf blades and stem segments at two stages of development (day of leaf ligule exposure and 20 days thereafter) and two insertion levels on tillers (lower and upper) of signalgrass (brachiaria decumbens), molassesgrass (melinis minutiflora) and tifton 85 bermudagrass (cynodon sp), were sampled in two seasons of the year (summer and autumn). the anatomical and chemical traits, and in vitro dry matter digestibility of blades and stems segments were evaluated. the correlations among these variables were established to associated values observed in leaf blade and stem, and to each fraction. the cell wall thickness was the anatomical trait to exhibit the highest correlation with all the chemical components, being positive with neutral detergent fiber, acid detergent fiber and lignin contents and negative with crude protein content. the proportion of mesophyll correlated positively with crude protein and negatively with acid detergent fiber content, while the proportion of sclerenchyma showed positive correlation with neutral detergent fiber content. the chemical components showed strong correlation among themselves and with the ivdmd. from the anatomical traits, the cell wall thickness was the only one to exhibit a significant correlation with the ivdmd, independent of fraction. the ivdmd correlated positively with leaf blade mesophyll and negatively with stem xylem.
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