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Search Results: 1 - 10 of 337502 matches for " Domingos S.;Castro "
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Chitosan/siloxane hybrid polymer: synthesis, characterization and performance as a support for immobilizing enzyme
Silva, Grazielle S.;Oliveira, Pedro C.;Giordani, Domingos S.;Castro, Heizir F. de;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000800003
Abstract: a hybrid polymer derived from siloxane and chitosan was obtained by sol-gel technique using tetraethoxysilane (teos) as a precursor. the hybrid support was chemically modified with epichlorohydrin and used to immobilize lipase from burkholderia cepacia. the hybrid sio2-chitosan formed new macromolecular structure in which the inorganic particles are dispersed at the nanometer scale in the organic host matrix and bounding through covalent bonds. a comparative study between free and immobilized lipase was provided in terms of ph, temperature, kinetic parameters and thermal stability. the ph for maximum hydrolysis activity shifted from 7.0 for the soluble lipase to 6.1 and the optimum temperature remained at 50 oc after immobilization. the patterns of heat stability indicated that the immobilization process provided the stabilization of the enzyme and the epoxy sio2-chitosan derivative was almost 30-fold more stable than soluble lipase at 60 oc.
Nota Introdutória
Ana Cristina Gon?alves,Domingos Mendes Lopes,Francisco Castro Rego,Jaime Sales Luís
Silva Lusitana , 2010,
Avalia??o da Produ??o Primária Líquida em Povoamentos Puros e Mistos de Quercus pyrenaica Willd. e Pinus pinaster L. no Distrito de Vila Real
Nunes,Leónia; Magalh?es,Marco; Patrício,Maria do Sameiro; Luís,Jaime Sales; Rego,Francisco Castro; Lopes,Domingos;
Silva Lusitana , 2010,
Abstract: with this study we quantified net primary production (npp) of pinus pinaster and quercus pyrenaica pure and mixed stands. this evaluation was based on sampling plots from the last national forest inventory and is exclusively located in the district of vila real. results from this study allowed the first npp figures for these kind of forest stands, and thus the quantification of these ecosystems potential for sequestering carbon. pure and mixed stands npp figures were compared. the results pointed to a greater production potential of mixed stands, though not statistically significant.
Estimate of Biomass and Carbon Storage by an Agrossilvipastoral System in the Zona da Mata Mineira Estimativa de Acúmulo de Biomassa e Carbono em Sistema Agrossilvipastoril na Zona da Mata Mineira
Marcelo Dias Müller,Elizabeth Nogueira Fernandes,Carlos Renato Tavares de Castro,Domingos Sávio Campos Paciullo
Pesquisa Florestal Brasileira , 2010, DOI: 10.4336/2012.pfb.60.11
Abstract: The Clean Development Mechanism (CDM), generated a global debate about the silviculture and agrossilviculture potential as an elegible project-based activities reducing GHG emissions. This study aimed to estimate the amount of carbon and biomass storage in a mixed silvopastoral system with Eucalyptus grandis and Acacia mangium at the Zona da Mata of Minas Gerais State. The system had a plant density of 105 plants per hectare which was 60 eucalyptus and 45 acacia. The stem volume of 10 year old trees was assessed using alometric equations and the residual mean pasture biomass was quantified. For the eucalyuptus plants, the estimative of biomass and carbon were 24.8 Mg ha-1 and 11.17 Mg.ha-1, respectively, while those for acacia were 6.94 Mg.ha-1 and 3.12 Mg.ha-1. The total amounts was 31.74 Mg.ha-1 of biomass and 14.29 Mg.ha-1 of carbon. It was estimated that the pasture, considering only the residues of pasturing, accumulated 1.28 Mg.ha-1 of biomass and 0.58 Mg.ha-1 of carbon. Com a cria o do Mecanismo de Desenvolvimento Limpo (MDL), foi gerado um amplo debate global sobre o potencial da silvicultura e da agrossilvicultura como atividades elegíveis para sequestro de carbono. O objetivo deste trabalho foi estimar o estoque de biomassa e carbono em um sistema silvipastoril misto com Eucalyptus grandis e Acacia mangium, implantado na Zona da Mata Mineira. O sistema apresenta uma densidade de árvores de 105 plantas por hectare, sendo 60 árvores de eucalipto e 45 árvores de acácia. Para tanto, primeiramente, foi feita a quantifica o do volume do fuste das árvores aos 10 anos de idade, por meio do ajuste de equa es alométricas e a quantifica o da biomassa residual média da pastagem durante o período de 4 anos. Para o eucalipto, foi estimado um total de 24,8 Mg.ha-1 de biomassa e 11,17 Mg.ha-1 de carbono, para a acácia foi estimado um total de 6,94 Mg.ha-1 de biomassa e 3,12 Mg.ha-1 de carbono, totalizando 31,74 Mg.ha-1 de biomassa e 14,29 Mg.ha-1 de carbono. Para o componente pastagem, foi estimado um acúmulo de 1,28 Mg.ha-1 de biomassa e 0,58 Mg.ha-1 de carbono somente no resíduo do pastejo. doi: 10.4336/2009.pfb.60.11
Características Agron micas, Massa de Forragem e Valor Nutritivo de Brachiaria decumbens em Sistema Silvipastoril Agronomics Characteristics, Forage Mass and Nutritional Value of Brachiaria decumbens in a Silvopastoral System
Carlos Renato Tavares Castro,Domingos Sávio Campos Paciullo,Carlos Augusto Miranda Gomide,Marcelo Dias Müller
Pesquisa Florestal Brasileira , 2010, DOI: 10.4336/2012.pfb.60.19
Abstract: Avaliaram-se os efeitos de três porcentagens de sombreamento (0, 29% e 45%), proporcionado pelas leguminosas arbóreas Acacia angustissima, A. mangium, A. auriculiformis, Albizia lebbek e Gliricidia sepium, sobre características agron micas, e o valor nutritivo do pasto de Brachiaria decumbens, durante o inverno, a primavera e o ver o. Foi adotado o delineamento experimental de blocos casualizados, com três repeti es. O sombreamento influenciou positivamente a massa de forragem, na primavera e no ver o. No inverno, a maior massa de forragem foi obtida sob sol pleno. Os teores de proteína bruta aumentaram com o sombreamento, na primavera, mas n o se modificaram em fun o das porcentagens de sombra, no inverno e no ver o. Pelo produto da massa de forragem e o teor de proteína bruta, obtiveram-se as quantidades de proteína bruta por área, que foram maiores sob sombreamento mais intenso, na primavera e no ver o. Os teores de fibra em detergente neutro e a digestibilidade in vitro da matéria seca n o apresentaram tendência consistente com as porcentagens de sombreamento, em fun o da forte intera o deste tratamento com a esta o do ano. doi: 10.4336/2009.pfb.60.19 The agronomic traits and nutritive value of Brachiaria decumbens pasture were evaluated under three shade percentages (0.29% and 45%), provided by leguminous trees (Acacia angustissima, A. mangium, A. auriculiformis, Albizia lebbek e Gliricidia sepium), during winter, spring and summer seasons. The experimental design was randomized blocks, with three replications. The forage mass was positively influenced by shading, in spring and summer seasons. In winter, the higher forage mass was observed in full sunlight condition. The values of crude protein increased in spring with shading, but did not vary with shade percentage in winter and summer seasons. The crude protein quantity per area, obtained by product between forage mass and crude protein concentration, was higher under more intensive shading, in spring and summer seasons. Fiber detergent neutral content and in vitro dry matter digestibility did not present consistent variation with shading, in function of the strong interaction between this variable and season of the year.
A saúde bucal dos idosos no Brasil
Andréa de Castro Domingos
Saúde Coletiva , 2008,
Crescimento de capim-braquiária influenciado pelo grau de sombreamento e pela esta??o do ano
Paciullo, Domingos Sávio Campos;Campos, Núbia Ribeiro;Gomide, Carlos Augusto Miranda;Castro, Carlos Renato Tavares de;Tavela, Roberto César;Rossiello, Roberto Oscar Pereyra;
Pesquisa Agropecuária Brasileira , 2008, DOI: 10.1590/S0100-204X2008000700017
Abstract: the objective of this work was to evaluate, in different seasons of the year, the morphogenetic and structural traits and dry matter production of brachiaria decumbens stapf., established under three shading conditions: exclusive b. decumbens pasture, area distant 12 m from trees, and area under trees cultivated with eucalyptus grandis mixed with leguminous trees (0, 18 and 50% shading level, respectively). the experimental design was the randomized blocks, in a split plot array in time, with four replications. shade caused an increase of leaf and stem elongation rates. shading levels have not influenced leaf appearance rates and leaf number per tiller. morphogenetic and structural traits and herbage production rates reduced during winter, independently of shading level. signalgrass presents phenotypical plasticity and responded to seasonal climatic variations and shade conditions; therefore, it has a good potential to be used in silvipastural systems.
The growth dynamics in Brachiaria species according to nitrogen dose and shade
Paciullo, Domingos Sávio Campos;Fernandes, Priscila Beligoli;Gomide, Carlos Augusto de Miranda;Castro, Carlos Renato Tavares de;Sobrinho, Fausto de Souza;Carvalho, Carlos Augusto Brand?o de;
Revista Brasileira de Zootecnia , 2011, DOI: 10.1590/S1516-35982011000200006
Abstract: it was studied the effects of shading (0, 36 and 54%) and of four nitrogen doses (0, 50, 100 and 150 mg n/dm3 of soil) on the morphogenetic traits and on the tillering of grasses of brachiaria genus (b. decumbens, b. ruziziensis and b. brizantha cv. marandu and cv. xaraes), cultivated in pots with 5 kg substrate. it was used a complete random design, in a 3 × 4 × 4 factorial scheme with three replications. nitrogen promoted increase in leaf appearance rate and in average leaf blade length, whereas shading increased stem elongation rate. leaf elongation rate and tillering varied with the interaction among shading percentages and nitrogen doses. shading increased response efficiency of leaf elongation rate to nitrogen doses, but reduced for tillering, evidencing priority existing tillering growth in detriment to appearance of new tillers when there is light restriction for the plants. phenotypic adjustments, in response to light reduction, indicate that the studied grasses present tolerance to moderate shading.
Morphogenesis of dwarf elephant grass clones in response to intensity and frequency of defoliation in dry and rainy seasons
Gomide, Carlos Augusto de Miranda;Paciullo, Domingos Sávio Campos;Costa, Igor de Almeida;Lima, Aline Medeiros;Castro, Carlos Renato Tavares de;Lédo, Francisco José da Silva;
Revista Brasileira de Zootecnia , 2011, DOI: 10.1590/S1516-35982011000700007
Abstract: the aim of this study was to evaluate during the dry and rainy seasons the morphogenesis traits of two clones of dwarf elephant grass under different management strategies. the study was conducted in a factorial 2 × 2 × 3 design, using two clones, one green and one purple, two residual heights, 25 and 45 cm, and three frequencies of defoliation according to the light interception of 90, 95 and 100%. the design was a randomized block with three replications. the variables were leaf elongation and leaf senescence rate, stem elongation rate and phyllochron. the leaf lifespan and the number of living leaves per tiller were also estimated. the clones presented low stem elongation rates, showing adaptation for grazing use. in the rainy season, the light interception of 100% promoted the highest stem elongation rate and increased the leaf senescence rate. in the dry season, the leaf elongation rate (ler) was higher for the purple clone than for the green one (23 vs 15 mm.tiller-1.day-1). in the rainy season, the ler of the green clone exceeded that of the purple one by 71% (149 vs. 87 mm.tiller-1.day-1). the phyllochron varied among clones only in the rainy season, when the value was 4.6 days.leaf-1 for the green clone and 8.4 days.leaf-1 for the purple one; both of these values are below the mean value observed during the drought (21,6 days.leaf-1). the residual heights did not affect, in an isolated way, any of the variables. the clones are well adapted to grazing, presenting low stem elongation rates. the interval between defoliations should consider the scope of light interception between 90 and 95%. the green clone, with a greater flow of biomass, requires handling with shorter defoliation intervals.
Economic analysis of an agrosilvipastoral system for a mountainous area in Zona da Mata Mineira, Brazil
Müller, Marcelo Dias;Nogueira, Gilciano Saraiva;Castro, Carlos Renato Tavares de;Paciullo, Domingos Sávio Campos;Alves, Frederico de Freitas;Castro, Renato Vinícius Oliveira;Fernandes, Elizabeth Nogueira;
Pesquisa Agropecuária Brasileira , 2011, DOI: 10.1590/S0100-204X2011001000005
Abstract: the objective of this work was to evaluate the economic viability of an agrosilvipastoral system developed for zona da mata mountainous areas in minas gerais state, brazil, as well as to compare different options for wood (eucalyptus grandis and acacia mangium) commercialization of the second thinning. the data were obtained from a 10 year-old agrosilvipastoral system established in four hectares at embrapa gado de leite station in coronel pacheco, mg, brazil. as evaluation criteria for the economic viability analysis, the adopted methods were the net present value (npv) and the internal rate of return (irr), both calculated at 6% interest rate. despite the small difference, adding value to forest products increased the attractiveness of the proposed system. considered separately, the agricultural activity was impracticable, whereas the forestry and livestock activities were independently viable. the studied system seems to be equally tolerant to price variations for forest and livestock products, as well as strongly tolerant to variations in production costs.
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