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Search Results: 1 - 10 of 611049 matches for " Gilberto L. J. P. da; "
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Influência do agente precipitante na prepara??o do óxido de nióbio (V) hidratado pelo método da precipita??o em solu??o homogênea
Tagliaferro, Geronimo Virginio;Silva, Maria Lúcia C. P. da;Silva, Gilberto L. J. P. da;
Química Nova , 2005, DOI: 10.1590/S0100-40422005000200016
Abstract: this work reports the preparation, characterization and study of the ion exchange behavior of hydrous niobium oxide prepared by a homogeneous precipitation method. the precipitating agent was obtained in aqueous solution by thermal decomposition of urea or ammonium carbonate. the compounds were chemically and physically characterized by x-ray diffractometry, thermal analysis (tg/dtg), surface area measurements and ion exchange behavior with sodium. the materials prepared with ammonium carbonate presented a higher degree of crystallinity and better ion exchange capacity with sodium than materials prepared with urea. in the homogeneous precipitation method, materials were obtained with specific surface area of 123 - 224 m2 g-1. a variation of the preparation process produced hydrous niobium oxide with a different degree of hydration and specific surface area. this provided materials with different physico-chemical properties.
Adsor??o de íons dicromato nos compósitos celulose/ZrO2.nH2O preparados pelos métodos da precipita??o convencional e em solu??o homogênea
Mulinari, Daniella Regina;Silva, Gilberto Luís J. P. da;Silva, Maria Lúcia Caetano P. da;
Química Nova , 2006, DOI: 10.1590/S0100-40422006000300017
Abstract: this article describes the preparation and characterization of the cellulose/ hydrated zirconium oxide composites prepared by conventional precipitation (pc) and homogeneous solution precipitation (psh) methods. the composite obtained by the pc method was prepared by using an ammonia solution as the precipitating agent, while the composite obtained by the psh method was prepared by using urea as the precipitating agent. the adsorption of dichromate ions on the composites was studied using factorial design 23. the variables were: initial concentration, agitation time and mass of the composite. the data obtained agree better for the composite obtained by the pc method.
Adsor o de íons dicromato nos compósitos celulose/ZrO2.nH2O preparados pelos métodos da precipita o convencional e em solu o homogênea
Mulinari Daniella Regina,Silva Gilberto Luís J. P. da,Silva Maria Lúcia Caetano P. da
Química Nova , 2006,
Abstract: This article describes the preparation and characterization of the cellulose/ hydrated zirconium oxide composites prepared by conventional precipitation (PC) and homogeneous solution precipitation (PSH) methods. The composite obtained by the PC method was prepared by using an ammonia solution as the precipitating agent, while the composite obtained by the PSH method was prepared by using urea as the precipitating agent. The adsorption of dichromate ions on the composites was studied using factorial design 23. The variables were: initial concentration, agitation time and mass of the composite. The data obtained agree better for the composite obtained by the PC method.
Sepse Brasil: estudo epidemiológico da sepse em Unidades de Terapia Intensiva brasileiras
Sales Júnior, Jo?o Andrade L.;David, Cid Marcos;Hatum, Rodrigo;Souza, Paulo César S. P.;Japiassú, André;Pinheiro, Cleovaldo T. S.;Friedman, Gilberto;Silva, Odin Barbosa da;Dias, Mariza D?Agostino;Koterba, Edwin;Dias, Fernando Suparregui;Piras, Cláudio;Luiz, Ronir Raggio;,;
Revista Brasileira de Terapia Intensiva , 2006, DOI: 10.1590/S0103-507X2006000100003
Abstract: background and objectives: sepsis represents the major cause of death in the icus all over the world. many studies have shown an increasing incidence over time and only a slight reduce in mortality. many new treatment strategies are arising and we should define the incidence and features of sepsis in brazil. methods: prospective cohort study in sixty-five hospitals all over brazil. the patients who were admitted or who developed sepsis during the month of september, 2003 were enrolled. they were followed until the 28th day and/or until their discharge. the diagnoses were made in accordance to the criteria proposed by accp/sccm. it were evaluated demographic features, apache ii score, sofa (sepsis-related organ failure assessment) score, mortality, sources of infections, microbiology, morbidities and length of stay (los). results: seventy-five icus from all regions of brazil took part in the study.3128 patients were identified and 521 (16.7%) filled the criteria of sepsis, severe sepsis or septic shock. mean age was 61.7 (iqr 39-79), 293 (55.7%) were males, and the overall 28-day mortality rate was 46.6%. average apache ii score was 20 and sofa score on the first day was 7 (iqr 4-10). sofa score in the mortality group was higher on day 1 (8, iqr 5-11), and had increased on day 3 (9, iqr 6-12). the mortality rate for sepsis, severe sepsis and septic shock was 16.7%, 34.4% and 65.3%, respectively. the average los was 15 days (iqr 5-22). the two main sources of infection were the respiratory tract (69%) and the abdomen one (23.1%). gram-negative bacilli were more prevalent (40.1%). gram-positive cocci were identified in 32.8% and fungi infections in 5%. mechanical ventilation was observed in 82.1% of the patients, swan-ganz catheter in 18.8%, vasopressors in 66.2% and hemotransfusion in 44.7%. conclusions: it was observed a high mortality of sepsis in the icus in brazil. the high frequency of septic shock demonstrated a group at high risk of death. in order to have a be
Efeito de doses de potássio e da freqüência de irriga??o na produ??o da alface-americana em ambiente protegido
Koetz, Marcio;Coelho, Gilberto;Costa, Claudionor C. da;Lima, Edson P.;Souza, Rovilson J. de;
Engenharia Agrícola , 2006, DOI: 10.1590/S0100-69162006000300009
Abstract: the production of the american lettuce type in greenhouse conditions using irrigation and fertilization, may contribute for the yield increase and expansion of the culture in the region of lavras - mg, brazil. in a greenhouse model chapel was carried out an experiment with the objective of evaluating the effects of irrigation frequencies and potassium doses on the yield of the american lettuce and the water use efficiency. the experiment was composed by the following treatments of irrigation frequency: (p1) - daily irrigation; (p2) _ every other day irrigation; (p3) - three in three days irrigation, and (p4) - four in four days irrigation. in the split plots four doses of potassium chloride (60% of k2o) were applied, by fertigation: (d1) - 100 kg kcl ha-1; (d2) - 150 kg kcl ha-1; (d3) - 200 kg kcl ha-1, and (d4) - 250 kg kcl ha-1. the variables evaluated were lettuce productivity in tons for hectare and water efficiency use, that is, the productivity for mm of water applied. it was possible to conclude that the highest productivity (44,06 t ha-1) was obtained with the dose of the 119,36 kg of k2o ha-1; the irrigation management for the american lettuce culture, in greenhouse conditions of lavras can be carried out in irrigation interval of four days. the treatments with higher irrigation intervals presented greater water use efficiency.
Características morfológicas do Paspalum atratum cv. Pojuca submetido ao pastejo rotacionado. Dinamica de perfilhamento e elonga??o de folhas
Cunha, Marcello Augusto Dias da;Leite, Gilberto Gon?alves;Diogo, José Mauro da Silva;Vivaldi, Lúcio J.;
Revista Brasileira de Zootecnia , 2001, DOI: 10.1590/S1516-35982001000400005
Abstract: this experiment was conducted at the brasília agricultural college - federal district, and studied the dynamics of appearance and death of tillers as well as leaf elongation in three positions of the stump (central, intermediate and peripheral) of paspalum atratum cv. pojuca, submitted to four rotational grazing cycle of 10 days use and 30 days resting. a descriptive analysis was applied using a hierarchical model. nitrogen was applied at a rate of 40 kg/ha, in the form of ammonium sulfate before each grazing cycle. the area was divided in two sets of four pickets of 0.4 ha each and two other areas of about 6 m2 used as a reference for the purpose of quantifying the effect of grazing. the tillers were counted in 120 squares with 0.25 m2 area distributed in the eight pickets and the other eight in the non grazed areas. the highest tillering occurred during cycle 2, coinciding with the highest precipitation. the species showed a low level of tiller death during the studied period. grazing did not reduce the tillering during the vegetative growth phase. leaf elongation had its highest values in cycles 1 and 2 and lowest in cycles 3 and 4. the highest elongations occurred in the periferic and middle positions and the lowest in the central position of the stump.
Características morfológicas do Paspalum atratum cv. Pojuca submetido ao pastejo rotacionado. Dinamica de perfilhamento e elonga o de folhas
Cunha Marcello Augusto Dias da,Leite Gilberto Gon?alves,Diogo José Mauro da Silva,Vivaldi Lúcio J.
Revista Brasileira de Zootecnia , 2001,
Abstract: Este trabalho foi conduzido no Colégio Agrícola de Brasília - Distrito Federal e buscou avaliar a dinamica do aparecimento e morte de perfilhos e elonga o de folhas em três localiza es da touceira (central, intermediária e periferia), do Paspalum atratum cv. Pojuca submetido ao pastejo rotacionado, com ciclo de 10 dias de utiliza o e 30 dias de descanso. Foram aplicados 40 kg/ha de N, na forma de sulfato de am nia antes da entrada dos animais nos piquetes em cada pastejo. As análises estatísticas basearam-se na utiliza o de um modelo hierárquico completo. A área de 3,2 ha foi dividida em dois grupos de quatro piquetes de 0,4 ha cada e mais duas áreas de 6 m2, contíguas às anteriores, onde n o houve pastejo, para que se pudesse comparar os efeitos deste. A contagem de perfilhos vivos e mortos foi realizada em 120 quadrados de 0,25 m2, distribuídos nos oito piquetes e mais oito quadrados nas áreas contíguas onde n o houve pastejo. O maior perfilhamento ocorreu no ciclo 2 coincidindo com o período de maior precipita o, porém apresentou baixa mortalidade de perfilhos durante todo o período avaliado. O desfolhamento n o reduziu o aparecimento de perfilhos no início da fase vegetativa da pastagem. A elonga o de folhas alcan ou valores maiores nos ciclos 1 e 2 de pastejo e os mais baixos, nos ciclos 3 e 4. As maiores elonga es ocorreram nas por es periférica e entremeio e a menor, na regi o central da touceira.
Evaluation of an indicator for water yield in a watershed of Alto Rio Grande Region, State of Minas Gerais , Brazil
Mattos, Roberto de;Silva, Ant?nio M. da;Coelho, Gilberto;Mello, Carlos R. de;Rezende, José L. P. de;
Engenharia Agrícola , 2012, DOI: 10.1590/S0100-69162012000400009
Abstract: the brazilian law stipulates that water is a limited natural resource doted of economic value, thus it is necessary to develop mechanisms for its adequate management. actions that encourage the farmers to apply soil conservation practices with the purpose of increase water yield from springs and to promote improvement of its quality, reducing production of sediment transportation, is being encouraged by governments, even with financial compensation for owners. from these assertions, this study aims to quantify the benefits of the conservation actions of the management units and to characterize a water yield indicator (wyi) to support sustainable actions in the watershed of alto rio grande region, in the state of minas gerais (mg). to assess the impact of actions it were identified four scenarios of land use and occupation of the watershed from marcela stream which is located in alto rio grande region. after analyzing the results, it can be stated that the scenarios simulation has demonstrated important changes in water yield and that the definition of the water yield index from the junction of the erosion potential with the water storage potential, has proved effective, as it integrate quantity and quality of water.
Temporal variability and progression of Neozygites sp. (Zygomycetes: Entomophthorales) in populations of Mononychellus tanajoa (Bondar) (Acari: Tetranychidae)
Delalibera Jr., Italo;Moraes, Gilberto J. de;Lapointe, Stephen L.;Silva, Carlos A. D. da;Tamai, Marco A.;
Anais da Sociedade Entomológica do Brasil , 2000, DOI: 10.1590/S0301-80592000000300015
Abstract: the objective of this study was to characterize epizootics of neozygites sp. by investigating the relationship between the pathogen, the host, mononychellus tanajoa (bondar) (cassava green mite = cgm), and climatic factors. epizootics were studied from march through october 1994 in nine cassava fields at piritiba, state of bahia, brazil. in all fields the pathogen appeared when cgm density was moderate to high. infected cgm were first detected in northwestern fields, with an apparent progression to the southeast. the onset of the epizootic in the earliest field was observed 23 days prior to the onset of the epizootic in the latest field. during the epizootic phase of most fields (late may to late june), daily mean rh ranged from 70% to 79% and daily mean temperature ranged between 21.1°c and 24.3°c. disease progression within cgm populations was documented in two of the nine fields. in the field where the slower spread of the pathogen was observed, the proportion of area with infected cgm increased from 14% to 100% in 14 days. neozygites sp. was detected in higher proportions in plots with the highest levels of cgm and in greater abundance on mites collected from apical leaves as compared with median leaves. resting spores of neozygites sp. were recovered during june and july, but during the remaining period, infected mites contained only hyphal bodies.
Efeito da temperatura na síntese de óxidos hidratados de nióbio e zirc?nio e adsor??o de íons Ag+ e Pb2+
Peixoto, A. L. C.;Silva, G. L. J. P. da;Silva, M. L. C. P. da;
Ceramica , 2006, DOI: 10.1590/S0366-69132006000400006
Abstract: this work reports the digestion temperature effect of precipitating agent on the physical and chemical characteristics of nb2o5.nh2o and zro2.nh2o. the compounds were obtained by homogeneous solution precipitation method with thermal decomposition of (nh4)2co3 at 45 oc and 90 oc. the x-ray diffraction analysis showed crystalline materials with interlamelar space for both nb2o5.nh2o, whereas zro2.nh2o is amorphous. by thermal analysis a similar hydration grade was observed for all materials. the langmuir adsorption isotherms show that the materials prepared at 90 oc, in both cases, have the best results.
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