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Search Results: 1 - 10 of 567988 matches for " Hélio de Oliveira Alves Júnior "
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Resposta de seis variedades de cana-de-a úcar a doses de potássio no cerrado de Roraima. = Performance of six sugarcane varieties to doses of potassium in savannah (cerrado) of Roraima.
Hélio de Oliveira Alves Júnior
Agro@mbiente On-line , 2009,
Abstract:
Efeito de subdoses de 2,4-D na produtividade do algod?o e suscetibilidade da cultura em fun??o de seu estádio de desenvolvimento
Constantin, Jamil;Oliveira Júnior, Rubens S. de;Fagliari, Júlio R.;Pagliari, Paulo H.;Arantes, Jo?o G. Z. de;Cavalieri, Sidnei D.;Framesqui, Vagner P.;Gon?alves, Diego A.;
Engenharia Agrícola , 2007, DOI: 10.1590/S0100-69162007000200004
Abstract: this research was aimed at evaluating the effects of sublethal rates of 2,4-d on cotton development and yield. two field experiments were carried out with cv. iapar-95, using two fold-checks. for the first trial, applications were accomplished at the beginning of cotton flowering (stage f1), by spraying rates of 0.84; 1.68; 3.36; 6.72; 13.44 and 26.88 g of acid equivalent (a.e.) per hectare, equivalent to drifts of 0.125; 0.25; 0.5; 1.0; 2.0 and 4.0% of a 670 g of a.e. ha-1 rate. in the second field trial, treatments were composed by the factorial combination of two rates (6.72 and 13.44 g a.e. ha-1) and three stages of crop development at the time the herbicide was applied (c1, c3/c4 e c6). analysis of the set of data from the first experiment showed that rates higher than 3.36 g of a.e. ha-1 (0.50%) applied during crop flowering decreased yield, being the floral buds drop the most harmful symptom concerning cotton yield. in the second trial, a strong increase in crop tolerance was observed as plants get older. the only treatment decreasing crop yield was the rate of 13.44 g of a.e. ha-1 (2.0%) applied at c1 stage. therefore, cotton sensibility to 2,4-d dropped substantially after boll formation.
Carboxylic Acids and Esters as Scaffold for Cavities in Porous Single Layer Anti-Reflective Coatings of Silica-Titania with Excellent Optical and Mechanical Properties  [PDF]
Elisabete H. S. de C. Menezes, Peter K?nig, Mohammad Hussein Jilavi, Peter William de Oliveira, Severino Alves Júnior
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.511078
Abstract: Anti-reflective (AR) single layer of silica-titania (SiO2-TiO2) coatings were obtained from sols containing pyromellitic dianhydride (PMDA) derivatives and Ti and Si precursors on glass substrate by dip-coating method. The coatings showed very high optical quality and the transmission was improved to up to 98.5%. Furthermore, the coatings also presented good mechanical stability.
Imazaquin sorption in surface and subsurface soil samples
Oliveira, Maurílio Fernandes de;Prates, Hélio Teixeira;Santanna, Derli Prudente;Oliveira Júnior, Rubem Silvério de;
Pesquisa Agropecuária Brasileira , 2006, DOI: 10.1590/S0100-204X2006000300013
Abstract: the objective of this work was to study the sorption and desorption of imazaquin, in surface and subsurface soil samples from brazil. sorption and desorption steps were carried out using batch equilibration and high performance liquid chromatography analytical routines. the value of kf,ads was positively correlated with clay content, and negatively correlated with ph of supernatant. samples from typic haplustox, clayey soil profile having high clay content, provided higher kf,ads values, and negative correlation with organic carbon, silt content, cation exchange capacity and ph.
ESSAY ON Elasmopalpus lignosellus (ZELLER, 1848) AND TO Syntermes sp., Procornitermes spp., AND Cornitermes spp. CONTROL IN MAIZE BY SEED TREATMENT ENSAIO DE CONTROLE à LAGARTA DO COLO Elasmopaplus lignosellus (Zeller, 1984) E AOS CUPINS Syntermes sp., Procornitermes spp. E Cornitermes spp., NA CULTURA DO MILHO, VIA TRATAMENTO DE SEMENTES
Ant?nio Lopes da Silva,lio da Silva Gon?alves,Luiz Carlos Corrêa de Oliveira Júnior
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v16i1.2455
Abstract: This study presents the results of the field experiments carried out in Goiania, Goiás State, Brazil, in 1985/86, to estimate the efficiency of insecticides in controlling the Lesser Cornstalk (Elasmopaplus lignosellus and the termites Syntermes sp., Procornitermes spp. and Cornitermes spp.) which attack corn plants, by seed treatment. The results show that benfuracarbe, carbofuran and thiodicarbe, respectively, were highly efficient in controlling both pests, lesser cornstalk borer and termites up to 21 days after seed germination. Foi realizado um experimento com milho no município de Goiania, Goiás, safra 1985/86, visando ao controle da lagarta do colo Elasmopaplus lignosellus e cupins Syntermes sp., Procornitermes spp. e Cornitermes spp., via tratamento de sementes. Pelos resultados obtidos concluiu-se que Thiodicarbe na dose de 700 g. i.a. (gramas de ingrediente ativo); Carbofuran na dose de 700 g. i.a. e Benfuracarbe nas doses de 800 e 1000 g. i.a. / 100 kg de sementes deram 84,3 , 97,1 e 96,5% de controle a E. lignosellus, respectivamente, e controlaram 82,7 , 100,0 e 96,0% de cupins, na mesma ordem, até 21 dias após germina o das sementes.
Estudo macular em olhos com óleo de silicone por meio da tomografia de coerência óptica
Maia Júnior, Otacílio de Oliveira;Takahashi, Walter Yukihiko;Nakashima, Yoshitaka;Primiano Júnior, Hélio Paulo;Takahashi, Beatriz Sayuri;Nakashima, Aloísio Fumio;
Arquivos Brasileiros de Oftalmologia , 2007, DOI: 10.1590/S0004-27492007000200017
Abstract: purpose: to demonstrate optical coherence tomography efficacy to evaluate macular anatomical outcomes, in eyes with silicone oil-filled vitreous cavity after vitrectomy. methods: a descriptive observational study of 28 (twenty-eight) patients submitted to pars plana vitrectomy having silicone oil as vitreous substitute. the macular findings were observed by means of indirect binocular ophthalmoscope, biomicroscopy and optical coherence tomography examinations. results: during the follow-up period the retina remained attached in all patients. in some cases, intraretinal cysts, epiretinal membrane and lamellar macular hole were observed only by optical coherence tomography examination. conclusion: optical coherence tomography provided improved imaging of finer retinal structures in eyes with silicone oil-filled vitreous cavity. therefore, optical coherence tomography examination should be systematically performed in eyes filled with silicone oil to recognize changes in retinal morphology.
Opacifica??o tardia de lente intra-ocular de polimetilmetacrilato (PMMA): relato de caso
Maia Júnior, Otacílio de Oliveira;Nakashima, Aloísio Fumio;Barbosa, Eduardo Parente;Primiano Júnior, Hélio Paulo;Nakashima, Yoshitaka;
Arquivos Brasileiros de Oftalmologia , 2005, DOI: 10.1590/S0004-27492005000500021
Abstract: the use of intraocular lenses was a great advance in visual recovery after cataract surgery. although usually with good biocompatibility, some alterations in the intraocular lens material may occur after implantation. polymethylmethacrylate was the first intraocular lens material to be used on a large scale and assumed to be inert and well-tolerated. we present a rare case of late opacification of a polymethylmethacrylate lens, discussing important aspects of its management such as the indication for intraocular lens exchange.
Estudo cinético por TG e DSC da decomposi o térmica de alguns adutos de haletos de cádmio
Farias Robson Fernandes de,Oliveira ótom Anselmo de,Scatena Júnior Hélio,Borges Filipe Martel de Magalh?es
Química Nova , 1998,
Abstract: By DSC data, the kinetical parameters Ea , n and A were calculated for the thermal decomposition of the adducts CdCl2.2dmf, CdCl2.dmf and CdBr2.dmf (dmf= dimethylformamide) by using Rogers and Smith method. The found values were : Ea = 85, 176 and 101 kJ mol-1 , n= 0.23, 0.25, and 0.17, A= 2.40x10(9), 1.89x10(19) and 1.07x10(9) respectively. By TGA data, the kinetical patameters for the thermal decomposition of the adduct CdCl2.1,5 dmeu (dmeu=dimethylethyleneurea) were calculated by using five different methods.
Sor??o do herbicida imazaquin em Latossolo sob plantio direto e convencional
Oliveira, Maurílio Fernandes de;Colonna, Ignácio;Prates, Hélio Teixeira;Mantovani, Evandro Chartuni;Gomide, Reinaldo Lúcio;Oliveira Júnior, Rubem Silvério de;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004000800009
Abstract: the objective of this study was to evaluate the effect of spatial variation of ph and organic matter of a dark red soil, under different managements, on imazaquin herbicide sorption. soil-water sorption partitioning coefficient (kd) was used in surface soil samples collected at 0-15 cm layer in a 38 ha area, under central pivot irrigation and with till and no-till management. herbicide sorption was most strongly related to soil organic matter content and ph, revealing greatest sorption in lower ph values with greater soil organic matter content. these samples were collected at no-till management area. the ph effects on imazaquin retention occur either by controlling the organic matter ionization form as also its speciation. the clay content in the whole area had no variation, however, it didn't affect the kd values. using multivariate regression and two independent variables (soil organic matter content and ph), the prediction of herbicide sorption by soil was good (r2 = 0.91).
Electrochemical behavior of steel-FeNbC composites used in the production of oxygen
Silva, Ariadne de Souza;Martinelli, Antonio Eduardo;Scatena Júnior, Hélio;Silva, Jorge Herbert Echude;Alves Júnior, Clodomiro;Távora, Michele Portela;
Materials Research , 2005, DOI: 10.1590/S1516-14392005000200010
Abstract: the electrocatalytic properties of steel-fenbc composites were evaluated after potentiostatic ageing with the purpose of establishing the potential use of such materials as electrodes for the industrial production of oxygen. the effect of processing parameters, involved in the production of the composites by powder metallurgy, such as milling conditions and compaction pressure, on the performance of the electrodes was also studied. the electrodes were characterized according to their electrical resistance in naoh 1m solution, considering that the purpose of the application requires this value to be ~ 0.5 w.cm2. this parameter was evaluated from repetitive electrochemical measurements carried out from 0.7 v to 1.5 v (vs. ag/agcl) by electrode anodization. changes in the electrochemical behavior of the electrodes, especially concerning the o2 evolution in alkaline medium, were studied as a function of the applied potential. the results revealed that the electrocatalytic activity of the electrodes increased upon ageing, probably as a consequence of the growth of oxide layers and/or increase in the conductivity of the material, resulting in current gain and corresponding decrease in the polarization resistance to 0.75 w cm2.
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