Green nanocomposites as carriers for slow-release of tebuconazole.

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Comparação de resultados antes e depois da implantação das normas nbr para extrativos totais e lignina insolúvel.

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Avaliação de unidade de apodrecimento de madeiras.

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Utilização de casca de pinhão para fabricação de compósitos.

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Mepiquat chloride application on cotton at variable rate.

Mepiquat chloride (1.1 - dimethylpiperidinium chloride) are used to control excessive vegetative growth in cotton (Gossypium hirsutum L.) broadcast sprayed by ground or air. As proven by previous researches the variability of the cotton plants height in the field is large enough to justify the application of Mepiquat at variable rate. The major advantages of it are: (i) yield increase; (ii) economy of the applied input; (iii) reducing the potential of environmental pollution. The main objective of this project was to develop a prototype device capable to accomplish the application of Mepiquat at variable rate in real time. This project used an equipment previously developed for automatic mapping of the cotton plants height based on ultrasound transducers. An electronic control device for ground sprayers was designed and constructed based on microcontroller PIC, using open source tools as Java, Linux operational system and IDE Netbeans. The device controls the pressure and flow in the spray line and uses Varitarget® nozzles due to its characteristics of linearity of flow and pressure. The calculation of the Mepiquat dosage to be applied is based on the obtained information of the plants heights and the map of previous application. The laboratory results demonstrate the accuracy of the equipment, with low response time considering the commercial sprayers velocity (3 m.s-1 to 5 m.s-1)

Alginate / cellulose beads as supports for slowrelease of nutrient.

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Flooding tolerance and cell wall alterations in maize mesocotyl during hypoxia.

ABSTRACT - This research aimed to characterize the tolerance to flooding and alterations in pectic and hemicellulose fractions from mesocotyl of maize tolerant to flooding when submitted to hypoxia. In order to characterize tolerance seeds from maize cultivars Saracura BRS-4154 and BR 107 tolerant and sensitive to low oxygen levels, respectively, were set to germinate. Plantlet survival was evaluated during five days after having been submitted to hypoxia. After fractionation with ammonium oxalate 0.5% (w/v) and KOH 2M and 4M, Saracura BRS-4154 cell wall was obtained from mesocotyl segments with different damage intensities caused by oxygen deficiency exposure. The cell wall fractions were analyzed by gel filtration and gas chromatography, and also by Infrared Spectrum with Fourrier Transformation (FTIR). The hypoxia period lasting three days or longer caused cell lysis and in advanced stages plant death. The gelic profile from pectic, hemicellulose 2M and 4M fractions from samples with translucid and constriction zone showed the appearance of low molecular weight compounds, similar to glucose. The main neutral sugars in pectic and hemicellulose fractions were arabinose, xilose and mannose. The FTIR spectrum showed a gradual decrease in pectic substances from mesocotyl with normal to translucid and constriction appearance respectively RESUMO - Objetivou-se caracterizar a tolerancia ao alagamento e alteracoes nas fracoes pecticas e hemicelulosicas de mesocotilos de milho submetidos a hipoxia. Sementes de milho cultivar Saracura BRS-4154 e BR 107, tolerante e sensivel a hipoxia, respectivamente, foram submetidas a germinacao e a sobrevivencia das plantulas em condicoes de hipoxia, foi avaliada durante cinco dias. O material de parede celular, obtido de segmentos de mesocotilos da cultivar Saracura BRS-4154 com diferentes intensidades de danos causados por hipoxia, foi submetido a fracionamento com oxalato de amonio 0,5% e KOH 2M e 4M. As fracoes de parede celular obtidas foram analisadas por cromatografia em gel, cromatografia gasosa e espectro de infravermelho com transformacao dos dados pela serie de Fourrier (FTIR). Periodos de hipoxia superiores a tres dias causaram a lise celular (aparencia translucida),e, em estadios mais avancados, a morte das plantas. O perfil gelico das fracoes pecticas, hemicelulose 2M e 4M das amostras de mesocotilos translucidos e com constricao apresentaram compostos de baixos pesos moleculares semelhantes a glicose. Os principais acucares neutros nas fracoes pecticas e hemicelulosicas foram arabinose, xilose e manose. O espectro de FTIR mostrou um decrescimo gradual nas substancias pecticas do mesocotilo com aparencia normal, para translucido e constricao respectivamente