982 resultados para Deriva litorânea


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The aim of the research was to evaluate the effect of adjuvants on the spray drift applications from mixture of 2,4-D + glyphosate. The trial was carried out in field conditions in a completely randomized design. The treatments corresponded to solutions containing mixture of the herbicides 2,4-D + glyphosate (670 and 1068g ha-1, respectively) adding the adjuvants (v v-1): mineral oil (0.5%); anti-drift agent (0.09%); spreader-sticker A (0.1%); liquid fertilizer (0.05%); spreader-sticker B (0.25%); and only herbicides without adjuvantes (control). Nylon strings were used to drift determination outside the application area (1, 5, 10, 20, 50, 100 and 200 m away) with 4 replications and six foam cylinders placed on the boom of the sprayer were used to collect the droplets subject to drift. The applications were performed simultaneously, using a specific salt tracer for each spray solution to quantify the deposits by spectrophotometer. It was not possible to verify effect of the adjuvants on drift at different distances of the application area. Based on droplets collected above the boom spray, it was found that susceptibility to drift was lower with the mineral oil and the anti-drift agent. The drift risk was higher with the liquid fertilizer and the spreader-sticker B.

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This experiment aimed to evaluate the effect of increasing clomazone (sprayed alone or in mixture with ametryn) drift simulation on quantitative and qualitative aspects of orange production when applied at two developmental plant stages: flowering and initial fruit development (fruits 2 cm diameter or smaller). Increasing drifts of clomazone, in two formulations, and clomazone in mixtures with ametryn were tested. Fruit morphological features, fruit color, flower and fruit abortion and leaf chlorophyll content were evaluated. Simulated drift similar to the recommended dose of clomazone and clomazone plus ametryn caused fruit abortion in citrus at the stage of fruits 2 cm diameter or smaller. Lower drift doses did not result in fruit abortion. Fruit diameter reduction was observed with drift off above 25% of clomazone alone recommended rate and 50% when in mixture with ametryn or in microcapsule formulation. Clomazone drift at 50% of the recommended rate (alone or in mixture with ametryn ) caused clorotic and necrotic spots in the fruit peel. Drift did not affect juice quality in any of the treatments tested.

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This paper concentrates on the analysis of how the typical voices of History are manifested, which is achieved by the aesthetics of the contemporary Portuguese narrative, as it aims at the same time the reflexion and the reformulation of the Lusitanian cultural imaginary in the course of O retorno, a novel by Dulce Maria Cardoso. The hypothesis that arises is that the trajectory of Rui’s individual experience, as wells as the other’s characters “retornados” looking for identity, is parallel to the proposed revision of the Portuguese nation collective cultural imaginary in the decolonization context, after the 25th April Revolution. It is its objective to investigate how the historical processes concerned to the concepts of exile and uprooting, displacement and belonging (BAUMAN, 2005) are fictionalized in the novel, seen as motes for Rui’s pursuit for identity and for the revision of the Portuguese Destiny theme

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The aim of this article is to discuss the contingence in literature texts since an approach that make the literary theory, the discourse analysis and the psychoanalysis dialogue. It is important to remark the importance of this different areas dialogue as an instrument that could help the understanding of the relations between tradition and invention and the modern writer’s obsession to control the derive of meanings and the originality of the creations as well.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Energia na Agricultura) - FCA

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The aim of this study was to build and validate a low cost reduced-scale wind tunnel for drift evaluation on pesticide application technology. The work was carried out at the NEMPA - Núcleo de Ensaio de Máquinas e Pneus Agroflorestais (NEMPA), FCA/UNESP, Departamento de Engenharia Rural, Botucatu/SP, Brazil. The wind tunnel main characteristics were an open circuit and a closed working section with a fan blowing air into the tunnel. Screens were fitted downstream after the fan in order to stabilize the air flow on the working section. The tunnel was built with 3.0 mm eucalyptus hardboard, with a total length of 4.8 m and a squared section of 0.56 m. The air flow was provided by a 180 W axial fan. The system was adjusted and calibrated to provide a laminar and stable flow at 2.0 m s-1. Validation studies were carried out by using a Teejet XR 8003 flat fan nozzle at 200 kPa (medium droplets) to apply a spray solutions containing water plus a food dye (Blue FDC) at 0,6% m v-1 mixed with two adjuvants: a polymer based anti drift formulation at 0,06% m v-1 and a sodium lauryl ether sulfate based surfactant at 0,2% v v-1. After a 10-second application the drift was collected on nylon strips transversally fixed along the tunnel at different distances from the nozzle and different high from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry. The wind tunnel had low levels of turbulence and high repeatability of the data, which means that the flow was uniform and able to be used for carrying out measures to estimate drift. The validation results showed that the tunnel was effective to enable comparative drift measurements on the spray solution used in this work making possible the evaluation of drift risk potential under those spray technologies. The use of an adjuvant based on a polymer reduced the amount of drift from the nozzle compared to the surfactant.

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The aim of this work was to evaluate the effect of the addition of different surfactants in physical and chemical properties of spray solutions, droplets spectra and drift potential on agricultural spraying. The surfactants and concentrations (v v-1) were: Haiten (0.1%), Antideriva and Intec (0.05% and 0.1%). The following characteristics were analyzed: surface tension, viscosity, density and electric conductivity. The droplet size spectrum was determined by a laser particle analyzer (Mastersizer S®, version 2.15) including measurements of volume medium diameter (VMD), the percent of droplets below 50 and 100 μm (V50 e V100) and index span. In order to estimate the drift potential, a series of wind tunnel tests were performed with a Teejet XR 8003 flat fan nozzle at 200 kPa (medium droplets) used to apply the spray solutions containing water, the adjuvants and a food color dye (Brilliant blue FD & C no 1) at 0,6% m v-1. The drift was collected on nylon strips transversally fixed along the tunnel at different distances from the nozzle and different high from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry. The results showed that the addition of adjuvants changed physical and chemical properties of spray solutions in different magnitudes according to the surfactant. Surfactants changed the droplet spectrum and drift potential, indicating that higher VMD and smaller V100 induced higher percentage of drift.

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