Investigação de injetores tipo y e efervescentes para a atomizacão da mistura de glicerina e etanol

Pós-graduação em Engenharia Mecânica - FEG

Análise do escoamento turbulento por um queimador industrial a gás utilizando dinâmica dos fluidos computacional

Pós-graduação em Engenharia Mecânica - FEG

Potential of adjuvants to reduce drift in agricultural spraying

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tamanho de gotas de pontas de pulverização em diferentes condições operacionais por meio da técnica de difração do raio laser

The present study aimed to evaluate the droplet spectrum of hydraulic nozzles, under different pressures and spray liquid compositions, using a laser particle size analyzer. In a completely randomized design, two air induction twin flat-fan nozzles (AD-IA/D 11002 and AD-IA/D11004) and two hollow-cone nozzles (MAG - 2 and MAG - 4) were evaluated, in factorial design 3 x 2: tree spray pressures (207, 276 and 345 kPa for twin flat-fan nozzles, and 414, 483 and 552 kPa for cone nozzles); and two spray liquid compositions (water and water plus phosphatydilcoline + propionic acid adjuvant). The addition of adjuvant reduced the volume median diameter for the AD-IA/D 11002 and 11004 nozzles; however it had an opposite effect with the MAG - 4 nozzles and not changed with the MAG - 2 nozzles. In adverse weather conditions, it is not recommended the use of hollow cone spray nozzle, even with the addition of adjuvant tested because of the high risk potential of drift.

Interferência da redução no volume de aplicação sobre o controle da mancha preta (Guignardia citricarpa Kiely) em frutos de laranja 'Valência'

The chemical control of the causal agent of citrus black spot (CBS) has been highlighted for the excessive required number of sprayings, considerably increasing citrus production costs. Improvements in the spray efficiency and reductions in the quantity of phytosanitary products have already been searched, but the results of that practice are not consistent yet for its use at commercial scale. Thus, the aim of the present study was to evaluate the interference of reduced spray volumes in black spot control in citrus fruits. The experiment was carried out in commercial citrus orchard with 16-year-old plants of 'Valencia' variety, during 2007 agricultural season. Treatments consisted of three spray volumes: 3.5; 4.5 and 8.5 liters.plant-1, applied with Arbus 2000/Export airblast sprayer with special manifold of hydraulic nozzles, using fungicides and periods recommended for the disease control, totaling four sprayings plus a control treatment (without spray). The disease incidence and severity were evaluated by visual diagrammatic scale of notes in two different periods (preharvest and harvest), at three plant heights (low, middle and top) and three horizontal sections (entrance, frontal and exit) in two sides of the plant. The fallen fruits were counted every fifteen days, for previously selected plants, from the beginning of maturation to harvest, and the production was quantified (kg.plant-1). The disease incidence and severity were significantly lower when sprayings were done with 8.5 liters.plant-1 in the first evaluation period (pre-harvest), but in the harvest period there were not differences between the same parameters when 4.5 or 8.5 liters.plant-1 were sprayed. None of those treatments reduced the disease on the top section of plants, compared to control. The plant sections with fruits more exposed to sun rays, top and right side of the plant, demonstrated higher disease incidence and severity. The volume reduction from 8.5 to 4.5 liters.plant-1 can be adopted for citrus orchards without damaging the CBS control level.

Caracterização da pulverização de mistura de tanque com diferentes pontas de jato plano

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

Numerical modeling of flow through an industrial burner orifice

This paper presents numerical modeling of a turbulent natural gas flow through a non-premixed industrial burner of a slab reheating furnace. The furnace is equipped with diffusion side swirl burners capable of utilizing natural gas or coke oven gas alternatively through the same nozzles. The study is focused on one of the burners of the preheating zone. Computational Fluid Dynamics simulation has been used to predict the burner orifice turbulent flow. Flow rate and pressure at burner upstream were validated by experimental measurements. The outcomes of the numerical modeling are analyzed for the different turbulence models in terms of pressure drop, velocity profiles, and orifice discharge coefficient. The standard, RNG, and Realizable k-epsilon models and Reynolds Stress Model (RSM) have been used. The main purpose of the numerical investigation is to determine the turbulence model that more consistently reproduces the experimental results of the flow through an industrial non-premixed burner orifice. The comparisons between simulations indicate that all the models tested satisfactorily and represent the experimental conditions. However, the Realizable k-epsilon model seems to be the most appropriate turbulence model, since it provides results that are quite similar to the RSM and RNG k-epsilon models, requiring only slightly more computational power than the standard k-epsilon model. (C) 2014 Elsevier Ltd. All rights reserved.

Qualidade da aplicação de inseticida em amendoim (arachis hypogaea l.), com e sem adjuvantes na calda, sob chuva simulada

The present work aimed to evaluate the volumetric distribution profiles, droplet spectra, surface tension, contact angle of droplet and the spraying liquid deposition over the peanut leaves (Arachis hypogaea L.), under artificial rain, in comparison with deposition without rain, using two hydraulic nozzle models of plain fan and insecticide spraying liquids with and without adjuvants addition. It were used a patternator for volumetric distribution analysis, a laser particles analyzer to evaluate droplet spectra produced by SF 110015 and XR 110015 nozzles and tensiometer for droplet tension and contact angle. The spraying liquids evaluated were: water, lambda-cialotrina, lambda-cialotrina + nitrogen fertilizer and lambda-cialotrina + mineral oil. All experiments followed a completely randomized design. Data were submitted to variance analysis by F test and the means comparisons by Scott-Knott test at 5% of probability. According to the results, it must be considered the maximum spacing in spray boom usage of 50 and 90 cm between the nozzles SF110015 and XR110015, respectively. The adjuvants effects on droplet spectra have shown addicted to the nozzle and the product used, and the adjuvants addition to the spraying liquid affected the potential risk of drift; The Volumetric Median Diameter (VMD) of produced droplets by nozzles filled into thin class and were not influenced by the adjuvants. The nitrogen fertilizer adjuvant may be indicated to promote improvements on coverage and droplet deposition on target.

Horários de aplicação localizada ou em área total e uso de adjuvantes para o controle de Spodoptera frugiperda (Lepidoptera: Noctuidae) na cultura do milho

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Infiltração de água em um podzólico vermelho-escuro sob dois métodos de preparo, usando chuva simulada com duas intensidades

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seletividade do herbicida saflufenacil aplicado em pós-emergência em dez variedades de cana-de-açúcar na condição de soca

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade da pulverização em volume reduzido para o controle do bicho-mineiro Leucoptera coffeella (Guérin-Mèneville & Perrottet, 1842) (Lepidoptera: Lyonetiidae)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Trimming and washing poultry carcass to reduce microbial contamination: A comparative study

The objective of this study was to compare the efficiency of washing and trimming broiler carcasses to reduce bacterial contamination. At the poste-visceration site, 100 broiler carcasses were collected during 4 visits to a slaughterhouse in Santa Catarina State, Brazil. Birds were from the same flock, age, and approximately 2.4 kg of weight. Groups were as follows: group 1, with fecal contamination; group 2, without fecal contamination; group 3, with fecal contamination and trimmed; group 4, with fecal contamination and washed; group 5, with fecal contamination, and washed and trimmed. Carcass washings were performed with at least 1.5 L/bird of potable water (0.5 to 1 mg/kg of residual chlorine) at room temperature (20-25 degrees C) using spray cabinets with 44 spray nozzles distributed into 2 chambers (pressure of 2 kgf/cm(2) and 4 kgf/cm(2)). Washed carcasses (trimmed or not) showed significantly (P < 0.05) lower counts of aerobic mesophiles (plate count agar) on the third evaluation, and even lower (P < 0.01) counts for total coliforms (CT) and fecal coliforms (Escherichia coli). Trimmed carcasses showed significantly lower counts (P < 0.05) for plate count agar; however, we observed higher counts for E. coli (P < 0.05). The association of both treatments (washing and trimming) showed significantly higher (P < 0.05) counts for coliforms (CT and E. coli). We can conclude that the washing method is overall more efficient than the trimming method to decontaminate chicken carcasses at the postevisceration site. Hopefully, our findings can help poultry companies to minimize production costs by applying the washing method for carcass decontamination.

INFLUENCE OF NOZZLE TYPE AND SPRAY RATES ON CORN AND WEED PLANTS DROP DEPOSITIONS

The objective of this study was to evaluate different nozzles and spray rates on drop deposition in corn (Zea mays), Euphorbia heterophylla and Brachiaria plantaginea, both weeds located at and between crop rows. The experimental design established was complete random blocks with treatments arranged at 2 x 2 factorial scheme (2 nozzles types: DG11002VS flat flan and medium droplets, TXVK08 cone and very fine droplets; and 2 rates: 100 and 200 L ha(-1)) with four replications. The spray applications occurred at 13 days after corn germination (3-5 expanded leaves), when E. heterophylla and B. plantaginea plants had 2-4 and 2-3 leaves, respectively. Solution of Brilliant Blue (FD&C-1) dye at 3,000 ppm was used as spray tracer. It was concluded that the greatest average deposits in corn plants was provided by TXVK08, independently of the spray rates used. The most uniform deposits occurred when the spray rates of 200 L ha(-1) was used. Spray deposits were most uniform in B. plantaginea compared to E. heterophylla when both weds were located at crop row, independently of nozzle or spray rates. However, the DG 11002VS spray nozzle provided the most uniform drop deposition on B. plantaginea located between the rows, while the most efficient deposition over E. heterophylla located between rows was TXVK08.

Distribuição de tensões em bocais de vasos de pressão

This work is to analyze the behavior of context concentrated stresses generated around a nozzle connected to a pressure vessel. For this analysis we used the finite element method via a computer interface, the software ANSYS WORKBENCH. It was first necessary to study and intensive training of the software used, and also a study of the ASME Code, Section VIII, which is responsible for the standards used in pressure vessels. We analyzed three cases, which differ primarily in the variation of the diameter of the nozzle in order to analyze the variation of the stresses according to the variation of the diameters. The nozzle diameters were 35, 75 and 105 mm. After the model designed vessel, a pressure was applied on the innervessel of 0.5 MPa. For the smallest diameter, was found the lowest tensions concentrated. Varying between 1 and 223 MPa. Increasing the diameter of the nozzle resulted in increased tensions concentrated around the junction nozzle /vessel. The maximum stresses increased by 78% when the value was increased in diameter from 35 to 75 mm. Since the increase in diameter from 75 to 105 mm, the values of the tensions increased around 43%. These figures emphasize that stress concentrations increased with increasing the diameter of the nozzles, but not linearly