Si-based thin film coating on Y-TZP: Influence of deposition parameters on adhesion of resin cement

This study evaluated the influence of deposition parameters for Si-based thin films using magnetron sputtering for coating zirconia and subsequent adhesion of resin cement. Zirconia ceramic blocks were randomly divided into 8 groups and specimens were either ground finished and polished or conditioned using air-abrasion with alumina particles coated with silica. In the remaining groups, the polished specimens were coated with Si-based film coating with argon/oxygen magnetron discharge at 8:1 or 20:1 flux. In one group, Si-based film coating was performed on air-abraded surfaces. After application of bonding agent, resin cement was bonded. Profilometry, goniometry, Energy Dispersive X-ray Spectroscopy and Rutherford Backscattering Spectroscopy analysis were performed on the conditioned zirconia surfaces. Adhesion of resin cement to zirconia was tested using shear bond test and debonded surfaces were examined using Scanning Electron Microscopy. Si-based film coating applied on air-abraded rough zirconia surfaces increased the adhesion of the resin cement (22.78 ± 5.2 MPa) compared to those of other methods (0-14.62 MPa) (p = 0.05). Mixed type of failures were more frequent in Si film coated groups on either polished or air-abraded groups. Si-based thin films increased wettability compared to the control group but did not change the roughness, considering the parameters evaluated. Deposition parameters of Si-based thin film and after application of air-abrasion influenced the initial adhesion of resin cement to zirconia. © 2013 Elsevier B.V. All rights reserved.

Desempenho de pontas de pulverização na deposição de gotas de pulverização na cultura do amendoim

The objective of this study was to evaluate the effect of nozzles on spray droplet deposition in the peanut crop cultivar 'Runner IAC 886'. The study was conducted in the field, and the applications of treatments performed in the vegetative stage (V1) and reproductive (R2). It was used the Brilliant Blue FDC - 1 as tracer in water solution, at 500 ppm. The treatments consisted of seven spray nozzle XR 110015 VS (150 L ha(-1)), XR 11002 VS (200 L ha(-1)), TX-VK 6 (150L ha(-1)), TX-VK 8 (200 L ha-1), AI 110015 VS (150 L ha(-1)), AI11002 VS (200 L ha(-1)) e TJ60 11002 VS (150 e 200 L ha(-1)). It was used a randomized blocks design, with four replications. After application, plants were immediately collected, and washed in 100 mL of distilled water for posterior tracer quantification in spectrophotometer. The data had been adjusted a regression curve for Gompertz model. The results had evidenced that at low volumes of application the nozzle AI 110015 VS and TJ60 11002 VS, were the ones with best distribution uniformity of spray on plants of peanut cultivar 'Runner IAC 886' in the vegetative stage (V1) and reproductive (R2) respectively, and the largest deposits and higher percentage of failures in applications have been found in younger plants by comparing the growth stages of application, regardless of the spray nozzle and volume.

Avaliação qualitativa e quantitativa na deposição de calda de pulverização em quatro espécies do gênero commelina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aspectos qualitativos e quantitativos em pulverização na cultura do amendoim e Brachiaria plantaginea (Link) Hitch

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Preparation of SrBi2Ta2O9 ferroelectric thick films by electrophoretic deposition using aqueous suspensions

SrBi2Ta2O9 ferroelectric thick films were prepared by electrophoretic deposition (EPD). For that, ceramic powders were prepared by chemical method in order to obtain compounds with chemical homogeneity. The polymeric precursor method was used for the synthesis of the SrBi2Ta2O9 powder. The crystallographic structure of the powder was examined by X-ray diffraction, and the surface area was determined by single point BET adsorption. The 0.03 vol% suspension was formed by dispersing the powder in water using two different polymers as dispersants: an ester polyphosphate (C213) and an ammonium polyacrilate (Darvan 821-A). The influence of the different dispersants on the powder surface properties were investigated by zeta potential measurements. The films were deposited on platinum-coated alumina and Pt/Ti/SiO2/Si substrates by electrophoretic deposition using a 4 mA constant current, for 10 min, with two parallel electrodes placed at a separation distance of 3 min in the suspension. Several cycles of deposition-drying of the deposit was carried out until the desired thickness was obtained. After thermal treatment at temperatures ranging from 700 to 1000degreesC, the films were characterized by X-ray diffraction and scanning electron microscopy.

Aerosol Deposition of Ba0.8Sr0.2TiO3 Thin Films

In this work we optimized conditions for aerosol deposition of homogeneous, nano-grained, smooth Ba0.8Sr0.2TiO3 thin films. Investigation involved optimization of deposition parameters, namely deposition time and temperature for different substrates. Solutions were prepared from titanium isopropoxide, strontium acetate and barium acetate. Films were deposited on Si (1 0 0) or Si covered by platinum (Pt (1 1 1) /Ti/SiO2/Si). Investigation showed that the best films were obtained at substrate temperature of 85 degrees C. After deposition films were slowly heated up to 650 degrees C, annealed for 30 min, and slowly cooled. Grain size of BST films deposited on Si substrate were in the range 40-70 nm, depending on deposition conditions, while the same films deposited on Pt substrates showed mean grain size in the range 35-50 nm. Films deposited under optimal conditions were very homogeneous, crack-free, and smooth with rms roughness lower than 4 nm for both substrates.

Relationship between citrus productivity and indicators of uniformity in trickle irrigation system

In trickle irrigation systems, the design is based on the pre-established emission uniformity (EU) which is the combined result of the equipment characteristics and its hydraulic configuration. However, this desired value of the EU may not be confirmed by the final project (in field conditions) and neither by the yield uniformity. The hypotheses of this research were: a) the EU of a trickle irrigation system at field conditions is equal to the emission uniformity pre-established in the its design; b) EU has always the lowest value when compared with other indicators of uniformity; c) the discharge variation coefficient (VC) is not equal to production variation coefficient in the operational unit; d) the difference between the discharge variation coefficient and the productivity variation coefficient depends on the water depth applied. This study aimed to evaluate the relationship between EU used in the irrigation system design and the final yield uniformity. The uniformity indicators evaluated were: EU, distribution uniformity (UD) and the index proposed by Barragan & Wu (2005). They were compared estimating the performance of a trickle irrigation system applied in a citrus orchard with dimensions of 400m x 600m. The design of the irrigation system was optimized by a Linear Programming model. The tree rows were leveled in the larger direction and the spacing adopted in the orchard was 7m x 4m. The manifold line was always operating on a slope condition. The sensitivity analysis involved different slopes, 0, 3, 6, 9 and 12%, and different values of emission uniformity, 60, 70, 75, 80, 85, 90 and 94%. The citrus yield uniformity was evaluated by the variation coefficient. The emission uniformity (EU) after design differed from the EU pre-established, more sharply in the initial values lower than 90%. Comparing the uniformity indexes, the EU always generated lower values when compared with the UD and with the index proposed by Barragan. The emitter variation coefficient was always lower than the productivity variation coefficient. To obtain uniformity of production, it is necessary to consider the irrigation system uniformity and mainly the water depth to be applied.

Distribuição volumétrica e diâmetro de gotas de pontas de pulverização de energia hidráulica para controle de corda-de-viola

As pontas de pulverização são responsáveis pela formação das gotas, e cada ponta apresenta características próprias relacionadas ao espectro de gotas e perfil de deposição, específicas para determinados alvos. Este trabalho teve o objetivo de caracterizar o diâmetro e a uniformidade das gotas e o perfil de distribuição volumétrica das pontas de pulverização AI 110015 e TTI 110015, bem como seu efeito sobre a mortalidade de corda-de-viola, com herbicida pré-emergente, associado ou não a adjuvantes. Avaliou-se o número de plantas emergidas e os pesos secos da parte aérea e radicular das plantas. Os perfis de distribuição volumétrica para a altura de 40 cm foram avaliados em mesa de deposição. A partir dos perfis de distribuição, simulou-se o padrão de deposição ao longo da barra de pulverização. O espectro do diâmetro de gotas foi determinado em analisador de tamanho de partículas por difração de luz laser . O herbicida diuron + hexazinona foi eficiente no controle em préemergência de corda-de-viola, podendo ser utilizado polimetil siloxano organomodificado ou óleo mineral como adjuvantes, associados às pontas de pulverização AI 110015 ou TTI 110015. O uso de adjuvantes proporcionou aumento no diâmetro mediano volumétrico e redução na porcentagem de gotas com diâmetro inferior a 100 µm. O espaçamento sugerido entre os bicos na barra de pulverização foi de 70 cm para o modelo AI 110015 e 80 cm para o modelo TTI 110015.

Automated system of seedling image analysis (SVIS) and electrical conductivity to assess sun hemp seed vigor

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

Postharvest Storage of 'Ponkan', 'Satsuma Okitusu' and 'Fremont' Tangerines and Their Minimally Processed Products Using Refrigeration and Controlled Atmosphere

This study aimed to evaluate the postharvest conservation of tangerines 'Fremont', 'Satsuma Okitsu' and 'Ponkan' when stored at different conditions, as well as the quality of the minimally processed product. Fruit were harvested when a sugar: acid ratio of 10.0 to 12.0 for 'S. Okitsu' and 'Fremont' and 16.0 to 19.0 for 'Ponkan' was reached, selected for uniformity of color, size, and absence of injuries. Whole fruits were stored at 3 degrees C, 85% RH and 7 degrees C, 95% RH, and after each storage period, fruits were brought to ambient conditions (22 degrees C, 65% RH) for 3 days before evaluation. The minimally processed products (peeled) were packed in polystyrene trays (22.4x14.8x3.7 cm) coated with polyvinyl chloride (PVC) stretchable, with 0.014 mm thickness, and in lidded packages (500 ml) of transparent polyethylene terephthalate. Fruit were analyzed for appearance, weight loss, respiratory rate, package atmosphere, rind and pulp color, soluble solids, titratable acidity and ascorbic acid content. Shelf life of tangerine 'Fremont' was limited to 42 days based on freshness. Its minimally processed product had a 9 day shelf-life for products packaged in PVC film. The mandarins 'S. Okitsu' had 35 days shelf-life at 7 degrees C, which was reduced to 28 days at 3 degrees C. Its fresh-cut product had a shelf-life of 15 days, stored in PVC or PET. 'Ponkan' fruit stored at 3 degrees C had a shelf life of 35 days, which was reduced to 28 days at 7 degrees C. When minimally processed, its shelf-life lasted for 15 days, whether packaged in PVC or PET. The 'Ponkan' had a shelf-life of 35 days at 3 degrees C and 28 days at 7 degrees C, also limited by loss of freshness. When minimally processed and stored in PVC or PET, its shelf life reached 15 days.

Genetic and environmental heterogeneity of residual variance of weight traits in Nellore beef cattle

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

Genetic variability of residual variance of production traits in Nellore beef cattle

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

Segregação de fertilizantes aplicados a lanço

A uniformidade transversal da distribuição de fertilizantes e corretivos a lanço tem grande dependência da qualidade e da condição física do produto a ser aplicado. Especialmente no caso das formulações, esse aspecto é relevante e por isso o presente trabalho teve o objetivo de verificar a distribuição dos grãos e a constância na formulação aplicada na extensão da largura de trabalho de uma máquina distribuidora a lanço com dois fertilizantes. Foram efetuadas análises químicas do produto depositado em coletores dispostos transversalmente e analisadas as distribuições individuais dos elementos das fórmulas. Os resultados evidenciam que os fertilizantes apresentaram diferenças na sua formulação ao longo da largura, sendo que o fertilizante que continha micronutrientes obteve maiores desvios (de até 100%) em relação à formulação aplicada, e sua segregação foi elevada em relação aos macronutrientes primários (até 9,5% para N) e secundários estudados (até 39,0% para Ca), o que também indica distribuição de pior qualidade dos fertilizantes. O outro fertilizante apresentou desvios de até 17,8% para N e 34,1% para K na formulação ao longo da largura de aplicação.

Efeito de diferentes concentrações de aterbane na deposição de calda em plantas de Pistia stratiotes

O objetivo deste trabalho foi avaliar o efeito do adjuvante Aterbane na deposição de calda de pulverização, aplicada sobre plantas de Pistia stratiotes. Os tratamentos foram constituídos por três concentrações do adjuvante Aterbane (0, 0,25 e 0,5%), usado na elaboração da calda de pulverização. As caldas foram preparadas utilizando-se o corante FDC-1 a 1.500 ppm como traçante. O delineamento experimental adotado foi o inteiramente casualizado com 30 repetições, sendo cada repetição constituída por uma planta com seis folhas. A aplicação foi feita com um pulverizador estacionário, à pressão constante de 2 bars, com consumo de calda de 200 L ha-1. Foram utilizadas pontas de jato plano Teejet 11002vs. Os resultados demonstraram que, quantitativamente, o Aterbane não promoveu nenhum efeito na deposição da calda, entretanto, qualitativamente, quanto maior a concentração utilizada maior foi a uniformidade de deposição de calda.

Efeito de pontas de pulverização na deposição e na dessecação em plantas de Brachiaria brizantha

Objetivou-se com este trabalho avaliar a eficiência de pontas de pulverização com diferentes vazões e tamanhos de gotas na deposição e na dessecação de plantas de Brachiaria brizantha cv. Marandu, além da quantificação das perdas da calda de pulverização para o solo. O delineamento experimental adotado foi o de blocos casualizados, com quatro repetições. Cada unidade experimental constituiu-se de três linhas de 5 m de comprimento, espaçadas de 1 m. A aplicação dos tratamentos foi realizada 16 meses após a semeadura da braquiária; 40 dias antes da aplicação foi realizada uma roçagem para uniformização da área. Foram avaliadas as pontas de pulverização de jato plano XR 11001 VS (100 L ha-1) e XR 11002 VS (200 L ha-1), jato cônico TX-4VS (100 L ha-1) e TX-8 VK (200 L ha-1), ponta com indução de ar AI 11002 VS (200 L ha-1) e jato plano duplo TJ60 11002 VS (200 L ha-1). A calda foi aplicada com o herbicida glyphosate na dose de 1.800 g ha-1, mais um traçador (FD&C nº1 2.000 ppm). Foram coletados imediatamente após a aplicação da calda 25 perfilhos por repetição, sendo lavadas separadamente as folhas e caules de cada perfilho em 150 ml de água destilada, para posterior quantificação do traçador em espectrofotômetro. Os dados foram ajustados à curva de regressão pelo modelo de Gompertz. Todas as pontas utilizadas foram eficientes na dessecação das plantas de B. brizantha, independentemente do volume utilizado, o que evidencia a possibilidade de redução do volume de aplicação e da dosagem do herbicida na dessecação de pastagens, considerando-se a utilização de herbicidas sistêmicos. Ressalta-se que houve diferença na quantidade e na uniformidade de distribuição da calda pulverizada nos alvos avaliados em função da ponta testada e, conseqüentemente, do volume utilizado.