Efeito da adição de óleos ao acaricida cyhexatin sobre o ácaro Brevipalpus phoenicis e na retenção de calda por folhas de citros

A adição de óleos à calda de pulverização, muitas vezes, é utilizada a campo sem o adequado conhecimento sobre a absorção do produto fitossanitário pelo alvo, retenção de calda e até mesmo sobre a praga e a cultura. O objetivo do trabalho foi avaliar o efeito da adição de óleos ao acaricida cyhexatin sobre o ácaro Brevipalpus phoenicis e na retenção de calda por folhas de citros. Avaliou-se a mortalidade de ácaros, utilizando-se de frutos de laranja com uma arena circundada com cola entomológica para confinar os ácaros. Adotou-se o delineamento inteiramente casualizado, em esquema fatorial, constituído pelos fatores: duas formulações de cyhexatin (WG e SC), dois tipos de óleo (mineral e vegetal) e duas concentrações dos óleos (0,5 e 1,0%), e mais dois tratamentos adicionais (acaricidas não adicionados de óleo) e uma testemunha sem aplicação. A aplicação dos produtos foi realizada sobre frutos de laranja até além do ponto de escorrimento. Logo após a aplicação, transferiram-se 10 ácaros B. phoenicis para cada fruto.A contagem dos ácaros vivos, mortos e retidos na barreira adesiva foi realizada um dia após a aplicação. Para a determinação da quantidade de calda retida, utilizaram-se folhas de laranjeira, que foram pulverizadas até além do ponto de escorrimento, adotando-se os mesmos tratamentos e o delineamento estatístico mencionados para a avaliação da mortalidade de ácaros, com exceção da testemunha sem aplicação. Determinou-se a massa de líquido retido após a aplicação dos produtos por folha, com auxílio de balança de precisão. Verificou-se que um dia após a aplicação dos produtos, todos os tratamentos apresentaram mortalidade de B. phoenicis acima de 99%. Dessa forma, a adição de óleo, seja mineral, seja vegetal, ao acaricida cyhexatin não afetou a eficácia biológica deste acaricida nas formulações SC e WG. A maior fuga de B. phoenicis para a barreira de cola foi verificada nos tratamentos com adição de óleos, em comparação ao cyhexatin aplicado isoladamente. A adição de óleo, seja mineral, seja vegetal, ao cyhexatin na calda de pulverização reduziu a quantidade máxima de líquido retido pelas folhas de citros, podendo contribuir para a redução da quantidade de calda necessária para uma boa cobertura da planta.

Effect of Spray Tips and Mix Deposition on Common Water Hyacinth Growing with Varied Population Arrangements of Salvinia and Water Lettuce

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spray deposition and losses in potato as a function of air-assistance and sprayer boom angle

A cultura da batata possui grande expressão econômica dentro do cenário agrícola. Para isso, equipamentos e técnicas de aplicação de produtos fitossanitários vêm sendo desenvolvidos visando melhorar o rendimento econômico da cultura. Neste sentido, experimentos foram conduzidos no delineamento em blocos ao acaso na cultura da batata cv. Ágata. Objetivando avaliar o efeito da assistência de ar combinada a diferentes ângulos de aplicação sobre a deposição da pulverização, bem como as perdas da calda para o solo utilizou-se um pulverizador com e sem assistência de ar junto à barra de pulverização posicionada a +30º, 0º e -30º (sinal + a favor e - contrário ao deslocamento) em relação a vertical. O volume de calda foi 400 L ha-1 utilizando-se pontas de jato cônico vazio JA-4 na pressão de 633 kPa. Para a avaliação dos depósitos utilizou-se um traçador cúprico. Os depósitos foram removidos dos folíolos por lavagem com água destilada, em ambas as superfícies foliares, nas posições superior e inferior das plantas de batata e quantificados por espectrofotometria de absorção atômica. As perdas da pulverização foram avaliadas em coletores plásticos colocados nas entrelinhas das parcelas experimentais. Os níveis dos depósitos do traçador cúprico nas diferentes posições da planta foram analisados pelo teste estatístico T² de Hotteling. Os maiores depósitos foram obtidos com a barra posicionada a 0º e +30º, em presença da assistência de ar, tanto na posição superior quanto inferior da planta. A presença do ar, além de propiciar maiores depósitos na parte inferior das plantas, possibilitou maior uniformidade na distribuição deles. As perdas da pulverização ficaram abaixo de 4%.

Air-assistance in spray booms which have different spray volumes and nozzle types for chemically controlling spodoptera frugiperda on corn

The study aimed to evaluate the performance of air assistance in spray booms using different types of nozzles and spray volumes. We took into account spray deposits, fall armyworm control and crop corn performance in a narrow row cropping system. The experiment was carried out at the experimental area of Sao Paulo State University, Botucatu/SP, Brazil, during the 2008/2009 agricultural season, in randomized blocks with a factorial scheme (2×2+1) and four replications. Two spray nozzles (flat fan nozzle and hollow cone nozzle) were tested, combined with two air assistance levels in the spray boom (with and without air assistance) and a treatment control. In the experimental spraying, Spinosad insecticide was sprayed in amounts of 48 g active substance (a.s.)/ha. The air assistance in the spray boom increased the spray deposits in the V 4 growth stage of the corn plants. Moreover, the application of this technology showed higher efficiency on fall armyworm control, reaching a 100% level 15 days after spraying, in the V 10 growth stage of the plants. The hollow cone nozzle increased the spray deposit level on the corn plants compared with the flat fan nozzle, at growth stage V 4. However, the flat fan nozzle, combined with air assistance technology, was more effective for controlling fall armyworm in the same growth stage (V 4), although the hollow cone nozzle increased the deposit levels on the plants. All the technologies tested in the study promoted a reduction of plant damage from fall armyworm attack. Corn productivity is directly related to the control efficiency of fall armyworm.

Effects of spray nozzles and spray volume on spodoptera frugiperda management and narrow row corn performance

The high demand of pesticides in the production systems makes the application technology one of the main alternatives to optimize the products efficiency. In this context, the study aimed to evaluate the effects of spray nozzles and spray volumes on spraying deposits, armyworm control and crop corn performance in narrow row sowing system. The experiment was carried out at experimental area of Sao Paulo State University, Campus of Botucatu/SP, Brazil, during the 2009/2010 agricultural season, in randomized blocks with factorial scheme (2x2+1) and four replications. It was tested two flat fan spray nozzles (with and without air induction) combined with two spray volumes (100 and 200 L ha-1) plus a control treatment. There was no influence of spray nozzles (without air induction) in the spray deposits levels on plants. However, the flat fan nozzle with air induction was more effective on fall armyworm, with 100% of control against 47.84% from other at 15 days after spraying. The increase in the spray volume promoted high spray deposits (415.4 and 388.6 μL g-1 dry mass for flat fan nozzle with and without air induction, respectively at V10 growth stage) and consequently, the highest spray volume (200 L-1) was more efficient in the fall armyworm suppression, with 100% of control. All the technologies tested showed lower plant injury from fall armyworm. The insecticide sprayed with different technologies did not affect the parameters of plant height and leaf area index. The corn productivity was directly related with control efficiency of fall armyworm. © 2012 Academic Journals Inc.

Optical properties of ZnMgO films grown by spray pyrolysis and their application to UV photodetection

This work presents a comprehensive optical characterization of Zn1−xMgxO thin films grown by spray pyrolysis (SP). Absorption measurements show the high potential of this technique to tune the bandgap from 3.30 to 4.11 eV by changing the Mg acetate content in the precursor solution, leading to a change of the Mg-content ranging from 0 up to 35%, as measured by transmission electron microscopy-energy dispersive x-ray spectroscopy. The optical emission of the films obtained by cathodoluminescence and photoluminescence spectroscopy shows a blue shift of the peak position from 3.26 to 3.89 eV with increasing Mg incorporation, with a clear excitonic contribution even at high Mg contents. The linewidth broadening of the absorption and emission spectra as well as the magnitude of the observed Stokes shift are found to significantly increase with the Mg content. This is shown to be related to both potential fluctuations induced by pure statistical alloy disorder and the presence of a tail of band states, the latter dominating for medium Mg contents. Finally, metal–semiconductor–metal photodiodes were fabricated showing a high sensitivity and a blue shift in the cut-off energy from 3.32 to 4.02 eV, i.e., down to 308 nm. The photodiodes present large UV/dark contrast ratios (102 − 107), indicating the viability of SP as a growth technique to fabricate low cost (Zn, Mg)O-based UV photodetectors reaching short wavelengths.

Regimes of spray vaporization and combustion in counterflow configurations

This article addresses the problem of spray vaporization and combustion in axisymmetric opposed-jet configurations involving a stream of hot air counterflowing against a stream of nitrogen carrying a spray of fuel droplets. The Reynolds numbers of the jets are assumed to be large, so that mixing of the two streams is restricted to a thin mixing layer that separates the counterflowing streams. The evolution of the droplets in their feed stream from the injection location is seen to depend fundamentally on the value of the droplet Stokes number, St, defined as the ratio of the droplet acceleration time to the mixing layer strain time close to the stagnation point. Two different regimes of spray vaporization and combustion can be identified depending on the value of St. For values of St below a critical value, equal to 1/4 for dilute sprays with small values of the spray liquid mass loading ratio, the droplets decelerate to approach the gas stagnation plane with a vanishing axial velocity. In this case, the droplets located initially near the axis reach the mixing layer, where they can vaporize due to the heat received from the hot air, producing fuel vapor that can burn with the oxygen in a diffusion flame located on the air side of the mixing layer. The character of the spray combustion is different for values of St of order unity, because the droplets cross the stagnation plane and move into the opposing air stream, reaching distances that are much larger than the mixing layer thickness before they turn around. The vaporization of these crossing droplets, and also the combustion of the fuel vapor generated by them, occur in the hot air stream, without significant effects of molecular diffusion, generating a vaporization-assisted nonpremixed flame that stands on the air side outside the mixing layer. Separate formulations will be given below for these two regimes of combustion, with attention restricted to the near-stagnation-point region, where the solution is self-similar and all variables are only dependent on the distance to the stagnation plane. The resulting formulations display a reduced number of controlling parameters that effectively embody dependences of the structure of the spray flame on spray dilution, droplet inertia, and fuel preferential diffusion. Sample solutions are given for the limiting cases of pure vaporization and of infinitely fast chemistry, with the latter limit formulated in terms of chemistry-free coupling functions that allow for general nonunity Lewis numbers of the fuel vapor.

Implementation of a Control Loop Experiment in a Network-Based Control System With LonWorks Technology and IP Networks

Considering the increasing popularity of network-based control systems and the huge adoption of IP networks (such as the Internet), this paper studies the influence of network quality of service (QoS) parameters over quality of control parameters. An example of a control loop is implemented using two LonWorks networks (CEA-709.1) interconnected by an emulated IP network, in which important QoS parameters such as delay and delay jitter can be completely controlled. Mathematical definitions are provided according to the literature, and the results of the network-based control loop experiment are presented and discussed.

The knowledge gap: A perspective on trade, industry, technology and policy from pre-war Australian music technology manufacturing (1903-30)

Australia struggles to achieve economic competitiveness, prevent expansion of the trade deficit and develop value-added production despite applications of policy strategies from protectionism to trade liberalisation. This article argues that these problems were emerging at the turn of the century, and that an investigation of music technology manufacturing in the first two decades of this century reveals fundamental problems in the conduct of relevant policy analysis. Analysis has focused on the trade or technology gap which is only symptomatic of an underlying knowledge gap. The article calls for a knowledge policy approach which can allow protection without the negative effects of isolation from global markets and without having to resort to unworkable utopian free-trade dogma. A shift of focus from a 'goods traded' view to a knowledge transaction (or diffusion) perspective is advocated.

ERCC1 protein, mRNA expression and T19007C polymorphism as prognostic markers in head and neck squamous cell carcinoma patients treated with surgery and adjuvant cisplatin-based chemoradiation

Adjuvant cisplatin-based chemoradiation improves survival in HNSCC patients presenting with risk features. ERCC1 (excision repair cross-complementation group 1) is associated with resistance to chemo- and radiation therapy and may have a prognostic value in HNSCC patients. Here we studied ERCC1 expression and the polymorphism T19007C as prognostic markers in these patients. This is a retrospective and translational analysis, where ERCC1 protein expression was evaluated by immunohistochemistry, using an H-score, and mRNA expression was determined by RT-PCR. T 19007C genotypes were detected by PCR-RFLP carried out using DNA template extracted from normal lymph nodes. A high H-score was seen in 32 patients (54%), who presented better 5-year overall survival (5-y OS: 50% vs. 18%, HR 0.43, p=0.026). Fifteen out of 45 patients (33%), with high mRNA expression, presented better 5-year overall survival (OS) (86% vs. 30%, HR 0.26, p=0.052). No OS difference was detected among T 19007C genotypes. High H-score and mRNA expression remained significant as favorable prognostic factors in a multivariate analysis. Collectively, our results suggest that high ERCC1 expression seems to be associated with better OS rates in HNSCC patients submitted to adjuvant cisplatin-based chemoradiation.

Relationship between use of technology and employment rates for people with physical disabilities in Australia: Implications for education and training programmes

This study examined the impact of computer and assistive device use on the employment status and vocational modes of people with physical disabilities in Australia. A survey was distributed to people over 15 years in age with physical disabilities living in the Brisbane area. Responses were received from 82 people, including those with spinal cord injuries, cerebral palsy and muscular dystrophy. Of respondents 46 were employed, 22 were unemployed, and 12 were either students or undertaking voluntary work. Three-quarters of respondents used a computer in their occupations, while 15 used assistive devices. Using logistic regression analysis it was found that gender, education, level of computer skill and computer training were significant predictors of employment outcomes. Neither the age of respondent nor use of assistive software were significant predictors. From information obtained in this study guidelines for a training programme designed to maximize the employability of people with physical disabilities were developed.