374 research outputs found

    Classificadora de cilindros divergentes para tomate de mesa: uma alternativa para pequenos produtores.

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    bitstream/CNPDIA-2010/12616/1/DOC46-2009.pd

    Modified Atmosphere Packaging for Perishable Plant Products

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    Modified atmosphere packaging. Passive. Active. O² and CO² limits. Types of plastic films used in MAP. Package parameters. Respiration rate. Temperature. Permeability. Respiration rats messurement. Plant responses of MAP

    Comparison between two methods used for evaluating cleaning effectiveness during fresh market tomato processing

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    The cleaning step of a packing line for fresh tomatoes is very important, because it removes surface residues of fruits; however, there are few methods used for evaluating the effectiveness of the cleaning process. The main goal of this work was to evaluate two new methodologies for evaluating the effectiveness of the cleaning process. The methodologies applied were the ones that used colorimeter and turbidimeter. The assays were carried out at the laboratory, in a cleaning step on a prototype developed and named UNIMAC (Harvesting aid equipment for tomatoes). Rubber spheres, with similar tomato weight, were artificially dirtied and submitted to the cleaning step on the prototype, with brushes of nylon bristles and rotation of 100 rpm. The results observed from the colorimeter method showed low accuracy and some limitations. This methodology did not give a representation of the dirt that remained on the spheres and, consequently, the process effectiveness. The turbidimeter method most precisely evaluated the spheres cleaning process, being this method the most effective.A etapa de limpeza em uma linha de beneficiamento para tomate de mesa é muito importante, pois retira as impurezas externas dos frutos, todavia poucos são os métodos utilizados para avaliar a eficácia desse processo. Assim, o objetivo deste trabalho foi avaliar duas metodologias com relação à eficácia do processo de limpeza. As metodologias estudadas foram: análise com o colorímetro e análise com o turbidímetro. Os ensaios foram realizados em laboratório, na etapa de limpeza do protótipo UNIMAC (Unidade Móvel de Auxílio à Colheita), utilizando-se de esferas de borracha, com peso similar ao tomate, que foram sujas artificialmente e passaram pela limpeza no protótipo com cerdas de náilon e rotação de 100 rpm. Observou-se que o método de análise com o colorímetro mostrou-se de baixa precisão e com algumas limitações, sendo que a análise de eficácia realizada com esse método não representou a quantidade de sujeira que ainda restava nas esferas e, consequentemente, a eficácia do processo. Por sua vez, a análise realizada com o método do turbidímetro avaliou mais precisamente o processo de limpeza das esferas, assim, concluiu-se que o método de análise com o turbidímetro é o mais eficaz.699704Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Designing Ln3+-doped BiF3 particles for luminescent primary thermometry and molecular logic

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    The design of molecular materials suitable for disparate fields could lead to new advances in engineering applications. In this work, a series of Ln3+-doped BiF3 sub-microparticles were synthesized through microwave-assisted synthesis. The effects of doping are evaluated from the structural and morphological viewpoint. In general, increasing the Ln3+ concentration the octahedral habitus is distorted to a spheric one, and some aggregates are visible without any differences in the crystalline phase. The optical response of the samples confirms that the BiF3 materials are suitable hosts for the luminescence of the tested trivalent lanthanide (Ln3+) ions (Ln = Eu, Tb, Tm, Ho, Er, Yb). A Yb3+/ Er3+ co-doped sample is presented as an illustrative example of all-photonic molecular logic operations and primary luminescent thermometry.publishe

    Real time determination of physical impact damage in packing lines and under laboratory conditions and its effects in tomato fruits quality

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    Tomatoes are one of the most important vegetable crops grown in Brazil and are among the crops that have one of the highest post-harvest losses indexes in the country. The present work aimed at evaluating impact damage observed in packing lines of fresh tomatoes as well as to determine, under laboratory conditions, quality alterations of tomato fruits submitted to impact damage in different surface types. Critical points evaluation was accomplished using an instrumented sphere. Critical transference points found showed variations in acceleration levels from 30 to 129 G (m s-2). Tests carried out under laboratory conditions showed that padded surfaces reduced up to 31% impact damage. Incidence of severe internal physical damage was evaluated by a subjective scale and increased by 79% on hard surfaces for the highest fall drop. On the other hand, it was observed an effective reduction in physical damage on fruits when padded surfaces were used. When a 10-cm drop was performed, the maximum reduction measured was 10% for hard surfaces and 5% for previously padded surfaces. For quality parameters, it was observed for high drops on hard surfaces, highest values for weight loss, total acidity, lower values for vitamin C and Soluble Solids.O tomate de mesa é uma das principais hortaliças consumidas no Brasil e apresenta elevados índices de perdas pós-colheita. O objetivo deste trabalho foi avaliar a magnitude dos impactos verificados em linhas de beneficiamento para tomate de mesa, bem como determinar, em laboratório, as alterações na qualidade de tomates submetidos a danos físicos controlados em diferentes superfícies. Para a avaliação dos pontos críticos e registro da magnitude dos impactos, foi usada uma esfera instrumentada. Os pontos críticos de transferência demonstraram valores de aceleração entre 30 e 129 G (m s-2). Os testes laboratoriais evidenciaram que superfícies acolchoadas reduziram em até 31% a magnitude de impacto. A incidência de danos físicos internos foi crescente e atingiu 79% em superfícies rígidas para a maior altura de queda livre. Por outro lado, observou-se redução na incidência de danos físicos nos frutos quando superfícies protetoras foram utilizadas, verificando-se na altura de 10 cm um limite mínimo de 5% de danos severos, enquanto para superfície rígida o mínimo correspondeu a 10%. As variáveis de qualidade foram alteradas, verificando-se maior perda de massa, maiores valores de acidez total, menores valores de ácido ascórbico e sólidos solúveis para maiores alturas de queda livre sobre superfícies rígidas.630641Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    A fully-analytical treatment of stray light in silicon pore optics for the ATHENA X-ray telescope

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    Just like in any other X-ray telescope, stray light is expected to be a potential issue for the ATHENA X-ray telescope, with a significant impact on the scientific goals. The most prominent cause of stray light in Wolter-I type optics is represented by rays that did not undergo double reflection and were reflected only singly, on either the parabolic or the hyperbolic segment. A minor contribution may, additionally, arise from the diffuse reflections on the backside of the pore membrane and ribs. Aiming at determining whether the resulting background is tolerable or not, the effective area for stray light has to be calculated. While ray-tracing is a standard and well-assessed tool to perform this task, it usually takes a considerable amount of computation time to trace a number of rays sufficient to reach an appropriate statistical significance, because only a minority of stray rays emerge unobstructed from the mirror assembly. In contrast, approaching the stray light from the analytical viewpoint takes several upsides: it is faster than ray-tracing, does not suffer from any statistical uncertainties, and allows one to better understand the role of the parameters at play. The only approximation involved is the double cone geometry, which however is largely applicable to ATHENA as far as the sole effective area is concerned. In this paper, we show how the analytical approach can be successfully adopted to model the stray light effective area in the ATHENA mirror assembly, as a function of the X-ray energy and of the source off-axis angle

    Probing the charged Higgs boson at the LHC in the CP-violating type-II 2HDM

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    We present a phenomenological study of a CP-violating two-Higgs-doublet Model with type-II Yukawa couplings at the Large Hadron Collider (LHC). In the light of recent LHC data, we focus on the parameter space that survives the current and past experimental constraints as well as theoretical bounds on the model. Once the phenomenological scenario is set, we analyse the scope of the LHC in exploring this model through the discovery of a charged Higgs boson produced in association with a W boson, with the former decaying into the lightest neutral Higgs and a second W state, altogether yielding a b\bar b W^+W^- signature, of which we exploit the W^+W^- semileptonic decays.Comment: 37 pages, 16 figures; v2 updated treatment of LHC constraint
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