2,417 research outputs found

    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

    ABS design and active suspension control based on HOSM

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    This paper tackles the control of a brake assisted with an active suspension. The goal of the paper is ensure an effective braking process improving the vehicle safety in adverse driving conditions. To address this, the wheel slip ratio is kept to a desired value reducing the effective braking distance by designing of a robust tracking controller based on high order sliding modes algorithms, imposing the anti-lock brake system feature. On the other hand, the active suspension problem is carried with a nested backward sliding surface design. The purpose of this control is to improve the driving comfort. To this aim, the designed controller compensate the effects of the unmatched perturbation coming from the road. This controller exploits a high order sliding modes observer, which guarantees theoretically exact state and perturbation estimation. In both cases, a continuous control action drives the state trajectories to the designed sliding manifolds and keeps them there in spite of the matched and unmatched perturbations. The feasibility of the proposed scheme has been exposed via simulations.Consejo Nacional de Ciencia y TecnologíaUniversity of Bordeau

    Lessons Learned to Improve the UX Practices in Agile Projects Involving Data Science and Process Automation

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    Context: User-Centered Design and Agile methodologies focus on human issues. Nevertheless, agile methodologies focus on contact with contracting customers and generating value for them. Usually, the communication between end users and the agile team is mediated by customers. However, they do not know the problems end users face in their routines. Hence, UX issues are typically identified only after the implementation, during user testing and validation. Objective: Aiming to improve the understanding and definition of the problem in agile projects, this research investigates the practices and difficulties experienced by agile teams during the development of data science and process automation projects. Also, we analyze the benefits and the teams' perceptions regarding user participation in these projects. Method: We collected data from four agile teams in an academia-industry collaboration focusing on delivering data science and process automation solutions. Therefore, we applied a carefully designed questionnaire answered by developers, scrum masters, and UX designers. In total, 18 subjects answered the questionnaire. Results: From the results, we identify practices used by the teams to define and understand the problem and to represent the solution. The practices most often used are prototypes and meetings with stakeholders. Another practice that helped the team to understand the problem was using Lean Inceptions. Also, our results present some specific issues regarding data science projects. Conclusion: We observed that end-user participation can be critical to understanding and defining the problem. They help to define elements of the domain and barriers in the implementation. We identified a need for approaches that facilitate user-team communication in data science projects and the need for more detailed requirements representations to support data science solutions

    Evaluation of fresh market tomato in packing houses

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    Quality evaluation of classification was done in two fresh market tomatoes packing house, using electronically and mechanical equipments in two harvest periods, summer and winter seasons. The main goal of this work was to evaluate size and color grading conformity with the standards proposed by the Brazilian Program for Horticulture Modernization and size grading obtainded with the one established by the packer. The cultivar studied was Carmen. The results showed that there was no grade conformity with the fresh tomato quality standards proposed by the Brazilian Program for Horticulture Modernization. The grade conformity obtained when compared with the one programmed by the packer, was only for large sizes, in both equipments. The electronically equipment has presented better performance, over the mechanical, considering grading quality and fruits post-harvest quality. However, the electronically equipment must be constantly monitored to achieve efficiency and investment return. On the other side, for mechanical equipment it will be necessary to review the actual system of size grading, in order to follow the fresh tomato quality standards.A avaliação da qualidade da classificação foi realizada em duas unidades de beneficiamento de tomates de mesa, com equipamentos de classificação eletrônica e mecânica, e em dois períodos de produção, safras de verão e inverno. O objetivo deste trabalho foi avaliar a conformidade de classificação por diâmetro e coloração dos equipamentos com o proposto pelo Programa Brasileiro para a Modernização da Horticultura (PBMH), e verificar a classificação obtida por diâmetro com os equipamentos, na regulagem programada pela unidade de beneficiamento, sendo utilizados tomates da cultivar Carmen. Os resultados obtidos mostraram que não houve conformidade entre a classificação por diâmetro e a coloração feita com os equipamentos, com o proposto nas normas de classificação do PBMH. Concordância da classificação obtida com a do programa foi encontrada somente para a classe de maior diâmetro, em ambos os equipamentos. O equipamento eletrônico apresentou melhor desempenho que o mecânico; no entanto, esse equipamento deverá ser monitorado em suas atividades visando à eficiência e à viabilização do investimento. Por sua vez, no equipamento mecânico, será necessário rever o sistema de classificação com correia de lona furada para que se possa atender à legislação de classificação para o tomate de mesa.579586Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Washing mechanism improvements for fresh market tomatoes cleaning equipment

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    The cleanness level in fresh market tomatoes cleaning equipment is essential for consumer acceptance and conservation of product quality. However, the washing process in cleaning current equipments demands an excessive volume of water, leading to serious economic and environmental concerns. The objective of this work was to contribute with technical information for the washing system optimization. The conventional washing system currently used in cleaning equipment, which consists of perforated PVC pipes, was compared with a proposed system which uses commercial sprays. Characteristic curves (flow rate versus pressure) for both systems were determined in lab conditions and the respective water consumptions were compared. The results confirmed the excess of water consumption in the conventional washing systems, and the proposed system proved that is possible to reduce it, and the use of sprays allowed the rational use of the water.A etapa de limpeza no sistema de beneficiamento do tomate de mesa é essencial tanto para a aceitação do produto pelo consumidor, quanto para a conservação da qualidade do fruto. Entretanto, a etapa de lavagem nos atuais sistemas de limpeza utilizados em unidades de beneficiamento, demanda volume excessivo de água, trazendo sérias preocupações econômicas e ambientais. O objetivo deste trabalho foi contribuir com informações para otimizar o sistema de lavagem em equipamentos de beneficiamento de tomate de mesa. Para tanto, comparou-se o sistema convencional de limpeza, utilizado atualmente, e constituído de tubos de PVC com orifícios, com sistema redimensionado utilizando-se sprays comerciais. Foram determinadas as curvas características (vazão versus pressão) para ambos os sistemas e comparados os respectivos consumos de água. Os resultados comprovaram o consumo excessivo de água no sistema convencional, e que é possível reduzi-lo significativamente, permitindo o uso racional da água.63764

    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

    Classification and standardization of tomatoes cv. Carmem and Debora in the CEAGESP - São Paulo - Brazil

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    The creation of the Brazilian Program for the Modernization of the Horticulture by the Secretariat of Agriculture and Supplying of the State of São Paulo at CEAGESP, determined the standardization of fruit and vegetables in the follow aspects: degree of coloration, format, calibers, defects and packing. Therefore, the main goal of this research is to correlate the classification given by the Brazilian Program with the one used by the wholesalers at CEAGESP, verifying if the established norms are being fulfilled for cultivar Carmen and Debora (SAKATA SEED). The results showed, that for cultivar Carmem, for the averages of the observed values it does not move away from the norms created by the Program for sizes small and medium. However, for the case of cultivar Debora, the results showed differences between the adopted classifications. The tomatoes were devaluated, because had been commercialized below of the standardization indicated for the Brazilian Program.A criação do Programa Brasileiro para a Modernização da Horticultura pela Secretaria de Agricultura e Abastecimento do Estado de São Paulo, em conjunto com a Companhia de Entrepostos e Armazéns Gerais de São Paulo (CEAGESP), determinou a padronização das hortaliças e frutas comercializadas nos seguintes aspectos: grau de coloração, formato, calibres, defeitos e embalagens, um trabalho iniciado em setembro de 1997. O objetivo deste trabalho foi relacionar a classificação fornecida pelo Programa Brasileiro com a realizada pelos atacadistas no mercado da CEAGESP, verificando se as normas estabelecidas estão sendo cumpridas para os tomates cultivares Carmem e Débora (SAKATA SEED). Os resultados mostraram que, para o tomate cultivar Carmem, a partir da análise de teste de hipótese de proporção, as médias dos valores observados não se afastam muito das normas criadas pelo Programa para os tamanhos pequeno e médio. Porém, para o caso do tomate cultivar Débora, encontraram-se, a partir dos resultados, diferenças entre as classificações adotadas, percebendo que os tomates estavam desvalorizados, pois estavam sendo comercializados em padronização inferior às normas indicadas pelo Programa Brasileiro.790798Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Valuation of the quality attributes of tomato for fresh market: a study with CEAGESP wholesalers

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    The great variation in the value of tomato from the same variety group, same classification and on the same day of marketing, registered by the Terminal Market of CEAGESP, were related to the difference in quality among the attributes of those fruits. The main goal of this work was to create a tool for the evaluation of the quality attributes considered important for tomatoes and from the assessment of these attributes target the most relevant for the difference in value practiced during commercialization at CEAGESP. Firstly, based on the interview with the agents of commercialization of tomatoes at CEAGESP, the main attributes seen by them, which determine the quality of tomato, were raised. Based on those answers, in a second stage, a gauge visual quality assessment was created to be used as a differential tool in the process of decision making. In a third stage, the maximum and minimum price for three classifications (big, medium and minute) were raised for lots of tomato in the same day and their quality attributes were evaluated for two systems: system I - the quality attributes were evaluated, based on banknotes of performance according to the loading gauge visual, and for system II - in addition to the assessment by notes according to the loading gauge visual, the frequency of occurrence of the attribute in a lot of tomato was measured. The attributes that determine the quality of tomato, according to the tomatoes commercialization agents from CEAGESP, are: size (type or size), fruit color, absence of defects, durability, packaging and flavor. The most important attributes to explain the variation of prices assessed by the system I are packaging that are suitable to be palletized and packaging that provides an appropriate pile, on the other hand, for system II, these attributes are: fruit without superficial skin damage and adequate protection of the package against mechanical injuries.A grande variação no valor do tomate de mesa, do mesmo grupo varietal, mesma classificação e no mesmo dia de comercialização, no mercado atacadista da CEAGESP, tem entre suas causas mais importantes a diferença de qualidade nos atributos destes frutos. O objetivo deste trabalho foi criar uma ferramenta de avaliação dos atributos de qualidade considerados importantes para o tomate de mesa e, a partir da avaliação, apontar os mais relevantes na diferença de valor praticado na comercialização da CEAGESP. Primeiramente, foram levantados os principais atributos que determinam a qualidade do tomate de mesa a partir de entrevista com agentes de comercialização de tomate da CEAGESP. A partir deste levantamento, foi criado um gabarito de avaliação visual da qualidade. Por fim, foram levantados os lotes de tomate de mesa de preço máximo e os de preço mínimo para três classificações (graúdo, médio e miúdo) comercializados no mesmo dia, avaliando-se os seus atributos de qualidade por dois sistemas: sistema I - avaliação dos atributos de qualidade por meio de notas de desempenho de acordo com o gabarito, e o sistema II - levantamento da frequência de ocorrência de cada atributo avaliado no lote de tomate. Os atributos que determinam a qualidade do tomate, segundo os agentes de comercialização de tomate da CEAGESP, são: o tamanho (tipo ou calibre), a coloração do fruto, a ausência de defeitos, durabilidade, embalagem e sabor. Os atributos determinantes na variação de preços avaliados pelo sistema I são embalagens paletizáveis e embalagens que proporcionem um adequado empilhamento, enquanto que, para o sistema II, estes atributos são: frutos sem danos superficiais de casca e proteção adequada da embalagem contra injúrias mecânicas.214219Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Fabrication of a MEMS micromirror based on bulk silicon micromachining combined with grayscale lithography

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    A 1D MEMS (Micro-Electro-Mechanical Systems) mirror for LiDAR applications, based on vertically asymmetric comb-drive electrostatic actuators, is presented in this work employing a novel fabrication process. This novel micromachining process combines typical SOI-based bulk micromachining and grayscale lithography, enabling the fabrication of combs actuators with asymmetric heights using a single lithography step in the active layer. With this technique, the fabrication process is simplified, and the overall costs are reduced since the number of required lithography steps decrease. The fabricated mirrors present self-aligned electrodes with a 2.8 mu m gap and asymmetric heights of the movable and the fixed electrodes of 20 mu m and 50 mu m, respectively. These asymmetric actuators are an essential feature for the operation mode of this device, enabling both in resonant and static mode operation. A mirror field of view (FOV) of 54 degrees at 838 Hz was achieved under low-pressure, when resonantly operated, and a FOV of 0.8 degrees in the static mode.This work was supported by the European Structural and Investment Funds in the FEDER Component through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) under Project 037902 (POCI-01-0247-FEDER-037902). The work of Carlos Ferreira was supported by the Fundacao para a Ciencia e Tecnologia (FCT) under Grant PD/BDE/135102/2017. Subject Editor M. Rais-Zadeh
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