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  1. 1

    Propostas de melhoria no processo de monitorização de temperatura na indústria dos lacticínios: um caso de estudo

    Publicação
    por Pereira, Ana Beatriz Vieira
    O acompanhamento da evolução térmica a que os produtos estão sujeitos desdeque são produzidos até chegarem ao consumidor final é uma obrigatoriedade para assegurara conformidade e a qualidade, especialmente no sector dos lacticínios em que sãomanipulados bens perecíveis.Neste estudo pretendeu-se, através do pensamento Lean e com uma metodologiabaseada neste princípio, designada de ciclo DMAIC, caracterizar primeiramente o panoramainicial, de seguida sugerir melhorias e, por fim, testar essas possíveis melhorias que visamaumentar a qualidade e previnem o desperdício de produto.A principal motivação que levou à elaboração deste projeto foi principalmente,a procura de melhorias que permitissem a garantia dos padrões de qualidade, mas também odesenvolvimento de ferramentas de auxílio nos momentos de auditoria ou apresentação deprova para o cliente. Uma vez que, o processo de monitorização da etapa do transporte secaracterizou como sendo rudimentar, maioritariamente manual e ainda com perdas deproduto associadas às descargas demoradas e à proximidade dos clientes. E ainda,relativamente ao armazenamento, revelou-se eficiente embora se tenham identificadopossíveis melhorias.Foram propostas melhorias para as duas etapas estudadas, armazenamento etransporte. Contudo, as relativas à segunda etapa apresentam uma maior relevância erobustez. Estas foram estudadas e foi analisado o seu impacto económico, sendo que aspropostas relativas ao transporte já se encontram a ser implementadas, e as sugeridas aorelativamente ao armazenamento, prevê-se que uma delas seja implementada ainda este anoe a outra no primeiro trimestre do próximo ano.
    2020 dissertação de mestrado Portugal acesso aberto
  2. 2

    Photoacoustic-based thermal image formation and optimization using an evolutionary genetic algorithm

    Publicação
    por Uliana,João Henrique
    Outros Autores: Sampaio,Diego Ronaldo Thomaz; Carneiro,Antonio Adilton Oliveira; Pavan,Theo Zeferino
    Origem: Oasisbr
    Abstract Introduction For improved efficiency and security in heat application during hyperthermia, it is important to monitor tissue temperature during treatments. Photoacoustic (PA) pressure wave amplitude has a temperature dependence given by the Gruenesein parameter. Consequently, changes in PA signal amplitude carry information about temperature variation in tissue. Therefore, PA has been proposed as an imaging technique to monitor temperature during hyperthermia. However, no studies have compared the performance of different algorithms to generate PA-based thermal images. Methods Here, four methods to estimate variations in PA signal amplitude for thermal image formation were investigated: peak-to-peak, integral of the modulus, autocorrelation of the maximum value, and energy of the signal. Changes in PA signal amplitude were evaluated using a 1-D window moving across the entire image. PA images were acquired for temperatures ranging from 36oC to 41oC using a phantom immersed in a temperature controlled thermal bath. Results The results demonstrated that imaging processing parameters and methods involved in tracking variations in PA signal amplitude drastically affected the sensitivity and accuracy of thermal images formation. The sensitivity fluctuated more than 20% across the different methods and parameters used. After optimizing the parameters to generate the thermal images using an evolutionary genetic algorithm (GA), the percentage of pixels within the acceptable error was improved, in average, by 7.5%. Conclusion Optimization of processing parameters using GA could increase the accuracy of measurement for this experimental setup and improve quality of PA-based thermal images.
    2018 artigo Brasil acesso aberto
  3. 3

    Comparative analysis of photovoltaic modules center and edge temperature using IoT embedded system

    Publicação
    por Pereira, Renata Imaculada Soares
    Outros Autores: Jucá, Sandro César Silveira; Carvalho, Paulo Cesar Marques de; Fernández Ramírez, Luis Miguel
    Origem: Oasisbr
    The main objective of this project is to develop and implement an Internet of Things (IoT) monitoring system to analyze the temperature at the center and at the edge of grid-connected photovoltaic (PV) modules at Maracanaú – CE, Brazil. The proposed IoT embedded system is based on free software and hardware using ESP 32 development board, allowing online distribution, free usage and communication with a server in the Cloud wirelessly via WiFi. The use of open source and cross-platform (Linux, Windows® and Mac OSX) allows greater interaction and accessibility to the user. A web page called Web Monitor was developed for online data consulting and for real-time monitoring of the PV temperature. Monitoring individual PV modules has the objective of providing data for the analysis of electricity generation efficiency and for fault detection in case of PV cells overheating. Meteorological data such as solar irradiance, ambient temperature, relative humidity and wind speed were also measured and monitored to allow a more complete analysis of the effect of these variables on the module temperature response. According to the results, the PV module edge temperature is 1.5 to 2ºC lower than the center temperature.
    2022 artigo Brasil acesso aberto
  4. 4

    Desenvolvimento de um sistema de telemetria para monitoramento térmico em casas de vegetação

    Publicação
    por Barbosa, Rogério Zanarde
    Outros Autores: Martins, João Eduardo Machado Perea
    Origem: Oasisbr
    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
    2016 artigo Brasil acesso aberto
  5. 5

    Irreversible temperature indicator based cellulose membranes conjugated with leuco-dye pigment

    Publicação
    por Carvalho, Margarida
    Outros Autores: Tavares, Ana P. M.; Marques, Maria A.; Alves, Joaquim J.; Figueira, Joana; Morais, Maria et al.
    This research focuses on the development of thermochromic membranes made of cellulose acetate (CA) for temperature monitoring of sensitive food products. Two dual TC membranes developed for the control of different temperature ranges were formulated using a three-component system: a leuco-dye membrane (crystal violet lactone, CVL) integrated with an acidic membrane containing the color developer (salicylic acid) and the acidic solvent with different melting points (decanoic acid, DA, or methacrylic acid, MA). The CVL membrane, together with the DA membrane, showed an irreversible color change when exposed to 35°C, which was facilitated by the melting of DA. The CVL membrane also underwent an irreversible color change when exposed to 15°C together with the MA membrane. The membranes were characterized in detail using scanning electron microscopy. The evaluation of color changes, reproducibility, specificity, and stability ensured the practical suitability of these membranes. Overall, this innovative approach has proven to be a reproducible, sustainable, cost-effective method to produce irreversible colorimetric temperature sensors. These sensors have significant potential for applications in the food and pharmaceutical industries and offer a promising way to improve product safety and quality.
    2024 artigo Portugal acesso aberto
  6. 6

    Consideração da temperatura no comportamento à reflexão de fendas dos reforços de pavimentos rodóviários flexíveis

    Publicação
    por Minhoto, Manuel J. C.
    Os pavimentos rodoviários flexíveis quando expostos às acções do tráfego e das variações de temperatura ficam sujeitos à ocorrência de um conjunto de degradações, das quais se destaca o fendilhamento. Este constitui uma das principais degradações dos pavimentos flexíveis e conduz a estados de ruína associados a situações de desconforto e de redução de segurança para os utentes. Além disso permite a entrada de água para as camadas do pavimento, com a consequente redução da capacidade de suporte, potenciando a ocorrência de outros tipos de degradações. Constitui, assim, uma preocupação das administrações rodoviárias atrasar ou, quando possível, evitar ocorrência de fendilhamento nos pavimentos flexíveis, tendo em vista o seu bom desempenho funcional e estrutural. O reforço de pavimentos constitui uma técnica de conservação estrutural, na qual se baseiam as estratégias de conservação mais utilizadas para benefíciação dos pavimentos, tendo em vista a reposição da sua capacidade estrutural. A maioria das metodologias existentes para dimensionamento de reforços, normalmente não consideram o mecanismo de ruína da propagação das fendas do pavimento existente para as camadas de reforço, e as que consideram, não envolvem o efeito das variações de temperatura associado àquele mecanismo. Efectivamente, a ocorrência de variações de temperatura nos pavimentos conduz ao agravamento do fenómeno da propagação de fendas, levando à ruína prematura dos reforços. Assim, é fundamental, para o dimensionamento do reforço de um pavimento, a consideração das variações de temperatura na avaliação do comportamento dos reforços à reflexão de fendas. Pretende-se com este trabalho estudar a influência das variações de temperatura no comportamento dos reforços à reflexão de fendas, contribuindo para uma melhoria dos métodos de concepção de reforços de pavimentos flexíveis que considerem a propagação de fendas como um dos critérios de mína. O desenvolvimento deste estudo foi baseado na simulação numérica do comportamento dos reforços, considerando a acção conjunta do tráfego e das variações de temperatura, desenvolvendo-se modelos térmicos e mecânicos baseados na metodologia dos elementos finitos.
    2007 tese de doutoramento Portugal acesso aberto
  7. 7

    Long-term in situ Eulerian Sea surface temperature records along the Portuguese Coast

    Publicação
    por Santos, Nuno Pessanha
    Outros Autores: Moura, Ricardo; Silva, Catarina Santos da; Lamas, Luisa; Lobo, Victor; Neto, Miguel de Castro
    Monitoring ocean surface temperature is critical to infer the variability of the upper layers of the ocean, from short temporal scales to climatic change scales. Analysis of the climatological trends and anomalies is fundamental to comprehend the long-term effects of climate change on marine ecosystems and coastal regions. The original data for the dataset presented was collected by the Portuguese Hydrographic Institute (Instituto Hidrográfico) using seven Ondograph and Meteo-oceanography buoys anchored offshore along the Portuguese coast to acquire ocean surface temperatures. The original raw data was pre-processed to provide averages over 3-hour periods and daily averages, and this cleaned data constitutes the provided dataset. The 3-hour temperature averages were obtained mainly between 2011 and 2015, and the daily temperature averages were obtained in intervals that vary with the considered buoy, having an average interval of 14 years per buoy. The data gathered provides a considerable temporal window, enabling the creation of data series and the implementation of data mining algorithms to develop decision support systems. Collecting data in situ makes it possible to validate simulated results obtained using approximation models. This allows for more accurate temperature readings and facilitates testing and correcting created models.
    2024 artigo Portugal acesso aberto
  8. 8

    Wireless body sensor design for intra-vaginal temperature monitoring

    Publicação
    por Garcia, João F.R.
    Outros Autores: Caldeira, J.M.L.P.; Rodrigues, Joel
    Sensor nodes are small devices able to collect and retrieve sensorial data. The use of these sensors for medical purposes offers valuable contributions to improve patients’ healthcare, both for diagnosis and therapeutics monitoring. An important and common parameter used on healthcare diagnosis is the body temperature. It is monitored on several matters related with gynecological and obstetrics issues but, usually it is measure at the skin surface. Then, this paper proposes the design concepts of a new intra-body sensor for long-term intra-vaginal temperature collection. The embedded IEEE 802.15.4 communication module allows the integration of this sensor in wireless sensor networks for remote data access and monitoring. It is presented the sensor architecture, the construction of the corresponding testbed, and its performance evaluation. This sensor may be used on several applications, including fertile and ovulation period detection, and preterm labor prevention.
    2010 documento de conferência Portugal acesso aberto
  9. 9

    A novel intra-body sensor for vaginal temperature monitoring

    Publicação
    por Rodrigues, Joel
    Outros Autores: Caldeira, J.M.L.P.; Vaidya, Binod
    Over the years some medical studies have tried to better understand the internal behavior of human beings. Many researchers in this domain have been striving to find relationships between intra-vaginal temperature and certain female health conditions, such as ovulation and fertile period since woman’s intra-vaginal temperature is one of the body parameters most preferred in such studies. However, due to lack of a appropriate technology, medical research devoted to studying correlations of such body parameters with certain womans’ body phenomena could not obtain better results. This article presents the design and implementation of a novel intra-body sensor for acquisition and monitoring of intra-vaginal temperatures. This novel intra-body sensor provides data collection that is used for studying the relation between temperature variations and female health conditions, such as anticipation and monitoring of the ovulation period, detection of pregnancy contractions, preterm labor prevention, etc.. The motivation for this work focuses on the development of this new intra-body sensor that will represent a major step in medical technology. The novel sensor was tested and validated on hospitalized women as well as normal healthy women. Finally our medical team has attested to the accuracy, usability and performance of this novel intra-body sensor.
    2009 artigo Portugal acesso aberto
  10. 10

    Core-body temperature acquisition tools for long-term monitoring and analysis

    Publicação
    por Caldeira, J.M.L.P.
    Outros Autores: Moutinho, José Fonseca; Rodrigues, Joel; Gilg, Marc; Lorenz, Pascal
    The detection of fertile and ovulation periods may be performed by women’s body temperature variations. These variations are more accurate if a core-body temperature for their detection is used. Previous medical studies concluded that the use of skin temperature could be influenced by environmental conditions. Since the increasing of the body temperature in this period is only about 0.5 ºC, it is crucial that measurements should be the most accurate as possible. Due to the lack of solutions to realize that in order to measure and analyze the core-body temperature, this paper presents a system to capture, display, and monitoring core-body temperature. It is considered a hardware solution (sensor) to be placed inside cervix and a computer application to communicate and gather the collected data by the sensor. Bluetooth is used to perform the communication between a computer and the sensor. The system evaluation is performed by a medical team in several volunteer women. Furthermore, the collected data by the sensor may be used to study the relation between temperature variations and women health conditions.
    2010 artigo Portugal acesso restrito