250 research outputs found

    Benchmarking of secondary schools based on students’ results in higher education

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    The performance of secondary schools is usually assessed based on students’ results on national exams at the end of secondary education. This research uses data on academic achievements by first-year univer- sity students to benchmark secondary schools on their ability to lead students to success in higher edu- cation. The analysis is conducted using data of University of Porto and Catholic University of Porto, Portu- gal, for a three-year period, corresponding to more than 10.0 0 0 students from 65 degrees, for which the school of origin is known. A number of variables representing students’ success in Higher education were constructed for each school in our sample and aggregated through a Benefit of the Doubt indicator. Re- sults suggest that the schools’ ranking based on schools’ ability to prepare students for university success is quite different from the ranking based on results on national exams. Given these findings, we propose complementing schools’ performance assessments (traditionally based on national exam results or indi- cators of value added) with indicators that account for the preparation of students for success in future challenges, which is indisputably a key objective of secondary education. We propose a composite indi- cator for the analysis of these complementary aims as well, and results show that frontier units indeed exhibit trade offs between traditional measures of performance and our new measure of performance.info:eu-repo/semantics/acceptedVersio

    Project-based learning in a mechanical engineering course: A new proposal based on student's views

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    The evolution of learning in higher education is nowadays evident. Several discussions and studies have been performed about new methodologies that can disrupt the way the classes are taught in universities. In this context, Project-Based Learning (PBL) is the most emphasized. In the Mechanical Engineering course at the University of Minho (UM), the Integration Project (IP) courses apply a PBL methodology, being these classes the differentiating element of the Integrated Master in Mechanical Engineering (IMME) compared with other Portuguese universities. However, even if the innovative aspect of this approach is recognized nationally, the opinions between students and Professors, about the structure and organization of this class, are still divided. In that sense, this work presents a new proposal for the IP courses in which the opinion of students and successful models implemented in international universities are considered. This study analyses the best PBL methodologies implemented in Engineering courses and presents a PBL model actually implemented at the IMME. This information is combined with the student's views obtained from a survey conducted at the Department of Mechanical Engineering (DEM), regarding the actual PBL model. Through this study, a new proposal for the IP courses is presented. This proposal intends to provide an effective answer to the necessity of the students, using successful tools and methodologies to improve the teaching and learning process in the IMME course. Through this proposal, it is expected to increase the learning process and motivation of the students making them better prepared for a productive profession.The first author would like to express her gratitude for the support given by the Portuguese Foundation for Science and Technology (FCT) and the MIT Portugal Program. This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 (ALGORITMI Center) and R&D Units Project Scope UIDP/04077/2020 (METRICS Center)

    Measurement errors and uncertainty estimation of an experimental set up using a 2D PIV technique

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    The study of the flow interaction and the heat transfer between air jets and a surface is of paramount importance in industrial processes that apply multiple air jet impingement. To ensure a good performance of the process, high heat transfer rates and uniformization of the flow over the target plate are required. To perform this analysis, a PIV technique was implemented for the measurement of the velocity fields of the flow. However, as any real experiment, the values recorded by the PIV method are subjected to several errors that compromise the reliability and accuracy of the measurements. These errors can have different sources, from the installation and alignment to the particles seeding and calibration procedure. To determine an interval that contains the measurement error, the uncertainty quantification is crucial. In that sense, this paper focus on the identification of measurement errors and uncertainty quantification of an experimental set up specially built for the analysis of the interaction between a non-isothermal jets and non-flat surfaces moving perpendicularly to the jet axis. To ensure the reliability of the results, preliminary tests were performed to guarantee a uniform and stable flow and to determine the range and conditions of operation. In addition, this work presents an analysis of the system, and the source of errors are identified, quantified and, when possible, corrected. The particle seeding, which consists of olive oil droplets, is characterized and its efficiency for the flow tracking is analysed. The test facility was tested to fully characterize the flow field in terms of mean velocity profile and turbulence intensity over a wide range of Reynolds numbers and temperature. Several velocity fields are then measured until convergence of the flow quantities is reached. The combination of these measurements with high spatial resolution and low measurement errors allow to obtain accurate and precise measurement values.Portuguese Foundation for Science and Technology (FCT) through the Research Grant PD/BD/128216/2016. This work has been supported by FCT within the Project Scope UID/CEC/00319/2019 (ALGORITMI) and Project Scope UID/EMS/04077/2019 (METRICS)

    Innovative solar concentration systems and its potential application in Angola

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    Energy demands have been increasing worldwide, endangering the future supply–demand energy balance. To provide a sustainable solution for future generations and to comply with the international goal to achieve Carbon Neutrality by 2050, renewable energies have been at the top of the international discussions, actively contributing to the energy transition and climatic policies. To achieve the international goal, Angola proposed a long-term strategy that promotes a fair and sustainable development of the national territory by means of improving the electric sector. Among all the renewable resources, solar energy is found to be the most promising solution since it has the second major renewable energy potential in Angola. However, the main problem related to solar energy is the efficiency of the solar systems and the electrical and thermal energy storage. As part of the solution, Concentration Solar Power (CSP) can make a sounder contribution to the transformation of the Angolan energy sector since it enables a significant increase in energy intensity through the concentration of solar energy. Moreover, the large applicability of this technology can contribute to the development of the rural regions which still struggle for energy equity. By considering the potential of CSP, this work presents the status of the Angolan energy sector, and focus is provided on the solar potential of the country. The advantages of the CSP technologies with emphasis on the parabolic dish systems are presented, and the contribution and innovative solutions for the enhancement of thermal efficiency are presented.This research was funded by FCT-Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 (ALGORITMI Center) and Project Scope UIDB/00319/2020 (METRICS Center)

    OTIMIZAÇÃO DE INVESTIMENTOS EM GESTÃO DE ATIVOS DE SISTEMAS DE ABASTECIMENTO DE ÁGUA UTILIZANDO O ÍNDICE DE VALOR DA INFRAESTRUTURA

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    The field of asset management provides a coordinated effort to extract value from physical assets, incorporating an integrated approach to deal with risks, costs and performance. This paper proposes an oriented approach to selecting infrastructure investment projects in an asset management framework. The standard metric used for project selection with multiple assets is the Infrastructure Value Index (IVI), which has been used to characterize water sector assets in several countries. Two mixed-integer linear programming models are developed in this paper. The first optimization model deals with a capital budget allocation problem that intends to select investment projects that maximize assets’ condition. The second optimization model deals with a budget planning problem aiming at minimizing the capital required to maintain the assets in the desired condition. The application of the models is illustrated by a case study of a company operating in the water sector in Portugal, namely in a pumping station from a water supply system. The results obtained in the different scenarios analysed are discussed with a view to supporting the design of more efficient asset management policies. A área de conhecimento associada à gestão de ativos potencia a extração de valor de ativos físicos, incorporando uma abordagem integrada que envolve riscos, custos e desempenho. Este trabalho propõe uma nova abordagem para selecionar projetos de investimento em infraestruturas no âmbito da gestão de ativos. A métrica padrão utilizada para a seleção de projetos em ativos múltiplos é o Índice de Valor de Infraestruturas (IVI), que tem sido utilizado para caracterizar ativos do setor de águas em diversos países. Este trabalho desenvolveu dois modelos de programação linear inteira mista. O primeiro modelo de otimização trata de um problema de alocação de orçamento de capital selecionando projetos de investimento com vista à maximização da condição dos ativos. O segundo modelo de otimização trata de um problema de planeamento de orçamento, visando minimizar o capital necessário para manter os ativos nas condições desejadas. A aplicação dos modelos é ilustrada por um estudo de caso de uma empresa que opera no setor da água em Portugal. Os resultados obtidos nos diferentes cenários analisados são discutidos com vista a apoiar o desenho de políticas de gestão de ativos mais eficientes

    Direito 4.0: o saber não ocupa espaço

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    - Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 342 D598q- Coordenado por: Antonio José F. de S. Pêcego.- Organizado por: Ana Flávia Messa, Bruno Bastos de Oliveira e Gustavo Barbosa de Mesquita Batista

    Characterization of the fetal membranes in buffalo cows in the first three months of gestation

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    Este estudo visou à caracterização das membranas fetais em búfalas (Bubalus bubalis, Linnaeus 1758) no terço inicial da gestação. As membranas fetais foram analisadas macroscópica e microscopicamente (luz e microscopia eletrônica de transmissão). O córion possui uma camada simples de células circulares, com núcleos de forma esférica, denominadas trofobláticas; há outro tipo celular, as células trofoblásticas gigantes, com dois ou mais núcleos. Ambas possuem uma grande quantidade de vesículas no citoplasma e retículo endoplasmático à microscopia de transmissão. O alantóide possui vasos preenchidos com eritrócitos, e contêm células alongadas, que formam um epitélio estratificado simples. O âmnion é uma membrana transparente, ou esbranquiçada; constituído por epitélio estratificado simples. A diferença principal entre o alantóide e o âmnion é que o último é avascular. O saco vitelínico é uma membrana opaca que desaparece durante a gestação; é a única membrana que não está em contato com as outras e apresenta três tipos diferentes de células que dão forma a três camadas distintas (endoderma, mesotélio, mesênquima)The aim of the study was to characterize the fetal membranes in buffalo cows (Bubalus bubalis, Linnaeus 1758) in the first 3 months of the gestation. The fetal membranes were analyzed gross and microscopically (light and ultrastructural analysis). The corion is a simple layer of circle cells, with spherical nucleus, named trofoblastics; there is another cellular type, named trophoblastic giant cells, with two or more nucleus. Both of them have many cytoplasmic and reticule endoplasmic vesicles on transmission electron microscopy. The allantoic has many vessels filled with eritrocytes, elongated cells which form a stratified simple epithelium. The amnion is transparent or sometimes whitish, consisting of a stratified simple epithelium. The main difference between the allantoic and amnion is that the latter is avascular. The yolk sac is an opaque membrane that disappears during gestation, and is the only membrane that is not in contact with the others; it presents three different types of cells which form three distinct layers (endoderm, mesothelium and mesenquimal

    DETECÇÃO MOLECULAR DE HEMOPLASMAS EM BOVINOS E OVINOS EM SISTEMA DE CRIAÇÃO CONSORCIADA DO NORDESTE DO BRASIL – DADOS PRELIMINARES

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    Micoplasmas hemotrópicos (hemoplasmas) são microrganismos gram-negativos e que ficam aderidos aos eritrócitos de diversas espécies de mamíferos. Em pequenos ruminantes, Mycoplasma ovis, e em bovinos, Mycoplasma wenyonii e ‘Candidatus Mycoplasma haemobos’ são as espécies já descritas. Nessas espécies animais a transmissão dos hemoplasmas pode estar relacionada à infestação por carrapatos ou picadas de moscas hematófagas. A infecção por hemoplasmas pode causar anemia hemolítica aguda, porém os sinais clínicos diferem de acordo com a espécie de hemoplasma envolvido, do animal parasitado, idade e sistema de produção em que é criado. Embora a hemoplasmose tenha sido relatada causando perdas econômicas significativas na criação de ruminantes em todo o mundo, dados de hemoplasmas em sistema de criação consorciada são inexistentes. Assim, o objetivo deste estudo é determinar a prevalência de hemoplasmas em bovinos e pequenos ruminantes provenientes de um sistema de criação consorciada no nordeste do Brasil. Até o momento, um total de 15 amostras (10 ovinos e cinco bovinos) foram triadas utilizando um protocolo de PCR para o gene 16S rRNA de hemoplasmas. As amostras positivas foram submetidas a uma PCR para o gene 23S rRNA de hemoplasmas. Todas as amostras foram positivas para o gene endógeno gliceraldeído 3-fosfato desidrogenase (gapdh). Todos as amostras de ovinos foram negativas para hemoplasmas. Três de cinco (60%) bovinos foram positivos para Mycoplasma spp. O estudo envolverá a triagem das amostras por PCR em tempo real
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