MIMO transmission for 4G wireless communications

Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

Simulador e compilador de micro-código para processador vectorial dedicado

Tese de mestrado integrado. Engenharia Electrotécnica e de Comunicações. Telecomunicações. Universidade do Porto. Faculdade de Engenharia. 201

Material compósito de granulado de borracha de pneus usados reciclado numa matriz polimérica

A presente invenção apresenta uma solução que incorpora e melhora a adesão entre o granulado de borracha de pneu usado e a matriz polimérica, pela adição de um agente compatibilizador que para além de compatibilizar os materiais, promove a homogeneidade da mistura e consequentemente obtém-se um material com boas propriedades mecânicas e com bom aspecto superficial. A presente invenção consiste na apresentação de novas formulações de materiais que incorporam borracha de pneu usado em matrizes poliméricas termoplásticas utilizando um agente compatibilizador. Desta mistura obtêm-se produtos com composição de borracha de pneu usado com uma matriz polimérica, recorrendo a aditivos para melhorar as propriedades finais do compósito. O custo é primordial para competir com produtos feitos de matérias virgens e como tal, este processo visa reduzir o custo do produto bem como a quantidade relativa da matéria virgem utilizada e o reaproveitamento da borracha reciclada

Perfil compósito para colector solar, respectivo método de produção e utilização

A presente invenção diz respeito a um perfil compósito para caixa modular utilizada em colectores solares para aquecimento de águas para uso doméstico ou industrial cujas principais vantagens passam pela: produção através de um processo de extrusão, redução das perdas energéticas do colector solar devido ao design com perfil alveolar, fácil portabilidade devido a redução do peso por metro quadrado de painel, utilização de compósitos recicláveis na sua composição usando entre outros: borracha de pneu usado reciclada, redução dos tempos de montagem dos colectores solares, eliminação da necessidade de colocação de isolantes adicionais à caixa modular e redução dos custos de produção

A Geo-energia em Portugal – o contributo do conhecimento geológico para a transição energética

A implementação das tecnologias de armazenamento geológico de dióxido de carbono e de energia requer um conhecimento detalhado da geologia profunda das bacias sedimentares. As atividades resultantes da prospeção e pesquisa de petróleo conduzidas em Portugal permitiram o consolidar de um legado inestimável em termos de dados, informação e metodologias que constituem a principal fonte de conhecimento sobre formações geológicas da subsuperfície, tanto em áreas do onshore como do offshore. Com base neste Acervo do Petróleo, diversos projetos de investigação têm sido desenvolvidos em vários ramos das geociências. Este artigo sintetiza alguns dos resultados obtidos em projetos realizados ou em curso no âmbito da geo-energia, como o armazenamento de CO2 em diferentes ambientes geológicos, e a utilização da subsuperfície para armazenar energia nas formas química, mecânica ou térmica. Em todos esses estudos o Acervo do Petróleo foi e é ainda essencial. Acresce, porém, a necessidade de promover programas de prospeção e pesquisa em território nacional e em tempo útil, suportados na geo-energia, que contribuam para a diminuição das emissões de gases de efeito de estufa e consequente mitigação dos problemas decorrentes das alterações climáticas

Reference Scenarios and Key Performance Indicators for 5G Ultra-dense Networks

The so-called 5G will revolutionize the way we live, and work. In order to demonstrate the profound changes, we can expect to experience within the next 5 to 10 years, we present use cases for the planned research within the TeamUp5G project. Some use cases are strongly linked to the network layer and aim at developing solutions capable of optimizing the main promising benefits of 5G: extremely low latency and extremely high bandwidth (e.g., handle video streams, traffic congestion, user profiles), in the most efficient way possible. Other use cases focus on commercial applications that make use of middleware applications to enhance their performance. The latter fall into two main areas: real-time virtual reality and live video streaming, which are extremely demanding in terms of latency and bandwidth to provide an acceptable QoE/QoS to multiple users. The use cases presented are built assuming that 5G is essential for their support with appropriate QoE/QoS. Key performance indicators and their range of variation are also identified.info:eu-repo/semantics/acceptedVersio

Photocatalytic activity of TiO2/graphene and TiO2/graphene oxide nanocomposites

Semiconductor-based heterogeneous photocatalysis has been one of the most promising processes for the treatment of contaminated water. Among the available catalysts, titanium dioxide (TiO2) presents the best photocatalytic properties, being chemically and biologically inert, stable, non-toxic, cheap and easy to produce. However, its energy bang gap lies in the ultraviolet (UV) range, which is responsible for a reduced spectral activation, since UV radiation corresponds to only 5% of the solar spectrum [1]. For this reason, one of the main purposes of the scientific community has been to improve the photocatalytic performance of TiO2, namely through an adequate doping of this material, or through the creation of nanocomposites, to enable photocatalysis occurrence by the incidence of visible light. One alternative concerns the application of nanocomposites of TiO2 with graphene and graphene oxide to photocatalytic processes [2]. In this work, nanocomposites of TiO2 with different weight concentrations of graphene and graphene oxide (namely 0.5%, 1%, 1.5% and 3%) were synthetized by a one-step hydrothermal method and characterized in terms of morphology, crystalline structure, vibrational modes and optical band gap. The photocatalytic activity of these nanocomposites was then evaluated through the degradation of methylene blue and ciprofloxacin solutions under UV and visible radiation. The results indicated that the studied nanocomposites presented higher degradation rates of the methylene blue than the pure TiO2, which increased with the content of graphene/graphene oxide. However, these composites proved to be less suitable to degrade the ciprofloxacin solution than the pure TiO2 nanoparticles.Portuguese Foundation for Science and Technology (FCT) - UID/FIS/04650/2013, PTDC/CTM-ENE/5387/2014 and SFRH/BD/98616/2013; Basque Government Industry Department under the ELKARTEK Program.info:eu-repo/semantics/publishedVersio

Single photon emission computed tomography, invasive coronary angiography and cardiac computed tomography angiography

Introduction: Diagnostic tests that use ionizing radiation play a central role in cardiology and their use has grown in recent years, leading to increasing concerns about their potential stochas-tic effects. The aims of this study were to compare the radiation dose of three diagnostic tests: single photon emission computed tomography (SPECT), invasive coronary angiography (ICA) and cardiac computed tomography (cardiac CT) and their evolution over time, and to assess the influence of body mass index on radiation dose. Methods: We assessed consecutive patients included in three prospective registries (SPECT, ICA and cardiac CT) over a period of two years. Radiation dose was converted to mSv and compared between the three registries. Differences over time were evaluated by comparing the first with the fourth semester. Results: A total of 6196 exams were evaluated: 35% SPECT, 53% ICA and 22% cardiac CT. Mean radiation dose was 10.7±1.2 mSv for SPECT, 8.1±6.4 mSv for ICA, and 5.4±3.8 mSv for cardiac CT (p<0.001 for all). With regard to the radiation dose over time, there was a very small reduction in SPECT (10.7 to 10.5 mSv, p=0.004), a significant increase (25%) in ICA (7.0 to 8.8mSv; p<0.001), and a significant reduction (29%) in cardiac CT (6.5 to 4.6 mSv, p<0.001). Obesity was associated with a significantly higher radiation dose in all three exams. Conclusions: Cardiac CT had a lower mean effective radiation dose than invasive coronary angiography, which in turn had a lower mean effective dose than SPECT. There was a significant increase in radiation doses in the ICA registry and a significant decrease in the cardiac CT registry over time.publishersversionpublishe

Patient-physician discordance in assessment of adherence to inhaled controller medication: a cross-sectional analysis of two cohorts

We aimed to compare patient's and physician's ratings of inhaled medication adherence and to identify predictors of patient-physician discordance.(SFRH/BPD/115169/2016) funded by Fundação para a Ciência e Tecnologia (FCT); ERDF (European Regional Development Fund) through the operations: POCI-01-0145-FEDER-029130 ('mINSPIRERS—mHealth to measure and improve adherence to medication in chronic obstructive respiratory diseases—generalisation and evaluation of gamification, peer support and advanced image processing technologies') cofunded by the COMPETE2020 (Programa Operacional Competitividade e Internacionalização), Portugal 2020 and by Portuguese Funds through FCT (Fundação para a Ciência e a Tecnologia).info:eu-repo/semantics/publishedVersio

Evaluation of The Medical Board Exam in Portugal

Introduction: There is a high heterogeneity in the structure of postgraduate medical training evaluation worldwide. However, in contrast to other countries, there have been no scientific studies of the final medical board examination, in Portugal. The present study aimed to evaluate the adequacy of the medical board examination including its validity as measured by its association with medical school grade average and national seriation examination. Material and Methods: Cross-sectional, observational study. We analyzed the final results on the medical board examination of 2439 physicians, across 47 specialties, who completed their training in 2016 and 2017, using measures of central tendency and variability. We assessed the association between these grades and the national exam to initiate residency, and the grade average in Medical School. Results: Measures of central tendency and variability, and consequent shape measures, revealed that the distribution of the scores of the final medical board exam is extremely negatively asymmetric and leptokurtic. A positive association was also found between the results in this exam and the score on national exam to initiate residency, and the grade average in Medical School. Conclusion: Although the medical board examination was, in general, positively associated with scores on the national exam to initiate residency, and the mean final Medical School grades, thus indicating its potential validity, our results demonstrate that this exam presents no satisfactory discriminative capacity. Therefore, there is room to improve the actual postgraduate medical examination model, including changes in its classification system and potentially consider other assessment models