Renewable energy systems: Industrial and home best practise case studies

The use of renewable energies and energy efficiency improvement systems is sometimes constrained by the investment needed for devices and its installation. However, governments have developed policies to reduce the initial costs to end-users. The increasing number of renewable energy systems can help in the reduction of the global dependency on fossil energy sources, and simultaneously can help to ensure that the carbon dioxide emissions quota is not exceeded, aiming a reduction of the green-house effect. In this sense, this paper presents two best practise case studies. One of them is in the industrial context and other in the residence context, concerning the use of renewable energy systems and energy efficiency improvement strategies. The best practice case study in industrial context involves the renewable energy systems design in an automotive sector factory, making use of solar thermal panels and energy efficiency measures. The non-industrial case study covers the analysis of the energy efficiency improvement using a thermal energy recovery system from hot water used in daily baths or showers. The direct benefits (savings) and indirect (impacts) are analysed for both case studies.info:eu-repo/semantics/publishedVersio

Experimental evaluation of an innovative command for hydronic radiant heating floors

This paper presents the results of an innovative control, regulation and command system for hydronic radiant floors, more flexible and efficient that guarantees a better thermal comfort to the user and simultaneously improves the energy efficiency of this type of heating system. The control algorithm is based on the calculation of PMV (Predicted Mean Vote) index as defined on Thermal Comfort Standard ISO 7730. To improve energy efficiency, the control algorithm was implemented on a microcontroller system that fea-tures wireless communication with sensors modules powered by energy harvesting systems. The experimental tests were performed in a hydraulic underfloor built into a laboratorial climatic chamber. The results show that for a water inlet of 35 ºC, the controller turn the valve on/off less than other control systems in order to adjust the PMV while maintaining the floor surface temperature less than 29 ºC as recommended by international standards.info:eu-repo/semantics/publishedVersio

Experimental Study of Thermal Performance of Different Fruit Packaging Box Designs

Packaging was recently identified as an essential element in addressing the key challenge of sustainable food supply and is gaining interest among researchers. It is a central element in food quality preservation due to its role in heat and mass exchange with the external atmosphere, contributing to the preservation of food quality during storage and extending food shelf life. This work proposes three new packaging configurations with the same size but different geometry and ventilation hole sizes and geometry, that change the conditions in which the heat and mass exchange occurs, during either the cooling period of fruits, inside the cooling chamber, or during the period when the packaging is exposed to ambient conditions, outside the cooling chamber. For this purpose, packages with fruit models that replicate the properties of real fruit were subjected to a cooling process inside a cooling chamber for 8 h. Subsequently, during the heating phase, the packages were exposed to ambient conditions for 10 h. Thermal conditions were also monitored, both inside and outside the chamber. Additionally, for comparative purposes, the thermal behavior of commercial packaging was also evaluated for the same operating conditions in the cooling and heating phases. The results show that the new packages do not substantially promote the preservation of fruits in the cooling phase, but in the heating phase, they ensure an extension of the period with proper thermal conditions of up to 50% in relation to the conventional packaging. This result is particularly important since the heating phase, in which fruits are outside the storage chamber, is the period with the greatest impact on the fruits’ useful life.This study was conducted within the activities of project “Pack2Life—High performance packaging”, project IDT in consortium n. 33792, call n. 03/SI/2017, Ref. POCI-01-0247-FEDER- 033792, promoted by COMPETE 2020 and co-funded by FEDER within Portugal 2020. The authors are grateful for the opportunity and financial support to continue this project to Fundação para a Ciência e a Tecnologia (FCT) and R&D Unit “Centre for Mechanical and Aerospace Science and Technologies” (C-MAST), under project UIDB/00151/2020.info:eu-repo/semantics/publishedVersio

Low-Complexity Equalisers for Offset Constellations in Massive MIMO Schemes

This work was supported in part by the European Regional Development Fund (FEDER), through the Competitiveness and Internationalization Operational Program of the Portugal 2020 Framework, in part by the Regional OP Centro under Grant POCI-01-0145-FEDER-030588, in part by the Regional OP Lisboa under Grant Lisboa-01-0145-FEDER-03058, in part by the FCT/MEC through national funds of MASSIVE5G Project under Grant SAICT-45-2017-02 and PES3N Project under Grant 2018-SAICT-45-2017-POCI-01-0145-FEDER-030629, in part by the UID/EEE/50008/2019 Project, and in part by the FCT Ph.D. under Grant SFRH/BD/108522/2015.Massive multi-input-multi-output (m-MIMO) schemes require low-complexity implementations at both the transmitter and the receiver side, especially for systems operation at millimeter wave (mmWave) bands. In this paper, we consider the use of offset constellations in m-MIMO systems operating at mmWave frequencies. These signals are designed to have either an almost constant envelope or be decomposed as the sum of constant-envelope signals, making them compatible with strongly nonlinear power amplifiers, which can have low-implementation complexity and high amplification efficient, making them particularly interesting for mmWave communications. We design and evaluate low-complexity frequency-domain receivers for offset signals. It is shown that the proposed receivers can have excellent performance/complexity trade-offs in m-MIMO scenarios, making them particularly interesting for future wireless systems operating at mmWave bands.publishersversionpublishe

Characterization of refrigeration systems in the Portuguese food processing industry

This study is within the activities of Project “PrunusPÓS - Optimization of processes for the storage, cold conservation, active and/or intelligent packaging and food quality traceability in post-harvested fruit products”, project n.º PDR2020-101-031695, Partnership n.º 87, initiative n.º 175, promoted by PDR 2020 and co-funded by FEADER within Portugal 2020.This paper presents the results of audits performed in 60 companies of the food processing industry, specifically of meat, dairy, horticultural and bread products. The refrigeration volume, type of refrigeration system, refrigerant, building and insulation materials of infrastructure and refrigeration chambers, average air temperature and humidity, and the energy consumption are presented, compared and discussed per sector. The analysis allows to provide several measures and best practices aimed for the improvement of the thermal performance and energy efficiency of the food processing industry. The implementation of simple and very cost-effective transversal electricity savings measures such as awareness and/or training of operators, proper maintenance and monitoring tasks can benefit the sector. Tailored energy efficiency measures by sector, which may offer savings on several levels, are discussed. These best practices may increase productivity and competitiveness and reduce the environmental impact, and thus improve the global sustainability of the Portuguese food sector.info:eu-repo/semantics/publishedVersio

A spatial scale assessment of habitat effects on arthropod communities of an oceanic island

Copyright © 2009 Elsevier Masson SAS. All rights reserved.Most habitats in the Azores have undergone substantial land-use changes and anthropogenic disturbance during the last six centuries. In this study we assessed how the richness, abundance and composition of arthropod communities change with: (1) habitat type and (2) the surrounding land-use at different spatial scales. The research was conducted in Terceira Island, Azores. In eighty-one sites of four different habitat types (natural and exotic forests, semi-natural and intensively managed pastures), epigaeic arthropods were captured with pitfall traps and classified as endemic, native or introduced. The land-use surrounding each site was characterized within a radius ranging from 100 to 5000 m. Non-parametric tests were used to identify differences in species richness, abundance and composition between habitat types at different spatial scales. Endemic and native species were more abundant in natural forests, while introduced species were more abundant in intensively managed pastures. Natural forests and intensively managed pastures influenced arthropod species richness and composition at all spatial scales. Exotic forests and semi-natural pastures, however, influenced the composition of arthropod communities at larger scales, promoting the connectivity of endemic and native species populations. Local species richness, abundance and composition of arthropod communities are mostly determined by the presence of nearby natural forests and/or intensively managed pastures. However, semi-natural pastures and exotic forests seem to play an important role as corridors between natural forests for both endemic and native species. Furthermore, exotic forests may serve as a refuge for some native species

Characterization of the use of household refrigerators and of food waste in the student community of the University of Beira Interior

Os elevados níveis de desperdício alimentar são preocupações prementes das sociedades e governos actuais. A maior parcela de desperdício alimentar encontra-se a nível doméstico, sendo que mais de 50% desse valor podia ser evitado. Os factores que levam a esse desperdício alimentar podem decorrer da má gestão dos alimentos conservados nos frigoríficos ou até mesmo da utilização indevida do equipamento. Este estudo compreende a análise dos resultados de dois inquéritos sobre o tipo de utilização do equipamento frigorífico e o desperdício alimentar, aplicados à comunidade estudantil da Universidade da Beira Interior. A amostra de inquiridos foi constituída por 51 elementos. Verifica-se que o comportamento dos estudantes na utilização dos equipamentos não é o mais adequado, embora estes tentem evitar o desperdício alimentar. A conclusão mais relevante consiste na pouca informação sobre desperdício alimentar e os métodos e procedimentos para o mitigar, evidenciando a necessidade de informação e esclarecimento e consciencialização sobre estes tópicos.The high levels of food waste are current concerns of society and governments nowadays. The largest share of food waste occurs in households and more than 50% of this waste could be avoided. The factors that lead to food waste may result from mismanagement of the food stored in the refrigerators or even the misuse of the equipment. This study comprises the analysis of the results of two surveys on the use of the refrigerator and food waste applied to the student community of the University of Beira Interior. The sample consisted of 51 elements. It is found that the behaviour of the students in the use of the equipment is not the most adequate, although they try to avoid food waste. The most important conclusion is the lack of information on food waste and the methods and procedures for mitigation. Thus, the survey results highlight the need for information, enlightenment and awareness about these topics.info:eu-repo/semantics/publishedVersio

Investigação no ensino de engenharia biomédica: dois casos de estudo

Desde os anos oitenta que os avanços das ciências básicas e das ciências da engenharia têm dado um impulso sem precedentes à investigação médica, o que criou as condições para a afirmação da Engenharia Biomédica como ramo autónomo da Engenharia. Este novo ramo da Engenharia impôs-se em domínios que incluem a imagiologia biomédica, a bioinformática, a biotecnologia, a biomecânica, os biomateriais, a engenharia de tecidos, próteses e orgãos artificiais, a análise e modelação de sinais fisiológicos e a gestão de sistemas de saúde. Já no século XXI, o volume de saber acumulado e a motivação para acelerar desenvolvimentos científicos e tecnológicos, levou à criação e organização nas universidades de uma oferta de cursos de graduação e pós-graduação em Engenharia Biomédica. Apesar do espectro muito largo da Engenharia Biomédica e dos cursos criados, é possível, mesmo ao nível de Mestrado pós-Bologna (licenciatura pré-Bologna), dar uma formação avançada que permita aos alunos realizar trabalhos de investigação complexos e com impacto clínico. Neste artigo apresentamos dois destes casos de sucesso, representativos do papel da investigação ao longo do ensino bem actual da Engenharia Biomédica. No primeiro, intitulado “Caracterização Tridimensional da Placa de Ateroma da Bifurcação Carotídea com Ultrasonografia 3D”, é apresentado um método inovador de diagnóstico da Aterosclerose, baseado na reconstrução e caracterização tridimensional da lesão aterosclerótica ao nível da bifurcação carotídea. O segundo trabalho, intitulado “Reconstrução da Frente de Onda e Simulação da Acuidade Visual no Estudo do Impacto das Aberrações Ópticas em Olhos Submetidos a Cirurgia”, apresenta uma ferramenta computacional que gera informação adicional sobre a medição da frente de onda obtida com aparelhos comerciais, permitindo estudar o impacto de aberrações ópticas na acuidade visual de diferentes olhos. Este artigo está organizado em quatro partes. A primeira parte é uma nota histórica introdutória à Engenharia Biomédica em geral. A segunda parte apresenta o que do ponto de vista de ensino superior em Engenharia Biomédica, ao nível de Mestrado Integrado de 1º e 2º ciclos, pode em geral viabilizar a fácil inserção dos estudantes na Investigação, conduzindo-os de imediato a resultados de investigação concretos. A terceira parte constitui a parte central deste artigo onde se apresentam dois exemplos ilustrativos do sucesso da formação de 5 anos em Engenharia Biomédica e da inserção da investigação, desde muito cedo, nessa formação. Por fim, na quarta secção apresentam-se as conclusões

Análise da sinistralidade na indústria têxtil Portuguesa

Nos dias de hoje, os modos de produzir, consumir e viver emergem de forma crescente e rápida, por isso a globalização económica associada à introdução de novas tecnologias e de novas formas de produção e trabalho acarretam implicações na mão-de-obra, nas relações sociais de produção e nas condições de trabalho, aumentando os riscos para os trabalhadores de uma empresa. Com efeito, a percepção das incapacidades e limitações para terminar uma tarefa dentro de determinado prazo, gera um ambiente de stress e conduz a um fraco desempenho profissional, aumentando as probabilidades de erro e consequentemente de ocorrência de acidentes. Este artigo tem como objectivo o estudo das problemáticas associadas à área da Segurança, Higiene e Saúde no Trabalho (SHST) na indústria têxtil a nível Nacional, permitindo identificar os acidentes de trabalho mais comuns. Os resultados possibilitam caracterizar a ocorrência de acidentes de trabalho segundo vários factores, permitindo às entidades patronais, com base nesta avaliação, analisar os seus casos, eliminando ou reduzindo assim os riscos a que os seus colaboradores estão expostos.info:eu-repo/semantics/publishedVersio

Food Insecurity Is Associated with Low Adherence to the Mediterranean Diet and Adverse Health Conditions in Portuguese Adults

Background: Food insecurity is a limited or uncertain access to the adequate food and is a significant public health problem. We aimed to assess determinants of food insecurity and the corresponding health impact in Portugal, a southern European country that faced a severe economic crisis. Methods: Data were derived from the Epidemiology of Chronic Diseases Cohort Study (EpiDoC), a population-based cohort of 10,661 individuals that were representative of the Portuguese adult population and followed since 2011. A cross-sectional analysis of the third wave of evaluation (EpiDoC 3) was performed between 2015 and 2016. Food insecurity was assessed with the household food insecurity psychometric scale. Socioeconomic, demographic, lifestyle, adherence to Mediterranean diet (MD), self-reported non-communicable disease, health-related quality of life (HRQoL) (EQ-5D-3L), physical function (HAQ score), and health resource consumption information was also collected. Results: The estimated proportion of food insecurity was 19.3% among a total of 5,653 participants. Food insecure households had low adherence to the MD (OR = 0.44; 95% IC 0.31-0.62). In addition, diabetes (OR = 1.69; 95% IC 1.20-2.40), rheumatic disease (OR = 1.67; 95% IC 1.07-2.60), and depression symptoms (OR = 1.50; 95% IC 1.09-2.06) were independently associated with food insecurity. On average, food insecure households had a lower HRQoL (OR = 0.18; 95% IC 0.11-0.31) and a higher disability (OR = 2.59; 95% IC 2.04-3.29). A significantly higher proportion of food insecure households reported being hospitalized (OR = 1.57; 95% IC 1.18-2.07) and had more public hospital medical appointments (OR = 1.48; 95% IC 1.12-1.94) in the previous 12 months. Conclusion: We found that food insecurity is highly prevalent in Portugal. Food insecurity was associated with low adherence to the MD, non-communicable chronic diseases, lower quality of life, and higher health resource consumption. Therefore, this study provides valuable insight into the relationship between food security and the diet and health of the population during an economic crisis.publishersversionpublishe