90 research outputs found

    Smart operation of transformers for sustainable electric vehicles integration and model predictive control for energy monitoring and management

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    The energy transmission and distribution systems existing today are stillsignificantly dependent on transformers,despite beingmore efficient and sustainable than those of decadesago. However, a large numberof power transformers alongwith other infrastructures have been in service for decades and are considered to be in their final ageing stage. Anymalfunction in the transformerscouldaffect the reliability of the entire electric network and alsohave greateconomic impact on the system.Concernsregardingurban air pollution, climate change, and the dependence on unstable and expensive supplies of fossil fuels have lead policy makers and researchers to explore alternatives to conventional fossil-fuelled internal combustion engine vehicles. One such alternative is the introduction of electric vehicles. A broad implementation of such mean of transportation could signify a drastic reduction in greenhouse gases emissions and could consequently form a compelling argument for the global efforts of meeting the emission reduction targets. In this thesis the topic of a high penetration of electric vehicles and their possible integration in insular networksis discussed. Subsequently, smart grid solutions with enabling technologies such as energy management systems and smart meters promote the vision of smart households, which also allows for active demand side in the residential sector.However, shifting loads simultaneously to lower price periods is likely to put extra stress on distribution system assets such as distribution transformers. Especially, additional new types of loads/appliances such as electric vehicles can introduce even more uncertaintyon the operation of these assets, which is an issue that needs special attention. Additionally, in order to improve the energy consumption efficiencyin a household, home energy management systems are alsoaddressed. A considerable number ofmethodologies developed are tested in severalcasestudies in order to answer the risen questions.Os sistemas de transmissão e distribuição de energia existentes hoje em dia sãosignificativamente dependentes dos transformadores, pese embora sejammais eficientes e sustentáveis do que os das décadas passadas. No entanto, uma grande parte dos transformadores ao nível dadistribuição, juntamente com outras infraestruturassubjacentes, estão em serviço há décadas e encontram-se nafasefinal do ciclo devida. Qualquer defeito no funcionamento dos transformadorespode afetara fiabilidadede toda a redeelétrica, para além de terum grande impactoeconómico no sistema.Os efeitos nefastos associadosàpoluição do arem centro urbanos, asmudançasclimáticasea dependência de fontes de energiafósseis têm levado os decisores políticos e os investigadores aexplorar alternativas para os veículos convencionais de combustão interna. Uma alternativa é a introdução de veículos elétricos. Umaampla implementação de tal meio de transporte poderia significar uma redução drástica dos gases de efeito de estufa e poderiareforçar os esforços globais para ocumprimento das metas de redução de emissõesde poluentes na atmosfera.Nesta tese é abordado o tema da elevada penetração dos veículos elétricose a sua eventual integração numarede elétricainsular. Posteriormente, são abordadas soluções de redeselétricasinteligentes com tecnologias específicas, tais como sistemas de gestão de energia e contadores inteligentes que promovamo paradigmadas casas inteligentes, que também permitem a gestão da procura ativano sector residencial.No entanto, deslastrando significativamente as cargaspara beneficiar de preçosmais reduzidosé suscetíveldecolocarconstrangimentosadicionaissobre os sistemas de distribuição, especialmentesobre ostransformadores.Osnovos tipos de cargas tais como os veículos elétricospodem introduzir ainda mais incertezassobre a operação desses ativos, sendo uma questão que suscitaespecial importância. Além disso, com ointuitode melhorar a eficiência do consumo de energia numa habitação, a gestão inteligente daenergia é um assunto que também éabordadonesta tese. Uma pletora de metodologias é desenvolvida e testadaemvários casos de estudos, a fim de responder às questões anteriormente levantadas

    A Smart Contract Architecture Framework for Successful Industrial Symbiosis Applications Using Blockchain Technology

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    Funding Information: Author acknowledges Fundação para a Ciência e a Tecnologia (FCT-MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI). Publisher Copyright: © 2023 by the authors.Industrial Symbiosis (IS) involves a network of organizations that exchange energy, materials, and by-products to lower production costs, reduce environmental impact, and conserve natural resources. Despite over two decades of extensive research into IS, its benefits are well known, but implementation remains challenging. This paper proposes utilizing blockchain technology (BCT) to digitize IS, making it more secure and transparent. First, drivers and barriers of BCT implementation in IS are identified. A smart contract architecture framework using Hyperledger Fabric is then proposed using the constructed theoretical background and abductive method. Finally, the paper discusses how this framework supports the implementation of BCT in IS by addressing its drivers and attempting to overcome its barriers. It is a resource for those seeking a comprehensive grasp of the foundational elements necessary for constructing a successful IS blockchain design, which is adaptable to all types of IS network configurations.publishersversionpublishe

    Controlo estatístico do processo: um estudo de caso numa empresa na área da indústria automóvel

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    No quadro de crescente globalização, a economia confronta as empresas com inúmeros desafios, já não chega produzir, as premissas actuais assentam na qualidade como condição para se atingir a produtividade e a competitividade. E, dado que a qualidade não é estática, está constantemente a ser alterada, porque os clientes são cada vez mais exigentes, qualquer organização empresarial, que queira ser competitiva, tem que inovar. No ambiente competitivo em que vivemos as organizações procuram cada vez mais produzir com qualidade com o menor custo possível, ao garantir assim a sua própria sobrevivência. Uma das respostas a essa procura é o Controlo Estatístico do Processo (CEP) – um poderoso método de gestão que permite a melhoria da qualidade e a eliminação de desperdícios. Este trabalho propõe-se a melhorar a qualidade de um processo através do uso do CEP numa empresa da indústria automóvel, bem como efectuar um estudo dos conceitos associados à metodologia e pretende demonstrar todas as vantagens associadas à sua utilização, como forma de melhoria de qualidade e redução de desperdícios. Para o efeito, foi estudada a metodologia existente da implantação do CEP nesse mesmo processo, e procurou-se uma maneira de a adaptar à realidade da empresa após ter sido efectuada a recolha de amostras e as interpretações das cartas de controlo, ou seja, as análises.In this context of an increasing globalization, the economy defies firms with numerous challenges, it is no longer enough to produce, the current principles are based on quality as a condition for achieving productivity and competitiveness. And given that the quality is not static, it is constantly being changed, and since customers are increasingly demanding, any business organization that aims to be competitive it has to innovate. In the competitive environment in which we live organizations increasingly seek to produce quality at the lowest possible cost, to ensure their own survival. One response to this claim is the Statistical Process Control (SPC) - a powerful management method which enables quality improvement and waste elimination. This paper suggests the improvement of the quality of a process through the use of SPC in an enterprise of the automotive industry, makes a study of concepts related with the methodology and aims to demonstrate all the advantages associated with its use as a method for improving quality and reducing waste. To accomplish this, after being completed the sample collection, the interpretations of control charts and its analysis, it has been made a study of the existing methodology of implementation of SPC in the same process, and it was sought a way to adapt it to the reality of the company

    Reporting of intellectual capital management using a scoring model

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    UIDB/00667/2020The global transformation of the economy, driven by digital transformation and sustainability challenges, is placing its focus on the evaluation of companies’ intangible assets. Thus, if the report of those intangible assets, namely intellectual capital (IC) management, is endowed with credible metrics, recognized, and accepted, it can work as a guarantee, ensuring the reliability and sustainability of an organization. The aim of this research is to propose a data-driven Intellectual Capital Management Scoring System to be used in the auditing of the IC management of organisations. This paper presents one of the first attempts to use Path Modelling and the Partial Least Squares (PLS) Methodology, combined with Biplots, to define and validate Intellectual Capital Scoring Systems. This system relies on a model estimated using the PLS Path Modelling methodology and uses data from two independent random samples of Portuguese small and medium-sized enterprises (SMEs), which, in turn, was used to obtain two independent model estimates. The results obtained with the mentioned methodology show a good consistency both in performance and very similar parameters estimates, suggesting the validity of the associated scoring function.publishersversionpublishe

    Influence of orchard cultural practices during the productive process of cherries through life cycle assessment

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    Funding Information: This study is within the activities of Project ?PrunusP?s?Optimization of processes for the storage, cold conservation, active and/or intelligent packaging and food quality traceability in post-harvested fruit products,? project n.? PDR2020-101-031695, Partnership n.? 87, initiative n.? 175, promoted by PDR 2020 and co-funded by FEADER within Portugal 2020. The authors are thankful for the opportunity and financial support to conduct this project from Fundação para a Ciência e Tecnologia (FCT) and R&D Unit ?Center for Mechanical and Aerospace Science and Technologies? (C-MAST), under project UIDB/00151/2020. Radu Godina acknowledges Funda??o para a Ciência e a Tecnologia (FCT?MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI). Acknowledgments: We thank Frutas com Vida for supplying the production data for the life cycle assessment. We thank AppiZ?zere for supplying relevant data of cherries production for the life cycle assessment.This study describes the influence of orchard cultural practices during the productive process of cherries on the environmental impact in terms of energy, air, soil and water through a “farm to market” Life Cycle Assessment (LCA). The results were used to identify the orchard cultural practices that contribute significantly to the environmental impact and to find solutions to reduce those impacts, serving as best practices guide to improving the environmental performance and as benchmarks for other national and international cherry and fruit growers. Primary data for production, harvest and post-harvest periods were gathered experimentally. The openLCA 1.10.2 software and the ecoinvent 3.5 database were used for modelling. Test case scenarios are modelled to identify the influence of cultural practices in low and high cherry production campaigns depending on climatic conditions and consequently diseases and plagues. Moreover, results are compared with other studies, not only covering cherries but also other fruits. The energy consumption per hectare in the production phase is similar in test scenarios. The energy consumption of orchard cultural practices related to tractor use, fertilizers and fungicides application are the main hotspots in terms of global warming, freshwater ecotoxicity and eutrophication, and terrestrial acidification. The use of electric vehicles, change the warehouse location or redefine transportation routes can reduce this impact, along with the optimization of the cherry’s quantity transported in each trip. In addition, the use of plant protection products, fertilizers and herbicides with less environmental impact will contribute to this objective. For that, the use of agriculture and precision systems to predict the need for fertilizers (nutrients), herbicides and fungicides, the use of decision support systems to define the dates of cultural practices, as well as innovative and emerging food and by-products processing methods are suggested. Thus, this study identifies and quantifies the environmental impacts associated with the production system of cherries and their main hotspots. It provides a best-practices guide for sustainable solutions in orchard management that contributes to the competitiveness and sustainability of fruit companies.publishersversionpublishe

    A LCA and LCC analysis of pure subtractive manufacturing, wire arc additive manufacturing, and selective laser melting approaches

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    Funding Information: João Pedro Oliveira acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the projects LA/P/0037/2020. This activity has received funding from the European Institute of Innovation and Technology (EIT) – Project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. This body of the European Union receives support from the European Union's Horizon 2020 - Research and Innovation Framework Programme . Publisher Copyright: © 2023 The AuthorsThe development of sustainable manufacturing solutions is gaining attention in the manufacturing sector due to increased awareness about climate change and the formulation of stricter environmental legislation. Sustainable manufacturing involves the development of solutions that are environmentally friendly and cost-effective at the same time. Considering the opportunities and limitations of metal subtractive and additive manufacturing approaches from a sustainability perspective, this study aims to compare the environmental impact and production costs associated with the manufacture of a marine propeller using pure subtractive CNC milling along with additive Wire arc additive manufacturing (WAAM) and Selective Laser Melting (SLM) approaches. Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) are used to quantify the environmental and economic impacts, respectively for each manufacturing approach. Based on the LCA and LCC models formulated, and the input data collected, the WAAM approach is observed to be the most environmentally and cost-efficient approach for the marine propeller analyzed. WAAM shows an environmental impact about 2.5 times and 3.4 times lower than pure CNC milling and SLM approaches, respectively mainly due to its better material and energy efficiencies. The effect of key variables on the environmental impact and production cost such as raw material, electricity, and post-processing parameters like a material allowance for finish machining and cutting velocity is also studied to suggest the parameters ensuring sustainable performance for a particular approach. WAAM is seen to be the most economical and ecological option for a post-processing material allowance under 4 mm and the finish machining velocities below 96 m/min. Additionally, an uncertainty assessment using the Monte Carlo analysis method is also performed to give a probabilistic range of environmental impacts and production costs considering the input data uncertainties for each approach. The methodology used in this study can be applied to other additive manufacturing processes. This study can be of potential help to AM practitioners in decision-making on selecting the most sustainable approach for manufacturing their products.publishersversionpublishe

    A review

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    Funding Information: Radu Godina acknowledges Fundação para a Ciência e a Tecnologia ( FCT - MCTES) for its financial support via the project UIDP/00667/2020 and UIDB/00667/2020 (UNIDEMI). JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020 , UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. This activity has received funding from the European Institute of Innovation and Technology (EIT) – Project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing . This body of the European Union receives support from the European Union's Horizon 2020 research and innovation programme. Publisher Copyright: © 2023 The AuthorsGrowing consciousness regarding the environmental impacts of additive manufacturing (AM) processes has led to research focusing on quantifying their environmental impacts using Life Cycle Assessment (LCA) methodology. The main objective of this paper is to review the state of the art of the existing LCA studies of AM processes. In this paper, a systematic literature review is carried out where a total of 77 papers focusing on LCA, including social-Life Cycle Assessment (S-LCA), are analyzed. Accordingly, the application of LCA methodology to different AM technologies was studied and different research themes such as the goal and scope of LCA studies, life cycle inventory data for different AM technologies, AM part quality and mechanical properties, the environmental, economic, and social performances of various AM technologies, and factors affecting AM´s sustainability potential were analyzed. Based on the critical analysis of the existing research, five major shortcomings of the existing research are realized: (i) some AM technologies are under studied; (ii) more focus only on the environmental sustainability dimension of AM, neglecting its economic and social dimensions; (iii) exclusion of AM pat quality and its mechanical performance from the sustainability assessment; (iv) not enough focus on the life cycle stages after product manufacture by AM; (v) effect of different product variables on AM´s sustainability not studied extensively. Lastly, based on these shortcomings realized, the following research directions for future works are suggested: (i) inclusion of new AM materials and technologies; (ii) transition to a triple-bottom-line sustainability assessment considering environmental, economic, and social dimensions of AM; (iii) extending the scope of LCA studies to post-manufacture stages of AM products; (iv) development of predictive environmental impact and cost models; (v) integration of quality and mechanical characterization with sustainability assessment of AM technologies.publishersversionpublishe

    Waste valorization through additive manufacturing in an industrial symbiosis setting

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    Given the current environmental concerns related to manufacturing, the introduction to the industrial symbiosis concept brought purpose to waste, instead of disposing it in landfills or eliminating it through incineration. The waste generated by industrial processes, or end-of-life products, is redirected to be used as a “new” input in another process by one or more organizations, which is a mutual benefit or a “symbiosis”. Despite its relevancy, the industrial symbiosis concept is marginally explored in the context of additive manufacturing; this emerging technology has disruptive potential regarding the use of different materials as secondary raw materials. This paper presents a systematic literature review regarding industrial symbiosis and additive manufacturing. The main objective is to identify how wastes can be used as input materials to additive manufacturing processes and what exchanges of resources occur in an industrial symbiosis setting. A final sample of 32 documents was reached and analyzed. Five examples of using waste streams in additive manufacturing processes to produce goods were highlighted and explored.publishersversionpublishe

    Key performance indicators selection through an analytic network process model for tooling and die industry

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    Funding Information: Radu Godina and Pedro Espadinha-Cruz acknowledge Funda??o para a Ci?ncia e a Tecnologia (FCT-MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI).In the last few decades, the fast technological development has caused high competitiveness among companies, encouraging a pursuit for strategies that allow them to gain competitive advantage, such as the monitoring of performance by using key performance indicators (KPIs). However, its selection process is complex since there are several KPIs available to evaluate performance and different relationships between them. To overcome this challenge, the use of a multiple criteria decision-making model (MCDM) was proposed, namely the analytic network process (ANP) through which a reduced number of them are prioritized. To identify which KPIs are suitable for the press cast and die manufacturing industry, a literature review was made, and 58 unique KPIs were identified. Thus, to validate the proposed methodology, a case study was carried out in an automotive press molding industry. With the implementation of the proposed ANP model it was possible to identify 9 KPIs that ensure the correct molding process monitoring, while being aligned with the Balanced Scorecard criteria. The results show that the proposed model is suitable for selecting KPIs for the molding industry.publishersversionpublishe

    Industrial applications of power electronics

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    Electronic applications use a wide variety of materials, knowledge, and devices, which pave the road to creative design, development, and the creation of countless electronic circuits with the purpose of incorporating them in electronic products. Therefore, power electronics have been fully introduced in industry, in applications such as power supplies, converters, inverters, battery chargers, temperature control, variable speed motors, by studying the effects and the adaptation of electronic power systems to industrial processes. Recently, the role of power electronics has been gaining special significance regarding energy conservation and environmental control. The reality is that the demand for electrical energy grows in a directly proportional manner with the improvement in quality of life. Consequently, the design, development, and optimization of power electronics and controller devices are essential to face forthcoming challenges. In this Special Issue, 19 selected and peer-reviewed papers discussing a wide range of topics contribute to addressing a wide variety of themes, such as motor drives, AC-DC and DC-DC converters, electromagnetic compatibility and multilevel converters.publishersversionpublishe
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