Associate Laboratory of Energy, Transports and Aeronautics

Funder

Organizational Unit

Publications

Life cycle analysis of a particleboard based on cardoon and starch/chitosan

Publication . Mata, Teresa Margarida; Freitas, Clara; Silva, Gabriela Ventura; Monteiro, Sandra; Martins, Jorge Manuel; Carvalho, Luísa Hora de; Silva, Luís Manuel; Martins, Antonio Areosa

This work analyzes the life cycle environmental impacts of producing a particleboard based on cardoon fibers and a starch/chitosan adhesive from a “cradle-to-gate” perspective, considering the following life cycle steps: raw material production, adhesive preparation (component mixing and heating), cardoon fiber preparation (crushing and sieving), adhesive and fiber mixing, hot-pressing and final processing. The functional unit is a particleboard with the dimensions of 220 × 220 × 16 mm3. For the life cycle inventory, experimental data obtained from the production of particleboard on a pilot scale were used. The Aspen Plus V9 software was used to simulate the heating process in the manufacture of the biological adhesive and obtain the data associated with this stage. Portuguese or European conditions were considered for the background processes, using data from the EcoInvent V3.5 LCI database. The environmental impacts were quantified using the RECIPE methodology. To complement the study, the VOCs present in the panel were analyzed using the “active headspace” technique. The results show that for most of the environmental impact categories, energy consumption is dominant, followed by starch and chitosan production. Using fully renewable electricity produced in photovoltaic panels, instead of the Portuguese electricity mix, significantly reduces the impacts in most of the environmental impact categories, for example, the carbon footprint is reduced by 34%. Future studies will analyze how the environmental impacts can be further reduced, and how process scale-up may influence them.

2023Journal article

Open access

Manufacturing companies Industry 4.0 maturity level: A multivariate analysis

Publication . Fonseca, Luís Miguel Ciravegna Martins da; Pereira, Teresa; Oliveira, Marisa; Ferreira, Fernanda; Busu, Mihail

This research investigates Portuguese manufacturing companies’ Industry 4.0 (I4.0) maturity perception level and proposes an index to measure that aim. The research results show that the most critical factors in evaluating the perception level of I4.0 Perception Maturity (IPM) are strategy, leadership, and customer experiences. The result for the Global Index was 53.50%. Hence, the global Index companies’ perception of the level of maturity of I4.0 in Portugal is medium.

2024Journal article

Open access

Strategic CSR: Framework for sustainability through management systems standards: Implementing and disclosing Sustainable Development Goals and results

Publication . Fonseca, Luís; Carvalho, Filipe; Santos, Gilberto

This study proposes a framework to integrate sustainability within management systems standards and subsequently implement and disclose sustainable development (SD) goals and results. Moreover, it investigates the SD goals (SDGs) and results (SDRs) that Portuguese organizations with integrated management systems (IMSs) disclose to their interested parties. The study, supported by content analysis, highlights that four most frequently disclosed SDGs are “life on land” (50.0%), “industry, innovation, and infrastructure” (47.1%), “responsible consumption and production” (47.1%), and “partnerships for the goals” (47.1%). The four SDRs most frequently disclosed are “employment” (82.4%), “economic performance” (79.4%), “anticorruption” (64.7%), and “occupational health and safety” (61.8%). Hence, SDG disclosure emphasizes the environmental dimension, while SDR disclosure highlights the social dimension (economic dimension present in both SDGs and SDRs). Finally, the disclosure of SDGs and SDRs in institutional reports presents a positive and strong correlation that is statistically significant. Overall, the contributions of this research are twofold. First, it highlights the awareness of SD goals and results publications within organizations with certified management systems standards, therefore supporting the integration of the SDGs within those organizations, and second, it stimulates the demonstration of their impacts on the SDGs (the SDRs).

2023Journal article

Open access

Meshless analysis of the stress singularity in composite adhesive joints

Publication . Ramalho, L.D.C.; Dionísio, J.M.M.; Sánchez-Arce, I.J.; Campilho, R.D.S.G.; Belinha, Jorge

Adhesives are an exceptionally well-suited method for joining composites. Unlike other methods, such as bolting or riveting, adhesives do not introduce holes in their joining material. This is a significant advantage in the case of composites because the holes required by bolting or riveting induce stress concentrations and can also lead to tears, burrs or delamination. A point of concern in adhesive joints is the adhesive/adherend interface corner where a stress singularity occurs, and failure usually initiates. Thus, it is crucial to study this stress singularity to better understand adhesive joints’ mechanical behaviour. The goal of this work is to validate the application of the Intensity of Singular Stress Fields (ISSF) criterion to meshless methods, in this case, the Radial Point Interpolation Method (RPIM). With this purpose, eight overlap lengths (LO) in single-lap joints (SLJ) composed of Carbon Fibre Reinforced Polymer (CFRP) and bonded with a brittle adhesive were experimentally and numerically tested. Furthermore, an extrapolation based method is implemented to determine the critical stress singularity components (Hc) necessary for the strength predictions. In the end, the experimental and numerical results are compared to assess the suitability of the method. It was found that the ISSF criterion can be accurately applied to meshless methods and composite materials successfully, given the simplicity of the method applied.

2022Journal article

Restricted access

3D printed devices to avoid hand contact with commonly shared surfaces

Publication . Pais, A.; Ferreira, C.; Pires, V.; Silva, V.; Alves, J. Lino; Bastos, João; Belinha, Jorge

In the context of the COVID-19 pandemic, public spaces had to be quickly adapted to the new circumstances especially under the uncertainty of the pandemic development. Door handles are some of the most touched surfaces and so, this point of contagion was chosen to be tackled and two solutions were developed that would prevent direct touch with the handle: a portable and a fixed device. The portable device (HYHOOK + HYTIP) is a hook-like device holding a finger cover, which permits to open doors and push buttons safely. The fixed device (HANDGENIC) is meant to be assembled in door handles to equip buildings, such as universities or schools. With the fixed device, the user can open the door using their forearm which makes them less likely to transfer any particles to eyes, nose or mouth. The 3D printing Fused Filament Fabrication (FFF) process was selected as manufacturing technique, which allows the fast production of prototypes. This work portrays the development process and design iterations taking into consideration the concerns about the functioning of the devices and possible failures or alternative uses. To assure structural integrity of the parts, finite element (FE) analysis was used to verify its mechanical response. As conclusion, it was found that FE analysis indicate that the devices are structurally sound to be used in public spaces and that 3D printing is a useful way to rapidly develop devices while testing several design possibilities.

2022Journal article

Restricted access