https://hdl.handle.net/10216/156 2026-04-17T08:31:14Z https://hdl.handle.net/10216/162903 Title: First Insight into Lignin Valorization as a Promising Biopolymer for the Modulation of the Physicochemical Properties of Port Wine Abstract: Lignosulfonate (LS), kraft lignin (KL), and organosolv lignin (OL) were evaluated as potential modulating agents of the physicochemical properties of Port wine at two different concentrations for 7 and 30 days. KL and LS demonstrated the ability to remove proteins and potentiate the anthocyanin concentration. LS reduced the tannin content and the interaction of salivary acidic proline-rich proteins with wine phenolic compounds. None of the lignin promoted a perceptible color change; however, the yellowish color of KL and OL at 100 g/hL contributed to an increase in the yellow tones of wines. Lignin improved wine aroma by reducing the amount of unwanted volatiles by 30% and increasing the content of ethyl esters associated with fruity aromas by up to 60%. The results suggest that lignin, especially LS, can be employed as a modulating agent, positively impacting wine's physicochemical properties. This valorization of a byproduct opens up new opportunities for the wine industry. 2024-01-01T00:00:00Z https://hdl.handle.net/10216/174046 Title: Influence of Fine Aggregates and Specimen Geometry on Mortar Compressive Strength 2026-03-01T00:00:00Z https://hdl.handle.net/10216/155660 Title: Assessment of Natural Radioactivity, Heavy Metals and Particulate Matter in Air and Soil around a Coal-Fired Power Plant-An Integrated Approach Abstract: A comprehensive study of the environmental radioactivity covered in a distance up to 20 km from a point source-two stacks of a coal-fired power plant. Airborne particulate matter was collected, and the element composition on the 30 cm soil profile was determined. The range of activity concentrations of Ra-226, Th-232 and K-40 from the studied areas varies from 8 Bq/kg to 41 Bq/kg, 5 to 72 Bq/kg and 62 to 795 Bq/kg, respectively. The activities values are increased by 44% for Ra-226, 37% for K-40, and 75% for Th-232 in the prevailing wind direction. For some elements, the respective concentration in the soil is above the maximum permissible level for all types of soil use, particularly for the arsenic concentration. The deposition flux ranged from 0.36 to 5.70 (g m(-2) per month) in the first sampling campaign and from 0.02 to 3.10 (g m(-2) per month) for the second sampling campaign. Maps on the spatial distribution of gamma dose rates, radionuclides activity concentrations, deposition flux and trace metals in topsoil were developed for the study region. These maps are in accordance with higher values in specific locations in the vicinity of the coal-fired power plant, showing the influence of point sources, and for locations within 6 and 20 km from the stacks, particularly in the prevailing wind direction. 2021-10-29T00:00:00Z https://hdl.handle.net/10216/164898 Title: A Zero-Shot Learning Approach for Task Allocation Optimization in Cyber-Physical Systems Abstract: The design and reorganization of Cyber-Physical Systems (CPSs) faces challenges due to the growing number of interconnected devices. To effectively handle disruptions and improve performance, rapid CPS design and development is crucial. The Task Resources Estimator and Allocation Optimizer (TREAO) addresses these challenges, by simulating and optimizing the tasks assignment to the CPS machines, recommending suitable software layouts for the CPS characteristics. It employs Zero-Shot Learning (ZSL) to predict task requirements in heterogeneous devices, enabling the characterization of software pipeline execution in distributed systems. The Genetic Algorithm (GA) component then optimizes the task assignment across available machines. Through experiments, the tool is evaluated for task characterization, CPS modeling and optimization performance. TREAO, when compared with similar tools, allows the simulation of more resource usage metrics (CPU, RAM, processing time and network delay) and increases flexibility in heterogeneous CPSs by predicting the task execution behavior and optimizing the task assignment. 2024-01-01T00:00:00Z https://hdl.handle.net/10216/169852 Title: Multifunctional Structural Electrolyte with Glass Fiber-Reinforced Polyvinyl Alcohol/Epoxy Matrix with Optimized Lithium Salt and Nanofiller Abstract: A novel multifunctional structural electrolyte is developed using plain-weave glass fiber reinforced with a composite polymer matrix for load-bearing energy-storage applications such as structural batteries. The composite matrix comprises polyvinyl alcohol (PVA) blended with epoxy, LiTFSI salt, and Al2O3 at optimized ratios. A set of techniques is used to evaluate and optimize the thermo-electro-mechanical properties of the matrix, including dynamic mechanical analysis (DMA), potentiostatic electrochemical impedance spectroscopy (PEIS), thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction. The optimization reveals a clear trade-off: increasing salt content enhances ionic conductivity but compromises mechanical properties, while the addition of nanofiller improves stiffness but reduces ionic conductivity. Based on multifunctionally balancing, a formulation of PVA0.34/epoxy0.14/LiTFSI0.32/(Al2O3)0.2 is obtained. The structural electrolyte, composed of glass fiber impregnated with the optimized matrix, is characterized using PEIS, DMA, tensile testing, and charge-discharge tests within lithium iron phosphate (LFP)/lithium metal and LFP/graphite cells. The electrolyte exhibits a storage modulus of 3 GPa, an ionic conductivity of 1.74 × 10−4 S cm−1, a bulk stiffness of 1.82 GPa, and a tensile strength of 56.9 MPa. Full-cell testing demonstrates long cycle life and stable cyclability for ≈240 cycles, maintaining a high Coulombic efficiency of around 95% throughout cycling. (c) 2025 The Author(s). Advanced Energy and Sustainability Research published by Wiley-VCH GmbH. 2026-01-01T00:00:00Z https://hdl.handle.net/10216/159433 Title: In vitro bioaccessibility and intestinal transport of retinoic acid in ethyl cellulose-based microparticles and impact of meal co-ingestion Abstract: The development of carrier-based delivery systems for oral administration of retinoic acid (RA), that provides its release and absorption at intestinal level, is of major relevance in the treatment of acute promyelocytic leukemia. The aim of this work was to evaluate RA bioaccessibility and intestinal transport on ethyl cellulose (EC)- and EC + polyethylene glycol (ECP)-based microparticles and to understand the impact of meal co-ingestion by applying in vitro assays. RA-loaded microparticles were produced by spray-drying with an encapsulation efficiency higher than 90 % for both formulations. The gastric bioaccessibility of RA (after in vitro static digestion of RA-loaded particles) was lower than 3 % for both types of microparticles, with and without meal co-ingestion. Whereas after intestinal digestion, RA bioaccessibility was significantly higher and affected by the type of microparticles and the presence of meal. The digestion of EC- and ECP-based microparticles without diet enabled a significantly higher bioaccessibility of RA when compared to the one recorded for the co-digestion of these microparticles with diet. Herein, RA bioaccessibility decreased from 84 ± 1 to 24 ± 6 % (p < 0.0001) for microparticles EC and 54 ± 4 to 25 ± 5 % (p < 0.001) for microparticles ECP. Moreover, comparing both types of microparticles, RA bioaccessibility was significantly higher for EC-based microparticles digested without diet (p < 0.0001). At last, the bioaccessibility of RA was similar among EC- and ECP-based microparticles when co-digested with diet. Intestinal transport experiments performed in Caco-2 monolayers evidenced that after 2 h of transport the amount of RA retained in the apical compartment was higher than the amount that reached the basolateral compartment evidencing a slow transport at intestinal level that was higher when RA is spiked in the blank of digestion and the meal digestion samples compared to RA dissolved in HBSS (44 ± 6 (p < 0.01) and 38 ± 1 (p < 0.05) vs 26 ± 2 %, respectively). (c) 2023 2024-01-01T00:00:00Z https://hdl.handle.net/10216/162846 Title: Thermophysical Properties of Mixtures Containing Cholinium l-Alaninate and Water, Ethanol, or Propan-1-ol Abstract: Choline amino acid ionic liquids (CAAILs) provide a greeneralternativeto classical ionic liquids, such as the ones based on imidazoliumcations, since they can be obtained from natural sources with largerbiodegradability. Given that most industrial extractions are performedin either aqueous or alcoholic media, the thermophysical characterizationof binary mixtures containing these solvents is very important forprocess design. In this work, the influences of the mole fractionof ionic liquid and of temperature on the thermophysical propertiesof binary mixtures containing water, ethanol, or propan-1-ol and cholinium l-alaninate ([Ch][Ala]), a well-known CAAIL, were studied. Dynamicviscosity, shear stress, torque (T = 288.15 -308.15 K), electrical conductivity (T = 298.15 K),and density (T = 293.15, 298.15, 303.15 K) were measuredat 0.1 MPa, and the corresponding excess volumes were calculated andfitted to a Redlich-Kister (RK) equation. Moreover, the effectof temperature on density (T = 288.15 - 323.15K), dynamic viscosity (T = 288.15 - 323.15K), and refractive index (T = 288.15 - 343.15K) of the synthesized [Ch][Ala] was also evaluated and compared withliterature. Dynamic viscosities of the pure components were determinedand fitted using the Vogel-Fulcher-Tammann-Hesse(VFTH) equation. 2023-01-01T00:00:00Z https://hdl.handle.net/10216/174024 Title: A parametric study on the stability analysis of tailings storage facilities with cemented berms 2025-01-01T00:00:00Z https://hdl.handle.net/10216/152995 Title: Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative Abstract: The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor gamma (PPAR gamma), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 mu M) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs. 2022-01-01T00:00:00Z https://hdl.handle.net/10216/148952 Title: A methodology to empower citizens towards a low-carbon economy. The potential of schools and sustainability indicators Abstract: Environmental empowering to control resource consumption and environmental impacts is critical to engage citizens to adopt more sustainable habits. This study demonstrates the potential benefits of innovative approaches based on sustainability indicators towards a low-carbon economy. A methodology to measure and promote sustainability in schools has been proposed and evaluated, aiming at showing the environmental performance and informing of potential environmental savings. The methodology, titled ClimACT, has two main purposes: measuring the environmental performance of schools through a school sustainability index based on measurable indicators in the areas of transport, procurement, green spaces, indoor air quality, energy, water and waste; and encouraging students, teachers and families towards an energy-efficient and low-carbon pathway through a structural procedure based on roles, activities and progress evaluation. The approach, applied to 39 pilot schools from Portugal, Spain, France and Gibraltar, achieved promising and encouraging results. All schools deployed the methodology successfully, achieving measurable environmental benefits in 95% of cases, with an average improvement of 10% in the global performance of schools after one year. Moreover, the 5112 surveys applied to school communities, before and after the methodology implementation, highlighted how the sustainable indicators had a significant influence on the daily lives of families, leading to improvements of their behaviour, with an average increase of 20% in indicators regarding good practices in transport, energy, water, waste and citizenship. The environmental empowering through measurable indicators is a step forward a lowcarbon economy. This methodology is open and adaptable to all sectors and requirements. 2021-02-16T00:00:00Z https://hdl.handle.net/10216/174008 Title: Effect of Sustained Loading on the Direct Shear Behaviour of Recycled C&D Material-Geosynthetic Interfaces Abstract: Recycled construction and demolition (C&D) wastes have been pointed out as a feasible alternative to traditional backfill materials of geosynthetic-reinforced structures, but the current knowledge about the interface behaviour between these unconventional (recycled) materials and the reinforcement is still limited, particularly as far as the time-dependent response is concerned. In this study, a series of large-scale direct shear tests was conducted using an innovative multistage method to evaluate the influence of shear creep loading on the direct shear response of the interfaces between a fine-grained C&D material and two different geosynthetic reinforcements (high-strength geotextile and geogrid). The peak and large-displacement interface shear strength parameters obtained from tests involving sustained loading were compared with those from conventional interface tests. Test results have shown that the shear creep deformation of the interfaces increased with the magnitude of sustained loading. The test specimens experienced additional vertical contraction during the creep stage, which tended to increase with the applied normal stress. For the recycled C&D material-geotextile interface, the sustained loading induced a reduction in the apparent cohesion and a slight increase in the friction angle, when compared to the values estimated from conventional tests. In turn, for the geogrid interface, the apparent cohesion values increased, whereas the friction angle did not significantly change upon shear creep loading. 2023-01-01T00:00:00Z https://hdl.handle.net/10216/174005 Title: Predicting Stabilized Soil Mixture Proportions for 3D Printing: Preliminary Study Using the Design of Experiments Approach Abstract: The development of three-dimensional (3D)-printed earth construction frameworks is limited. From a materials science perspective, the mix proportioning of earth-based printable materials is a critical issue, primarily due to (1) the requirements in the fresh state, (2) the need for adequate stabilization, and (3) the variability of raw natural materials, which necessitates their characterization. This study aims to investigate stabilized soil for 3D printing. To achieve this, a central composite design (CCD) was followed in order to identify statistical models capable that can describe key properties of stabilized earth mixtures, namely, slump, Casagrande (CS), mass loss, and compressive strength, as functions of the following mixture input parameters: water-to-powder volume ratio (Vw/Vp), superplasticizer-to-powder weight ratio (Sp/p), and limestone filler-to-cement weight ratio (lf/c). Both potential printable and nonprintable stabilized earth mixtures were obtained, and Vw/Vp exhibited the main effect in all output properties evaluated. On the other hand, the mixture parameter lf/c did not influence the selected output properties. This is not surprising because the lf/c proportion in the earth composite is very small compared with the other powder materials (cement and soil). The superplasticizer had a significant impact on the fresh state, slump, and CS. A numerical optimization technique based on the desirability function was applied to the derived models to determine potential stabilized soil printable mixture ratios. Solutions were found for Vw/Vp ranging from 1.760 to1.852, while covering all Sp/p ranges of the CCD. 2025-01-01T00:00:00Z https://hdl.handle.net/10216/174004 Title: Hourly Discharge Modelling and Forecast for a Run-of-river Dam Abstract: -Water resources have become a growing concern in society. This is largely due to the scarcity of this natural asset and the realisation that increasing demand could lead to future conflicts. Sometimes, human action limits access to water or alters natural flows. Run-of-river hydropower schemes manage river flows on a short-term basis, altering the natural flow of rivers according to the energy needs of consumers or the risk of flooding. The aim of this work is to show how to model and predict the hourly flow in a run-of-river reservoir, using the Crestuma-Lever dam on the river Douro (Portugal) as a case study. Data collected from 1998 to 2020 will be used. The study focuses on the use of time series models capable of dealing with multiple periodicities, such as the TBATS model. The findings show that the model can be used for 48-hour to weekly forecasting. In general, it captures the large fluctuations in the turbine discharges and most peak discharges. However, it does not capture most zeros and has difficulty in dealing with low flow values. The results of the time-series model are also compared with those obtained using three machine learning algorithms: the Seasonal Naïve, the Neural Network, and the Random Forest. (c) 2025, World Scientific and Engineering Academy and Society. All rights reserved. 2025-01-01T00:00:00Z https://hdl.handle.net/10216/174003 Title: Laboratory study on scour development around a monopile in layered soils 2025-09-01T00:00:00Z https://hdl.handle.net/10216/173967 Title: Heat transfer in a 3D-printed multilayer wall system: An experimental and numerical analysis 2025-01-01T00:00:00Z https://hdl.handle.net/10216/144285 Title: Quantitative Risk Assessment of Environmental Hazards Generated by a Tailings Embankment: case study Cabeço do Pião, Portugal [Evaluación Cuantitativa de Riesgos Ambientales Generados por Una Presa de Relaves: caso de estudio Cabeço do Pião, Portugal] Abstract: The Panasqueira mine is a world-class tungsten mine and probably one of the most important in Europe, having been continuously in operation since 1898. Between 1927 and 1996, the ore was fully or partially processed in a processing plant located on the left bank of the Zêzere River. The tailings were stored along the bank, in an extension of about 1.5 km. The fine particles, locally known as sludge, were stored in a self-cons-tructed embankment located on a steep hillside. The current average slope is about 36°. The sludge has high concentrations of some heavy metals (Cu, Zn, W and Cd) but has a particularly high concentration in arsenic (about 15%). This tailings storage was not included in the National Plan for Rehabilitation of Abandoned Mi-nes, despite presenting a high environmental risk. A quantitative environmental risk assessment characterises this situation, considering two possible alternati-ves: the current state with continuous release of contaminants or, alternatively, the situation that would arise from an eventual collapse of the storage embankment. In the first situation, we used a classical methodology of risk assessment to estimate the concentrations of arsenic in the affected compartments using a conser-vative exposure scenario and inferring the doses to which the local population is subjected. These doses are compared with reference acceptable values. In the second situation, the creation of a dispersed source of contamination encompasses a much higher dispersion area, a larger population and more expensive rehabilitation costs. 2021-01-01T00:00:00Z https://hdl.handle.net/10216/147864 Title: Occupational Exposure to Mineral Dust in Mining and Earthmoving Works: A Scoping Review Abstract: Anthropogenic activity is related to several environmental imbalances, including dust. Particulate matter can also hinder humans with numerous health consequences, such as asthma, cancer, and pneumoconiosis. With a particular focus on mineral dust, this review is intended to determine in which circumstances occupational exposure occurs in the mining and earthmoving industries. Research followed the guidelines provided by the preferred reporting items for systematic review and meta-analysis protocols and its extension for scoping reviews. Of the 8993 records identified, only 24 passed both exclusion and inclusion criteria. Within the pool of results, it was possible to identify the following variables related to dust exposure: job-related (activity, job category, and site), engineering (equipment, transport system), technical (distance), and physical (season and weather) variables. Due to the significant variance in protocol settings, it was challenging to perform a general analysis, resulting in a study-by-study approach. The most significant conclusion of this study is not related to the setting of occupational exposure, although it derives from it. The necessity of adopting standard procedures for data collection, independent of research objective, was demonstrated within the context of occupational exposure to mineral dust. 2022-01-01T00:00:00Z https://hdl.handle.net/10216/171330 Title: A Comprehensive Laboratory Experiment on the Synthesis and Characterization of Sustainable Carbon Materials from Wastes 2025-01-01T00:00:00Z https://hdl.handle.net/10216/172723 Title: Parameter estimation of a size-exclusion simulated moving bed for protein purification via meta-heuristic methods with estimability analysis and uncertainty evaluation Abstract: This study aims to enhance the modelling of myoglobin (Mb) and bovine serum albumin (BSA) separation in size-exclusion gel systems by leveraging experimental data and computational methods. The objective is to estimate the parameters of a mathematical model that accurately represents this separation process. To achieve this, optimization problems with adequate objective functions are solved via Particle Swarm Optimization (PSO), which has been shown to be more efficient than comparable deterministic methods Comprehensive estimability and uncertainty analyses were also conducted to thoroughly assess the model's reliability and accuracy. The initial phase of the study involved estimating parameters for a fixed bed system. During this phase, it was discerned through estimability analysis that the mass transfer coefficient parameters, denoted as kh, had minimal impact on the model's outputs, leading to their exclusion from subsequent estimations. The focus then shifted to refining the model parameters to simultaneously fit both the fixed bed and Simulated Moving Bed (SMB) experimental data. The comparative analysis between these parameters and the fixed bed parameters highlighted notable differences, particularly in the axial dispersion parameter (Dax) and the BSA size exclusion constant (KSEC,BSA). An uncertainty evaluation was successfully executed after completing this study, providing confidence intervals for each parameter, and propagating the uncertainty to the prediction of the developed model. This comprehensive approach ensures a more accurate and reliable understanding of the separation dynamics in size-exclusion gel processes for Mb and BSA. 2026-01-25T00:00:00Z https://hdl.handle.net/10216/124087 Title: Evidence of occupational accidents with equipment in mining a systematic review protocol Abstract: <jats:p>Mining industry due to its great technical challenges continues to be one of the main high-risk industries. Many features can be attributed to this issue, such as workers age and experience, but also to environmental factors as well as equipment failure and misuse. This systematic review protocol outlines the principal procedures to conduct a systematic review which intends to find evidence of occupational accidents due to mining equipment usage. In order to accomplish this primary objective, the main engineering databases and journals were selected (i.e. Scopus, Science Direct and Web of Science) and a set of keywords was defined to latter sequenced combination. The selection process of the papers is also described, in an attempt to contribute to further research on this field. All of the data treatment is detailed, including the risk of bias and attempts to manage it.</jats:p> 2018-10-03T00:00:00Z