CIMO - Publicações em Proceedings Indexadas à WoS/Scopus
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- An Efficient Feature Extraction Method for Identifying Signatures of Viral Genomic VariantsPublication . Souza, Felipe Bueno de; Pimenta-Zanon, Matheus Henrique; Henriques, Dora; Pinto, M. Alice; Balsa, Carlos; Rufino, José; Lopes, Fabrício MartinsGenomic analysis is a powerful way to understand viral pathogens and their variations. However, most of the genomic analysis methods are based on sequence alignment, which has a high computational cost. This study introduces a novel methodology to extract discriminative regions from viral genomes. Using exclusive k-mers through strategically defined sliding windows, our approach identifies genomic regions with high concentrations of variant-specific signatures, showcasing high-accuracy classification while requiring modest computational resources. The data-driven and nonparametric nature of our approach enables pattern extraction without imposing predefined distributions, enhancing both analytical flexibility and result interpretability. By balancing minimal k-mer sizes with maximum discriminative power, our method achieves remarkable generalization capability even with limited training samples. The computational efficiency of the methodology alongside the biological transparency and explainability in the results makes it accessible to research environments with restricted processing capacity, potentially accelerating genomic signature discovery across diverse viral pathogens and contributing to better variant tracking and characterization, thus opening up even more possibilities in genomic analysis studies.
- Chemical evaluation of agro-industrial wastes for composting water hyacinthPublication . Oliveira, Verónica; Rodrigues, Manuel Ângelo; Arrobas, Margarida; Rodrigues, Edite; Simões, P.; Miguens, Filomena; Santos, DanielaWater hyacinth (WH) waste removed from watercourses can be valued through composting. In this study it was determined the elemental composition of WH waste and other local organic residues to prepare suitable mixtures for composting. Rice husk, straw and woodchip showed high C/N ratios (> 80). In turn, farmyard manures and vegetables displayed low C/N ratios (< 20). WH tissues showed increased C/N ratios with the aging process (from 17.4 to 37.1). WH tissues had low P (< 2 g kg-1) and high Fe (>5000 mg kg-1) and Mn (2476.7-- 12885.8 mg kg-1) concentrations. Fe and Mn levels were particularly high in the roots (31706.8 and 38335.2 mg kg-1, respectively). Such high levels of Mn and Fe may impair the composting process and restrict the agricultural use of compost. Thus, the composting piles must be prepared from an optimized combination of organic materials that avoids either of those problems.
- Valorization of water hyacinth waste through compostingPublication . Oliveira, Veronica; Rodrigues, Manuel Ângelo; Arrobas, Margarida; Rodrigues, Edite; Simões, P.; Pato, Rosinda; Miguens, Filomena; Santos, DanielaWater hyacinth composts can be used in agriculture to improve soil fertility and crop yield, reducing the dependence on synthetic fertilizers. This study aimed to monitor physicochemical parameters of the composting of water hyacinth waste blended with other organic wastes. Two composting piles were assembled using different organic materials: water hyacinth waste, potato residue, olive pomace and dairy cow manure (pile 1) or rice straw (pile 2). Composting pile 1 ran for 251 days and pile 2 lasted 244 days. Both piles registered temperatures above 55 oC for several weeks, whereas moisture and pH values were found within adequate intervals, ensuring good conditions for sanitation and microbial activity. The C/N ratio decreased during the composting period, stabilizing in values close to those that are commonly referred as adequate (12.6, pile 1; 10.9, pile 2). Measured quality parameters indicate that the final organic compost is very suitable for agricultural use.
- Analysis of land use land cover changes and their impacts on the urban heat island effect in Bragança, PortugalPublication . Almeida, Cátia Rodrigues de; Alírio, João; Gonçalves, Artur; Teodoro, Ana CláudiaThe viability of urban life requires a series of changes in Land Use Land Cover (LULC), incorporating anthropic elements at the expense of vegetated areas, changing the land cover, which affects surface albedo. One of the impacts could be the formation of an Urban Heat Island (UHI), where temperatures are higher in cities compared to the vegetated surrounding areas, especially after sunset. Remote Sensing (RS) data, such as Land Surface Temperature (LST), image classification algorithms, and vegetation indices, can be used to understand this dynamic. This research aimed to assess the sensitivity of RS products to LULC changes and evaluate the surface thermal behaviour of (Portugal) between 2016 and 2023, during summer and winter. RS was able to identify some changes in LULC and ascertain that LST, in general, was higher in anthropic areas, especially during the summer.
- Impact of Ecological Issues on Buy Intention: A Portuguese Quantitative StudyPublication . Ribeiro, Maria Isabel; Lopes, Isabel Maria; Fernandes, António Pedro Ribeiro; Fernandes, Ana Isabel Ribeiro; Fernandes, AntónioCurrently, ecological consumption is a topic that has generated a lot of interest and discussion, gaining importance in society due to the harmful environmental consequences and social and economic inequalities resulting from the rapid and disorganized economic and industrial growth of the last century. For these reasons, this study investigates how sustainable purchasing habits and environmental awareness impact the intention to buy ecological products by Portuguese consumers. Secondary data was collected to analyze the state of the art. Subsequently, a survey was carried out using a non-random convenience sampling procedure. The data (n = 1376) were processed and analyzed using the exploratory factor analysis, selecting the principal components method, and multivariate linear regression. The results reveal that environmental awareness, as well as sustainable purchasing habits, are predictors of the intention to buy ecological products. The results of this study identify determinants of the intention to buy green products and provide information to companies on the factors that could improve their economic results by increasing sales, attracting consumers with environmental concerns, and adopting a more sustainable business model.
- Mechanical Characterization of Eco-Friendly Composites: Green Epoxy Resin Reinforced with Coir FibersPublication . Ribeiro, J.E.; Lopes, Hernani; Rocha, JoãoThe increasing demand for sustainable materials has fostered the development of natural fiber-reinforced composites as eco-friendly alternatives to petroleum-based systems. This work investigates the mechanical performance of GreenPoxy resin reinforced with coir fibers through a comprehensive experimental program. Fiber properties were first characterized by density and tensile tests, while the resin was evaluated under tensile and flexural loading. Composite laminates were then fabricated by hand lay-up using 3% and 6% fiber volume fractions, with both untreated and retted fibers. Mechanical behavior was analyzed using Taguchi design and ANOVA to assess the effects of fiber treatment and content. Untreated fibers displayed slightly higher intrinsic strength, while mercerization enhanced fiber–matrix adhesion, particularly at higher fractions. The composites exhibited promising properties, confirming the potential of coir/GreenPoxy systems for sustainable structural applications.
- Influence of Time and Temperature Variables on the Heat Treatment of an AL-MG SI AlloyPublication . Ribeiro, J.E.; Lopes, Hernani; Rocha, JoãoThis study investigates the effect of time and temperature on the heat treatment of 6082 Al-Mg-Si alloy. Solubilization, quenching, and artificial aging were performed under parameter combinations defined using the Taguchi method. Mechanical testing supported the development of a multiple linear regression model, which identified aging temperature as the most significant factor influencing ultimate tensile strength and yield strength. High aging temperatures promoted coarse precipitate formation and reduced strength, while lower temperatures minimized this effect and maintained or improved mechanical performance. The results demonstrate the potential of combining statistical design with predictive modeling to optimize heat treatment parameters and enhance alloy performance for industrial applications.
- Development of Polyethersulphone Mixed Matrix Zeolite Membranes Functionalized with Ionic Liquids and Deep Eutectic Solvents for CO2 SeparationPublication . Cardoso, Jonathan; Lin, Zhi; Brito, Paulo; Ferreira, LicínioMixed matrix membranes (MMM) combine the flexibility of polymers and the strength and durability presented by inorganic solids. In an economically point of view, the advantages of membrane separation are low capital investment and space requirements, high process flexibility and lower energy consumption, helping for a more cost-effective separation process and providing a high separation degree. The molecular sieves based on nano-sized silicoaluminophosphates (SAPO) appear as one of the main materials in MMM for gas separation because the pore size of chabazite (CHA) (0.38 nm) is near the kinetic diameter of gases like H2 (0.29 nm), CO2 (0.33 nm), N2 (0.36 nm), CO (0.37 nm), CH4 (0.38 nm) and reduced crystal size improves the dispersion and decreases interfacial defects. Doping SAPO-34 are intended to increase the potential of these solids. The use of isomorphic substitution by transition metals (Fe, Ni, Co, Mn), results in materials with different acidity that differ from the original SAPO in interactions with other compounds. Besides, the addition of ionic liquids (IL) or Deep Eutectic Solvents (DES) with high affinity and selectivity to CO2, onto the particle surface and then dispersing it in a polymer membrane can enhance the separation characteristics, resulting in better permeation and selectivity properties.
- Post-treatment Modification Using Deep Eutectic Solvent in PES and PES/ SAPO-34 Membranes for Gas SeparationPublication . Cardoso, Jonathan; Lin, Zhi; Brito, Paulo; Ferreira, LicínioMixed matrix membranes (MMM) are heavily studied and the main concern by researchers is the difficulty to obtain a high selectivity membrane with low defects, mainly interfacial voids due to the poor interaction between polymer matrix and filler. The functionalization of zeolite surface in PolyEtherSulphone (PES)/ Silico-AluminoPhosphate-34 (SAPO-34) led to membranes with higher compati-bility. Recently, the use of ionic liquids in the particles surface to improve the gas permeability and separation efficiency has presented advanced results. Although, the cost and environmental issues on Ionic Liquids (ILs) still represent a limit to its use. The Deep Eutectic Solvents (DESs) present an alternative route to replace ILs, with low-cost and environmentally friend. This paper aims to study the potential use of choline chloride/urea, a DES mixture, in ratio 1:2, to replace ILs as a post-healing methodology, showing a 20% increase in CO2 permeability in PES membranes and 15% increase in CO2/N2 selectivity in PES/SAPO-34 membranes due to an increase in compatibility between polymer and zeolite promoted by the post-treatment using DES.
- Reactive Materials and Solutions Towards Treatment and Reuse of Waters with Contaminants of Emerging ConcernPublication . Silva, Adriano S.; Roman, Fernanda F.; Silva, Ana P. F.; Díaz de Tuesta, Jose Luis; Kalmakhanova, Marzhan; Snow, D.; Gomes, Helder T.Intense population growth has significantly impacted the quality and access to water, resulting in increased production and release of contaminants of emerging concern (CECs), such as pharmaceutical compounds. Catalytic wet peroxide oxidation (CWPO) is a promising technology for the removal of CECs that relies on the use of solid catalysts to accelerate the reaction, its reactivity and stability depending greatly on the catalyst used. This work aims to compare three typically studied catalysts: a clay-based, a carbon-based and a hybrid material, consisting in carbon-shell metal nanoparticle structure. Hybrid catalysts combine the benefits of metal-based catalysts (high activity) and carbon-based catalysts (low leaching), indicating to be a suitable choice. However, it is highlighted that the development of proper soludons for treatment and reuse of waters must pass through detailed identification and quantification of CECs, allowing better catalyst evaluations under real scenario conditions.