CIMO - Artigos em Revistas Indexados à WoS/Scopus
URI permanente para esta coleção:
Navegar
Percorrer CIMO - Artigos em Revistas Indexados à WoS/Scopus por Objetivos de Desenvolvimento Sustentável (ODS) "11:Cidades e Comunidades Sustentáveis"
A mostrar 1 - 6 de 6
Resultados por página
Opções de ordenação
- Comprehensive assessment of PM10 from home heating using different appliances and biomass fuels: Chemical composition, oxidative potential, and ecotoxicityPublication . Cipoli, Yago Alonso; Vicente, Estela D.; Charres, Isabella; Evtyugina, Margarita; Alfosea-Simón, Marina; Lucarelli, Franco; Kováts, Nora; Ryšavý, Jiří; Feliciano, Manuel; Alves, CéliaThe European Union has implemented policies to promote renewable energy, with an emphasis on biomass for heat generation. However, residential biomass combustion is a major source of particulate matter (PM10), and its chemical constituents pose health concerns worldwide. This study characterised the organic and inorganic composition, oxidative potential (OP), and ecotoxicity of PM10 indoors and outdoors during the operation of two heating appliances fuelled with different types of biomasses: a modern hydronic stove and a traditional wood stove. PM10 concentrations were higher in the room equipped with the traditional system during the combustion of briquettes (95.9 f 74.9 mu g m-3) and firewood (50.1 f 25.6 mu g m- 3), compared to the modern stove using pellets (27.1 f 11.8 mu g m-3) and olive stone (23.0 f 4.5 mu g m- 3). While element oxides accounted for similar PM10 mass fractions (7 %), the wood stove produced higher levels of organic constituents, including carbonaceous fractions, polycyclic aromatic hydrocarbons (PAHs), quinones and saccharides. Significant correlations between OP assays and concentrations of PAHs, quinones and phenolic compounds were found in the room equipped with wood stove, with indoor to outdoor (I/O) ratios higher than 1. In contrast, I/O ratios below 1 were observed for OP in PM10 samples collected during hydronic stove operation. Ecotoxicity assays using Aliivibrio fischeri classified indoor PM10 from the wood stove as 'very toxic', whereas samples from the hydronic stove exhibited lower toxicity and OP levels. These findings highlight the need to reconcile renewable energy goals with air quality and public health.
- A comprehensive mechanical and physico-chemical characterization of fly ash-based geopolymersPublication . Silva, Ana P. F.; Natal, Ana Paula S.; Oliveira, Isaac; Bezerra, Ana J.B.; Baldo, Arthur P.; Silva, Adriano S.; Diaz de Tuesta, Jose Luis; Peres, José A.; Ferreira, Débora; Gomes, Helder T.This work focuses on developing a predictive optimization method for geopolymer concrete, addressing both mechanical strength and water absorption. Despite numerous formulations proposed in the literature, no systematic method has been established to evaluate these properties simultaneously. This research addresses this gap by employing a Design of Experiments approach to systematically explore the effects of key variables such as NaOH molar concentration, sodium silicate-to-sodium hydroxide ratio, and alkaline solution-to-fly ash ratio. After 28 days, geopolymer concrete exhibits competitive compressive strength (geopolymer concrete: 25 MPa, reference Ordinary Portland concrete: 27 MPa), and after 365 days, its compressive strength surpasses that of traditional Ordinary Portland concrete (geopolymer concrete: 56 MPa, reference Ordinary Portland concrete: 27 MPa). Moreover, through Response Surface Methodology, an optimization model indicates that geopolymer concrete compressive strength can reach up to 64 MPa, with a strong influence from the alkaline solution-to-fly ash ratio. Additionally, the materials were characterized in terms of crystalline phases, surface chemistry, thermal stability, and surface area to gain a deeper understanding of the behaviour of these materials.
- Effect of melatonin implants on carcass characteristics and meat quality of slow-growing chickensPublication . Nieto, Jaime; Leite, Ana; Vasconcelos, Lia; Plaza, Javier; Abecia, José-Alfonso; Revilla, Isabel; Palacios, Carlos; Teixeira, AlfredoThis study evaluated the effect of melatonin implants on carcass characteristics and meat quality of slow-growing broilers slaughtered at 43 and 97 days (d) of age. A total of 128 one day-old male broilers (Coloryeld) were randomly divided into two groups, which in turn were divided into 8 groups (replicates) of 8 broilers each one. One group (64 animals) was the control group (C) and the other received a melatonin implant (18 mg melatonin per animal) at 8 d of age (M). The animals were reared for 97 d. For the first 42 d they were kept in an enclosed facility and then allowed access to the outside. Two culls were performed: one at 43 d and one at 97 d, randomly selecting 8 chicks from each group at each time (N = 8 × 2 × 2= 32). Carcass traits and meat quality were evaluated on these samples. Chickens slaughtered at older ages had higher dead-plucked, leg and carcass weights (P < 0.05). In terms of meat quality, chickens slaughtered at 97 days had higher L* (P < 0.001), lower a*, b* and chroma values (P < 0.01), as well as lower pH (P = 0.006), higher shear strength (P < 0.001), water holding capacity (P < 0.001) and water activity (P = 0.036). The melatonin implants did not influence carcass characteristics (P>0.05). Luminosity, tone and water activity decreased with melatonin implants at 43 d of age (P <0.001), whereas pH increased (P = 0.004). At 97 d after slaughter, meat yellowness was lower (P = 0.028) and firmness increased (P = 0.029). At both time points, melatonin caused reddening of the meat (P < 0.001). Lipid oxidisability tended to be reduced, extending the shelf life of the meat (P = 0.068). The fatty acid profile was little affected by the placement of the implants. Age and melatonin have different effects on the meat quality of slow-growing chickens. While age affects several factors such as texture and fatty acid profile, melatonin improves colour, water activity and lipid oxidation. Its use could improve preservation and extend the shelf life of meat
- First long-term air quality assessment in Luanda, Angola: Performance evaluation of a low-cost monitoring station against reference equipmentPublication . Silva, Alan Victor; Furst, Leonardo; Cipoli, Yago A.; Soares, Marlene J.S.; Leitão, Anabela G.A.; Feliciano, Manuel; Alves, Célia A.Low-cost air quality monitoring stations (LCMS), which integrate sensors for gases and particulate matter (PM), offer an economical solution for expanding monitoring networks. However, their reliability requires validation, particularly in rapidly urbanising regions with limited infrastructure. This study presents the first long-term, continuous, multi-pollutant air quality assessment in Luanda, Angola - where no monitoring stations currently exist - by evaluating the performance of an LCMS against reference-grade equipment. Daily averages, correlation metrics (R-2, RMSE), and a hybrid Bland-Altman/regression analyses were used to evaluate the agreement. Results indicated strong correlation for CO (R-2 = 0.96; RMSE = 0.24 ppm) and good for NO2 (R-2 = 0.81; RMSE = 6.35 ppb), although limitations near detection limits were noted. Significant challenges were identified in O-3 measurements (R-2 = 0.77, RMSE = 7.13 ppb), primarily due to strong cross-sensitivity to high ambient NO2 levels and potential sensor ageing. For PM10 and PM2.5, although good linear correlations (R-2 similar to 0.82) were observed with reference methods, the LCMS exhibited considerable systematic bias (RMSE over 46 mu g/m(-3)) and consistently underestimate concentrations. The study also registered frequent and severe exceedances of WHO AQG and EU standards for PM10, PM2.5, and NO2, underscoring significant public health risks. Despite limitations, particularly for O-3 measurements and biases in PM data, the LCMS demonstrates potential as a cost-effective tool to complement reference networks, enhance spatial monitoring coverage, identify pollution hotspots, and support air quality management in resource-constrained settings, since continuous calibration and validation procedures are implemented to mitigate measurement uncertainties.
- PM10-bound elements in Luanda's urban atmosphere: Concentrations, sources, and their environmental and health impactsPublication . Alves, Célia A.; Campa, Ana Sanchez de la; Cipoli, Yago; Furst, Leonardo; Higawa, Gustavo; Leitão, Anabela; Silva, Alan Victor; Feliciano, ManuelAn unprecedented study was carried out in the megacity of Luanda, Angola, involving daily sampling of particulate matter (PM10) from June to November 2023. The analysis was focused on the detection of 56 metal(loid)s and complemented by the application of several contamination and health risk indices. PM10 levels ranged from 23.6 to 108 μg/m3, averaging 59.3 μg/m3, exceeding WHO’s 24-h guideline on 83% of days. In addition to crustal elements, the most abundant constituents were Zn (159 ng/m3), Ba (43.2 ng/m3), Pb (17.8 ng/m3), Cu (10.5 ng/m3), Sr (7.0 ng/m3), Ni (4.5 ng/m3), Sb (3.7 ng/m3) and Cr (3.5 ng/m3). Mineral dust, primarily from unpaved roads and local soils, accounted for 31 wt% of PM10, while sea salt contributed 6%. Geochemical markers (e.g., Ce-La-V relationships) suggest that vanadium originates predominantly from upper crust weathering. Elemental ratios such as Fe/Cu, Cu/Sb, and Zn/Sb indicate significant contributions from traffic-related emissions (e.g., brake and tyre wear) and industrial sources. Sulphur, an important PM10 component, likely stems from fossil fuel combustion and petroleum refining. Luanda experiences severe air pollution, with high inputs from Sb, Cd, Zn, and other elements linked to traffic, industrial emissions, and biomass burning. The extremely high ecological risk (RI = 4360 ± 2440) highlights critical contamination, driven primarily by Cd and Sb, while the Nemerow risk index (1990 ± 1530) underscores urgent public health concerns. Non-cancer hazard indices (HI) exceeded safe thresholds for children (2.29) and adults (2.18), with Fe, Mn, Be, Pb, Ni, Co, and Sb identified as key contributors. Carcinogenic risks from PM10 inhalation (2.34 × 10 3 for children and 1.36 ×10 3 for adults) also exceeded acceptable levels, emphasising the need for targeted pollution mitigation strategies.
- School air quality and thermal comfort: a multi-pollutant seasonal assessmentPublication . Charres, Isabella; Furst, Leonardo; Furst, Leonardo; Vicente, Estela D.; Soares, Marlene; Viegas, Carla; Cervantes, Renata; Cerqueira, Mário; Pena, Pedro; Feliciano, Manuel; Alves, CéliaAs evidence of children's vulnerability to air pollution grows, research on school air quality has increased significantly in the 21st century. Given the complex factors influencing indoor and outdoor air quality in schools, each study offers valuable insights. This study contributes by assessing particulate matter, gaseous pollutants, thermal comfort and microorganisms in a large school encompassing different education levels over two seasons. The assessment combined passive and continuous sampling using various techniques, including chromatography and estimations of air change and ventilation rates. Classroom ventilation was insufficient to ensure adequate air renewal. During class hours, CO2 concentrations ranged from 760 to 1,118 ppm in winter and from 807 to 1,022 ppm in spring, repeatedly exceeding 1,000 ppm. CO2 and PM10 concentrations were significantly higher during school hours than when the classrooms were empty, indicating the strong influence of school activities. In contrast, PM1 and PM2.5 concentrations were more influenced by external factors, especially outside of school hours. The lack of thermal comfort created an unhealthy environment. Carbonyl concentrations were higher in classrooms (average: 68.8 mu g m-3) compared to the schoolyard (3.86 mu g m-3), in both seasons. Microbial analysis revealed the presence of fungi with toxigenic potential, with the highest fungal diversity observed in spring. These findings highlight that while some pollutant levels may appear low, they can occasionally reach extremely high levels, even in newer buildings. The novelty of this research lies in demonstrating that, despite recent improvements and numerous studies, significant progress is still needed to ensure healthier school settings.