Publications

Abstract This study analyses the Portuguese Corporate Income Tax (CIT) exemption provided under Article 53 of the Tax Benefits Code (TBC). This exemption applies exclusively to entities responsible for managing integrated systems of specific waste flows, such as packaging, tyres, used oils and electronic equipment, batteries and accumulators, and end-of-life vehicles. Duly licensed under the General Waste Management Regime (WMR), these entities benefit from tax exemption on reinvested profits or those allocated to legally designated purposes. The results show that, between 2013 and 2022, this exemption was used by the eligible entities despite the amounts claimed annually being relatively modest compared to the total tax benefits granted by the Portuguese government. This may be attributed to the limited number of entities eligible, given the legal requirement for licensing under the WMR, and to the narrow scope of the benefit itself, which applies only to profits that are either reinvested or allocated to legally defined purposes. Nevertheless, this measure has the potential to contribute to the sector’s economic competitiveness, ensuring reinvestment in technology and more efficient processes, strengthening beneficiary entities’ role in promoting the circular economy and the implementation of the European Union directives for waste management. It will also specify the Portuguese tax system's ability to integrate environmental objectives into public policies, highlighting the relevance of extra-fiscal instruments in driving the green transition and supporting the achievement of the global Sustainable Development Goals (SDGs). © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.

Abstract Waste separation is a crucial step toward sustainable waste management. Understanding public perception and participation in this process is essential for its success. This study evaluates public perception and participation in the selective collection of general waste and biowaste in Guarda, Portugal, identifying key motivations, barriers, and areas for improvement. A cross-sectional analytical study was conducted using an online survey with 205 residents. Results indicate that 83.4% (95% CI: 77.9%-88.0%) of participants separate waste in the household, while workplace separation is lower (65.9%, 95% CI: 59.2%-72.1%). Paper and cardboard are the most frequently separated materials, whereas used cooking oil receives the least attention (95% CI: 16.5%-30.6%). Regarding biowaste, 92.2% (95% CI: 87.9%-95.3%) of respondents understand the concept, and all recognize its environmental benefits. However, 43.4% (95% CI: 36.8%-50.3%) are unaware of the municipal biowaste collection network, and 57.1% (95% CI: 50.2%-63.7%) find the existing infrastructure inadequate. Municipalities should expand and optimize waste collection systems to improve participation while strengthening public awareness campaigns. Social media is the preferred information channel (91.2%, 95% CI: 86.8%-94.5%), but traditional outreach methods, such as school initiatives and community meetings, could enhance engagement. Addressing infrastructure gaps and promoting consistent separation practices across different settings are key to optimizing waste management. This study highlights the need for improved public engagement and infrastructure to ensure the success of selective waste collection, particularly for biowaste, contributing to enhanced sustainability efforts in the region. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.

Abstract <jats:p>Geralmente os alunos apresentam dificuldades na aprendizagem dos conteúdos de Química, sendo necessário encontrar estratégias didáticas para minimizar essas dificuldades.</jats:p>

Abstract Haemoglobin (Hb) concentration is a key biomarker for several diseases. Traditional laboratory methods often have limitations due to their time-consuming nature, the need for skilled personnel, or the use of high-cost instrumentation. This work presents a sensing strategy for developing new point-of-care tests (POCTs) for Hb detection via a proof of concept. The proposed sensing approach is implemented using plasmonic plastic optical fiber (POF) sensor chips that integrate an electropolymerized molecularly imprinted polymer (eMIP) film on the plasmonic surface for Hb-selective detection. The developed sensor system demonstrates an ultra-low detection limit of 80 fM in buffer, about five orders of magnitude lower than that of other comparable Hb sensors. Selectivity tests against common interfering proteins, such as bovine serum albumin (BSA) and immunoglobulin G (IgG), confirmed high specificity towards the target analyte. Moreover, the sensor's performance was tested using a whole-blood sample, yielding results consistent with those of standard haematology analysis. The proposed sensor system, based on simple equipment, provides a quick (about 10 min) and cost-effective (about 10 euros per chip) label-free diagnostic tool for POCTs in real-world scenarios, such as finger-prick sampling, offering a less invasive alternative to traditional laboratory methods, towards devices useful for Internet of Medical Things (IoMT).

Abstract Stimuli-responsive surfactant self-assembly offers versatile opportunities to tailor colloidal structure and function through simple formulation strategies. Here, we report a photoresponsive catanionic vesicle system composed of the double-chained cationic surfactant didodecyldimethylammonium bromide (DDAB) and an anionic amphiphilic 2-hydroxychalcone derivative bearing a sulfonate headgroup (C8SCh). The self-assembly and phase behavior of the individual components and their mixtures are characterized, revealing a broad vesicle-forming compositional range. Notably, three molar fractions (xCh = 0.10, 0.20, and 0.80) yield dispersions composed exclusively of vesicles, enabling the formation of either positively or negatively charged vesicles using the same pair of molecular building blocks. Strong synergistic interactions between DDAB and C8SCh are evidenced by markedly reduced critical aggregation concentrations and negative interaction parameters. The incorporation of the chalcone photoswitch endows the vesicles with light responsiveness, inducing composition-dependent morphological rearrangements in both DDAB-rich and C8SCh-rich regimes. Under mildly acidic conditions (pH = 4.5), partial conversion of the chalcone to its flavylium form introduces an additional, independent stimulus that further modulates the structure of C8SCh-rich vesicles. This intrinsic charge tunability enables highly efficient, charge-selective electrostatic entrapment of both anionic and cationic molecular probes-carboxyfluorescein (CF) and doxorubicin (DOX), respectively-without the need for active loading strategies. Importantly, cargo release is selectively modulated by vesicle composition and external stimuli: light stimulation enhances the release of CF from DDAB-rich vesicles, while the combined action of acidification and irradiation significantly increases DOX release from C8SCh-rich vesicles. Overall, these results establish a simple catanionic system in which surface charge, morphology, and release behavior are jointly controlled by composition, light, and pH, offering a versatile and readily formulated platform with potential applications in controlled delivery.

Abstract <jats:p>Detection of leaks in hydrogen (H2) infrastructure is required on a large scale to enable a safe widespread use of this clean energy source. Sensing solutions must be low-cost, use scalable fabrication methods and allow multiplexed detection while providing reliable safety alarms as fast as possible. Optical methods can make this possible while avoiding the risk of ignition due to electronics at the point of detection. Metal hydride-based micro-mirror configurations benefit from a simple interrogation scheme, as long as the sensitive element can produce a large optical response. Magnesium thin films undergo a drastic variation of properties when hydrogenated, making them suitable for this application. In this work, a micro-mirror device using single-mode fibers capable of detecting the presence of H2 with a loading t10 and t90 of 1.2 and 3.0 s, respectively, is demonstrated. A complete interrogation unit was developed, presenting a solution suited for widespread deployment using industry-standard optical components and equipment.</jats:p>

Abstract The high costs of equipment and maintenance for Chemistry laboratories are a barrier to quality education in this science. However, the emergence of user-friendly and low-cost technological tools helps to mitigate this problem. This paper presents a STEM proposal for exploring distillation collaboratively in a remote laboratory with live data transmission and sharing online. The approach was analyzed by four teachers from Mozambique who, in that context, highlighted the positive potential for knowledge exchange between schools and cultures and the negative lack of technological means in schools for its implementation. They recognize great potential for implementation in higher education, as institutions have better resources. Thus, richer learning experiences can be promoted for all participants.

Abstract Student-centred learning requires a variety of approaches, such as inquiry-based learning and the tackling of authentic and problem-based learning activities, to make the teaching and learning process more meaningful and to encourage students to participate more actively in class. The inquiry approach enables students to investigate solutions to real problems, awakening their need to ask questions, design and conduct research, collect and analyse data, interpret results and present them in a structured way. This study investigates the influence of an inquiry-based science education (IBSE) module on the development of oral and written communication skills among 10th grade students. The study is set in a secondary school context and focuses on a problem-based learning approach centred around gases and dispersions. A total of 111 students participated in this one-group post-assessment qualitative study, where evaluation rubrics were applied to assess students' written and oral communication, focusing on correctness, clarity and mastery of scientific language. The results showed that the majority of students performed well in both written and oral tasks, demonstrating improved scientific communication skills. This suggests that IBSE, particularly in the context of secondary education, can be an effective approach to fostering students' abilities to communicate scientific concepts. The study has implications for enhancing pedagogical practices and encourages further research on the long-term effects of IBSE on student learning.

Abstract An acid-base titrator connected to the Internet was developed for conducting remote investigative experiments. The experiment was broadcasted in a high school senior classroom, with the presence of a facilitating teacher. The activity required students to determine the indicator present in the solution. To carry out the activity, students added acid or base to sweep the pH range from 0 to 14 and noted the corresponding coloration to the pH through video analysis. The results obtained were very satisfactory, both in the identification of the indicator and in the acceptance and engagement of the students in the activity.

Abstract Educators cannot overlook the affect's potential for students’ educational success. In this study, affective analogies are proposed as a didactic resource to foster students’ affect for chemistry learning and positive attitudes towards the physics-chemistry subject. To examine the influence of the affective analogies on it, we grouped contents of this subject into three modules (Kinetic-molecular theory; Quantum model of the atom; Chemical elements and their isotopes) and developed analogies between chemistry and music for each (affective analogies), which were then compared to homologous undifferentiated analogies (familiar analogues without affective qualities in addition) and teaching strategies without analogies. An explanatory mixed-method design was used. Data were collected through questionnaires and interviews, with a convenience sample of 147 students attending the 7th grade of a middle school music course. The results show that the affective dimension of analogies promotes positive affect for learning at much higher levels than the familiar dimension. We proposed a mechanism through which this occurs. However, if analogies are familiar, it seems that their positive affective dimension is not as important for students’ learning levels. More than interesting, analogies should perhaps be non-aversive. As for attitudes towards physics-chemistry, teaching with affective analogies is the most beneficial strategy. This results from students’ perception that this teaching approach promoted positive affect for the study of physics-chemistry, compared to undifferentiated analogies and without analogies. Furthermore, it favoured learning and achievement in physics-chemistry, compared to the absence of analogies, because without analogies it is more difficult to understand abstract or difficult concepts. © 2025 Fırtına Akademi A.Ş. All rights reserved. This article published by TUSED is released under the CC BY-NC-ND license.