Publications

Abstract Chemical recycling can be used to separate fibers that are constituents of different types of fabrics. This type of process can be considered one of the most effective forms of recycling, given that a large part of fabrics is made up of fiber mixtures. As part of an innovative circular strategy, the main goal of this work was to study the conditions for extracting cellulose from mixed textile wastes by acid hydrolysis and further transform it into cellulose derivatives, thus contributing to reduce such wastes and expanding the possible sources of cellulose. Our work covers a wide range of textile wastes and addresses the main technical challenges of this recycling methodology. The percentage of recovered cellulose powder varies between 65 and 88%. To evaluate the feasibility of using the extracted cellulose as raw material to produce cellulose derivatives, two strategies were applied: etherification to obtain sodium carboxymethylcellulose (with degree of substituion between 0.27 and 0.61) and esterification, to obtain cellulose acetate (with degree of substituion of 2.59). The cellulose derivatives obtained are very useful as additives in the textile industry, and hence the concept and practice of a circular economy are promoted.

Abstract This paper focuses on developing and assessing a non-obtrusive and transformative method, based on virtual reality, to evaluate science communication projects in science centres. The method was tested using deep-sea cutting-edge scientific content. We applied a mixed design, with 72 adult participants randomly assigned to experimental conditions (with/without exhibition exposure). Results showed that the exhibition promoted a better understanding of science. The non-obtrusive measures on awareness and engagement were positively related with questions posed via questionnaire and interview. The study adds theoretical and empirical support to the design and implementation of non-obtrusive and transformative evaluation experiences in science exhibitions in science centres and museums.

Abstract This paper examines the relationship between science and religion in the education system of Roman-Catholic Portuguese society. In particular, we explored perceptions of the relationship between science and religion for religious education teachers. We surveyed 198 Portuguese religious education teachers about how they view science and religion. The questionnaires' results revealed a number of similarities: religious education teachers are highly involved in religious practices and exposed to science; they perceived a compatibility between science and religion; and they have an openness to dialogue between both. They do not adhere to anti-scientific perspectives, but they simultaneously try to limit what can be explained by science. Thus, an interpretative view of dialogue and/or integration seems to best explain the perceptions of religious education teachers of the relationship between science and religion. These findings allow a space of discussion, enabling teachers to possibly foster the science-religion dialogue in their contexts of pedagogical activity.

Abstract The focus of this work is the establishment of energetic-structural correlations of compounds containing a pentagonal heterocyclic ring with different substituents, and consequent contribution on the assessment of their thermodynamic stability and a thorough insight on the thiol-thione tautomeric equilibrium. In this work we report an experimental and computational thermochemical study of three mercaptothiadiazoles: 2-mercapto-1,3,4-thiadiazole, 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,5-dimethyl1,3,4-thiadiazole. The experimental data were determined mainly from calorimetric techniques and from effusion method. Thermochemical properties such as the enthalpies of formation, both in crystalline and gaseous phases, the enthalpies of fusion and of sublimation of each compound, as well as the Gibbs energies of formation were derived. Thus, the methyl-substituted thiadiazole is the more stable species in both gaseous and crystalline phases. In addition, quantum chemical calculations were carried out for those isolated molecules. This approach confirms the thione form as the predominant tautomer for the mercaptothiadiazoles. Finally, the activation energies of the tautomeric equilibrium of the mercaptothiadiazoles were calculated in the gas-phase, aqueous and dimethylsulfoxide solutions, showing that the thiol ? thione single hydrogen transfers are quite unfavourable reactions in gas phase and in a presence of polar solvents. (c) 2021 Elsevier Ltd.

Abstract <jats:p>The use of digital games as support tools for education has proven to be effective. To explore their potential, it is crucial to design them carefully. This chapter considers the design of games for education, where players cultivate their knowledge and practice their skills by multiplying numerous hindrances during gaming. Educational elements are integrated into the gameplay, which players acquire while playing. The game's effectiveness depends on the players' ability to form a cheerful and encouraging environment to continue playing while increasing their interest in gameplay and improving academic performance. Following a design-first development approach, an innovative proposal for this design is presented, adding a new dimension to the game's tetrad: learning dynamics. Benefiting from years of professional practice, this game pentad design framework fulfills the learning and user experience requirements while overcoming the design limitations of more conventional approaches not based on an educational purpose. </jats:p>

Abstract Recently, new data about deep-sea ecosystems has stirred scientific, economic, and ecological agendas, but little is known about the public’s perspectives of the deep sea. Our goal is to explore the public’s common sense knowledge of the deep sea, with a view to inform science communication efforts. Based on social representations theory, we investigated the relationship between the public’s meanings associated with the deep sea and psychosocial and positional variables, such as attitudes and education level, and reflected on the implications of the findings for science communication. The study was conducted in Portugal, a coastal, sea-connected country. The sample consisted of 315 adults from different age groups and social strata. Participants were asked to elicit and rank their thoughts about the deep sea using a ranked association technique and fill in questions about sociodemographic information, perceptions, and attitudes concerning the deep sea. Results showed that the social representations of the deep sea were structured as emotional versus rational views and as superficial ocean knowledge versus novel or unusual views. Moreover, results evinced a relationship between representations and psychosocial and positional variables. The gap between scientific and common sense knowledge was evident amongst participants with a low education level and low science engagement, whilst highly educated and science-engaged participants’ representations seemed to be narrowed by instrumental views on science. This research is significant to better directing science communication to increase well-informed public participation in decision-making related to deep sea management and other socio-scientific issues by responding to audience’s background knowledge.

Abstract The determination of the reliable thermodynamic properties of 2-benzoxazolinone derivatives is the main goal of this work. Some correlations are established between the energetic properties determined and the structural characteristics of the title compounds, and the reactivity of this class of compounds is also evaluated. Static-bomb combustion calorimetry and high-temperature Calvet microcalorimetry were used to determine, respectively, the standard molar enthalpies of formation in the solid state and the standard molar enthalpies of sublimation, both at T = 298.15 K. Using the results obtained for each compound, the respective gas-phase standard molar enthalpy of formation was derived. High-level quantum chemical calculations were performed to estimate the same property and the results evidence good accordance. Moreover, the gas-phase relative thermodynamic stability of 2-benzoxazolinone derivatives was also evaluated using the respective gas-phase standard molar Gibbs energy of formation. In addition, the relationship between the energetic and structural characteristics of the benzoxazolinones is presented, evidencing the enthalpic increments associated with the presence of a methyl and a nitro groups in the molecule, and this effect is compared with similar ones in other structurally related compounds.

Abstract An experimental study based on the thermal analysis of 5-methyl-1H-benzotriazole and 5,6-dimethyl-1H-benzotriazole was developed, by using differential scanning calorimetry. Additionally, a summary of the experimental techniques and computational methodology being performed, in order to complement the energetic study of both compounds, is described. The knowledge of the thermochemical, thermophysical and structural properties of functionalized benzotriazoles is relevant for the evaluation of their chemical behaviour, as well as in the prediction of the reactivity of similar compounds that have not been thermodynamically characterized. © 2022, Universidade do Porto - Faculdade de Engenharia. All rights reserved.

Abstract Scientific literacy is an important skill for students' success, given the characteristics of today's society. However, not all students have a natural predisposition toward science, chemistry in particular. Considering the relevance of transdisciplinary learning, schools should foster the scientific abilities for which students may have less aptitude or interest by taking advantage of areas and subjects that they have more inclination and knowledge. The use of analogies through comparisons between familiar and unfamiliar domains can potentiate the learning of abstract, unknown, or complex chemistry concepts. This article describes a case study regarding the use of a marching band analogy that was developed to teach kinetic-molecular theory. The study involved a convenience sample of 50 Portuguese seventh grade students attending a middle school music course, from four specialized music education schools. Data was collected through a questionnaire and an interview. Results reveal that the marching band analogy for kinetic-molecular theory, considering the students' profile, is didactic and suitable, enhances their attention and interest, and promotes their chemistry learning. In order to benefit chemistry education, we recommend the development and use of analogies between chemistry and music with students of similar profiles or the use of different areas and subjects for other student profiles.

Abstract The active participation of citizens in scientific research, through citizen science, has been proven successful. However, knowledge on the potential of citizen science within formal chemistry learning, at the conceptual and procedural levels, remains insufficiently explored. We developed a citizen science project - PVC: Perceiving the Value of Chemistry behind water and microplastics - which sought to involve students in monitoring the physicochemical parameters of coastal water quality, through the detection of microplastics in these waters, in addition to the qualitative identification of plastic contaminants on beaches. The project was conducted throughout the 2018/2019 school year and involved 442 middle school students (Key Stage 3 (KS3) aged 12-14, in Portuguese schools) and 9 chemistry teachers, in the northern coastal region of Portugal. The data on learning outcomes was collected through knowledge tests, applied after project conclusion, and was then compared to data collected up to six months later (retention test). In addition, interviews were conducted with participants, and researchers' field notes were recorded and analyzed. Data analysis suggests the PVC project promoted conceptual chemistry learning related to the analysis of physicochemical water parameters (pH, temperature, turbidity, salinity, nitrate and nitrite concentrations and dissolved oxygen), as well as polymers (polymer types, formation and structure). A positive knowledge retention was registered a few months after the project conclusion. At a process level, participants learned laboratory techniques (sieving, gravity and reduced pressure filtrations and crystallization) and the handling of laboratory materials. Furthermore, teachers recognized that their students' participation in the PVC project fostered the development of their argumentation skills, as well as their reflexive and critical thinking skills. The ability to communicate ideas and results, along with the development of students' digital skills, was also mentioned.