Design and evaluation of a chemistry subject in an engineering degree

The beginning of a new Degree at UPC was the opportunity to design a Chemistry subject from the start. It was designed under the criteria of focusing the process on student learning, following the indications of the last meeting of the European Higher Education Area in Rome, November 2020. The objective of the design was to comply with the regulatory requirements and incorporate the learning outcomes that were already defined in other engineering areas, as well as to facilitate the learning of students who had not studied chemistry in high school (between 20 and 30%). To this end, videos have been created with embedded questions, tests, summary preparation criteria, various cooperative work methodologies, ... to which part of the subject's grade (10%) has been assigned in order to facilitate student commitment to weekly completion. Each academic year (3 normal and one in confinement have been developed) an assessment has been made with the students, both of the methodology and the material. In all cases, they reflect that continuous work and immediate or very close feedback is one of the points that has helped them the most in their process. They have also commented (in each academic year) on possibilities for improvement in which they have been directly involved and have helped to bring it to completion. The material is currently ready to be made public on the University website and accessible to all students

AVALQUIM: herramienta autoaprendizaje de química

La web de avalquim está diseñada para facilitar la autoevaluación y el autoaprendizaje de alumnos de Química de primeros cursos: • autoevaluación: resolución de exámenes generados de forma aleatoria. Los exámenes están compuestos por un número fijo de problemas catalogados como "problemas de autoevaluación". Una vez resuelto el examen se ofrece la solución y la nota obtenida. • autoaprendizaje: resolución de problemas de forma consecutiva. Una vez resuelto uno se ofrece la solución y la opción de continuar resolviendo más hasta que el alumno quiera. Los problemas utilizados están catalogados como "problemas de autoaprendizaje". La clasificación es, por tanto: problemas de autoevaluación y de autoaprendizaje (también llamados problemas pautados). La diferencia entre unos y otros es que los segundos (autoaprendizaje) disponen de una serie de pautas (o pistas para la resolución) mientras que los primeros no. Ambos tipos de problemas se extraen de un repositorio común de problemas que ofrece la web y que ha sido previamente creado a través de las herramientas de que se dispone, con una colección de más de 1000 problemas en este momento. En estos momentos se está trabajando en ampliar el repositorio de problemas pautados y en contextualizarlos, desde un punto de vista medioambiental y de conexión con la realidad profesional

Science and technology: interest and attitude of teenagers based on data from the ROSES project

El proyecto ROSES es un estudio comparativo internacional que profundiza en el interés y la actitud que muestran las y los adolescentes hacia la ciencia. El instrumento utilizado es un cuestionario validado con 188 ítems. En el presente artículo se presentan los resultados obtenidos en la categoría “Mis clases de ciencias”. Han participado 1316 estudiantes de la ESO de 15 centros escolares durante 2020-2021 de Cataluña y Andorra. Realizado un análisis estadístico de los resultados diferenciando por sexo, se observa un ligero aumento en el interés por la ciencia y sensación de la ciencia como materia difícil respecto al inicio del siglo XXI (Proyecto ROSE, 2002) tanto en chicos como en chicas. Existen diferencias significativas (a=0.05) entre chicos y chicas, en 8 respuestas de los 12 ítems estudiados.Peer ReviewedPostprint (published version

Thermo-mechanical and antioxidant properties of eugenol-loaded carrageenan-cellulose nanofiber films for sustainable packaging applications

This study aimed to investigate the thermomechanical and antioxidant properties of an active film composed of carrageenan and cellulose nanofibers incorporating (0.1%v/v–0.5%v/v) eugenol (Eu), intended for active packaging applications. The mechanical, physical, morphology, and thermal properties of the active film were extensively characterized, and the antioxidant activity was monitored over a 34-day-storage period. Broido's model was employed to assess the thermomechanical properties and activation energy of the films towards the Eu structure in carrageenan and cellulose nanofiber film. The findings revealed that the addition of Eu had a negative impact on the activation energy of the film's decomposition while positively affecting the release of antioxidants during storage. The film containing 0.4% Eu demonstrated optimal physical and mechanical characteristics, including a tensile strength of 38.08 ± 2.06 MPa and elongation at break of 21.95% ± 9.02%. Furthermore, the SGC-0.4% (SGC stand for Semi refined carragenan + Glycerol + Cellulose nanofiber) Eu film exhibited a higher activation energy (365.82 kJ/mol), suggesting enhanced stability and durability compared with other films. The film with 0.4% Eu content showed the highest release rate of polyphenols (614.9290 mg gallic acid/L sample) up to 28 days of storage. Additionally, it exhibited a 58% efficiency of radical scavenging activity. Overall, these results highlight the potential of the SGC-0.4% Eu film as a biodegradable packaging solution that offers prolonged food shelf life

Synthesis of active hybrid films reinforced with cellulose nanofibers as active packaging material

Active packaging films derived from renewable biopolymers with an antioxidant formulation are a promising alternative in prolonging food shelf life. This study aimed to develop active hybrid films from semi-refined carrageenan, plasticized with glycerol, incorporating α-tocopherol, and enhanced with cellulose nanofibers derived from empty fruit bunch as reinforcing agents for improved film function in active packaging. The active hybrid films were characterized for their properties, and the release of antioxidant α-tocopherol was observed in food simulant and fresh meat. The application of the active hybrid films reinforced with cellulose nanofibers as active packaging for food products is presented

GREDIQ-RIMA: The evolution of a teaching project of experimentation in chemistry

Authors of this project belong to the Resources Chemistry Teaching Group (GReDiQ) involved in RIMA (Research and innovation in learning methodologies). The audiovisual and multimedia material productions realized have been grouped into three themes: Basic Techniques of Experimentation in Chemistry, Safety in Chemistry Laboratories and Advanced Techniques of Experimentation in Chemistry. This work has been awarded a prize of the Universitat Politècnica de Catalunya (UPC–BARCELONATECH), one of the Autonomous Region of Catalunya and another one of a State scopePostprint (author’s final draft

Material docent en format digital per a assignatures d'experimentació en química

En aquesta comunicació es presenta un projecte elaborat arran de l’interès mostrat per un grup de professorat en disposar de material audiovisual propi i comú per a assignatures experimentals de química de diferents titulacions impartides per diferents centres de la Universitat Politècnica de Catalunya (UPC). Els autors d’aquest treball pertanyen al Grup de Recursos per a la Didàctica de la Química (GReDiQ), integrat en el projecte RIMA (http://www.upc.edu/rima) de l’Institut de Ciències de l’Educació de la UPC. L’elaboració de material audiovisual digital constitueix un dels objectius principals plantejats pel GReDiQ i pretén generar tant un material de suport per a les activitats pre-laboratorio, com un element motivador i que faciliti l’aprenentatge de l’alumnat en les sessions de laboratori de les matèries de Química i Enginyeria química, que apareixen com assignatures de formació bàsica en gairebé tots els plans d’estudi dels nous Graus d’Enginyeria que s’ estan implantant a la UPC. La utilització del material audiovisual digital possibilita que l’alumnat prengui consciència de les activitats de laboratori, així com dels hàbits bàsics de manipulació i seguretat en el laboratori, del fonament d’operacions bàsiques o instrumentació a utilitzar.Peer Reviewe

L’evolució d’un projecte de millora de la docència

Peer Reviewe

Material docente en formato digital para asignaturas de experimentación en química de la UPC

Postprint (published version

Antioxidant and Antiradical Activities of <i>Hibiscus sabdariffa</i> L. Extracts Encapsulated in Calcium Alginate Spheres

The interest in natural sources with high antioxidant powder has recently increased in several sectors. Ionic gelation methods could be used to protect bioactive substances to control the kinetics and release of these ingredients to the food matrix. This study dealt with the evaluation of the antioxidant capacity and scavenging activity of extracts of Hibiscus Sabdariffa L. (HSL) (with 50% ethanol) encapsulated in calcium alginate spheres as a new source for preserving food against oxidative damage. Their antioxidant activity was measured in different o/w emulsions in which HSL spheres reduced the formation of hydroperoxides (~80%) and thiobarbituric-acid-reactive substance products (~20%). The scavenging activity of HSL extracts was measured in different food simulants (water, water acidified with 3% acetic acid, ethanol at 50%, and pure ethanol), and corresponded to 0.20–0.43, 0.31–0.62, and 11.13–23.82 mmol Trolox/mL extract for Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenylpicrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, respectively. In general, the best antiradical activity was observed in the ethanolic and acidified mediums, in which the highest concentration of released polyphenols ranged from 0.068 to 0.079 mg GAE/mL. This work indicates the potential of alginate spheres for encapsulating antioxidant compounds as an innovative strategy for several industrial applications