Samuel Antonio Rosas-Meléndez

The effectiveness of the use of PhET educational simulators as didactic tools in the teaching of physics concepts was evaluated, comparing their effects on motivation and self-efficacy in engineering students when performing traditional laboratory practices since their impact on STEM disciplines, commitment, and understanding are crucial for academic success. The sample consisted of 236 first-year students divided into an experimental group using simulators and a control group that performed the practices in the physics laboratory. The Reduced Instructional Materials Motivation Scale (RIMMS) and the self-efficacy subscale of the MSLQ, translated and validated in Spanish, were used. The results showed that the experimental group exhibited a significant increase in motivation. No statistically significant differences were found in self-efficacy, suggesting that its impact on this aspect is limited and possibly requires more activities with simulators. This study concludes that simulators can complement and improve traditional practices, especially to increase student motivation.

El siguiente artículo expone un estudio cuasiexperimental para medir el impacto de la realidad aumentada (RA) en el aprendizaje de alumnos que cursan el segundo semestre de Física en la Universidad Nacional Autónoma de México (UNAM) y del primer semestre de Ingeniería en el Instituto Tecnológico y de Estudios Superiores de Monterrey (TEC), Campus Santa Fe. En ambas poblaciones, se midió la ganancia en el aprendizaje (g), mediante la escala de Hake, aplicando una prueba de conocimientos teóricos en dos prácticas de laboratorio, antes y después de usar esta herramienta. También se llevó a cabo una encuesta con el objetivo de medir el interés por el uso de esta tecnología en clase y se verificó su confiabilidad: los resultados muestran que hubo una mejora en el aprendizaje al utilizar RA como herramienta de apoyo teórico durante las clases. Luego de esta experiencia, en los estudiantes se observó un aumento de su atención en clase y de su interés por la asignatura, lo que seguramente los enriquecerá con una innovadora manera de aprender.

The increment in water pollution due to the massive development in the industrial sector is a worldwide concern due to its impact on the environment and human health. Therefore, the development of new and sustainable alternatives for water remediation is needed. In this context, aerogels present high porosity, low density, and a remarkable adsorption capacity, making them candidates for remediation applications demonstrating high efficiency in removing pollutants from the air, soil, and water. Specifically, polymer-based aerogels could be modified in their high surface area to integrate functional groups, decrease their hydrophilicity, or increase their lipophilicity, among other variations, expanding and enhancing their efficiency as adsorbents for the removal of various pollutants in water. The aerogels based on natural polymers such as cellulose, chitosan, or alginate processed by different techniques presented high adsorption capacities, efficacy in oil/water separation and dye removal, and excellent recyclability after several cycles. Although there are different reviews based on aerogels, this work gives an overview of just the natural biopolymers employed to elaborate aerogels as an eco-friendly and renewable alternative. In addition, here we show the synthesis methods and applications in water cleaning from pollutants such as dyes, oil, and pharmaceuticals, providing novel information for the future development of biopolymeric-based aerogel.

The study of Chemistry is unpopular to students because their lack of connection to their daily life. Project-based learning in a laboratory environment have shown to change the students' perception. In this work in progress, a methodology is presented where the students relate their Chemistry laboratory course with the project of brewing beer. The objective is to observe how the implementation of the project influences the perception of the students taking the course. A pre-experimental research was designed and implemented with a sample of 29 students of the First-Undergraduate Year for different bachelor degrees in Engineering. The students related some concepts shown during the class with some steps of the process of brewing beer. They also got the experience of speaking with experts that work in the field. Three stages of the project are presented and described. The results, measured by the Institutional Opinion Survey of the Student and the comments the students, show that the teaching methodology satisfies the expectations of the students. As a future work, it is proposed to implement a control group in order to compare the experience of the students in the same course. We also propose to include other variables of analysis and to use a broader instrument of measurement in order to perform parametric statistical tests.

Double‐helix microstructures consisting of two parallel strands of hundreds of multi‐walled carbon nanotubes (MWCNTs) have been synthesized by chemical vapour deposition of ferrocene/toluene vapours on metal substrates. Growth of coiled carbon nanostructures with site selectivity is achieved by varying the duration of thermochemical pretreatment to deposit a layer of SiO_x on the metallic substrate. Production of multibranched structures of MWCNTs converging in SiO_x microstructure is also reported. magnified image In the abstract figure, panel (a) shows a coloured micrograph of a typical double‐helix coiled microstructure of MWCNTs grown on SiO_x covered steel substrate. Green and blue show each of the two individual strands of MWCNTs. Panel (b) is an amplification of a SiO_x microparticle (white) on the tip of the double‐stranded coil (green and blue). The microparticle guides the collective growth of hundreds of MWCNTs to form the coiled structure.