Two-dimensional films of graphene oxide (GO) have been synthesized using various oxidation methods such as the conventional or modified Hummers method. The redox method for graphite has shown promise at producing GO films on a large scale. However, this method is a very exothermic process that liberates gases that are harmful to the environment and humans. This article addresses the characterization of graphene oxide from alternative sources of carbon and using the dry method. Comparative studies performed using Raman spectroscopy suggest that this method is both promising and more environmentally friendly.

The current work aimed to produce acrylonitrile butadiene styrene (ABS) filament with cellulose microfibers additive for three-dimensional (3D)-printing and perform initial mechanical characterizations. 3D printing is a Fourth Industrial Revolution enabling technology aimed at smart production process. Cellulose is an organic molecule extremely common in nature with potential application as materials reinforcement. Highly crystalline cellulose microfibers were extracted from certified Eucalyptus grandis wood. E. grandis is a species native to Australia, but widely used in reforestation initiatives on a global scale. Cellulose microfiber was inserted at 0.5% in weight into commercial ABS to produce filaments for 3D printing. After the production of pure ABS and ABS with microcellulose filaments, specimens were printed using fused deposition modeling for traction, flexion, and impact tests, in addition to measuring the melt flow index. The results between the two materials were compared, revealing that most of the mechanical properties were similar within the limits of experimental errors, but the strain at break in the traction test was improved in microfibers composite, in addition to an improvement in the elastic modulus and stress at break in flexion test. On melt flow index measurement, both materials were found to be considerably more fluid than the polymer from commercial producer sources. This is an indication that the ABS degraded throughout the process, losing molar mass. However, our work demonstrated that it is possible to add highly crystalline cellulose microfibers to ABS to form filaments for 3D printing.

Three different processes for the synthetization of exfoliated graphite intercalation compound have been tested in two different type of graphite, one in powder form and the other one as flakes. Each graphite was oxidized applying the same experimental conditions (sonification, neutralization, filtering and drying) but using three different auxiliary oxidizers (H2O2, HNO3 and KClO3) previously mixed with H2SO4. The resulting synthesized samples were characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. The Raman spectra analysis of the oxidized samples correspond to that of a graphene of few layers. Stronger delamination and exfoliation were observed in the samples of graphite, originally in powder form, treated with H2SO4/HNO3.

La utilización de los sistemas multimedia en la educación, responde a una nueva concepción en la enseñanza como un proceso no lineal, y a la integración de texto, imágenes y sonido, habitualmente bajo el control de un ordenador. Debido a las aportaciones de la multimedia y la forma en que se aprovecha e integran diversos medios, para transmitir información; se diseñó y creó un sistema interactivo multimedia utilizando las siguientes herramientas para producción multimedia como: Neobook 5.7, Fireworks, Flash y Astro Flash Creator. El sistema está formado por una pantalla de inicio, la cual nos enlaza al menú principal del sistema multimedia, la pantalla de menú principal nos permite navegar en el sistema y tiene las opciones siguientes; Glosario, Objetivo, Contenido, Actividades de repaso, Rompecabezas, Para más información, Requisitos del Sistema, Ayuda, Referencias y Galería. De esta manera los usuarios podrán realizar actividades que les permitan interactuar con el sistema multimedia y lograrán asimilar conocimientos de una mejor manera sobre el tema de los Tornados. DOI:https://doi.org/10.56238/futuroeducpesqutrans-033

La necesidad de flexibilizar la oferta educativa transitando a la modalidad semi-presencial así como la innovación en la creación de Objetos de Aprendizaje (OAs) son algunos de nuestros objetivos, presentamos la implementación de un repositorio de OAs, enfocado a fortalecer la comunicación oral y escrita, además de construir y delinear el pensamiento lógico y estructurado de los alumnos que cursan el primer semestre en ingeniería específicamente en la materia de programación. Como es sabido, las nuevas tecnologías son permisibles en el sentido que es posible realizar las cosas en forma diferente a las efectuadas con tecnologías tradicionales y fuimos cuidadosos en crear escenarios de aprendizaje significativos cuidando que los contenidos fuesen claros para el alumno que utilizaría esos OAs. No solo mostramos una vía para mejorar la práctica docente sino también mostramos el resultado conjunto de un equipo multidisciplinario y su contribución bajo el auspicio de Redes Digitales para el Aprendizaje en Educación Superior (CODAES).

Crystalline cellulose can be obtained from alternative sources like waste wood by hydrolysis with hydrochloric or sulfuric acid. In this study we report a process for producing crystals with high cellulose crystallinity index of approximately 82%. We chose to work with eucalyptus FSC certified as a way to ensure the reproducibility of experiments. Said wood samples were subjected to acid hydrolysis with nitric acid. The resulting mass was dried out and measured by the X-ray diffraction method.