This study proposes a laboratory practice at the university level that allows active participation and helps understand the concepts of physical-chemical properties and molecular structures with experimentation as a teaching-learning strategy for microscale chemistry. For it, a quartz crystal microbalance is used to detect variations of small amounts of mass. The microbalance is built with low-cost electronic components, an Arduino UNO board, and an OLED screen to determine the evaporation time at room temperature of pure substances and mixtures with different degrees of volatility: Propan-2-ol, ethanol, and water. And with its use, reduce the cost of the chemical reagents used, the amount of waste generated, and reduce the time in the experiments to allow greater participation in the debate and discussion between students and teachers during practice.

La presente investigación tuvo como objetivo determinar la viabilidad del Lactobacillus acidophilus en queso fresco con goma de Algarroba (Prosopis Mida) en unidades formadoras de colonia por gramo de muestra (UFC/g) con respecto al tiempo; como también sus propiedades fisicoquímicas y organolépticas. Para el cumplimiento de dicho objetivo se formularon dos tratamientos diferentes. En el primero se inoculó el Lactobacillus acidophílus en el queso fresco con goma de Algarroba (Prosopis pallida) y en el segundo se inoculó en un queso fresco sin goma de Algarroba (Prosopis pallída), ambos quesos se almacenaron a 8°C por 15 días. La identificación y recuento diario del Lactobacillus acidophilus en ambos quesos frescos se realizó mediante sembrado en medio agar MRS de esta forma se determinó la tasa de crecimiento microbiano (UFC/g versus tiempo). La semejanza o diferencia entre ...

The 2022 quarantine period exposed the need to design laboratory instruments that were accessible to students, allowing them to conduct experiments from home. Although many magnetism studies have developed manually displaced gaussmeters, only a few of them have been automated. Therefore, this study presents the design of a gaussmeter made with construction toy parts and an Arduino UNO development board to quantify the magnetic flux density in permanent magnets. To evaluate its operation, precision and robustness tests were carried out. In this way, the Kruskal-Wallis test showed similarity in the experimental readings with the WSH315 sensor between 1.62–3.54 cm. Meanwhile, the Wilcoxon-Mann-Whitney test showed limitations in terms of accuracy. And the Youden-Steiner test showed robustness to polarity rotation in the magnet at a distance of 1.19 cm with the AD22151 sensor. Finally, the ...

La presente tesis tuvo como propósito elaborar un modelo de plan estratégico para MYPES de consultoría para la satisfacción de su potencial humano a partir del desarrollo del caso: GIAB SAC. En orden para Iograr el propósito de esta investigación, se realizó un análisis FORD y una encuesta de satisfacción Iaboral. Finalmente los resultados . presentan estrategias que permitirén la estabilidad laboral, crecimiento Iaboral, remuneraciones (salarios) acordes al mercado de empleo y la autorrealización de sus trabajadores.