This work proposes the design of a commutation function to solve the output voltage trajectory tracking problem in the DC-DC Buck power electronic converter. Through a Lyapunov-type analysis, sufficient conditions are established, taking into account the discontinuous model, to ensure asymptotic convergence to the desired trajectories. Based on this analysis, a state-dependent switching function was designed to guarantee the closed-loop stability of the tracking error. To validate the control performance, circuit numerical simulations were carried out under abrupt disturbances in the source and load of the converter. The results demonstrate that the voltage tracking at the output of the converter is satisfactorily achieved.

Compression fractures in the lumbar region are usually caused by excessive pressure at the level of the vertebral body. The fracture occurs when the vertebral body is crushed, causing the anterior part of the vertebral body to acquire a wedge shape. Bone tissue inside the vertebral body is crushed or compressed. Compression fractures due to trauma may be due to a fall, a strong jump, a car accident, or any other event that emphasizes the spine beyond its breaking point [1]. In a simulation of the fracture in recent studies, loads are applied to real vertebral samples (destructive tests), where both compression loads are fixed on the upper and lower faces of the vertebral body. The literature mentions tests with loads of approximately 8000N emulating a daily accident, so this research aims to obtain a precise model with the use of an optical scanner, which will allow the obtaining of points (meshing) of the piece in real time with an individual measurement of up to 16 million independent measurement points captured from 1 to 2 seconds. The measurement data is characterized by a very detailed reproduction and therefore also allows the measurement of sample components up to 38mm.

Este estudio presenta un innovador modelo de enseñanza para la nanotecnología en la educación básica, que integra estrategias diseñadas para fomentar el aprendizaje significativo. Se aplica la taxonomía SOLO para evaluar la efectividad de las respuestas de los estudiantes. En un esfuerzo por avanzar en la calidad educativa a nivel mundial, México se enfrenta a desafíos derivados de factores tanto externos como internos. Este modelo se basa en la metodología de sistemas blandos, tratando el proceso educativo como un sistema influido por su contexto social y político. La evaluación de la calidad educativa se realiza a través del análisis de índices de deserción escolar y eficiencia terminal, adoptando un enfoque sistémico para identificar y tratar los principales factores que impactan estos indicadores en la enseñanza de las ciencias a nivel básico. El modelo prioriza los aspectos críticos de la educación: contenido, evaluación, valores, entorno educativo y los roles fundamentales de profesores y estudiantes. Aunque específicamente desarrollado para la enseñanza de nanotecnología y nanociencia, el modelo ofrece flexibilidad para adaptarse a otras materias, asegurando una armonía entre los objetivos, metas y recursos disponibles dentro del contexto de la Nueva Escuela Mexicana.