Application of lagrange equations for a rotating system with angular misalignment

El desbalanceo del motor y el desalineamiento son las causas principales de la generación de vibraciones en las máquinas rotativas. Estos problemas ocasionan daños en los rodamientos, árbol de transmisión y acoples. El objetivo de este estudio es analizar el comportamiento de rotación de un árbol de transmisión con un desalineamiento angular inducido. Esta primera parte consiste en desarrollar un modelo analítico utilizando las ecuaciones de Lagrange, teniendo en cuenta la energía disipativa de los rodamientos y el efecto del momento inercial de la masa del árbol. La metodología y los resultados obtenidos mostraron una buena correlación de los parámetros que caracterizan el desalineamiento angular.Abstract: The motor unbalance and misalignment are the main causes of the generation of vibrations in rotating machinery. These problems cause damage to the bearings and shaft couplings. The aim of this study is to analyze the behavior of a rotating shaft with an angular misalignment induced. This first part is to develop an analytical model using the Lagrange equations, taking into account the dissipative energy of the bearings and the effect of the inertial moment of the mass of the shaft. The methodology and the results showed a good correlation between the parameters characterizing the angular misalignment

Modelo de gestión urbana sostenible

Este libro tiene como propósito brindar al lector un compendio de opiniones y puntos de vista generados por expertos desde diferentes áreas del conocimiento, que le permitan tener una visión global de los elementos que se deben considerar cuando se busca entender y generar soluciones a problemas que emergen de sistemas urbanos. Vale mencionar que lo presentado aquí no contiene todos los puntos de vista y opiniones posibles, y que en muchos casos es factible aportar desde algún tópico no incluido aquí. Este libro está dirigido a todas aquellas personas que tengan algún interés en el análisis de problemas urbanos, así como a un público más amplio que pueda encontrar aquí ideas y opiniones que le permitan formarse las suyas propias sobre estos asuntos

Innovar para Educar: Prácticas universitarias exitosas. Tomo 5

La Universidad del Norte y el Centro para la Excelencia Docente (CEDU), interesados en compartir con la comunidad académica y público en general las experiencias pedagógicas exitosas realizadas por docentes de diferentes áreas disciplinares, trae ahora el tomo 5 de la colección “Innovar para Educar: Prácticas universitarias exitosas”, en donde encontrarán 8 capítulos que describen las diferentes propuestas de 14 docentes de la institución, que en un momento de reflexión decidieron cambiar el desarrollo habitual de sus clases. Este impulso los condujo por caminos de planificación, implementación y evaluación sistemática que hoy se ven reflejados en su buena práctica de aula y en los resultados de aprendizaje de sus estudiantes

Multi-parametric MR Imaging Biomarkers Associated to Clinical Outcomes in Gliomas: A Systematic Review

[EN] Purpose: To systematically review evidence regarding the association of multi-parametric biomarkers with clinical outcomes and their capacity to explain relevant subcompartments of gliomas. Materials and Methods: Scopus database was searched for original journal papers from January 1st, 2007 to February 20th , 2017 according to PRISMA. Four hundred forty-nine abstracts of papers were reviewed and scored independently by two out of six authors. Based on those papers we analyzed associations between biomarkers, subcompartments within the tumor lesion, and clinical outcomes. From all the articles analyzed, the twenty-seven papers with the highest scores were highlighted to represent the evidence about MR imaging biomarkers associated with clinical outcomes. Similarly, eighteen studies defining subcompartments within the tumor region were also highlighted to represent the evidence of MR imaging biomarkers. Their reports were critically appraised according to the QUADAS-2 criteria. Results: It has been demonstrated that multi-parametric biomarkers are prepared for surrogating diagnosis, grading, segmentation, overall survival, progression-free survival, recurrence, molecular profiling and response to treatment in gliomas. Quantifications and radiomics features obtained from morphological exams (T1, T2, FLAIR, T1c), PWI (including DSC and DCE), diffusion (DWI, DTI) and chemical shift imaging (CSI) are the preferred MR biomarkers associated to clinical outcomes. Subcompartments relative to the peritumoral region, invasion, infiltration, proliferation, mass effect and pseudo flush, relapse compartments, gross tumor volumes, and high-risk regions have been defined to characterize the heterogeneity. For the majority of pairwise cooccurrences, we found no evidence to assert that observed co-occurrences were significantly different from their expected co-occurrences (Binomial test with False Discovery Rate correction, alpha=0.05). The co-occurrence among terms in the studied papers was found to be driven by their individual prevalence and trends in the literature. Conclusion: Combinations of MR imaging biomarkers from morphological, PWI, DWI and CSI exams have demonstrated their capability to predict clinical outcomes in different management moments of gliomas. Whereas morphologic-derived compartments have been mostly studied during the last ten years, new multi-parametric MRI approaches have also been proposed to discover specific subcompartments of the tumors. MR biomarkers from those subcompartments show the local behavior within the heterogeneous tumor and may quantify the prognosis and response to treatment of gliomas.This work was supported by the Spanish Ministry for Investigation, Development and Innovation project with identification number DPI2016-80054-R.Oltra-Sastre, M.; Fuster García, E.; Juan -Albarracín, J.; Sáez Silvestre, C.; Perez-Girbes, A.; Sanz-Requena, R.; Revert-Ventura, A.... (2019). 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Celdas de combustible Una alternativa amigable con el medio ambiente para la generación de potencia y su impacto en el desarrollo sostenible de Colombia en el siglo xxi

Este artículo trata sobre la utilización en un futuro próximo de las celdas de combustible como fuente de generación de potencia; así como también de su forma de operación, su eficiencia y rendimiento, previa descripción de la misma

Aplicación de las ecuaciones de lagrange para un sistema rotatorio con desalineamiento angular

The motor unbalance and misalignment are the main causes of the generation of vibrations in rotating machinery. These problems cause damage to the bearings and shaft couplings. The aim of this study is to analyze the behavior of a rotating shaft with an angular misalignment induced. This first part is to develop an analytical model using the Lagrange equations, taking into account the dissipative energy of the bearings and the effect of the inertial moment of the mass of the shaft. The methodology and the results showed a good correlation between the parameters characterizing the angular misalignment.El desbalanceo del motor y el desalineamiento son las causas principales de la generación de vibraciones en las máquinas rotativas. Estos problemas ocasionan daños en los rodamientos, árbol de transmisión y acoples. El objetivo de este estudio es analizar el comportamiento de rotación de un árbol de transmisión con un desalineamiento angular inducido. Esta primera parte consiste en desarrollar un modelo analítico utilizando las ecuaciones de Lagrange, teniendo en cuenta la energía disipativa de los rodamientos y el efecto del momento inercial de la masa del árbol. La metodología y los resultados obtenidos mostraron una buena correlación de los parámetros que caracterizan el desalineamiento angular

Análisis comparativo de un modelo teórico de mediciones sonoras y el software SOUNDPLAN Ver. 6.2 aplicado a el tráfico vehicular

A nivel internacional se ha demostrado que la contaminación acústica es uno de los principales impactos ambientales que afecta a la población y al medio urbano, y su diversidad en fuentes e intensidades sonoras dificulta mucho su control. El control y la evaluación del impacto ambiental en la infraestructura vial es relativamente reciente en los países en vía de desarrollo y la tendencia mundial apunta en la incorporación de los estudios de impacto ambiental dentro de los planes de ordenamiento territorial y la disponibilidad de herramientas ambientales que permitan desarrollar los planes, programas y proyectos preventivos correctivos o de seguimiento con el fin de identificar las fuentes generadoras potenciales que futuros proyectos urbanos generarían en el medio ambiente. Debido a la importancia en el ámbito urbano, el Ministerio De Ambiente, Vivienda y Desarrollo Territorial, MAVDT, emitió la resolución 0627 del 7 de abril de 2006, con el fin de establecer niveles máximos de ruido y la elaboración de los mapas de ruidos por parte de las autoridades ambientales. Un modelo de predicción de ruido del parque vehicular es una herramienta que permite determinar los niveles de intensidades sonoras y simular varias situaciones adversas y favorables que se producirán en una vía de circulación de tráfico rodado o bien una modificación a una vía existente.En este estudio se realizará una comparación de los resultados arrojados por un modelo teórico y uno computacional, la cual nos permitirá validar el modelo teórico y reconocer la desviación porcentual entre sus intensidades sonoras calculadas. Con los resultados obtenidos se realizará una correlación con la normatividad vigente colombiana y otra norma alemana RLS90 con el fin de conocer la desviación existente con los niveles permisibles legales. La modelación computacional también nos permitirá predecir el ruido generado por el crecimiento del flujo vehicular y realizar recomendaciones para reducir la contaminación acústica en el sector urbano