Inercia

Este trabajo presenta los cálculos realizados para el diseño de un polipasto industrial, se calcula el momento de inercia reducida del
sistema de elevación al eje motor del polipasto estudiado y el cálculo de los parámetros de un árbol motriz, en este caso el árbol del eje motor. En primera instancia, se calculan los momentos de carga referidos a los ejes de los árboles del sistema, posteriormente, se calcula la
contribución de inercia para cada elemento del polipasto, así
como para sus conjuntos de elementos con el fin de obtener
el valor de la inercia reducida de todo el sistema. En el
siguiente punto, tomando en cuenta los requerimientos del
sistema se realiza la selección de un motor que pueda cubrir tales
requerimientos, la selección de este motor nos llevará a
obtener el punto de operación del sistema y se realiza el
cálculo del tiempo de arranque del sistema, el siguiente punto
es calcular las reacciones en el árbol a diseñar, se realizan
los diagramas de fuerzas cortantes y momentos flectores, así
como el diagrama de momentos torsores del árbol motriz.
Como punto final, se calcula el
diámetro del árbol, así como su factor de seguridad.

A right selection of filler, its type, shape, size, amount and its compatibility with other co-fillers decide the performance of a friction material (FM) at selected operating condition. Amongst various types of metallic fillers, copper is one of the most important fillers used in such multi-ingredient composite system. It not only enhances the thermal conductivity of composite but also plays an important role in friction and wear mechanism. In spite of these facts, in depth systematic studies on investigation role of copper with varying amount and shape and evaluation as per standard procedure are not documented. Hence, in this work investigation on the role of copper (particles and fibers) in FMs were done. Two series of NAO friction composites with varying amount of copper powder and fibers (0, 10 and 20wt.%) were developed in laboratory. These were characterized for physical, thermo-physical, chemical and mechanical properties. For tribo-evaluation inertia brake-dynamometer test...

A right selection of filler, its type, shape, size, amount and its compatibility with other co-fillers decide the performance of a friction material (FM) at selected operating condition. Amongst various types of metallic fillers, copper is one of the most important fillers used in such multi-ingredient composite system. It not only enhances the thermal conductivity of composite but also plays an important role in friction and wear mechanism. In spite of these facts, in depth systematic studies on investigation role of copper with varying amount and shape and evaluation as per standard procedure are not documented. Hence, in this work investigation on the role of copper (particles and fibers) in FMs were done. Two series of NAO friction composites with varying amount of copper powder and fibers (0, 10 and 20wt.%) were developed in laboratory. These were characterized for physical, thermo-physical, chemical and mechanical properties. For tribo-evaluation inertia brake-dynamometer test...

This work investigates dynamics of a two-stage gear system involving backlash and time-dependent mesh stiffness. This paper mainly consists to develop a 12 degree of freedom gear dynamic model. The model consists of a two-stage spur gear, three shafts, and two inertias representing load and prime mover and three bearings. Gear contact is characterised by a periodically changing stiffness and

El e-gobierno se presenta como una herramienta al servicio de la mejora de la eficacia y eficiencia en la prestación de los servicios públicos. Pero, pese a los esfuerzos por lograr una adopción generalizada del e-gobierno, éste presenta unas tasas de uso inferiores a las anheladas. Si bien dicho fenómeno ha sido estudiado desde diferentes perspectivas, en el presente trabajo se presenta la perspectiva conductual como enfoque que responda a tal reto. Para ello, se analiza la relación entre diferentes sesgos cognitivos vinculados a la tendencia del statu quo (hábito, inercia y resistencia) con la intención (de uso para los usuarios y de continuación para los usuarios). Los datos fueron captados tras un trabajo cualitativo (dos sesiones de grupo) y un trabajo cuantitativo (923 cuestionarios), dirigido a dos muestras diferentes de ciudadanos (no-usuarios y usuarios del e-gobierno). Los resultados constatan la presencia de la tendencia al statu quo en el uso del e-gobierno. Mientras en el caso de los no-usuarios del e-gobierno se encuentran presentes los sesgos cognitivos analizados, llevando a dilatar su uso, entre los usuarios del e-gobierno carece de relevancia el hábito, por lo que se mantienen en su uso como canal de acceso a los servicios públicos.

E-government is conceived as a tool to improve efficiency and effectiveness in the provision of public services. However, in spite of the efforts to achieve a widespread adoption of e-government, it has lower usage rates than expected. Although this fact has been studied from different viewpoints, in the present work the behavioral perspective is presented as an approach that may answer to this challenge. To get it, the relationship between different cognitive biases linked to the SQB (habit, inertia and resistance) with the intention (of use for users and continuation for users) is analyzed. The data were collected after a qualitative (two group sessions) and a quantitative work (923 questionnaires), aimed at two different samples of citizens (non-users and users of e-government). The results confirm the presence of the trend towards the status quo in the use of e-government. Besides, while in the case of non-users of e-government the cognitive biases analyzed are present, leading to delay its use, among the users of e-government habit lacks relevance, so they remain in use as a channel of access to public services.

This paper addresses the boundedness property of the inertia matrix and the skew-symmetric property of the Coriolis matrix for vehicle-manipulator systems. These properties are widely used in control theory and Lyapunov-based stability proofs and thus important to identify. The skew-symmetric property does not depend on the system at hand but on the parameterization of the Coriolis matrix, which is not unique. It is the authors’ experience that many researchers take this assumption for granted without taking into account that several parameterizations exist. In fact, most researchers refer to references that do not show this property for vehicle-manipulator systems but for other systems such as single rigid bodies or fixed-base manipulators. As a result, the otherwise rigorous stability proofs fall apart. In this paper, we list some relevant references and give the correct proofs for some commonly used parameterizations for future reference. Depending on the choice of state variable...

A right selection of filler, its type, shape, size, amount and its compatibility with other co-fillers decide the performance of a friction material (FM) at selected operating condition. Amongst various types of metallic fillers, copper is one of the most important fillers used in such multi-ingredient composite system. It not only enhances the thermal conductivity of composite but also plays an important role in friction and wear mechanism. In spite of these facts, in depth systematic studies on investigation role of copper with varying amount and shape and evaluation as per standard procedure are not documented. Hence, in this work investigation on the role of copper (particles and fibers) in FMs were done. Two series of NAO friction composites with varying amount of copper powder and fibers (0, 10 and 20wt.%) were developed in laboratory. These were characterized for physical, thermo-physical, chemical and mechanical properties. For tribo-evaluation inertia brake-dynamometer test...

Durante los años de gestación de la Teoría General de la Relatividad (TGR) y de la subsiguiente cosmología relativista, Albert Einstein esperaba que su teoría de gravitación satisficiera las ideas de Mach sobre la inercia. Para esto calculó un par de efectos que debían garantizar la consonancia de TGR con el origen material de la inercia à la Mach. Estos efectos fueron: (A) El aumento de la masa inercial cuando se aglomera materia en su vecindad y (B) el arrastre de los marcos inerciales. En este articulo se hace un estudio histórico-conceptual del primero(A). Mientras que el arrastre es considerado como una predicción real de TGR, el aumento de la masa inercial ha llegado a desecharse como un artificio de coordenadas no impugnable a la variedad espacio-temporal estudiada. Se presenta una revisión técnica con clarificaciones conceptuales es presentada.

As an important issue, we first address in this paper the problem of a regression matrix with non-homogeneous physical units in the parameter estimation of multibody systems. This matrix contains the most important information about the motion of the system. Attention must be ...