Gear rattle dynamics: lubricant force formulation analysis on stationary conditions

Gear rattle is a common and inherent phenomenon to multi-stage-constant-mesh gearboxes, since this kind of transmission consist of two different types of gear pairs: active and inactive stages. The former is in charge of transmitting the energy, whilst the latter, although its teeth are engaged, is loosely connected to the output shaft. Gear rattle problematic resides in undesirable impacts and fluctuations in the inactive gears provoked by their interaction with the active stage, leading to vibrations which can produce fails in elements connected or belonging to the gearbox. In this regard, understanding the lubricant role is crucial, being this aspect the key to comprehend the dynamic behaviour of low-loaded gear transmissions and to palliate these phenomenon consequences as the ultimate goal of this research. Within this context, in this work, six formulations, which consider both entraining and squeeze fluid effects, were implemented in gear transmission models previously developed by the authors in order to calculate the hydrodynamic forces. Special attention was paid to the fluid viscosity influence on the dynamic behaviour under stationary conditions.This work has been supported by project DPI2017-85390-P funded by the Spanish Ministry of Science and Technology

Design of asymptotically optimal improper constellations with hexagonal packing

This paper addresses the problem of designing asymptotically optimal improper constellations with a given circularity coefficient (correlation coefficient between the constellation and its complex conjugate). The designed constellations are optimal in the sense that, at high signal-to-noise-ratio (SNR) and for a large number of symbols, yield the lowest probability of error under an average power constraint for additive white Gaussian noise channels. As the number of symbols grows, the optimal constellation is the intersection of the hexagonal lattice with an ellipse whose eccentricity determines the circularity coefficient. Based on this asymptotic result, we propose an algorithm to design finite improper constellations. The proposed constellations provide significant SNR gains with respect to previous improper designs, which were generated through a widely linear transformation of a standard M-ary quadrature amplitude modulation constellation. As an application example, we study the use of these improper constellations by a secondary user in an underlay cognitive radio network.The work of Jesús A. López-Fernández and R. G. Ayestarán was partly supported by the Ministerio de Ciencia, Innovación y Universidades under project TEC2017-86619-R (ARTEINE), and by the Gobierno del Principado de Asturias under project GRUPIN-IDI2018-000191. The work of I. Santamaria was partly supported by the Ministerio de Economía y Competitividad (MINECO) of Spain, and AEI/FEDER funds of the E.U., under grant TEC2016-75067-C4-4-R (CARMEN) and TEC2015-69648-REDC (Red COMONSENS). The work of C. Lameiro was supported by the German Research Foundation (DFG) under grant LA 4107/1-1

Coordinación de recursos digitales sobre catálogos on line de las colecciones de arte en museos e instituciones de Castilla y León para la enseñanza en asignaturas de Historia del Arte y Bellas Artes

Memoria ID-0056. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2016-2017

Interrelaciones entre el proyecto artístico y el espacio expositivo. La exposición como proceso de aprendizaje y desarrollo de competencias.

Memoria ID-324. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2013-2014

Programa aeróbico de alta intensidad, fuerza y cáncer de mama

Para la realización de esta investigación se utilizó el método Empírico - Analítico de corte cuasi experimental, teniéndose como objetivo identificar los efectos de un programa de entrenamiento aérobico fraccionado de alta intensidad y de fuerza en los niveles plasmáticos de la hormona IGF-1 y su transportadora IGFBP3 en pacientes de cáncer de mama que terminaron sus tratamientos adyuvantes. En los resultados se evidencio un aumento mayor en la proteína IGFBP3 9,1% que en la hormona IGF-1 0,17%. A manera de conclusión podemos decir que un programa de entrenamiento aeróbico fraccionado de alta intensidad y de fuerza durante 22 semanas 3 veces por semana de manera personalizado en pacientes con cáncer de mama que finalizaron sus tratamientos adyuvantes, aumenta los niveles plasmáticos de IGFBP3 considerado como un agente protector al riesgo del cáncer de mama.Mesa 7. Educación física y salud.Facultad de Humanidades y Ciencias de la Educació

Frictional power losses on spur gears with tip reliefs. The load sharing role

The load sharing impact on the efficiency of spur gears with modified profile was assessed in this work. The aim was to analyse the influence of the profile modifications on the load sharing, which also considers the effect of the torque level on the system deflections, and how these load sharing variations affected the system efficiency. Due to the frictional effect importance on power losses, in the operating conditions considered, sliding friction between teeth in presence of lubricant was studied in this proposal. The results established that tip relief improves the efficiency of the system due to the reduction of effective contact ratio. Moreover, there is a tip relief which makes optimal the efficiency in specific operating conditions, corresponding to the unit value of the effective contact ratio. Thus, the main conclusion of this work is that the tip relief which makes optimal the efficiency coincides with the theoretical dynamic optimum of the transmission.The authors would like to acknowledge Project DPI 2013-44860 funded by the Spanish Ministry of Science and Technology and the COST ACTION TU 1105 for supporting this research

Analysis of human-induced vibrations in a lightweight framework

This article analyzes the vibratory behavior of a Material-Composed Sandwich (MCS) framework for residential buildings. It has been observed qualitatively that the use of this kind of framework leads to poor comfort levels. The goal of this study is to find out the sources of this lack of comfort, in order to suggest guidelines that can enhance the performance of the MCS framework, without jeopardizing its advantages with respect to the traditional frameworks. To achieve this objective, an Experimental Modal Analysis (EMA) of a sample MCS framework has been carried out in order to determine the dynamic parameters. Then, a numerical Finite Element (FE) model of said sample MCS framework has been developed and adjusted with the results obtained in the experimental test. Based on this, a real-dimension MCS framework FE model has been built and the resultant behavior compared with that of a commonly used framework made of reinforced concrete. This comparison is finally used to assess the uncomfortable dynamic response of the MCS framework and to draw conclusions on the design guidelines in order to enhance the MCS framework vibratory behaviorThe authors would like to acknowledge Project DPI2013-44860 funded by the Spanish Ministry of Science and Technology and COST ACTION TU 1105 for supporting this research

Enhancement of Mechanical Engineering Degree through student design competition as added value. Considerations and viability

This paper proposes using a student design competition as a learning tool in the Mechanical Engineering Degree for enhancing the general competences and motivation of the students, transferring theoretical knowledge to practical situations and bringing together all courses involved under a common framework. This constitutes an added value that the in-person universities should offer to their students as a consequence of the Bologna process and the raising of open online resources for self-learning. In order to assess the viability of this proposal, a pilot competition design activity (CDA) is presented using project-based learning methods during a Mechanism Theory course for sophomore students. Meanwhile, 27 participants of a 45-student course from a European university took part in the pilot CDA, which consisted of redesigning the motorbike rear suspension used in a student design competition. Participants also completed mid-term and final exams as well as a survey to get their perception of this activity. Based on the success of the pilot CDA, the authors are planning to implement the proposal, including similar CDAs in other Mechanical Engineering courses to use the competition as a link between them and to encourage students to participate on the competition.This work [Project DPI2013-44860] was supported by the Spanish Ministry of Science and Technology and Vicerrector Primero y de Profesorado of the University of Cantabria

Programa aeróbico de alta intensidad, fuerza y cáncer de mama

Para la realización de esta investigación se utilizó el método Empírico - Analítico de corte cuasi experimental, teniéndose como objetivo identificar los efectos de un programa de entrenamiento aérobico fraccionado de alta intensidad y de fuerza en los niveles plasmáticos de la hormona IGF-1 y su transportadora IGFBP3 en pacientes de cáncer de mama que terminaron sus tratamientos adyuvantes. En los resultados se evidencio un aumento mayor en la proteína IGFBP3 9,1% que en la hormona IGF-1 0,17%. A manera de conclusión podemos decir que un programa de entrenamiento aeróbico fraccionado de alta intensidad y de fuerza durante 22 semanas 3 veces por semana de manera personalizado en pacientes con cáncer de mama que finalizaron sus tratamientos adyuvantes, aumenta los niveles plasmáticos de IGFBP3 considerado como un agente protector al riesgo del cáncer de mama.Mesa 7. Educación física y salud.Facultad de Humanidades y Ciencias de la Educació

Programa aeróbico de alta intensidad, fuerza y cáncer de mama

Para la realización de esta investigación se utilizó el método Empírico - Analítico de corte cuasi experimental, teniéndose como objetivo identificar los efectos de un programa de entrenamiento aérobico fraccionado de alta intensidad y de fuerza en los niveles plasmáticos de la hormona IGF-1 y su transportadora IGFBP3 en pacientes de cáncer de mama que terminaron sus tratamientos adyuvantes. En los resultados se evidencio un aumento mayor en la proteína IGFBP3 9,1% que en la hormona IGF-1 0,17%. A manera de conclusión podemos decir que un programa de entrenamiento aeróbico fraccionado de alta intensidad y de fuerza durante 22 semanas 3 veces por semana de manera personalizado en pacientes con cáncer de mama que finalizaron sus tratamientos adyuvantes, aumenta los niveles plasmáticos de IGFBP3 considerado como un agente protector al riesgo del cáncer de mama.Mesa 7. Educación física y salud.Facultad de Humanidades y Ciencias de la Educació