System Identification of Tunnel Response to Ground Motion Considering a Simplified Model

This paper presents a simplified model using coupled Bernoulli and shear beams supported by Winkler-type springs for system identification of tunnels subjected to earthquake induced ground motions. The model formulation is introduced and closed-form solutions to the modal characteristic equation and mode shapes are derived. The latter are verified against the results of numerical models. Then, the system identification algorithm is presented, showcasing its ability to recover model parameters when recorded acceleration time histories along the tunnel are compromised by noise and sensor locations are varied. The presented framework can be used to initially and, simply, recover tunnel response when monitoring data is available, or to plan for monitoring campaigns in newly constructed or existing tunnels

El voleibol como estrategia didáctica, para desarrollar las relaciones interpersonales en el curso 503 del colegio Nicolás Esguerra jornada nocturna.

Se pretende desarrollar las relaciones interpersonales, por medio del voleibol como estrategia didáctica, mejorando el bienestar personal y ambiente social del curso 503 del Colegio Nicolás Esguerra jornada nocturna, buscando en el desarrollo de la clase de educación física, un mejor trabajo cooperativo y desarrollo integral del ser humano en los estudiantes, donde se involucre en el grupo en conjunto, para así obtener resultados positivos con los compañeros quienes son que los rodean en su jornada estudiantil y de la misma forma aprendan a relacionarse en diferentes roles donde se encuentren. Los estudiantes del curso 503 del Colegio Nicolás Esquerra muestran dificultad al relacionarse en su jornada estudiantil, en la clase de educación física, esto; debido a que en su plan de estudio en jornada nocturna, no se establece la asignatura de educación física como materia oficial. Debido a que en la jornada nocturna de esta institución en su currículo, el proceso pedagógico y formativo es validar dos años en uno. Esto no permite que puedan tener un mejor desarrollo cooperativo en todas las asignaturas, espacios de su rol social y educativo

Suitability of equivalent linear soil models for analysing the seismic response of a concrete tunnel

Current methods of analysis for the seismic response of tunnels rely on linear elastic soil constitutive behaviour. This has obvious benefits in terms of minimising the number of soil parameters required and the complexity compared to more sophisticated soil models. However, it has recently become possible to parameterise sophisticated soil models using only routine data from boreholes or in-situ testing. This paper will therefore review the effectiveness of seismic analyses using an equivalent linear soil constitutive model, by comparison of 2D Finite Element simulations with those using an advanced non-linear elastic model with isotropic hardening plasticity. In the elastic case, the parameters have been estimated using Equivalent-linear Earthquake site Response Analyses software (EERA) and consideration will be given to the amount of sublayering that is required to match the variation of soil properties with depth. The tunnel considered is of horseshoe shape and sprayed concrete construction (New Austrian Tunnelling Method), based on metro tunnels in Santiago, Chile, subjected to the Llolleo ground motion from the 1985 Valparaiso Earthquake. The results will focus the differences in the induced structural forces within the tunnel lining and modification to the ground motion in the near-field of the tunnel, and discuss the implications of this for tunnel design

The ballast pick-up problem. A theoretical approach and two experimental campaigns

The aim of this contribution is to present a theoretical approach and two experimental campaigns (on wind tunnel and on the track) concerning the research work about the ballast train-induced-wind erosion (BTIWE) phenomenon. When a high speed train overpasses the critical speed, it produces a wind speed close to the track large enough to start the motion of the ballast elements, eventually leading to the rolling of the stones (Kwon and Park, 2006) and, if these stones get enough energy, they can jump and then initiate a saltation-like chain reaction, as found in the saltation processes of soil eolian erosion (Bagnold, 1941). The expelled stones can reach a height which is larger than the lowest parts of the train, striking them (and the track surroundings) producing considerable damage that should be avoided. There is not much published work about this phenomenon, in spite of the great interest that exists due to its relevant applications in increasing the maximum operative train speed. Particularly, the initiation of flight of ballast due to the pass of a high speed train has been studied by Kwon and Park (2006) by performing field and wind tunnel experiments

On the difference of torus geometry between hidden and non-hidden broad line active galactic nuclei

We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGN) with clumpy torus models. We compiled high spatial resolution ($\sim 0.3$--$0.7$ arcsec) mid-IR $N$-band spectroscopy, $Q$-band imaging and nuclear near- and mid-IR photometry from the literature. Combining these nuclear near- and mid-IR observations, far-IR photometry and clumpy torus models, enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties; type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without any published HBLR signature (NHBLR). Comparing the torus model parameters gives us the first quantitative torus geometrical view for each subgroup. We find that NHBLR AGN have smaller torus opening angles and larger covering factors than those of HBLR AGN. This suggests that the chance to observe scattered (polarized) flux from the BLR in NHBLR could be reduced by the dual effects of (a) less scattering medium due to the reduced scattering volume given the small torus opening angle and (b) the increased torus obscuration between the observer and the scattering region. These effects give a reasonable explanation for the lack of observed HBLR in some type-2 AGN.Comment: 13 pages, 5 figures, accepted for publication in Ap

Age-dependent defective TGF-beta1 signaling in patients undergoing coronary artery bypass grafting

Background: Transforming growth factor beta (TGF-beta 1) is a pleiotropic cytokine, which is deregulated in atherosclerosis; however the role of age in this process is unknown. We aimed to assess whether TGF-beta 1 signaling is affected by age. Methods: Vascular smooth muscle cells (VSMC) were obtained from patients undergoing abdominal surgery. Levels of TGF-beta 1 were measured by ELISA in sera from 169 patients undergoing coronary artery bypass grafting (CABG). The p27 expression was determined by Western blot from internal mammary arteries (IMA) obtained from CABG patients (n = 13). In VSMC from these patients undergoing abdominal surgery, secretion of TGF-beta 1 was determined by ELISA of cell-conditioned media. Results: In VSMC from aged patients we observed a lower TGF-beta 1 secretion, measured as TGF-beta 1 concentration in cell conditioned medium (p < 0.001). This effect was correlated to an age-dependent decrease of p27 expression in IMA from aged CABG patients. In a similar manner, there was an age-dependent decrease of serum TGF-beta 1 levels in CABG patients (p = 0.0195). Conclusions: VSMC from aged patients showed a higher degree of cellular senescence and it was associated to a lower TGF-beta 1 secretion and signaling.S

Plan de negocios para la reestructuración del complejo recreacional “La Cabaña” ubicado en Huancayo - Junín

Este proyecto trata sobre la reestructuración del complejo recreacional “La Cabaña” en Miraflores-Sapallanga, con el objetivo de incrementar la cantidad de visitas anuales. El complejo recreacional ofrece servicios como un menú a base de truchas, pesca deportiva, áreas de asados y lounge, pista todo terreno para cuatrimotos, tirolesa, juegos infantiles y venta de truchas protegidas. Una investigación del mercado mostró que los visitantes no están completamente conformes con los servicios ofrecidos en los recreos campestres, lo que representa una oportunidad para “La Cabaña”. Tras reestructurar su propuesta de valor en local, entretenimiento, sabor y presentación de los platos y juegos, se espera incrementar las visitas anuales tanto en el mercado de parejas, familias y grupos de amigos como en el mercado de turistas que viajan con agencias de turismo para el 2024 en adelante. La reestructuración comprende una mejor presentación de los platos, un mejor sabor, un local que comunique lujo y sea campestre y actividades para entretenimiento en un ambiente orientado al servicio de atención al cliente

A Fast 0.5 T Prepolarizer Module for Preclinical Magnetic Resonance Imaging

We present a magnet and high power electronics for Prepolarized Magnetic Resonance Imaging (PMRI) in a home-made, special-purpose preclinical system designed for simultaneous visualization of hard and soft biological tissues. The sensitivity of MRI systems grows with field strength, but so do their costs. PMRI can boost the signal-to-noise ratio (SNR) in affordable low-field scanners by means of a long and strong magnetic pulse. However, this must be rapidly switched off prior to the imaging pulse sequence, in timescales shorter than the spin relaxation (or T1) time of the sample. We have operated our prepolarizer at up to 0.5 T and demonstrated enhanced magnetization, image SNR and tissue contrast with PMRI of tap water, an ex vivo mouse brain and food samples. These have T1 times ranging from hundreds of milli-seconds to single seconds, while the preliminary high-power electronics setup employed in this work can switch off the prepolarization field in tens of milli-seconds. In order to make this system suitable for solid-state matter and hard tissues, which feature T1 times as short as 10 ms, we are developing new electronics which can cut switching times to ~ 300 μs. This does not require changes in the prepolarizer module, opening the door to the first experimental demonstration of PMRI on hard biological tissues

Pintando caballos: Estudio de la Anatomía y Biomecánica Equina a través de la Pintura sobre el Animal Vivo

Creación de un material docente (para web y plataformas móviles) pintando las estructuras anatómicas músculo-esqueléticas sobre caballos vivos para el aprendizaje de la anatomía funcional y biomecánica equina de forma sencilla, visual y didáctica

Evaluación formativa con feedback rápido mediante mandos interactivos en la docencia de Prótesis III

El objetivo es diseñar y elaborar un sistema de evaluación continuada mediante el empleo de mandos interactivos para la docencia de Prótesis III, que permitan mejorar la enseñanza clínica, y el aprendizaje tanto individual como en equipo