Numerical Estimation of Stresses in Railway Axles Using a Train-Track Interaction Model

The fatigue design of railway axles requires that the stresses arising in the axle in real service are accurately quantified. This paper describes a method to compute the dynamic stresses arising in railway axles as the effect of train track interaction, based on the numerical simulation of the dynamic interaction between a flexible wheelset and a flexible track. The wheelset is modelled as a flexible rotating body using an Eulerian approach, whereas track is regarded as an infinite periodic system with the rail modelled as a Timoshenko beam resting on discrete elastic supports, considering the inertia associated with the sleepers. The paper presents an application of the proposed procedure to the calculation of the dynamic stresses caused in the axle by different types of geometric imperfection occurring on the wheel and rail surfaces, considering the cases of a single harmonic rail corrugation, random rail roughness and a wheelflat.The authors gratefully acknowledge the support for this work provided by the Project TRA2010-15669 (Ministerio de Ciencia e Innovacion) and TRA2007-67167 (Ministerio de Educacion y Ciencia-FEDER).Martínez Casas, J.; Mazzola, L.; Baeza González, LM.; Bruni, S. (2013). Numerical Estimation of Stresses in Railway Axles Using a Train-Track Interaction Model. International Journal of Fatigue. 47:18-30. https://doi.org/10.1016/j.ijfatigue.2012.07.006S18304

A comprehensive model of the railway wheelset-track interaction in curves

Train-track interaction has been extensively studied in the last 40 years at least, leading to modelling approaches that can deal satisfactorily with many dynamic problems arising at the wheel/rail interface. However, the available models are usually not considering specifically the running dynamics of the vehicle in a curve, whereas a number of train-track interaction phenomena are specific to curve negotiation. The aim of this paper is to define a model for a flexible wheelset running on a flexible curved track. The main novelty of this work is to combine a trajectory coordinate set with Eulerian modal coordinates; the former permits to consider curved tracks, and the latter models the small relative displacements between the trajectory frame and the solid. In order to reduce the computational complexity of the problem, one single flexible wheelset is considered instead of one complete bogie, and suitable forces are prescribed at the primary suspension seats so that the mean values of the creepages and contact forces are consistent with the low frequency curving dynamics of the complete vehicle. The wheelset model is coupled to a cyclic track model having constant curvature by means of a wheel/rail contact model which accounts for the actual geometry of the contacting profiles and for the non-linear relationship between creepages and creep forces. The proposed model can be used to analyse a variety of dynamic problems for railway vehicles, including rail corrugation and wheel polygonalisation, squeal noise, numerical estimation of the wheelset service loads. In this paper, simulation results are presented for some selected running conditions to exemplify the application of the model to the study of realistic train-track interaction cases and to point out the importance of curve negotiation effects specifically addressed in the work.The authors acknowledge the financial contribution of the Spanish Ministry of Economy and Competitiveness through the project TRA2013-45596-C2-1-R.Martínez Casas, J.; Di Gialleonardo, E.; Bruni, S.; Baeza González, LM. (2014). A comprehensive model of the railway wheelset-track interaction in curves. Journal of Sound and Vibration. 333(18):4152-4169. https://doi.org/10.1016/j.jsv.2014.03.032S415241693331

Percepción de la discriminación masculina en la publicidad de Chile

Se ha comprobado que la cultura patriarcal de la sociedad chilena y su carácter de sociedad neoconservadora, es la principal herencia de los roles sociales del hombre y la mujer, que se han constituido como producto de relaciones de poder y creencias que se tenían de estos; hoy en día estos roles se han visto envueltos en un cambio sustancial en el tiempo, que no ha sido representado del todo en la comunicación publicitaria.¿Qué sucede si la publicidad no representa la realidad de la sociedad y omite ciertas construcciones sociales de los roles del hombre, dando lugar a la Discriminación Publicitaria Masculina

Plan de tratamiento miofuncional: Una propuesta para el abordaje de los hábitos orales inadecuados

PublishedUn plan de tratamiento es un conjunto de procedimientos para cada caso diagnóstico que busca abordar la rehabilitación de una alteración a partir de objetivos planteados de manera secuencial y lógica, considerando las miradas interdisciplinares para lograr la efectividad del mismo en el menor tiempo posible, y por tanto, evitar la progresión de las alteraciones y la aparición de complicaciones. De ahí que para el diseño de un plan de tratamiento se tenga en cuenta el motivo de consulta, la disponibilidad de tiempo, las condiciones sociodemográficas, la complejidad del diagnóstico y las prioridades terapéuticas (Carpenter, 2007). En caso de ser un menor de edad, el compromiso recaerá en los padres y/o cuidadores, dándoles a conocer que el abordaje de las alteraciones dará mejor resultado si la terapia se refuerza en casa (Bigenzahn, 2004)

A practical solution to estimate the sample size required for clinical prediction models generated from observational research on data

[EN] Background Estimating the required sample size is crucial when developing and validating clinical prediction models. However, there is no consensus about how to determine the sample size in such a setting. Here, the goal was to compare available methods to define a practical solution to sample size estimation for clinical predictive models, as applied to Horizon 2020 PRIMAGE as a case study. Methods Three different methods (Riley's; "rule of thumb" with 10 and 5 events per predictor) were employed to calculate the sample size required to develop predictive models to analyse the variation in sample size as a function of different parameters. Subsequently, the sample size for model validation was also estimated. Results To develop reliable predictive models, 1397 neuroblastoma patients are required, 1060 high-risk neuroblastoma patients and 1345 diffuse intrinsic pontine glioma (DIPG) patients. This sample size can be lowered by reducing the number of variables included in the model, by including direct measures of the outcome to be predicted and/or by increasing the follow-up period. For model validation, the estimated sample size resulted to be 326 patients for neuroblastoma, 246 for high-risk neuroblastoma, and 592 for DIPG. Conclusions Given the variability of the different sample sizes obtained, we recommend using methods based on epidemiological data and the nature of the results, as the results are tailored to the specific clinical problem. In addition, sample size can be reduced by lowering the number of parameter predictors, by including direct measures of the outcome of interest.This work is funded by the HORIZON2020 PRIMAGE project (RIA, topic SC1DTH 07-2018), from the EU Framework Programme for Research and Innovation of the European Commission.Baeza-Delgado, C.; Cerdá Alberich, L.; Carot Sierra, JM.; Veiga-Canuto, D.; Martinez De Las Heras, B.; Raza, B.; Marti-Bonmati, L. (2022). A practical solution to estimate the sample size required for clinical prediction models generated from observational research on data. European Radiology Experimental. 6(1). https://doi.org/10.1186/s41747-022-00276-y6

Synthesis and biological properties of β-turned Aβ31-35 constrained analogues

A series of constrained pentapeptide analogues of the fragment Aβ31–35 has been prepared using solid phase synthesis protocols. The results of conformational studies and surface plasmon resonance (SPR) experiments seem to indicate that the affinity of these constrained analogues for immobilized Aβ25–35 peptide could be related to their ability to adopt a Leu34N-Ile31O β-turn-like folded conformation.This work has been supported by the Spanish Ministry of Education and Science (SAF 2006-01205) and the Comunidad de Madrid (GR/SAL/0846/2004). Work at Universitat Pompeu Fabra was supported by Generalitat de Catalunya (SGR2005-00494). We thank Dr. M.L. Jimeno and Dr. M. Martı´n-Martı´nez for NMR and molecular modeling studies, respectively. J.L.B. and C.J.C. thank the Spanish Ministry of Education and Science for predoctoral fellowships

PMo11V@N-CNT electrochemical properties and its application as electrochemical sensor for determination of acetaminophen

A polyoxometalate-nanocarbon composite, PMo11V@N-CNT, was prepared by a simple procedure which consisted of the immobilization of phosphovanadomolybdate (PMo11V) onto N-doped carbon nanotubes (N-CNT). The FTIR and XPS characterizations confirmed its successful synthesis. The cyclic voltammograms of glassy carbon electrode (GCE) modified with PMo11V and PMo11V@N-CNT showed four Mo-centred redox processes (MoVI/V) and a vanadium redox process (VV/IV). All were surface-confined redox processes. Additionally, PMo11V@N-CNT/GCE showed good stability and well-resolved redox peaks with high current intensities. The electrocatalytic sensing properties of PMo11V@N-CNT/GCE towards acetaminophen (AC) in the presence of tryptophan (TRP) were evaluated by square wave voltammetry. Under the conditions used, the peak current increased linearly with AC concentration in the presence of TRP, with a linear range from 1.5 × 10−6 to 3.9 × 10−4 mol dm−3 and a detection limit of 1.0 × 10−6 mol dm−3.info:eu-repo/semantics/publishedVersio

Actividades ecoturísticas del ejido Emiliano Zapata dentro del área natural protegida del bosque de La Primavera

El presente Informe aborda las cuestiones relativas al “Proyecto de Actividades Ecoturísticas del Ejido Emiliano Zapata dentro del Área Natural Protegida de la Primavera”; Comienza con una visión amplia del panorama al cual se enfrentó, para después tocar los objetivos del Proyecto y el porqué es importante llevar a cabo dicho proyecto, tomando en cuenta los antecedentes y el contexto de las circunstancias. Consecuentemente se tocan las estrategias llevadas a cabo para mitigar el problema al cual se enfrentaba el Ejido “Emiliano Zapata”, las cuales implican todas las labores de investigación realizadas, y el producto de dichas investigaciones. Teniendo como alcance la posible coordinación entre el Organismo Público Descentralizado y el Ejido ya mencionado En la parte final del documento se abordan cuestiones relativas al resultado del proyecto, y a las reflexiones personales por parte del equipo sobre lo elaborado a lo largo del mismo.ITESO, A.C

Hábitos orales, un abordaje interdisciplinar

PublishedEl Programa de Fonoaudiología de la Universidad Santiago de Cali, ofrece a los estudiantes y profesionales de fonoaudiología el presente libro de texto; en él encontrarán una serie de planteamientos y orientaciones para el trabajo de la fonoaudiología en la especialidad de terapia miofuncional orofacial. El libro inicia con la contextualización histórica de la profesión de la fonoaudiología en el mundo, Latinoamérica y en Colombia, para posteriormente integrar la historia de la terapia y motricidad orofacial en los mismos ámbitos; al mismo tiempo describe los inicios de la terapia miofuncional de la mano del desarrollo de la profesión de odontología