Research related to vibrations from high speed railway traffic

We discuss here recent results from several research programmes related to dynamic aspects and vibrations induced by high speed railway traffic, developed at the computational mechanics group, within the “Escuela de Ingenieros de Caminos” of the Technical University of Madrid. The first part of this work concerns the dynamic response of railway bridges and structures under high speed traffic. The study of vertical dynamic effects in bridges has lead recently to improved understanding and practical design concepts, embodied in the new engineering codes [1,2,3,4,5]. Some special and seldom considered features of the dynamic response are also discussed. In the second part we present some results for lateral dynamic effects. These have not been so widely studied as the vertical vibrations, however they may pose significant problems for bridges. Finally, in the third part we discuss recent results of ongoing research for the mechanical response of slab track and ballast track, focusing on the vertical vibration of the track and the associated dynamic traffic loads

Dynamic effect of high speed railway traffic loads on the ballast track settlement

The traditional ballast track structures are still being used in high speed railways lines with success, however technical problems or performance features have led to non-ballast track solution in some cases. A considerable maintenance work is needed for ballasted tracks due to the track deterioration. Therefore it is very important to understand the mechanism of track deterioration and to predict the track settlement or track irregularity growth rate in order to reduce track maintenance costs and enable new track structures to be designed. The objective of this work is to develop the most adequate and efficient models for calculation of dynamic traffic load effects on railways track infrastructure, and then evaluate the dynamic effect on the ballast track settlement, using a ballast track settlement prediction model, which consists of the vehicle/track dynamic model previously selected and a track settlement law. The calculations are based on dynamic finite element models with direct time integration, contact between wheel and rail and interaction with railway cars. A initial irregularity profile is used in the prediction model. The track settlement law is considered to be a function of number of loading cycles and the magnitude of the loading, which represents the long-term behavior of ballast settlement. The results obtained include the track irregularity growth and the contact force in the final interaction of numerical simulatio

El uso de la noticia jurídica como nuevo método de enseñanza en la asignatura Sistema Judicial Español

En el sistema de educación superior en el que nos hayamos inmersos, venimos constatando una endémica carencia de formación práctica en nuestros estudiantes. Esta situación, herencia de planes de estudio anteriores, resulta en la actualidad intolerable, sobre todo si pretendemos una adecuada implantación del Espacio Europeo de Educación Superior. Desde el área de Derecho Procesal de la Universidad de Murcia venimos afrontando desde hace un tiempo este problema estructural en la formación del estudiante con distintas metodologías -algunas de ellas tradicionales- que permiten al alumno acercarse a la práctica forense. La siguiente comunicación aborda el estudio de la noticia jurídica como instrumento especialmente útil para la enseñanza de la asignatura de primero de grado en Derecho “Sistema judicial español”. Para ello, se parte de una exhaustiva revisión bibliográfica existente sobre la materia y de la experiencia adquirida en el desarrollo de las mismas en la Universidad de Murcia. En la presente contribución presentamos una serie de propuestas metodológicas sistematizadas en atención a la correcta ubicación de la actividad en el calendario académico, los sujetos intervinientes en la misma, los requisitos necesarios para su preparación y desarrollo y, finalmente, su evaluación

La simulación de juicios en la asignatura de Derecho Procesal III: algunas propuestas metodológicas

La siguiente comunicación aborda el estudio de la simulación de juicios como instrumento especialmente útil para la enseñanza práctica del derecho procesal en el EEES. Para ello, se parte de una exhaustiva revisión de la bibliografía existente sobre la materia y de la experiencia adquirida en las simulaciones de la facultad de derecho de la Universidad de Murcia, en concreto, de las realizadas en la asignatura de Derecho Procesal III. A la luz de dicha experiencia se presentan una serie de propuestas metodológicas sistematizadas en atención a la correcta ubicación de la actividad en el calendario académico, los sujetos intervinientes en la misma, los requisitos necesarios para su preparación y desarrollo y, finalmente, su evaluación. Paralelamente, se ofrece una exposición de los resultados alcanzados, teniendo en cuenta el objetivo principal que se pretende alcanzar con la implementación de este ejercicio práctico, esto es: proporcionar al alumno una enseñanza práctica lo más cercana posible a la praxis forense

Numerical and experimental study of mode I delamination failure in composite laminates

Delamination is one of the most critical failure mechanisms in laminated composites. Usually it is assumed that delamination grows in a combination of modes I and II, but dominated by the mode I. In this work an experimental and numerical study of mode I delamination of laminated glass/epoxy [0/90]8S manufactured by resin infusion has been carried out. The value of has been obtained by the Double Cantilever Beam (DCB) test. Digital Image Correlation (DIC) has been used to measure the crack’s length. The numerical simulation was performed using two numerical techniques: Virtual Crack Closure Technique (VCCT) and the Cohesive Zone Model (CZM). Both techniques predict the onset of delamination. The VCCT is simple to use but it needs to define the area where delamination is going to start. The CZM allows the determination of the initial delamination area but it requires defining correctly the properties of the cohesive element.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Clinical research in pediatric organ transplantation

Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments