A rational fraction polynomials model to study vertical dynamic wheel-rail interaction

This paper presents a model designed to study vertical interactions between wheel and rail when the wheel moves over a rail welding. The model focuses on the spatial domain, and is drawn up in a simple fashion from track receptances. The paper obtains the receptances from a full track model in the frequency domain already developed by the authors, which includes deformation of the rail section and propagation of bending, elongation and torsional waves along an infinite track. Transformation between domains was secured by applying a modified rational fraction polynomials method. This obtains a track model with very few degrees of freedom, and thus with minimum time consumption for integration, with a good match to the original model over a sufficiently broad range of frequencies. Wheel-rail interaction is modelled on a non-linear Hertzian spring, and consideration is given to parametric excitation caused by the wheel moving over a sleeper, since this is a moving wheel model and not a moving irregularity model. The model is used to study the dynamic loads and displacements emerging at the wheel-rail contact passing over a welding defect at different speeds.

Diferencias estéticas entre teatro y cine. Hacia una teoría de la adaptación dramática

Eguíluz, Federico; Merino, Raquel; Olsen, Vickie; Pajares, Eterio; Santamaría, José Miguel (eds.)

All the King's Men: del Pulitzer al Oscar

Eterio Pajares, Raquel Merino y José Miguel Santamaría (eds.)

Desarrollo y aplicación de técnicas avanzadas de medida de compuestos orgánicos volátiles en la atmósfera

331 p.

Creating a German–Basque Electronic Dictionary for German Learners

Revista OJS

Nuevos monumentos funerarios de Belorado (Burgos)

[ES] En el siguiente trabajo se dan a conocer cuatro nuevas estelas funerarias de época romana de Belorado (Burgos). Como la inmensa mayoría de las estelas localizadas en este lugar, estas también guardan una serie de peculiaridades externas e internas comunes que han llevado a considerarlo un conjunto epigráfico específico del lugar. Es por ello que en las siguientes páginas presentaremos una descripción y análisis de las mismas a la vez que las contextualizamos dentro del conjunto y el lugar donde fueron localizadas.

New Nuclear SNP Markers Unravel the Genetic Structure and Effective Population Size of Albacore Tuna (Thunnus alalunga)

In the present study we have investigated the population genetic structure of albacore (Thunnus alalunga, Bonnaterre 1788) and assessed the loss of genetic diversity, likely due to overfishing, of albacore population in the North Atlantic Ocean. For this purpose, 1,331 individuals from 26 worldwide locations were analyzed by genotyping 75 novel nuclear SNPs. Our results indicated the existence of four genetically homogeneous populations delimited within the Mediterranean Sea, the Atlantic Ocean, the Indian Ocean and the Pacific Ocean. Current definition of stocks allows the sustainable management of albacore since no stock includes more than one genetic entity. In addition, short-and long-term effective population sizes were estimated for the North Atlantic Ocean albacore population, and results showed no historical decline for this population. Therefore, the genetic diversity and, consequently, the adaptive potential of this population have not been significantly affected by overfishing.