From Gods to men: A historical overview of the discovery of the chemical elements

To achieve the apparently simple Periodic Table of the Elements has implied tremendous efforts over thousands of years. In this paper we present a brief history of the discovery of the chemical elements from prehistory to the present day, revealing the controversies that arose on the way and claiming the important work performed by alchemists in the advancement of knowledge. This is especially important if we consider that alchemy had a period of existence of many thousands of years, while the "Chemistry", officially established as a science in the eighteenth century, has operated as such for only a few hundred years. Even so, if we consider the progress of discovery and isolation of chemical elements throughout history, it can be observed that the number of elements identified is achieved mainly in the nineteenth and twentieth centuries, reflecting the development of instrumental techniques, that facilitated this task.

Optimizing the Curie temperature of pseudo-binary RxR2-x ' Fe-17 (R, R ' = rare earth) for magnetic refrigeration

Several pseudo-binary RxR2-x'Fe-17 alloys (with R = Y, Ce, Pr, Gd and Dy) were synthesized with rhombohedral Th2Zn17-type crystal structure determined from x-ray and neutron powder diffraction. The choice of compositions was done with the aim of tuning the Curie temperature (T-C) in the 270 +/- 20 K temperature range, in order to obtain the maximum magneto-caloric effect around room temperature. The investigated compounds exhibit broad isothermal magnetic entropy changes, Delta S-M(T), with moderate values of the refrigerant capacity, even though the values of Delta S-M(Peak) are relatively low compared with those of the R2Fe17 compounds with R = Pr or Nd. The reduction on the Delta S-M(Peak) is explained in terms of the diminution in the saturation magnetization value. Furthermore, the Delta S-M(T) curves exhibit a similar caret-like behavior, suggesting that the magneto-caloric effect is mainly governed by the Fe-sublattice. A single master curve for Delta S-M/Delta S-M(Peak)(T) under different values of the magnetic field change are obtained for each compound by rescaling of the temperature axis.

Narratze-trebetasunen garapena: ipuin bera eta ume bera hiru adin ezberdinetan

Libro-homenaje editado por Mª José Ezeizabarrena y Ricardo Gómez

Erreferentziakidetasun-sareen etiketatze-metodologia EPEC Corpusean tratamendu konputazionalari begira

Libro-homenaje editado por Mª José Ezeizabarrena y Ricardo Gómez

Biochemical biomarkers in samples processed by different methods in Environmental Specimen Banks

In the last decades the creation of new Environmental Specimen Banks (ESB) is increasing due to the necessity of knowing the effects of pollutants in both the environment and human populations. ESBs analyze and store samples in order to understand the effects of chemicals, emerging substances and the environmental changes in biota. For a correct analysis of the effect induced by these variables, there is a need to add biological endpoints, such as biomarkers, to the endpoints based on chemical approaches which have being used until now. It is essential to adapt ESB´s sampling strategies in order to enable scientists to apply new biological methods. The present study was performed to obtain biochemical endpoints from samples stored in the BBEBB (Biscay Bay Environmental Biospecimen Bank) of the Marine Station of Plentzia (PIE - UPV/EHU). The main objective of the present work was to study the variability caused in biochemical biomarkers by different processing methods in mussels (Mytilus galloprovincialis) from two localities (Plentzia and Arriluze) with different pollution history. It can be concluded that the selected biomarkers (glutathione S-transferase and acetylcholinesterase) can be accurately measured in samples stored for years in the ESBs. The results also allowed the discrimination of both sampling sites. However, in a further step, the threshold levels and baseline values should be characterized for a correct interpretation of the results in relation to the assessment of the ecosystem health status.

Configuración de una red de sensores inalámbricos para adquisición de datos en tiempo real. Acondicionamiento y procesado de señales mediante FPGAs.

El análisis de las vibraciones es utilizado comúnmente en el mantenimiento de los motores. Es por ello que en la industria resulta imprescindible la monitorización de todas las máquinas que estén en funcionamiento; ya que el fallo de uno de los equipos puede causar grandes pérdidas. La adquisición de las vibraciones mediante una red de sensores y el posterior procesado de datos permiten monitorizar en tiempo real el estado de cada uno de los motores. Este trabajo tiene como objetivo diseñar e implementar un sistema para la medición de vibraciones y su posterior procesado para el análisis de los datos en el dominio de la frecuencia. La toma de datos éstos se realizará mediante una red de sensores inalámbricos, haciendo uso de un acelerómetro, y el procesado mediante una FPGA.

Máquinas de aprendizaje extremo para aplicaciones en ingeniería: implementaciones de alta velocidad sobre FPGAs

Los principales objetivos del presente trabajo son el estudio de las redes neuronales artificiales, los dispositivos reconfigurables de alta velocidad, como son las FPGAs, y su aplicación a un ejemplo concreto: el reconocimiento en tiempo real de diferentes tipos de suelo en imágenes de satélite. Con este fin se propone el diseño de una red neuronal y su implementación en un dispositivo de lógica programable usando el lenguaje de descripción del hardware VHDL (Very High Description Language). Otro de los objetivos del trabajo es conocer los entornos de desarrollo que los fabricantes de dispositivos de lógica programable ponen a disposición de los diseñadores y manejar herramientas de software matemático como Matlab.