Hydrogeological characterization of heterogeneous volcanic aquifers in the Canary Islands using recession analysis of deep water gallery discharge

Aquifers constitute the main freshwater supply of oceanic islands. Maintaining groundwater quantity and quality is of critical concern as demographic and climatic changes place additional pressures on already fragile water resources systems. Islands with heterogeneous volcanic aquifers pose additional difficulties in assessing their water resources. This work proposes an approach for improving the hydrogeological characterization of heterogeneous volcanic aquifer systems by making use of recession coefficients from deep water gallery discharge. To demonstrate the usefulness of this approach, hydrographs and recession curves from groundwater discharge of 30 water galleries on La Palma (Canary Islands) were evaluated. This analysis allowed us to obtain the main hydrogeological parameters of a volcanic aquifer system, in terms of hydraulic diffusivity. A Maillet-Boussinesq model with an exponential decay law was adopted, according to field observations of drainage discharge. The alpha coefficients of recession values ranged between 10−3 and 4·10−4 day−1 and showed significant spatial correlation with insular geology. Additionally, hydraulic diffusivity values of island hydrogeological domains were obtained from recession coefficients using the Rorabaugh-Singh method. Weighted storage coefficients for volcanic materials were in the range of 3% to 7%, with an average transmissivity in the range of 15 to 150 m2·day−1. The methodology proposed has demonstrated its usefulness in coping with local uncertainty in hydraulic characterization of insular aquifers associated with volcanic heterogeneity. This is an improvement compared to standard pumping tests, thus providing hydraulic parameters prior to numerical analysis for water management planning.This research was partially supported by the European Union's Horizon 2020 research and innovation programme under grant agreement 101037424, project ARSINOE (Climate resilient regions through systemic solutions and innovations), and the Spanish Research Agency (project SAGE4CAN PID2020-114218RA-100)

Structural integrity assessment of a nuclear vessel through ASME and master curve approaches using irradiation embrittlement predictions

ABSTRACT: The assessment of the structural integrity of nuclear vessels is based on a series of procedures developed in the 1970s and 1980s. On one hand, curves that, according to the American Society of Mechanical Engineers code, describe the relationship between steel toughness and temperature in the ductile-to-brittle transition region, based on the reference temperature concept RTNDT, were adopted in 1972. On the other hand, the material embrittlement derived from the exposure of steel to neutron irradiation is determined through the model included in “Regulatory Guide 1.99 Rev. 2,” published in 1988. Since then, there have been enormous advances in this field. For example, the Master Curve, based on the reference temperature T0, describes the relationship between toughness and temperature in the transition zone more realistically and with much more robust microstructural and mechanical foundations and uses the elastic-plastic fracture toughness KJc. Moreover, improved models have been developed to estimate the embrittlement of steel subjected to neutron irradiation, such as ASTM E900, Standard Guide for Predicting Radiation-Induced Transition Temperature Shift in Reactor Vessel Materials. This study is aimed at comparing the results obtained using traditional procedures to the improved alternatives developed later. For this purpose, the behavior of the steel of a nuclear vessel that is currently under construction has been experimentally characterized through RTNDT and T0 parameters. In addition, the material embrittlement has been quantified using “Regulatory Guide 1.99 Rev. 2” and ASTM E900. These experimental results have been transferred to the assessment of the structural integrity of the vessel to determine the pressure-temperature limit curves and size of the maximum admissible defect as a function of the operation time of the plant. The results have allowed the implicit overconservatism present in the traditional procedures to be quantified.This project was carried out with the financial support of Sociedad para el Desarrollo Regional de Cantabria (SODERCAN) and Equipos Nucleares S.A. (ENSA), to whom the authors would like to express their gratitude

Ingeniería Geológica en Terrenos Volcánicos. Métodos, Técnicas y Experiencias en las Islas Canarias

La presente obra es un compendio de conceptos, metodologías y técnicas útiles para acometer proyectos y obras en terrenos volcánicos desde el punto de vista de la ingeniería geológica y la geotecnia. El libro se presenta en tres partes diferenciadas. La primera es conceptual y metodológica, con capítulos que tratan sobre la clasificación de las rocas volcánicas con fines geotécnicos, la caracterización geomecánica, los problemas geotécnicos y constructivos asociados a los distintos materiales, y una guía metodológica para la redacción de informes geotécnicos para la edificación. La segunda parte aborda las aplicaciones a obras de ingeniería, incluyendo deslizamientos, obras subterráneas,infraestructuras marítimas y obras públicas. La tercera parte recoge capítulos dedicados a describir distintos casos prácticos de obras y proyectos en los que la problemática geotécnica en terrenos volcánicos ha tenido un papel relevante. Los capítulos han sido elaborados por técnicos y científicos de reconocido prestigio en el campo de la ingeniería geológica en terrenos volcánicos, que han plasmado en ellos sus conocimientos y experiencias en la materia.Los editores y autores de parte de los capítulos del libro, los Doctores Luis E. Hernández Gutiérrez (Geólogo) y Juan Carlos Santamarta Cerezal (Ingeniero de Montes, Civil y Minas), son los responsables del grupo de investigación INGENIA (Ingeniería Geológica, Innovación y Aguas). Su actividad investigadora comprende más de 200 publicaciones en el área de la ingeniería geológica, la geotecnia, medio ambiente y el aprovechamiento del agua en islas y terrenos volcánicos. En relación a la docencia han impartido y dirigido más de 90 seminarios y cursos de especialización a nivel nacional e internacional, incluyendo la organización de 4 congresos internacionales. Fueron premiados por la Universidad de La Laguna en los años 2012, 2013 y 2014 por su calidad docente e innovación universitaria, y son pioneros en los laboratorios virtuales para la enseñanza de la ingeniería. Participan activamente como profesores colaboradores e investigadores en varias universidades e instituciones españolas e internacionales. Todas sus publicaciones están disponibles en internet, con libre acceso. Ingeniería geológica en terrenos volcánicos, es una obra de gran interés para, consultores, técnicos de administraciones públicas, proyectistas y demás profesionales implicados en obras y proyectos de infraestructuras en terrenos volcánicos; también es útil para académicos y estudiantes de ingeniería o ciencias geológicas que quieran investigar o iniciarse en las singularidades que presentan los materiales volcánicos en la edificación o en la ingeniería civil y minera

Entramados emocionales: cuidados, vivencias y redes sociales virtuales

Este volumen explora las emociones a partir de las narrativas y prácticas del cuidado, su relación estrecha y compleja con la vivencia y la experiencia o en sus nexos con las redes virtuales. Los autores, en su estudio, colocan en el centro el análisis del trabajo y regulación emocional de cuidadoras y cuidadores. Dirigido a profesionistas, investigadoras e investigadores, así como estudiantes de las ciencias sociales y humanidades, este libro aborda la virtualidad en las emociones, un ámbito poco explorado por lo que los expertos ensayan propuestas sobre su vinculación con las lógicas mercantiles o sobre el papel del humor virtual en la configuración de la política nacional.ITESO, A.C

European Atlas of Natural Radiation

Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose. This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations. This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity; • be informed about the levels of natural radioactivity caused by different sources; • have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor; • and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.JRC.G.10-Knowledge for Nuclear Security and Safet

The mental health of young people looked after by local authorities in England A survey carried out in 2002 by the Survey Division of the Office for National Statistics on behalf of the Department of Health : summary report

SIGLEAvailable from British Library Document Supply Centre- DSC:m03/29479 / BLDSC - British Library Document Supply CentreGBUnited Kingdo