Application of well log tomography to the Dundee and Rogers City Limestones, Michigan Basin, USA

The Michigan Basin is located in the upper Midwest region of the United States and is centered geographically over the Lower Peninsula of Michigan. It is filled primarily with Paleozoic carbonates and clastics, overlying Precambrian basement rocks and covered by Pleistocene glacial drift. In Michigan, more than 46,000 wells have been drilled in the basin, many producing significant quantities of oil and gas since the 1920s in addition to providing a wealth of data for subsurface visualization. Well log tomography, formerly log-curve amplitude slicing, is a visualization method recently developed at Michigan Technological University to correlate subsurface data by utilizing the high vertical resolution of well log curves. The well log tomography method was first successfully applied to the Middle Devonian Traverse Group within the Michigan Basin using gamma ray log curves. The purpose of this study is to prepare a digital data set for the Middle Devonian Dundee and Rogers City Limestones, apply the well log tomography method to this data and from this application, interpret paleogeographic trends in the natural radioactivity. Both the Dundee and Rogers City intervals directly underlie the Traverse Group and combined are the most prolific reservoir within the Michigan Basin. Differences between this study and the Traverse Group include increased well control and “slicing” of a more uniform lithology. Gamma ray log curves for the Dundee and Rogers City Limestones were obtained from 295 vertical wells distributed over the Lower Peninsula of Michigan, converted to Log ASCII Standard files, and input into the well log tomography program. The “slicing” contour results indicate that during the formation of the Dundee and Rogers City intervals, carbonates and evaporites with low natural radioactive signatures on gamma ray logs were deposited. This contrasts the higher gamma ray amplitudes from siliciclastic deltas that cyclically entered the basin during Traverse Group deposition. Additionally, a subtle north-south, low natural radioactive trend in the center of the basin may correlate with previously published Dundee facies tracts. Prominent trends associated with the distribution of limestone and dolomite are not observed because the regional range of gamma ray values for both carbonates are equivalent in the Michigan Basin and additional log curves are needed to separate these lithologies.

Visible and Infrared Spectroscopical Applications

Spectra in the visible (VIS) and infrared (IR) region contain a wide variety of information about inorganic and organic substances in sediments. The information from the spectra enables a wide array of applications that allow quantitative, semiquantitative, and qualitative characterization of sediment. Due to the fact that instrument/experimental setups are simple, rapid, and cost-saving and that only small sample quantities are required, the technique has become valuable in paleolimnological and Quaternary science. This article summarizes the theoretical background of VIS and IR spectroscopy, explains the analytical process, introduces statistical tools used for interpretation of spectra, and provides examples of applications in Quaternary science.

Influence of the background wind on the local soil moisture-precipitation feedback

The importance of soil moisture anomalies on airmass convection over semiarid regions has been recognized in several studies. The underlying mechanisms remain partly unclear. An open question is why wetter soils can result in either an increase or a decrease of precipitation (positive or negative soil moisture–precipitation feedback, respectively). Here an idealized cloud-resolving modeling framework is used to explore the local soil moisture–precipitation feedback. The approach is able to replicate both positive and negative feedback loops, depending on the environmental parameters. The mechanism relies on horizontal soil moisture variations, which may develop and intensify spontaneously. The positive expression of the feedback is associated with the initiation of convection over dry soil patches, but the convective cells then propagate over wet patches where they strengthen and preferentially precipitate. The negative feedback may occur when the wind profile is too weak to support the propagation of convective features from dry to wet areas. Precipitation is then generally weaker and falls preferentially over dry patches. The results highlight the role of the midtropospheric flow in determining the sign of the feedback. A key element of the positive feedback is the exploitation of both low convective inhibition (CIN) over dry patches (for the initiation of convection) and high CAPE over wet patches (for the generation of precipitation).

A proposed framework to operationalize ESS for the mitigation of soil threats

Despite various research activities in the last decades across the world, many challenges remain to integrate the concept of ecosystem services (ESS) in decision-making, and a coherent approach to assess and value ESS is still lacking. There are a lot of different – often context-specific – ESS frameworks with their own definitions and understanding of terms. Based on a thorough review, the EU FP7 project RECARE (www.recare-project.eu) suggests an adapted framework for ecosystem services related to soils that can be used for practical application in preventing and remediating degradation of soils in Europe. This lays the foundation for the development and selection of appropriate methods to measure, evaluate, communicate and negotiate the services we obtain from soils with stakeholders in order to improve land management. Similar to many ESS frameworks, the RECARE framework distinguishes between an ecosystem and human well-being part. As the RECARE project is focused on soil threats, this is the starting point on the ecosystem part of the framework. Soil threats affect natural capital, such as soil, water, vegetation, air and animals, and are in turn influenced by those. Within the natural capital, the RECARE framework focuses especially on soil and its properties, classified in inherent and manageable properties. The natural capital then enables and underpins soil processes, while at the same time being affected by those. Soil processes, finally, are the ecosystem’s capacity to provide services, thus they support the provision of soil functions and ESS. ESS may be utilized to produce benefits for individuals and human society. Those benefits are explicitly or implicitly valued by individuals and human society. The values placed on those benefits influence policy and decision-making and thus lead to a societal response. Individual (e.g. farmers’) and societal decision making and policy determine land management and other (human) driving forces, which in turn affect soil threats and natural capital. In order to improve ESS with Sustainable Land Management (SLM) – i.e. measures aimed to prevent or remediate soil threats, the services identified in the framework need to be “manageable” (modifiable) for the stakeholders. To this end, effects of soil threats and prevention / remediation measures are captured by key soil properties as well as through bio-physical (e.g. reduced soil loss), socio-economic (e.g. reduced workload) and socio-cultural (e.g. aesthetics) impact indicators. In order to use such indicators in RECARE, it should be possible to associate the changes in soil processes to impacts of prevention / remediation measures (SLM). This requires the indicators to be sensitive enough to small changes, but still sufficiently robust to provide evidence of the change and attribute it to SLM.

Particle Accelerators and Detectors for medical Diagnostics and Therapy

This Habilitationsschrift (Habilitation thesis) is focused on my research activities on medical applications of particle physics and was written in 2013 to obtain the Venia Docendi (Habilitation) in experimental physics at the University of Bern. It is based on selected publications, which represented at that time my major scientific contributions as an experimental physicist to the field of particle accelerators and detectors applied to medical diagnostics and therapy. The thesis is structured in two parts. In Part I, Chapter 1 presents an introduction to accelerators and detectors applied to medicine, with particular focus on cancer hadrontherapy and on the production of radioactive isotopes. In Chapter 2, my publications on medical particle accelerators are introduced and put into their perspective. In particular, high frequency linear accelerators for hadrontherapy are discussed together with the new Bern cyclotron laboratory. Chapter 3 is dedicated to particle detectors with particular emphasis on three instruments I contributed to propose and develop: segmented ionization chambers for hadrontherapy, a proton radiography apparatus with nuclear emulsion films, and a beam monitor detector for ion beams based on doped silica fibres. Selected research and review papers are contained in Part II. For copyright reasons, they are only listed and not reprinted in this on-line version. They are available on the websites of the journals.

Cosmogenic activation of xenon and copper

Rare event search experiments using liquid xenon as target and detection medium require ultra-low background levels to fully exploit their physics potential. Cosmic ray induced activation of the detector components and, even more importantly, of the xenon itself during production, transportation and storage at the Earth's surface, might result in the production of radioactive isotopes with long half-lives, with a possible impact on the expected background. We present the first dedicated study on the cosmogenic activation of xenon after 345 days of exposure to cosmic rays at the Jungfraujoch research station at 3470m above sea level, complemented by a study of copper which has been activated simultaneously. We have directly observed the production of 7Be, 101Rh, 125Sb, 126I and 127Xe in xenon, out of which only 125Sb could potentially lead to background for a multi-ton scale dark matter search. The production rates for five out of eight studied radioactive isotopes in copper are in agreement with the only existing dedicated activation measurement, while we observe lower rates for the remaining ones. The specific saturation activities for both samples are also compared to predictions obtained with commonly used software packages, where we observe some underpredictions, especially for xenon activation.

Actividad insecticida de Ricinus Communis L. sobre Plodia Interpunctella Hbn. (Lepidoptera: Phycitinae).

La aplicación de insecticidas sintéticos como principal sistema de control de plagas de granos y productos almacenados ha originado el desarrollo de poblaciones de insectos resistentes a dichos químicos, la contaminación del medio ambiente y la acumulación de sustancias tóxicas en los alimentos. En este trabajo se evaluaron los efectos de la aplicación de molido de hojas de ricino sobre larvas de la «polilla de las harinas» (Lepidoptera: Phycitinae). Los molidos vegetales se obtuvieron a partir de hojas de Ricinus communis L. secadas en estufa a 40 ± 2 °C durante 48 horas y posteriormente molidas hasta lograr un polvo de textura similar a la harina de maíz, material con el que se mezcló a fin de lograr concentraciones de 5, 10 y 15 % y un testigo sin ricino. Las unidades experimentales consistieron en cajas de Petri con seis larvas de primer y segundo estadio y se efectuaron cinco repeticiones por tratamiento (n=120). Se registró el número de larvas, pupas y adultos vivos, cada cuatro días, hasta que las larvas sobrevivientes llegaron al estado adulto. Se calcularon los porcentajes de eficacia mediante la fórmula de Abbott. Los resultados se evaluaron por ANVA y test de Tukey. Se determinaron el tiempo efectivo medio (TE50) y concentración efectiva media (CE50) por el método Probit. Los resultados de mortalidad indicaron que la concentración al 15 % superó significativamente al resto de los tratamientos y al testigo.

Geochemistry and radionuclide content of sediment and water samples obtained from the Ob and Irtysh river, Russia

This paper reports the results of the investigations of 2006-2007 on the distribution and migration forms of artificial radionuclides and chemical elements in the Ob-Irtysh water system. Three regions were studied. One of them is a local segment of the Ob River upstream from the confluence with the Irtysh River; its investigation allowed us to estimate the general radioecological state of the aquatic environment affected by the activity of the Tomsk 7 plant. The second region is a local segment of the Irtysh River upstream from its confluence with the Ob River, where the influence of emissions from the NPO Mayak could be estimated. The third region is the water area of the Ob River after its confluence with the Irtysh River. It characterizes the real level of radioactive and chemical contamination of the middle reaches of the Ob River. In order to explain horizontal variations in the distribution of radionuclides in the upper layer of bottom sediments collected at various sites, the results of sorption-kinetic experiments with radioactive tracers in the precipitate-solution system were used. The investigation of the migration forms of trace elements and radionuclides occurring in river water was based on the method of tangential-flow membrane filtration. Chemical element contents were determined in 400-ml water samples. A set of Millipore polysulfone membranes with pore sizes of 8, 1.2, 0.45, 0.1, and 0.025 µm was employed. Taking into account the ultralow specific concentrations of radionuclides in the water, they were analyzed in 300-500 litre samples using Millipore polysulfone membranes with pore sizes of 0.45 µm and 15 kDa. This allowed us to estimate the percentages of cesium-137 and plutonium-239, 240 in the suspended particulate fraction, colloids, and dissolved species.

DISPRO datasets for validation of coastal hydrodynamic models

Appropriate field data are required to check the reliability of hydrodynamic models simulating the dispersion of soluble substances in the marine environment. This study deals with the collection of physical measurements and soluble tracer data intended specifically for this kind of validation. The intensity of currents as well as the complexity of topography and tides around the Cap de La Hague in the center of the English Channel makes it one of the most difficult areas to represent in terms of hydrodynamics and dispersion. Controlled releases of tritium - in the form of HTO - are carried out in this area by the AREVA-NC plant, providing an excellent soluble tracer. A total of 14 493 measurements were acquired to track dispersion in the hours and days following a release. These data, supplementing previously gathered data and physical measurements (bathymetry, water-surface levels, Eulerian and Lagrangian current studies) allow us to test dispersion models from the hour following release to periods of several years which are not accessible with dye experiments. The dispersion characteristics are described and methods are proposed for comparing models against measurements. An application is proposed for a 2 dimensions high-resolution numerical model. It shows how an extensive dataset can be used to build, calibrate and validate several aspects of the model in a highly dynamic and macrotidal area: tidal cycle timing, tidal amplitude, fixed-point current data, hodographs. This study presents results concerning the model's ability to reproduce residual Lagrangian currents, along with a comparison between simulation and high-frequency measurements of tracer dispersion. Physical and tracer data are available from the SISMER database of IFREMER (www.ifremer.fr/sismer/catal). This tool for validation of models in macro-tidal seas is intended to be an open and evolving resource, which could provide a benchmark for dispersion model validation.

El microclima urbano en los espacios abiertos : estudio de casos en Madrid

El microclima urbano juega un rol importante en el consumo energético de los edificios y en las sensaciones de confort en los espacios exteriores. La urgente necesidad de aumentar la eficiencia energética, reducir las emisiones de los contaminantes y paliar la evidente falta de sostenibilidad que afecta a las ciudades, ha puesto la atención en el urbanismo bioclimático como referente para una propuesta de cambio en la forma de diseñar y vivir la ciudad. Hasta ahora las investigaciones en temas de microclima y eficiencia energética se han concentrado principalmente en como orientar el diseño de nuevos desarrollo. Sin embargo los principales problemas de la insostenibilidad de las actuales conurbaciones son el resultado del modelo de crecimiento especulativo y altamente agotador de recursos que han caracterizado el boom inmobiliario de las últimas décadas. Vemos entonces, tanto en España como en el resto de los Países Europeos, la necesidad de reorientar el sector de la construcción hacía la rehabilitación del espacio construido, como una alternativa capaz de dar una solución más sostenible para el mercado inmobiliario. En este propósito de mejorar la calidad de las ciudades actuales, el espacio público juega un papel fundamental, sobre todo como lugar para el encuentro y la socialización entre los ciudadanos. La sensación térmica condiciona la percepción de un ambiente, así que el microclima puede ser determinante para el éxito o el fracaso de un espacio urbano. Se plantea entonces cómo principal objetivo de la investigación, la definición de estrategias para el diseño bioclimático de los entornos urbanos construidos, fundamentados en las componentes morfotipológica, climática y de los requerimientos de confort para los ciudadanos. Como ulterior elemento de novedad se decide estudiar la rehabilitación de los barrios de construcción de mediado del siglo XX, que en muchos casos constituyen bolsas de degrado en la extendida periferia de las ciudades modernas. La metodología empleada para la investigación se basa en la evaluación de las condiciones climáticas y de confort térmico de diferentes escenarios de proyecto, aplicados a tres casos de estudio situados en un barrio periurbano de la ciudad de Madrid. Para la determinación de los parámetros climáticos se han empleado valores obtenidos con un proceso de simulación computarizada, basados en los principios de fluidodinámica, termodinámica y del intercambio radioactivo en el espacio construido. A través de uso de programas de simulación podemos hacer una previsión de las condiciones microclimáticas de las situaciones actuales y de los efectos de la aplicación de medidas. La gran ventaja en el uso de sistemas de cálculo es que se pueden evaluar diferentes escenarios de proyecto y elegir entre ellos el que asegura mejores prestaciones ambientales. Los resultados obtenidos en los diferentes escenarios han sido comparados con los valores de confort del estado actual, utilizando como indicador de la sensación térmica el índice UTCI. El análisis comparativo ha permitido la realización de una tabla de resumen donde se muestra la evaluación de las diferentes soluciones de rehabilitación. Se ha podido así demostrar que no existe una solución constructiva eficaz para todas las aplicaciones, sino que cada situación debe ser estudiada individualmente, aplicando caso por caso las medidas más oportunas. Si bien los sistemas de simulación computarizada pueden suponer un importante apoyo para la fase de diseño, es responsabilidad del proyectista emplear las herramientas más adecuadas en cada fase y elegir las soluciones más oportunas para cumplir con los objetivos del proyecto. The urban microclimate plays an important role on buildings energy consumption and comfort sensation in exterior spaces. Nowadays, cities need to increase energy efficiency, reduce the pollutants emissions and mitigate the evident lack of sustainability. In reason of this, attention has focused on the bioclimatic urbanism as a reference of change proposal of the way to design and live the city. Hitherto, the researches on microclimate and energy efficiency have mainly concentrated on guiding the design of new constructions. However the main problems of unsustainability of existing conurbations are the result of the growth model highly speculative and responsible of resources depletion that have characterized the real estate boom of recent decades. In Spain and other European countries, become define the need to redirect the construction sector towards urban refurbishment. This alternative is a more sustainable development model and is able to provide a solution for the real estate sector. In order to improve the quality of today's cities, the public space plays a key role, especially in order to provide to citizens places for meeting and socializing. The thermal sensation affects the environment perception, so microclimate conditions can be decisive for the success or failure of urban space. For this reasons, the main objective of this work is focused on the definition of bioclimatic strategies for existing urban spaces, based on the morpho-typological components, climate and comfort requirements for citizens. As novelty element, the regeneration of neighborhoods built in middle of the twentieth century has been studied, because are the major extended in periphery of modern cities and, in many cases, they represent deprived areas. The research methodology is based on the evaluation of climatic conditions and thermal comfort of different project scenarios, applied to three case studies located in a suburban neighborhood of Madrid. The climatic parameters have been obtained by computer simulation process, based on fluid dynamics, thermodynamics and radioactive exchange in urban environment using numerical approach. The great advantage in the use of computing systems is the capacity for evaluate different project scenarios. The results in the different scenarios were compared with the comfort value obtained in the current state, using the UTCI index as indicator of thermal sensation. Finally, an abacus of the thermal comfort improvement obtained by different countermeasures has been performed. One of the major achievement of doctoral work is the demonstration of there are not any design solution suitable for different cases. Each situation should be analyzed and specific design measures should be proposed. Computer simulation systems can be a significant support and help the designer in the decision making phase. However, the election of the most suitable tools and the appropriate solutions for each case is designer responsibility.

Impacto y protección radiológica asociados al transporte de residuos de alta actividad (RAA) al almacén temporal centralizado (ATC) en España

Las cuestiones relacionadas con el transporte de residuos radiactivos de alta actividad (RAA) al previsto almacén temporal centralizado (ATC) en Villar de Cañas (Cuenca) están de actualidad, debido a la movilidad que se espera en un futuro próximo, el compromiso con el medio ambiente, la protección de las personas, así, como la normativa legal reguladora. En esta tesis se ha evaluado el impacto radiológico asociado a este tipo de transportes mediante una nueva herramienta de procesamiento de datos, que puede ser de utilidad y servir como documentación complementaria a la recogida en el marco legal del transporte. Además puede facilitar el análisis desde una perspectiva más científica, para investigadores, responsables públicos y técnicos en general, que pueden utilizar dicha herramienta para simular distintos escenarios de transportes radiactivos basados únicamente en datos de los materiales de entrada y las rutas elegidas. Así, conociendo el nivel de radiación a un metro del transporte y eligiendo una ruta, obtendremos los impactos asociados, tales como las poblaciones afectadas, la dosis recibida por la persona más expuesta, el impacto radiológico global, las dosis a la población en el trayecto y el posible detrimento de su salud. En España se prevé una larga “ruta radiactiva” de más de 2.000 kilómetros, por la que el combustible nuclear gastado se transportará presumiblemente por carretera desde las centrales nucleares hasta el ATC, así como los residuos vitrificados procedentes del reprocesado del combustible de la central nuclear Vandellos I, que en la actualidad están en Francia. Como conclusión más importante, se observa que la emisión de radiaciones ionizantes procedentes del transporte de residuos radiactivos de alta actividad en España, en operación normal, no es significativa a la hora de generar efectos adversos en la salud humana y su impacto radiológico puede considerarse despreciable. En caso de accidente, aunque la posibilidad del suceso es remota, las emisiones, no serán determinantes a la hora de generar efectos adversos en la salud humana. Issues related to the transport of high level radioactive wastes (HLW) to the new centralised temporary storage facility to be built in Villar de Cañas (Cuenca) are attracting renewed attention due to the mobility expected in the near future for these materials, the commitment to the environment, the protection of persons and the legal regulatory standards. This study assesses the radiological impacts associated with this type of transport by means of a new dataprocessing tool, which may be of use and serve as documentation complementary to that included in the legal framework covering transport. Furthermore, it may facilitate analysis from a more scientific perspective for researchers, public servants and technicians in general, who may use the tool to simulate different radioactive transport scenarios based only on input materials data and the routes selected. Thus, by knowing the radiation level at a distance of one metre from the transport and selecting a route, it is possible to obtain the associated impacts, such as the affected populations, the dose received by the most exposed individual, the overall radiological impact and the doses to the public en route and the possible detriment to their health. In Spain a long “radioactive route” of more than 2,000 kilometres is expected, along which spent nuclear fuels will be transported – foreseeably by road – from the nuclear power plants to the CTS facility. The route will also be used for the vitrified wastes from fuel reprocessing of the fuel from Vandellós I nuclear power plant, which are currently in France. In conclusion, it may be observed that the emission of ionising radiations from transport of high level radioactive wastes in Spain is insignificant, in normal operations, as regards the generation of adverse effects for human health, and that the radiological impact may be considered negligible. In the event of an accident, the possibility of which is remote, the emissions will not be also a very determining factor as regards adverse effects for human health.

Caracterización de los parámetros de resistencia al corte y erosionabilidad del suelo para su aplicación en los problemas de estabilidad de taludes en obras lineales

La tesis se organiza en un volumen de Memoria integrada por once capítulos que constituyen el cuerpo de la tesis y otro volumen de Apéndices titulado “Caracterización geotécnica de Base de los suelos de España” que reúne en forma de cuadros las características de textura, permeabilidad, humedad-succión, erosionabilidad y resistencia al corte de los cuarenta y dos perfiles de suelos representativos de los tipos del Mapa de suelos De España. Estos cuadros han sido elaborados originalmente por la doctorando durante sus estudios para la obtención del DEA de la Suficiencia Investigadora, excepto los de resistencia al corte que lo han sido también por la doctorando de forma original, pero ya en la etapa de redacción de la tesis. En el Capítulo 1 “Introducción” se describe la motivación, antecedentes, alcance y contenido de la tesis, ordenado según el índice que en él se incluye. Los Capítulos 2 “Meteorización, 3 “Balance Hídrico” y 4 “Humedades características” constituyen el “estado del arte” en el momento actual de los temas de geotecnia ambiental relacionados con la degradación de la superficie terrestre y la estabilidad de taludes. El Capítulo 2, tras matizar algunas generalidades, aporta elementos para la cuantificación de la alteración de rocas como el “índice climático de Weinert” y de la erosión de suelos como la “ecuación universal de pérdida de suelo (U.S.L.E.)” El Capítulo 3, partiendo de los fenómenos de precipitación y evapotranspiración, plantea el balance hídrico en vertientes con instrumentos para evaluar la infiltración y la escorrentía, conceptos imprescindibles para adentrarse en los de resistencia y erosionabilidad del conjunto suelo-agua. En los Apéndices A1 y A2, se recogen valores de coeficientes de infiltración en condiciones saturadas y no saturadas de los perfiles de suelos del Mapa de España. El Capítulo 4 se dedica al estudio de este conjunto suelo-agua con la definición de conceptos que lo caracterizan, basados en la relación entre los contenidos de ambos elementos o “humedad”, sus valores máximos y mínimos y la forma en la que es retenida el agua por el suelo. Este capítulo acaba con el concepto de “Curva característica Suelo-Agua/Soil Water Characteristic curve (SWCC)”, que liga el contenido de agua de un suelo con la tensión a la que está retenida (uauw) “succión” o con su expresión más usual “pF”. En el Apéndice A 3 se adjuntan las SWCC de los perfiles de suelos del Mapa de suelos de España. En el Capítulo 5 “Resistencia al corte de los suelos”, se detalla la influencia que tienen sobre la resistencia de los suelos factores como el paso del tiempo, el contenido de humedad y la presencia y tipo de vegetación en la superficie del suelo estudiado. El Capítulo 6 “Evaluación de la erosión”, analiza el factor de erosionabilidad del suelo “factor K” de la U.S.L.E., su evaluación en función de la textura, estructura y permeabilidad del suelo, con la estimación hecha para los cuarenta y dos perfiles de suelos del Mapa de España, contenida en el Apéndice 4. En el Capítulo 7 “Metodología de diseño” se hacen en su primera parte unas consideraciones geoambientales de diseño aplicables al estudio de los problemas de inestabilidades en taludes. La segunda parte constituye el núcleo de la tesis con la propuesta de “estimación de los parámetros de resistencia al corte del suelo”, consecuente con las teorías y metodología de análisis expuesta en los capítulos anteriores. En el Apéndice A 5 se presentan los valores de los parámetros coulombianos de resistencia al corte, ”c y Ф” estimados según la caracterización climática a partir del índice de Thornthwaite, en condicionesde diseño para humedades naturales máxima y mínima de los cuarenta y dos perfiles de suelos del Mapa de suelos de España. El Capítulo 8 “Aplicación a casos reales” se considera de gran interés al constituir una auténtica continuación de la segunda parte del capítulo anterior, desarrollando la metodología expuesta en él a cuatro problemáticas de infraestructuras de obras lineales, relacionadas con problemas de erosión y deslizamientos en taludes. El Capítulo 9 “Ensayos de referencia” se incluye como punto de apoyo (referencia) a las teorías expuestas, valorando la idoneidad de los tipos de ensayos y tipos de suelos seleccionados (Laboratorio de Geotecnia del CEDEX y Laboratorio Hong-Kong University of Science and Technology), utilizados para la obtención, por correlaciones deducidas, de las curvas SWCC de los perfiles de suelos del Mapa de España, incluídas en el Apéndice A 3, como se ha citado antes. En el Capítulo 10 “Conclusiones y Futuras Líneas de Investigación”se apuntan en primer lugar unas conclusiones que, a juicio de la doctorando, se pueden extraer con interés de esta tesis y a continuación se esbozan unas posibles líneas de investigación, fundamentalmente de tipo experimental, que complementarían los avances derivados de esta tesis o podrían esclarecer y abrir nuevas interpretaciones de los fenómenos naturales de erosión y estabilidad de taludes en los que ésta se ha centrado. Finalmente, en el Capítulo 11 “Bibliografía” se han reunido 328 referencias que reflejan una visión amplia y bastante completa del tema tratado, obtenida complementando las de tesis anteriores sobre esta singular materia (“Efecto estabilizador de la vegetación en taludes”, L Fort 1975 y “Determinación de las características de fricción en el contacto suelo-geotextil a diferentes succiones, mediante equipos de laboratorio singulares”, E Asanza 2009), con propias de la doctorando (9) y las consideradas de mayor interés de los últimos Congresos sobre Suelos no saturados,”Unsat 95”, “Unsat 2002” y “Unsat 2011” entre otros. ABSTRACT The thesis is organized in a volume of Memory composed of eleven chapters that make up the body of the thesis and other Appendices volume entitled "Geotechnical characterization of basis of the soils of Spain" that combines the characteristics of texture, permeability, moisture-suction, erosionability, and shear strength of forty-two profiles of soils representative of the types of the soil of Spain map in the form of pictures. These pictures have been produced originally by the student during their studies to obtain the DEA of the research, except those of the shear strength, also been done by the PhD student in an original way, but already at the stage of drafting of the thesis. Chapter 1 "Introducción" describes the motivation, background, scope and content of the thesis, ordered according to the index that is included. The Chapters: 2 "Weathering, 3 “Water Balance” and 4 “moisture characteristics" are the "State of the art" at the present time of geotechnical environmental issues related to the degradation of the Earth's surface and the slope stability. Chapter 2 after clarify some general information, provides elements for the quantification of the alteration of rocks as "Weinert climate index" and soil erosion as the "universal equation of loss of soil (U.S.L.E.)" Chapter 3, on the basis of the phenomena of precipitation and evapotranspiration, raises the water balance in sheds with instruments to evaluate infiltration and runoff, essential concepts into the resistance and erosionability water-soil joint. Values of soils coefficients of infiltration in saturated and unsaturated conditions from the Spain map of profiles are collected in the Appendices A1 and A2. Chapter 4 is dedicated to the study of this joint “soil-water”, with the definition of concepts that characterize it, based on the relationship between the contents of both elements or “moisture”, their maximum and minimum values and the way in which water is retained by the soil. This chapter ends with the concept of “Soil Water Characteristic curve (SWCC)", which linked the water content of a soil with the stress that it is retained (ua-uw) "suction" or its expression more usual "pF". The SWCC of the profiles of soils of the Spain soils Map are attached in the Appendix 3. In Chapter 5 “Soils shear strength”,is detailed the influence that they have on the resistance of soils factors such as the passage of time, the content of moisture and the presence and type of vegetation on the surface of the studied soil. Chapter 6 "Assessment of erosion", analyses the soil erodibility factor "Kfactor" of the U.S.L.E., its evaluation based on texture, structure and permeability of the soil, with the estimate for forty-two profiles of soils on the Spain Soils Map, contained in Appendix 4. Chapter 7 "Design methodology" some considerations are made in the first part geo-environmental design applicable to the study of the problems of instabilities in slopes. The second part constitutes the core of the thesis with the proposal of “estimation of parameters of shear strength”, of the soils consistent with theories and analytical methodology outlined in the previous chapters. Appendix A 5 presents the values of the coulombians parameters of shear strength, "c and Ф" according to the characterization of climate from the index of Thornthwaite, in design for natural moisture conditions maximum and minimum of forty-two profils of Spain Soils Map Chapter 8 "Application to real cases" is considered of great interest to constitute a true continuation of the second part of the previous chapter, developing the methodology exposed it to four problems of civil-works infrastructure, related to problems of erosion and landslides in slopes. Chapter 9 "Tests of reference" is included as point of support (reference) to the theories exposed, assessing the suitability of the types of tests and types of selected soils (Geotechnical laboratory of CEDEX and laboratory Hongkong University of Science and Technology), used to obtain, by deduced correlations, of curves SWCC of soils profiles on the Spain Soils Map, included in Appendix A. 3, as it was mentioned before. Chapter 10 "Conclusions and future research lines" are running first conclusions which, in the opinion of the candidate, can be extracted with interest of this thesis, and then, it outlines some possible lines of research, mainly experimental, which would complement the advances arising from this thesis or could clarify and open new interpretations of natural phenomena of erosion and slope stability in which it has focused. Finally, in Chapter 11 "Bibliography" 328 references have been included which reflect a broad and fairly comprehensive view of the subject matter, obtained complementing those of the previous theses on this singular issue ("Vegetation stabilizing effect on slopes", L Fort 1975, and "Determination of the characteristics of friction in the contact soil-geotextile to different-suctions, through special laboratory equipment", E Asanza 2009) with some of them from of the candidate (9) and the others from of the considered as the most interesting of recent conferences on unsaturated soils, "Unsat 95", "Unsat2002" and "Unsat 2011" among others.

Implementation of the Heated Pulsed Theory using actively heated fiber optics: measurements of soil volumetric water content and soil volumetric heat capacity

Existe una creciente necesidad de hacer el mejor uso del agua para regadío. Una alternativa eficiente consiste en la monitorización del contenido volumétrico de agua (θ), utilizando sensores de humedad. A pesar de existir una gran diversidad de sensores y tecnologías disponibles, actualmente ninguna de ellas permite obtener medidas distribuidas en perfiles verticales de un metro y en escalas laterales de 0.1-1,000 m. En este sentido, es necesario buscar tecnologías alternativas que sirvan de puente entre las medidas puntuales y las escalas intermedias. Esta tesis doctoral se basa en el uso de Fibra Óptica (FO) con sistema de medida de temperatura distribuida (DTS), una tecnología alternativa de reciente creación que ha levantado gran expectación en las últimas dos décadas. Específicamente utilizamos el método de fibra calentada, en inglés Actively Heated Fiber Optic (AHFO), en la cual los cables de Fibra Óptica se utilizan como sondas de calor mediante la aplicación de corriente eléctrica a través de la camisa de acero inoxidable, o de un conductor eléctrico simétricamente posicionado, envuelto, alrededor del haz de fibra óptica. El uso de fibra calentada se basa en la utilización de la teoría de los pulsos de calor, en inglés Heated Pulsed Theory (HPP), por la cual el conductor se aproxima a una fuente de calor lineal e infinitesimal que introduce calor en el suelo. Mediante el análisis del tiempo de ocurrencia y magnitud de la respuesta térmica ante un pulso de calor, es posible estimar algunas propiedades específicas del suelo, tales como el contenido de humedad, calor específico (C) y conductividad térmica. Estos parámetros pueden ser estimados utilizando un sensor de temperatura adyacente a la sonda de calor [método simple, en inglés single heated pulsed probes (SHPP)], ó a una distancia radial r [método doble, en inglés dual heated pulsed probes (DHPP)]. Esta tesis doctoral pretende probar la idoneidad de los sistemas de fibra óptica calentada para la aplicación de la teoría clásica de sondas calentadas. Para ello, se desarrollarán dos sistemas FO-DTS. El primero se sitúa en un campo agrícola de La Nava de Arévalo (Ávila, España), en el cual se aplica la teoría SHPP para estimar θ. El segundo sistema se desarrolla en laboratorio y emplea la teoría DHPP para medir tanto θ como C. La teoría SHPP puede ser implementada con fibra óptica calentada para obtener medidas distribuidas de θ, mediante la utilización de sistemas FO-DTS y el uso de curvas de calibración específicas para cada suelo. Sin embargo, la mayoría de aplicaciones AHFO se han desarrollado exclusivamente en laboratorio utilizando medios porosos homogéneos. En esta tesis se utiliza el programa Hydrus 2D/3D para definir tales curvas de calibración. El modelo propuesto es validado en un segmento de cable enterrado en una instalación de fibra óptica y es capaz de predecir la respuesta térmica del suelo en puntos concretos de la instalación una vez que las propiedades físicas y térmicas de éste son definidas. La exactitud de la metodología para predecir θ frente a medidas puntuales tomadas con sensores de humedad comerciales fue de 0.001 a 0.022 m3 m-3 La implementación de la teoría DHPP con AHFO para medir C y θ suponen una oportunidad sin precedentes para aplicaciones medioambientales. En esta tesis se emplean diferentes combinaciones de cables y fuentes emisoras de calor, que se colocan en paralelo y utilizan un rango variado de espaciamientos, todo ello en el laboratorio. La amplitud de la señal y el tiempo de llegada se han observado como funciones del calor específico del suelo. Medidas de C, utilizando esta metodología y ante un rango variado de contenidos de humedad, sugirieron la idoneidad del método, aunque también se observaron importantes errores en contenidos bajos de humedad de hasta un 22%. La mejora del método requerirá otros modelos más precisos que tengan en cuenta el diámetro del cable, así como la posible influencia térmica del mismo. ABSTRACT There is an increasing need to make the most efficient use of water for irrigation. A good approach to make irrigation as efficient as possible is to monitor soil water content (θ) using soil moisture sensors. Although, there is a broad range of different sensors and technologies, currently, none of them can practically and accurately provide vertical and lateral moisture profiles spanning 0-1 m depth and 0.1-1,000 m lateral scales. In this regard, further research to fulfill the intermediate scale and to bridge single-point measurement with the broaden scales is still needed. This dissertation is based on the use of Fiber Optics with Distributed Temperature Sensing (FO-DTS), a novel approach which has been receiving growing interest in the last two decades. Specifically, we employ the so called Actively Heated Fiber Optic (AHFO) method, in which FO cables are employed as heat probe conductors by applying electricity to the stainless steel armoring jacket or an added conductor symmetrically positioned (wrapped) about the FO cable. AHFO is based on the classic Heated Pulsed Theory (HPP) which usually employs a heat probe conductor that approximates to an infinite line heat source which injects heat into the soil. Observation of the timing and magnitude of the thermal response to the energy input provide enough information to derive certain specific soil thermal characteristics such as the soil heat capacity, soil thermal conductivity or soil water content. These parameters can be estimated by capturing the soil thermal response (using a thermal sensor) adjacent to the heat source (the heating and the thermal sources are mounted together in the so called single heated pulsed probe (SHPP)), or separated at a certain distance, r (dual heated pulsed method (DHPP) This dissertation aims to test the feasibility of heated fiber optics to implement the HPP theory. Specifically, we focus on measuring soil water content (θ) and soil heat capacity (C) by employing two types of FO-DTS systems. The first one is located in an agricultural field in La Nava de Arévalo (Ávila, Spain) and employ the SHPP theory to estimate θ. The second one is developed in the laboratory using the procedures described in the DHPP theory, and focuses on estimating both C and θ. The SHPP theory can be implemented with actively heated fiber optics (AHFO) to obtain distributed measurements of soil water content (θ) by using reported soil thermal responses in Distributed Temperature Sensing (DTS) and with a soil-specific calibration relationship. However, most reported AHFO applications have been calibrated under laboratory homogeneous soil conditions, while inexpensive efficient calibration procedures useful in heterogeneous soils are lacking. In this PhD thesis, we employ the Hydrus 2D/3D code to define these soil-specific calibration curves. The model is then validated at a selected FO transect of the DTS installation. The model was able to predict the soil thermal response at specific locations of the fiber optic cable once the surrounding soil hydraulic and thermal properties were known. Results using electromagnetic moisture sensors at the same specific locations demonstrate the feasibility of the model to detect θ within an accuracy of 0.001 to 0.022 m3 m-3. Implementation of the Dual Heated Pulsed Probe (DPHP) theory for measurement of volumetric heat capacity (C) and water content (θ) with Distributed Temperature Sensing (DTS) heated fiber optic (FO) systems presents an unprecedented opportunity for environmental monitoring. We test the method using different combinations of FO cables and heat sources at a range of spacings in a laboratory setting. The amplitude and phase-shift in the heat signal with distance was found to be a function of the soil volumetric heat capacity (referred, here, to as Cs). Estimations of Cs at a range of θ suggest feasibility via responsiveness to the changes in θ (we observed a linear relationship in all FO combinations), though observed bias with decreasing soil water contents (up to 22%) was also reported. Optimization will require further models to account for the finite radius and thermal influence of the FO cables, employed here as “needle probes”. Also, consideration of the range of soil conditions and cable spacing and jacket configurations, suggested here to be valuable subjects of further study and development.