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The presence of radon in soil poses a significant health risk when it enters and concentrates indoors. The primary health problem associated with radon exposure is lung cancer, but it can also contribute to other respiratory issues. Estimating radon potential is a challenging task caused by the interaction of various environmental, geological, and variability factors. Although efforts are ongoing to improve radon potential assessment methodologies, there is a lack of software tools that estimate and model radon potential in different scenarios. The paper aims to develop a novel web-based software tool, RadonPotential, that predicts Geogenic Radon Potential by considering variations in climate and soil textures. The program runs using a constant radon concentration or estimates its concentration from the radium activity. RadonPotential calculates the transport of radon through a soil profile based on water content and soil texture. It also determines the dynamics of soil water content in different climates, incorporating long-term weather data under various climatic scenarios and local weather time series. The web-based format of the program increases its dissemination, usage, and manageability among a larger user base compared to an installable computer program. The program aims to provide a simplified and effective characterization of radon potential levels accessible to a wide range of scientists, technical experts and policymakers in developing strategies not only for radon measurement and mitigation buildings but also for developing more reliable large-scale radon potential maps.

Esta tesis consiste en tres trabajos enfocados al desarrollo de varios sistemas que sean capaces de registrar el movimiento sísmico de la tierra y grabarlo en ficheros para su posterior análisis. Partimos de la base de la creación de una serie de sensores para el registro del ruido sísmico, dispuestos en forma circular y así poder detectar las ondas sismológicas. La hipótesis con la que trabajamos es la de interconectar entre si los nodos sensoriales y de esta manera crear una red sensorial la cual reporte las muestras de ruido sísmico a un servidor y éste sea capaz de mostrar la forma de las señales en tiempo real. Este sistema nos facilitará el almacenamiento y tratamiento de los datos registrados por cada uno de los nodos con la posibilidad de análisis casi instantáneo. Como línea de partida, se ha implementado un sistema de comunicación sensorial a través de una red wifi en la cual se monitoriza en tiempo real un sistema de climatización y se optimiza el consumo de éste regulando distintos factores en función de los valores de los sensores distribuidos por toda el área afectada. Este trabajo ha generado el primer artículo de investigación publicado en la revista Sensors (doi:10.3390/s20133611). El código generado junto con la experiencia, las pruebas realizadas y los resultados obtenidos nos van a servir para los sensores sísmicos. En el segundo trabajo se ha diseñado, implementado y probado un sistema de zonificación mediante una red wireless de sensores triaxiales los cuales son capaces de registrar en tiempo real el movimiento sísmico de edificios y mostrar estas señales en un navegador cliente ubicado en Internet. Este trabajo ha generado el segundo artículo de investigación publicado en la revista Sensors (doi: 10.3390/s21113875). En el tercer y último trabajo se ha diseñado, implementado y probado un sistema de grabación del ruido sísmico en array por medio de una red de sensores wireless. El sistema es capaz de utilizar sensores verticales de 4,5Hz de baj

La velocidad a la que actualmente se producen los avances tecnológicos conlleva que muchos equipos de adquisición de datos sísmicos puedan quedar obsoletos mucho antes de que acabe su vida útil real. Esto ocurre, por ejemplo, con los acelerógrafos Altus K2 de la marca Kinemetrics, que no están preparados para enviar las señales que registran al software de monitorización sísmica SeisComP, que actualmente se está convirtiendo en el estándar de facto que se utiliza en la mayoría de los observatorios sismológicos de todo el mundo. Para poder recuperar y poner en valor estos equipos, se propone la implementación de una pasarela de comunicaciones, que permita por una parte adquirir las señales sísmicas proporcionadas por los acelerógrafos Altus K2, y por otra enviarlos mediante el protocolo SeedLink a un servidor SeisComP. Se requiere que el sistema sea de bajo coste y bajo consumo, para que pueda ser trasladado al campo y permita la integración de las señales de los acelerógrafos en el sistema de monitorización de datos sísmicos en tiempo real SeisComP.

Al realizar una grabación de audio cerca de cualquier dispositivo conectado a la red eléctrica se puede observar que, a parte de las frecuencias que se quieren grabar, aparece una interferencia en torno a los 50 Hz. Esta interferencia es la fluctuación de la frecuencia de la red eléctrica, la cual oscila en valores alrededor de 50 Hz y es completamente aleatoria. La fluctuación de la red eléctrica se puede observar directamente a través de una toma de corriente analizando los niveles de voltaje de la señal eléctrica de la misma. Este análisis se puede realizar utilizando un sensor de corriente no invasivo apoyado de una placa con microcontrolador capaz de procesar los valores entregados por el sensor a través de un circuito electrónico. Si se almacenan los valores de la fluctuación de la frecuencia eléctrica cada cierto tiempo, se creará una base de datos con los valores aleatorios de la misma, lo cual se podrá usar para ubicar una evidencia en el tiempo con fines forenses.

Raw data corresponding to the paper "Geophysical Study of a Large Landslide Affecting the Urban Area of Albuñuelas (S Spain)"

The urban area of Albuñuelas, a small town located to the south of Granada (S Spain), has been developed in terrain affected by a large-scale rotational landslide with very slow rate of movement. Despite this situation, the internal structure of the landslide and how it has evolved to its present state has not been analyzed in depth up to now. In this paper, we present the first study performed on this landslide to define its configuration and characteristics. For this purpose, ambient noise single-station and array measurements were carried out along several cross-sections of the landslide. The inversion of the measurements has allowed for the estimation of the soil stratigraphy at each site of measurement. These geophysical results have been constrained by data from a borehole drilled in the zone and from field observations of the local geology, allowing for the reduction in uncertainties in the results. A geological–geophysical model of the landslide has been built from these data, showing that the landslide thicknesses is greater than 50 m in its central parts and above 60 m in the upper ones. This model reveals that the evolution of the landslide was complex, with several dislodged elements (blocks) that moved in sequence (retrogression) and were partially eroded in order to explain present morphology. The future evolution of this landslide will be controlled by the composition of the materials surveyed along the foot of the valley, being the western part where there are more erodible materials according to the obtained results.

Spatial mapping is one of the most useful methods to display information about the seismic parameters of a certain area. As in b-value time series, there is a certain arbitrariness regarding the function selected as smoothing kernel (which plays the same role as the window size in time series). We propose a new method for the calculation of the smoothing kernel as well as its parameters. Instead of using the spatial cell-event distance we study the distance between events (event-event distance) in order to calculate the smoothing function, as this distance distribution gives information about the event distribution and the seismic sources. We examine three different scenarios: two shallow seismicity settings and one deep seismicity catalog. The first one, Italy, allows calibration and showcasing of the method. The other two catalogs: the Lorca region (Spain) and Vrancea County (Romania) are examples of different function fits and data treatment. For these two scenarios, the prior to earthquake and after earthquake b-value maps depict tectonic stress changes related to the seismic settings (stress relief in Lorca and stress build-up zone shifting in Vrancea). This technique could enable operational earthquake forecasting (OEF) and tectonic source profiling given enough data in the time span considered.

The northern part of Algeria is located in the border zone between the African and Eurasian plates. The collision between the two plates is expressed by a moderate to high seismicity, generally localized at the margins of the Neogene basins. The Middle-Chelif Basin is located in the northwestern part of Algeria, between the northern and southern Tellian Atlas mountain belts. The seismic activity is mainly generated by the El-Asnam fault, a 40 km long reverse fault located on the western edge of the basin. The 1980 El-Asnam earthquake caused significant damage in the cities of the basin. In particular, the cities of Oued-Fodda, El-Attaf and El-Abadia were heavily affected. In the western part of the alluvial plain of the Middle-Chelif, phenomena of cracks, settlements, landslides and liquefaction, have also occurred following the earthquake. This research aims to quantify dynamic properties of the soils of the Middle-Chelif Basin in terms of shear-wave velocity (Vs), fundamental frequency or vulnerability index (Kg) for the estimation of liquefaction potential. The calculation of dynamic soil properties allows a better assessment of the seismic hazard in the region. We have focused more on the characterization of the Vs structure of the superficial sedimentary layers in the entire Middle-Chelif Plain because of the role it plays in the amplification of the seismic waves during an earthquake. Secondly, these same soil parameters allow the creation of microzonation maps classifying the surface soil according to the criteria of NEHRP (National Earthquake Hazard Reduction Program). For this purpose, techniques based on single-station and array ambient vibration measurements are applied. Ambient vibrations were recorded at 323 sites using single-station, and at 18 sites using array measurements. The measurements were densified within urban areas. This thesis is divided into three main parts; the first one consists in a seismic microzonation of the city of Oued-Fodda, loca

Many previous research studies have shown how local and even regional earthquakes can significantly affect the release of radon in the soil. The aim of this work is to investigate the relationship between radon measurements and the daily seismic activity rate and develop a methodology that allows estimating the seismic activity rate using only radon measurements. To carry out this study, the earthquake catalogue of the Vrancea region (Romania) has been used to estimate the daily seismic activity rate during a given time period, in which radon measurements were also recorded, from January 2016 to September 2020. The Vrancea zone represents the most active seismic zone in Europe and is located on the eastern edge of the strongly bent Carpathian arc. In the case of the radon measurements, seasonal behaviours and linear trends due to non-seismic factors have been identified and subsequently removed. The discrete wavelet transform has been used to analyse the radon signal at two different scales: long and short periods. From the analysis carried out on a long-period scale, an approximate linear relationship has been obtained between the radon series and the daily seismic activity rate, which provides insights into the behaviour of the seismic activity in the study region with only the radon information. In addition, the study reveals certain characteristics that could be used as precursors of earthquakes at different scales: weeks in the case of the estimated daily seismic activity rate, and days in the case of the short-period signal obtained by the wavelet analysis. The results obtained for this region allow us to hope that the analysis of the radon time series can become an effective complement to the conventional seismic analysis used in operational earthquake forecasting.

The Internet of things concept empowered by low-cost sensor technologies and headless computers has upscaled the applicability of vibration monitoring systems in recent years. Raspberry Shake devices are among those systems, constituting a crowdsourcing framework and forming a worldwide seismic network of over a thousand nodes. While Raspberry Shake devices have been proven to densify seismograph arrays efficiently, their potential for structural health monitoring (SHM) is still unknown and is open to discovery. This paper presents recent findings from existing buildings located in Bucharest (Romania) equipped with Raspberry Shake 4D (RS4D) devices, whose signal recorded under multiple seismic events has been analyzed using different modal identification algorithms. The obtained results show that RS4D modules can capture the building vibration behavior despite the short-duration and low-amplitude excitation sources. Based on 15 RS4D device readings from five different multistorey buildings, the results do not indicate damage in terms of modal frequency decay. The findings of this research propose a baseline for future seismic events that can track the changes in vibration characteristics as a consequence of future strong earthquakes. In summary, this research presents multi-device, multi-testbed, and multi-algorithm evidence on the feasibility of RS4D modules as SHM instruments, which are yet to be explored in earthquake engineering.

A partir de la Ley 2/2020 de la Generalitat Valenciana, el Institut Cartogràfic Valencià adquiere la responsabilidad de la creación y mantenimiento de la red sísmica de la Comunidad Valenciana. Dicha red se creará a partir de la ya existente Red Sísmica de la Universidad de Alicante (RSUA) y ampliará su cobertura espacial hasta cubrir todo el territorio de la Comunidad Valenciana. El objetivo de esta futura red, que se prevé plenamente operativa en el último trimestre de 2022, es servir de portal de información y concienciación del fenómeno sísmico en la comunidad, así como suministrar información científica útil para todos aquellos grupos de investigación interesados en la sismicidad y la tectónica activa en la Comunidad Valenciana., After the enact of Law 2/2020 of the Generalitat Valenciana, the Institut Cartogràfic Valencià acquires responsibility for the creation and maintenance of the seismic network of the Valencian Community. This network will be created from the already existing Seismic Network of the University of Alicante (RSUA) and will expand to cover the entire territory of the Valencian Community. The goal of this future network, which is expected to be fully operational in the last quarter of 2022, is to serve as a portal for information and awareness of the seismic phenomenon in the community, as well as to provide useful scientific information for all those research groups interested in seismicity and the active tectonics in the Valencian Community.

The present work is focused on basic electronics subjects and specifically on the understanding and interpretation of amplifier circuits based on bipolar junction transistors. In this context, students acquire the skills to identify the different configurations, algebraically analyze the circuit and obtain the necessary parameters to characterize the behavior of the amplifier. However, from a practical point of view, students have more difficulties in understanding and interpreting the connection between the theoretical concepts and the real behavior of the circuit. In this sense, the objective of this research work is to develop and provide students with an online simulation tool that allows them to interact with the amplifier circuits studied in the theory class and understand how they behave with different configurations, component values or signals. The incorporation of circuit simulation in theory class has been investigated by the authors themselves during several courses. Compared to other courses, in which these simulations were not introduced, an improvement was observed in the obtained results. Additionally, students positively valued the inclusion of these simulation tools in the theory class and considered that it helps them to better understand the theoretical concepts. From this survey, it was deduced that students would like to have these same simulation tools outside the classroom in order to complement the non-face-to-face study.

In this work, a wireless data acquisition system for seismic noise array measurements is presented. The developed system is composed of a series of nodes and a central server arranged in a point-to-multipoint topology. The nodes consist of a CC3200 microcontroller, an analog-to-digital converter, and a low-noise conditioning circuit designed specifically to register seismic noise, and which is connected to the seismic sensor. As a server, a Raspberry Pi 4B has been used that will receive the samples from the nodes via Wi-Fi and will save them in files. It also incorporates a Web interface developed with JavaScript node.js technology that allows to configure the number of nodes as well as different options, to start and stop the records, and to view in real time the different signals received from the nodes. The system can be deployed anywhere since each of the nodes use independent batteries as a power supply. In addition, it is possible to operate the system remotely if internet connectivity is available. The prototype has been tested in four different locations in the Alicante province (southeast Spain), demonstrating its suitability for seismic noise array measurements.

The city of Oran experienced several earthquakes. Therefore, the characterization of its subsurface is crucial for a better evaluation of the seismic hazard. Using ambient vibration single-station and array measurements at 193 sites, the HVSR curves showed a variation of the fundamental frequency peak between 0.3 and 7.4 Hz, growing towards the west, with maximum amplitude of ∼6. The shallow structure has been explored by means of F–K analysis. Joint inversion of the HVSR and Rayleigh wave dispersion curves showed 3 layers of soft and stiff sediments of varying thicknesses overlying the bedrock. The shear-wave velocity (Vs) of the sediments varies between 280 and 1300 m/s and that of the bedrock can reach 2500 m/s. Cross sections show a decrease in sediments thickness from east to west where bedrock outcrops. The maximum depth of bedrock is 1050 m northeast of the city. The obtained Vs models support a soil classification ranging from stiff soil to hard rock.

The Middle-Chelif basin, in northwestern Algeria, is located in a seismically active region. In its western part lies the El-Asnam fault, a thrust fault responsible for several strong earthquakes. The most important being the El-Asnam earthquake (Ms = 7.3) of 1980. In the present study, ambient vibration data with single-station and array techniques were used to investigate the dynamic properties of the ground and to estimate the Vs30 structure in the main cities of the basin. Soil resonance frequencies vary from 1.2 to 8.3 Hz with a maximum amplitude of 8.7 in. Collapsing behavior has also been demonstrated west of the city of El-Attaf, reflecting a strong potential for liquefaction. A Vs30 variation map and a soil classification for each city were obtained mainly by inversion of the HVSR and Rayleigh wave dispersion curves. Finally, an empirical prediction law of Vs30 for the Middle-Chelif basin was proposed.

The reactivation of very large landslides may cause severe damage to society. Its prevention and management requires detailed information on the geometry and structure of these landslides, but the use of standard techniques (boreholes) may be prohibitive from an economic point of view. To overcome these difficulties, geophysical techniques are of special interest because they allow for studying very large areas at a reasonable cost. In this paper, we present a case study wherein the analysis of ambient noise allowed us to produce a model of a large landslide near Granada (southern Spain). The geometry and location of the failure zone, as well as the assessment of the state of involved materials, were estimated by combining two available boreholes and different geophysical techniques (downhole tests and the spectral analysis of ambient noise, horizontal to vertical spectral ratios (HVSR) and the frequency-wavenumber (f-k) methods). The results have allowed us to differentiate between values within the landslide mass with respect to those of stable materials, and to perform for the first time a comprehensive geological model of this unstable mass. Differences were also observed within the landslide mass (earth flow vs. slide zones), which are attributed to differences in the degree of alteration and the disturbance of the internal structure of materials constituting the landslide mass. These results show that techniques based on the measurement of ambient noise are of special interest for studying very large, highly remolded landslide masses., Ministerio de Economía y Competitividad (MINECO)/FEDER, Junta de Andalucía, Universidad de Alicante, Universidad de Jaén, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub

El presente estudio evalúa cómo el alumnado de la Universidad de Alicante interpreta el grado de incertidumbre asociado a las predicciones meteorológicas de viento y precipitación. En primer lugar, se ha comprobado la respuesta del alumnado ante la predicción determinista de la velocidad del viento y la cantidad de precipitación. En segundo lugar, se ha evaluado si el alumnado toma alguna medida ante distintas situaciones de riesgo relacionadas con dichos parámetros, tanto cuando la información se presenta en términos deterministas como de probabilidad. Los resultados indican que un pequeño porcentaje del alumnado espera pronósticos perfectos, mientras que la mayoría reconoce cierto grado de incertidumbre inherente a los pronósticos meteorológicos. En este sentido, el alumnado espera una desviación de ±5-10 km/h para la velocidad del viento, y de ±30 mm para el caso de la cantidad de precipitación. Por otro lado, el alumnado tomaría acciones de precaución ante situaciones de riesgo por fenómenos extremos de viento y precipitación, si bien hay una mayor variedad de respuestas en relación a cuándo y cómo el alumnado tomaría una acción determinada para la predicción de estos mismos parámetros meteorológicos expresados en términos de probabilidad.

In order to better assess the seismic hazard in the northern region of Algeria, the shear-wave velocity structure in the Middle-Chelif Basin is estimated using ambient vibration single-station and array measurements. The Middle-Chelif Basin is located in the central part of the Chelif Basin, the largest of the Neogene sedimentary basins in northern Algeria. This basin hosts the El-Asnam fault, one of the most important active faults in the Mediterranean area. In this seismically active region, most towns and villages are built on large unconsolidated sedimentary covers. Application of the horizontal-to-vertical spectral ratio (HVSR) technique at 164 sites, and frequency–wavenumber (F–K) analysis at 7 other sites, allowed for the estimation of the ground resonance frequencies, shear-wave velocity profiles, and sedimentary cover thicknesses. The electrical resistivity tomography method was used at some sites to further constrain the thickness of the superficial sedimentary layers. The soil resonance frequencies range from 0.75 Hz to 12 Hz and the maximum frequency peak amplitude is 6.2. The structure of the estimated shear-wave velocities is presented in some places as 2D profiles to help interpret the existing faults. The ambient vibration data allowed us to estimate the maximum depth in the Middle-Chelif Basin, which is 760 m near the city of El-Abadia.

En esta Red ICE se ha propuesto y desarrollado una metodología docente para ser implementada en la asignatura de Señales y Sistemas del Grado en Sonido e Imagen en Ingeniería de Telecomunicación de la Universidad de Alicante (España). Generalmente, tanto en universidades españolas como extranjeras, esta asignatura suele ser un punto de inflexión en la formación del estudiante en Ingeniería de Telecomunicación. Además, suele ser una asignatura cuya ratio de aprobados está por debajo de la media de la titulación, ya que supone un reto y una dificultad nueva para los estudiantes de primeros cursos. La metodología enfatiza la aplicación práctica de la asignatura, su aplicabilidad directa en sistemas reales y su validación como posible método de enseñanza a partir de los resultados obtenidos.

En este trabajo se recoge la estrategia utilizada para superar las dificultades derivadas del modelo de Docencia Dual (DD) en el ámbito experimental de las asignaturas: Técnicas Experimentales IV del Grado de Física, y Acústica del Grado en Ingeniería en Sonido e Imagen en Telecomunicación. La implantación de la DD y los turnos implica una reducción de las horas presenciales en el laboratorio. Para mitigar este inconveniente se han elaborado una serie de vídeos demostrativos en los cuales se muestra paso a paso todos los procedimientos que el alumnado debería de realizar de forma presencial en el laboratorio. Se ha diseñado y facilitado una encuesta con el objetivo de evaluar la satisfacción por estos materiales. Se ha validado la encuesta a través de SPSS, y los resultados cuantitativamente arrojan en general una muy buena recepción de los materiales audiovisuales elaborados, ya que más del 80% del alumnado encuestado considera que los vídeos han sido de utilidad desde el punto de vista del aprendizaje autónomo/online.

Debido a la COVID-19 y las restricciones sanitarias, la Universidad de Alicante implantó la docencia dual. En este trabajo se recoge la estrategia utilizada para superar las dificultades derivadas de este modelo educativo en el ámbito experimental de las asignaturas: Técnicas Experimentales IV del Grado de Física, y Acústica del Grado en Ingeniería en Sonido e Imagen en Telecomunicación. El impacto de la docencia dual principalmente repercute en una disminución en el número de horas que el alumnado puede disfrutar de forma presencial en el laboratorio. Para mitigar este inconveniente se han elaborado una serie de vídeos demostrativos en los cuales se muestra paso a paso el montaje a realizar en el laboratorio, configuración de instrumentos, adquisición de las medidas y en general todos los procedimientos que el alumnado debería de realizar de forma presencial. Para evaluar las ventajas y desventajas de la aplicación de esta iniciativa educativa se ha elaborado una encuesta que se ha facilitado a todo el alumnado. En primer lugar, se ha validado la encuesta a través de los análisis estadísticos pertinentes a través de SPSS, y los resultados cuantitativamente arrojan en general una muy buena recepción de los materiales audiovisuales elaborados, ya que más del 80% del alumnado encuestado considera que los vídeos han sido de utilidad desde el punto de vista del aprendizaje autónomo/online.