Efectos de la actividad sísmica en la Ionosfera: características y posibles aplicaciones

En los últimos años el estudio de las perturbaciones ionosféricas vinculadas con la actividad sísmica ha experimentado un gran desarrollo debido, en gran medida, a la utilización de datos obtenidos a partir de los retrasos ionosféricos registrados en estaciones GPS y de observaciones realizadas in situ por satélites diseñados para este objetivo. Estos datos han permitido establecer de una manera sólida que la actividad sísmica afecta a la ionosfera. Aunque las perturbaciones resultantes de esta influencia no pueden ser utilizadas todavía para la predicción de terremotos y queda mucho trabajo por hacer, los resultados obtenidos permiten ser optimistas respecto de su incorporación a sistemas de alerta, especialmente para el caso de tsunamis. Este artículo describe algunos rasgos de la investigación que ha llevado a la detección de este fenómeno, sus características y su encuadre en el campo de la predicción sísmica.Peer Reviewe

Actualidad de la meteorología espacial

Peer reviewe

Electrochemical technologies to reduce the environmental and sanitary impact of Hospital Urines

In last years, the occurrence of bacteria with the capacity of survive and multiply in the presence of the antibiotics specifically designed to kill them, the so-called Antibiotic-Resistant Bacteria (ARB) has become a global concern because of the potential threats they can pose to human health. Diseases produced by these ARB cannot be effectively treated with antibiotics, being responsible for more than 700,000 human deaths per year. ARB can transfer their antibiotic resistance genes (ARGs) from one bacterium to another, favouring the spread of antibiotic resistance in the environment. The World Health Organization (WHO) has considered ARB as one of the three main threats of the 21st century due to the large number of infections and deaths they cause worldwide each year. One of the most concentrated sources of ARB are hospital effluents and, specifically, urine from immunocompromised patients where simultaneously coexist bacteria causing urinary tract infections with excreted pharmaceuticals. Currently, hospital urines are typically merged with other hospital effluents and then, discharged into the municipal sewer system and treated together with urban effluents in municipal wastewater treatment facilities (WWTPs). The inefficiency of biological treatments from WWTPs to treat hospital effluents leads the spread of ARB and ARGs in the environmental water sources, negatively affecting aquatic organisms and human health. This makes urine treatment a key objective for reducing the environmental and health impact of hospital effluents. For this reason, the priority of this project is to face the problem directly in the pollution source, within the framework of the regional and national projects "Electrochemical technologies for the treatment of hospital urines: reduction of environmental and health impact (SBPLY/17/180501/000396) and "Electrochemical technologies facing the challenge of hospital urine treatment (PID2019-110904RB-I00), respectively. In this context, electrochemical oxidation (EO) has aroused great interest among disinfection processes since EO has been reported to attain complete disinfection in urban wastewaters thanks to the in-situ generation of disinfectant species from the electrooxidation of the ions naturally contained in the effluent treated. This PhD Thesis is focused on the removal of bacteria from hospital urines based on our previous works related to the disinfection of urban treated wastewater, facing the challenge of the reactor layout. Specifically, the main objective of the present PhD Thesis is to assess the technical feasibility of different electrochemical processes including electrolysis and photoelectrolysis, to reduce the environmental and health impact of ARB from hospital urines, avoiding the formation of undesired disinfection by-products. To meet this general objective, results presented in Chapter 5 have been divided in the following five different sections, which correspond to the five partial objectives of this work. In section 5.1, a prospective study of pathogens causing Urinary Tract Infections (UTIs) was carried out within the period 2014 to 2018. This study was accomplished in collaboration with the University Hospital Complex of Albacete, Spain (CHUA) as model of sanitary facility. This allows to evaluate the occurrence and fate of ARB in a real environment as well as the problematic associated with ARB in a hospital complex. The study proved that E. coli was the most significant bacteria found in Positive Urines (PUs) and that gram-negative bacteria (E. coli, K. pneumoniae, P. aeruginosa and P. mirabilis) predominated over gram-positive bacteria (E. faecalis) and yeasts (C. albicans). K. pneumoniae showed the highest percentages of antibiotic resistance. However, the research carried out on the disinfection processes of ARB was mainly related to the removal of E. coli, which confirms that the importance given to K. pneumoniae as ARB from a sanitary viewpoint does not correspond to the research carried out on the disinfection processes. Hence, it was pointed out the need to search and develop novel technologies that allow to remove K. pneumoniae for decreasing the sanitary and environmental impact of the effluents infected with this bacterium. In section 5.2, a preliminary study of the electrochemical technology as an alternative for the removal of bacteria in two different treatment scenarios (synthetic urban wastewater and synthetic hospital urines) was conducted using a parallel flow reactor with BDD anodes at 10 A m-2. This study proved that even the bacterial removal efficiency was lower in hospital urines (competitive oxidation reactions), the occurrence of hazardous disinfection by-products was avoided in this matrix since the production of hypochlorite and the subsequent formation of inorganic chloramines were favoured. Subsequently, a preliminary evaluation of electrolysis for the reduction of the potential chemical risk of hospital urines was also conducted. Chloramphenicol (CAP) was selected as a model of antibiotic and the influence of anodic material (BDD and MMO) and current density (50, 25, 12.5 A m-2) was evaluated. This study concluded that the electrochemical oxidation with BDD anodes applying 12.5 A m-2 (8 Ah dm-3) allows to degrade CAP from hospital urines, increasing their biodegradability up to 40 % follows the Zahn-Wellens method. However, this study also pointed out that the electrical charges required for the removal of antibiotics were much higher than those required for disinfection (8 Ah dm-3 vs. < 0.15 Ah dm-3) and then, other parallel studies out of this thesis were carried out on this topic. In this regard, the development of suitable disinfection technologies as a pre- treatment to remove K. pneumoniae from hospital urines was evaluated in section 5.3. The main objective of this section was to gain insight into the role of the electro- generated oxidants on the disinfection process. Firstly, the contribution of chloramines on the electrochemical disinfection process was evaluated testing two concepts of electrochemical cell design with MMO anodes: a conventional parallel flow reactor and a microfluidic flow-through reactor. The influence of current density (5-50 A m-2) was also studied, and results were compared with other simpler "urine" matrices and with chemical disinfection tests. Results showed that the disinfection process of K. pneumoniae from hospital urines relies on the current density and the reactor layouts. The presence of chlorides in hospital urines contributed to the generation of hypochlorite and chloramines. The formation of chloramines was enhanced using the flow-through reactor layout. Additionally, chemical disinfection tests proved a stronger bactericidal effect of hypochlorite in comparison with chloramines. However, chloramines played a key role in the disinfection process since they contribute not only as disinfectants but avoiding the generation of chlorine derived by-products. Additionally, the contribution of ozone on the electrochemical disinfection process was also evaluated testing a PEM-electrolyzer (MIKROZON® cell) especially designed to produce ozone in low-conductivity water. The influence of current intensity and hospital urine composition was studied. Results showed that the MIKROZON® cell reached total disinfection from current intensities higher than 0.5 A. The combined effect of ozone and chlorine disinfectants attained higher disinfection rates than the values obtained when single ozone was the main disinfectant electrogenerated (urine without chlorides) at current intensities lower than 0.5 A. At values of 1.0 A, the disinfection rates were quite similar which revealed that large amounts of ozone were electrogenerated. The crystal violet assay showed that the combined effect of all disinfectants promoted higher cell damages, increasing the cell wall permeability. Ozone was proved to attack DNA to a greater extent from current intensities higher than 0.5 A. Finally, during the treatment of diluted urines at 1.0 A, higher disinfection rates were obtained due to the minimization of competitive reactions. Electrochemical oxidation can promote the formation of hydroxyl radicals and disinfectant species from water electrolysis which may be activated by the irradiation of UV light, increasing the quantity of free radicals available for disinfection purposes. In section 5.4, the assessment of coupling of electrochemical oxidation with UV light was developed using a microfluidic flow-through reactor for the removal of K. pneumoniae in hospital urines. The influence of the current density (5-50 A m-2) and the anode material (BDD and MMO) was tested on the production of disinfectants not only of hypochlorite but also monochloramine, dichloramine and trichloramine. Results showed that UV disinfection could not reach the complete disinfection of K. pneumoniae. However, electrochemical oxidation with BDD and MMO anodes led to complete removal of ARB from urine when applying 50 A m-2. The disinfection rate was higher when working with MMO anodes since BDD anodes favoured competitive oxidation reactions between bacteria and the organics contained in urine. Finally, photoelectrolysis was proved to enhance single UV disinfection and electrolysis performances. A marked synergistic effect was found when UV disinfection was enhanced by electrolysis at 5 A m-2 with BDD and MMO anodes. In section 5.5, the validation of electrochemical technology for the treatment of complex synthetic urine matrices (polymicrobial urines) was carried out. The polymicrobial hospital urines simulates real hospital urines since the pandemic caused by the coronavirus SARS-CoV-2 did not allow us to validate the electrochemical technology in a real environment due to the sanitary restrictions. Firstly, the simultaneous occurrence of more than one pathogen causing UTIs in real hospital urines was analysed based on data supplied by the Microbiology and Parasitology Service from CHUA. From this study, the most prevalent combinations of bacteria presented in real urines from hospitalized patients were: 1) E. faecalis and K. pneumoniae, 2) E. coli and E. faecalis, and 3) K. pneumoniae and E. coli. Subsequently, the microfluidic flow- through reactor and the MIKROZON® cell were evaluated for the abatement of ARB pairs working under the most suitable operating conditions reported in previous sections. Hence, the microfluidic flow-through reactor was tested with MMO anodes at 50 A m-2 and the MIKROZON® cell worked at 1 A. Results showed that the microfluidic flow-through reactor achieved removal rates between 5 and 6 logs after 180 min whereas the MIKROZON® cell reached the total disinfection (7 logs) after 60 min. Additionally, the denaturation of DNA and ARGs in polymicrobial hospital urines was also considered. While no noticeable changes in the ARGs concentration were observed with the flow-through reactor, the MIKROZON® cell reached a mean decrease in ARGs ranked as follows: blaKPC (4.18-logs) > blaTEM (3.96-logs) > ermB (3.23-logs), offering a mean depletion of 3.77-logs for all ARGs tested. Finally, Scanning Electron Microscope (SEM) images confirmed the complete disinfection attained using the MIKROZON® cell where severe damages were induced in the cell walls, resulting in the integrity loss of bacterial structures

Recuperación mejorada de petróleo mediante concentración solar

La demanda de energía de un país está estrechamente relacionada con su producto interno bruto, con su capacidad industrial y con el estándar de vida alcanzado por sus habitantes. Es por ello que el petróleo, como fuente energética principal desde mediados del siglo XX, juega un papel estratégico en nuestra sociedad. La creciente demanda de este combustible fósil durante los últimos años, y las reservas limitadas de los crudos más económicos, están incrementando el interés de la industria en la extracción de crudos pesados. De entre todos los métodos disponibles para la extracción de crudos pesados, la inyección de vapor es el método más extendido. El incremento de la movilidad del crudo como resultado del efecto de la cámara de vapor en el interior del yacimiento, hace viable la explotación de crudos tradicionalmente poco rentables. La generación del vapor de inyección implica sin embargo un sobrecoste económico y medioambiental importante. Razón por la cual, la concentración solar, como fuente alternativa de energía para la generación de vapor de inyección, ha despertado el interés de la industria petrolera desde el nacimiento de la tecnología. Pese al temprano interés en la tecnología, su aplicación a proyectos reales ha sido limitada debido a los desafíos tecnológicos existentes. Uno de los más importantes es la diferencia entre la duración de la inyección de vapor en el yacimiento (alrededor de 7 años), y la vida útil del campo solar (hasta 25 años). Esta diferencia hace que en la mayoría de los casos, el campo solar únicamente puede aprovecharse durante una fracción reducida de su vida útil, lo que dificulta la viabilidad económica del proyecto. En esta tesis se detalla el diseño y la implementación real de un captador de concentración solar, que permite ser desmontado y transportado de manera económica al finalizar la fase de inyección de vapor. Permitiendo acompañar de esta forma la explotación secuencial de las zonas de inyección de un campo de petróleo. En el diseño de este captador transportable se compara de manera teórica, las posibles alternativas constructivas existentes para cada uno de los componentes principales. Las hipótesis que se asumen en el estudio teórico se comprueban y validan durante el proceso de implementación real del captador (a través de dos prototipos funcionales), y su ensayo en la Plataforma Solar de Almería. Consiguiendo medidas reales de los tiempos y costes de fabricación, montaje y transporte. Así como de la producción energética. Para validar la viabilidad económica del captador diseñado en proyectos de inyección de vapor, se desarrolla además un código de simulación para este tipo de aplicaciones. El código permite estimar la rentabilidad de un sistema solar para generación de vapor de inyección, utilizando tanto captadores convencionales como captadores transportables.The energy demand of a country is closely related to its gross domestic product, its industrial capacity, and the standard of living of its inhabitants. That is the reason oil, as the main energy source since the middle of the 20th century, plays a strategic role in our society. The growing demand for this fossil fuel in recent years, and the limited reserves of cheap oil, are increasing the interest of the industry in the extraction of heavy crudes. Among the methods available today for the extraction of heavy oil, steam injection is by far the most widespread. The increased mobility of the oil as a result of the effect of the steam chamber within the reservoir, makes the exploitation of traditionally unprofitable reservoirs, economically feasible. The generation of injection steam comes nevertheless with a significant economic and environmental burden. Consequently, solar concentration as an alternative source of energy for the steam generation, has attracted the interest of the oil industry since the birth of technology. Despite the early interest in the technology, its application in real projects has been limited due to existing technological challenges. One of the most important is the difference between the duration of the steam injection in the reservoir (around 7 years), and the lifetime of the solar field (up to 25 years). This difference means that in most cases, the solar field can only be used during a small fraction of its lifetime, which ultimately makes the project not feasible. This thesis details the design and real implementation of a solar concentrating collector, capable of being disassembled and transported at the end of the steam injection phase. Allowing the solar generation to follow the development of the different injection areas within the oil field. The theoretical design of the collector comprises a detailed comparison between different constructive alternatives for each of its main components. The design principles assumed during the development are verified and validated during the actual implementation of the collector (through two functional prototypes), and the test campaign carried out at Plataforma Solar de Almería. In which real data on manufacturing, assembly and transport costs, as well as energy production have been acquired. The potential of the collector for its application in steam injection projects has been assessed through theoretical simulations using a simulator developed in this thesis. The simulator allows reservoir and solar field calculations using conventional and transportable collectors

Recognition and management of hereditary colorectal cancer syndromes

Over 1,900 colorectal tumors will arise in association with a hereditary colorectal cancer syndrome in Spain in 2009. The genetic defects responsible for the most common syndromes have been discovered in recent years. Genetic testing helps diagnose affected individuals and allows identification of individuals at-risk. Colonoscopy and prophylactic colectomy decrease colorectal cancer incidence and overall mortality in patients with hereditary colon cancer. Extracolonic tumors are frequent in these syndromes, so specific surveillance strategies should be offere

Behavior of the ionosphere over Europe during two geomagnetic storms which caused tongues of ionization over North America

Poster presentado en la EGU General Assembly 2015, 12-17 April, 2015, Vienna, AustriaThis work presents the effect of two geomagnetic storms on the ionospheric total electron content (TEC) over Europe. Those geomagnetic storms occurred on July 14th, 2013 and February 19th, 2014 and originated a tongue of ionization over North America. Following the criteria of Gonzalez et al.(1994), the July storm can be classified as a moderate one because the Dst index reached a value of -72nT, whereas the February storm as an intense event considering that Dst index dropped to -112nT. For this study we have used RINEX files obtained from GNSS stations belonging to International GPS Service, IGS, EUREF Permanent Network, and University Navstar Consortium, UNAVCO, networks. The data has been divided into two groups in function of the region: Europe or North America. For each group we have used all the available stations. The RINEX files have been processed using a technique developed by Ciraolo (2012) which assumes the ionospheric thin shell model to obtain the vertical total electron content (vTEC) from the slant total electron content (sTEC) at the Ionospheric Pierce Point, IPP, the point where the line-of-sight between the satellite and the ground receiver intersects the ionosphere. The data were obtained at 1 minute sampling in periods of geomagnetic storms and quiet days close to them. In both storms a tongue of ionization, ToI, appeared over North America from afternoon to dusk (between 19:00 and 3:00 GMT). The behavior of the ionosphere over Europe was very different in eachcase. In July, the TEC decreased respect the quiet days during the ToI time. In the February storm the behavior of the ionosphere over Europe was similar to that of a quiet day but the following day appeared a phenomenom similar to the ToI.Peer reviewe

Ionospheric biases correction for coordinates derived from GPS single point positioning

Most GPS users employ low cost receivers. These receivers do not allow users to record the pseudorange that they observe, but the computed coordinates. This work presents an original and simple method to correct ionospheric biases introduced in GPS signals. The originality of this method is based on the fact that no pseudorange is needed to correct the biases, only the calculated coordinates are used. This distinguishes this method from other classic alternatives. This paper evaluates the efficiency of the method with the use of real data.Facultad de Ciencias Astronómicas y Geofísica

Worst cases for a one-hop high frequency link

The characterisation of a HF channel by means of monthly electron density profiles can be complemented with a detailed study of radio propagation «worst cases» on situations with extremes conditions of radiopropagation for a given period. These «worst cases» correspond to conditions that can be identified by means of cumulative distributions of the key parameter f0F2. This paper analyses the main parameters of the HF channel: time delay, apogee, elevation angle and transmission frequency with mean and extreme conditions. The method used to characterise the ionospheric channel is based on ray-tracing techniques.National Institute of Aerospace Technology (INTA)Dr. Moorhead of Neptune Radar Ltd.Gloucester U.

La coevaluación como estrategia para mejorar la dinámica del trabajo en grupo: una experiencia en Ciencias del Deporte

The aim of this study was to analyze if the perceptions of students before and after carrying out the work, that is, their perception of different aspects of the functioning of the group, the working skills acquired as well as those they think that need to be improved, varied depending on whether the contribution of the different members of the group was being co-evaluated or not. 144 students of Physical Activity and Sport Sciences participated in this study. In order to analyze the students' perception of group work the adapted questionnaire by Bourne et al. (2001) was used. Results showed that groups which implemented co-evaluation assessed more negatively the experience in general than those which did not. However, co-evaluation groups perceived their competence to work as a team had improved to a greater extent than the groups without co-evaluation, evaluating more positively both the performance and the result of work and increasing their knowledge of the other team members. Using a co-evaluation system seems to generate both a better assessment of the running of the team and the result of its work.El objetivo del estudio fue analizar si la percepción del trabajo grupal se modificaba en función de la introducción o no de la coevaluación. Participaron 144 alumnos de Ciencias de la Actividad Física y el Deporte. Para analizar la percepción de los alumnos del trabajo cooperativo se utilizó el cuestionario adaptado por Bourne et al. (2001). Los resultados mostraron que los grupos en los se introdujo la coevaluación valoraron de forma más negativa la experiencia (menos agradable, inspiradora, positiva y creativa) que los grupos en los que no se introdujo la coevaluación. Sin embargo, los grupos con coevaluación percibieron que su competencia para trabajar en equipo había mejorado en mayor medida que los grupos sin coevaluación, valorando de forma más positiva tanto el funcionamiento como el resultado del trabajo e incrementaron en mayor medida sus conocimientos sobre el resto de los componentes. El uso de un sistema de coevaluación como el propuesto parece generar una mejor valoración tanto del funcionamiento del equipo como del resultado de su trabajo