Sporadic Aurora near Geomagnetic Equator: In the Philippines, on 27 October 1856

While low latitude auroral displays are normally considered to be a manifestation of magnetic storms of considerable size, Silverman (2003, JGR, 108, A4) reported numerous "sporadic auroras" which appear locally at relatively low magnetic latitudes during times of just moderate magnetic activity. Here, a case study is presented of an aurora near the geomagnetic equator based on a report from the Philippine Islands on 27 October 1856. An analysis of this report shows it to be consistent with the known cases of sporadic aurorae except for its considerably low magnetic latitude. The record also suggests that extremely low-latitude aurora is not always accompanied with large magnetic storms. The description of its brief appearance leads to a possible physical explanation based on an ephemeral magnetospheric disturbance provoking this sporadic aurora.Comment: 15 pages, 3 figures, accepted for publication in Annales Geophysicae on 18 August 201

Ball lightning: a Renaissance account from Zafra (Spain)

Se analiza la historia de un globo de fuego observado en Zafra (España) a mediados del siglo XVI. Durante una fuerte tormenta, el Conde Don Pedro observó lo que describió como un globo de fuego que se dirigió contra la ciudad y cambió bruscamente de rumbo. Él atribuyó el cambio en curso a un milagro. No describió ningún daño ni sonido.An analysis is given of the account of a globe of fire observed in Zafra (Spain) in the middle of the 16th century. During a strong storm, Conde Don Pedro observed what he described as a globe of fire that was directed against the city and abruptly changed course. He attributed the change in course to a miracle. He described neither any damage nor sound.• Junta de Extremadura. Proyecto IB16127 • Junta de Extremadura y Fondos FEDER. Ayuda GR15137 • Ministerio de Economía y Competitividad. Proyecto AYA2014-57556-P (I+D+i)peerReviewe

Annual report on Sunspot Counting Program 2014

Este programa observación nació a finales del año 2012 en la Universidad de Extremadura con el fin de ampliar aún más nuestra investigación en la reconstrucción de la actividad solar. Desde el 1 de Enero de 2013, nuestros recuentos de manchas solares se han presentado al Real Observatorio de Bélgica (ROB) como contribución a los esfuerzos internacionales de mantener y actualizar el número internacional de Manchas Solares. Para ello, hemos utilizado un pequeño refractor apocromático de 80 mm de diámetro de objetivo y 550 mm de longitud focal, a fin de proyectar una imagen de 150 mm de diámetro en una plantilla. Este informe proporciona un conjunto completo de los datos obtenidos durante el año 2014, con cuatro tablas que muestran nuestros datos. Por otra parte, el índice de referencia de las manchas solares se compara con nuestros resultados. Esperamos que esta publicación sea de utilidad a la comunidad científica que estudia el número de manchas solares: la mayor serie de índices solares derivadas de la observación directa del Sol.This program was born in late 2012 at the University of Extremadura in order to further extend our research in the reconstruction of past solar activity. Since 1st January 2013, our sunspot counts have been submitted to the Royal Observatory of Belgium (ROB) as a contribution to the international effort of maintaining and updating the International Sunspot Number. For this purpose, we have used a small apochromatic refractor –80mm of objective diameter and 550mm of focal length– to project a 150mm diameter image onto a template. In this report, we provide a complete set of data obtained throughout the year 2014, with four Tables showing our data. Moreover, the reference sunspot index is compared with our results. We hope that this publication be useful to the scientific community studying the sunspot number: the longest solar index series derived from direct observation of the Sun

Resolution Uniformity and Sensitivity of the NIH ATLAS Small Animal PET Scanner: Comparison to Simulated LSO Scanners Without Depth-of-Interaction Capability

Positron emission tomography (PET) scanners designed to image animals the size of rats and mice should possess simultaneously high and uniform spatial resolution and high sensitivity. ATLAS (Advanced Technology Laboratory Animal Scanner), a 6.0 cm diameter effective transverse field-of-view (FOV), 2 cm axial FOV ring-type research scanner seeks these goals by surrounding the animal with eighteen 15 mm deep, LGSO (7 mm)/GSO (8 mm) phoswich detector modules. A Monte Carlo simulation was used to compare the variation of resolution across the FOV and the absolute central point source sensitivity (ACS) of ATLAS to similar systems comprised only of LSO arrays of different depths with no depth-of-interaction (DOI) capability. For ATLAS radial spatial resolution deteriorated by 27% from the center to 3 cm off-axis. Scanners comprised of 15 mm deep, 10 mm deep and 7 mm deep LSO crystals deteriorated by 100%, 51%, and 20%, respectively, over the same distance. Simulated ACS (absorbed energies ≥250 keV) for ATLAS was 2.0% and for the 15 mm, 10 mm deep and 7 mm deep LSO scanners 2.4%, 1.5%, and 0.9%, respectively. Radial resolution loss 3 cm off-axis and ACS measured for the actual ATLAS scanner were similar to the values obtained by simulation (27% resolution loss, 1.8% ACS). The phoswich design thus achieves good resolution uniformity over a 6 cm FOV while preserving sensitivity compared to equivalent non-DOI LSO scanners with a range of crystal depths.Publicad

Interacciones microorganismo-hormigón: métodos de evaluación y posibles soluciones

La interacción microorganismo–hormigón es un proceso que, debido a la naturaleza porosa del hormigón, lo hace susceptible de ser colonizado por los microorganismos presentes en prácticamente todos los hábitats. Esta interacción puede provocar cambios indeseables en el hormigón o hacer que éste sea un foco de contaminación microbiológica, si bien, en algunos casos, la presencia de microorganismos puede ser beneficiosa. La presente tesis doctoral se focaliza en las interacciones negativas y tiene como objetivos principales, en primer lugar, realizar una selección de sustancias químicas y valorar su efectividad frente a microorganismos patógenos para el ser humano y/o su actividad (Escherichia coli, Staphylococcus aureus, Aspergillus niger,) o frente al crecimiento de microorganismos que pueden provocar el biodeterioro del hormigón (Scenedesmus vacoulatus, Stichococcus bacillaris y Thiobacillus thiooxidans). En segundo lugar, desarrollar una metodología global (ensayos en laboratorio y ensayos de campo) que permita evaluar la efectividad de diferentes agentes químicos frente a diferentes factores a lo largo del tiempo. A nivel de laboratorio se realizan tres campañas de ensayos, en las que se evalúan las prestaciones antimicrobianas de 15 formulados diferentes (10 monocomponente y 5 multicomponente) que contienen 10 principios activos distintos. En la 1ª campaña de ensayos se valora la eficacia de los formulados monocomponente, poniéndose de manifiesto que ninguno de ellos alcanza los objetivos requeridos y, por tanto, se descartan debido a las siguientes razones: perjudicar las prestaciones fundamentales del hormigón (desarrollo de resistencias, densidad y consistencia), lixiviación del principio activo y, no alcanzar los niveles de actividad antimicrobiana aceptables. En la 2ª campaña se emplearon formulados multicomponente, obteniendo excelentes resultados con el formulado PL-UV H+M-2B, el cual presentó una efectividad antimicrobiana duradera en el tiempo sin comprometer el resto de prestaciones. Estas fueron confirmadas en condiciones reales de uso en la fase experimental de campo (puerto de Barcelona) retrasando la aparición de algas sobre la superficie de hormigón hasta en 16 semanas. Por último, en la 3ª campaña se evalúa la efectividad del formulado BXT/ I frente el ataque ácido sulfúrico biogénico producido por el metabolismo del Thiobacillus thiooxidans. En primera instancia se realizan los ensayos por impregnación mediante los cuales se demuestra, de forma cualitativa, que el formulado BXT / I inhibe el desarrollo del Thiobacillus thiooxidans. Posteriormente se lleva a cabo un ensayo en el que simula la acción del ácido sulfúrico biogénico siguiendo el método descrito por Vincke (1999), demostrándose que el empleo del formulado BXT/I reduce en más de un 30% la pérdida de masa de hormigón debida al metabolismo del Thiobacillus thiooxidans, considerándose, de esta manera, una solución efectiva contra este proceso de biodegradación. Desde el punto de vista metodológico, esta tesis doctoral propone una nueva metodología de evaluación global de la eficacia de principios activos antimicrobianos, en la que se abarca el estudio de la influencia del principio activo en las propiedades del hormigón, la posible lixiviación del principio activo, la eficacia del efecto antimicrobiano (cultivo microbiológico en placa de Petri) y su durabilidad, tanto a nivel de laboratorio como en ensayos de campoMicroorganism-concrete interaction is a process which makes concrete a very porous material very susceptible to colonization by microorganism present in almost any habitat. This interaction may cause undesirable changes in the concrete and turn it a source of microbiological contamination. Although in some cases, the presence of microorganisms in concrete may be beneficial.This investigation is focused just on the negative interactions. Its main objectives are two, first one, to make a selection of chemicals and evaluate their effectiveness against pathogenic to humans and / or their activity (Escherichia coli, Staphylococcus aureus, Aspergillus niger) or against the microorganisms growth that could cause concrete biodeterioration (Scenedesmus vacoulatus, and Thiobacillus thiooxidans, Stichococcus bacillaris). The second objetives is to develop a comprehensive methodology (laboratory tests and field trials) to evaluate the different chemicals effectiveness against different factors over time. The laboratory tests are divided in three phases, in which the antimicrobial efficiency of 15 different formulations (10 and 5 multi-component) containing 10 different active ingredients is evaluated. In the first phase the monocomponent products efficacy was assessed, evidencing that none of them reaches the required objectives and thus are discarded for the following reasons: key concrete properties were prejudiced (strength development, density and slump), chemical leaching and acceptable antimicrobial activity not reached. In the second phase multicomponent formulations were evaluated and when using PL-UV PL-H+M-2B excellent results were reached. This product presents a long lasting antimicrobial effect without compromising the rest of concrete performancesThese good results obtained with PL-UV PL-H+M-2B, were confirmed in real use conditions field trials conducted in the port of Barcelona, in which the algae appearance was delayed up to 16 weeks. Finally, in the third phase the BXT/I effectiveness against biogenic sulfuric acid (Thiobacillus thiooxidans metabolism) attack was evaluated. Firstly, impregnation tests were done and demonstrate, qualitatively, that BXT/I inhibits the T. thiooxidans growth. Subsecquently, sulfuric acid attack simulation tests were carried out, following the method described by Vincke (1999), showing that the use of formulated BXT/I reduced by more than 30% concrete mass loss due T. thiooxidans metabolism; hence, this treatment can be considered effective against this biodeterioration process. From the methodological point of view, this PhD proposes a new methodology to evaluate the antimicrobial chemicals efficacy by studying the chemical influence in concrete properties, its possible leaching, antimicrobial effectiveness (microbiological cultures in Petri plate) and its durability, both laboratory and field trials

Revisiting the Sunspot Number

Our knowledge of the long-term evolution of solar activity and of its primary modulation, the 11-year cycle, largely depends on a single direct observational record: the visual sunspot counts that retrace the last 4 centuries, since the invention of the astronomical telescope. Currently, this activity index is available in two main forms: the International Sunspot Number initiated by R. Wolf in 1849 and the Group Number constructed more recently by Hoyt and Schatten (1998a,b). Unfortunately, those two series do not match by various aspects, inducing confusions and contradictions when used in crucial contemporary studies of the solar dynamo or of the solar forcing on the Earth climate. Recently, new efforts have been undertaken to diagnose and correct flaws and biases affecting both sunspot series, in the framework of a series of dedicated Sunspot Number Workshops. Here, we present a global overview of our current understanding of the sunspot number calibration. While the early part of the sunspot record before 1800 is still characterized by large uncertainties due to poorly observed periods, the more recent sunspot numbers are mainly affected by three main inhomogeneities: in 1880-1915 for the Group Number and in 1947 and 1980-2014 for the Sunspot Number. The newly corrected series clearly indicates a progressive decline of solar activity before the onset of the Maunder Minimum, while the slowly rising trend of the activity after the Maunder Minimum is strongly reduced, suggesting that by the mid 18th century, solar activity had already returned to the level of those observed in recent solar cycles in the 20th century. We finally conclude with future prospects opened by this epochal revision of the Sunspot Number, the first one since Wolf himself, and its reconciliation with the Group Number, a long-awaited modernization that will feed solar cycle research into the 21st century

Intensity correction for high resolution imaging using a transmitter/receiver surface coil

[Abstract] European Society for Magnetic Resonance in Medicine and Biology, ESMRMB 1996 13th Scientific Meeting, September 18 - 21, 1997, Prague, Czech RepublicPublicad

Annual report on Sunspot Counting Program 2017

Este programa observación nació a finales del año 2012 en la Universidad de Extremadura con el fin de ampliar aún más nuestra investigación en la reconstrucción de la actividad solar. Desde el 1 de Enero de 2013, nuestros recuentos de manchas solares se han presentado al Real Observatorio de Bélgica (ROB) como contribución a los esfuerzos internacionales de mantener y actualizar el número internacional de Manchas Solares. Para ello, hemos utilizado un pequeño refractor apocromático de 80 mm de diámetro de objetivo y 550 mm de longitud focal, a fin de proyectar una imagen de 150 mm de diámetro en una plantilla. Este informe proporciona un conjunto completo de los datos obtenidos durante el año 2017, con cuatro tablas que muestran nuestros datos. Por otra parte, el índice de referencia de las manchas solares se compara con nuestros resultados. Esperamos que esta publicación sea de utilidad a la comunidad científica que estudia el número de manchas solares: la mayor serie de índices solares derivadas de la observación directa del Sol.This program was born in late 2012 at the University of Extremadura (Badajoz, 38°53′ N 6°58′ W) in order to further extend our research in the reconstruction of past solar activity (see, for example, Vaquero, 2007). Since 1st January 2013, our sunspot counts have been submitted to the Royal Observatory of Belgium (ROB) as a contribution to the international effort of maintaining and updating the International Sunspot Number. For this purpose, we use a small apochromatic refractor –80 mm of objective diameter and 550 mm of focal length– to project a 150 mm diameter image onto a template. Then, a drawing is done so we obtain our sunspot counts from it. In this report, we provide a complete set of data obtained throughout the year 2017, with four tables showing our data. Moreover, the reference sunspot index is compared with our results. We hope that this publication is useful to the scientific community studying the sunspot number: the longest solar index series derived from direct observation of the Sun.• Ministerio de Educación, Cultura y Deporte: Ayuda FPU / grant FPU. • Fondos FEDER-Junta de Extremadura: Ayuda al Grupo de Investigación GR15137 y Proyecto IB16127 / Research Group Grant GR15137 and project IB16127 • Ministerio de Economía y Competitividad of the Spanish Government AYA2014-57556-P y CGL2017-87917-P

Annual report on Sunspot Counting Program 2017

Este programa observación nació a finales del año 2012 en la Universidad de Extremadura con el fin de ampliar aún más nuestra investigación en la reconstrucción de la actividad solar. Desde el 1 de Enero de 2013, nuestros recuentos de manchas solares se han presentado al Real Observatorio de Bélgica (ROB) como contribución a los esfuerzos internacionales de mantener y actualizar el número internacional de Manchas Solares. Para ello, hemos utilizado un pequeño refractor apocromático de 80 mm de diámetro de objetivo y 550 mm de longitud focal, a fin de proyectar una imagen de 150 mm de diámetro en una plantilla. Este informe proporciona un conjunto completo de los datos obtenidos durante el año 2017, con cuatro tablas que muestran nuestros datos. Por otra parte, el índice de referencia de las manchas solares se compara con nuestros resultados. Esperamos que esta publicación sea de utilidad a la comunidad científica que estudia el número de manchas solares: la mayor serie de índices solares derivadas de la observación directa del Sol.This program was born in late 2012 at the University of Extremadura (Badajoz, 38°53′ N 6°58′ W) in order to further extend our research in the reconstruction of past solar activity (see, for example, Vaquero, 2007). Since 1st January 2013, our sunspot counts have been submitted to the Royal Observatory of Belgium (ROB) as a contribution to the international effort of maintaining and updating the International Sunspot Number. For this purpose, we use a small apochromatic refractor –80 mm of objective diameter and 550 mm of focal length– to project a 150 mm diameter image onto a template. Then, a drawing is done so we obtain our sunspot counts from it. In this report, we provide a complete set of data obtained throughout the year 2017, with four tables showing our data. Moreover, the reference sunspot index is compared with our results. We hope that this publication is useful to the scientific community studying the sunspot number: the longest solar index series derived from direct observation of the Sun.• Ministerio de Educación, Cultura y Deporte: Ayuda FPU / grant FPU. • Fondos FEDER-Junta de Extremadura: Ayuda al Grupo de Investigación GR15137 y Proyecto IB16127 / Research Group Grant GR15137 and project IB16127 • Ministerio de Economía y Competitividad of the Spanish Government AYA2014-57556-P y CGL2017-87917-P