177 research outputs found

    Active zone self-similarity of fractal sierpinski antenna verified using infra-red thermograms

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    The surface current distribution of a Sierpinski fractal antenna shows a self-similar behaviour determined by the self-similar properties of its geometry. The application of infra-red thermography to electromagnetic near field detection allows the experimental verification of the active region scaling of a fractal antenna operating at different bands.Peer ReviewedPostprint (published version

    A new tool to simulate ground shaking and earthquake losses

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    The main purpose of this suite is Planning and Management of Seismic Emergencies before and after future damaging earthquake. This tool is written in ArcGIS software executing a fast and efficient determination of the estimated shakemaps and damage scenarios. The tool allows to select the earthquake source parameters through a defined database; moreover ground motion prediction equations can be chosen and they can be combined according to the study area features. The local site effects are characterized from Vs30 values, which have been achieved by topographic slope as a proxy (even with local correlations) obtained from digital elevation model. The elements exposed to risk are incorporated from the cadastral database after inputs has been refined through an automated analysis. Vulnerability and estimated losses can be determined either empirically (EMS-98 scale and Vulnerability Index, Iv) or analytically (Capacity spectrum). Additionally, a vulnerability modifier is implemented to account soil-structure resonance. Epistemic uncertainties are quantified in the input parameters using a logic tree. This tool has been validated through a representative seismic scenario: the 1910 Adra earthquake (southern Spain) with moment magnitude (Mw) 6.3 and macroseismic intensity VIII (EMS-98 scale) proving the reliability of this program.The Spanish Science and Innovation Ministry (Research Project CGL2011-30187-C02-02) and CGL2016-77688-R (AEI/FEDER, UE) have funded this research

    Documenting Paintings with Gigapixel Photography

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    [EN] Digital photographic capture of pictorial artworks with gigapixel resolution (around 1000 megapixels or greater) is a novel technique that is beginning to be used by some important international museums as a means of documentation, analysis, and dissemination of their masterpieces. This line of research is extremely interesting, not only for art curators and scholars but also for the general public. The results can be disseminated through online virtual museum displays, offering a detailed interactive visualization. These virtual visualizations allow the viewer to delve into the artwork in such a way that it is possible to zoom in and observe those details, which would be negligible to the naked eye in a real visit. Therefore, this kind of virtual visualization using gigapixel images has become an essential tool to enhance cultural heritage and to make it accessible to everyone. Since today's professional digital cameras provide images of around 40 megapixels, obtaining gigapixel images requires some special capture and editing techniques. This article describes a series of photographic methodologies and equipment, developed by the team of researchers, that have been put into practice to achieve a very high level of detail and chromatic fidelity, in the documentation and dissemination of pictorial artworks. The result of this research work consisted in the gigapixel documentation of several masterpieces of the Museo de Bellas Artes of Valencia, one of the main art galleries in Spain. The results will be disseminated through the Internet, as will be shown with some examples.This research was carried out within the Research Project entitled Captura fotografica de resolucion gigapixel para la documentacion y divulgacion del patrimonio pictorico (01/01/19-01/01/21), reference SP20180066. Project funded with the help of Primeros Proyectos de Investigacion (PAID-06-18), Vicerrectorado de Investigacion,Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), Valencia, Spain.Cabezos Bernal, PM.; Rodríguez Navarro, P.; Gil Piqueras, T. (2021). Documenting Paintings with Gigapixel Photography. Journal of imaging. 7(8):1-20. https://doi.org/10.3390/jimaging70801561207

    Documenting Paintings Using Gigapixel SfM Photogrammetry

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    [EN] Capturing paintings with gigapixel resolution (resolution around 1000 megapixels or greater) is an innovative technique that is starting to be used by some important international museums for documenting, analysing, and disseminating their masterpieces. This line of research is extremely interesting, not only for art curators and scholars, but also for the general public. The results can be disseminated through online virtual tours, offering a detailed interactive visualization. These virtual tours allow the viewer to delve into the artwork, in such a way, that it is possible to zoom in and observe those details, which would be negligible to the naked eye in a real visit. Therefore, this kind of virtual visualization using gigapixel images becomes an essential tool to enhance this cultural heritage and to make it accessible to everyone. This article will describe an affordable methodology, based on SfM photogrammetry techniques, with which it will be possible to achieve a very high level of detail and chromatic fidelity, when documenting and disseminating pictorial artworks. As a practical example, there will be shown a case study of the altarpiece, from the Museo de Bellas Artes de Valencia (Spain), entitled Virgen de las fiebres, painted around 1500 by Bernardino di Benedetto di Biagio, nicknamed `Il Pinturicchio' (Perugia, ca. 1454 ¿ Siena, 1513).This research was carried out within the Research Project entitled Captura fotográfica de resolución gigapíxel para la documentación y divulgación del patrimonio pictórico (01/01/19- 01/01/21), reference SP20180066. Project funded with the help of Primeros Proyectos de Investigación (PAID-06-18), Vicerrectorado de Investigación,Innovación y Transferencia de la Universitat Politècnica de València (UPV), València, SpainCabezos Bernal, PM.; Rodríguez Navarro, P.; Gil Piqueras, T. (2021). Documenting Paintings Using Gigapixel SfM Photogrammetry. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. 93-100. https://doi.org/10.5194/isprs-archives-XLVI-M-1-2021-93-20219310

    Using drones under 250 g for documenting the architectural heritage

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    [EN] The emergence of drones in recent years has revolutionized the field of photogrammetry due to the advantages that their use entails. opening a new variety of possibilities, as the use of close-range aerial photogrammetry. Therefore, the main objective of this contribution is to analyse the legal limits for this kind of drones under 250 g and to determine the quality of the results that can be obtained when they are used for graphic surveying. The methodology consisted in carrying out the survey of a renaissance courtyard, which is known as the Patio del Embajador Vich, one of the most relevant spaces in the city of Valencia that is currently integrated inside of the Museo de Bellas Artes de Valencia. The courtyard constitutes an excellent test bench due to the complexity of its sculptural forms and its combination with the large stucco panels. The photogrammetric survey was carried out with a DJI mini 2 drone, weighting less than 250 gr, equipped with a 1/2.3¿ CMOS sensor with a resolution of 12 Mp. In addition, a survey with a laser scanner Leica RTC 360 was also carried out to compare both of them and to estimate the precision of the photogrammetric survey. Two types of photogrammetric surveys were carried out, the first of which was taken at a medium distance to achieve the restitution of part of the general volume, while the second consisted of a very close-range survey of one of the original capitals, in order to restore a more detailed model. The conclusions of this study, that arises from the comparison and study of the models obtained, will reveal the convenience of using this kind of drones and its application to architectural heritage surveying.This contribution is part of the R+D+i project / Grant PID2020-119469RB-I00, funded by the Ministry of Science and Innovation/ State Research Agency/10.13039/501100011033.Rodríguez Navarro, P.; Cabezos Bernal, PM.; Gil Piqueras, T.; Giménez Ribera, M. (2022). Using drones under 250 g for documenting the architectural heritage. DisegnareCon. 15(29):1-19. https://doi.org/10.20365/disegnarecon.29.2022.1119152

    Resiliencia a desastres y capital social. Análisis de redes sociales en barrios periféricos de la ciudad de Cusco, Perú

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    El estudio de las implicaciones de las formas de organización social en la determinación de la resiliencia frente a desastres ha venido cobrando mayor interés en los últimos tiempos. En este trabajo se propone el análisis de las redes sociales como una forma de determinar el capital social y su vinculación con la resiliencia. La metodología propuesta ha sido aplicada en 18 barrios periféricos de la ciudad de Cusco, Perú, y supone la determinación para cada barrio de indicadores de cohesión interna (bonding), vinculación con el resto de barrios (bridging) e integración con organizaciones de segundo nivel y con el gobierno local (linking). Se obtiene finalmente el mayor o menor nivel de capital social de cada barrio como contribución a su resiliencia, lo que además puede ser utilizado para orientar de forma más adecuada la gestión del riesgo de desastres

    Caracterización de la acción sísmica enfocada a estudios de riesgo sísmico a escala urbana. Aplicaciones en Almería y Alhama de Granada.

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    Una de las principales diferencias entre estudios de riesgo símico a escalas regional y urbana se refiere a la caracterización de la acción sísmica. En los estudios regionales, se impone el método probabilista, en el que habitualmente el resultado se expresa por medio de mapas de aceleración esperada para un periodo de retorno dado y espectros de peligrosidad uniforme. Sin embargo, en los estudios urbanos se requiere un mayor grado de detalle, tanto en la definición de las fuentes sismogenéticas como en la caracterización del movimiento esperado, sobre el que inciden de manera fundamental posibles efectos de resonancia con el suelo en el emplazamiento y/o con las estructuras asentadas en el mismo. En este trabajo se presentan diversas propuestas de caracterización de la acción sísmica en entornos urbanos. Para su aplicación práctica, se usarán datos de dos localidades concretas: Almería, donde se usará un escenario sísmico compatible con el sismo de control de la peligrosidad en rangos de aceleración esperados para un periodo de retorno de 475 años y en Alhama de Granada, donde el movimiento sísmico corresponde al que generaría un terremoto similar al de Andalucía de 1884, con fuente en la falla de Zafarraya

    Electron Transfer Pathways and Dynamics of Chloroplast NADPH-dependent Thioredoxin Reductase C (NTRC)

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    NADPH-dependent thioredoxin reductases (NTRs) contain a flavin cofactor and a disulfide as redox-active groups. The catalytic mechanism of standard NTR involves a large conformational change between two configurations. Oxygenic photosynthetic organisms possess a plastid-localized NTR, called NTRC, with a thioredoxin module fused at the C terminus. NTRC is an efficient reductant of 2-Cys peroxiredoxins (2-Cys Prxs) and thus is involved in the protection against oxidative stress, among other functions. Although the mechanism of electron transfer of canonical NTRs is well established, it is not yet known in NTRC. By employing stopped-flow spectroscopy, we have carried out a comparative kinetic study of the electron transfer reactions involving NTRC, the truncated NTR module of NTRC, and NTRB, a canonical plant NTR. Whereas the three NTRs maintain the conformational change associated with the reductive cycle of catalysis, NTRC intramolecular electron transfer to the thioredoxin module presents two kinetic components (kET of ∼2 and 0.1 s−1), indicating the occurrence of additional dynamic motions. Moreover, the dynamic features associated with the electron transfer to the thioredoxin module are altered in the presence of 2-Cys Prx. NTRC shows structural constraints that may locate the thioredoxin module in positions with different efficiencies for electron transfer, the presence of 2-Cys Prx shifting the conformational equilibrium of the thioredoxin module to a specific position, which is not the most efficien

    Mapa preliminar de períodos predominantes del suelo en Puerto Príncipe (Haití) a partir de medidas de ruido ambiental.

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    The 2010 Haiti earthquake, occurred on January 12th at 16:53:09 local time (21:53:09 UTC) with epicentral distance of 15 km from the capital Port au Prince, MW 7.0 and 13 km hypocenter deep, was the strongest event in the area since happened in 1770. The maximum macroseismic intensity was estimated as X (MMI scale). The aim of this research is to obtain a preliminary zonation of Port-au-Prince in terms of predominant resonance periods of ground. A total of 36 short-period ambient noise records have been carried out on a grid of about 500x500m. H/V spectral ratio method (HVSR) has been applied to determine the predominant period at each point. The lowest values ( 0.45s) correspond to the center and western parts, composed of Pleistocene-Holocene alluvial deposits and anthropogenic land reclaimed from the sea. We have determined the ground VS30 structure inside National Palace garden, using simultaneous ambient noise measurements. An array made up of 6 sensors were used, with 5 of them uniformly distributed along a circumference and a sixth one placed in its centre. The records were analyzed by using the spatial autocorrelation method (SPAC). The VS 30 value obtained was 331m/sec, in good agreement with the average values obtained for this area by other authors, using prospecting techniques

    Seismic hazard in Andalucia region (Southern Spain)

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    The global objective of the SISMOSAN Project has been to provide a general seismic risk assessment of Andalusian region (Southern Spain) associated with the ground motions expected for a return period of 475 years. The project was financed by Civil Defence of Andalusia and its results will be applied to the definition of regional emergency plans. We present here the study and main results of the first phase of the project, aimed at evaluating seismic hazard. In contrast to most of the previous studies in the region, which were performed for peak ground accelerations (PGA) making use of Intensity-to-PGA relationships, hazard was here calculated in terms of magnitude and using published spectral ground-motion models. Moreover, we have considered distinct models for the Atlantic earthquakes, since the attenuation of those motions seem to be slower, as evidenced by the extensive macroseismic areas of the 1755, 1969 and 2007 earthquakes. A comprehensive revision of the seismic catalogue, as well as of the seismogenic models proposed for the region (including those for North Africa, which is part of the influence area) has been done. In a first step, seismic hazard was evaluated at generic rock sites covering the entire region, using a seismic catalogue homogenized to moment magnitude and considering attenuation models in terms of PGA and spectral ordinates (SA). A Probabilistic Seismic Hazard Assessment (PSHA) methodology was followed using a logic tree, in order to constrain the epistemic uncertainty, including two nodes for different options of zonification and attenuation models. In a second step, a geotechnical characterization of the whole region has been carried out, mainly inferred from geological maps and refined with on-site data, which are combined with rock acceleration estimates, in order to compose hazard maps that incorporate local soil effects
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