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Search Results: 1 - 10 of 546725 matches for " M. D. Rodríguez Frías "
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The Atmospheric Monitoring system of the JEM-EUSO telescope
S. Toscano,A. Neronov,M. D. Rodríguez Frías,S. Wada for the JEM-EUSO Collaboration
Physics , 2014, DOI: 10.1007/s10686-014-9378-1
Abstract: The JEM-EUSO observatory on board of the International Space Station (ISS) is a proposed pioneering space mission devoted to the investigation of Ultra High Energy Cosmic Rays (UHECRs). Looking downward at the earth's atmosphere with a 60$^\circ$ Field of View (FoV), the JEM-EUSO telescope will detect the fluorescence and Cherenkov UV emission from UHECR induced Extensive Air Showers (EAS) penetrating in the atmosphere. The capability of reconstructing the properties of the primary cosmic ray depends on the accurate measurement of the atmospheric conditions in the region of EAS development. The Atmospheric Monitoring system of JEM-EUSO will continuously monitor the atmosphere at the location of the EAS candidates and between the EAS and the JEM-EUSO telescope. With an UV LIDAR and an Infrared (IR) Camera the system will monitor the cloud cover and retrieve the cloud top altitude with an accuracy of $\sim$ 500 m and the optical depth profile of the atmosphere with an accuracy of $\Delta\tau \leq$ 0.15 and a resolution of 500 m. In this contribution the Atmospheric Monitoring system of JEM-EUSO will be presented. After a brief description of the system, the capability to recover the cloud top height and optical depth and to reconstruct the shower profile will be shown based on satellites data and simulation studies.
Energy reconstruction of hadron-initiated showers of ultra-high energy cosmic rays
G. Ros,G. A. Medina-Tanco,A. D. Supanitsky,L. del Peral,M. D. Rodríguez-Frías
Physics , 2015, DOI: 10.1016/j.astropartphys.2015.04.001
Abstract: The current methods to determine the primary energy of ultra-high energy cosmic rays (UHECRs) are different when dealing with hadron or photon primaries. The current experiments combine two different techniques, an array of surface detectors and fluorescence telescopes. The latter allow an almost calorimetric measurement of the primary energy. Thus, hadron-initiated showers detected by both type of detectors are used to calibrate the energy estimator from the surface array (usually the interpolated signal at a certain distance from the shower core S(r0)) with the primary energy. On the other hand, this calibration is not feasible when searching for photon primaries since no high energy photon has been unambiguously detected so far. Therefore, pure Monte Carlo parametrizations are used instead. In this work, we present a new method to determine the primary energy of hadron-induced showers in a hybrid experiment based on a technique previously developed for photon primaries. It consists on a set of calibration curves that relate the surface energy estimator, S(r0), and the depth of maximum development of the shower, Xmax, obtained from the fluorescence telescopes. Then, the primary energy can be determined from pure surface information since S(r0) and the zenith angle of the incoming shower are only needed. Considering a mixed sample of ultra-high energy proton and iron primaries and taking into account the reconstruction uncertainties and shower to shower fluctuations, we demonstrate that the primary energy may be determined with a systematic uncertainty below 1% and resolution around 16% in the energy range from 10^{18.5} to 10^{19.6} eV. Several array geometries, the shape of the energy error distributions and the uncertainties due to the unknown composition of the primary flux have been analyzed as well.
A new composition-sensitive parameter for Ultra-High Energy Cosmic Rays
G. Ros,A. D. Supanitsky,G. A. Medina-Tanco,L. del Peral,J. C. D'Olivo,M. D. Rodríguez-Frías
Physics , 2011, DOI: 10.1016/j.astropartphys.2011.06.011
Abstract: A new family of parameters intended for composition studies in cosmic ray surface array detectors is proposed. The application of this technique to different array layout designs has been analyzed. The parameters make exclusive use of surface data combining the information from the total signal at each triggered detector and the array geometry. They are sensitive to the combined effects of the different muon and electromagnetic components on the lateral distribution function of proton and iron initiated showers at any given primary energy. Analytical and numerical studies have been performed in order to assess the reliability, stability and optimization of these parameters. Experimental uncertainties, the underestimation of the muon component in the shower simulation codes, intrinsic fluctuations and reconstruction errors are considered and discussed in a quantitative way. The potential discrimination power of these parameters, under realistic experimental conditions, is compared on a simplified, albeit quantitative way, with that expected from other surface and fluorescence estimators.
Multi Anode Photomultiplier Tube Reliability Assessment for the JEM-EUSO Space Mission
H. Prieto-Alfonso,L. del Peral,M. Casolino,K. Tsuno,T. Ebisuzaki,M. D. Rodríguez Frías,JEM-EUSO Collaboration
Physics , 2015, DOI: 10.1016/j.ress.2014.08.014
Abstract: Reliability assessment in concerned with the analysis of devices and systems whose individual components are prone to fail. This reliability analysis documents the process and results of reliability determination of the JEM-EUSO photomultiplier tube component using the methods 217 Plus. Quantum efficiency degradation and radiation hardness assurance. In conclussion, the levels of damage suffered by the PMTs which comprise the focal surface of JEM-EUSO Space Telescope, are acceptable. The results show as well the greatest contribution to the failure is due to radiation SET. The guaranteed performance of this equipment is a 99.45 per cent, an accepted value of reliability thus fulfilling the objectives and technological challenges of JEM-EUSO.
Thin and thick cloud top height retrieval algorithm with the Infrared Camera and LIDAR of the JEM-EUSO Space Mission
G. Sáez-Cano,J. A. Morales de los Ríos,L. del Peral,A. Neronov,S. Wada,M. D. Rodríguez Frías,for the JEM-EUSO Collaboration
Physics , 2015, DOI: 10.1051/epjconf/20158903001
Abstract: The origin of cosmic rays have remained a mistery for more than a century. JEM-EUSO is a pioneer space-based telescope that will be located at the International Space Station (ISS) and its aim is to detect Ultra High Energy Cosmic Rays (UHECR) and Extremely High Energy Cosmic Rays (EHECR) by observing the atmosphere. Unlike ground-based telescopes, JEM-EUSO will observe from upwards, and therefore, for a properly UHECR reconstruction under cloudy conditions, a key element of JEM-EUSO is an Atmospheric Monitoring System (AMS). This AMS consists of a space qualified bi-spectral Infrared Camera, that will provide the cloud coverage and cloud top height in the JEM-EUSO Field of View (FoV) and a LIDAR, that will measure the atmospheric optical depth in the direction it has been shot. In this paper we will explain the effects of clouds for the determination of the UHECR arrival direction. Moreover, since the cloud top height retrieval is crucial to analyze the UHECR and EHECR events under cloudy conditions, the retrieval algorithm that fulfills the technical requierements of the Infrared Camera of JEM-EUSO to reconstruct the cloud top height is presently reported.
Design of the Front End Electronics for the Infrared Camera of JEM-EUSO, and manufacturing and verification of the prototype model
Oscar Maroto,Laura Díez-Merino,Jordi Carbonell,Albert Tomàs,Marcos Reyes,Enrique Joven,Yolanda Martín,J. A. Morales de los Ríos,Luis Del Peral,M. D. Rodríguez Frías
Physics , 2015,
Abstract: The Japanese Experiment Module (JEM) Extreme Universe Space Observatory (EUSO) will be launched and attached to the Japanese module of the International Space Station (ISS). Its aim is to observe UV photon tracks produced by ultra-high energy cosmic rays developing in the atmosphere and producing extensive air showers. The key element of the instrument is a very wide-field, very fast, large-lense telescope that can detect extreme energy particles with energy above $10^{19}$ eV. The Atmospheric Monitoring System (AMS), comprising, among others, the Infrared Camera (IRCAM), which is the Spanish contribution, plays a fundamental role in the understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. It is used to detect the temperature of clouds and to obtain the cloud coverage and cloud top altitude during the observation period of the JEM-EUSO main instrument. SENER is responsible for the preliminary design of the Front End Electronics (FEE) of the Infrared Camera, based on an uncooled microbolometer, and the manufacturing and verification of the prototype model. This paper describes the flight design drivers and key factors to achieve the target features, namely, detector biasing with electrical noise better than $100 \mu$V from $1$ Hz to $10$ MHz, temperature control of the microbolometer, from $10^{\circ}$C to $40^{\circ}$C with stability better than $10$ mK over $4.8$ hours, low noise high bandwidth amplifier adaptation of the microbolometer output to differential input before analog to digital conversion, housekeeping generation, microbolometer control, and image accumulation for noise reduction.
Sugars, Organic Acids and Total Phenols in Varieties of Chestnut Fruits from Tenerife (Spain)  [PDF]
M. Hernández Suárez, B. Rodríguez Galdón, D. Ríos Mesa, C. Díaz Romero, E. Rodríguez Rodríguez
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.36096
Abstract: The sugar, organic and total phenol contents were determined in 21 varieties of chestnut from Tenerife (Spain). Sucrose, fructose and glucose were determined by HPLC/refraction index being the sucrose the sugar with the highest content. The organic acids were determined by HPLC/diode array, and the chestnuts had an organic acids profile characterized by the following compounds: oxalic, glutamic, tartaric, pyruvic, malic, ascorbic, citric, fumaric and cis-aconitic acids. Ascorbic, citric and malic acids were the major organic acids. There were differences in the composition of sugars, total phenols and organic acids between the chestnut varieties. The production zone only significantly affected the contents of moisture, sucrose, total phenols and fructose. The correlations between glucose-fructose, malic acid-fumaric acid, tartaric acid-oxalic acid could be emphasized. An important contribution to the intake of antioxidants is observed for the consumption of chestnuts.
Caracterización mecánica de un acero ferrítico/martensítico de activación reducida de producción espa ola
Rodríguez, D.,Serrano, M.
Revista de Metalurgia , 2012,
Abstract: This paper shows the first results concerning the characterization of two heats of a reduced activation 9 Cr ferritic/martensitic steel (RAFM) made in Spain, called AF1B and AF2A. The results of this characterization are compared with their European counterparts, EUROFER97-2, which was chosen as reference material. All activities described were performed in the Structural Materials Unit of CIEMAT, within the national project TECNO-FUS CONSOLIDER INGENIO.The two Spanish heats have the same production process and heat treatment. Both heats have a similar tensile behaviour similar to EUROFER97-2, but on the other hand impact properties are lower. The microstructure of AF1B reveals large biphasic inclusions that affecting its mechanical properties, especially the impact properties. AF2A casting was free of these inclusions. En este documento se reflejan los primeros resultados referentes a la caracterización de dos coladas de un acero 9 Cr ferrítico/martensítico de activación reducida (RAFM) producido en Espa a, denominadas AF1B y AF2A. Los resultados obtenidos en dicha caracterización se compararán con su homólogo europeo, el EUROFER97-2, el cual se eligió como material de referencia. Todas las actividades detalladas se realizaron en la Unidad de Materiales Estructurales del CIEMAT, dentro del proyecto TECNO-FUS CONSOLIDER INGENIO. Ambas coladas, producidas en una planta piloto de la Fundación ITMA, presentan el mismo proceso de producción y tratamiento térmico final. Asimismo presentan un comportamiento a tracción similar al del EUROFER97-2. Por el contrario, las propiedades a impacto son menores a las del homólogo europeo. En la microestructura de la colada AF1B se han detectado inclusiones bifásicas de gran tama o que afectan a sus propiedades mecánicas, sobre todo a las de impacto. Estas inclusiones no se detectaron en la AF2A.
Influence of agronomic variables on quality of tomato fruits  [PDF]
Marcos Hernández Suárez, Eladia Pe?a Méndez, Beatriz Rodríguez Galdón, Elena Rodríguez Rodríguez, Carlos Díaz Romero
Agricultural Sciences (AS) , 2011, DOI: 10.4236/as.2011.24054
Abstract: In order to study interactions between agronomic variables and chemical composition that determine the quality of tomato fruits, a group of statistical techniques were applied: discriminant analysis (DA), cluster analysis (CA) and princepal component analysis (PCA) combined with ANOVA. The results of DA when characterizing the agronomic parameters were successful, especially when the collection date was used as a factor for classification. CA showed the importance of the chemical variables related to the metabolic relationships, while the principal component analysis and ANOVA provide information on the interaction between variables related to the production and chemical composition of tomatoes. The combined use of PCA and ANOVA is a suitable tool for studying the complex interactions between agronomy and chemical composition. Collection date was the main agronomic parameter effected the chemical composition, while variety and production system had a minor effect. The application of PCAANOVA showed that the taste of tomato depends on three factors: sugars (glucose and fructose), acidity (citric, malic and ascobirc acids), and minerals (Na and Mg). For the tomatoes with same maturity degree, the taste depends on interaction of date collection and system production.
Microscopic Characterization of Ecological Concrete Polymeric  [PDF]
A. D. Rodríguez, M. L. Domínguez, R. M. Melgoza
Microscopy Research (MR) , 2014, DOI: 10.4236/mr.2014.21003
Abstract:

The Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) with integrated digital camera are techniques that are used in the present investigation, for the morphological characterization of a new composite material called “organic polymer concrete” in which microparticles added fibers and polyethylene terephthalate (PET) recycling mechanically (RM). Polymer concrete (PC) is a new composite material (MC) in the application considered as an alternative material of construction in which reinforcement particles are recycled polymers which have approximately the same dimensions in all directions. Therefore, the particles can be rods, spheres, chips and many other shapes whose appearance reasons are about 10 microns. These MC, the size, shape and distribution and the ratio and the modulus of the particles affect the properties of the material.

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