Search results for "53"
showing 10 items of 2908 documents
Theoretical Approach to the Radiance-to-Flux Conversion in the EarthCARE Mission Framework.
2008
The research of the Thesis, "Theoretical Approach to the Radiance-to-Flux Conversion in the EarthCARE Framework", is aimed at studying the instantaneous TOA radiance-to-flux conversion for the prospective Broad-Band Radiometer (BBR) on-board the EarthCARE (Earth Clouds Aerosols and Radiation Explorer) platform, through the development of theoretical angular distribution models based on the specific designing features of the instrument. The inversion procedure has been undertaken to obtain the apparent TOA fluxes according to the flux retrieval accuracy required for the mission. The ADMs employed in previous missions make use of a single radiance in the inversion process. With the specific B…
Vegetation monitoring through retrieval of NDVI and LST time series from historical databases.
2008
The PhD dissertation presented here falls into the Earth Observation field, specifically vegetation monitoring. This work consists in the extensive exploitation of historical databases of satellite images for vegetation monitoring through two parameters, which are the land surface temperature (LST) and a vegetation index (NDVI). Up to now, vegetation monitoring has been limited to the use of vegetation indices, so the addition of the land surface temperature parameter represents the main innovative character of this PhD study.This dissertation is divided into 5 chapters. The first chapter begins by introducing the theoretical aspects of NDVI and LST parameters, addressing the means for retr…
Caracterización de los aerosoles atmosféricos en Valencia mediante fotometría solar.
2006
A pesar de que en el Protocolo de Kyoto (1997) no se tomaron medidas para restringir la emisión a la atmósfera de las partículas de origen antropogénico, la influencia que tienen éstas sobre el clima se estima comparable a la de los gases de efecto invernadero. La ausencia de directrices estuvo motivada por el escaso conocimiento de las propiedades y mecanismos de formación y eliminación de los aerosoles en la atmósfera, y por tanto su efecto neto sobre el clima futuro. El presente trabajo se enmarca dentro de la necesidad de mejorar la comprensión del sistema. Para ello se aborda experimentalmente la caracterización climatológica de las propiedades de los aerosoles y de sus mecanismos de t…
Evapotranspiración de la cubierta vegetal mediante la determinación del coeficiente de cultivo por teledetección. Extensión a escala regional: Acuífe…
2006
En el seguimiento de las necesidades h´ýdricas de las cubiertas vegetales se utiliza,en pr´acticamente todo el mundo, la metodolog´ýa Kc−ETo (conocida comometodolog´ýa en dos pasos), donde Kc es el coeficiente de cultivo y ETo la evapotranspiraci´on de referencia.Desde la perspectiva operacional, la determinaci´on desde sat´elite del coeficientede cultivo Kc permite hacer una estimaci´on continua de la evapotranspiraci´on, y, por tanto, unas previsiones de las necesidades h´ýdricas de la cubiertavegetal. La teledetecci´on permite determinar dicho coeficiente sobre grandes´areas. Teniendo en cuenta estos precedentes, esta tesis es una continuaci´onde los trabajos previos existentes en …
Compensación de la dispersión cromática asociada a la propagación de la luz en el espacio libre. Diseño de dispositivos acromáticos basados en la dif…
2002
El gran interés suscitado por las técnicas de tratamiento óptico de la información durante las últimas décadas tiene su origen, al menos parcialmente, en la capacidad inherente que presentan los sistemas ópticos para la manipulación en paralelo a la velocidad de la luz, de señales de entrada bidimensionales, en contraste con el tratamiento en serie de los sistemas electrónicos de procesado digital. Sin embargo, los procesadores coherentes son sistemas que proporcionan una redundancia nula en el tratamiento de la información, por lo que son muy vulnerables al ruido coherente generado por la presencia de polvo o defectos en los elementos ópticos. Por todo ello, a parte de este procesado conve…
Coherence in ultrashort light pulses and applications in temporal optics.
2008
In the last decades, the generation of lasers delivering pulses with durations in the order of femtosecond has constituted an important research topic for the Physics and Engineering communities. The characteristics of this kind of radiation, i.e., broadband spectrum, enormous temporal resolution, high peak-power with low energy average, potentially high repetition rate and high spatial coherence make it an indispensable tool in order to develop many applications in different fields of science and technology. Ultrafast laser technology is ready to offer real world applications ranging from high-tech, such us high-speed circuit testing and biological imaging, to more industrial applications …
Mass measurements of As, Se, and Br nuclei, and their implication on the proton-neutron interaction strength toward the N=Z line
2021
Mass measurements of the $^{69}$As, $^{70,71}$Se and $^{71}$Br isotopes, produced via fragmentation of a $^{124}$Xe primary beam at the FRS at GSI, have been performed with the multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) of the FRS Ion Catcher with an unprecedented mass resolving power of almost 1,000,000. For the $^{69}$As isotope, this is the first direct mass measurement. A mass uncertainty of 22 keV was achieved with only 10 events. For the $^{70}$Se isotope, a mass uncertainty of 2.6 keV was obtained, corresponding to a relative accuracy of $\delta$m/m = 4.0$\times 10^{-8}$, with less than 500 events. The masses of the $^{71}$Se and $^{71}$Br isotopes were measured…
Nuclear mean-square charge radii of $^{63,64,66,68−82}$Ga nuclei: No anomalous behavior at N=32
2012
Collinear laser spectroscopy was performed on the 63,64,66,68−82Ga isotopes with neutron numbers from N = 32 to N = 51. These measurements were carried out at the ISOLDE radioactive ion beam facility at CERN. Here we present the nuclear mean-square charge radii extracted from the isotope shifts and, for the lighter isotopes, new spin and moment values. New ground-state nuclear spin and moments were extracted from the hyperfine spectra of 63,70Ga, measured on an atomic transition in the neutral atom. The ground-state spin of 63Ga is determined to be I = 3/2. Analysis of the trend in the change in mean-square charge radii of the gallium isotopes demonstrates that there is no evidence of anoma…
Visual cues improve students’ understanding of divergence and curl: Evidence from eye movements during reading and problem solving
2019
The coordination of multiple external representations is important for learning, but yet a difficult task for students, requiring instructional support. The subject in this study covers a typical relation in physics between abstract mathematical equations (definitions of divergence and curl) and a visual representation (vector field plot). To support the connection across both representations, two instructions with written explanations, equations, and visual representations (differing only in the presence of visual cues) were designed and their impact on students’ performance was tested. We captured students’ eye movements while they processed the written instruction and solved subsequent c…
Las formas cotidianas de la felicidad y sus mandatos: Pedagogías del pensamiento positivo, trabajo docente y subjetividad en el neoliberalismo contem…
2020
Positive thinking constitutes one of the great traditions that lead to the idea of the subject as an entrepreneur of himself and is perhaps one of the best that has successfully condensed cultural, political, social and pedagogical processes linked to reflection on well-being in this historical time. The teaching work is especially moved by the pregnancy of these perspectives that challenge the pedagogical field and the education workers as ?agents of change, or at least one more school available to give the discussion on well-being and happiness (yours and the students?) is celebrated and encouraged. In this article, I intend to understand what is being built as pedagogical discourses abou…