Development of an advanced technique based on acoustic resonance in gases for determining relevant thermodynamic constants and properties

Se desarrolla una técnica de resonancia acústica y de microondas para la caracterización de mezclas de gases energéticos no convencionales y para realizar una termometría acústica en Argón. La resonancia de microondas se lleva acabo simultáneamente con la acústica para caracterizar el radio interno del resonador esférico y reducir así la incertidumbre en la velocidad del sonido en Argón. Se realizan medidas de la velocidad del sonido en Argón a diferentes presiones manteniendo siempre la temperatura constante a la temperatura del punto triple del agua. Al extrapolar la isoterma a presión nula se pueden obtener medidas con muy baja incertidumbre (aproximadamente 20 ppm) de la constante de Boltzman para la definición del nuevo Kelvin. Con un procedimiento parecido pero más simple y rápido es posible determinar tanto la ecuación del virial acústico como las capacidades caloríficas como gas perfecto de los gases y mezclas de gases estudiados.Departamento de Ingeniería Energética y FluidomecánicaDoctorado en Investigación en Ingeniería Termodinámica de Fluido

Alimentación de la oveja con mezclas completas ofrecidas a libre disposición en comederas de autoconsumo

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Using ultrashort xuv laser pulses to investigate symmetry breaking in one-photon single-ionization of H2

ABSTRACT: We have evaluated photoelectron angular distributions from xed-in-space molecular hydrogen exposed to ultrashort xuv laser pulses. The theoretical method is based on the solution of the time-dependent Schrodinger equation in a basis of stationary states that include all electronic and vibrational degrees of freedom. We conclude that the origin of the asymmetry in these angular distributions is the interference of the two dissociative ionization channels (1s(sigma)g and 2p(sigma)u) due to delayed ionization from the H2 doubly excited states

Plant phenomics: an overview of image acquisition technologies and image data analysis algorithms

The study of phenomes or phenomics has been a central part of biology. The field of automatic phenotype acquisition technologies based on images has seen an important advance in the last years. As with other high-throughput technologies, it addresses a common set of problems, including data acquisition and analysis. In this review, we give an overview of the main systems developed to acquire images. We give an in-depth analysis of image processing with its major issues and the algorithms that are being used or emerging as useful to obtain data out of images in an automatic fashion.This work was funded by grants FEDER BFU2013-45148-R, Fundación Séneca 19398/PI/14 to MEC and FEDER ViSelTR (TIN2012-39279) to PJN

Evaluación de errores en el posicionamiento con receptores GPS de doble frecuencia bajo cubierta arbolada de Pinus dadiata D.Don

El uso de receptores GPS en el ámbito forestal se ha generalizando y sus aplicaciones son muy variadas (localización de parcelas de inventario, guiado de maquinaria forestal, uso recreativo, etc.). El objetivo de este trabajo fue evaluar la precisión y exactitud del posicionamiento GPS bajo la cubierta de masas de Pinus radiata. Para ello se identificaron 12 puntos de muestreo en parcelas con 4 densidades diferentes (3 parcelas en cada nivel de densidad) y 1 punto en una zona despejada para poder comparar la influencia de la cobertura arbórea. En cada punto se hicieron observaciones estáticas por un período de una hora. Se determinaron las coordenadas X,Y,Z para cada segundo, se calcularon las exactitudes y se identificaron las distribuciones teóricas que mejor se ajustaban a los valores de exactitud obtenidos para cada tipo de masa. Del análisis de los resultados se pude deducir que: i) las variables dasométricas que más influyen en la exactitud planimétrica son el número de pies por ha (N) y el diámetro medio cuadrático (dg); ii) la probabilidad de que la exactitud planimétrica sea menor de 1 m y de que la exactitud altimétrica sea menor de 3 m es del 70%. Los resultados obtenidos permitirán planificar más adecuadamente las observaciones con receptores GPS en zonas arboladas.The use of GPS receivers in forestry has been widespread and this technology is used for location of inventory plots, guided forest machinery, recreational use and navigation, etc. The aim objective of this study was to evaluate the accuracy and positioning accuracy of dual-frequency GPS receivers under tree canopy of Pinus radiate stands. In order to compare the influence of tree canopy in the GPS positioning, 12 points were established in 4 stands with different densities (three plots of each density level). An additional point was located in a nearby area without trees. At each point, static observations were made for a period of one hour and the coordinates X,Y,Z were calculated for each second. Precisions, accuracies and theoretical distributions were identified for each type of stands. The stand variables related to horizontal accuracy were the number of trees per hectare (N), the Hart-Becking index (IH) and the quadratic mean diameter (dg). The probability that both the horizontal accuracy is less than 1 m and the vertical accuracy is less than 3 m is 70%. The results obtained will allow a more adequately planning of observations with GPS receivers in forest areas

Asymmetric electron angular distributions in resonant dissociative photoionization of H2 with ultrashort xuv pulses

ABSTRACT: Photoelectron angular distributions from fixed-in-space H2 molecules exposed to ultrashort xuv laser pulses have been evaluated. The theoretical method is based on the solution of the time-dependent Schrödinger equation in a basis of stationary states that include all electronic and vibrational degrees of freedom. Asymmetric angular distributions are observed as a consequence of the delayed ionization from the H2 doubly excited states, which induces interferences between gerade and ungerade ionization channels. The analysis of this asymmetry as a function of pulse duration can provide an estimate of the corresponding autoionization widths

Two-photon dissociative ionization of H2 by ultrashort xuv laser pulses

ABSTRACT: Ab initio calculations of H2 photoionization induced by low-intensity ultrashort xuv laser pulses are reported in the region of two-photon absorption. Our computational approach is based on the solution of the time-dependent Schr¨odinger equation including all electronic and vibrational degrees of freedom. We find that, as one approaches the one-photon ionization threshold, dissociative ionization largely dominates over non dissociative ionization. We show that this behavior is mostly induced by the presence of molecular autoionizing states in this photon energy region

Amorphous zinc borate as a simple standard for baseline correction in Raman spectra

In this paper, our research group proposes a simple solution to a usual problem that appears in the Raman analysis of some substances, which is the presence of weak Raman signals, probably in combination with a high‐intensity luminescence background, affected by the presence of distortions in the baseline. Under this condition, the spectroscopist has to face spectra hard to edit and correct and thus hard to study. There are already some standard solutions that allow the correction of spectra from relative intensity to absolute intensity that also solves this problem and also allow quantitative analyses. But these solutions imply expensive standards or devices that could not be a worthy option when not working in absolute intensity or the Raman analyses stay at qualitative level and a quantitative study is not needed. The alternative Do It Yourself solution proposed in this paper is based on the use of amorphous zinc borate, an easy‐to‐find substance, which after a simple processing allows us to correct the baseline of Raman spectra qualitatively, offering a useful and economic reference when an absolute intensity correction is not needed. In order to evaluate the effectiveness of this procedure, some spectra were corrected using amorphous zinc borate and then compared the signal‐to‐noise ratio of some Raman signals before and after this correction. Copyright © 2017 John Wiley & Sons, Ltd.MINECO ESP2014-56138-C3-1-

Single polarized Tm3+ laser in Zn-diffused LiNbO3 channel waveguides

Copyright (2005) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 86 (2005): 161119 and may be found at http://apl.aip.org

Aircraft flight trajectory deviation in the standard instrument departures. Operators penalties.

In the recent years many problems are emerging due to the aircraft noise on the airport surrounding areas. The solution to this problem is not easy considering that the neighbourhood asks for the reduction of the number of aircraft operations and the airlines ask for a growing demand in the number of operations in the major airports. So the airport and regulatory authorities try to get a solution imposing a fine to the aircraft which its actual trajectory differs from the nominal one more than a lateral deviation. But, which is the value of this deviation?. The current situation is that many operators have to pay a lot of money for exceeding a deviation which has been established without operational criteria. This paper presents the results of a research program which is being carried out by the authors which aims to determine the "delta" deviation to be used for this purpose. In addition it is proposed a customized method per SID and per airport to be used for determining the maximum allowed lateral deviation by which if the aircraft is within it, then none fine will be imposed