Determination of reflectance and transmittance of multi-layer of InGaAs and theoretical methods for obtaining of optical constants

5 páginas, 3 figuras, 2 tablas.-- Trabajo presentado al 1st International Congress on Instrumentation and Applied Sciences celebrado en Cancún (México) del 26 al 29 de Octubre de 2010.The theoretical concepts are necessary to obtain the optical constants of several materials in InGaAs Photodiode and are possible to obtain from experimental dates of reflectance and transmittance and several optical coverings can be designed. In this work we will show how to calculate the reflectance of photodiode for all the wavelengths (each 50 nm, according to the data of refractive index), as well as changing to the angle of incidence and polarization s and p, besides the calculation of the transmittance of a multi-layer ones of InGaAs. A multi-layer is constituted by a series of piled up laminae some on others and in this work we will suppose that they are homogenous, isotropic and plane-parallel, the structure is in the first case we have a transparent layer of NSi, late second layer of InP (Zn), soon a third layer of InGaAs and finally a later of InP (S). These multilayers are destined for optical applications, in our case will be case of study in the case of the photodiodes, the thicknesses of the layers will be of the order of the wavelength of incident radiation, which in the case of radiation IR/NIR is translated in thicknesses of approximately between 1y 100 nm. For the determination of optical constants they are possible to be done of different ways in our case we will concentrate in 1) Measured of reflectance in normal incidence. These measures only provide the value of n in the case of means transparents.2) Measured of reflectance in two angles of incidence. It allows to the use of natural light or polarized.3) Two measures of R p R s in two angles of incidence outside the normal one. 4) Rs and Rp in a single angle of incidence outside the normal one.Peer reviewe

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Käytännön kosteikkosuunnittelu

Maatalouden vesiensuojelua edistetään monin tavoin. Ravinteita ja eroosioainesta sisältäviä valumavesiä pyritään puhdistamaan erilaisissa kosteikoissa. Tämä opas on kirjoitettu avuksi pienimuotoisten kosteikkojen perustamiseen. Oppaassa esitetään käytännönläheisesti kosteikon toteuttamisen eri vaiheet paikan valinnasta suunnitteluun ja rakentamiseen. Vuonna 2010 julkaistun painoksen tiedot on saatettu ajantasalle. Julkaisu on toteutettu osana Tehoa maatalouden vesiensuojeluun (TEHO) -hanketta ja päivitetty TEHO Plus -hankkeen toimesta. Oppaan toivotaan lisäävän kiinnostusta kosteikkojen suunnitteluun ja edelleen niiden rakentamiseen

Covid-19: consecuencias y desafíos en la economía colombiana. Una mirada desde las universidades

Este libro reúne diferentes hallazgos, perspectivas y efectos ante un fenómeno que, más de un año después, todavía representa un reto científico, médico y social para todos. Igualmente, esta obra representa el objetivo de la Red Investigadores de Economía: aunar esfuerzos para encontrar respuestas y para fortalecer la investigación en el país, aumentar la difusión de trabajos de calidad y propiciar el encuentro entre académicos, universidades y el Banco de la República. Las investigaciones expuestas en este libro pasaron por un proceso de selección por parte del comité científico, asegurando que hubiese una pluralidad de miradas y de instituciones educativas, además del Banco, donde se relacionaran los efectos de la pandemia y la actividad económica en el país, las consecuencias sociales y regionales. El texto está dividido en cuatro partes. En la primera se hace un análisis macroeconómico de los efectos de la pandemia; para ello se examinan los efectos de la emergencia sanitaria a nivel nacional y regional mediante modelos macroeconómicos que permiten obtener respuestas ante preguntas muy relevantes. La segunda sección trata sobre el impacto en el mercado laboral, el efecto del Covid-19 en la distribución del ingreso y el efecto de corto plazo en el mercado urbano. La tercera parte aborda los efectos de la pandemia en los agentes económicos y en otros mercados. Ello incluye la exposición del empleo al Covid-19, la vulnerabilidad económica de los hogares en el país y su respuesta en el consumo, patrones de actividad laboral y salud mental, efectos en la educación, inseguridad alimentaria de la población migrante, entre otros. Por último, el cuarto segmento hace un énfasis especial en los efectos diferenciales entre las regiones del país y la heterogeneidad de dicho impacto; para ello se analizan temas de informalidad, vulnerabilidad, fuerza de trabajo disponible, entre otros, en distintas regiones del país