Measuring the reflectance of InGaAs/InP photodiodes

A. L. Muñoz Zurita agradece a CONACyT, México, por la beca mixta que le ha otorgado para su estancia en el IFA-CSIC[ES]La reflectancia de un fotodiodo, junto con su eficiencia cuántica interna, determinan el valor de la responsividad espectral, característica radiométrica fundamental de estos dispositivos usados en la medida de radiación óptica. En este trabajo se presenta el montaje experimental y los resultados obtenidos al medir la reflectancia de fotodiodos de InGaAs/InP de los usados habitualmente en laboratorios nacionales, procedentes de tres fabricantes diferentes. Asimismo se estudia la variación de la reflectancia con el estado de polarización de la radiación incidente para ángulos pequeños. Los resultados obtenidos indican que algunos modelos poseen una estructura antirreflejante en su superficie sensible y que para ángulos menores que 7,4º, la reflectancia no cambia con el estado de polarización, dentro de la incertidumbre de las medidas.[EN]Both the reflectance and the internal quantum efficiency determine the photodiode spectral responsivity, which is the radiometric characteristic of interest in the fields where these devices can be used for optical radiation measurements. In this work, we present the experimental set-up for measuring the photodiode reflectance as well as the results of such measurements related to InGaAs/InP-photodiodes exploited in national laboratories and coming from three different manufacturers. Changing the reflectance with varying the polarization state of the incoming optical radiation for small angles of incidence has been also studied. The obtained experimental results show that some models of photodiodes have got an anti-reflecting coating on their sensitive facets and that reflectance does not change with varying the light polarization state within the measurement uncertainty, when the angles of incidence were smaller that 7,4º.%3EPeer reviewe

Present-Day Crustal Stress Field from Gcmt Focal Mechanisms Based on the Slip Model.

The Slip Model is applied to the Global Centroid Moment Tensor database to determine the present day state of stress. Thus, from each focal mechanism the horizontal shortening direction (Dey) and the shape factor of the strain ellipsoid (k`), defined as the relationship between the maximum horizontal shortening and the vertical axis, are calculated. Additionally, this method proposed the neoformed plane from the calculated nodal planes. In this study, to determine the stress configuration at crustal scale, only depths < 40 km are included. Focal mechanisms are grouped in reverse, strike-slip and normal, to analyse its distribution and to determine the b-parameter from Gutenberg-Richter law. Finally, global shape factor and horizontal shortening direction maps are presented

Alpine kink bands on foliated rocks of the Central System variscan basement

La asociación espacial y cinemática entre kink bands en rocas con foliación varisca y cabalgamientos alpinos en el basamento del Sistema Central, permiten deducir que los primeros tienen una edad cenozoica, y no varisca o tardivarisca. Sistemáticamente, la dirección de los ejes de los kinks es subparalela a los cabalgamientos. Se estudian tres afloramientos clave: El Cabalgamiento de Villares de Jadraque, el Cabalgamiento de Valdesotos y el Retrocabalgamiento de El Atazar.The spatial and kinematic association between kink bands in rocks with variscan foliation and alpine thrusts in the Central System basement, allow us to deduce that the former have a Cenozoic age, and not variscan or late-variscan. Systematically, the fold axes trend of the kinks is sub-parallel to the strike of the thrusts. Three key outcrops are studied: the Villares de Jadraque thrust, the Valdesotos thrust and the El Atazar back-thrust.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Is trivial the antiferromagnetic RP(2) model in four dimensions?

We study the antiferromagnetic RP(2) model in four dimensions. We find a second order transition with two order parameters, one ferromagnetic and the other antiferromagnetic. The antiferromagnetic sector has mean-field critical exponents and a renormalized coupling which goes to zero in the continuum limit. The exponents of the ferromagnetic channel are not the mean-field ones, but the difference can be interpreted as logarithmic corrections. We perform a detailed analysis of these corrections and conclude the triviality of the continuum limit of this model.Comment: 21 pages, 5 figures, LaTeX2

Biological and Health-promoting Activity of Vinification Byproducts Produced in Spanish Vineyards

Several by-products are produced in the Spanish agricultural system. Among them, fresh and vinifiedgrape skins represent an abundant source of phenols with a potential nutraceutical value. Fresh grape skinextracts (FGSE) and vinification of grape skin extracts (VGSE) obtained by a microwave-assisted methodhave been chemically and biologically characterised. Their role in the maintenance of genetic stabilitywas stated by in vivo genotoxic and antigenotoxic evaluations (Drosophilla melanogaster wing spot test), aswell as by their potential chemopreventive effect (in an HL60 in vitro model). Total phenolic, anthocyaninand resveratrol contents were chemically characterised in the two extracts, showing some qualitativedifferences. Both extracts and resveratrol were not mutagenic in the Drosophila somatic mutation andrecombination tests, and exerted antigenotoxic activities against hydrogen peroxide. They also showedcytotoxic activity to HL60 leukaemia cells, with an IC50 of 4.5μL/mL, 4.6μL/mL and 98μM respectively andinduced apoptotic internucleosomic fragmentation in the HL60 cell line

Benchmarking of human Y-chromosomal haplogroup classifiers with whole-genome and whole-exome sequence data

In anthropological, medical, and forensic studies, the nonrecombinant region of the human Y chromosome (NRY) enables accurate reconstruction of pedigree relationships and retrieval of ancestral information. Using high-throughput sequencing (HTS) data, we present a benchmarking analysis of command-line tools for NRY haplogroup classification. The evaluation was performed using paired Illumina data from whole-genome sequencing (WGS) and whole-exome sequencing (WES) experiments from 50 unrelated donors. Additionally, as a validation, we also used paired WGS/WES datasets of 54 individuals from the 1000 Genomes Project. Finally, we evaluated the tools on data from third-generation HTS obtained from a subset of donors and one reference sample. Our results show that WES, despite typically offering less genealogical resolution than WGS, is an effective method for determining the NRY haplogroup. Y-LineageTracker and Yleaf showed the highest accuracy for WGS data, classifying precisely 98% and 96% of the samples, respectively. Yleaf outperforms all benchmarked tools in the WES data, classifying approximately 90% of the samples. Yleaf, Y-LineageTracker, and pathPhynder can correctly classify most samples (88%) sequenced with third-generation HTS. As a result, Yleaf provides the best performance for applications that use WGS and WES. Overall, our study offers researchers with a guide that allows them to select the most appropriate tool to analyze the NRY region using both second- and third-generation HTS data