350 research outputs found
A practical and general methodology for efficiency calibration of coaxial Ge detectors
The correct determination of artificial and natural radionuclides like 152Eu, 137,134Cs, 60,57Co, etc., and 234,228Th, 228,226Ra, 210Pb and 40K, respectively, is essential for many environmental science fields. For this, a general function was obtained for the full-energy peak efficiency (FEPE) by gamma-ray spectrometry using coaxial Ge detectors. Then, the experimental FEPE values, obtained fixing the energy, Eγ, were fitted varying the thickness, h, of cylindrical standards. The parameters resulted from these fittings were fitted, in turn, versus Eγ, obtaining a general efficiency function, εc (Eγ, h). εc (Eγ, h) was validated, obtaining very good zscore, except for Eγ affected by TCS effects. Consequently, a practical and general method was developed, recalibrating the detector by varying the sample-detector distance, d. εc (Eγ, h, d) was obtained, achieving very good zscore. Furthermore, this practical method was also employed to correct high self-absorptions and high dead times.This research has partially funded by the projects of the Regional Government of Andalusia called “Basic processes regulating the fractionations and enrichments of natural radionuclides under acid mine drainage conditions” (Ref.: UHU-1255876), and “Treatment of acid leachates from phosphogypsum piles located at Huelva, and transport modelling of the released radionuclides” (Ref.: P20_00096), the project funded by the Spanish Ministry of Science, Innovation and Universities’ Research Agency “Development and optimization of a process for removing natural radionuclides in phosphogypsum leachates” (Ref.: PID2020-116461RB-C21), and the Project for Novel Principal Investigators “Quantitative study of the variables involved in the radonexhalation rate for granular solids; application to rafts of granular solid phosphogypsum” (Ref.: UHUPJ-00005-632). The authors acknowledge the funding for open access charge provided by Universidad de Huelva/CBUA
A new efficiency calibration methodology for different atmospheric filter geometries by using coaxial Ge detectors
The study of the different pollutants present in atmospheric aerosols such as trace elements and radionuclides is essential to assess the air quality. To analyze the particulate matter (PM), atmospheric filters with different dimensions and geometries (rectangular, circular, slotted, and square filters) are usually employed. Regarding the pollutants existing in atmospheric aerosols, radionuclides are usually analyzed due to their multiple applications such as either in the environmental radiological control or as tracers of atmospheric processes. Therefore, this study aims to develop a new and general methodology to calibrate in efficiency coaxial Ge detectors to properly determine radionuclides present in the PM by gamma-ray spectrometry for several filter types. For this, granular certified reference materials (CRM) containing only natural radionuclides (²³⁸U-series, ²³²Th-series, and ⁴⁰ K) were selected. Several granular solid CRMs were chosen allowing us to reproduce the same PM deposition geometry and to assure the homogeneity of the added CRMs. These are the main advantages in relation to the typical methods that use liquid CRMs. Furthermore, for filters whose surfaces are relatively large, they were cut in several pieces and placed one on top of the other, achieving the same geometry than the PM deposited onto the filter. Then, the experimental full-energy peak efficiencies (FEPEs) were obtained for each energy of interest (Eγ) and they were fitted versus Eγ, finding a general FEPE function for each filter type. Finally, this methodology was validated for both natural and artificial radionuclides (from 46 to 1332 keV) by using different filter types employed in proficiency test exercises, obtaining |zscore|< 2 for all cases.Funding for open access publishing: Universidad de Huelva / CBUA This research has partially funded by the projects of the Regional Government of Andalusia called “Treatment of acid leachates from phosphogypsum piles located at Huelva, and transport modelling of the released radionuclides” (Ref.: P20_00096) and “Valorization of inorganic wastes enriched in natural radioactivity for sustainable building materials” (Ref.: FEDER-UHU-202020); the project funded by the Spanish Nuclear Safety Council (CSN) “Radon exhalation from building materials; radiological impact and corrective measures” (Ref.: SUBV-4/2021); the project funded by the Spanish Ministry of Science, Innovation and Universities’ Research Agency “Development and optimization of a process for removing natural radionuclides in phosphogypsum leachates” (Ref.: PID2020-116461RB-C21); and the Project for Novel Principal Investigators “Quantitative study of the variables involved in the radon exhalation rate for granular solids; application to rafts of granular solid phosphogypsum” (Ref.: UHUPJ-00005–632)
On the extension of LES methods from incompressible to compressible turbulent flows with application to turbulent channel flow
Published under licence in Journal of Physics: Conference Series by IOP Publishing Ltd.
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.The objective of the present work is to validate the compressible Large-Eddy Simulation (LES) models implemented in the in house parallel unstructured CFD code TermoFluids. Our research team has implemented and tested several LES models over the past years for the incompressible regimen. In order to be able to solve complex
turbulent compressible flows, the models are revisited and modified if necessary. In addition, the performance of the implemented hybrid advection scheme is an issue of interest for the numerical simulation of turbulent compressible flows. The models are tested in the well known turbulent channel flow problem at different compressible regimens.Peer ReviewedPostprint (published version
Diseño y desarrollo de un driver de control para la estación SPS30 y su integración en FreeRTOS
De acuerdo con la EPA (Agencia de Protección Ambiental de Estados Unidos), el tamaño de las partículas
está directamente vinculado a su potencial para generar problemas de salud. Los dos grupos en los
que se suele hacer distinción son:
- Partículas con diámetro menor a 10 µm (PM10), que pueden alcanzar los pulmones en la respiración
normal.
- Partículas con diámetro menor a 2.5 µm (PM2.5), que además pueden llegar a penetrar en la sangre.
Estas partículas son sensiblemente más pequeñas que el cabello humano, de ahí su facilidad para adentrarse en nuestro sistema respiratorio. En la Figura 1 se muestra una comparación de los diámetros de
dichas partículas con el cabello.
(extraído de la Introducción)Universidad de Sevilla. Grado en Ingeniería Electrónica, Robótica y Mecatrónic
Diseño y desarrollo web. Análisis de casos
The present project exposes the development of a website aimed at promoting
an artist or designer. It describes the disciplines that encompasses
this work and explain their differences. It introduces the development that
has followed the Web to date, in order to provide context for the reader and
study the current trends. Contains details of the methodology used, the study
design and the process of development needed for development a website.
Includes a small study, realized with Google Analytics, based on operating
systems and browsers of users who visited the website. It has a specific bibliography
about Web design, consisting of documents, books and websites.En el presente trabajo se expone la elaboración de un sitio web destinado
a la promoción de un artista o diseñador. Se describen las disciplinas
que comprenden esta labor y se explican sus diferencias. Se hace una introducción
al desarrollo que ha seguido la Web hasta el momento actual, con
el objetivo de situar en contexto al lector y estudiar las tendencias actuales.
Narra al detalle la metodología utilizada, el estudio de diseño y el proceso de
desarrollo necesarios para la elaboración de una web. Incluye un pequeño
estudio, realizado con Google Analytics, sobre los navegadores y sistemas
operativos de los usuarios que visitaron el sitio web. Dispone de bibliografía
específica sobre diseño de websites, formada por documentos, libros y páginas
web.Barba Soler, JP. (2014). Diseño y desarrollo web. Análisis de casos. http://hdl.handle.net/10251/49757.Archivo delegad
Detección de genes productores de enzimas modificadoras de aminoglucócidos (EMAs) en aislados hospitalarios de Pseudomonas aeruginosa
La resistencia bacteriana a antibióticos representa un problema de salud pública de rápido crecimiento, ocasionado, entre otras causas, por el inadecuado uso de antimicrobianos y la rápida dispersión de genes de resistencia. Pseudomonas aeruginosa tiene gran relevancia debido a su alta incidencia en infecciones nosocomiales y al surgimiento de cepas multiresistentes. Los aminoglucósidos representan un grupo de antimicrobianos fundamental en la terapia de infecciones cuyo agente etiológico es Pseudomonas aeruginosa. El objetivo de este estudio fue detectar la presencia / ausencia de genes que codifican enzimas modificadoras de aminoglucósidos (EMAs) en aislados hospitalarios de Pseudomonas aeruginosa
Diseño y desarrollo web. Análisis de casos
The present project exposes the development of a website aimed at promoting
an artist or designer. It describes the disciplines that encompasses
this work and explain their differences. It introduces the development that
has followed the Web to date, in order to provide context for the reader and
study the current trends. Contains details of the methodology used, the study
design and the process of development needed for development a website.
Includes a small study, realized with Google Analytics, based on operating
systems and browsers of users who visited the website. It has a specific bibliography
about Web design, consisting of documents, books and websites.En el presente trabajo se expone la elaboración de un sitio web destinado
a la promoción de un artista o diseñador. Se describen las disciplinas
que comprenden esta labor y se explican sus diferencias. Se hace una introducción
al desarrollo que ha seguido la Web hasta el momento actual, con
el objetivo de situar en contexto al lector y estudiar las tendencias actuales.
Narra al detalle la metodología utilizada, el estudio de diseño y el proceso de
desarrollo necesarios para la elaboración de una web. Incluye un pequeño
estudio, realizado con Google Analytics, sobre los navegadores y sistemas
operativos de los usuarios que visitaron el sitio web. Dispone de bibliografía
específica sobre diseño de websites, formada por documentos, libros y páginas
web.Barba Soler, JP. (2014). Diseño y desarrollo web. Análisis de casos. http://hdl.handle.net/10251/49757.Archivo delegad
Monetising the social value of inclusive entrepreneurship: the case of the Abono Café social economy enterprise
The fact that so many people with disabilities are unemployed is a cause for concern among those responsible for employment and creating social policies, and also for families and stakeholders themselves. Self-employment, which is understood as the creation of businesses, could be a means to mitigate this problem. The market evaluation of this type of company should consider not only its economic, but also its social results in terms of both cost savings for various public administrations and the generation of social value. This includes taking advantage of the talent of an important part of the population or increasing the wellbeing of people with disabilities, thus making decent employment possible as regards all that is sought by Sustainable Development Objective (SDA) 8 of the United Nations (UN) Agenda 2030. The objective of this work is, therefore, to monetise the social value of this type of undertaking through the use of a case study: that of the Abono Café company. The results show that the non-market value of this company greatly exceeds its market value, thus confirming its potential to generate social value for its stakeholders. The multiplying effect of the funds that Public Administrations allocate to the promotion of this type of initiative among people with disabilities makes them a useful tool and represents a change in the design of public policies, both on a social and employment level
An upgraded lab-based method to determine natural γ-ray emitters in NORM samples by using Ge detectors
The regulation existing on NORM activities requires the accurate and quick measurement of natural radionuclides in a wide range of matrices by gamma spectrometry. The aim of this work has been to develop a comprehensive and accurate methodology to determine natural long-lived radionuclides (210Pb, 228,226Ra, 234,228Th and 40K) by gamma spectrometry with Ge detectors in NORM samples. An exhaustive calibration method to obtain the full-energy peak efficiency (FEPE), for each gamma emission energy, as a function of the thickness, apparent density and matrix composition of the cylindrical sample, has been developed. The selected certified calibration standards contain only natural radionuclides belonging to the 238U- and 232Th-series as well as 40K (codes RGU-1, RGTh-1 and RGK-1 from IAEA). Then, the obtained FEPE curves were validated using Genie 2000 simulations and Certified Reference Materials, for which the self-attenuation corrections were considered. Finally, a study on 222Rn losses was done for several samples.Funding for open access charge: Universidad de Huelva / CBU
Desarrollo de simulador de negocios
Se presenta el análisis realizado para la toma de decisiones en la industria de sensores electrónicos, las cuales estuvieron basadas en el estudio de distintas teorías sobre estrategia, casos reales de empresas líderes en el mercado actual, además de las situaciones específicas que sucedieron en la simulación de la industria.ITESO, A.C
- …