GEANT4 application for the simulation of the head of a siemens primus linac

The Monte Carlo simulation of the head of a Siemens Primus Linac used at Virgen Macarena Hospital (Sevilla, Spain) has been performed using the code GEANT4 [1-2], version 9.2. In this work, the main features of the application built by our group are presented. They are mainly focused in the optimization of the performance of the simulation. The geometry, including the water phantom, has been entirely wrapped by a shielding volume which discards all the particles escaping far away through its walls. With this, a factor of four in the time spent by the simulation can be saved. An interface to read and write phase-space files in IAEA format has been also developed to save CPU time in our simulations [3-4]. Finally, some calculations of the dose absorption in the water phantom have been done and compared with the results given by EGSnrc [5] and with experimental data obtained for the calibration of the machine

Point process methods in epidemiology: application to the analysis of human immunodeficiency virus/acquired immunodeficiency syndrome mortality in urban areas

The analysis of spatio-temporal patterns of disease or death in urban areas has been developed mainly from the ecological studies approach. These designs may have some limitations like the ecological fallacy and instability with few cases. The objective of this study was to apply the point process methodology, as a complement to that of aggregated data, to study HIV/AIDS mortality in men in the city of Alicante (Spain). A case-control study in residents in the city during the period 2004-2011 was designed. Cases were men who died from HIV/AIDS and controls represented the general population, matched by age to cases. The risk surfaces of death over the city were estimated using the log-risk function of intensities, and we contrasted their temporal variations over the two periods. High risk significant areas of death by HIV/AIDS, which coincide with the most deprived areas in the city, were detected. Significant spatial change of the areas at risk between the periods studied was not detected. The point process methodology is a useful tool to analyse the patterns of death by HIV/AIDS in urban areas

Use of a drone equipped with microthermal sensors to estimate the quality of the atmosphere for astronomical observation

A drone was used to obtain thermal profiles to estimate atmospheric turbulence for the purposes of astronomical observation. The first 150m of height were studied in two areas in the southeast of the Iberian Peninsula. The preliminary results have validated the use of drones as a suitable means of transport for obtaining microthermal measurements. We have also assessed the influence of the planetary boundary layer on the quality of the image for astronomical purposes. In future research, we intend to check these measurements with fixed microthermal sensors installed in meteorological towers.Departamento de Análisis Geográfico Regional y Geografía Física de la Universidad de Granad

Hoy.

Poema incluido en el libro "Poesía a instancia de parte"

Del otro lado de la vida.

Poema incluido en la «plaquette» "Un hombre que espera quién sabe qué"

La medición de televisión en España: propuesta para el cálculo de la audiencia híbrida total

El entorno televisivo ha sufrido una auténtica revolución digital en los últimos años, amparada por una amplia oferta de soportes y plataformas, y la facilidad de conexión e intercambio de contenidos audiovisuales. Este cambio ha fomentado la transformación del consumo televisivo hacia una hiperfragmentación de la audiencia, digna de estudio. En este contexto, la principal empresa encargada de la medición de audiencia de la televisión lineal en España, Kantar Media, ha decidido dar un paso más allá hacia una medición crossmedia; lo que significa aplicar los métodos de mensuración tradicionales con tratamientos digitales. Pero el gran proceso de digitalización empuja a realizar una medición de audiencia mucho más completa de la que se está planteando en el sector audiovisual; de esta manera, en la presente investigación se muestra, como alternativa, una medición híbrida total para los contenidos audiovisuales que se emiten en las diferentes plataformas. Y se señala, al mismo tiempo, la necesidad de la creación de un organismo que vele por la veracidad de los datos que se puedan obtener, y por la privacidad y derechos de usuarios

Determination of the cosmic-ray-induced neutron flux and ambient dose equivalent at flight altitude

Journal of Physics: Conference Series, Volumen 630There is interest in modeling the atmosphere in the South Atlantic Magnetic Anomaly in order to obtain information about the cosmic-ray induced neutron spectrum and angular distribution as functions of altitude. In this work we use the Monte Carlo codes MCNPX and Geant4 to determine the cosmic-ray-induced neutron flux in the atmosphere produced by the cosmic ray protons incident on the top of the atmosphere and to estimate the ambient dose equivalent rate as function of altitude. The results present a reasonable conformity to other codes (QARM and EXPACS) based on other parameterizations