Search results for "Detector"
showing 10 items of 3491 documents
Quantitative structural analysis of trabecular alveolar bone in the mandible by multidetector computed tomography: Differences according to tooth pre…
2019
Background and objective: There is a lack of quantitative measures of the quality of alveolar trabecular bone, an important factor in implantology. This study aimed to develop a method of objectively assessing the quality of trabecular bone by means of image processing and structural analysis of multidetector computed tomography images and to establish differences between tooth types and tooth presence/absence. Materials and methods: We analyzed 20 patients who underwent multidetector computed tomography to evaluate mandibular bone and tooth positioning. Image analysis included automatic segmentation of the mandible, obtainment of sections perpendicular to the dental arch, and structural an…
Advanced Virgo Status
2015
Abstract The detection of a gravitational wave signal in September 2015 by LIGO interferometers, announced jointly by LIGO collaboration and Virgo collaboration in February 2016, opened a new era in Astrophysics and brought to the whole community a new way to look at - or “listen” to - the Universe. In this regard, the next big step was the joint observation with at least three detectors at the same time. This configuration provides a twofold benefit: it increases the signal-to-noise ratio of the events by means of triple coincidence and allows a narrower pinpointing of GW sources, and, in turn, the search for Electromagnetic counterparts to GW signals. Advanced Virgo (AdV) is the second ge…
Diseño e implementación de un SPECT pre-clínico basado en cristales continuos
2012
El trabajo de esta tesis consiste en el desarrollo y puesta en marcha de dos prototipos SPECT para animales pequeños utilizando la mini gammacámara desarrollada previamente por nuestro grupo de Física Médica. Se realiza en primer lugar una primera prueba de concepto con el objetivo de comprobar la viabilidad del proyecto, dicho prototipo se diseña y desarrollolla en el Servicio de Medicina Nuclear del Hospital Clínico y Provincial de Barcelona. En el segundo prototipo se pretende ampliar la prueba de concepto y desarrollar un nuevo prototipo con el que se obtenga un mayor rendimiento del SPECT con la misma gammacámara. Para ello, este prototipo dispone de 2 detectores montadas opuestas en e…
Environment recognition applied to particle detectors
2017
Resumen en español Introducción Los detectores de partículas son dispositivos que registran la radiación ionizante, bien de sistemas activos (rayos X, aceleradores, etc.) o bien de isótopos radiactivos. Para poder realizar medidas de precisión con estos instrumentos, es necesario modelar geométricamente el entorno, contorno o escena bajo estudio. Estas condiciones geométricas se pueden determinar de forma más o menos precisa en algunos experimentos de física de partículas/nuclear, y en algunos sistemas de imagen, como las tomografías. Sin embargo, este escenario no es necesariamente el habitual. El propósito principal de este trabajo de tesis es desarrollar técnicas e instrumentos que aport…
Photodétecteurs UV à base GaAlN
2004
Trigger and aperture of the surface detector array of the Pierre Auger Observatory
2010
The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive airshowers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidates howers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above 3 x 1018 eV, for all zenith angles between 03 and 603, independently of the position of the impact point and of the mass of the primary particl…
Modeling, Design and Experimentation of Wearable RFID Sensor Tag
2010
Design of effective wearable tags for UHF RFID applications involving persons is still an open challenge due to the strong interaction of the antenna with the human body which is responsible of impedance detuning and efficiency degradation. A new tag geometry combining folded conductors and tuning slots is here discussed through numerical analysis and extensive experimentation also including the integration of a passive motion detector. The achieved designs, having size comparable with a credit card, may be applied to any part of the body. The measured performance indicates a possible application of these body-worn tags for the continuous tracking of human movements in a conventional room.
Implementation and performance of the ATLAS second level jet trigger
2008
ATLAS is one of the four major LHC experiments, designed to cover a wide range of physics topics. In order to cope with a rate of 40 MHz and 25 interactions per bunch crossing, the ATLAS trigger system is divided in three different levels. The first one (LVL1, hardware based) identifies signatures in 2 microseconds that are confirmed by the the following trigger levels (software based). The Second Level Trigger (LVL2) only looks at a region of the space around the LVL1 signature (called Region of Interest or ROI), confirming/rejecting the event in about 10 ms, while the Event Filter (Third Level Trigger, EF) has potential full event access and larger processing times, of the order of 1 s. T…
The Upgrade of the ATLAS Level-1 Central Trigger Processor
2013
The ATLAS Level-1 Central Trigger Processor (CTP) combines information from calorimeter and muon trigger processors as well as other sources and makes the final Level-1 Accept (L1A) decision. Due to the increasing luminosity of the LHC and the growing demands of physics and monitoring placed on the ATLAS Level-1 trigger system, the current CTP has reached its design limits. Therefore and in order to provide some margin for future operation, the CTP will be upgraded during the LHC shutdown of 2013/14.
The SuperK-Gd Project
2018
The SuperK-Gd project is the proposed and approved upgrade of the Super-Kamiokande detector in order to enable it to efficiently detect thermal neutrons. The project consists in dissolving a Gd salt into SK at a concentration of 0.2%.