Search results for "CLEAR"
showing 10 items of 27042 documents
Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering Determined by the OLYMPUS Experiment
2017
The OLYMPUS collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, $R_{2\gamma}$, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of $\approx 20\degree$ to $80\degree$. The relative luminosity between the two beam species was mo…
Structured reporting of rectal cancer staging and restaging: A consensus proposal
2021
Background: Structured reporting (SR) in oncologic imaging is becoming necessary and has recently been recognized by major scientific societies. The aim of this study was to build MRI-based structured reports for rectal cancer (RC) staging and restaging in order to provide clinicians all critical tumor information. Materials and Methods: A panel of radiologist experts in abdominal imaging, called the members of the Italian Society of Medical and Interventional Radiology, was established. The modified Delphi process was used to build the SR and to assess the level of agreement in all sections. The Cronbach’s alpha (Cα) correlation coefficient was used to assess the internal consistency of ea…
PROVE ED ESPERIMENTI DI VERIFICA DELLA SICUREZZA DEL REATTORE NUCLEARE DI RICERCA AGN-201 “COSTANZA”
2011
The “Zero Power” Nuclear Reactor AGN-201 “Costanza” available at Nuclear Engineering Department of Palermo University is a valuable tool for educational purpose and research. Besides being a useful tool for training of operators, without the time period limits on start-up and shut-down of the larger reactors, it allows the study of some phenomena regarding nuclear reactor physics, applied neutronics, neutron dosimetry, nuclear measurements as well as testing of nuclear instrumentation and methods. The experience of work and the obtained results highlight the simplicity of AGN-201 reactor control, its intrinsic safety and its overall versatility in various fields of Nuclear Engineering.
The Experimental Study of Heat Waste Conversion into Useful Electric Power
2009
This paper presents the practical results ofthe design solutions, executing and experimentaltesting of a prototype model of o thermoelectricgenerator, based on the conversion of residualthermical energy into electric power, by improving theSeebeck effect. To this purpose, high performancethermoelectric modules have been used, taken from therecent production of the American Corporation Hi-ZTechnology. The prototype thermoelectric generatorbuilt for a demonstrative purposes has got the lowefficiency category. The results taken from the testsand experimental measurements have showntheimportance of the constructive solution of materialsand technologies that have been used. These resultsdirect t…
RELAP5 simulation of two-phase flow experiments in vertical helical tubes
2010
In the framework of the studies concerning the thermalfluid dynamic phenomena in helicoidal pipes of the innovative nuclear reactor IRIS steam generators, the Department of Nuclear Engineering of the University of Palermo in collaboration with the Politecnico di Torino Department of Energetics has been engaged in a work aimed to adapt, by implementing new suitable models, RELAP5/mod3.2.2β code to simulate the thermalfluid-dynamics and geometries such as the ones involved in helicoidal pipes. In fact this code is based on one-dimensional thermal-hydraulic relationships and presents limitations to model complicated geometry such as helicoidal pipes. Therefore the code was improved with additi…
Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at √s, √sNN = 5.02 TeV
2021
Jet fragmentation transverse momentum (jT) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at √sNN = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT distributions are compared with a variety of parton-shower models. Herwig and Pythia 8 based models describe the data well for the higher jT region, while they underestimate the low…
Dangerous Effects Induced on Power MOSFETs by Terrestrial Neutrons
2013
This paper investigates the effects that terrestrial neutrons can induce on power MOSFETs when they are biased during their normal working conditions especially in inverters for photovoltaic applications. After a brief review of power MOSFETs failure phenomena caused by neutron irradiation (with emphasis on so called “Single Event Effects” (SEE)), the results of an accelerated test performed with the Am-Be source at the University of Palermo are discussed.
Aplicaciones de la Resonancia Magnética Nuclear en el estudio de la Infertilidad
2015
En los últimos años se ha producido una reducción en el número de nacimientos en muchos países, fundamentalmente europeos. Esta reducción puede ser debida a diversos factores que afecten a la fertilidad de la mujer tales como factores culturales, sociales y económicos que aumentan la edad de la mujer para concebir su primer hijo, causas inmunitarias, alteraciones del aparato reproductor femenino, causas hipotalámico-hipofisarias y factores relacionados con el estilo de vida entre otros. Estos problemas de fertilidad se pueden solucionar mediante diversos tratamientos de reproducción asistida, como la inseminación artificial o la fecundación in vitro. En estos últimos, el ovocito que se empl…
Characterization of the metabolic profile and identification of potential therapeutic targets in advanced prostate cancer patients
2023
INTRODUCCIÓN El cáncer de próstata (CaP) representa el segundo tumor en incidencia en hombres y es la quinta causa de muerte por cáncer a nivel global. El CaP es un tumor hormono-dependiente, que requiere de la activación del receptor de andrógenos (AR) para su proliferación. Clínicamente, se caracteriza por una gran variabilidad en su evolución, progresando desde una condición indolente hasta un fenotipo agresivo que puede diseminarse y metastatizar a los nodos linfáticos y huesos. Actualmente, el diagnóstico temprano del CaP se realiza mediante la determinación sérica del antígeno prostático específico (PSA) y el examen rectal digital (DRE). Si estas pruebas dan resultados anómalos y hay …
Evaluación morfológica y morfométrica de neuroimágenes retinianas y cerebrales como factor pronóstico de la función visual en pacientes con esclerosi…
2013
El propósito de esta tesis doctoral es estudiar la proporción de pérdida neurológica en el tiempo a nivel cerebral y retiniano en relación con la deficiencia sensorial y motora en pacientes diagnosticados de esclerosis múltiple. La muestra está constituida por 35 pacientes clasificados en tres grupos en función del subtipo de enfermedad (síndromes clínicos aislados, formas remitentes-recurrentes y formas progresivas) diagnosticados de esclerosis múltiple según los criterios de McDonald, aunque a efectos del análisis estadístico, las unidades de observación fueron los 70 ojos correspondientes. Se recopiló información mediante la anamnesis y revisión de la historia clínica de los pacientes re…