Noise reduction in muon tomography for detecting high density objects

The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented

Excited states at interfaces of a metal-supported ultrathin oxide film

We report layer-resolved measurements of the unoccupied electronic structure of ultrathin MgO films grown on Ag(001). The metal-induced gap states at the metal/oxide interface, the oxide band gap, and a surface core exciton involving an image-potential state of the vacuum are revealed through resonant Auger spectroscopy of the MgKL23L23 Auger transition. Our results demonstrate how to obtain new insights on empty states at interfaces of metal-supported ultrathin oxide films

Study of the electron trigger efficiency of the CMS Experiment using test beam data

A study of the electron identification and selection efficiency of the L1 Trigger algorithm has been performed using the combined ECAL/HCAL test beam data. A detailed discussion of the electron isolation and its impact on the selection efficiency is presented. The L1 electron algorithm is studied for different beam energies and the results indicate that efficiencies of 98% or more can be achieved for electrons with energies between 15 and 100 GeV. The fraction of charged hadrons with energies from 3 up to 100 GeV rejected by the L1 electron trigger algorithm is estimated to be larger than 93%.Comment: 22 pages, 14 figure

Survey of risk factors in the Faculty of Veterinary Sciences, National University of La Plata

El conocimiento de los factores de riesgo existentes en la FCV UNLP, representa la instancia inicial para abordar la cuestión de la bioseguridad y la seguridad laboral asociada al ejercicio profesional del médico veterinario. Con el objetivo de recolectar información se implementó una matriz cuali-cuantitativa (1) que permitió identificar calificar y cuantificar según nivel de riesgo y peligro a cada factor. El instrumento agrupó a los factores como: biológicos, químicos, traumáticos y físicos. Se constató una alta participación, representada por el 80,64% de las unidades de análisis. El 68% de las áreas presenta factores de riesgo alto, el 12% de riesgo moderado, y el 20% de riesgo con potencialidad catastrófica. El 80% presenta factores de riesgo químico de moderado a con potencialidad catastrófica. El 44%, de riesgo traumático de moderado a alto. El 32%, factores de riesgo físico de moderado a alto y el 28%, factores de riesgo biológico de moderado a alto. En el 52% conviven dos o más tipos de riesgos calificados de moderado a con potencialidad catastrófica. Como conclusión, se debe continuar con el relevamiento de aquella información que vincule la existencia de los factores ya identificados con las condiciones de manejo requeridas específicamente para cada factor.Risk factor awareness at the Faculty of Veterinary Sciences represents the first step to wards improving biosecurity and safety in the work place for veterinarians. In order to collect formation, a quali and quantitative survey was implemented which allowed identification and classification of risks acccording to level and degree of danger. Risk factors were classified as biological, chemical, traumatic or physical. Participant involvement was high (80,9% of analysis units). 12% of analysis units presented high risk factors, 68% had high risk factors and 20% had potentially catastrophic risk factors. 80% of analysis units reported moderate to potentially catastrophic chemical risk factors, 44% had moderate to high traumatic risk factors, 32% had moderate to high physical risk factors and 28% had moderate to high biological risk factors. Two or more types of moderate to high risk factors are present in 52% of analysis units. It is necessary to continue with collection of information related to the identified risk factors in order to establish adequate management practices for each situation.Facultad de Ciencias Veterinaria

Survey of risk factors in the Faculty of Veterinary Sciences, National University of La Plata

El conocimiento de los factores de riesgo existentes en la FCV UNLP, representa la instancia inicial para abordar la cuestión de la bioseguridad y la seguridad laboral asociada al ejercicio profesional del médico veterinario. Con el objetivo de recolectar información se implementó una matriz cuali-cuantitativa (1) que permitió identificar calificar y cuantificar según nivel de riesgo y peligro a cada factor. El instrumento agrupó a los factores como: biológicos, químicos, traumáticos y físicos. Se constató una alta participación, representada por el 80,64% de las unidades de análisis. El 68% de las áreas presenta factores de riesgo alto, el 12% de riesgo moderado, y el 20% de riesgo con potencialidad catastrófica. El 80% presenta factores de riesgo químico de moderado a con potencialidad catastrófica. El 44%, de riesgo traumático de moderado a alto. El 32%, factores de riesgo físico de moderado a alto y el 28%, factores de riesgo biológico de moderado a alto. En el 52% conviven dos o más tipos de riesgos calificados de moderado a con potencialidad catastrófica. Como conclusión, se debe continuar con el relevamiento de aquella información que vincule la existencia de los factores ya identificados con las condiciones de manejo requeridas específicamente para cada factor.Risk factor awareness at the Faculty of Veterinary Sciences represents the first step to wards improving biosecurity and safety in the work place for veterinarians. In order to collect formation, a quali and quantitative survey was implemented which allowed identification and classification of risks acccording to level and degree of danger. Risk factors were classified as biological, chemical, traumatic or physical. Participant involvement was high (80,9% of analysis units). 12% of analysis units presented high risk factors, 68% had high risk factors and 20% had potentially catastrophic risk factors. 80% of analysis units reported moderate to potentially catastrophic chemical risk factors, 44% had moderate to high traumatic risk factors, 32% had moderate to high physical risk factors and 28% had moderate to high biological risk factors. Two or more types of moderate to high risk factors are present in 52% of analysis units. It is necessary to continue with collection of information related to the identified risk factors in order to establish adequate management practices for each situation.Facultad de Ciencias Veterinaria

Precision measurements of Linear Scattering Density using Muon Tomography

We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.Comment: 16 pages, 4 figure