Search results for "ground"
showing 10 items of 2432 documents
The IceCube realtime alert system
2016
Following the detection of high-energy astrophysical neutrinos in 2013, their origin is still unknown. Aiming for the identification of an electromagnetic counterpart of a rapidly fading source, we have implemented a realtime analysis framework for the IceCube neutrino observatory. Several analyses selecting neutrinos of astrophysical origin are now operating in realtime at the detector site in Antarctica and are producing alerts to the community to enable rapid follow-up observations. The goal of these observations is to locate the astrophysical objects responsible for these neutrino signals. This paper highlights the infrastructure in place both at the South Pole detector site and at IceC…
Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
2020
Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these longlived particles (LLPs) can decay far from the interaction vertex of the primary proton–proton collision. Such LLP signatures are distinct from those of promptly decaying particles that are targeted by the majority of searches for new physics at the LHC, often requiring customized techniques to identify, for example, significantly displaced decay vertices, tracks with atypical properties, and short track segments. Given their non-standard nature, a comprehensive overview of LLP…
Nonlinear Hanle effect in Cs vapor under strong laser excitation
2002
We report results of a theoretical and experimental study of the ground state nonlinear Hanle effect under strong laser excitation. It is shown that besides the well-known zero-magnetic field suppression of absorption on F g = F→F e = F - 1 transitions caused by population trapping, an optical pumping induced enhanced absorption occurs on F g = F→F e = F + 1 transitions for small B-fields. The latter effect becomes more pronounced for high F values. The experiment with atomic vapor of Cs (D2 line, F g = 4) confirms an increase of the spectrally unresolved fluorescence yield at zero magnetic field and 600 mW/cm2 laser intensity by 9% or 42%, when excitation occurs with linearly or circularly…
Assessment of the Microbiological Quality of Groundwater in Three Regions of the Valencian Community (Spain)
2014
Urban groundwater development was traditionally constrained by concerns about its quality. This study was conducted in the regions of La Ribera Alta and Ribera Baja and La Plana de Requena-Utiel of the Valencian Community (Valencia, Spain) where population density, demand for drinking water and agricultural activities are high. Groundwater bodies (GWBs) are regarded as management areas within each territory, and were used to establish protection policies. This study analyzed eleven GWBs. We used two databases with microbiological measurements from 154 wells over a 7-year period (2004–2011), risk factors and groundwater information. Wells were grouped according to frequency of microbiologica…
dentity Narrative in informal family and non-family caregivers of people on dialysis
2019
Objetivo. Explorar la identidad narrativa de las cuidadoras informales familiares o no, de personas en diálisis. Método. Entrevistas en profundidad a 9 cuidadoras de personas de programas de Hemodiálisis o Diálisis Peritoneal del Hospital General Universitario. Se obtuvo autorización del Comité de Ética y los consentimientos informados de los participantes. El análisis se hizo desde la Teoría Fundamentada. Las narraciones transcritas y codificadas fueron sometidas a reflexión hermenéutica. Resultados. La enfermedad genera un impacto y las cuidadoras asumen el cuidado como pueden. Surge el sentimiento de “cuidado como destino” y como dotación intrínseca de “ser mujer”, percibido como una esp…
AUTOMATIC DETECTION OF SMALL SPHERICAL LESIONS USING MULTISCALE APPROACH IN 3D MEDICAL IMAGES
2013
International audience; Automated detection of small, low level shapes such as circular/spherical objects in images is a challenging computer vision problem. For many applications, especially microbleed detection in Alzheimer's disease, an automatic pre-screening scheme is required to identify potential seeds with high sensitivity and reasonable specificity. A new method is proposed to detect spherical objects in 3D medical images within the multi-scale Laplacian of Gaussian framework. The major contributions are (1) breaking down 3D sphere detection into 1D line profile detection along each coordinate dimension, (2) identifying center of structures by normalizing the line response profile …
Groundwater in sedimentary basins: Section abstract book (Faculty of Geography and Earth Sciences, Riga, 30 January 2012)
2012
The session is organised in the scope of the European Social Fund project “Establishment of interdisciplinary scientist group and modelling system for groundwater research” (Project contract Nr. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060). Project is implemented by University of Latvia, Faculty of Geography and Earth Sciences and Faculty of Physics and Mathematics in collaboration with Latvia University of Agriculture, Faculty of Rural Engineering, Department of Environmental Engineering and Water Management.
Is there a need for a new cultural policy strategy in the Nordic welfare state?
1996
Cultural policies have existed as a structural element of the Nordic welfare states from the very beginning. Today these policies are being re‐evaluated, and there are some indications that they may be gradually dismantled. Local cultural politicians in municipalities (cultural boards) and professionals (e.g. cultural secretaries) have become uncertain and anxious about their future role and legitimacy. This new situation is addressed and analysed by using the ideas of Goffman's on‐and off‐stage representations, and Foucault's governmentality. Important background factors in the development of cultural policies both in the past, present and future are identified and used to explain the pres…
A survey of active galaxies at TeV photon energies with the HAWC gamma-ray observatory
2020
The High Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) continuously detects TeV photons and particles within its large field-of-view, accumulating every day a deeper exposure of two thirds of the sky. We analyzed 1523~days of HAWC live data acquired over four and a half years, in a follow-up analysis of {138} nearby ($z<0.3$) active galactic nuclei from the {\em Fermi} 3FHL catalog culminating within $40^\circ$ of the zenith at Sierra Negra, the HAWC site. This search for persistent TeV emission used a maximum-likelihood analysis assuming intrinsic power-law spectra attenuated by pair production of gamma-ray photons with the extragalactic background light. HAWC clearly detects persi…
Impeded Dark Matter
2016
We consider dark matter models in which the mass splitting between the dark matter particles and their annihilation products is tiny. Compared to the previously proposed Forbidden Dark Matter scenario, the mass splittings we consider are much smaller, and are allowed to be either positive or negative. To emphasize this modification, we dub our scenario "Impeded Dark Matter". We demonstrate that Impeded Dark Matter can be easily realized without requiring tuning of model parameters. For negative mass splitting, we demonstrate that the annihilation cross-section for Impeded Dark Matter depends linearly on the dark matter velocity or may even be kinematically forbidden, making this scenario al…