1,153 research outputs found

    Horizontal rotation signals detected by "G-Pisa" ring laser for the Mw=9.0, March 2011, Japan earthquake

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    We report the observation of the ground rotation induced by the Mw=9.0, 11th of March 2011, Japan earthquake. The rotation measurements have been conducted with a ring laser gyroscope operating in a vertical plane, thus detecting rotations around the horizontal axis. Comparison of ground rotations with vertical accelerations from a co-located force-balance accelerometer shows excellent ring laser coupling at periods longer than 100s. Under the plane wave assumption, we derive a theoretical relationship between horizontal rotation and vertical acceleration for Rayleigh waves. Due to the oblique mounting of the gyroscope with respect to the wave direction-of-arrival, apparent velocities derived from the acceleration / rotation rate ratio are expected to be always larger than, or equal to the true wave propagation velocity. This hypothesis is confirmed through comparison with fundamental-mode, Rayleigh wave phase velocities predicted for a standard Earth model.Comment: Accepted for publication in Journal of Seismolog

    Influence of Mandrel s Surface on the Mechanical Properties of Joints Produced by Electromagnetic Compression

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    Electromagnetic compression of tubular profiles with high electrical conductivity is an innovative joining process for the manufacturing of lightweight structures. Taking conventional interference fits into account, the contact area s influence on the joint s quality seems to be of significance, as e.g. the contact area and the friction coefficient between the joining partners determine an allowed axial load or torsional momentum proportionally. Therefore, different contact area surfaces were prepared by shot peening and different machining operations and strategies. The mandrel s surfaces were prepared by shot peening with glass beads and Al2O3 particles. Alternatively, preparation was done using simultaneous five axis milling, because potential joining partners in lightweight frame structures within the Transregional Collaborative Research Centre SFB/TR10 would be manufactured similarly. After that, the manufactured surfaces were characterized by measuring the surface roughness and using confocal whitelight microscopy. After joining by electromagnetic compression, the influence of different mandrel s surface conditions on the joint s mechanical properties were analyzed by tensile tests. Finally, conclusions and design rules for the manufacturing of joints by electromagnetic compression are given

    Cost analysis for cancer subgroups

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    Beam Test of Silicon Strip Sensors for the ZEUS Micro Vertex Detector

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    For the HERA upgrade, the ZEUS experiment has designed and installed a high precision Micro Vertex Detector (MVD) using single sided micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 microns, with five intermediate strips (20 micron strip pitch). An extensive test program has been carried out at the DESY-II testbeam facility. In this paper we describe the setup developed to test the ZEUS MVD sensors and the results obtained on both irradiated and non-irradiated single sided micro-strip detectors with rectangular and trapezoidal geometries. The performances of the sensors coupled to the readout electronics (HELIX chip, version 2.2) have been studied in detail, achieving a good description by a Monte Carlo simulation. Measurements of the position resolution as a function of the angle of incidence are presented, focusing in particular on the comparison between standard and newly developed reconstruction algorithms.Comment: 41 pages, 21 figures, 2 tables, accepted for publication in NIM

    A translational research experience in Argentina.

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    Background: The Argentinean programwas initiatedmore than a decade ago as the first experience of systematic translational research focused on NCL in Latin America. The aim was to overcome misdiagnoses and underdiagnoses in the region. Subjects: 216 NCL suspected individuals from 8 different countries and their direct family members. Methods: Clinical assessment, enzyme testing, electron microscopy, and DNA screening. Results and discussion: 1) The study confirmed NCL disease in 122 subjects. Phenotypic studies comprised epileptic seizures and movement disorders, ophthalmology, neurophysiology, image analysis, rating scales, enzyme testing, and electron microscopy, carried out under a consensus algorithm; 2) DNA screening and validation of mutations in genes PPT1 (CLN1), TPP1 (CLN2), CLN3, CLN5, CLN6, MFSD8 (CLN7), and CLN8: characterization of variant types, novel/knownmutations and polymorphisms; 3) Progress of the epidemiological picture in Latin America; and 4) NCL-like pathology studies in progress. The Translational Research Program was highly efficient in addressing the misdiagnosis/underdiagnosis in the NCL disorders. The study of “orphan diseases” in a public administrated hospital should be adopted by the health systems, as it positively impacts upon the family's quality of life, the collection of epidemiological data, and triggers research advances. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”publishedVersio

    Uma Metodologia para o Desenvolvimento de Ontologias

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     Ontologias são um importante meio de representar, formalizar e compartilhar conhecimento. No contexto da Engenharia de Ontologias, várias metodologias de desenvolvimento são propostas, cada qual com suas características em relação ao ciclo de vida de ontologias. Por conseguinte, não há uma metodologia estabelecida como padrão para o propósito geral de desenvolvimento de ontologias. Por isso, na literatura acadêmica enfatiza-se a combinação de metodologias. Mediante o estudo de algumas metodologias, atentando as características de simplicidade, expressividade e funcionalidade, é abstraído um conjunto de elementos para o desenvolvimento de ontologias. Como resultado, tem-se uma nova metodologia, a qual compreende as atividades, as tarefas e a sugestão de ferramentas em um processo de desenvolvimento de ontologias, sendo que tal metodologia foi validada em pesquisas exploratórias e/ou aplicadas

    The wavefront of the radio signal emitted by cosmic ray air showers

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    Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above 101710^{17}\,eV and zenith angles smaller than 4545^\circ, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances 50\gtrsim 50\,m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately 140140\,g/cm2^2. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, XmaxX_\mathrm{max}, better than 3030\,g/cm2^2. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too.Comment: accepted by JCA
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