Search results for "Instrument"
showing 10 items of 5652 documents
Underground multi-muon experiment EMMA
2011
EMMA is a new experiment designed for cosmic-ray composition studies around the knee energy operating at the shallow depth underground in the Pyhäsalmi mine, Finland. The array has sufficient coverage and resolution to determine the multiplicity, the lateral density distribution and the arrival direction of high-energy muons on an event by event basis. Preliminary results on the muon multiplicity extracted using one detector station of the array are presented. peerReviewed
Precise Determination of the Unperturbed 8B Neutrino Spectrum
2012
The measurement was performed at the Kernfysisch Versneller Instituut (KVI) at the University of Groningen, The Netherlands.; A measurement of the final state distribution of the 8B $\beta$ decay, obtained by implanting a 8B beam in a double-sided silicon strip detector, is reported here. The present spectrum is consistent with a recent independent precise measurement performed by our collaboration at the IGISOL facility, Jyvâskylä [O. S. Kirsebom et al., Phys. Rev. C 83, 065802 (2011)]. It shows discrepancies with previously measured spectra, leading to differences in the derived neutrino spectrum. Thanks to a low detection threshold, the neutrino spectrum is for the first time directly ex…
TANAMI II. Additional sources
2018
TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of -30{deg} declination including high-resolution Very Long Baseline Interferometry (VLBI) imaging, radio, optical/UV, X-ray and {gamma}-ray studies. We have previously published first-epoch 8.4GHz VLBI images of the parsec-scale structure of the initial sample. In this paper, we present images of 39 additional sources. The full sample comprises most of the radio- and {gamma}-ray brightest AGN in the southern quarter of the sky, overlapping with the region from which high-energy (>100TeV) neutrino events have been found. We characterize the parsec-scale radio properties of the jets and compare with the quasi-s…
Neutrinos from GRBs with ANTARES
2013
A search for muon neutrinos in coincidence with gamma-ray bursts with the ANTARES neutrino detector using data from the end of 2007 to 2011 is performed. Expected neutrino fluxes are calculated for each burst individually. The most recent numerical calculations of the spectra using the NeuCosmA code are employed, which include Monte Carlo simulations of the full underlying photohadronic interaction processes. The discovery probability for a selection of 296 gamma-ray bursts in the given period is optimised using an extended maximum-likelihood strategy. No significant excess over background is found in the data, and 90% confidence level upper limits are placed on the total expected flux acco…
Baryon Acoustic Oscillations in LRGs
2012
Baryon Acoustic Oscillations (BAO) have been previously detected using correlation functions and power spectra of the galaxy distribution. In this work, we present a new method for the detection of the real-space structures associated with this feature. These baryon acoustic structures are spherical shells with a relatively small density contrast, surrounding high density central regions. We design a specific wavelet adapted to the search for shells, and exploit the physics of the process by making use of two different mass tracers, introducing a specific statistic to detect the BAO features. We apply our method to the detection of BAO in a galaxy sample drawn from the Sloan Digital Sky Sur…
Galaxy clusters from SDSS DR8
2012
The study of the signatures of multimodality in groups and clusters of galaxies, an environment for most of the galaxies in the Universe, gives us information about the dynamical state of clusters and about merging processes, which affect the formation and evolution of galaxies, groups and clusters, and larger structures - superclusters of galaxies and the whole cosmic web. We search for the presence of substructure, a non-Gaussian, asymmetrical velocity distribution of galaxies, and large peculiar velocities of the main galaxies in clusters with at least 50 member galaxies, drawn from the SDSS DR8. Cone search capability for table J/A+A/540/A123/table3 (Data on clusters)
Obturación de los conductos radiculares con cementos biocerámicos y gutapercha recubierta del mismo material: análisis morfológico de las interfases …
2020
OBJETIVO Evaluar la relación entre cuatro cementos endodónticos (uno basado en resina y tres basados en materiales biocerámicos) y la dentina del conducto radicular, así como la unión entre el núcleo de gutapercha (convencional y recubierta de material biocerámico) y los cementos. MATERIAL Y MÉTODOS Se seleccionaron 80 dientes unirradiculares, verificados previamente de forma radiográfica. Estos se se dividieron en 4 grupos (n=20) de acuerdo al cemento de obturación: 1 (MTA FillApex), 2 (EndoSequence BC Sealer), 3 (Bio Root) y 4 (AHPlus). A su vez cada grupo se dividió en dos (ni=10) según la gutapercha empleada, convencional o recubierta de material biocerámico. Los dientes se decoronaron …
Opettajan ohjauskäytänteet alkuopetuksessa
2016
Tässä tutkimuksessa tarkasteltiin opettajan ohjauskäytänteitä alkuopetuksessa. Syksyllä 2016 astuu voimaan uusi opetussuunnitelma, joka korostaa lapsikeskeistä ohjauskäytäntöä. Tämän takia tutkimuksessa haluttiin tutkia, millaisia ohjauskäytänteitä opettajat soveltavat opetuksessaan ennen uuden opetussuunnitelman käyttöönottoa. Tarkoituksena oli tutkia, mitä ohjauskäytännettä sovelletaan alkuopetuksessa eniten ja millä ulottuvuuksilla sekä millaisia nämä ohjauskäytänteet ovat. Tutkimukseen osallistui viisi alkuopetuksen luokanopettajaa. Aineiston ensimmäinen osa kerättiin havainnoimalla jokaiselta opettajalta neljä oppituntia. Tämä aineisto analysoitiin teorialähtöisesti hyödyntämällä ECCOM…
Radioluminescence Response of Ce-, Cu-, and Gd-Doped Silica Glasses for Dosimetry of Pulsed Electron Beams
2021
Radiation-induced emission of doped sol-gel silica glass samples was investigated under a pulsed 20-MeV electron beam. The studied samples were drawn rods doped with cerium, copper, or gadolinium ions, which were connected to multimode pure-silica core fibers to transport the induced luminescence from the irradiation area to a signal readout system. The luminescence pulses in the samples induced by the electron bunches were studied as a function of deposited dose per electron bunch. All the investigated samples were found to have a linear response in terms of luminescence as a function of electron bunch sizes between 10−5 Gy/bunch and 1.5×10−2 Gy/bunch. The presented results show that these…
Measurement of nonlinear and chromatic dispersion parameters of optical fibers using modulation instability
2006
International audience; We present a simple method for the measurement of Kerr, second- and third-order dispersion coefficients in optical fibers using power and dispersion dependences of modulation instability near the zero-dispersion wavelength. We also complete the analysis by the accurate determination of the zero-dispersion wavelength of the fiber using the phase-matched four wave mixing process which occurs near this specific wavelength.