25 research outputs found
Changes and trends of climate elements and indices in the region of Mediterranean Croatia
Climate is complex ecological factor described by different climate elements and phenomena that effect development of vegetation and its natural distribution. Climate elements the most important for vegetation are air temperatures, amount of precipitations, air humidity and wind. The aim of this research was to determine trends and changes of climate elements in the region of Mediterranean Croatia. Meteorological stations with the longest monitoring period in the region of the Mediterranean Croatia were chosen in order to determine trends of the climate elements. Decreasing or increasing trends of individual climate elements and indices were analysed using linear trend of regression analysis. Climate elements and indices of the referent line were compared with period between 1991 and 2010. At all meteorological stations was found negative trend of annual amount of precipitations and Lang ´s rain factor. Exception was meteorological station Rijeka with increase of annual amount of precipitations and Lang ´s rain factor. Trends of air temperatures at all meteorological stations were positive. Values of Lang ´s rain factor in the researched region are decreasing resulting higher aridity of the region. Trends of potential evapotranspiration are significant and positive at all meteorological stations. Changes of air temperatures are more noticeable than those of precipitations, while changes of potential evapotranspiration are more noticeable than those of Lang ´s rain factor. Forest vegetation and crop plants of Mediterranean Croatia are adapted to certain climate conditions predominating in this region. This conditions change through time effecting growth and development of all organisms
Search for transient optical counterparts to high-energy IceCube neutrinos with Pan-STARRS1
In order to identify the sources of the observed diffuse high-energy neutrino flux, it is crucial to discover their electromagnetic counterparts. To increase the sensitivity of detecting counterparts of transient or variable sources by telescopes with a limited field of view, IceCube began releasing alerts for single high-energy (E-v > 60 TeV) neutrino detections with sky localisation regions of order 1 degrees radius in 2016. We used Pan-STARRS1 to follow-up five of these alerts during 2016-2017 to search for any optical transients that may be related to the neutrinos. Typically 10-20 faint m(ip1) less than or similar to 22.5 mag) extragalactic transients are found within the Pan-STARRS1 footprints and are generally consistent with being unrelated field supernovae (SNe) and AGN. We looked for unusual properties of the detected transients, such as temporal coincidence of explosion epoch with the IceCube timestamp, or other peculiar light curve and physical properties. We found only one transient that had properties worthy of a specific follow-up. In the Pan-STARRS1 imaging for IceCube-160427A (probability to be of astrophysical origin of similar to 50%), we found a SN PS16cgx, located at 10.0' from the nominal IceCube direction. Spectroscopic observations of PS16cgx showed that it was an H-poor SN at redshift z = 0.2895 +/- 0.0001. The spectra and light curve resemble some high-energy Type Ic SNe, raising the possibility of a jet driven SN with an explosion epoch temporally coincident with the neutrino detection. However, distinguishing Type Ia and Type Ic SNe at this redshift is notoriously difficult. Based on all available data we conclude that the transient is more likely to be a Type Ia with relatively weak Sin absorption and a fairly normal rest-frame r-band light curve. If, as predicted, there is no high-energy neutrino emission from Type Ia SNe, then PS16cgx must be a random coincidence, and unrelated to the IceCube-160427A. We find no other plausible optical transient for any of the five IceCube events observed down to a 5 sigma limiting magnitude of mip1 approximate to 22 mag, between 1 day and 25 days after detection
Improved limits on dark matter annihilation in the Sun with the 79-string IceCube detector and implications for supersymmetry
Finite volume method to solve electromagnetic diffraction problem
Communication to : ICOLSE'99 international conference on lightning and static electricity, Toulouse (France), June 22-24, 1999Available from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1999 n.65 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc
Improved limits on dark matter annihilation in the Sun with the 79-string IceCube detector and implications for supersymmetry
Point, linear and areal elements, which are two-dimensional and of a graphic nature, are the morphological elements employed when designing tactile maps and symbols for visually impaired users.
However, beyond the two-dimensional domain, there is a fourth group of elements – volumetric elements – which mapmakers do not take sufficiently into account when it comes to designing tactile maps and symbols.
This study analyses the effect of including volumetric, or 3D, symbols within a tactile map. In order to do so, the researchers compared two tactile maps. One of them uses only two-dimensional elements and is produced using thermoforming, one of the most popular systems in this field, while the other includes volumetric symbols, thus highlighting the possibilities opened up by 3D printing, a new area of production.
The results of the study show that including 3D symbols improves the efficiency and autonomous use of these products.he work reported here is part of the research project entitled ‘Estudio y diseño de elementos de orientación, soportes de comunicación y otros accesorios para la mejora de la accesibilidad en distintos ámbitos de interpretación del patrimonio natural y/o construidos’ supported by the Spanish Ministry of Science and Innovation (project DPI2008-03981/DPI). The authors wish to thank the Centre de Recursos Educatius (Organización Nacional de Ciegos Españoles-ONCE) and the Associació Discapacitat Visual Cataluña B1+B2+B3 in Barcelona, as well as the ONCE offices in Castellón, Tarragona and Valencia for supporting this research. Finally, this work has also been supported by the Programa de Mobilitat del Personal Investigador de la Universitat Jaume I (E-2010-32) and the Fundació Caixa Castelló-Bancaixa
Алапаевская искра. 2010. № 141
The Precision IceCube Next Generation Upgrade (PINGU) is a proposed lowenergy in-fill extension to the IceCube Neutrino Observatory. With detection technology modeled closely on the successful IceCube example, PINGU will provide a 6 Mton effective mass for neutrino detection with an energy threshold of a few GeV. With an unprecedented sample of over 60 000 atmospheric neutrinos per year in this energy range, PINGU will make highly competitive measurements of neutrino oscillation parameters in an energy range over an order of magnitude higher than long-baseline neutrino beam experiments. PINGU will measure the mixing parameters Θ23 and Δm232, including the octant of Θ23 for a wide range of values, and determine the neutrino mass ordering at 3σ median significance within five years of operation. PINGU's high precision measurement of the rate of nt appearance will provide essential tests of the unitarity of the 3 ×3 PMNS neutrino mixing matrix. PINGU will also improve the sensitivity of searches for low mass dark matter in the Sun, use neutrino tomography to directly probe the composition of the Earth's core, and improve IceCube's sensitivity to neutrinos from Galactic supernovae. Reoptimization of the PINGU design has permitted substantial reduction in both cost and logistical requirements while delivering performance nearly identical to configurations previously studied
In-situ calibration of the single-photoelectron charge response of the IceCube photomultiplier tubes
We describe an improved in-situ calibration of the single-photoelectron charge distributions for each of the in-ice Hamamatsu Photonics R7081-02[MOD] photomultiplier tubes in the IceCube Neutrino Observatory. The characterization of the individual PMT charge distributions is important for PMT calibration, data and Monte Carlo simulation agreement, and understanding the effect of hardware differences within the detector. We discuss the single photoelectron identification procedure and how we extract the single-photoelectron charge distribution using a deconvolution of the multiple-photoelectron charge distribution
Constraints on neutrino emission from nearby galaxies using the 2MASS redshift survey and IceCube
The distribution of galaxies within the local universe is characterized by anisotropic features. Observatories searching for the production sites of astrophysical neutrinos can take advantage of these features to establish directional correlations between a neutrino dataset and overdensities in the galaxy distribution in the sky. The results of two correlation searches between a seven-year time-integrated neutrino dataset from the IceCube Neutrino Observatory, and the 2MASS Redshift Survey (2MRS) catalog are presented here. The first analysis searches for neutrinos produced via interactions between diffuse intergalactic Ultra-High Energy Cosmic Rays (UHECRs) and the matter contained within galaxies. The second analysis searches for low-luminosity sources within the local universe, which would produce subthreshold multiplets in the IceCube dataset that directionally correlate with galaxy distribution. No significant correlations were observed in either analyses. Constraints are presented on the flux of neutrinos originating within the local universe through diffuse intergalactic UHECR interactions, as well as on the density of standard candle sources of neutrinos at low luminosities
Searching for eV-scale sterile neutrinos with eight years of atmospheric neutrinos at the IceCube Neutrino Telescope
We report in detail on searches for eV-scale sterile neutrinos, in the context of a 3+1 model, using eight years of data from the IceCube Neutrino Telescope. By analyzing the reconstructed energies and zenith angles of 305,735 atmospheric νμ and ν¯μ events we construct confidence intervals in two analysis spaces: sin2(2θ24) vs Δm412 under the conservative assumption θ34=0; and sin2(2θ24) vs sin2(2θ34) given sufficiently large Δm412 that fast oscillation features are unresolvable. Detailed discussions of the event selection, systematic uncertainties, and fitting procedures are presented. No strong evidence for sterile neutrinos is found, and the best-fit likelihood is consistent with the no sterile neutrino hypothesis with a p value of 8% in the first analysis space and 19% in the second
Search for PeV Gamma-Ray Emission from the Southern Hemisphere with 5 Yr of Data from the IceCube Observatory
The measurement of diffuse PeV gamma-ray emission from the Galactic plane would provide information about the energy spectrum and propagation of Galactic cosmic rays, and the detection of a pointlike source of PeV gamma-rays would be strong evidence for a Galactic source capable of accelerating cosmic rays up to at least a few PeV. This paper presents several unbinned maximum-likelihood searches for PeV gamma-rays in the Southern Hemisphere using 5 yr of data from the IceTop air shower surface detector and the in-ice array of the IceCube Observatory. The combination of both detectors takes advantage of the low muon content and deep shower maximum of gamma-ray air showers and provides excellent sensitivity to gamma-rays between 3c0.6 and 100 PeV. Our measurements of pointlike and diffuse Galactic emission of PeV gamma-rays are consistent with the background, so we constrain the angle-integrated diffuse gamma-ray flux from the Galactic plane at 2 PeV to 2.61
7 10-19 cm-2 s-1 TeV-1 at 90% confidence, assuming an E -3 spectrum, and we estimate 90% upper limits on pointlike emission at 2 PeV between 10-21 and 10-20 cm-2 s-1 TeV-1 for an E -2 spectrum, depending on decl. Furthermore, we exclude unbroken power-law emission up to 2 PeV for several TeV gamma-ray sources observed by the High Energy Spectroscopic System and calculate upper limits on the energy cutoffs of these sources at 90% confidence. We also find no PeV gamma-rays correlated with neutrinos from IceCube's high-energy starting event sample. These are currently the strongest constraints on PeV gamma-ray emission