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81.
International Conference on Functional Nanomaterials and Nanodevices
Polina Mladenova, Dominik Eder, Saim Emin, 2018, other monographs and other completed works

Found in: ključnih besedah
Summary of found: ... energy conversion, catalysis, nanomaterials, nanobiotechnologies...
Keywords: energy conversion, catalysis, nanomaterials, nanobiotechnologies
Published: 17.09.2018; Views: 2682; Downloads: 0
.pdf Fulltext (3,62 MB)

82.
Multi-Messenger Physics With the Pierre Auger Observatory
Karl-Heinz Kampert, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, original scientific article

Found in: ključnih besedah
Summary of found: ...Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics...
Keywords: Pierre Auger Observatory, ultra-high energy cosmic rays, photons, neutrinos, protons, multi-messenger physics and astrophysics
Published: 06.05.2019; Views: 1943; Downloads: 81
.pdf Fulltext (2,46 MB)

83.
Mass composition of ultra-high energy cosmic rays at the Pierre Auger Observatory
Gašper Kukec Mezek, 2019, doctoral dissertation

Abstract: Cosmic rays with energies above 10^18 eV, usually referred to as ultra-high energy cosmic rays (UHECR), have been a mystery from the moment they have been discovered. Although we have now more information on their extragalactic origin, their direct sources still remain hidden due to deviations caused by galactic magnetic fields. Another mystery, apart from their production sites, is their nature. Their mass composition, still uncertain at these energies, would give us a better understanding on their production, acceleration, propagation and capacity to produce extensive air showers in the Earth's atmosphere. Mass composition studies of UHECR try to determine their nature from the difference in development of their extensive air showers. In this work, observational parameters from the hybrid detection system of the Pierre Auger Observatory are used in a multivariate analysis to obtain the mass composition of UHECR. The multivariate analysis (MVA) approach combines a number of mass composition sensitive variables and tries to improve the separation between different UHECR particle masses. Simulated distributions of different primary particles are fitted to measured observable distributions in order to determine individual elemental fractions of the composition. When including observables from the surface detector, we find a discrepancy in the estimated mass composition between a mixed simulation sample and the Pierre Auger data. Our analysis results from the Pierre Auger data are to a great degree independent on hadronic interaction models. Although they differ at higher primary masses, the different models are more consistent, when combining fractions of oxygen and iron. Compared to previously published results, the systematic uncertainty from hadronic interaction models is roughly four times smaller. Our analysis reports a predominantly heavy composition of UHECR, with more than a 50% fraction of oxygen and iron at low energies. The composition is then becoming heavier with increasing energy, with a fraction of oxygen and iron above 80% at the highest energies.
Found in: ključnih besedah
Keywords: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, machine learning, multivariate analysis
Published: 03.04.2019; Views: 2835; Downloads: 133
.pdf Fulltext (17,53 MB)

84.
Potentials and Limitations of Local Fiscal Policies as Instruments for Sustainable Development in Slovenia
Vladimir Prebilič, Irena Bačlija Brajnik, Marjana Šijanec-Zavrl, Henrik Gjerkeš, Miha Tomšič, 2019, published scientific conference contribution

Abstract: Local communities are one of the main cornerstones of sustainable development. They play a vital role in utilisation of national policy instruments and exhibit the largest influence on the energy use in the building and transport sectors. Sensible energy management can also positively enhance evolution of local sustainability features by incorporating concepts of local energy self-supply, decentralised energy production and circular economy. Positive economic and social impacts can be generated by adapting strategies and policies to the local environment while considering its endogenous potentials. By analysing the current status, identifying and quantifying potentials, and setting clear delimitation of responsibilities and legal constraints, local authorities can be helped to shape innovative local fiscal policies focused on intensification of use of local renewable energy sources and fostering of more efficient use of energy both in public and private sectors. Those revenues whose height and content can be determined by local authorities have a very different role in the budget already in 8 analysed Slovenian municipalities. They were quantified and used as an analytical basis for solution-oriented steps in the design of measures to adapt local fiscal policies to the increased use of renewable resources energy.
Found in: ključnih besedah
Summary of found: ...instruments and exhibit the largest influence on the energy use in the building and transport sectors....
Keywords: fiscal policy, municipality, energy use, renewables, sustainability
Published: 27.03.2019; Views: 2643; Downloads: 0
.pdf Fulltext (599,51 KB)

85.
Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layout
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Samo Stanič, A. Acharyya, 2019, original scientific article

Found in: ključnih besedah
Summary of found: ...very-high energy gamma-ray astronomy, Cherenkov Telescope Array, array layout...
Keywords: very-high energy gamma-ray astronomy, Cherenkov Telescope Array, array layout optimisation, Monte Carlo studies
Published: 18.04.2019; Views: 1783; Downloads: 0
.pdf Fulltext (3,46 MB)

86.
Mass composition of cosmic rays with energies from 10^17.2 eV to 10^20 eV using surface and fluorescence detectors of the Pierre Auger Observatory
Gašper Kukec Mezek, 2018, published scientific conference contribution

Abstract: Ultra-high-energy cosmic rays (UHECRs) are highly energetic particles with EeV energies, exceeding the capabilities of man-made colliders. They hold information on extreme astrophysical processes that create them and the medium they traverse on their way towards Earth. However, their mass composition at such energies is still unclear, because data interpretation depends on our choice of high energy hadronic interaction models. With its hybrid detection method, the Pierre Auger Observatory has the possibility to detect extensive air showers with an array of surface water-Cherenkov stations (SD) and fluorescence telescopes (FD). We present recent mass composition results from the Pierre Auger Collaboration using observational parameters from SD and FD measurements. Using the full dataset of the Pierre Auger Observatory, implications on composition can be made for energies above 10^17.2 eV.
Found in: ključnih besedah
Summary of found: ...Ultra-high- energy cosmic rays (UHECRs) are highly energetic particles...
Keywords: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, fluorescence telescopes, water-Cherenkov stations
Published: 24.05.2019; Views: 2060; Downloads: 80
.pdf Fulltext (573,00 KB)

87.
Study of Ultra-High Energy Cosmic Ray composition using Telescope Array’s Middle Drum detector and surface array in hybrid mode
Jon Paul Lundquist, R.U. Abbasi, 2015, original scientific article

Abstract: Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly’s Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.
Found in: ključnih besedah
Keywords: Ultra-High Energy Cosmic Rays, Cosmic ray composition, Atmospheric fluorescence, Extensive air shower array, Hybrid, Telescope Array
Published: 24.04.2020; Views: 1692; Downloads: 0
.pdf Fulltext (3,45 MB)

88.
Evidence for Declination Dependence of Ultrahigh Energy Cosmic Ray Spectrum in the Northern Hemisphere
J. P. Lundquist, R.U. Abbasi, 2018, other component parts

Abstract: The energy of the ultrahigh energy spectral cutoff was measured, integrating over the northern hemisphere sky, by the Telescope Array (TA) collaboration, to be 10^19.78±0.06 eV, in agreement with the High Resolution Fly's Eye (HiRes) experiment, whereas the Pierre Auger experiment, integrating over the southern hemisphere sky, measured the cutoff to be at 10^19.62±0.02 eV. An 11% energy scale difference between the TA and Auger does not account for this difference. However, in comparing the spectra of the Telescope Array and Pierre Auger experiments in the band of declination common to both experiments ( −15.7∘<δ<24.8∘ ) we have found agreement in the energy of the spectral cutoff. While the Auger result is essentially unchanged, the TA cutoff energy has changed to 10^19.59±0.06 eV. In this paper we argue that this is an astrophysical effect.
Found in: ključnih besedah
Keywords: Astrophysics, High Energy Astrophysical Phenomena, UHECR, Cosmic Rays, Anisotropy, Energy Spectrum
Published: 27.04.2020; Views: 1631; Downloads: 54
.pdf Fulltext (687,87 KB)

89.
Search for Anisotropy in the Ultra High Energy Cosmic Ray Spectrum using the Telescope Array Surface Detector
J. P. Lundquist, R.U. Abbasi, 2017, other component parts

Abstract: The Telescope Array (TA) experiment is located in the western desert of Utah, USA, and observes ultra high energy cosmic rays (UHECRs) in the Northern hemisphere. At the highest energies, E>10~EeV, the shape of cosmic ray energy spectrum may carry an imprint of the source density distribution along the line of sight different in different directions of the sky. In this study, we search for such directional variations in the shape of the energy spectrum using events observed with the Telescope Array's surface detector. We divide the TA field of view into two nearly equal-exposure regions: the "on-source" region which we define as ±30∘ of the supergalactic plane containing mostly nearby structures, and the complementary "off-source" region where the sources are further away on average. We compare the UHECR spectra in these regions by fitting them to the broken power law and comparing the resulting parameters. We find that the off-source spectrum has an earlier break at highest energies. The chance probability to obtain such or larger difference in statistically equivalent distributions is estimated as 6.2±1.1×10−4 (3.2σ) by a Monte-Carlo simulation. The observed difference in spectra is in a reasonable quantitative agreement with a simplified model that assumes that the UHECR sources trace the galaxy distribution from the 2MRS catalogue, primary particles are protons and the magnetic deflections can be neglected.
Found in: ključnih besedah
Keywords: cosmic radiation: UHE, detector: surface, cosmic radiation: spectrum, cosmic radiation: energy spectrum, deflection: magnetic, numerical calculations: Monte Carlo, anisotropy
Published: 27.04.2020; Views: 1511; Downloads: 52
.pdf Fulltext (169,05 KB)

90.
The energy spectrum of cosmic rays above 1017.2 eV measured by the fluorescence detectors of the Telescope Array experiment in seven years
J. P. Lundquist, R.U. Abbasi, 2016, original scientific article

Abstract: The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at two stations of TA are newly constructed and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 10^17.2eV measured by the fluorescence detectors and a comparison with previously published results.
Found in: ključnih besedah
Keywords: Cosmic rays, Ultra-high energy, Fluorescence detector, Energy spectrum, Ankle, GZK cutoff
Published: 27.04.2020; Views: 1547; Downloads: 0
.pdf Fulltext (1,23 MB)

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