Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bolonia study programme


161 - 170 / 172
First pagePrevious page9101112131415161718Next pageLast page
Equilibrium axisymmetric halo model for the Milky Way and its implications for direct and indirect dark matter searches
Mihael Petač, 2020, original scientific article

Abstract: We for the first time provide self-consistent axisymmetric phase-space distribution models for the Milky Way's dark matter (DM) halo which are carefully matched against the latest kinematic measurements through Bayesian analysis. By using broad priors on the individual galactic components, we derive conservative estimates for the astrophysical factors entering the interpretation of direct and indirect DM searches. While the resulting DM density profiles are in good agreement with previous studies, implying ρ⊙≈10-2 M⊙/pc3, the presence of baryonic disc leads to significant differences in the local DM velocity distribution in comparison with the standard halo model. For direct detection, this implies roughly 30% stronger cross section limits at DM masses near detectors maximum sensitivity and up to an order of magnitude weaker limits at the lower end of the mass range. Furthermore, by performing Monte Carlo simulations for the upcoming DARWIN and DarkSide-20k experiments, we demonstrate that upon successful detection of heavy DM with coupling just below the current limits, the carefully constructed axisymmetric models can eliminate bias and reduce uncertainties by more then 50% in the reconstructed DM coupling and mass, but also help in a more reliable determination of the scattering operator. Furthermore, the velocity anisotropies induced by the baryonic disc can lead to significantly larger annual modulation amplitude and sizable differences in the directional distribution of the expected DM-induced events. For indirect searches, we provide the differential J factors and compute several moments of the relative velocity distribution that are needed for predicting the rate of velocity-dependent annihilations. However, we find that accurate predictions are still hindered by large uncertainties regarding the DM distribution near the galactic center.
Found in: ključnih besedah
Summary of found: ...dark matter, astrophysics, galaxies, high energy physics, experiments, phenomenology...
Keywords: dark matter, astrophysics, galaxies, high energy physics, experiments, phenomenology
Published: 01.10.2021; Views: 544; Downloads: 15
URL Fulltext (0,00 KB)
This document has many files! More...

Experimental bounds on sterile-active neutrino mixing angles
Mihael Petač, 2015, master's thesis

Abstract: Despite the success of the Standard Model in the last few decades, we know it is not complete. There is strong motivation for assuming the existence of additional heavy neutral leptons, which can account for active neutrino masses and possibly also have cosmological implications. In this work I consider the Standard Model with two neutral lepton singlets (sterile neutrinos) with degenerated masses in the range 20MeV - 2GeV. The constraints on the active-sterile neutrino mixing angles are evaluated based on recent neutrino oscillations data. Using these constraints the bounds from accelerator experiments are reanalyzed for the case of the considered model. Finally, the results are compared with cosmological constraints coming from Big Bang nucleosynthesis and the nMSM resonant leptogenesis.
Found in: ključnih besedah
Summary of found: ...Sterile neutrinos, Neutrino mixing, See-saw, High- Energy Physics - Phenomenology, High-Energy Physics - Experiments...
Keywords: Sterile neutrinos, Neutrino mixing, See-saw, High-Energy Physics - Phenomenology, High-Energy Physics - Experiments
Published: 01.10.2021; Views: 527; Downloads: 16
.pdf Fulltext (1,93 MB)

Monetisation of the ecological footprint in energy supply of buildings
Henrik Gjerkeš, Marjana Šijanec-Zavrl, 2021, short scientific article

Abstract: The ecological footprint of modern life exceeds the biocapacity of our environment in Slovenia as well. With a simplified monetization of natural resources and waste, the economic and environmental advantages of renewables compared to fossil sources in the case of energy supply of buildings were illustrated. Experience with current energy market volatility and the extension of the EU-ETS are strong signals to accelerate the energy transition towards sustainable energy also in the building sector.
Found in: ključnih besedah
Keywords: energy supply, renewable energy sources, EU-ETS, buildings
Published: 29.10.2021; Views: 504; Downloads: 0
.pdf Fulltext (731,91 KB)

Testing effects of Lorentz invariance violation in the propagation of astroparticles with the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Serguei Vorobiov, Samo Stanič, Jon Paul Lundquist, Andrej Filipčič, P. Abreu, Lukas Zehrer, 2022, original scientific article

Found in: ključnih besedah
Summary of found: ...cosmic ray experiments, ultra high energy, cosmic rays, physics of the early universe,...
Keywords: cosmic ray experiments, ultra high energy, cosmic rays, physics of the early universe, Pierre Auger Observatory, Lorentz invariance violation effects
Published: 18.01.2022; Views: 377; Downloads: 9
URL Fulltext (0,00 KB)
This document has many files! More...

Stefan Subotić, master's thesis

Abstract: The master thesis aims to find the optimal model for a new energy company that considers regional potential, supports sustainable development, and fits the circular economy concept in a region. The idea of sustainable development is crucial today when we have more city areas and less countryside around the globe. Increased global population, industrial trends and modern living style are some of the reasons why the burden on our environment is more significant than ever in the history of humanity. The idea is to launch the new company in the Croatian region Osijek-Baranja, which is less developed and not attractive to tourists. A newly established company will produce electric energy from renewable energy sources. The multi-criterion decision support methods were used to determine the optimal energy source between wind, biogas and sun. Results show that the biogas has the most significant sustainable potential in chosen boundary conditions. The cash flows and other economic indicators are shown for a farm of 500 milking cows in the chosen region as a source of biogas. The risk assessments method estimated the boundaries of the company success and adaptability to possible changes. One of the critical aspects of the project is the company's organizational structure, where a vertical hierarchy with a flexible and fluid, circular organization model with network culture was proposed. Clear communication about the project will help establish trust with the local community. Based on the biogas plant, the proposed company reduces biodegradable waste in the green energy production process. It is shown quantitatively that besides being economically sustainable, it also suits the region's potential, supports energy self-supply, and involves local people - it aims to the long-term sustainable growth of the region, rather than short-term capital growth.
Found in: ključnih besedah
Keywords: Circular economy, sustainable development, regional potential, renewable energy sources, company structure, communication
Published: 18.02.2022; Views: 444; Downloads: 20
.pdf Fulltext (2,75 MB)

Interface engineering of Ta[sub]3N[sub]5 thin film photoanode for highly efficient photoelectrochemical water splitting
Kazunari Domen, Yanbo Li, Chao Feng, Naoya Shibata, Nadiia Pastukhova, Yequan Xiao, Jie Fu, Zeyu Fan, Mamiko Nakabayashi, Huanxin Ju, 2022, original scientific article

Abstract: Interface engineering is a proven strategy to improve the efficiency of thin film semiconductor based solar energy conversion devices. Ta3N5 thin film photoanode is a promising candidate for photoelectrochemical (PEC) water splitting. Yet, a concerted effort to engineer both the bottom and top interfaces of Ta3N5 thin film photoanode is still lacking. Here, we employ n-type In:GaN and p-type Mg:GaN to modify the bottom and top interfaces of Ta3N5 thin film photoanode, respectively. The obtained In:GaN/Ta3N5/Mg:GaN heterojunction photoanode shows enhanced bulk carrier separation capability and better injection efficiency at photo- anode/electrolyte interface, which lead to a record-high applied bias photon-to-current efficiency of 3.46% for Ta3N5-based photoanode. Furthermore, the roles of the In:GaN and Mg:GaN layers are distinguished through mechanistic studies. While the In:GaN layer con- tributes mainly to the enhanced bulk charge separation efficiency, the Mg:GaN layer improves the surface charge inject efficiency. This work demonstrates the crucial role of proper interface engineering for thin film-based photoanode in achieving efficient PEC water splitting.
Found in: ključnih besedah
Summary of found: ...efficiency of thin film semiconductor based solar energy conversion devices. Ta3N5 thin film photoanode is...
Keywords: photocatalysis, renewable energy
Published: 09.02.2022; Views: 321; Downloads: 14
URL Fulltext (0,00 KB)
This document has many files! More...

Electrolysis energy efficiency of highly concentrated FeCl[sub]2 solutions for power-to-solid energy storage technology
Matjaž Valant, Uroš Luin, 2022, original scientific article

Abstract: An electrochemical cycle for the grid energy storage in the redox potential of Fe involves the electrolysis of a highly concentrated aqueous FeCl2 solution yielding solid iron deposits. For the high overall energy efficiency of the cycle, it is crucial to maximize the energy efficiency of the electrolysis process. Here we present a study of the influence of electrolysis parameters on the energy efficiency of such electrolysis, performed in an industrial-type electrolyzer. We studied the conductivity of the FeCl2 solution as a function of concentration and temperature and correlated it with the electrolysis energy efficiency. The deviation from the correlation indicated an important contribution from the conductivity of the ion-exchange membrane. Another important studied parameter was the applied current density. We quantitatively showed how the contribution of the resistance polarization increases with the current density, causing a decrease in overall energy efficiency. The highest energy efficiency of 89 ± 3% was achieved using 2.5 mol L−1 FeCl2 solution at 70 °C and a current density of 0.1 kA m−2. In terms of the energy input per Fe mass, this means 1.88 Wh g−1. The limiting energy input per mass of the Fe deposit was found to be 1.76 Wh g−1.
Found in: ključnih besedah
Keywords: electrolysis, ferrous chloride, iron deposition, energy efficiency
Published: 16.02.2022; Views: 313; Downloads: 9
.pdf Fulltext (1,99 MB)
This document has many files! More...

Catalog of long-term transient sources in the first 10 yr of Fermi-LAT data
L. Baldini, J. Ballet, D. Bastieri, J. Becerra Gonzalez, R. Bellazzini, A. Berretta, E. Bissaldi, R. D. Blandford, E. D. Bloom, Gabrijela Zaharijas, 2021, original scientific article

Found in: ključnih besedah
Summary of found: ...high energy astrophysics, active galactic nuclei, gamma-ray bursts, solar...
Keywords: high energy astrophysics, active galactic nuclei, gamma-ray bursts, solar flares, solar gamma-ray emission
Published: 17.02.2022; Views: 342; Downloads: 6
.pdf Fulltext (32,75 MB)
This document has many files! More...

Probing the fundamental nature of Dark Matter with the Large Synoptic Survey Telescope
Alex Drlica-Wagner, Yao-Yuan Mao, Susmita Adhikari, Robert Armstrong, Arka Banerjee, Nilanjan Banik, Keith Bechtol, Simeon Bird, Christopher Eckner, Gabrijela Zaharijas, 2019, project documentation (preliminary design, working design)

Found in: ključnih besedah
Summary of found: ...dark matter, high energy physics, astrophysical observations, cosmological observations, Large Synoptic...
Keywords: dark matter, high energy physics, astrophysical observations, cosmological observations, Large Synoptic Survey Telescope (LSST)
Published: 03.05.2022; Views: 133; Downloads: 3
URL Fulltext (0,00 KB)
This document has many files! More...

Search done in 0 sec.
Back to top