Processing math: 100%
Repository of University of Nova Gorica

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

There are two search modes available: simple and advanced. The simple search mode searches by title, abstract, key words and full text. The advanced search mode offers several attributes and search operators to search with. This search method also allows the use of Boolean operators.

Help
Search in:
Options:
 


51 - 60 / 200
First pagePrevious page234567891011Next pageLast page
51.
Integrating cultural heritage and urban subway infrastructures : spatial distribution, value assessment, and impacts of the Beijing metro line on cultural heritage regional development
Haisheng Hu, 2025, doctoral dissertation

Abstract: This research examines the spatial patterns and economic significance of cultural heritage sites along Beijing’s metro lines, with an emphasis on how urban infrastructure influences heritage preservation. Using spatial analysis methods, including the nearest-neighbor index, geographic concentration index, and location entropy, the research identifies patterns in the distribution of cultural heritage sites - such as ancient architecture, industrial heritage, and tombs - particularly concentrated within Beijing’s second ring road. The study highlights the connectivity provided by key metro lines, including Lines 1, 2, 4, 5, 7, and 8, which link cultural sites in a point distribution pattern. On these premises, the research established a hierarchical framework to evaluate cultural heritage based on proximity to metro stations, with historical and artistic values being the most significant factors. The findings suggest that heritage sites within one kilometre of metro stations exert more significant influence on their surrounding areas and emphasize the importance of integrating metro infrastructure with cultural heritage preservation. This study contributes to understanding the spatial dynamics of cultural heritage in urban environments, offering a framework for assessing the impact of heritage within contemporary infrastructure systems. Practically, the study offers insights for urban planners, metro authorities, and cultural preservation bodies, proposing thematic routes along metro lines—such as Line 1 representing a fusion of Chinese and Western cultures and Line 5 emphasizing religious culture—to enhance cultural tourism. It also emphasizes the need for coordinated efforts between stakeholders to balance heritage conservation and urban development for sustainable growth.
Keywords: dissertations, linear cultural heritage, national cultural heritage, Beijing, spatial distribution, economic assessment
Published in RUNG: 31.03.2025; Views: 349; Downloads: 9
.pdf Full text (12,56 MB)

52.
Lattice-matched Ta3N5/Nb5N6 interface enables a bulk charge separation efficiency of close to 100%
Yitong Liu, Zeyu Fan, Ronghua Li, Andraž Mavrič, Iztok Arčon, Matjaž Valant, Gregor Kapun, Beibei Zhang, Chao Feng, Zemin Zhang, 2025, original scientific article

Abstract: The interface between the semiconductor light absorber and the metal electrode is critical for facilitating the extraction of photogenerated charges in photoelectrodes. Achieving a lattice-matched semiconductor/electrode interface with low defect density is highly desirable but remains a challenge for Ta3N5 photoanodes. In this study, we synthesized niobium nitride thin film electrodes with controllable crystallographic phases to achieve a lattice-matched Ta3N5/Nb5N6 back contact. This results in an enhanced crystallinity of the Ta3N5 film and reduced interfacial defect density. Consequently, the photoanode with the lattice-matched back contact attains a record half-cell solar-to-hydrogen conversion efficiency of 4.1%, attributed to the bulk carrier separation efficiency of nearly 100%. This work highlights lattice-matching as an effective strategy to enhance the efficiency of thin film-based solar energy conversion devices.
Keywords: photoelectrochemistry, photoanode, interface, semiconductors
Published in RUNG: 28.03.2025; Views: 370; Downloads: 5
URL Link to file
This document has many files! More...

53.
Search for the anomalous events detected by ANITA using the Pierre Auger Observatory
A. Abdul Halim, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, original scientific article

Abstract: A dedicated search for upward-going air showers at zenith angles exceeding 110° and energies E>0.1  EeV has been performed using the Fluorescence Detector of the Pierre Auger Observatory. The search is motivated by two “anomalous” radio pulses observed by the ANITA flights I and III that appear inconsistent with the standard model of particle physics. Using simulations of both regular cosmic-ray showers and upward-going events, a selection procedure has been defined to separate potential upward-going candidate events and the corresponding exposure has been calculated in the energy range [0.1–33] EeV. One event has been found in the search period between January 1, 2004, and December 31, 2018, consistent with an expected background of 0.27 ± 0.12 events from misreconstructed cosmic-ray showers. This translates to an upper bound on the integral flux of (7.2±0.2)×10[sup]−21  cm[sup]−2 sr[sup]−1 y[sup]−1 and (3.6±0.2)×10−20  cm[sup]−2 sr[sup]−1 y[sup]−1 for an E[sup]−1 and E[sup]−2 spectrum, respectively. An upward-going flux of showers normalized to the ANITA observations is shown to predict over 34 events for an E[sup]−3 spectrum and over 8.1 events for a conservative E[sup]−5 spectrum, in strong disagreement with the interpretation of the anomalous events as upward-going showers.
Keywords: ultra-high-energy cosmic rays, extensive air showers, upward-going air showers, Pierre Auger Observatory, Fluorescence Detector, anomalous ANITA events
Published in RUNG: 28.03.2025; Views: 374; Downloads: 5
.pdf Full text (447,09 KB)
This document has many files! More...

54.
Subluminal pulses in the surface-scintillator detectors of AugerPrime
Tobias Schulze, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, published scientific conference contribution

Abstract: In extensive air showers, the signals from the electromagnetic and muonic components typically span a few microseconds in scintillation detectors. Neutrons are the only stable neutral hadrons over the timescale of air showers. They lose energy exclusively through hadronic interactions and quasi-elastic scattering, which results in their high abundance at ground level. These neutrons can produce delayed pulses in scintillation detectors, appearing up to several milliseconds after the primary shower signal. This allows us to probe hadronic interactions in the development of air showers. In this study, we characterize such subluminal pulses using the first measurements from the scintillator surface detectors of the AugerPrime upgrade of the Pierre Auger Observatory.
Keywords: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, AugerPrime upgrade
Published in RUNG: 28.03.2025; Views: 372; Downloads: 7
.pdf Full text (318,77 KB)
This document has many files! More...

55.
Highlights from the Auger Engineering Radio Array
Bjarni Pont, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, published scientific conference contribution

Abstract: The Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory is an array of 153 radio-antenna stations that measure the 30−80 MHz radio emission produced in extensive air showers in the energy range between 0.1 and 10 EeV. It has been taking data for over a decade. In this contribution, we present the recent results of AERA. We show the measurements of the depths of the shower maxima (Xmax) using the radio footprint and using interferometry, demonstrating compatibility and competitiveness with the established fluorescence detection method. We also show the measurement of the stability of the radio signal over close to a decade determined using the Galactic radio background as a calibration source, demonstrating that a radio detector can be used to lower systematic uncertainties on the energy scale of, for example, fluorescence and water-Cherenkov detectors.
Keywords: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, radio emission
Published in RUNG: 28.03.2025; Views: 361; Downloads: 5
.pdf Full text (805,13 KB)
This document has many files! More...

56.
Mass composition of ultra-high-energy cosmic rays at the Pierre Auger Observatory
Thomas Fitoussi, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, published scientific conference contribution

Abstract: For the past 20 years, the Pierre Auger Observatory has collected the largest dataset of ultra-high-energy cosmic rays (UHECRs) ever achieved using a hybrid detector. The study of this dataset has led to numerous unexpected discoveries that enhance our understanding of the origins of UHECRs. One of the key points in this study is their mass composition. In this work, we will present the most recent results regarding the mass composition of UHECRs at the Pierre Auger Observatory. In particular, we will focus on the measurement of the depth of the maximum of air-shower profiles, denoted as Xmax . This determination has been achieved through both direct measurements from the Fluorescence Detector data and the application of machine learning for estimating Xmax on an event-by-event basis using the Surface Detector data. The latter has allowed us to extend the measurement to energies up to 100 EeV and indicates a correlation between changes in composition and three features of the energy spectrum (ankle, instep, steepening). Moreover, the results provide evidence of a heavy and nearly pure primary beam for energies greater than 50 EeV that is independent of the hadronic interaction model. The implications of these findings for astrophysics and for modelling hadronic interactions will be discussed.
Keywords: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, UHECR mass composition
Published in RUNG: 28.03.2025; Views: 358; Downloads: 8
.pdf Full text (1,66 MB)
This document has many files! More...

57.
Testing the declination dependency of the spectrum measured by the Pierre Auger Observatory
Diego Ravignani, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, published scientific conference contribution

Abstract: The distribution of the arrival directions of cosmic rays observed by the Pierre Auger Observatory has a dipolar component that implies a flux dependence on declination. Previously, we showed that the spectrum built from events arriving with a zenith angle less than 60° is qualitatively consistent with the dipole. In this work, we go one step further and show that the Auger spectrum cannot reject the hypothesis of a declination-independent flux. By using events of up 80°, we extend the previous survey from +25° of declination to +45°, thus covering 85% of the sky.
Keywords: ultra-high-energy cosmic rays, Pierre Auger Observatory, UHECR arrival directions, large-scale dipolar anisotropy
Published in RUNG: 28.03.2025; Views: 353; Downloads: 6
.pdf Full text (364,62 KB)
This document has many files! More...

58.
Measuring the proton-proton interaction cross section with hybrid data of the Pierre Auger Observatory
Olena Tkachenko, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, published scientific conference contribution

Abstract: The depth of the maximum of an air shower development, Xmax, as observed with fluorescence telescopes, is among the most sensitive observables for studying the interaction characteristics and primary composition of ultra-high-energy cosmic rays. However, precise measurement of the interaction cross section remains challenging, as standard analyses often rely on assumptions about the composition, which are closely tied to the validity of specific hadronic interaction models. In this work, we discuss a method for the simultaneous estimation of the proton-proton interaction cross section and primary mass composition, addressing the limitations of separate measurements. The inclusion of the Xmax scale into the fit further accounts for systematic uncertainties in the data and theoretical uncertainties in particle production. The performance of the method is evaluated using simulations that include detector responses under realistic conditions and with a particular focus on assessing the systematic uncertainties of the fit.
Keywords: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, air shower maximum depth
Published in RUNG: 28.03.2025; Views: 341; Downloads: 8
.pdf Full text (3,00 MB)
This document has many files! More...

59.
Overview of hadronic interaction studies at the Pierre Auger Observatory
Jakub Vícha, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2025, published scientific conference contribution

Abstract: The combination of fluorescence and surface detectors at the Pierre Auger Observatory offers unprecedented precision in testing models of hadronic interactions at center-of-mass energies around 70 TeV and beyond. However, for some time, discrepancies between model predictions and measured air-shower data have complicated efforts to accurately determine the mass composition of ultra-high-energy cosmic rays. A key inconsistency is the deficit of simulated signals compared to those measured with the surface detectors, typically interpreted as a deficit in the muon signal generated by the hadronic component of simulated showers. Recently, a new global method has been applied to the combined data from the surface and fluorescence detectors at the Pierre Auger Observatory. This method simultaneously determines the mass composition of cosmic rays and evaluates variations in the simulated depth of the shower maximum and hadronic signals on the ground. The findings reveal not only the alleviated muon problem but also show that all current models of hadronic interactions predict depths of the shower maximum that are too shallow, offering new insights into deficiencies in these models from a broader perspective.
Keywords: ultra-high-energy cosmic rays, Pierre Auger Observatory, extensive air showers, hadronic interactions
Published in RUNG: 28.03.2025; Views: 339; Downloads: 8
.pdf Full text (782,91 KB)
This document has many files! More...

60.
Search done in 0.06 sec.
Back to top