1. Multi-messenger insights into ultra-high-energy cosmic rays from FR0 radio galaxies : emission spectrum, composition, and secondary photons and neutrinosJon Paul Lundquist, Serguei Vorobiov, Lukas Merten, Anita Reimer, Margot Boughelilba, Paolo Da Vela, Fabrizio Tavecchio, Giacomo Bonnoli, Chiara Righi, 2025, published scientific conference contribution Abstract: Despite their low individual luminosity, Fanaroff-Riley Type 0 (FR0) radio galaxies have emerged as potentially significant contributors to the observed flux of ultra-high-energy cosmic rays (UHECRs, E≥10 EeV) due to their substantial prevalence in the local universe. Outnumbering more powerful FR radio galaxies by approximately fivefold within redshifts of z≤0.05, FR0s may contribute a considerable fraction of the total UHECR energy density. The presented comprehensive study employs CRPropa3 simulations to estimate the mass composition and energy spectra of UHECRs emitted by FR0 galaxies. These simulations, which integrate extrapolated FR0 properties and various configurations of intergalactic magnetic fields (both random and structured), are compared to recent data from the Pierre Auger Observatory using three extensive air-shower models. By fitting the simulated spectral indices, rigidity cutoffs, and elemental fractions to Auger’s observed energy spectrum and ⟨lnA⟩ composition, we probe the contribution of FR0 sources to the UHECR flux. Furthermore, we predict the secondary photon and neutrino fluxes resulting from UHECR interactions with cosmic photon backgrounds and compare these results with current upper limits and theoretical models. This multi-messenger approach provides valuable insights into the role of low-luminosity FR0 radio galaxies within the UHECR landscape.
Keywords: ultra-high-energy cosmic rays, energy spectrum, mass composition, Fanaroff-Riley type 0
Published in RUNG: 24.03.2025; Views: 301; Downloads: 8
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2. Performance of a proposed event-type based analysis for the Cherenkov Telescope ArrayTarek Hassan, Saptashwa Bhattacharyya, Barbara MARČUN, Judit Pérez Romero, Samo Stanič, Veronika Vodeb, Serguei Vorobiov, Gabrijela Zaharijas, Marko Zavrtanik, Danilo Zavrtanik, Miha Živec, 2021, published scientific conference contribution Abstract: The Cherenkov Telescope Array (CTA) will be the next-generation observatory in the field of very-high-energy (20 GeV to 300 TeV) gamma-ray astroparticle physics. Classically, data analysis in the field maximizes sensitivity by applying quality cuts on the data acquired. These cuts, optimized using Monte Carlo simulations, select higher quality events from the initial dataset. Subsequent steps of the analysis typically use the surviving events to calculate one set of instrument response functions (IRFs). An alternative approach is the use of event types, as implemented in experiments such as the Fermi-LAT. In this approach, events are divided into sub-samples based on their reconstruction quality, and a set of IRFs is calculated for each sub-sample. The sub-samples are then combined in a joint analysis, treating them as independent observations. This leads to an improvement in performance parameters such as sensitivity, angular and energy resolution. Data loss is reduced since lower quality events are included in the analysis as well, rather than discarded. In this study, machine learning methods will be used to classify events according to their expected angular reconstruction quality. We will report the impact on CTA high-level performance when applying such an event-type classification, compared to the classical procedure.
Keywords: Cherenkov Telescope Array, very-high-energy gamma-rays, event-type based analysis
Published in RUNG: 18.09.2023; Views: 2032; Downloads: 9
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3. Effects of a Mixed O/F Ligand in the Tavorite-Type LiVPO4O StructureSorour Semsari Parapari, Jean-Marcel Ateba Mba, Elena Tchernychova, Gregor Mali, Iztok Arčon, Gregor Kapun, Mehmet Ali Gülgün, Robert Dominko, 2020, original scientific article Abstract: We report the synthesis and detailed structural
and chemical characterization including electrochemical
properties of a lithium vanadium oxy/fluoro-phosphate
material. To the best of our knowledge, we have for the first
time synthesized a LiVPO4O-type phase with a mixed O/F
ligand. In the synthesis procedure, the LiVPO4O precursor
compound was fluorinated via LiF incorporation, with
preservation of the LiVPO4O framework structure. The
operating potential of the synthesized material is increased
compared to that of the LiVPO4O precursor (4.12 V vs 3.95 V
versus metallic lithium, respectively). The related increase in
operating potential was assigned to the effect of the
intermixing O/F ligand, which is attained via the successful
fluorine incorporation into the LiVPO4O structure. A characterization of the investigated materials was performed using
microscale-covering XRD, XANES, and NMR techniques as well as nanoscale spatially resolved imaging and analytical STEM
techniques. The obtained oxy/fluoro-phosphate phase is isostructural to LiVPO4O; however, the presence of the mixed O/F
ligand promoted a higher symmetry of vanadium octahedra. These variations of the vanadium local environment along with the
observed inhomogeneous distribution of the incorporated fluorine gave rise to the minor local deviations in vanadium valence.
Our results clearly emphasize the connection among the fluorine ligand incorporation, its local distribution, and the
electrochemical properties of the material.
Keywords: LiVPO4O, XRD, SEM, V XANES, Tavorite-Type, electrochemical properties
Published in RUNG: 17.02.2020; Views: 4237; Downloads: 0
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4. WEAK CLOSURE OPERATIONS WITH SPECIAL TYPES IN LOWER BCK-SEMILATTICESHashem bordbar, Young Bae Jun, 2017, original scientific article Abstract: The notions of (strong) quasi prime mapping on the set of all ideals, t- type weak closure operation, and tender (resp., naive, sheer, feeble tender) weak closure operation are introduced, and their relations and properties are investigated. Conditions for a weak closure operation to be of t-type are provided. Given a weak closure operation, conditions for the new weak closure operation to be of t-type and to be a naive (sheer, feeble tender) weak closure operation are considered. We show that the new weak closure operation is the smallest tender weak closure operation containing the given weak closure operation.
Keywords: (strong) quasi prime mapping, t-type weak closure operation, naive (sheer, tender, feeble tender) weak closure operation.
Published in RUNG: 02.12.2019; Views: 4287; Downloads: 0
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5. Tender and naive weak closure operations on lower BCK-semilattices.Hashem bordbar, 2018, original scientific article Abstract: The notion of tender and naive weak closure operation is introduced, and their relations and properties are investigated. Using a weak closure operation "d" and an ideal A of a lower BCK-semilattice X with the greatest element 1, a new ideal K of X containing the ideal Acl of X is established. Using this ideal K, a new function clt : I(X) → I(X); A → K is given, and related properties are considered. We show that if "cl" is a tender (resp., naive) weak closure operation on I(X), then so are "clt" and clf.
Keywords: zeromeet element, meet ideal, relative annihilator, (finite type, tender, naive) weak closure operation.
Published in RUNG: 02.12.2019; Views: 4159; Downloads: 0
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6. Weak closure operations on ideals of BCK-algebrasHashem bordbar, 2017, original scientific article Abstract: Weak closure operation, which is more general form than closure operation, on ideals of BCK- algebras is introduced, and related properties are investigated. Regarding weak closure operation, finite type and (strong) quasi-primeness are considered. Also positive implicative (resp., commutative and implicative) weak closure operations are discussed.
Keywords: weak closure operation of finite type, (quasi-prime, positive implicative, commutative, implica- tive) weak closure operation.
Published in RUNG: 01.12.2019; Views: 4666; Downloads: 0
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7. SEMI-PRIME CLOSURE OPERATIONS ON BCK-ALGEBRAHashem bordbar, 2015, original scientific article Abstract: In this paper we study the (good) semi-prime closure oper- ations on ideals of a BCK-algebra, lower BCK-semilattice, Noetherian BCK-algebra and meet quotient ideal and then we give several theorems that make different (good) semi-prime closure operations. Moreover, by giving some examples, we show that the given different notions are independent together, for instance, there is a semi-prime closure operation, which is not a good semi-prime. Finally by given the notion of “cf-Max X”, we prove that every member of “cf-Max X” is a prime ideal. Also, we conclude some more related results.
Keywords: BCI-algebra, BCK-algebra, closure operation, finite type closure operation, semi-prime closure operation.
Published in RUNG: 01.12.2019; Views: 4020; Downloads: 0
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8. A Finite type Closure Operations on BCK-algebrasHashem bordbar, 2016, original scientific article Abstract: In this article we study the (finite-type, cl-closed) closure operations on ideals of a BCK-algebra, with an emphasis on structural properties. Also we give several theorems that make different closure operations, especially on a quotient and Noetherian BCK-algebra. In particular, we show that the intersection and union (by imposing some additional conditions) of closure operations is a closure operation and every closure operation is a finite type on any finitely generated ideal. Moreover by given the notions of residuated quotient ideals and the meet of two ideals, we conclude some related results.
Keywords: BCI-algebra, BCK-algebra, closure operation, finite type closure operation.
Published in RUNG: 01.12.2019; Views: 3988; Downloads: 0
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9. Magnesium Modifies the Structural Features of Enzymatically Mineralized Collagen Gels Affecting the Retraction Capabilities of Human Dermal Fibroblasts Embedded within This 3D SystemFederica Boraldi, Angelica Bartolomeo, Giulia Annovi, Romain Debret, Daniela Quaglino, 2016, original scientific article Keywords: collagen type I, alkaline phosphatase, fibroblast, three dimensional gel, morphology, mineralization
Published in RUNG: 23.08.2019; Views: 4115; Downloads: 0
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10. Aerosol monitoring over Vipava valley using Raman polarization lidarLonglong Wang, Samo Stanič, Klemen Bergant, William Eichinger, Asta Gregorič, Griša Močnik, Luka Drinovec, 2018, published scientific conference contribution abstract Abstract: Vipava valley in southwest Slovenia is a representative hot-spot for complex mixtures of different aerosol types of both anthropogenic and natural origin in mountainous terrain. An investigation of aerosol properties throughout the troposphere in different atmospheric conditions was made possible by a deployment of a two-wavelength polarization Raman lidar system combining with in-situ measurements in the valley (in the town of Ajdovščina) from September 2017. Using its aerosol identification capabilities, which are based on particle depolarization ratio and lidar ratio measurements, it was possible to identify predominant aerosol types in the observed atmospheric structures, for example in different atmospheric layers in the case of stratified atmosphere. Primary anthropogenic aerosols within the valley were found to be mainly emitted from two sources: individual domestic heating systems, which mostly use biomass fuel, and from traffic. A considerable fraction of natural aerosols (for example mineral dust and sea salt), transported over large distances, were observed both above and entering into the planetary boundary layer. According to the properties of different aerosol types, backscatter contribution of each aerosol type was evaluated and the corresponding extinction contribution was derived from lidar observations. Statistical analysis of the presence of different aerosol types was performed on the entire available dataset from 2017 and 2018.
Keywords: lidar, aerosol type, Vipava valley
Published in RUNG: 03.12.2018; Views: 5835; Downloads: 0
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