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Rekurzije i grafovi rekurzija
No full textIn the first part of the dissertation, we count tilings of narrow strips in the hexagonal grid with a given number and type of tiles and investigate identities involving the obtained enumerating sequences. On the same substrate, we also study the number of tilings in which both the number and the shape of tiles are free. In both cases, the enumerating sequences satisfy linear recurrences with constant coefficients. In contrast to the first part where linear recurrences are obtained as a solution to the problem, the central part of the work uses them as a starting point. Namely, it is dedicated to the family of graphs that generalize Fibonacci cubes and whose number of vertices satisfies the recursion . We determine basic enumerative and metric properties and show that the family retains many desirable properties of Fibonacci cubes. Canonical decomposition and distribution of degrees will be investigated, as well as the existence of Hamiltonian paths and cycles. In the last part, we explore the possibility of extending the family of graphs to the Horadam recursion .U prvom dijelu rada prebrojavamo popločenja uskih traka šesterokutne mreže s unaprijed poznatim brojem pločica određenog tipa i istražujemo mogućnost dobivanja identiteta o nizovima koje tako dobivamo. Preciznije, istražujemo na koliko se načina može popločati uska šesterokutna mreža koristeći samo monomere i dimere, a s unaprijed određenim brojem dimera. Nadalje, proučavamo sličan problem, ali umjesto horizontalnih dimera koristimo trimere, dobivene od tri uzastopna šesterokuta na mreži. Na istom supstratu promatramo i ukupni broj podjela promatrane šesterokutne mreže, tj. broj popločenja u kojima su i broj i oblik pločica proizvoljni. U ovom slučaju dobivamo jednostavan odgovor, broj načina na koji možemo podijeliti usku šesterokutnu mrežu odgovara Fibonaccijevim brojevima neparnog indexa. U svim slučajevima dobivaju se nizovi zadani linearnim rekurzijama. Središnji dio rada posvećen je familiji grafova koja poopćuje Fibonaccijeve kocke. Broj vrhova u grafovima takve familije također zadovoljava linearnu rekurziju, . Određujemo njihova osnovna enumerativna i metrička svojstava te pokazujemo da familija zadržava mnoga poželjna svojstva Fibonaccijevih kocaka. Određivanjem kanonske dekompozicije pokazujemo da se grafovi mogu dekomponirati u više grafova iste vrste, a manje dimenzije. Također, dekomponirajući ih u rešetke, pronalazimo još jednu vezu promatrane familije i Fibonaccijevih kocki. Određujemo i raspodjelu stupnjeva vrhova i dajemo nužne uvjete za postojanje Hamiltonovih putova i ciklusa. U posljednjem dijelu rada istražujemo mogućnost proširenja familije grafova na Horadamovu rekurziju , i pokazujemo da se mnoga svojstva Fibonaccijevih i metalnih kocaka nasljeđuju za grafove te familije
Finite-temperature effects in magnetic dipole transitions
No full textFinite-temperature effects in electromagnetic transitions in nuclei contribute to many aspects of nuclear structure and astrophysically relevant nuclear reactions. While electric dipole transitions have already been extensively studied, the temperature sensitivity of magnetic transitions remains largely unknown. This work comprises the study of isovector magnetic dipole excitations (1) occurring between spin-orbit (SO) partner states using the recently developed self-consistent finite-temperature relativistic quasiparticle random-phase approximation (FT-RQRPA) in the temperature range from = 0 to 2 MeV. The 1 strength distributions of 40−60Ca and 100−140Sn isotopic chains exhibit a considerable temperature dependence. The 1 strength peaks shift significantly towards the lower energies due to the decrease in SO splitting energies and weakening of the residual interaction, especially above the critical temperatures where the pairing correlations vanish. By exploring the relevant two-quasiparticle configurations contributing to the 1 strength of closed- and open-shell nuclei, new proton and neutron excitation channels between SO partners are observed in low- and high-energy regions due to the thermal unblocking effects around the Fermi level. At higher temperatures, we have noticed an interesting result in 40,60Ca nuclei, the appearance of 1 excitations, which are forbidden at zero temperature due to fully occupied (or fully vacant) spin-orbit partner states
Illuminating the Dark Side of Cosmic Star Formation. III. Building the Largest Homogeneous Sample of Radio-selected Dusty Star-forming Galaxies in COSMOS with PhoEBO
No full textIn the last decades, an increasing scientific interest has been growing in the elusive population of dark (i.e., lacking an optical/near-IR, hereafter NIR, counterpart) dusty star-forming galaxies (DSFGs). Although extremely promising for their likely contribution to the cosmic star formation rate density (SFRD) and for their possible role in the evolution of the first massive and passive galaxies around z ∼ 3, the difficulty in selecting statistically significant samples of dark DSFGs is limiting their scientific potentialities. This work presents the first panchromatic study of a sample of 263 radio-selected NIR-dark (RS-NIRdark) galaxies discovered in the COSMOS field following the procedure by Talia et al. These sources are selected as radio-bright galaxies (S 3 GHz > 12.65 μJy) with no counterpart in the NIR-selected COSMOS2020 catalog (Ks ≳ 25.5 mag). For these sources, we build a new photometric catalog including accurate photometry from the optical to the radio obtained with a new deblending pipeline (Photometry Extractor for Blended Objects, or PHOEBO). We employ this catalog to estimate the photo-zs and the physical properties of the galaxies through an spectral energy distribution-fitting procedure performed with two different codes (MAGPHYS and CIGALE). Finally, we estimate the active galactic nucleus contamination in our sample by performing a series of complementary tests. The high values of the median extinction (A v ∼ 4) and star formation rate (SFR ∼ 500 M ⊙ yr‑1) confirm the likely DSFG nature of the RS-NIRdark galaxies. The median photo-z (z ∼ 3) and the presence of a significant tail of high-z candidates (z > 4.5) suggest that these sources are important contributors to the cosmic SFRD and the evolutionary path of galaxies at high redshifts
Computing tools for effective field theories
No full textIn recent years, theoretical and phenomenological studies with effective field theories have become a trending and prolific line of research in the field of high-energy physics. In order to discuss present and future prospects concerning automated tools in this field, the SMEFT-Tools 2022 workshop was held at the University of Zurich from 14th–16th September 2022. The current document collects and summarizes the content of this workshop
Closing the door on the “puzzle of decoherence” of annihilation quanta
No full textIn positron annihilation, exploration of the polarization correlations of the emerging gamma quanta has gained interest, since they offer a possibility to improve signal-to-background in medical imaging using positron emission tomography. The annihilation quanta, which are predicted to be in an entangled state, have orthogonal polarizations and this property may be exploited to discriminate them from two uncorrelated gamma photons contributing to the background. Recent experimental studies of polarization correlations of the annihilation quanta after a prior Compton scattering of one of them, had rather different conclusions regarding the strength of the correlation after the scattering, showing its puzzling nature. The scattering was described as a decoherence process. In the present work, we perform for the first time, a study of the polarization correlations of annihilation quanta after decoherence via Compton scattering in the angular range 0° − 50° using single-layer gamma ray polarimeters. In addition, we compare the measured polarization correlations after Compton scattering at 30° with an active and a passive scatterer element. The measured azimuthal correlation of back-to-back annihilation quanta is consistent with the Pryce-Ward formulation, as confirmed by Monte Carlo simulations. Further, the results indicate that the correlation, expressed in terms of the polarimetric modulation factor, shows no significant difference at small scattering angles (0° − 30°) compared to the correlation measured for direct photons, while a moderate indication of a lower modulation is observed for 50° scattering angle. The measured modulation is larger at all scattering angles than the one expected from the simulation of orthogonally polarized, independent annihilation quanta
Photoproduction of +− Pairs in Ultraperipheral Collisions
No full text+− pairs may be produced in photonuclear collisions, either from the decays of photoproduced (1020) mesons or directly as nonresonant +− pairs. Measurements of +− photoproduction probe the couplings between the (1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere. We present the first measurement of coherent photoproduction of +− pairs on lead ions in ultraperipheral collisions using the ALICE detector, including the first investigation of direct +− production. There is significant +− production at low transverse momentum, consistent with coherent photoproduction on lead targets. In the mass range 1.1<<1.4 GeV/2 above the (1020) resonance, for rapidity ||<0.8 and ,<0.1 GeV/, the measured coherent photoproduction cross section is d/d=3.37±0.61(stat)±0.15(syst) mb. The center-of-mass energy per nucleon of the photon-nucleus (Pb) system Pb, ranges from 33 to 188 GeV, far higher than previous measurements on heavy-nucleus targets. The cross section is larger than expected for (1020) photoproduction alone. The mass spectrum is fit to a cocktail consisting of (1020) decays, direct +− photoproduction, and interference between the two. The confidence regions for the amplitude and relative phase angle for direct +− photoproduction are presented
Deindustrialization and revitalization of "brownfields" in Osijek
No full textTijekom prve polovice 20. stoljeća Osijek je bio industrijski grad u kojem je poslovao veliki broj industrijskih poduzeća s više tisuća zaposlenih. Razvoj industrije nastavio se do 1990-ih kada započinje intenzivna deindustrijalizacija. Danas propala industrijska područja ili „brownfieldi“ imaju veliki razvojni potencijal. Industrijski (kompleksi nalaze na najboljim lokacijama u gradu i postaju sve atraktivniji investitorima. Industrijsko graditeljsko nasljeđe iz razdoblja prve polovice 20. stoljeća, koje je trajno odredilo identitet i sliku Osijeka, lošim planiranjem sve više gubi na vrijednosti i značenju. Zato je bitno osmisliti načine kako revitalizirati i obnoviti „brownfielde“.
Cilj ovog rada je analizirati kako je deindustrijalizacija utjecala na prostor grada te fokus staviti na razvojne potencijalne grada Osijeka s naglaskom na prenamjenu napuštenih industrijskih područja. Budući da se dio tih napuštenih pogona nalazi u urbanom tkivu Osijeka, javlja se potreba za njihovom sanacijom i prenamjenom u kontekstu urbane regeneracije. U radu će se koristiti statistički podaci iz različitih izvora (npr. popisi stanovništva, statistički ljetopisi, podaci od Hrvatske gospodarske komore itd.), te odgovarajuća prostorno-planska dokumentacija. Za potrebe rada provest će se terensko istraživanje, a uz pomoć GIS alata vizualizirat će se rezultati istraživanja.In the first half of the 20th century, Osijek was an industrial city with a large number of industrial companies employing several thousand workers. The development of industry continued until the 1990s, when an intensive process of deindustrialization began. Today, abandoned industrial areas or "brownfields" hold great potential for development. These industrial complexes are located in the best areas of the city and are becoming increasingly attractive to investors. However, the industrial architectural heritage from the first half of the 20th century, which has permanently shaped the identity and image of Osijek, is losing its value and significance due to poor planning. It is therefore important to develop strategies for the revitalization and renewal of these "brownfields"
The aim of this paper is to analyze how deindustrialization has affected the urban space of the city, focusing on the development potential of Osijek, especially on the reuse of abandoned industrial areas. As some of these abandoned facilities are located in the urban area of Osijek, there is a growing need for their redevelopment and reuse in the context of urban regeneration. The work will use statistical data from various sources (e.g. censuses, statistical yearbooks, data from the Croatian Chamber of Commerce, etc.) as well as relevant spatial planning documents. For the purpose of this study, field research will be conducted and the results will be visualized using GIS tools
"Croatian Island Product" in fostering integral island development
No full textProgramom „Hrvatski otočni proizvod“ (HOP), koji između ostalog uključuje i označavanje otočnih proizvoda istoimenom oznakom kvalitete prepoznato je kako potencijal hrvatskog otočja kao jedinstvene otočne geografske cjeline nije samo u turizmu, već i u izvornosti, tradicionalnosti te društvenim, gospodarskim i proizvodnim aktivnostima. Navedenu oznaku dodjeljuje Ministarstvo regionalnoga razvoja i fondova Europske unije kako bi se potaknula proizvodnja i plasman, kao i promocija izvornih i kvalitetnih proizvoda s hrvatskih otoka te baštine i tradicije. Cilj je rada identificirati ulogu označavanja otočnih proizvoda oznakom HOP u poticanju integralnog razvoja hrvatskih otoka, s naglaskom na lokalnu, otočnu zajednicu. Prilikom istraživanja koristilo se nekoliko metoda uključujući analizu relevantne znanstvene i stručne literature, statističke i grafičke metode, kartografsku vizualizaciju uz pomoć GIS alata, anketno istraživanje provedeno na uzorku od 78 ispitanika – otočnih proizvođača, dobitnika oznake HOP u razdoblju 2007. – 2023., četiri polustrukturirana intervjua s predstavnicima Uprave za otoke Ministarstva regionalnoga razvoja i fondova Europske unije te SWOT analizu. Istraživanje je utvrdilo kako označavanje otočnih proizvoda oznakom HOP doprinosi svim razmatranim elementima lokalnog razvoja otoka, od kojih se posebno ističe očuvanje otočne tradicije, identiteta i baštine, a idući je element prema doprinosu označavanja otočnih proizvoda promocija otoka kao turističke destinacije. Najvažnije su značajke otočnih proizvoda s oznakom HOP kvaliteta i autohtonost – otočni identitet.The "Croatian Island Product" (HOP) Program, which includes the designation of island products with the same name quality label, recognizes that the potential of Croatian islands as a unique geographical entity is not solely in tourism but also in originality, tradition, and socio-economic and production activities. This label is awarded by the Ministry of Regional Development and EU Funds to promote the production, placement and promotion of authentic and high-quality products from Croatian islands, along with their heritage and tradition. The objective of this study is to identify the role of the HOP label in fostering the integral development of Croatian islands, with a focus on local, island communities. The research employed various methods, including an analysis of relevant scientific and professional literature, statistical and graphical methods, cartographic visualization using GIS tools, a survey conducted with a sample of 78 respondents - island producers who received the HOP label between 2007 and 2023, four semi-structured interviews with representatives from the Department for Islands of the Ministry of Regional Development and EU Funds, and a SWOT analysis. The study found that labeling island products with the HOP designation contributes to all aspects of local island development, with particular emphasis on preserving island tradition, identity, and heritage. The promotion of the islands as tourist destinations also emerged as a significant benefit of the HOP labeling. The most important features of HOP-labeled island products are their quality and authenticity - the island identity
The role of flavonoids in protecting the plant organism from environmental stress
No full textFlavonoidi su specijalizirani metaboliti prisutni u biljkama poznati po ulozi u obrambenim odgovorima na stres. Zbog sve češćih ekstremnih uvjeta u okolišu poput suša, poplava, visokih i niskih temperatura, povećane koncentracije teških metala u tlu i pojačanog intenziteta UV zračenja, biljkama su potrebni efikasni mehanizmi zaštite. Ovakvi abiotički faktori stresa često paralelno biljke čine podložnijima i biotičkim stresorima, tj. patogenima. Flavonoidi doprinose zaštiti biljnog organizma prvenstveno svojom antioksidacijskom aktivnosti koja omogućuje neutralizaciju reaktivnih kisikovih vrsta (ROS, reactive oxygen species), spojeva čija se koncentracija značajno povećava kao posljedica stresa. Flavonoidi su prisutni u različitim staničnim organelima, poput vakuole, jezgre i kloroplasta, gdje pomažu pri inhibiciji ROS-ova i stabilizaciji staničnih membrana. U ovome radu prikazana su odabrana istraživanja povezana s flavonoidima i njihovom ulogom u odgovoru na stres, pritom naglašavajući njihov značaj u stjecanju otpornosti biljaka uslijed promjenjivih okolišnih uvjeta.Flavonoids are specialized metabolites present in plants known for their role in defense responses to stress. Due to increasingly frequent extreme conditions in the environment such as drought, flood, high and low temperatures, increased concentration of heavy metals in the soil and increased intensity of UV radiation, plants need efficient protection mechanisms. Such abiotic stress factors often simultaneously make plants more susceptible to biotic stressors, i.e. pathogens. Flavonoids contribute to the protection of the plant organism primarily through their antioxidant activity, which enables the neutralization of reactive oxygen species (ROS), compounds whose concentration increases significantly as a result of stress. Flavonoids are present in various cell organelles, such as the vacuole, nucleus and chloroplast, where they help inhibit ROS and stabilize cell membranes. This paper presents selected researches related to flavonoids and their role in the response to stress, emphasizing their importance in the acquisition of plant resistance due to changing environmental conditio
Entanglement in multinucleon transfer reactions
No full textNuclear reactions present an interesting case for studies of the time evolution of entanglement between complex quantum systems. In this work, the time-dependent nuclear density-functional theory is employed to explore entanglement in multinucleon transfer reactions. As an illustrative example, for the reaction Ca40+Pb208 at Elab=249MeV, in the interval of impact parameters 4.65-7.40fm, and the relativistic density-functional PC-PK1, we compute the von Neumann entropies, entanglement between fragments, nucleon-number fluctuations, and Shannon entropy for the nucleon-number observable. A simple linear correlation is established between the entanglement and nucleon-number fluctuation of the final fragments. The entanglement between the fragments can be related to the corresponding excitation energies and angular momenta. The relationship between the von Neumann entropy and the Shannon entropy for the nucleon-number observable is analyzed, as well as the time evolution of the entanglement (nucleon-number fluctuation). The entanglement is also calculated for a range of incident energies and it is shown how, depending on the impact parameter, the entanglement increases with the collision energy