cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Design of double- and multi-bend achromat lattices with large dynamic aperture and approximate invariants
Creators: name: Li, Yongjun
name: Hwang, Kilean
name: Mitchell, Chad
name: Rainer, Robert
name: Ryne, Robert
name: Smaluk, Victor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: A numerical method to design nonlinear double- and multi-bend achromat (DBA and MBA) lattices with approximate invariants of motion is investigated. The search for such nonlinear lattices is motivated by Fermilab's Integrable Optics Test Accelerator (IOTA), whose design is based on an integrable Hamiltonian system with two invariants of motion. While it may not be possible to design an achromatic lattice for a dedicated synchrotron light source storage ring with one or more exact invariants of motion, it is possible to tune the sextupoles and octupoles in existing DBA and MBA lattices to produce approximate invariants. In our procedure, the lattice is tuned while minimizing the turn-by-turn fluctuations of the Courant-Snyder actions $J_x$ and $J_y$ at several distinct amplitudes, while simultaneously minimizing diffusion of the on-energy betatron tunes. The resulting lattices share some important features with integrable ones, such as a large dynamic aperture, trajectories confined to invariant tori, robustness to resonances and errors, and a large amplitude-dependent tune-spread. Compared to the nominal NSLS-II lattice, the single- and multi-bunch instability thresholds are increased and the bunch-by-bunch feedback gain can be reduced.
description: 10 pages, 20 figures, accepted by "Physical Review Accelerators and Beams"
Transcription of file 028_A (collection LA 256)
Creators: name: Parker, Verdena
name: Newbold, Lindsey
name: Spence, Justin
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio files VP-160512-04 and VP-160512-05: Transcription of file 028_A (referred to here as 029_A) from LA 256 (a collection of recordings given to the Berkeley Language Center by Verdena), from the beginning of the file to 2:47 (VP-160512-04) and from 2:47 to 3:46 (VP-160512-05). The file was assigned a provisional identifier 029_A that was changed to 028_A in the final cataloging for the collection; file 028_A was subsequently assigned the identifier LA256.028A and associated with the bundle LA256.028 in the California Language Archive.
Μελέτες αλληλεπίδρασης ενός συμπλόκου του αργύρου με ένζυμα του μεταβολισμού του DNA και βακτηριακό βιοφίλμ. Πιθανή αντιμικροβιακή και αντιοξειδωτική δράση πολυμερών εμπλουτισμένων με πρόπολη
Creators: name: Καραγκιαούρη, Μαρία Στυλιανού
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Σύμπλοκο αργύρου
Αλληλεπίδραση με DNA
Πολυμερή πρόπολης
Silver Complex
Interaction with DNA
Propolis polymers

description: Η παρούσα εργασία χωρίζεται σε δύο μέρη. Στο πρώτο μέρος πραγματοποιήθηκαν διάφορες βιοχημικές μελέτες πάνω σε ένα σύμπλοκο του αργύρου (Ι) με δύο μόρια μίας πυραζολίνης. Αρχικά αποδείχθηκε η σύνδεση του συμπλόκου πάνω στο δίκλωνο μόριο του DNA και εν συνεχεία ελέγχθηκε η επίδραση αυτής της σύνδεσης στη δράση ενζύμων του μεταβολισμού του DNA. Τα ένζυμα που μελετήθηκαν ήταν η ανθρώπινη τοποϊσομεράση ΙΙα, η DNάση Ι και η XhoI, που είναι ένζυμο περιορισμού. Στη συνέχεια μελετήθηκε η αντιμικροβιακή του δράση και η ικανότητα του να αναστέλλει την σύνθεση βιοφίλμ από Gram θετικά και αρνητικά βακτήρια. Ελέγχθηκε, επιπλέον, η πιθανή αντιοξειδωτική δράση του συμπλόκου αυτού. Για το δεύτερο μέρος της εργασίας χρησιμοποιήθηκε μια σειρά πολυμερών που ήταν εμπλουτισμένα με διαφορετικές συγκεντρώσεις πρόπολης ή πρόπολης και καρβακρόλης. Σε αυτά τα πολυμερή μελετήθηκε η αντιβακτηριακή τους δράση και πιθανώς η ικανότητα τους να αναστέλλουν την προσκόλληση των βακτηρίων πάνω στην επιφάνεια τους. Τέλος, εξετάστηκε η αντιοξειδωτική τους ικανότητα.
description: The experiments conducted during this thesis can be separated in two distinct parts. During the first part the item of focus was a silver (I) complex with two molecules of the same pyrazoline derivative as ligands. In the first step was proving that the complex could bind to the double helix DNA molecule. After that, the impact of the binding on the activity of the following enzymes was tested: topoisomerase IIa (human), DNase I and XhoI, which is a restriction enzyme. Antibacterial and anti-biofilm assays were also conducted using both gram positive and negative bacteria. Finally, its possible antioxidant ability was examined. For the second part, a series of polymer films was used. Each polymer film was enriched with different concentrations of propolis or propolis and carvacrol. The polymers were tested for their antibacterial, anti-adhesive and antioxidant abilities.
The link between gas and stars in the S254-S258 star-forming region
Creators: name: Ladeyschikov, D. A.
name: Kirsanova, M. S.
name: Sobolev, A. M.
name: Thomasson, M.
name: Ossenkopf-Okada, V.
name: Juvela, M.
name: Khaibrakhmanov, S. A.
name: Popova, E. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The paper aims to study relation between the distributions of the young stellar objects (YSOs) of different ages and the gas-dust constituents of the S254-S258 star-formation complex. This is necessary to study the time evolution of the YSO distribution with respect to the gas and dust compounds which are responsible for the birth of the young stars. For this purpose we use correlation analysis between different gas, dust and YSOs tracers. We compared the large-scale CO, HCO$^+$, near-IR extinction, and far-IR {\it Herschel} maps with the density of YSOs of the different evolutionary Classes. The direct correlation analysis between these maps was used together with the wavelet-based spatial correlation analysis. This analysis reveals a much tighter correlation of the gas-dust tracers with the distribution of Class I YSOs than with that of Class II YSOs. We argue that Class I YSOs which were initially born in the central bright cluster S255-IR (both N and S parts) during their evolution to Class II stage ($\sim$2 Myr) had enough time to travel through the whole S254-S258 star-formation region. Given that the region contains several isolated YSO clusters, the evolutionary link between these clusters and the bright central S255-IR (N and S) cluster can be considered. Despite the complexity of the YSO cluster formation in the non-uniform medium, the clusters of Class II YSOs in the S254-258 star-formation region can contain objects born in the different locations of the complex.
description: Accepted for publication in MNRAS
Ο Συμβολικός και Αισθητικός χαρακτήρας της Βυζαντινής Τέχνης κατά την παλαιοχριστιανική περίοδο
Creators: name: Καρύδα, Στυλιανή Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Σύμβολο
Αισθητική
Παλαιοχριστιανική Τέχνη
Symbol
Aesthetic
Εarly Christian Αrt

description: Στόχος της παρούσας εργασίας ήταν η συνολική μελέτη του συμβολισμού στην παλαιοχριστιανική τέχνη και η ανάδεικη της αξίας και της πνευματικής της ωφέλειας για κάθε άνθρωπο, ώστε να καλυφθεί το κενό που άφηνε η μελέτη μεμονωμένων συμβολισμών και θεμάτων αυτής της τέχνης. Αρχικά αναφερθήκαμε στην συμ¬βολή της τέχνης στον άνθρωπο και στην έννοια του συμβόλου. Ερευνήσαμε την έννοια και τις πηγές της βυζαντινής τέχνης, καθώς και τον ρόλο του συμβολισμού σ' αυτήν. Αναλύσαμε τα σύμβολα στην παλαιο-χριστιανική τέχνη και τα θέματα των συμβολικών παραστάσεων. Παρουσιάσαμε την αισθητική της βυζα-ντινής εικόνας με την ευρύτερη έννοια και την συμβολή της στην πίστη και στην λατρεία. Αναφερθήκαμε στα θέματα των παραστάσεων στη βυζαντινή τέχνη αυτής της περιόδου και ερευνήσαμε την τεχνοτροπία και τα υλικά της βυζαντινής τέχνης που υπηρετούν τον συμβολισμό και την αισθητική της λατρείας.
description: The aim of this study was the overall study of symbolism in early Christian art and the highlighting of its value and spiritual benefit for each person, filling the gap left by the study of individual symbolism and themes of this art. We first referred to the contribution of art to man and the concept of the symbol. We explored the meaning and sources of Byzantine art, as well as the role of symbolism in it. We analyzed the symbols in early Christian art and the themes of the symbolic representations. We presented the aesthetics of the Byzantine image in the broadest sense and its contribution to faith and worship. We referred to the themes of the visual re¬presentations in Byzantine art of this period and researched the style and materials of Byzantine art that serve the symbolism and aesthetics of worship.
On Gautschi's conjecture for generalized Gauss-Radau and Gauss-Lobatto formulae
Creators: name: Joulak, Hedi
name: Beckermann, Bernhard
Publisher: name: arXiv
Year: 2008
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65D30; 42C05

description: Recently, Gautschi introduced so-called generalized Gauss-Radau and Gauss-Lobatto formulae which are quadrature formulae of Gaussian type involving not only the values but also the derivatives of the function at the endpoints. In the present note we show the positivity of the corresponding weights; this positivity has been conjectured already by Gautschi. As a consequence, we establish several convergence theorems for these quadrature formulae.
description: Reference added and typos corrected
Υποβρύχια μουσεία
Creators: name: Κίτσιος, Φίλιππος Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Μουσείo
Υποβρύχιο περιβάλλον
Καταδύσεις
Museum
Underwater
SCUBA DIVING

description: Η διπλωματική αυτή εργασία ασχολείται με τα υποβρύχια μουσεία, τα οποία μπορεί να επισκεφθεί το κοινό με την τεχνική των αυτόνομων ψυχαγωγικών καταδύσεων. Το φαινόμενο αυτό αναδύθηκε στον 21ο αιώνα και μέσα σε λιγότερο από δύο δεκαετίες έχει εξαπλωθεί σε διάφορες περιοχές. Παράλληλα, εξελίσσονται ταχύτατα οι διαδικασίες ίδρυσης νέων υποβρύχιων μουσείων μέσα στα επόμενα χρόνια σε ακόμα περισσότερα σημεία του πλανήτη. Με αυτή τη μελέτη επιχειρούμε να κατανοήσουμε το πολιτισμικό πλαίσιο μέσα στο οποίο δημιουργήθηκε αυτό το σύγχρονο φαινόμενο και τους λόγους για τους οποίους έλαβε συγκεκριμένα χαρακτηριστικά. Αρχικά, εξετάζουμε πώς μεταβλήθηκε ιστορικά η κυρίαρχη αντίληψη για τον βυθό και τις καταδύσεις στα πλαίσια του δυτικού νεωτερικού πολιτισμού. Στη συνέχεια, μελετάμε τους υλικούς παράγοντες που διαδραματίζουν κεντρικό ρόλο στη διαδικασία κατάδυσης του ανθρώπινου σώματος στο υποβρύχιο περιβάλλον. Επιλέγουμε δέκα παραδείγματα υποβρύχιων μουσείων από διάφορα μέρη του πλανήτη και παρουσιάζουμε τα ειδικά χαρακτηριστικά τους. Στο τέλος, κοιτάζουμε τα συγκεκριμένα παραδείγματα μέσα από το πρίσμα του πολιτισμικού πλαισίου και της υποβρύχιας υλικής συνθήκης, προκειμένου να κατανοήσουμε σε βάθος το πολιτισμικο φαινόμενο των υποβρύχιων μουσείων.
description: This thesis focuses on the cultural phenomenon of underwater museums that are accessible through the technique of recreational SCUBA diving. This phenomenon emerged in the 21st century and within less than two decades has spread across the world. Currently, new submarine museums are due to open within the next years all over the world, expanding further the list of this kind of cultural expression. In this study we try to understand the cultural context in which this contemporary phenomenon was created and the reasons it adopted its particular characteristics. First, we examine how the dominant concept of “undersea” and “diving” has historically changed in Western societies. Then we study the physical aspects of diving and how underwater museums are affected by the physical factors that play a key role when the human body submerges into the water. After that, ten different examples of such museums from different parts of the world are presented and their special features are analyzed. In our conclusion, we look at those examples through the perspective of the cultural context and the underwater material reality, in order to reach a deeper understanding of the phenomenon of underwater museums.
description: Σε συνεργασία με: Παιδαγωγικό Δημοτικής Εκπαίδευσης (Πανεπιστήμιο Δυτικής Μακεδονίας)
Bright OB stars in the Galaxy - III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Halpha, IR and radio analysis
Creators: name: Puls, J.
name: Markova, N.
name: Scuderi, S.
name: Stanghellini, C.
name: Taranova, O. G.
name: Burnley, A. W.
name: Howarth, I. D.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent results strongly challenge the canonical picture of massive star winds: various evidence indicates that currently accepted mass-loss rates, Mdot, may need to be revised downwards significantly. This is because the most commonly used mass-loss diagnostics are affected by ``clumping'' (small-scale density inhomogeneities), influencing our interpretation of observed spectra and fluxes. Such downward revisions would have dramatic consequences for the evolution of, and feedback from, massive stars, and thus robust determinations of the clumping properties and mass-loss rates are urgently needed. Here, we present a first attempt to constrain the radial stratification of the so-called clumping factor. To this end, we have analyzed a sample of 19 Galactic O-type supergiants/giants, by combining data for Halpha, IR, mm and radio fluxes, and using appropriate analysis methods. Clumping has been included into our analysis in the ``conventional'' way, by assuming the inter-clump matter to be void. Because (almost) all our diagnostics depends on the square of density, we cannot derive absolute clumping factors, but only factors normalized to a certain minimum. This minimum was usually found to be located in the outermost, radio-emitting region, i.e., the radio mass-loss rates are the lowest ones, compared to Mdot derived from Halpha and the IR. The radio rates agree well with those predicted by theory, but are only upper limits, due to unknown clumping in the outer wind. Our most important result concerns a (physical) difference between denser and thinner winds: for denser winds, the innermost region is more strongly clumped than the outermost one (with a normalized clumping factor of 4.1+/-1.4), whereas thinner winds have similar clumping properties in the inner and outer regions.
description: 40 pages, 17 figures, accepted by A&A
Effect of an electric field on a floating lipid bilayer: a neutron reflectivity study
Creators: name: Lecuyer, Sigolène
name: Fragneto, Giovanna
name: Charitat, Thierry
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We present here a neutron reflectivity study of the influence of an alternative electric field on a supported phospholipid double bilayer. We report for the first time a reproducible increase of the fluctuation amplitude leading to the complete unbinding of the floating bilayer. Results are in good agreement with a semi-quantitative interpretation in terms of negative electrostatic surface tension.
description: 12 pages, 7 figures, 1 table accepted for publication in European Physical Journal E Replaced with with correct bibliography
Robust Identification of Topological Phase Transition by Self-Supervised Machine Learning Approach
Creators: name: Ho, Chi-Ting
name: Wang, Daw-Wei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We propose a systematic methodology to identify the topological phase transition through a self-supervised machine learning model, which is trained to correlate system parameters to the non-local observables in time-of-flight experiments of ultracold atoms. Different from the conventional supervised learning approach, where the predicted phase transition point is very sensitive to the training region and data labeling, our self-supervised learning approach identifies the phase transition point by the largest deviation of the predicted results from the known system parameters and by the highest confidence through a systematic shift of the training regions. We demonstrate the robust application of this approach results in various 1D and 2D exactly solvable models, using different input features (time-of-flight images, spatial correlation function or density-density correlation function). As a result, our self-supervised approach should be a very general and reliable method for many condensed matter or solid-state systems to observe new states of matters solely based on experimental measurements, even without a priori knowledge of the phase transition models.
description: 13 pages and 7 figures
A fractal analysis of premixed turbulent flames
Creators: name: Das, Aurobindo K.
Publisher: name: University of British Columbia
Year: 2008

description: In this experimental study, the fractal behavior of lean premixed wrinkled turbulent flames was investigated over a range of turbulence conditions. For this purpose a turbulent combustion rig was designed and built in which the turbulence intensity and scale could be independently varied by means of a set of grids. The relative turbulence intensity varied from 0.5 to 8.6 times the laminar flame speed. The turbulent Reynolds number range was 10 to 360. The premixed lean flame was stabilized by means of a small pilot burner. A cross section of the wrinkled flame was visualized by an Argon-ion laser sheet and the flame contour was recorded at high shutter speeds by a 35 mm camera. The images were digitized at a high resolution and analyzed to determine their fractal parameters. The experimental technique of this study represents considerable improvements over previous studies. It was observed that premixed wrinkled flames exhibit fractal behavior over a range of turbulence conditions. The measured values of fractal dimension were observed to increase with turbulence intensity and were within 5% of the values reported by others. The inner cutoff scale, representing the smallest scale of surface wrinkling, was determined to be approximately three and a half times the laminar flame thickness. However, for turbulence levels below three times the laminar flame speed, the inner cutoff was found to increase with decreasing turbulence. This provided experimental verification of an earlier hypothesis regarding the smoothing effect of flame propagation at the smaller scales of wrinkling. The turbulent flame speeds based on the fractal parameters measured in this study were compared to those measured directly from the flame cone-angle determined from long-exposure photographs. It was found that, generally, flame speeds estimated from fractal analysis were in poor agreement with the directly measured values, as well as those predicted from a correlation of previous experimental data. There was fair agreement at values of turbulence intensity less than the laminar flame speed, but at higher values of intensity the fractal-based predictions severly [sic] underestimate the flame speed. It appears that the flame surface may not be an isotropic fractal object as presumed in the application of fractal concepts to wrinkled flames. To estimate this anisotropy, fractal analysis of flame contours obtained from simultaneous images in orthogonal planes is, perhaps, necessary. The role of turbulent transport of heat and mass from the flame front is not taken into account in fractal analysis. At higher turbulence levels, the predominant effect on flame propagation may be this transport of heat and mass rather than the relatively small increase in flame area predicted from fractal analysis.
Bright Source of Cold Ions for Surface-Electrode Traps
Creators: name: Cetina, Marko
name: Grier, Andrew
name: Campbell, Jonathan
name: Chuang, Isaac
name: Vuletic, Vladan
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We produce large numbers of low-energy ions by photoionization of laser-cooled atoms inside a surface-electrode-based Paul trap. The isotope-selective trap loading rate of $4\times10^{5}$ Yb$^{+}$ ions/s exceeds that attained by photoionization (electron impact ionization) of an atomic beam by four (six) orders of magnitude. Traps as shallow as 0.13 eV are easily loaded with this technique. The ions are confined in the same spatial region as the laser-cooled atoms, which will allow the experimental investigation of interactions between cold ions and cold atoms or Bose-Einstein condensates.
description: Paper submitted to PRL for review on 2/1/06
Competing magnetic fluctuations in Sr3Ru2O7 probed by Ti doping
Creators: name: Hooper, J.
name: Fang, M. H.
name: Zhou, M.
name: Fobes, D.
name: Dang, N.
name: Mao, Z. Q.
name: Feng, C. M.
name: Xu, Z. A.
name: Yu, M. H.
name: OConnor, C. J.
name: Xu, G. J.
name: Andersen, N.
name: Salamon, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report the effect of nonmagnetic Ti4+ impurities on the electronic and magnetic properties of Sr3Ru2O7. Small amounts of Ti suppress the characteristic peak in magnetic susceptibility near 16 K and result in a sharp upturn in specific heat. The metamagnetic quantum phase transition and related anomalous features are quickly smeared out by small amounts of Ti. These results provide strong evidence for the existence of competing magnetic fluctuations in the ground state of Sr3Ru2O7. Ti doping suppresses the low temperature antiferromagnetic interactions that arise from Fermi surface nesting, leaving the system in a state dominated by ferromagnetic fluctuations.
description: 5 pages, 4 figures, 1 table
Strong Reduction of Quasiparticle Fluctuations in a Superconductor due to Decoupling of the Quasiparticle Number and Lifetime
Creators: name: de Rooij, Steven A. H.
name: Baselmans, Jochem J. A.
name: Murugesan, Vignesh
name: Thoen, David J.
name: de Visser, Pieter J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We measure temperature dependent quasiparticle fluctuations in a small Al volume, embedded in a NbTiN superconducting microwave resonator. The resonator design allows for read-out close to equilibrium. By placing the Al film on a membrane, we enhance the fluctuation level and separate quasiparticle from phonon effects. When lowering the temperature, the recombination time saturates and the fluctuation level reduces a factor $\sim$100. From this we deduce that the number of free quasiparticles is still thermal. Therefore, the theoretical, inverse relation between quasiparticle number and recombination time is invalid in this experiment. This is consistent with quasiparticle trapping, where on-trap recombination limits the observed quasiparticle lifetime.
description: Main text: 5 pages, 3 figures; Supplemental material: 11 pages, 8 figures
A holomorphic representation of the multidimensional Jacobi algebra
Creators: name: Berceanu, Stefan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 81R30; 32WXX; 12E10; 33C47; 32Q15; 81V80

description: We present a holomorphic representation of the Jacobi algebra $\mathfrak{h}_n\rtimes \mathfrak{sp}(n,\R)$ by first order differential operators with polynomial coefficients on the manifold $\mathbb{C}^n\times \mathcal{D}_n$. We construct the Hilbert space of holomorphic functions on which these differential operators act.
description: 26 pages, To appear in the Proceedings of the Third Operator Algebras and Mathematical Physics Conference, Bucharest, Romania, August 10 -- 17, 2005, corrected typos
Elastic turbulence in von Karman swirling flow between two disks
Creators: name: Burghelea, Teodor
name: Segre, Enrico
name: Steinberg, Victor
Publisher: name: arXiv
Year: 2006
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We discuss the role of elastic stress in the statistical properties of elastic turbulence, realized by the flow of a polymer solution between two disks. The dynamics of the elastic stress are analogous to those of a small scale fast dynamo in magnetohydrodynamics, and to those of the turbulent advection of a passive scalar in the Batchelor regime. Both systems are theoretically studied in literature, and this analogy is exploited to explain the statistical properties, the flow structure, and the scaling observed experimentally. Several features of elastic turbulence are confirmed experimentally and presented in this paper: (i) saturation of the rms of the vorticity and of velocity gradients in the bulk, leading to the saturation of the elastic stress; (ii) large rms of the velocity gradients in the boundary layer, linearly growth with Wi; (iii) skewed PDFs of the injected power, with exponential tails, which indicate intermittency; PDF of the acceleration exhibit well-pronounced exponential tails too; (iv) a new length scale, i.e the thickness of the boundary layer, as measured from the profile of the rms of the velocity gradient, is found to be relevant and much smaller than the vessel size; (v) the scaling of the structure functions of the vorticity, velocity gradients, and injected power is found to be the same as that of a passive scalar advected by an elastic turbulent velocity field.
description: submitted to Physics of Fluids; 31 pages, 29 figures (resolution reduced to screen quality)
First observation of quantum interference in the process phi -> KS KL ->pi+pi-pi+pi-: a test of quantum mechanics and CPT symmetry
Creators: name: KLOE Collaboration
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present the first observation of quantum interference in the process phi -> KS KL ->pi+pi-pi+pi-. This analysis is based on data collected with the KLOE detector at the e^+e^- collider DAFNE in 2001--2002 for an integrated luminosity of about 380pb^-1. Fits to the distribution of Delta t, the difference between the two kaon decay times, allow tests of the validity of quantum mechanics and CPT symmetry. No deviations from the expectations of quantum mechanics and CPT symmetry have been observed. New or improved limits on various decoherence and CPT violation parameters have been obtained
description: submitted to Physics Letter B one number changed old:gamma=(1.1+2.9-2.4)10^-21 GeV new:(1.3+2.8-2.4)10^-21GeV corrected typos
Οι κρατικές ενισχύσεις υπό το πρίσμα του φορολογικού δικαίου: Η περίπτωση των tax rulings
Creators: name: Κυριαζοπούλου, Νικολέτα Κωνσταντίνου
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Κρατικές ενισχύσεις
Φορολογική απόφαση
Αρχή τήρησης των ίσων αποστάσεων
Tax rulings
State aid
Arm’s length principle

description: Σκοπός της διατριβής ήταν η μελέτη των κρατικών ενισχύσεων υπό το πρίσμα του φορολογικού δικαίου και ειδικότερα η μελέτη των φορολογικών αποφάσεων τύπου tax rulings. Αρχικά, εξετάσθηκε η φορολογική αυτονομία των κρατών μελών σε αντιδιαστολή με την αρμοδιότητα της Ένωσης για την εφαρμογή των κανόνων ανταγωνισμού. Στη συνέχεια εξετάσθηκε η έννοια των tax rulings, ως προς τη φύση τους, τη μορφή τους, τη σκοπιμότητα τους και την πρακτική τους εφαρμογή καθώς και η ρύθμισή τους στο ελληνικό δίκαιο και ακολούθησε η εξέταση της έννοιας της κρατικής ενίσχυσης του άρθρου 107 (1) της Συνθήκης για τη Λειτουργία της Ευρωπαϊκής Ένωσης. Κατόπιν της ανάλυσης των δύο εννοιών, γίνεται μία ολοκληρωμένη επισκόπηση της αρχής της τήρησης των ίσων αποστάσεων, αρχή η οποία χρησιμοποιείται ως μέσο για την αξιολόγηση της ύπαρξης επιλεκτικού πλεονεκτήματος, και κατ’ επέκταση για την ύπαρξη κρατικής ενίσχυσης. Τέλος, αναλύονται οι πιο σημαντικές πρόσφατες αποφάσεις της Ευρωπαϊκής Επιτροπής, αλλά και του Γενικού Δικαστηρίου, όπου υπάρχουν, σχετικά με την χορήγηση κρατικής ενίσχυσης μέσω tax rulings. Στο τελευταίο κεφάλαιο εξετάζεται η διαδικασία ανάκτησης των παράνομων κρατικών ενισχύσεων και η διακριτή αλλά συμπληρωματική σχέση της Επιτροπής και των κρατών-μελών στα πλαίσια αυτά.
description: The aim of the present thesis was the study of the fiscal state aid, and more particularly the tax rulings. At the outset, the fiscal autonomy of the Member States in comparison with the EU competence for the implementation of competition rules was examined. Subsequently, an analysis of the tax rulings, regarding their nature, form, purpose and to which extent they are regulated in the Greek law, was conducted. Following this analysis, the concept of state aid, as envisaged in article 107(1) TFEU, was thoroughly examined. Upon the analysis of these concepts, the author considered necessary to provide a comprehensive overview of the arm’s length principle, the latter being a tool for the assessment of the existence of a selective advantage and, by implication, state aid. In the last chapter, the recovery procedure of the illegal state and the separate but complementing relationship of the European Commission and the Member States is examined.
Theory of decoherence in Bose-Einstein condensate interferometry
Creators: name: Dalton, B J
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A full treatment of decoherence and dephasing effects in BEC interferometry has been developed based on using quantum correlation functions for treating interferometric effects. The BEC is described via a phase space distribution functional of the Wigner type for the condensate modes and the positive P type for the non-condensate modes. Ito equations for stochastic condensate and non-condensate field functions replace the functional Fokker-Planck equation for the distribution functional and stochastic averages of field function products determine the quantum correlation functions.
description: Proceedings DICE 06 Conference, 11-15 Sept 2006, Piombino, Italy
Trust Me If You Can: Trusted Transformation Between (JSON) Schemas to Support Global Authentication of Education Credentials
Creators: name: More, Stefan
name: Grassberger, Peter
name: Hörandner, Felix
name: Abraham, Andreas
name: Klausner, Lukas Daniel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: Recruiters and institutions around the world struggle with the verification of diplomas issued in a diverse and global education setting. Firstly, it is a nontrivial problem to identify bogus institutions selling education credentials. While institutions are often accredited by qualified authorities on a regional level, there is no global authority fulfilling this task. Secondly, many different data schemas are used to encode education credentials, which represents a considerable challenge to automated processing. Consequently, significant manual effort is required to verify credentials. In this paper, we tackle these challenges by introducing a decentralized and open system to automatically verify the legitimacy of issuers and interpret credentials in unknown schemas. We do so by enabling participants to publish transformation information, which enables verifiers to transform credentials into their preferred schema. Due to the lack of a global root of trust, we utilize a distributed ledger to build a decentralized web of trust, which verifiers can query to gather information on the trustworthiness of issuing institutions and to establish trust in transformation information. Going beyond diploma fraud, our system can be generalized to tackle the generalized problem for other domains lacking a root of trust and agreements on data schemas.
description: 16 pages, 4 figures
Νευρομυϊκά χαρακτηριστικά του πρόσθιου κνημιαίου κατά την υπομέγιστη ισομετρική ραχιαία κάμψη και προσαγωγή
Creators: name: Χλιαρά, Παναγιώτα Ιωάννη
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Μεταβλητότητα δύναμης
Διλειτουργικότητα
Μυϊκές συνέργειες
Force variability
Bifunctionality
Co-contractions

description: Σκοπός της παρούσας έρευνας ήταν να εξεταστούν τα νευρομυϊκά χαρακτηριστικά του πρόσθιου κνημιαίου κατά την εκτέλεση υπομέγιστης ισομετρικής ραχιαίας κάμψης και προσαγωγής στο 5, 10, 20, 40 και 60% της Μέγιστης Εκούσιας Συστολής (ΜΕΣ). Στην έρευνα έλαβαν μέρος εικοσιπέντε υγιείς νέοι, ηλικίας 20.5 ± 1.8 ετών. Εξετάστηκαν, η σταθερότητα του μυός και στις δύο λειτουργίες του (ραχιαία κάμψη και προαγωγή) με την αξιολόγηση του συντελεστή διακύμανσης, καθώς και η σχετικοποιημένη ΗΜΓ του δραστηριότητα. Τα αποτελέσματα έδειξαν ότι ενώ η μέγιστη ραχιαία κάμψη (185.7 ± 43.9 Ν) ήταν σημαντικά (p < 0.05) μικρότερη από τη μέγιστη προσαγωγή (406.8 ± 171.9 Ν), η σταθερότητά της ήταν σημαντικά (p < 0.05) μεγαλύτερη από αυτήν της προσαγωγής σε όλα τα ποσοστά δύναμης, εκτός από το 5% της ΜΕΣ. Η ΗΜΓ δραστηριότητα του πρόσθιου κνημιαίου ήταν παρόμοια μεταξύ των δύο λειτουργιών και αυξανόταν όσο αυξανόταν το ποσοστό δύναμης. Το ίδιο παρατηρήθηκε και για την ΗΜΓ δραστηριότητα του υποκνημιδίου. Η ραχιαία κάμψη είναι πιο σταθερή από ότι η προσαγωγή της ποδοκνημικής, και αυτό μπορεί να οφείλεται είτε στα διαφορετικά χαρακτηριστικά εκπόλωσης των κινητικών μονάδων του πρόσθιου κνημιαίου, είτε στην αδυναμία καλής συνέργειας με τον υποκνημίδιο που ενεργεί ως συναγωνιστής κατά την προσαγωγή
description: The purpose of the present study was to examine the neuromuscular characteristics of Tibialis Anterior (TA) during submaximal isometric dorsiflexion and adduction at 5, 10, 20, 40 and 60% of the Maximum Voluntary Contraction (MVC). Twenty-five young healthy males, aged 20.5 ± 1.8 years, participated in this study. Force fluctuations during dorsiflexion and adduction of the ankle were evaluated by calculating the coefficient of variation as well as the integrated EMG activity. While the maximum dorsiflexion (185.7 ± 43.9 N) was significantly (p < 0.05) lower than the maximum adduction of the ankle (406.8 ± 171.9 N), its steadiness was significantly (p < 0.05) greater than that of the adduction in all force levels except at 5% MVC. The EMG activity of the TA was similar between the two functions and increased as the level of force increased. The same was observed for EMG activity of the soleus (SOL). Dorsiflexion isometric force fluctuates less than adduction of the ankle and this could be related to different discharge rate and coding of the TA motor units or to less efficient synergy between TA and SOL which act as an agonist during the adduction of the ankle
Transcription of the second Pear Film narration
Creators: name: Parker, Verdena
name: Escamilla, Ramón
name: Newbold, Lindsey
name: Spence, Justin
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2022
Subjects: subject: hup

description: Audio file VP-160512-02: Transcription of the second narration of the Pear Film produced immediately after watching it (file VP-240208-04), from 2:12 the end of file.
On dark stars, Planck cores and the nature of dark matter
Creators: name: Nikitin, Igor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Dark stars are compact massive objects, described by Einstein gravitational field equations with matter. The type we consider possesses no event horizon, instead, there is a deep gravitational well with a very strong redshift factor. Observationally, dark stars can be identified with black holes. Inside dark stars, Planck density of matter is reached, Planck cores are formed, where the equations are modified by quantum gravity. In the paper, several models of dark stars with Planck cores are considered, resulting in the following hypothesis on the composition of dark matter. The galaxies are flooded with low-energetic radiation from the dark stars. The particle type can be photons and gravitons from the Standard Model, can also be a new type of massless particles. The model estimations show that the extremely large redshift factor $z\sim10^{49}$ and the emission wavelength $λ_0\sim10^{14}$m can be reached. The particles are not registered directly in the existing dark matter experiments. They come in a density sufficient to explain the observable rotation curves. The emission has a geometric dependence of density on radius $ρ\sim r^{-2}$, producing flat rotation curves. The distribution of sources also describes the deviations from the flat shape. The model provides a good fit of experimental rotation curves. Outbreaks caused by a fall of an external object on a dark star lead to emission wavelength shifted towards smaller values. The model estimations give the outbreak wavelength $λ\sim1$m compatible with fast radio bursts. The paper raises several principal questions. White holes with Planck core appear to be stable. Galactic rotation curves in the considered setup do not depend on the matter type. Inside the galaxy, dark matter can be of hot radial type. At cosmological distances, it can behave like the cold uniform type.
A Survey of Orthogonal Moments for Image Representation: Theory, Implementation, and Evaluation
Creators: name: Qi, Shuren
name: Zhang, Yushu
name: Wang, Chao
name: Zhou, Jiantao
name: Cao, Xiaochun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Image representation is an important topic in computer vision and pattern recognition. It plays a fundamental role in a range of applications towards understanding visual contents. Moment-based image representation has been reported to be effective in satisfying the core conditions of semantic description due to its beneficial mathematical properties, especially geometric invariance and independence. This paper presents a comprehensive survey of the orthogonal moments for image representation, covering recent advances in fast/accurate calculation, robustness/invariance optimization, definition extension, and application. We also create a software package for a variety of widely-used orthogonal moments and evaluate such methods in a same base. The presented theory analysis, software implementation, and evaluation results can support the community, particularly in developing novel techniques and promoting real-world applications.
description: ACM Computing Surveys, Volume 55, Issue 1, January 2023, Article No 1, pp 1-35, https://doi.org/10.1145/3479428
Drag reduction of cube-van through boundary-layer control: wind tunnel experiments and prototype road tests
Creators: name: St Hill, Simon
Publisher: name: University of British Columbia
Year: 2008

description: Due to increasing fuel cost and emphasis on energy conservation as well as pollution control, there has been considerable interest in improving propulsive efficiency of road vehicles. Reduction in aerodynamic resistance is one aspect of it. Although aerodynamically contoured automobiles has become a standard design practice. Trucks have changed little over the past three decades. The thesis presents results of an organized and extensive wind tunnel test-program, complemented by full-scale road tests, aimed at assessing the effectiveness of two boundary-layer control procedures for reduction of the pressure drag of a cube-van. Wind tunnel results, obtained using 1/6th scale models, at a subcritical Reynolds number of 105, suggest that both the Moving Surface Boundary-layer Control (MSBC) as well as the tripping of the boundary-layer using fences reduce the pressure drag coefficient. Although both the concepts are promising, application of the entirely passive fence procedure appears more attractive from an economic consideration as well as the ease of implementation. The road tests with a full-size cube-van substantiated the trends indicated by the fence data although the actual drag reduction observed was lower (yet quite significant, = 16.6%) than that predicted by the wind tunnel tests. This may be attributed to a wide variety of factors including the differences in the geometry (models; fences and their orientation),operating conditions (Reynolds number; yaw; wind variations in magnitude and direction; turbulence; road boundary-layer; road surface condition), and measurement errors. However, the objective of the study was to assess potential of the concepts which, indeed, is quite promising. Fuel consumption results also substantiated the drag reduction trend. As expected they depend on the gearing condition and hence no general expression applicable to all speed ranges is available. As anticipated the data show a rapid increase in the fuel consumption efficiency at the top end of the speed range. It is concluded that fences can lead to a significant improvement in drag reduction and fuel consumption when applied to flat-faced trucks if positioned correctly. They represent a more elegant, versatile, and cheaper alternative to the 'nose cones' and deflectors available in the market. It is recommended that further road tests should be conducted using both boundary-layer control devices.
Volume independence in large Nc QCD-like gauge theories
Creators: name: Kovtun, Pavel
name: Unsal, Mithat
name: Yaffe, Laurence G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Volume independence in large $\Nc$ gauge theories may be viewed as a generalized orbifold equivalence. The reduction to zero volume (or Eguchi-Kawai reduction) is a special case of this equivalence. So is temperature independence in confining phases. In pure Yang-Mills theory, the failure of volume independence for sufficiently small volumes (at weak coupling) due to spontaneous breaking of center symmetry, together with its validity above a critical size, nicely illustrate the symmetry realization conditions which are both necessary and sufficient for large $\Nc$ orbifold equivalence. The existence of a minimal size below which volume independence fails also applies to Yang-Mills theory with antisymmetric representation fermions [QCD(AS)]. However, in Yang-Mills theory with adjoint representation fermions [QCD(Adj)], endowed with periodic boundary conditions, volume independence remains valid down to arbitrarily small size. In sufficiently large volumes, QCD(Adj) and QCD(AS) have a large $\Nc$ ``orientifold'' equivalence, provided charge conjugation symmetry is unbroken in the latter theory. Therefore, via a combined orbifold-orientifold mapping, a well-defined large $\Nc$ equivalence exists between QCD(AS) in large, or infinite, volume and QCD(Adj) in arbitrarily small volume. Since asymptotically free gauge theories, such as QCD(Adj), are much easier to study (analytically or numerically) in small volume, this equivalence should allow greater understanding of large $\Nc$ QCD in infinite volume.
description: 32 pages, 4 figures
Χαρακτηριστικά επίδοσης στο γραπτό αφηγηματικό λόγο παιδιών Ε’ και ΣΤ’ δημοτικού σε επικινδυνότητα για Μαθησιακές Δυσκολίες
Creators: name: Λιάση, Παναγιώτα Πέτρου
Publisher: name: Aristotle University of Thessaloniki
Year: 2020
Subjects: Μαθησιακές Δυσκολίες
Αφηγηματικός λόγος
Γραπτός λόγος
Learning Disabilities
Narrative discourse
Written discourse

description: Αντικείμενο της παρούσας έρευνας αποτέλεσε η μελέτη των γλωσσικών χαρακτηριστικών και της επίδοσης στο γραπτό αφηγηματικό λόγο παιδιών με τυπική ανάπτυξη και παιδιών με προφίλ ενδεικτικό των Μαθησιακών Δυσκολιών των τάξεων της Ε’ και της Στ’ Δημοτικού. Το δείγμα της έρευνας αποτέλεσαν 51 μαθητές και μαθήτριες των δύο τελευταίων τάξεων του δημοτικού, οι οποίοι επιλέχθηκαν τυχαία από δημοτικά σχολεία του κέντρου της Θεσσαλονίκης. Συγκεκριμένα, το δείγμα αποτελείται από 28 παιδιά, τα οποία ανήκουν στην ομάδα των παιδιών με ενδείξεις εμφάνισης Μαθησιακών Δυσκολιών και 23 παιδιά, τα οποία ανήκουν στην ομάδα των παιδιών με τυπική ανάπτυξη. Για την επιλογή του δείγματος εφαρμόστηκε το σταθμισμένο στον ελληνικό πληθυσμό ψυχομετρικό κριτήριο μαθησιακής επάρκειας Detroit Test of Aptitude – 4 (DTLA- 4). Επίσης, για την αξιολόγηση γλωσσικής επάρκειας εφαρμόστηκε το ψυχομετρικό κριτήριο γλωσσικής επάρκειας Λ-α-Τ-ω ΙΙ, ενώ για την αξιολόγηση του γραπτού αφηγηματικού λόγου δόθηκε στα παιδιά μια ημιτελής ιστορία.
description: The aim of this research was the study of language characteristics and performance in written narrative discourse of children with typical development and children with profile indicative of Learning Disabilities of the 5th and 6th grades. The sample of the research consisted of 51 students of the last two grades of primary school, who were randomly selected from primary schools in the center of Thessaloniki. Specifically, the sample consists of 28 children, who belong to the group of children with signs of Learning Disabilities, and 23 children, who belong to the group of children with typical development. For the selection of the sample, the Detroit Test of Aptitude-4 (DTLA-4), a psychometric criterion weighted in the Greek population, was applied. Also, for the evaluation of linguistic competence, the psychometric criterion of linguistic competence of L-a-T-o II (Λ-α-Τ-ω ΙΙ) was applied, while for the evaluation of the written narrative discourse, the children were given an incomplete story.
4D singular oscillator and generalized MIC-Kepler system
Creators: name: Mardoyan, L. G.
name: Petrosyan, M. G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It is shown that the generalized MIC-Kepler system and four-dimensional singular oscillator are dual to each other and the duality transformation is the generalized version of the Kustaanheimo-Stiefel transformation.
description: 6 pages
Triaxial vs. Spherical Dark Matter Halo Profiles
Creators: name: Knebe, Alexander
name: Wiessner, Volkmar
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: When analysing dark matter halos forming in cosmological N-body simulations it is common practice to obtain the density profile utilizing spherical shells. However, it is also known that the systems under investigation are far from spherical symmetry and rather follow a triaxial mass distribution. In this study we present an estimator for the error introduced by spherically averaging an elliptical mass distribution. We systematically investigate the differences arising when using a triaxial density profile under the assumption of spherical symmetry. We show that the variance in the density can be as large as 50% in the outer parts of dark matter halos for extreme (but still credible) axis ratios of 0.55:0.67:1. The inner parts are less affected but still show a scatter at the 16% level for these prolate systems. For more moderate ellipticities, i.e. axis ratios of 0.73:0.87:1, the error is smaller but still as large as 10-20% depending on distance. We further provide a simple formula that allows to estimate this variance as a function of radius for arbitrary axis ratios. We conclude that highly prolate and/or oblate systems are better fit by analytical profiles that take into account the triaxial nature of cosmological objects.
description: 4 pages. 3 figures, accepted for publication in PASA