cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A simple model for quasar density evolution
Creators: name: Horst, Hannes
name: Duschl, Wolfgang J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: It is widely agreed upon that AGN and Quasars are driven by gas accretion onto a supermassive black hole. The origin of the latter however still remains an open question. In this work we present the results of an extremely simple cosmological model combined with an evolutionary scenario in which both the formation of the black hole as well as the gas accretion onto it are triggered by major mergers of gas-rich galaxies. Despite its very generous approximations our model reproduces the quasar density evolution in remarkable agreement with observations.
description: 3 pages, 2 figures, to appear in the proceedings of "Relativistic Astrophysics and Cosmology - Einstein's Legacy" (Eds.: B. Aschenbach, V. Burwitz, G. Hasinger, and B. Leibundgut), 7 - 11 November 2005, Munich, Bavaria, Germany
Nonlinear dynamic intertwining of rods with self-contact
Creators: name: Goyal, Sachin
name: Perkins, N. C.
name: Lee, Christopher L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Twisted marine cables on the sea floor can form highly contorted three-dimensional loops that resemble tangles. Such tangles or hockles are topologically equivalent to the plectomenes that form in supercoiled DNA molecules. The dynamic evolution of these intertwined loops is studied herein using a computational rod model that explicitly accounts for dynamic self-contact. Numerical solutions are presented for an illustrative example of a long rod subjected to increasing twist at one end. The solutions reveal the dynamic evolution of the rod from an initially straight state, through a buckled state in the approximate form of a helix, through the dynamic collapse of this helix into a near-planar loop with one site of self-contact, and the subsequent intertwining of this loop with multiple sites of self-contact. This evolution is controlled by the dynamic conversion of torsional strain energy to bending strain energy or, alternatively by the dynamic conversion of twist (Tw) to writhe (Wr). KEY WORDS Rod Dynamics, Self-contact, Intertwining, DNA Supercoiling, Cable Hockling
description: 35 pages, 9 figures, submitted to Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
The relative orientation between the magnetic field and gas density structures in non-gravitating turbulent media
Creators: name: Körtgen, Bastian
name: Soler, Juan D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Magnetic fields are a dynamically important agent for regulating structure formation in the interstellar medium. The study of the relative orientation between the local magnetic field and gas (column-) density gradient has become a powerful tool to analyse the magnetic field's impact on the dense gas formation in the Galaxy. In this study, we perform numerical simulations of a non-gravitating, isothermal gas, where the turbulence is driven either solenoidally or compressively. We find that only simulations with an initially strong magnetic field (plasma-$β<1$) show a change in the preferential orientation between the magnetic field and isodensity contours, from mostly parallel at low densities to mostly perpendicular at higher densities. Hence, compressive turbulence alone is not capable of inducing the transition observed towards nearby molecular clouds. At the same high initial magnetisation, we find that solenoidal modes produce a sharper transition in the relative orientation with increasing density than compressive modes. We further study the time evolution of the relative orientation and find that it remains unchanged by the turbulent forcing after one dynamical timescale.
description: accepted for publication by MNRAS
Determination of the influence of interdendritic segregation during the solidification of freckle-prone alloys
Creators: name: Auburtin, Philippe Bernard Lucien
Publisher: name: University of British Columbia
Year: 2009

description: Freckles are presently one of the major defects encountered in advanced casting technology. The current state-of-the-art knowledge about freckles is discussed in an extensive critical literature review, including the main physical characteristics of freckles, the current theory of density inversion leading to channel segregation and the various experiments and mathematical models developed so far. This review emphasizes the fact that no quantitative research on freckles has been carried out on actual industrial alloys yet. The goal of this thesis is to start this quantitative research by measuring interdendritic segregation profiles and evaluating the extent of density inversion in the mushy zone and its possible effects on freckle formation. Chemical compositions and segregation were measured by electron microprobe on directionally solidified and quenched samples of the following alloys : IN718, MAR-M002, MAR-M247, C-276 and T l . Freckled samples were also chemically analyzed. Densities, function of temperature and composition, were estimated by a numerical model. It was found that freckles initiated from density inversion of the order of 0.01 (g/cm3)/°C under typical superalloy casting conditions. In superalloys, it was estimated that freckles tend to initiate relatively close to the top of the mushy zone (20°C below the liquidus temperature) where fraction liquid is still high (about 40-60%). In high carbon alloys, especially tool steels, precipitation of heavy alloying elements into carbides may act as a trigger for freckling. Finally, the potential importance in the analysis of freckles of the segregation of minor alloying light elements such as carbon, silicon, zirconium, manganese, phosphorus, etc. was outlined.
Developments in Lorentz and CPT Violation
Creators: name: Kostelecky, Alan
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: This talk at the CPT'19 meeting outlines a few recent developments in Lorentz and CPT violation, with particular attention to results obtained by researchers at the Indiana University Center for Spacetime Symmetries.
description: 4 pages, presented at the Eighth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, May 12-16, 2019
ТИЛ ВА МАДАНИЯТ ЎРТАСИДАГИ МУНОСАБАТЛАР
Creators: name: Ахмедова Муяссар Хадиматовна, Тошкент давлат педагогика университети Умумий психология кафедраси доценти, психол.ф.д.
name: Ахмедова Малика Қудратовна, Педагог -дефектолог, модератор, Шимкент шаҳар давлат коммунал муассасаси, "Сайрам ёрдамчи мактаб-интернат-колледж" таълим бошқармаси, Қозоғистон Республикаси
Publisher: name: Zenodo
Year: 2024

description: Сўнги йилларда жаҳон тилшунослигида лингвокултурологик масалаларга бағишланган кўплаб тадқиқотлар юзага кела бошлади. Чунки маълумотларнинг асосий қисми инсонга лингвистик йўналиш орқали етиб келади. Мақолада лингвокултурология соҳасининг пайдо бўлиши ҳамда ривожланиши илмий манбалар асосида ифодаланган. Унда тил структурасини тўлиқ тасвирлаш «тилнинг табиати»ни очиб беришда лингвокултурология муҳим аҳамиятга эга эканлиги баён этилган

Калит сўзлар: тилшунослик, лингвокултурология, тафаккур, характер, маданият, категория, консепция.
Το ίδιο θέλουμε να πούμε αν και διαφορετικά μιλούμε.» Εφαρμογή πολυγλωσσικού υλικού στο πολυπολιτισμικό νηπιαγωγείο
Creators: name: Γιαννοπούλου, Ευαγγελία Στυλιανού
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Γλωσσική συνειδητότητα
πολυγλωσσικό υλικό
ανάδειξη μητρικής γλώσσας όλων των μαθητών
Language awareness
multilingual activities
raising all students’ first language

description: Στόχος της παρούσας εργασίας είναι η εφαρμογή πολυγλωσσικού υλικού στο πολυπολιτισμικό νηπιαγωγείο. Σύμφωνα με τα θεωρητικά ζητήματα που σχετίζονται με το θέμα είναι αναγκαία η αποδοχή και έκφραση του γλωσσικού κεφαλαίου όλων των παιδιών . Επιπλέον το μοντέλο της γλωσσικής συνειδητότητας που δεν θέτει ως στόχο την εκμάθηση των ξένων γλωσσών αλλά μέσω της ακρόασης τη γνωριμία με διαφορετικές γλώσσες συμβάλλει στην αποδοχή του διαφορετικού και δημιουργεί τη διαπολιτισμική οπτική των παιδιών . Η μικρής εμβέλειας έρευνα δράσης παρουσιάζει το πολύγλωσσο υλικό που χρησιμοποιήθηκε σε ένα ελληνικό νηπιαγωγείο αλλά και τις αντιδράσεις των παιδιών στις δραστηριότητες. Η ανατροφοδότηση μεγάλωσε και έκανε πιο ενδιαφέρον το βασικό υλικό της ερευνήτριας και η χρήση νέων τεχνολογιών και του υπολογιστή έγινε ένα χρήσιμο εργαλείο εξερευνώντας τον κόσμο των γλωσσών. Πριν και μετά την έρευνα δράση έγιναν συνεντεύξεις στα παιδιά . Παρόλο που τα αγγλικά φαίνεται να είναι η πιο δημοφιλής ξένη γλώσσα , τα παιδιά απόλαυσαν την ακρόαση γνωστών παραμυθιών σε διαφορετικές γλώσσες, τα δίγλωσσα βιβλία αλλά και γνωστά τραγούδια σε διαφορετικές γλώσσες οπότε προσπαθούσαν να βρουν αυθόρμητα ομοιότητες και διαφορές. Εν κατακλείδι το σχολείο θα μπορούσε να συνεισφέρει διευρύνοντας τις οπτικές των παιδιών και να τα προετοιμάσει ώστε να γίνουν «πολίτες του κόσμου».
description: The aim of the present thesis is the use of multilingual material in the multicultural kindergarten. According to theoretical issues that are related to the subject the main target is to highlight all students’ linguistic capital in school .Furthermore, the model of language awareness could create children’s intercultural perspective through listening different languages .This small-scale action research project presents multilingual material that is used in a Greek kindergarten and the reactions of children . The feedback is making the material bigger and more interesting than the basic and technology –a personal computer- is being a useful tool exploring languages. There are data from children’s interviews before and after the use of multilingual material Αlthough English seems to be the most popular foreign language in our kindergarten, children loved listening fairytales, bilingual books and songs in many different languages and tried to find similarities and differences.Ιn conclusion school should contribute broadening children’s perspectives and prepare them to become «citizens of the world».
Satellite-based photonic quantum networks are small-world
Creators: name: Brito, Samuraí
name: Canabarro, Askery
name: Cavalcanti, Daniel
name: Chaves, Rafael
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Recent milestone experiments establishing satellite-to-ground quantum communication are paving the way for the development of the quantum internet, a network interconnected by quantum channels. Here we employ network theory to study the properties of the photonic networks that can be generated by satellite-based quantum communication and compare it with the optical-fiber counterpart. We predict that satellites can generate small-world networks, implying that physically distant nodes are actually near from a network perspective. We also analyse the connectivity properties of the network and show, in particular, that they are robust against random failures. This puts satellite-based quantum communication as the most promising technology to distribute entanglement across large distances in quantum networks of growing size and complexity.
description: 11 pages, 8 figures
BCS-BEC crossover in a relativistic boson-fermion model beyond mean field approximation
Creators: name: Deng, Jian
name: Wang, Jin-cheng
name: Wang, Qun
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the fluctuation effect of the di-fermion field in the crossover from Bardeen-Cooper-Schrieffer (BCS) pairing to a Bose-Einstein condensate (BEC) in a relativistic superfluid. We work within the boson-fermion model obeying a global U(1) symmetry. To go beyond the mean field approximation we use Cornwall-Jackiw-Tomboulis (CJT) formalism to include higher order contributions. The quantum fluctuations of the pairing condensate is provided by bosons in non-zero modes, whose interaction with fermions gives the two-particle-irreducible (2PI) effective potential. It changes the crossover property in the BEC regime. With the fluctuations the superfluid phase transition becomes the first order in grand canonical ensemble. We calculate the condensate, the critical temperature $T_{c}$ and particle abundances as functions of crossover parameter the boson mass.
description: The model Lagrangian is re-formulated by decomposing the complex scalar field into its real and imaginary parts. The anomalous propagators of the complex scalar are then included at tree level. All numerical results are updated. ReVTex 4, 13 pages, 10 figures, PRD accepted version
Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. IV. The alpha-Element-Enhanced Metal-Poor Star BS16934-002
Creators: name: Aoki, Wako
name: Honda, Satoshi
name: Beers, Timothy C.
name: Takada-Hidai, Masahide
name: Iwamoto, Nobuyuki
name: Tominaga, Nozomu
name: Umeda, Hideyuki
name: Nomoto, Ken'ichi
name: Norris, John E.
name: Ryan, Sean G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A detailed elemental abundance analysis has been carried out for the very metal-poor ([Fe/H]=-2.7) star BS16934-002, which was identified in our previous work as a star exhibiting large overabundances of Mg and Sc. A comparison of the abundance pattern of this star with that of the well-studied metal-poor star HD122563 indicates excesses of O, Na, Mg, Al, and Sc in BS16934-002. Of particular interest, no excess of C or N is found in this object, in contrast to CS22949-037 and CS29498-043, two previously known carbon-rich, extremely metal-poor stars with excesses of the alpha elements. No established nucleosynthesis model exists that explains the observed abundance pattern of BS16934-002. A supernova model, including mixing and fallback, assuming severe mass loss before explosion, is discussed as a candidate progenitor of BS16934-002.
description: 34 pages, 4 tables, 7 figures, Astrophysical Jounal, in press
Recycling steel slag as a cement additive
Creators: name: Murphy, Jeffrey N.
Publisher: name: University of British Columbia
Year: 2009

description: In Canada, approximately 1 million tonnes of steel slag are produced annually, but, at the present time, there is no economic outlet for the large scale recycling of this by-product. The overall objective of this work was to determine whether steel slag might be processed into a sufficiently cementitious material to allow it to be recycled as an additive to ordinary Portland cement clinker. Blending steel slag with with clinker in a modest ratio of 1:10, it would be possible to effectively recycle all of this steelmaking by-product. Although steel slag has a composition which is similar to that of Portland cement, (consisting mainly of lime, silica, and iron oxide), there are important compositional, mineralogical, and process related differences. Steel slag has limited cementitious properties due to both a lack of tricalcium silicate and the presence of wustite solid solutions as a predominant mineral phase. Even though wustite (FeO) possesses no inherent cementitious properties, it has been shown that hematite (Fe2C<3) will form hydraulic minerals when cooled from a slag melt. Thus, the valence state of the iron oxide in slag and cement systems will directly influence the cementitious properties of the material. This work explores the effects of Fe oxidation state, overall composition, and cooling rate on the mineral structure, crystalline formation, and glass forming ability of several synthetic slags and one commercial BOF slag. XRD, SEM, and EDX analyses were performed on both slow cooled and quenched slags, which had been oxidized. These analyses, of both synthetic and commercial slag, suggest that the trivalent iron (Fe2C«3) promoted both cementitious mineral formation in the slow cooled slags and glass formation in the quenched slags. The rate of cooling directly influenced the crystalline formation and mineral structure in the solidified product. The slow cooled slags tended to form highly crystalline polycomponent mineral systems, whereas the rapidly cooled granulated slags formed a predominantly amorphous material containing the primary Portland cement minerals.This granulated slag product was blended with Portland cement in varying ratios and hydrated to form cylindrical compression specimens. The preliminary compression results indicate that, for a hydration period of 1 to 35 days, blends with a 10% slag addition had increased strength relative to that of Portland cement. Blends with 20% slag maintained the same strength as Portland cement, while those with a 45% slag addition exhibited a significant loss in strength, for the hydration period tested. Therefore, the optimization of certain slag processing conditions enhanced the cementitious nature of the material allowing it to be blended with Portland cement, (at additions of up to 20% by weight), without affecting the strength performance of the material.
Crystals of Na+ ions at the surface of a silica hydrosol
Creators: name: Tikhonov, Aleksey M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: I used x-ray grazing incidence diffraction to measure the spatial correlations between sodium ions adsorbed with Bjerrum's density at the surface of a monodispersed 22-nm-particle colloidal silica solution stabilized by NaOH with a total bulk concentration mol/L. My findings show that the surface compact layer is in a two-dimensional crystalline state (symmetry p2), with four ions forming the unit cell and a ~30 Angstrom translational correlation length between sodium ions.
description: 13 pages, 4 figures
The Massive Binary System 9 Sgr Revisited: New Insights into Disentangling Methods
Creators: name: Quintero, Edwin A.
name: Eenens, Philippe
name: Rauw, Gregor
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Disentangling techniques are often needed to obtain the spectra of the individual components of binary or multiple systems. A thorough analysis of the shift-and-add algorithm of Marchenko, Moffat, & Eenens (1998) reveals that in many cases the line fluxes are poorly reproduced and spurious wings appear. The causes of these discrepancies are discussed and a new disentangling package, QER20, is presented which significantly reduces these errors and vastly increases the performance. When applied to the massive binary 9 Sgr, our new code yields line fluxes which are notably different from those previously published and lead us to revise the spectral classification to slightly earlier subtypes: O3V((f +)) for the primary and O5V((f)) for the secondary. We show that with the MME98 algorithm the classification of massive stars in binaries can be off by several subtypes whilst there are no such errors when the QER20 package is used.
description: Accepted for publication in Astronomical Notes, 12 pages, 10 figures
Giant planet migration during the disc dispersal phase
Creators: name: Monsch, Kristina
name: Picogna, Giovanni
name: Ercolano, Barbara
name: Kley, Wilhelm
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Transition discs are expected to be a natural outcome of the interplay between photoevaporation (PE) and giant planet formation. Massive planets reduce the inflow of material from the outer to the inner disc, therefore triggering an earlier onset of disc dispersal due to PE through a process known as Planet-Induced PhotoEvaporation (PIPE). In this case, a cavity is formed as material inside the planetary orbit is removed by PE, leaving only the outer disc to drive the migration of the giant planet. We investigate the impact of PE on giant planet migration and focus specifically on the case of transition discs with an evacuated cavity inside the planet location. This is important for determining under what circumstances PE is efficient at halting the migration of giant planets, thus affecting the final orbital distribution of a population of planets. For this purpose, we use 2D FARGO simulations to model the migration of giant planets in a range of primordial and transition discs subject to PE. The results are then compared to the standard prescriptions used to calculate the migration tracks of planets in 1D planet population synthesis models. The FARGO simulations show that once the disc inside the planet location is depleted of gas, planet migration ceases. This contradicts the results obtained by the impulse approximation, which predicts the accelerated inward migration of planets in discs that have been cleared inside the planetary orbit. These results suggest that the impulse approximation may not be suitable for planets embedded in transition discs. A better approximation that could be used in 1D models would involve halting planet migration once the material inside the planetary orbit is depleted of gas and the surface density at the 3:2 mean motion resonance location in the outer disc reaches a threshold value of $0.01\,\mathrm{g\,cm^{-2}}$.
description: 16 pages, 11 figures; accepted for publication in A&A
Συγκριτική μελέτη των εκλογικών συστημάτων της Νοτιοανατολικής Ασίας: οι περιπτώσεις της Ταϋλάνδης, της Μαλαισίας και των Φιλιππίνων
Creators: name: Lasote, Phanuwat Manit
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Εκλογικό σύστημα Ταϋλάνδης
Εκλογικό σύστημα Μαλαισίας
Εκλογικό σύστημα Φιλιππίνων
Electoral system of Thailand
Electoral system of Malaysia
Electoral system of the Philippines

description: Στην παρούσα διατριβή έχουμε σκοπό να εξετάσουμε τα εκλογικά συστήματα τριών χωρών της Νοτιανατολικής Ασίας και συγκεκριμένα της Μαλαισίας, της Ταϊλάνδης και των Φιλιππινών. Με βάση τις κυριότερες θεωρίες που έχουν αναπτυχθεί γύρω από τον σχεδιασμό των εκλογικών συστημάτων, αναλύουμε τα εκλογικά συστήματα των χωρών που προαναφέραμε και προσπαθούμε να αναδείξουμε και να εξηγήσουμε τα προβλήματα που ανακύπτουν μέσα από τη λειτουργία τους. Τέλος, βασισμένοι στην ανάλυση που πραγματοποιήσαμε προτείνουμε διάφορες λύσεις απέναντι στις στρεβλώσεις του σχεδιασμού τους. Πηγή της έρευνας μας αποτελεί η θεωρία των εκλογικών συστημάτων, τα κριτήρια του IDEA σχετικά με τον σχεδιασμό τους καθώς επίσης και το Σύνταγμα και οι εκλογικοί νόμοι των τριών ασιατικών χωρών. Αυτό που θέλουμε να πετύχουμε είναι αφού προσεγγίσουμε συγκριτικά το ζήτημα και προσπαθήσουμε να βρούμε τις συνέπειες του σχεδιασμού των εκλογικών συστημάτων, να προτείνουμε νέες ιδέες και λύσεις στα προβλήματα που ανακύπτουν.
description: This dissertation aims to examine the electoral systems of three countries in Southeast Asian namely Malaysia, Thailand and the Philippines. Based on the main theories related to the design of electoral systems, we analyze the electoral systems of the three countries and try to focus on the problems that arise through the function of their electoral systems as well as political culture. Finally, based on the analysis we did recommend various solutions against the distortion of their design. Source of our research is the theory of electoral systems, the criteria of the IDEA on their design as well as the Constitution and electoral laws of the three Asian countries. What we want to achieve is as comparative approach the issue and try to find the effects of the design of electoral systems, to propose new ideas and solutions to political problems and conflicts.
The mixed functors of the category Fquad: a first study
Creators: name: Vespa, Christine
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Topology (math.AT)
subject: Category Theory (math.CT)
subject: FOS: Mathematics
subject: 18A25; 16D90; 20C20

description: In previous work, we defined the category of functors Fquad, associated to vector spaces over the field with two elements equipped with a nondegenerate quadratic form. In this paper, we define a special family of objects in the category Fquad, named the mixed functors. We give the complete decompositions of two elements of this family that give rise to two new infinite families of simple objects in the category Fquad.
description: 24 pages
Έλεγχος ακρίβειας σαρωτή Laser και εγχειρίδιο χρήσης Faro Laser Scanner Focus 3D
Creators: name: Αγγελέτος, Ηλίας Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Σαρωτής
Έλεγχος ακρίβειας
Εγχειρίδιο χρήσης
Scanner
Accuracy assessment
Operation manual

description: Η παρούσα διπλωματική με τίτλο «Έλεγχος Ακρίβειας Σαρωτή Laser και Εγχειρίδιο Χρήσης Faro Laser Scanner Focus 3D» εκπονήθηκε στα πλαίσια του μεταπτυχιακού προγράμματος σπουδών «Γεωπληροφορική» του τμήματος Αγρονόμων και Τοπογράφων Μηχανικών του Α.Π.Θ. στην κατεύθυνση «Τοπογραφικές Εφαρμογές Υψηλής Ακριβείας». Σκοπός της διπλωματικής αυτής ήταν ο έλεγχος των αποτελεσμάτων του Faro Laser Scanner Focus 3D, συγκρίνοντάς τα με τα αντίστοιχα ενός γεωδαιτικού σταθμού υψηλής ακριβείας και του φωτογραμμετρικού λογισμικού Photomodeler Scanner, καθώς και η εξέταση ορισμένων παραμέτρων σάρωσής του. Επίσης, δημιουργήθηκε και το εγχειρίδιο χρήσης του οργάνου στα ελληνικά, βάση του manual που έφερε ο εξοπλισμός του οργάνου.
description: The present thesis, entitled “Accuracy assessment of laser scanner and operation manual of Faro Laser Scanner Focus 3D”, was prepared during the Master Program in Geoinformatics, specialized in “Topographical Applications of High Precision”, of the Rural and Surveying Engineering Department of the Aristotle University of Thessaloniki. The aim of this thesis is the inspection of the data that were acquired with the use of the Faro Laser Scanner Focus 3D in comparison with the corresponding data that were acquired with the use of a Geodetic Station of High Precision and the Photogrammetric software Photomodeler Scanner, moreover an examination of certain scanning parameters of the scanning process was made. In addition, the manual of the examined instrument was translated in Greek language, which was based on the manual that was given with the instrument’s equipment.
Matrix Theory for the DLCQ of Type IIB String Theory on the AdS/Plane-wave
Creators: name: Torabian, Mahdi
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose a recipe to construct the DLCQ Hamiltonian of type IIB string theory on the AdS (and/or plane-wave) background. We consider a system of J number of coincident unstable non-BPS D0-branes of IIB theory in the light-cone gauge and on the plane-wave background with a compact null direction, the dynamics of which is described by the world-line U(J) gauge theory. This configuration suffers from tachyonic instabilities. Having instabilities been cured through the process of open string tachyon condensation, by expanding the theory about true minima of the effective potential and furthermore taking low energy limit to decouple the heavy modes, we end up with a 0+1-dimensional supersymmetric U(J) gauge theory, a Matrix Theory. We conjecture that the Hamiltonian of this Matrix Theory is just the DLCQ Hamiltonian of type IIB string theory on the AdS or equivalently plane-wave background in a sector with J units of light-cone momentum. We present some pieces of evidence in support of the proposal.
description: LaTeX, 35 pages, 2 eps figures; v2: minor changes, references added; v3: minor changes
Majorana corner states in square and Kagome quantum spin liquids
Creators: name: Wang, Haoran
name: Principi, Alessandro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Quantum spin liquids hosting Majorana excitations have recently experienced renewed interest for potential applications to topological quantum computation. Performing logical operations with reduced poisoning requires to localize such quasiparticles at specific point of the system, with energies that are well defined and inside the bulk energy gap. These are two defining features of second order topological insulators (SOTIs). Here, we show two spin models that support quantum spin liquid phases characterised by Majorana excitations and that behave as SOTIs, one of which is analytically solvable thanks to a theorem by Lieb. We show that, depending on the values of spin couplings, it is possible to localize either fermions or Majorana particles at their corners.
description: 4+epsilon pages, 3 figures, 1 appendix (supplemental material - included in the main arXiv text)
Spectral conditions on Lie and Jordan algebras of compact operators
Creators: name: Kennedy, Matthew
name: Radjavi, Heydar
Publisher: name: arXiv
Year: 2008
Subjects: subject: Operator Algebras (math.OA)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47A10, 47A15 (Primary); 47L70 (Secondary)

description: We investigate the properties of bounded operators which satisfy a certain spectral additivity condition, and use our results to study Lie and Jordan algebras of compact operators. We prove that these algebras have nontrivial invariant subspaces when their elements have sublinear or submultiplicative spectrum, and when they satisfy simple trace conditions. In certain cases we show that these conditions imply that the algebra is (simultaneously) triangularizable.
description: 14 pages
Wigner's friend, Feynman's paths and material records
Creators: name: Matzkin, A.
name: Sokolovski, D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The place and role of an Observer in quantum mechanics has been a subject of an ongoing debate since the theory's inception. Wigner brought this question to the fore in a celebrated scenario in which a super-Observer observes a Friend making a measurement. Here we briefly review why this \e{Wigner Friend scenario} has been taken to require the introduction of the Observer's consciousness, or alternatively to show the inconsistency of quantum measurement theory. We will argue that quantum theory can consistently leave observers outside its narrative, by making only minimal assumptions about how the information about the observed results is stored in material records.
description: 7 pages, 2 figures
$B\to K^*\ell^+\ell^-$ Forward-backward Asymmetry and New Physics
Creators: name: Hovhannisyan, Artyom
name: Hou, Wei-Shu
name: Mahajan, Namit
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The forward-backward asymmetry ${\cal A}_{\rm FB}$ in $B\to K^*\ell^+\ell^-$ decay is a sensitive probe of New Physics. Previous studies have focused on the sensitivity in the position of the zero. However, the short distance effective couplings are in principle complex, as illustrated by $B\to ρ\ell^+\ell^-$ decay within the Standard Model. Allowing the effective couplings to be complex, but keeping the $B\to K^*γ$ and $K^*\ell^+\ell^-$ rate constraints, we find the landscape for ${\cal A}_{\rm FB}(B\to K^*\ell^+\ell^-)$ to be far richer than from entertaining just sign flips, which can be explored by future high statistics experiments.
description: RevTex 4 pages including 5 eps figures; Minor changes made, references added
Dynamic Community Detection into Analyzing of Wildfires Events
Creators: name: Marli, Alessandra
name: Vega-Oliveros, Didier A
name: Cotacallapa, Moshé
name: Ferreira, Leonardo N
name: Macau, Elbert EN
name: Quiles, Marcos G
Publisher: name: arXiv
Year: 2020
Subjects: subject: Social and Information Networks (cs.SI)
subject: Machine Learning (cs.LG)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: The study and comprehension of complex systems are crucial intellectual and scientific challenges of the 21st century. In this scenario, network science has emerged as a mathematical tool to support the study of such systems. Examples include environmental processes such as wildfires, which are known for their considerable impact on human life. However, there is a considerable lack of studies of wildfire from a network science perspective. Here, employing the chronological network concept -- a temporal network where nodes are linked if two consecutive events occur between them -- we investigate the information that dynamic community structures reveal about the wildfires' dynamics. Particularly, we explore a two-phase dynamic community detection approach, i.e., we applied the Louvain algorithm on a series of snapshots. Then we used the Jaccard similarity coefficient to match communities across adjacent snapshots. Experiments with the MODIS dataset of fire events in the Amazon basing were conducted. Our results show that the dynamic communities can reveal wildfire patterns observed throughout the year.
description: 16 pages, 8 figures
Diffusive wave dynamics beyond the continuum limit
Creators: name: Dieterle, Paul
name: Amir, Ariel
Publisher: name: arXiv
Year: 2021
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Scientists have observed and studied diffusive waves in contexts as disparate as population genetics and cell signaling. Often, these waves are propagated by discrete entities or agents, such as individual cells in the case of cell signaling. For a broad class of diffusive waves, we characterize the transition between the collective propagation of diffusive waves -- in which the wave speed is well-described by continuum theory -- and the propagation of diffusive waves by individual agents. We show that this transition depends heavily on the dimensionality of the system in which the wave propagates and that disordered systems yield dynamics largely consistent with lattice systems. In some system dimensionalities, the intuition that closely packed sources more accurately mimic a continuum can be grossly violated.
description: 15 pages, 3 figures
Global Well-posedness for the focusing cubic NLS on the product space $\mathbb{R} \times \mathbb{T}^3$
Creators: name: Yu, Xueying
name: Yue, Haitian
name: Zhao, Zehua
Publisher: name: arXiv
Year: 2020
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we prove the global well-posedness for the focusing, cubic nonlinear Schrödinger equation on the product space $\mathbb{R} \times \mathbb{T}^3$ with initial data below the threshold that arises from the the ground state in the Euclidean setting. The defocusing analogue was discussed and proved in Ionescu-Pausader \cite{IPRT3} (Comm. Math. Phys. 312 (2012), no. 3, 781-831).
description: 27 pages. Comments are welcome!
The Cosmogony of Super-Massive Black Holes
Creators: name: Duschl, Wolfgang J.
name: Strittmatter, Peter A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report results of a project investigating the growth of super-massive black holes (BHs) by disk accretion. We find that the BH mass growth is quick enough to account for the inferred masses in the highest-redshift quasars, and the growth time is an inverse function of the final BH mass as seems to be required by recent X-ray surveys.
description: 5 pages, 2 figures, to appear in the proceedings of "Relativistic Astrophysics and Cosmology - Einstein's Legacy" (Eds.: B. Aschenbach, V. Burwitz, G. Hasinger, and B. Leibundgut), 7 - 11 November 2005, Munich, Bavaria, Germany
The dependence of the galaxy stellar-to-halo mass relation on galaxy morphology
Creators: name: Correa, Camila A.
name: Schaye, Joop
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the dependence of the local galaxy stellar-to-halo mass relation (SHMR) on galaxy morphology. We use data from the Sloan Digital Sky Survey DR7 with morphological classifications from Galaxy Zoo, and compare with the EAGLE cosmological simulation. At fixed halo mass in the mass range $10^{11.7}-10^{12.9}M_{\odot}$, the median stellar masses of SDSS disc galaxies are up to a factor of 1.4 higher than the median masses of their elliptical counterparts. However, when we switch from the stellar masses from Kauffmann et al. to those calculated by Chang et al. or Brinchmann et al., the median SHMR from discs and ellipticals coincide in this mass range. For halo masses larger than $10^{13}M_{\odot}$, discs are less massive than ellipticals in same-mass haloes, regardless of whose stellar mass estimates we use. However, we find that for these high halo masses the results for discs may be affected by central/satellite misclassifications. The EAGLE simulation predicts that discs are up to a factor of 1.5 more massive than elliptical galaxies residing in same-mass haloes less massive than $10^{13}M_{\odot}$, in agreement with the Kauffmann et al. data. Haloes with masses between $10^{11.5}$ and $10^{12}M_{\odot}$, that host disc galaxies, were assembled earlier than those hosting ellipticals. This suggests that the discs are more massive because they had more time for gas accretion and star formation. In $10^{12}-10^{12.5}M_{\odot}$ haloes, the central black holes in elliptical galaxies grew faster and became more massive than their counterparts in disc galaxies. This suggests that in this halo mass range the ellipticals are less massive because AGN feedback ejected more of the halo's gas reservoir, reducing star formation, and suppressing the (re)growth of stellar discs.
description: Accepted for publication in MNRAS, 18 pages, 16 figures. Comments welcome!
Το Ανώτατο Ειδικό Δικαστήριο ως αυθεντικός ερμηνευτής του νόμου και του Συντάγματος
Creators: name: Παπαδοπούλου, Ευθυμία Σοφοκλή
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Ανώτατο Ειδικό Δικαστήριο
Στατιστική επεξεργασία
Αποτελεσματικότητα
Special Supreme Court
Statistical elaboration
Effectiveness

description: Η παρούσα διπλωματική εργασία έχει ως κεντρική υπόθεση εργασίας της την αποτίμηση της αποτελεσματικότητας του Α.Ε.Δ. και συγκεκριμένα το ζήτημα εάν το δικαστήριο αυτό ανταπεξήλθε ικανοποιητικά στη συνταγματικώς κατοχυρωμένη αποστολή του αναφορικά με την άρση της αμφισβήτησης ως προς την ουσιαστική αντισυνταγματικότητα και την έννοια διάταξης τυπικού νόμου. Η απάντηση στον ως άνω προβληματισμό θα δοθεί μέσα από επεξεργασία των αποφάσεών του από την ίδρυση του μέχρι και σήμερα (1976 – 2015) υπό το πρίσμα της στατιστικής. Το βασικό συμπέρασμα που προκύπτει από την ανωτέρω επεξεργασία είναι ότι το Ειδικό αυτό Δικαστήριο έχει εξελιχθεί σε ένα θεσμό οριακής χρησιμότητας, καθώς οι αποφάσεις που έχει εκδώσει ως προς το ζήτημα της άρσης αμφισβήτησης για την ουσιαστική αντισυνταγματικότητα διάταξης τυπικού νόμου δεν ξεπερνούν, από το έτος της έναρξης της λειτουργίας του έως και σήμερα, κατά μέσο όρο τη μία το χρόνο. Όσον αφορά δε στην απόδοση της ορθής ερμηνείας σε διάταξη τυπικού νόμου ως προς την οποία έχει επέλθει αμφισβήτηση, το Α.Ε.Δ. έχει εκδώσει ως προς το ζήτημα αυτό, από το 1976 έως και σήμερα, πέντε αποφάσεις το χρόνο κατά μέσο όρο. Μάλιστα, αν λάβουμε υπόψη μας ότι άρση της επίδικης αμφισβήτησης, που αποτελεί και το διακύβευμα σε κάθε περίπτωση προκειμένου να αποκατασταθεί η ανασφάλεια δικαίου, έλαβε χώρα σε ποσοστό 48% και 43% αντίστοιχα για κάθε ομάδα υποθέσεων, τότε το ως άνω συμπέρασμα επιβεβαιώνεται ακόμα περισσότερο.
description: The present dissertation deals mainly with the valuation of the Special Supreme Court’s effectiveness and in particular with the issue if this Court coped satisfactorily with its special mission referring to the settlement of controversies on whether the content of a statute enacted by Parliament is contrary to the Constitution and on the meaning of a statute’s provision which is prescribed by the Greek Constitution. The answer to the above issue will be given through the statistical elaboration of the Court’s judgments from its establishment until today (1976-2015). The basic conclusion is that this Special Court has controversial effectiveness since its judgments referring to the settlement of controversies on whether the content of a statute enacted by Parliament is contrary to the Constitution are not more than one every year on average. As far as the settlement of controversies on the meaning of a statute’s provision is concerned, the Special Supreme Court has issued five judgments every year on average since 1976. The above conclusion is confirmed even more if we take into account that the settlement of this controversy, which is the goal in order for the uncertainty of law to be restored, comes up to 48% and 43% respectively for each of the afforementionted categories.
Quantum Error Correction via Convex Optimization
Creators: name: Kosut, Robert L.
name: Lidar, Daniel A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show that the problem of designing a quantum information error correcting procedure can be cast as a bi-convex optimization problem, iterating between encoding and recovery, each being a semidefinite program. For a given encoding operator the problem is convex in the recovery operator. For a given method of recovery, the problem is convex in the encoding scheme. This allows us to derive new codes that are locally optimal. We present examples of such codes that can handle errors which are too strong for codes derived by analogy to classical error correction techniques.
description: 16 pages
Opportunities and Challenges in MOCVD of β-Ga2O3 for Power Electronic Devices
Creators: name: Mastro, M. A.
name: Hite, J. K.
name: Eddy,, C. R.
name: Tadjer, M. J.
name: Pearton, S. J.
name: Ren, F.
name: Kim, J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Recent breakthroughs in bulk crystal growth of beta-Ga2O3 by the edge-defined film-fed technique has led to the commercialization of large-area beta-Ga2O3 substrates. Standard epitaxy approaches are being utilized to develop various thin-film beta-Ga2O3 based devices including lateral transistors. This article will discuss the challenges for metal organic chemical vapor deposition (MOCVD) of beta-Ga2O3 and the design criteria for use of this material system in power electronic device structures.
Σύνθεση και μελέτη της βιοενεργής συμπεριφοράς ενός βιοκεραμικού υλικού που περιέχει ιόντα ψευδαργύρου ή/και χαλκού
Creators: name: Πέτσι, Σοφία Πέτρου
Publisher: name: Aristotle University of Thessaloniki
Year: 2015
Subjects: Φυσική
Βιοενεργή ύαλος
Στρώμα βιολογικού υδροξυαπατίτη
Physics
Bioactive glass
Biologically hydroxyapatite layer

description: Στόχος της παρούσας εργασίας ήταν η εισαγωγή ιόντων Cu/Ζn σε μια βιοενεργή πυριτική ύαλο με την τεχνική κολλοειδούς γέλης (sol-gel), καθώς και ο χαρακτηρισμός τους ως προς την ικανότητα σχηματισμού απατίτη. Για την επίτευξη αυτού του σκοπού πραγματοποιήθηκε, η σύνθεση με τη μέθοδο της κολλοειδούς γέλης, και η μελέτη της βιοενεργής συμπεριφοράς έξι βιοκεραμικών υλικών. Προκειμένου να εξεταστεί η βιοενεργότητα των υλικών, εμβαπτίστηκαν υπό τη μορφή σκόνης, κοκκομετρίας μικρότερης από 40 μm, σε διάλυμα που προσομοιώνει τα σωματικά υγρά και το πλάσμα του αίματος (c-SBF), από 0 έως και 25 ημέρες (όποτε αυτό ήταν εφικτό). Έπειτα τα δείγματα χαρακτηρίστηκαν με τις τεχνικές της φασματοσκοπίας υπερύθρου και των ακτίνων-Χ, πριν και μετά την εμβάπτιση και τα αποτελέσματα κυτταροτοξοξικότητας των υλικών αξιολογήθηκαν με τη μέθοδο ΜΤΤ.
description: The aim of the present work was the introduction of Cu/Zn ions in a silicate based sol-gel derived bioactive glass, as well as the characterization of its apatite forming ability. In order to achieve that, six sol-gel systems were synthesized and their potential bioactive behavior was evaluated in inorganic environment (SBF solution). The product was sieved to powder of grain size <40 μm. Bioactivity test was performed by soaking in Simulated Body Fluid (c-SBF) for several immersion times. Among the available techniques used for characterization, X–Ray Diffraction (XRD), and Fourier Transformed Infrared Spectroscopy (FTIR) have been applied towards monitoring the bioactive behaviour of the synthesized material. The results cytotoxicity was evaluated by the MTT method.
description: Σε συνεργασία με το Ινστιτούτο Τεχνολογίας Γκρενόμπλ (Γαλλία), το ΕΚΕΦΕ Δημόκριτος, και το CNRS (Centre National de la Researche Scientifique, Γαλλία)
Magnetic detwinning and biquadratic magnetic interaction in EuFe2As2 revealed by 153Eu NMR
Creators: name: Ding, Q. -P.
name: Sangeetha, N. S.
name: Meier, W. R.
name: Xu, M.
name: Bud'ko, S. L.
name: Canfield, P. C.
name: Johnston, D. C.
name: Furukawa, Y.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In the nematic state of iron-based superconductors, twin formation often obscures the intrinsic, anisotropic, in-plane physical properties.Relatively high in-plane external magnetic fields $H_{\rm ext}$ greater than the typical lab-scale magnetic fields 10--15 T are usually required to completely detwin a sample. However, recently a very small in-plane $H_{\rm ext} \sim$ 0.1 T was found to be sufficient for detwinning the nematic domains in EuFe$_2$As$_2$. To explain this behavior, a microscopic theory based on biquadratic magnetic interactions between the Eu and Fe spins has been proposed. Here, using $^{153}$Eu nuclear magnetic resonance (NMR) measurements below the Eu$^{2+}$ ordering temperature, we show experimental evidence of the detwinning under small in-plane $H_{\rm ext}$. Our NMR study also reveals the evolution of the angles between the Eu and Fe spins during the detwinning process, which provides the first experimental evidence for the existence of biquadratic coupling in the system.
description: 5 pages, 3 figures, accepted for publication in Phys. Rev. B rapid communication