cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Theoretical study of interacting hole gas in p-doped bulk III-V semiconductors
Creators: name: Schliemann, John
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the homogeneous interacting hole gas in $p$-doped bulk III-V semiconductors. The structure of the valence band is modelled by Luttinger's Hamiltonian in the spherical approximation, giving rise to heavy and light hole dispersion branches, and the Coulomb repulsion is taken into account via a self-consistent Hartree-Fock treatment. As a nontrivial feature of the model, the self-consistent solutions of the Hartree-Fock equations can be found in an almost purely analytical fashion, which is not the case for other types of effective spin-orbit coupling terms. In particular, the Coulomb interaction renormalizes the Fermi wave numbers for heavy and light holes. As a consequence, the ground state energy found in the self-consistent Hartree-Fock approach and the result from lowest-order perturbation theory do not agree. We discuss the consequences of our observations for ferromagnetic semiconductors, and for the possible observation of the spin-Hall effect in bulk $p$-doped semiconductors. Finally, we also investigate elementary properties of the dielectric function in such systems.
description: 9 pages, 5 figures, title slightly changed in the course of editorial process, a few references added, version to appear in Phys. Rev. B
Super-resonant transport of topological surface states subjected to in-plane magnetic fields
Creators: name: Zhang, Song-Bo
name: Li, Chang-An
name: Peña-Benitez, Francisco
name: Surówka, Piotr
name: Moessner, Roderich
name: Molenkamp, Laurens W.
name: Trauzettel, Björn
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Magnetic oscillations of Dirac surface states of topological insulators are expected to be associated with the formation of Landau levels or the Aharonov-Bohm effect. We instead study the conductance of Dirac surface states subjected to an in-plane magnetic field in presence of a barrier potential. Strikingly, we find that, in the case of large barrier potentials, the surface states exhibit pronounced oscillations in the conductance when varying the magnetic field, in the \textit{absence} of Landau levels or the Aharonov-Bohm effect. These novel magnetic oscillations are attributed to the emergence of \textit{super-resonant regimes} by tuning the magnetic field, in which almost all propagating electrons cross the barrier with perfect transmission. In the case of small and moderate barrier potentials, we also identify a positive magnetoconductance which is due to the increase of the Fermi surface by tilting the surface Dirac cone. Moreover, we show that for weak magnetic fields, the conductance displays a shifted sinusoidal dependence on the field direction with period $π$ and phase shift determined by the tilting direction with respect to the field direction. Our predictions can be applied to many topological insulators, such as HgTe and Bi$_{2}$Se$_{3}$, and provide important insights into exploring and understanding exotic magnetotransport properties of topological surface states.
description: 5+2 pages, 4 figures
Superconductivity of neutral modes in quantum Hall edges
Creators: name: Väyrynen, Jukka I.
name: Goldstein, Moshe
name: Gefen, Yuval
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Edges of quantum Hall phases give rise to a multitude of exotic modes supporting quasiparticles of different values of charge and quantum statistics. Among these are neutralons (chargeless anyons with semion statistics), which were found to be ubiquitous in fractional quantum Hall matter. Studying and manipulating the neutral sector is an intriguing and interesting challenge, all the more so since these particles are accessible experimentally. Here we address the limit of strongly-interacting neutralons giving rise to neutralon superconductivity, where pairing is replaced by a quarteting mechanism. We discuss several manifestations of this effect, realizable in existing experimental platforms. Furthermore, this superconducting gapping mechanism may be exploited to facilitate the observation of interference of the accompanying charged anyons.
description: 5+5 pages, 2+2 figures; v3 with new title and introduction to emphasize the main novelty
title: Numerical Analysis Group Progress Report : January 2008 - December 2009
Creators: name: Scott, JA
Publisher: name: Science and Technology Facilities Council
Year: 2010
Subjects: numerical linear algebra
stopping criteria
HSL
iterative methods
ordering techniques
direct methods
large-scale optimization
parallel
CUTEr
GALAHAD
sparse matrices
multicore

description: We discuss the research activities of the Numercal Analysis Group in the Computational Science and Engineering Department at the Rutherford Appleton Laboratory of the Science and Technology Facilities Council for the period January 2008 to December 2009. The work was principally supported by EPSRC grants EP/E053351/1, EP/F006535/1 and EP/F005369/1.
Gravitino Dark Matter in R-Parity Breaking Vacua
Creators: name: Buchmuller, Wilfried
name: Covi, Laura
name: Hamaguchi, Koichi
name: Ibarra, Alejandro
name: Yanagida, Tsutomu
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We show that in the case of small R-parity and lepton number breaking couplings, primordial nucleosynthesis, thermal leptogenesis and gravitino dark matter are naturally consistent for gravitino masses m_{3/2} \gsim 5 GeV. We present a model where R-parity breaking is tied to B-L breaking, which predicts the needed small couplings. The metastable next-to-lightest superparticle has a decay length that is typically larger than a few centimeters, with characteristic signatures at the LHC. The photon flux produced by relic gravitino decays may be part of the apparent excess in the extragalactic diffuse gamma-ray flux obtained from the EGRET data for a gravitino mass m_{3/2} \sim 10 GeV. In this case, a clear signal can be expected from GLAST in the near future.
description: 18 pages. Typos corrected
Reducing of phase retrieval errors in Fourier analysis of 2-dimensional digital model interferograms
Creators: name: Gladic, Jadranko
name: Vucic, Zlatko
name: Lovric, Davorin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In order to measure the radial displacements of facets on surface of a growing spherical Cu_{2-δ}Se crystal with sub-nanometer resolution, we have investigated the reliability and accuracy of standard method of Fourier analysis of fringes obtained applying digital laser interferometry method. Guided by the realistic experimental parameters (density and orientation of fringes), starting from 2-dimensional model interferograms and using unconventional custom designed Gaussian filtering window and unwrapping procedure of the retrieved phase, we have demonstrated that for considerable portion of parameter space the non-negligible inherent phase retrieval error is present solely due to non-integer number of fringes within the digitally recorded image (using CCD camera). Our results indicate the range of experimentally adjustable parameters for which the generated error is acceptably small. We also introduce a modification of the (last part) of the usual phase retrieval algorithm which significantly reduces the error in the case of small fringe density.
description: 24 pages, 5 figures, submitted to JOSA A
Dual View on Clear-Sky Top-of-Atmosphere Albedos from Meteosat Second Generation Satellites
Creators: name: Payez, Alexandre
name: Dewitte, Steven
name: Clerbaux, Nicolas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Geostationary observations offer the unique opportunity to resolve the diurnal cycle of the Earth's Radiation Budget at the top of the atmosphere (TOA), crucial for climate-change studies. However, a drawback of the continuous temporal coverage of the geostationary orbit is the fixed viewing geometry. As a consequence, imperfections in the angular distribution models (ADMs) used in the radiance-to-flux conversion process or residual angular-dependent narrowband-to-broadband conversion errors can result in systematic errors of the estimated radiative fluxes. In this work, focusing on clear-sky reflected TOA observations, we compare the overlapping views from Meteosat Second Generation satellites at 0° and 41.5°E longitude which enable a quantification of viewing-angle-dependent differences. Using data derived from SEVIRI, we identify some of the main sources of discrepancies, and show that they can be significantly reduced at the level of one month. This is achieved, separately for each satellite, via a masking procedure followed by an empirical fit at the pixel-level that takes into account all the clear-sky data from that satellite, calculated separately per timeslot of the day, over the month of November 2016. The method is then applied to each month of 2017, and gives a quadratic mean of the albedo root-mean squared difference over the dual-view region which is comparable from month to month, with a 2017 average value of 0.01. Sources of discrepancies include the difficulty to estimate the flux over the sunglint ocean region close to the limbs, the fact that the data processing does not include dedicated angular distribution models for the aerosol-over-ocean case, and the existence of an observer-dependent diurnal-asymmetry artefact affecting the clear-sky-albedo dependence on the solar zenith angle particularly over land areas.
description: Accepted for publication in Remote Sensing. 19 pages
Urban food production in Bandung, Indonesia
Creators: name: Hietkamp, Fern
Publisher: name: University of British Columbia
Year: 2009

description: Urban food production has many immediately observable, as well as long-term, benefits. It provides a means of self-help for the poor; is a stepping stone for urban environmental management; and is a productive, as well as aesthetic, use for open or marginal urban land. Yet it is an activity that is poorly understood; why, how, and to what extent, people engage in urban food production activities is only beginning to be researched. Certainly, in most cities in the world, this activity does not have institutional support. Lack of coordination of urban land uses and the ever increasing pace of development in urban areas, mean that urban food production, where it occurs, will become more and more difficult to sustain. This study undertakes to expand the understanding of urban food production. Urban food production includes food growing activities carried out by urban dwellers within or on the periphery of the urban area, for distribution to, and consumption by, other, local, urban dwellers, or themselves. A literature review with examples from around the world presents the various roles urban food production plays. This review provides a context for the research, conducted in Bandung, Indonesia. Urban food production in Bandung is described through interviews and observation. Constraints and opportunities at the city system level and at the food producer level are identified. This investigation shows that with the current rate of development in Bandung, food production is becoming more difficult because of the increasing competition with other urban activities for resources such as water, air and land. However, many opportunities exist within the current framework of city management that can support food production within the city. This study makes a number of recommendations which can support and promote urban food production in Bandung.
Analysis of a large-scale weighted network of one-to-one human communication
Creators: name: Onnela, Jukka-Pekka
name: Saramaki, Jari
name: Hyvonen, Jorkki
name: Szabo, Gabor
name: de Menezes, M. Argollo
name: Kaski, Kimmo
name: Barabasi, Albert-Laszlo
name: Kertesz, Janos
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We construct a connected network of 3.9 million nodes from mobile phone call records, which can be regarded as a proxy for the underlying human communication network at the societal level. We assign two weights on each edge to reflect the strength of social interaction, which are the aggregate call duration and the cumulative number of calls placed between the individuals over a period of 18 weeks. We present a detailed analysis of this weighted network by examining its degree, strength, and weight distributions, as well as its topological assortativity and weighted assortativity, clustering and weighted clustering, together with correlations between these quantities. We give an account of motif intensity and coherence distributions and compare them to a randomized reference system. We also use the concept of link overlap to measure the number of common neighbors any two adjacent nodes have, which serves as a useful local measure for identifying the interconnectedness of communities. We report a positive correlation between the overlap and weight of a link, thus providing strong quantitative evidence for the weak ties hypothesis, a central concept in social network analysis. The percolation properties of the network are found to depend on the type and order of removed links, and they can help understand how the local structure of the network manifests itself at the global level. We hope that our results will contribute to modeling weighted large-scale social networks, and believe that the systematic approach followed here can be adopted to study other weighted networks.
description: 25 pages, 17 figures, 2 tables
The axial-vector contributions in two-photon reactions: pion transition form factor and deeply-virtual Compton scattering at NNLO in QCD
Creators: name: Braun, V. M.
name: Manashov, A. N.
name: Moch, S.
name: Schoenleber, J.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Using the approach based on conformal symmetry we calculate the two-loop coefficient function for the axial-vector contributions to two-photon processes in the $\overline{\rm MS}$ scheme. This is the last missing element for the complete next-to-next-to-leading order (NNLO) calculation of the the pion transition form factor $γ^\astγ\to π$ in perturbative QCD. The corresponding high-statistics measurement is planned by the Belle II collaboration and will allow one to put strong constraints on the pion light-cone distribution amplitude. The calculated NNLO corrections prove to be rather large and have to be taken into account. The same coefficient function determines the contribution of the axial-vector generalized parton distributions to deeply-virtual Compton scattering which is investigated at the JLAB 12 GeV accelerator, by COMPASS at CERN, and in the future will be studied at the Electron Ion Collider EIC.
description: Published version. Two misprints corrected in the ancillary file
[Field notebook XIV]
Creators: name: Francis, Adelene
name: George, Mary
name: Harry, Noel George
name: Paul, David
name: Paul, Maggie
name: Paul, Tommy
name: Wilson, Ambrose
name: Davis, John H.
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2024
Subjects: subject: coo

description: 1 PDF file. Researcher indicates overall page range as 744-783.
Post-radiation evolution of black holes
Creators: name: Vilkovisky, G. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The expectation-value equations for the collapse of a macroscopic, spherically symmetric, and uncharged body are integrated up to the limit of validity of semiclassical theory. The collapse finishes with a true stable black hole of the mass microscopically exceeding the vacuum-induced charge. The apparent horizon is almost closed. The most important feature of the solution is the presence of an irremovable Cauchy horizon.
description: 19 pages, 2 figures. Latex 2.09. Figures PostScript
Topological Aspects of Antiferromagnets
Creators: name: Bonbien, V.
name: Zhuo, Fengjun
name: Salimath, A.
name: Ly, O.
name: Abbout, A.
name: Manchon, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The long fascination antiferromagnetic materials have exerted on the scientific community over about a century has been entirely renewed recently with the discovery of several unexpected phenomena including various classes of anomalous spin and charge Hall effects and unconventional magnonic transport, but also homochiral magnetic entities such as skyrmions. With these breakthroughs, antiferromagnets standout as a rich playground for the investigation of novel topological behaviors, and as promising candidate materials for disruptive low-power microelectronic applications. Remarkably, the newly discovered phenomena are all related to the topology of the magnetic, electronic or magnonic ground state of the antiferromagnets. This review exposes how non-trivial topology emerges at different levels in antiferromagnets and explores the novel mechanisms that have been discovered recently. We also discuss how novel classes of quantum magnets could enrich the currently expanding field of antiferromagnetic spintronics and how spin transport can in turn favor a better understanding of exotic quantum excitations.
description: 77 pages, 47 figures
Establishing a seismic retrofit policy : Implications for buildings with historical significance in the lower mainland of British Columbia
Creators: name: Keenan, Kathleen Marie
Publisher: name: University of British Columbia
Year: 2009

description: Earthquakes, such as the ones capable of affecting the Lower Mainland of British Columbia, can have a devastating effect on the environment that people live and work in. The purpose of this thesis is to examine methods of dealing with the hazards and problems created by existing, often historically significant, unreinforced buildings in earthquake-prone areas. Gaining an understanding of the complexity of this problem and the issues involved in establishing hazard mitigation policies gives insight into the policy-making process. The research indicates that a number of internal and external factors affect the formulation, adoption, and implementation of hazard mitigation policies. Despite limited awareness of the problem, low political salience of the issue, and limited resources in most communities, there are many steps that can be taken that will reduce the public's exposure to the risks created by unreinforced buildings and strengthen historically significant buildings that hold value, socially, economically, and culturally. Establishing more extensive mitigative measures, such as implementing a seismic retrofit policy, requires a decision-making process that must involve the people who live and work within that community. Each community, through a process of consultation with the stakeholders, needs to decide if it is in their interest to pursue hazard mitigation strategies to reduce the seismic risk. There is a need to integrate hazard mitigation strategies into the daily decision-making process of politicians and planners. The thesis concludes with some points for stakeholders to consider in designing policy to reduce the earthquake hazard that all the communities in the Lower Mainland of British Columbia face.
Relation between the pole and the minimally subtracted mass in dimensional regularization and dimensional reduction to three-loop order
Creators: name: Marquard, P.
name: Mihaila, L.
name: Piclum, J. H.
name: Steinhauser, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We compute the relation between the pole quark mass and the minimally subtracted quark mass in the framework of QCD applying dimensional reduction as a regularization scheme. Special emphasis is put on the evanescent couplings and the renormalization of the epsilon-scalar mass. As a by-product we obtain the three-loop on-shell renormalization constants Zm(OS) and Z2(OS) in dimensional regularization and thus provide the first independent check of the analytical results computed several years ago.
description: 22 pages
Joule heating effects in high transparency Josephson junctions
Creators: name: Tomi, Matti
name: Samatov, Mikhail R.
name: Vasenko, Andrey S.
name: Laitinen, Antti
name: Hakonen, Pertti
name: Golubev, Dmitry S.
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 study, both theoretically and experimentally, the features on the current-voltage characteristic of a highly transparent Josephson junction caused by transition of the superconducting leads to the normal state. These features appear due to the suppression of the Andreev excess current. We show that by tracing the dependence of the voltage, at which the transition occurs, on the bath temperature and by analyzing the suppression of the excess current by the bias voltage one can recover the temperature dependence of the heat flow out of the junction. We verify theory predictions by fabricating two highly transparent superconductor-graphene-superconductor (SGS) Josephson junctions with suspended and non-suspended graphene as a non-superconducting section between Al leads. Applying the above mentioned technique we show that the cooling power of the suspended junction depends on the bath temperature as $\propto T_{\rm bath}^{3.1}$ close to the superconducting critical temperature.
description: 10 pages, 6 figures
Anatomy of HH 111 from CO observations : a bow shock driven molecular outflow
Creators: name: Lefloch, B.
name: Cernicharo, J.
name: Reipurth, B.
name: Pardo, J. R.
name: Neri, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present millimeter line observations of the HH 111 outflow and its driving source. The molecular gas emission observed with IRAM 30m and the CSO reveals a small condensation of cold and dense gas. The low-velocity outflow has been mapped with the IRAM PdBI interferometer. The cold gas is distributed in a hollow cylinder surrounding the optical jet. The formation of this cavity and its kinematics are well accounted for in the frame of outflow gas entrainment by jet bow shocks. Evidence of gas acceleration is found along the cavity walls, correlated with the presence of optical bow shocks. The cavity has been expanding with a mean velocity of 4 km/s on a timescale of 8700 yr, similar to the dynamical age of the optical jet. The separation of the inner walls reaches 8"-10", which matches the transverse size of the wings in the bow shock. CSO observations of the J=7-6 line show evidence of a high-velocity and hot gas component (T=300-1000 K) with a low filling factor, associated with shocked molecular gas in the jet. [CI] observations are consistent with C-type non-dissociative shocks. Mapping of the high-velocity molecular bullets B1-B3 located beyond the optical jet, with the PdBI, reveals small structures of 3" by 7" flattened perpendicular to the flow direction. They are made of cold gas of moderate density(a few 10^3 cm-3). The bullets appear to expand into the low-density surrounding medium. We conclude that they are probably shocked gas knots resulting from past time-variable ejections in the jet.
description: 21 pages + 4 figures (JPG). To appear in Astrophysical Journal
Prevalence of hearing loss and refractive error among students inOngkharak district, Nakhon Nayok province according to gender and age groups:Cross sectional study
Creators: name: Kittipong Kongsomboon
Publisher: name: Faculty of Medicine,Srinakharinwirot University
Year: 2007
Subjects: Hearing impairment, refractive error

description: 1, 14, Journal of Medicine and Health Sciences
Health problems among students in Ongkharak district, Nakhon Nayok provinceaccording to gender and class: Cross sectional study
Creators: name: Kittipong Kongsomboon, Somboon Chansakulporn
Publisher: name: Faculty of Medicine,Srinakharinwirot University
Year: 2007
Subjects: Health problems, school children

description: 1, 14, Journal of Medicine and Health Sciences
[Field notebook XIII]
Creators: name: Francis, Adelene
name: George, Mary
name: Harry, Noel George
name: Harry, Steve
name: Pallen, Fred
name: Paul, Tommy
name: Wilson, Nora
name: Wilson, Ronnie
name: Davis, John H.
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2024
Subjects: subject: coo

description: 1 PDF file. Researcher indicates overall page range as 670-743.
Regulation of cytochrome P450 and P450 mRNA in human granulosa-luteal cells
Creators: name: Ge, Hong
Publisher: name: University of British Columbia
Year: 2009

description: This thesis investigated the expression and regulation of cytochrome P450s, aromatase (P450arom) and cholesterol side chain cleavage (P450scc) enzyme mRNAs in human granulosa-luteal cells using reverse transcription-polymerase chain reaction (RT-PCR). The two enzymes are instrumental in steroid hormone biosynthesis. The steroid hormone biosynthesis by the ovary is determined in part by the pattern of gonadotropin secretion and also appears to be under the influence of local regulators which provide the fine tuning at a local level in a gonadotropin dependent or independent way. In this study, the granulosa-luteal cells were aspirated from preovulatory follicles obtained from women undergoing in vitro fertilization. A highly sensitive method, reverse transcription-polymerase chain reaction (RT-PCR), was used to quantitate P450arom and P450scc mRNA expression. Two sets of primers designed from cDNA sequences were used to amplify cDNAs from granulosa-luteal cells. The authenticity of the PCR products was confirmed by Southern blot hybridization with specific cDNA probes. It was shown that cAMP and hCG increased the levels of P450arom and P450scc mRNA by 2-3 fold and 4-5 fold. GnRH at 10⁻⁶ M had no significant effects either on basal or on hCG or cAMP stimulated P450arom and P450scc mRNA expression. Under the same cell culture conditions, GnRH at lower concentrations 10⁻⁸ or 10⁻⁹ M did not show significant effects on basal P450arom and P450scc gene expression, but significantly inhibited hCG-stimulated P450arom and P450scc gene expression and progesterone production. By contrast, GnRH treatment had no significant effect on exogenous 8-br-cAMP-stimulated P450arom and P450scc gene expression. Studies on the time course for the inhibitory effect indicated that GnRH at 10⁻⁶ M significantly inhibited hCG stimulated P450arom and P450scc mRNA expression from 24 to 48 hour of treatment. These results provide evidence that chorionic gonadotropin stimulates P450arom and P450scc mRNA expression and cAMP could be a mediator for a positive regulation. GnRH not only plays a role in neuroendocrine regulation, but also has local effects on extrapituitary sites. In human ovary, the paracrine/autocrine effects of GnRH on steroidogenesis of human granulosa-luteal cells may play an important role in determining an individual follicles's response to gonadotropins.
Ultrafast Enhancement of Ferromagnetism via Photoexcited Holes in GaMnAs
Creators: name: Wang, J.
name: Cotoros, I.
name: Dani, K. M.
name: Chemla, D. S.
name: Liu, X.
name: Furdyna, J. K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on the observation of ultrafast photo-enhanced ferromagnetism in GaMnAs. It is manifested as a transient magnetization increase on a 100-ps time scale, after an initial sub-ps demagnetization. The dynamic magnetization enhancement exhibits a maximum below the Curie temperature Tc and dominates the demagnetization component when approaching Tc. We attribute the observed ultrafast collective ordering to the p-d exchange interaction between photoexcited holes and Mn spins, leading to a correlation-induced peak around 20K and a transient increase in Tc.
description: 4 pages
Από τη Νομαρχιακή στη Περιφερειακή Αυτοδιοίκηση. Μελέτη του πολιτικού ανταγωνισμού στη Περιφέρεια Αττικής
Creators: name: Κούσα, Ευαγγελία Αναστασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Β΄ Τοπική Αυτοδιοίκηση
Πολιτικός Ανταγωνισμός
Κόμματα
B΄ Local Self - Government
Political Antagonism
Parties

description: Σκοπός της διατριβής είναι να παρουσιάσει και να αναλύσει τον πολιτικό ανταγωνισμό των κομμάτων κατά τη διάρκεια των τριών τελευταίων εκλογικών αναμετρήσεων στις Νομαρχιακές εκλογές του 2006 και στις Περιφερειακές εκλογές 2010 – 2014 στην Περιφέρεια Αττικής. Εξετάσθηκαν, σε κάθε εκλογική αναμέτρηση ξεχωριστά, η πολιτική – οικονομική – κοινωνική κατάσταση της χώρας εκείνη τη περίοδο, οι συνδυασμοί που συμμετείχαν και ποια κόμματα τους στήριζαν, οι προγραμματικές τους δηλώσεις και αναλύθηκαν τα αποτελέσματα των εκλογών. Προσδιορίσθηκε ο βαθμός πολιτικού ανταγωνισμού σύμφωνα με τους άξονες «Αριστερά-Δεξιά», «Εσωστρέφεια- Εξωστρέφεια» και «Αυταρχισμός – Φιλελευθερισμός». Επίσης αναλύθηκαν τα χαρακτηριστικά των υποψηφίων προκειμένου να διαπιστωθεί ποια ήταν τα κοινά των εκλεγμένων συμβούλων των εκλογών ανά συνδυασμό. Για την ολοκλήρωση της μελέτης ελέγχθηκε με τη στατιστική μέθοδο του χ2 εάν οι διαδοχικές εκλογικές αναμετρήσεις σχετίζονταν μεταξύ τους αποδεικνύοντας πως οι ψηφοφόροι ψηφίζουν βάση της κομματικής τους ταυτότητας ή εάν επηρεάζονται και από άλλους παράγοντες όπως από τα πρόσωπα που συμμετέχουν στους συνδυασμούς ή από τα θέματα επικαιρότητας
description: The aim of the present thesis is to present and analyze the political antagonism of parties during the last three electoral contests to the prefectural elections of 2006 and regional elections of 2010 – 2014 in the prefecture of Attica. Ιt was investigated , in every electoral contest separately, the political – financial – social situation of Greece at that period, the candidate parties which take place and which political parties supported theme, their program statements. It was defined the degree of political antagonism according to the dipolar axis “Left – Right” ,”Introversion – Extroversion”, “Authoritarianism – Liberalism” . Also it was analyzed the characteristics of the candidates in order to find out the common one per candidate party. In order to complete this study it was examined, by statistical method of chi-square, if the successive elections had the same results or not, proving by that if the voters are voting their party or they are affected by the candidates or even by current affairs
Augmenting the Sensing Performance of Entangled Photon Pairs through Asymmetry
Creators: name: Michael, Yoad
name: Jonas, Isaac
name: Bello, Leon
name: Meller, Mallachi-Ellia
name: Cohen, Eliahu
name: Rosenbluh, Michael
name: Pe'er, Avi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We analyze theoretically and experimentally cases of asymmetric detection, stimulation, and loss within a quantum nonlinear interferometer of entangled pairs. We show that the visibility of the SU(1,1) interference directly discerns between loss on the measured mode (signal) and the conjugated mode (idler). This asymmetry also affects the phase sensitivity of the interferometer, where coherent seeding is shown to mitigate losses that are suffered by the conjugated mode; therefore increasing the maximum threshold of loss that permits sub-shot-noise phase detection. Our findings can improve the performance of setups that rely on direct detection of entangled pairs, such as quantum interferometry and imaging with undetected photons.
Functional Renormalization Group calculation of the Fermi surface of a spin-ladder
Creators: name: Abramovici, Gilles
name: Héritier, Michel
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study non conventional superconductivity on a ladder, improving the predictions of the Hubbard model. The determination of the Fermi surface, in 2 or 3 dimensions, remains a very hard task, but it is exactly solvable for a single ladder. We use functional Renormalisation Group methods, which prove, here, scheme-dependant. In the superconducting phase, the binding/antibinding gap is stabilized, but in the antiferromagnetic phase, it shrinks and the ladder turns one-dimensional.
Averaging Generalized Scalar Field Cosmologies II: Locally Rotationally Symmetric Bianchi I and flat Friedmann-Lemaître-Robertson-Walker models
Creators: name: Leon, Genly
name: Cuéllar, Sebastián
name: González, Esteban
name: Lepe, Samuel
name: Michea, Claudio
name: Millano, Alfredo D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Scalar field cosmologies with a generalized harmonic potential and a matter fluid with a barotropic Equation of State (EoS) with barotropic index $γ$ for the Locally Rotationally Symmetric (LRS) Bianchi I and flat Friedmann-Lemaître-Robertson-Walker (FLRW) metrics are investigated. Methods from the theory of averaging of nonlinear dynamical systems are used to prove that time-dependent systems and their corresponding time-averaged versions have the same late-time dynamics. Therefore, the simplest time-averaged system determines the future asymptotic behavior. Depending on the values of $γ$, the late-time attractors of physical interests are flat quintessence dominated FLRW universe and Einstein-de Sitter solution. With this approach, the oscillations entering the system through the Klein-Gordon (KG) equation can be controlled and smoothed out as the Hubble parameter $H$ - acting as time-dependent perturbation parameter - tends monotonically to zero. Numerical simulations are presented as evidence of such behavior.
description: Research Program Averaging Generalized Scalar Field Cosmologies, part II. 27 pages, 7 compound figures. Minor revision. References updated. Discussion improved
Κλινική μελέτη για την αντιμετώπιση της οδοντινικής υπερευαισθησίας
Creators: name: Παπαδοπούλου, Αγγελική Ανέστη
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Οδοντινική υπερευαισθησία
Φωτοβιοδιαμόρφωση
Αμινοφθοριούχες ενώσεις
Dental hypersensitivity
Photobiomodulation
Giomer

description: Σκοπός της διατριβής ήταν η μελέτη των παγιωμένων εκφράσεων της νεοελληνικής γλώσσας. Εξετάσαμε την ορολογία που χρησιμοποιείται για τις παγιωμένες εκφράσεις και τους ορισμούς που έχουν προταθεί. Στη συνέχεια παρουσιάσαμε αναλυτικά τα χαρακτηριστικά των παγιωμένων εκφράσεων, καθώς και τους περιορισμούς που ισχύουν όσον αφορά το λεξιλόγιο, τη γραμματική και τη σύνταξή τους. Ακόμη αναφερθήκαμε αναλυτικά στα μοντέλα κατανόησης των παγιωμένων εκφράσεων που έχουν προταθεί και μας απασχόλησε η κατανόηση των παγιωμένων εκφράσεων από τα παιδιά καθώς και η διδασκαλία τους σε ξενόγλωσσους. Ένα άλλο θέμα που θίξαμε ήταν η συγγραφή λεξικών παγιωμένων εκφράσεων και παρουσιάσαμε ορισμένα που έχουν γραφεί για την ελληνική. Ασχοληθήκαμε επιπλέον με την ιστορική διάσταση των παγιωμένων εκφράσεων της νέας ελληνικής και διαπιστώσαμε την παρουσία τους από την αρχαιότητα μέχρι σήμερα
description: The aim of the present thesis was the study of frozen expressions (idioms) in Modern Greek. We examined the proposed terminology and the definitions given for frozen expressions. Then we presented the features of frozen expressions and the restrictions on vocabulary, grammar, and syntax. Furthermore, we analyzed the models concerning the comprehension of frozen expressions and we examined children’s ability to produce and understand frozen expressions as well as ways of teaching them to foreign learners. We also examined the compilation of dictionaries of frozen expressions and we presented selected Greek dictionaries written in the last two decades. Another aim of this study was to examine the historical dimension of frozen expressions
Magnetic-field-controlled spin fluctuations and quantum criticality in Sr3Ru2O7
Creators: name: Lester, C.
name: Ramos, S.
name: Perry, R. S.
name: Croft, T. P.
name: Laver, M.
name: Bewley, R. I.
name: Guidi, T.
name: Hiess, A.
name: Wildes, A.
name: Forgan, E. M.
name: Hayden, S. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: When the transition temperature of a continuous phase transition is tuned to absolute zero, new ordered phases and physical behaviour emerge in the vicinity of the resulting quantum critical point. Sr3Ru2O7 can be tuned through quantum criticality with magnetic field at low temperature. Near its critical field Bc it displays the hallmark T-linear resistivity and a T log(1/T) electronic heat capacity behaviour of strange metals. However, these behaviours have not been related to any critical fluctuations. Here we use inelastic neutron scattering to reveal the presence of collective spin fluctuations whose relaxation time and strength show a nearly singular variation with magnetic field as Bc is approached. The large increase in the electronic heat capacity and entropy near Bc can be understood quantitatively in terms of the scattering of conduction electrons by these spin-fluctuations. On entering the spin density wave (SDW) phase present near Bc, the fluctuations become stronger suggesting that the SDW order is stabilised through an "order-by-disorder" mechanism.
Analyses of Laser Propagation Noises for TianQin Gravitational Wave Observatory Based on the Global Magnetosphere MHD Simulations
Creators: name: Su, Wei
name: Wang, Yan
name: Zhou, Chen
name: Lu, Lingfeng
name: Zhou, Ze-Bing
name: Li, T.
name: Shi, Tong
name: Hu, Xin-Chun
name: Zhou, Ming-Yue
name: Wang, Ming
name: Yeh, Hsien-Chi
name: Wang, Han
name: Chen, P. F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: TianQin is a proposed space-borne gravitational wave (GW) observatory composed of three identical satellites orbiting around the geocenter with a radius of $10^5$ km. It aims at detecting GWs in the frequency range of 0.1 mHz -- 1 Hz. The detection of GW relies on the high precision measurement of optical path length at $10^{-12}$~m level. The dispersion of space plasma can lead to the optical path difference (OPD, $Δl$) along the propagation of laser beams between any pair of satellites. Here, we study the OPD noises for TianQin. The Space Weather Modeling Framework is used to simulate the interaction between the Earth magnetosphere and solar wind. From the simulations, we extract the magnetic field and plasma parameters on the orbits of TianQin at four relative positions of the satellite constellation in the Earth magnetosphere. We calculate the OPD noise for single link, Michelson combination, and Time-Delay Interferometry (TDI) combinations ($α$ and $X$). For single link and Michelson interferometer, the maxima of $|Δl|$ are on the order of 1 pm. For the TDI combinations, these can be suppressed to about 0.004 and 0.008 pm for $α$ and $X$. The OPD noise of the Michelson combination is colored in the concerned frequency range; while the ones for the TDI combinations are approximately white. Furthermore, we calculate the ratio of the equivalent strain of the OPD noise to that of TQ, and find that the OPD noises for the TDI combinations can be neglected in the most sensitive frequency range of TQ.
description: 19 pages, 10 figures
Entropy Wave Instability in Dirac and Weyl Semimetals
Creators: name: Sukhachov, P. O.
name: Gorbar, E. V.
name: Shovkovy, I. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Hydrodynamic instabilities driven by a direct current are analyzed in 2D and 3D relativisticlike systems with the Dyakonov-Shur boundary conditions supplemented by a boundary condition for temperature. Besides the conventional Dyakonov-Shur instability for plasmons, we find an entropy wave instability in both 2D and 3D systems. The entropy wave instability is a manifestation of the relativisticlike nature of electron quasiparticles and a nontrivial role of the energy current in such systems. These two instabilities occur for the opposite directions of fluid flow. While the Dyakonov-Shur instability is characterized by the plasma frequency in 3D and the system size in 2D, the frequency of the entropy wave instability is tunable by the system size and the flow velocity.
description: 6+11 pages, 1+6 multi-panel figures
Response to ``Comment on `Primordial magnetic seed field amplification by gravitational waves' "
Creators: name: Betschart, G.
name: Zunkel, C.
name: Dunsby, P. K. S.
name: Marklund, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Here we respond to the comment by Tsagas (gr-qc/0503042) on our paper gr-qc/0503006. We show that the results in that comment are flawed and cannot be used for drawing conclusion about the nature of magnetic field amplification by gravitational waves, and give further support that the results of gr-qc/0503006 are correct.
description: 4 pages, 2 figures, to appear in Physical Review D
Μελέτη σε βάθος του Εκλογικού Ανταγωνισμού στην Περιφέρεια Πελοποννήσου για τις εκλογικές αναμετρήσεις από το 2006-2014. Κόμματα, Πρόσωπα, Θέματα
Creators: name: Τζίνεβης, Χαράλαμπος Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: εκλογές
υποψήφιοι
τοπική αυτοδιοίκηση
elections
candidates
local government

description: Η παρούσα εργασία εκπονείται στα πλαίσια του μεταπτυχιακού προγράμματος με τίτλο «Διακυβέρνηση». Στην αρχή της διπλωματικής εργασίας, αφιερώνεται μια ενότητα στη μετάβαση της τοπικής αυτοδιοίκησης από το σχέδιο «Καποδίστρια» (Ν.2539/97) στο μεταρρυθμιστικό Νόμο του «Καλλικράτη» (Ν.3852/2010). Στη συνέχεια γίνεται μια σχετικά σύντομη αναφορά στους όρους και τα χαρακτηριστικά του πολιτικού μάρκετινγκ. Η εργασία έχει ως στόχο την πλήρη καταγραφή και ποιοτική ανάλυση όλων των στοιχείων που συνέθεσαν το τοπίο του πολιτικού ανταγωνισμού κατά τη διάρκεια των νομαρχιακών/περιφερειακών εκλογών την περίοδο 2006-2014 για την Περιφέρεια Πελοποννήσου. Ακόμη, εξετάζεται το σχήμα «Κόμματα – Πρόσωπα- Θέματα» ώστε να καταγράψουμε την κομματική ταύτιση των υποψηφίων αλλά και των ψηφοφόρων, την ατζέντα των παρατάξεων-συνδυασμών, τα θέματα, τις προτάσεις των υποψηφίων αλλά και τα ιδιαίτερα χαρακτηριστικά των υποψηφίων που διαμορφώνουν το προφίλ τους
description: This work prepared in the postgraduate programme entitled "governance". At the beginning of the dissertation, devoted a section to the transition of local government from the capodistria plan (law 2539/97) on the reform of Law "Kallikratis" (n. 3852/2010). Then it becomes a relatively brief reference in terms and characteristics of political marketing. The work aims at the full record and qualitative analysis of all elements composing the landscape of political competition during the departmental/regional elections during the period 2006-2014 for the region of Peloponnese. Still, considering the shape ' Parties – Persons-Subjects "to record the partisan identification of candidates as well as voters, the agenda of factions-combinations, the issues, the candidates ' proposals, as well as the specific features of candidates are shaping their profile. In addition, although whether it influenced the election of candidates their characteristics but also the consistency of their reasons. This objective will be achieved by means of a questionnaire for the 15 characteristics of candidates (The study of political competition, the case of candidates, Theodore Chadjipadelis) while there is another section before the conclusions, which analyzes whether the regional elections are elections b class. Finally, it ends in conclusions, literature and Web sources
Ανοικτή Διακυβέρνηση και Ανοικτά Δεδομένα
Creators: name: Μάγγος, Νικόλαος Μιχαήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2018
Subjects: Ανοικτή Διακυβέρνηση
Ανοικτά Δεδομένα
Διαύγεια
Open Government
Open Data
Diavgeia

description: Σκοπός της παρούσας εργασίας είναι να αποδώσει σε βάθος το περιεχόμενο του όρου της Ανοικτής Διακυβέρνησης και να καταγράψει την υφιστάμενη κατάσταση στον ελλαδικό χώρο και όχι μόνο, στον τομέα της πρωτοβουλίας για την Ανοικτή Διακυβέρνηση. Έρευνες έχουν δείξει ότι η είσοδος της Ηλεκτρονικής Διακυβέρνησης σε ισχυρές οικονομίες κρατών και η μετάβαση στην Ανοικτή Διακυβέρνηση αποτέλεσαν τους κυριότερους λόγους ενίσχυσης της παραγωγικότητας του δημόσιου τομέα, ο οποίος λειτουργεί αποδοτικότερα και με μεγαλύτερη διαφάνεια, αφήνοντας πίσω τα πιθανά φαινόμενα διαφθοράς. Επίσης, έχει σαν βασικό αντικείμενο ενασχόλησής της, τα Ανοικτά Δεδομένα που διατίθενται στο κοινό χωρίς περιορισμούς ως προς την αντιγραφή, περαιτέρω χρήση και διάθεση ή τροποποίηση αυτών ή των τροποποιημένων αντιγράφων τους. Όλα αυτά, σύμφωνα με ήδη ψηφισμένο νόμο (4305/2014), ο οποίος όμως δεν εφαρμόζεται ή στην καλύτερη των περιπτώσεων εφαρμόζεται ελλιπέστατα. Άλλωστε δεν είναι τυχαίο ότι τα Ανοικτά Δεδομένα θεωρούνται τα τελευταία χρόνια ο οδηγός της παγκόσμιας ανάπτυξης. Η Ελλάδα θα πρέπει και οφείλει να εντείνει τις προσπάθειές της προς αυτή την κατεύθυνση, ειδικότερα τώρα που βιώνει μια ιδιαίτερα δύσκολη οικονομική κατάσταση. Συμμετέχοντας, λοιπόν, στο Open Government Partnership, μια παγκόσμια πρωτοβουλία για τη διασφάλιση συγκεκριμένων κυβερνητικών δεσμεύσεων για την προώθηση της διαφάνειας, η χώρα μας στην κλίμακα αξιολόγησης ανήκει στην κατηγορία των «υποκριτών», καθώς αδυνατεί να τηρήσει τις αυτοδεσμεύσεις που αναλαμβάνει στο άνοιγμα των δεδομένων.
description: The purpose of this paper is to provide an in-depth content of the term Open Government and to record the current situation in Greece and not only in the area of the Open Government Initiative. Surveys have shown that the entry of e-Government into strong state economies and the transition to Open Government have been the main reasons for boosting public sector productivity, which works more efficiently and with greater transparency, leaving behind potential corruption phenomena. It also has as its main object of work the Open Data made available to the public without restrictions on the copying, re-use and disposal or modification of these or their modified copies. All this, according to law already passed (4305/2014), but which is not applicable or in the best of cases is poorly implemented. Besides, it is no coincidence that Open Data are in recent years the driver of global growth. Greece should and must step up its efforts in this direction, especially now that it is experiencing a particularly difficult economic situation. By participating, therefore, in the Open Government Partnership, a global initiative to ensure specific government commitments to promote transparency, our country in the rating scale belongs to the "hypocrites" category as it fails to keep its self-commitments in the opening of data.