cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Traditional ways Shuswap people identified and nurtured gifted and talented girls: Shuswap eminent women tell their stories
Creators: name: Jules, Diena Marie
Publisher: name: University of British Columbia
Year: 2009

description: Much of the literature on First Nations education is written by Euro- Canadians. However, in recent years, American Indian scholars have initiated research on gifted and talented First Nations children. The purpose of this paper is to present eminent Shuswap womens' perspectives of traditional ways gifted and talented girls were identified and nurtured over their lifetime. Seven eminent Shuswap Elder women from the Interior of British Columbia, whose gifts and talents were identified and nurtured form the nucleus of the study. Because Shuswap people traditionally have an oral culture very little was written of the Shuswap peoples' experiences, therefore, interviewing was deemed the most appropriate research technique. Through the Elder's own words, the experiences of the identification and nurturance of their gifts and talents in the four phases of life (childhood, adolescence, adult, Elder) are presented. The Elders were selected to represent various time periods and several different bands of the Shuswap Nation. All of them have been recognized for their service to the people locally, provincially, or nationally. The most outstanding feature which is revealed by this study is the extent to which the Elders struggled to stay on the path paved for them throughout their lives since their grandparents identified their gifts and talents. Their struggles may be viewed the same way First Nation people continue their fight for their aboriginal rights. The need to continue the work of preserving, recording, perpetuating and enhancing the Shuswap language, history and culture is shown here. Implications for further qualitative research are numerous. From specific aspects of culture such as the Shuswap concept of giftedness and the traditional ways Shuswap people identified and nurtured boys to more general comparisons of finding a national First Nations concept of giftedness or trying to determine how band-operated school are trying to identify and nurture their gifted and talented students, there are many possibilities. What has emerged is strong individuals and cultural group healing, adapting and surviving very well despite the dark ages.
Density structure of the interstellar medium and the star formation rate in galactic disks
Creators: name: Wada, Keiichi
name: Norman, Colin
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The probability distribution functions (PDF) of density of the ISM in galactic disks and global star formation rate are discussed. Three-dimensional hydrodynamic simulations show that the PDFs in globally stable, inhomogeneous ISM in galactic disks are well fitted by a single log-normal function over a wide density range. The dispersion of the log-normal PDF (LN-PDF) is larger for more gas-rich systems, and whereas the characteristic density of LN-PDF, for which the volume fraction becomes the maximum, does not significantly depend on the initial conditions. %At the characteristic density, thermal pressure and kinetic %pressure due to turbulent motion are comparable, and the material is %statistically stagnated in a turbulent flow. Supposing the galactic ISM is characterized by the LN-PDF, we give a global star formation rate (SFR) as a function of average gas density, a critical local density for star formation, and star formation efficiency. We find that the observed SFR is well-fitted by the theoretical SFR in a wide range of the global gas density ($10 - 10^4 M_\odot$ pc$^{-2}$). Star formation efficiency (SFE) for high density gas ($n > 10^3$ cm$^{-3}$) is SFE $= 0.001 - 0.01$ for normal spiral galaxies, and SFE $= 0.01 - 0.1$ for starburst galaxies. The LN-PDF and SFR proposed here could be applicable for modeling star formation on a kpc-scale in galaxies or numerical simulations of galaxy formation, in which the numerical resolution is not fine enough to describe the local star formation.
description: 20 pages with 19 figures, ApJ accepted
Spectral functions from the real-time functional renormalization group
Creators: name: Huelsmann, Sven
name: Schlichting, Soeren
name: Scior, Philipp
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We employ the functional renormalization group approach formulated on the Schwinger-Keldysh contour to calculate real-time correlation functions in scalar field theories. We provide a detailed description of the formalism, discuss suitable truncation schemes for real-time calculations as well as the numerical procedure to self-consistently solve the flow equations for the spectral function. Subsequently, we discuss the relations to other perturbative and non-perturbative approaches to calculate spectral functions, and present a detailed comparison and benchmark in $d=0+1$ dimensions.
description: 40 pages + 16 pages appendix, 8 figures
Η Ενδοευρωπαϊκή Μετανάστευση μετά το 1990 και οι Οικονομικές της Επιπτώσεις:
Creators: name: Γαλατιανός, Στυλιανός Εμμανουήλ
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Μετανάστευση
Οικονομική Αναπτυξη
Επιπτώσεις της μετανάστευσης
Migration
Economic Development
Impact of migration

description: Η παρούσα μελέτη αποτελεί μία προσπάθεια εξήγησης του φαινομένου της μετανάστευσης ως πηγή οικονομικής ανάπτυξης στις χώρες υποδοχής και προέλευσης του μετανάστη καθώς οι μετακινήσεις πληθυσμών αποτελούσαν πάντα μέρος της ιστορίας της ανθρωπότητας. Η θεωρητική και εμπειρική μεθοδολογία αποτέλεσαν τον τρόπο για την ολοκλήρωση της παρούσας εργασίας. Αναλυτικότερα η εργασία είναι βασισμένη σε δευτερογενή (βιβλιογραφική) έρευνα. Με την επεξήγηση του φαινομένου της μετανάστευσης έχουν ασχοληθεί πολλοί επιστημονικοί κλάδοι έχοντας αναπτύξει μοντέλα και θεωρίες βασιζόμενοι σε διαφορετικές αντιλήψεις και ιδεολογίες. Γι’ αυτό άλλωστε η μετανάστευση αποτελεί ένα διαχρονικό, πολύπλοκο, πολυδιάστατο και πολυσύνθετο φαινόμενο. Έτσι λόγω της φύσης και της διεπιστημονικότητας του θέματος της μετανάστευσης, η συγκεκριμένη μελέτη, πέρα της οικονομικής ανάλυσης ακολουθεί μια ευρύτερη προσέγγιση κοινωνικών επιστημών.
description: The present study is an attempt to explain the phenomenon of migration as a source of economic development both in the host country and the country of origin of the migrant since population displacement has always been a part of the human history. The conduct of the present study was based on a relevant theoretical and empirical methodology. More precisely, it is based on a secondary (bibliographic) research. Many scientific fields have worked on the explanation of the phenomenon of migration and they have developed models and theories according to various perceptions and ideologies. Therefore, migration is a constant, complicated, multidimensional and multifold phenomenon. Hence, because of the nature and the interdisciplinary character of the issue of migration, the present study, beyond the economic analysis, follows a wider approach of social sciences.
Asymptotics of the Number of Endpoints of a Random Walk on a Certain Class of Directed Metric Graphs
Creators: name: Chernyshev, Vsevolod
name: Tolchennikov, Anton
Publisher: name: arXiv
Year: 2021
Subjects: subject: Combinatorics (math.CO)
subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: A certain class of directed metric graphs is considered. Asymptotics for a number of possible endpoints of a random walk at large times is found.
Intense Star-formation and Feedback at High Redshift: Spatially-resolved Properties of the z=2.6 Submillimeter Galaxy SMMJ14011+0252
Creators: name: Nesvadba, N. P. H.
name: Lehnert, M. D.
name: Genzel, R.
name: Eisenhauer, F.
name: Baker, A. J.
name: Seitz, S.
name: Davies, R.
name: Lutz, D.
name: Tacconi, L.
name: Tecza, M.
name: Bender, R.
name: Abuter, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a detailed analysis of the spatially-resolved properties of the lensed submillimeter galaxy SMMJ14011+0252 at z=2.56, combining deep near-infrared integral-field data obtained with SPIFFI on the VLT with other multi-wavelength data sets. The broad characteristics of SMMJ14011+0252 are in agreement with what is expected for the early evolution of local massive spheroidal galaxies. From continuum and line flux, velocity, and dispersion maps, we measure the kinematics, star-formation rates, gas densities, and extinction for individual subcomponents. The star formation intensity is similar to low-redshift ``maximal starbursts'', while the line fluxes and the dynamics of the emission line gas provide direct evidence for a starburst-driven wind with physical properties very similar to local superwinds. We also find circumstantial evidence for "self-regulated" star formation within J1. The relative velocity of the bluer companion J2 yields a dynamical mass estimate for J1 within about 20 kpc, M_dyn \sim 1\times 10^{11} M_sun. The relative metallicity of J2 is 0.4 dex lower than in J1n/s, suggesting different star formation histories. SED fitting of the continuum peak J1c confirms and substantiates previous suggestions that this component is a z=0.25 interloper. When removing J1c, the stellar continuum and H-alpha line emission appear well aligned spatially in two individual components J1n and J1s, and coincide with two kinematically distinct regions in the velocity map, which might well indicate a merging system. This highlights the close similarity between SMGs and ULIRGs, which are often merger-driven maximal starbursts, and suggests that the intrinsic mechanisms of star-formation and related feedback are similar to low-redshift strongly star-forming systems.
description: Some of the figures changed from b/w to color
Abelian Toda solitons revisited
Creators: name: Nirov, Kh. S.
name: Razumov, A. V.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: We present a systematic and detailed review of the application of the method of Hirota and the rational dressing method to abelian Toda systems associated with the untwisted loop groups of complex general linear groups. Emphasizing the rational dressing method, we compare the soliton solutions constructed within these two approaches, and show that the solutions obtained by the Hirota's method are a subset of those obtained by the rational dressing method.
description: minor corrections (mostly stylistic), version to appear in Rev. Math. Phys
Effective interactions and dielectric study of polymer nanocomposite thin films of polyvinylidene fluoride and graphene oxide
Creators: name: John, Feba Anna
name: Thomas, Paulose
name: Jacob, George
name: Jose, Ajith James
Publisher: name: Taylor & Francis
Year: 2023
Subjects: Biochemistry
Space Science
Physical Sciences not elsewhere classified
Medicine
Chemical Sciences not elsewhere classified
Biological Sciences not elsewhere classified

description: Polyvinylidene fluoride (PVDF) is a well-known fluoropolymer for its electronic applications. The present work investigates the influence of Graphene oxide (GO) in various weight percentages over the dielectric profile of the PVDF matrix. Field emission scanning electron microscopy (FESEM) is used to explain the morphological features of the samples. The thermal stability of the PVDF polymer with the addition of GO was studied using thermogravimetric analysis (TGA). X-ray diffraction spectroscopy (XRD), confocal Raman microscopy (CRM), and Fourier Transform infrared spectroscopy (FTIR) were used to interpret the appreciable interfacial interactions between the matrix and the nanofiller and possible phase transformations. The presence of polar and non-polar polymorphic phases in PVDF was verified with the help of XRD, FTIR, and CRM analyses. The band gap energy of the samples was determined using the Tauc-plot method from UV–visible observations. The variation in the polarity of the matrix with the inclusion of GO is also noted. The dielectric and AC conductivity measurements were done at 100 Hz and 2 MHz. All these ascertain the candidacy of PVDF/GO nanocomposite thin films to be incorporated into electronic devices of this era.
Semileptonic Lambda(b)-->Lambda neutrino antineutrino decay in the Leptophobic Z-prime model
Creators: name: Sirvanli, Berin Belma
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the exclusive flavor chancing neutral current process Lambda(b)-->Lambda neutrino antineutrino in the leptophobic Z-prime model, where charged leptons do not couple to the extra Z-prime boson. The branching ratio, as well as, the longitudinal,transversal and normal polarizations are calculated. It has been shown that all these physical observables are very sensitive to the existence of new physics beyond the standard model and their experimental measurements can give valuable information about it.
description: 12 pages, 5 figures
Monitoring the radio emission of Proxima Centauri
Creators: name: Pérez-Torres, Miguel
name: Gómez, José Francisco
name: Ortiz, José Luis
name: Leto, Paolo
name: Anglada, Guillem
name: Gómez, José Luis
name: Rodríguez, Eloy
name: Trigilio, Corrado
name: Amado, Pedro J.
name: Alberdi, Antonio
name: Anglada-Escudé, Guillem
name: Osorio, Mayra
name: Umana, Grazia
name: Berdiñas, Zaira
name: López-González, María José
name: Morales, Nicolás
name: Rodríguez-López, Cristina
name: Chibueze, James
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We present results from the most comprehensive radio monitoring campaign towards the closest star to our Sun, Proxima Centauri. We report 1.1 to 3.1 GHz observations with the Australian Telescope Compact Array over 18 consecutive days in April 2017. We detect radio emission from Proxima Centauri for most of the observing sessions, which spanned $\sim$1.6 orbital periods of the planet Proxima b. The radio emission is stronger at the low-frequency band, centered around 1.6 GHz, and is consistent with the expected electron-cyclotron frequency for the known star's magnetic field intensity of about 600 Gauss. The 1.6 GHz light curve shows an emission pattern that is consistent with the orbital period of the planet Proxima b around the star Proxima, with its maxima of emission happening near the quadratures. We also observed two short-duration (a few minutes) flares and a long-duration (about three days) burst whose peaks happened close to the quadratures. We find that the frequency, large degree of circular polarization, change of the sign of circular polarization, and intensity of the observed radio emission are all consistent with expectations from electron cyclotron-maser emission arising from sub-Alfvénic star-planet interaction. We interpret our radio observations as signatures of interaction between the planet Proxima b and its host star Proxima. We advocate for monitoring other dwarf stars with planets to eventually reveal periodic radio emission due to star-planet interaction, thus opening a new avenue for exoplanet hunting and the study of a new field of exoplanet-star plasma interaction.
description: 14 pages, 11 figures. Accepted on December 2, 2020 in A&A (main journal), several typos corrected
Two New Vortex Liquids
Creators: name: Anderson, Philip W
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: It is suggested that the observations of nonlinear susceptibility and Nernst effect in cuprate superconductors above Tc, and those of non-classical rotational inertia in solid He, are two manifestations of a state of matter we call a vortex liquid, distinct from a conventional liquid in that its properties are dominated by conserved supercurrents flowing around a thermally fluctuating tangle of vortices.
title: Impacts of parental involvement on students’ lives in an inclusive postsecondary education program
title: A case study
titleType: Subtitle
Creators: name: Chen, Xingyao
Publisher: name: Washington State University
Year: 2024
Subjects: parental involvement
Inclusive Postsecondary Education
Intellectual Disabilities
Developmental Disabilities

description: Research has found the importance of parental involvement from K-12 through higher education, yet its effects on students with intellectual and developmental disabilities (IDDs) in Inclusive Postsecondary Education (IPSE) programs remain underexplored. This qualitative case study investigates the areas, methods, and differences from K-12, as well as the reasons, impacts, and challenges of parental involvement for students with IDDs in an IPSE program at Washington State University. Semi-structured interviews with nine parents revealed that participants were involved in various aspects of students’ development, such as academics, employment, and independent living, primarily through phone and in-person visits. Compared to their involvement in K-12 education, participants emphasized students’ independence more, interacted less with staff, and focused more on non-academic support. Parental involvement was driven by students’ unique needs, parental expectations, and parenting styles. While most parental involvement was
description: beneficial, overinvolvement occasionally had negative effects. Challenges faced by participants included scheduling conflicts, travel costs, lack of resource platforms, and communication barriers. The results of the study indicate the need for structured parental involvement and highlight the importance of IPSE programs providing guidance to better support students’ transitions into adulthood. Recommendations for IPSE programs and implications for future study are discussed based on these results.
Quantum dynamics of repulsively bound atom pairs in the Bose-Hubbard model
Creators: name: Wang, Li
name: Hao, Yajiang
name: Chen, Shu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We investigate the quantum dynamics of repulsively bound atom pairs in an optical lattice described by the periodic Bose-Hubbard model both analytically and numerically. In the strongly repulsive limit, we analytically study the dynamical problem by the perturbation method with the hopping terms treated as a perturbation. For a finite-size system, we numerically solve the dynamic problem in the whole regime of interaction by the exact diagonalization method. Our results show that the initially prepared atom pairs are dynamically stable and the dissociation of atom pairs is greatly suppressed when the strength of the on-site interaction is much greater than the tunneling amplitude, i.e., the strongly repulsive interaction induces a self-localization phenomenon of the atom pairs.
description: 7 pages, 6 figures, significant changes made
Parametrization of C-shocks. Evolution of the Sputtering of Grains
Creators: name: Jimenez-Serra, I.
name: Caselli, P.
name: Martin-Pintado, J.
name: Hartquist, T. W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Context: The detection of narrow SiO lines toward the young shocks of the L1448-mm outflow has been interpreted as a signature of the magnetic precursor of C-shocks. In contrast with the low SiO abundances (<10E-12) in the ambient gas, the narrow SiO emission at almost ambient velocities reveals enhanced SiO abundances of 10E-11. This enhancement has been proposed to be produced by the sputtering of the grain mantles at the first stages of C-shocks. However, modelling of the sputtering of grains has usually averaged the SiO abundances over the dissipation region of C-shocks, which cannot explain the recent observations. Aims: To model the evolution of the gas phase abundances of SiO, CH3OH and H2O, produced by the sputtering of grains as the shock propagates through the ambient gas. Methods: We propose a parametric model to describe the physical structure of C-shocks as a function of time. Using the known sputtering yields for water mantles (with minor constituents like silicon and CH3OH) and olivine cores by collisions with H2, He, C, O, Si, Fe and CO, we follow the evolution of the abundances of silicon, CH3OH and H2O ejected from grains. Results: The evolution of these abundances shows that CO seems to be the most efficient sputtering agent in low velocity shocks. The velocity threshold for the sputtering of silicon from the grain mantles is reduced by 5-10 km s-1 by CO compared to other models. The sputtering by CO can generate SiO abundances of 10E-11 at the early stages of low velocity shocks, consistent with those observed in the magnetic precursor of L1448-mm. Our model also satisfactorily reproduce the progressive enhancement of SiO, CH3OH and H2O observed in this outflow by the coexistence of two shocks with vs=30 and 60kms-1 within the same region.
description: 12 pages, 7 figures, accepted for publication in A&A
First-order formalism for dark energy and dust
Creators: name: Bazeia, D.
name: Losano, L.
name: Rodrigues, J. J.
name: Rosenfeld, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This work deals with first-order formalism for dark energy and dust in standard cosmology, for models described by real scalar field in the presence of dust in spatially flat space. The field dynamics may be standard or tachyonic, and we show how the equations of motion can be solved by first-order differential equations. We investigate a model to illustrate how the dustlike matter may affect the cosmic evolution using this framework.
description: 5 pages, 1 figure; title changed, new author included, discussions extended, references added, version to appear in EPJC
Atomic and electronic structure of cesium lead triiodide surfaces
Creators: name: Seidu, Azimatu
name: Dvorak, Marc
name: Rinke, Patrick
name: Li, Jingrui
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The (001) surface of the emerging photovoltaic material cesium lead triiodide (CsPbI3 ) is studied. Using first-principles methods, we investigate the atomic and electronic structure of cubic (α) and orthorhombic (γ) CsPbI3 . For both phases, we find that CsI-termination is more stable than PbI2-termination. For the CsI-terminated surface, we then compute and analyse the surface phase diagram. We observe that surfaces with added or removed units of nonpolar CsI and PbI2 are most stable. The corresponding band structures reveal that the α phase exhibits surface states that derive from the conduction band. The surface reconstructions do not introduce new states in the band gap of CsPbI3, but for the α phase we find additional surface states at the conduction band edge.
Second language learning and academic achievement revisited : a connectionist deconstruction of the cognitive consequences of bilingualism
Creators: name: Hawson, Anne
Publisher: name: University of British Columbia
Year: 2009

description: The original Threshold Hypothesis proposed in 1976 by Cummins as a reasonable explanation of the data gathered to that date on the cognitive consequences of learning a second language has gained widespread acceptance in second language teaching circles, but has been the subject of considerable debate among second language researchers. An examination of the critiques of the hypothesis as well as the responses invoked by these critiques reveals that much of the criticism is well-founded. Given that the Threshold Hypothesis proposes that "cognitive" benefits or deficits can accrue through the learning of a second language, the conceptualization of cognition underpinning the hypothesis is important in understanding its inadequacies. Upon examination of Cummins' work, it is concluded that cognitive processing is considered by Cummins to be a discrete category of brain processing operating at the conceptual level. A fundamental premise of this thesis is that connectionism, which proposes that cognition is more appropriately described as operating on a sub-conceptual level, and as being intimately intertwined and dependent upon what have been regarded as "noncognitive" aspects of brain functioning such as emotion, attention, and sensory processing, provides a new and potentially enlightening perspective on cognitive issues. A critique of connectionism as a valid model of learning in the brain suggests that it has considerable validity, but cannot yet describe all types and/or all processes involved in learning. Nevertheless, it is concluded that a model of second language learning built upon the conjectures of connectionism could bring new insights into how second language learning in immersion situations affects brain processing, and thereby provide clues which might explain perceived cognitive benefits and deficits. The model developed proposes that, under immersion conditions, second language learners may be undergoing an attentional shift in information processing towards the visual system, and away from the auditory. If this hypothesis can be substantiated by empirical tests, it could explain why second language learners in immersion situations are in danger of becoming poor readers, and may provide fertile ground for the development of remedial educational treatments. This is a wholly theoretical study based on literature research.
Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology
Creators: name: Ge, Zhehao
name: Joucken, Frederic
name: Quezada, Eberth
name: da Costa, Diego R.
name: Davenport, John
name: Giraldo, Brian
name: Taniguchi, Takashi
name: Watanabe, Kenji
name: Kobayashi, Nobuhiko P.
name: Low, Tony
name: Velasco, Jairo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Electrostatically defined quantum dots (QDs) in Bernal stacked bilayer graphene (BLG) are a promising quantum information platform because of their long spin decoherence times, high sample quality, and tunability. Importantly, the shape of QD states determines the electron energy spectrum, the interactions between electrons, and the coupling of electrons to their environment, all of which are relevant for quantum information processing. Despite its importance, the shape of BLG QD states remains experimentally unexamined. Here we report direct visualization of BLG QD states by using a scanning tunneling microscope. Strikingly, we find these states exhibit a robust broken rotational symmetry. By using a numerical tight-binding model, we determine that the observed broken rotational symmetry can be attributed to low energy anisotropic bands. We then compare confined holes and electrons and demonstrate the influence of BLG's nontrivial band topology. Our study distinguishes BLG QDs from prior QD platforms with trivial band topology.
Experimental Tests of Asymptotic Freedom
Creators: name: Bethke, Siegfried
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: History and Philosophy of Physics (physics.hist-ph)
subject: FOS: Physical sciences

description: Quantum Chromodynamics (QCD), the gauge field theory of the Strong Interaction, has specific features, asymptotic freedom and confinement, which determine the behaviour of quarks and gluons in particle reactions at high and at low energy scales. QCD predicts that the strong coupling strength $\as$ decreases with increasing energy or momentum transfer, and vanishes at asymptotically high energies. In this review, the history and the status of experimental tests of asymptotic freedom are summarised. The world summary of measurements of $\as$ is updated, leading to an unambiguous verification of the running of $\as$ and of asymptotic freedom, in excellent agreement with the predictions of QCD. Averaging a set of measurements balanced between different particle processes and the available energy range, results in a new and improved world average of $\amz = 0.1189 \pm 0.0010 .$
description: 38 pages, 18 figures
Fractional solitons in non-Euclidian elastic plates
Creators: name: Sun, Kai
name: Mao, Xiaoming
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that minimal-surface non-Euclidean elastic plates share the same low-energy effective theory as Haldane's dimerized quantum spin chain. As a result, such elastic plates support fractional excitations, which take the form of charge-$1/2$ solitons between degenerate states of the plates, in strong analogy to their quantum counterpart. These fractional solitons exhibit properties similar to fractional excitations in quantum fractional topological states, including deconfinement and braiding, as well as unique new features such as holographic properties and diode-like nonlinear response, demonstrating great potentials for applications as mechanical metamaterials.
description: 8 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1907.06620
Cosmological magnetic fields from nonlinear effects
Creators: name: Kobayashi, Tsutomu
name: Maartens, Roy
name: Shiromizu, Tetsuya
name: Takahashi, Keitaro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In the standard cosmological model, magnetic fields and vorticity are generated during the radiation era via second-order density perturbations. In order to clarify the complicated physics of this second-order magnetogenesis, we use a covariant approach and present the electromagneto-dynamical equations in the nonlinear regime. We use the tight-coupling approximation to analyze Thomson and Coulomb scattering. At the zero-order limit of exact tight-coupling, we show that the vorticity is zero and no magnetogenesis takes place at any nonlinear order. We show that magnetogenesis also fails at all orders if either protons or electrons have the same velocity as the radiation, and momentum transfer is neglected. Then we prove a key no-go result: at first-order in the tight-coupling approximation, magnetic fields and vorticity still cannot be generated even via nonlinear effects. The tight-coupling approximation must be broken at first order, for the generation of vorticity and magnetic fields, and we derive a closed set of nonlinear evolution equations that governs this generation. We estimate that the amplitude of the magnetic field at recombination on the horizon scale is $\sim 10^{-27} $G.
description: 8 pages; v2: Estimate of the magnetic field computed; minor corrections and improvements
A Continuous Path of Singular Masas in the Hyperfinite II_1 Factor
Creators: name: Sinclair, Allan
name: White, Stuart
Publisher: name: arXiv
Year: 2006
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L10

description: Using methods of R.J.Tauer we exhibit an uncountable family of singular masas in the hyperfinite $\textrm{II}_1$ factor $\R$ all with Pukánszky invariant $\{1\}$, no pair of which are conjugate by an automorphism of $R$. This is done by introducing an invariant $Γ(A)$ for a masa $A$ in a \IIi factor $N$ as the maximal size of a projection $e\in A$ for which $A e$ contains non-trivial centralising sequences for $eN e$. The masas produced give rise to a continuous map from the interval $[0,1]$ into the singular masas in $\R$ equiped with the $d_{\infty,2}$-metric. A result is also given showing that the Pukánszky invariant is $d_{\infty,2}$-upper semi-continuous. As a consequence, the sets of masas with Pukánszky invariant $\{n\}$ are all closed.
description: 18 pages
Stable bundle extensions on elliptic Calabi-Yau threefolds
Creators: name: Andreas, Bjorn
name: Curio, Gottfried
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 14J60, 14J32, 81T30, 83E30

description: We construct stable bundle extensions on elliptically fibered Calabi-Yau threefolds. We show that these bundles can solve the topological anomaly constraint in heterotic string theory without the need of invoking background fivebranes.
description: 18 pages, minor changes
Comparison of the scaling analysis of the mixed-state magnetization data with direct measurements of the upper critical field in Y-123
Creators: name: Landau, I. L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: By comparison of recent direct measurements of the temperature dependence of the upper critical field $H_{c2}$ in an Y-123 high temperature superconductor with the scaling analysis of magnetization data, collected in fields H << H_c2, we demonstrate that that the temperature dependence of the Ginzburg-Landau parameter kappa is negligible. Another conclusion is that the normalized temperature dependence of H_c2 is independent of the orientation of the magnetic field in respect to crystallographic axes of the sample. We also discuss that isotropy of the temperature dependence of H_c2 straightforwardly follows from the Ginzburg-Landau theory if kappa does not depend on temperature.
description: 3 pages, 1 figure
Mobile Apps for Foot Measurement: A Scoping Review
Creators: name: Kabir, Muhammad Ashad
name: Rahman, Sowmen
name: Islam, Mohammad Mainul
name: Ahmed, Sayed
name: Laird, Craig
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: With the proliferation of smart phone, a major growth in the use of apps related to the health category, specifically those concerned with foot health can be observed. Although new, these apps are being used practically for scanning feet with an aim to providing accurate information about various properties of the human foot. With the availability of many 'foot scanning and measuring apps' in the app stores, the need for an evaluation system for such apps can be deemed necessary as little information regarding the evidence-based quality of these apps is available. To characterize the assessment of measurement techniques and essential software quality characteristics of mobile foot measuring apps, and determine their effectiveness for potential use as commercial professional tools for foot care health professionals such as pedorthists, podiatrists, orthotists and so on, to assist in measuring foot for custom shoes, and for individuals to enhance the awareness of foot health and hygiene and prevention of foot-related problems. An electronic search across Android and iOS app stores was conducted between July 2020 and August 2020 for apps related to foot measurement. Mobile apps with stated goals of foot measurement and general foot health were identified and selected by three independent raters and discrepancies regarding the selected apps were resolved via a fourth rater. Evaluation inferences found all apps failing to meet even half of the measurement-specific criteria required for the proper manufacturing of custom-made footwear. 23% (6/26) of apps were found to utilize either external scanners or advanced algorithms to reconstruct 3D models of user foot that can possibly be used for ordering custom-made footwear and medical casts for fitting irregular foot sizes and shapes. Overall, current apps for foot measurement do not follow any specific guidelines for measurement purposes.
Carter subgroups of finite almost simple groups
Creators: name: Evgenii, Vdovin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: 20D06, 20G40

description: In the paper we complete the classification of Carter subgroups in finite almost simple groups. In particular, we prove that Carter subgroups of every finite almost simple group are conjugate. Togeather with previous results by author and F. Dalla Volta, A. Lucchini, and M. C. Tamburini, as a corollary, it follows that Carter subgroups of every finite group are conjugate.
description: To appear in "Algebra and Logic"
Enhancing informal learning in an Aquarium
Creators: name: McIntosh, Lisa M
Publisher: name: University of British Columbia
Year: 2009

description: Educators in zoo sand a quaria today present general information in an attempt to educate visitors about animals and conservation issues. This presentation of biological information is isolated from the any observable animal activity in the exhibit. The Vancouver Aquarium has a different approach to visitor learning. This thesis examines one of its innovative approaches to visitor education designed to initiate visitor involvement with animals in the exhibits. This innovative approach uses changeable , handwritten whiteboards to highlight new animal events in the Vancouver Aquarium. Qualitative and quantitative methods were used to investigate the effect of these whiteboards on the behaviour of groups of visitors at an exhibit through observations and short group interviews. Sixty-two percent of the visitors observed in the study used the whiteboard. The average time whiteboard users spent viewing the exhibit (57.06 seconds) was significantly greater (t = 36.65, df = 129, p < 0.001) than the time non-whiteboard users spent viewing the exhibit (25.94 seconds). Whiteboard users also exhibited a significantly higher level of interactivity (the number of behaviours , pointing, peering , conversing and rereading the whiteboard an individual demonstrates while at an exhibit) than the non-whiteboard users (X2 = 237.16, p < 0.01). Interview comments revealed that whiteboard users understood the Vancouver Aquarium's intent to convey real, relevant, current and changing information about animals within the exhibits using whiteboards.
Magic Numbers from New Systematics
Creators: name: Basu, Chinmay
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: A new systematics from the separation energy of deuteron is used to examine the magicity of stable as well as nuclei towards dripline.
description: 11 pages, 4 figures, accepted for publication in IJMPE
Improving the open cluster census. I. Comparison of clustering algorithms applied to Gaia DR2 data
Creators: name: Hunt, Emily L.
name: Reffert, Sabine
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The census of open clusters in the Milky Way is in a never-before seen state of flux. Recent works have reported hundreds of new open clusters thanks to the incredible astrometric quality of the Gaia satellite, but other works have also reported that many open clusters discovered in the pre Gaia era may be associations. We aim to conduct a comparison of clustering algorithms used to detect open clusters, attempting to statistically quantify their strengths and weaknesses by deriving the sensitivity, specificity, and precision of each as well as their true positive rate against a larger sample. We selected DBSCAN, HDBSCAN, and Gaussian mixture models for further study, owing to their speed and appropriateness for use with Gaia data. We developed a preprocessing pipeline for Gaia data and developed the algorithms further for the specific application to open clusters. We derived detection rates for all 1385 open clusters in the fields in our study as well as more detailed performance statistics for 100 of these open clusters. DBSCAN was sensitive to 50% to 62% of the true positive open clusters in our sample, with generally very good specificity and precision. HDBSCAN traded precision for a higher sensitivity of up to 82%, especially across different distances and scales of open clusters. Gaussian mixture models were slow and only sensitive to 33% of open clusters in our sample, which tended to be larger objects. Additionally, we report on 41 new open cluster candidates detected by HDBSCAN, three of which are closer than 500 pc. When used with additional post-processing to mitigate its false positives, we have found that HDBSCAN is the most sensitive and effective algorithm for recovering open clusters in Gaia data. Our results suggest that many more new and already reported open clusters have yet to be detected in Gaia data.
description: 28 pages, 13 figures, and 8 tables. Accepted in A&A. Supporting data is available on request until archiving at the CDS is completed
Historical Shoreline Changes in Response to Environmental Conditions in West Delaware Bay
Creators: name: French, Gregory T.
Publisher: name: Digital Repository at the University of Maryland
Year: 1990
Subjects: Delaware Bay
coastal engineering
erosion

description: This study quantified historical changes in the
coastline of the west shore of Delaware Bay. Shoreline
changes were measured through the compilation of
historical maps and photographs utilizing the Metric
Mapping technique. These changes were correlated with
various environmental conditions and with human
influences.
The results portray a 135 year pattern of overall
erosion, with long-term rates averaging -4.5 ftjyr,
which is considerably greater than the u.s. Atlantic
coast average. Coastal engineering (e.g., groins,
jetties and beach nourishment) were locally effective
in reducing erosion rates and in some cases promoting
limited accretion. Perhaps more importantly, there
were few associated negative effects alongshore
suggesting that various forms of coastal engineering
can be effective in a low-energy environment, even when
done in a somewhat unorganized fashion.
A correlation was found between erosion rates and
underlying Pleistocene morphology. Where pre-Holocene
sediments were exposed in the nearshore, erosion rates
were lower. However, erosion rates were substantially
higher along marshy shorelines.
This erosion is not continuous either spatially or
temporally, but instead is largely storm-driven.
Periods of relative quiescence corresponded with
lowered rates of average annual shoreline recession.
With the exception of the northernmost marshy areas,
severe erosion occurs along all shorelines, regardless
of morphology, in response to major coastal storms.
Complex permittivity of a biased superlattice
Creators: name: Hernández-Cabrera, A.
name: Aceituno, P.
name: Vasko, F. T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Intersubband response in a superlattice subjected to a homogeneous electric field (biased superlattice with equipopulated levels) is studied within the tight-binding approximation, taking into account the interplay between homogeneous and inhomogeneous mechanisms of broadening. The complex dielectric permittivity is calculated beyond the Born approximation for a wide spectral region. A detectable gain below the resonance is obtained for the low-doped $GaAs$-based biased superlattice in the THz spectral region. Conditions of the stimulated emission regime for metallic and dielectric waveguide structures are discussed.
description: 7 pages, 5 figures
Symmetry breaking from Scherk-Schwarz compactification
Creators: name: Salvatori, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyze the classical stable configurations of an extra-dimensional gauge theory, in which the extra dimensions are compactified on a torus. Depending on the particular choice of gauge group and the number of extra dimensions, the classical vacua compatible with four-dimensional Poincaré invariance and zero instanton number may have zero energy. For SU(N) on a two-dimensional torus, we find and catalogue all possible degenerate zero-energy stable configurations in terms of continuous or discrete parameters, for the case of trivial or non-trivial 't Hooft non-abelian flux, respectively. We then describe the residual symmetries of each vacua.
description: 24 pages, 1 figure, Section 4 modified
Downflowing umbral flashes as an evidence of standing waves in sunspot umbrae
Creators: name: Felipe, T.
name: Henriques, V. M. J.
name: Rodríguez, J. de la Cruz
name: Socas-Navarro, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Umbral flashes are sudden brightenings commonly visible in the core of chromospheric lines. Theoretical and numerical modeling suggest that they are produced by the propagation of shock waves. According to these models and early observations, umbral flashes are associated with upflows. However, recent studies have reported umbral flashes in downflowing atmospheres. We aim to understand the origin of downflowing umbral flashes. We explore how the existence of standing waves in the umbral chromosphere impacts the generation of flashed profiles. We performed numerical simulations of wave propagation in a sunspot umbra with the code MANCHA. The Stokes profiles of the Ca II 8542 Å line were synthesized with NICOLE. For freely-propagating waves, the chromospheric temperature enhancements of the oscillations are in phase with velocity upflows. In this case, the intensity core of the Ca II 8542 Å atmosphere is heated during the upflowing stage of the oscillation. If we consider a different scenario with a resonant cavity, the wave reflections at the sharp temperature gradient of the transition region lead to standing oscillations. In this situation, temperature fluctuations are shifted backward and temperature enhancements partially coincide with the downflowing stage of the oscillation. In umbral flashes produced by standing oscillations, the reversal of the emission feature is produced when the oscillation is downflowing. The chromospheric temperature keeps increasing while the atmosphere is changing from a downflow to an upflow. During the appearance of flashed Ca II 8542 Å cores, the atmosphere is upflowing most of the time, and only 38\% of the flashed profiles are associated with downflows. We find a scenario that remarkably explains the recent empirical findings of downflowing umbral flashes as a natural consequence of the presence of standing oscillations above sunspot umbrae.
description: Letter accepted for publication in A&A