cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Phase diagram of the vortex system in layered superconductors with strong columnar pinning
Creators: name: Dasgupta, Chandan
name: Valls, Oriol T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present the results of a detailed investigation of the low-temperature properties of the vortex system in strongly anisotropic layered superconductors with a random array of columnar pinning centers. Our method involves numerical minimization of a free energy functional in terms of the time-averaged local vortex density. It yields the detailed vortex density distribution for all local free-energy minima, and therefore allows the computation of any desired correlation function of the time-averaged local vortex density. Results for the phase diagram in the temperature vs. pin concentration plane at constant magnetic induction are presented. We confirm that for very low pin concentrations, the low-temperature phase is a Bragg glass, which melts into an interstitial liquid phase via two first-order steps, separated by a Bose glass phase. At higher concentrations, however, the low-temperature phase is a Bose glass, and the melting transition becomes continuous. The transition is then characterized by the onset of percolation of liquid-like regions across the sample. Inhomogeneous local melting of the Bose glass is found to occur. There is also a depinning crossover between the interstitial liquid and a completely unpinned liquid at higher temperatures. At sufficiently large pin concentrations, the depinning line merges with the Bose glass to interstitial liquid transition. Many of the features we find have been observed experimentally and in simulations. We discuss the implications of our results for future experimental and theoretical work.
description: 15 pages including Figures
Role of Compressive Viscosity and Thermal Conductivity on the Damping of Slow Waves in the Coronal Loops With and Without Heating-Cooling Imbalance
Creators: name: Prasad, Abhinav
name: Srivastava, A. K.
name: Wang, T. J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In the present paper, we derive a new dispersion relation for slow magnetoacoustic waves invoking the effect of thermal conductivity, compressive viscosity, radiation and unknown heating term along with the consideration of heating cooling imbalance from linearized MHD equations. We solve the general dispersion relation to understand role of compressive viscosity and thermal conductivity in damping of the slow waves in coronal loops with and without heating cooling imbalance. We have analyzed wave damping for the range of loop length $L$=50-500 Mm, temperature $T$=5-30 MK, and density $ρ$=10$^{-11}$-10$^{-9}$ kg m$^{-3}$. It was found that inclusion of compressive viscosity along with thermal conductivity significantly enhances the damping of fundamental mode oscillations in shorter (e.g., $L$=50 Mm) and super-hot ($T>$10 MK) loops. However, role of the viscosity in damping is insignificant in longer (e.g., $L$=500 Mm) and hot loops (T$\leq$10 MK) where, instead, thermal conductivity along with the presence of heating cooling imbalance plays a dominant role. For the shorter loops at the super-hot regime of the temperature, increment in loop density substantially enhances damping of the fundamental modes due to thermal conductivity when the viscosity is absent, however, when the compressive viscosity is added the increase in density substantially weakens damping. Thermal conductivity alone is found to play a dominant role in longer loops at lower temperatures (T$\leq$10 MK), while compressive viscosity dominates in damping at super-hot temperatures ($T>$10 MK) in shorter loops. The predicted scaling law between damping time ($τ$) and wave period ($P$) is found to better match to observed SUMER oscillations when heating cooling imbalance is taken into account in addition to thermal conductivity and compressive viscosity for the damping of the fundamental slow mode oscillations.
description: 40 Pages; 13 Figures; 01 Table; Solar Physics (in press)
Gene Expression of Cytochrome P450 1A in Hybrid Catfish (Clarias gariepinus ? Clarias macrocephalus) Exposed to Chlorpyrifos or Carbaryl Insecticides
Creators: name: Chawanrat Somnuek
name: Chuta Boonphakdee
name: Voravit Cheevaporn
name: Tanaka, Keiichi
name: Khobkul Nongnutch
Publisher: name: Thai Society of Higher Education Institutes on Environment
Year: 2012
Subjects: cytochrome P450 1A,chlorpyrifos,carbaryl,hybrid catfish,EROD activity,real-time PCR

description: 2, 5, EnvironmentAsia
Levoglucosan as an Indicator of Biomass Burning from Selected Tropical Plants
Creators: name: Mohd Talib Latif
name: Meia, Chan Siew
name: Norfazrin Mohd Hanif
name: Thunwadee Srithawirat
Publisher: name: Thai Society of Higher Education Institutes on Environment
Year: 2012
Subjects: levoglucosan,biomass burning,tropical plants,indicator,air pollution

description: 2, 5, EnvironmentAsia
The CaFe Project: Optical FeII and Near-Infrared Ca II triplet emission in active galaxies. II. The driver(s) of the Ca II and Fe II and its potential use as a chemical clock
Creators: name: Martínez-Aldama, Mary Loli
name: Panda, Swayamtrupta
name: Czerny, Bożena
name: Marinello, Murilo
name: Marziani, Paola
name: Dultzin, Deborah
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this second paper in the series, we carefully analyze the observational properties of the optical FeII and NIR CaII triplet in Active Galactic Nuclei, as well as the luminosity, black hole mass, and Eddington ratio in order to define the driving mechanism behind the properties of our sample. The CaII shows an inverse Baldwin effect, bringing out the particular behavior of this ion with respect to the other low-ionization lines such as H$β$. We performed a Principal Component Analysis, where 81.2% of the variance can be explained by the first three principal components drawn from the FWHMs, luminosity, and equivalent widths. The first principal component (PC1) is primarily driven by the combination of black hole mass and luminosity with a significance over 99.9%, which in turn is reflected in the strong correlation of the PC1 with the Eddington ratio. The observational correlations are better represented by the Eddington ratio, thus it could be the primary mechanism behind the strong correlations observed in the CaII-FeII sample. Since calcium belongs to the $α$-elements, the FeII/CaII flux ratio can be used as a chemical clock for determining the metal content in AGN and trace the evolution of the host galaxies. We confirm the de-enhancement of the ratio FeII/CaII by the Eddington ratio, suggesting a metal enrichment of the BLR in intermediate-$z$ with respect to low-$z$ objects. A larger sample, particularly at $z$>2, is needed to confirm the present results.
description: 35 pages, 16 figures, 4 tables. Accepted for publication in ApJ
Differential approximation for Kelvin-wave turbulence
Creators: name: Nazarenko, Sergey
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: I present a nonlinear differential equation model (DAM) for the spectrum of Kelvin waves on a thin vortex filament. This model preserves the original scaling of the six-wave kinetic equation, its direct and inverse cascade solutions, as well as the thermodynamic equilibrium spectra. Further, I extend DAM to include the effect of sound radiation by Kelvin waves. I show that, because of the phonon radiation, the turbulence spectrum ends at a maximum frequency $ω^* \sim (ε^3 c_s^{20} / κ^{16})^{1/13}$ where $ε$ is the total energy injection rate, $c_s$ is the speed of sound and $κ$ is the quantum of circulation.
description: Prepared of publication in JETP Letters
Disturbing practice : reading and writing (social studies) teacher education as text
Creators: name: Segall, Avner
Publisher: name: University of British Columbia
Year: 2009

description: Although preservice teacher education comprises only a small part of student teachers' socialization into the teaching profession, it nevertheless has an important impact of student teachers imagination through an educative world it renders both possible and the intelligible. Anchored in a secondary social studies methods course at the University of British Columbia, and following six of its student teacher participants through their university- and practicum-based experiences, this year-long ethnographic study explores the production of knowledge and knowing in presevice teacher education. As such, it examines how particular versions and visions of education, teaching, and learning are made possible as well as on what they, in turn, make possible for prospective social studies teachers learning to teach. Exploring how teachers' ways of being are dependent, in part, on student teachers' ways of becoming, this study examines what happens to student teachers during their preservice education and, as a result, what they make happen because of what happens to them. Examining the complex relationship between the knowledge student teachers are given and the knowledge they themselves produce, this dissertation considers not only what student teachers choose to say and do but also what structures their choices. Disturbing the practice of teacher education by examining how discourses use and are used and what, in the process, gets covered over, silenced, and ignored, this dissertation attempts to extend the traditional exploration of how prospective social studies student teachers learn to manage ideas and theories in the teacher education classrooms to the examination of how the use of ideas and theories in those very classrooms manages those who attempt to engage them. Organized as a multivocal text in which the running narrative is interrupted and interrogated by the researcher's own reflexive comments about the impossibilities of knowing and those of the participants about the study and its textualization, this dissertation focuses on the problematics and possibilities in the process of learning to teach, highlighting and publicly engaging them in order to bring more of what we do in university-based teacher education classrooms into the fold of the discussion both about and in teacher education
Calculating Milnor Numbers and Versal Component Dimensions from P-Resolution Fans
Creators: name: Ilten, Nathan Owen
Publisher: name: arXiv
Year: 2008
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14B07, 14M25

description: We use Altmann's toric fan description of P-resolutions to formulate a new description of deformation theory invariants for two-dimensional cyclic quotient singularities. In particular, we show how to calculate the dimensions of the (reduced) versal base space components as well as Milnor numbers of smoothings over them.
description: 8 pages; 2 figures; v2 added section on Milnor numbers, reworked proof of dimension formula, new example, and new title
Solitary states in the mean-field limit
Creators: name: Kruk, Nikita
name: Maistrenko, Yuri
name: Koeppl, Heinz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study active matter systems where the orientational dynamics of underlying self-propelled particles obey second order equations. By primarily concentrating on a spatially homogeneous setup for particle distribution, our analysis combines theories of active matter and oscillatory networks. For such systems, we analyze the appearance of solitary states via a homoclinic bifurcation as a mechanism of the frequency clustering. By introducing noise, we establish a stochastic version of solitary states and derive the mean-field limit described by a partial differential equation for a one-particle probability density function, which one might call the continuum Kuramoto model with inertia and noise. By studying this limit, we establish second order phase transitions between polar order and disorder. The combination of both analytical and numerical approaches in our study demonstrates an excellent qualitative agreement between mean-field and finite size models.
Bulk Electronic Structure of Lanthanum Hexaboride (LaB6) by Hard X-ray Angle-Resolved Photoelectron Spectroscopy
Creators: name: Rattanachata, A.
name: Nicolaï, L.
name: Martins, H. P.
name: Conti, G.
name: Verstraete, M. J.
name: Gehlmann, M.
name: Ueda, S.
name: Kobayashi, K.
name: Vishik, I.
name: Schneider, C. M.
name: Fadley, C. S.
name: Gray, A. X.
name: Minár, J.
name: Nemšák, S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In the last decade rare-earth hexaborides have been investigated for their fundamental importance in condensed matter physics, and for their applications in advanced technological fields. Among these compounds, LaB$_6$ has a special place, being a traditional d-band metal without additional f- bands. In this paper we investigate the bulk electronic structure of LaB$_6$ using hard x-ray photoemission spectroscopy, measuring both core-level and angle-resolved valence-band spectra. By comparing La 3d core level spectra to cluster model calculations, we identify well-screened peak residing at a lower binding energy compared to the main poorly-screened peak; the relative intensity between these peaks depends on how strong the hybridization is between La and B atoms. We show that the recoil effect, negligible in the soft x-ray regime, becomes prominent at higher kinetic energies for lighter elements, such as boron, but is still negligible for heavy elements, such as lanthanum. In addition, we report the bulk-like band structure of LaB$_6$ determined by hard x-ray angle-resolved photoemission spectroscopy (HARPES). We interpret HARPES experimental results by the free-electron final-state calculations and by the more precise one-step photoemission theory including matrix element and phonon excitation effects. In addition, we consider the nature and the magnitude of phonon excitations in HARPES experimental data measured at different temperatures and excitation energies. We demonstrate that one step theory of photoemission and HARPES experiments provide, at present, the only approach capable of probing true bulk-like electronic band structure of rare-earth hexaborides and strongly correlated materials.
description: Total 26 pages, Total 11 figures
Interplay of orbitally polarized and magnetically ordered phases in doped transition metal oxides
Creators: name: Fresard, R.
name: Raczkowski, M.
name: Oles, A. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the magnetic instabilities of the two-dimensional model of interacting e_g electrons for hole doping away from two electrons per site in the mean-field approximation. In particular, we address the occurrence of orbitally polarized states due to the inequivalent orbitals, and their interplay with ferromagnetic and antiferromagnetic spin order. The role played by the Hund's exchange coupling J_H and by the crystal field orbital splitting E_z in stabilizing one of the competing phases is discussed in detail.
description: 7 pages, 4 figures
`Local' Quantum Criticality at the Nematic Quantum Phase Transition
Creators: name: Lawler, Michael J.
name: Fradkin, Eduardo
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We discuss the finite temperature properties of the fermion correlation function near the fixed point theory of the nematic quantum critical point (QCP) of a metallic Fermi system. We show that though the fixed point theory is above its upper critical dimension, the equal time fermion correlation function takes on a universal scaling form in the vicinity of the QCP. We find that in the quantum critical regime, this equal-time correlation function has an ultra local behavior in space, while the low-frequency behavior of the equal-position auto correlation function is that of a Fermi liquid up to subdominant terms. This behavior should also apply to other quantum phase transitions of metallic Fermi systems.
description: 4 pages, this version with minor changes/clarifications and new references
Spacetime metric from local and linear electrodynamics: a new axiomatic scheme
Creators: name: Hehl, Friedrich W.
name: Obukhov, Yuri N.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: We consider spacetime to be a 4-dimensional differentiable manifold that can be split locally into time and space. No metric, no linear connection are assumed. Matter is described by classical fields/fluids. We distinguish electrically charged from neutral matter. Electric charge and magnetic flux are postulated to be conserved. As a consequence, the inhomogeneous and the homogeneous Maxwell equations emerge expressed in terms of the excitation H and the field strength F, respectively. H and F are assumed to fulfill a local and linear "spacetime relation" with 36 constitutive functions. The propagation of electromagnetic waves is considered under such circumstances in the geometric optics limit. We forbid birefringence in vacuum and find the light cone including its Lorentzian signature. Thus the conformally invariant part of the metric is recovered. If one sets a scale, one finds the pseudo-Riemannian metric of spacetime.
description: Latex, 27 pages, 8 eps figures (better quality files are available from the authors). Invited lecture, 339th WE Heraeus Seminar on Special Relativity, Potsdam, Germany, 13-18 February 2005, To be published in the Proceedings
Revealing Efficient Dust-Formation at Low Metallicity in Extragalactic Carbon-Rich Wolf-Rayet Binaries
Creators: name: Lau, Ryan M.
name: Hankins, Matthew J.
name: Kasliwal, Mansi M.
name: Bond, Howard E.
name: De, Kishalay
name: Jencson, Jacob E.
name: Moffat, Anthony F. J.
name: Smith, Nathan
name: Williams, Peredur M.
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: We present Spitzer/IRAC observations of dust formation from six extragalactic carbon-rich Wolf-Rayet (WC) binary candidates in low-metallicity (Z $\lesssim0.65$ Z$_\odot$) environments using multi-epoch mid-infrared (IR) imaging data from the SPitzer InfraRed Intensive Transients Survey (SPIRITS). Optical follow-up spectroscopy of SPIRITS~16ln, 19q, 16df, 18hb, and 14apu reveals emission features from C IV $\lambda5801\text{-}12$~and/or the C III-IV $\lambda4650$ He II $\lambda4686$~blend that are consistent with early-type WC stars. We identify SPIRITS~16ln as the variable mid-IR counterpart of the recently discovered colliding-wind WC4+O binary candidate, N604-WRXc, located in the sub-solar metallicity NGC 604 H II~region in M33. We interpret the mid-IR variability from SPIRITS~16ln as a dust-formation episode in an eccentric colliding-wind WC binary. SPIRITS~19q, 16df, 14apu, and 18hb exhibit absolute [3.6] magnitudes exceeding one of most IR-luminous dust-forming WC systems known, WR~104 (M$_\mathrm{[3.6]}\lesssim-12.3$). An analysis of dust formation in the mid-IR outburst from SPIRITS~19q reveals a high dust production rate of $\dot{M}_d\gtrsim2\times10^{-6}$ M$_\odot$ yr$^{-1}$, which may therefore exceed that of the most efficient dust-forming WC systems known. We demonstrate that efficient dust-formation is feasible from early-type WC binaries in the theoretical framework of colliding-wind binary dust formation if the systems host an O-type companion with a high mass-loss rate ($\dot{M}\gtrsim1.6\times10^{-6}$ M$_\odot$ yr$^{-1}$). This efficient dust-formation from early-type WC binaries highlights their potential role as significant sources of dust in low-metallicity environments.
description: 28 pages, 10 Figures, and 5 Tables. Accepted to ApJ on 2021 Jan 4 (Replacement of version submitted to arXiv on 2020 Nov 19)
Block Copolymers in Electric Fields: A Comparison of Single-Mode and Self-Consistent Field Approximations
Creators: name: Tsori, Yoav
name: Andelman, David
name: Lin, Chin-Yet
name: Schick, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We compare two theoretical approaches to dielectric diblock copolymer melts in an external electric field. The first is a relatively simple analytic expansion in the relative copolymer concentration, and includes the full electrostatic contribution consistent with that expansion. It is valid close to the order-disorder transition point, the weak segregation limit. The second employs self-consistent field (SCF) theory and includes the full electrostatic contribution to the free energy at any copolymer segregation. It is more accurate but computationally more intensive. Motivated by recent experiments, we explore a section of the phase diagram in the three-dimensional parameter space of the block architecture, the interaction parameter and the external electric field. The relative stability of the lamellar, hexagonal and distorted body-centered-cubic (bcc) phases is compared within the two models. As function of an increasing electric field, the distorted bcc region in the phase diagram shrinks and disappears above a triple point, at which the lamellar, hexagonal and distorted bcc phases coexist. We examine the deformation of the bcc phase under the influence of the external field. While the elongation of the spheres is larger in the one-mode expansion than that predicted by the full SCF theory, the general features of the schemes are in satisfactory agreement. This indicates the general utility of the simple theory for exploratory calculations.
description: 6 pages, 3 figures, submitted
cij: A Python code for quasiharmonic thermoelasticity
Creators: name: Luo, Chenxing
name: Deng, Xin
name: Wang, Wenzhong
name: Shukla, Gaurav
name: Wu, Zhongqing
name: Wentzcovitch, Renata M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The Wu-Wentzcovitch semi-analytical method (SAM) is a concise and predictive formalism to calculate the high-pressure and high-temperature (high-PT) thermoelastic tensor (Cij) of crystalline materials. This method has been successfully applied to materials across different crystal systems in conjunction with ab initio calculations of static elastic coefficients and phonon frequencies. Such results have offered first-hand insights into the composition and structure of the Earth's mantle. Here we introduce the cij package, a Python implementation of the SAM-Cij formalism. It enables a thermoelasticity calculation to be initiated from a single command and fully configurable from a calculation settings file to work with solids within any crystalline system. These features allow SAM-Cij calculations to work on a personal computer and to be easily integrated as a part of high-throughput workflows. Here we show the performance of this code for three minerals from different crystal systems at their relevant PTs: diopside (monoclinic), akimotoite (trigonal), and bridgmanite (orthorhombic).
The product of two independent Su-Schrieffer-Heeger chains yields a two-dimensional Chern insulator
Creators: name: Mera, Bruno
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mathematical Physics (math-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We provide an extensive look at Bott periodicity in the context of complex gapped topological phases of free fermions. In doing so, we remark on the existence of a product structure in the set of inequivalent phases induced by the external tensor product of vector bundles -- a structure which has not yet been explored in condensed-matter literature. Bott periodicity appears in the form of a generalized Dirac monopole built out of a given phase, which is equivalent to the product of a Dirac monopole phase with that same given phase. The complex K-theory cohomology ring is presented as a natural way to store the information of these phases, with a grading corresponding to the number of Clifford symmetries modulo $2$. The Künneth formula allows us to derive the result that, for band insulators, the Su-Schrieffer-Heeger (SSH) chain in one dimension allows one to generate the K-cohomology of the $d$-dimensional Brillouin zone. In particular, we find that the product of two SSH chains in independent momentum directions yields a two-dimensional Chern insulator. The results obtained relate the associated topological phases of charge-conserving band insulators and their topological invariants in all spatial dimensions in a unified way.
description: 18 pages; closer to published version
Laura Buszard-Welcher Papers on the Potawatomi language
Creators: name: Alloway, Jim
name: BIlls, Arthur
name: Battese, BIll
name: Bendix, J
name: Cooper, Walter
name: Daniels Jr., Billy
name: Daniels, Billy
name: Daniels, Mary
name: Deverney, Mabel
name: Ellis, Lu
name: George, Mary
name: Green, Orlando (Mazhi)
name: Kegg, Maude
name: Lavier, Tony
name: Lonelodge, Dorothy
name: , Lorenzo
name: Marshno, Alberta
name: Meeks
name: Nioce, Frank
name: Nyholm, Earl
name: Onzuway, Bud
name: Patterson, Sarah
name: Perrote, Don
name: Pukkee, Jane
name: Shuckahosee, Ruby
name: Spear, Alice
name: Spear, Jim
name: Stevens, Maggie
name: Stoney, Nora
name: Thunder Sr., Jim
name: Wabnum, Tom
name: Wensaut, Mary
name: Billot S.J., Cardinal Louis
name: Buszard-Welcher, Laura
name: Costa, David J.
name: Dunn, Jacob
name: Gailland S.J., Rev. Maurice
name: Handy, Chas N.
name: Hockett, Charles
name: Hoecken, Christian
name: Johnson, I.V.B.
name: Luthin, Herb
name: Mitchell, Gary
name: , Norman
name: Rhodes, Richard
name: Shoenmaker S.J., Rev. F.
name: , Suzanne
name: Terrien S.J., J.-B.
name: Villada, Paolo
name: Volney, Count
name: Lykins, Johnston
name: Mathieu, Rev. Georges P.
name: Nicholas, John
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2021

description: The collection is organized into three series, which reflect the major types of materials in the collection. Series 1 contains grammatical and lexical notes on Potawatomi, along with field notes from Laura Welcher. Series 2 contains materials related to the work of Charles Hockett including field notes, lexical file slips, and texts. Series 3 contains a variety of materials collected by Laura Welcher, including field notes, educational materials, and historical documents relating to the Potawatomi language.
Quasi-static Ionization of Rydberg Alkali-metal Atoms: a classical view of the n^(-5) scaling
Creators: name: Perotti, Luca
Publisher: name: arXiv
Year: 2005
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: A fully classical explanation of the nonhydrogenic ionization threshold for low angular momentum Rydberg states of Alkali-metal atoms in a linearly polarized low frequency monochromatic microwave field is given: the classical equivalent to the quantum rate-limiting step, which is responsible for the n^(-5) scaling and which according to the literature initiates what then continues as essentially classical diffusion, is found.
description: 10 pages, 9 figures
Collective clutter and co-emerging complexity : enactivism and mathematical paths of understanding
Creators: name: Thom, Jennifer Susan
Publisher: name: University of British Columbia
Year: 2009

description: This thesis reports on a qualitative study in which three fifth grade children were presented with six nonroutine mathematical problems involving six different 3-D pyramids, constructed out of multi-link cubes1. The children were videotaped while they worked without any adult help as a cooperative group to solve the pyramid problems. During these sessions, the students produced various 3-D cube models, 2-D drawings, and written records of arithmetic calculations as their solutions to the six problems. Through the lens of enactivism, this study describes and interprets the coevolutionary processes of the group's path of mathematical understandings as it unfolded during the six videotaped sessions. The results revealed building, drawing, and numbering as modes of representation of this group's problem solving work. An analysis of these three modes of representation explored the co-emergence of the children's individual and collective understandings, as well as the interrelationships which existed between their spatial structuring and their use of numerical operations in solving the pyramid problems.
Effective non-intercommutation of local cosmic strings at high collision speeds
Creators: name: Achucarro, Ana
name: de Putter, Roland
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present evidence that Abrikosov-Nielsen-Olesen (ANO) strings pass through each other for very high speeds of approach due to a double intercommutation. In near-perpendicular collisions numerical simulations give threshold speeds bounded above by $\sim 0.97 c$ for type I, and by $\sim 0.90 c$ for deep type II strings. The second intercommutation occurs because at ultra high collision speeds, the connecting segments formed by the first intercommutation are nearly static and almost antiparallel, which gives them time to interact and annihilate. A simple model explains the rough features of the threshold velocity dependence with the incidence angle. For deep type II strings and large incidence angles a second effect becomes dominant, the formation of a loop that catches up with the interpolating segments. The loop is related to the observed vortex - antivortex reemergence in two-dimensions. In this case the critical value for double intercommutation can become much lower.
description: 5 pages, 4 figures. data points added, plots for deep type II regime showing lower critical velocities, some minor changes in text
Bi-Smoothed Functional Independent Component Analysis for EEG Artifact Removal
Creators: name: Vidal, Marc
name: Rosso, Mattia
name: Aguilera, Ana M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Methodology (stat.ME)
subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Motivated by mapping adverse artifactual events caused by body movements in electroencephalographic (EEG) signals, we present a functional independent component analysis based on the spectral decomposition of the kurtosis operator of a smoothed principal component expansion. A discrete roughness penalty is introduced in the orthonormality constraint of the covariance eigenfunctions in order to obtain the smoothed basis for the proposed independent component model. To select the tuning parameters, a cross-validation method that incorporates shrinkage is used to enhance the performance on functional representations with large basis dimension. This method provides an estimation strategy to determine the penalty parameter and the optimal number of components. Our independent component approach is applied to real EEG data to estimate genuine brain potentials from a contaminated signal. As a result, it is possible to control high-frequency remnants of neural origin overlapping artifactual sources to optimize their removal from the signal. An R package implementing our methods is available at CRAN.
description: 9 pages, 3 figures, 1 table
Exact Solution for the Hypergeometric Green's Function Describing Spectral Formation in X-Ray Pulsars
Creators: name: Becker, Peter A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: An eigenfunction expansion method involving hypergeometric functions is used to solve the partial differential equation governing the transport of radiation in an X-ray pulsar accretion column containing a radiative shock. The procedure yields the exact solution for the Green's function, which describes the scattering of monochromatic radiation injected into the column from a source located near the surface of the star. Collisions between the injected photons and the infalling electrons cause the radiation to gain energy as it diffuses through the gas and gradually escapes by passing through the walls of the column. The presence of the shock enhances the energization of the radiation and creates a power-law spectrum at high energies, which is typical for a Fermi process. The analytical solution for the Green's function provides important physical insight into the spectral formation process in X-ray pulsars, and it also has direct relevance for the interpretation of spectral data for these sources. Additional interesting mathematical aspects of the problem include the establishment of a closed-form expression for the quadratic normalization integrals of the orthogonal eigenfunctions, and the derivation of a new summation formula involving products of hypergeometric functions. By taking various limits of the general expressions, we also develop new linear and bilinear generating functions for the Jacobi polynomials.
description: Accepted for publication in JMP
An Electrokinetic Process Coupled Activated Carbon Barrier for Nickel Removal from Kaolinite
Creators: name: Zanjani, Ahmad Jamshidi
name: Saeedi, Mohsen
name: Chih-Huang WENG
Publisher: name: Thai Society of Higher Education Institutes on Environment
Year: 2012
Subjects: activated carbon,barriers,electrokinetic,nickel,soil remediation

description: 2, 5, EnvironmentAsia
Effects of Bio-sludge Concentration and Dilution Rate on the Efficiency of Sequencing Batch Reactor (SBR) System for Textile Wastewater Treatment
Creators: name: Suntud Sirianuntapiboon
name: Sarun Maneewon
Publisher: name: Thai Society of Higher Education Institutes on Environment
Year: 2012
Subjects: disperse dye,disperse blue 60,disperse red 60,Sequencing Batch Reactor (SBR) system,textile wastewater

description: 2, 5, EnvironmentAsia
Previous analyses: Peeke and Sargent
Creators: name: Peeke, Catherine
name: Sargent, Mary
name: Beier, Christine
name: Michael, Lev
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2021
Subjects: subject: anb

description: Contains one PDF that includes two short discussions of Andoa [anb]:
(1) Peeke, Catherine. Shimigae, idioma que se extingue. pp.18-28.
(2) Peeke, Catherine & Mary Sargent. Pronombres personales en shimigae. pp.29-42.
These were published in 1959 as the following title: Estudios acerca de las lenguas Huarani (Auca), Shimigae y Zapara. Documentos de Trabajo del ILV/ Ecuador. As of 2021, this resource is listed in the Language & Culture Archives of SIL International at this link: https://www.sil.org/resources/archives/17554.
Observation of Nitrogen and Phosphorus Removals and Accumulations in Surface Flow Constructed Wetland (SFCW)
Creators: name: Suntud Sirianuntapiboon
name: Prapa Sohsalam
Publisher: name: Thai Society of Higher Education Institutes on Environment
Year: 2012
Subjects: nitrogen,nutrients accumulation,phosphorus,seafood industrial wastewater,durface flow constructed wetland

description: 2, 5, EnvironmentAsia
On Filter Generalization for Music Bandwidth Extension Using Deep Neural Networks
Creators: name: Sulun, Serkan
name: Davies, Matthew E. P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Audio and Speech Processing (eess.AS)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Sound (cs.SD)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: In this paper, we address a sub-topic of the broad domain of audio enhancement, namely musical audio bandwidth extension. We formulate the bandwidth extension problem using deep neural networks, where a band-limited signal is provided as input to the network, with the goal of reconstructing a full-bandwidth output. Our main contribution centers on the impact of the choice of low pass filter when training and subsequently testing the network. For two different state of the art deep architectures, ResNet and U-Net, we demonstrate that when the training and testing filters are matched, improvements in signal-to-noise ratio (SNR) of up to 7dB can be obtained. However, when these filters differ, the improvement falls considerably and under some training conditions results in a lower SNR than the band-limited input. To circumvent this apparent overfitting to filter shape, we propose a data augmentation strategy which utilizes multiple low pass filters during training and leads to improved generalization to unseen filtering conditions at test time.
description: Qualitative examples on https://serkansulun.com/bwe. Source code on https://github.com/serkansulun/deep-music-enhancer
Modeling and mitigation of cross-talk effects in readout noise with applications to the Quantum Approximate Optimization Algorithm
Creators: name: Maciejewski, Filip B.
name: Baccari, Flavio
name: Zimborás, Zoltán
name: Oszmaniec, Michał
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce a correlated measurement noise model that can be efficiently described and characterized, and which admits effective noise-mitigation on the level of marginal probability distributions. Noise mitigation can be performed up to some error for which we derive upper bounds. Characterization of the model is done efficiently using Diagonal Detector Overlapping Tomography -- a generalization of the recently introduced Quantum Overlapping Tomography to the problem of reconstruction of readout noise with restricted locality. The procedure allows to characterize $k$-local measurement cross-talk on $N$-qubit device using $O(k2^klog(N))$ circuits containing random combinations of X and identity gates. We perform experiments on 15 (23) qubits using IBM's (Rigetti's) devices to test both the noise model and the error-mitigation scheme, and obtain an average reduction of errors by a factor $>22$ ($>5.5$) compared to no mitigation. Interestingly, we find that correlations in the measurement noise do not correspond to the physical layout of the device. Furthermore, we study numerically the effects of readout noise on the performance of the Quantum Approximate Optimization Algorithm (QAOA). We observe in simulations that for numerous objective Hamiltonians, including random MAX-2-SAT instances and the Sherrington-Kirkpatrick model, the noise-mitigation improves the quality of the optimization. Finally, we provide arguments why in the course of QAOA optimization the estimates of the local energy (or cost) terms often behave like uncorrelated variables, which greatly reduces sampling complexity of the energy estimation compared to the pessimistic error analysis. We also show that similar effects are expected for Haar-random quantum states and states generated by shallow-depth random circuits.
description: 27+25 pages, 6+2 figures, 0+3 table, 0+3 algorithmic boxes; v2: fixed typos, added omitted references, expanded acknowledgments; v3: updated to version accepted in Quantum, improved main narration, fixed typos;comments and suggestions are welcome
Exact Analysis of Level-Crossing Statistics for (d+1)-Dimensional Fluctuating Surfaces
Creators: name: Bahraminasab, A.
name: Movahed, M. Sadegh
name: Nassiri, S. D.
name: Masoudi, A. A.
name: Sahimi, Muhammad
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We carry out an exact analysis of the average frequency $ν_{αx_i}^+$ in the direction $x_i$ of positive-slope crossing of a given level $α$ such that, $h({\bf x},t)-\bar{h}=α$, of growing surfaces in spatial dimension $d$. Here, $h({\bf x},t)$ is the surface height at time $t$, and $\bar{h}$ is its mean value. We analyze the problem when the surface growth dynamics is governed by the Kardar-Parisi-Zhang (KPZ) equation without surface tension, in the time regime prior to appearance of cusp singularities (sharp valleys), as well as in the random deposition (RD) model. The total number $N^+$ of such level-crossings with positive slope in all the directions is then shown to scale with time as $t^{d/2}$ for both the KPZ equation and the RD model.
description: 22 pages, 3 figures
Baryonic Higgs and Dark Matter
Creators: name: Perez, Pavel Fileviez
name: Murgui, Clara
name: Plascencia, Alexis D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We discuss the correlation between dark matter and Higgs decays in gauge theories where the dark matter is predicted from anomaly cancellation. In these theories, the Higgs responsible for the breaking of the gauge symmetry generates the mass for the dark matter candidate. We investigate the Higgs decays in the minimal gauge theory for Baryon number. After imposing the dark matter density and direct detection constraints, we find that the new Higgs can have a large branching ratio into two photons or into dark matter. Furthermore, we discuss the production channels and the unique signatures at the Large Hadron Collider.
description: 24 pages. v2: minor changes to the text, accepted for publication in JHEP
UMA ANÁLISE DA ARQUITETURA DA INFORMAÇÃO NO WEBSITE DA ASSOCIAÇÃO NACIONAL DAS TRAVESTIS E TRANSEXUAIS (ANTRA)
Creators: name: Brito, Jean Fernandes
name: Puerta-Díaz, Mirelys
name: Oliveira, Lais Pereira de
name: Martínez-Ávila, Daniel
name: Vidotti, Silvana Aparecida Borsetti Gregorio
Publisher: name: Zenodo
Year: 2019
Subjects: Arquitetura da Informação
Comunidade LGBTQ
ANTRA

description: Aborda a Arquitetura da Informação no contexto digital, detendo-se especificamente ao universo informacional da comunidade das lésbicas, gays, bissexuais, travestis e queers (LGBTQ). Objetiva analisar a Arquitetura da Informação no website da Associação Nacional de Travestis e Transexuais. Orienta-se a partir das abordagens da temática LGBTQ desde a homosexualidade e da Ciência da Informação a partir da busca efetuada nas bases de dados Library and Information Science Abstracts (LISA), Web of Science (WoS) e Base de Dados Referencial de Artigos de Periódicos em Ciência da Informação (BRAPCI). Nessa medida, busca constatar quais as características do ambiente da referida associação desde a perspectiva da Arquitetura da Informação. Metodologicamente, constitui pesquisa descritiva de abordagem qualitativa pois analisa e descreve os elementos da Arquitetura da Informação no website da Associação Nacional de Travestis e Transexuais. Os resultados demonstram que a Arquitetura da Informação no website da Associação Nacional de Travestis e Transexuais precisa ser revista, principalmente no que diz respeito ao Sistema de Busca e ao Sistema de Rotulagem, que representam o discurso identitário das pessoas trans.
Mean field limit of Ensemble Square Root Filters -- discrete and continuous time
Creators: name: Lange, Theresa
name: Stannat, Wilhelm
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60H35, 93E11, 60F99

description: Consider the class of Ensemble Square Root filtering algorithms for the numerical approximation of the posterior distribution of nonlinear Markovian signals partially observed with linear observations corrupted with independent measurement noise. We analyze the asymptotic behavior of these algorithms in the large ensemble limit both in discrete and continuous time. We identify limiting mean-field processes on the level of the ensemble members, prove corresponding propagation of chaos results and derive associated convergence rates in terms of the ensemble size. In continuous time we also identify the stochastic partial differential equation driving the distribution of the mean-field process and perform a comparison with the Kushner-Stratonovich equation.
description: Accepted for publication in Foundations of Data Science. Revised version: corrected typos, added more explanations, updated Theorem 3.1 (holds for all p >=2)
Nonlinear force-free modeling of the solar coronal magnetic field
Creators: name: Wiegelmann, T.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The coronal magnetic field is an important quantity because the magnetic field dominates the structure of the solar corona. Unfortunately direct measurements of coronal magnetic fields are usually not available. The photospheric magnetic field is measured routinely with vector magnetographs. These photospheric measurements are extrapolated into the solar corona. The extrapolated coronal magnetic field depends on assumptions regarding the coronal plasma, e.g. force-freeness. Force-free means that all non-magnetic forces like pressure gradients and gravity are neglected. This approach is well justified in the solar corona due to the low plasma beta. One has to take care, however, about ambiguities, noise and non-magnetic forces in the photosphere, where the magnetic field vector is measured. Here we review different numerical methods for a nonlinear force-free coronal magnetic field extrapolation: Grad-Rubin codes, upward integration method, MHD-relaxation, optimization and the boundary element approach. We briefly discuss the main features of the different methods and concentrate mainly on recently developed new codes.
description: 33 pages, 3 figures, Review article
Following up the Kepler field: Masses of Targets for transit timing and atmospheric characterization
Creators: name: Jontof-Hutter, Daniel
name: Wolfgang, Angie
name: Ford, Eric B.
name: Lissauer, Jack J.
name: Fabrycky, Daniel C.
name: Rowe, Jason F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We identify a set of planetary systems observed by Kepler that merit transit timing variation (TTV) analysis given the orbital periods of transiting planets, the uncertainties for their transit times and the number of transits observed during the Kepler mission. We confirm the planetary nature of 4 KOIs within multicandidate systems. We forward model each of the planetary systems identified to determine which systems are likely to yield mass constraints that may be significantly improved upon with follow-up transit observations. We find projected TTVs diverge by more than 90 minutes after 6000 days in 27 systems, including 22 planets with orbital periods exceeding 25 days. Such targets would benefit the most from additional transit timing data. TTV follow-up could push exoplanet characterization to lower masses, at greater orbital periods and at cooler equilibrium temperatures than is currently possible from the Kepler dataset alone. Combining TTVs and recently revised stellar parameters, we characterize an ensemble of homogeneously selected planets and identify planets in the Kepler field with large enough estimated transmission annuli for atmospheric characterization with JWST.
description: 70 pages, 33 figures