cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Polarization observations of SNR G156.2+5.7 at lambda 6cm
Creators: name: Xu, J. W.
name: Han, J. L.
name: Sun, X. H.
name: Reich, W.
name: Xiao, L.
name: Reich, P.
name: Wielebinski, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: G156.2+5.7 is a large supernova remnant (SNR) first discovered in the ROSAT X-ray survey but radio observations are rare because of its low surface brightness and large size. Radio continuum and polarization images of the SNR G156.2+5.7 at lambda 6 cm are presented for the first time to be discussed in the context with available data to investigate its physical properties. We obtained an integrated flux density for G156.2+5.7 of S6cm= 2.5+-0.5Jy. The spectral index of the integrated emission is alpha=-0.48+-0.08 between lambda 74 cm and 6 cm excluding compact radio sources. We also obtained a spectral index map, which shows little variation between the shells and the central area of the SNR. This is consistent with the constant integrated flux density spectrum. Highly polarized radio emission has been detected from the SNR shell, but also from a central patch, which probably originates in the front part of the spherical SNR shell. We derived the distribution of rotation measure from polarization data at 11 cm and 6 cm and found RM gradients of opposite direction in the SNR shell. The SNR G156.2+5.7 is unusual by its exceptionally high X-ray brightness and very low surface-brightness in the radio range. The magnetic field is very well ordered along the shell periphery as expected for a compressed ambient magnetic field. A toroidal magnetic field component is indicated by the RM distribution. (abridged)
description: 8 pages, 8 figures -- accepted by A&A
Geodesic orbit metrics in a class of homogeneous bundles over quaternionic Stiefel manifolds
Creators: name: Arvanitoyeorgos, Andreas
name: Souris, Nikolaos Panagiotis
name: Statha, Marina
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C25, 53C30

description: Geodesic orbit spaces (or g.o. spaces) are defined as those homogeneous Riemannian spaces $(M=G/H,g)$ whose geodesics are orbits of one-parameter subgroups of $G$. The corresponding metric $g$ is called a geodesic orbit metric. We study the geodesic orbit spaces of the form $(\Sp(n)/\Sp(n_1)\times \cdots \times \Sp(n_s), g)$, with $0
description: 15 pages. arXiv admin note: substantial text overlap with arXiv:2103.02908
Improved photometry of SDSS crowded field images: Structure and dark matter content in the dwarf spheroidal galaxy Leo I
Creators: name: Smolcic, V.
name: Zucker, D.
name: Bell, E. F.
name: Coleman, M. G.
name: Rix, H. W.
name: Schinnerer, E.
name: Ivezic, Z.
name: Kniazev, A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We explore how well crowded field point-source photometry can be accomplished with SDSS data: We present a photometric pipeline based on DoPhot, and tuned for analyzing crowded-field images from the SDSS. Using Monte Carlo simulations we show that the completeness of source extraction is above 80% to i < 21 (AB) and a stellar surface density of about 200 sq.amin. Hence, a specialized data pipeline can efficiently be used for e.g. nearby resolved galaxies in SDSS images, where the standard SDSS photometric package Photo, when applied in normal survey mode, gives poor results. We apply our pipeline to an area of about 3.55sq.deg. around the dwarf spheroidal galaxy (dSph) Leo I, and construct a high S/N star-count map of Leo I via an optimized filter in color-magnitude space (g,r,i). Although the radial surface-density profile of the dwarf deviates from the best fit empirical King model towards outer radii, we find no evidence for tidal debris out to a stellar surface-density of 4*10^(-3) of the central value. We determine the total luminosity of Leo I, and model its mass using the spherical and isotropic Jeans equation. Assuming that 'mass follows light' we constrain a lower limit of the total mass of the dSph to be (1.7+/-0.2)*10^7 Msol. Contrary, if the mass in Leo I is dominated by a constant density dark-matter (DM) halo, then the mass within the central 12' is (2+/-0.6)*10^8 Msol. This leads to a mass-to-light ratio of >>6 (Ic_sol), and possibly >75 if the DM halo dominates the mass and extends further out than 12'. In summary, our results show that Leo I is a symmetric, relaxed and bound system; this supports the idea that Leo I is a dark-matter dominated system.
description: 13 pages, 11 figures; accepted for publication in AJ
On Montgomery's pair correlation conjecture: a tale of three integrals
Creators: name: Carneiro, Emanuel
name: Chandee, Vorrapan
name: Chirre, Andrés
name: Milinovich, Micah B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 11M06, 11M26, 41A30

description: We study three integrals related to the celebrated pair correlation conjecture of H. L. Montgomery. The first is the integral of Montgomery's function $F(α, T)$ in bounded intervals, the second is an integral introduced by Selberg related to estimating the variance of primes in short intervals, and the last is the second moment of the logarithmic derivative of the Riemann zeta-function near the critical line. The conjectured asymptotic for any of these three integrals is equivalent to Montgomery's pair correlation conjecture. Assuming the Riemann hypothesis, we substantially improve the known upper and lower bounds for these integrals by introducing new connections to certain extremal problems in Fourier analysis. In an appendix, we study the intriguing problem of establishing the sharp form of an embedding between two Hilbert spaces of entire functions naturally connected to Montgomery's pair correlation conjecture.
description: 38 pages, 5 figures; v2 typos corrected. To appear in Journal f\"{u}r die reine und angewandte Mathematik
Accurate prediction and measurement of vibronic branching ratios for laser cooling linear polyatomic molecules
Creators: name: Zhang, Chaoqun
name: Augenbraun, Benjamin L.
name: Lasner, Zack D.
name: Vilas, Nathaniel B.
name: Doyle, John M.
name: Cheng, Lan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We report a generally applicable computational and experimental approach to determine vibronic branching ratios in linear polyatomic molecules to the $10^{-5}$ level, including for nominally symmetry forbidden transitions. These methods are demonstrated in CaOH and YbOH, showing approximately two orders of magnitude improved sensitivity compared with the previous state of the art. Knowledge of branching ratios at this level is needed for the successful deep laser cooling of a broad range of molecular species.
A Potential Flow Model of a Fire Sprinkler Head
Creators: name: Myers, Taylor Macks
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Mechanical engineering
subject: FOS: Mechanical engineering
subject: Fire
subject: Fire Sprinkler
subject: Fluid Dynanics
subject: Model
subject: Potential Flow
subject: Sprinkler

description: Understanding fire sprinkler sprays fills a critical gap in the modeling of fire suppression systems. Previous research has shown that a modeling framework consisting of an instability model coupled with a stochastic transport model can paint most of the sprinkler spray picture, but requires input in the form of the thickness and velocity of unstable fluid sheets. The model outlined forgoes traditional CFD to solve for water jet-deflector interactions, and instead describes the sheet formation as a potential flow boundary value problem, utilizing a free surface formulation and the superposition of the Green's function. The resulting model allows for the determination of the complete flow field over a fire sprinkler head of arbitrary geometry and input conditions. A hypothetical axisymmetric sprinkler is explored to provide insight into the impact of sprinkler head geometry on local fluid as well as complete spray behavior. The resulting flow splits, sheet thicknesses, and sheet velocities are presented for various sprinkler head geometries.
The poset metrics that allow binary codes of codimension m to be m-, (m-1)-, or (m-2)-perfect
Creators: name: Kim, Hyun Kwang
name: Krotov, Denis
Publisher: name: arXiv
Year: 2007
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 94B60

description: A binary poset code of codimension M (of cardinality 2^{N-M}, where N is the code length) can correct maximum M errors. All possible poset metrics that allow codes of codimension M to be M-, (M-1)- or (M-2)-perfect are described. Some general conditions on a poset which guarantee the nonexistence of perfect poset codes are derived; as examples, we prove the nonexistence of R-perfect poset codes for some R in the case of the crown poset and in the case of the union of disjoin chains. Index terms: perfect codes, poset codes
description: 6pp, 33fig. V2: revised
An examination of in vitro erythropoiesis by utilizing agents that mimic the in vitro activity of erythropoietin
Creators: name: Murthy, Sudish C.
Publisher: name: University of British Columbia
Year: 2010

description: The major in vivo hormonal regulator of terminal erythropoiesis is erythropoietin (Ep). This 38,000 dalton acidic glycoprotein has been shown to stimulate the formation of hemoglobinizing erythroblasts. Two in vitro assays designed to measure Ep bioactivity were utilized to determine if other agents could mimic Ep activity in vitro. It was hoped that this approach might yield insights into the mechanism of action of Ep. Several agents have now been identified, and two, dimethyl sulfoxide (DMSO) and sodium orthovanadate had previously been shown (in other systems) to stimulate membrane phosphorylation changes. Accordingly, Ep, DMSO and sodium orthovanadate were assayed with Ƴ-³²P-ATP and plasma membranes purified from Ep-responsive cells to determine if each could induce significant phosphorylation changes as assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. It was found that while both sodium orthovanadate and DMSO effected profound phosphorylation alterations, Ep did not elicit any detectable phosphorylation changes. Specifically, vanadate caused a generalized increase in membrane base-stable phosphoproteins, and DMSO reproducibly stimulated the base resistant phosphorylation of a 35 Kd membrane-associated protein. It is reasonable to postulate that the latter phosphorylation event might be responsible for the stimulatory activity of DMSO on terminally differentiating erythroid cells. To understand whether Ep and Ep-mimicking agents were operative on the same target cell population, homogeneous, virally-infected, erythroblasts were cultured in vitro and assayed for ³H-thymidine incorporation in the presence of each agent at various intervals during erythroid cell differentiation. It was found that Ep greatly stimulated very early, as well as differentiated, erythroblasts to proliferate, while four different Ep-mimicking agents could only effect thymidine incorporation into a more mature erythroid population. From this work it is conceivable that Ep-mimicking agents stimulate in vitro erythropoiesis through specific membrane phosphorylation changes and function primarily on late erythroblasts, while the mechanism of action of Ep on primitive and late erythroblasts remains unresolved.
Direct generation of charge carriers in c-Si solar cells due to embedded nanoparticles
Creators: name: Kirkengen, Martin
name: Bergli, Joakim
name: Galperin, Yuri M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: It is known that silicon is an indirect band gap material, reducing its efficiency in photovoltaic applications. Using surface plasmons in metallic nanoparticles embedded in a solar cell has recently been proposed as a way to increase the efficiency of thin film silicon solar cells. The dipole mode that dominates the plasmons in small particles produces an electric field having Fourier components with all wave numbers. In this work, we show that such a field creates electron-hole-pairs without phonon assistance, and discuss the importance of this effect compared to radiation from the particle and losses due to heating.
description: 1 figure
The linear programming relaxation permutation symmetry group of an orthogonal array defining integer linear program
Creators: name: Arquette, David M.
name: Bulutoglu, Dursun A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 52B15

description: There is always a natural embedding of $S_s\wr S_k$ into the linear programming (LP) relaxation permutation symmetry group of an orthogonal array integer linear programming (ILP) formulation with equality constraints. The point of this paper is to prove that in the $2$ level, strength $1$ case the LP relaxation permutation symmetry group of this formulation is isomorphic to $S_2\wr S_k$ for all $k$, and in the $2$ level, strength $2$ case it is isomorphic to $S_2^k\rtimes S_{k+1}$ for $k\geq 4$. The strength $2$ result reveals previously unknown permutation symmetries that can not be captured by the natural embedding of $S_2\wr S_k$. We also conjecture a complete characterization of the LP relaxation permutation symmetry group of the ILP formulation.
description: 17 pages
BOSHLANG'ICH SINF O'QUVCHILARINING O'QUV FAOLLIKLARINI O'YIN TEXNOLOGIYALARIDAN FOYDALANIB RIVOJLANTIRISHNI PEDAGOGIK ADABIYOTLARNI TAHLIL QILISH
Creators: name: Bekmetova, Gulnoza
Publisher: name: Zenodo
Year: 2023

description: Mazkur tezisda umumiy o’rta ta’limning quyi bosqichida o’quvchilarning o’quv faolliklarini o’yin texnologiyalaridan foydalanib rivojlantirishni texnologiyalarini ilmiy tahlili bo’yicha munozaralar yuritilgan.
Critical Droplets and sharp asymptotics for Kawasaki dynamics with strongly anisotropic interactions
Creators: name: Baldassarri, Simone
name: Nardi, Francesca R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: In this paper we analyze metastability and nucleation in the context of the Kawasaki dynamics for the two-dimensional Ising lattice gas at very low temperature. Let $Λ\subset\mathbb{Z}^2$ be a finite box. Particles perform simple exclusion on $Λ$, but when they occupy neighboring sites they feel a binding energy $-U_1<0$ in the horizontal direction and $-U_2<0$ in the vertical one. Thus the Kawasaki dynamics is conservative inside the volume $Λ$. Along each bond touching the boundary of $Λ$ from the outside to the inside, particles are created with rate $ρ=e^{-Δβ}$, while along each bond from the inside to the outside, particles are annihilated with rate $1$, where $β>0$ is the inverse temperature and $Δ>0$ is an activity parameter. Thus, the boundary of $Λ$ plays the role of an infinite gas reservoir with density $ρ$. We consider the parameter regime $U_1>2U_2$ also known as the strongly anisotropic regime. We take $Δ\in{(U_1,U_1+U_2)}$, so that the empty (respectively full) configuration is a metastable (respectively stable) configuration. We investigate how the transition from empty to full takes place with particular attention to the critical configurations that asymptotically have to be crossed with probability 1. The derivation of some geometrical properties of the saddles allows us to identify the full geometry of the minimal gates and their boundaries for the nucleation in the strongly anisotropic case. We observe very different behaviors for this case with respect to the isotropic ($U_1=U_2$) and weakly anisotropic ($U_1<2U_2$) ones. Moreover, we derive mixing time, spectral gap and sharp estimates for the asymptotic transition time for the strongly anisotropic case.
description: 51 pages and 14 figures. In this paper we consider, with the same authors, the same model as our previous work arXiv:2108.02017, but in a complementary range of parameter values. Thus sections 1, 2, 3 and 4.1 in the present paper are similar to sections 1, 2, 3.1 and 4.1 in the previous paper arXiv:2108.02017
title: JULES DE GONCOURT, SYPHILIS, LITTÉRATURE ET THERMALISME
Creators: name: Daviet-Noual, Fortunade
Publisher: name: Société française de médecine thermale
Year: 2017

description: L’écrivain Jules de Goncourt a la syphilis. Un peu plus de quinze ans après avoir été contaminé, les souffrances deviennent de plus en plus envahissantes. On l’envoie à trois reprises en cure thermale en Auvergne, et il suit en outre un traitement hydrothérapique dans la clinique réputée du docteur Béni-Barde, à Auteuil. Rien n’y fait. Les douleurs physiques, l’ataxie, l’aphasie, l’égarement de sa raison deviennent son quotidien, jusqu’à son décès le 20 juin 1870. Sa mort est immortalisée dans les pages du Journal par son frère Edmond, qui, impuissant devant cette agonie, n’a plus qu’une seule raison de vivre : écrire.
description: The writer Jules de Goncourt had syphilis. Some fifteen years after he had been contaminated, the affliction became more and more aggressive. On three occasions, he was sent for thermal cures in the Auvergne region, while he also followed a painful hydrotherapeutic treatment in a reputed clinic run by doctor Beni-Barde, in Auteuil. Nothing worked. Harrowing physical pains, Ataxia, Aphasia, the losing of his mind, became his daily agony right up to the end, when he died on the 20th June 1870. The transcription of his death was immortalised in the published pages of ‘Jounal’ written by his brother Edmond, who, helpless in front of his brother’s torment and death throes, could only do one thing : write.
Calculations of Time-Reversal Symmetry Violation Sensitivity Parameters Based on Analytic Relativistic Coupled-Cluster Gradient Theory
Creators: name: Zhang, Chaoqun
name: Zheng, Xuechen
name: Cheng, Lan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We develop an analytic-gradient based method for relativistic coupled-cluster calculations of effective electric field, $\mathcal{E}_{\text{eff}}$, with improved efficiency and robustness over the previous state of the art. The enhanced capability to calculate this time-reversal symmetry violation sensitivity parameter enables efficient screening of candidate molecules for the electron electric dipole moment (eEDM) search. As examples, the |$\mathcal{E}_{\text{eff}}$| values of metal methoxides including BaOCH$_3$, YbOCH$_3$, and RaOCH$_3$ are shown to be as large as those of the corresponding fluorides and hydroxides, which supports the recent proposal of using these symmetric-top molecules to improve the sensitivity of eEDM measurements. The computational results also show that molecules containing late actinide elements, NoF, NoOH, LrO, and LrOH$^+$, exhibit particularly large |$\mathcal{E}_{\text{eff}}$| values of around 200 GV/cm.
title: The intellectual origins and social landscapes of Patrick Geddes, ca. 1880-1899
Creators: name: Wyant, Cody James
Publisher: name: University of St Andrews
Year: 2020

description: This thesis aims to examine the intellectual origins and social landscapes of Patrick Geddes. It provides a scope for establishing a clearer picture of his initiatives in Edinburgh between 1880 and 1899. Its contribution to Scottish history is highly valuable in fashioning a critical evaluation of the historical figure through the lens of available archival documentation. Most of this work has been derived from documents housed at the National Library of Scotland and the vast collection of Patrick Geddes papers at the University of Strathclyde. The great majority of archives that have been sourced have yet to be fully assessed or published. The scope of this research has been to reconstruct a narrative around Geddes’ intellectual origins in relation to the development of his early activity. It further intends to be a starting-point for filling a large gap in Geddesian studies. Moreover, it traces the construction of P.G.’s diverse social landscape through co-operative means and crafts a new focus for assessing the Scottish context of his generalist philosophy. Furthermore, this thesis furnishes a new perspective relating to his intellectual upbringing, professional evolution and generalist practice. More broadly, this research firmly places Geddes in the tradition of Scottish intellectual history.
IS-ENES3 White Paper on provenance handling in the model evaluation process
Creators: name: Andela, Bouwe
name: Bedia, Joaquin
name: Cofiño, Antonio
name: Kazeroni, Rémi
name: Pagé, Christian
name: San Martín, Daniel
name: Sénési, Stéphane
name: Servonnat, Jérôme
name: Spinuso, Alessandro
name: Veldhuizen, Mats
name: Zimmermann, Klaus
Publisher: name: Zenodo
Year: 2021

description: This document provides recommendations in the context of projet IS-ENES3 work package 3, and of climate model evaluation process, regarding the handling of provenance information and of documentation
Solutions in folded geometries, and associated cloaking due to anomalous resonance
Creators: name: Milton, Graeme W.
name: Nicorovici, Nicolae-Alexandru P.
name: McPhedran, Ross C.
name: Cherednichenko, Kirill
name: Jacob, Zubin
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Solutions for the fields in a coated cylinder where the core radius is bigger than the shell radius are seemingly unphysical, but can be given a physical meaning if one transforms to an equivalent problem by unfolding the geometry. In particular the unfolded material can act as an impedance matched hyperlens, and as the loss in the lens goes to zero finite collections of polarizable line dipoles lying within a critical region surrounding the hyperlens are shown to be cloaked having vanishingly small dipole moments. This cloaking, which occurs both in the folded geometry and the equivalent unfolded one, is due to anomalous resonance, where the collection of dipoles generates an anomalously resonant field, which acts back on the dipoles to essentially cancel the external fields acting on them.
description: 23 pages, 6 figures, in the new version one figure has been added, also the meaning of folded geometries has been clarified
Constraining the Epoch of Reionization With Highly Dispersed Fast Radio Bursts
Creators: name: Pagano, Michael
name: Fronenberg, Hannah
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The period in which hydrogen in the intergalactic medium (IGM) is ionized, known as the Epoch of Reionization (EoR) is still poorly understood. The timing and duration of the EoR is expected to be governed by the underlying astrophysics. Furthermore, most models of reionization predict a correlation between the density and ionization field. Here we consider using the mean dispersion measure (DM) of high redshift Fast Radio Bursts (FRBs) as a probe of the underlying astrophysics and morphology of the EoR. To do this, we forecast observational scenarios by building mock data sets of non-repeating FRBs between redshifts $8\leq z \leq 10$. It is assumed that all FRBs have accompanying spectroscopic redshift measurements. We find that samples of 100 high redshift FRBs, in the above mentioned narrow redshift range, can rule out uncorrelated reionization at $68\%$ credibility, while larger samples, $\geq 10^4$ FRBs, can rule out uncorrelated reionization at $95\%$ credibility. We also find 100 high redshift FRBs can rule out scenarios where the Universe is entirely neutral at $z = 10$ with $68\%$ credibility. Further with $\geq 10^5$ FRBs, we can constrain the duration $Δz$ of reionization (duration between mean ionized fraction 0.25 to 0.75) to $Δz = 2.0^{+0.5}_{-0.4}$, and the midpoint of reionization to $z = 7.8^{+0.4}_{-0.2}$ at $95\%$ credibility.
description: 12 pages, 7 Figures, 2 Tables
Angular-Independent Photonic Pigments via the Controlled Micellization of Amphiphilic Bottlebrush Block Copolymers.
Creators: name: Zhao, Tianheng
name: Jacucci, Gianni
name: Chen, Xi
name: Song, Dong-Po
name: Vignolini, Silvia
name: Parker, Richard
Publisher: name: Apollo - University of Cambridge Repository
Year: 2020

description: Photonic materials with angular-independent structural color are highly desirable because they offer the broad viewing angles required for application as colorants in paints, cosmetics, textiles, or displays. However, they are challenging to fabricate as they require isotropic nanoscale architectures with only short-range correlation. Here, porous microparticles with such a structure are produced in a single, scalable step from an amphiphilic bottlebrush block copolymer. This is achieved by exploiting a novel "controlled micellization" self-assembly mechanism within an emulsified toluene-in-water droplet. By restricting water permeation through the droplet interface, the size of the pores can be precisely addressed, resulting in structurally colored pigments. Furthermore, the reflected color can be tuned to reflect across the full visible spectrum using only a single polymer (Mn = 290 kDa) by altering the initial emulsification conditions. Such "photonic pigments" have several key advantages over their crystalline analogues, as they provide isotropic structural coloration that suppresses iridescence and improves color purity without the need for either refractive index matching or the inclusion of a broadband absorber.
description: National Natural Science Foundation of China [51873098] Winton Programme for the Physics of Sustainability
Active metamaterial polarization modulators for the Terahertz frequency range
Creators: name: Kindness, SJ
name: Almond, NW
name: Michailow, W
name: Wei, B
name: Braeuninger-Weimer, P
name: Hofmann, Stephan
name: Beere, Harvey
name: Ritchie, David
name: Degl'Innocenti, R
Publisher: name: Apollo - University of Cambridge Repository
Year: 2020
Subjects: Paper

description: Abstract Active control of chirality in the terahertz frequency range is of great importance in many scientific areas, which include research into fundamental optical phenomena, investigation of novel materials, spectroscopy, imaging, wireless communications and chemistry. The lack of efficient, integrated and fast-reconfigurable polarization modulators has hindered, so far, the full exploitation of applications in all the aforementioned fields. Metamaterials are artificial resonant elements possessing unique remarkable properties such as high efficiency and miniaturization capability. The interplay of metallic metamaterial arrays with electrostatically tunable monolayer graphene has been demonstrated to be a valid approach for the realization of a novel class of THz devices. In this work, the realization of active chiral graphene/metamaterial modulator is presented. The versatility of this experimental approach allowed the device integration with broadband sources such as terahertz time domain spectrometers as well as with quantum cascade lasers. A continuous rotation of the polarization plane > 30° has been reported with a reconfiguration speed > 5 MHz. These results pave the way to the integration of fast terahertz polarization modulators in all the applications where these devices are in great demand.
The symbiotic star H1-36. A composite model of line and continuum spectra from radio to ultraviolet
Creators: name: Angeloni, R.
name: Contini, M.
name: Ciroi, S.
name: Rafanelli, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In this paper we analyse the spectra of D-type SS H1-36 within a colliding-wind scenario. We aim to analyse the properties of this object taking into account the observational data along the whole electromagnetic spectrum, in order to derive a self-consistent picture able to interpret the nature of the system as a whole. After constraining the relative physical conditions by modelling more than 40 emission lines from radio to UV, we are able to explain the continuum spectral energy distribution by taking into account all the emitting contributions arising from both the stars, the dust shells and the gaseous nebulae. A comprehensive model of the radio spectra allows to reproduce the different slopes of the radio profile and the turnover frequency, as well as the different size of the observed shocked envelope at different frequencies in the light of the different contributions from the expanding and reverse nebulae. The IR continuum unveils the presence of two dust shells with different radii and temperatures, which might be a distinctive feature of D-type symbiotic systems as a class of objects. The broad profiles of IR lines direct us to investigate whether an X-ray jet may be present. This insight leads us to indicate H1-36 as a promising X-ray target and to encourage observations and studies which consistently take into account the complex nature of symbiotic stars throughout the whole electromagnetic spectrum.
description: 8 pages, 3 figures, 5 tables, accepted for publication in A&A on 2th May 2007
Hexagonal parquet tilings: k-isohedral monotiles with arbitrarily large k
Creators: name: Socolar, Joshua E. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: General Mathematics (math.GM)
subject: Metric Geometry (math.MG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: This paper addresses the question of whether a single tile with nearest neighbor matching rules can force a tiling in which the tiles fall into a large number of isohedral classes. A single tile is exhibited that can fill the Euclidean plane only with a tiling that contains k distinct isohedral sets of tiles, where k can be made arbitrarily large. It is shown that the construction cannot work for a simply connected 2D tile with matching rules for adjacent tiles enforced by shape alone. It is also shown that any of the following modifications allows the construction to work: (1) coloring the edges of the tiling and imposing rules on which colors can touch; (2) allowing the tile to be multiply connected; (3) requiring maximum density rather than space-filling; (4) allowing the tile to have a thickness in the third dimension.
description: 7 pages, 8 figures. Published in The Mathematical Intelligencer. NOTE: The MI mistakenly published an earlier draft
Early Science with the Large Millimeter Telescope: Constraining the Gas Fraction of a Compact Quiescent Galaxy at z=1.883
Creators: name: Caliendo, Joyce N.
name: Whitaker, Katherine E.
name: Akhshik, Mohammad
name: Wilson, Grant
name: Williams, Christina C.
name: Spilker, Justin S.
name: Mahler, Guillaume
name: Pope, Alexandra
name: Sharon, Keren
name: Aguilar, Emmaly
name: Bezanson, Rachel
name: Dagastino, Miguel Chavez
name: Gómez-Ruiz, Arturo I.
name: Montaña, Alfredo
name: Toft, Sune
name: De La Rosa, Miguel Velazquez
name: Zeballos, Milagros
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present constraints on the dust continuum flux and inferred gas content of a gravitationally lensed massive quiescent galaxy at $z$=1.883$\pm$0.001 using AzTEC 1.1mm imaging with the Large Millimeter Telescope. MRG-S0851 appears to be a prototypical massive compact quiescent galaxy, but has evidence that it experienced a centrally concentrated rejuvenation event in the last 100 Myr (see Akhshik et al. 2020). This galaxy is undetected in the AzTEC image but we calculate an upper limit on the millimeter flux and use this to estimate the H$_2$ mass limit via an empirically calibrated relation that assumes a constant molecular gas-to-dust ratio of 150. We constrain the 3$σ$ upper limit of the H$_2$ fraction from the dust continuum in MRG-S0851 to be ${M_{H_2}/M_{\star}}$ $\leq$ 6.8%. MRG-S0851 has a low gas fraction limit with a moderately low sSFR owing to the recent rejuvenation episode, which together results in a relatively short depletion time of $
description: 8 pages, 4 figures, accepted for publication in Astrophysical Journal Letters in January 2021 (in press)
Critical Droplets and sharp asymptotics for Kawasaki dynamics with weakly anisotropic interactions. Extended version
Creators: name: Baldassarri, Simone
name: Nardi, Francesca R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: In this paper we analyze metastability and nucleation in the context of the Kawasaki dynamics for the two-dimensional Ising lattice gas at very low temperature with periodic boundary conditions. Let $β>0$ be the inverse temperature and let $Λ\subsetΛ^β\subset\mathbb{Z}^2$ be two boxes. We consider the asymptotic regime corresponding to the limit as $β\rightarrow\infty$ for finite volume $Λ$ and $\lim_{β\rightarrow\infty}\frac{1}β\log|Λ^β|=\infty$. We study the simplified model, in which particles perform independent random walks on $Λ^β\setminusΛ$ and inside $Λ$ particles perform simple exclusion, but when they occupy neighboring sites they feel a binding energy $-U_1<0$ in the horizontal direction and $-U_2<0$ in the vertical one. Thus the Kawasaki dynamics is conservative inside the volume $Λ^β$. The initial configuration is chosen such that $Λ$ is empty and $ρ|Λ^β|$ particles are distributed randomly over $Λ^β\setminusΛ$. Our results will use a deep analysis of a local model, i.e., particles perform Kawasaki dynamics inside $Λ$ and along each bond touching the boundary of $Λ$ from the outside to the inside, particles are created with rate $ρ=e^{-Δβ}$, while along each bond from the inside to the outside, particles are annihilated with rate $1$, where $Δ>0$ is an activity parameter. Thus, in the local model the boundary of $Λ$ plays the role of an infinite gas reservoir with density $ρ$. We take $Δ\in{(U_1,U_1+U_2)}$, so that the empty (respectively full) configuration is a metastable (respectively stable) configuration. We investigate how the transition from empty to full takes place in the local model with particular attention to the critical configurations that asymptotically have to be crossed with probability 1.
description: 74 pages and 26 figures
Hydrostatic equilibrium of causally consistent and dynamically stable neutron star models
Creators: name: Negi, P. S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We show that the mass-radius $(M-R)$ relation corresponding to the stiffest equation of state (EOS) does not provide the necessary and sufficient condition of dynamical stability for the equilibrium configurations, since such configurations can not satisfy the `compatibility criterion'. In this connection, we construct sequences composed of core-envelope models such that, like the stiffest EOS, each member of these sequences satisfy the extreme case of causality condition, $v = c = 1$, at the centre. We, thereafter, show that the $M-R$ relation corresponding to the said core-envelope model sequences can provide the necessary and sufficient condition of dynamical stability only when the `compatibility criterion' for these sequences is `appropriately' satisfied. However, the fulfillment of `compatibility criterion' can remain satisfied even when the $M-R$ relation does not provide the necessary and sufficient condition of dynamical stability for the equilibrium configurations. In continuation to the results of previous study, these results explicitly show that the `compatibility criterion' {\em independently} provides, in general, the {\em necessary} and {\em sufficient} condition of hydrostatic equilibrium for any regular sequence. Beside its fundamental feature, this study can also explain simultaneously, both (the higher as well as lower) values of the glitch healing parameter observed for the Crab and the Vela-like pulsars respectively, on the basis of starquake model of glitch generation.
description: 14 pages (including 6 figures and 5 tables), accepted for publication in MNRAS
Thresholds for the Dust Driven Mass Loss from C-rich AGB Stars
Creators: name: Mattsson, Lars
name: Wahlin, Rurik
name: Hoefner, Susanne
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: It is well established that mass loss from AGB stars due to dust driven winds cannot be arbitrarily low. We model the mass loss from carbon rich AGB stars using detailed frequency-dependent radiation hydrodynamics including dust formation. We present a study of the thresholds for the mass loss rate as a function of stellar parameters based on a subset of a larger grid of such models and compare these results to previous observational and theoretical work. Furthermore, we demonstrate the impact of the pulsation mechanism and dust formation for the creation of a stellar wind and how it affects these thresholds and briefly discuss the consequences for stellar evolution.
description: 2 pages, 1 figure. To be published in the proceedings of IAU Symp. 241 on Stellar Populations as Building Blocks of Galaxies, ed. A. Vazdekis et al. (2007). Replaced to match edited version
Infiltration and surface ponding on a sand-based sportsfield
Creators: name: Murrie, W. Trevor
Publisher: name: University of British Columbia
Year: 2010

description: The thesis addresses the problem of ponding as it pertains to sand-based sportsfields. The Lower Premier Sportsfield, in the District of North Vancouver, was specifically studied. It is located in a high rainfall location. The hypothesis is that a 'surface layer' at the top of the soil profile was directly responsible for the reduced surface infiltration necessary for the ponding observed. The accumulation and compaction of detrital organic matter within the pore space of this layer was assumed to be the source of the ponding problem. Pond depth hydrographs were derived from field measurements to illustrate the behaviour of the pond in response to various rainfall conditions. Furthermore, a semi-empirical model was devised to determine the water balance of the pond for an incident rainfall event. Results from the model show that overland flow from the area concentrically adjacent to the pond contributed approximately four times as much water to the pond as was contributed directly by rainfall. From the analysis, it was determined that a low 'surface layer' saturated hydraulic conductivity, of the order of 10⁻⁸ m.s⁻¹ was necessary for this to occur. Recommendations emphasize preventative management that limits the accumulation of detrital plant matter and the employment of groundskeeping techniques to control the formation of the hydrologically restrictive 'surface layer'. Furthermore, to avoid the concentration of surface runoff, it is essential that surface.
The LHCb Upgrade
Creators: name: Dijkstra, H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The LHCb detector has been designed to study CP violation and other rare phenomena in B-meson decays up to a luminosity of $\sim 5.10^{32}\rm cm^{-2}s^{-1}$. This paper will describe what is limiting LHCb to exploit the much higher luminosities available at the LHC, and what are the baseline modifications which will remedy these limitations. The aim of SuperLHCb is to increase the yields in hadronic B-decay channels by about a factor twenty compared to LHCb, while for channels with leptons in the final state a factor ten increase in statistics is envisaged.
description: Flavor Physics & CP Violation Conference, Bled, 2007
On the Zero Point Constant of the Bolometric Correction Scale
Creators: name: Eker, Z.
name: Bakis, V.
name: Soydugan, F.
name: Bilir, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Arbitrariness attributed to the zero point constant of the $V$ band bolometric corrections ($BC_V$) and its relation to "bolometric magnitude of a star ought to be brighter than its visual magnitude" and "bolometric corrections must always be negative" was investigated. The falsehood of the second assertion became noticeable to us after IAU 2015 General Assembly Resolution B2, where the zero point constant of bolometric magnitude scale was decided to have a definite value $C_{Bol}(W)= 71.197~425~...$~. Since the zero point constant of the $BC_V$ scale could be written as $C_2=C_{Bol}-C_V$, where $C_V$ is the zero point constant of the visual magnitudes in the basic definition $BC_V=M_{Bol}-M_V=m_{bol}-m_V$, and $C_{Bol}>C_V$, the zero point constant ($C_2$) of the $BC_V$ scale cannot be arbitrary anymore; rather, it must be a definite positive number obtained from the two definite positive numbers. The two conditions $C_2>0$ and $0
description: 12 pages, including 3 figures and 1 table, accepted for publication in Monthly Notices of the Royal Astronomical Society
Dense prediction of label noise for learning building extraction from aerial drone imagery
Creators: name: Ahmed, Nahian
name: Rahman, Rashedur M.
name: Adnan, Mohammed Sarfaraz Gani
name: Ahmed, Bayes
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Neuroscience
subject: Physiology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Label noise is a commonly encountered problem in learning building extraction tasks; its presence can reduce performance and increase learning complexity. This is especially true for cases where high resolution aerial drone imagery is used, as the labels may not perfectly correspond/align with the actual objects in the imagery. In general machine learning and computer vision context, labels refer to the associated class of data, and in remote sensing-based building extraction refer to pixel-level classes. Dense label noise in building extraction tasks has rarely been formalized and assessed. We formulate a taxonomy of label noise models for building extraction tasks, which incorporates both pixel-wise and dense models. While learning dense prediction under label noise, the differences between the ground truth clean label and observed noisy label can be encoded by error matrices indicating locations and type of noisy pixel-level labels. In this work, we explicitly learn to approximate error matrices for improving building extraction performance; essentially, learning dense prediction of label noise as a subtask of a larger building extraction task. We propose two new model frameworks for learning building extraction under dense real-world label noise, and consequently two new network architectures, which approximate the error matrices as intermediate predictions. The first model learns the general error matrix as an intermediate step and the second model learns the false positive and false-negative error matrices independently, as intermediate steps. Approximating intermediate error matrices can generate label noise saliency maps, for identifying labels having higher chances of being mis-labelled. We have used ultra-high-resolution aerial images, noisy observed labels from OpenStreetMap, and clean labels obtained after careful annotation by the authors. When compared to the baseline model trained and tested using clean labels, our intermediate false positive-false negative error matrix model provides Intersection-Over-Union gain of 2.74% and F1-score gain of 1.75% on the independent test set. Furthermore, our proposed models provide much higher recall than currently used deep learning models for building extraction, while providing comparable precision. We show that intermediate false positive-false negative error matrix approximation can improve performance under label noise.
The spiritual life from the perspectives of Islam and Christianity : the stages of the spiritual life in the teachings of al-Ghazālī and St. Teresa of Ávila
Creators: name: Christensen, Linda
Publisher: name: University of British Columbia
Year: 2010

description: In this thesis I attempt to illustrate that there is common ground between Christianity and Islam in the area of spirituality. The procedure taken is one of describing the spiritual path from the perspectives of al-Ghazālī (d. 1111) and St. Teresa of Ávila (d. 1582) in a comparative manner. The three-fold categorization of the spiritual path as consisting of the stages of purgation, illumination, and union, is used to provide the format for this comparison. Chapter one deals with biographical material and historical contexts, noting similarities in their experiences, contexts, and contributions. Chapter two discusses the beginning stage of the spiritual path — purgation — dealing with the requirements of renunciation of the world and of one's self, repentance and the battle of the spirit with and victory over the flesh. The next stage — illumination — comprises chapter three. Here it is seen how the purgation of the self from all vice is a prerequisite to receiving divine manifestations to the soul. The roles of prayer, obedience, and the cultivation of virtues are discussed. Union, the final stage, is dealt with in chapter four. The meaning of union is discussed, including its various degrees, and how the mystic is consequently transformed. The conclusion summarizes the findings of the previous chapters. It is seen that there is a great deal of commonality in the teachings of al-Ghazālī and St. Teresa; but differences also arise marking their spiritualities as being uniquely Muslim and Christian, respectively.
The Role of Social Institutions in Determining Aid Effectiveness
Creators: name: Foa, Roberto Stefan
Publisher: name: International Institute of Social Studies, the Hague
Year: 2012
Subjects: Social Institutions
Aid Effectiveness
Governance
Development
Social Capital

description: In recent years, scholars and policymakers have placed growing attention on the issue of aid effectiveness, that is, the efficiency of donor assistance in achieving stated economic and human development objectives. While research has tended to highlight the need for greater capacity building and improved governance as mechanisms to make aid 'effective', the social origins of such mechanisms have not been thoroughly examined. Using the latest cross-country indicator series on aid effectiveness from the OECD and the Indices of Social Development, hosted at the Institute of Social Studies in the Hague, this paper examines the determinants of effective aid spending, and finds a significant effect linking the quality of aid assistance to social institutions relating to public order and trust. These effects are verified when instrumenting social institutions by measures of state history, suggesting that long-term political development is the main source of public order and the presence of state institutions capable of effective management of aid flows.