cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A new technique for determining Substorm Onsets and Phases from Indices of the Electrojet (SOPHIE)
Creators: name: Forsyth, C.
name: Rae, I. J.
name: Coxon, J. C.
name: Freeman, M. P.
name: Jackman, C. M.
name: Gjerloev, J.
name: Fazakerley, A. N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We present a new quantitative technique that determines the times and durations of substorm expansion and recovery phases and possible growth phases based on percentiles of the rate of change of auroral electrojet indices. By being able to prescribe different percentile values, we can determine the onset and duration of substorm phases for smaller or larger variations of the auroral index or indeed any auroral zone ground-based magnetometer data. We apply this technique to the SuperMAG AL (SML) index and compare our expansion phase onset times with previous lists of substorm onsets. We find that more than 50% of events in previous lists occur within 20 min of our identified onsets. We also present a comparison of superposed epoch analyses of SML based on our onsets identified by our technique and existing onset lists and find that the general characteristics of the substorm bay are comparable. By prescribing user-defined thresholds, this automated, quantitative technique represents an improvement over any visual identification of substorm onsets or indeed any fixed threshold method.
Solvable points on smooth projective varieties
Creators: name: Wooley, Trevor D.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 14G05, 11D72, 11E76

description: We establish that smooth, geometrically integral projective varieties of small degree are not pointless in suitable solvable extensions of their field of definition, provided that this field is algebraic over $\Bbb Q$.
description: 11 pages
Design matters: Course document design's effect on language learners' perceptions
Creators: name: Lege, Ryan
Publisher: name: figshare
Year: 2023
Subjects: Applied linguistics and educational linguistics
LOTE, ESL and TESOL curriculum and pedagogy

description: Literature in L1 learning contexts has indicated that the design of course documents can influence learner beliefs and attitudes toward the teacher and the learning process (Wolfe et al., 2019). In immersive L2 learning contexts, learners must navigate an additional layer of linguistic complexity as they interact with course documents. The current study explores the effect of course document design on language learners’ perceptions of instructors and institutions in tertiary EFL classrooms. Three versions of a syllabus were created using differing degrees of document design principles. A counterbalanced within-subjects design was employed in which participants (N=56) were exposed to the different syllabi and asked for their impressions of both the author of the document and the university. Course document design had a significant impact on ratings of the instructor and university, suggesting that language learners’ perceptions and attitudes about a teacher and learning context are influenced by course document design.
Electromagnetic effects on meson production: a new tool for studying the space-time evolution of heavy ion collisions
Creators: name: Rybicki, Andrzej
name: Szczurek, Antoni
name: Klusek-Gawenda, Mariola
name: Davis, Nikolaos
name: Ozvenchuk, Vitalii
name: Kielbowicz, Miroslaw
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We review our studies of spectator-induced electromagnetic (EM) effects on the emission of charged mesons in the final state of ultrarelativistic heavy ion collisions. We argue that these effects offer sensitivity to the distance $d_E$ between the charged meson formation zone at freeze-out and the spectator system. As such, they can serve as an independent, new tool to probe the space-time and longitudinal evolution of the system created in the collision. As a phenomenological application for this tool in the context of resonance production and decay, we obtain a first estimate of the time of pion emission from EM effects. This we compare to existing HBT data.
description: conference
Stars, black holes and explosive transients
Creators: name: Eyles, Robert
Publisher: name: University of Leicester
Year: 2022
Subjects: Uncategorized

description: Gamma-ray bursts and tidal disruption events are some of the most cataclysmic and energetic events in the universe. Both result in highly luminous and complex emission across the entire electromagnetic spectrum and such transients provide invaluable clues to the behaviour of matter under extreme forces and how the properties of the universe have arisen. Short gamma-ray bursts are powered by the merger of a neutron star with either another neutron star or a stellar mass black hole. The extreme gravitational forces involved can squeeze neutron rich ejecta out of the neutron star and cause an additional fast evolving thermal optical transient called a kilonova. Kilonovae are sites of r-process nucleosynthesis and are responsible for the production of some of the heaviest elements in the universe. I have performed an in depth investigation of the short gamma-ray burst GRB 071227 and found it to have an optical excess. However, I found this excess to be inconsistent with a kilonova origin and instead is most likely due to the dust content of the source distorting the afterglow. A small excess does still remain, however, which could indicate a further thermal contribution. Tidal disruption events, on the other hand, occur when a star approaches a supermassive black hole at an oblique angle. The enormous gravity of the black hole overcomes the selfgravity of the star and it is torn apart. The debris falls onto the black hole at high rates, possibly beyond what can be accreted by the black hole. How the black hole responds to such high fallback rates is currently poorly understood and here I have investigated one model of its behaviour, the zero-Bernoulli accretion model. I have produced optical light curves of such super-Eddington tidal disruption events and found them to have properties resembling those of observed events, although there were also signi?cant discrepancies and I therefore proposed improvements to the model. I also used the model light curves to evaluate the Gravitational-wave Optical Transient Observer's suitability for observing such events and derive optimal observing strategies. I found that up to 150 tidal disruption events could be observed per year, although this number is caveated by several assumptions. Finally, I have used the Second Swift-XRT Point Source catalogue to search for previously unknown rare X-ray transients. Such efforts have been successfully applied to other X-ray catalogues to ?find new tidal disruption events, for instance. From the 206,335 sources in the catalogue, I identi?ed flaring extragalactic sources and analysed their light curves and other properties to classify them. This produced 19 new possible transients and I have explored some of their properties. I evaluated my methodology and found the fi?nal sample to have a completeness of ~ 65% and proposed improvements that could both improve the completeness and enable the identi?cation of transients in near real time with the future live version of the catalogue.
Posterior Mean Super-Resolution with a Compound Gaussian Markov Random Field Prior
Creators: name: Katsuki, Takayuki
name: Inoue, Masato
Publisher: name: arXiv
Year: 2012
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: This manuscript proposes a posterior mean (PM) super-resolution (SR) method with a compound Gaussian Markov random field (MRF) prior. SR is a technique to estimate a spatially high-resolution image from observed multiple low-resolution images. A compound Gaussian MRF model provides a preferable prior for natural images that preserves edges. PM is the optimal estimator for the objective function of peak signal-to-noise ratio (PSNR). This estimator is numerically determined by using variational Bayes (VB). We then solve the conjugate prior problem on VB and the exponential-order calculation cost problem of a compound Gaussian MRF prior with simple Taylor approximations. In experiments, the proposed method roughly overcomes existing methods.
description: 5 pages, 20 figures, 1 tables, accepted to ICASSP2012 (corrected 2012/3/23)
3d Quantum Gravity: Coarse-Graining and q-Deformation
Creators: name: Livine, Etera R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The Ponzano-Regge state-sum model provides a quantization of 3d gravity as a spin foam, providing a quantum amplitude to each 3d triangulation defined in terms of the 6j-symbol (from the spin-recoupling theory of SU(2) representations). In this context, the invariance of the 6j-symbol under 4-1 Pachner moves, mathematically defined by the Biedenharn-Elliot identity, can be understood as the invariance of the Ponzano-Regge model under coarse-graining or equivalently as the invariance of the amplitudes under the Hamiltonian constraints. Here we look at length and volume insertions in the Biedenharn-Elliot identity for the 6j-symbol, derived in some sense as higher derivatives of the original formula. This gives the behavior of these geometrical observables under coarse-graining. These new identities turn out to be related to the Biedenharn-Elliot identity for the q-deformed 6j-symbol and highlight that the q-deformation produces a cosmological constant term in the Hamiltonian constraints of 3d quantum gravity.
description: 18 pages
Sums of three cubes, II
Creators: name: Wooley, Trevor D.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11P05, 11L15, 11P55

description: Estimates are provided for $s$th moments of cubic smooth Weyl sums, when $4\le s\le 8$, by enhancing the author's iterative method that delivers estimates beyond classical convexity. As a consequence, an improved lower bound is presented for the number of integers not exceeding $X$ that are represented as the sum of three cubes of natural numbers.
description: 25 pages
Severe and localized GNSS scintillation at the poleward edge of the nightside auroral oval during intense substorm aurora
Creators: name: van der Meeren, Christer
name: Oksavik, Kjellmar
name: Lorentzen, Dag A.
name: Rietveld, Michael T.
name: Clausen, Lasse B. N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: In this paper we study how GPS, GLONASS, and Galileo navigation signals are compromised by strong irregularities causing severe phase scintillation ($\mathit{σ}_{ϕ}$ > 1) in the nightside high-latitude ionosphere during a substorm on 3 November 2013. Substorm onset and a later intensification coincided with polar cap patches entering the auroral oval to become auroral blobs. Using Global Navigation Satellite Systems (GNSS) receivers and optical data, we show severe scintillation driven by intense auroral emissions in the line of sight between the receiver and the satellites. During substorm expansion, the area of scintillation followed the intense poleward edge of the auroral oval. The intense auroral emissions were colocated with polar cap patches (blobs). The patches did not contain strong irregularities, neither before entering the auroral oval nor after the aurora had faded. Signals from all three GNSS constellations were similarly affected by the irregularities. Furthermore, two receivers spaced around 120km apart reported highly different scintillation impacts, with strong scintillation on half of the satellites in one receiver and no scintillation in the other. This shows that areas of severe irregularities in the nightside ionosphere can be highly localized. Amplitude scintillations were low throughout the entire interval.
Supplementary Material from Surface texture heterogeneity in maculated bird eggshells
Creators: name: Attard, Marie R. G.
name: Bowen, James
name: Portugal, Steven J.
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Environmental Science
classificationCode: 110601
subject: Biomechanics

description: Full model output tables, species list and source of images
The HII Galaxy Hubble Diagram Strongly Favors $R_{\rm h}=ct$ over $Λ$CDM
Creators: name: Wei, Jun-Jie
name: Wu, Xue-Feng
name: Melia, Fulvio
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We continue to build support for the proposal to use HII galaxies (HIIGx) and giant extragalactic HII regions (GEHR) as standard candles to construct the Hubble diagram at redshifts beyond the current reach of Type Ia supernovae. Using a sample of 25 high-redshift HIIGx, 107 local HIIGx, and 24 GEHR, we confirm that the correlation between the emission-line luminosity and ionized-gas velocity dispersion is a viable luminosity indicator, and use it to test and compare the standard model $Λ$CDM and the $R_{\rm h}=ct$ Universe by optimizing the parameters in each cosmology using a maximization of the likelihood function. For the flat $Λ$CDM model, the best fit is obtained with $Ω_{\rm m}= 0.40_{-0.09}^{+0.09}$. However, statistical tools, such as the Akaike (AIC), Kullback (KIC) and Bayes (BIC) Information Criteria favor $R_{\rm h}=ct$ over the standard model with a likelihood of $\approx 94.8\%-98.8\%$ versus only $\approx 1.2\%-5.2\%$. For $w$CDM (the version of $Λ$CDM with a dark-energy equation of state $w_{\rm de}\equiv p_{\rm de}/ρ_{\rm de}$ rather than $w_{\rm de}=w_Λ=-1$), a statistically acceptable fit is realized with $Ω_{\rm m}=0.22_{-0.14}^{+0.16}$ and $w_{\rm de}= -0.51_{-0.25}^{+0.15}$ which, however, are not fully consistent with their concordance values. In this case, $w$CDM has two more free parameters than $R_{\rm h}=ct$, and is penalized more heavily by these criteria. We find that $R_{\rm h}=ct$ is strongly favored over $w$CDM with a likelihood of $\approx 92.9\%-99.6\%$ versus only $0.4\%-7.1\%$. The current HIIGx sample is already large enough for the BIC to rule out $Λ$CDM/$w$CDM in favor of $R_{\rm h}=ct$ at a confidence level approaching $3σ$.
description: 21 Pages, 4 Figures, 3 Tables. Accepted for publication in MNRAS
Permutability graphs of subgroups of some finite non-abelian groups
Creators: name: Rajkumar, R.
name: Devi, P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C25, 05C07, 05C15, 05C45, 05C69, 20K27

description: In this paper, we study the structure of the permutability graphs of subgroups, and the permutability graphs of non-normal subgroups of the following groups: the dihedral groups $D_n$, the generalized quaternion groups $Q_n$, the quasi-dihedral groups $QD_{2^n}$ and the modular groups $M_{p^n}$. Further, we investigate the number of edges, degrees of the vertices, independence number, dominating number, clique number, chromatic number, weakly perfectness, Eulerianness, Hamiltonicity of these graphs.
description: 35 pages, 1 figure
Cultura como Esquemas: Capturando a Heterogeneidade de Significados Compartilhados e seu Efeito na Ação
Creators: name: , Rossoni
Publisher: name: Zenodo
Year: 2023
Subjects: esquemas culturais
cultura organizacional
cultura declarativa e não declarativa

description: Palestra apresentada no Pesquisa em Foco do Programa de Pós-Graduação em Administração da Universidade Federal de Viçosa.
Study of Parametric Instability of gravitational wave detectors using silicon test masses
Creators: name: Zhang, Jue
name: Zhao, Chunnong
name: Ju, Li
name: Blair, David
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Parametric instability is an intrinsic risk in high power laser interferometer gravitational wave detectors, in which the optical cavity modes interact with the acoustic modes of the mirrors leading to exponential growth of the acoustic vibration. In this paper, we investigate the potential parametric instability for a proposed next generation gravitational wave detector based on cooled silicon test masses. It is shown that there would be about 2 unstable modes per test mass, with the highest parametric gain of ~76. The importance of developing suitable instability suppression schemes is emphasized.
An extensive survey of dayside diffuse aurora based on optical observations at Yellow River Station
Creators: name: Han, De-Sheng
name: Chen, Xiang-Cai
name: Liu, Jian-Jun
name: Qiu, Qi
name: Keika, K.
name: Hu, Ze-Jun
name: Liu, Jun-Ming
name: Hu, Hong-Qiao
name: Yang, Hui-Gen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: By using 7 years optical auroral observations obtained at Yellow River Station (magnetic latitude $76.24\,^{\circ}{\rm C}$N) at Ny-Alesund, Svalbard, we performed the first extensive survey for the dayside diffuse auroras (DDAs) and acquired observational results as follows. (1) The DDAs can be classified into two broad categories, i.e., unstructured and structured DDAs. The unstructured DDAs are mainly distributed in the morning and afternoon, but the structured DDAs predominantly occurred around the magnetic local noon (MLN). (2) The unstructured DDAs observed in morning and afternoon present obviously different properties. The afternoon ones are much stable and seldom show pulsating property. (3) The DDAs are more easily observed under geomagnetically quiet times. (4) The structured DDAsmainly show patchy, stripy, and irregular forms and are often pulsating and drifting. The drifting directions are mostly westward (with speed $\sim$5km/s), but there are cases showing eastward or poleward drifting. (5) The stripy DDAs are exclusively observed near theMLN and,most importantly, their alignments are confirmed to be consistent with the direction of ionospheric convection near the MLN. (6) A new auroral form, called throat aurora, is found to be developed from the stripy DDAs. Based on the observational results and previous studies, we proposed our explanations to the DDAs. We suggest that the unstructured DDAs observed in the morning are extensions of the nightside diffuse aurora to the dayside, but that observed in the afternoon are predominantly caused by proton precipitations. $\textit{(Abstract continues in PDF).}$
Kinematics of the Galaxy from Cepheids with proper motions from the Gaia DR1 catalogue
Creators: name: Bobylev, V. V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The sample of classic Cepheids with known distances and line-of-sight velocities is supplemented by the proper motions from the Gaia DR1 catalog. From spatial velocities of 260 stars the components of the peculiar Solar velocity: (U,V,W)_\odot=(7.90,11.73,7.39)+/-(0.65,0.77,0.62) km/s, parameters of the Galactic rotation curve: Ω_0 =28.840+/-.33 km/s/kpc, Ω'_0=-4.05+/-0.10 km/s/kpc^2, Ω''_0=0.805+/-0.067 km/s/kpc^3 are obtained. For the adopted Galactocentric Solar distance R_0=8 kpc the linear circular velocity of the Local Standard of Rest is found as V_0=231+/-6 km/s.
description: 11 pages, 4 figures, 2 tables. arXiv admin note: text overlap with arXiv:1611.00794
Calibrating Column Density Tracers with Gamma-ray Observations of the $ρ$ Ophiuchi Molecular Cloud
Creators: name: Abrahams, Ryan D.
name: Teachey, Alex
name: Paglione, Timothy A. D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Diffuse gamma-ray emission from interstellar clouds results largely from cosmic ray (CR) proton collisions with ambient gas, regardless of the gas state, temperature, or dust properties of the cloud. The interstellar medium is predominantly transparent to both CRs and gamma-rays, so GeV emission is a unique probe of the total gas column density. The gamma-ray emissivity of a cloud of known column density is then a measure of the impinging CR population and may be used to map the kpc-scale CR distribution in the Galaxy. To this end, we test a number of commonly used column density tracers to evaluate their effectiveness in modeling the GeV emission from the relatively quiescent, nearby $ρ$ Ophiuchi molecular cloud. We confirm that both \hi\ and an appropriate H$_2$ tracer are required to reproduce the total gas column densities probed by diffuse gamma-ray emisison. We find that the optical depth at 353 GHz $τ_{353}$ from Planck reproduces the gamma-ray data best overall based on the test statistic across the entire region of interest, but near infrared stellar extinction also performs very well, with smaller spatial residuals in the densest parts of the cloud.
description: 17 pages, 11 figures, 2 tables. Accepted for publication in ApJ
A Mecke-type characterization of the Dirichlet-Ferguson measure
Creators: name: Schiavo, Lorenzo Dello
name: Lytvynov, Eugene W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G57

description: We prove a characterization of the Dirichlet-Ferguson measure over an arbitrary finite diffuse measure space. We provide an interpretation of this characterization in analogy with the Mecke identity for Poisson point processes.
description: 12 pages. To appear in Electron. Commun. Probab
Quasi-periodic pulsations in solar and stellar flares: an overview of recent results
Creators: name: Van Doorsselaere, Tom
name: Kupriyanova, Elena G.
name: Yuan, Ding
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Quasi-periodic pulsations (or QPPs) are periodic intensity variations in the flare emission, across all wavelength bands. In this paper, we review the observational and modelling achievements since the previous review on this topic by Nakariakov & Melnikov (2009). In recent years, it has become clear that QPPs are an inherent feature of solar flares, because almost all flares exhibit QPPs. Moreover, it is now firmly established that QPPs often show multiple periods. We also review possible mechanisms for generating QPPs. Up to now, it has not been possible to conclusively identify the triggering mechanism or cause of QPPs. The lack of this identification currently hampers possible seismological inferences of flare plasma parameters. QPPs in stellar flares have been detected for a long time, and the high quality data of the Kepler mission allows to study the QPP more systematically. However, it has not been conclusively shown whether the time scales of stellar QPPs are different or the same as those in solar flares.
Correlation-driven topological phase transition from in-plane magnetized quantum anomalous Hall to Mott insulating phase in monolayer transition metal trichlorides
Creators: name: Sheng, Xian-Lei
name: Nikolic, Branislav K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Based on density functional theory (DFT) calculations, we predict that a monolayer of OsCl$_3$---a layered material whose interlayer coupling is weaker than in graphite---possesses a quantum anomalous Hall (QAH) insulating phase generated by the combination of honeycomb lattice of osmium atoms, their strong spin-orbit coupling (SOC) and ferromagnetic ground state with {\em in-plane} easy-axis. The band gap opened by SOC is \mbox{$E_g \simeq 67$ meV} (or \mbox{$\simeq 191$ meV} if the easy-axis can be tilted out of the plane by an external electric field), and the estimated Curie temperature of such {\em anisotropic planar rotator} ferromagnet is $T_\mathrm{C} \lesssim 350$ K. The Chern number $\mathcal{C}=-1$, generated by the manifold of Os $t_{2g}$ bands crossing the Fermi energy, signifies the presence of a single chiral edge state in nanoribbons of finite width, where we further show that edge states are spatially narrower for zigzag than armchair edges and investigate edge-state transport in the presence of vacancies at Os sites. Since $5d$ electrons of Os exhibit {\em both} strong SOC and moderate correlation effects, we employ DFT+U calculations to show how increasing on-site Coulomb repulsion $U$: gradually reduces $E_g$ while maintaining $\mathcal{C} = -1$ for $0 < U < U_c$; leads to metallic phase with $E_g = 0$ at $U_c$; and opens the gap of topologically trivial Mott insulating phase with $\mathcal{C}=0$ for $U > U_c$.
description: 6 pages, 5 color PDF figures, PDFLaTeX
Scintillation and loss of signal lock from poleward moving auroral forms in the cusp ionosphere
Creators: name: Oksavik, K.
name: van der Meeren, C.
name: Lorentzen, D. A.
name: Baddeley, L. J.
name: Moen, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We present two examples from the cusp ionosphere over Svalbard,where poleward moving auroral forms (PMAFs) are causing significant phase scintillation in signals from navigation satellites. The data were obtained using a combination of ground-based optical instruments and a newly installed multiconstellation navigation signal receiver at Longyearbyen. Both events affected signals from GPS and Global Navigation Satellite System (GLONASS). When one intense PMAF appeared, the signal from one GPS spacecraft also experienced a temporary loss of signal lock. Although several polar cap patches were also observed in the area as enhancements in total electron content, the most severe scintillation and loss of signal lock appear to be attributed to very intense PMAF activity. This shows that PMAFs are locations of strong ionospheric irregularities, which at times may cause more severe disturbances in the cusp ionosphere for navigation signals than polar cap patches.
Chiral oily streaks in a smectic-A liquid crystal
Creators: name: Nemitz, Ian R.
name: Ferris, Andrew J.
name: Lacaze, Emmanuelle
name: Rosenblatt, Charles
Publisher: name: arXiv
Year: 2016
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The liquid crystal octylcyanobiphenyl (8CB) was doped with the chiral agent CB15 and spin-coated onto a substrate treated for planar alignment of the director, resulting in a film of thickness several hundred nm in the smectic-A phase. In both doped and undoped samples, the competing boundary conditions - planar alignment at the substrate and vertical alignment at the free surface - cause the liquid crystal to break into a series of flattened hemicylinders to satisfy the boundary conditions. When viewed under an optical microscope with crossed polarizers, this structure results in a series of dark and light stripes ("oily streaks") of period ~ 1 $μ$m. In the absence of chiral dopant the stripes run perpendicular to the substrate's easy axis. However, when doped with chiral CB15 at concentrations up to c = 4 wt-%, the stripe orientation rotates by a temperature-dependent angle $ϕ$ with respect to the c = 0 stripe orientation, where $ϕ$ increases monotonically with c. $ϕ$ is largest just below the nematic -- smectic-A transition temperature TNA and decreases with decreasing temperature. As the temperature is lowered, $ϕ$ relaxes to a steady-state orientation close to zero within ~1$^\circ$ C of TNA. We suggest that the rotation phenomenon is a manifestation of the surface electroclinic effect: The rotation is due to the weak smectic order parameter and resulting large director tilt susceptibility with respect to the smectic layer normal near TNA, in conjunction with an effective surface electric field due to polar interactions between the liquid crystal and substrate.
Differential Equation over Banach Algebra
Creators: name: Kleyn, Aleks
Publisher: name: arXiv
Year: 2018
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics
subject: 34A05, 35F10, 35F40

description: In the book, I considered differential equations of order $1$ over Banach $D$\Hyph algebra: differential equation solved with respect to the derivative; exact differential equation; linear homogeneous equation. I considered examples of differential equations in quaternion algebra. In order to study homogeneous system of linear differential equations, I considered vector space over division $D$-algebra, solving of linear equations over division $D$-algebra and the theory of eigenvalues in non commutative division $D$-algebra.
description: English text - 345 pages; Russian text - 362 pages
Network analysis of geomagnetic substorms using the SuperMAG database of ground-based magnetometer stations
Creators: name: Dods, J.
name: Chapman, S. C.
name: Gjerloev, J. W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: The overall morphology and dynamics of magnetospheric substorms is well established in terms of the observed qualitative auroral features seen in ground-based magnetometers. This paper focuses on the quantitative characterization of substorm dynamics captured by ground-based magnetometer stations. We present the first analysis of substorms using dynamical networks obtained from the full available set of ground-based magnetometer observations in the Northern Hemisphere. The stations are connected in the network when the correlation between the vector magnetometer time series from pairs of stations within a running time window exceeds a threshold. Dimensionless parameters can then be obtained that characterize the network and by extension, the spatiotemporal dynamics of the substorm under observation. We analyze four isolated substorm test cases as well as a steady magnetic convection (SMC) event and a day in which no substorms occur. These test case substorms are found to give a consistent characteristic network response at onset in terms of their spatial correlation. Such responses are differentiable from responses to the SMC event and nonsubstorm times. We present a method to optimize network parametrization with respect to the different individual station responses, the spatial inhomogeneity of stations in the Northern Hemisphere, and the choice of correlation window sizes. Our results suggest that dynamical network analysis has potential to quantitatively categorize substorms.
Dickson's Lemma, Higman's Theorem and Beyond: a survey of some basic results in order theory
Creators: name: Aichinger, Erhard
name: Aichinger, Florian
Publisher: name: arXiv
Year: 2018
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 06A06

description: We provide proofs for the fact that certain orders have no descending chains and no antichains.
description: Survey paper
Supplementary Text from Physical interactions in non-ideal fluids promote Turing patterns
Creators: name: Menou, Lucas
name: Luo, Chengjie
name: Zwicker, David
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Biophysics
classificationCode: 90499
subject: Chemical Engineering not elsewhere classified
subject: Computational Biology

description: Turing’s mechanism is often invoked to explain periodic patterns in nature, although direct experimental support is scarce. Turing patterns form in reaction–diffusion systems when the activating species diffuse much slower than the inhibiting species, and the involved reactions are highly nonlinear. Such reactions can originate from co-operativity, whose physical interactions should also affect diffusion. We here take direct interactions into account and show that they strongly affect Turing patterns. We find that weak repulsion between the activator and inhibitor can substantially lower the required differential diffusivity and reaction nonlinearity. By contrast, strong interactions can induce phase separation, but the resulting length scale is still typically governed by the fundamental reaction–diffusion length scale. Taken together, our theory connects traditional Turing patterns with chemically active phase separation, thus describing a wider range of systems. Moreover, we demonstrate that even weak interactions affect patterns substantially, so they should be incorporated when modelling realistic systems.
A generalization of the Minkowski distance and a new definition of the ellipse
Creators: name: Çolakoğlu, Harun Barış
Publisher: name: arXiv
Year: 2019
Subjects: subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 51K05, 51K99, 51N20

description: In this paper, we generalize the Minkowski distance by defining a new distance function in n-dimensional space, and we show that this function determines also a metric family as the Minkowski distance. Then, we consider three special cases of this family, which generalize the taxicab, Euclidean and maximum metrics respectively, and finally we determine circles of them with their some properties in the real plane. While we determine some properties of circles of the generalized Minkowski distance, we also discover a new definition for the ellipse.
description: 18 pages, 18 figures
Scaling in driven dynamics starting in the vicinity of a quantum critical point
Creators: name: Yin, Shuai
name: Lo, Chung-Yu
name: Chen, Pochung
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the driven critical dynamics with an equilibrium initial state near a quantum critical point. In contrast to the original Kibble-Zurek mechanism, which describes the driven dynamics starting from an adiabatic stage that is far from the critical point, the initial adiabacity is broken in this scenario. As a result, the scaling behavior cannot be described by the original Kibble-Zurek scaling. In this work we propose a scaling theory, which includes the initial parameters as additional scaling variables, to characterize the scaling behavior. In particular, this scaling theory can be used to describe the driven scaling behavior starting from a finite-temperature equilibrium state near a quantum critical point. We numerically confirm the scaling theory by simulating the real-time dynamics of the one-dimensional quantum Ising model at both zero and finite temperatures.
description: 6 pages, 5 figures
Counting abelian varieties over finite fields via Frobenius densities
Creators: name: Achter, Jeff
name: Altug, Salim Ali
name: Garcia, Luis
name: Gordon, Julia
name: Li, Wen-Wei
name: Rüd, Thomas
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: Let $[X,λ]$ be a principally polarized abelian variety over a finite field with commutative endomorphism ring; further suppose that either $X$ is ordinary or the field is prime. Motivated by an equidistribution heuristic, we introduce a factor $ν_v([X,λ])$ for each place $v$ of $\mathbb Q$, and show that the product of these factors essentially computes the size of the isogeny class of $[X,λ]$. The derivation of this mass formula depends on a formula of Kottwitz and on analysis of measures on the group of symplectic similitudes, and in particular does not rely on a calculation of class numbers.
description: Added author; significantly simplified global calculation in section 5; made other, smaller improvements
Spatial structure and temporal evolution of energetic particle injections in the inner magnetosphere during the 14 July 2013 substorm event
Creators: name: Gkioulidou, Matina
name: Ohtani, S.
name: Mitchell, D. G.
name: Ukhorskiy, A. Y.
name: Reeves, G. D.
name: Turner, D. L.
name: Gjerloev, J. W.
name: Nosé, M.
name: Koga, K.
name: Rodriguez, J. V.
name: Lanzerotti, L. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Recent results by the Van Allen Probes mission showed that the occurrence of energetic ion injections inside geosynchronous orbit could be very frequent throughout the main phase of a geomagnetic storm. Understanding, therefore, the formation and evolution of energetic particle injections is critical in order to quantify their effect in the inner magnetosphere. We present a case study of a substorm event that occurred during a weak storm $\textit{ Dst }$ $\sim$ -40nT on 14 July 2013. Van Allen Probe B, inside geosynchronous orbit, observed two energetic proton injections within 10min, with different dipolarization signatures and duration. The first one is a dispersionless, short-timescale injection pulse accompanied by a sharp dipolarization signature, while the second one is a dispersed, longer-timescale injection pulse accompanied by a gradual dipolarization signature. We combined ground magnetometer data from various stations and in situ particle and magnetic field data from multiple satellites in the inner magnetosphere and near-Earth plasma sheet to determine the spatial extent of these injections, their temporal evolution, and their effects in the inner magnetosphere. Our results indicate that there are different spatial and temporal scales at which injections can occur in the inner magnetosphere and depict the necessity of multipoint observations of both particle and magnetic field data in order to determine these scales.
Determination of magic wavelengths for the $7s ~ {^2}S_{1/2}-7p ~ {^2}P_{3/2,1/2}$ transitions in Fr atom
Creators: name: Singh, Sukhjit
name: Sahoo, B. K.
name: Arora, Bindiya
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Magic wavelengthsfor the $7S_{1/2}-7P_{1/2,3/2}$ transitions in Fr were reported by Dammalapati \textit{et al.} in [Phys. Rev. A 93, 043407 (2016)]. These $λ_{\rm{magic}}$ were determined by plotting dynamic polarizabilities ($α$) of the involved states with the above transitions against a desired range of wavelength. Electric dipole (E1) matrix elements listed in [J. Phys. Chem. Ref. Data 36, 497 (2007)], from the measured lifetimes of the $7P_{1/2,3/2}$ states and from the calculations considering core-polarization effects in the relativistic Hartree-Fock (HFR) method, were used to determine $α$. However, contributions from core correlation effects and from the E1 matrix elements of the $7P-7S$, $7P-8S$ and $7P-6D$ transitions to $α$ of the $7P$ states were ignored. In this work, we demonstrate importance of these contributions and improve accuracies of $α$ further by replacing the E1 matrix elements taken from the HFR method by the values obtained employing relativistic coupled-cluster theory. Our static $α$ are found to be in excellent agreement with the other available theoretical results; whereas substituting the E1 matrix elements used by Dammalapati \textit{et al.} give very small $α$ values for the $7P$ states. Owing to this, we find disagreement in $λ_{\rm{magic}}$ reported by Dammalapati \textit{et al.} for linearly polarized light; especially at wavelengths close to the D-lines and in the infrared region. As a consequence, a $λ_{\rm{magic}}$ reported at 797.75 nm which was seen supporting a blue detuned trap in their work is now estimated at 771.03 nm and is supporting a red detuned trap. Also, none of our results match with the earlier results for circularly polarized light. Moreover, our static values of $α$ will be very useful for guiding experiments to carry out their measurements.
description: 11 pages, 3 figures, accepted for publication in Phys. Rev. A
Algebraic Relations Between Partition Functions and the $j$-Function
Creators: name: Lin, Alice
name: McSpirit, Eleanor
name: Vishnu, Adit
Publisher: name: arXiv
Year: 2019
Subjects: subject: Number Theory (math.NT)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: We obtain identities and relationships between the modular $j$-function, the generating functions for the classical partition function and the Andrews $spt$-function, and two functions related to unimodal sequences and a new partition statistic we call the "signed triangular weight" of a partition. These results follow from the closed formula we obtain for the Hecke action on a distinguished harmonic Maass form $\mathscr{M}(τ)$ defined by Bringmann in her work on the Andrews $spt$-function. This formula involves a sequence of polynomials in $j(τ)$, through which we ultimately arrive at expressions for the coefficients of the $j$-function purely in terms of these combinatorial quantities.
Electronic Supplementary Material from Diet and the evolution of ADH7 across seven orders of mammals
Creators: name: Pinto, Swellan L.
name: Janiak, Mareike C.
name: Dutyschaever, Gwen
name: Barros, Marília A. S.
name: Chavarria, Adrian Guadamuz
name: Martin, Maria Pia
name: Tuh, Fred Y. Y.
name: Valverde, Carmen Soto
name: Sims, Lisa M.
name: Barclay, Robert M. R.
name: Wells, Konstans
name: Dominy, Nathaniel J.
name: Pessoa, Daniel M. A.
name: Carrigan, Matthew A.
name: Melin, Amanda D.
Publisher: name: The Royal Society
Year: 2023
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Supplemental Tables 1-5
title: Combining Molecular and Imaging Biomarkers to Enhance MALDI Biomarker Analysis
Creators: name: Vadlamudi, Ayyappa Chowdary
Publisher: name: Old Dominion University
publisherIdentifier: https://ror.org/04zjtrb98
publisherIdentifierScheme: ROR
Year: 2010

description: This thesis presents a three-step method to predict prostate cancer (PCa) regions on biopsy tissue samples based on high confident, low resolution PCa regions marked by a pathologist. First, a prediction model is designed to predict PCa regions using matrix-assisted laser desorption mass spectrometry (MALDI-MS) tissue imaging data from one prostate tissue slice. Second, a texture analysis technique is applied to a high magnification optical image for the same purpose from an adjacent tissue slice. Finally, those two results are fused to obtain the PCa regions that will assist MALDI imaging biomarker analysis. Experiments show that the texture analysis based prediction is sensitive but not specific, and the prediction based on the MALDI-MS data is specific while less sensitive. By combing those two results, a much better prediction for PCa regions on the adjacent slice can be achieved. This thesis focuses on the MALDI-MS based PCa region prediction and fusion of prediction from texture analysis and that from MALDI-MS data process mg.
Moduli spaces of framed sheaves and quiver varieties
Creators: name: Bartocci, Claudio
name: Lanza, Valeriano
name: Rava, Claudio L. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14D20, 14D21, 14J60, 16G20

description: In the first part of this paper we provide a survey of some fundamental results about moduli spaces of framed sheaves on smooth projective surfaces. In particular, we outline a result by Bruzzo and Markushevich, and discuss a few significant examples. The moduli spaces of framed sheaves on $\mathbb{P}^2$, on multiple blowup of $\mathbb{P}^2$ are described in terms of ADHM data and, when this characterization is available, as quiver varieties. The second part is devoted to a detailed study of framed sheaves on the Hirzebruch surface $Σ_n$ in the case when the invariant expressing the necessary and sufficient condition for the nonemptiness of moduli spaces attains its minimum (what we call the "minimal case"). Our main result is that, under this assumption, the corresponding moduli space is isomorphic to a Grassmannian (when $n=1$), or to the direct sum of $n-1$ copies of the cotangent bundle of a Grassmannian (when $n\geq 2$). Finally, by slightly generalizing a construction due to Nakajima, we prove that these moduli spaces admit a description as quiver varieties.
Completing and Debugging Ontologies: state of the art and challenges
Creators: name: Lambrix, Patrick
Publisher: name: arXiv
Year: 2019
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: As semantically-enabled applications require high-quality ontologies, developing and maintaining ontologies that are as correct and complete as possible is an important although difficult task in ontology engineering. A key step is ontology debugging and completion. In general, there are two steps: detecting defects and repairing defects. In this paper we discuss the state of the art regarding the repairing step. We do this by formalizing the repairing step as an abduction problem and situating the state of the art with respect to this framework. We show that there are still many open research problems and show opportunities for further work and advancing the field.
description: 56 pages
Separation of lignin from beech wood hydrolysate using polymeric resins and zeolites – Determination and application of adsorption isotherms
Creators: name: Nitzsche, Roy
name: Gröngröft, Arne
name: Kraume, Matthias
Publisher: name: Technische Universität Berlin
Year: 2018
Subjects: subject: 660 Chemische Verfahrenstechnik
subject: lignocellulose biorefinery
subject: beech wood hydrolysate
subject: polymeric resins
subject: zeolite
subject: adsorption isotherms

description: Separation of lignin from hemicellulose sugar out of beech wood hydrolysate (BWH) by four polymeric and one zeolitic adsorbents was investigated. First, by means of single and binary model solutions (MS), consisting of 3.1 g/L phenol and/or 4.2 g/L xylose, the two most suitable adsorbents were chosen and single- and multi-component isotherms were determined. Second, the isotherm model parameters from the MS were applied to the equilibrium measurements of BWH and statistically evaluated regarding their adaptability. All experiments were carried out in batch mode. Of the five tested adsorbents, Amberlite XAD7HP and SEPABEADS SP700 were found to be the most efficient. Phenol and lignin removal was 100% and over 93% respectively and xylose and hemicellulose sugar recovery was greater 92% at an adsorbent-to-solution ratio of 1:5 w/v (g/mL). Phenol adsorption agreed best to Freundlich equation and xylose adsorption to Langmuir equation for XAD7HP and SP700 in the single-component experiments. In a multi-component system, adsorption behavior of both phenol and xylose for the two adsorbents can be fitted best to an extended Freundlich isotherm. For practical applications, it is reasonable to use Freundlich and extended Freundlich isotherms for xylose adsorption onto XAD7HP and SP700. Application and evaluation of the isotherm model parameters determined by the MS to the equilibrium data from adsorption experiments of BWH onto XAD7HP and SP700 showed that the valid isotherm type and thus the predominant adsorption mechanisms can be predicted accurately. However, the isotherm model parameters of the MS do not adequately describe the specific adsorption process of the BWH onto the resins. Hence, they have to be determined individually. More than 90% of adsorbed lignin and 95% of adsorbed hemicellulose sugar were desorbed using 50 wt% ethanol solution.