cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Instability toward Formation of Quasi-One-Dimensional Fermi Surface in Two-Dimensional t-J Model
Creators: name: Yamase, Hiroyuki
name: Kohno, Hiroshi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show within the slave-boson mean field approximation that the two-dimensional t-J model has an intrinsic instability toward forming a quasi-one-dimensional (q-1d) Fermi surface. This q-1d state competes with, and is overcome by, the d-wave pairing state for a realistic parameter choice. However, we find that a small spatial anisotropy in t and J exposes the q-1d instability which has been hidden behind the d-wave pairing state, and brings about the coexistence with the d-wave pairing. We argue that this coexistence can be realized in La_{2-x}Sr_{x}CuO_4 systems
description: 15 pages, 10 figures, for those who cannot download JPSJ papers
A Generalisation of Dyson's Integration Theorem for Determinants
Creators: name: Akemann, Gernot
name: Shifrin, Leonid
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mathematical Physics (math-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Dyson's integration theorem is widely used in the computation of eigenvalue correlation functions in Random Matrix Theory. Here we focus on the variant of the theorem for determinants, relevant for the unitary ensembles with Dyson index beta = 2. We derive a formula reducing the (n-k)-fold integral of an n x n determinant of a kernel of two sets of arbitrary functions to a determinant of size k x k. Our generalisation allows for sets of functions that are not orthogonal or bi-orthogonal with respect to the integration measure. In the special case of orthogonal functions Dyson's theorem is recovered.
description: 7 pages, Latex. v2: typos corrected + reference added. v3: degenerate case added, to be published in J.Phys.A FTC
NATURAL ALCOHOLS, POLYHYDRIC ALCOHOLS AND PHENOLS
Creators: name: Yusufova, Sabina
Publisher: name: Zenodo
Year: 2024

description: The relevance of this topic is undeniable. Monohydric alcohols are used in various fields of work, especially widely in medicine. For example, if you ask yourself how to give an injection correctly, it turns out that it is simply impossible to do them without alcohol, and alcohols are the main base for the production of many medicines. Purpose of the article is to systematize the acquired knowledge about natural alcohols, polyhydric alcohols, and also to consider various areas of application.
Dangerous Liouville Wave -- exactly marginal but non-conformal deformation
Creators: name: Ho, Chiu Man
name: Nakayama, Yu
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We give a non-trivially interacting field theory example of scale invariant but non-conformal field theory. The model is based on the exactly solvable Liouville field theory coupled with free scalars deformed by an exactly marginal operator. We show non-vanishing of the trace of the energy-momentum tensor by using the quantum Schwinger-Dyson equation for the Liouville field theory, which is a sophistication of the quantum higher equations of motion for the Liouville field theory introduced by Alyosha Zamolodchikov. Possibly dangerous implications for the super-critical string theory will be discussed.
description: Improved version to appear in JHEP
The circumbinary disk of HD 98800 B: Evidence for disk warping
Creators: name: Akeson, R. L.
name: Rice, W. K. M.
name: Boden, A. F.
name: Sargent, A. I.
name: Carpenter, J. M.
name: Bryden, G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The quadruple young stellar system HD 98800 consists of two spectroscopic binary pairs with a circumbinary disk around the B component. Recent work by Boden and collaborators using infrared interferometry and radial velocity data resulted in a determination of the physical orbit for HD 98800 B. We use the resulting inclination of the binary and the measured extinction toward the B component stars to constrain the distribution of circumbinary material. Although a standard optically and geometrically thick disk model can reproduce the spectral energy distribution, it can not account for the observed extinction if the binary and the disk are co-planar. We next constructed a dynamical model to investigate the influence of the A component, which is not in the Ba-Bb orbital plane, on the B disk. We find that these interactions have a substantial impact on the inclination of the B circumbinary disk with respect to the Ba-Bb orbital plane. The resulting warp would be sufficient to place material into the line of sight and the non-coplanar disk orientation may also cause the upper layers of the disk to intersect the line of sight if the disk is geometrically thick. These simulations also support that the dynamics of the Ba-Bb orbit clear the inner region to a radius of ~3 AU. We then discuss whether the somewhat unusual properties of the HD 98800 B disk are consistent with material remnant from the star formation process or with more recent creation by collisions from larger bodies.
description: 19 pages, 3 figures, to appear in the Astrophysical Journal
The Anatomy of an Unusual Edge-on Protoplanetary Disk I. Dust Settling in a Cold Disk
Creators: name: Wolff, S.
name: Duchêne, G.
name: Stapelfeldt, K.
name: Ménard, F.
name: Flores, C.
name: Padgett, D.
name: Pinte, C.
name: Villenave, M.
name: van der Plas, G.
name: Perrin, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: As the earliest stage of planet formation, massive, optically thick, and gas rich protoplanetary disks provide key insights into the physics of star and planet formation. When viewed edge-on, high resolution images offer a unique opportunity to study both the radial and vertical structures of these disks and relate this to vertical settling, radial drift, grain growth, and changes in the midplane temperatures. In this work, we present multi-epoch HST and Keck scattered light images, and an ALMA 1.3 mm continuum map for the remarkably flat edge-on protoplanetary disk SSTC2DJ163131.2-242627, a young solar-type star in $ρ$ Ophiuchus. We model the 0.8 $μ$m and 1.3 mm images in separate MCMC runs to investigate the geometry and dust properties of the disk using the MCFOST radiative transfer code. In scattered light, we are sensitive to the smaller dust grains in the surface layers of the disk, while the sub-millimeter dust continuum observations probe larger grains closer to the disk midplane. An MCMC run combining both datasets using a covariance-based log-likelihood estimation was marginally successful, implying insufficient complexity in our disk model. The disk is well characterized by a flared disk model with an exponentially tapered outer edge viewed nearly edge-on, though some degree of dust settling is required to reproduce the vertically thin profile and lack of apparent flaring. A colder than expected disk midplane, evidence for dust settling, and residual radial substructures all point to a more complex radial density profile to be probed with future, higher resolution observations.
description: Accepted for publication in AJ
Satellite survival in cold dark matter cosmology
Creators: name: Boily, C. M.
name: Nakastao, N.
name: Spurzem, R.
name: Tsuchiya, T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the survival of substructures (clumps) within larger self-gravitating dark matter halos. Building on scaling relations obtained from N-body calculations of violent relaxation, we argue that the tidal field of galaxies and halos can only destroy substructures if spherical symmetry is imposed at formation. We explore other mechanisms that may tailor the number of halo substructures during the course of virialization. Unless the larger halo is built up from a few large clumps, we find that clump-clump encounters are unlikely to homogenize the halo on a dynamical timescale. Phase mixing would proceed faster in the inner parts and allow for the secular evolution of a stellar disk.
description: 5 pages, no figures
Possible Quasi-One-Dimensional Fermi Surface in La_{2-x}Sr_{x}CuO_4
Creators: name: Yamase, Hiroyuki
name: Kohno, Hiroshi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: To reconcile the two experimental findings on La_{2-x}Sr_{x}CuO_4, namely, Fermi surface (FS) observed by angle-resolved photoemission spectroscopy and sharp incommensurate magnetic peaks by neutron scattering, we propose a picture that a quasi-one-dimensional FS (q-1dFS) is realized in each CuO_{2} plane whose q-1d direction alternates along the c-axis.
description: 10 pages, 6 figures, for those who cannot download JPSJ papers
D6.3 RIDE2RAIL Project Leaflet
Creators: name: van Hek, Charlotte
name: Rizzi, Giuseppe
Publisher: name: Zenodo
Year: 2020
Subjects: RIDE2RAIL
Transport
Shift2Rail
Visual identity
Leaflet

description: The deliverable describes the objectives, structure, and look and feel of the RIDE2RAIL leaflet. The leaflet is considered an essential tool within the project to reach objectives concerning communication, including strengthening the RIDE2RAIL identity, raising awareness and disseminating project developments to key stakeholders and external actors.
The effects of co-varying diel-cycling hypoxia and pH on disease susceptibility, growth, and feeding in Crassostrea virginica
Creators: name: Keppel, Andrew George
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: Environmental science
subject: Environmental management
subject: acidification
subject: crassostrea
subject: diel-cycling
subject: disease
subject: growth
subject: hypoxia

description: Diel-cycling hypoxia and pH co-occur in shallow waters world-wide.  Eutrophication tends to increase the occurrence and severity of diel cycles.  We used laboratory experiments to investigate effects of diel-cycling DO and pH on acquisition and progression of infections by Perkinsus marinus, the protistan parasite which causes Dermo disease, as well as hemocyte activity, growth, and feeding in the eastern oyster, Crassostrea virginica, an important estuarine species.  Diel-cycling DO increased P. marinus infection and cycling DO and pH stimulated hemocyte activity and reduced oyster growth.  However, ambient environmental conditions and oyster age modulated some of these effects.   Co-varying DO and pH cycles sometimes had less severe effects than either cycle independently.  Oysters may acclimate to, or compensate for, effects of cycling conditions on growth.  Variation in magnitude and spatial extent of cycling conditions is an important consideration when choosing restoration sites, as severe cycling conditions may hinder re-establishment of estuarine populations.
Statistics and dynamics of coherent structures on turbulent grid-flow
Creators: name: Loewen, Stuart Reid
Publisher: name: University of British Columbia
Year: 2010

description: This thesis examines the statistics and dynamics of turbulent flow structures generated by towing a grid through a tank of water. The structures were made visible by recording the paths of aluminum tracers moving with the water surface. Flow patterns recorded using a time-exposure method were manually analyzed to extract information on the structure statistics. This two-dimensional flow field was found to be composed of closed rotating 'surface eddies', open and largely translational 'river' motion and stagnant regions. Energy distributions of the eddies and rivers were obtained and characterized by Boltzmann type distributions. A newly developed computer-automated structure identification and flow field analysis system was used to study the structure dynamics. The system analyzes digital images obtained from video recordings of the tracer motion. The predominant evolution processes of initial vortex production, eddy pairing, viscous decay and the omega decay were examined. Flow Reynolds numbers, based on bar spacing, of about 10,000 were examined. The structure statistics and dynamics study was performed in order to examine the validity and viability of a new model for turbulence. The model predicts the evolution of a population of structures using rate equations where the rate coefficients are determined by the individual structure dynamics. A summary of the model is presented and contrasted with models based the the Reynolds stresses as well as computational models.
"Nothing About the Rape:" Generative Silencing in Nalo Hopkinson's Midnight Robber
Creators: name: Webb, Calvin Allan
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Literature
subject: Canadian literature
subject: Caribbean literature
subject: Black Feminism
subject: Feminism
subject: Haitian Revolution
subject: Science Fiction
subject: Slavery
subject: Speculative Fiction

description: This project, which focuses on Nalo Hopkinson's Midnight Robber, explores the relationship between storytelling, witnessing, and lived experience. By interrogating the intersection of black feminism, speculative fiction, and slave narratives in the backdrop of the Haitian Revolution, Hopkinson's work shows that some silencing can be constructive, even essential, for survival.
Anisotropic diffusion of ellipsoidal tracers in microswimmer suspensions
Creators: name: Nordanger, Henrik
name: Morozov, Alexander
name: Stenhammar, Joakim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Tracer particles immersed in suspensions of biological microswimmers such as E. coli or C. reinhardtii display phenomena unseen in conventional equilibrium systems, including strongly enhanced diffusivity relative to the Brownian value and non-Gaussian displacement statistics. In dilute, 3-dimensional suspensions, these phenomena have typically been explained by the hydrodynamic advection of point tracers by isolated microswimmers, while, at higher concentrations, correlations between pusher microswimmers such as E. coli can increase the effective diffusivity even further. Anisotropic tracers in active suspensions can be expected to exhibit even more complex behaviour than spherical ones, due to the presence of a nontrivial translation-rotation coupling. Using large-scale lattice Boltzmann simulations of model microswimmers described by extended force dipoles, we study the motion of ellipsoidal point tracers immersed in 3-dimensional microswimmer suspensions. We find that the rotational diffusivity of tracers is much less affected by swimmer-swimmer correlations than the translational diffusivity. We furthermore study the anisotropic translational diffusion in the particle frame and find that, in pusher suspensions, the diffusivity along the ellipsoid major axis is higher than in the direction perpendicular to it, albeit with a smaller ratio than for Brownian diffusion. Thus, we find that far field hydrodynamics cannot account for the anomalous coupling between translation and rotation observed in experiments, as was recently proposed. Finally, we study the probability distributions (PDFs) of translational and rotational displacements. In accordance with experimental observations, for short observation times we observe strongly non-Gaussian PDFs that collapse when rescaled with their variance, which we attribute to the ballistic nature of tracer motion at short times.
In Situ Burning Alternatives
Creators: name: Cohen, Brian
Publisher: name: Digital Repository at the University of Maryland
Year: 2014
Subjects: subject: Engineering

description: In situ burns have been used to remove oil spills for decades. They are relatively easy and inexpensive to administer, and are one of the only methods that is effective for crude oil spill remediation over a body of water. There are, however, environmental implications stemming from burning large quantities of crude oil, which has brought about the need for alternative removal techniques.

Skimming and chemical dispersant procedures are frequently employed but have severe limitations and environmental drawbacks. Several new methods have been developed that use elements of nature such as cotton and peat moss, but these are only effective when implemented close to the shoreline. For spills that occur in the middle of the ocean, these processes are rendered useless, and as such, require the implementation of in situ burning.

This study assesses a way in which in situ burning can be improved in order to minimize the environmental damage that can occur with crude oil removal. Through the research conducted in this thesis, it is proposed that the application of a fire whirl may mitigate the damage while also improving the removal rate of a crude oil spill located on a body of water.
Optimal weighting for false discovery rate control
Creators: name: Roquain, Etienne
name: Van De Wiel, Mark
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62J15 ; 62G10

description: How to weigh the Benjamini-Hochberg procedure? In the context of multiple hypothesis testing, we propose a new step-wise procedure that controls the false discovery rate (FDR) and we prove it to be more powerful than any weighted Benjamini-Hochberg procedure. Both finite-sample and asymptotic results are presented. Moreover, we illustrate good performance of our procedure in simulations and a genomics application. This work is particularly useful in the case of heterogeneous $p$-value distributions.
Immaginazione e ontologia della relazione. Note per una ricerca
Creators: name: Morfino, Vittorio
Publisher: name: Università degli Studi di Milano
Year: 2015
Subjects: Spinoza; transindividuale; immaginazione; ontologia della relazione

description: A partire dagli anni Settanta del secolo scorso è stata sottolineata a più riprese l’originalità del concetto spinoziano di imaginatio e allo stesso tempo il suo ruolo chiave all’interno del sistema. Nella storia del pensiero Occidentale, da Aristotele a Wittgnestein passando per Kant, l’immaginazione costituisce una soglia, il punto di raccordo tra  mondo e pensiero. Ma l’immaginazione costituisce una soglia anche in un altro senso: per la modernità filosofica l’immaginazione costituisce la soglia tra interno ed esterno.

Ora, che cosa accade dell’immaginazione una volta che si rifiuti la mossa cartesiana della separazione di un interno e un esterno, mossa che senza dubbio fonda la linea filosofica dominante della modernità? Come deve essere ripensata? Per comprenderlo è necessario rileggere Spinoza nell'ottica di una ‘ontologia della relazione’.
description: Nóema, No 6-1 (2015): La materia
Alkanethiol-Based Single-Molecule Transistors
Creators: name: Ma, Chun-Lan
name: Nghiem, Diu
name: Chen, Yu-Chang
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The transport properties of unsubstituted and amino-substituted butanethiol molecules sandwiched between Au electrodes are investigated by using first-principles approaches. New states are observed around the Fermi levels when -NH2 is substituted for -H in the bridging butanethiol. The amino-substituted states lead to a sharp increase of the current which is credited to the resonant tunneling in the junction. We observe a novel conductance peak at VSD = 0.1 V and negative differential resistance (NDR) in a certain range of source-drain bias. In addition to the I-VSD characteristics, we also investigate the current as a function of gate voltage (I-VG) and find that, for a fixed source-drain bias (VSD = 0.01 V), the gate voltage can modulate the conductance by up to 30 times in the amino-substituted butanethiol junction. These I-VG characteristics suggest that the amino-substituted butanethiol molecular junction may be a promising candidate for field-effect transistors.
description: 4 pages
Studies of dense plasmas in laser generated shock wave experiments
Creators: name: Parfeniuk, Dean Allister
Publisher: name: University of British Columbia
Year: 2010

description: Shock waves generated by laser-driven ablation in solids have provided a great opportunity for the study of dense plasmas. The work presented in this thesis include measurements of Hugoniot curves and the reflectivity of shocked aluminum. In these experiments, planar aluminum targets were irradiated with a 0.53µm, 2ns (FWHM) laser pulse at irradiances up to ~ 10¹⁴/cm². Temporally and spectrally resolved measurements of the target rear surface luminous emission have yielded the shock speed and temperature Hugoniot curve which showed good agreement with equation of state predictions. In addition, temporally resolved reflectivity measurements of the shocked target rear surface compared well with a theoretical model for the electrical conductivity of a dense plasma. For copper and molybdenum targets, both the luminescence and the reflectivity measurements indicated that the heating of the dense target material was dominated by radiation transport from the coronal plasma rather than shock heating. An analysis of the molybdenum results indicate that x-ray shine-through may be the dominant energy transport mechanism to the target rear surface, whereas for the copper targets the transport process appears to be much more complex.
Towards mirror symmetry à la SYZ for generalized Calabi-Yau manifolds
Creators: name: Grange, Pascal
name: Schafer-Nameki, Sakura
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Fibrations of flux backgrounds by supersymmetric cycles are investigated. For an internal six-manifold M with static SU(2) structure and mirror \hat{M}, it is argued that the product M x \hat{M} is doubly fibered by supersymmetric three-tori, with both sets of fibers transverse to M and \hat{M}. The mirror map is then realized by T-dualizing the fibers. Mirror-symmetric properties of the fluxes, both geometric and non-geometric, are shown to agree with previous conjectures based on the requirement of mirror symmetry for Killing prepotentials. The fibers are conjectured to be destabilized by fluxes on generic SU(3)xSU(3) backgrounds, though they may survive at type-jumping points. T-dualizing the surviving fibers ensures the exchange of pure spinors under mirror symmetry.
description: 30 pages, 3 figures, LaTeX; v2: references added
Energy-momentum tensor of the nucleon on the light front: Abel tomography case
Creators: name: Kim, June-Young
name: Kim, Hyun-Chul
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We investigate the two-dimensional energy-momentum-tensor (EMT) distributions of the nucleon on the light front, using the Abel transforms of the three-dimensional EMT ones. We explicitly show that the main features of all EMT distributions are kept intact in the course of the Abel transform. We also examine the equivalence between the global and local conditions for the nucleon stability in the three-dimensional Breit frame and in the two-dimensional transverse plane on the light front. We also discuss the two-dimensional force fields inside a nucleon on the light front.
description: 10 pages and 5 figures
Gold, copper, silver and aluminum nanoantennas to enhance spontaneous emission
Creators: name: Mohammadi, Ahmad
name: Sandoghdar, Vahid
name: Agio, Mario
Publisher: name: arXiv
Year: 2008
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We compute the decay rates of emitters coupled to spheroidal nanoantennas made of gold, copper, silver, and aluminum. The spectral position of the localized surface plasmon-polariton resonance, the enhancement factors and the quantum efficiency are investigated as a function of the aspect ratio, background index and the metal composing the nanoantenna. While copper yields results similar to gold, silver and aluminum exhibit different performances. Our results show that with a careful choice of the parameters these nanoantennas can enhance emitters ranging from the UV to the near-IR spectrum.
description: 7 pages, 10 figures
The Anatomy of an Unusual Edge-on Protoplanetary Disk. II. Gas temperature and a warm outer region
Creators: name: Flores, Christian
name: Duchene, Gaspard
name: Wolff, Schuyler
name: Villenave, Marion
name: Stapelfeldt, Karl
name: Williams, Jonathan P.
name: Pinte, Christophe
name: Padgett, Deborah
name: Connelley, Michael S.
name: van der Plas, Gerrit
name: Menard, Francois
name: Perrin, Marshall D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We present high-resolution $^{12}$CO and $^{13}$CO 2-1 ALMA observations, as well as optical and near-infrared spectroscopy, of the highly-inclined protoplanetary disk around SSTC2D J163131.2-242627. The spectral type we derive for the source is consistent with a $\rm 1.2 \, M_{\odot}$ star inferred from the ALMA observations. Despite its massive circumstellar disk, we find little to no evidence for ongoing accretion on the star. The CO maps reveal a disk that is unusually compact along the vertical direction, consistent with its appearance in scattered light images. The gas disk extends about twice as far away as both the submillimeter continuum and the optical scattered light. CO is detected from two surface layers separated by a midplane region in which CO emission is suppressed, as expected from freeze-out in the cold midplane. We apply a modified version of the Topographically Reconstructed Distribution method presented by Dutrey et al. 2017 to derive the temperature structure of the disk. We find a temperature in the CO-emitting layers and the midplane of $\sim$33 K and $\sim$20 K at $\rm R<200$ au, respectively. Outside of $\rm R>200$ au, the disk's midplane temperature increases to $\sim$30 K, with a nearly vertically isothermal profile. The transition in CO temperature coincides with a dramatic reduction in the sub-micron and sub-millimeter emission from the disk. We interpret this as interstellar UV radiation providing an additional source of heating to the outer part of the disk.
description: 27 pages, 18 figures, 1 table
Can quarkonia survive deconfinement ?
Creators: name: Mocsy, Agnes
name: Petreczky, Peter
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We study quarkonium correlators and spectral functions at zero and finite temperature in QCD with only heavy quarks using potential models combined with perturbative QCD. First, we show that this approach can describe the quarkonium correlation function at zero temperature. Using a class of screened potentials based on lattice calculations of the static quark-antiquark free energy we calculate spectral functions at finite temperature. We find that all quarkonium states, with the exception of the $1S$ bottomonium, dissolve in the deconfined phase at temperatures smaller than $1.5T_c$, in contradiction with the conclusions of recent studies. Despite this the temperature dependence of the quarkonium correlation functions calculated on the lattice is well reproduced in our model. We also find that even in the absence of resonances the spectral function at high temperatures is significantly enhanced over the spectral function corresponding to free quark antiquark propagation.
description: Version accepted in Phys. Rev. D, 20 pages, 25 figures
title: Practice-Based Design for Professional Learning and Knowledge Sharing: Adapting the ‘Key Situation Model’ for Social Work in England
Creators: name: Staempfli, Adi
Publisher: name: Goldsmiths, University of London
Year: 2020

description: How can social workers be supported to continuously develop knowledgeable and ethical practice? Acknowledging the dilemmas and uncertainties in social work practice that unfolds in complex environments, this thesis turns to practice-based perspectives in response to the main question. It foregrounds the interplay of humans within physical and social environments with a focus on ‘practices’ and considers the challenges for social workers as practitioners, professionals and knowledge workers. In relation to individual decision-making, the role of research, theory, tools, emotions, experience and reflective deliberation are explored. On an organisational level, evidence-informed and best practice, knowledge transfer, group reflection approaches and the role of technology are examined. The author argues that knowledgeable and ethical practice emerges from knowledge related (epistemic) practices within organisations that are grounded in what professionals do. This requires reflexive and mindful professionals who are able to weave together different forms of knowledge and ethical principles with practice situations and with organisations who will support epistemic practices and environments for reflective learning, knowledge co-production and the sharing of knowledge. Building on earlier work (Tov et al., 2016; Staempfli et al., 2012), the author argues that the Key Situation Model can support both practices and environments. Key situations are the typical practices that social workers regularly encounter and thus reflect what social workers actually do. 116 key situations in social work in England are developed and validated in a modified three-round Delphi study with experienced social workers from diverse sectors from across England (n1= 13, n2= 88 and n3= 41). Based on these and informed by the Activity Centred Analysis and Design (ACAD) framework, this thesis presents design options for social work organisations for the implementation of the Key Situation Model’s blended reflective learning and knowledge sharing. These design options could support the development of knowledgeable and ethical practice.
Magnetic Excitation of t-J Model with Quasi-One-Dimensional Fermi Surface -- Possible Relevance to LSCO Systems
Creators: name: Yamase, Hiroyuki
name: Kohno, Hiroshi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: On the basis of the picture of a quasi-one-dimensional (q-1d) Fermi surface (FS), recently proposed by authors for LSCO systems, spin excitation spectrum, Im chi(q,omega), is calculated in the 'RPA' within the slave-boson mean-field approximation to the t-J model. It is found that Im chi(q,omega) shows both incommensurate (IC) and diagonal IC (DIC) peaks, whose realization does not depend on the existence of the d-wave gap. The peak positions do not change appreciably with omega and the sharp peaks survive down to the low hole doping rate. The d-wave gap suppresses both the IC peak and the DIC peak, but the degree of suppression as a function of omega is different between them. Taking these results together with results for the two-dimensional FS, we argue that essential features of magnetic excitation in LSCO systems can be understood in terms of the q-1d picture of the FS.
description: 31 pages, 17 pages, for those who cannot download JPSJ papers
Observational Evidences of the Cosmological Deceleration of Time
Creators: name: Taganov, Igor N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Constancy of the speed of light together with the Hubble law lead in a doctrine of expanding universe to a conclusion that universe evolution is not only an expansion of space but also a deceleration of the course of physical time (Taganov, 2003). Duration of any physical process measured by decelerating physical time is always longer, than corresponding duration, measured by a scale of invariable uniform Newtonian time. All the processes uniform or moderately decelerating in physical time appear accelerating when interpreted in terms of uniform invariable Newtonian time. The article describes several observational evidences of a phenomenon of the cosmological deceleration of time: the redshift survey of distant supernovae demonstrates apparent acceleration of the universe expansion; accelerations in the Earth-Moon system reveal reliable differences if estimated with the use of ancient and contemporary astronomical data. Deceleration of the physical time reveals itself in isotopic chronology by systematic divergence of samples Newtonian ages, estimated with the use of isotopes with different rates of decay.
description: 12 pages, proceedings of the conference Problems of Practical Cosmology, June 2008, see http://ppc08.astro.spbu.ru/text_proc.html
Extended electron tails in electrostatic microinstabilities and the nonadiabatic response of passing electrons
Creators: name: Hardman, M. R.
name: Parra, F. I.
name: Chong, C.
name: Adkins, T.
name: Anastopoulos-Tzanis, M. S.
name: Barnes, M.
name: Dickinson, D.
name: Parisi, J. F.
name: Wilson, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Ion-gyroradius-scale microinstabilities typically have a frequency comparable to the ion transit frequency. Due to the small electron-to-ion mass ratio and the large electron transit frequency, it is conventionally assumed that passing electrons respond adiabatically in ion-gyroradius-scale modes. However, in gyrokinetic simulations of ion-gyroradius-scale modes in axisymmetric toroidal magnetic fields, the nonadiabatic response of passing electrons can drive the mode, and generate fluctuations with narrow radial layers, which may have consequences for turbulent transport in a variety of circumstances. In flux tube simulations, in the ballooning representation, these instabilities reveal themselves as modes with extended tails. The small electron-to-ion mass ratio limit of linear gyrokinetics for electrostatic instabilities is presented, in axisymmetric toroidal magnetic geometry, including the nonadiabatic response of passing electrons and associated narrow radial layers. This theory reveals the existence of ion-gyroradius-scale modes driven solely by the nonadiabatic passing electron response, and recovers the usual ion-gyroradius-scale modes driven by the response of ions and trapped electrons, where the nonadiabatic response of passing electrons is small. The collisionless and collisional limits of the theory are considered, demonstrating parallels in structure and physical processes to neoclassical transport theory. By examining initial-value simulations of fastest-growing eigenmodes, the predictions for mass-ratio scaling are tested and verified numerically for a range of collision frequencies. Insights from the small electron-to-ion mass ratio theory may lead to a computationally efficient treatment of extended modes.
description: 75 pages, 23 figures
Anomalous lifetime distributions and topological traps in ordering dynamics
Creators: name: Castello, X.
name: Toivonen, R.
name: Eguiluz, V. M.
name: Saramaki, J.
name: Kaski, K.
name: Miguel, M. San
Publisher: name: arXiv
Year: 2007
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We address the role of community structure of an interaction network in ordering dynamics, as well as associated forms of metastability. We consider the voter and AB model dynamics in a network model which mimics social interactions. The AB model includes an intermediate state between the two excluding options of the voter model. For the voter model we find dynamical metastable disordered states with a characteristic mean lifetime. However, for the AB dynamics we find a power law distribution of the lifetime of metastable states, so that the mean lifetime is not representative of the dynamics. These trapped metastable states, which can order at all time scales, originate in the mesoscopic network structure.
description: 7 pages; 6 figures
On the Log-Concavity of Hilbert Series of Veronese Subrings and Ehrhart Series
Creators: name: Beck, Matthias
name: Stapledon, Alan
Publisher: name: arXiv
Year: 2008
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05A15 (Primary), 13C14, 52B20, 52C07 (Secondary)

description: For every positive integer $n$, consider the linear operator $\U_{n}$ on polynomials of degree at most $d$ with integer coefficients defined as follows: if we write $\frac{h(t)}{(1 - t)^{d + 1}} = \sum_{m \geq 0} g(m) t^{m}$, for some polynomial $g(m)$ with rational coefficients, then $\frac{\U_{n}h(t)}{(1- t)^{d + 1}} = \sum_{m \geq 0} g(nm) t^{m}$. We show that there exists a positive integer $n_{d}$, depending only on $d$, such that if $h(t)$ is a polynomial of degree at most $d$ with nonnegative integer coefficients and $h(0) \geq 1$, then for $n \geq n_{d}$, $\U_{n}h(t)$ has simple, real, strictly negative roots and positive, strictly log concave and strictly unimodal coefficients. Applications are given to Ehrhart $δ$-polynomials and unimodular triangulations of dilations of lattice polytopes, as well as Hilbert series of Veronese subrings of Cohen--MacCauley graded rings.
description: 11 pages, replaces "Asymptotics of Ehrhart $\delta$-Vectors"
MFDFA: Efficient Multifractal Detrended Fluctuation Analysis in Python
Creators: name: Gorjão, Leonardo Rydin
name: Hassan, Galib
name: Kurths, Jürgen
name: Witthaut, Dirk
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: Multifractal detrended fluctuation analysis (MFDFA) has become a central method to characterise the variability and uncertainty in empiric time series. Extracting the fluctuations on different temporal scales allows quantifying the strength and correlations in the underlying stochastic properties, their scaling behaviour, as well as the level of fractality. Several extensions to the fundamental method have been developed over the years, vastly enhancing the applicability of MFDFA, e.g. empirical mode decomposition for the study of long-range correlations and persistence. In this article we introduce an efficient, easy-to-use python library for MFDFA, incorporating the most common extensions and harnessing the most of multi-threaded processing for very fast calculations.
description: 12 pages, 6 figures, software in https://github.com/LRydin/MFDFA
Spinor-Vector Duality in Heterotic SUSY Vacua
Creators: name: Catelin-Jullien, Tristan
name: Faraggi, Alon E.
name: Kounnas, Costas
name: Rizos, John
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We elaborate on the recently discovered spinor-vector duality in realistic free fermionic heterotic vacua. We emphasize the interpretation of the freely-acting orbifolds carried out on the six internal dimensions as coordinate-dependent compactifications; they play a central role in the duality, especially because of their ability to break the right-moving superconformal algebra of the space-time supersymmetric heterotic vacua. These considerations lead to a simple and intuitive proof of the spinor-vector duality, and to the formulation of explicit rules to find the dual of a given model. We discuss the interest of such a duality, notably concerning the structure of the space of vacua of superstring theory.
description: 28 pages, 6 tables
The tripartite separability of density matrices of graphs
Creators: name: Wang, Zhen
name: Wang, Zhixi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The density matrix of a graph is the combinatorial laplacian matrix of a graph normalized to have unit trace. In this paper we generalize the entanglement properties of mixed density matrices from combinatorial laplacian matrices of graphs discussed in Braunstein {\it et al.} Annals of Combinatorics, {\bf 10}(2006)291 to tripartite states. Then we proved that the degree condition defined in Braunstein {\it et al.} Phys. Rev. A {\bf 73}, (2006)012320 is sufficient and necessary for the tripartite separability of the density matrix of a nearest point graph.
description: 12 pages
Sketch-Based Interface and Modelling of Stratigraphy and Structure in 3D
Creators: name: Jacquemyn, Carl
name: Pataki, Margaret E.H.
name: Hampson, Gary J.
name: Jackson, Matthew D.
name: Petrovskyy, Dmytro
name: Geiger, Sebastian
name: Marques, Clarissa C.
name: Silva, Julio D. Machado
name: Sicilia Judice
name: Fazilatur Rahman
name: Sousa, Mario Costa
Publisher: name: Geological Society of London
Year: 2021
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences

description: Supplementary figures S1–S4
A Complete Statistical Analysis for the Quadrupole Amplitude in an Ellipsoidal Universe
Creators: name: Gruppuso, Alessandro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A model of Universe with a small eccentricity due to the presence of a magnetic field at the decoupling time (i.e. an Ellipsoidal Universe) has been recently proposed for the solution of the low quadrupole anomaly of the angular power spectrum of cosmic microwave background anisotropies. We present a complete statistical analysis of that model showing that the probability of increasing of the amplitude of the quadrupole is larger than the probability of decreasing in the whole parameters' space.
description: 5 pages, 3 figures
STROKE PREVENTION AWARENESS AND PRACTICES AMONG MEDICAL STAFF IN A NIGERIAN TERTIARY HEALTHCARE SETTING
Creators: name: Oluwaseun, Michael Adediran
name: Chidinma, Grace Okafor
Publisher: name: AYDEN JOURNAL
Year: 2024
Subjects: Attitude, knowledge, practice, stroke, prevention

description: Introduction:

Stroke is increasingly a problem of public health significance globally. It is a major cause of disability and mortality. Healthcare professionals must have a good attitude, sufficient knowledge, and practice of stroke prevention to reduce the burden of the disease.

Methods:

This study utilized a cross-sectional design among 200 Healthcare workers in the Federal Medical Centre, Asaba, Nigeria, selected by systematic sampling technique. A semi-structured questionnaire was used to collect data on the research variables. Data were analyzed using the IBM SPSS version 25 statistical package.

Results:

A total of 200 Healthcare workers participated in the study. About 77% and 84% of respondents have good aggregate attitudes and knowledge towards stroke prevention respectively. This did not influence their poor practice (54%) of stroke prevention. There was a significant association (p < 0.0001) of good knowledge of stroke by Clinical Healthcare workers [Chi-squares =27.1, 95%CI= (0.029-0.256)] when compared with non-clinical healthcare workers. This is in contrast with their poor practice of stroke prevention (Chi-squares=3.570, p = 0.02, 95%CI (0.321-1.023). However, there was no significant association (p=0.423) between the good attitude toward stroke prevention by the Clinical Health care workers [Chi-square=0.130, 95%CI= (0.458-1.713)], when compared with Non-Clinical Health care workers.

Conclusion: It is possible to improve the practice of stroke prevention by encouraging health educational programs on Knowledge and behavior-changing strategies towards stroke prevention.
Understanding entanglement as resource: locally distinguishing unextendible product bases
Creators: name: Cohen, Scott M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: It is known that the states in an unextendible product basis (UPB) cannot be distinguished perfectly when the parties are restricted to local operations and classical communication (LOCC). Previous discussions of such bases have left open the following question: What entanglement resources are necessary and/or sufficient for this task to be possible with LOCC? In this paper, I present protocols which use entanglement more efficiently than teleportation to distinguish certain classes of UPB's. The ideas underlying my approach to this problem offer rather general insight into why entanglement is useful for such tasks.
description: Final, published version. Many revisions following very useful suggestions of the referee have been added. In particular, Appendix A has been completely rewritten
Tailoring optical nonlinearities via the Purcell effect
Creators: name: Bermel, Peter
name: Rodriguez, Alejandro
name: Joannopoulos, John D.
name: Soljacic, Marin
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We predict that the effective nonlinear optical susceptibility can be tailored using the Purcell effect. While this is a general physical principle that applies to a wide variety of nonlinearities, we specifically investigate the Kerr nonlinearity. We show theoretically that using the Purcell effect for frequencies close to an atomic resonance can substantially influence the resultant Kerr nonlinearity for light of all (even highly detuned) frequencies. For example, in realistic physical systems, enhancement of the Kerr coefficient by one to two orders of magnitude could be achieved.
A study of stimulated Raman scattering in a CO₂ laser produced plasma
Creators: name: McIntosh, Grant William John
Publisher: name: University of British Columbia
Year: 2010

description: Stimulated Raman scattering (SRS) has been studied experimentally in a CO₂ laser plasma interaction. A N₂ gas jet target was irradiated with CO₂ laser light (wavelength, ⋋ = 10.6 µm and frequency, ѡ₀) at intensities up to 10¹⁴ Wcm⁻². SRS occurs at intensities greater than 3 x 10¹³ Wcm⁻², which is fair agreement with threshold predictions for a plasma with an electron temperature of 300eV and a density scale length of 300µm. After this intensity is reached, the plasma waves grow exponentially in time with a growth rate of 6 x 10⁻³ѡ₀. This was measured with ps resolution ruby laser Thomson scattering. Spatial growth was also observed. Scattered infrared light at 2⋋ was found. Weak IR light in a broad band near 15µm was also found. The saturated plasma wave level and the number of hot electrons at 150 keV are well correlated, which indicates that trapping is responsible for the electrons. However, trapping is not responsible for the saturation of the instability. Frequency resolved Thomson scattering revealed that ion acoustic waves start at the peak of the SRS fluctuations. Once the ion acoustic waves grow to a large amplitude, SRS is quenched and does not reappear.