cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: A mixed methods study examining the role of professional YouTubers in young people’s health behaviours in the UK: implications for health interventions
Creators: name: Harris, J
Publisher: name: Liverpool John Moores University
Year: 2021

description: YouTubers are popular among young people and produce plentiful health content. Research suggests YouTube health content varies in quality and social media health interventions remain scarce. However, popular media and public health organisations are increasingly recognising YouTubers’ potential influence as a source of health information for young people. Little research has considered the nature of YouTuber content, young people’s engagement or YouTubers’ motives for producing it. This programme of research sought to examine the role professional YouTubers play in young people’s health behaviours in the UK. The research adopted a four-stage mixed methods sequential design. A questionnaire with 13-18 year olds (n=931) provided a sampling frame for three qualitative studies. These were a netnographic analysis of health-related videos (n=133) from 7 UK YouTubers, 8 focus groups with 13-18 year olds (n=85) and semi-structured interviews with UK YouTubers (n=3). Participating young people were from one county in North West England. The findings confirm YouTubers are a recognised source of health information for young people. YouTubers produce content on a range of topics with numerous perceived benefits. A successful trait is YouTubers’ ability to foster a sense of community; this familiarity and trust allows them to endorse health-related products or behaviours. YouTubers were thus viewed as role models by young viewers. Several complexities of YouTuber health content production were also highlighted. Young people and YouTubers were concerned giving advice beyond their expertise could lead to misdiagnosis, triggering or worsening of health conditions. There was an inherent tension between self-promotion and health promotion with YouTubers reluctant to expose themselves to criticism, compromise their brand and authenticity or engage in self-regulatory practices. The distinction between commercial, NHS or charity sponsored, and unsponsored content and sponsor intentions (health promotion or commercial) were not always clear. The impact of YouTuber health content is therefore dependent on young people’s critical literacy skills, which increased with age. Overall, the research confirms YouTubers’ considerable potential to contribute to young people’s health improvement interventions, but successful interventions must consider factors that affect young people’s engagement and YouTubers’ production of health content.
An invariance principle for semimartingale reflecting Brownian motions in domains with piecewise smooth boundaries
Creators: name: Kang, W.
name: Williams, R. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60F17, 60J60, 60K25, 90B15, 93E03 (Primary)

description: Semimartingale reflecting Brownian motions (SRBMs) living in the closures of domains with piecewise smooth boundaries are of interest in applied probability because of their role as heavy traffic approximations for some stochastic networks. In this paper, assuming certain conditions on the domains and directions of reflection, a perturbation result, or invariance principle, for SRBMs is proved. This provides sufficient conditions for a process that satisfies the definition of an SRBM, except for small random perturbations in the defining conditions, to be close in distribution to an SRBM. A crucial ingredient in the proof of this result is an oscillation inequality for solutions of a perturbed Skorokhod problem. We use the invariance principle to show weak existence of SRBMs under mild conditions. We also use the invariance principle, in conjunction with known uniqueness results for SRBMs, to give some sufficient conditions for validating approximations involving (i) SRBMs in convex polyhedrons with a constant reflection vector field on each face of the polyhedron, and (ii) SRBMs in bounded domains with piecewise smooth boundaries and possibly nonconstant reflection vector fields on the boundary surfaces.
description: Published at http://dx.doi.org/10.1214/105051606000000899 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Time-Domain Formulation of Electromagnetic Scattering Based on a Polarization Mode Expansion and the Principle of Least Action
Creators: name: Forestiere, Carlo
name: Miano, Giovanni
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A fresh approach to the full wave analysis of time evolution of the polarization induced in the electromagnetic scattering from dispersive non magnetic particles is presented. It is grounded on the combination of the Hopfield model for the polarization field, the expansion of the polarization field in terms of static longitudinal and transverse modes of the particle, the expansion of the radiation field in terms of transverse wave modes of free space, and the principle of least action. The polarization field is linearly coupled to the electromagnetic field. The losses of the matter are provided through a linear coupling of the polarization field to a bath of harmonic oscillators with a continuous range of natural frequencies. The set of linear ordinary differential integral equations of convolution type of the overall system is reduced by eliminating both the radiation degrees of freedoms and the bath degrees of freedom, and the reduced system of equations is studied. The role played by the radiation field in the coupling between the longitudinal and transverse mode amplitudes of the polarization is described. The principal characteristics of the temporal evolution of the mode amplitudes are found as the particle size varies, including the impulse response. Results are presented for the analytically solvable spherical particle. The proposed approach leads to a general method for the analysis of the temporal evolution of the polarization field induced in dispersive particles of any shape, as well as for the computation of transients and steady states.
title: Parade sauvage. 2011, n° 22
title: Revue d'études rimbaldiennes
titleType: Subtitle
Creators: name: (:Unap)
Publisher: name: Classiques Garnier
Year: 2011
Subjects: subject: Littérature du XIXe siècle
subject: Poésie
subject: Versification
subject: Métrique
subject: Symbolisme

description: Rimbaud fut un poète réellement complet. Maître en versification, « prodigieux linguiste » ainsi que l'écrit Verlaine, il peut aussi bien se définir comme un écrivain engagé que comme un virtuose du verbe. Il n'a jamais cessé d'être l'homme qui réfléchit sur le contemporain, capable en un poème de réinterpréter le monde, sans pour autant se séparer des thèmes qui lui sont chers. De la vie à l'œuvre, de l'œuvre à la vie, Rimbaud apparaît comme un poète d'une incontestable continuité et cohérence.
description: Master of versification, "a prodigious linguist" wrote Verlaine, Rimbaud can be defined as political writer as well as a virtuoso of the word.
Growth of Aluminum Nitride on a Silicon Nitride Substrate for Hybrid Photonic Circuits
Creators: name: Terrasanta, G.
name: Müller, M.
name: Sommer, T.
name: Geprägs, S.
name: Gross, R.
name: Althammer, M.
name: Poot, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Aluminum nitride (AlN) is an emerging material for integrated quantum photonics with its excellent linear and nonlinear optical properties. In particular, its second-order nonlinear susceptibility $χ^{(2)}$ allows single-photon generation. We have grown AlN thin films on silicon nitride via reactive DC magnetron sputtering. The thin films have been characterized using X-ray diffraction, optical reflectometry, atomic force microscopy, and scanning electron microscopy. The crystalline properties of the thin films have been improved by optimizing the nitrogen to argon ratio and the magnetron DC power of the deposition process. X-ray diffraction measurements confirm the fabrication of high-quality c-axis oriented thin films with a full width at half maximum of the rocking curves of 3.9 deg. for 300-nm-thick films. Atomic force microscopy measurements reveal a root mean square surface roughness below 1 nm. The AlN deposition on SiN allows us to fabricate hybrid photonic circuits with a new approach that avoids the challenging patterning of AlN.
Spatiotemporal Tensor Completion for Improved Urban Traffic Imputation
Creators: name: Said, Ahmed Ben
name: Erradi, Abdelkarim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Effective management of urban traffic is important for any smart city initiative. Therefore, the quality of the sensory traffic data is of paramount importance. However, like any sensory data, urban traffic data are prone to imperfections leading to missing measurements. In this paper, we focus on inter-region traffic data completion. We model the inter-region traffic as a spatiotemporal tensor that suffers from missing measurements. To recover the missing data, we propose an enhanced CANDECOMP/PARAFAC (CP) completion approach that considers the urban and temporal aspects of the traffic. To derive the urban characteristics, we divide the area of study into regions. Then, for each region, we compute urban feature vectors inspired from biodiversity which are used to compute the urban similarity matrix. To mine the temporal aspect, we first conduct an entropy analysis to determine the most regular time-series. Then, we conduct a joint Fourier and correlation analysis to compute its periodicity and construct the temporal matrix. Both urban and temporal matrices are fed into a modified CP-completion objective function. To solve this objective, we propose an alternating least square approach that operates on the vectorized version of the inputs. We conduct comprehensive comparative study with two evaluation scenarios. In the first one, we simulate random missing values. In the second scenario, we simulate missing values at a given area and time duration. Our results demonstrate that our approach provides effective recovering performance reaching 26% improvement compared to state-of-art CP approaches and 35% compared to state-of-art generative model-based approaches.
Dissipative quantum repeater
Creators: name: Ghasemi, M
name: Tavassoly, MK
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: By implementing a quantum repeater protocol, our aim in this paper is the production of entanglement between two two-level atoms locating far from each other. To make our model close to experimental realizations, the atomic and field sources of dissipations are also taken into account. We consider eight of such atoms (1, 2, ..., 8) sequentially located in a line which begins (ends) with atom 1 (8). We suppose that, initially the four atomic pairs (i; i + 1), i = 1; 3; 5; 7 are mutually prepared in maximally entangled states. Clearly, the atoms 1; 8, the furthest atoms which we want to entangle them are never entangled, initially. To achieve the purpose of paper, at first we perform the interaction between the atoms (2; 3) as well as (6; 7) which results in the entanglement creation between (1; 4) and (5; 8), separately. In the mentioned interactions we take into account spontaneous emission rate for atoms and field decay rate from the cavities as two important and unavoidable dissipation sources. In the continuation, we transfer the entanglement to the objective pair (1; 8) by two methods: i ) Bell state measurement (BSM), and ii ) cavity quantum electrodynamics (QED). The successfulness of our protocol is shown via the evaluation of concurrence as the well-established measure of entanglement between the two (far apart) qubits (1; 8). We also observe that, if one chooses the cavity and the atom such that holds, the effect of dissipations is effectively removed from the entanglement dynamics in our model. In this condition, the time evolutions of concurrence and success probability are regularly periodic. Also, concurrence and success probability reach to their maximum values in a large time interval by decreasing the detuning in the presence of dissipation.
Application of a biconical dense medium cyclone to pre-treat a low-grade Pb-Zn sulfide ore
Creators: name: Jian, Sheng
name: Sun, Wei
name: Zheng, Yong-Xing
Publisher: name: Faculty of Geoengineering, Mining and Geology, Wrocław University of Technology, Wrocław
Year: 2019
Subjects: Pb-Zn sulfide ore, Low-grade ore, Pretreatment, Biconical dense medium cyclone

description: Physicochemical Problems of Mineral Processing; ISSN 2084-4735
Effects of the space plasma density oscillation on the inter-spacecraft laser ranging for TianQin gravitational wave observatory
Creators: name: Lu, Ling-Feng
name: Su, Wei
name: Zhang, Xuefeng
name: He, Zhao-Guo
name: Duan, Hui-Zong
name: Jiang, Yuan-Ze
name: Yeh, Hsien-Chi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Space Physics (physics.space-ph)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The TianQin space Gravitational Waves (GW) observatory will contain 3 geocentric and circularly orbiting spacecraft with an orbital radius of 10^5 km, to detect the GW in the milli-hertz frequency band. Each spacecraft pair will establish a 1.7*10^5 km-long laser interferometer immersed in the solar wind and the magnetospheric plasmas to measure the phase deviations induced by the GW. GW detection requires a high-precision measurement of the laser phase. The cumulative effects of the long distance and the periodic oscillations of the plasma density may induce an additional phase noise. This paper aims to model the plasma induced phase deviation of the inter-spacecraft laser signals, using a realistic orbit simulator and the Space Weather Modeling Framework (SWMF) model. Preliminary results show that the plasma density oscillation can induce the phase deviations close to 2*10^-6 rad/Hz^1/2 or 0.3pm/Hz^1/2 in the milli-hertz frequency band and it is within the error budget assigned to the displacement noise of the interferometry. The amplitude spectrum density of phases along three arms become more separated when the orbital plane is parallel to the Sun-Earth line or during a magnetic storm. Finally, the dependence of the phase deviations on the orbital radius is examined.
The concept of self in a life-span, life event context
Creators: name: De Vries, Brian
Publisher: name: University of British Columbia
Year: 2010

description: This dissertation advanced a life story model of the self-concept, linking the presently understood past and the anticipated future with the experienced present of the individual story-teller. The central components of this model were identified as the story structure (defined as integrative complexity, an information-processing variable) and story content (defined as the significant life events recalled and anticipated by the participants). The nuclear thesis of this dissertation examined the relationship between these two components in various forms and explored their association with other (individual difference) variables. Participants were 30 males and 30 females drawn in equal numbers from three age groups (young, middle, and later adulthood). These participants completed an extensive questionnaire which entailed a written self-evaluation (which was coded for complexity), the identification and evaluation of significant life events (on scales of event pleasantness, outcome desirability, and event intensity, responsibility, adjustment, and anticipation), and the completion of a series of individual difference measures (life satisfaction, attitudes toward aging, repression-sensitization, and self-esteem). Participants were also interviewed regarding the personal significance of each event, discussions which were coded for integrative complexity and a measure of self in relation to others. The major results indicated that the complexity of self-evaluation (and not chronological age) was associated (curvilinearly) with the number of identified events (with low and high complexity characteristic of fewer events than moderate complexity). A similar pattern emerged between life satisfaction and this measure of complexity, but complexity was not related to any of the other individual difference variables. Unpleasant and undesirable events were discussed in more complex terms than were pleasant, desirable events. There was a similar pattern for high versus low intensity events. However, low responsibility, low adjustment, and low anticipation were associated with greater complexity than were events high on these dimensions. Women identified a greater number of events and discussed them more in terms of connectedness with significant others than did men. These results are presented in the context of the life story and their implications for this model of the self-concept are discussed.
Additional file 1 of Renal 99mTc-DMSA pharmacokinetics in pediatric patients
Creators: name: Plyku, Donika
name: Ghaly, Michael
name: Li, Ye
name: Brown, Justin L.
name: O’Reilly, Shannon
name: Khamwan, Kitiwat
name: Goodkind, Alison B.
name: Sexton-Stallone, Briana
name: Cao, Xinhua
name: Zurakowski, David
name: Fahey, Frederic H.
name: Treves, S. Ted
name: Bolch, Wesley E.
name: Frey, Eric C.
name: Sgouros, George
Publisher: name: figshare
Year: 2021
Subjects: subject: Space Science
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Biotechnology
subject: Science Policy

description: Additional file 1: Table 1. Patients’ Characteristics Data.
Quantum Kasner transition in a locally rotationally symmetric Bianchi II universe
Creators: name: Alonso-Serrano, Ana
name: Brizuela, David
name: Uria, Sara F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Belinski-Khalatnikov-Lifshitz (BKL) conjecture predicts a chaotic alternation of Kasner epochs in the evolution of generic classical spacetimes towards a spacelike singularity. As a first step towards understanding the full quantum BKL scenario, we analyze a vacuum Bianchi II model with local rotational symmetry, which presents just one Kasner transition. During the Kasner epochs, the quantum state is coherent and it is thus characterized by constant values of the different quantum fluctuations, correlations and higher-order moments. By computing the constants of motion of the system we provide, for any peaked semiclassical state, the explicit analytical transition rules that relate the parametrization of the asymptotic coherent state before and after the transition. In particular, we obtain the modification of the transition rules for the classical variables due to quantum back-reaction effects. This analysis is performed by considering a high-order truncation in moments (the full computations are performed up to fifth-order, which corresponds to neglecting terms of an order $\hbar^3$), providing a solid estimate about the quantum modifications to the classical model. Finally, in order to understand the dynamics of the state during the transition, we perform some numerical simulations for an initial Gaussian state, that show that the initial and final equilibrium values of the quantum variables are connected by strong and rapid oscillations.
description: Version accepted in PRD. Minor typos corrected
Experimental Free Energy Surface Reconstruction From Single-Molecule Force Spectroscopy Using Jarzynski's Equality
Creators: name: Harris, Nolan C.
name: Song, Yang
name: Kiang, Ching-Hwa
Publisher: name: arXiv
Year: 2007
Subjects: subject: Biological Physics (physics.bio-ph)
subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: We used the atomic force microscope to manipulate and unfold individual molecules of the titin I27 domain and reconstructed its free energy surface using Jarzynski's equality. The free energy surface for both stretching and unfolding was reconstructed using an exact formula that relates the nonequilibrium work fluctuations to the molecular free energy. In addition, the unfolding free energy barrier, i.e. the activation energy, was directly obtained from experimental data for the first time. This work demonstrates that Jarzynski's equality can be used to analyze nonequilibrium single-molecule experiments, and to obtain the free energy surfaces for molecular systems, including interactions for which only nonequilibrium work can be measured.
description: 4 pages, 3 figures. Phys. Rev. Lett. (2007) accepted
Distribution and pressure of active Lévy swimmers under confinement
Creators: name: Zhou, Tingtao
name: Peng, Zhiwei
name: Gulian, Mamikon
name: Brady, John F.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences
subject: 60G51

description: Many active matter systems are known to perform Lévy walks during migration or foraging. Such superdiffusive transport indicates long-range correlated dynamics. These behavior patterns have been observed for microswimmers such as bacteria in microfluidic experiments, where Gaussian noise assumptions are insufficient to explain the data. We introduce \textit{active Lévy swimmers} to model such behavior. The focus is on ideal swimmers that only interact with the walls but not with each other, which reduces to the classical Lévy walk model but now under confinement. We study the density distribution in the channel and force exerted on the walls by the Lévy swimmers, where the boundaries require proper explicit treatment. We analyze stronger confinement via a set of coupled kinetics equations and the swimmers' stochastic trajectories. Previous literature demonstrated that power-law scaling in a multiscale analysis in free space results in a fractional diffusion equation. We show that in a channel, in the weak confinement limit active Lévy swimmers are governed by a modified Riesz fractional derivative. Leveraging recent results on fractional fluxes, we derive steady state solutions for the bulk density distribution of active Lévy swimmers in a channel, and demonstrate that these solutions agree well with particle simulations. The profiles are non-uniform over the entire domain, in contrast to constant-in-the-bulk profiles of active Brownian and run-and-tumble particles. Our theory provides a mathematical framework for Lévy walks under confinement with sliding no-flux boundary conditions and provides a foundation for studies of interacting active Lévy swimmers.
description: 25 pages, 4 figures
Finite Drude weight for 1D low temperature conductors
Creators: name: Heidarian, Dariush
name: Sorella, Sandro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We apply well established finite temperature Quantum Monte Carlo techniques to one dimensional Bose systems with soft and hardcore constraint, as well as to spinless fermion systems. We give clear and robust numerical evidence that, as expected, no superfluid density for Bosons or Meissner fraction for fermions. is possible at {\em any} non zero temperature in one dimensional interacting Bose or fermi lattice models, whereas a finite Drude weight is generally observed in gapless systems, in partial disagreement to previous expectations.
description: 4 pages, 4 figures
Quantum algorithms for powering stable Hermitian matrices
Creators: name: González, Guillermo
name: Trivedi, Rahul
name: Cirac, J. Ignacio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Matrix powering is a fundamental computational primitive in linear algebra. It has widespread applications in scientific computing and engineering, and underlies the solution of time-homogeneous linear ordinary differential equations, simulation of discrete-time Markov chains, or discovering the spectral properties of matrices with iterative methods. In this paper, we investigate the possibility of speeding up matrix powering of sparse stable Hermitian matrices on a quantum computer. We present two quantum algorithms that can achieve speedup over the classical matrix powering algorithms -- (i) an adaption of quantum-walk based fast forwarding algorithm (ii) an algorithm based on Hamiltonian simulation. Furthermore, by mapping the N-bit parity determination problem to a matrix powering problem, we provide no-go theorems that limit the quantum speedups achievable in powering non-Hermitian matrices.
Density dependent hadronic models and the relation between neutron stars and neutron skin thickness
Creators: name: Avancini, S. S.
name: Marinelli, J. R.
name: Menezes, D. P.
name: de Moraes, M. M. W.
name: Providência, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the present work we investigate the main differences in the lead neutron skin thickness, binding energy, surface energy and density profiles obtained with two different density dependent relativistic hadronic models, within the Thomas-Fermi approximation. We show that the asymmetry parameter for low momentum transfer polarized electron scattering is not sensitive to the model parametrization differences.
description: 13 pages, 10 figures, accepted for publication in Phys. Rev. C
Ground State Phase Diagram of the $t$-$t'$-$J$ model
Creators: name: Jiang, Shengtao
name: Scalapino, Douglas J.
name: White, Steven R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report results of large scale ground state density matrix renormalization group(DMRG) calculations on $t$-$t'$-$J$ cylinders with circumferences 6 and 8. We determine a rough phase diagram which appears to approximate the 2D system. While for many properties, positive and negative $t'$ values ($t'/t = \pm 0.2$) appear to correspond to electron and hole doped cuprate systems, respectively, the behavior of superconductivity itself shows an inconsistency between the model and the materials. The $t'<0$ (hole doped) region shows antiferromagnetism limited to very low doping, stripes more generally, and the familiar Fermi-surface of the hole doped cuprates. However, we find $t'<0$ strongly suppresses superconductivity. The $t'>0$ (electron doped) region shows the expected circular Fermi pocket of holes around the $(π,π)$ point and a broad low-doped region of coexisting antiferromagnetism and $d$-wave pairing with a strong triplet $p$ component at wave-vector $(π,π)$ induced by the antiferromagnetism and $d$-wave pairing. The pairing for the electron low-doped system with $t'>0$ is strong and unambiguous in the DMRG simulations. At larger doping another broad region with stripes in addition to weaker $d$-wave pairing and striped $p$-wave pairing appears. In a small doping region near $x=0.08$ for $t'\sim-0.2$, we find a new type of stripe involving unpaired holes located predominantly on chains spaced three lattice spacings apart. The undoped two-leg ladder regions in between mimic the short-ranged spin correlations seen in two-leg Heisenberg ladders.
Iterated integrals over letters induced by quadratic forms
Creators: name: Ablinger, J.
name: Blümlein, J.
name: Schneider, C.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Symbolic Computation (cs.SC)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: An automated treatment of iterated integrals based on letters induced by real-valued quadratic forms and Kummer--Poincaré letters is presented. These quantities emerge in analytic single and multi--scale Feynman diagram calculations. To compactify representations, one wishes to apply general properties of these quantities in computer-algebraic implementations. We provide the reduction to basis representations, expansions, analytic continuation and numerical evaluation of these quantities.
description: 14 pages LATEX, 1 anc. file
Résultats à l'enquête nationale sur le travail à distance des étudiants de l'université pendant la pèriode d'enseignement à distance lié au covid-19
Creators: name: MARTIN, PERRINE
name: GEBEIL, SOPHIE
name: FELIX, CHRISTINE
Publisher: name: Zenodo
Year: 2021
Subjects: enseignement à distance, université, étudiant, COVID-19

description: Les résultats de cette enquête contribuent aux débats autour des questions de l’usage du numérique et des nouvelles formes d’enseignement à distance. Ces résultats ont été obtenus à partir de la diffusion d'un questionnaire qui à permis d'obtenir 11516 réponses.Ce questionnaire a été diffusé à partir du 2 décembre 2020 et clôturer le 11/02/2021 à tous les étudiants en France en vue de comprendre comment ils et elles s’efforcent d’organiser leur travail à distance pour répondre aux demandes de leurs enseignants et aux exigences de leur formation universitaire. Cette recherche fait suite à un premier travail réalisé dans le cadre du projet O.U.F. (Observation des Usages numériques dans l’activité enseignante à distance à des fins de Formation) associant plusieurs disciplines.
The Virtual Observatory Ecosystem Facing the European Open Science Cloud
Creators: name: Molinaro, Marco
name: Allen, Mark
name: Genova, Françoise
name: Schaaff, André
name: Neves, Margarida Castro
name: Demleitner, Markus
name: Bertocco, Sara
name: Morris, Dave
name: Bonnarel, François
name: Voutsinas, Stelios
name: Boisson, Catherine
name: Taffoni, Giuliano
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The International Virtual Observatory Alliance (IVOA) has developed and built, in the last two decades, an ecosystem of distributed resources, interoperable and based upon open shared technological standards. In doing so the IVOA has anticipated, putting into practice for the astrophysical domain, the ideas of FAIR-ness of data and service resources and the Open-ness of sharing scientific results, leveraging on the underlying open standards required to fill the above. In Europe, efforts in supporting and developing the ecosystem proposed by the IVOA specifications has been provided by a continuous set of EU funded projects up to current H2020 ESCAPE ESFRI cluster. In the meantime, in the last years, Europe has realised the importance of promoting the Open Science approach for the research communities and started the European Open Science Cloud (EOSC) project to create a distributed environment for research data, services and communities. In this framework the European VO community, had to face the move from the interoperability scenario in the astrophysics domain into a larger audience perspective that includes a cross-domain FAIR approach. Within the ESCAPE project the CEVO Work Package (Connecting ESFRI to EOSC through the VO) has one task to deal with this integration challenge: a challenge where an existing, mature, distributed e-infrastructure has to be matched to a forming, more general architecture. CEVO started its works in the first months of 2019 and has already worked on the integration of the VO Registry into the EOSC e-infrastructure. This contribution reports on the first year and a half of integration activities, that involve applications, services and resources being aware of the VO scenario and compatible with the EOSC architecture.
description: 14 pages, 9 figures Proceedings of SPIE 2020 Astronomical Telescopes + Instrumentation Conference 11449 Observatory Operations: Strategies, Processes, and Systems VIII
The Distance to SS433/W50 and its Interaction with the ISM
Creators: name: Lockman, Felix J.
name: Blundell, Katherine M.
name: Goss, W. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: [ABRIDGED] The distance to the relativistic jet source SS433 and the related supernova remnant W50 is re-examined using new observations of HI in absorption from the VLA, HI in emission from the GBT, and 12CO emission from the FCRAO. The new measurements show HI in absorption against SS433 to a velocity of 75 km/s but not to the velocity of the tangent point, which bounds the kinematic distance at 5.5 < d_k < 6.5 kpc. This is entirely consistent with a 5.5 +/- 0.2 kpc distance determined from light travel-time arguments (Blundell & Bowler 2004). The HI emission map shows evidence of interaction of the lobes of W50 with the interstellar medium near the adopted systemic velocity of V_LSR = 75 km/s. The western lobe sits in a cavity in the HI emission near the Galactic plane, while the eastern lobe terminates at an expanding HI shell. The expanding shell has a radius of 40 pc, contains 8 +/- 3 x 10^3 M_sun of HI and has a measured kinetic energy of 3 +/- 1.5 x 10^{49} ergs. There may also be a static HI ring or shell around the main part of W50 itself at an LSR velocity of 75 km/s, with a radius of 70 pc and a mass in HI of 3.5 - 10 x 10^4 M_sun. We do not find convincing evidence for the interaction of the system with any molecular cloud or with HI at other velocities. The HI emission data suggest that SS433 lies in an interstellar environment substantially denser than average for its distance from the Galactic plane. This Population I system, now about 200 pc below the Galactic plane, most likely originated as a runaway O-star binary ejected from a young cluster in the plane. New astrometric data on SS433 show that the system now has a peculiar velocity of a few tens of km/s in the direction of the Galactic plane. From this peculiar velocity and the symmetry of the W50 remnant we derive a time since the SN of < 10^5 yr.
description: accepted for publication in MNRAS
title: Rapport de voyage, Annam (1898) : Ligne de Chine, 1902, voyage n°26
Creators: name: Girard, R.
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2023
Subjects: subject: Compagnie des Messageries Maritimes
subject: Transports maritimes - Histoire
subject: Marine marchande
subject: Journaux de bord

description: Chapitrage : Rapport du commandant
description: Source: French Lines & Compagnies, 1997 002 3939-31
description: Coverage: 1902-09-21/1902-12-13
Photoconductance of organic single-molecule contacts
Creators: name: Viljas, J. K.
name: Pauly, F.
name: Cuevas, J. C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We study the dc conductance of organic single-molecule contacts in the presence of external electromagnetic radiation (photoconductance). In agreement with previous predictions, we find that the radiation can lead to large enhancements of the conductance of such contacts by bringing off-resonant levels into resonance through photoassisted processes. In our analysis we make use of the simplifying fact that, under certain assumptions, the photoconductance can be expressed in terms of the transmission function in the absence of the radiation. The conductance enhancement is demonstrated for oligophenylene molecules between gold electrodes, whose electronic structure is calculated based on density-functional theory. It is shown that the exponential decay of the conductance with the length of the molecule can be replaced by a length-independent value in the presence of radiation.
description: 4 pages, 2 figures
Surface-charging and particles aggregation behavior of ascharite
Creators: name: Li, Zhihang
name: Han, Yuexin
name: Zuo, Kesheng
Publisher: name: Faculty of Geoengineering, Mining and Geology, Wrocław University of Technology, Wrocław
Year: 2019
Subjects: ascharite, surface charge, incongruent dissolution, particles aggregation

description: Physicochemical Problems of Mineral Processing; ISSN 2084-4735
Collection of Online Learning Notices (Korean Ministry of Education)
Creators: name: Hamacher, Alaric
Publisher: name: Zenodo
Year: 2021
Subjects: Covid19
Online Learning
Copyright
Privacy

description: Collection of Online Learning notices published by the Korean Ministry of education between 2020.05.08 and 2020.05.11. The material in English contains information for Teachers and Students regarding Copyright and Privacy questions. The present files contain the archive of three pages: 1. Here's what you need to know about online classes in the wake of COVID-19 (2020-05-11) 2. Let’s protect teachers’ educational activities all of our personal information! (2020-05-08) 3. Protecting copyrights in online classes(For teachers) (2020-05-08) The above documents have been created and authored by the ministry of education of the Republic of Korea. The author archives and shares theses publications for present and future research purposes and documentation.
Incommensurate magnetic structure in the orthorhombic perovskite ErMnO_3
Creators: name: Ye, F.
name: Lorenz, B.
name: Huang, Q.
name: Wang, Y. Q.
name: Sun, Y. Y.
name: Chu, C. W.
name: Fernandez-Baca, J. A.
name: Dai, Pengcheng
name: Mook, H. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: By combining dielectric, specific heat, and magnetization measurements and high-resolution neutron powder diffraction, we have investigated the thermodynamic and magnetic/structural properties of the metastable orthorhombic perovskite ErMnO_3 prepared by high-pressure synthesis. The system becomes antiferromagnetically correlated below 42 K and undergoes a lock-in transition at 28 K with propagation wave vector (0,k_b,0), which remains incommensurate at low temperature. The intercorrelation between the magnetic structure and electric properties and the role of the rare earth moment are discussed.
description: 4 pages, 3 figures
X-ray Spectral Signatures of the Photon Bubble Model for Ultraluminous X-ray Sources
Creators: name: Finke, Justin
name: Boettcher, Markus
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The nature of ultraluminous X-ray sources in nearby galaxies is one of the major open questions in modern X-ray astrophysics. One possible explanation for these objects is an inhomogeneous, radiation dominated accretion disk around a $\sim 10 M_{\odot}$ black hole -- the so-called ``photon bubble'' model. While previous studies of this model have focused primarily on its radiation-hydrodynamics aspects, in this paper, we provide an analysis of its X-ray spectral (continuum and possible edge and line) characteristics. Compton reflection between high and low density regions in the disk may provide the key to distinguishing this model from others, such as accretion onto an intermediate mass black hole. We couple a Monte Carlo/Fokker-Planck radiation transport code with the XSTAR code for reflection to simulate the photon spectra produced in a photon bubble model for ULXs. We find that reflection components tend to be very weak and in most cases not observable, and make predictions for the shape of the high-energy Comptonizing spectra. In many cases the Comptonization dominates the spectra even down to $\sim$ a few keV. In one simulation, a $\sim 9 \kev$ feature was found, which may be considered a signature of photon bubbles in ULXs; furthermore, we make predictions of high energy power-laws which may be observed by future instruments.
description: Accepted for publication in the Astrophysical Journal
Determination of mineral surface energy using impact of rough topography
Creators: name: Can, Muhammed Fatih
name: Çiftçi, Caner
Publisher: name: Faculty of Geoengineering, Mining and Geology, Wrocław University of Technology, Wrocław
Year: 2019
Subjects: micro-nano roughness, natural stones, surface energy, air gap

description: Physicochemical Problems of Mineral Processing; ISSN 2084-4735
Untersuchung zur Anwendung der Nanostrukturierung in der Thermoelektrik
Creators: name: Merten, Dominik
Publisher: name: Technische Universität Dortmund
Year: 2020
Subjects: subject: Thermoelektrischer Generator
subject: TEG
subject: Nanostrukturierung
subject: Bismuttellurid
subject: Bi2Te3
subject: Spannungswandler
subject: 620
subject: Spannungswandler
subject: Thermoelektrischer Generator

description: Der Wunsch nach umweltfreundlicher und effizient erzeugter Energie gewinnt zunehmend an Relevanz. Insbesondere die Rückgewinnung kleinster Energiemengen ist für das low-power-Segment, beispielsweise für autarke Sensorsysteme oder das Internet of Things, von großer Bedeutung. In diesem Zusammenhang bieten thermoelektrische Generatoren (TEG) die Möglichkeit der direkten Umwandlung von thermischer in elektrische Energie und somit des Energy Harvestings ungenutzter Abwärme. Aufgrund des geringen Wirkungsgrades übersteigen TEG bisher nicht den Status eines Nischenproduktes. Aktuelle Forschungsarbeiten zeigen jedoch die Möglichkeit zur Steigerung des Wirkungsgrades bei Verwendung nanostrukturierter thermoelektrischer Materialien. Im Rahmen dieses Buches wird daher die Anwendung der Nanostrukturierung in der Thermoelektrik untersucht. Dies beinhaltet die Entwicklung eines grundlegenden Prozessablaufs zur Herstellung nanostrukturierter TEG. Hierzu werden mithilfe des Depositions- und Rückätzverfahrens quasieindimensionale Strukturen aus Bismuttellurid hergestellt und charakterisiert. Darüber hinaus wird unter Verwendung von FEM-Simulationen der Einfluss verschiedener Geometrieparameter diskutiert. Hierbei wird insbesondere die Veränderung des Generatorinnenwiderstandes sowie der Thermospannung analysiert. Des Weiteren erfolgt die Simulation und Realisierung einer Spannungswandlerschaltung speziell für hochohmige, nanostrukturierte TEG. Das zweistufige System nutzt einen Meißner-Oszillator als Anlaufschaltung und einen Aufwärtswandler mit Maximum-PowerPoint-Tracking als effektive Endstufe.
On the over-barrier reflection in quantum mechanics with multiple degrees of freedom
Creators: name: Levkov, D. G.
name: Panin, A. G.
name: Sibiryakov, S. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Chaotic Dynamics (nlin.CD)
subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We present an analytic example of two dimensional quantum mechanical system, where the exponential suppression of the probability of over-barrier reflection changes non-monotonically with energy. The suppression is minimal at certain "optimal" energies where reflection occurs with exponentially larger probability than at other energies.
description: Journal version. Introduction expanded, references added
Molecular circuits based on graphene nano-ribbon junctions
Creators: name: Xu, Zhiping
Publisher: name: arXiv
Year: 2007
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Graphene nano-ribbons junctions based electronic devices are proposed in this Letter. Non-equilibrium Green function calculations show that nano-ribbon junctions tailored from single layer graphene with different edge shape and width can act as metal-semiconductor junctions and quantum dots can be implemented. In virtue of the possibilities of patterning monolayer graphene down to atomic precision, these structures, quite different from the previously reported two-dimensional bulk graphene or carbon nanotube devices, are expected to be used as the building blocks of the future nano-electronics.
description: 10 pages, including 4 figures
Chaotic Behavior of Quantum Cascade Lasers at Ignition
Creators: name: Önder, D. E.
name: Kalaee, A. A. S.
name: Winge, D. O.
name: Wacker, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Chaotic Dynamics (nlin.CD)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The ignition of Quantum Cascade Lasers can occur from a state of oscillating fie ld domains. Here, the interplay between lasing and the kinetics of traveling dom ain boundaries provides complex oscillation scenarios. We analyze our numerical findings in detail for a device operating at terahertz frequencies and manifest chaotic evolution by positive Lyapunov exponents. This shows that these importan t devices can exhibit chaotic behavior even without periodic driving, which need s to be taken into account in their design.
Computational coarse graining of a randomly forced 1-D Burgers equation
Creators: name: Ahuja, S.
name: Yakhot, V.
name: Kevrekidis, I. G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We explore a computational approach to coarse graining the evolution of the large-scale features of a randomly forced Burgers equation in one spatial dimension. The long term evolution of the solution energy spectrum appears self-similar in time. We demonstrate coarse projective integration and coarse dynamic renormalization as tools that accelerate the extraction of macroscopic information (integration in time, self-similar shapes, and nontrivial dynamic exponents) from short bursts of appropriately initialized direct simulation. These procedures solve numerically an effective evolution equation for the energy spectrum without ever deriving this equation in closed form.
description: 21 pages, 7 figures
The S-matrix of the Faddeev-Reshetikhin Model, Diagonalizability and PT Symmetry
Creators: name: Das, Ashok
name: Melikyan, A.
name: Rivelles, V. O.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the question of diagonalizability of the Hamiltonian for the Faddeev-Reshetikhin (FR) model in the two particle sector. Although the two particle S-matrix element for the FR model, which may be relevant for the quantization of strings on $AdS_{5}\times S^{5}$, has been calculated recently using field theoretic methods, we find that the Hamiltonian for the system in this sector is not diagonalizable. We trace the difficulty to the fact that the interaction term in the Hamiltonian violating Lorentz invariance leads to discontinuity conditions (matching conditions) that cannot be satisfied. We determine the most general quartic interaction Hamiltonian that can be diagonalized. This includes the bosonic Thirring model as well as the bosonic chiral Gross-Neveu model which we find share the same S-matrix. We explain this by showing, through a Fierz transformation, that these two models are in fact equivalent. In addition, we find a general quartic interaction Hamiltonian, violating Lorentz invariance, that can be diagonalized with the same two particle S-matrix element as calculated by Klose and Zarembo for the FR model. This family of generalized interaction Hamiltonians is not Hermitian, but is $PT$ symmetric. We show that the wave functions for this system are also $PT$ symmetric. Thus, the theory is in a $PT$ unbroken phase which guarantees the reality of the energy spectrum as well as the unitarity of the S-matrix.
description: 32 pages, 1 figure; references added, version published in JHEP