cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Structural and optical properties of beta irradiated YAlO3 single crystals
Creators: name: Suganya, M.
name: Ganesan, K.
name: Vijayakumar, P.
name: Jakathamani, S.
name: Gill, Amirdha Sher
name: Annalakshmi, O.
name: Srivastava, S. K.
name: Sarguna, R. M.
name: Ganesamoorthy, S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report on the growth, structural and optical properties of YAlO3 single crystals grown by optical floating zone technique. Powder X-ray diffraction and Raman spectroscopic studies confirm the phase purity of the crystals. Raman analysis reveals that the intensity and line-width of Raman bands increase significantly with beta irradiation indicating the formation of structural defects in YAlO3 lattice. The optical properties are studied through UV-visible absorption, and photoluminescence emission and excitation spectroscopies under pre- and post- beta irradiation. The optical studies indicate the presence of Sm and Cr impurities by exhibiting characteristic emission lines in the orange red region. Further, a systematic study on the thermoluminescence (TL) characteristics of the crystal is also carried out at different doses of beta irradiation. The crystals exhibit a prominent TL glow peak at 239 C for less than 5 Gy doses while a weak second glow peak evolves at higher doses. Also, the crystals show a nearly linear dose response in the studied range from 0.1 to 10 Gy. The glow curve analysis reveals that the TL emission obeys the first order kinetics model. Based on the optical studies, the plausible mechanism for the TL glow curve is discussed in terms of the intrinsic defects and impurities that are present in the crystal.
description: 21 pages, 9 figures; Accepted for publication in "Optical Materials"
Skyrmion Stars: Astrophysical motivations and implications
Creators: name: Jaikumar, Prashanth
name: Ouyed, Rachid
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study mass-radius relations for compact stars employing an equation of state (EOS) of dense matter based on a Skyrme fluid. The zero-temperature mean-field model is based on mesonic excitations, incorporates the scale breaking of QCD, and accommodates baryons (nucleons) which arise as a solitonic configuration of mesonic fields. Stable configurations are obtained for central densities $ρ_c/ρ_n\leq 5.0$ where $ρ_n=2.575\times 10^{14}$ g/cc is the nuclear saturation density. These {\it Skyrmion Stars} are mostly fluid, with a crust which we describe by the EOS of Baym, Pethick and Sutherland. Their masses and radii are in the range $0.4 \le M/M_{\odot} \le 3.6$ and $13 {\rm km} \le R \le 23 {\rm km}$, respectively. The minimum spin period is computed to be between $0.7 {\rm ms}\le P \le 2.1 {\rm ms}$. They appear to have a mass-radius curve quite different from either neutron or quark stars, and provide a suitable description of the heavier mass neutron stars discovered recently due to the inherently stiff EOS. Within the same model, we compute the dominant neutrino emissivity in neutron-rich $β$-equilibrated matter, and determine the cooling behaviour of Skyrmion stars.
description: 28 pages and 5 figures; this version to appear in the Astrophysical Journal
Test of classical nucleation theory on deeply supercooled high-pressure simulated silica
Creators: name: Saika-Voivod, Ivan
name: Poole, Peter H.
name: Bowles, Richard K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We test classical nucleation theory (CNT) in the case of simulations of deeply supercooled, high density liquid silica, as modelled by the BKS potential. We find that at density $ρ=4.38$~g/cm$^3$, spontaneous nucleation of crystalline stishovite occurs in conventional molecular dynamics simulations at temperature T=3000 K, and we evaluate the nucleation rate J directly at this T via "brute force" sampling of nucleation events. We then use parallel, constrained Monte Carlo simulations to evaluate $ΔG(n)$, the free energy to form a crystalline embryo containing n silicon atoms, at T=3000, 3100, 3200 and 3300 K. We find that the prediction of CNT for the n-dependence of $ΔG(n)$ fits reasonably well to the data at all T studied, and at 3300 K yields a chemical potential difference between liquid and stishovite that matches independent calculation. We find that $n^*$, the size of the critical nucleus, is approximately 10 silicon atoms at T=3300 K. At 3000 K, $n^*$ decreases to approximately 3, and at such small sizes methodological challenges arise in the evaluation of $ΔG(n)$ when using standard techniques; indeed even the thermodynamic stability of the supercooled liquid comes into question under these conditions. We therefore present a modified approach that permits an estimation of $ΔG(n)$ at 3000 K. Finally, we directly evaluate at T=3000 K the kinetic prefactors in the CNT expression for J, and find physically reasonable values; e.g. the diffusion length that Si atoms must travel in order to move from the liquid to the crystal embryo is approximately 0.2 nm. We are thereby able to compare the results for J at 3000 K obtained both directly and based on CNT, and find that they agree within an order of magnitude.
description: corrected calculation, new figure, accepted in JCP
Neubauer, Reinhard, Geschenke und umkämpfte Gerechtigkeit
Creators: name: Buchholz, Werner
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 13 Nr. 3 (1964): Ökumenische Rundschau, Band 13, Heft 3
A perspective on hybrid quantum opto- and electromechanical systems
Creators: name: Chu, Yiwen
name: Gröblacher, Simon
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum opto- and electromechanical systems interface mechanical motion with the electromagnetic modes of optical resonators and microwave circuits. The capabilities and promise of these hybrid devices have been showcased through a variety of recent experimental advances that demonstrated exquisite control over the quantum state of solid-state mechanical objects. In this perspective, we offer an overview of the current state, as well as an outlook of the future directions, challenges, and opportunities for this growing field of research. We focus in particular on the prospects for ground state cooling of mechanical modes and their use in quantum circuits, transducers, and networks.
description: 7 pages, 3 figures. Comments welcome
A Note on Conditional Expectation for Markov Kernels
Creators: name: Nogales, A. G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: G.3
subject: 60Exx, 60J35

description: A known property of conditional expectation is extended to the framework of Markov kernels. Its meaning in terms of densities is provided. Some examples located in the field of clinical diagnosis are presented to delimit the main result of the paper.
description: 9 pages, 1 figure
Fabrication and Characterization of Electrostatic Quantum Dots in a Si/SiGe 2D Electron Gas, Including an Integrated Read-out Channel
Creators: name: Sakr, M. R.
name: Yablonovitch, E.
name: Croke, E. T.
name: Jiang, H. W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A new fabrication technique is used to produce quantum dots with read-out channels in silicon/silicon-germanium two-dimensional electron gases. The technique utilizes Schottky gates, placed on the sides of a shallow etched quantum dot, to control the electronic transport process. An adjacent quantum point contact gate is integrated to the side gates to define a read-out channel and thus allow for noninvasive detection of the electronic occupation of the quantum dot. Reproducible and stable Coulomb oscillations and the corresponding jumps in the read-out channel resistance are observed at low temperatures. The fabricated dot combined with the read-out channel represent a step towards the spin-based quantum bit in Si/SiGe heterostructures.
description: 3 pages, 4 figs
Density-functional theory for fermions in the unitary regime
Creators: name: Papenbrock, T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Superconductivity (cond-mat.supr-con)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the unitary regime, fermions interact strongly via two-body potentials that exhibit a zero range and a (negative) infinite scattering length. The energy density is proportional to the free Fermi gas with a proportionality constant $ξ$. We use a simple density functional parametrized by an effective mass and the universal constant $ξ$, and employ Kohn-Sham density-functional theory to obtain the parameters from fit to one exactly solvable two-body problem. This yields $ξ=0.42$ and a rather large effective mass. Our approach is checked by similar Kohn-Sham calculations for the exactly solvable Calogero model.
description: 5 pages, 2 figures
Chemically peculiar A and F stars with enhanced s-process and iron-peak elements: stellar radiative acceleration at work
Creators: name: Xiang, Maosheng
name: Rix, Hans-Walter
name: Ting, Yuan-Sen
name: Ludwig, Hans-Günter
name: Coronado, Johanna
name: Zhang, Meng
name: Zhang, Hua-Wei
name: Buder, Sven
name: Tio, Piero Dal
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present $\gtrsim 15,000$ metal-rich (${\rm [Fe/H]}>-0.2$dex) A and F stars whose surface abundances deviate strongly from Solar abundance ratios and cannot plausibly reflect their birth material composition. These stars are identified by their high [Ba/Fe] abundance ratios (${\rm [Ba/Fe]}>1.0$dex) in the LAMOST DR5 spectra analyzed by Xiang et al. (2019). They are almost exclusively main sequence and subgiant stars with $T_{\rm eff}\gtrsim6300$K. Their distribution in the Kiel diagram ($T_{\rm eff}$--$\log g$) traces a sharp border at low temperatures along a roughly fixed-mass trajectory (around $1.4M_\odot)$ that corresponds to an upper limit in convective envelope mass fraction of around $10^{-4}$. Most of these stars exhibit distinctly enhanced abundances of iron-peak elements (Cr, Mn, Fe, Ni) but depleted abundances of Mg and Ca. Rotational velocity measurements from GALAH DR2 show that the majority of these stars rotate slower than typical stars in an equivalent temperature range. These characteristics suggest that they are related to the so-called Am/Fm stars. Their abundance patterns are qualitatively consistent with the predictions of stellar evolution models that incorporate radiative acceleration, suggesting they are a consequence of stellar internal evolution particularly involving the competition between gravitational settling and radiative acceleration. These peculiar stars constitute 40% of the whole population of stars with mass above 1.5$M_\odot$, affirming that "peculiar" photospheric abundances due to stellar evolution effects are a ubiquitous phenomenon for these intermediate-mass stars. This large sample of Ba-enhanced chemically peculiar A/F stars with individual element abundances provides the statistics to test more stringently the mechanisms that alter the surface abundances in stars with radiative envelopes.
description: 21 pages, 17 figures, accepted for publication in ApJ
Asteroseismic stellar modelling: systematics from the treatment of the initial helium abundance
Creators: name: Moedas, Nuno
name: Nsamba, Benard
name: Clara, Miguel T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Despite the fact that the initial helium abundance is an essential ingredient in modelling solar-type stars, its abundance in these stars remains a poorly constrained observational property. This is because the effective temperature in these stars is not high enough to allow helium ionization, not allowing any conclusions on its abundance when spectroscopic techniques are employed. To this end, stellar modellers resort to estimating the initial helium abundance via a semi-empirical helium-to-heavy element ratio, anchored to the the standard Big Bang nucleosynthesis value. Depending on the choice of solar composition used in stellar model computations, the helium-to-heavy element ratio, ($ΔY/ΔZ$) is found to vary between 1 and 3. In this study, we use the Kepler "LEGACY" stellar sample, for which precise seismic data is available, and explore the systematic uncertainties on the inferred stellar parameters (radius, mass, and age) arising from adopting different values of $ΔY/ΔZ$, specifically, 1.4 and 2.0. The stellar grid constructed with a higher $ΔY / ΔZ$ value yields lower radius and mass estimates. We found systematic uncertainties of 1.1 per cent, 2.6 per cent, and 13.1 per cent on radius, mass, and ages, respectively.
description: 6 pages, 2 figures, proceeding submited for the conference "Dynamics of the Sun & Stars - Honoring the Life and Work of Michael J. Thompson"
Quantum Advantage without Entanglement
Creators: name: Kenigsberg, Dan
name: Mor, Tal
name: Ratsaby, Gil
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: Computational Complexity (cs.CC)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We study the advantage of pure-state quantum computation without entanglement over classical computation. For the Deutsch-Jozsa algorithm we present the maximal subproblem that can be solved without entanglement, and show that the algorithm still has an advantage over the classical ones. We further show that this subproblem is of greater significance, by proving that it contains all the Boolean functions whose quantum phase-oracle is non-entangling. For Simon's and Grover's algorithms we provide simple proofs that no non-trivial subproblems can be solved by these algorithms without entanglement.
description: 10 pages
ECOLOGIA HUMANA E A TEORIA BIOECOLÓGICA DE BRONFENBRENNER: DIÁLOGOS POSSÍVEIS
Creators: name: Bitencourt, Ricardo
name: Viana, Esdriane Cabral
name: Souza, Pascoal Eron Santos de
Publisher: name: SABEH
Year: 2023
Subjects: Bronfenbrenner
ecologia humana
pesquisa qualitativa
PPCT
inserção ecológica

description: A Ecologia Humana (EH) suscita o debate sobre a complexa relação humano-natureza no contexto acadêmico. Sua condição múltipla, seja adisciplinar, científica, disciplinar ou como constructo teórico-epistemológico, possibilita processos de produção científica que contribuem para a consolidação desse campo de conhecimento que parece estar em um contínuo processo de construção. Por valorizar o constante diálogo com outras áreas, sem, necessariamente, perder sua essência, é possível que teorias inicialmente consolidadas em outras ciências se aproximem da Ecologia Humana, contribuindo para a compreensão dos fenômenos por ela estudados. Desta forma, este trabalho se propõe a discutir eventuais aproximações da teoria Bioecológica do Desenvolvimento Humano de Urie Bronfenbrenner, surgida no campo da psicologia, com a Ecologia Humana.
Embedding of the Kerr-Newman Black Hole Surface in Euclidean Space
Creators: name: Frolov, Valeri P.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We obtain a global embedding of the surface of a rapidly rotating Kerr-Newman black hole in an Euclidean 4-dimensional space.
description: 5 pages, 6 figures
Parity-Violation With Electrons: Theoretical Perspectives
Creators: name: Ramsey-Musolf, M. J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: I review recent progress and developments in parity-violating electron scattering as it bears on three topics: strange quarks and hadron structure, electroweak radiative corrections, and physics beyond the Standard Model. I also discuss related developments in parity-conserving scattering with transversely polarized electrons as a probe of two-photon processes. I conclude with a perspective on the future of the field.
description: Talk given at the International Workshop on Parity Violation and Hadronic Structure, Grenoble, France (June, 2004). Seven pages
Viskovatov algorithm for Hermite-Padé polynomials
Creators: name: Ikonomov, N. R.
name: Suetin, S. P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Complex Variables (math.CV)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 30E10, 41A21

description: We propose an algorithm for producing Hermite-Padé polynomials of type I for an arbitrary tuple of $m+1$ formal power series $[f_0,\dots,f_m]$, $m\geq1$, about $z=0$ ($f_j\in{\mathbb C}[[z]]$) under the assumption that the series have a certain (`general position') nondegeneracy property. This algorithm is a straightforward extension of the classical Viskovatov algorithm for construction of Padé polynomials (for $m=1$ our algorithm coincides with the Viskovatov algorithm). The algorithm proposed here is based on a recurrence relation and has the feature that all the Hermite-Padé polynomials corresponding to the multiindices $(k,k,k,\dots,k,k)$, $(k+1,k,k,\dots,k,k)$, $(k+1,k+1,k,\dots,k,k),\dots$, $(k+1,k+1,k+1,\dots,k+1,k)$ are already known by the time the algorithm produces the Hermite-Padé polynomials corresponding to the multiindex $(k+1,k+1,k+1,\dots,k+1,k+1)$. We show how the Hermite-Padé polynomials corresponding to different multiindices can be found via this algorithm by changing appropriately the initial conditions. The algorithm can be parallelized in $m+1$ independent evaluations at each $n$th step.
description: Bibliography: 28 titles
Oligarchic and giant impact growth of terrestrial planets in the presence of gas giant planet migration
Creators: name: Fogg, Martyn J.
name: Nelson, Richard P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of N--body simulations which examine the effect that gas giant planet migration has on the formation of terrestrial planets. The models incorporate a 0.5 Jupiter mass planet undergoing type II migration through an inner protoplanet--planetesimal disk, with gas drag included. Each model is initiated with the inner disk being at successively increased levels of maturity, so that it is undergoing either oligarchic or giant impact style growth as the gas giant migrates. In all cases, a large fraction of the disk mass survives the passage of the giant, either by accreting into massive terrestrial planets shepherded inward of the giant, or by being scattered into external orbits. Shepherding is favored in younger disks where there is strong dynamical friction from planetesimals and gas drag is more influential, whereas scattering dominates in more mature disks where dissipation is weaker. In each scenario, sufficient mass is scattered outward to provide for the eventual accretion of a set of terrestrial planets in external orbits, including within the system's habitable zone. An interesting result is the generation of massive, short period, terrestrial planets from compacted material pushed ahead of the giant. These planets are reminiscent of the short period Neptune mass planets discovered recently, suggesting that such `hot Neptunes' could form locally as a by-product of giant planet migration.
description: 17 pages, 11 figures, to be published in A&A. Higher resolution pdf available at: http://www.users.globalnet.co.uk/~mfogg/3453fogg.pdf
Field Theory Approaches to Nonequilibrium Dynamics
Creators: name: Tauber, Uwe C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: It is explained how field-theoretic methods and the dynamic renormalisation group (RG) can be applied to study the universal scaling properties of systems that either undergo a continuous phase transition or display generic scale invariance, both near and far from thermal equilibrium. Part 1 introduces the response functional field theory representation of (nonlinear) Langevin equations. The RG is employed to compute the scaling exponents for several universality classes governing the critical dynamics near second-order phase transitions in equilibrium. The effects of reversible mode-coupling terms, quenching from random initial conditions to the critical point, and violating the detailed balance constraints are briefly discussed. It is shown how the same formalism can be applied to nonequilibrium systems such as driven diffusive lattice gases. Part 2 describes how the master equation for stochastic particle reaction processes can be mapped onto a field theory action. The RG is then used to analyse simple diffusion-limited annihilation reactions as well as generic continuous transitions from active to inactive, absorbing states, which are characterised by the power laws of (critical) directed percolation. Certain other important universality classes are mentioned, and some open issues are listed.
description: 54 pages, 9 figures, Lecture Notes for Luxembourg Summer School "Ageing and the Glass Transition", submitted to Springer Lecture Notes in Physics (www.springeronline/com/series/5304/)
Flavor Twisted Boundary Conditions and the Nucleon Axial Current
Creators: name: Tiburzi, Brian C.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: With twisted boundary conditions on the quark fields, we study nucleon matrix elements of the axial current utilizing twisted heavy baryon chiral perturbation theory. One can explore the momentum transfer dependence of the axial form factors more easily than by using ordinary lattice quantized momenta alone. As examples, we derive expressions for the nucleon axial radius and pseudoscalar form factor.
description: 11 pages, Refs. added, sign error corrected
QCD Thermodynamics with an almost realistic quark mass spectrum
Creators: name: Schmidt, C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We will report on the status of a new large scale calculation of thermodynamic quantities in QCD with light up and down quarks corresponding to an almost physical light quark mass value and a heavier strange quark mass. These calculations are currently being performed on the QCDOC Teraflops computers at BNL. We will present new lattice calculations of the transition temperature and various susceptibilities reflecting properties of the chiral transition. All these quantities are of immediate interest for heavy ion phenomenology.
description: 10 pages, 4 figures, talk presented at the Particles and Nuclei International Conference, October 24-28, 2005, Santa Fe, NM, USA
Observation of Two-dimensional Superconductivity in an Ultrathin Iron-Arsenic Superconductor
Creators: name: Zhang, Chi
name: Hu, Tao
name: Wang, Teng
name: Wu, Yufeng
name: Yu, Aobo
name: Chu, Jianan
name: Zhang, Han
name: Xiao, Hong
name: Peng, Wei
name: Di, Zengfeng
name: Qiao, Shan
name: Mu, Gang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two-dimensional (2D) superconductors supply important platforms for exploring new quantum physics and high-$T_c$ superconductivity. The intrinsic superconducting properties in the 2D iron-arsenic superconductors are still unknown owing to the difficulties in the preparation of ultrathin samples. Here we report the fabrication and physical investigations of the high quality single-crystalline ultrathin films of the iron-arsenic superconductor KCa$_2$Fe$_4$As$_4$F$_2$. For the sample with the thickness of 2.6$\sim$5 nm (1$\sim$2 unit cells), a sharp superconducting transition at around 30 K (onset point) is observed. Compare with the bulk material, the ultrathin sample reveals a relatively lower $T_c$, wider transition width, and broader flux liquid region under the in-plane field. Moreover, the angle dependent upper critical field follows the Tinkham model, demonstrating the two-dimensional superconductivity in ultrathin KCa$_2$Fe$_4$As$_4$F$_2$.
description: 5 pages, 4 figures
Nuclear Quantum Effects in Scattering of H and D from Graphene
Creators: name: Jiang, Hongyan
name: Tao, Xuecheng
name: Kammler, Marvin
name: Ding, Feizhi
name: Wodtke, Alec M.
name: Kandratsenka, Alexander
name: Miller, Thomas F.
name: Bünermann, Oliver
Publisher: name: arXiv
Year: 2020
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We present a detailed study of the nuclear quantum effects in H/D sticking to graphene, comparing classical, quantum and mixed quantum/classical simulations to results of scattering experiments. Agreement with experimentally derived sticking probabilities is improved when nuclear quantum effects are included using ring polymer molecular dynamics. Specifically, the quantum motion of the carbon atoms enhances sticking, showing that an accurate description of graphene phonons is important to capturing the adsorption dynamics. We also find an inverse H/D isotope effect arising from Newtonian mechanics.
HRJust WP4 (Taiwan) Method Memo, January 2024
Creators: name: Tai, Ching-Yun
name: Chen, Shun-Ling
name: Su, Hui-Chieh
name: Huang, Yu-Ling
name: Han, Hsin-Yi
Publisher: name: Zenodo
Year: 2024

description: This memo provides a comprehensive review of how the Taiwanese government holds itself accountable for its use of human rights justifications through both international and national lenses. This includes an analysis of the legal framework and institutional mechanisms, as well as an exploration of how these oversight mechanisms were weakened during the COVID-19 pandemic.
Stellar Structures in $f(\mathcal{G})$ Gravity Admitting Noether Symmetries
Creators: name: Shamir, M. Farasat
name: Naz, Tayyaba
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: This work aims to investigate some possible emergence of relativistic compact stellar objects in modified $f(\mathcal{G})$ gravity using Noether symmetry approach. For this purpose, we assume static spherically symmetric spacetime in the presence of isotropic matter distribution. We construct Noether symmetry generators along with associated conserved quantities by considering the standard choice of viable $f(\mathcal{G})$ gravity model i.e. $f(\mathcal{G})= α\mathcal{G}^{n}$, where $α$ is the model parameter. In particular, we use conservation relation acquired from the classical Noether approach by imposing some appropriate initial conditions to construct the metric potentials. The obtained conserved quantity play vital role in describing the stellar structure of compact stars. Moreover, by considering an appropriate numerical solution, some salient features of compact stellar structures like effective energy density, pressure, energy conditions, stability against equilibrium of the forces and speed of sound are discussed by assigning the suitable values of model parameter involved. Our study reveals that the compact objects in $f(\mathcal{G})$ gravity from Noether symmetry approach depend on the conserved quantity obtained and the model parameter $α$. In nutshell, Noether symmetries are quite helpful to generate solutions that follow physically accepted phenomena. Moreover, we observed that these obtained solutions are consistent with the astrophysical observational data, which depicts the viability of our proposed Noether symmetry scheme.
description: 11 pages, 5 figures
Location Sensitive Image Retrieval and Tagging
Creators: name: Gomez, Raul
name: Gibert, Jaume
name: Gomez, Lluis
name: Karatzas, Dimosthenis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences
subject: I.2.10
subject: 68T07

description: People from different parts of the globe describe objects and concepts in distinct manners. Visual appearance can thus vary across different geographic locations, which makes location a relevant contextual information when analysing visual data. In this work, we address the task of image retrieval related to a given tag conditioned on a certain location on Earth. We present LocSens, a model that learns to rank triplets of images, tags and coordinates by plausibility, and two training strategies to balance the location influence in the final ranking. LocSens learns to fuse textual and location information of multimodal queries to retrieve related images at different levels of location granularity, and successfully utilizes location information to improve image tagging.
Skydsgaard, Kristen (Hrsg.) / Vischer, Lukas (Hrsg.), Schrift und Tradition
Creators: name: Küppers, Werner
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 13 Nr. 3 (1964): Ökumenische Rundschau, Band 13, Heft 3
Wall modeled immersed boundary method for high Reynolds number flow over complex terrain
Creators: name: Liu, Luoqin
name: Stevens, Richard J. A. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Modeling the effect of complex terrain on high Reynolds number flows is important to improve our understanding of flow dynamics in wind farms and the dispersion of pollen and pollutants in hilly or mountainous terrain as well as the flow in urban areas. Unfortunately, simulating high Reynolds number flows over complex terrain is still a big challenge. Therefore, we present a simplified version of the wall modeled immersed boundary method by Chester et al. (J. Comput. Phys. 2007; 225: 427-448). By preventing the extrapolation and iteration steps in the original method, the proposed approach is much easier to implement and more computationally efficient. Furthermore, the proposed method only requires information that is available to each processor and thus is much more efficient for simulations performed on a large number of cores. These are crucial considerations for algorithms that are deployed on modern supercomputers and will allow much higher grid resolutions to be considered. We validate our method against wind tunnel measurements for turbulent flows over wall-mounted cubes, a two dimensional ridge, and a three-dimensional hill. We find very good agreement between the simulation results and the measurement data, which shows this method is suitable to model high Reynolds number flows over complex terrain.
description: 20 pages, 11 figures, accepted for publication in Computer and Fluids
Implementations and applications of the sparse Radon transform
Creators: name: Trad, Daniel
Publisher: name: University of British Columbia
Year: 2009

description: The Radon transform (RT) has many desirable properties which make it particularly useful for multiple removal and interpolation of seismic reflections. However many practical difficulties arise as a consequence of poor sampling and limited aperture in the offset dimension. Furthermore the ever increasing volumes of seismic data make computing time a key issue in any practical implementation. The standard implementations of the Radon transform used in seismic processing fulfill very well the requirement of a fast transform but do not allow proper handling of problems associated with sampling and aperture. Many of these difficulties can be partially solved by using inverse theory to compute the transform subject to a sparseness constraint. The main thrust and contribution of this thesis lies in the exploration of the sparseness constraint and the design and implementation of the RT. Although this technique reduces sampling and aperture problems, it also considerably increases the computation time. Some of the possible solutions to decrease computation time discussed in this thesis are conjugate gradient methods, irregularly sampled model space and efficient operations with sparse matrices. Real data often have very complicated structure that makes sparseness criteria difficult to implement. Noise, non hyperbolic events and amplitude variation with offset conspire against sparseness. Therefore, the success of this method depends on the applied algorithms and on a delicate balance between sparseness and fit of data. Several real data examples of multiple removal and interpolation show the success of the proposed algorithms to achieve this balance. Another aspect of this thesis is the design of new applications for the Radon transform in seismic processing. Many new applications can be developed by designing new types of Radon operators. Some new applications implemented in this thesis are elliptical and hybrid linear-hyperbolic Radon transforms that should prove to be useful for slant-stack processing and ground roll removal respectively. As a final topic, this thesis presents an application of the RT to the enhancement of a prestack time migration method. Multiple attenuation, artifact filtering and automatic velocity model corrections result from the merging of the R T with equivalent offset migration.
Variability of Broad and Blueshifted Component of [OIII]$λ$5007 in IZWI
Creators: name: Wang, J.
name: Wei, J. Y.
name: He, X. T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Although the existence of asymmetrical profile of [OIII]$λ$5007 has been discovered for ages, its filiation and physics are poorly understood. Two new spectra of I ZWI taken on Nov 16, 2001 and on Dec 3, 2002 were compared with the spectra taken by BG92. Following results are obtained. 1)The certain variations of broad [OIII] during about 10 years separating the observations are identified. The inferred length scale of broad [OIII] emitting region ranges from 0.3pc to 3pc. By assuming a Keplerian motion in emitting region, the material emitting broad [OIII] is likely to be located at transient emission line region, between BLR and NLR. 2)We find a positive relation between the FeII emission and flux of H$β$(or continuum). On the other hand, the parameter RFe decreases with ionizing continuum marginally. 3)We detect a low ionized NLR in I ZWI, because of the low flux ratios $\rm{[OIII]_{n}/Hβ_{n}}$($\sim1.7$).
description: 14 pages, 3 figures, NewA in press
What Do Livestock Feeders Want from Seed Corn Companies?
Creators: name: Hayes, Dermot J.
name: Wendt, Noah
name: Hayes, Dermot J.
name: Wendt, Noah
Publisher: name: Unknown
Year: 2000
Subjects: Agribusiness
Livestock Production/Industries

description: This report combines existing research and further economic analysis to suggest that, with one notable exception, animal feed customer are unlikely to be willing to pay a premium for many of the genetic modifications that are under development in seed corn. This conclusion is based on an assessment of apparent economic barriers to adoption of new genetic modifications; barriers that are unique to the animal feed industry. The conclusion contradicts previous work by the co-author of this paper, Dermot Hayes, and others at Iowa State University.* First, and most important, the widespread use of least-cost rations in the animal feed industry ensures that any genetic modification will be valued at the commodity cost of the modification. This makes the interests of the animal feed customer different from those of other consumers who typically demand, and are prepared to pay a premium for, a customized bundle of attributes. Second, animal feeding is an old- and well-researched industry. As nutritional deficiencies have been discovered in traditional grain rations, industries have arisen to produce the missing attributes. These industries have very inelastic supply curves, and any attempt to supplant the synthetic additive will result in a price drop for that additive. Third, U.S. grain processing and transportation systems have achieved large economies of scale in the handling and processing of undifferentiated crops. Therefore, initial attempts to market differentiated products will incur significant additional costs. This report suggests that the most economically profitable scientific research in the seed corn business is that which increases yields (or reduces production costs) for bulk commodity corn. A second profitable avenue is one that would double the protein content of corn while maintaining yields at 80 percent or more of current levels. A third advance is one that would anticipate a federal or state mandate to reduce the phosphorus and nitrogen content of animal waste. And, a fourth possible avenue of research is to monitor developments in new additives (flavor enhanced milk substitutes, enzymes), and to modify the corn plant to produce these additives before capital-intensive production facilities are built.
Confirmation of Monoperiodicity Above 20 Seconds for Two Blue Large-Amplitude Pulsators
Creators: name: McWhirter, Paul Ross
name: Lam, Marco C.
name: Steele, Iain A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Blue Large-Amplitude Pulsators (BLAPs) are a new class of pulsating variable star. They are located close to the hot subdwarf branch in the Hertzsprung-Russell diagram and have spectral classes of late O or early B. Stellar evolution models indicate that these stars are likely radially pulsating, driven by iron group opacity in their interiors. A number of variable stars with a similar driving mechanism exist near the hot subdwarf branch with multi-periodic oscillations caused by either pressure (p) or gravity (g) modes. No multi-periodic signals were detected in the OGLE discovery light curves since it would be difficult to detect short period signals associated with higher-order p modes with the OGLE cadence. Using the RISE instrument on the Liverpool Telescope, we produced high cadence light curves of two BLAPs, OGLE-BLAP-009 ($m_{\mathrm{v}}=15.65$ mag) and OGLE-BLAP-014 ($m_{\mathrm{v}}=16.79$ mag) using a $720$ nm longpass filter. Frequency analysis of these light curves identify a primary oscillation with a period of $31.935\pm0.0098$ mins and an amplitude from a Fourier series fit of $0.236$ mag for BLAP-009. The analysis of BLAP-014 identifies a period of $33.625\pm0.0214$ mins and an amplitude of $0.225$ mag. Analysis of the residual light curves reveals no additional short period variability down to an amplitude of $15.20\pm0.26$ mmag for BLAP-009 and $58.60\pm3.44$ mmag for BLAP-014 for minimum periods of $20$ s and $60$ s respectively. These results further confirm that the BLAPs are monoperiodic.
description: 10 pages, 9 figures, 4 tables, accepted to MNRAS
A new Look at the Electron Diffusion Region in Asymmetric Magnetic Reconnection
Creators: name: Hesse, Michael
name: Norgren, Cecilia
name: Tenfjord, Paul
name: Burch, James L.
name: Liu, Yi-Hsin
name: Bessho, Naoki
name: Chen, Li-Jen
name: Wang, Shan
name: Kolstø, Håkon
name: Spinnangr, Susanne F.
name: Ergun, Robert E.
name: Moretto, Therese
name: Kwagala, Norah K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Space Physics (physics.space-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A new look at the structure of the electron diffusion region in collisionless magnetic reconnection is presented. The research is based on a particle-in-cell simulation of asymmetric magnetic reconnection, which include a temperature gradient across the current layer in addition to density and magnetic field gradient. We find that none of X-point, flow stagnation point, and local current density peak coincide. Current and energy balance analyses around the flow stagnation point and current density peak show consistently that current dissipation is associated with the divergence of nongyrotropic electron pressure. Furthermore, the same pressure terms, when combined with shear-type gradients of the electron flow velocity, also serve to maintain local thermal energy against convective losses. These effects are similar to those found also in symmetric magnetic reconnection. In addition, we find here significant effects related to the convection of current, which we can relate to a generalized diamagnetic drift by the nongyrotropic pressure divergence. Therefore, only part of the pressure force serves to dissipate the current density. However, the prior conclusion that the role of the reconnection electric field is to maintain the current density, which was obtained for a symmetric system, applies here as well. Finally, we discuss related features of electron distribution function in the EDR.
Early recombination as a solution to the $H_0$ tension
Creators: name: Sekiguchi, Toyokazu
name: Takahashi, Tomo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show that the $H_0$ tension can be resolved by making recombination earlier, keeping the fit to cosmic microwave background (CMB) data almost intact. We provide a suite of general necessary conditions to give a good fit to CMB data while realizing a high value of $H_0$ suggested by local measurements. As a concrete example for a successful scenario with early recombination, we demonstrate that a model with time-varying $m_e$ can indeed satisfy all the conditions. We further show that such a model can also be well fitted to low-$z$ distance measurements of baryon acoustic oscillation (BAO) and type-Ia supernovae (SNeIa) with a simple extension of the model. Time-varying $m_e$ in the framework of $Ω_kΛ$CDM is found to be a sufficient and excellent example as a solution to the $H_0$ tension, yielding $H_0=72.3_{-2.8} ^{+2.7}\,$km/sec/Mpc from the combination of CMB, BAO and SNeIa data even without incorporating any direct local $H_0$ measurements. Apart from the $H_0$ tension, this model is also favored from the viewpoint of the CMB lensing anomaly.
description: 6 pages, 3 figures, 1 table
RETHINKING AGRICULTURAL DOMESTIC SUPPORT UNDER THE WORLD TRADE ORGANIZATION
Creators: name: Beghin, John C.
name: Hart, Chad E.
name: Beghin, John C.
name: Hart, Chad E.
Publisher: name: Unknown
Year: 2004
Subjects: subject: Agricultural and Food Policy
subject: International Relations/Trade
subject: aggregate measure of support
subject: agricultural domestic support
subject: amber box
subject: AMS
subject: blue box
subject: Doha
subject: green box
subject: World Trade Organization
subject: WTO

description: This paper focuses on the third pillar of the Uruguay Round Agreement on Agriculture (URAA) of the World Trade Organization (WTO), the discipline of agricultural domestic support. The paper examines the current definition of agricultural domestic support used by the WTO, focusing on the Aggregate Measure of Support (AMS) and other forms of support that are less to least distorting (Blue and Green Box payments). The analysis looks at the recent experience of four member states (the United States, the European Union, Japan, and Brazil). The structure of recent support varies considerably by country. Some countries, notably the United States, have strategically used the de minimis exemption to deflate their support figures substantially in order to remain within AMS limits, even though total support has exceeded these limits. The paper investigates the possible effects of changing the definition of the AMS so that it better reflects current support conditioned by market forces. If market prices (world and/or domestic) were to be used to compute current market support, a greater variability of the AMS would result, and violations of AMS limits would be more likely given the anticyclical nature of policies included in the AMS, especially for the United States and European Union. We also identify possible changes that would lead to more substantial trade reforms. In particular, we argue for phasing out the de minimis exemption and Blue Box support, adding a generous Green Box definition, which would allow countries to move quickly away from trade-distorting policies (Amber Box and the most trade-distorting Blue Box policies), followed by a phase-down of Green Box payments over time. The recent reforms of the European Unionï¿½s Common Agricultural Policy (CAP) exemplify the spirit of the first part of the recommendation, while resistance to phase-down of Green Box payments may be overcome by a "reasonable" reduction schedule.
Aging dynamics of ferromagnetic and reentrant spin glass phases in stage-2 Cu$_{0.80}$C$_{0.20}$Cl$_{2}$ graphite intercalation compound
Creators: name: Suzuki, Masatsugu
name: Suzuki, Itsuko S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Aging dynamics of a reentrant ferromagnet stage-2 Cu$_{0.8}$Co$_{0.2}$Cl$_{2}$ graphite intercalation compound has been studied using DC magnetic susceptibility. This compound undergoes successive transitions at the transition temperatures $T_{c}$ ($\approx 8.7$ K) and $T_{RSG}$ ($\approx 3.3$ K). The relaxation rate $S_{ZFC}(t)$ exhibits a characteristic peak at $t_{cr}$ below $T_{c}$. The peak time $t_{cr}$ as a function of temperature $T$ shows a local maximum around 5.5 K, reflecting a frustrated nature of the ferromagnetic phase. It drastically increases with decreasing temperature below $T_{RSG}$. The spin configuration imprinted at the stop and wait process at a stop temperature $T_{s}$ ($
description: 9 pages, 9 figures; submitted to Physical Review B
Supersoft X-Ray Phases of Recurrent Novae as an Indicator of their White Dwarf Masses
Creators: name: Kato, Mariko
name: Hachisu, Izumi
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We have examined the optical/X-ray light curves of seven well-observed recurrent novae, V745 Sco, M31N 2008-12a, LMC N 1968, U Sco, RS Oph, LMC N 2009a, T Pyx, and one recurrent nova candidate LMC N 2012a. Six novae out of the eight show a simple relation that the duration of supersoft X-ray source (SSS) phase is 0.70 times the total duration of the outburst ($=$ X-ray turnoff time), i.e., $t_{\rm SSS}=0.70 t_{\rm off}$, the total duration of which ranges from 10 days to 260 days. These six recurrent novae show a broad rectangular X-ray light curve shape, first half a period of which is highly variable in the X-ray count rate. The SSS phase corresponds also to an optical plateau phase that indicates a large accretion disk irradiated by a hydrogen-burning WD. The other two recurrent novae, T Pyx and V745 Sco, show a narrow triangular shape of X-ray light curve without an optical plateau phase. Their relations between $t_{\rm SSS}$ and $t_{\rm off}$ are rather different from the above six recurrent novae. We also present theoretical SSS durations for recurrent novae with various WD masses and stellar metallicities ($Z=$0.004, 0.01, 0.02, and 0.05) and compare with observed durations of these recurrent novae. We show that the SSS duration is a good indicator of the WD mass in the recurrent novae with a broad rectangular X-ray light curve shape.
description: 19 pages, 14 figures, accepted for publication in PASJ