cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Quantum repeaters in space
Creators: name: Liorni, Carlo
name: Kampermann, Hermann
name: Bruss, Dagmar
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Long-distance entanglement is a very precious resource, but its distribution is very difficult due to the exponential losses of light in optical fibres. A possible solution consists in the use of quantum repeaters, based on entanglement swapping or quantum error correction. Alternatively, satellite-based free-space optical links can be exploited, achieving better loss-distance scaling. We propose to combine these two ingredients, quantum repeaters and satellite-based links, into a scheme that allows to achieve entanglement distribution over global distances with a small number of intermediate untrusted nodes. The entanglement sources, placed on satellites, send quantum states encoded in photons towards orbiting quantum repeater stations, where entanglement swapping is performed. The performance of this repeater chain is assessed in terms of the secret key rate achievable by the BB-84 cryptographic protocol. We perform a comparison with other repeater chain architectures and show that our scheme is superior in almost every situation, achieving higher key rates, reliability and flexibility. Finally, we analyse the feasibility of the implementation in the mid-term future and discuss exemplary orbital configurations. The integration of satellite-based links with ground repeater networks can be envisaged to represent the backbone of the future Quantum Internet.
description: 12 pages, 5 figures, 2 tables
Quasi-phase-matched up- and down-conversion in periodically poled layered semiconductors
Creators: name: Trovatello, Chiara
name: Ferrante, Carino
name: Yang, Birui
name: Bajo, Josip
name: Braun, Benjamin
name: Xu, Xinyi
name: Peng, Zhi Hao
name: Jenke, Philipp K.
name: Ye, Andrew
name: Delor, Milan
name: Basov, D. N.
name: Park, Jiwoong
name: Walther, Philip
name: Rozema, Lee A.
name: Dean, Cory
name: Marini, Andrea
name: Cerullo, Giulio
name: Schuck, P. James
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Nonlinear optics lies at the heart of classical and quantum light generation. The invention of periodic poling revolutionized nonlinear optics and its commercial applications by enabling robust quasi-phase-matching in crystals such as lithium niobate. However, reaching useful frequency conversion efficiencies requires macroscopic dimensions, limiting further technology development and integration. Here we realize a periodically poled van der Waals semiconductor (3R-MoS$_2$). Due to its exceptional nonlinearity, we achieve macroscopic frequency conversion efficiency of 0.03% at the relevant telecom wavelength over a microscopic thickness of 3.4$μ$m (that is, 3 poling periods), $10-100\times$ thinner than current systems with similar performances. Due to unique intrinsic cavity effects, the thickness-dependent quasi-phase-matched second harmonic signal surpasses the usual quadratic enhancement by $50\%$. Further, we report the broadband generation of photon pairs at telecom wavelengths via quasi-phase-matched spontaneous parametric down-conversion, showing a maximum coincidence-to-accidental-ratio of $638 \pm 75$. This work opens the new and unexplored field of phase-matched nonlinear optics with microscopic van der Waals crystals, unlocking applications that require simple, ultra-compact technologies such as on-chip entangled photon-pair sources for integrated quantum circuitry and sensing.
Marsch zu "Jephta"
Creators: name: Händel, Georg Friedrich
name: Reiter, Ernst
Publisher: name: [s.n.]
Year: 1860

description: [von G.F. Händel] ; instrumentiert von Ernst Reiter 1860 zum Musikfest in Basel
description: Geschenk 1935 *35.2332 Öffentliche Bibliothek der Universität Basel
description: Verzeichnung=Description=Inventaire 2009 Übernahme Rekatalogis. AK UB durch Medea 2002-2005
description: Digitalisierung=Digitization=Numérisation Juli 2024 TIFF
Epidemics with asymptomatic transmission: Sub-critical phase from recursive contact tracing
Creators: name: Baumgarten, Lorenz
name: Bornholdt, Stefan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The challenges presented by the COVID-19 epidemic have created a renewed interest in the development of new methods to combat infectious diseases. A prominent property of the SARS-CoV-2 transmission is the significant fraction of asymptomatic transmission. This may influence the effectiveness of the standard contact tracing procedure for quarantining potentially infected individuals. However, the effects of asymptomatic transmission on the epidemic threshold of epidemic spreading on networks are largely unknown. Here we study the critical percolation transition in a simple epidemic network model in the presence of a recursive contact tracing algorithm for instant quarantining. We find that, above a certain fraction of asymptomatic transmission, standard contact tracing loses its ability to suppress spreading below the epidemic threshold. However, we also find that recursive contact tracing opens a possibility to contain epidemics with a large fraction of asymptomatic or presymptomatic transmission. In particular, we calculate the required fraction of network nodes participating in the contact tracing for networks with arbitrary degree distributions and for varying recursion depths and discuss the influence of recursion depth and asymptomatic rate on the epidemic percolation phase transition. We test and illustrate our theoretical results using numerical simulations on infection trees and networks. We anticipate recursive contact tracing to provide a basis for digital, app-based contact tracing tools that extend the efficiency of contact tracing to diseases with a large fraction of asymptomatic transmission.
description: 8 pages, 6 figures
Adaptive designs CONSORT Extension: draft checklist for Delphi round 1 survey
Creators: name: ACE Steering Committee
Publisher: name: The University of Sheffield
Year: 2018
Subjects: subject: 119999 Medical and Health Sciences not elsewhere classified
subject: FOS: Other medical sciences
subject: 10402 Biostatistics
subject: FOS: Mathematics
subject: 10401 Applied Statistics
subject: Statistics

description: This repository contains the draft checklist used for the Delphi round 1 survey
L'accesso aperto alla letteratura scientifica e l'esperienza di "Archeologia e Calcolatori"
Creators: name: Moscati, Paola
Publisher: name: Zenodo
Year: 2021
Subjects: Archaeology
Digital Archaeology
Open Access

description: Presentazione relativa all'intervento tenuto al webinar "Le scienze del patrimonio culturale on Air. ISPC e la politica Open Access" (15-03-2021). I temi trattati sono l'accesso aperto alla letteratura scientifica e l'esperienza della rivista internazionale "Archeologia e Calcolatori"
A Geometric Embedding for Standard Analytic Modules
Creators: name: Bratten, Tim
Publisher: name: arXiv
Year: 2005
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 22E46

description: In this manuscript we make a general study of the representations realized, for a reductive Lie group of Harish-Chandra class, on the compactly supported sheaf cohomology groups of an irreducible finite-rank polarized homogeneous vector bundle defined in a generalized complex flag space. In particular, we show that the representations obtained are minimal globalizations of Harish-Chandra modules and that there exists a whole number q, depending only on the orbit, such that all cohomologies vanish in degree less than q. The representation realized on the q-th cohomology group is called a standard analytic module. Our main result is a geometric proof that a standard analytic module embeds naturally in an associated standard module defined on the full flag space of Borel subalgebras. As an application, we give geometric realizations for irreducible submodules of some principal series representations in case the group is complex.
description: 21 pages
Aus der Jugendzeit
Unser Neujahrlied : An des Jahres Vesper singen lasset uns ein Vesperlied
Feld- und Waldlied : In frischer Luft und Sonnenschein
Creators: name: Fröhlich, Friedrich Theodor
name: Rückert, Friedrich
name: Wackernagel, Wilhelm
Publisher: name: [s.n.]
Year: 1832

description: [Friedrich Theodor Fröhlich]
description: "Aus der Jugendzeit von Rükkert" in einer Fassung für gem. Chor, datiert "22 Decbr. 32", und in einer undatierten Fassung für Männerchor ; "Unser Neujahrlied" für gem. Chor, datiert "Weihnachtmorgen 1832" ; "Feld- und Waldlied von W. Wkrngl" für gem. Chor und 4 Hörner, unvollständig
description: Geschenk 1956 *56,397 Öffentliche Bibliothek der Universität Basel
description: Deutsch
description: Verzeichnung=Description=Inventaire 2009 Übernahme Rekatalogis. AK UB durch Medea 2002-2005
description: Digitalisierung=Digitization=Numérisation Juli 2024 TIFF
Random oriented Trees: a Model of drainage networks
Creators: name: Gangopadhyay, Sreela
name: Roy, Rahul
name: Sarkar, Anish
Publisher: name: arXiv
Year: 2004
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 05C80, 60K35. (Primary)

description: Consider the d-dimensional lattice Z^d where each vertex is ``open'' or ``closed'' with probability p or 1-p, respectively. An open vertex v is connected by an edge to the closest open vertex w such that the dth co-ordinates of v and w satisfy w(d)=v(d)-1. In case of nonuniqueness of such a vertex w, we choose any one of the closest vertices with equal probability and independently of the other random mechanisms. It is shown that this random graph is a tree almost surely for d=2 and 3 and it is an infinite collection of distinct trees for d\geq4. In addition, for any dimension, we show that there is no bi-infinite path in the tree and we also obtain central limit theorems of (a) the number of vertices of a fixed degree νand (b) the number of edges of a fixed length l.
Characterizing the magnetic noise power spectrum of dark spins in diamond
Creators: name: Williams, Ethan Q.
name: Ramanathan, Chandrasekhar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Coherence times of spin qubits in solid-state platforms are often limited by the presence of a spin bath. While some properties of these typically dark bath spins can be indirectly characterized via the central qubit, it is important to characterize their properties by direct measurement. Here we use pulsed electron paramagnetic resonance (pEPR) based Carr-Purcell-Meiboom-Gill (CPMG) dynamical decoupling to measure the magnetic noise power spectra for ensembles of P1 (substitutional nitrogen) centers in diamond that typically form the bath for NV (nitrogen-vacancy) centers. The experiments on the P1 centers were performed on a low [N] CVD (chemical vapor deposition) sample and a high [N] HPHT (high-temperature, high-pressure) sample at 89 mT. We characterize the NV centers of the latter sample using the same 2.5 GHz pEPR spectrometer. All power spectra show two distinct features, a broad component that is observed to scale as approximately $1/ω^{0.7-1.0}$, and a prominent peak at the $^{13}$C Larmor frequency. The behavior of the broad component is consistent with an inhomogeneous distribution of Lorentzian spectra due to clustering of P1 centers, which has recently been shown to be prevalent in HPHT diamond. It is unknown if such clustering occurs in CVD diamond. We develop techniques utilizing harmonics of the CPMG filter function to improve characterization of high-frequency signals, which we demonstrate on the $^{13}$C nuclear Larmor frequency. At 190 mT this is 2.04 MHz, 5.7 times higher than the CPMG modulation frequency ($<357$ kHz, hardware-limited). We assess the robustness of our methods in the presence of finite pulse widths and flip angle errors. Understanding the interactions of dark spins will inform methods of diamond fabrication for quantum technology. These techniques are applicable to ac magnetometry for nanoscale nuclear magnetic resonance and chemical sensing.
description: 55 pages, 21 figures
Rota-Baxter Algebras and Dendriform Algebras
Creators: name: Ebrahimi-Fard, Kurusch
name: Guo, Li
Publisher: name: arXiv
Year: 2005
Subjects: subject: Rings and Algebras (math.RA)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 16A06, 47B99

description: In this paper we study the adjoint functors between the category of Rota-Baxter algebras and the categories of dendriform dialgebras and trialgebras. In analogy to the well-known theory of the adjoint functor between the category of associative algebras and Lie algebras, we first give an explicit construction of free Rota-Baxter algebras and then apply it to obtain universal enveloping Rota-Baxter algebras of dendriform dialgebras and trialgebras. We further show that free dendriform dialgebras and trialgebras, as represented by binary planar trees and planar trees, are canonical subalgebras of free Rota-Baxter algebras.
description: Typos corrected and the last section on analog of Poincare-Birkhoff-Witt theorem deleted for a gap in the proof
Opposite current-induced spin polarizations in bulk-metallic Bi2Se3 and bulk-insulating Bi2Te2Se topological insulator thin flakes
Creators: name: Tian, Jifa
name: Şahin, Cüneyt
name: Miotkowski, Ireneusz
name: Flatté, Michael E.
name: Chen, Yong P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: One of the most fundamental and exotic properties of 3D topological insulators (TIs) is spin-momentum-locking (SML) of their topological surface states (TSSs), promising for potential applications in future spintronics. However, other possible conduction channels, such as a trivial two-dimensional electron gas (2DEG) with strong Rashba type spin-orbit interaction (SOI) and bulk conducting states that may possess a spin Hall effect (SHE), can coexist in 3D TIs, making determining the origin of the current induced spin polarization (CISP) difficult. In this work, we directly compared the CISP between bulk-insulating Bi2Te2Se (BTS221) and bulk-metallic Bi2Se3 thin flakes using spin potentiometry. In the bulk insulating BTS221, the observed CISP has a sign consistent with the expected helicity of the SML of the TSS, but an opposite sign to its calculated bulk spin Hall conductivity (SHC). However, compared to BTS221, an opposite CISP is observed in the bulk metallic Bi2Se3, consistent instead with both the expectations of its Rashba-Edelstein effect of the band-bending induced 2DEG and bulk spin Hall Effect (SHE). Our results provide an electrical way to distinguish the TSS from other possible conducting channels in spin transport measurements on 3D TIs, and open ways for the potential applications in charge-spin conversion devices.
description: 15 pages, 6 figures
Degeneracy-breaking and Long-lived Multimode Microwave Electromechanical Systems Enabled by Cubic Silicon-Carbide Membrane Crystals
Creators: name: Liu, Yulong
name: Sun, Huanying
name: Liu, Qichun
name: Wu, Haihua
name: Sillanpää, Mika A.
name: Li, Tiefu
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Cubic silicon-carbide crystals (3C-SiC), known for their high thermal conductivity and in-plane stress, hold significant promise for the development of high-quality ($Q$) mechanical oscillators. We reveal degeneracy-breaking phenomena in 3C-phase crystalline silicon-carbide membrane and present high-$Q$ mechanical modes in pairs or clusters. The 3C-SiC material demonstrates excellent microwave compatibility with superconducting circuits. Thus, we can establish a coherent electromechanical interface, enabling precise control over 21 high-$Q$ mechanical modes from a single 3C-SiC square membrane. Benefiting from extremely high mechanical frequency stability, this interface enables tunable light slowing with group delays extending up to an impressive duration of \emph{an hour}. Coherent energy transfer between distinct mechanical modes are also presented. In this work, the studied 3C-SiC membrane crystal with their significant properties of multiple acoustic modes and high-quality factors, provide unique opportunities for the encoding, storage, and transmission of quantum information via bosonic phonon channels.
description: 22 pages, 5 figures, 2 tables
Evolution of the infrared luminosity density and star formation history up to z~1: preliminary results from MIPS
Creators: name: Floc'h, E. Le
name: Papovich, C.
name: Dole, H.
name: Egami, E.
name: Perez-Gonzalez, P.
name: Rieke, G.
name: Rieke, M.
name: Bell, E.
name: team, the Spitzer/MIPS GTO
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using deep observations of the Chandra Deep Field South obtained with MIPS at 24mic, we present our preliminary estimates on the evolution of the infrared (IR) luminosity density of the Universe from z=0 to z~1. We find that a pure density evolution of the IR luminosity function is clearly excluded by the data. The characteristic luminosity L_IR* evolves at least by (1+z)^3.5 with lookback time, but our monochromatic approach does not allow us to break the degeneracy between a pure evolution in luminosity or an evolution in both density and luminosity. Our results imply that IR luminous systems (L_IR > 10^11 L_sol) become the dominant population contributing to the comoving IR energy density beyond z~0.5-0.6. The uncertainties affecting our measurements are largely dominated by the poor constraints on the spectral energy distributions that are used to translate the observed 24mic flux into luminosities.
description: 4 pages, 2 figures. To be published in "Starbursts: From 30 Doradus to Lyman Break Galaxies", held in Cambridge, 6-10 September 2004, Ed. R. de Grijs & R. M. Gonzalez Delgado
Discovery of 18 stars with -3.10 < [Fe/H] < -1.45 in the Sagittarius dwarf galaxy
Creators: name: Chiti, Anirudh
name: Hansen, Kylie Y.
name: Frebel, Anna
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Studies of the early chemical evolution of some larger dwarf galaxies ( $>10^7$ solar masses) are limited by the small number of stars known at low metallicities in these systems. Here we present metallicities and carbon abundances for eighteen stars with metallicities between $-3.08 \le \text{[Fe/H]} \le -1.47$ in the Sagittarius dwarf spheroidal galaxy, using medium-resolution spectra from the MagE spectrograph on the Magellan-Baade Telescope. This sample more than doubles the number of known very metal-poor stars ([Fe/H] $\leq -2.0$) in the Sagittarius dwarf galaxy, and identifies one of the first known extremely metal-poor stars ([Fe/H] $\leq -3.0$) in the system. These stars were identified as likely metal-poor members of Sagittarius using public, metallicity-sensitive photometry from SkyMapper DR1.1 and proper motion data from Gaia DR2, demonstrating that this dearth of metal-poor stars in some dwarf galaxies can be addressed with targeted searches using public data. We find that none of the stars in our sample are enhanced in carbon, in contrast to the relative prevalence of such stars in the Milky Way halo. Subsequent high-resolution spectroscopy of these stars would be key in detailing the early chemical evolution of the system.
description: 13 pages, 7 figures, 3 tables; Accepted for publication in ApJ
A Characterization of Hedging Portfolios for Interest Rate Contingent Claims
Creators: name: Carmona, Rene
name: Tehranchi, Michael
Publisher: name: arXiv
Year: 2004
Subjects: subject: Probability (math.PR)
subject: Portfolio Management (q-fin.PM)
subject: FOS: Mathematics
subject: FOS: Economics and business
subject: 60H35 (Primary) 60H07, 91B28 (Secondary)

description: We consider the problem of hedging a European interest rate contingent claim with a portfolio of zero-coupon bonds and show that an HJM type Markovian model driven by an infinite number of sources of randomness does not have some of the shortcomings found in the classical finite-factor models. Indeed, under natural conditions on the model, we find that there exists a unique hedging strategy, and that this strategy has the desirable property that at all times it consists of bonds with maturities that are less than or equal to the longest maturity of the bonds underlying the claim.
Efficient Two-Electron Ansatz for Benchmarking Quantum Chemistry on a Quantum Computer
Creators: name: Smart, Scott E.
name: Mazziotti, David A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum chemistry provides key applications for near-term quantum computing, but these are greatly complicated by the presence of noise. In this work we present an efficient ansatz for the computation of two-electron atoms and molecules within a hybrid quantum-classical algorithm. The ansatz exploits the fundamental structure of the two-electron system, and treating the nonlocal and local degrees of freedom on the quantum and classical computers, respectively. Here the nonlocal degrees of freedom scale linearly with respect to basis-set size, giving a linear ansatz with only $\mathcal{O}(1)$ circuit preparations required for reduced state tomography. We implement this benchmark with error mitigation on two publicly available quantum computers, calculating accurate dissociation curves for 4- and 6- qubit calculations of ${\rm H}_\textrm{2}^{}$ and ${\rm H}_\textrm{3}^+$.
Attractors and Black Rings
Creators: name: Kraus, Per
name: Larsen, Finn
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The attractor mechanism is usually thought of as the fixing of the near horizon moduli of a BPS black hole in terms of conserved charges measured at infinity. Recent progress in understanding BPS solutions in five dimensions indicates that this is an incomplete story. Moduli can instead be fixed in terms of dipole charges, and their corresponding values can be found by extremizing a certain attractor function built out of these charges. BPS black rings provide an example of this phenomenon. We give a general derivation of the attractor mechanism in five dimensions based on the recently developed classification of BPS solutions. This analysis shows when it is the dipole charges versus the conserved charges that fix the moduli. It also yields explicit expressions for the fixed moduli.
description: 18 pages, Harvmac
Estudo da utilização de válvula gaveta submarina de águas profundas em poços produtores de baixa lâmina d'água
Creators: name: Lanuciano Cristiano Da Silva
name: Pereira, Leonardo Dias
name: Bentes, Flavio
Publisher: name: figshare
Year: 2020
Subjects: subject: Mechanical Engineering
subject: FOS: Mechanical engineering

description: This article presents a study the use of a gate valve model designed to be used in oil wells with deep water depth (401 meters to 1500 meters) in shallow water producing wells. (up to 400m). This paper presents a comparison between the performance curves for fail safe closed (FSC) and fail safe open (FSO) sets identifying their main differences, operation and high criticality points.
A mixture representation of πwith applications in Markov chain Monte Carlo and perfect sampling
Creators: name: Hobert, James P.
name: Robert, Christian P.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 62C15 (Primary) 60J05 (Secondary)

description: Let X={X_n:n=0,1,2,...} be an irreducible, positive recurrent Markov chain with invariant probability measure π. We show that if X satisfies a one-step minorization condition, then πcan be represented as an infinite mixture. The distributions in the mixture are associated with the hitting times on an accessible atom introduced via the splitting construction of Athreya and Ney [Trans. Amer. Math. Soc. 245 (1978) 493-501] and Nummelin [Z. Wahrsch. Verw. Gebiete 43 (1978) 309-318]. When the small set in the minorization condition is the entire state space, our mixture representation of πreduces to a simple formula, first derived by Breyer and Roberts [Methodol. Comput. Appl. Probab. 3 (2001) 161-177] from which samples can be easily drawn. Despite the fact that the derivation of this formula involves no coupling or backward simulation arguments, the formula can be used to reconstruct perfect sampling algorithms based on coupling from the past
Coronavirus: Case for Digital Money?
Creators: name: Kakushadze, Zura
name: Liew, Jim Kyung-Soo
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Finance (q-fin.GN)
subject: FOS: Economics and business

description: We discuss the pros of adopting government-issued digital currencies as well as a supranational digital iCurrency. One such pro is to get rid of paper money (and coinage), a ubiquitous medium for spreading germs, as highlighted by the recent coronavirus outbreak. We set forth three policy recommendations for adapting mobile devices as new digital wallets, regulatory oversight of sovereign digital currencies and user data protection, and a supranational digital iCurrency for facilitating international digital monetary linkages.
description: 12 pages
Chandra High-Resolution X-ray Spectroscopy of the Fe K Line in the Seyfert 1 Galaxy NGC 3783
Creators: name: Yaqoob, T.
name: Reeves, J. N.
name: Markowitz, A.
name: Serlemitsos, P. J.
name: Padmanabhan, U.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the results of detailed X-ray spectroscopy of the Fe K region in the Seyfert 1 galaxy NGC 3783 from five ~170 ks observations with the Chandra high energy gratings. Monitoring was conducted over an interval of ~125 days in 2001. The combined data constitute the highest signal-to-noise Fe K spectrum having the best velocity resolution in the Fe K band to date (FWHM ~1860 km/s). The data show a resolved Fe K line core with a center energy of 6.397 +/- 0.003 keV, consistent with an origin in neutral or lowly ionized Fe, located between the BLR and NLR, as found by Kaspi et al. (2002). We also find that excess flux around the base of the Fe K line core can be modeled with either a Compton scattering ``shoulder'' or an emission line from a relativistic accretion disk, having an inclination angle of 11 degrees or less. This disk line model is as good as a Compton-shoulder model for the base of the Fe K line core. In the latter model, the column density is 7.5 [+2.7,-0.6] x 10^{23} cm^{-2}, which corresponds to a Thomson optical depth of ~0.60. An intrinsic width of 1500 [+460,-340] km/s FWHM is still required in this model. Moreover, more complicated scenarios involving both a Compton-shoulder and a disk line cannot be ruled out. We confirm an absorption feature due to He-like Fe (FWHM = 6405 [+5020,-2670] km/s), found in previous studies.
description: To be published in the ApJ, 10 July 2005. 15 pages, six figures, 4 in color. One table. Abstract is abridged.Corrected/added some citations for accuracy
Whole-examination AI estimation of fetal biometrics from 20-week ultrasound scans
Creators: name: Venturini, Lorenzo
name: Budd, Samuel
name: Farruggia, Alfonso
name: Wright, Robert
name: Matthew, Jacqueline
name: Day, Thomas G.
name: Kainz, Bernhard
name: Razavi, Reza
name: Hajnal, Jo V.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences
subject: I.4.7; J.3

description: The current approach to fetal anomaly screening is based on biometric measurements derived from individually selected ultrasound images. In this paper, we introduce a paradigm shift that attains human-level performance in biometric measurement by aggregating automatically extracted biometrics from every frame across an entire scan, with no need for operator intervention. We use a convolutional neural network to classify each frame of an ultrasound video recording. We then measure fetal biometrics in every frame where appropriate anatomy is visible. We use a Bayesian method to estimate the true value of each biometric from a large number of measurements and probabilistically reject outliers. We performed a retrospective experiment on 1457 recordings (comprising 48 million frames) of 20-week ultrasound scans, estimated fetal biometrics in those scans and compared our estimates to the measurements sonographers took during the scan. Our method achieves human-level performance in estimating fetal biometrics and estimates well-calibrated credible intervals in which the true biometric value is expected to lie.
description: 14 pages, 16 figures. Submitted to NPJ digital medicine. For associated video file, see http://wp.doc.ic.ac.uk/ifind/wp-content/uploads/sites/79/2023/12/realtime.gif
Measurement of the W Boson Polarization in Top Decay at CDF at s**(1/2) = 1.8 TeV
Creators: name: CDF Collaboration
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The polarization of the $W$ boson in $t \to W b$ decay is unambiguously predicted by the Standard Model of weak interactions and is a powerful test of our understanding of the $tbW$ vertex. The subsequent $W \to l ν$ decay serves as a polarimeter for the $W$, and the invariant mass of the lepton and $b$ quark in top decay provides a measurement of the $W$ decay angle. In this paper we present a measurement of the decay rate of the W produced from the decay of the top quark in the hypothesis of V+A structure of the tWb vertex. We find no evidence for the non-standard V+A vertex and set a limit on $f_{V+A}$ $
description: 7 pages, 3 figures, submitted to PRD-RC
Supplementary material to New locality records of Xenophrys zunhebotoensis Mathew and Sen 2007 (Anura: Megophryidae: Megophryinae) from India
Creators: name: Lalronunga, Samuel
name: , Malsawmdawngliana
name: Lalkhawngaiha Sailo
name: Lalhmingliani, Esther
Publisher: name: figshare
Year: 2021
Subjects: subject: 60301 Animal Systematics and Taxonomy
subject: FOS: Biological sciences

description: Supplementary material
Investigation of erosive-corrosive wear in the low pressure die casting of aluminum A35
Creators: name: Miller, Ainsley Elizabeth
Publisher: name: University of British Columbia
Year: 2009

description: Low pressure die casting is a process commonly used to produce aluminum wheels. Die surfaces are exposed to a wide range of operating conditions, including high temperatures, high local pressures, and varying melt velocity, which can result in erosive-corrosive wear. The sprue is an integral component of the die and channels liquid aluminum into the wheel cavity. Typically sprues are made from steel and have a protective coating applied to the surface to provide insulation from the effects of liquid aluminum. However, flow-related phenomena can prematurely wear away this coating, resulting in accelerated surface wear. Erosive-corrosive wear experiments were performed to investigate the effect of geometry on sprue material wear in liquid aluminum alloy A356. Experiments were performed using a laboratory rotating pin apparatus, similar to other tests in literature, examining the effect of pin geometry, velocity, material, temperature, and time on wear behaviour. A profiled cross-section incorporating features from the sprue geometry was used to evaluate the influence of geometry. To ensure that test velocities were realistic, fluid flow models were developed to simulate die cavity filling during low pressure die casting and velocity profiles along the rotating pin surface. The pins were primarily made from 4140 steel, with two profiled pins made from HI3 steel and titanium alloy Ti-6A1-4V. Additional tests were performed with cylindrical pins to validate test set-up and evaluate the effect of additional parameters. Wear increased with increasing velocity, temperature, and time. The titanium pin showed the least amount of wear, followed by the H13 steel pin. The profiled cross-section produced regions of different pressure and velocity along the surface, promoting accelerated wear at some locations. Most wear was observed along the leading edge of the rotating pin. The flow in the sprue exit region was more closely represented by flow along the pin trailing edge. Along both surfaces, flow simulation predicted a region of flow separation. This region was largest for the 15° pin, which experienced the least wear along the trailing edge and may have implications on accelerated sprue wear. More study needs to be completed in terms of the influence of flow on wear, however, preliminary results suggest that larger pin/sprue draft angles may improve wear performance.
The Entangled Quantum Polynomial Hierarchy Collapses
Creators: name: Grewal, Sabee
name: Yirka, Justin
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Computational Complexity (cs.CC)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We introduce the entangled quantum polynomial hierarchy $\mathsf{QEPH}$ as the class of problems that are efficiently verifiable given alternating quantum proofs that may be entangled with each other. We prove $\mathsf{QEPH}$ collapses to its second level. In fact, we show that a polynomial number of alternations collapses to just two. As a consequence, $\mathsf{QEPH} = \mathsf{QRG(1)}$, the class of problems having one-turn quantum refereed games, which is known to be contained in $\mathsf{PSPACE}$. This is in contrast to the unentangled quantum polynomial hierarchy $\mathsf{QPH}$, which contains $\mathsf{QMA(2)}$.
 We also introduce a generalization of the quantum-classical polynomial hierarchy $\mathsf{QCPH}$ where the provers send probability distributions over strings (instead of strings) and denote it by $\mathsf{DistributionQCPH}$. Conceptually, this class is intermediate between $\mathsf{QCPH}$ and $\mathsf{QPH}$. We prove $\mathsf{DistributionQCPH} = \mathsf{QCPH}$, suggesting that only quantum superposition (not classical probability) increases the computational power of these hierarchies. To prove this equality, we generalize a game-theoretic result of Lipton and Young (1994) which says that the provers can send distributions that are uniform over a polynomial-size support. We also prove the analogous result for the polynomial hierarchy, i.e., $\mathsf{DistributionPH} = \mathsf{PH}$. These results also rule out certain approaches for showing $\mathsf{QPH}$ collapses.
 Finally, we show that $\mathsf{PH}$ and $\mathsf{QCPH}$ are contained in $\mathsf{QPH}$, resolving an open question of Gharibian et al. (2022).
description: 24 pages, 1 figure, 1 table
Bifurcation study for a surface-acoustic-wave driven meniscus
Creators: name: Mitas, Kevin David Joachim
name: Manor, Ofer
name: Thiele, Uwe
Publisher: name: arXiv
Year: 2020
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: A thin-film model for a meniscus driven by Rayleigh surface acoustic waves (SAW) is analysed, a problem closely related to the classical Landau-Levich or dragged-film problem where a plate is withdrawn at constant speed from a bath. We consider a mesoscopic hydrodynamic model for a partially wetting liquid, were wettability is incorporated via a Derjaguin (or disjoining) pressure and combine SAW driving with the elements known from the dragged-film problem. For a one-dimensional substrate, i.e., neglecting transverse perturbations, we employ numerical path continuation to investigate in detail how the various occurring steady and time-periodic states depend on relevant control parameters like the Weber number and SAW strength. The bifurcation structure related to qualitative transitions caused by the SAW is analysed with particular attention on the {appearance and interplay of Hopf bifurcations where branches of time-periodic states emerge. The latter correspond to the regular shedding of liquid ridges from the meniscus. The obtained information is relevant to the entire class of dragged-film problems.
Dissipationless Merging and the Assembly of Central Galaxies
Creators: name: Cooray, Asantha
name: Milosavljevic, Milos
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We reanalyze the galaxy-mass correlation function measured by the Sloan Digital Sky Survey to obtain host dark matter halo masses at galaxy and galaxy group scales. We extend the data to galaxy clusters in the 2MASS catalog and study the relation between central galaxy luminosity and halo mass. While the central galaxy luminosity scales as ~M^{0.7-0.8} at low masses, the relation flattens to ~M^{<0.3} above ~4x10^{13} M_sun. The total luminosity of galaxies in the halo, however, continues to grow as a power-law ~M^{0.8-0.9}. Starting from the hypothesis that the central galaxies grow by merging ("galactic cannibalism"), we develop a simple model for the evolution of their luminosities as a consequence of the accretion of satellite galaxies. The luminosity-mass relation flattens when the time scale on which dynamical friction induces orbital decay in the satellite galaxies exceeds the age of the dark matter halo. Then, the growth of the central galaxy is suppressed as it can cannibalize only the rare, massive satellite galaxies. The model takes the dependence of the total luminosity of galaxies in a halo on its mass and the global galaxy luminosity function as input, and reproduces the observed central galaxy luminosity-mass relation over three decades in halo mass, (10^{12}-10^{15}) M_sun. The success of the model suggests that gas cooling and subsequent star formation did not play an important role in the final assembly of central galaxies from sub-L_star precursors.
description: 4 pages, 2 figures, submitted
Origin of Radio Emission from Nearby Low-Luminosity Active Galactic Nuclei
Creators: name: Wu, Qingwen
name: Cao, Xinwu
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use the observational data in radio, optical and X-ray wavebands, for a sample of active galactic nuclei (AGNs) with measured black hole masses, to explore the origin of radio emission from nearby low-luminosity active galactic nuclei (LLAGNs). We find that the radio luminosities are higher than the maximal luminosities expected from the ADAF model, for most sources in this sample. This implies that the radio emission is dominantly from the jets in these sources. The radio emission from a small fraction of the sources in this sample can be explained by the ADAF model. However, comparing the observed multi-band emission data with the spectra calculated for the ADAF or ADIOS cases, we find that neither ADAF nor ADIOS models can reproduce the observed multi-band emission simultaneously, with reasonable magnetic field strengths, for these radio-weak sources. A variety of other possibilities are discussed, and we suggest that the radio emission is probably dominated by jet emission even in these radio-weak LLAGNs.
description: 25 pages, some references were added, accepted for publication in ApJ
Spin, charge and orbital fluctuations in a multi-orbital Mott insulator
Creators: name: Koga, Akihisa
name: Kawakami, Norio
name: Rice, T. M.
name: Sigrist, Manfred
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The two-orbital degenerate Hubbard model with distinct hopping integrals is studied by combining dynamical mean-field theory with quantum Monte Carlo simulations. The role of orbital fluctuations for the nature of the Mott transition is elucidated by examining the temperature dependence of spin, charge and orbital susceptibilities as well as the one-particle spectral function. We also consider the effect of the hybridization between the two orbitals, which is important particularly close to the Mott transition points. The introduction of the hybridization induces orbital fluctuations, resulting in the formation of a Kondo-like heavy-fermion behavior, similarly to $f$ electron systems, but involving electrons in bands of comparable width.
description: 8 pages, 9 figures
Thermal radiation dominated heat transfer in nanomechanical silicon nitride drum resonators
Creators: name: Piller, Markus
name: Sadeghi, Pedram
name: West, Robert G.
name: Luhmann, Niklas
name: Martini, Paolo
name: Hansen, Ole
name: Schmid, Silvan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Nanomechanical silicon nitride (SiN) drum resonators are currently employed in various fields of applications that arise from their unprecedented frequency response to physical quantities. In the present study, we investigate the thermal transport in nanomechanical SiN drum resonators by analytical modelling, computational simulations, and experiments for a better understanding of the underlying heat transfer mechanism causing the thermal frequency response. Our analysis indicates that radiative heat loss is a non-negligible heat transfer mechanism in nanomechanical SiN resonators limiting their thermal responsivity and response time. This finding is important for optimal resonator designs for thermal sensing applications as well as cavity optomechanics.
description: 8 pages, 4 figures in main text, 3 figures in supplementary
Simulation-Based Learning in Electronics: Modified TAM and DeLone & McLean IS Success Model
Creators: name: Pardiñan, Eric
name: Loremia, Romarico
Publisher: name: figshare
Year: 2020
Subjects: subject: 80110 Simulation and Modelling
subject: FOS: Computer and information sciences

description: The study analyzed the satisfaction and intention towards actual use of the circuit simulation software as the basis for technology adoption in education, particularly in teaching electronics in Higher Education (HE). The study introduced a new model called TAM-IS (Technology Acceptance Model-Integrated System). A modified TAM (Davis, 1989) and D&M Success Model (DeLone & McLean, 2003) crafted in adopting simulation-based instructional material for electronics instruction. The study demonstrated excellent internal consistency confirmed by the results of the analysis utilizing Confirmatory Factor Analysis (CFA), Kaiser – Meyer – Olkin (KMO), Cronbach Alpha and Barlette Test. The respondents' responses were unanimous, which confirmed their acceptability of simulation-based learning in electronics. The behavioral intention & attitude towards the use of the technology confirmed the acceptability of adopting simulation software platform in teaching-learning electronics. However, the study recommended needs assessment, proper orientation and evaluation of technology to be utilized. Future studies involving a larger pool of experts from different sectors and continued research may be beneficial since technology is continually evolving and becoming more accessible.
Complexity Classification of Product State Problems for Local Hamiltonians
Creators: name: Kallaugher, John
name: Parekh, Ojas
name: Thompson, Kevin
name: Wang, Yipu
name: Yirka, Justin
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Computational Complexity (cs.CC)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Product states, unentangled tensor products of single qubits, are a ubiquitous ansatz in quantum computation, including for state-of-the-art Hamiltonian approximation algorithms. A natural question is whether we should expect to efficiently solve product state problems on any interesting families of Hamiltonians.
 We completely classify the complexity of finding minimum-energy product states for Hamiltonians defined by any fixed set of allowed 2-qubit interactions. Our results follow a line of work classifying the complexity of solving Hamiltonian problems and classical constraint satisfaction problems based on the allowed constraints. We prove that estimating the minimum energy of a product state is in P if and only if all allowed interactions are 1-local, and NP-complete otherwise. Equivalently, any family of non-trivial two-body interactions generates Hamiltonians with NP-complete product-state problems. Our hardness constructions only require coupling strengths of constant magnitude.
 A crucial component of our proofs is a collection of hardness results for a new variant of the Vector Max-Cut problem, which should be of independent interest. Our definition involves sums of distances rather than squared distances and allows linear stretches.
 We similarly give a proof that the original Vector Max-Cut problem is NP-complete in 3 dimensions. This implies that optimizing over product states for Quantum Max-Cut (the quantum Heisenberg model) is NP-complete, even when every term is guaranteed to have positive unit weight.
description: 35 pages. Updated to prove hardness of product-state local Hamiltonian problem with inverse-polynomial gaps. ITCS 2025
mussa et al. external fixation of trochanteric fractures of the femur..pdf
Creators: name: Mussa, Mohamed
Publisher: name: figshare
Year: 2020
Subjects: subject: 110314 Orthopaedics
subject: FOS: Clinical medicine

description: Introduction: Recent published studies have compared the use of external fixation in elderly patients withtrochanteric fractures with the more conventional methods of fixation such as sliding hip screw. This is thefirst prospective study to report outcomes of external fixation in a larger patient population which includesyoung and healthy adults. Materials and Methods: 200 patients with intertrochanteric fractures were treatedwith a newly developed uniplanar external fixator (AlexFix®). All patients received local anaesthesia in theform of femoral and lateral cutaneous nerve blocks. 60 patients were males and 140 were females with a meanage of 71.09 (24 to 91) years. Patients were followed up for a period of 24 ± 2.1 months. Results: Averageoperative time (and standard deviation) was 26.22 ± 5.9 minutes. Average use of radiation intra-operativelywas 16.67 ± 3.5 seconds. Hospital stay was short with an average of 4.3 ± 1 days. No intra-operativecomplications were encountered. Blood loss was negligible and none of the patients received any bloodtransfusion. Mean time for union was 10.5 ± 1.1 weeks. The most common post-operative complicationsencountered were superficial pin tract infection in 16 patients (8%) and deep pin tract infection in 7 patients(3.5%). Varus malunion occurred in 5 patients (2.5%). No implant failure or re-fracture was recorded.Discussion: External fixation of trochanteric fractures is an effective, safe and reliable treatment method. Itoffers minimal operative and anaesthetic risks, no blood loss, early mobilization and a short hospital stay,with low morbidity and mortality.