cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
There Is No Monster Outside: It's A Virus! (English)
Creators: name: Irby, Beverly
name: Lara-Alecio, Rafael
name: Abdelrahman, Nahed
name: Tong, Fuhui
name: Schiller, Pam
Publisher: name: Dual Language Research and Practice Journal
Year: 2020

description: No Abstract needed.
description: Dual Language Research and Practice Journal, Vol. 4 No. 1 (2020): There Is No Monster Outside: It's a Virus!
Effect of Substrate Roughness on Oxidation Resistance of an Aluminized Ni-Base Superalloy
Creators: name: Nowak, Wojciech J.
name: Ocha, Kamil
name: Wierzba, Patrycja
name: Gancarczyk, Kamil
name: Wierzba, Bartek
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In the present work, it is shown that the surface preparation method used on two Ni-based superalloys prior to aluminizing chemical vapor deposition (CVD) is one of the most important factors determining the oxidation resistance of aluminized Ni-based superalloys. It was found that grit blasting the substrate surface negatively affects the oxidation resistance of the aluminized coatings. For grit blasted and aluminized IN 625, a thicker outer NiAl coating was formed compared to that of IN 738. In contrast, no effect on NiAl coating thickness was found for grit blasted and aluminized IN 738. However, a thicker interdiffusion zone (IDZ) was observed. It was shown that the systems with grit-blasted surfaces reveal worse oxidation resistance during thermal shock tests, namely, a higher mass loss was observed for both grit blasted and aluminized alloys, as compared to ground and aluminized alloys. A possible reason for this effect of remaining alumina particles originating from surface grit blasting on the diffusion processes and stress distribution at the coating/substrate is proposed.
description: Accepted manuscript Metals 2019
There Is No Monster Outside: It's A Virus! (Spanish)
Creators: name: Lara-Alecio, Rafael
name: Irby, Beverly
name: Tong, Fuhui
name: Abdelrahman, Nahed
name: Schiller, Pam
Publisher: name: Dual Language Research and Practice Journal
Year: 2020

description: non abstract needed
description: Dual Language Research and Practice Journal, Vol. 4 No. 1 (2020): There Is No Monster Outside: It's a Virus!
Going Big!: The Case of a Large District’s Effort to Maximize the Benefits of Dual Language Programming for their Children
Creators: name: Willey, Craige
name: Kigamwa, James
Publisher: name: Dual Language Research and Practice Journal
Year: 2019

description: Dual language (DL) programs have been held up as a promising means by which to reach student achievement goals across demographics (Collier & Thomas, 2004). Yet, the social and political risks associated with implementing DL programs are significant. This paper analyzes one large metropolitan school district’s rationale and preparedness for initiating its DL program, as well as the outcomes of its efforts to scale up the DL program to reach thousands of students, most of whom are children of color. The findings suggest that the district personnel used three pillars to rationalize their decision to implement their DL program: legal, research, and student demographics. In addition, the school district administrators, teachers, and parents showed varying levels of preparedness for the mass implementation of the DL program. While a young program with few quantitative data points to showcase its success, the qualitative data revealed that the program’s structure and professional development efforts for the teachers and principals benefited from a clear and ambitious vision and the unwavering support of the district’s executive leadership. In addition to the extensive data compiled from interviews with key stakeholders, case studies of two schools from the district are provided in order to highlight emergent tensions and showcase how the district’s efforts have materialized into intentional and dynamic DL learning environments.
description: Dual Language Research and Practice Journal, Vol. 1 (2017)
Leading neutron spectra
Creators: name: Kaidalov, A. B.
name: Khoze, V. A.
name: Martin, A. D.
name: Ryskin, M. G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is shown that the observation of the spectra of leading neutrons from proton beams can be a good probe of absorptive and migration effects. We quantify how these effects modify the Reggeized pion-exchange description of the measurements of leading neutrons at HERA. We are able to obtain a satisfactory description of all the features of these data. We also briefly discuss the corresponding data for leading baryons produced in hadron-hadron collisions.
description: 17 pages, 8 figures; sentence and reference added, reference corrected, to be published in EPJC
Light meson spectrum and classical symmetries of QCD
Creators: name: Afonin, S. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Modern spectroscopic data on light non-strange meson spectrum is analyzed. It is argued that the observed regularities of experimental spectrum for highly excited states favour a partial restoration of all approximate classical symmetries of QCD Lagrangian (conformal, chiral and axial) broken by the quantum corrections. The rate of restoration of classical symmetries is estimated. The dependence of the resonance widths from the corresponding masses is systematically checked. On average, it turns out to be universal for the high excitations as predicted by the effective string description.
description: 9 pages, 1 figure. Some estimates and clarifying comments are added
An analytical approach to the Mean--Return-Time~Phase of isotropic stochastic oscillators
Creators: name: Holzhausen, Konstantin
name: Thomas, Peter J.
name: Lindner, Benjamin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: One notion of phase for stochastic oscillators is based on the mean return-time (MRT): a set of points represents a certain phase if the mean time to return from any point in this set to this set after one rotation is equal to the mean rotation period of the oscillator (irrespective of the starting point). For this so far only algorithmically defined phase, we derive here analytical expressions for the important class of isotropic stochastic oscillators. This allows us to evaluate cases from the literature explicitly and to study the behavior of the MRT phase in the limits of strong noise. We also use the same formalism to show that lines of constant return time variance (instead of constant mean return time) can be defined, and that they in general differ from the MRT-isochrons.
description: 5 pages, 4 figures
Latina Dual Language Teachers’ Pedagogical Practices: Transnational Perspectives
Creators: name: Aranda, Brenda
Publisher: name: Dual Language Research and Practice Journal
Year: 2019

description: This ethnographic study explored how the linguistic repertoires of K-2 Latina dual language teachers shape their pedagogical practices within public education on the U.S.-Mexico borderlands, the frontera (Anzaldúa, 1987; Staudt, 2008). Within a transnational context, pedagogical practices related to language use were analyzed drawing from theories of Funds of Knowledge (Moll, Amanti, Neff, & González, 1992; González, Moll, & Amanti, 2005), which values culturally developed pedagogies. The continua model of biliteracy (Hornberger, 2003) offers a theoretical lens through which to see teaching practice in complex bilingual settings. Drawing from sociocultural theory (NLG, 1996; Hornberger, 2004), data collection and analysis of interviews, observations, and artifacts, showed the intertwining of language and identity in practitioners’ narratives and practices. Within the borderlands, bilingualism and biliteracy practices illustrate both structure and agency. Bilingual educators benefit from practice that incorporates the full range of linguistic repertoires. The findings painted a portrait of how DL teachers’ languages, literacies, and identities intertwined to shape their pedagogical practice. The individual and collective stories of DL teachers, indicate that teacher preparation programs need to provide ample opportunities to explore identity formation, develop academic Spanish skills, and increase knowledge about the structure and implementation of bilingual education program models.
description: Dual Language Research and Practice Journal, Vol. 2
Exploring the relativistic regime with Newtonian hydrodynamics: II. An effective gravitational potential for rapid rotation
Creators: name: Mueller, Bernhard
name: Dimmelmeier, Harald
name: Mueller, Ewald
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present the generalization of a recently introduced modified gravitational potential for self-gravitating fluids. The use of this potential allows for an accurate approximation of general relativistic effects in an otherwise Newtonian hydrodynamics code also in cases of rapid rotation. We test this approach in numerical simulations of astrophysical scenarios related to compact stars, like supernova core collapse with both a simplified and detailed microphysical description of matter, and rotating neutron stars in equilibrium. We assess the quality of the new potential, and demonstrate that it provides a significant improvement compared to previous formulations for such potentials. Newtonian simulations of compact objects employing such an effective relativistic potential predict inaccurate pulsation frequencies despite the excellent agreement of the collapse dynamics and structure of the compact objects with general relativistic results. We analyze and discuss the reason for this behavior.
description: 15 pages, 12 figures, minor modifications
Going Big!: The Case of a Large District’s Effort to Maximize the Benefits of Dual Language Programming for their Children
Creators: name: Willey, Craig
name: Kigamwa, James
Publisher: name: Dual Language Research and Practice Journal
Year: 2018

description: Dual language (DL) programs have been held up as a promising means by which to reach student achievement goals across demographics (Collier & Thomas, 2004). Yet, the social and political risks associated with implementing DL programs are significant. This paper analyzes one large metropolitan school district’s rationale and preparedness for initiating its DL program, as well as the outcomes of its efforts to scale up the DL program to reach thousands of students, most of whom are children of color. The findings suggest that the district personnel used three pillars to rationalize their decision to implement their DL program: legal, research, and student demographics. In addition, the school district administrators, teachers, and parents showed varying levels of preparedness for the mass implementation of the DL program. While a young program with few quantitative data points to showcase its success, the qualitative data revealed that the program’s structure and professional development efforts for the teachers and principals benefited from a clear and ambitious vision and the unwavering support of the district’s executive leadership. In addition to the extensive data compiled from interviews with key stakeholders, case studies of two schools from the district are provided in order to highlight emergent tensions and showcase how the district’s efforts have materialized into intentional and dynamic DL learning environments.
description: Dual Language Research and Practice Journal, Vol. 1 (2017)
Gröbner-nice pairs of ideals
Creators: name: Cimpoeaş, Mircea
name: Stamate, Dumitru I.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 13P10, 13F20 (Primary) 13P99 (Secondary)

description: We introduce the concept of a Gröbner nice pair of ideals in a polynomial ring and we present some applications.
description: 14 pages
Effective Dual Immersion School Transitions: An Expert Panel Synthesis
Creators: name: Sellards, Regula
name: Block, Nicholas
name: Schneider, Stephanie
Publisher: name: Dual Language Research and Practice Journal
Year: 2018

description: Using the Delphi method, this study was designed and undertaken due to a lack of existing research regarding key factors that support successful transitions of TWI students from elementary to middle and high school. The purpose of this study was first to identify the opinions of experts and practitioners in the field of TWI programs on key factors that support these transitions, and then to rate the importance of these factors as they pertain to the student’s designation as a dual language student. Subsequently, based on the results from the panel of 16 experts, the researchers investigated how a group of parents ranked the key factors that the expert panel identified as most and least important for successful transitions. The experts identified teacher qualification, curriculum and program planning, communication among school personnel, and administrative support as the most important factors to support student transitions. The group of parents rated the factors determined to be important by the panel highly, generally more highly than the expert panel itself, but parents also deemed
description: Dual Language Research and Practice Journal, Vol. 1 (2017)
Modified gravity models for inflation: In conformity with observations
Creators: name: Zhang, Xinyi
name: Chen, Che-Yu
name: Reyimuaji, Yakefu
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We consider a modified gravity framework for inflation by adding to the Einstein-Hilbert action a direct $f(ϕ)T$ term, where $ϕ$ is identified as the inflaton and $T$ is the trace of the energy-momentum tensor. The framework goes to Einstein gravity naturally when the inflaton decays out. We investigate inflation dynamics in this $f(ϕ)T$ gravity (not to be confused with torsion-scalar coupled theories) on a general basis and then apply it to three well-motivated inflationary models. We find that the predictions for the spectral tilt and the tensor-to-scalar ratio are sensitive to this new $f(ϕ)T$ term. This $f(ϕ)T$ gravity brings chaotic and natural inflation into better agreement with data and allows a larger tensor-to-scalar ratio in the Starobinsky model.
description: 16 pages, 3 figures. Match the version accepted for publication in PRD
A new coexistence result for competing contact processes
Creators: name: Chan, Benjamin
name: Durrett, Richard
Publisher: name: arXiv
Year: 2006
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60K35 (Primary)

description: Neuhauser [Probab. Theory Related Fields 91 (1992) 467--506] considered the two-type contact process and showed that on $\mathbb{Z}^2$ coexistence is not possible if the death rates are equal and the particles use the same dispersal neighborhood. Here, we show that it is possible for a species with a long-, but finite, range dispersal kernel to coexist with a superior competitor with nearest-neighbor dispersal in a model that includes deaths of blocks due to ``forest fires.''
description: Published at http://dx.doi.org/10.1214/105051606000000132 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Expanding Immersion Programs: A Leadership Perspective
Creators: name: Peterson, Deborah
Publisher: name: Dual Language Research and Practice Journal
Year: 2018

description: How best to educate recent immigrants has become more important over the past 30 years as the number of immigrants in our k-12 schools increases. This article presents a phenomenological study of an urban principal in the US who expanded her school’s Spanish immersion program to respond to the needs of immigrant families. This study provides considerations for other school systems looking to expand their immersion programs and implications for school principals leading the change effort. While this study is based on the needs of recent immigrants in the US, the findings apply to schools in other countries working to successfully educate recent immigrants.
description: Dual Language Research and Practice Journal, Vol. 1 (2017)
Solution methods for differential systems subject to algebraic inequality constraints
Creators: name: Spiteri, Raymond J.
Publisher: name: University of British Columbia
Year: 2009

description: The method of programmed constraints has recently been proposed as an executable specification language for robot programming. The mathematical structures behind such problems are viability problems for control systems described by ordinary differential equations subject to user-defined inequality constraints. Although these types of problems are common in applications, practical algorithms and software are generally lacking. This thesis describes a new method for the numerical solution of such viability problems. The algorithm presented is composed of three parts: delay-free discretization, local planning, and local control. Delay-free discretizations are shown to be consistent discretizations of control systems described by ordinary differential equations with discontinuous inputs. The generalization of delay-free discretizations to higher order in the context of implicit-explicit Runge-Kutta methods represents a potentially powerful new class of time integrators for ordinary differential equations that contain terms requiring different discretizations. The local planning aspect is a computationally inexpensive way to increase the robustness in finding a solution to the viability problems of interest, making it a refinement to a strategy based on viability alone. The local control is based on the minimization of an artificial potential function in the form of a logarithmic barrier. Theoretical examples are given of situations where the choice of such a control can be interpreted to yield heavy solutions. Simulations of two robotic systems are then used to validate the particular strategy investigated. Some complementarity is shown between the programmedconstraint approach to robot programming and optimal control. Moreover, we demonstrate the relative efficiency of our algorithm compared to optimal control in the case of programming a mobile robot: our method is able to find a solution on the order of one hundred times faster than a typical optimal control solver. Some simulations on the control of a simple robot arm are also presented.
Calculating the polarization in bi-partite lattice models: application to an extended Su-Schrieffer-Heeger model
Creators: name: Hetényi, Balázs
name: Pulcu, Yetkin
name: Doğan, Serkan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We address the question of different representation of Bloch states for lattices with a basis, with a focus on topological systems. The representations differ in the relative phase of the Wannier functions corresponding to the diffferent basis members. We show that the phase can be chosen in such a way that the Wannier functions for the different sites in the basis both become eigenstates of the position operator in a particular band. A key step in showing this is the extension of the Brillouin zone. When the distance between sites within a unit cell is a rational number, $p/q$, the Brillouin extends by a factor of $q$. For irrational numbers, the Brillouin zone extends to infinity. In the case of rational distance, $p/q$, the Berry phase "lives" on a cyclic curve in the parameter space of the Hamiltonian, on the Brillouin zone extended by a factor of $q$. For irrational distances the most stable way to calculate the polarization is to approximate the distance as a rational sequence, and use the formulas derived here for rational numbers. The use of different bases are related to unitary transformations of the Hamiltonian, as such, the phase diagrams of topological systems are not altered, but each phase can acquire different topological characteristics when the basis is changed. In the example we use, an extended Su-Schrieffer-Heeger model, the use of the diagonal basis leads to toroidal knots in the Hamiltonian space, whose winding numbers give the polarization.
Interplay between core and corona components in high-energy nuclear collisions
Creators: name: Kanakubo, Yuuka
name: Tachibana, Yasuki
name: Hirano, Tetsufumi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We establish the updated version of dynamical core--corona initialization framework (DCCI2) as a unified description from small to large colliding systems and from low to high transverse momentum ($p_T$) regions. Using DCCI2, we investigate effects of interplay between locally equilibrated and non-equilibrated systems, in other words, core and corona components in high-energy nuclear collisions. Given experimental multiplicity distributions and yield ratios of $Ω$ baryons to charged pions as inputs, we extract the fraction of core and corona components in p+p collisions at $\sqrt{s}=7$ TeV and Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. We find core contribution overtakes corona contribution as increasing multiplicity above $\langle dN_{\mathrm{ch}}/dη\rangle_{|η|<0.5} \sim 18$ regardless of the collision system or energy. We also see that the core contribution exceeds the corona contribution only in 0.0-0.95\% multiplicity class in p+p collisions. Notably, there is a small enhancement of corona contribution with $\sim20$\% below $p_T\sim 1$ GeV even in minimum bias Pb+Pb collisions. We find that the corona contribution at low $p_T$ gives $\sim 15$-$38$ $\%$ correction on $v_2\{2\}$ at $N_{\mathrm{ch}}\lesssim 370$. This raises a problem in conventional hydrodynamic analyses in which low $p_T$ soft hadrons originate solely from core components. We finally scrutinize the roles of string fragmentation and the longitudinal expansion in the transverse energy per unit rapidity, which is crucial in initial conditions for hydrodynamics from event generators based on string models.
description: 25 pages, 9 figures (bug in viewing PDF file is fixed)
FitzHugh–Nagumo oscillators on complex networks mimic epileptic-seizure-related synchronization phenomena
Creators: name: Gerster, Moritz
name: Berner, Rico
name: Sawicki, Jakub
name: Zakharova, Anna
name: Škoch, Antonín
name: Hlinka, Jaroslav
name: Lehnertz, Klaus
name: Schöll, Eckehard
Publisher: name: Technische Universität Berlin
Year: 2020
Subjects: subject: 530 Physik
subject: diffusion tensor imaging
subject: non-linear dynamics
subject: brain imaging
subject: coupled oscillators
subject: complex systems theory
subject: FitzHugh-Nagumo model
subject: chimeras
subject: network theory

description: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Chaos 30, 123130 (2020) and may be found at https://doi.org/10.1063/5.0021420
description: We study patterns of partial synchronization in a network of FitzHugh–Nagumo oscillators with empirical structural connectivity measured in human subjects. We report the spontaneous occurrence of synchronization phenomena that closely resemble the ones seen during epileptic seizures in humans. In order to obtain deeper insights into the interplay between dynamics and network topology, we perform long-term simulations of oscillatory dynamics on different paradigmatic network structures: random networks, regular nonlocally coupled ring networks, ring networks with fractal connectivities, and small-world networks with various rewiring probability. Among these networks, a small-world network with intermediate rewiring probability best mimics the findings achieved with the simulations using the empirical structural connectivity. For the other network topologies, either no spontaneously occurring epileptic-seizure-related synchronization phenomena can be observed in the simulated dynamics, or the overall degree of synchronization remains high throughout the simulation. This indicates that a topology with some balance between regularity and randomness favors the self-initiation and self-termination of episodes of seizure-like strong synchronization.
Double-core evolution and the formation of neutron-star binaries with compact companions
Creators: name: Dewi, J. D. M.
name: Podsiadlowski, Ph.
name: Sena, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of a systematic exploration of an alternative evolutionary scenario to form double neutron-star binaries, first proposed by Brown (1995), which does not involve a neutron star passing through a common envelope. In this scenario, the initial binary components have very similar masses, and both components have left the main sequence before they evolve into contact; preferably the primary has already developed a CO core. We have performed population synthesis simulations to study the formation of double neutron star binaries via this channel and to predict the orbital properties and system velocities of such systems. We obtain a merger rate for DNSs in this channel in the range of 0.1 - 12/Myr. These rates are still subject to substantial uncertainties such as the modelling of the contact phase.
description: MNRAS, accepted
Strong near-field light–matter interaction in plasmon-resonant tip-enhanced Raman scattering in indium nitride
Creators: name: Poliani, Emanuele
name: Seidlitz, Daniel
name: Ries, Maximilian
name: Choi, Soo J.
name: Speck, James S.
name: Hoffmann, Axel
name: Wagner, Markus R.
Publisher: name: Technische Universität Berlin
Year: 2020
Subjects: subject: 530 Physik
subject: molecular beam epitaxy
subject: phonons
subject: plasmonics
subject: Raman spectroscopy
subject: resonance structures

description: We report a detailed study of the strong near-field Raman scattering enhancement, which takes place in tip-enhanced Raman scattering (TERS) in indium nitride. In addition to the well-known first-order optical phonons of indium nitride, near-field Raman modes, not detectable in the far-field, appear when approaching the plasmonic probe. The frequencies of these modes coincide with calculated energies of second-order combinational modes consisting of optical zone center phonons and acoustic phonons at the edge of the Brillouin zone. The appearance of strong combinational modes suggests that TERS in indium nitride represents a special case of Raman scattering in which a resonance condition on the nanometer scale is achieved between the localized surface plasmons (LSPs) and surface plasmon polaritons (SPPs) of the probe with the surface charge oscillation of the material. We suggest that the surface charge accumulation (SCA) in InN, which can render the surface a degenerate semiconductor, is the dominating reason for the unusually large enhancement of the TERS signal as compared to other inorganic semiconductors. Thus, the plasmon-resonant TERS (PR-TERS) process in InN makes this technique an excellent tool for defect characterization of indium-rich semiconductor heterostructures and nanostructures with high carrier concentrations.
Oblate Schwarzschild approximation for polarized radiation from rapidly rotating neutron stars
Creators: name: Loktev, Vladislav
name: Salmi, Tuomo
name: Nättilä, Joonas
name: Poutanen, Juri
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We have developed a complete theory for the calculation of the observed Stokes parameters for radiation emitted from the surface of a rapidly rotating neutron star (NS) using the oblate Schwarzschild approximation. We accounted for the rotation of the polarization plane due to relativistic effects along the path from the stellar surface to the observer. The results were shown to agree with those obtained by performing full numerical general relativistic ray-tracing with the \textsc{arcmancer} code. We showed that the obtained polarization angle (PA) profiles may differ substantially from those derived for a spherical star. We demonstrated that assuming incorrect shape for the star can lead to biased constraints for NS parameters when fitting the polarization data. Using a simplified model, we also made a rough estimate of how accurately the geometrical parameters of an accreting NS can be determined using the X-ray polarization measurements of upcoming polarimeters like the Imaging X-ray Polarimeter Explorer (IXPE) or the enhanced X-ray Timing and Polarimetry (eXTP) mission.
description: 11 pages, 10 figures, accepted in A&A
On the relation between the neutrino flux from Centaurus A and the associated diffuse neutrino flux
Creators: name: Koers, Hylke B. J.
name: Tinyakov, Peter
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Based on recent results obtained by the Pierre Auger Observatory (PAO), it has been hypothesized that Centaurus A (Cen A) is a source of ultra-high-energy cosmic rays (UHECRs) and associated neutrinos. We point out that the diffuse neutrino flux may be used to constrain the source model if one assumes that the ratio between the UHECR and neutrino fluxes outputted by Cen A is representative for other sources. Under this assumption we investigate the relation between the neutrino flux from Cen A and the diffuse neutrino flux. Assuming furthermore that Cen A is the source of two UHECR events observed by PAO, we estimate the all-sky diffuse neutrino flux to be ~200-5000 times larger than the neutrino flux from Cen A. As a result, the diffuse neutrino fluxes associated with some of the recently proposed models of UHECR-related neutrino production in Cen A are above existing limits. Regardless of the underlying source model, our results indicate that the detection of neutrinos from Cen A without the accompanying diffuse flux would mean that Cen A is an exceptionally efficient neutrino source.
description: 12 pages, 5 figures, revtex4. Accepted for publication in PRD. (v2) Expanded significantly compared to the previous version; conclusions remain valid
Two ring ditch excavations at Willington, Derbyshire, 2014
Creators: name: Ingham, David
Publisher: name: Archaeology Data Service
Year: 2021

description: The Derbyshire Archaeological Journal, 136, 33-34
description: The upcoming construction of a housing estate on the northern edge of Willington led to a programme of trial trenching, followed by two small areas of archaeological excavation. One area contained the heavily truncated remains of a hengi-form ceremonial monument, defined by two concentric ring ditches with a grave at the centre. Little evidence was found to date the monument, but it remained a focus of activity until at least the Middle Bronze Age from its origin in the Late Neolithic or Early Bronze Age. The other area was focused on a single ring ditch: the ditch itself was essentially undated, but a nearby cluster of pits contained pottery and loom weights dating to the Late Bronze Age.
Search for missing baryon resonances via associated strangeness photoproduction
Creators: name: Saghai, B.
name: David, J. -C.
name: Julia-Diaz, B.
name: Lee, T. -S. H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Differential cross-section and single polarization observables in the process gamma p --> K^+ Lambda are investigated within a constituent quark model and a dynamical coupled-channel formalism. The effects of two new nucleon resonances and of the K*(892)- and K1(1270)-exchanges are briefly presented.
description: Contributed paper to the IVth International Conference on Quarks and Nuclear Physics, Madrid June 5-10, 2006
CCD Photometry of the globular cluster M2. RR Lyrae physical parameters and new variables
Creators: name: Lazaro, C.
name: Ferro, A. Arellano
name: Arevalo, M. J.
name: Bramich, D. M.
name: Giridhar, S.
name: Poretti, E.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the results of CCD V and R photometry of the RR Lyrae stars in M2. The periodicities of most variables are revised and new ephemerides are calculated. Light curve decomposition of the RR Lyrae stars was carried out and the corresponding mean physical parameters [Fe/H] = -1.47, Teff = 6276 K, log L = 1.63 Lsun and Mv = 0.71 from nine RRab and [Fe/H] = -1.61, M = 0.54 Msun, Teff = 7215 K, log L = 1.74 Lsun and Mv = 0.71 from two RRc stars were calculated. A comparison of the radii obtained from the above luminosity and temperature with predicted radii from nonlinear convective models is discussed. The estimated mean distance to the cluster is 10.49 +- 0.15 kpc. These results place M2 correctly in the general globular cluster sequences Oosterhoff type, mass, luminosity and temperature, all as a function of the metallicity. Mean relationships for M, log L/Lsun, Teff and Mv as a function of [Fe/H] for a family of globular clusters are offered. These trends are consistent with evolutionary and structural notions on the horizontal branch. Eight new variables are reported.
description: 13 Pages, 10 Figures, Accepted for publication in MNRAS
O'ZBEK TILINING IZOHLI LUG'ATLARIDAGI AKT TERMINLARINING SEMANTIK TUZILISHI
Creators: name: Amrullayeva, Mohinur
Publisher: name: Zenodo
Year: 2024

description: Mazkur tezisda o‘zbek tilining izohli lug‘atlaridagi axborot kommunikatsiya texnologiyalari terminlarining semantik tuzilishi va xususiyatlari haqida so‘z yuritilgan.O‘zbek tilida mavjud AKT sohasiga oid terminlar tilshunoslikda sohaning o‘zi kabi alohida mikrosistema. Bu esa AKT terminlarining semantik tuzilishida umumiy va farqlovchi jihatlarni aniqlash, terminlarning ifoda planida mavjud imkoniyatlarni tadqiq qilish orqali kompyuter tilini tashkil etuvchi mazkur terminlarning muayyan semantik guruhlarga o‘rinli birlashtirilishi hamda shu asosda axborot texnologiyalariga oid tushunchalarni nomlash, shuningdek, ularni lug‘atda berish mezonlarini belgilash kabi jarayonlarda o‘ziga xos ahamiyatga egaligini ko‘rsatadi.
SpaceGroupIrep: A package for irreducible representations of space group
Creators: name: Liu, Gui-Bin
name: Chu, Miao
name: Zhang, Zeying
name: Yu, Zhi-Ming
name: Yao, Yugui
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We have developed a Mathematica program package SpaceGroupIrep which is a database and tool set for irreducible representations (IRs) of space group in BC convention, i.e. the convention used in the famous book "The mathematical theory of symmetry in solids" by C. J. Bradley & A. P. Cracknell. Using this package, elements of any space group, little group, Herring little group, or central extension of little co-group can be easily obtained. This package can give not only little-group (LG) IRs for any k-point but also space-group (SG) IRs for any k-stars in intuitive table form, and both single-valued and double-valued IRs are supported. This package can calculate the decomposition of the direct product of SG IRs for any two k-stars. This package can determine the LG IRs of Bloch states in energy bands in BC convention and this works for any input primitive cell thanks to its ability to convert any input cell to a cell in BC convention. This package can also provide the correspondence of k-points and LG IR labels between BCS (Bilbao Crystallographic Server) and BC conventions. In a word, the package SpaceGroupIrep is very useful for both study and research, e.g. for analyzing band topology or determining selection rules.
description: 28 pages (main text) + 629 pages (supplementary material), 11 figures
Policy Challenges to Governing Learner Appropriate Online Class Sizes in Higher Education
Creators: name: Irby, Beverly J.
name: Torres, Mario
name: Lara-Alecio, Rafael
name: Tong, Fuhui
name: Tabron, Lolita
Publisher: name: Education Law and Policy Briefs Journal
Year: 2017

description: One of the more intriguing policy developments in education today is the expansion of blended and fully online course delivery. Often at the behest of lawmakers and lobbyists, many colleges and universities are devoting massive resources in support. It is fast becoming a prominent feature in many institutions. To be sure, research over online programming and how it impacts student learning is ongoing. One key aspect to online learning is class size.
description: Education Law and Policy Briefs Journal, Vol. 1 (2017)
A multi-phase prehistoric site in a middle Trent Valley landscape: excavations at Aston Hall Hospital, Aston on Trent, Derbyshire
Creators: name: Flintoft, Paul
name: Stein, Samantha
Publisher: name: Archaeology Data Service
Year: 2021

description: The Derbyshire Archaeological Journal, 136, 35-45
description: The features uncovered at Aston Hall Hospital demonstrate a long-lived, possibly continuous, prehistoric use of the landscape overlooking the River Trent, which expands the timeline of the use of the landscape, and demonstrates the changes of use of space in the later prehistoric period. Pits dating throughout the Neolithic and the Early Bronze Age, and possibly the Mesolithic, dominate the early prehistoric landscape; although these pits do not have a clear function, their presence predates the local large-scale funerary landscape such as that at Swarkestone Lowes barrows and the Aston Cursus monument. The site shows a slow decline through the Middle and Late Bronze Age. The site is completely restructured in the Iron Age, with the implementation of linear ditched enclosures, trackways and pit alignments. Petrographic analysis of the Iron Age pottery also demonstrates a trade or migration network as far as Leicester, with Mountsorrel Granodiorite inclusions in some of the earlier Iron Age pottery.
High-resolution spectroscopy of the intermediate polar EX Hydrae. I. Kinematic study and Roche tomography
Creators: name: Beuermann, K.
name: Reinsch, K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: EX Hya is one of the few double-lined eclipsing cataclysmic variables that allow an accurate measurement of the binary masses. We analyze orbital phase-resolved UVES/ VLT high resolution spectroscopic observations of EX Hya with the aims of deriving the binary masses and obtaining a tomographic image of the illuminated secondary star. We present a novel method for determining the binary parameters by directly fitting an emission model of the illuminated secondary star to the phase-resolved line profiles of NaI lambda 8183/ 8195 in absorption and emission and CaII lambda 8498 in emission. The fit to the NaI and CaII line profiles, combined with the published K1, yields a white-dwarf mass M1 = 0.790 +/- 0.026 Msun, a secondary mass M2 = 0.108 +/- 0.008 Msun, and a velocity amplitude of the secondary star K2 = 432.4 +/- 4.8 km s-1. The secondary is of spectral type dM5.5 +/- 0.5 and has an absolute K-band magnitude of MK = 8.8. Its Roche radius places it on or very close to the main sequence of low-mass stars. It differs from a main sequence star by its illuminated hemisphere that faces the white dwarf. The secondary star contributes only 5% to the observed spin-phase averaged flux at 7500 A, 7.5% at 8200 A, and 37% in the K-band. We present images of the secondary star in the light of the NaI doublet and the CaII emission line derived with a simplified version of Roche tomography. We have discovered narrow spectral lines from the secondary star in EX Hya that delineate its orbital motion and allow us to derive accurate masses of both components. The primary mass significantly exceeds recently published values. The secondary is a low-mass main sequence star that displays a rich emission line spectrum on its illuminated side, but lacks chromospheric emission on its dark side.
description: 15 pages, 15 figures, accepted for publication in Astronomy & Astrophysics
Bulk transport paths through defects in floating zone and Al flux grown SmB$_6$
Creators: name: Eo, Yun Suk
name: Rakoski, Alexa
name: Sinha, Shriya
name: Mihaliov, Dmitri
name: Fuhrman, Wesley T.
name: Saha, Shanta R.
name: Rosa, Priscila F. S.
name: Fisk, Zachary
name: Hatnean, Monica Ciomaga
name: Balakrishnan, Geetha
name: Chamorro, Juan R.
name: Koohpayeh, Seyed M.
name: McQueen, Tyrel M.
name: Kang, Boyoun
name: Song, Myung-suk
name: Cho, Beongki
name: Fuhrer, Michael S.
name: Paglione, Johnpierre
name: Kurdak, Cagliyan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the roles of disorder on low-temperature transport in SmB$_6$ crystals grown by both the Al flux and floating zone methods. We used the inverted resistance method with Corbino geometry to investigate whether low-temperature variations in the standard resistance plateau arises from a surface or a bulk channel in floating zone samples. The results show significant sample-dependent residual bulk conduction, in contrast to smaller amounts of residual bulk conduction previously observed in Al flux grown samples with Sm vacancies. We consider hopping in an activated impurity band as a possible source for the observed bulk conduction, but it is unlikely that the large residual bulk conduction seen in floating zone samples is solely due to Sm vacancies. We therefore propose that one-dimensional defects, or dislocations, contribute as well. Using chemical etching, we find evidence for dislocations in both flux and floating zone samples, with higher dislocation density in floating zone samples than in Al flux grown samples. In addition to the possibility of transport through one-dimensional dislocations, we also discuss our results in the context of recent theoretical models of SmB$_6$.
description: 22 pages, 4 figures
Tests of stellar model atmospheres by optical interferometry IV: VINCI interferometry and UVES spectroscopy of Menkar
Creators: name: Wittkowski, M.
name: Aufdenberg, J. P.
name: Driebe, T.
name: Roccatagliata, V.
name: Szeifert, T.
name: Wolff, B.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present K-band interferometric and optical spectroscopic observations of Menkar obtained with the instruments VINCI and UVES at Paranal Observatory. Spherically symmetric PHOENIX stellar model atmospheres are constrained by comparison to our interferometric and spectroscopic data, and high-precision fundamental parameters of Menkar are obtained. Our high-precision VLTI/VINCI observations in the first and second lobes of the visibility function directly probe the model-predicted strength of the limb darkening effect in the K-band and the stellar angular diameter. The high spectral resolution of UVES allows us to confront observed and model-predicted profiles of atomic lines and molecular bands. We show that our derived PHOENIX model atmosphere for Menkar is consistent with both the measured strength of the limb-darkening in the near-infrared K-band and the profiles of spectral bands around selected atomic lines and TiO bandheads. At the detailed level of our high spectral resolution, however, noticeable discrepancies between observed and synthetic spectra exist. We obtain a Rosseland angular diameter of Theta_Ross=12.20 mas pm 0.04 mas. Together with the Hipparcos parallax, it corresponds to R_Ross=89 pm 5 R_sun, and together with the bolometric flux to T_eff=3795 K pm 70 K.Our approach illustrates the power of combining interferometry and high-resolution spectroscopy to constrain and calibrate stellar model atmospheres. The simultaneous agreement of the model atmosphere with our interferometric and spectroscopic data increases confidence in the reliability of the modelling of this star, while discrepancies at the detailed level of the high resolution spectra can be used to further improve the underlying model.
description: 11 pages, 5 figures, accepted by A&A. Also available from http://www.aanda.org/articles/aa/pdf/forth/aa6032_06.pdf
Elastic scattering of slow electrons by carbon nanotubes
Creators: name: Amusia, M. Ya.
name: Baltenkov, A. S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: In this paper we calculate the elastic scattering cross sections of slow electron by carbon nanotubes. The corresponding electron-nanotube interaction is substituted by a zero-thickness cylindrical potential that neglects the atomic structure of real nanotubes, thus limiting the range of applicability of our approach to sufficiently low incoming electron energies. The strength of the potential is chosen the same that was used in describing scattering of electrons by fullerene C60. We present results for total and partial electron scattering cross sections as well as respective angular distributions, all with account of five lowest angular momenta contributions. In the calculations we assumed that the incoming electron moves perpendicular to the nanotube axis, since along the axis the incoming electron moves freely.
description: 10 pages, 2 figures
Robust Market Equilibria under Uncertain Cost
Creators: name: Biefel, Christian
name: Liers, Frauke
name: Rolfes, Jan
name: Schewe, Lars
name: Zöttl, Gregor
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: G.1.6
subject: 90C33

description: This work studies equilibrium problems under uncertainty where firms maximize their profits in a robust way when selling their output. Robust optimization plays an increasingly important role when best guaranteed objective values are to be determined, independently of the specific distributional assumptions regarding uncertainty. In particular, solutions are to be determined that are feasible regardless of how the uncertainty manifests itself within some predefined uncertainty set. Our mathematical analysis adopts the robust optimization perspective in the context of equilibrium problems. First, we present structural insights for a single-stage, nonadjustable robust setting. We then go one step further and study the more complex two-stage or adjustable case where a part of the variables can adjust to the realization of the uncertainty. We compare equilibrium outcomes with the corresponding centralized robust optimization problem where thesum of all profits are maximized. As we find, the market equilibrium for the perfectly competitive firms differs from the solution of the robust central planner, which is in stark contrast to classical results regarding the efficiency of market equilibria with perfectly competitive firms. For the different scenarios considered, we furthermore are able to determine the resulting price of anarchy. In the case of non-adjustable robustness, for fixed demand in every time step the price of anarchy is bounded whereas it is unbounded if the buyers are modeled by elastic demand functions. For the two-stage adjustable setting, we show how to compute subsidies for the firms that lead to robust welfareoptimal equilibria.
description: 26 pages