cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Putative helimagnetic phase in the kagome metal Co_3Sn_2-xIn_xS_2
Creators: name: Guguchia, Z.
name: Zhou, H.
name: Wang, C. N.
name: Yin, J. -X.
name: Mielke, C.
name: Tsirkin, S. S.
name: Belopolski, I.
name: Zhang, S. -S.
name: Cochran, T. A.
name: Neupert, T.
name: Khasanov, R.
name: Amato, A.
name: Jia, S.
name: Hasan, M. Z.
name: Luetkens, H.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The exploration of topological electronic phases that result from strong electronic correlations is a frontier in condensed matter physics. One class of systems that is currently emerging as a platform for such studies are so-called kagome magnets based on transition metals. Using muon spin-rotation, we explore magnetic correlations in the kagome magnet Co$_{3}$Sn$_{2-x}$In$_{x}$S$_{2}$ as a function of In-doping, providing putative evidence for an intriguing incommensurate helimagnetic (HM) state. Our results show that, while the undoped sample exhibits an out-of-plane ferromagnetic (FM) ground state, at 5 ${\%}$ of In-doping the system enters a state in which FM and in-plane antiferromagnetic (AFM) phases coexist. At higher doping, a HM state emerges and becomes dominant at the critical doping level of only $x_{\rm cr,1}$ ${\simeq}$ 0.3. This indicates a zero temperature first order quantum phase transition from the FM, through a mixed state, to a helical phase at $x_{\rm cr,1}$. In addition, at $x_{\rm cr,2}$ ${\simeq}$ 1, a zero temperature second order phase transition from helical to paramagnetic phase is observed, evidencing a HM quantum critical point (QCP) in the phase diagram of the topological magnet Co$_{3}$Sn$_{2-x}$In$_{x}$S$_{2}$. The observed diversity of interactions in the magnetic kagome lattice drives non-monotonous variations of the topological Hall response of this system.
description: 16 pages, 8 figures. This work builds on our earlier finding on Co3Sn2S2, arXiv:1904.09353, and expands our findings to Co3Sn2-xInxS2
A bipolar Hardy inequality on Finsler manifolds
Creators: name: Mester, Ágnes
name: Kristály, Alexandru
Publisher: name: arXiv
Year: 2020
Subjects: subject: Differential Geometry (math.DG)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We establish a bipolar Hardy inequality on complete, not necessarily reversible Finsler manifolds. We show that our result strongly depends on the geometry of the Finsler structure, namely on the reversibility constant $r_F$ and the uniformity constant $l_F$. Our result represents a Finslerian counterpart of the Euclidean multipolar Hardy inequality due to Cazacu and Zuazua (2013) and the Riemannian case considered by Faraci, Farkas and Kristály (2018).
Diffuse Neutrino and Gamma-ray Emissions of the Galaxy above the TeV
Creators: name: Evoli, Carmelo
name: Grasso, Dario
name: Maccione, Luca
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We simulate the neutrino and $γ$-ray emissions of the Galaxy which are originated from the hadronic scattering of cosmic rays (CR) with the interstellar medium (ISM). Rather than assuming a uniform CR density, we estimate the spatial distribution of CR nuclei by means of numerical simulations. We consider several models of the galactic magnetic field and of the ISM distribution finding only a weak dependence of our results on their choice. We found that by extrapolating the predicted $γ$-ray spectra down to few GeV we get a good agreement with EGRET measurements. Then, we can reliably compare our predictions with available observations above the TeV both for the $γ$-rays and the neutrinos. We confirm that the excesses observed by MILAGRO in the Cygnus region and by HESS in the Galactic Centre Ridge cannot be explained without invoking significant CR over-densities in those regions. Finally, we discuss the perspectives that a km$^3$ neutrino telescope based in the North hemisphere has to measure the diffuse emission from the inner Galaxy.
description: 27 pages, 13 figures. Several figures have been added or replaced. A new model for the ISM distribution has been considered. Accepted for publication in JCAP
D terms from D-branes, gauge invariance and moduli stabilization in flux compactifications
Creators: name: Villadoro, Giovanni
name: Zwirner, Fabio
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We elucidate the structure of D terms in N=1 orientifold compactifications with fluxes. As a case study, we consider a simple orbifold of the type-IIA theory with D6-branes at angles, O6-planes and general NSNS, RR and Scherk-Schwarz geometrical fluxes. We examine in detail the emergence of D terms, in their standard supergravity form, from an appropriate limit of the D-brane action. We derive the consistency conditions on gauged symmetries and general fluxes coming from brane-localized Bianchi identities, and their relation with the Freed-Witten anomaly. We extend our results to other N=1 compactifications and to non-geometrical fluxes. Finally, we discuss the possible role of U(1) D terms in the stabilization of the untwisted moduli from the closed string sector.
description: 1+31 pages, 1 figure
Lower Bounds for Complementation of omega-Automata Via the Full Automata Technique
Creators: name: Yan, Qiqi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: F.4.1; F.4.3

description: In this paper, we first introduce a lower bound technique for the state complexity of transformations of automata. Namely we suggest first considering the class of full automata in lower bound analysis, and later reducing the size of the large alphabet via alphabet substitutions. Then we apply such technique to the complementation of nondeterministic ω-automata, and obtain several lower bound results. Particularly, we prove an ω((0.76n)^n) lower bound for Büchi complementation, which also holds for almost every complementation or determinization transformation of nondeterministic omega-automata, and prove an optimal (ω(nk))^n lower bound for the complementation of generalized Büchi automata, which holds for Streett automata as well.
Heterotic String Dynamics in the Solvable Lie Algebra Gauge
Creators: name: Yilmaz, Nejat Tevfik
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A revision of the torodial Kaluza-Klein compactification of the massless sector of the E(8)xE(8) heterotic string is given. Under the solvable Lie algebra gauge the dynamics of the O(p,q)/(O(p)xO(q)) symmetric space sigma model which is coupled to a dilaton, N abelian gauge fields and the Chern-Simons type field strength is studied in a general formalism. The results are used to derive the bosonic matter field equations of the massless sector of the D-dimensional compactified E(8)xE(8) heterotic string.
description: 47 pages
A comprehensive analysis of NGC 2158 in Gaia era: photometric parameters, apex and orbit
Creators: name: Sariya, Devesh P.
name: Jiang, Ing-Guey
name: Sizova, M. D.
name: Postnikova, E. S.
name: Bisht, D.
name: Chupina, N. V.
name: Vereshchagin, S. V.
name: Yadav, R. K. S.
name: Rangwal, G.
name: Tutukov, A. V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present an investigation of NGC 2158 using Gaia-DR2 data. We identified 800 most likely cluster members with membership probability higher than 90%. The mean proper motions of this object are determined as (mu_{x}=-0.203 \pm 0.003, mu_{y}=-1.99 \pm 0.004) mas yr^{-1}. The limiting radius, log(age), and distance of the cluster are obtained as 23.5 arcmin, 9.38 \pm 0.04 Gyr and 4.69 \pm 0.22 kpc, respectively. The overall mass function slope (0.93 \pm 0.14) is flatter than the Salpeter value (1.35) within the mass range 1.17-1.44 M_\odot. This cluster also shows the mass-segregation effect and our study demonstrates that NGC 2158 is a dynamically relaxed open cluster. Using the AD-diagram, the apex coordinates of the cluster are obtained in different ways and examined using (μ_{U},μ_{T}) diagram. The best value of apex coordinates is determined as A=87.24^\circ \pm 1.60^\circ, D=-36.61^\circ \pm 5.30 ^\circ. We also determined the orbit of the cluster and found that NGC 2158 moves almost in the Solar antapex direction. The resulting spatial velocity of NGC 2158 is 51 km s^{-1}. A significant oscillations along the Z-coordinate up to 529~pc is detected. Various scenarios regarding the origin of this cluster are also discussed.
description: 36 pages, 15 figures. Original submission on 25th June 2020 and accepted for the publication by The Astronomical Journal (AJ) on 10th December 2020
Discovery of a new high redshift QSO at z=5.96 with the Subaru telescope
Creators: name: Goto, Tomotsugu
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report a discovery of a new high redshift quasar at $z=5.96$, observed with the FOCAS long-slit spectrograph on board the Subaru telescope. The spectrum shows strong and broad Ly$α$+NV emission lines with a sharp discontinuity to the blue side. A Ly$β$+OVI emission line is also detected, providing a consistent redshift measurement with the Ly$α$+NV emission. The QSO has an absolute magnitude of $M_{AB,1450}=-26.9$ ($H_{0}=50$km s$^{-1}$ Mpc$^{-1}$, $q_0=0.5$). The spectrum shows significant flux in the region 8000-8300 $Å$ and thus does not show a complete Gunn-Peterson trough in the redshift range 5.58 to 5.82, along the line of sight to this $z=5.96$ QSO. Therefore the Universe was already highly ionized at $z=5.82$
description: accepted for publication in MNRAS
Atresia of the dominant ovarian follicle in cattle
Creators: name: Manikkam, Mohan
Publisher: name: University of British Columbia
Year: 2009

description: During each bovine estrous cycle, two to three dominant follicles (DFs) develop. The DF that develops at the time of corpus luteum (CL) regression ovulates. The first or second DF reaches an ovulatory size, and is capable of ovulation during the luteal phase, but undergoes morphological and functional atresia, probably due to a lack of high frequency luteinizing hormone (LH) pulses which are regulated by high plasma progesterone (P₄) concentrations. The focus of this thesis was to further investigate some of the causes and mechanisms of atresia of the DF in cattle. A Norgestomet-maintained proestrus DF was chosen as an experimental model to study atresia. It was possible to monitor this DF daily, through ultrasonography in a noninvasive manner, without interference from other follicles. In heifers, P₄ , estradiol-17β (E₂) and testosterone (T) when administered, caused regression of the DF, which was associated with a reduction in systemic LH. The role of gonadotropins in the prevention of atresia of the DF was examined by their deprivation, using bovine follicular fluid (BFF) and luteinizing hormone releasing hormone antagonist (LHRHa). Both BFF and LHRHa caused regression of the DF, but there was no FSH suppression by BFF; L H was significantly reduced by LHRHa treatment. The role of FSH on the maintenance and ovulation of the DF was studied using BFF. The DF regressed when BFF was given during maintenance phase, although there was no decrease in FSH. Regression of the DF occurred in one subgroup during the ovulatory phase, and in the other subgroup ovulation of the DF ensued. BFF injections abolished FSH and L H surges after implant withdrawal. The mechanism of atresia of the DF was investigated in cows after P₄ treatment. The DF showed a decline in insulin-like growth factors-I and -II (IGF-I and II), increase in low molecular weight IGF-binding proteins on ligand blots, a drastic reduction in aromatase activity (AA), reduced E₂ content and increased apoptotic index. High concentrations of steroids and(or) low concentrations of gonadotropins cause atresia of the DF, and the mechanism of P₄-induced atresia of the DF involves changes in IGF system, and a reduction AA.
General analytic theory of classical collinear three wave mixing in a monolithic cavity
Creators: name: Santandrea, Matteo
name: Stefszky, Michael
name: Silberhorn, Christine
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Integrated, monolithic nonlinear cavities are of high interest in both classical and quantum optics experiments for their high efficiency and stability. However, a general, analytic theory of classical three wave mixing in such systems that encompasses multiple monolithic designs, including both linear and nonlinear regions, as well as any three-wave mixing process has not yet been fully developed. In this paper, we present the analytic theory for a general, classical three wave mixing process in a cavity with arbitrary finesse and non-zero propagation losses, encompassing second harmonic, sum frequency and difference frequency generation - SHG, SFG and DFG respectively. The analytic expression is derived under the sole assumption of low single-pass conversion efficiency (or equivalently operating in the non-depleted pump regime). We demonstrate remarkable agreement between the presented model and the experimentally obtained highly complex second-harmonic spectrum of a titanium-diffused lithium niobate waveguide cavity that includes both a linear and nonlinear section. We then show the effect that reversing the linear and nonlinear regions has on the output spectrum, highlighting the importance of system design. Finally, we demonstrate that the model can be extended to include the effect of phase modulation applied to the cavity.
Strong Memory in Time Series of Human Magnetoencephalograms Can Identify Photosensitive Epilepsy
Creators: name: Yulmetyev, R. M.
name: Yulmetyeva, D. G.
name: Khusaenova, E. V.
name: Hänggi, P.
name: Shimojo, S.
name: Bhattacharya, J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: To discuss the salient role of the statistical memory effects in the human brain functioning we have analyzed a set of stochastic memory quantifiers that reflects the dynamical characteristics of neuromagnetic brain responses to a flickering stimulus of different color combinations from a group of control subjects which is contrasted with those from a patient with photosensitive epilepsy (PSE). We have discovered the emergence of strong memory and the accompanying transition to a regular and robust regime of chaotic behavior of the signals in the separate areas for a patient with PSE. This finding most likely identifies the regions of the location the protective mechanism in a human organism against occurrence of PSE.
description: 10 pages, 5 figures, Accepted for publication in JETP, February 2007
Generation of mean flows in rotating anisotropic turbulence: The case of solar near-surface shear layer
Creators: name: Barekat, A.
name: Käpylä, M. J.
name: Käpylä, P. J.
name: Gilson, E. P.
name: Ji, H.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The radial gradient of the rotation rate in the near-surface shear layer (NSSL) of the Sun is independent of latitude and radius. Theoretical mean-field models have been successful in explaining this property of the solar NSSL, while global direct convection models have been unsuccessful. We investigate reason for this discrepancy by measuring the mean flows, Reynolds stress, and turbulent transport coefficients under NSSL conditions. Simulations have minimal ingredients. These ingredients are inhomogeneity due to boundaries, anisotropic turbulence, and rotation. Parameters of the simulations are chosen such they match the weakly rotationally constrained NSSL. The simulations probe locally Cartesian patches of the star at a given depth and latitude. The depth of the patch is varied by changing the rotation rate such that the resulting Coriolis numbers<1. We measure the turbulent transport coefficient relevant for the non-diffusive and diffusive parts of the Reynolds stress and compare them with predictions of current mean-field theories. A negative radial gradient of mean flow similar to the solar NSSL is generated only at the equator where meridional flows are absent. At other latitudes the meridional flow is comparable to the mean flow corresponding to differential rotation. We also find that meridional components of the Reynolds stress cannot be ignored. Additionally, we find that the turbulent viscosity is quenched by rotation by about 50\% from the surface to the bottom of the NSSL. Our local simulations do not validate the explanation for the generation of the NSSL from mean-field theory where meridional stresses are neglected. However, the rotational dependence of turbulent viscosity in our simulations is in good agreement with theoretical prediction. Our results are in qualitative agreement with global convection simulations in that a NSSL obtained near the equator.
BaCuS2: a superconductor with moderate electron-electron correlation
Creators: name: Gu, Yuhao
name: Wu, Xianxin
name: Jiang, Kun
name: Hu, Jiangping
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We show that the layered-structure BaCuS$_2$ is a moderately correlated electron system in which the electronic structure of the CuS layer bears a resemblance to those in both cuprates and iron-based superconductors. Theoretical calculations reveal that the in-plane $d$-$p$ $σ^*$-bonding bands are isolated near the Fermi level. As the energy separation between the $d$ and $p$ orbitals are much smaller than those in cuprates and iron-based superconductors, BaCuS$_2$ is expected to be moderately correlated. We suggest that this material is an ideal system to study the competitive/collaborative nature between two distinct superconducting pairing mechanisms, namely the conventional BCS electron-phonon interaction and the electron-electron correlation, which may be helpful to establish the elusive mechanism of unconventional high-temperature superconductivity.
Treaty Commitment Preferences: The Case of the Philippines on the Proposed ASEAN Extradition
Creators: name: Batiles, Kieren Roevi A.
Publisher: name: Zenodo
Year: 2020

description: Treaty commitment preferences of each State vary from one another. Wagner (2003), Lupu (2014), Simmons (2002) and Parillo (2009) recommended the general treaty commitment preferences in the European context, notably the form of government, incumbent administration’s priority plans, capacity to comply and foreseen benefits. Thus, this study was conducted to validate the applicability of the suggested preferences in the Philippine context through the lens of the proposed Association of Southeast Asian Nations (ASEAN) Extradition Treaty.
 Interview with the prominent negotiators of extradition law and ASEAN instruments were conducted in order to validate the preferences and/or identify other relevant preferences that may be deemed applicable for the Philippines. The results of the study presented that, unlike the theoretical propositions, the form of government and incumbent administration’s priority plans are not considered as treaty commitment preferences of the country. On the other hand, the capacity to comply, foreseen benefits, challenges, status/situation of transnational crimes in the region, as well as the legal framework of the Contracting Parties, are proven to be the significant preferences in the Philippine context.
 The above implies that the abovementioned preferences may serve as the foundation of the possible general framework of the Philippines’ treaty commitment preferences on various treaties and international agreements in different areas of cooperation. This, in turn, may likewise serve as the basis of negotiators when drafting and negotiating international agreements.
description: Masters Thesis
Influence of chemical and magnetic interface properties of Co-Fe-B / MgO / Co-Fe-B tunnel junctions on the annealing temperature dependence of the magnetoresistance
Creators: name: Schmalhorst, J.
name: Thomas, A.
name: Reiss, G.
name: Kou, X.
name: Arenholz, E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The knowledge of chemical and magnetic conditions at the Co40Fe40B20 / MgO interface is important to interpret the strong annealing temperature dependence of tunnel magnetoresistance of Co-Fe-B / MgO / Co-Fe-B magnetic tunnel junctions, which increases with annealing temperature from 20% after annealing at 200C up to a maximum value of 112% after annealing at 350C. While the well defined nearest neighbor ordering indicating crystallinity of the MgO barrier does not change by the annealing, a small amount of interfacial Fe-O at the lower Co-Fe-B / MgO interface is found in the as grown samples, which is completely reduced after annealing at 275C. This is accompanied by a simultaneous increase of the Fe magnetic moment and the tunnel magnetoresistance. However, the TMR of the MgO based junctions increases further for higher annealing temperature which can not be caused by Fe-O reduction. The occurrence of an x-ray absorption near-edge structure above the Fe and Co L-edges after annealing at 350C indicates the recrystallization of the Co-Fe-B electrode. This is prerequisite for coherent tunneling and has been suggested to be responsible for the further increase of the TMR above 275C. Simultaneously, the B concentration in the Co-Fe-B decreases with increasing annealing temperature, at least some of the B diffuses towards or into the MgO barrier and forms a B2O3 oxide.
Strategies for controlling through-space charge transport in metal-organic frameworks via structural modifications
Creators: name: Winkler, Christian
name: Zojer, Egbert
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In recent years, charge transport in metal-organic frameworks (MOFs) has shifted into the focus of scientific research. In this context, systems with efficient through-space charge transport pathways resulting from pi-stacked conjugated linkers are of particular interest. In the current manuscript, we use density functional theory based simulations to provide a detailed understanding of such MOFs, which in the present case are derived from the prototypical Zn2(TTFTB) system. In particular we show that factors like the relative arrangement of neighboring linkers and the details of the structural conformations of the individual building blocks have a profound impact on band widths and charge transfer. Considering the helical stacking of individual tetrathiafulvalene (TTF) molecules around a screw axis as the dominant symmetry element in Zn2(TTFTB)-derived materials, the focus here is primarily on the impact of the relative rotation of neighboring molecules. Not unexpectedly, also changing the stacking distance in the helix plays a distinct role, especially for structures, which display large electronic couplings to start with. The presented results provide guidelines for achieving structures with improved electronic couplings. It is, however, also shown that structural defects (especially missing linkers) provide major obstacles to charge transport in the studied, essentially one-dimensional systems. This suggests that especially the sample quality is a decisive factor for ensuring efficient through-space charge transport in MOFs comprising stacked pi-systems.
Sensitive Data Interest Group The Research Data Alliance: Presentation to the Australia Sensitive Data CoP
Creators: name: Spreadborough, Kristal
Publisher: name: Zenodo
Year: 2021

description: These slides accompany the presentation given to the Australian Sensitive Data CoP. More information is available here: ARDC communities page: https://ardc.edu.au/events/sensitive-data-community/. Australian Sensitive Data CoP page: https://sites.google.com/ardc.edu.au/sensitive-data-cop/home Abstract: The Research Data Alliance (RDA) is a community-driven initiative where international experts come together to exchange views and come to agreements with the aim of promoting the sharing and re-use of research data. The Sensitive Data Interest Group is a new RDA group (working towards official endorsement) that brings together experts in sensitive research data from different fields and regions of the world. In this session we will introduce the aims and objectives of the Interest Group and report back on what was discussed at our session at the recent RDA Plenary.
Rate of decoherence for an electron weakly coupled to a phonon gas
Creators: name: Adami, Riccardo
name: Erdos, Laszlo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 81V99

description: We study the dynamics of an electron weakly coupled to a phonon gas. The initial state of the electron is the superposition of two spatially localized distant bumps moving towards each other, and the phonons are in a thermal state. We investigate the dynamics of the system in the kinetic regime and show that the time evolution makes the non-diagonal terms of the density matrix of the electron decay, destroying the interference between the two bumps. We show that such a damping effect is exponential in time, and the related decay rate is proportional to the total scattering cross section of the electron-phonon interaction.
description: 27 pages, 2 figures
BILIMLARNI O'ZLASHTIRISH DAVOMIDA O'QUVCHILARNING  MANTIQIY BILIMLARINI RIVOJLANTIRISH
Creators: name: Quvanov Zahriddin, Shahrisabz davlat pedagogika instituti Boshlang'ich ta'lim kafedrasi  o'qituvchisi
Publisher: name: Zenodo
Year: 2024

description: Maqolada  o‘quvchilarni  mantiqiy  fikrlashga  o‘rgatish  masalasining ahamiyati  va  dolzarbligi  yoritilgan.  Ta’lim-tarbiya  jarayonining  samaradorligini oshirish uchun o’quvchilarning bilish faoliyatini  rivojlantirish usullari ko‘rsatilgan. Maqola oxirida xulosa berilgan.
Orbital solutions derived from radial velocities and time delays for four {\it Kepler} systems with A/F-type (candidate) hybrid pulsators
Creators: name: Lampens, P.
name: Vermeylen, L.
name: Frémat, Y.
name: Sódor, Á.
name: Skarka, M.
name: Samadi-Ghadim, A.
name: Bognár, Zs.
name: Lehmann, H.
name: De Cat, P.
name: Goswami, A.
name: Dumortier, L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The presence of A/F-type {\it Kepler} hybrid stars extending across the entire $δ$ Sct-$γ$ Dor instability strips and beyond remains largely unexplained. In order to better understand these particular stars, we performed a multi-epoch spectroscopic study of 49 candidate A/F-type hybrid stars and one cool(er) hybrid object detected by the {\it Kepler} mission. We determined a lower limit of 27 % for the multiplicity fraction. For six spectroscopic systems, we also reported long-term variations of the time delays. For four systems, the time delay variations are fully coherent with those of the radial velocities and can be attributed to orbital motion. We aim to improve the orbital solutions for those systems with long orbital periods (order of 4-6 years) among the {\it Kepler} hybrid stars. The orbits are computed based on a simultaneous modelling of the RVs obtained with high-resolution spectrographs and the photometric time delays derived from time-dependent frequency analyses of the {\it Kepler} light curves. We refined the orbital solutions of four spectroscopic systems with A/F-type {\it Kepler} hybrid component stars: KIC 4480321, 5219533, 8975515 and KIC 9775454. Simultaneous modelling of both data types analysed together enabled us to improve the orbital solutions, obtain more robust and accurate information on the mass ratio, and identify the component with the short-period $δ$ Sct-type pulsations. In several cases, we were also able to derive new constraints for the minimum component masses. From a search for regular frequency patterns in the high-frequency regime of the Fourier transforms of each system, we found no evidence of tidal splitting among the triple systems with close (inner) companions. However, some systems exhibit frequency spacings which can be explained by the mechanism of rotational splitting.
description: 11 pages, 15 figures and 5 tables. Accepted for publication in A&A
Effect of sterile phases on degeneracy resolution capabilities of LBL experiments
Creators: name: Chatla, Akshay
name: Bambah, Bindu A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In sterile neutrino (3+1) parameterisation, we observe that sterile phases ($δ_{14},δ_{24}$) are always together in oscillation probability, even when the MSW effect is considered. We see that the difference between the sterile phases has a more dominating effect over event rates compared to small variations due to changes in individual values. In this work, we show the value of sterile phase difference ($δ_{14}-δ_{24}$) that least affects the parameter degeneracy resolution of $δ_{13},θ_{23}$ at long-baseline experiments.
description: 5 pages, 4 figures, Prepared for the proceedings of The 5th international conference on particle physics and astrophysics, Moscow (05-09 October 2020)
Charge Fluctuation of Dust Grain and Its Impact on Dusty-Acoustic Wave Damping
Creators: name: Atamaniuk, B.
name: Zuchowski, K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We consider the influence of dust charge fluctuations on damping of the dust-ion-acoustic waves. It is assumed that all grains have equal masses but charges are not constant in time - they may fluctuate in time. The dust charges are not really independent of the variations in the plasma potentials. All modes will influence the charging mechanism, and feedback will lead to several new interesting and unexpected phenomena. The charging of the grains depends on local plasma characteristics. If the waves disturb these characteristic, then charging of the grains is affected and the grain charge is modified, with a resulting feedback on the wave mode. In the case considered here, when the temperature of electrons is much greater than the temperature of the ions and the temperature of electrons is not great enough for further ionization of the ions, we show that attenuation of the acoustic wave depends only on one phenomenological coefficient
description: 4 pages, 4th International Conference on the Physics of Dusty Plasmas, Orleans-France
Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. III. Optical Variability and X-ray/UV/Optical Correlations
Creators: name: Desroches, Louis-Benoit
name: Filippenko, Alexei V.
name: Kaspi, Shai
name: Laor, Ari
name: Maoz, Dan
name: Ganeshalingam, Mohan
name: Li, Weidong
name: Moran, Edward C.
name: Swift, Brandon
name: Bentz, Misty C.
name: Ho, Luis C.
name: Nandra, Kirpal
name: O'Neill, Paul M.
name: Peterson, Bradley M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present optical observations of the low-luminosity Seyfert 1 nucleus of NGC 4395, as part of a multiwavelength reverberation-mapping program. Observations were carried out over two nights in 2004 April at Lick, Wise, and Kitt Peak Observatories. We obtained V-band and B-band photometry, and spectra over the range 3500-6800 Angstroms. Simultaneous Hubble Space Telescope UV and Chandra X-ray observations are presented in companion papers. Even though NGC 4395 was in an extremely low state of activity, we detect significant continuum variability of 2-10%, increasing toward shorter wavelengths. The continuum light curves, both spectroscopic and photometric, are qualitatively similar to the simultaneous UV and X-ray light curves. Inter-band cross-correlations suggest that the optical continuum emission lags behind the UV continuum emission by 24 +7/-9 min, and that the optical continuum emission lags behind the X-ray continuum emission by 44 +/- 13 min, consistent with a reprocessing model for active galactic nucleus emission. There are also hints of Balmer emission lines lagging behind the optical continuum by an amount slightly larger than the emission-line lag detected in the UV. These results are all similar to those of other Seyfert 1 nuclei. The emission-line lag yields a mass measurement of the central black hole, which although not very significant, is consistent with the value derived from the simultaneous UV data.
description: 29 pages, 16 figures, emulateapj, accepted for publication in ApJ
The fluctuation-dissipation theorem and the linear Glauber model
Creators: name: Hase, M. O.
name: Salinas, S. R.
name: Tomé, T.
name: de Oliveira, M. J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We obtain exact expressions for the two-time autocorrelation and response functions of the $d$-dimensional linear Glauber model. Although this linear model does not obey detailed balance in dimensions $d\geq 2$, we show that the usual form of the fluctuation-dissipation ratio still holds in the stationary regime. In the transient regime, we show the occurence of aging, with a special limit of the fluctuation-dissipation ratio, $X_{\infty}=1/2$, for a quench at the critical point.
description: Accepted for publication (Physical Review E)
Searching for Massive Black Hole Binaries in the first Mock LISA Data Challenge
Creators: name: Cornish, Neil J.
name: Porter, Edward K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Mock LISA Data Challenge is a worldwide effort to solve the LISA data analysis problem. We present here our results for the Massive Black Hole Binary (BBH) section of Round 1. Our results cover Challenge 1.2.1, where the coalescence of the binary is seen, and Challenge 1.2.2, where the coalescence occurs after the simulated observational period. The data stream is composed of Gaussian instrumental noise plus an unknown BBH waveform. Our search algorithm is based on a variant of the Markov Chain Monte Carlo method that uses Metropolis-Hastings sampling and thermostated frequency annealing. We present results from the training data sets and the blind data sets. We demonstrate that our algorithm is able to rapidly locate the sources, accurately recover the source parameters, and provide error estimates for the recovered parameters.
description: 11 pages, 6 figures, Submitted to CQG proceedings of GWDAW 11, AEI, Germany, Dec 2006
Hot and cold gas accretion and feedback in radio-loud active galaxies
Creators: name: Hardcastle, M. J.
name: Evans, D. A.
name: Croston, J. H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have recently shown that X-ray observations of the population of `low-excitation' radio galaxies, which includes most low-power, Fanaroff-Riley class I sources as well as some more powerful Fanaroff-Riley class II objects, are consistent with a model in which the active nuclei of these objects are not radiatively efficient at any waveband. In another recent paper Allen et al. have shown that Bondi accretion of the hot, X-ray emitting phase of the intergalactic medium (IGM) is sufficient to power the jets of several nearby, low-power radio galaxies at the centres of clusters. In this paper we combine these ideas and suggest that accretion of the hot phase of the IGM is sufficient to power all low-excitation radio sources, while high-excitation sources are powered by accretion of cold gas that is in general unrelated to the hot IGM. This model explains a number of properties of the radio-loud active galaxy population, and has important implications for the energy input of radio-loud active galactic nuclei into the hot phase of the IGM: the energy supply of powerful high-excitation sources does not have a direct connection to the hot phase.
description: MNRAS accepted. 8 pages, 1 figure
A study on wisdom, wisdom in teaching, teacher efficacy, and teaching performance
Creators: name: Fung, Mary Lena
Publisher: name: University of British Columbia
Year: 2009

description: Despite a rising interest in studying the effects and the antecedents of teacher efficacy, a review of literature indicated that an important individual variable has been left out of these studies. This is the cognitive component which Bandura (1977) suggests is central to the process of efficacy formulation. Specifically Bandura (1977) argues that for performance to be instructive for efficacy formulation, a type of cognitive appraisal needs to be present. To date, this cognitive appraisal has not been identified in teacher efficacy studies. The purpose of this thesis is to search for a way to represent this cognitive component and to examine its role in teaching performance and efficacy formulation. Two variables are selected as possible representations of this cognitive component. They are wisdom and wisdom in teaching. The two research questions developed for this study are: (1) What is the relative contribution of wisdom, wisdom in teaching, personal teaching efficacy, and general teaching efficacy to teaching performance? And (2) What is the relative contribution of wisdom, wisdom in teaching, and teaching performance to the formulation of personal teaching efficacy and general teaching efficacy? Eighty-nine final year student teachers were asked to respond to three instruments that measured their level of wisdom, wisdom in teaching, and teacher efficacy. These instruments were: (1) Life planning dilemma "Jack" (Smith & Baltes, 1987), (2) Teaching dilemma "Perimeter" (Arlin, 1987), and (3) The teacher efficacy scale (Gibson & Dembo, 1984). The participants were also asked to submit their teaching practicum marks. This mark represents their teaching performance. Teaching performance was best explained by the combined effects of wisdom in teaching and personal teaching efficacy than by either of them alone. Jointly these two variables accounted for 54% of variance in teaching performance. Wisdom in teaching and teaching performance provided a better explanation for the formulation of personal teaching efficacy than each taken in turn. The joint effects of wisdom, wisdom in teaching, and teaching performance accounted for 7% of variance in the formulation of both personal teaching efficacy and general teaching efficacy. An important finding from this study is that wisdom in teaching has the greatest impact on teaching performance. An implication of this finding is that teacher educators should develop and provide programmes which can help facilitate the growth of wisdom in teaching.
Radiative energy loss in a finite dynamical QCD medium
Creators: name: Djordjevic, Magdalena
name: Heinz, Ulrich W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The radiative energy loss of a quark jet traversing a finite size QCD medium with dynamical constituents is calculated to first order in opacity. Although finite size corrections reduce the energy loss relative to an infinite dynamical QCD medium, under realistic conditions it remains significantly larger than in a static medium. Quantitative predictions of jet suppression in relativistic heavy ion collisions must therefore account for the dynamics of the medium's constituents. Finite size effects are shown to induce a non-linear path length dependence of the energy loss. Our results suggest a simple general mapping between energy loss expressions for static and dynamical QCD media.
description: 4 pages, 3 figures
Table 1 Full clinical details of KTRs with an acute rejection episode and stable controls is shown
Creators: name: Betts, Gareth
name: Net, Jeroen Van Der
name: Shankar, Sushma
name: Friend, Peter
name: Harden, Paul
name: Wood, Kathryn
Publisher: name: F1000Research
Year: 2015

description: Columns A-F represent patient demographics; columns G-K initial immunosuppression; column L initial graft function; columns M-Q biopsy data; column R long-term outcomes.
Table 2 Gene expression Ct values for DUSP1, MAPK9, PBEF1 (NAMPT), NKTR, PSEN1 and the endogenous control HPRT
Creators: name: Betts, Gareth
name: Net, Jeroen Van Der
name: Shankar, Sushma
name: Friend, Peter
name: Harden, Paul
name: Wood, Kathryn
Publisher: name: F1000Research
Year: 2015

description: Data was collected in duplicate tubes and the average gene expression was determined. The average of HPRT expression was subtracted from the average gene expression of the target gene, to create ΔCt values for target genes. ΔΔCt values were subsequently derived by subtracting ΔCt of the preoperative time point from the ΔCt of the time point of interest: e.g. (AR time point ΔCt DUSP1) – (preoperative time point ΔCt DUSP1) = ΔΔCt DUSP1. ΔΔCt values were expressed as 2-ΔΔCt values.
Wide binaries in Planetary Nebulae with Gaia DR2
Creators: name: González-Santamaría, I.
name: Manteiga, M.
name: Manchado, A.
name: Gómez-Muñoz, M. A.
name: Ulla, A.
name: Dafonte, C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Gaia Data Release 2 (DR2) was used to select a sample of 211 central stars of planetary nebulae (CSPNe) with good quality astrometric measurements, that we refer to as GAPN, Golden Astrometry Planetary Nebulae. Gaia astrometric and photometric measurements allowed us to derive accurate distances and radii, and to calculate luminosities with the addition of self-consistent literature values. Such information was used to plot the position of these stars in a Hertzsprung-Russel (HR) diagram and to study their evolutionary status in comparison with CSPNe evolutionary tracks. The extremely precise measurement of parallaxes and proper motions in Gaia DR2 has allowed us to search for wide binary companions in a region close to each of the central stars in the GAPN sample. We limited our search to a region around 20,000 AU of each CSPN to minimise accidental detections, and only considered stars with good parallax and proper motions data, i.e. with errors below 30% in DR2. We determined that the hypothetical binary pairs should show a statistically significant agreement for the three astrometric quantities, i.e. parallax and both components of proper motions. We found 8 wide binary systems among our GAPN sample. One of them is in a triple system. We compiled the astrometric and photometric measurements of these binary systems and discussed them in comparison with previously published searches for binaries in PNe. By analysing the position in the HR diagram of the companion stars using Gaia photometry, we are able to estimatetheir temperatures, luminosities, masses and, for one star, the evolutionary age. The derived quantities yield a consistent scenario when compared with the corresponding values as obtained for the central stars using stellar evolutionary models in the postAGB phase.
Influence of unsymmetrical periodicity on extraordinary transmission through periodic arrays of subwavelength holes
Creators: name: Ren, Xi-Feng
name: Guo, Guo-Ping
name: Huang, Yun-Feng
name: Wang, Zhi-Wei
name: Guo, Guang-Can
Publisher: name: arXiv
Year: 2006
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Quadrate hole array is explored to study the influence of unsymmetrical periodicity on extraordinary optical transmission through periodic arrays of subwavelength holes. It is found that the transmission efficiency of light and the ratio between transmission efficiencies of horizontal and vertical polarized light can be continuously tuned by rotating the quadrate hole array. We can calculate out the transmission spectra (including the heights and locations of peaks) for any rotation angle $θ$ with a simple theoretical model.
description: 6 pages, 5 figures
A persistent quiet-Sun small-scale tornado III. Waves
Creators: name: Tziotziou, Kostas
name: Tsiropoula, Georgia
name: Kontogiannis, Ioannis
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Vortex flows can foster a variety of wave modes. A recent oscillatory analysis of a persistent 1.7 h vortex flow with a significant substructure has suggested the existence of various types of waves within it. We investigate the nature and characteristics of waves within this quiet-Sun vortex flow to better understand its physics and dynamics. We used a cross-wavelet spectral analysis between pairs of Ha and Ca II 8542 intensity time series at different wavelengths and, hence, atmospheric heights, acquired with CRISP/SST, as well as the derived Ha Doppler velocity and full width at half maximum (FWHM) time series. We constructed halftone frequency-phase difference plots and investigated the existence and propagation characteristics of different wave modes. Our analysis suggests the existence of upwards propagating Alfvenic type waves with phase speeds of ~20-30 km/s. The dominant wave mode seems to be the fast kink wave mode; however, our analysis also suggests the existence of localised Alfvenic torsional waves related to the dynamics of individual chromospheric swirls that characterise the substructure of the vortex flow. The Ha V-I phase difference analysis seems to imply the existence of a standing wave pattern possibly arising from the interference of upwards propagating kink waves with downwards propagating ones that are reflected at the transition region or the corona. Moreover, the results provide further evidence that the central chromospheric swirl drives the dynamics of the vortex flow. This is the first exhaustive phase difference analysis within a vortex flow that explores the nature and dynamics of different wave modes within it. The questions, however, of whether, and how, the dissipation of the derived wave modes occurs and if vortex flows ultimately play a role in the energy budget of the upper layers of the solar atmosphere remain open.
Nonlinear high-frequency magnetic response of magnetoferritin metacrystals governed by spin thermodynamics
Creators: name: Kavokin, K. V.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: A theory is developed of the time-dependent magnetization of the metacrystal composed of magnetoferritin macromolecules. Such superstructures, comprising up to several millions of superparamagnetic nanoparticles encapsulated in protein shells, can be created artificially using biochemical assembling technologies. They have been also shown to occur naturally in sensitive cells of the inner ear of birds, which suggests their possible involvement in the detection of the geomagnetic field for orientation and navigation of migratory animals. The dynamics of the magnetic system of the magnetoferritin metacrystal, comprising a very large number of magnetic moments coupled by long-range dipole forces, is exceedingly complex. In order to find the response of the metacrystal to high-frequency magnetic fields, we used a thermodynamic approach borrowed from the theory of nuclear spin systems of solids. The resulted theory yields the time-dependent superspin temperature and magnetization induced by oscillating magnetic fields of arbitrary strength. The predicted dependence of the high-frequency response on the static magnetic field can be used for experimental detection and characterization of magnetoferritin metacrystals in biological tissues.