cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Structures of the magnetoionic media around the FR I radio galaxies 3C 31 and Hydra A
Creators: name: Laing, R. A.
name: Bridle, A. H.
name: Parma, P.
name: Murgia, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use high-quality VLA images of the Fanaroff & Riley Class I radio galaxy 3C 31 at six frequencies in the range 1365 to 8440MHz to explore the spatial scale and origin of the rotation measure (RM) fluctuations on the line of sight to the radio source. We analyse the distribution of the degree of polarization to show that the large depolarization asymmetry between the North and South sides of the source seen in earlier work largely disappears as the resolution is increased. We show that the depolarization seen at low resolution results primarily from unresolved gradients in a Faraday screen in front of the synchrotron-emitting plasma. We establish that the residual degree of polarization in the short-wavelength limit should follow a Burn law and we fit such a law to our data to estimate the residual depolarization at high resolution. We show that the observed RM variations over selected areas of 3C 31 are consistent with a power spectrum of magnetic fluctuations in front of 3C 31 whose power-law slope changes significantly on the scales sampled by our data. The power spectrum can only have the form expected for Kolmogorov turbulence on scales <5 kpc. On larger scales we find a flatter slope. We also compare the global variations of RM across 3C 31 with the results of three-dimensional simulations of the magnetic-field fluctuations in the surrounding magnetoionic medium. We show that our data are consistent with a field distribution that favours the plane perpendicular to the jet axis - probably because the radio source has evacuated a large cavity in the surrounding medium. We also apply our analysis techniques to the case of Hydra A, where the shape and the size of the cavities produced by the source in the surrounding medium are known from X-ray data. (Abridged)
description: 33 pages, 25 figures, accepted for publication in MNRAS
The electronics and data acquisition system for the DarkSide-50 veto detectors
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2016
Subjects: Front-end electronics for detector readout
Data acquisition concepts
Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators)
Detector control systems (detector and experiment monitoring and slow control systems, architecture, hardware, algorithms, databases)

description: © 2016 IOP Publishing Ltd and Sissa Medialab srl. DarkSide-50 is a detector for dark matter candidates in the form of weakly interacting massive particles. It utilizes a liquid argon time projection chamber for the inner main detector, surrounded by a liquid scintillator veto (LSV) and a water Cherenkov veto detector (WCV). The LSV and WCV act as the neutron and cosmogenic muon veto detectors for DarkSide-50. This paper describes the electronics and data acquisition system used for these two detectors. The system is made of a custom built front end electronics and commercial National Instruments high speed digitizers. The front end electronics, the DAQ, and the trigger system have been used to acquire data in the form of zero-suppressed waveform samples from the 110 PMTs of the LSV and the 80 PMTs of the WCV. The veto DAQ system has proven its performance and reliability. This electronics and DAQ system can be scaled and used as it is for the veto of the next generation DarkSide-20k detector.
DBI-Curvaton
Creators: name: Li, Sheng
name: Cai, Yi-Fu
name: Piao, Yun-Song
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we study a curvaton model described by a Dirac-Born-Infeld-like action. We calculate the spectrum of curvature perturbation induced by DBI-curvaton and estimate its non-Gaussianity. We find that in the limit of low sound speed the amplitude of curvature perturbation is enhanced more than that in DBI inflation. This result also means that the inflationary scale with DBI-curvaton may be lower than that in usual curvaton model. In addition, we also find that the local non-Gaussianity level in DBI-curvaton is generally about 10 times larger than that in usual curvaton model, which is interesting for current observations. This work in some sense explores a new application of brane-cosmology in inflation.
description: 7 pages, several references added
Band structure effects on the Be(0001) acoustic-surface-plasmon energy dispersion
Creators: name: Silkin, V. M.
name: Pitarke, J. M.
name: Chulkov, E. V.
name: Diaconescu, B.
name: Pohl, K.
name: Vattuone, L.
name: Savio, L.
name: Hoffmann, Ph.
name: Farias, D.
name: Rocca, M.
name: Echenique, P. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report first-principles calculations of acoustic surface plasmons on the (0001) surface of Be, as obtained in the random-phase approximation of many-body theory. The energy dispersion of these collective excitations has been obtained along two symmetry directions. Our results show a considerable anisotropy of acoustic surface plasmons, and underline the capability of experimental measurements of these plasmons to {\it map} the electron-hole excitation spectrum of the quasi two-dimensional Shockley surface state band that is present on the Be(0001) surface.
description: 9 pages, 2 figures
Commuting integral and differential operators and the master symmetries of the Korteweg-de Vries equation
Creators: name: Grunbaum, F. Alberto
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 47A, 42A, 33C, 44A

description: The singular value decomposition going with many problems in medical imaging, non-destructive testing, geophysics, is of central importance. Unfortunately the effective numerical determination of the singular functions in question is a very ill-posed problem. The best known remedy to this problem goes back to the work of D. Slepian, H.Landau and H. Pollak, Bell Labs 1960-1965. We show that the master symmetries of the Korteweg-de Vries equation give a way to extend the remarkable result of D. Slepian in connection with the Bessel integral kernel and the existence of a differential operator that commutes with the corresponding integral operator. The original results of the Bell Labs group has already played an important role in the study of the limited angle problem in X-ray tomography as well as in Random Matrix theory.
Bianchi I with variable $G$ and $Λ$. Self-Similar approach
Creators: name: Belinchón, José Antonio
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper we study how to attack under the self-similarity hypothesis a perfect fluid Bianchi I model with variable $G,$and $Λ,$ but under the condition $\operatorname{div}T\neq0.$ We arrive to the conclusion that: $G$ and $Λ$ are decreasing time functions (the sing of $Λ$ depends on the equation of state), while the exponents of the scale factor must satisfy the conditions $\sum_{i=1}^{3}α_{i}=1$ and $\sum_{i=1}^{3}α_{i}^{2}<1,$ $\forallω\in(-1,1) ,$ relaxing in this way the Kasner conditions. We also show the connection between the behavior of $G$ and the Weyl tensor.
description: 15 pages. accepted in IJMPA
Sex Differences in Anthropometrics and Heading Kinematics Among Division I Soccer Athletes: A Pilot Study
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2017
Subjects: biomechanics
head injuries/concussion
neck strength
cervical musculature

description: © 2016, © 2016 The Author(s). Background: Soccer players head the ball repetitively throughout their careers; this is also a potential mechanism for a concussion. Although not all soccer headers result in a concussion, these subconcussive impacts may impart acceleration, deceleration, and rotational forces on the brain, leaving structural and functional deficits. Stronger neck musculature may reduce head-neck segment kinematics. Hypothesis: The relationship between anthropometrics and soccer heading kinematics will not differ between sexes. The relationship between anthropometrics and soccer heading kinematics will not differ between ball speeds. Study Design: Pilot, cross-sectional design. Level of Evidence: Level 3. Methods: Division I soccer athletes (5 male, 8 female) were assessed for head-neck anthropometric and neck strength measurements in 6 directions (ie, flexion, extension, right and left lateral flexions and rotations). Participants headed the ball 10 times (25 or 40 mph) while wearing an accelerometer secured to their head. Kinematic measurements (ie, linear acceleration and rotational velocity) were recorded at 2 ball speeds. Results: Sex differences were observed in neck girth (t = 5.09, P < 0.001), flexor and left lateral flexor strength (t = 3.006, P = 0.012 and t = 4.182, P = 0.002, respectively), and rotational velocity at both speeds (t = −2.628, P = 0.024 and t = −2.227, P = 0.048). Neck girth had negative correlations with both linear acceleration (r = −0.599, P = 0.031) and rotational velocity at both speeds (r = −0.551, P = 0.012 and r = −0.652, P = 0.016). Also, stronger muscle groups had lower linear accelerations at both speeds (P < 0.05). Conclusion: There was a significant relationship between anthropometrics and soccer heading kinematics for sex and ball speeds. Clinical Relevance: Neck girth and neck strength are factors that may limit head impact kinematics.
Position space method for the nucleon magnetic moment in lattice QCD
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2016
Subjects: hep-lat

description: © 2016 American Physical Society. The extraction of the magnetic form factor of the nucleon at zero momentum transfer is usually performed by adopting a parametrization for its momentum dependence and fitting the results obtained at finite momenta. We present a position space method that allows us to remove the momentum prefactor in the form factor decomposition and hence compute the magnetic form factor directly at zero momentum without the need to assume a functional form for its momentum dependence. The method is explored on one ensemble using Nf=2+1+1 Wilson twisted mass fermions with a light quark mass corresponding to Mπ=373 MeV and a lattice spacing of a≈0.082 fm. We obtain results for the isovector magnetic moment and for the proton and neutron magnetic moments. The value we find for the isovector magnetic moment is larger as compared to fitting the form factor at the discrete values of the lattice momentum transfers using a dipole Ansatz, bringing it closer to the experimental value.
Pulling back stability with applications to Out (F n) and relatively hyperbolic groups:
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2017
Subjects: math.GT
math.GR
math.MG

description: © 2017 London Mathematical Society. We prove that stability - a strong quasiconvexity property - pulls back under proper actions on proper metric spaces. This result has several applications, including that convex cocompact subgroups of both mapping class groups and outer automorphism groups of free groups are stable. We also characterize stability in relatively hyperbolic groups whose parabolic subgroups have linear divergence.
Signatures of gaugino mass non-universality in cascade Higgs production at the LHC
Creators: name: Bandyopadhyay, Priyotosh
name: Datta, AseshKrishna
name: Mukhopadhyaya, Biswarup
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Supersymmetric cascades, involving charginos and neutralinos at various stages, contribute in a significant way to Higgs production at the LHC. We explore the nature of such cascades, completely relaxing the universality of the gaugino masses. It is found that the deviation from the scenario with universal gaugino masses would be reflected in the relative production rates for the lightest Higgs and the charged Higgses, two characteristic particles of an extended Higgs sector.
description: 14 pages, 22 figures
Limb preference in the gallop of dogs and the half-bound of pikas on flat ground
Creators: name: Hackert, Rémi
name: Maes, Ludovic
name: Herbin, Marc
name: Abourachid, Anick
name: Libourel, P. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: During fast locomotion - gallop, half bound - of quadruped mammals, the ground contact of the limbs in each pair do not alternate symmetrically. Animals using such asymmetrical gait thus choose whether the left or the right limb will contact the ground first, and this gives rise to limb preference. Here, we report that dogs (Mammalia, Carnivora) and pikas (Mammalia, Lagomorpha) prefer one forelimb as trailing limb and use it as such almost twice as often as the other. We also show that this choice depends on the individual and is not a characteristic of the species, and that the strength of the preference was not dependent on the animal's running speed.
Organic metals : studies related to the synthesis of acceptors derived from TCNQ
Creators: name: Hammond, Gerald Bruce
Publisher: name: University of British Columbia
Year: 2010

description: Since a report that the complex of TTF.TCNQ showed novel solid state properties including high room temperature conductivity, there has been considerable interest in the study of these so called "organic metals." This thesis describes the synthesis of new acceptors derived from TCNQ. First the synthesis of 2-methoxycarbonyl-7,7,8,8-tetracyanoquino-dimethane (56) is presented. Bromination of methyl 2,5-dimethylbenzoate followed by treatment with sodium cyanide yielded the dicyano compound 60 which was converted to the dihydro-TCNQ 62 via the corresponding phenylenetetracyanodiacetate intermediate. Oxidation of 62 afforded 2-methoxycarbonyl-7,7,8,8-tetracyanoquinodimethane (56), which was found to be unstable. The synthesis of 2,3-dimethoxycarbonyl-7,7,8,8-tetra-cyanoquinodimethane was attempted in the following manner: the Diels-Alder cyclization of trans,trans-2,4-hexadiene and dimethyl acetylenedi-carboxylate followed by dehydrogenation of the adduct gave dimethyl 3,6-dimethylphthalate. Benzylic bromination of this material followed by displacement of the bromines by cyanide yielded the dicyano compound 73. However, several attempts to convert 73 to the corresponding tetraester 78 were unsuccessful. The synthesis of 2,3-dimethyl-7,7,8,8-tetracyanoquinodimethane is presented. The intermediate 2,3-dimethylcyclohexane-l,4-dione (87) was prepared from 2,3-dimethylphenol by standard means. It was then condensed with malononitrile, and the product was treated with bromine/pyridine to give the dihydro-DMTCNQ 89. When this compound was treated with a mixture of palladium and sulfur at 180°C the desired 2,3-dimethyl-TCNQ 83 was obtained in low yield. The second part of this thesis describes the preparation of 11,11, 12 ,12-tetracyano-4,5,9,10-tetrahydropyreno-2,7-quinodimethane (TCNTP) from mesitylene. This compound was bisbrominated to give 3,5-bis-(bromomethyl)toluene, which was then coupled with 3,5-bis(mercaptomethyl)-toluene to produce the dithia[3.3jmetacyclophane 98. This was converted to the dimethyl[2.2]metacyclophane 96 via Wittig rearrangement followed by reduction with lithium in liquid ammonia. This cyclophane was then brominated and the resulting dibromo compound was converted to the corresponding dicyano-94. The latter compound was treated with bromine in the presence of iron powder to produce 2,7-bis(cyanomethyl)-4,5,9,10-tetrahydropyrene. Introduction of the remaining two nitrile groups was accomplished via use of the tetracyanodiacetate intermediate 92. Hydrolysis and decarboxylation of 92 followed by oxidation with NBS/triethylamine at -78°C furnished the desired TCNTP (90).
Metal Coupled Folding of Cys2His2 Zinc-Finger
Creators: name: Li, Wenfei
name: Zhang, Jian
name: Wang, Jun
name: Wang, Wei
Publisher: name: arXiv
Year: 2008
Subjects: subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: Zinc-fingers, which widely exist in eukaryotic cell and play crucial roles in life processes, depend on the binding of zinc ion for their proper folding. To computationally study the zinc coupled folding of the zinc-fingers, charge transfer and metal induced protonation/deprotonation effects have to be considered. Here, by attempting to implicitly account for such effects in classical molecular dynamics and performing intensive simulations with explicit solvent for the peptides with and without zinc binding, we investigate the folding of the Cys2His2 type zinc-finger motif and the coupling between the peptide folding and zinc binding. We find that zinc ion not only stabilizes the native structure, but also participates in the whole folding process. It binds to the peptide at early stage of folding, and directs or modulates the folding and stabilizations of the component beta-hairpin and alpha-helix. Such a crucial role of zinc binding is mediated by the packing of the conserved hydrophobic residues. We also find that the packing of the hydrophobic residues and the coordination of the native ligands are coupled. Meanwhile, the processes of zinc binding, mis-ligation, ligand exchange and zinc induced secondary structure conversion, as well as the water behaviour, due to the involvement of zinc ion are characterized. Our results are in good agreement with related experimental observations, and provide significant insight into the general mechanisms of the metal-cofactor dependent protein folding and other metal induced conformational changes of biological importance.
description: 26 pages
When efficient star formation drives cluster formation
Creators: name: Parmentier, G.
name: Fritze, U.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the impact of the star formation efficiency in cluster forming cores on the evolution of the mass in star clusters over the age range 1-100Myr, when star clusters undergo their infant weight-loss/mortality phase. Assuming a constant formation rate of gas-embedded clusters and a weak tidal field, we show that the ratio between the total mass in stars bound to the clusters over that age range and the total mass in stars initially formed in gas-embedded clusters is a strongly increasing function of the averaged local SFE, with little influence from any assumed core mass-radius relation. Our results suggest that, for young starbursts with estimated tidal field strength and known recent star formation history, observed cluster-to-star mass ratios, once corrected for the undetected clusters, constitute promising probes of the local SFE, without the need of resorting to gas mass estimates. Similarly, the mass ratio of stars which remain in bound clusters at the end of the infant mortality/weight-loss phase depends sensitively on the mean local SFE, although the impacts of the width of the SFE distribution function and of the core mass-radius relation require more careful assessment in this case. Following the recent finding by Bastian (2008) that galaxies form, on the average, 8% of their stars in bound clusters regardless of their star formation rate, we raise the hypothesis that star formation in the present-day Universe is characterized by a near-universal distribution for the local SFE. A related potential application of our model consists in tracing the evolution of the local SFE over cosmological lookback times by comparing the age distribution of the total mass in star clusters to that in field stars. We describe model aspects which are still to be worked out before achieving this goal.
description: 8 pages, accepted in ApJ
J-PLUS: A first glimpse at spectrophotometry of asteroids -- The MOOJa catalog
Creators: name: Morate, David
name: Carvano, Jorge Marcio
name: Alvarez-Candal, Alvaro
name: De Prá, Mário
name: Licandro, Javier
name: Galarza, Andrés
name: Mahlke, Max
name: Solano-Márquez, Enrique
name: Cenarro, Javier
name: Cristóbal-Hornillos, David
name: Hernández-Monteagudo, Carlos
name: López-Sanjuan, Carlos
name: Marín-Franch, Antonio
name: Moles, Mariano
name: Varela, Jesús
name: Ramió, Héctor Vázquez
name: Alcaniz, Jailson
name: Dupke, Renato
name: Ederoclite, Alessandro
name: de Oliveira, Claudia Mendes
name: 10, Laerte Sodré Jr.
name: Angulo, Raul E.
name: Jiménez-Esteban, Francisco M.
name: Siffert, Beatriz B.
name: collaboration, the J-PLUS
Publisher: name: arXiv
Year: 2021
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Context: The Javalambre Photometric Local Universe Survey (J-PLUS) is an observational campaign that aims to obtain photometry in 12 ultraviolet-visible filters (0.3-1 μm) of approximately 8 500 deg{^2} of the sky observable from Javalambre (Teruel, Spain). Due to its characteristics and strategy of observation, this survey will let us analyze a great number of Solar System small bodies, with improved spectrophotometric resolution with respect to previous large-area photometric surveys in optical wavelengths. Aims: The main goal of this work is to present here the first catalog of magnitudes and colors of minor bodies of the Solar System compiled using the first data release (DR1) of the J-PLUS observational campaign: the Moving Objects Observed from Javalambre (MOOJa) catalog. Methods: Using the compiled photometric data we obtained very-low-resolution reflectance (photospectra) spectra of the asteroids. We first used a σ-clipping algorithm in order to remove outliers and clean the data. We then devised a method to select the optimal solar colors in the J-PLUS photometric system. These solar colors were computed using two different approaches: on one hand, we used different spectra of the Sun, convolved with the filter transmissions of the J-PLUS system, and on the other, we selected a group of solar-type stars in the J-PLUS DR1, according to their computed stellar parameters. Finally, we used the solar colors to obtain the reflectance spectra of the asteroids. Results: We present photometric data in the J-PLUS filters for a total of 3 122 minor bodies (3 666 before outlier removal), and we discuss the main issues of the data, as well as some guidelines to solve them
High domain wall velocities due to spin currents perpendicular to the plane
Creators: name: Khvalkovskiy, A. V.
name: Zvezdin, K. A.
name: Gorbunov, Ya. V.
name: Cros, V.
name: Grollier, J.
name: Zvezdin, A. K.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We consider long and narrow spin valves composed of a first magnetic layer with a single domain wall (DW), a normal metal spacer and a second magnetic layer that is a planar or a perpendicular polarizer. For these structures, we study numerically DW dynamics taking into account the spin torques due to the perpendicular spin currents. We obtain high DW velocities: 50 m/s for planar polarizer and 640 m/s for perpendicular polarizer for J = 5*10^6 A/cm^2. These values are much larger than those predicted and observed for DW motion due to the in-plane spin currents. The ratio of the magnitudes of the torques, which generate the DW motion in the respective cases, is responsible for these large differences.
description: 10 pages, 2 figures
title: Frontmatter, Table of Contents, Preface, Conference Organization, External Reviewers
Creators: name: Chakraborty, Supratik
name: Kumar, Amit
Publisher: name: Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Year: 2011
Subjects: subject: Frontmatter
subject: Table of Contents
subject: Preface
subject: Conference Organization
subject: External Reviewers

description: Frontmatter, Table of Contents, Preface, Conference Organization, External Reviewers
description: LIPIcs, Vol. 13, IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2011), pages i-xv
Effects of dark matter annihilation on the first stars
Creators: name: Iocco, F.
name: Bressan, A.
name: Ripamonti, E.
name: Schneider, R.
name: Ferrara, A.
name: Marigo, P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the evolution of the first stars in the universe (Population III) from the early pre-Main Sequence until the end of helium burning in the presence of WIMP dark matter annihilation inside the stellar structure. The two different mechanisms that can provide this energy source are the contemporary contraction of baryons and dark matter, and the capture of WIMPs by scattering off the gas with subsequent accumulation inside the star. We find that the first mechanism can generate an equilibrium phase, previously known as a "dark star", which is transient and present in the very early stages of pre-MS evolution. The mechanism of scattering and capture acts later, and can support the star virtually forever, depending on environmental characteristic of the dark matter halo and on the specific WIMP model.
description: Proceedings of the IAU Symposium 255, "Low-Metallicity Star Formation: From the First Stars to Dwarf Galaxies"; L.K. Hunt, S. Madden and R. Schneider eds
Polar dust obscuration in broad-line active galaxies from the XMM-XXL field
Creators: name: Buat, V.
name: Mountrichas, G.
name: Yang, G.
name: Boquien, M.
name: Roehlly, Y.
name: Burgarella, D.
name: Stalevski, M.
name: Ciesla, L.
name: Theulé, P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Dust is observed in the polar regions of nearby AGN and it is known to contribute substantially to their mid-IR emission and to the obscuration of their UV to optical emission. We selected a sample of 1275 BLAGN in the XMM-XXL field, with optical to infrared photometric data. These AGN are seen along their polar direction and we expect a maximal impact of dust located around the poles when it is present. We used X-CIGALE, which introduces a dust component to account for obscuration along the polar directions, modeled as a foreground screen, and an extinction curve that is chosen as it steepens significantly at short wavelengths or is much grayer. By comparing the results of different fits, we are able to define subsamples of sources with positive statistical evidence in favor of or against polar obscuration and described using the gray or steep extinction curve. We find a similar fraction of sources with positive evidence for and against polar dust. Applying statistical corrections, we estimate that half of our sample could contain polar dust and among them, 60% exhibit a steep extinction curve and 40% a flat extinction curve; although these latter percentages are found to depend on the adopted extinction curves. The obscuration in the V-band is not found to correlate with the X-ray column density, while A_V/N_H ratios span a large range of values and higher dust temperatures are found with the flat, rather than with the steep extinction curve. Ignoring this polar dust component in the fit of the spectral energy distribution of these composite systems leads to an overestimation of the stellar contribution. A single fit with a polar dust component described with an SMC extinction curve efficiently overcomes this issue but it fails at identifying all the AGN with polar dust obscuration.
description: 12 pages, 11 figures, accepted for publication in Astronomy & Astrophysics
Toeplitz operators on symplectic manifolds
Creators: name: Ma, Xiaonan
name: Marinescu, George
Publisher: name: arXiv
Year: 2008
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: Complex Variables (math.CV)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 58F06; 81S10;32A25;47B35

description: We study the Berezin-Toeplitz quantization on symplectic manifolds making use of the full off-diagonal asymptotic expansion of the Bergman kernel. We give also a characterization of Toeplitz operators in terms of their asymptotic expansion. The semi-classical limit properties of the Berezin-Toeplitz quantization for non-compact manifolds and orbifolds are also established.
description: 40 pages
Long-Term Evolution of Magnetic Fields in Flaring Active Region NOAA 12673
Creators: name: Muhamad, Johan
name: Nurzaman, Muhamad Zamzam
name: Dani, Tiar
name: Pamutri, Arun Relung
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: During the lifetime of AR 12673, its magnetic field evolved drastically and produced numerous large flares. In this study, using full maps of the Sun observed by the Solar Dynamics Observatory and the Solar Terrestrial Relations Observatory, we identified that AR 12673 emerged in decayed AR 12665, which had survived for two solar rotations. Although both ARs emerged at the same location, they possessed different characteristics and different flare productivities. Therefore, it is important to study the long-term magnetic evolution of both ARs to identify the distinguishing characteristics of an AR that can produce large solar flares. We used the Spaceweather Helioseismic and Magnetic Imager Active Region Patch data to investigate the evolution of the photospheric magnetic field and other physical properties of the recurring ARs during five Carrington rotations. All these investigated parameters dynamically evolved through a series of solar rotations. We compared the long-term evolution of AR 12665 and AR 12673 to understand the differences in their flare-producing properties. We also studied the relation of the long-term evolution of these ARs with the presence of active longitude. We found that the magnetic flux and complexity of AR 12673 developed much faster than those of AR 12665. Our results confirmed that a strong emerging flux that emerged in the pre-existing AR near the active longitude created a very strong and complex AR that produced large flares.
description: Accepted in Research in Astronomy and Astrophysics
EMPLOYING INTERACTIVE TECHNIQUES IN THE INSTRUCTION OF ENGLISH FOR MECHANICAL ENGINEERING STUDENTS
Creators: name: Omonova, Laylo
Publisher: name: Zenodo
Year: 2025

description: This article explores the implementation of interactive techniques in the instruction of English for Mechanical Engineering students. As the global landscape increasingly demands proficiency in English, particularly in technical fields, adopting teaching methodologies that enhance engagement and comprehension becomes essential. The study investigates various interactive strategies, including collaborative learning, role-playing, and technology-integrated activities, to foster a more dynamic learning environment. Through qualitative and quantitative analyses, the effectiveness of these techniques is evaluated in terms of student participation, motivation, and language acquisition. Insights from this research highlight the importance of creating a learner-centered classroom that not only improves English language skills but also equips students with the necessary communication abilities to succeed in their engineering careers.
Unsupervised Image Segmentation by Mutual Information Maximization and Adversarial Regularization
Creators: name: Mirsadeghi, S. Ehsan
name: Royat, Ali
name: Rezatofighi, Hamid
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Semantic segmentation is one of the basic, yet essential scene understanding tasks for an autonomous agent. The recent developments in supervised machine learning and neural networks have enjoyed great success in enhancing the performance of the state-of-the-art techniques for this task. However, their superior performance is highly reliant on the availability of a large-scale annotated dataset. In this paper, we propose a novel fully unsupervised semantic segmentation method, the so-called Information Maximization and Adversarial Regularization Segmentation (InMARS). Inspired by human perception which parses a scene into perceptual groups, rather than analyzing each pixel individually, our proposed approach first partitions an input image into meaningful regions (also known as superpixels). Next, it utilizes Mutual-Information-Maximization followed by an adversarial training strategy to cluster these regions into semantically meaningful classes. To customize an adversarial training scheme for the problem, we incorporate adversarial pixel noise along with spatial perturbations to impose photometrical and geometrical invariance on the deep neural network. Our experiments demonstrate that our method achieves the state-of-the-art performance on two commonly used unsupervised semantic segmentation datasets, COCO-Stuff, and Potsdam.
Enlightening the structure and dynamics of Abell 1942
Creators: name: Capelato, H. V.
name: Proust, D.
name: Neto, G. B. LIma
name: Santos, W. A.
name: Sodre, L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a dynamical analysis of the galaxy cluster Abell 1942 based on a set of 128 velocities obtained at the European Southern Observatory. Data on individual galaxies are presented and the accuracy of the determined velocities is discussed as well as some properties of the cluster. We have also made use of publicly available Chandra X-ray data. We obtained an improved mean redshift value z = 0.22513 \pm 0.0008 and velocity dispersion sigma = 908^{+147}_{-139} km/s. Our analysis indicates that inside a radius of ~1.5 h_{70}^{-1} Mpc (~7 arcmin) the cluster is well relaxed, without any remarkable feature and the X-ray emission traces fairly well the galaxy distribution. Two possible optical substructures are seen at ~5 arcmin from the centre towards the Northwest and the Southwest direction, but are not confirmed by the velocity field. These clumps are however, kinematically bound to the main structure of Abell 1942. X-ray spectroscopic analysis of Chandra data resulted in a temperature kT = 5.5 \pm 0.5 keV and metal abundance Z = 0.33 \pm 0.15 Z_odot. The velocity dispersion corresponding to this temperature using the T_X-sigma scaling relation is in good agreement with the measured galaxies velocities. Our photometric redshift analysis suggests that the weak lensing signal observed at the south of the cluster and previously attributed to a "dark clump", is produced by background sources, possibly distributed as a filamentary structure.
description: Accepted for publication in Astronomy & Astrophysics, 15 pages, 15 figures, table w/ positions, photometric data and redshifts
Energetic particle transport in optimized stellarators
Creators: name: Bader, A
name: Anderson, D T
name: Drevlak, M
name: Faber, B J
name: Hegna, C C
name: Henneberg, S
name: Landreman, M
name: Schmitt, J C
name: Suzuki, Y
name: Ware, A
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Nine stellarator configurations, three quasiaxisymmetric, three quasihelically symmetric and three non-quasisymmetric are scaled to ARIES-CS size and analyzed for energetic particle content. The best performing configurations with regard to energetic particle confinement also perform the best on the neoclassical Γc metric, which attempts to align contours of the second adiabatic invariant with flux surfaces. Quasisymmetric configurations that simultaneously perform well on Γc and quasisymmetry have the best overall confinement, with collisional losses under 3%, approaching the performance of ITER with ferritic inserts.
description: 18 pages, 10 figures, 1 Table
YANGI O'ZBEKISTONDA FUQAROLIK JAMIYATI INSTITUTLARI SHAKLLANISHINING SIYOSIY-HUQUQIY ASOSLARI
Creators: name: Xojageldiev, Abatbay
Publisher: name: Zenodo
Year: 2023

description: Mazkur maqolada bugungi kunda O‘zbekistonda demokratik huquqiy davlat va adolatli fuqarolik jamiyatini barpo etishning ahamiyati, ustuvor yo‘nalishlari haqida so‘z etilgan. Yangi O‘zbekistonda fuqarolik jamiyati institutlari shakllanishining siyosiy-huquqiy asoslari yoritib berilgan.
D-Branes on C^3_6 part I: prepotential and GW-invariants
Creators: name: Cacciatori, Sergio Luigi
name: Compagnoni, Marco
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This is the first of a set of papers having the aim to provide a detailed description of brane configurations on a family of noncompact threedimensional Calabi-Yau manifolds. The starting point is the singular manifold C^3/Z_6, which admits five distinct crepant resolutions. Here we apply local mirror symmetry to partially determine the prepotential encoding the GW-invariants of the resolved varieties. It results that such prepotential provides all numbers but the ones corresponding to curves having null intersection with the compact divisor. This is realized by means of a conjecture, due to S. Hosono, so that our results provide a check confirming at least in part the conjecture.
description: 66 pages, 18 figures, 15 tables; added references
Use of camphor in terpenoid syntheses
Creators: name: Lamb, Nancy Ching-Yun
Publisher: name: University of British Columbia
Year: 2010

description: Camphor has been functionalised at the C(5), C(6), C(8) and C(9) positions by procedures previously developed and the corresponding derivatives have subsequently been utilised as key intermediates in mono- and sesquiterpenoid syntheses. The monoterpenoid analogues of the plant growth-promotor (-)-cis-sativenediol and the growth-inhibitor (-)-helminthosporal, (-)-5-exo, 6-exo-dihydroxycamphene and (+)-1,4-diformyl-2,3,3-trimethylcyclopentene respectively, have been prepared from (-)-camphor by a synthetic route involving the 'remote oxidation' of (+)-isobornyl acetate to a mixture of 5- and 6-oxoisobornyl acetates. The trans-diol (-)-5-endo, 6-exo-dihydroxycamphene was also obtained during this study. The synthetic monoterpenoids and their enantiomers were found to be devoid of growth-promoting or growth-inhibiting properties on two varieties of rice (Oryza sativa). The 'remote oxidation' technique has also been applied to the synthesis of nojigiku alcohol [(+)-6-exo-hydroxycamphene], a metabolite of Chrysanthemum japonense, from (+)-camphor. The structure, absolute configuration, and physical constants of this monoterpenoid alcohol and its derivatives have thus been established. (+)-9-Bromocamphor was used as a starting material for two unsuccessful synthetic approaches to the trisnorsesquiterpenoid albene, a metabolite of plants of the genera Petasites albus (L.) Gearth and Adenostyles alliariae (G.) Kern. One of these routes was based on the proposal that epi-β- santalene, a natural sesquiterpenoid which had previously been synthesised in our laboratory, could be a biosynthetic precursor of albene. However, during these investigations the original structure of albene was revised and a third synthetic route to this compound using (+)-8-bromocamphor as starting material was therefore studied. (+)-8-Bromocamphor has also been utilised as the starting material in a synthetic approach to clausantalene, a sesquiterpenoid isolated from Clausena indica 0liv. (Rutaceae). A synthesis of dehydroclausantalene and epidehydroclausantalene T_9-hydroxy-9-(3' -methyl-V -butenyl )camphenes] has been accomplished but the regio- and stereoselective hydration of these two compounds to clausantalene and its epimer respectively is still under investigation.
Density analysis for estimating the degree of on-site correlation on transition-metal atoms in extended systems
Creators: name: Kalantari, Leila
name: Tran, Fabien
name: Blaha, Peter
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In the context of the modified Becke-Johnson (mBJ) potential, we recently underlined that $\bar{g}$, the average of $\left\vert\nablaρ\right\vert/ρ$ in the unit cell, has markedly different values in transition-metal oxides and pure transition metals [Tran et al., J. Appl. Phys. 126, 110902 (2019)]. However, since $\bar{g}$ is a constant it is not able to provide local information about a particular atom in the system. Furthermore, while $\overline{g}$ can be used only for periodic bulk solids, a local (i.e., position-dependent) version would allow us to consider also low-dimensional systems and interfaces. Such a local function has been proposed by Rauch et al. [J. Chem. Theory Comput. 16, 2654 (2020)] for the local mBJ potential. Actually, a local version of $\overline{g}$, or of another similar quantity like the reduced density gradient $\overline{s}$, could also be used in the framework of other methods. Here, we explored the idea to use such a local function $\tilde{g}$ (or $\tilde{s}$), defined as the average of $g$ (or $s$) over a certain region around a transition-metal atom, to estimate the degree of on-site correlation on this atom. We found a large difference in our correlation estimators between non-correlated and correlated materials, proving its usefulness and reliability. Our estimators can subsequently be used to determine whether or not a Hubbard $U$ on-site correction in the DFT+$U$ method should be applied to a particular atom. This is particularly interesting in cases where the degree of correlation of the transition-metal atoms is not clear, like interfaces between correlated and non-correlated materials or oxygen-covered metal surfaces. In such cases, our estimators could also be used for an interpolation of $U$ between correlated and non-correlated atoms.
Quantum control of the tin-vacancy spin qubit in diamond
Creators: name: Debroux, Romain
name: Michaels, Cathryn P.
name: Purser, Carola M.
name: Wan, Noel
name: Trusheim, Matthew E.
name: Martínez, Jesús Arjona
name: Parker, Ryan A.
name: Stramma, Alexander M.
name: Chen, Kevin C.
name: de Santis, Lorenzo
name: Alexeev, Evgeny M.
name: Ferrari, Andrea C.
name: Englund, Dirk
name: Gangloff, Dorian A.
name: Atatüre, Mete
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Group-IV color centers in diamond are a promising light-matter interface for quantum networking devices. The negatively charged tin-vacancy center (SnV) is particularly interesting, as its large spin-orbit coupling offers strong protection against phonon dephasing and robust cyclicity of its optical transitions towards spin-photon entanglement schemes. Here, we demonstrate multi-axis coherent control of the SnV spin qubit via an all-optical stimulated Raman drive between the ground and excited states. We use coherent population trapping and optically driven electronic spin resonance to confirm coherent access to the qubit at 1.7 K, and obtain spin Rabi oscillations at a rate of $Ω/2π$=3.6(1) MHz. All-optical Ramsey interferometry reveals a spin dephasing time of $T_2^*$=1.3(3)$μ$s and two-pulse dynamical decoupling already extends the spin coherence time to $T_2$=0.33(14) ms. Combined with transform-limited photons and integration into photonic nanostructures, our results make the SnV a competitive spin-photon building block for quantum networks.
Exact solution for the simplest binary system of Kerr black holes
Creators: name: Manko, V. S.
name: Rodchenko, E. D.
name: Ruiz, E.
name: Sadovnikov, B. I.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The full metric describing two counter-rotating identical Kerr black holes separated by a massless strut is derived in the explicit analytical form. It contains three arbitrary parameters which are the Komar mass M, Komar angular momentum per unit mass a of one of the black holes (the other has the same mass and equal but opposite angular momentum) and the coordinate distance R between the centers of the horizons. In the limit of extreme black holes, the metric becomes a special member of the Kinnersly-Chitre five-parameter family of vacuum solutions generalizing the Tomimatsu-Sato delta=2 spacetime, and we present the complete set of metrical fields defining this limit.
description: 9 pages, 1 figure, typos corrected, a footnote on p.6 extended
Estimation of the lowest limit of 1/f noise in semiconductor materials
Creators: name: Grueneis, Ferdinand
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: A lowest limit of 1/f noise in semiconductor materials has not yet been reported; we do not even know if such a lowest limit exists. 1/f noise in semiconductors has recently been brought into relation with 1/f noise in quantum dots and other materials. These materials exhibit on-off states which are power-law distributed over a wide range of timescales. We transfer such findings to semiconductors, assuming that the g-r process is also controlled by such on-off states. As a result, we obtain 1/f noise which can be expressed in the form of the Hooge relation. Based on the intermittent g-r process, we estimate the lowest limit of 1/f noise in semiconductor materials. We show that this limit is inversely proportional to the dopant concentration; to detect the lowest limit of 1/f noise, the number of centers should be as small as possible. We also find a smooth dependence of 1/f noise and g-r noise on time.
description: 10 pages, 9 figures. arXiv admin note: substantial text overlap with arXiv:2108.07155
Coexistence of amplitude and frequency modulations in intracellular calcium dynamics
Creators: name: De Pitta, Maurizio
name: Volman, Vladislav
name: Levine, Herbert
name: Pioggia, Giovanni
name: De Rossi, Danilo
name: Ben-Jacob, Eshel
Publisher: name: arXiv
Year: 2008
Subjects: subject: Cell Behavior (q-bio.CB)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Biological sciences

description: The complex dynamics of intracellular calcium regulates cellular responses to information encoded in extracellular signals. Here, we study the encoding of these external signals in the context of the Li-Rinzel model. We show that by control of biophysical parameters the information can be encoded in amplitude modulation, frequency modulation or mixed (AM and FM) modulation. We briefly discuss the possible implications of this new role of information encoding for astrocytes.
description: 4 pages, 4 figures