cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Sobre evaluación del aprendizaje / On Assessment for Learning
Creators: name: Amorós Poveda, Lucía
Publisher: name: UC del Maule
Year: 2007

description: English below

Estudio teórico del significado de evaluar aportando pinceladas para comprender la evaluación del aprendizaje en el contexto de una sociedad marcada por las nuevas tecnologías. Tomando como punto de partida la evaluación formal se llega a asumir la evaluación como proceso complejo, integral y constructivo. El soporte principal toma un modelo de evaluación democrática. En un segundo momento se trabaja sobre la evaluación de tecnologías recurriendo al enfoque Ciencia, Tecnología y Sociedad (CTS). Desde él se avanza hacia la evaluación  con medios en la enseñanza, incidiendo en aplicaciones con hipermedia, sus ventajas, limitaciones y estrategias de enseñanza dirigidas al aprendizaje.

 

Theoretical study of the meaning of evaluation, providing insights to understand the evaluation of learning in the context of a society marked by new technologies. Taking formal assessment as a starting point, we come to see assessment as a complex, comprehensive and constructive process. The main support takes a model of democratic evaluation. In a second stage, work is done on the evaluation of technologies using the Science, Technology and Society (STS) approach. From there, we move on to evaluation with media in teaching, focusing on hypermedia applications, their advantages, limitations and teaching strategies aimed at learning.
Showers with both northern and southern solutions
Creators: name: Neslušan, L.
name: Jopek, T. J.
name: Rudawska, R.
name: Hajduková, M.
name: Kokhirova, G.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Meteoroids of a low-inclination stream hit the Earth arriving from a direction near the ecliptic. The radiant area of stream like this is often divided into two parts: one is situated northward and the other southward of the ecliptic. In other words, two showers are caused by such a stream. Well-known examples of such showers are the Northern Taurids, #17, and Southern Taurids, #2, or the Northern $δ$-Aquariids, #26, and Southern $δ$-Aquariids, #5. While the meteoroids of the northern shower collide with the Earth in the descending node, those of the southern shower collide with our planet in the ascending node of their orbits. Because of this circumstance and tradition, the northern and southern showers must be distinguished. Unfortunately, this is not always the case with meteor showers listed in the IAU Meteor Data Center (MDC). For the same shower, some authors reported a set of its mean parameters corresponding to the northern shower and other authors to the southern shower. We found eleven such cases in the MDC. In this paper, we propose corrections of these mis-identifications.
description: Accepted: Planetary and Space Science
MPEC 2023-R219 : 2023 PS2
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 PS2

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
A global view of velocity fluctuations in the corona below 1.3 $R_\odot$ with CoMP
Creators: name: Morton, R. J.
name: Tomczyk, S.
name: Pinto, R. F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The Coronal Multi-channel Polarimeter (CoMP) has previously demonstrated the presence of Doppler velocity fluctuations in the solar corona. The observed fluctuations are thought to be transverse waves, i.e. highly incompressible motions whose restoring force is dominated by the magnetic tension, some of which demonstrate clear periodicity. We aim to exploit CoMP's ability to provide high cadence observations of the off-limb corona to investigate the properties of velocity fluctuations in a range of coronal features, providing insight into how(if) the properties of the waves are influenced by the varying magnetic topology in active regions, quiet Sun and open fields regions. An analysis of Doppler velocity time-series of the solar corona from the $10,747$~Å Iron XIII line is performed, determining the velocity power spectra and using it as a tool to probe wave behaviour. Further, the average phase speed and density for each region are estimated and used to compute the spectra for energy density and energy flux. In addition, we assess the noise levels associated with the CoMP data, deriving analytic formulae for the uncertainty on Doppler velocity measurements and providing a comparison by estimating the noise from the data. It is found that the entire corona is replete with transverse wave behaviour. The corresponding power spectra indicates that the observed velocity fluctuations are predominately generated by stochastic processes, with the spectral slope of the power varying between the different magnetic regions. Most strikingly, all power spectra reveal the presence of enhanced power occurring at $ \sim3$~mHz, potentially implying that the excitation of coronal transverse waves by $p$-modes is a global phenomenon.
description: Accepted in ApJ
On the Origin of Non-Saturating Linear Magnetoresistivity
Creators: name: Kisslinger, Ferdinand
name: Ott, Christian
name: Weber, Heiko B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The observation of non-saturating classical linear magnetoresistivity has been an enigmatic phenomenon in solid state physics. We present a study of a two-dimensional ohmic conductor, including local Hall effect and a self-consistent consideration of the environment. An equivalent-circuit scheme delivers a simple and convincing argument why the magnetoresistivity is linear in strong magnetic field, provided that current and biasing electric field are misaligned by a nonlocal mechanism. A finite-element model of a two-dimensional conductor is suited to display the situations that create such deviating currents. Besides edge effects next to electrodes, charge carrier density fluctuations are efficiently generating this effect. However, mobility fluctuations that have frequently been related to linear magnetoresistivity are barely relevant. Despite its rare observation, linear magnetoresitivity is rather the rule than the exception in a regime of low charge carrier densities, misaligned current pathways and strong magnetic field.
description: One Manuscript incl. 9 pages manuscript and 8 pages supporting information
Cross-linker design determines microtubule network organization by opposing motors.
Creators: name: Henkin, Gil
name: Chew, Wei-Xiang
name: Nédélec, François
name: Surrey, Thomas
Publisher: name: The Francis Crick Institute
Year: 2022
Subjects: Synthetic Biology
Imaging
Structural Biology & Biophysics
Cell Biology
Computational & Systems Biology

description: During cell division, cross-linking motors determine the architecture of the spindle, a dynamic microtubule network that segregates the chromosomes in eukaryotes. It is unclear how motors with opposite directionality coordinate to drive both contractile and extensile behaviors in the spindle. Particularly, the impact of different cross-linker designs on network self-organization is not understood, limiting our understanding of self-organizing structures in cells but also our ability to engineer new active materials. Here, we use experiment and theory to examine active microtubule networks driven by mixtures of motors with opposite directionality and different cross-linker design. We find that although the kinesin-14 HSET causes network contraction when dominant, it can also assist the opposing kinesin-5 KIF11 to generate extensile networks. This bifunctionality results from HSET's asymmetric design, distinct from symmetric KIF11. These findings expand the set of rules underlying patterning of active microtubule assemblies and allow a better understanding of motor cooperation in the spindle.
3D WKB solution for fast magnetoacoustic wave behaviour around an X-line
Creators: name: McLaughlin, J. A.
name: Botha, G. J. J.
name: Regnier, S.
name: Spoors, D. L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study the propagation of a fast magnetoacoustic wave in a 3D magnetic field created from two magnetic dipoles. The magnetic topology contains an X-line. We aim to contribute to the overall understanding of MHD wave propagation within inhomogeneous media, specifically around X-lines. We investigate the linearised, 3D MHD equations under the assumptions of ideal and cold plasma. We utilise the WKB approximation and Charpit's method during our investigation. It is found that the behaviour of the fast magnetoacoustic wave is entirely dictated by the local, inhomogeneous, equilibrium Alfvén speed profile. All parts of the wave experience refraction during propagation, where the magnitude of the refraction effect depends on the location of an individual wave element within the inhomogeneous magnetic field. The X-line, along which the Alfvén speed is identically zero, acts as a focus for the refraction effect. There are two main types of wave behaviour: part of the wave is either trapped by the X-line or escapes the system, and there exists a critical starting region around the X-line that divides these two types of behaviour. For the set-up investigated, it is found that $15.5\%$ of the fast wave energy is trapped by the X-line. We conclude that linear, $β=0$ fast magnetoacoustic waves can accumulate along X-lines and thus these will be specific locations of fast wave energy deposition and thus preferential heating. The work here highlights the importance of understanding the magnetic topology of a system. We also demonstrate how the 3D WKB technique described in this paper can be applied to other magnetic configurations.
description: 16 pages, 11 figures
Demystifying the Command line (Arabic)
Creators: name: Almarzouq, Batool
Publisher: name: Zenodo
Year: 2022
Subjects: open science
CC-BY
open educational resources
version control
git

description: This is a very short introduction (50 mins) to the command line for beginners to help them navigate the terminal and start using git (in Arabic). It was delivered by Batool Almarzouq to JeelAIDM students. You can access the presentation using this link.
Catching a nova X-ray/UV flash in the visible? Early spectroscopy of the extremely slow Nova Velorum 2022 (Gaia22alz)
Creators: name: Aydi, E.
name: Chomiuk, L.
name: Mikołajewska, J.
name: Brink, J.
name: Metzger, B. D.
name: Strader, J.
name: Buckley, D. A. H.
name: Harvey, E. J.
name: Holoien, T. W. -S.
name: Izzo, L.
name: Kawash, A.
name: Linford, J. D.
name: Molaro, P.
name: Mollina, B.
name: Mróz, P.
name: Mukai, K.
name: Orio, M.
name: Panurach, T.
name: Senchyna, P.
name: Shappee, B. J.
name: Shen, K. J.
name: Sokoloski, J. L.
name: Sokolovsky, K. V.
name: Urquhart, R.
name: Williams, R. E.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present early spectral observations of the very slow Galactic nova Gaia22alz, over its gradual rise to peak brightness that lasted 180 days. During the first 50 days, when the nova was only 3--4 magnitudes above its normal brightness, the spectra showed narrow (FWHM $\approx$ 400 km s$^{-1}$) emission lines of H Balmer, He I, He II, and C IV, but no P Cygni absorption. A few weeks later, the high-excitation He II and C IV lines disappeared, and P Cygni profiles of Balmer, He I, and eventually Fe II lines emerged, yielding a spectrum typical of classical novae before peak. We propose that the early spectra of Gaia22alz are produced in the white dwarf's envelope or accretion disk, reprocessing X-ray and ultraviolet emission from the white dwarf after a dramatic increase in the rate of thermonuclear reactions, during a phase known as the ``early X-ray/UV flash''. If true, this would be one of the rare times that the optical signature of the early X-ray/UV flash has been detected. While this phase might last only a few hours in other novae and thus be easily missed, it was possible to detect in Gaia22alz due to its very slow and gradual rise and thanks to the efficiency of new all-sky surveys in detecting transients on their rise. We also consider alternative scenarios that could explain the early spectral features of Gaia22alz and its unusually slow rise.
description: 20 pages, 12 figures, 2 tables. Submitted to MNRAS
Investigating the $M_{GCS}-M_h$ Relation in the Most Massive Galaxies
Creators: name: Dornan, Veronika
name: Harris, William E.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The relation between the total mass contained in the globular clusters of a galaxy and the mass of its dark matter halo has been found observationally to be nearly linear over five decades of mass. However, the high-mass end of this relation is not well determined from previous data and shows large scatter. We analyze the globular cluster systems (GCSs) of a homogeneous sample of 11 brightest cluster galaxies (BCGs) through DOLPHOT photometry of their deep Hubble Space Telescope (HST) images in the F814W filter. We standardize the definition of $M_{GCS}$, the total GCS mass, by using the GC total population within a limiting radius of $0.1 R_{virial}$, while the dark-matter halo mass $M_h$ is determined from the weak-lensing calibration of $M_h$ versus $M_{bary}$. When these 11 BCGs are added to the previously studied homogeneous catalogue of Virgo member galaxies, a total value for $η= M_{GCS}/M_h$ is found to be $(3.0\pm1.8_{internal})\times10^{-5}$, slightly higher than previous estimates but with much reduced uncertainty. Perhaps more importantly, the results suggest that the relation continues to have a near-linear shape at the highest galaxy masses, strongly reinforcing the conclusion that accreted GCs make a major contribution to the GC populations at high galaxy mass.
description: 20 pages, 8 figures, accepted for publication in The Astrophysical Journal
A 3D view of dwarf galaxies with Gaia and VLT/FLAMES I. The Sculptor dwarf spheroidal
Creators: name: Tolstoy, Eline
name: Skúladóttir, Ása
name: Battaglia, Giuseppina
name: Brown, Anthony G. A.
name: Massari, Davide
name: Irwin, Michael J.
name: Starkenburg, Else
name: Salvadori, Stefania
name: Hill, Vanessa
name: Jablonka, Pascale
name: Salaris, Maurizio
name: van Essen, Thom
name: Olsthoorn, Carla
name: Helmi, Amina
name: Pritchard, John
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a new homogeneous survey of VLT/FLAMES LR8 line-of-sight radial velocities (vlos) for 1604 resolved red giant branch stars in the Sculptor dwarf spheroidal galaxy. In addition, we provide reliable Ca II triplet metallicities, [Fe/H], for 1339 of these stars. From this combination of new observations (2257 individual spectra) with ESO archival data (2389 spectra), we obtain the largest and most complete sample of vlos and [Fe/H] measurements for individual stars in any dwarf galaxy. Our sample includes VLT/FLAMES LR8 spectra for 55% of the red giant branch stars at G $<20$ from Gaia DR3, and $>70$% of the brightest stars, G $<18.75$. Our spectroscopic velocities are combined with Gaia DR3 proper motions and parallax measurements for a new and more precise membership analysis. We look again at the global characteristics of Sculptor, deriving a mean metallicity of $\langle$[Fe/H]$\rangle = -1.82 \pm 0.45$ and a mean line-of-sight velocity of $\langle$vlos$\rangle = +111.2 \pm 0.25$km/s. There is a clear metallicity gradient in Sculptor, -0.7deg/dex, with the most metal-rich population being the most centrally concentrated. Furthermore, the most metal-poor population in Sculptor, [Fe/H]$<-2.5$, appears to show kinematic properties distinct from the rest of the stellar population. Finally, we combine our results with the exquisite Gaia DR3 multi-colour photometry to further investigate the colour-magnitude diagram of the resolved stellar population in Sculptor. Our detailed analysis shows a similar global picture as previous studies, but with much more precise detail, revealing that Sculptor has more complex properties than previously thought. This survey emphasises the role of the stellar spectroscopy technique and this galaxy as a benchmark system for modelling galaxy formation and evolution on small scales.
description: A&A, in press
Unintegrated double parton distributions
Creators: name: Golec-Biernat, K.
name: Stasto, A. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the construction of unintegrated double parton distribution functions which include dependence on transverse momenta of partons. We extend the formulation which was used to obtain the single unintegrated parton distributions from the standard, integrated parton distribution functions. Starting from the homogeneous part of the evolution equations for the integrated double parton distributions, we construct the unintegrated double parton distributions as the convolutions of the integrated double distributions and the splitting functions, multiplied by the Sudakov form factors. We show that there exist three domains of external hard scales which require three distinct forms of the unintegrated double distributions. The additional transverse momentum dependence which arises through the Sudakov form factors leads to non-trivial correlations in the parton momenta. We also discuss the non-homogeneous contribution to the unintegrated double parton distributions, which arises due to the splitting of a single parton into daughter partons with high transverse momenta. We analyze two cases, the unfolding of the transverse momenta dependence from the last step of the evolution of two partons, and the case where the transverse momenta are generated directly from the single parton splitting.
description: 18 pages, 5 figures
Enhancement of mechanical and thermal properties of poly methyl methacrylate composite bone cements with zinc oxide nanostructures modified carbon fibres additives
Creators: name: Aykaç, Ahmet
name: Akkaş, Emine Özge
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biophysics
subject: Space Science
subject: Physical Sciences not elsewhere classified
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Physiology
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: Acrylic bone cement, which primarily consists of polymethyl methacrylate (PMMA), is widely used in orthopaedics, dentistry, and particularly in joint arthroplasty surgery. However, bone cements (BCs) have several limitations, including low mechanical properties, bioactivity issues, and high heat generation during polymerization. In recent years, there has been significant interest in studying the development of mechanical, thermal, and antibacterial properties of bone cement. In this study, ZnO nanostructures modified CFs were added to PMMA BCs at concentrations ranging from 0.10 wt% to 1.00 wt%, and the mechanical and thermal properties of the novel PMMA composite BCs were investigated. The novel composite materials were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). Mechanical tests including compression and 4-point bending were performed on the composite structures, along with thermogravimetric analysis (TGA). The results revealed that the composite cement containing 0.25 wt% ZnO/CFs reinforcement agent exhibited the best mechanical properties and thermal stability. The flexural strength of the 0.25 wt% ZnO/CFs reinforced PMMA composite BCs increased by 78.9%, while the compression strength increased by 277.4% compared to the control group.
Using multiobjective optimization to reconstruct interferometric data (I)
Creators: name: Müller, Hendrik
name: Mus, Alejandro
name: Lobanov, Andrei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Optimization and Control (math.OC)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Imaging in radioastronomy is an ill-posed inverse problem. Particularly the Event Horizon Telescope (EHT) Collaboration investigated the fidelity of their image reconstructions convincingly by large surveys solving the problem with different optimization parameters. This strategy faces a limitation for the existing methods when imaging the active galactic nuclei (AGN): large and expensive surveys solving the problem with different optimization parameters are time-consumptive. We present a novel nonconvex, multiobjective optimization modeling approach that gives a different type of claim and may provide a pathway to overcome this limitation. To this end we used a multiobjective version of the genetic algorithm (GA): the Multiobjective Evolutionary Algorithm Based on Decomposition, or MOEA/D. GA strategies explore the objective function by evolutionary operations to find the different local minima, and to avoid getting trapped in saddle points. First, we have tested our algorithm (MOEA/D) using synthetic data based on the 2017 Event Horizon Telescope (EHT) array and a possible EHT + next-generation EHT (ngEHT) configuration. We successfully recover a fully evolved Pareto front of non-dominated solutions for these examples. The Pareto front divides into clusters of image morphologies representing the full set of locally optimal solutions. We discuss approaches to find the most natural guess among these solutions and demonstrate its performance on synthetic data. Finally, we apply MOEA/D to observations of the black hole shadow in Messier 87 (M87) with the EHT data in 2017. MOEA/D is very flexible, faster than any other Bayesian method and explores more solutions than Regularized Maximum Likelihood methods (RML).
description: to appear in A&A
The limit distribution in the $q$-CLT for $q \ge 1$ is unique and can not have a compact support
Creators: name: Umarov, Sabir
name: Tsallis, Constantino
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In a paper by Umarov, Tsallis and Steinberg (2008), a generalization of the Fourier transform, called the $q$-Fourier transform, was introduced and applied for the proof of a $q$-generalized central limit theorem ($q$-CLT). Subsequently, Hilhorst illustrated (2009 and 2010) that the $q$-Fourier transform for $q>1$ is not invertible in the space of density functions. Indeed, using an invariance principle, he constructed a family of densities with the same $q$-Fourier transform and noted that "as a consequence, the $q$-central limit theorem falls short of achieving its stated goal". The distributions constructed there have compact support. We prove now that the limit distribution in the $q$-CLT is unique and can not have a compact support. This result excludes all the possible counterexamples which can be constructed using the invariance principle and fills the gap mentioned by Hilhorst.
description: 17 pages. To appear soon in Journal of Physics A. arXiv admin note: substantial text overlap with arXiv:1012.1814
Chemical Differentiation around Five Massive Protostars Revealed by ALMA -Carbon-Chain Species, Oxygen-/Nitrogen-Bearing Complex Organic Molecules-
Creators: name: Taniguchi, Kotomi
name: Majumdar, Liton
name: Caselli, Paola
name: Takakuwa, Shigehisa
name: Hsieh, Tien-Hao
name: Saito, Masao
name: Li, Zhi-Yun
name: Dobashi, Kazuhito
name: Shimoikura, Tomomi
name: Nakamura, Fumitaka
name: Tan, Jonathan C.
name: Herbst, Eric
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present Atacama Large Millimeter/submillimeter Array Band 3 data toward five massive young stellar objects (MYSOs), and investigate relationships between unsaturated carbon-chain species and saturated complex organic molecules (COMs). An HC$_{5}$N ($J=35-34$) line has been detected from three MYSOs, where nitrogen(N)-bearing COMs (CH$_{2}$CHCN and CH$_{3}$CH$_{2}$CN) have been detected. The HC$_{5}$N spatial distributions show compact features and match with a methanol (CH$_{3}$OH) line with an upper-state energy around 300 K, which should trace hot cores. The hot regions are more extended around the MYSOs where N-bearing COMs and HC$_{5}$N have been detected compared to two MYSOs without these molecular lines, while there are no clear differences in the bolometric luminosity and temperature. We run chemical simulations of hot-core models with a warm-up stage, and compare with the observational results. The observed abundances of HC$_{5}$N and COMs show good agreements with the model at the hot-core stage with temperatures above 160 K. These results indicate that carbon-chain chemistry around the MYSOs cannot be reproduced by warm carbon-chain chemistry, and a new type of carbon-chain chemistry occurs in hot regions around MYSOs.
description: Accepted by the publication for The Astrophysical Journal Supplement Series, 32 pages,18 figures, 11 tables
Precision gaugino mass measurements as a probe of large trilinear soft terms at ILC
Creators: name: Bae, Kyu Jung
name: Baer, Howard
name: Nagata, Natsumi
name: Serce, Hasan
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In supersymmetric models with radiatively-driven naturalness, higgsino-like electroweak-inos (EW-inos) are expected to lie in a mass range 100--300 GeV, the lighter the more natural. Such states can be pair-produced at high rates at ILC where their masses are nearly equal to the value of the superpotential mu parameter while their mass splittings depend on the gaugino masses M_1 and M_2. The gaugino masses in turn depend on trilinear soft terms---the A parameters, which are expected to lie in the multi-TeV range owing to the 125 GeV Higgs mass---via two-loop contributions to renormalization group running. We examine the extent to which ILC is sensitive to large A-terms via precision EW-ino mass measurement. Extraction of gaugino masses at the percent level should allow for interesting probes of large trilinear soft SUSY breaking terms under the assumption of unified gaugino masses.
description: 14 pages; 10 .png figures
Efficient electrolysis of 5-hydroxymethylfurfural to the biopolymer-precursor furandicarboxylic acid in a zero-gap MEA-type electrolyzer
Creators: name: Hauke, Philipp
name: Klingenhof, Malte
name: Wang, Xingli
name: De Araújo, Jorge Ferreira
name: Strasser, Peter
Publisher: name: Elsevier BV
Year: 2021
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: 500 Naturwissenschaften und Mathematik::540 Chemie::541 Physikalische Chemie
subject: electrocatalysis
subject: biomass
subject: sustainability
subject: electrolysis
subject: renewability
subject: Elektrokatalyse
subject: Biomasse
subject: Nachhaltigkeit
subject: Elektrolyse
subject: Erneuerbarkeit

description: Replacement of today’s established chemical production processes by “green” sustainable alternatives has become a scientific priority. The oxidative conversion of 5-hydroxymethylfurfural (5-HMF) to the biopolymer component 2.5-furandicarboxylic acid paired with green electrolytic hydrogen production is a promising emerging green process. Here, we present a family of active selective and stable interlayer anion-tuned NiX (X = Fe, Mn, Co, V) bimetallic-layered, double-hydroxide catalysts for the selective oxidation of 5-HMF to 2.5-furandicarboxylic acid in a zero-gap MEA-type electrolyzer. We report that tuning the structural interlayer distance of the catalyst by anion exchange gives rise to previously unachieved catalytic performance for the anodic production of the biopolymer building block. Operando differential electrochemical mass spectrometry analysis reveals the electrode window for the perfectly selective HMF conversion. The role of the catalyst dopants, their real surface areas, the stability of the catalytic interface, and aspects of its favorable techno-economics are discussed.
Barriers and Self-Efficacy: A Large-Scale Study on the Impact of OSS Courses on Student Perceptions
Creators: name: Salerno, Larissa
name: Tonhão, Simone de França
name: Steinmacher, Igor
name: Treude, Christoph
Publisher: name: arXiv
Year: 2023
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Open source software (OSS) development offers a unique opportunity for students in Software Engineering to experience and participate in large-scale software development, however, the impact of such courses on students' self-efficacy and the challenges faced by students are not well understood. This paper aims to address this gap by analyzing data from multiple instances of OSS development courses at universities in different countries and reporting on how students' self-efficacy changed as a result of taking the course, as well as the barriers and challenges faced by students.
Hairy black holes in AdS with Robin boundary conditions
Creators: name: Harada, Tomohiro
name: Ishii, Takaaki
name: Katagiri, Takuya
name: Tanahashi, Norihiro
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We study hairy black holes in Einstein-Maxwell-complex scalar theory in four-dimensional asymptotically global anti-de Sitter (AdS) spacetime when the Robin boundary conditions are imposed on the scalar field. This setup is dual to the double trace deformation of strongly interacting field theory on $R \times S^2$ by charged scalar operators. We identify the instability of the Reissner-Nordström-AdS (RNAdS) black holes under the Robin boundary conditions and construct backreacted geometries branching at the onset of the instability. Also considering associated horizonless geometries called boson stars, we obtain phase diagrams with fairly rich structure in the grand canonical ensemble depending on the boundary condition parameter or the deformation parameter, where phase transition occurs between thermal AdS, RNAdS, charged boson stars, and hairy black holes.
description: 30 pages, 10 figures v2: version accepted for publication in JHEP
The Strength of the Sheared Magnetic Field in the Galactic's Circum-Nuclear Disk
Creators: name: Guerra, J. A.
name: Lopez-Rodriguez, E.
name: Chuss, D. T.
name: Butterfield, N. O.
name: Schmelz, J. T.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Recent high-resolution 53-$μ$m polarimetric observations from SOFIA/HAWC+ have revealed the inferred plane-of-the-sky magnetic field (B-field) orientation in the Galactic center's Circum-Nuclear Disk (CND). The B-field is mostly aligned with the steamers of ionized material falling onto Sgr A* at large, differential velocities (shear). In such conditions, estimating the B-field strength with the ``classical" Davis-Chandrasekhar-Fermi (DCF) method does not provide accurate results. We derive a ``modified'' DCF method by solving the ideal MHD equations from first principles considering the effects of a large-scale, shear flow on the propagation of a fast magnetosonic wave. In the context of the DCF approximation, both the value of the shear and its Laplacian affect the inferred B-field strength. Using synthetic polarization data from MHD simulations for a medium dominated by shear flows, we find that the ``classical'' DCF determines B-field strengths only within $>50$\% of the true value where the ``modified" DCF results are improved significantly ($\sim$3-22\%). Applying our ``modified'' DCF method to the CND revealed B-field strengths of 1 - 16 mG in the northern arm, 1 - 13 mG in the eastern arm, and 3 - 27 mG in the western arm at spatial scales $\lesssim1$ pc, with median values of $5.1\pm0.8$, $4.0\pm1.2$, and $8.5\pm2.3$ mG, respectively. The balance between turbulent gas energy (kinetic plus hydrostatic) and turbulent magnetic energy densities suggest that, along the magnetic-field-flow direction, magnetic effects become less dominant as the shear flow increases and weakens the B-field via magnetic convection. Our results indicate that the transition from magnetically to gravitationally dominated accretion of material onto Sgr A* starts at distances $\sim$ 1 pc.
description: Accepted for publication in the Astronomical Journal
Fe3O4 thin films: controlling and manipulating an elusive quantum material
Creators: name: Liu, X. H.
name: Chang, C. F.
name: Rata, A. D.
name: Komarek, A. C.
name: Tjeng, L. H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Fe3O4 (magnetite) is one of the most elusive quantum materials and at the same time one of the most studied transition metal oxide materials for thin film applications. The theoretically expected half-metallic behavior generates high expectations that it can be used in spintronic devices. Yet, despite the tremendous amount of work devoted to preparing thin films, the enigmatic first order metal-insulator transition and the hall mark of magnetite known as the Verwey transition, is in thin films extremely broad and occurs at substantially lower temperatures as compared to that in high quality bulk single crystals. Here we have succeeded in finding and making a particular class of substrates that allows the growth of magnetite thin films with the Verwey transition as sharp as in the bulk. Moreover, we are now able to tune the transition temperature and, using tensile strain, increase it to substantially higher values than in the bulk.
New Sequence Alignment Algorithm using AI Rules and Dynamic Seeds
Creators: name: Suchindra
name: Nagaraj, Preetam
Publisher: name: arXiv
Year: 2023
Subjects: subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: DNA sequence alignment is important today as it is usually the first step in finding gene mutation, evolutionary similarities, protein structure, drug development and cancer treatment. Covid-19 is one recent example. There are many sequencing algorithms developed over the past decades but the sequence alignment using expert systems is quite new. To find DNA sequence alignment, dynamic programming was used initially. Later faster algorithms used small DNA sequence length of fixed size to find regions of similarity, and then build the final alignment using these regions. Such systems were not sensitive but were fast. To improve the sensitivity, we propose a new algorithm which is based on finding maximal matches between two sequences, find seeds between them, employ rules to find more seeds of varying length, and then employ a new stitching algorithm, and weighted seeds to solve the problem
description: 15. arXiv admin note: substantial text overlap with arXiv:2305.00329
All-optical switching in a continuously operated and strongly coupled atom-cavity system
Creators: name: Dutta, Sourav
name: Rangwala, S. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We experimentally demonstrate collective strong coupling, optical bi-stability (OB) and all-optical switching in a system consisting of ultracold 85Rb atoms, trapped in a dark magneto-optical trap (DMOT), coupled to an optical Fabry-Perot cavity. The strong coupling is established by measuring the vacuum Rabi splitting (VRS) of a weak on-axis probe beam. The dependence of VRS on the probe beam power is measured and bi-stability in the cavity transmission is observed. We demonstrate control over the transmission of the probe beam through the atom-cavity system using a free-space off-axis control beam and show that the cavity transmission can be switched on and off in micro-second timescales using micro-Watt control powers. The utility of the system as a tool for sensitive, in-situ and rapid measurements is envisaged.
description: 5 pages, 4 figures
A contact interaction model for the $η$ and $η'$ mesons in a SDE-BSE approach to QCD: masses, decay widths and transition form factors
Creators: name: Zamora, Bilgai Almeida
name: Martínez, Enrique Carreon
name: Segovia, Jorge
name: Cobos-Martínez, J. J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We construct a contact interaction model for the $η$ and $η'$ mesons in the SDE-BSE approach to QCD and compute several static properties of these mesons and their transition form factors. We find that this model gives an excellent description of the $η$ and $η'$ static properties, namely their masses, decay width and decay constants. However, a contact interaction disagrees with experimental data for $Q^2$ greater than 2 GeV$^2$, and produces transition form factors in conflict with perturbative QCD prediction. This is not surpring and the reasons for this are explained
description: 10 pages, 4 figures, submitted to PRD
Quench dynamics of the three-dimensional U(1) complex field theory: geometric and scaling characterisation of the vortex tangle
Creators: name: Kobayashi, Michikazu
name: Cugliandolo, Leticia F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a detailed study of the equilibrium properties and stochastic dynamic evolution of the U(1)-invariant relativistic complex field theory in three dimensions. This model has been used to describe, in various limits, properties of relativistic bosons at finite chemical potential, type II su- perconductors, magnetic materials and aspects of cosmology. We characterise the thermodynamic second-order phase transition in different ways. We study the equilibrium vortex configurations and their statistical and geometrical properties in equilibrium at all temperatures. We show that at very high temperature the statistics of the filaments is the one of fully-packed loop models. We identify the temperature, within the ordered phase, at which the number density of vortex lengths falls-off algebraically and we associate it to a geometric percolation transition that we characterise in various ways. We measure the fractal properties of the vortex tangle at this threshold. Next, we perform infinite rate quenches from equilibrium in the disordered phase, across the thermo- dynamic critical point, and deep into the ordered phase. We show that three time regimes can be distinguished: a first approach towards a state that, within numerical accuracy, shares many features with the one at the percolation threshold, a later coarsening process that does not alter, at sufficiently low temperature, the fractal properties of the long vortex loops, and a final approach to equilibrium. These features are independent of the reconnection rule used to build the vortex lines. In each of these regimes we identify the various length-scales of the vortices in the system. We also study the scaling properties of the ordering process and the progressive annihilation of topological defects and we prove that the time-dependence of the time-evolving vortex tangle can be described within the dynamic scaling framework.
description: 81 pages, 40 figures
Strong coupling of Rydberg atoms and surface phonon polaritons on piezoelectric superlattices
Creators: name: Sheng, Jiteng
name: Chao, Yuanxi
name: Shaffer, James P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We propose a hybrid quantum system where the strong coupling regime can be achieved between a Rydberg atomic ensemble and propagating surface phonon polaritons on a piezoelectric superlattice. By exploiting the large electric dipole moment and long lifetime of Rydberg atoms as well as tightly confined surface phonon polariton modes, it is possible to achieve a coupling constant far exceeding the relevant decay rates. The frequency of the surface mode can be selected so it is resonant with a Rydberg transition by engineering the piezoelectric superlattice. We describe a way to observe the Rabi splitting associated with the strong coupling regime under realistic experimental conditions. The system can be viewed as a new type of optomechanical system.
Precise Age for the Binary Star System 12 Com in the Coma Berenices Cluster
Creators: name: Lam, Rex
name: Sandquist, Eric L.
name: Schaefer, Gail H.
name: Farrington, Christopher D.
name: Monnier, John D.
name: Anugu, Narsireddy
name: Lanthermann, Cyprien
name: Klement, Robert
name: Ennis, Jacob
name: Setterholm, Benjamin R.
name: Gardner, Tyler
name: Kraus, Stefan
name: Davies, Claire L.
name: Orosz, Jerome A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present measurements of the interferometrically-resolved binary star system 12 Com and the single giant star 31 Com in the cluster Coma Berenices. 12 Com is a double-lined spectroscopic binary system consisting of a G7 giant and an A3 dwarf at the cluster turnoff. Using an extensive radial velocity dataset and interferometric measurements from PTI and the CHARA array, we measured masses $M_1 =2.64 \pm 0.07 M_\odot$ and $M_2 =2.10 \pm 0.03 M_\odot$. Interferometry also allows us to resolve the giant, and measure its size as $R_1 = 9.12 \pm 0.12 \pm 0.01 R_\odot$. With the measured masses and radii, we find an age of $533 \pm 41 \pm 42$ Myr. For comparison, we measure the radius of 31 Com to be $8.36 \pm 0.15 R_\odot$. Based on the photometry and radius measurements, 12 Com A is likely the most evolved bright star in the cluster, large enough to be in the red giant phase, but too small to have core helium burning. Simultaneous knowledge of 12 Com A's mass and photometry puts strong constraints on convective core overshooting during the main sequence phase, which in turn reduces systematic uncertainties in the age. Increased precision in measuring this system also improves our knowledge of the progenitor of the cluster white dwarf WD1216+260.
Pathlengths of open channels in multiple scattering media
Creators: name: Bosch, Jeroen
name: Goorden, Sebastianus A.
name: Mosk, Allard P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optics (physics.optics)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report optical measurements of the spectral width of open transmission channels in a three-dimensional diffusive medium. The light transmission through a sample is enhanced by efficiently coupling to open transmission channels using repeated digital optical phase conjugation. The spectral properties are investigated by enhancing the transmission, fixing the incident wavefront and scanning the wavelength of the laser. We measure the transmitted field to extract the field correlation function and the enhancement of the total transmission. We find that optimizing the total transmission leads to a significant increase in the frequency width of the field correlation function. Additionally we find that the enhanced transmission persists over an even larger frequency bandwidth. This result shows open channels in the diffusive regime are spectrally much wider than previous measurements in the localized regime suggest.
The He I 10830 A line: Radiative transfer and differential illumination effects
Creators: name: Arevalo, Andres Vicente
name: Stepan, Jiri
name: Aleman, Tanausu del Pino
name: Gonzalez, Maria Jesus Martinez
Publisher: name: arXiv
Year: 2023
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We study the formation of the Stokes profiles of the He I multiplet at 10830 A when relaxing two of the approximations that are often considered in the modeling of this multiplet, namely the lack of self-consistent radiation transfer and the assumption of equal illumination of the individual multiplet components. This He I multiplet is among the most important ones for the diagnostic of the outer solar atmosphere from spectropolarimetric observations, especially in prominences, filaments, and spicules. However, the goodness of these approximations is yet to be assessed, especially in situations where the optical thickness is of the order or larger than one, and radiation transfer has a significant impact in the local anisotropy and the ensuing spectral line polarization. This issue becomes particularly relevant in the ongoing development of new inversion tools which take into account multi-dimensional radiation transfer effects. To relax these approximations we generalize the multi-term equations for the atomic statistical equilibrium to allow for differential illumination of the multiplet components and implement them in a one-dimensional radiative transfer code. We find that, even for this simple geometry and relatively small optical thickness, both radiation transfer and differential illumination effects have a significant impact on the emergent polarization profiles. This should be taken into account in order to avoid potentially significant errors in the inference of the magnetic field vector.
description: 8 pages, 4 figures, submitted to Astronomy & Astrophysics
OH absorption in on-chip high-Q resonators
Creators: name: Wu, Lue
name: Gao, Maodong
name: Liu, Jin-Yu
name: Chen, Hao-Jing
name: Colburn, Kellan
name: Blauvelt, Henry A.
name: Vahala, Kerry J.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Thermal silica is a common dielectric used in all silicon-photonic circuits. And bound hydroxyl ions (Si-OH) can provide a significant component of optical loss in this material on account of the wet nature of the thermal oxidation process. A convenient way to quantify this loss relative to other mechanisms is through OH-absorption at 1380 nm. Here, using ultra-high-Q thermal-silica wedge microresonators, the OH absorption loss peak is measured and distinguished from the scattering loss base line over a wavelength range from 680 nm to 1550 nm. Record-high on-chip resonator Q factors are observed for near-visible and visible wavelengths, and the absorption limited Q factor is as high as 8 billion in the telecom band. OH ion content level around 2.4 ppm (weight) is inferred from both Q measurements and by Secondary Ion Mass Spectroscopy (SIMS) depth profiling.
description: 4 pages, 3 figures