cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
A detailed study of the barium central star of the planetary nebula Abell 70
Creators: name: Jones, David
name: Boffin, Henri M. J.
name: Brown, Alex J.
name: Zak, Jiri
name: Hume, George
name: Munday, James
name: Miszalski, Brent
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a detailed study of the barium star at the heart of the planetary nebula Abell 70. Time-series photometry obtained over a period of more than ten years demonstrates that the barium-contaminated companion is a rapid rotator with temporal variability due to spots. The amplitude and phasing of the photometric variability changes abruptly, however there is no evidence for a change in the rotation period (P = 2.06~d) over the course of the observations. The co-addition of 17 high-resolution spectra obtained with VLT-UVES allow us to measure the physical and chemical properties of the companion, confirming it to be a chromospherically-active, late G-type sub-giant with more than +1~dex of barium enhancement. We find no evidence of radial velocity variability in the spectra, obtained over the course of approximately 130~d with a single additional point some 8 years later, with the radial velocities of all epochs approximately $-$10 \kms{} from the previously measured systemic velocity of the nebula. This is perhaps indicative that the binary has a relatively long period (P $\gtrsim$ 2~yr) and high eccentricity ($e\gtrsim$ 0.3), and that all the observations were taken around radial velocity minimum. However, unless the binary orbital plane is not aligned with the waist of the nebula or the systemic velocity of the binary is not equal to the literature value for the nebula, this would imply an unfeasibly large mass for the nebular progenitor.
description: Accepted for publication in MNRAS
Characterization of 3 mm Glass Electrodes and Development of RPC Detectors for $INO-ICAL$ Experiment
Creators: name: Kaur, Daljeet
name: Kumar, Ashok
name: Gaur, Ankit
name: Kumar, Purnendu
name: Hasbuddin, Md.
name: Mishra, Swati
name: Kumar, Praveen
name: Naimuddin, Md.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: India-based Neutrino Observatory (INO) is a multi-institutional facility, planned to be built up in South India. The INO facility will host a 51 kton magnetized Iron CALorimeter (ICAL) detector to study atmospheric muon neutrinos. Iron plates have been chosen as the target material whereas Resistive Plate Chambers (RPCs) have been chosen as the active detector element for the ICAL experiment. Due to the large number of RPCs needed ($\sim$ 28,000 of $2~m \times 2~m$ in size) for ICAL experiment and for the long lifetime of the experiment, it is necessary to perform a detailed $R\&D$ such that each and every parameter of the detector performance can be optimized to improve the physics output. In this paper, we report on the detailed material and electrical properties studies for various types of glass electrodes available locally. We also report on the performance studies carried out on the RPCs made with these electrodes as well as the effect of gas composition and environmental temperature on the detector performance. We also lay emphasis on the usage of materials for RPC electrodes and the suitable enviormental conditions applicable for operating the RPC detector for optimal physics output at INO-ICAL experiment.
description: Published in NIMA
Path integral Monte Carlo simulations of the geometrical effects in KDP crystals
Creators: name: Torresi, F.
name: Lasave, J.
name: Koval, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Path integral Monte Carlo (PIMC) simulations with very simple models were used in order to unveil the physics behind the isotope effects in H-bonded ferroelectrics. First, we studied geometrical effects in the H-bonds caused by deuteration with a general three-site model based on a back-to-back double Morse potential plus a Morse potential between oxygens, fitted to explain different general features for a wide set of H-bonded compounds. Our model results show the Ubbelohde or geometrical effect (GE), i.e., the expansion of the H-bond with deuteration, in agreement to what is observed in H-bonded ferroelectrics with short H-bonds. Moreover, adjusting the potential parameters to ab initio results, we have developed a 1D model which considers the bilinear proton-proton interaction in mean-field to study nuclear quantum effects that give rise to the GE in KDP crystals. PIMC simulations reveal that protons tunnel more efficiently than deuterons along the 1D chain, giving rise to a strong attraction center that pulls the oxygens together. This mechanism, which is based on the correlation between tunneling and geometrial modifications of the H-bonds, leads to a strong GE in the ordered phase of the chain at low temperature which is in good agreement with the experimental data.
description: 12 pages, 6 figures, 3 tables
Shell-model and first-principles calculations of vibrational, structural and ferroelectric properties of KH$_2$PO$_4$
Creators: name: Menchón, R. E.
name: Torresi, F.
name: Lasave, J.
name: Koval, S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We develop a shell model (SM) for potassium dihydrogen phosphate (KDP) which is fitted to ab initio (AI) results that include nonlocal van der Waals corrections. The SM is comprehensively tested by comparing results of structural, vibrational and ferroelectric properties with AI and experimental data. The relaxed structural parameters are in very good agreement with the AI results and the available experimental data. The $Γ$-point phonons and the total phonon densities of states (DOSs) in the ferroelectric and paraelectric phases calculated with the developed SM are in good overall agreement with the corresponding AI and experimental data. We also compute the effective Debye temperature as a function of $T$ which shows good accordance with the corresponding AI and experimental results. Classical molecular dynamics (MD) simulations obtained with the developed SM show a FE-PE phase transition at $\approx 360$ K in remarkable agreement with ab initio MD calculations.
description: 12 pages, 3 figures, 3 tables
A hydrodynamical perspective on the turbulent transport of bacteria in rivers
Creators: name: Krayer, Michael Werner Tobias
Publisher: name: KIT Scientific Publishing
Year: 2023
Subjects: Partikelströmungen
Turbulenz
Exakte kohärente Strukturen
Sedimentation
Gewässerverschmutzung
Particle-laden flows
Turbulence
Exact coherent structures
Aquatic pollution

description: The transport of bacteria in turbulent river-like environments is addressed, where bacterial populations are frequently encountered attached to solids. This transport mode is investigated by studying the transient settling of heavy particles in turbulent channel flows featuring sediment beds. A numerical method is used to fully resolve turbulence and finite-size particles, which enables the assessment of the complex interplay between flow structures, suspended solids and river sediment.
Temporal Embedding in Convolutional Neural Networks for Robust Learning of Abstract Snippets
Creators: name: Liu, Jiajun
name: Zhao, Kun
name: Kusy, Brano
name: Wen, Ji-rong
name: Jurdak, Raja
Publisher: name: arXiv
Year: 2015
Subjects: subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: The prediction of periodical time-series remains challenging due to various types of data distortions and misalignments. Here, we propose a novel model called Temporal embedding-enhanced convolutional neural Network (TeNet) to learn repeatedly-occurring-yet-hidden structural elements in periodical time-series, called abstract snippets, for predicting future changes. Our model uses convolutional neural networks and embeds a time-series with its potential neighbors in the temporal domain for aligning it to the dominant patterns in the dataset. The model is robust to distortions and misalignments in the temporal domain and demonstrates strong prediction power for periodical time-series. We conduct extensive experiments and discover that the proposed model shows significant and consistent advantages over existing methods on a variety of data modalities ranging from human mobility to household power consumption records. Empirical results indicate that the model is robust to various factors such as number of samples, variance of data, numerical ranges of data etc. The experiments also verify that the intuition behind the model can be generalized to multiple data types and applications and promises significant improvement in prediction performances across the datasets studied.
description: a submission to kdd 15'
Templated Growth of Magnetic Recording Media
Creators: name: Vignesh  Sundar
Publisher: name: Figshare
Year: 2018
Subjects: subject: 91299 Materials Engineering not elsewhere classified
subject: FOS: Materials engineering

description: Current and potential next-generation magnetic recording technologies are based on the writing and reading of bits on a magnetic thin film with a granular microstructure, with grains of the magnetic material surrounded by an amorphous segregant. In order to realize the highest achievable data storage capabilities, there is a need for better control of the magnetic media microstructure, particularly in terms of minimizing grain size and grain boundary thickness distributions. In this work, a guided magnetic media growth is attempted by creating a pre-fabricated template with a specific material and morphology. The template is designed in such a way that, when magnetic media consisting of the magnetic alloy and segregant are sputtered, the sites on the template result in a controlled two-phase growth of magnetic media. The template is fabricated using self-assembling block copolymers, which can be used to fabricate nanostructures with a regular hexagonal lattice of spheres of one block in the other’s matrix. These are then used as etch-masks to fabricate the template. In this thesis, we describe the approach used to fabricate these templates and demonstrate the two-phase growth of magnetic recording media. In such an approach, the magnetic grain size is defined by the uniform pitch of the block copolymer pattern, resulting in a uniform microstructure with much better grain size distribution than can be obtained with conventional un-templated media growth. The templated growth technique is also a suitable additive technique for the fabrication of Bit Patterned Media, another potential next-generation technology wherein the magnetic bits are isolated patterned islands. Combining nanoimprint lithography with templated growth, we can generate a long range spatially ordered array of magnetic islands with no etching of the magnetic material.
AMS :: ATX March 2022 Blog Archive
Creators: name: Department Of American Studies
Publisher: name: The University of Texas at Austin
Year: 2022
Subjects: American Studies
Twitter

description: @AmStudies is a Twitter feed dedicated to representing the many activities and interests of the department of American Studies at The University of Texas at Austin. Together with the department’s blog, this feed exists to serve the AMS and Austin communities by acting as a hub for up-to-date information on events and opportunities at UT and beyond.
Error estimates of floating-point numbers and Jacobian matrix computation in Clad
Creators: name: Vassilev, Vassil
name: Penev, Alexander
name: Shakhov, Roman
Publisher: name: Zenodo
Year: 2020

description: Automatic differentiation(AD) is a method in computer algebra to evaluate the derivative of a function defined by source code, it's an alternative to symbolic and numerical differentiation. AD uses the fact than any algorithm can be decomposed to differentiable elementary operation and thereby differentiated using a chain rule. Clad is a Clang plugin based on source code transformation. Given C++ source code of a mathematical function, it can automatically generate C++ code for computing derivatives of the function. It supports both forward-mode and reverse-mode AD. Our talk covers two features of Clad. The first one is Jacobian matrix computation using forward and reverse modes. Jacobian matrix have applications in such fields as machine learning and computational physics. The second one is error estimates of floating-point numbers. It allows to monitor the estimated relative error during a computation involving differentiated function produced by clad. It achieved by source code transformation, Clad can produce code for error estimation along with AD.
Electric field induced polarization rotation in squaric acid crystals revisited
Creators: name: Moina, A. P.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using the previously developed model we revisit the problem of the electric field induced polarization rotation in antiferroelectric crystals of squaric acid. We test an alternative set of the model parameters, according to which the dipole moments associated with the H$_2$C$_4$O$_4$ groups are assumed to be parallel to the diagonals of the $ac$ plane. The $T$-$E$ phase diagrams and the polarization curves $P(E)$ for the fields directed along the $a$ axis and along one of the diagonals are considered. Comparison of the theoretical results with the newly published experimental data confirm the validity of the model. The calculations reveal no apparent advantage of the new set of the parameters over the previously used set.
description: 9 pages, 4 figures, 1 table. arXiv admin note: text overlap with arXiv:2112.09942
AMS :: ATX April 2022 Blog Archive
Creators: name: Department Of American Studies
Publisher: name: The University of Texas at Austin
Year: 2022
Subjects: American Studies
Twitter

description: @AmStudies is a Twitter feed dedicated to representing the many activities and interests of the department of American Studies at The University of Texas at Austin. Together with the department’s blog, this feed exists to serve the AMS and Austin communities by acting as a hub for up-to-date information on events and opportunities at UT and beyond.
Short Duration Accretion States of Polars as seen in TESS and ZTF data
Creators: name: Duffy, C.
name: Ramsay, G.
name: Wu, Kinwah
name: Mason, Paul A.
name: Hakala, P.
name: Steeghs, D.
name: Wood, M. A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Polars are highly magnetic cataclysmic variables which have been long observed to have both high and low brightness states. The duration of these states has been previously seen to vary from a number of days up to years. Despite this; these states and their physical origin has not been explained in a consistent manner. We present observations of the shortest duration states of a number of Polars observed by ZTF and TESS. This has allowed us to determine that short duration states are a relatively common feature across the population of Polars. Furthermore we have been able to generalise the model of star spot migration to explain both short lived high and low states in Polars by incorporating the interaction between the magnetic field of the white dwarf and that of the star spots.
description: 16 pages, 9 Figures. Final accepted version to MNRAS
AMS :: ATX May 2022 Blog Archive
Creators: name: Department Of American Studies
Publisher: name: The University of Texas at Austin
Year: 2022
Subjects: American Studies
Twitter

description: @AmStudies is a Twitter feed dedicated to representing the many activities and interests of the department of American Studies at The University of Texas at Austin. Together with the department’s blog, this feed exists to serve the AMS and Austin communities by acting as a hub for up-to-date information on events and opportunities at UT and beyond.
Radio monitoring of transient Be/X-ray binaries and the inflow-outflow coupling of strongly-magnetized accreting neutron stars
Creators: name: Eijnden, J. van den
name: Degenaar, N.
name: Russell, T. D.
name: Miller-Jones, J. C. A.
name: Escorial, A. Rouco
name: Wijnands, R.
name: Sivakoff, G. R.
name: Santisteban, J. V. Hernández
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Strongly-magnetized ($B\geq10^{12}$ G) accreting neutron stars (NSs) are prime targets for studying the launching of jets by objects with a solid surface; while classical jet-launching models predict that such NSs cannot launch jets, recent observations and models argue otherwise. Transient Be/X-ray binaries (BeXRBs) are critical laboratories for probing this poorly-explored parameter space for jet formation. Here, we present the coordinated monitoring campaigns of three BeXRBs across four outbursts: giant outbursts of SAX 2103.5+4545, 1A 0535+262, and GRO J1008-57, as well as a Type-I outburst of the latter. We obtain radio detections of 1A 0535+262 during ten out of twenty observations, while the other targets remained undetected at typical limits of $20$-$50$ $μ$Jy. The radio luminosity of 1A 0535+262 positively correlates with its evolving X-ray luminosity, and inhabits a region of the $L_X$-$L_R$ plane continuing the correlation observed previously for the BeXRB Swift J0243.6+6124. We measure a BeXRB $L_X$-$L_R$ coupling index of $β= 0.86 \pm 0.06$ ($L_R \propto L_X^β$), similar to the indices measured in NS and black hole low-mass X-ray binaries. Strikingly, the coupling's $L_R$ normalisation is $\sim 275$ and $\sim 6.2\times10^3$ times lower than in those two comparison samples, respectively. We conclude that jet emission likely dominates during the main peak of giant outbursts, but is only detectable for close-by or super-Eddington systems at current radio sensitivities. We discuss these results in the broader context of X-ray binary radio studies, concluding that our results suggest how supergiant X-ray binaries may host a currently unidentified additional radio emission mechanism.
description: Re-submitted to MNRAS after minor comments. 18 pages, 9 Figures. Online Supplementary Materials added as appendix
Additional file 1 of What are the current anti-COVID-19 drugs? From traditional to smart molecular mechanisms
Creators: name: Aboul-Fotouh, Sawsan
name: Mahmoud, Ahmed Nageh
name: Elnahas, Esraa M.
name: Habib, Mohamed Z.
name: Abdelraouf, Sahar M.
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Pharmacology
subject: Biotechnology
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: Mental Health
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Additional file 1. Additional Table 1: Updates of COVID-19 treatment guideline recommendations (NIH, IDSA, and NICE) and FDA approval/EUA for drug therapy of COVID-19.
The formation of clusters and OB associations in different density spiral arm environments
Creators: name: Dobbs, C. L.
name: Bending, T. J. R.
name: Pettitt, A. R.
name: Buckner, A. S. M.
name: Bate, M. R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present simulations of the formation and evolution of clusters in spiral arms. The simulations follow two different spiral arm regions, and the total gas mass is varied to produce a range of different mass clusters. We find that including photoionizing feedback produces the observed cluster mass radius relation, increasing the radii of clusters compared to without feedback. Supernovae have little impact on cluster properties. We find that in our high density, high gas mass simulations, star formation is less affected by feedback, as star formation occurs rapidly before feedback has much impact. In our lowest gas density simulation, the resulting clusters are completely different (e.g. the number of clusters and their masses) to the case with no feedback. The star formation rate is also significantly suppressed. The fraction of stars in clusters in this model decreases with time flattening at about 20\%. In our lowest gas simulation model, we see the formation of a star forming group with properties similar to an OB association, in particular similar to Orion Ia. We suggest that low densities, and stronger initial dynamics are conducive to forming associations rather than clusters. In all models cluster formation is complex with clusters merging and splitting. The most massive clusters which form have tended to undergo more mergers.
description: 23 pages, 19 figures, accepted for publication in MNRAS, movies available at https://icybob.co.uk/movies.html (lowest 2 panels)
Forecasting Cropland Vegetation Condition Using Digital Earth Africa Data Cube
Creators: name: Digital Earth Africa
Publisher: name: GEO Knowledge Hub
Year: 2022
Subjects: Sentinel 2
crop mask
autoregression
data methods
forecasting

description:  
What is it about
Background
This notebook conducts time-series forecasting of vegetation condition (NDVI) using SARIMAX, a variation on autoregressive-moving-average (ARMA) models which includes an integrated (I) component to difference the time-series so it becomes stationary, a seasonal (S) component, and can consider exogenous (X) variables. In this example, we will conduct a forecast on a univariate NDVI time series. That is our forecast built on temporal patterns in NDVI. Conversely, multivariate approaches can account for influences of variables such as soil moisture and rainfall.
This notebook allows for easy replication of analysis across Africa, by simply changing the analysis parameters. The user guide provides an overview of the research, resources used/supplied, and directions on reproducing the research.
This knowledge package includes the necessary data, computational resources, and instructions to reproduce the methodology used in Digital Earth Africa's 'Forecasting cropland vegetation condition' Jupyter Notebook. 
The User's Guide provides an overview of the application.
The Application of Atom Transfer Radical Polymerization to Improve The Preparation of Porous Polymer-Based Materials
Creators: name: Lamson, Melissa A.
Publisher: name: Figshare
Year: 2018
Subjects: subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences

description: work explores the application of Atom Transfer Radical Polymerization (ATRP) to improve various aspects of synthesizing well-defined porous polymer-based materials. The thesis specifically focuses on two particular classes on materials; mesoporous nitrogen-doped nanostructured carbons (N-doped nanocarbons) and polymerized high internal phase emulsions (polyHIPEs). The introductory chapter discusses, in great detail, reversible deactivation radical polymerization (RDRP) methods, including ATRP, that can be used to synthesize polyacrylonitrile-based precursors for the preparation N-doped nanocarbons and discusses their potential applications. The introduction chapter also details the requirements for formation of HIPEs and polyHIPEs, with a focus on the various hurdles that must be overcome for polyHIPEs to become commercially viable and widely applicable materials. Chapter 2 focuses on the synthesis of PAN-containing block copolymer (BCP) precursors by initiators for continuous activator regeneration (ICAR) and metal free (MF) ATRP, which allow for a significant reduction in the concentration of Cu-catalyst required for synthesis of well-defined BCPs; to 1 ppm in ICAR ATRP or no metal catalyst in MF ATRP. Chapter 3 discusses the synthesis of a range of PAN-based stars and characterization of carbon materials derived from these precursors. Chapter 4 discusses the synthesis and use of tetrazine cross-linked SiO2-g-Poly(4-cyanostyrene) as precursor for nitrogen-doped nanocarbons. The application of ATRP to prepare materials for use in HIPE systems and synthesize polyHIPEs was investigated in Chapter 5, where optimized conditions for activators generated by electron transfer (AGET) ATRP were developed to synthesize fully degradable polyHIPEs from commercially available monomers and cross-linker. Chapter 6 details the synthesis poly(ethylene oxide) and poly(n-butyl acrylate) mikto-arm stars that preferentially formed water in oil HIPEs and were able to stabilize water-in-xylene emulsions with star loading (vs. total emulsion) down to 0.005 wt% and water-in-styrene HIPEs down to 0.04 wt%. In a final step towards preparing a surfactant free stable polyHIPEs these mikto-arm stars were functionalized with reactive alkyl halide or vinyl moieties, so they could be incorporated into the polyHIPE network, as well as stabilize the HIPE, which is discussed in Chapter 7.
CERVICAL SPINE MOTION AND COLLEGIATE ATHLETIC TRAINER CONFIDENCE DURING HELMET REMOVAL: A MULTI METHODS STUDY
Creators: name: Hersch, Rebecca Faye
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2022

description: Catastrophic cervical spine injuries are injures with damage to the upper-portion of the spinal cord. Current recommendations for athletic trainers treating these injuries are based on literature for American football equipment with limited research available for other sports. The purpose of this study was to evaluate the cervical spine motion during helmet removal for various helmet types and assess athletic trainer confidence for each helmet type. Spine motion was evaluated using three-dimensional motion capture, which provided real-time feedback about the cervical spine during helmet removal. Confidence was evaluated using a five-point Likert scale and collected throughout the data collection period. There was no significant difference between cervical spine motion across all helmet types. There was a significant difference for confidence while removing American football helmets compared to men’s lacrosse and field hockey helmets. Athletic trainers are able to successfully complete tasks without training, but feel less confident in their execution.
AMS :: ATX August 2022 Blog Archive
Creators: name: Department Of American Studies
Publisher: name: The University of Texas at Austin
Year: 2022
Subjects: American Studies
Twitter

description: @AmStudies is a Twitter feed dedicated to representing the many activities and interests of the department of American Studies at The University of Texas at Austin. Together with the department’s blog, this feed exists to serve the AMS and Austin communities by acting as a hub for up-to-date information on events and opportunities at UT and beyond.
On Codazzi tensors on a hyperbolic surface and flat Lorentzian geometry
Creators: name: Bonsante, Francesco
name: Seppi, Andrea
Publisher: name: arXiv
Year: 2015
Subjects: subject: Differential Geometry (math.DG)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Using global considerations, Mess proved that the moduli space of globally hyperbolic flat Lorentzian structures on $S\times\mathbb{R}$ is the tangent bundle of the Teichmüller space of $S$, if $S$ is a closed surface. One of the goals of this paper is to deepen this surprising occurrence and to make explicit the relation between the Mess parameters and the embedding data of any Cauchy surface. This relation is pointed out by using some specific properties of Codazzi tensors on hyperbolic surfaces. As a by-product we get a new Lorentzian proof of Goldman's celebrated result about the coincidence of the Weil-Petersson symplectic form and the Goldman pairing. In the second part of the paper we use this machinery to get a classification of globally hyperbolic flat space-times with particles of angles in $(0,2π)$ containing a uniformly convex Cauchy surface. The analogue of Mess' result is achieved showing that the corresponding moduli space is the tangent bundle of the Teichmüller space of a punctured surface. To generalize the theory in the case of particles, we deepen the study of Codazzi tensors on hyperbolic surfaces with cone singularities, proving that the well-known decomposition of a Codazzi tensor in a harmonic part and a trivial part can be generalized in the context of hyperbolic metrics with cone singularities.
description: 49 pages, 4 figures
Corporate Naming Rights for Collegiate Athletic Venues: An Analysis of Valuation, Attendance, and Donations
Creators: name: Centracchio, Brett
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2022

description: The first purpose of this study was to re-examine the valuation of collegiate sport venue naming rights agreements in light of the significant growth in deals since prior work by Gerrard et al. (2007) and Popp et al. (2016). An OLS regression model was developed utilizing a sample of 74 collegiate sports venue naming rights agreements. Average prior attendance, all-time winning percentage, and construction cost were found to be significant predictors of average annual deal value. The second purpose was to determine whether the announcement of a corporate naming rights agreement for a collegiate venue had any relationship with event attendance or donations to the athletics departments. Two fixed-effects models analyzing within- subject variation were employed utilizing a sample of 38 college sports venue naming rights agreements from 2013-2019. This study found there was no significant difference in attendance or donations after a naming rights deal was signed.
Electrocaloric and barocaloric effects in CsH$_2$PO$_4$ ferroelectric
Creators: name: Vdovych, A. S.
name: Levitskii, R. R.
name: Zachek, I. R.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: To investigate the caloric effects in the CsH$_2$PO$_4$ ferroelectric, a modified pseudospin model of this crystal is used, which takes into account the dependence of the parameters of interaction between pseudospins on lattice strains. The model also takes into account the dependence of the effective dipole moment of a pseudospin on the order parameter. In the two-particle cluster approximation, the influence of the longitudinal electric field and hydrostatic pressure on the molar entropy of the crystal was studied. The electrocaloric and barocaloric effects were studied. The calculated electrocaloric temperature change is about $1$ K; it can change its sign under the influence of hydrostatic pressure. Barocaloric temperature change is about $-0.5$ K; lattice anharmonicities were not taken into account in its calculations.
description: 14 pages, 8 figures. arXiv admin note: text overlap with arXiv:2206.15259, arXiv:2009.14688
Spherically Symmetric Accretion onto a Compact Object through a Standing Shock: The Effects of General Relativity in the Schwarzschild Geometry
Creators: name: Kundu, Suman Kumar
name: Coughlin, Eric R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A core-collapse supernova is generated by the passage of a shockwave through the envelope of a massive star, where the shock wave is initially launched from the ``bounce'' of the neutron star formed during the collapse of the stellar core. Instead of successfully exploding the star, however, numerical investigations of core-collapse supernovae find that this shock tends to ``stall'' at small radii ($\lesssim$ 10 neutron star radii), with stellar material accreting onto the central object through the standing shock. Here, we present time-steady, adiabatic solutions for the density, pressure, and velocity of the shocked fluid that accretes onto the compact object through the stalled shock, and we include the effects of general relativity in the Schwarzschild metric. Similar to previous works that were carried out in the Newtonian limit, we find that the gas ``settles'' interior to the stalled shock; in the relativistic regime analyzed here, the velocity asymptotically approaches zero near the Schwarzschild radius. These solutions can represent accretion onto a material surface if the radius of the compact object is outside of its event horizon, such as a neutron star; we also discuss the possibility that these solutions can approximately represent the accretion of gas onto a newly formed black hole following a core-collapse event. Our findings and solutions are particularly relevant in weak and failed supernovae, where the shock is pushed to small radii and relativistic effects are large.
description: 8 pages, 3 figures, MNRAS accepted
Dilogarithm ladders from Wilson loops
Creators: name: Bianchi, Marco S.
name: Leoni, Matias
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider a light-like Wilson loop in N=4 SYM evaluated on a regular n-polygon contour. Sending the number of edges to infinity the polygon approximates a circle and the expectation value of the light-like WL is expected to tend to the localization result for the circular one. We show this explicitly at one loop, providing a prescription to deal with the divergences of the light-like WL and the large n limit. Taking this limit entails evaluating certain sums of dilogarithms which, for a regular polygon, evaluate to the same constant independently of n. We show that this occurs thanks to underpinning dilogarithm identities, related to the so-called polylogarithm ladders, which appear in rather different contexts of physics and mathematics and enable us to perform the large n limit analytically.
description: 11 pages, 3 figures
Apparent molar volume anomaly in water-dimethyl sulfoxide liquid mixtures. Molecular dynamics computer simulations
Creators: name: Aguilar, M.
name: Dominguez, H.
name: Pizio, O.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We have studied the composition dependence of density of liquid water-DMSO mixtures at different temperatures by using the isobaric-isothermal (NPT) molecular dynamics computer simulations. The non-polarizable semi-flexible, P1 and P2 models for the DMSO molecule combined with the TIP4P-2005 water model are considered. The excess mixing volume and the apparent molar volumes of the species are reported. We have established that the P1-TIP4P-2005 model for the mixture provides a very good description of the location of the minimum of apparent molar volume for DMSO species indicating the anomaly. Most important is that the temperature interval where the hydrophobic effect exists, is correctly captured with this modelling, in contrast to the P2-TIP4P-2005 model.
description: 6 pages, 4 figures
The Approximability of Learning and Constraint Satisfaction Problems
Creators: name: Wu, Yi
Publisher: name: Figshare
Year: 2018
Subjects: subject: 89999 Information and Computing Sciences not elsewhere classified
subject: FOS: Computer and information sciences

description: An α-approximation algorithm is an algorithm guaranteed to output a solution
that is within an α ratio of the optimal solution. We are interested in the
following question: Given an NP-hard optimization problem, what is the best
approximation guarantee that any polynomial time algorithm could achieve?
We mostly focus on studying the approximability of two classes of NP-hard
problems: Constraint Satisfaction Problems (CSPs) and Computational Learning Problems.

For CSPs, we mainly study the approximability of MAX CUT, MAX 3-CSP,
MAX 2-LINR, VERTEX-PRICING, as well as serval variants of the UNIQUEGAMES.
• The problem of MAX CUT is to find a partition of a graph so as to maximize
the number of edges between the two partitions. Assuming the
Unique Games Conjecture, we give a complete characterization of the approximation
curve of the MAX CUT problem: for every optimum value of
the instance, we show that certain SDP algorithm with RPR2 rounding
always achieve the optimal approximation curve.
• The input to a 3-CSP is a set of Boolean constraints such that each constraint
contains at most 3 Boolean variables. The goal is to find an assignment
to these variables to maximize the number of satisfied constraints.
We are interested in the case when a 3-CSP is satisfiable, i.e.,
there does exist an assignment that satisfies every constraint. Assuming
the d-to-1 conjecture (a variant of the Unique Games Conjecture), we
prove that it is NP-hard to give a better than 5/8-approximation for the
problem. Such a result matches a SDP algorithm by Zwick which gives
a 5/8-approximation problem for satisfiable 3-CSP. In addition, our result
also conditionally resolves a fundamental open problem in PCP theory on
the optimal soundness for a 3-query nonadaptive PCP system for NP with
perfect completeness.
• The problem of MAX 2-LINZ involves a linear systems of integer equations;
these equations are so simple such that each equation contains at
most 2 variables. The goal is to find an assignment to the variables so as
to maximize the total number of satisfied equations. It is a natural generalization
of the Unique Games Conjecture which address the hardness of
the same equation systems over finite fields. We show that assuming the
Unique Games Conjecture, for a MAX 2-LINZ instance, even that there
exists a solution that satisfies 1−ε of the equations, it is NP-hard to find
one that satisfies ² of the equations for any ε > 0.
Near-infrared spectroscopy of embedded protostars in the massive metal-poor star-forming region NGC 346
Creators: name: Jones, O. C.
name: Reiter, M.
name: Sanchez-Janssen, R.
name: Evans, C. J.
name: Robertson, C. S.
name: Meixner, M.
name: Ochsendorf, B.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present medium-resolution (R $\sim$ 4000) YJ, H \& K band spectroscopy of candidate young stellar objects (YSOs) in NGC~346, the most active star-formation region in the metal-poor (Z = 1/5 Z$_{\sun}$) Small Magellanic Cloud. The spectra were obtained with the KMOS (K-Band Multi Object Spectrograph) integral field instrument on the Very Large Telescope. From our initial sample of 18 candidate high-mass YSOs previously identified from mid-IR photometry and radiative transfer model fits to their spectral energy distributions, approximately half were resolved into multiple components by our integral-field data. In total, we detect 30 continuum sources and extract reliable spectra for 12 of these objects. The spectra show various features including hydrogen recombination lines, and lines from H$_2$, He~{\sc i} and [Fe~{\sc ii}], which are indicative of accretion, discs and outflowing material in massive YSOs. We spectroscopically confirm the youthful nature of nine YSO candidates and identify two others as OB stars. All of the confirmed YSOs have Br$γ$ in emission, but no emission is seen from the CO bandhead, despite other disc tracers present in the spectra. He\,{\sc i}~1.083 $μ$m emission is also detected at appreciably higher rates than for the Galaxy.
description: 15 pages, 6 figures. Accepted for publication MNRAS
The alignment between brightest cluster galaxies and host clusters
Creators: name: Yuan, Z. S.
name: Wen, Z. L.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The alignment between brightest cluster galaxies (BCGs) and host clusters can reveal the mystery of formation and evolution for galaxy clusters. We measure cluster orientations in optical based on the projected distribution of member galaxies and in X-ray by fitting the morphology of intra-cluster medium (ICM). Cluster orientations determined in the two wavelengths are generally consistent. The orientation alignment between BCGs and host clusters is confirmed and more significant than previous works. We find that BCGs are more aligned with cluster orientations measured in X-ray than those from optical data. Clusters with a brighter BCG generally show a stronger alignment. We argue that the detected redshift evolution of the alignment is probably caused by observational bias rather than intrinsic evolution. The alignment is not related to the ellipticity of BCGs, and the richness, ellipticity and dynamical state of host clusters. The strong alignment between BCGs and morphology of ICMs may be the consequence of the co-evolution between the central massive galaxy and host clusters.
description: 8 pages, 8 figures, 3 tables, accepted for publication in MNRAS
An Improved Method of Estimating the Uncertainty of Air-Shower Size at Ultra-High Energies
Creators: name: Coleman, Alan
name: Billoir, Pierre
name: Deligny, Oliver
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The collection of a statistically significant number detected of cosmic rays with energy above $10^{17}$ to $10^{18}$ eV requires widely-spaced particle detectors at the ground level to detect the extensive air showers induced in the atmosphere. The air-shower sizes, proxies of the primary energies, are then estimated by fitting the observed signals to a functional form for expectations so as to interpolate the signal at a reference distance. The functional form describes the rapid falloff of the expected signal with the distance from the shower core, using typically two logarithmic slopes to account for the short-range and long-range decreases of signals. The uncertainties associated to the air-shower sizes are determined under the assumption of a quadratic dependence of the log-likelihood on the fitted parameters around the minimum, so that a meaningful variance-covariance matrix is provided. In this paper, we show that for an event topology where one signal is much larger than the others, the quadratic dependence of the fitted function around the minimum is a poor approximation that leads to an inaccurate estimate of the uncertainties. To restore a quadratic shape, we propose to use the polar coordinates around the detector recording the largest signal, projected onto the plane of the shower front, to define the likelihood function in terms of logarithmic polar distances, polar angles and logarithmic shower sizes as free parameters. We show that a meaningful variance-covariance matrix is then recovered in the new coordinate system, as the dependence of the fitted function on the modified parameters is properly approximated by a quadratic function. The use of the uncertainties in the new coordinate system for subsequent high-level analyses is illustrated.
description: Accepted in Astroparticle Physics
Explicit formulas and global uniqueness for phaseless inverse scattering in multidimensions
Creators: name: Novikov, Roman
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider phaseless inverse scattering for the Schrödinger equation with compactly supported potential in dimension $d\ge 2$. We give explicit formulas for solving this problem from appropriate data at high energies. As a corollary, we give also a global uniqueness result for this problem with appropriate data on a fixed energy neighborhood.
Information Warfare during the George Floyd Protests
Creators: name: Johnson, Daniel
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2022

description: On May 25, 2020, Minneapolis police officer Derek Chauvin kneeled on George Floyd’s neck for 9 and a half minutes, ultimately killing him (Willis et al., 2020). The next day, Darnella Frazier, who witnessed the incident while visiting a nearby grocery store, uploaded the video of Floyd during those last moments that led to his death (Mannix, 2020). During the protests, BLM supporters utilized tactics akin to those used in the military- jamming police radios (Main, 2020) utilizing social media uploads to provide intelligence on police movements and undercover officers, and countering outside agitators by uploading footage that specifically pointed out hostile behavior in the same way the U.S. military uses combat camera personnel to counter opponent disinformation (Hamstra, 2008).       Currently, most studies focus separately on either military of foreign use of information warfare tactics (Arif et al., 2018; Freelon & Wells, 2020) rather than domestic social movements using these techniques. Existing research on “cop watching” (Canella, 2018), hacktivism (Tanczer, 2016) citizen journalism (Wall, 2015), and media witnessing (Richardson, 2016) are limited in their definitions as the purposes and techniques of domestic social movements evolve. This paper aims to fill in and extend the literature by empirically demonstrating the limits of such terms such as media witnessing and counter surveillance and how the military terms of counterintelligence, combat camera, and others allows us to fully understand protest events.       This paper analyzed 1200 tweets covering the George Floyd protests from a period of May 29, 2020, to June 27, 2020, utilizing the concept of information warfare and its seven information related activities as a lens. In the context of social movements, I offer a new term to define how these activities in protests: Social Movement Information Related Tactics (SMIRT). This study utilized mixed methods- two phases of data analysis were conducted: how often do these tactics appear (quantitative), and how were they used (qualitative), and puts forward four main contributions to the literatures of social movements, information warfare, and the connection between both civil and military like protest tactics.