cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Modularity and 4D-2D spectral equivalences for large-N gauge theories with adjoint matter
Creators: name: Cherman, A.
name: Dienes, K.R.
name: McGady, D.A.
name: Basar, G.
Publisher: name: Springer Verlag
Year: 2016

description: In recent work, we demonstrated that the confined-phase spectrum of non-supersymmetric pure Yang-Mills theory coincides with the spectrum of the chiral sector of a two-dimensional conformal field theory in the large-N limit. This was done within the tractable setting in which the gauge theory is compactified on a three-sphere whose radius is small compared to the strong length scale. In this paper, we generalize these observations by demonstrating that similar results continue to hold even when massless adjoint matter fields are introduced. These results hold for both thermal and (−1)F -twisted partition functions, and collectively suggest that the spectra of large-N confining gauge theories are organized by the symmetries of two-dimensional conformal field theories.
Sign problem and Monte Carlo calculations beyond Lefschetz thimbles
Creators: name: Bedaque, P.F.
name: Basar, G.
name: Warrington, N.C.
name: Alexandru, A.
name: Ridgway, G.W.
Publisher: name: Springer Verlag
Year: 2016

description: Abstract: We point out that Monte Carlo simulations of theories with severe sign problems can be profitably performed over manifolds in complex space different from the one with fixed imaginary part of the action (“Lefschetz thimble”). We describe a family of such manifolds that interpolate between the tangent space at one critical point (where the sign problem is milder compared to the real plane but in some cases still severe) and the union of relevant thimbles (where the sign problem is mild but a multimodal distribution function complicates the Monte Carlo sampling). We exemplify this approach using a simple 0+1 dimensional fermion model previously used on sign problem studies and show that it can solve the model for some parameter values where a solution using Lefschetz thimbles was elusive.
Experimental study of secure quantum key distribution with source and detection imperfections
Creators: name: Chen, Ye
name: Huang, Chunfeng
name: Chen, Zihao
name: He, Wenjie
name: Zhang, Chengxian
name: Sun, Shihai
name: Wei, Kejin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The quantum key distribution (QKD), guaranteed by the principle of quantum physics, is a promising solution for future secure information and communication technology. However, device imperfections compromise the security of real-life QKD systems, restricting the wide deployment of QKD. This study reports a decoy-state BB84 QKD experiment that considers both source and detection imperfections. In particular, we achieved a rigorous finite-key security bound over fiber links of up to 75 km by applying a systematic performance analysis. Furthermore, our study considers more device imperfections than most previous experiments, and the proposed theory can be extended to other discrete-variable QKD systems. These features constitute a crucial step toward securing QKD with imperfect practical devices.
description: 11 pages
The Spinless Relativistic Kink-Like Problem
Creators: name: Lucha, Wolfgang
name: Schöberl, Franz F.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: Nuclear Theory (nucl-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We constrain the possible bound-state solutions of the spinless Salpeter equation (the most obvious semirelativistic generalization of the nonrelativistic Schrödinger equation) with an interaction between the bound-state constituents given by the kink-like potential (a central potential of hyperbolic-tangent form) by formulating a bunch of very elementary boundary conditions to be satisfied by all solutions of the eigenvalue problem posed by a bound-state equation of this type, only to learn that all results produced by a procedure very much liked by some quantum-theory practitioners prove to be in severe conflict with our expectations.
description: 8 pages
Updated characterization of long-period single companion by combining radial velocity, relative astrometry, and absolute astrometry
Creators: name: Philipot, F.
name: Lagrange, A. -M.
name: Rubini, P.
name: Kiefer, F.
name: Chomez, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Thanks to more than 20 years of monitoring, the radial velocity (RV) method has detected long-period companions (P > 10yr) around several dozens of stars. Yet, the true nature of these companions remains unclear because of the uncertainty as to the inclination of the companion orbital plane. Aims. We wish to constrain the orbital inclination and the true mass of long-period single companions. Methods. We used a Markov Chain Monte Carlo (MCMC) fitting algorithm to combine RV measurements with absolute astrometry and, when available, relative astrometry data. Results. We have lifted the sin(i) indetermination for 7 seven long-period companions. We find true masses in the planetary mass range for the candidate planets detected in the following systems: Epsilon Indi A, HD 13931, HD 115954, and HD 222155. The mass of HD 219077 b is close to the deuterium-burning limit and its nature is uncertain because of the imprecise mass of the host star. Using additional RV measurements, we refine the orbital parameters of HIP 70849 b and find a mass in the planetary range. By combining RV data with absolute and relative astrometry, we significantly improve the characterization of HD 211847 B and properly determine its mass, which appears to be in the low-mass star range. This work illustrates how Gaia and Hipparcos allow for the orbital properties and masses of long-period RV companions to be further constrained.
description: 17 pages, 15 figures
Revealing Carrier-Envelope Phase through Frequency Mixing and Interference in Frequency Resolved Optical Gating
Creators: name: Snedden, Edward W.
name: Walsh, David A.
name: Jamison, Steven P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate that full temporal characterisation of few-cycle electromagnetic pulses, including retrieval of the carrier envelope phase (CEP), can be directly obtained from Frequency Resolved Optical Gating (FROG) techniques in which the interference between non-linear frequency mixing processes is resolved. We derive a framework for this scheme, defined Real Domain-FROG (ReD-FROG), as applied to the cases of interference between sum and difference frequency components and between fundamental and sum/difference frequency components. A successful numerical demonstration of ReD-FROG as applied to the case of a self-referenced measurement is provided. A proof-of-principle experiment is performed in which the CEP of a single-cycle THz pulse is accurately obtained and demonstrates the possibility for THz detection beyond the bandwidth limitations of electro-optic sampling.
description: 7 pages, 4 figures. To be submitted for publication in Optics Express, January 2015
Cell response in free-packed granular systems
Creators: name: Cunha, Ana F.
name: Matias, André F. V.
name: Dias, Cristóvão S.
name: Oliveira, Mariana B.
name: Araújo, Nuno A. M.
name: Mano, João F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The study of the interactions of living adherent cells with mechanically stable (visco)elastic materials enables understanding and exploiting physiological phenomena mediated by cell-extracellular communication. However, insight on the interaction of cells and surrounding objects with different stability patterns upon cell contact might unveil cell responses that may be engineered for innovative applications. Here, it is hypothesized that the efficiency of cell attachment, spreading and movement across a free-packed granular bed of microparticles depend on microparticle diameter, raising the possibility of a necessary minimum traction force for the reinforcement of cell-particle bonds, and long-term cell adhesion. The results suggest that microparticles with 14-20 μm are prone to cell-mediated mobility, holding the potential of inducing early cell detachment, while objects with diameters from 38-85 μm enable long-lasting cell adhesion and proliferation. An in-silico hybrid particle-based model that addresses time-dependent biological mechanisms of cell adhesion is proposed, providing inspiration for engineering platforms to address healthcare-related challenges.
Nontopological self-dual Maxwell-Higgs vortices
Creators: name: Bazeia, D.
name: Casana, R.
name: Ferreira, M. M.
name: da Hora, E.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study the existence of self-dual nontopological vortices in generalized Maxwell-Higgs models recently introduced in Ref. \cite{gv}. Our investigation is explicitly illustrated by choosing a sixth-order self-interaction potential, which is the simplest one allowing the existence of nontopological structures. We specify some Maxwell-Higgs models yielding BPS nontopological vortices having energy proportional to the magnetic flux, $Φ_{B}$, and whose profiles are numerically achieved. Particularly, we investigate the way the new solutions approach the boundary values, from which we verify their nontopological behavior. Finally, we depict the profiles numerically found, highlighting the main features they present.
description: 6 pages, 4 figures
Spinel Cu-Mn-Cr Oxide Nanoparticle-Pigmented Solar Selective Coatings Maintaining >94% Efficiency at 750 degrees C
Creators: name: Xu, Can
name: Wang, Xiaoxin
name: Liu, Jifeng
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applied Physics (physics.app-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: High-temperature concentrating solar power (CSP) system is capable of harvesting and storing solar energy as heat towards cost-effective dispatchable solar electricity. Solar selective coating is a critical component to boost its efficiency by maximizing solar absorptance and minimizing thermal emittance losses. However, maintaining a high solar-thermal conversion efficiency >90% for long-term operation at >750 degrees C remains a significant challenge. Herein, we report spray-coated spinel Cu-Mn-Cr oxide nanoparticle-pigmented solar selective coatings on Inconel tube sections maintaining >94% efficiency at 750 degrees C and >92.5% at 800 degrees C under 1000x solar concentration after 60 simulated day-night thermal cycles in air, each cycle comprising 12h at 750 degrees C/800 degrees C and 12h cooling to 25 degrees C. The solar spectral selectivity is intrinsic to the band-to-band and d-d transitions of non-stoichiometric spinel Cu-Mn-Cr oxide nanoparticles by balancing the lattice site inversion of Cu2+ and Mn3+ on tetrahedral vs. octahedral sites. This feature offers a large fabrication tolerance in nanoparticle volume fraction and coating thickness, facilitating low-cost and scalable spray-coated high-efficiency solar selective absorbers for high-temperature CSP systems.
description: This is the orginal version of our paper later published in ACS Applied Materials and Interfaces. Some revisions are made in the final version, which is provided in the DOI and journal reference info
Method for finding mechanism and activation energy of magnetic transitions, applied to skyrmion and antivortex annihilation
Creators: name: Bessarab, Pavel F.
name: Uzdin, Valery M.
name: Jónsson, Hannes
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A method for finding minimum energy paths of transitions in magnetic systems is presented and used to determine the mechanism and estimate the activation energy of skyrmion and antivortex annihiliation in nano-systems. The path is optimized with respect to orientation of the magnetic vectors while their magnitudes are fixed or obtained from separate calculations. The curvature of the configuration space is taken into account by: (1) using geodesics to evaluate distances and displacements of the system during the optimization, and (2) projecting the path tangent and the magnetic force on the tangent space of the manifold defined by all possible orientations of the magnetic vectors. The method, named geodesic nudged elastic band (GNEB), and its implementation are illustrated with calculations of complex transitions involving annihilation and creation of skyrmion and antivortex states. The lifetime of the latter was determined within harmonic transition state theory using a noncollinear extension of the Alexander-Anderson model.
Water Detection with Sentinel-1 Using Digital Earth Africa Data Cube
Creators: name: Digital Earth Africa
Publisher: name: GEO Knowledge Hub
Year: 2022
Subjects: sentinel-1
SAR
Water

description: What is it about
Background
The impacts of coastal change and erosion present challenges to the valuable coastal infrastructure and ecological habitats. With the ever-changing coastal environment, it is vital to have updated data on the position of the coastline to help coastal managers identify and minimize the impacts of coastal change and erosion. Monitoring of water extent is therefore vital for the protection and conservation of coastal ecosystems.
As demonstrated in the coastal erosion notebook, coastline and water extent can be monitored using optical data, however, there are challenges since the images can be strongly affected by the weather. This particular problem is in cloudy regions where clouds in the wet season prevent the optical satellites from taking clear images. Therefore, the two sentinel -1 satellites operated by ESA as part of the Copernicus program provide radar observations unaffected by cloud cover, making all-weather observation possible every 6 to 12 days over Africa.
This notebook allows for easy replication of analysis across Africa, by simply changing the analysis parameters. The user guide provides an overview of the analysis, resources used/supplied, and directions on how to reproduce the analysis.
This knowledge package includes the necessary data, computational resources, and instructions required to reproduce the methodology used in Digital Earth Africa's 'Water Detection with Sentinel-1' Jupyter Notebook. 
The User's Guide provides an overview of the application.
Inventor Mobility, Knowledge Spillovers and Spinoff Entry in the U.S. Semiconductor Industry: Regional Patterns, Determinants, and Learning Implications
Creators: name: Cristobal A. Cheyre Forestier
Publisher: name: Figshare
Year: 2018
Subjects: subject: 160510 Public Policy
subject: FOS: Political science
subject: 99999 Engineering not elsewhere classified
subject: FOS: Other engineering and technologies

description: This dissertation systematically analyzes the link between inventor mobility and knowledge diffusion in the semiconductor industry. It looks at how incumbents and recent entrants benefit from hiring inventors by analyzing geographical mobility patterns, the determinants of inventor mobility, and the types of learning that results from hiring. The analysis is based on data on the origins of all semiconductor producers with larger sales, and on patent filings and patent citations. Three papers comprise the dissertation.
The first paper argues that the higher mobility of inventors in Silicon Valley can be explained mostly through the rate of spinoff entry in the region. The empirical evidence shows that inventor mobility was high in Silicon Valley since spinoffs started entering in large numbers, which happened before the industry clustered there. Agglomeration economies and the ban of non-compete covenants can facilitate the continued entry of spinoffs, but they cannot explain the initial wave of entry. Further evidence of the effect of entry on mobility rates is provided by spinoffs outside of Silicon Valley, which also hire many inventors from their parents and other local firms.
The second paper identifies and tests several drivers of worker turnover associated with matching and learning. Incumbents, recent entrants, and spinoffs have different goals when hiring experienced inventors. Incumbents hire many workers without prior patents, while younger firms hire mostly experienced inventors. For inventors hired by incumbents, the main determinant is matching. Instead, movements from parent to spinoffs seem to be motivated by the acquisition of knowledge from the parent. None of the drivers previously identified seem to apply to recent entrants.
The last paper analyzes the effect of hiring experienced inventors on the citations made by the hiring firm. In movements to incumbents, or from parent to spinoffs, there is an increase in citations from the hiring to the origin firm. However, movements to recent entrants are associated with increases in citations to other firms. This is related to what firms learn from hiring. While incumbents and spinoff access firm specific knowledge from moving inventors, recent entrants seem to be more concerned with the knowledge about the industry that the inventor possesses.
Monte Carlo Study of Real Time Dynamics on the Lattice
Creators: name: Başar, G.
name: Alexandru, A.
name: Warrington, N.C.
name: Bedaque, P.F.
name: Vartak, S.
Publisher: name: American Physical Society
Year: 2016

description: Monte Carlo studies involving real time dynamics are severely restricted by the sign problem that emerges from a highly oscillatory phase of the path integral. In this Letter, we present a new method to compute real time quantities on the lattice using the Schwinger-Keldysh formalism via Monte Carlo simulations. The key idea is to deform the path integration domain to a complex manifold where the phase oscillations are mild and the sign problem is manageable. We use the previously introduced "contraction algorithm" to create a Markov chain on this alternative manifold. We substantiate our approach by analyzing the quantum mechanical anharmonic oscillator. Our results are in agreement with the exact ones obtained by diagonalization of the Hamiltonian. The method we introduce is generic and, in principle, applicable to quantum field theory albeit very slow. We discuss some possible improvements that should speed up the algorithm.
The Complex North Transition Region of Centaurus A: Radio Structure
Creators: name: Neff, Susan G.
name: Eilek, Jean A.
name: Owen, Frazer N.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present deep radio images of the inner 50 kpc of Centaurus A, taken with the Karl G. Jansky Very Large Array (VLA) at 90cm. We focus on the Transition Regions between the inner galaxy - including the active nucleus, inner radio lobes, and star-forming disk - and the outer radio lobes. We detect previously unknown extended emission around the Inner Lobes, including radio emission from the star-forming disk. We find that the radio-loud part of the North Transition Region, known as the North Middle Lobe, is significantly overpressured relative to the surrounding ISM. We see no evidence for a collimated flow from the Active Galactic Nucleus (AGN) through this region. Our images show that the structure identified by Morganti et al. (1999) as a possible large-scale jet appears to be part of a narrow ridge of emission within the broader, diffuse, radio-loud region. This knotty radio ridge is coincident with other striking phenomena: compact X-ray knots, ionized gas filaments, and streams of young stars. Several short-lived phenomena in the North Transition Region, as well as the frequent re-energization required by the Outer Lobes, suggest that energy must be flowing through both Transition Regioins at the present epoch. We suggest that the energy flow is in the form of a galactic wind.
description: 23 pages, 10 figures, accepted for publication in Astrophysical Journal. A version with higher quality figures may be found at http://www.aoc.nrao.edu/~fowen/papers/CenA/
Design of dye-sensitized TiO$_2$ materials for photocatalytic hydrogen production: light and shadow
Creators: name: Zani, Lorenzo
name: Melchionna, Michele
name: Montini, Tiziano
name: Fornasiero, Paolo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Visible light-driven production of fuels and value-added chemicals is currently one of the most intensely investigated research topics across various scientific disciplines, due to its potential to ease the World s dependence on fossil fuels. In this perspective, we recapitulate some of the main features of dye-sensitized photocatalytic systems aimed at solar H$_2$ production, focusing in particular on TiO$_2$-based three-component assemblies with organic sensitizers. Relevant aspects include the structural and electronic properties of the sensitizers, the nature of the semiconductor and the hydrogen evolution catalysts, the role of the sacrificial donor and the effect of the reaction parameters on H$_2$ production rate and stability. Besides presenting the most significant recent developments of the field, we also analyse some of its common practices in terms of experimental design, laboratory procedures and data presentation, trying to highlight their weaknesses and suggesting possible improvements. We then conclude with a short paragraph discussing the possible future development of this exciting research area.
OGLE-2019-BLG-0362Lb: A super-Jovian-mass planet around a low-mass star
Creators: name: Chung, Sun-Ju
name: Yee, Jennifer C.
name: Udalski, Andrej
name: Gould, Andrew
name: Albrow, Michael D.
name: Jung, Youn Kil
name: Hwang, Kyu-Ha
name: Han, Cheongho
name: Ryu, Yoon-Hyun
name: Shin, In-Gu
name: Shvartzvald, Yossi
name: Zang, Weicheng
name: Cha, Sang-Mok
name: Kim, Dong-Jin
name: Kim, Seung-Lee
name: Lee, Chung-Uk
name: Lee, Dong-Joo
name: Lee, Yongseok
name: Park, Byeong-Gon
name: Pogge, Richard W.
name: Poleski, Radek
name: Pietrukowicz, Przemek Mróz Paweł
name: Skowron, Jan
name: Szymański, Michał K.
name: Soszyński, Igor
name: Kozłowski, Szymon
name: Rybicki, Krzysztof A.
name: Iwanek, Patryk
name: Wrona, Marcin
name: Gromadzki, Mariusz
name: Ulaczyk, Krzysztof
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We present the analysis of a planetary microlensing event OGLE-2019-BLG-0362 with a short-duration anomaly $(\sim 0.4\, \rm days)$ near the peak of the light curve, which is caused by the resonant caustic. The event has a severe degeneracy with $Δχ^2 = 0.9$ between the close and the wide binary lens models both with planet-host mass ratio $q \simeq 0.007$. We measure the angular Einstein radius but not the microlens parallax, and thus we perform a Bayesian analysis to estimate the physical parameters of the lens. We find that the OGLE-2019-BLG-0362L system is a super-Jovian-mass planet $M_{\rm p}=3.26^{+0.83}_{-0.58}\, M_{\rm J}$ orbiting an M dwarf $M_{\rm h}=0.42^{+0.34}_{-0.23}\, M_\odot$ at a distance $D_{\rm L} =5.83^{+1.04}_{-1.55}\, \rm kpc$. The projected star-planet separation is $a_{\perp} = 2.18^{+0.58}_{-0.72}\, \rm AU$, which indicates that the planet lies beyond the snow line of the host star.
description: 8 pages, 5 figures, Accepted in JKAS
Hydrodynamics, resurgence, and transasymptotics
Creators: name: Başar, G.
name: Dunne, G.V.
Publisher: name: American Physical Society
Year: 2015

description: The second order hydrodynamical description of a homogeneous conformal plasma that undergoes a boost-invariant expansion is given by a single nonlinear ordinary differential equation, whose resurgent asymptotic properties we study, developing further the recent work of Heller and Spalinski [Phys. Rev. Lett. 115, 072501 (2015)]. Resurgence clearly identifies the nonhydrodynamic modes that are exponentially suppressed at late times, analogous to the quasinormal modes in gravitational language, organizing these modes in terms of a trans-series expansion. These modes are analogs of instantons in semiclassical expansions, where the damping rate plays the role of the instanton action. We show that this system displays the generic features of resurgence, with explicit quantitative relations between the fluctuations about different orders of these nonhydrodynamic modes. The imaginary part of the trans-series parameter is identified with the Stokes constant, and the real part with the freedom associated with initial conditions.
Additional file 3 of A critical review: developing a birth integrity framework for epidemiological studies through meta-ethnography
Creators: name: Batram-Zantvoort, Stephanie
name: Wandschneider, Lisa
name: Razum, Oliver
name: Miani, Céline
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 3. PRISMA 2020 flow diagram and adapted PRISMA for reporting systematic reviews reporting of qualitative and quantitative evidence.
System Architecture and Planetary Obliquity: Implications for Long-Term Habitability
Creators: name: Vervoort, Pam
name: Horner, Jonathan
name: Kane, Stephen R.
name: Turner, Sandra Kirtland
name: Gilmore, James
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In the search for life beyond our Solar system, attention should be focused on those planets that have the potential to maintain habitable conditions over the prolonged periods of time needed for the emergence and expansion of life as we know it. The observable planetary architecture is one of the determinants for long-term habitability as it controls the orbital evolution and ultimately the stellar fluxes received by the planet. With an ensemble of n-body simulations and obliquity models of hypothetical planetary systems, we demonstrate that the amplitude and period of eccentricity, obliquity, and precession cycles of an Earth-like planet are sensitive to the orbital characteristics of a giant companion planet. A series of transient, ocean-coupled climate simulations show how these characteristics of astronomical cycles are decisive for the evolving surface conditions and long-term fractional habitability relative to the modern Earth. The habitability of Earth-like planets increases with the eccentricity of a Jupiter-like companion, provided that the mean obliquity is sufficiently low to maintain temperate temperatures over large parts of its surface throughout the orbital year. A giant companion closer in results in shorter eccentricity cycles of an Earth-like planet but longer, high-amplitude, obliquity cycles. The period and amplitude of obliquity cycles can be estimated to first order from the orbital pathways calculated by the n-body simulations. In the majority of simulations, obliquity amplitude relates directly to the orbital inclination whereas the period of obliquity cycles is a function of nodal precession and the proximity of a giant companion.
description: 20 pages, 12 figures, accepted for publication in The Astronomical Journal
Stellar models in Brane Worlds
Creators: name: Linares, Francisco X.
name: Garcia-Aspeitia, Miguel A.
name: Ureña-Lopez, L. Arturo
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider here a full study of stellar dynamics from the brane-world point of view in the case of constant density and of a polytropic fluid. We start our study cataloguing the minimal requirements to obtain a compact object with a Schwarszchild exterior, highlighting the low and high energy limit, the boundary conditions, and the appropriate behavior of Weyl contributions inside and outside of the star. Under the previous requirements we show an extensive study of stellar behavior, starting with stars of constant density and its extended cases with the presence of nonlocal contributions. Finally, we focus our attention to more realistic stars with a polytropic equation of state, specially in the case of white dwarfs, and study their static configurations numerically. One of the main results is that the inclusion of the Weyl functions from braneworld models allow the existence of more compact configurations than within General Relativity.
description: 9 pages, 6 figures
4D-2D equivalence for large- N Yang-Mills theory
Creators: name: Başar, G.
name: McGady, D.A.
name: Cherman, A.
name: Dienes, K.R.
Publisher: name: American Physical Society
Year: 2015

description: General string-theoretic considerations suggest that four-dimensional large-N gauge theories should have dual descriptions in terms of two-dimensional conformal field theories. However, for nonsupersymmetric confining theories such as pure Yang-Mills theory, a long-standing challenge has been to explicitly show that any such dual descriptions actually exist. In this paper, we consider the large-N limit of four-dimensional pure Yang-Mills theory compactified on a three-sphere in the solvable limit where the sphere radius is small compared to the strong length scale, and demonstrate that the confined-phase spectrum of this gauge theory coincides with the spectrum of an irrational two-dimensional conformal field theory.
Modeling and Stability of the Horizontal Ribbon Growth Process
Creators: name: Patiño, German Andrés Oliveros
Publisher: name: Figshare
Year: 2018
Subjects: subject: 90499 Chemical Engineering not elsewhere classified
subject: FOS: Chemical engineering

description: This thesis contains a theoretical analysis of the Horizontal Ribbon Growth (HRG) process for growing silicon wafers. In the HRG process, a thin silicon ribbon is crystallized and extracted continuously from the melt, using the fact that silicon oats on its melt just like ice oats on top of water. In our work, we assess two technical issues reported in previous experimental studies: meniscus stability and interface stability. The first law of thermodynamics along with the tools of variational calculus are used to find the existence and stability conditions of the meniscus formed between the silicon wafer and the surface of the crucible. Analytical expressions describing the shapes of the meniscii are found in terms of a single-valued function and in parametric form. These functions give the feasible configurations of the HRG system in terms of operating parameters and material properties, such as ribbon length and thickness, melt level, pulling angle, contact angle, and crucible edge geometry. From the existence conditions we show that the feasible configurations place a part or the entire meniscus above the melt level. The stability condition shows that every part of the meniscus must remain above the surface of the crucible. A dynamic crystallization model that incorporates an extended version of the Mullins-Sekerka analysis describes the stability of the solid-liquid interface. The effect of solute segregation in the system and its effect on interface stability is measured as a function of the crystallization velocity. Two surface cooling methods-active and passive- are used to model the crystallization of a silicon ribbon of a given thickness. We show that low temperature gradients promote the homogeneous segregation of impurities in the melt, whereas high temperature gradients induce the formation of a solute enriched boundary layer. For both cases we found the thermal conditions that impede the growth of applied sinusoidal perturbations to the interface. We found that setting the crystallization model in a Lagrangean frame of reference provides an alternative way to calculate the shape of the silicon wafer.
Dynamics of Large Scale Solar Wind Streams Obtained by the Double Superposed Epoch Analysis: 5. Influence of the Solar Activity Decrease
Creators: name: Yermolaev, Yuri I.
name: Lodkina, Irina G.
name: Khokhlachev, Alexander A.
name: Yermolaev, Michael Yu.
name: Riazantseva, Maria O.
name: Rakhmanova, Liudmila S.
name: Borodkova, Natalia L.
name: Sapunova, Olga V.
name: Moskaleva, Anastasiia V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: In solar cycles 23-24, solar activity noticeably decreased, and, as a result, solar wind parameters decreased. Based on the measurements of the OMNI base for the period 1976-2019, the time profiles of the main solar wind parameters and magnetospheric indices for the main interplanetary drivers of magnetospheric disturbances (solar wind types CIR, Sheath, ejecta and MC) are studied using the double superposed epoch method. The main task of the research is to compare time profiles for the epoch of high solar activity at 21-22 solar cycles and the epoch of low activity at 23-24 solar cycles. The following results were obtained. (1) The analysis did not show a statistically significant change in driver durations during the epoch of minimum. (2) The time profiles of all parameters for all types of SW in the epoch of low activity have the same shape as in the epoch of high activity, but locate at lower values of the parameters. (3) In CIR events, the longitude angle of the solar wind flow has a characteristic S-shape, but in the epoch of low activity it varies in a larger range than in the previous epoch.
description: 22 pages, 8 figures
Detailed accretion history of the supermassive black hole in NGC 5972 over the past $\gtrsim$10$^4$ years through the extended emission line region
Creators: name: Finlez, C.
name: Treister, E.
name: Bauer, F.
name: Keel, W.
name: Koss, M.
name: Nagar, N.
name: Sartori, L.
name: Maksym, W. P.
name: Venturi, G.
name: Tubin, D.
name: Harvey, T.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present integral field spectroscopic observations of NGC 5972 obtained with the Multi Unit Spectroscopic Explorer (MUSE) at VLT. NGC 5972 is a nearby galaxy containing both an active galactic nucleus (AGN), and an extended emission line region (EELR) reaching out to $\sim 17$ kpc from the nucleus. We analyze the physical conditions of the EELR using spatially-resolved spectra, focusing on the radial dependence of ionization state together with the light travel time distance to probe the variability of the AGN on $\gtrsim 10^{4}$ yr timescales. The kinematic analysis suggests multiple components: (a) a faint component following the rotation of the large scale disk; (b) a component associated with the EELR suggestive of extraplanar gas connected to tidal tails; (c) a kinematically decoupled nuclear disk. Both the kinematics and the observed tidal tails suggest a major past interaction event. Emission line diagnostics along the EELR arms typically evidence Seyfert-like emission, implying that the EELR was primarily ionized by the AGN. We generate a set of photoionization models and fit these to different regions along the EELR. This allows us to estimate the bolometric luminosity required at different radii to excite the gas to the observed state. Our results suggests that NGC 5972 is a fading quasar, showing a steady gradual decrease in intrinsic AGN luminosity, and hence the accretion rate onto the SMBH, by a factor $\sim 100$ over the past $5 \times 10^{4}$ yr.
description: To be published in The Astrophysical Journal
Consumer acceptance of the use of artificial intelligence in online shopping: evidence from Hungary
Creators: name: Nagy, Szabolcs
name: Hajdu, Noemi
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business

description: The rapid development of technology has drastically changed the way consumers do their shopping. The volume of global online commerce has significantly been increasing partly due to the recent COVID-19 crisis that has accelerated the expansion of e-commerce. A growing number of webshops integrate Artificial Intelligence (AI), state-of-the-art technology into their stores to improve customer experience, satisfaction and loyalty. However, little research has been done to verify the process of how consumers adopt and use AI-powered webshops. Using the technology acceptance model (TAM) as a theoretical background, this study addresses the question of trust and consumer acceptance of Artificial Intelligence in online retail. An online survey in Hungary was conducted to build a database of 439 respondents for this study. To analyse data, structural equation modelling (SEM) was used. After the respecification of the initial theoretical model, a nested model, which was also based on TAM, was developed and tested. The widely used TAM was found to be a suitable theoretical model for investigating consumer acceptance of the use of Artificial Intelligence in online shopping. Trust was found to be one of the key factors influencing consumer attitudes towards Artificial Intelligence. Perceived usefulness as the other key factor in attitudes and behavioural intention was found to be more important than the perceived ease of use. These findings offer valuable implications for webshop owners to increase customer acceptance
Additional file 1 of Antifungal activity of Co(II) and Cu(II) complexes containing 1,3-bis(benzotriazol-1-yl)-propan-2-ol on the growth and virulence traits of fluconazole-resistant Candida species: synthesis, DFT calculations, and biological activity
Creators: name: Murcia-Galán, Ricardo A.
name: Durán, Sandra M.
name: Leal-Pinto, Sandra M.
name: Roa-Cordero, Martha V.
name: Vargas, Jose D.
name: Herrera, Laura V.
name: Muñoz-Castro, Alvaro
name: MacLeod-Carey, Desmond
name: Naranjo, Tonny W.
name: Rodríguez-Kessler, Peter L.
name: Hurtado, John J.
Publisher: name: figshare
Year: 2024
Subjects: subject: Biochemistry
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Plant Biology
subject: FOS: Biological sciences

description: Additional file 1. Additional figures and tables.
Multi-layered Energy Conversion and Frequency Control in Complex Electric Power Systems
Creators: name: Nipun Popli
Publisher: name: Figshare
Year: 2018
Subjects: subject: Computer Engineering
subject: 90699 Electrical and Electronic Engineering not elsewhere classified
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: The main performance objective in an electric power grid entails timely and efficient generation and delivery to the time-varying electricity demand. As the electricity industry is witnessing proliferation of the mainstream renewables, the minute-by-minute variations in wind and solar power generation may result in temporary electricity scarcity that jeopardizes grid stability and quality of service. The evolving electricity markets are aimed at incentivizing the conventional generators to reinforce their operating flexibility. This dissertation concerns the goal of enhancing the dynamic response rates of interconnected controllable resources by means of a multi-layered fuel input control of electrically coupled heterogeneous energy conversion components. Both power engineering and large-scale control contributions are made in support of this enhancement. First, improved fuel input controls are designed to enable flexible physics-based energy conversion dynamics required by the interconnected grid. To efficiently utilize the resources load-following and regulation problems are stated. The efficacy of proposed fuel input control designs in enhancing the dynamic response rates is illustrated on IEEE 14-bus system. Second, the problem is formalized as multi-input multioutput time-varying trajectory tracking based on a decentralized spatiotemporal composite control design. The concepts of vector-Lyapunov function and singular perturbation are invoked to formalize model decompositions, over space and time, respectively. Next, the assumptions for model simplifications are relaxed and the problem of parametric uncertainty is addressed. A minimumcost resilient co-design approach is introduced for storage-sensors-communication channels in a complex electric power grid. The notion of selective strong structural fixed modes is explored as a characterization of feasible decentralized control laws for an arbitrary system realization satisfying a pre-specified structure. Finally, it is proposed that planning of generation portfolio must be driven by the objective of maintaining adequate operating flexibility in the system. The goal is to ensure sufficient ramp capacity to sustain the significant integration of intermittent renewable resources.
A characterization of the wave front set defined by the iterates of an operator with constant coefficients
Creators: name: Boiti, Chiara
name: Jornet, David
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35A18, 35A20, 35A21

description: We characterize the wave front set $WF^P_\ast(u)$ with respect to the iterates of a linear partial differential operator with constant coefficients of a classical distribution $u\in{\mathcal D}'(Ω)$, $Ω$ an open subset in ${\mathbb R}^n$. We use recent Paley-Wiener theorems for generalized ultradifferentiable classes in the sense of Braun, Meise and Taylor. We also give several examples and applications to the regularity of operators with variable coefficients and constant strength. Finally, we construct a distribution with prescribed wave front set of this type.
Multiscale Design of Polymeric Biomaterials for Reducing Epidermal Downgrowth in Percutaneous Devices
Creators: name: Pitirat  Pholpabu
Publisher: name: Figshare
Year: 2018
Subjects: subject: 90399 Biomedical Engineering not elsewhere classified
subject: FOS: Medical engineering

description: Percutaneous devices are necessary tools in modern healthcare. More than one hundred fifty million percutaneous catheters have been purchased annually for various medical procedures, such as blood monitoring, urine drainage, and drug administration. However, catheter-related bloodstream infections occur in a high rate, up to 250,000 cases each year, and lead up to 25% mortality rate. One of the key causes is the skindevice incompatibility. It contributes to chronic inflammation and skin migration that generates a deep gap around the device. The lack of body outer barrier in such small area is ample for bacteria that accumulate near the insertion site to penetrate into the blood system, leading to a high risk of infections. Engineering of physical, chemical, and mechanical properties of percutaneous biomaterials is promising to improve host responses and ultimately prevent the infections. In this study, we design percutaneous biomaterials using three main approaches, i.e. surface topography, macrophage modulation, and protein-adsorption resisting materials, to attenuate the dermal downgrowth. The material in each design is characterized in in vitro environments to obtain physical, chemical, and mechanical properties, and also in in vivo milieu using a mouse model to profoundly investigate host responses. This work provides an insight of promising percutaneous material designs that reduce catheter-related complications and infections.
Additional file 2 of A critical review: developing a birth integrity framework for epidemiological studies through meta-ethnography
Creators: name: Batram-Zantvoort, Stephanie
name: Wandschneider, Lisa
name: Razum, Oliver
name: Miani, Céline
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Additional file 2. eMERGE meta-ethnography reporting guidance.
NuSTAR Observations of Intrinsically X-ray Weak Quasar Candidates: An Obscuration-Only Scenario
Creators: name: Wang, Chaojun
name: Luo, B.
name: Brandt, W. N.
name: Alexander, D. M.
name: Bauer, F. E.
name: Gallagher, S. C.
name: Huang, Jian
name: Liu, Hezhen
name: Stern, D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We utilize recent NuSTAR observations (co-added depth $\approx55$-120 ks) of PG $1001+054$, PG $1254+047$, and PHL 1811 to constrain their hard X-ray ($\gtrsim5$ keV) weakness and spectral shapes, and thus to investigate the nature of their extreme X-ray weakness. These quasars showed very weak soft X-ray emission, and they were proposed to be intrinsically X-ray weak, with the X-ray coronae producing weak continuum emission relative to their optical/UV emission. However, the new observations suggest an alternative explanation. The NuSTAR 3-24 keV spectral shapes for PG $1001+054$ and PHL 1811 are likely flat (effective power-law photon indices $Γ_{\rm eff}=1.0^{+0.5}_{-0.6}$ and $Γ_{\rm eff}=1.4^{+0.8}_{-0.7}$, respectively), while the shape is nominal for PG $1254+047$ ($Γ_{\rm eff}=1.8\pm0.3$). PG $1001+054$ and PHL 1811 are significantly weak at hard X-ray energies (by factors of $\approx26$-74 at rest-frame 8 keV) compared to the expectations from their optical/UV emission, while PG $1254+047$ is only hard X-ray weak by a factor of $\approx3$. We suggest that X-ray obscuration is present in all three quasars. We propose that, as an alternative to the intrinsic X-ray weakness + X-ray obscuration scenario, the soft and hard X-ray weakness of these quasars can be uniformly explained under an obscuration-only scenario. This model provides adequate descriptions of the multi-epoch soft and hard X-ray data of these quasars, with variable column density and leaked fraction of the partial-covering absorber. We suggest that the absorber is the clumpy dust-free wind launched from the accretion disk. These quasars probably have super-Eddington accretion rates that drive powerful and high-density winds.
description: 21 pages, 8 figures, accepted for publication in ApJ
Temperature-reflection symmetry
Creators: name: Yamazaki, M.
name: Başar, G.
name: Cherman, A.
name: McGady, D.A.
Publisher: name: American Physical Society
Year: 2015

description: We point out the presence of a T→-T temperature-reflection (T-reflection) symmetry for the partition functions of many physical systems. Without knowledge of the origin of the symmetry, we have only been able to test the existence of T-reflection symmetry in systems with exactly calculable partition functions. We show that T-reflection symmetry is present in a variety of conformal and nonconformal field theories and statistical mechanics models with known partition functions. For example, all minimal model partition functions in two-dimensional conformal field theories are invariant under T-reflections. An interesting property of the T-reflection symmetry is that it can be broken by shifts of the vacuum energy.