cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Nematic and chiral orders for planar spins on triangular lattice
Creators: name: Park, Jin-Hong
name: Onoda, Shigeki
name: Nagaosa, Naoto
name: Han, Jung Hoon
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We propose a variant of the antiferromagnetic XY model on the triangular lattice to study the interplay between the chiral and nematic orders in addition to the magnetic order. The model has a significant bi-quadratic interaction of the planar spins. When the bi-quadratic exchange energy dominates, a large temperature window is shown to exist over which the nematic and the chiral orders co-exist without the magnetic order, thus defining a chiral-nematic state. The phase diagram of the model and some of its critical properties are derived by means of the Monte Carlo simulation.
description: minor changes
Dissociation of Relativistic Projectiles with the Continuum-Discretized Coupled-Channels Method
Creators: name: Ogata, K.
name: Bertulani, C. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Relativistic effects in the breakup of weakly-bound nuclei at intermediate energies are studied by means of the continuum-discretized coupled-channels method with eikonal approximation. Nuclear coupling potentials with Lorentz contraction are newly included and those effects on breakup cross sections are investigated. We show that relativistic corrections lead to larger breakup cross sections. Coupled-channel effects on the breakup cross sections are also discussed.
description: 9 pages, 7 figures, to be published in Prog. Theo. Phys
Epitaxial Thin Films of a Chalcogenide Perovskite
Creators: name: Surendran, Mythili
name: Chen, Huandong
name: Zhao, Boyang
name: Thind, Arashdeep Singh
name: Singh, Shantanu
name: Orvis, Thomas
name: Zhao, Huan
name: Han, Jae-Kyung
name: Htoon, Han
name: Kawasaki, Megumi
name: Mishra, Rohan
name: Ravichandran, Jayakanth
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Chalcogenide perovskites have emerged as a new class of electronic materials, but fundamental properties and applications of chalcogenide perovskites remain limited by the lack of high quality epitaxial thin films. We report epitaxial thin film growth of BaZrS3, a prototypical chalcogenide, by pulsed laser deposition. X-ray diffraction studies show that the films are strongly textured out of plane and have a clear in-plane epitaxial relationship with the substrate. Electron microscopy studies confirm the presence of epitaxy for the first few layers of the film at the interface, even though away from the interface the films are polycrystalline with a large number of extended defects suggesting the potential for further improvement in growth. X-Ray reflectivity and atomic force microscopy show smooth film surfaces and interfaces between the substrate and the film. The films show strong light absorption near the band edge and photoluminescence in the visible region. The photodetector devices show fast and efficient photo response with the highest ON/OFF ratio reported for BaZrS3 films thus far. Our study opens up opportunities to realize epitaxial thin films, heterostructures, and superlattices of chalcogenide perovskites to probe fundamental physical phenomena and the resultant electronic and photonic device technologies.
Post-harvest floor changes and nitrogen mobilization in an Engelmann spruce-subalpine fir forest
Creators: name: David, Clive Addison
Publisher: name: University of British Columbia
Year: 2010

description: Engelmann spruce-subalpine fir [Picea engelmannii Parry ex Engelm.-Abies lasiocarpa (Hook.) Nutt.] (ESSF) forests occupy large portions of western North America, and of British Columbia (B.C.) in particular. These areas represent a harsh environment for plant growth. The ESSF forests of B.C. have presented serious problems of regeneration following harvesting; several factors stimulated speculation as to whether N supply limitations were involved. This study was intended to highlight the post-harvest N dynamics of an ESSF forest, and the implications of the latter for silvicultural practices. Its general objectives included characterization of the post-harvest assart effect, and investigation of the N status and growth of advance regeneration. These were achieved by means of a comparative study of an age sequence of harvested sites. The assart effect lasted for at least eight years after harvesting, with a peak of change between years three and six. There were no major physical changes in the forest floor. Low C/N ratios between 19 and 32 were believed to have contributed to increased N availability. ESSF forests may have a generally higher level of N availability than previously supposed. The advance regeneration benefited from the assart effect. Nutrient uptake appeared to increase generally from at least three years after harvesting; increases of up to 78% were noted for N. There appeared to be no general macronutrient or micronutrient limitation to growth. However, evidence of S deficiencies was encountered in some trees. Moreover, the critical levels used for N may be in need of revision. A revised critical level of 1.40% for foliar N concentrations is proposed for subalpine fir advance regeneration. If this is accurate, regeneration may have been at least temporarily N-limited from year eight after harvesting. A more rigorous investigation of these possibilities is needed. The cutting method applied to the sites approximated a one-cut shelterwood method. The method as encountered in this study should not be considered a viable silvicultural option for similar ESSF forests. Its successful application would involve some degree of forest floor manipulation to improve seedbed conditions and soil microclimatic regimes. The findings of this study demonstrate that the environmental and biological characteristics of ESSF forests make high levels of planning and care a prerequisite for the success of silvicultural practices. The question of what comprises realistic growth and yield expectations of second-rotation stands in the ESSF zone needs to be addressed urgently.
VU Data Conversations: Open Data, Open Methods, Reproducible Research
Creators: name: Cruz, Maria
name: Hettne, Kristina
name: Knapen, Tomas
name: Plomp, Esther
name: van Peursen, Wido
Publisher: name: Zenodo
Year: 2019
Subjects: Data Conversations
Open Data
Open Methods
FAIR data
Research Data Management
Reproducibility
Open Science

description: Presentations given at the first edition of Data Conversations held at the Vrije Universiteit Amsterdam and organised by the VU University Library on 17 June 2019. The theme of this first edition was "Open Data, Open Methods, Reproducible Research".

Open data, open methods, and reproducible and transparent research are increasingly endorsed by funders, publishers, institutions and learned societies. But what does making research open, transparent and reproducible mean in practice? What are the advantages and the pitfalls? In this Data Conversations researchers from different Faculties, Institutes and disciplines had a chance to hear and learn from each other about their experiences with opening up data and methods and moving towards truly reproducible research.

Agenda:

Wido van Peursen (VU Faculty of Religion of Theology) "Github as a meeting place for Biblical scholars. Open Science and community building"

Tomas Knapen (VU Faculty of Behavioural and Movement Sciences) "Open science methods: Lessons from neuroimaging"

Kristina Hettne (Centre for Digital Scholarship, Leiden University Libraries) "FAIR principles applied: a case study in reproducible data science research"

Esther Plomp (VU Amsterdam and TU Delft) "Following laboratory protocols: Filling in the gaps using protocols.io"

About Data Conversations

Data Conversations started at the University of Lancaster in the UK. The Lancaster Data Conversations aim to bring data practitioners together to talk about how researchers create, collect, use and share data. The Data Conversations at the VU Amsterdam share the same aim and are intended to provide a forum for researchers from different subjects and disciplines to exchange practices and ideas around open data, FAIR data, research data management and related open science topics.
Chiral Perturbation Theory with tensor sources
Creators: name: Cata, Oscar
name: Mateu, Vicent
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We construct the most general chirally-invariant Lagrangian for mesons in the presence of external sources coupled to the tensor current \barψσ_{μν}ψ. In order to have only even terms in the chiral expansion, we consider the new source of O(p^2). With this choice, we build the even-parity effective Lagrangian up to the p^6-order (NLO). While there are only 4 new terms at the p^4-order, at p^6-order we find 78 terms for n_f=2 and 113 terms for n_f=3. We provide a detailed discussion on the different mechanisms that ensure that our final set of operators is complete and non-redundant. We also examine the odd-parity sector, to conclude that the first operators appear at the p^8-order (NNLO).
description: 23 pages, one figure; typos corrected, one paragraph added, new section added, references added, published version
Improving performance of a research project by continuous learning – a systematic approach
Creators: name: Ekambaram, Anandasivakumar
name: Økland, Andreas
Publisher: name: Zenodo
Year: 2018

description: This poster is presented at the European Conference on Knowledge Management, University of Padua, Italy, 6-7th September 2018.

This poster is connected to a research project called Rezbuild. Website: https://rezbuildproject.eu/
Making squeezed-coherent states concrete by determining their wavefunction
Creators: name: Munguia-Gonzalez, Eduardo
name: Rego, Sheldon
name: Freericks, J. K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: With the successes of the Laser Interferometer Gravitational-wave Observatory, we anticipate increased interest in working with squeezed states in the undergraduate and graduate quantum-mechanics classroom. Because squeezed-coherent states are minimum uncertainty states, their wavefunctions in position and momentum space must be Gaussians. But this result is rarely discussed in treatments of squeezed states in quantum textbooks or quantum optics textbooks. In this work, we show three different ways to construct the wavefunction for squeezed-coherent states: (i) a differential equation-based approach; (ii) an approach that uses an expansion in terms of the simple-harmonic oscillator wavefunctions; and (iii) a fully operator-based approach. We do this to illustrate that the concept of the wavefunction can be introduced no matter what methodology an instructor wishes to use. We hope that working with the wavefunction will help demystify the concept of a squeezed-coherent state.
description: (27 pages, 1 figure, accepted for publication in Am. J. Phys.)
Astrophysical S factor and rate of $^{7}{\rm Be}(p, γ)^{8}{\rm B}$ direct capture reaction in a potential model
Creators: name: Tursunov, E. M.
name: Turakulov, S. A.
name: Kadyrov, A. S.
name: Blokhintsev, L. D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The astrophysical $^7{\rm Be}(p, γ)^8{\rm B}$ direct capture process is studied in the framework of a two-body single-channel model with potentials of the Gaussian form. A modified potential is constructed to reproduce the new experimental value of the $S$-wave scattering length and the known astrophysical $S$ factor at the Gamow energy, extracted from the solar neutrino flux. The resulting potential is consistent with the theory developed by Baye [Phys. Rev. C {\bf 62} (2000) 065803] according to which the $S$-wave scattering length and the astrophysical $S$ factor at zero energy divided by the square of ANC are related. The obtained results for the astrophysical $S$ factor at intermediate energies are in good agreement with the two data sets of Hammache {\it et al.} [Phys. Rev. Lett. {\bf 86}, 3985 (2001); {\it ibid.} {\bf 80}, 928 (1998)]. Linear extrapolation to zero energy yields $ S_{17}(0) \approx (20.5 \pm 0.5) \, \rm eV \, b $, consistent with the Solar Fusion II estimate. The calculated reaction rates are substantially lower than the results of the NACRE II collaboration.
description: 16 pages, 5 figures, 2 tables
A Pilot Survey for the H$_2$O Southern Galactic Plane Survey (HOPS)
Creators: name: Walsh, Andrew J.
name: Lo, Nadia
name: Burton, Michael G.
name: White, Graeme L.
name: Purcell, Cormac R.
name: Longmore, Steven N.
name: Phillips, Chris J.
name: Brooks, Kate J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We describe observations with the Mopra radiotelescope designed to assess the feasibility of the H$_2$O maser southern Galactic plane survey (HOPS). We mapped two one-square-degree regions along the Galactic plane using the new 12 mm receiver and the UNSW Mopra spectrometer (MOPS). We covered the entire spectrum between 19.5 and 27.5 GHz using this setup with the main aims of finding out which spectral lines can be detected with a quick mapping survey. We report on detected emission from H$_2$O masers, NH$_3$ inversion transitions (1,1), (2,2) and (3,3), HC$_3$N (3-2), as well as several radio recombination lines.
description: accepted by PASA
Colored scalar particles production in $pp$-collisions and possible mass limits for scalar gluons from future LHC data
Creators: name: Martynov, M. V.
name: Smirnov, A. D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Cross sections of the colored scalar particle production in $pp$-collisions are calculated and differential and total cross sections of the corresponding parton subprocesses are obtained. The total cross section of scalar gluon production in $pp$-collisions at the LHC is estimated and the dominant decays of scalar gluons are discussed. The production cross section of scalar gluons $F$ with masses $m_F\lesssim 1300$ GeV is shown to be sufficient for the effective production of these particles at the LHC.
description: 10 pages, 3 figures, to be published in Mod. Phys. Lett. A
Vacuum Expectation Values of the Quantum Fields
Creators: name: Zinoviev, Yury M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The new axiomatic system for the quantum field theory is proposed. The new axioms are the description of the distributions. For the finite series these distributions satisfy the linear Wightman axioms.
description: 26 pages
The Zamolodchikov-Faddeev algebra for open strings attached to giant gravitons
Creators: name: Ahn, Changrim
name: Nepomechie, Rafael
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We extend the Zamolodchikov-Faddeev algebra for the superstring sigma model on $AdS_{5}\times S^{5}$, which was formulated by Arutyunov, Frolov and Zamaklar, to the case of open strings attached to maximal giant gravitons, which was recently considered by Hofman and Maldacena. We obtain boundary $S$-matrices which satisfy the standard boundary Yang-Baxter equation.
description: 22 pages, no figure; added a reference
Deconstructing active region AR10961 using STEREO, Hinode, TRACE & SOHO
Creators: name: Noglik, Jane B.
name: Walsh, Robert W.
name: Maclean, Rhona C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Active region 10961 was observed over a five day period (2007 July 2-6) by instrumentation on-board STEREO, Hinode, TRACE and SOHO. As it progressed from Sun centre to the solar limb a comprehensive analysis of the EUV, X-ray and magnetic field data reveals clearly observable changes in the global nature of the region. Temperature analyses undertaken using STEREO EUVI double filter ratios and XRT single and combined filter ratios demonstrate an overall cooling of the region from between 1.6 - 3.0 MK to 1.0 - 2.0 MK over the five days. Similarly, Hinode EIS density measurements show a corresponding increase in density of 27%. Moss, cool (1 MK) outer loop areas and hotter core loop regions were examined and compared with potential magnetic field extrapolations from SOHO MDI magnetogram data. In particular it was found that the potential field model was able to predict the structure of the hotter X-ray loops and that the larger cool loops seen in 171 Angstrom images appeared to follow the separatrix surfaces. The reasons behind the high density moss regions only observed on one side of the active region are examined further.
description: Submitted ApJ
Formalizing Graph Trail Properties in Isabelle/HOL
Creators: name: Kovacs, Laura
name: Lachnitt, Hanna
name: Szeider, Stefan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We describe a dataset expressing and proving properties of graph trails, using Isabelle/HOL. We formalize the reasoning about strictly increasing and decreasing trails, using weights over edges, and prove lower bounds over the length of trails in weighted graphs. We do so by extending the graph theory library of Isabelle/HOL with an algorithm computing the length of a longest strictly decreasing graph trail starting from a vertex for a given weight distribution, and prove that any decreasing trail is also an increasing one. This preprint has been accepted for publication at CICM 2020.
Thermal Analysis of Human Eye for Biomedical Applications
Creators: name: Gongal, Dipika
Publisher: name: University of Illinois at Chicago
Year: 2024

description: Thermal analysis of the human eye using finite element analysis is a very useful tool to predict the outcome of medical treatment without the need for in-vivo or invasive laboratory experiments. In this research work, a three-dimensional thermal model of the human eye was generated for two biomedical applications. First, we studied the thermal response of the eye under operating an intraocular projection prosthesis device to treat corneal opacity. Based on the simulation result, the power budget of the device was established such that the temperature elevation in the living tissues satisfied the limit imposed by the international standard for implantable devices. The second application involved simulations of localized hypothermia treatment to prevent retina ischemia using a sclera cooling ring device. The simulation result showed that the cooling ring device can effectively reduce the temperature of the retina and optic nerve head to a therapeutic temperature range within the desired timeframe.
The thermal models used for the analysis includes conduction, convection, and radiation thermal processes. Evaporation of the tear film from the eye and convection flow of aqueous humor were also considered in developing the thermal model. A realistic thermoregulating blood flow model was introduced that considers eye tissue, inflowing blood, and outflowing blood as three phases of a porous media.
Sensitivity analysis was performed on all the parameters of the thermal model, which included material properties, and thermal and blood perfusion parameters. A model validation was also carried out using five pig eye models. The validation result showed that the thermal response of the pig eye models matched very closely to the in-vitro result.
Integrating users' needs into multimedia information retrieval system
Creators: name: Maghrebi, Hanène
name: David, Amos
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: The exponential growth of multimedia information and the development of various communication media generated new problems at various levels including the rate of flow of information, problems of storage and management. The difficulty which arises is no longer the existence of information but rather the access to this information. When designing multimedia information retrieval system, it is appropriate to bear in mind the potential users and their information needs. We assumed that multimedia information representation which takes into account explicitly the users' needs and the cases of use could contribute to the adaptation potentials of the system for the end-users. We believe also that responses of multimedia information system would be more relevant to the users' needs if the types of results to be used from the system were identified before the design and development of the system. We propose the integration of the users' information needs. More precisely integrating usage contexts of resulting information in an information system (during creation and feedback) should enhance more pertinent users' need. The first section of this study is dedicated to traditional multimedia information systems and specifically the approaches of representing multimedia information. Taking into account the dynamism of users, these approaches do not permit the explicit integration of the users' information needs. In this paper, we will present our proposals based on economic intelligence approach. This approach emphasizes the importance of starting any process of information retrieval witch the user information need.
Experimental study of clusters in dense granular gas and implications for the particle stopping time in protoplanetary disks
Creators: name: Schneider, Niclas
name: Musiolik, Grzegorz
name: Kollmer, Jonathan E.
name: Steinpilz, Tobias
name: Kruss, Maximilian
name: Jungmann, Felix
name: Demirci, Tunahan
name: Teiser, Jens
name: Wurm, Gerhard
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In protoplanetary disks, zones of dense particle configuration promote planet formation. Solid particles in dense clouds alter their motion through collective effects and back reaction to the gas. The effect of particle-gas feedback with ambient solid-to-gas ratios $ε> 1$ on the stopping time of particles is investigated. In experiments on board the International Space Station we studied the evolution of a dense granular gas while interacting with air. We observed diffusion of clusters released at the onset of an experiment but also the formation of new dynamical clusters. The solid-to-gas mass ratio outside the cluster varied in the range of about $ε_{\rm avg} \sim 2.5 - 60$. We find that the concept of gas drag in a viscous medium still holds, even if the medium is strongly dominated in mass by solids. However, a collective factor has to be used, depending on $ε_{\rm avg} $, i.e. the drag force is reduced by a factor 18 at the highest mass ratios. Therefore, flocks of grains in protoplanetary disks move faster and collide faster than their constituents might suggest.
The crystal structure, chemical bonding and magnetic properties of the intercalation compounds Cr$_x$ZrTe$_2$ ($x$ = 0-0.3)
Creators: name: Shkvarin, A. S.
name: Titov, A. A.
name: Merentsov, A. I.
name: Shkvarina, E. G.
name: Postnikov, M. S.
name: Pis, I.
name: Nappini, S.
name: Agzamova, P. A.
name: Volegov, A. S.
name: Titov, A. N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: New intercalation compounds Cr$_x$ZrTe$_2$ were synthesized in the Cr concentration range of x=0-0.3. A thorough study of the crystal and electronic structure has been performed. It was found that there is competition in the distribution of the Cr atoms over the octa- and tetrahedral sites in the van der Waals gap, depending on the Cr content. The ordering of the Cr atoms was found at x = 0.25; at the same time, the lattice symmetry decreases from trigonal P-3m1 to monoclinic F2/m. This ordering stabilizes the octahedral coordination of the Cr atoms by Te atoms. The analysis of the experimental data on the electronic structure and DOS calculations showed that the Cr 3d states are spin-split.
A framework for fostering transparency in shared artificial intelligence models by increasing visibility of contributions
Creators: name: Barclay, Iain
name: Taylor, Harrison
name: Preece, Alun
name: Taylor, Ian
name: Verma, Dinesh
name: de Mel, Geeth
Publisher: name: arXiv
Year: 2021
Subjects: subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Increased adoption of artificial intelligence (AI) systems into scientific workflows will result in an increasing technical debt as the distance between the data scientists and engineers who develop AI system components and scientists, researchers and other users grows. This could quickly become problematic, particularly where guidance or regulations change and once-acceptable best practice becomes outdated, or where data sources are later discredited as biased or inaccurate. This paper presents a novel method for deriving a quantifiable metric capable of ranking the overall transparency of the process pipelines used to generate AI systems, such that users, auditors and other stakeholders can gain confidence that they will be able to validate and trust the data sources and contributors in the AI systems that they rely on. The methodology for calculating the metric, and the type of criteria that could be used to make judgements on the visibility of contributions to systems are evaluated through models published at ModelHub and PyTorch Hub, popular archives for sharing science resources, and is found to be helpful in driving consideration of the contributions made to generating AI systems and approaches towards effective documentation and improving transparency in machine learning assets shared within scientific communities.
description: This is the pre-peer reviewed version of the following article: Barclay I, Taylor H, Preece A, Taylor I, Verma D, de Mel G. A framework for fostering transparency in shared artificial intelligence models by increasing visibility of contributions. Concurrency Computat Pract Exper. 2020;e6129. arXiv admin note: substantial text overlap with arXiv:1907.03483
Localization in Quantum Walks with a Single Lattice Defect: A Comparative Study
Creators: name: Teles, Laurita I. da S.
name: Amorim, Edgard P. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study how a single lattice defect in a discrete time quantum walk affects the return probability of a quantum particle. This defect at the starting position is modeled by a quantum coin that is distinct from the others over the lattice. This coin has a dependence on $ω$ which quantifies the intensity of the localization. For some sorts of lattice defects, we show how the localization can have a dependence just on $ω$, and also, the polar $α$ and azimuth $β$ angles of the initial qubit by numerical calculations. We propose a lattice defect whose localization has additional dependence on $β+ω$, leading to extra localization profiles. We compare the quantum walks with our lattice defect to the earlier ones, and we discuss their spreading and survival probability.
description: 6 pages, 7 figures, two columns
Broadband Quasi-Periodic Radio and X-ray Pulsations in a Solar Flare
Creators: name: Fleishman, G. D.
name: Bastian, T. S.
name: Gary, D. E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We describe microwave and hard X-ray observations of strong quasiperiodic pulsations from the GOES X1.3 solar flare on 15 June 2003. The radio observations were made jointly by the Owens Valley Solar Array (OVSA), the Nobeyama Polarimeter (NoRP), and the Nobeyama Radioheliograph (NoRH). Hard X-ray observations were made by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Using Fourier analysis, we study the frequency- and energy-dependent oscillation periods, differential phase, and modulation amplitudes of the radio and X-ray pulsations. Focusing on the more complete radio observations, we also examine the modulation of the degree of circular polarization and of the radio spectral index. The observed properties of the oscillations are compared with those derived from two simple models for the radio emission. In particular, we explicitly fit the observed modulation amplitude data to the two competing models. The first model considers the effects of MHD oscillations on the radio emission. The second model considers the quasi-periodic injection of fast electrons. We demonstrate that quasiperiodic acceleration and injection of fast electrons is the more likely cause of the quasiperiodic oscillations observed in the radio and hard X-ray emission, which has important implications for particle acceleration and transport in the flaring sources.
description: ApJ, accepted
Black Hole Superradiance in the Presence of Lorentz Symmetry Violation
Creators: name: Khodadi, Mohsen
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we consider the massive scalar perturbation on the top of a small spinning-like black hole in context of Einstein-bumblebee modified gravity in order to probe the role of spontaneous Lorentz symmetry breaking on the superradiance scattering and corresponding instability. We show that at the low-frequency limit of the scalar wave the superradiance scattering will be enhanced with the Lorentz-violating parameter $α<0$ and will be weakened with $α>0$. Moreover, by addressing the black hole bomb issue, we extract an improved bound in the instability regime indicating that $α<0$ increases the parameter space of the scalar field instability, while $α>0$ decreases it.
description: 18 pages, 4 figures, to appear in PRD
Determination of robot trajectories satisfying joint limit and interference constraints using an optimization method
Creators: name: Buchal, Ralph Oliver
Publisher: name: University of British Columbia
Year: 2010

description: An important problem in robotics research is the automatic off-line planning of optimal robot trajectories to perform specified tasks while satisfying physical constraints. This thesis proposes a method for finding an optimal geometric robot trajectory subject to the constraints of joint displacement limits and interference avoidance. A geometric method for calculating the distance between convex polyhedra is presented, and the method is implemented in two dimensions for the calculation of interference. Point-to-point trajectory planning is posed as a two-point boundary value problem in the calculus of variations. The kinematic constraints are formulated as exterior penalty functions and are combined with other optimization criteria to form a cost functional. The problem is solved by discretizing the problem and numerically minimizing the cost functional by using a steepest-descent approach to iteratively modify the trajectory. Any starting trajectory which satisfies the boundary conditions is acceptable, but different starting trajectories may converge to different locally optimal final trajectories. The method has been implemented for the two-dimensional case by an interactive FORTRAN program running on a VAX 11/750 computer. Successful results were obtained for a number of test cases, and further work has been identified to allow application of the method to a wide range of problems.
Determination of anisotropic Hc2 up to 60 T in (Ba0.55K0.45)Fe2As2 single crystals
Creators: name: Altarawneh, M.
name: Collar, K.
name: Mielke, C. H.
name: Ni, N.
name: Bud'ko, S. L.
name: Canfield, P. C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The radio frequency penetration depth was measured in the superconductor (Ba$_{0.55}$K$_{0.45}$)Fe$_{2}$As$_{2}$ under pulsed magnetic fields extending to 60 tesla and down to 14 K. Using these data we are able to infer a $H_{c2}(T)$, $H-T$ phase diagram, for applied fields parallel and perpendicular to the crystallographic c-axis. The upper critical field curvature is different for the respective orientations but they each remain positive down to 14 K. The upper critical field anisotropy is moderate, $\approx 3.5$ close to $T_c$, and drops with the decrease of temperature, reaching $\approx 1.2$ at $14 K$. These data and analysis indicate that (i) (Ba$_{0.55}$K$_{0.45}$)Fe$_{2}$As$_{2}$ anisotropy diminishes with temperature and has an unusual temperature dependence, (ii) $H_{c2} (T=0)$ for this compound may easily approach fields of 75 tesla.
description: published version
Heat Transfer in MHD Squeezing Flow using Brinkman Model
Creators: name: Satish Chandra RAJVANSHI, Sargam WASU
Publisher: name: Walailak University
Year: 2014
Subjects: Squeezing flow, permeable plates, porous medium, heat transfer, MHD, radiation

description: 11, 11, Walailak Journal of Science and Technology
Variational Approach Applied to Study the Lifting of a Non-Newtonian Fluid on a Vertically Moving Belt
Creators: name: Ali Ahmad FAROOQ, Abdul Majeed SIDDIQUI
Publisher: name: Walailak University
Year: 2014
Subjects: Thin film flow, moving belt, Williamson fluid model, nonlinear problem, VIM

description: 11, 11, Walailak Journal of Science and Technology
Another derivation of Weinberg's formula
Creators: name: Wang, Zhi-Yong
name: Xiong, Cai-Dong
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: To investigate how quantum effects might modify special relativity, we will study a Lorentz transformation between classical and quantum reference frames and express it in terms of the four-dimensional (4D) momentum of the quantum reference frame. The transition from the classical expression of the Lorentz transformation to a quantum-mechanical one requires us to symmetrize the expression and replace all its dynamical variables with the corresponding operators, from which we can obtain the same conclusion as that from quantum field theory (given by Weinberg's formula): owing to the Heisenberg's uncertainty relation, a particle (as a quantum reference frame) can propagate over a spacelike interval.
description: 14 pages, to be published in Physics Letters B
Collective excitations of trapped one-dimensional dipolar quantum gases
Creators: name: Pedri, P.
name: De Palo, S.
name: Orignac, E.
name: Citro, R.
name: Chiofalo, M. L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We calculate the excitation modes of a 1D dipolar quantum gas confined in a harmonic trap with frequency $ω_0$ and predict how the frequency of the breathing n=2 mode characterizes the interaction strength evolving from the Tonks-Girardeau value $ω_2=2ω_0$ to the quasi-ordered, super-strongly interacting value $ω_2=\sqrt{5}ω_0$. Our predictions are obtained within a hydrodynamic Luttinger-Liquid theory after applying the Local Density Approximation to the equation of state for the homogeneous dipolar gas, which are in turn determined from Reptation Quantum Monte Carlo simulations. They are shown to be in quite accurate agreement with the results of a sum-rule approach. These effects can be observed in current experiments, revealing the Luttinger-liquid nature of 1D dipolar Bose gases.
description: 5 pages, 2 EPS figures, RevTeX 4
Monhystera vietnamica Tsalolikhin 2020, sp. nov.
Creators: name: Tsalolikhin, S. Ya.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Adenophorea
Monhysterida
Monhysteridae
Monhystera
Monhystera vietnamica

description: Monhystera vietnamica sp. nov.
(Figs 1−4)
Holotype. Female, Vietnam, Tuyn Quang Prov., Na Hang Distr., Tung Vui Commune, pond in forest, 400 m a.s.l., 22°19′46″N, 105°25′47″E, 16 June 2019, coll. L. Iogansen. Microscope slide No. A-9238, ZISP.
Paratypes. 9 females, same data as for holotype.
Description. Females. Morphometric description of the holotype and paratypes is given in Table 1. Cuticle thin, about 1 µm. Space between internal organs with small cristalloid bodies of various sizes. Head not offset from body outline. Labial papillae undetectable. Diameter of amphidial fovea corresponding to 30% of body width. Ocellus present at about 20–26 (23) µm from anterior end. Cheilostome medium-sized, with thin walls. Esophagus muscular, gradually dilating towards its base. Cardium mushroom-shaped. Renette more or less oval, located somewhat below cardium; canal of renette and excretory pore not visible. Reproductive system monodelphic, prodelphic. Oocytes arranged in several rows in germinal zone. Uterus usually containing one or two eggs: 29–36 x 14–23 µm. Vagina very long, cuticularised, noticeably longer than one vulval body diameter. Paravulval gland present. Rectum longer than anal diameter. Tail slender, filiform.
Male not found.
Comparision. The new species Monhystera vietnamica sp. nov. most closely resembles M. uncigubernaculum Zeidan, Jacobs et Geraert, 1989, which was described from Africa (Zeidan, Jacobs & Geraert, 1989), and M. rolandi Khan et Tahseen, 2006 from India (Khan & Tahseen, 2005). The main differences of the new species from M. uncigubernaculum are the following: vagina 45–52 µm (vs 25–37 µm), rectum/anal body diameter 0.9 (vs 0.7), and tail filiform (vs tail with slightly swollen spinneret). The main differences of the new species from M. rolandi are: ocellus present (vs absence of ocellus), cephalic setae 5 µm (vs 3–4 µm), and tail filiform (vs tail gradually tapering).
Etymology. This species name is a Latinized toponym.
description: Published as part of Tsalolikhin, S. Ya., 2020, Two new species of free-living nematodes (Nematoda) from Vietnam, pp. 11-16 in Zoosystematica Rossica (Zoosyst. Rossica) (Zoosyst. Rossica) 29 (1) on page 12, DOI: 10.31610/zsr/2020.29.1.11, http://zenodo.org/record/10124222
Determination of Planetary Nebulae angular diameters from radio continuum Spectral Energy Distribution modeling
Creators: name: Bojicic, I. S.
name: Filipovic, M. D.
name: Urosevic, D.
name: Parker, Q. A.
name: Galvin, T.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Powerful new, high resolution, high sensitivity, multi-frequency, wide-field radio surveys such as the Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) are emerging. They will offer fresh opportunities to undertake new determinations of useful parameters for various kinds of extended astrophysical phenomena. Here, we consider specific application to angular size determinations of Planetary Nebulae (PNe) via a new radio continuum Spectral Energy Distribution (SED) fitting technique. We show that robust determinations of angular size can be obtained, comparable to the best optical and radio observations but with the potential for consistent application across the population. This includes unresolved and/or heavily obscured PNe that are extremely faint or even non-detectable in the optical.
description: accepted for publication in MNRAS
Laminar Chaos
Creators: name: Müller, David
name: Otto, Andreas
name: Radons, Günter
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: We show that the output of systems with time-varying delay can exhibit a new kind of chaotic behavior characterized by laminar phases, which are periodically interrupted by irregular bursts. Within each laminar phase the output intensity remains almost constant, but its level varies chaotically from phase to phase. In scalar systems the periodic dynamics of the lengths and the chaotic dynamics of the intensity levels can be understood and also tuned via two one-dimensional maps, which can be deduced from the nonlinearity of the delay equation and from the delay variation, respectively.
description: 6 pages, 4 figures
Multilinear Hölder-type inequalities on Lorentz sequence spaces
Creators: name: Carando, Daniel
name: Dimant, Verónica
name: Sevilla-Peris, Pablo
Publisher: name: arXiv
Year: 2008
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46A46, 46B45

description: We establish Hölder type inequalities for Lorentz sequence spaces and their duals. In order to achieve these and some related inequalities, we study diagonal multilinear forms in general sequence spaces, and obtain estimates for their norms. We also consider norms of multilinear forms in different Banach multilinear ideals.
Effects of myo-inositol and, or triiodothyronine (T₃) treatment on cardiac dysfunction and elevated myocardial lipid levels in STZ-diabetic rats
Creators: name: Xiang, Hong
Publisher: name: University of British Columbia
Year: 2010

description: A number of experimental studies have implied a link between diabetes-induced lipid accumulation in the myocardium and the development of cardiomyopathy. Since diabetics excrete large amounts of myo-inositol which is a lipotropic agent, this study was undertaken to investigate the effects of myo-inositol on the elevated myocardial lipid levels and the depressed cardiac performance of diabetic rats. Diabetes was induced in female Wistar rats (190-215 g) with streptozotocin (STZ) (55 mg/kg, i.v.). Three days after diabetes induction, myo-inositol was administered in the drinking water (2.5 g/kg/day) for a 8 week period. Untreated diabetics exhibited a loss of body weight, hyperglycemia, hypoinsulinemia and hypothyroidism. These effects were not altered after myo-inositol treatment. STZ-diabetes also produced a significant elevation of plasma and myocardial triacylglycerol, cholesterol and phospholipid. Myo-inositol treatment decreased these lipid levels. In addition, hearts from diabetic animals had a decreased ability to develop left ventricular developed pressure (LVDP) and both the rate of pressure rise (+dP/dt) and the rate of pressure decline (-dP/dt) were also reduced. Hearts from myo-inositol-treated diabetic animals showed a partial but definite improvement of cardiac function. As diabetes-induced hypothyroidism was not altered after myo-inositol supplementation, a combination treatment of both myo-inositol (2.5 g/kg/day, p.o. daily) and T₃ (30 ug/kg/day, s.c. daily) was then undertaken to determine whether heart function of diabetic rats could be further improved. STZ-diabetic rats were characterized by a loss of body weight, hyperglycemia and hypoinsulinemia; none of which were altered by either T₃ or myo-inositol plusT₃ treatment. T₃ treatment normalized the thyroid state of diabetic animals as shown by Tahiliani and McNeill (1984). However, plasma and myocardial triacylglycerol, cholesterol and phospholipid levels of diabetic rats either remained elevated or were further increased with T₃ or myo-inositol plus T₃ treatment. In addition, T₃ treatment alone did not prevent cardiac dysfunction in diabetic rats. There was, however, some improvement in heart function in the groups treated with both myo-inositol and T₃, but the improvement was not as pronounced as with myo-inositol treatment alone.
Renormalization Group Analysis of Boundary Conditions in Potential Scattering
Creators: name: Valderrama, M. Pavon
name: Arriola, E. Ruiz
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We analyze how a short distance boundary condition for the Schrodinger equation must change as a function of the boundary radius by imposing the physical requirement of phase shift independence on the boundary condition. The resulting equation can be interpreted as a variable phase equation of a complementary boundary value problem. We discuss the corresponding infrared fixed points and the perturbative expansion around them generating a short distance modified effective range theory. We also discuss ultraviolet fixed points, limit cycles and attractors with a given fractality which take place for singular attractive potentials at the origin. The scaling behaviour of scattering observables can analytically be determined and is studied with some emphasis on the low energy nucleon-nucleon interaction via singular pion exchange potentials. The generalization to coupled channels is also studied.
description: 31 pages, 8 figures
Detecting photoelectrons from spontaneously formed excitons
Creators: name: Fukutani, Keisuke
name: Stania, Roland
name: Kwon, Chang Il
name: Kim, Jun Sung
name: Kong, Ki Jeong
name: Kim, Jaeyoung
name: Yeom, Han Woong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Excitons, quasiparticles of electrons and holes bound by Coulombic attraction, are created transiently by light and play an important role in optoelectronics, photovoltaics and photosynthesis. While they are also predicted to form spontaneously in a small gap semiconductor or a semimetal, leading to a Bose-Einstein condensate at low temperature, their material realization has been elusive without any direct evidence. Here we detect the direct photoemission signal from spontaneously formed excitons in a debated excitonic insulator candidate Ta2NiSe5. Our symmetry-selective angle-resolved photoemission spectroscopy reveals a characteristic excitonic feature above the transition temperature, which provides detailed properties of excitons such as anisotropic Bohr radius. The present result evidences so called preformed excitons and guarantees the excitonic insulator nature of Ta2NiSe5 at low temperature. Direct photoemission can be an important tool to characterize steady-state excitons.