cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Transverse fluctuations control the assembly of semiflexible filaments
Creators: name: Sorichetti, Valerio
name: Lenz, Martin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Physical sciences

description: The kinetics of the assembly of semiflexible filaments through end-to-end annealing is key to the structure of the cytoskeleton, but is not understood. We analyze this problem through scaling theory and simulations, and uncover a regime where filaments ends find each other through bending fluctuations without the need for the whole filament to diffuse. This results in a very substantial speed-up of assembly in physiological regimes, and could help understand the dynamics of actin and intermediate filaments in biological processes such as wound healing and cell division.
description: Main: 5 pages, 4 figures. Supplementary: 10 pages, 9 figures. To be published in Physical Review Letters
Digital Transformation and Public Service Delivery
Creators: name: Ahmed, Abdikarim Mohaidin
Publisher: name: SORER
Year: 2021
Subjects: Digital
Transformation
Public
Service
Delivery
SomNOG5
SomNOG

description: Eng. Abdikarim Mohaidin Ahmed, the Director for International Cooperation, SIMAD University delivered this presentation as a keynote speech at the 5th Annual Conference of the Somali Network Operators' Group (SomNOG)
Einstein static universes are unstable in generic f(R) models
Creators: name: Seahra, Sanjeev S.
name: Boehmer, Christian G.
Publisher: name: arXiv
Year: 2009
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study Einstein static universes in the context of generic f(R) models. It is shown that Einstein static solutions exist for a wide variety of modified gravity models sourced by a barotropic perfect fluid with equation of state w=p/rho, but these solutions are always unstable to either homogeneous or inhomogeneous perturbations. Our general results are in agreement with specific models investigated in that past. We also discuss how our techniques can be applied to other scenarios in f(R) gravity.
description: 7 pages, 2 figures. Minor corrections. Minor changes and references added to match version accepted by Phys. Rev. D
Pfleiderer2: identification of a new globular cluster in the Galaxy
Creators: name: Ortolani, Sergio
name: Bonatto, Charles
name: Bica, Eduardo
name: Barbuy, Beatriz
Publisher: name: arXiv
Year: 2009
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We provide evidence that indicate the star cluster Pfleiderer 2, which is projected in a rich field, as a newly identified Galactic globular cluster. Since it is located in a crowded field, core extraction and decontamination tools were applied to reveal the cluster sequences in B, V and I Color-Magnitude Diagrams (CMDs). The main CMD features of Pfleiderer 2 are a tilted Red Giant Branch, and a red Horizontal Branch, indicating a high metallicity around solar. The reddening is E(B-V)=1.01. The globular cluster is located at a distance from the Sun d$_{\odot}$ = 16$\pm$2 kpc. The cluster is located at 2.7 kpc above the Galactic plane and at a distance from the Galactic center of R$_{\rm GC}$=9.7 kpc, which is unusual for a metal-rich globular cluster.
description: Accepted by The Astronomical Journal
Petrology of the earth's deep crust and upper mantle and the origins of magmas in the earth and moon
Creators: name: Green, DH
Publisher: name: University Of Tasmania
Year: 2023

description: The publications forming this thesis are grouped in three themes: 1.Petrology of the Earth's upper mantle, and of mantle-derived magmas and petrology of lunar magmas (publications in series A, B, C, D). 2.Petrology of the deep crust with emphasis on geothermometry and geobarometry as a means of investigating high pressure/high temperature metamorphism (publications in series E). 3.Roles of volatiles, particularly C-H-0 fluids, in deep crust and upper mantle (publications in series B, D).
Temperature jump in degenerate quantum gases in the presence of a Bose - Einstein condensate
Creators: name: Latyshev, A. V.
name: Yushkanov, A. A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 82B40; 80A99

description: We construct a kinetic equation modeling the behavior of degenerate quantum Bose gases whose collision rate depends on the momentum of elementary excitations. We consider the case where the phonon component is the decisive factor in the elementary excitations. We analytically solve the half-space boundary value problem of the temperature jump at the boundary of the degenerate Bose gas in the presence of a Bose -- Einstein condensate.
description: 9 pages, 2 figures
Kagome and honeycomb flat bands in moiré graphene
Creators: name: Scheer, Michael G.
name: Lian, Biao
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a class of graphene-based moiré systems hosting flat bands on kagome and honeycomb moiré superlattices. These systems are formed by stacking a graphene layer on a 2D substrate with lattice constant approximately $\sqrt{3}$ times that of graphene. When the moiré potentials are induced by a 2D irreducible corepresentation in the substrate, the model shows a rich phase diagram of low energy bands including eigenvalue fragile phases as well as kagome and honeycomb flat bands. Spin-orbit coupling in the substrate can lift symmetry protected degeneracies and create spin Chern bands, and we observe spin Chern numbers up to three. We additionally propose a moiré system formed by stacking two graphene-like layers with similar lattice constants and Fermi energies but with Dirac Fermi velocities of opposite sign. This system exhibits multiple kagome and honeycomb flat bands simultaneously. Both models we propose resemble the hypermagic model of [Scheer $\textit{et al.}$, Phys. Rev. B $\textbf{106}$, 115418 (2022)] and may provide ideal platforms for the realization of strongly correlated topological phases.
description: 43 pages, 8 figures
The petrology of some young subvolcanic and volcanic rocks from West Kalimantan, Indonesia
Creators: name: Harahap, Bhakti Hamonangan
Publisher: name: University Of Tasmania
Year: 2023

description: The northern part of West Kalimantan, which is the northern part of Sundaland, has been a continental margin since the Cretaceous time. The southern part of West Kalimantan is occupied by a belt of Cretaceous granitoids Nest Borneo Basement), while the western part is composed of Jurassic-Cretaceous sediments, and Late Palaeozoic granitic and metamorphic rocks. The northern and central parts are now a sedimentary basin and a melange belt. There is a distinct unconformity between the Cretaceous and the Tertiary. Three episodes of volcanic activity (Cretaceous, Tertiary and Quaternary) have been recognized in western and central West Kalimantan. The Cretaceous volcanics are mainly basalts and dacites and minor andesites. The basalts are characterized by the presence of quartz xenocrysts and biotite in the groundmass. They have higher Si02 and lower TiO2' P205' La and Zr contents than the Tertiary volcanic rocks. These volcanics have been metamorphosed to greenschist facies. They are mainly distributed in the western part of West Kalimantan. These volcanics have an island-arc tholeiite character, which may be a response to the southward subduction recorded in the Lupar Line and the Boyan Melange. The Tertiary volcanics are largely dacites with less common rhyolites, and minor basalts and andesites. They are mainly distributed in the central West Kalimantan (CWK). The basalts are tholeiitic, and the dacites, andesites and rhyolites are calcalkaline. A few rhyolites from the southern province of the CWK are alkaline and in the central province trondhjemite occurs. The basalts from the northern province have a .different source from those of the southern province. The Tertiary volcanics contaminated by lower crustal material have a substantially different chemical signature from north to south. In the southern province, the Tertiary volcanics intrude into the belt of Cretaceous granitoids. These volcanics have the most siliceous character and the highest enrichment in K-type elements. In the northern province the Tertiary volcanics intrude the Boyan Mlange belt and the Tertiary sediments of the Kentungau Basin. The andesites and dacites have a high TiO2 content and the spidergrarn patterns are similar to those of ocean-island basalt which is contaminated by sediments. In the central province the Tertiary volcanics intrude the thick sedimentary succession of the Melawi Basin and the Cretaceous turbidite sediments. The volcanics found here are dacites and rhyolites. The Tertiary volcanics from CWE: may be related to the southeast subduction beneath the Sarawak accretionary prism. Mineral evidence indicates magma mixing has taken place in th dacites. The Quaternary lavas from Mt Niut are trachybasalts and basaltic andesites. The lavas display the geochemical features of continental tholeiites which are similar to transitional mid-oceanic ridge basalt (MORB).
Planning power play : community education through gaming
Creators: name: Burgess, Robert Vernon
Publisher: name: University of British Columbia
Year: 2011

description: This thesis is primarily involved with the development of a planning teaching game called Planning Power Play, and the testing of this game's effectiveness as an educational tool with residents of a local community. The rapid growth of our North American urban centres has brought with it an increasing demand that the citizens be allowed to participate in the planning of their own local residential areas. However, the art of citizen involvement in the modern planning context suffers from a lack of effective techniques of implementation which in part explains the reluctance of many policy makers to initiate such programmes at all. This thesis is intended to assist in overcoming this shortcoming by introducing a new method of encouraging active citizen participation in the planning process. The study hypothesizes that a planning game can be developed that will be an effective educational tool in citizen involvement programmes in the neighbourhood setting. The thesis initially reviews much of the literature pertaining to teaching games citing examples of the effectiveness of existing teaching games, and building a theory of teaching game draftsmanship. It then proceeds to explain the development of a new teaching game called Planning Power Play. Five test sessions of Planning Power Play indicated that it was a successful teaching game and potentially useful tool in situations where citizen contact was required. The game fostered an informal social atmosphere facilitating discussion between the planner and the citizens, with the result that both parties learned from the experience. The tests indicated that Planning Power Play taught the players the practical constraints imposed upon the development of their local area by the variety of interest groups expressing their divergent viewpoints through the municipal political bargaining process. In addition, the game was practical for use in the citizen participation milieu where many participants were novice game players. The game proved to be engrossing, easy to learn, quick to play, and extremely portable and adaptable. The conclusion was reached that this thesis was primarily an exploratory study. Planning Power Play is a satisfactory teaching game, but it is not meant to be the final word on planning teaching games. Rather, it is hoped that this game will constitute an initial step encouraging further research in this relatively new aspect of urban planning.
On the resolution of cosmic coincidence problem and phantom crossing with triple interacting fluids
Creators: name: Jamil, Mubasher
name: Rahaman, Farook
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We here investigate a cosmological model in which three fluids interact with each other involving certain coupling parameters and energy exchange rates. The motivation of the problem stems from the puzzling `triple coincidence problem' which naively asks why the cosmic energy densities of matter, radiation and dark energy are almost of the same order of magnitude at the present time. In our model, we determine the conditions under triple interacting fluids will cross the phantom divide.
description: 22 pages, 6 figures, to appear in Eur. Phys. J. C (2009)
Tetrahedral triple-Q magnetic ordering and large spontaneous Hall conductivity in the metallic triangular antiferromagnet Co1/3TaS2
Creators: name: Park, Pyeongjae
name: Cho, Woonghee
name: Kim, Chaebin
name: An, Yeochan
name: Kang, Yoon-Gu
name: Avdeev, Maxim
name: Sibille, Romain
name: Iida, Kazuki
name: Kajimoto, Ryoichi
name: Lee, Ki Hoon
name: Ju, Woori
name: Cho, En-Jin
name: Noh, Han-Jin
name: Han, Myung Joon
name: Zhang, Shang-Shun
name: Batista, Cristian D.
name: Park, Je-Geun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The triangular lattice antiferromagnet (TLAF) has been the standard paradigm of frustrated magnetism for several decades. The most common magnetic ordering in insulating TLAFs is the 120 structure. However, a new triple-Q chiral ordering can emerge in metallic TLAFs, representing the short wavelength limit of magnetic skyrmion crystals. We report the metallic TLAF Co1/3TaS2 as the first example of tetrahedral triple-Q magnetic ordering with the associated topological Hall effect (non-zero σ_{xy}(H=0)). We also present a theoretical framework that describes the emergence of this magnetic ground state, which is further supported by the electronic structure measured by angle-resolved photoemission spectroscopy. Additionally, our measurements of the inelastic neutron scattering cross section are consistent with the calculated dynamical structure factor of the tetrahedral triple-Q state.
description: 23 pages, 4 figures, SI not included. Accepted for publication in Nature Communications
Rapid in-situ quantification of rheo-optic evolution for cellulose spinning in ionic solvents
Creators: name: Du, Jianyi
name: Paez, Javier
name: Otero, Pablo
name: Sanchez, Pablo B.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Applied Physics (physics.app-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: It is critical to monitor the structural evolution during deformation of complex fluids for the optimization of many manufacturing processes, including textile spinning. However, in situ measurements in a textile spinning process suffer from paucity of non-destructive instruments and interpretations of the measured data. In this work, kinetic and rheo-optic properties of a cellulose/ionic liquid solution were measured simultaneously while fibers were regenerated in aqueous media from a miniature wet spinline equipped with a customized polarized microscope. This system enables to control key spinning parameters, while capturing and processing the geometrical and structural information of the spun fiber in a real-time manner. We identified complex flow kinematics of a deformed fiber during the coagulation process via feature tracking methods, and visualized its morphology and birefringent responses before and during regeneration at varying draw ratios and residence time. Meanwhile, a three-dimensional physical rheological model was applied to describe the non-linear viscoelastic behavior in a complex wet-spinning process incorporating both shear and extensional flows. We subsequently compared the birefringent responses of fibers under coagulation with the transient orientation inferred from the rheological model, and identified a superposed structure-optic relationship under varying spinning conditions. Such structural characterizations inferred from the flow dynamics of spinning dopes are readily connected with key mechanical properties of fully-regenerated fibers, thus enabling to predict the spinning performance in a non-destructive protocol.
description: 28 pages, 6 figures
Public Private Partnerships for Digital Infrastructure Development
Creators: name: Hussein, Abdullahi Bihi
Publisher: name: SORER
Year: 2021
Subjects: PPP
Digital
Infrastructure
SomNOG5
SomNOG
Partnership

description: Eng. Abdullahi Bihi Hussein, the CEO of Somali Research and Education Network (SomaliREN) delivered this presentation as a keynote speech at the 5th Annual event of the Somali Network Operators' Group (SomNOG).
Influence of high-angle grain boundaries on the charge order formation in the $\mathrm{YBa_2Cu_3O_{7-δ}}$
Creators: name: Boyko, Vladimir S.
name: Kezerashvili, Roman Ya.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We are examining the possibility of the formation of charge order in the high-temperature superconductor $\mathrm{YBa_2Cu_3O_{7-δ}}$ (YBCO) due to interaction between the charged oxygen vacancies or di-vacancies. The molecular dynamics method is used to analyze the displacement fields around these defects. The distribution of displacements around a single charged oxygen vacancy and di-vacancy, determination of binding energy of oxygen vacancy in di-vacancy demonstrate that there is, in principle, the possibility of the charge order formation in YBCO by charged oxygen vacancies or di-vacancies. It is shown that the charge order formation first of all should be formed near crystal lattice defects and that the high-angle grain boundaries (GBs) regions are preferable places for this formation. The adsorption capability of high-angle GBs with respect to the stripe embryo formation is determined. It is shown that there is a proportional dependence between the repetition distance along the high-angle GBs and an energy advantage of the stripe embryo formation in GBs.
description: 7 pages, 4 figures
Phase-dependent Andreev molecules and superconducting gap closing in coherently coupled Josephson junctions
Creators: name: Matsuo, Sadashige
name: Imoto, Takaya
name: Yokoyama, Tomohiro
name: Sato, Yosuke
name: Lindemann, Tyler
name: Gronin, Sergei
name: Gardner, Geoffrey C.
name: Nakosai, Sho
name: Tanaka, Yukio
name: Manfra, Michael J.
name: Tarucha, Seigo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Josephson junction (JJ) is an essential element of superconducting (SC) devices for both fundamental and applied physics. The short-range coherent coupling of two adjacent JJs forms the Andreev molecule states (AMSs), which will provide a new ingredient to engineer the SC transport in JJs and control the Andreev qubits. However, no experimental evidence of the AMSs in the coupled JJs has been reported. Here we provide the tunnel spectroscopic results of electrically controllable two planar JJs sharing one SC electrode. We discover that the coupled JJ results are highly modulated from the single JJ results, due to formation of the phase-dependent AMSs, meaning that the two JJs are coherently coupled. In addition, the superconducting gap closing due to the AMS formation is observed. Our results would help in understanding the microscopic mechanism of the coherent coupling and promoting the AMS physics to apply for research of the topological superconductivity and quantum information technology.
Mapping light-dressed Floquet bands by highly nonlinear optical excitations and valley polarization
Creators: name: Galler, Anna
name: Rubio, Angel
name: Neufeld, Ofer
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ultrafast nonlinear optical phenomena in solids have been attracting major interest as novel methodologies for femtosecond spectroscopy of electron dynamics and control of material properties. Here, we theoretically investigate strong-field nonlinear optical transitions in a prototypical two-dimensional material, hBN, and show that the k-resolved conduction band charge occupation patterns induced by an elliptically-polarized laser can be understood in a multi-photon resonant picture; but remarkably, only if using the Floquet light-dressed states instead of the undressed matter states. Consequently, our work establishes a direct measurable signature for band-dressing in nonlinear optical processes in solids, and opens new paths for ultrafast spectroscopy and valley manipulation.
On a stochastic model for the spin-down of solar type stars
Creators: name: Leprovost, Nicolas
name: Kim, Eun-Jin
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Modeling the rotation history of solar-type stars is still an unsolved problem in modern astrophysics. One of the main challenges is to explain the dispersion in the distribution of stellar rotation rate for young stars. Previous works have advocated dynamo saturation or magnetic field localization to explain the presence of fast rotators and star-disk coupling in pre-main sequence to account for the existence of slow rotators. Here, we present a new model that can account for the presence of both types of rotators by incorporating fluctuations in the solar wind. This renders the spin-down problem probabilistic in nature, some stars experiencing more braking on average than others. We show that random fluctuations in the loss of angular momentum enhance the population of both fast and slow rotators compared to the deterministic case. Furthermore, the distribution of rotational speed is severely skewed towards large values in agreement with observations.
All-Optical Switching Demonstrated with Photoactive Yellow Protein Films
Creators: name: Petrovszki, Daniel
name: Krekic, Szilvia
name: Valkai, Sandor
name: Heiner, Zsuzsanna
name: Dér, András
Publisher: name: Humboldt-Universität zu Berlin
Year: 2021
Subjects: subject: optical switching
subject: integrated optics
subject: photonics
subject: photoactive yellow protein
subject: 570 Biologie

description: Integrated optics (IO) is a field of photonics which focuses on manufacturing circuits similar to those in integrated electronics, but that work on an optical basis to establish means of faster data transfer and processing. Currently, the biggest task in IO is finding or manufacturing materials with the proper nonlinear optical characteristics to implement as active components in IO circuits. Using biological materials in IO has recently been proposed, the first material to be investigated for this purpose being the protein bacteriorhodopsin; however, since then, other proteins have also been considered, such as the photoactive yellow protein (PYP). In our current work, we directly demonstrate the all-optical switching capabilities of PYP films combined with an IO Mach–Zehnder interferometer (MZI) for the first time. By exploiting photoreactions in the reaction cycle of PYP, we also show how a combination of exciting light beams can introduce an extra degree of freedom to control the operation of the device. Based on our results, we discuss how the special advantages of PYP can be utilized in future IO applications.
The synthesis of a free-piston power saw
Creators: name: Fandrich, Helmut Edward
Publisher: name: University of British Columbia
Year: 2011

description: The object of this study was to apply the technique of synthesis to the design of a small power saw. The study produced experimental data on optimum chain speeds, engine vibrations, noise levels, and heat transfer coefficients for reciprocating cylinder heads, and led to a simple free-piston configuration in which a piston oscillated between a mixture of air and fuel in one end of a closed cylinder and a spring in the other. The feasibility of developing the configuration into a practical reciprocating engine was verified by designing, building and testing a prototype. The prototype incorporated such novel features as instant, effortless starting and stopping, automatic throttling, self-cooling, compression ignition of a carbureted air-fuel mixture, and a balanced engine. Uncontrolled ignition timing reduced engine efficiency, and the lack of inertia made engine stalling easy and carburetor adjustment difficult. The computed results suggest that a developed 3 lb free-piston power saw will produce 1.0 hp at 6,400 cpm and have a specific fuel consumption of .9 lb/shp-hr.
Some problems in the Athenian strategia of the fifth century B.C.
Creators: name: Henning, PI
Publisher: name: University Of Tasmania
Year: 2023

description: At the beginning of the fifth century the Athenian strategia constituted, together with the polemarch, the chief military executive institution of the newly established democracy. It soon outgrew its purely military function and became the single most important magistracy of the state at the heart of fifth-century Athenian politics and government. Possession of the strategia was the only way to political prominence and power, at least until the demagogues found an alternative path. All the most important and influential politicians of the fifth century from Themistocles to Alcibiades, including Aristeides Cimon, Pericles, Nicias and Clean, only became or remained the leaders of Athens as generals. It is not surprising therefore that the strategia has been the subject of close attention by modern scholars. Our knowledge of the character of the Athenian democracy is certainly not complete without an understanding of the workings of its major executive institution. However, modem scholarship has failed to resolve many of the problems concerned with the strategia and has produced a wealth of argument without any general measure of agreement, rather than any basic conclusions. It is the purpose of this thesis to submit some of these problems to a reexamination. Many of them, admittedly, have come under the scrutiny of Charles W. Fomara, and his recent work (\The Athenian Board of Generals from 501 to 404\" Historia Einzelschriften Heft 16 1971) is the most valuable recent contribution to the subject. I agree with much of Fornara's analysis but concerning many important considerations I am unable to accept his conclusions. In what follows I argue that the reform of 501/0 established the electoral procedure whereby the generals were elected by the whole Demos. At the beginning of the fifth century each general was elected from a different tribe one general being chosen from each of Cleisthenes' ten tribes but an electoral reform of about 480 or one or two years earlier removed the requirement providing for tribal representation. ... In some years of the fifth century there is a numerical increase in the strength of the board. The Athenians elected extra generals as circumstances dictated. Finally the principle of collegiality was strictly maintained in practice throughout the fifth century except for one minor aberration in 407/06. A strict differentiation can be drawn between the political prestige and influence pertaining to an individual and the official authority which he possessed as a general."
FAIR4Health Metadata
Creators: name: FAIR4Health Consortium
Publisher: name: Zenodo
Year: 2021
Subjects: health research
Health data
Metadata
FAIR Principles
Open Science
Data Science

description: The overall objective of FAIR4Health is to facilitate and encourage the EU health research community to FAIRify, share and reuse their datasets derived from publicly-funded research initiatives. This publication collects the metadata generated when FAIRifying health datasets in the implementation of the FAIR4Health project demonstrators.
The Far-Infrared--Radio Correlation at High Redshifts: Physical Considerations and Prospects for the Square Kilometer Array
Creators: name: Murphy, Eric J.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: (Abridged) I present a predictive analysis for the behavior of the FIR--radio correlation as a function of redshift in light of the deep radio continuum surveys which may become possible using the SKA. To keep a fixed ratio between the FIR and predominantly non-thermal radio continuum emission of a normal star-forming galaxy requires a nearly constant ratio between galaxy magnetic field and radiation field energy densities. While the additional term of IC losses off of the cosmic microwave background (CMB) is negligible in the local Universe, the rapid increase in the strength of the CMB energy density (i.e. $\sim(1+z)^{4})$ suggests that evolution in the FIR-radio correlation should occur with infrared (IR; $8-1000 \micron$)/radio ratios increasing with redshift. At present, observations do not show such a trend with redshift; $z\sim6$ radio-quiet QSOs appear to lie on the local FIR-radio correlation while a sample of $z\sim4.4$ and $z\sim2.2$ SMGs exhibit ratios that are a factor of $\sim$2.5 {\it below} the canonical value. I also derive a 5$σ$ point-source sensitivity goal of $\approx$20 nJy (i.e. $σ_{\rm RMS} \sim 4$ nJy) requiring that the SKA specified be $A_{\rm eff}/T_{\rm sys}\approx 15000$ m$^{2}$ K$^{-1}$; achieving this sensitivity should enable the detection of galaxies forming stars at a rate of $\ga25 M_{\sun} {\rm yr}^{-1}$, at all redshifts if present. By taking advantage of the fact that the non-thermal component of a galaxy's radio continuum emission will be quickly suppressed by IC losses off of the CMB, leaving only the thermal (free-free) component, I argue that deep radio continuum surveys at frequencies $\ga$10 GHz may prove to be the best probe for characterizing the high-$z$ star formation history of the Universe unbiased by dust.
description: 16 pages, 8 figures, accepted for publication in ApJ
Energy systems and policy planning : a multi-level optimization approach
Creators: name: Islam, S M Nazrul
Publisher: name: University Of Tasmania
Year: 2023

description: The objective of this study is to formulate an optimum multi-level energy plan that can resolve the underlying energy policy issues and options and can, thus, deal with the energy sector problems. The main hypothesis of this study is that since there exists a multi-(two) level policy making system in the energy sector (government and private sector decision making), the formulation of a multi-level energy plan should take into account the choices and decisions of these decision makers. To accomplish this, an optimum multi-level energy plan should be developed within a framework of a multi-level optimization approach (MO). To support the hypothesis, a theoretical energy planning model/approach is developed within the framework of (1) the theory of economic policy planning; (2) policy systems analysis; and (3) multi-level programming (MLP) (an operational multi-level optimization method). On the basis of this theoretical model, an Australian Energy Policy System Optimization Model (AEPSOM) has been developed. The Parametric Programming Search (PPS) algorithm has been developed in order to provide an alternative algorithm for solving MLP which was adopted to solve AEPSOM. The MLO model has been used to formulate an Australian multi-level energy plan. The results of this study suggest that a reformulation of existing Australian energy policies is needed. This study also draws a conclusion that an MLO approach can provide an operational methodology and a framework for optimum multi-level energy planning.
$G_0W_0$ Ionization Potentials of First-Row Transition Metal Aqua Ions
Creators: name: Mejia-Rodriguez, Daniel
name: Kunitsa, Alexander A.
name: Aprà, Edoardo
name: Govind, Niranjan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We report computations of the vertical ionization potentials within the $GW$ approximation of the near-complete series of first-row transition metal (V-Cu) aqua ions in their most common oxidation states, i.e. V$^{3+}$, Cr$^{3+}$, Cr$^{2+}$, Mn$^{2+}$, Fe$^{3+}$, Fe$^{2+}$, Co$^{2+}$, Ni$^{2+}$, and Cu$^{2+}$. The $d$-orbital occupancy of these systems spans a broad range from $d^2$ to $d^9$. All the structures were first optimized at the density functional theory level using a large cluster of explicit water molecules that are embedded in a continuum solvation model. Vertical ionization potentials were computed with the one-shot $G_0W_0$ approach on a range of transition metal ion clusters (6, 18, 40, and 60 explicit water molecules) wherein the convergence with respect to the basis set size was evaluated using the systems with 40 water molecules. We assess the results using three different density functional approximations as starting points for the vertical ionization potential calculations, namely $G_0W_0$@PBE, $G_0W_0$@PBE0, and $G_0W_0$@r$^2$SCAN. While the predicted ground-state structures are similar with all three exchange-correlation functionals, the vertical ionization potentials were in closer agreement with the experiment when using the $G_0W_0$@PBE0 and $G_0W_0$@r$^2$SCAN approaches, with the r2SCAN based calculations being significantly less expensive. Computed bond distances and vertical ionization potentials for all structures were compared with available experimental data and are in good agreement.
title: Praxis für die Zukunft?!
title: Potenziale und Herausforderungen kooperativen Religionsunterrichts
titleType: Subtitle
Creators: name: Ebrahim, Ranja
name: Juen, Maria
Publisher: name: Universität Graz
Year: 2021

description: Die Frage nach zukunftsfähigen Modellen religiöser Bildung an öffentlichen
Schulen ist drängender denn je. Aktuelle Forschungsprojekte an österreichischen
und deutschen Schulen, die im Rahmen der Tagung „Praxis für die Zukunft.
Erfahrungen, Beispiele und Modelle kooperativen Religionsunterrichts“ präsentiert
wurden, geben einen facettenreichen Einblick in die Potenziale und Herausforderungen
eines religionskooperativen oder konfessionsübergreifenden Unterrichts.
Der Beitrag bietet einen kurzen Überblick über die Forschungsergebnisse,
Verbesserungsvorschläge und die daraus formulierten und diskutierten Schlussfolgerungen
aus der Perspektive der zwei abschließenden Tagungsresümees.
description: The research area of future oriented models of religious education in public
schools is more topical than ever. The conference entitled “Practice for the
Future. Experiences, Examples and Models of Cooperative Religious Education”
gave a diverse and rich insight into the potentials and the challenges of interreligious
instructions and instructions of overlapping the denominations. This contribution
expresses a brief insight into the different research results, development
suggestions and conclusions taken at the conference from the perspective
of the two final conclusions presented at the closure of the congress.
description: Schlagworte:
interreligiöses Lernen – religionskooperativer Unterricht – Teamteaching –
zukunftsfähiger Religionsunterricht – Pluralitätsfähigkeit
description: Keywords:
interreligious learning – overlapping denominations – team teaching –
future oriented religious edcuation – ability to plurality
description: ÖRF 29 (2021) 2, 180–192
On Donaldson-Thomas invariants of threefold stacks and gerbes
Creators: name: Gholampour, Amin
name: Tseng, Hsian-Hua
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We present a construction of Donaldson-Thomas invariants for three-dimensional projective Calabi-Yau Deligne-Mumford stacks. We also study the structure of these invariants for etale gerbes over such stacks.
description: 13 pages, Preliminary version, comments are welcome
Visualizing Skiers' Trajectories in Monocular Videos
Creators: name: Dunnhofer, Matteo
name: Sordi, Luca
name: Micheloni, Christian
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Trajectories are fundamental to winning in alpine skiing. Tools enabling the analysis of such curves can enhance the training activity and enrich broadcasting content. In this paper, we propose SkiTraVis, an algorithm to visualize the sequence of points traversed by a skier during its performance. SkiTraVis works on monocular videos and constitutes a pipeline of a visual tracker to model the skier's motion and of a frame correspondence module to estimate the camera's motion. The separation of the two motions enables the visualization of the trajectory according to the moving camera's perspective. We performed experiments on videos of real-world professional competitions to quantify the visualization error, the computational efficiency, as well as the applicability. Overall, the results achieved demonstrate the potential of our solution for broadcasting media enhancement and coach assistance.
description: 2023 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), CVsports workshop
Algebraic reasoning in lambda calculi
Creators: name: Kazmierczak, EA
Publisher: name: University Of Tasmania
Year: 2023

description: This dissertation examines some aspects of the relationship between ˜í¬™ calculus and universal algebra. Motivated by the desire to understand the implementation of abstract data types in functional languages we use ˜í¬™ algebras, or models of the pure ˜í¬™˜í‚â§ calculus, as a universe in which models for specifications are to be constructed. Given an arbitrary ˜í¬™ algebra M we construct from it a cartesian closed category with sum objects which we call C(M) . The objects of C(M) are interpreted as types while the arrows can be thought of as effective functions. Unlike set theory where the semantics of an abstract data type is often chosen to be the (isomorphism) class of initial models the simple model of types and functions presented here contains no initial object. This means more care is required when choosing the semantics of an abstract data type. In particular the category C(M) , which is an extension of the cartesian closed monoids of [Koy82, LS86, Bar84] is cartesian closed (4.1.6) and so the basic properties of functional languages such as currying and higher order functions can be modelled. Using the idea of a T-algebra [LS81, SP82] we construct algebras as the greatest fixed points of endofunctors over C(M) (4.2.5). While in general systems of equations do not always exhibit computational properties in many cases they do, especially if a set of Church-Rosser and strongly normalising rewrite rules can be extracted from the equations by a technique such as the Knuth-Bendix completion procedure [KB70]. It is known [KS81] that a Church-Rosser strongly normalising set of rewrite rules is associated with the word problem in the free algebra and if the word problem is solvable then there is a recursive function taking each term in the free algebra to its normal form. We construct models for systems of Church-Rosser, strongly normalising sets of rewrite rules based on this characterisation of the word problem (4.3.14). Secondly a calculus, ˜í¬™˜í¬£E , is given for reasoning about these models. ˜í¬™˜í¬£E is a simply typed ˜í¬™ calculus augmented with the operations and equations of the original specification. It is shown that this calculus is a conservative extension of the usual equational calculus if a strongly normalising and Church-Rosser set of rewrite rules can be generated from the original equations (5.2.10). Thirdly, given a specification and an arbitrary model of that specification in C(M) , the soundness of deduction in ˜í¬™˜í¬£E is proved (6.1.5). Finally, a theorem relating the equational theory to ˜í¬™˜í¬£E , namely that for every model of the equational theory there exists a unique model of ˜í¬™˜í¬£E .
Character of magnetic instabilities in CaFe2As2
Creators: name: Samolyuk, G. D.
name: Antropov, V. P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The density functional non-interacting susceptibility has been analyzed in different phases of CaFe2As2 and compared with similar data for pure d-metals. The conditions for the "no local moment" itinerant state with large frustrations are found for the "collapsed" phase (corresponding to superconducting phase). This itineracy determines the instability versus the incommensurate magnetic order for the narrow region of wave vectors. For the ambient pressure phase, the local moments on Fe atoms with much less frustrated antiferromagnetic interactions are stabilized and a magnetic short or long range order for all wave vectors is developed.
Policy & Regulatory Approaches for Digital Infrastructure and Services
Creators: name: Kasim, Liban Abdulkadir
Publisher: name: SORER
Year: 2021
Subjects: Policy
Regulatory
Digital
Infrastructure
Services
SomNOG5

description: Eng. Liban Abdulkadir Kasim, the Licensing and Regulatory Advisor of the National Communications Authority (NCA) delivered this presentation at the 5th Annual Conference of the Somali Network Operators' Group (SomNOG).
Very high resolution canopy height maps from RGB imagery using self-supervised vision transformer and convolutional decoder trained on Aerial Lidar
Creators: name: Tolan, Jamie
name: Yang, Hung-I
name: Nosarzewski, Ben
name: Couairon, Guillaume
name: Vo, Huy
name: Brandt, John
name: Spore, Justine
name: Majumdar, Sayantan
name: Haziza, Daniel
name: Vamaraju, Janaki
name: Moutakanni, Theo
name: Bojanowski, Piotr
name: Johns, Tracy
name: White, Brian
name: Tiecke, Tobias
name: Couprie, Camille
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Vegetation structure mapping is critical for understanding the global carbon cycle and monitoring nature-based approaches to climate adaptation and mitigation. Repeated measurements of these data allow for the observation of deforestation or degradation of existing forests, natural forest regeneration, and the implementation of sustainable agricultural practices like agroforestry. Assessments of tree canopy height and crown projected area at a high spatial resolution are also important for monitoring carbon fluxes and assessing tree-based land uses, since forest structures can be highly spatially heterogeneous, especially in agroforestry systems. Very high resolution satellite imagery (less than one meter (1m) Ground Sample Distance) makes it possible to extract information at the tree level while allowing monitoring at a very large scale. This paper presents the first high-resolution canopy height map concurrently produced for multiple sub-national jurisdictions. Specifically, we produce very high resolution canopy height maps for the states of California and Sao Paulo, a significant improvement in resolution over the ten meter (10m) resolution of previous Sentinel / GEDI based worldwide maps of canopy height. The maps are generated by the extraction of features from a self-supervised model trained on Maxar imagery from 2017 to 2020, and the training of a dense prediction decoder against aerial lidar maps. We also introduce a post-processing step using a convolutional network trained on GEDI observations. We evaluate the proposed maps with set-aside validation lidar data as well as by comparing with other remotely sensed maps and field-collected data, and find our model produces an average Mean Absolute Error (MAE) of 2.8 meters and Mean Error (ME) of 0.6 meters.
Spin correlations near the edge as probe of Dimer order in square-lattice Heisenberg models
Creators: name: Pardini, T.
name: Singh, R. R. P.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Recent numerical and analytical work has shown that for the square-lattice Heisenberg model the boundary can induce Dimer correlations near the edge which are absent in spin-wave theories and non-linear sigma model approaches. Here, we calculate the nearest-neighbor spin correlations parallel and perpendicular to the boundary in a semi-infinite system for two different square-lattice Heisenberg models: (i) A frustrated $J_1-J_2$ model with nearest and second neighbor couplings and (ii) a spatially anisotropic Heisenberg model, with nearest-neighbor couplings $J$ perpendicular to the boundary and $J^\prime$ parallel to the boundary. We find that in the latter model, as $J^\prime/J$ is reduced from unity the Dimer correlations near the edge become longer ranged. In contrast, in the frustrated model, with increasing $J_2$, dimer correlations are strengthened near the boundary but they decrease rapidly with distance. These results imply that deep inside the Néel phase of the $J_1-J_2$ Heisenberg model, dimer correlations remain short-ranged. Hence, if there is a direct transition between the two it is either first order or there is a very narrow critical region.
description: 4 pages, 7 figures added references
Large-scale streaks in a turbulent bluff body wake
Creators: name: Nekkanti, Akhil
name: Nidhan, Sheel
name: Schmidt, Oliver T.
name: Sarkar, Sutanu
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: A turbulent circular disk wake database (Chongsiripinyo \& Sarkar, \textit{J. Fluid Mech.}, vol. 885, 2020) at Reynolds number $\textit{Re} = U_\infty D/ν= 5 \times 10^{4}$ is interrogated to identify the presence of large-scale streaks - coherent elongated regions of streamwise velocity. The unprecedented streamwise length - until $x/D \approx 120$ - of the simulation enables investigation of the near and far wake. The near wake is dominated by the vortex shedding (VS) mode residing at azimuthal wavenumber $m=1$ and Strouhal number $\textit{St} = 0.135$. After filtering out the VS structure, conclusive evidence of large-scale streaks with frequency $\textit{St} \rightarrow 0$, equivalently streamwise wavenumber $k_x \rightarrow 0$ in the wake, becomes apparent in visualizations and spectra. These streaky structures are found throughout the simulation domain beyond $x/D \approx 10$. Conditionally averaged streamwise vorticity fields reveal that the lift-up mechanism is active in the near as well as the far wake, and that ejections contribute more than sweep to events of intense $-u'_xu'_r$. Spectral proper orthogonal decomposition (SPOD) is employed to extract the energy and the spatiotemporal features of the large-scale streaks. The streak energy is concentrated in the $m=2$ azimuthal mode over the entire domain. Finally, bispectral mode decomposition (BMD) is conducted to reveal strong interaction between $m=1$ and $\textit{St} = \pm 0.135$ modes to give the $m=2, \textit{St} = 0$ streak mode. Our results indicate that the self-interaction of the VS mode generates the $m=2, \textit{St} = 0$ streamwise vortices, which leads to streak formation through the lift-up process. To the authors' knowledge, this is the first study that reports and characterizes large-scale low-frequency streaks and the associated lift-up mechanism in a turbulent wake.