cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Structural Geology of the Southern Sheeprock Mountains, Utah: Regional Significance
Creators: name: Christie-Blick, Nicholas
Publisher: name: Columbia University
Year: 1983
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences
subject: Geomorphology
subject: Plate tectonics

description: The Sheeprock Mountains are part of a horst of Proterozoic, Paleozoic and Cenozoic sedimentary and igneous rocks located in the transitional region between the Cordilleran fold-thrust belt and the hinterland in the Basin-Range province of west-central Utah. Prominent structural elements in the Sheeprock Mountains are the Sheeprock Thrust, juxtaposing Proterozoic rocks above Paleozoic ones with a stratigraphic separation exceeding 10 km; the Pole Canyon Thrust, thought to be an upper plate imbrication of the Sheeprock Thrust; the Pole Canyon Anticline, a recumbent fold vergent to the northeast and cut by the Pole Canyon Thrust; the east-northeast-striking Indian Springs (tear) Fault; and two low-angle normal faults (the Harker and Lion Hill Faults) which together account for stratigraphic omission of several kilometres. The Pole Canyon Anticline is thought to have developed in the late Mesozoic during propagation of the thrusts parallel to the Indian Springs Fault, and this transport direction is corroborated by minor structures. Fault geometry suggests that the Harker and Lion Hill Faults are younger than the thrusts and probably of late Cenozoic age, although some mid-Cenozoic or even earlier displacement cannot be entirely ruled out. My [The author's] preferred interpretation of the structural history of the Sheep rock Mountains is consistent with minimal regional extension before the mid-Cenozoic and with the view that crustal shortening in the fold-thrust belt is for the most part unrelated to hinterland extension.
Study of corrugated board cutting by high velocity liquid jet
Creators: name: Szymani, Richard
Publisher: name: University of British Columbia
Year: 2011

description: The application of high velocity liquid jets for corrugated board cutting was investigated as a possible new method of slitting operations. Eleven types of corrugated board ranging from 91 pounds per 1,000 square feet board weight (125 psi - nominal burst test) to 297 pounds per 1,000 square feet (350 psi - burst test) were selected for the study. Plain water or water with polymer additive were used as the cutting fluids. The conditions under which cutting of corrugated boards was carried out were as follows: nozzle diameters 0.0082 and 0.0102 in., pressure levels 20,000, 30,000 and 40,000 psi; feed rates 300, 500 and 700 fpm. The obtained results indicate that slitting speeds with high velocity liquid jets are well above those achievable by the existing conventional methods. It has also been shown that the use of a low concentration of polyethylene oxide (Polyox WSR - 301) resulted in a marked increase in cutting efficiency as compared with plain water. Measurements of liquid retention after cutting.-have shown that wetting of corrugated boards during the cutting operation is insignificant and as such can be neglected. It has been demonstrated that the edgewise compression strength of corrugated board, cut with the liquid jet, is almost twice that cut with the typical conventional slitter. Based on the analysis of scanning electron micrographs it has been observed that the principal failure mechanism during cutting with high velocity liquid jet involves breaking of the interfibre bond with resulting separation of fibres. Corrugated board cutting with high velocity liquid jets has been found to eliminate crushing and tearing of the board as well as dust generation. The concept provides a means to reduce trim waste and particle contamination. Jet cutting is ideally suited for numerically controlled systems and appears to lend itself for adaptation to commercial application.
Star formation histories of resolved galaxies
Creators: name: Tosi, Monica
Publisher: name: arXiv
Year: 2009
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The colour-magnitude diagrams of resolved stellar populations are the best tool to study the star formation histories of the host galactic regions. In this review the method to derive star formation histories by means of synthetic colour-magnitude diagrams is briefly outlined, and the results of its application to resolved galaxies of various morphological types are summarized. It is shown that all the galaxies studied so far were already forming stars at the lookback time reached by the observational data, independently of morphological type and metallicity. Early-type galaxies have formed stars predominantly, but in several cases not exclusively, at the earliest epochs. All the other galaxies appear to have experienced rather continuous star formation activities throughout their lifetimes, although with significant rate variations and, sometimes, short quiescent phases.
description: 10 pages. Invited review, to appear in "The Ages of Stars", proceedings of IAU Symp. 258; revised figure
Axios/Ipsos Coronavirus Index Wave 49
Creators: name: Axios
Publisher: name: Roper Center for Public Opinion Research
Year: 2021

description: Changes in health in last week (2); activities in last week (7); changes in work and household over last few weeks (2); risk of different activities (13); safety procedures when leaving the house (8); health issues in last month (5); concern about coronavirus (COVID-19) outbreak (1); Delta variant of coronavirus (2); trust in organizations/politicians to provide accurate information about coronavirus (6); coronavirus vaccine (17); coronavirus testing (5); main source of news (1).
Mechanism for bipolar resistive switching in transition metal oxides
Creators: name: Rozenberg, M. J.
name: Sanchez, M. J.
name: Weht, R.
name: Acha, C.
name: Gomez-Marlasca, F.
name: Levy, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We introduce a model that accounts for the bipolar resistive switching phenomenom observed in transition metal oxides. It qualitatively describes the electric field-enhanced migration of oxygen vacancies at the nano-scale. The numerical study of the model predicts that strong electric fields develop in the highly resistive dielectric-electrode interfaces, leading to a spatially inhomogeneous oxygen vacancies distribution and a concomitant resistive switching effect. The theoretical results qualitatively reproduce non-trivial resistance hysteresis experiments that we also report, providing key validation to our model.
description: Accepted for publication in Physical Review B, 6 twocolumn pages, 5 figures
Pre-Mesozoic Palinspastic Reconstruction of the Eastern Great Basin (Western United States)
Creators: name: Levy, Marjorie
name: Christie-Blick, Nicholas
Publisher: name: Columbia University
Year: 1989
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences
subject: Plate tectonics
subject: Geomorphology

description: The Great Basin of the western United States has proven important for studies of Proterozoic and Paleozoic geology [2500 to 245 million years ago (Ma)] and has been central to the development of ideas about the mechanics of crustal shortening and extension. An understanding of the deformational history of this region during Mesozoic and Cenozoic time (245 Ma to the present) is required for palinspastic reconstruction of now isolated exposures of older geology in order to place these in an appropriate regional geographic context. Considerable advances in unraveling both the crustal shortening that took place during Mesozoic to early Cenozoic time (especially from about 150 to 50 Ma) and the extension of the past 37 million years have shown that earlier reconstructions need to be revised significantly. A new reconstruction is developed for rocks of middle Proterozoic to Early Cambrian age based on evidence that total shortening by generally east-vergent thrusts and folds was at least 104 to 135 kilometers and that the Great Basin as a whole accommodated ∼250 kilometers of extension in the direction 287° ± 12° between the Colorado Plateau and the Sierra Nevada. Extension is assumed to be equivalent at all latitudes because available paleomagnetic evidence suggests that the Sierra Nevada experienced little or no rotation with respect to the extension direction since the late Mesozoic. An estimate of the uncertainty in the amount of extension obtained from geological and paleomagnetic uncertainties increases northward from ±56 kilometers at 36°30N to -87+108 kilometers at 40°N. On the basis of the reconstruction, the original width of the preserved part of the late Proterozoic and Early Cambrian basin was about 150 to 300 kilometers, about 60 percent of the present width, and the basin was oriented slightly more north-south with respect to present-day coordinates.
Comparison of tumor delineation using dual energy computed tomography versus magnetic resonance imaging in head and neck cancer re-irradiation cases
Creators: name: Sweet Ng
name: CE Cardenas
name: H Elhalawani
name: C Pollard
name: B Elgohari
name: P Fang
name: M Meheissen
name: N Guha-Thakurta
name: H Bahig
name: JM Johnson
name: M Kamal
name: AS Garden
name: JP Reddy
name: SY Su
name: R Ferrarotto
name: SJ Frank
name: G Brandon Gunn
name: AC Moreno
name: DI Rosenthal
name: CD Fuller
name: J Phan
Publisher: name: La Trobe
Year: 2021
Subjects: Uncategorized

description: © 2020 In treatment planning, multiple imaging modalities can be employed to improve the accuracy of tumor delineation but this can be costly. This study aimed to compare the interobserver consistency of using dual energy computed tomography (DECT) versus magnetic resonance imaging (MRI) for delineating tumors in the head and neck cancer (HNC) re-irradiation scenario. Twenty-three patients with recurrent HNC and had planning DECT and MRI were identified. Contoured tumor volumes by seven radiation oncologists were compared. Overall, T1c MRI performed the best with median DSC of 0.58 (0–0.91) for T1c. T1c MRI provided higher interobserver agreement for skull base sites and 60 kV DECT provided higher interobserver agreement for non-skull base sites.
Non-Abelian Duality and Confinement in N=2 Supersymmetric QCD
Creators: name: Shifman, M.
name: Yung, A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In N=2 supersymmetric QCD with the U(N) gauge group and N_f>N we study the crossover transition from the weak coupling regime at large ξto strong coupling at small ξwhere ξis the Fayet--Iliopoulos parameter. We find that at strong coupling a dual non-Abelian weakly coupled N=2 theory exists which describes low-energy physics at small ξ. The dual gauge group is U(N_f-N) and the dual theory has N_f flavors of light dyons, to be compared with N_f quarks in the original U(N) theory. Both, the original and dual theories are Higgsed and share the same global symmetry SU(N) x SU(N_f-N) x U(1), albeit the physical meaning of the SU(N) and SU(N_f-N) factors is different in the large- and small-ξregimes. Both regimes support non-Abelian semilocal strings. In each of these two regimes particles that are in the adjoint representations with respect to one of the factor groups exist in two varieties: elementary fields and composite states bound by strings. These varieties interchange upon transition from one regime to the other. We conjecture that the composite stringy states can be related to Seiberg's M fields. The bulk duality that we observed translates into a two-dimensional duality on the world sheet of the non-Abelian strings. At large ξthe internal dynamics of the semilocal non-Abelian strings is described by the sigma model of N orientational and (N_f-N) size moduli, while at small ξthe roles of orientational and size moduli interchange. The BPS spectra of two dual sigma models (describing confined monopoles/dyons of the bulk theory) coincide. It would be interesting to trace parallels between the non-Abelian duality we found and string theory constructions.
description: 55 pages, 6 figures
The Coherent Structures of Shallowwater Turbulence: Deformationradius Effects, Cyclone/Anticyclone Asymmetry and Gravitywave Generation
Creators: name: Polvani, Lorenzo M.
name: McWilliams, J. C.
name: Spall, M. A.
name: Ford, R.
Publisher: name: Columbia University
Year: 1994
Subjects: subject: Atmosphere
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Mathematics
subject: FOS: Mathematics

description: Over a large range of Rossby and Froude numbers, we investigate the dynamics of initially balanced decaying turbulence in a shallow rotating fluid layer. As in the case of incompressible two‐dimensional decaying turbulence, coherent vortex structures spontaneously emerge from the initially random flow. However, owing to the presence of a free surface, a wealth of new phenomena appear in the shallow‐water system. The upscale energy cascade, common to strongly rotating flows, is arrested by the presence of a finite Rossby deformation radius. Moreover, in contrast to near‐geostrophic dynamics, a strong asymmetry is observed to develop as the Froude number is increased, leading to a clear dominance of anticyclonic vortices over cyclonic ones, even though no β effect is present in the system. Finally, we observe gravity waves to be generated around the vortex structures, and, in the strongest cases, they appear in the form of shocks. We briefly discuss the relevance of this study to the vortices observed in Jupiter’s atmosphere.
Are Proterozoic Cap Carbonates and Isotopic Excursions a Record of Gas Hydrate Destabilization Following Earth’s Coldest Intervals
Creators: name: Kennedy, Martin J.
name: Christie-Blick, Nicholas
name: Sohl, Linda E.
Publisher: name: Columbia University
Year: 2001
Subjects: subject: Paleoclimatology
subject: Geochemistry
subject: FOS: Earth and related environmental sciences
subject: Geology

description: Regionally persistent, thin intervals of carbonate rock directly and ubiquitously overlie Proterozoic glacial deposits on almost every continent, and are commonly referred to as cap carbonates. Their unusual facies, stratigraphically abrupt basal and upper contacts, and strongly negative carbon isotopic signature (δ13C values between ∼0‰ and −5‰) suggest a chemical oceanographic origin, the details of which remain unresolved. Here we propose that these enigmatic deposits are related to the destabilization of gas hydrate in terrestrial permafrost following rapid postglacial warming and flooding of widely exposed continental shelves and interior basins. Supporting evidence for this hypothesis includes (1) the common occurrence within the cap carbonates of unusual fabrics, similar to those produced by cold methane seeps; (2) a distinctive time evolution for the carbon isotopic excursions indicative of a pulse addition of isotopically depleted carbon to the ocean- atmosphere system; and (3) agreement between mass-balance estimates of carbon released by hydrate destabilization and carbon buried in the cap carbonate. We infer that during times of low-latitude glaciation, characteristic of the Neoproterozoic, gas hydrates may have been in greater abundance than at any other time in Earth history.
Numerically Converged Solutions of the Global Primitive Equations for Testing the Dynamical Core of Atmospheric GCMs
Creators: name: Polvani, Lorenzo M.
name: Scott, R. K.
name: Thomas, S. J.
Publisher: name: Columbia University
Year: 2004
Subjects: subject: Atmosphere
subject: Meteorology
subject: Mathematics
subject: FOS: Mathematics

description: Solutions of the dry, adiabatic, primitive equations are computed, for the first time, to numerical convergence. These solutions consist of the short-time evolution of a slightly perturbed, baroclinically unstable, midlatitude jet, initially similar to the archetypal LC1 case of Thorncroft et al. The solutions are computed with two distinct numerical schemes to demonstrate that they are not dependent on the method used to obtain them. These solutions are used to propose a new test case for dynamical cores of atmospheric general circulation models. Instantaneous horizontal and vertical cross sections of vorticity and vertical velocity after 12 days, together with tables of key diagnostic quantities derived from the new solutions, are offered as reproducible benchmarks. Unlike the Held and Suarez benchmark, the partial differential equations and the initial conditions are here completely specified, and the new test case requires only 12 days of integration, involves no spatial or temporal averaging, and does not call for physical parameterizations to be added to the dynamical core itself.
Testing Hořava-Lifshitz gravity using thin accretion disk properties
Creators: name: Harko, Tiberiu
name: Kovács, Zoltán
name: Lobo, Francisco S. N.
Publisher: name: arXiv
Year: 2009
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: Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Horava. The theory reduces to Einstein gravity with a non-vanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(A)dS solution, has also been obtained for the Horava-Lifshitz theory. The exact asymptotically flat Schwarzschild type solution of the gravitational field equations in Horava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR modified Horava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Horava gravity by using the accretion disk properties around black holes. The energy flux, temperature distribution, the emission spectrum as well as the energy conversion efficiency are obtained, and compared to the standard general relativistic case. Particular signatures can appear in the electromagnetic spectrum, thus leading to the possibility of directly testing Horava gravity models by using astrophysical observations of the emission spectra from accretion disks.
description: 7 pages, 4 figures. V2: minor additions and references added; to appear in Phys. Rev. D
An integrated approach to the greenhouse effect : Tasmania as a case study
Creators: name: Kinrade, P
Publisher: name: University Of Tasmania
Year: 2023

description: This thesis argues that a positive and effective response to the greenhouse effect can and should be taken at the regional level despite uncertainties which surround the issue. By recognising the interconnections between the greenhouse effect and other environmental, economic and social issues it should be possible to devise a combination of mitigation and adaptation strategies which are of societal benefit, regardless of the extent and direction of climate change. This is the concept of an 'integrated approach'. If Tasmania and other like minded regions could successfully adopt this approach, it may act as a 'spur' to much needed, but contentious, international action. An examination of all aspects of the greenhouse effect from a Tasmanian perspective demonstrates the potential benefits to be gained from developing an integrated approach at the regional level. A comprehensive analysis of Tasmania's greenhouse gas emissions has been undertaken. The relative contribution of energy use in Tasmania to total greenhouse gas emissions (47%) is somewhat less than the corresponding share globally (57%), but emissions from land use modification in Tasmania (principally deforestation and biomass burning) contribute, proportionally, a high share to total greenhouse gas emissions (17%). Tasmania's 'mix' of greenhouse gas producing activities varies considerably from the rest of Australia and other parts of the world. Furthermore, the location of Tasmania in a distinct climatic zone suggests that climate changes predicted for other regions of Australia are not directly analogous to Tasmania. These examples indicate that Tasmania's interests will be best served by adopting mitigation and adaptation strategies that are suited to its own particular circumstances. By integrating greenhouse strategies with other long term environmental, economic and social objectives Tasmania stands to gain, regardless of the outcome of global warming, especially if those objectives are aimed at increasing the diversity, flexibility and sustainability of human and non-human systems.
The Frequency and Dynamics of Stratospheric Sudden Warmings in the 21st Century
Creators: name: Charlton-Perez, A. J.
name: Polvani, Lorenzo M.
name: Austin, J.
name: Li, F.
Publisher: name: Columbia University
Year: 2008
Subjects: Atmosphere, Upper
Atmosphere
Meteorology

description: Changes to stratospheric sudden warmings (SSWs) over the coming century, as predicted by the Geophysical Fluid Dynamics Laboratory (GFDL) chemistry climate model [Atmospheric Model With Transport and Chemistry (AMTRAC)], are investigated in detail. Two sets of integrations, each a three-member ensemble, are analyzed. The first set is driven with observed climate forcings between 1960 and 2004; the second is driven with climate forcings from a coupled model run, including trace gas concentrations representing a midrange estimate of future anthropogenic emissions between 1990 and 2099. A small positive trend in the frequency of SSWs is found. This trend, amounting to 1 event/decade over a century, is statistically significant at the 90% confidence level and is consistent over the two sets of model integrations. Comparison of the model SSW climatology between the late 20th and 21st centuries shows that the increase is largest toward the end of the winter season. In contrast, the dynamical properties are not significantly altered in the coming century, despite the increase in SSW frequency. Owing to the intrinsic complexity of our model, the direct cause of the predicted trend in SSW frequency remains an open question.
Factorization constraints for soft anomalous dimensions in QCD scattering amplitudes
Creators: name: Gardi, Einan
name: Magnea, Lorenzo
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the factorization of soft and collinear singularities in dimensionally-regularized fixed-angle scattering amplitudes in massless gauge theories. Our factorization is based on replacing the hard massless partons by light-like Wilson lines, and defining gauge-invariant jet and soft functions in dimensional regularization. In this scheme the factorized amplitude admits a powerful symmetry: it is invariant under rescaling of individual Wilson-line velocities. This symmetry is broken by cusp singularities in both the soft and the eikonal jet functions. We show that the cancellation of these cusp anomalies in any multi-leg amplitude imposes all-order constraints on the kinematic dependence of the corresponding soft anomalous dimension, relating it to the cusp anomalous dimension. For amplitudes with two or three hard partons the solution is unique: the constraints fully determine the kinematic dependence of the soft function. For amplitudes with four or more hard partons we present a minimal solution where the soft anomalous dimension is a sum over colour dipoles, multiplied by the cusp anomalous dimension. In this case additional contributions to the soft anomalous dimension at three loops or beyond are not excluded, but they are constrained to be functions of conformal cross ratios of kinematic variables.
description: v1: 35 pages, v2: minor changes - some clarifying remarks and references added. Journal version (to appear in JHEP)
Reply
Creators: name: Kennedy, Martin J.
name: Christie-Blick, Nicholas
name: Sohl, Linda E.
Publisher: name: Columbia University
Year: 2002
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences
subject: Submarine geology
subject: Geochemistry

description: The authors address additional comments on their hypothesis for the origin of Neoproterozoic postglacial cap carbonates and their isotopic excursions.
Spatiotemporal interaction of optical beams in bi-dispersive media
Creators: name: Moshonas, Nikolaos
name: Kominis, Yannis
name: Papagiannis, Panagiotis
name: Hizanidis, Kyriakos
name: Christodoulides, Demetrios N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: The interaction of optical beams in bi-dispersive nonlinear media with self-focusing nonlinearity is numerically investigated. Under proper conditions, the interaction of spatially separated beams can lead to the creation of two prominent filaments along the other spatial or temporal dimension and, thus to an effective beam exchange. This X-wave generation-based effect could potentially be exploited in optical realizations of spatial or spatio-temporal filtering.
On the Subtropical Edge of the Stratospheric Surf Zone
Creators: name: Polvani, Lorenzo M.
name: Waugh, D. W.
name: Plumb, R. Alan
Publisher: name: Columbia University
Year: 1995
Subjects: subject: Atmosphere
subject: Atmosphere, Upper
subject: Geophysics
subject: FOS: Earth and related environmental sciences

description: The formation of a subtropical “transport barrier” in the wintertime stratosphere is investigated in the context of a high-resolution shallow-water model in which Rossby waves are topographically forced on a zonally symmetric basic state. Two sets of experiments are performed: in the first “adiabatic” set, no dissipation or forcing of the mean state is imposed; in the second set, the layer thickness is relaxed to an equilibrium state taken to be representative of middle stratospheric radiative equilibrium temperatures. It is found that in the adiabatic case only a very weak subtropical barrier forms for forcing amplitudes that generate realistically steep potential vorticity gradients at the edge of the polar vortex; the vigorous wave breaking in the surf zone generates secondary waves that spread and, in turn, break well into the summer hemisphere. In contrast, the inclusion of relaxation to a realistic thermal equilibrium leads to the formation of a subtropical region of steep PV gradients. The strong subtropical shear induced by die diabatic relaxation is shown to be an important factor for the formation of the subtropical edge of the surf zone. Furthermore, the authors demonstrate that a simple one-layer shallow-water model can capture the full process of the formation of a surf zone with both polar and tropical edges starting from conditions typical of the early fall–that is, with a flow in which the polar vortex is not initially present. Finally, the authors quantify the mixing of polar and subtropical air into the midlatitude surf zone with the help of the contour advection technique. Although the quantitative estimates depend sensitively on how the edges of the surf zone are defined, our results indicate that more tropical than polar air is entrained into the surf zone.
Endnote 20 Workshop for Windows
Creators: name: Learning And Research Services HKU Libraries
Publisher: name: The University of Hong Kong
Year: 2021
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: Endnote 20 is a citation management software and the HKU site license covers current HKU staff and students.
 Through this workshop, you will learn how to: Create an EndNote 20 library Build your Endnote 20 library by exporting citations from FIND@HKUL, Academic Search Complete and Google Scholar Create in-text citations and reference list in Word document using Cite While You Write Manage EndNote 20 library by creating groups
Barotropic Vortex Pairs on a Rotating Sphere
Creators: name: DiBattista, Mark T.
name: Polvani, Lorenzo M.
Publisher: name: Columbia University
Year: 1998
Subjects: subject: Atmosphere
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Mathematics
subject: FOS: Mathematics

description: Using a barotropic model in spherical geometry, we construct new solutions for steadily travelling vortex pairs and study their stability properties. We consider pairs composed of both point and finite-area vortices, and we represent the rotating background with a set of zonal strips of uniform vorticity. After constructing the solution for a single point-vortex pair, we embed it in a rotating background, and determine the equilibrium configurations that travel at constant speed without changing shape. For equilibrium solutions, we find that the stability depends on the relative strength (which may be positive or negative) of the vortex pair to the rotating background: eastward-travelling pairs are always stable, while westward-travelling pairs are unstable when their speeds approach that of the linear Rossby–Haurwitz waves. This finding also applies (with minor differences) to the case when the vortices are of finite area; in that case we find that, in addition to the point-vortex-like instabilities, the rotating background excites some finite-area instabilities for vortex pairs that would otherwise be stable. As for practical applications to blocking events, for which the slow westward pairs are relevant, our results indicate that free barotropic solutions are highly unstable, and thus suggest that forcing mechanisms must play an important role in maintaining atmospheric blocking events.
Unveiling the female `I' : autobiographies by Australian women born in the 1920s
Creators: name: Holzer, Valarie
Publisher: name: University Of Tasmania
Year: 2023

description: This study fulfils the need for research into autobiographies of writers who have a number ot common traits which will provide specific conclusions about the art of autobiography. Unveiling the Female ' I' ; Autobiographies by Australian Women Born in the 1920s looks at works by fourteen writers who share the same nationality, gender and decade of birth. The Introduction documents the elusiveness of women's autobiographies and briefly surveys the critical situation to date, noting the lack of consensus in just what an autobiography is. Criteria have been established for extracting women's autobiographies from the large range of female autobiographical writings and the validity of the linguistic devices used to examine these works is justified. Working from the proposition by Chodorow that women are defined through process and by \other\". Chapter 1 looks at character and style in four autobiographies of childhood to establish how this forms the identity ot Australian women born in the 1920s. Chapter 2 discusses two autobiographies of childhood which focus on other aspects of personal development: Spence's Another October Child presents a portrait of the development of a writer and Lindsay's Portrait of Pa is argued to be an autobiograpby of Jane rather than a biography or Norman Lindsay. The life stories of adults treated in Chapter 3 demonstrate the fallacy of the \"quest\" metaphor for female writers and offer other life metaphors as more appropriate for conveying their truths of identity. The position of women in Australian society has received close attention in recent years and the autobiographies by migrant and Aboriginal women which are the topic of Chapter 4 illustrate their alienation through their lack of cultural experience. Place becomes cultural as well as physical for these women. Dorothy Hewett's recently published Wild Card both confirms and confounds the pattern of Australian women's autobiography depicting the same period in a highly and elaborately patterned way. Chapter 5 examines its statement about the role of truth in autobiography. Chapter 6 continues this direction and breaks new ground by looking at the implications of \"naming\" and photographs in both the structural and metaphoric strands of the re-creation of identity. The Conclusion considers how Australian women born in the 1920s see their world and their values in comparison with the male view of history. The study draws together the threads of identity world and truth as represented in these self- life-writings."
Drag force on an impurity below the superfluid critical velocity in a quasi-one-dimensional Bose-Einstein condensate
Creators: name: Sykes, Andrew G.
name: Davis, Matthew J.
name: Roberts, David C.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: The existence of frictionless flow below a critical velocity for obstacles moving in a superfluid is well established in the context of the mean-field Gross-Pitaevskii theory. We calculate the next order correction due to quantum and thermal fluctuations and find a non-zero force acting on a delta-function impurity moving through a quasi-one-dimensional Bose-Einstein condensate at all subcritical velocities and at all temperatures. The force occurs due to an imbalance in the Doppler shifts of reflected quantum fluctuations from either side of the impurity. Our calculation is based on a consistent extension of Bogoliubov theory to second order in the interaction strength, and finds new analytical solutions to the Bogoliubov-de Gennes equations for a gray soliton. Our results raise questions regarding the quantum dynamics in the formation of persistent currents in superfluids.
description: 7 pages (including supplementary material)
The Contour-Advective Semi-Lagrangian Algorithm for the Shallow Water Equations
Creators: name: Dritschel, David G.
name: Polvani, Lorenzo M.
name: Mohebalhojeh, Ali R.
Publisher: name: Columbia University
Year: 1999
Subjects: subject: Atmosphere
subject: Mathematics
subject: FOS: Mathematics
subject: Geophysics
subject: FOS: Earth and related environmental sciences

description: A new method for integrating shallow water equations, the contour-advective semi-Lagrangian (CASL) algorithm, is presented. This is the first implementation of a contour method to a system of equations for which exact potential vorticity invertibility does not exist. The new CASL method fuses the recent contour-advection technique with the traditional pseudospectral (PS) method. The potential vorticity field, which typically develops steep gradients and evolves into thin filaments, is discretized by level sets separated by contours that are advected in a fully Lagrangian way. The height and divergence fields, which are intrinsically broader in scale, are treated in an Eulerian way: they are discretized on an fixed grid and time stepped with a PS scheme. In fact, the CASL method is similar to the widely used semi-Lagrangian (SL) method in that material conservation of potential vorticity along particle trajectories is used to determine the potential vorticity at each time step from the previous one. The crucial difference is that, whereas in the CASL method the potential vorticity is merely advected, in the SL method the potential vorticity needs to be interpolated at each time step. This interpolation results in numerical diffusion in the SL method. By directly comparing the CASL, SL, and PS methods, it is demonstrated that the implicit diffusion associated with potential vorticity interpolation in the SL method and the explicit diffusion required for numerical stability in the PS method seriously degrade the solution accuracy compared with the CASL method. Moreover, it is shown that the CASL method is much more efficient than the SL and PS methods since, for a given solution accuracy, a much coarser grid can be used and hence much faster computations can be performed.
On the Mix-Down Times of Dynamically Active Potential Vorticity Filaments
Creators: name: Esler, J. Gavin
name: Polvani, Lorenzo M.
name: Plumb, R. Alan
Publisher: name: Columbia University
Year: 1999
Subjects: subject: Atmosphere
subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Mathematics
subject: FOS: Mathematics

description: A simple model is used to study the evolution of potential vorticity filaments, viewed in cross-section, subject to steady shear and deformation flows representative of the large-scale atmospheric circulation. It is found that the balanced,ageostrophic circulation induced by the anomalous potential vorticity can cause the evolution of a dynamically active filament to differ substantially from that of a dynamically passive filament in a similar background flow. It is suggested that estimates of the mix-down time of material contained in atmospheric filaments need to be corrected to allow for this effect.
National PID Infrastructure Strategy for Open Research: the view from Down Under
Creators: name: Simons, Natasha
name: Burton, Adrian
Publisher: name: Zenodo
Year: 2021
Subjects: persistent identifiers
research
data
infrastructure
FAIR
strategy

description: Australia (also known as “Down Under”) is often used by tech companies to test new technologies and products, since it is relatively affluent, cohesive, and manageable in size. Perhaps that makes it a good place to test national approaches to infrastructure that support open research, and the National Research Infrastructure Strategy has been a two decade experiment in applying leading edge technologies at national scale to support leading edge research. The establishment in 2019 of the Australian Research Data Commons was the latest development in this 20 year strategy. The ARDC conducted a review of previous approaches to providing PID services and has issued a new PID policy, strategy, and portfolio of PID services. In this talk we cover why we think PIDs are essential to leading edge research, which PIDs we consider essential to the portfolio, and how we evolve our delivery.
The Effect of a Hadley Circulation on the Propagation and Reflection of Planetary Waves in a Simple One-Layer Model
Creators: name: Esler, J. Gavin
name: Polvani, Lorenzo M.
name: Plumb, R. Alan
Publisher: name: Columbia University
Year: 2000
Subjects: subject: Geophysics
subject: FOS: Earth and related environmental sciences
subject: Atmosphere
subject: Physics

description: The effect of a simple representation of the Hadley circulation on the propagation and nonlinear reflection of planetary-scale Rossby waves in the winter hemisphere is investigated numerically in a single-layer shallow-water model. In the first instance, waves are forced by a zonal wavenumber three topography centered in the extratropics. In the linear limit the location of the low-latitude critical line at which the waves are absorbed is displaced poleward by the Hadley circulation. At finite forcing amplitude the critical layer regions where the waves break are found to be displaced poleward by a similar distance. The Hadley circulation is also found to inhibit the onset of nonlinear reflection by increasing the dissipation of wave activity in the critical layer. Second, for waves generated by an isolated mountain, the presence of the Hadley circulation further inhibits nonlinear reflection by generating a strong westerly flux of wave activity within the critical layer. This westerly flux is shown to be largely advective and is explained by the poleward displacement of the critical line into the region of westerly flow. A simple expression is derived for the minimum zonal wind strength allowing propagation in the case of a quasigeostrophic β-plane flow when the mean meridional wind ̅υ greater than 0.
The frequency agile HF antenna
Creators: name: Hellicar, D
Publisher: name: University Of Tasmania
Year: 2023

description: This thesis examines the theory and practice of the 'AT' series antenna man-ufactured by MOONRAKER AUSTRALIA. A model has been developed based on the superposition of symmetric and asymmetric dipoles, which has been confirmed by numerical techniques. A test system has been developed which allows the manufacturer to rapidly test production, using unskilled staff, whilst building a data base for future analysis of the antenna and its production.
Reanalysis of pion pion phase shifts from K -> pi pi decays
Creators: name: Cirigliano, V.
name: Ecker, G.
name: Pich, A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We re-investigate the impact of isospin violation for extracting the s-wave pion pion scattering phase shift difference delta_0(M_K) - delta_2(M_K) from K -> pi pi decays. Compared to our previous analysis in 2003, more precise experimental data and improved knowledge of low-energy constants are used. In addition, we employ a more robust data-driven method to obtain the phase shift difference delta_0(M_K) - delta_2(M_K) = (52.5 \pm 0.8_{exp} \pm 2.8_{theor}) degrees.
description: 8 pages
title: Using Videodisc Technology and the Index of Nutritional Quality to Teach Dietary Guidance to Young Adults
Creators: name: Edmunds, Glenda Wigginton
Publisher: name: Utah State University
Year: 1983

description: A review of the literature indicated a need for nutrition education materials to be current with prevailing scientific knowledge, using advanced instructional technology. Individuals need help in applying nutrition principles to their dietary practices.
A nutrition education program utilizing the nutrient density concept and the dietary guidelines for use on videodisc with microcomputer interface was developed and evaluated. The evaluation of the program did not prove to be effective statistically but learners did show an interest in the program and had positive feedback in regard to the information presented and the technology used.
Analysis of B and Be Star Populations of the Double Cluster h and chi Persei
Creators: name: Marsh, Amber N.
name: McSwain, M. Virginia
name: Currie, Thayne
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present blue optical spectra of 92 members of h and chi Per obtained with the WIYN telescope at Kitt Peak National Observatory. From these spectra, several stellar parameters were measured for the B-type stars, including V sin i, T_eff, log g_polar, M_star, and R_star. Stromgren photometry was used to measure T_eff and log g_polar for the Be stars. We also analyze photometric data of cluster members and discuss the near-to-mid IR excesses of Be stars.
description: 4 pages, to appear in the proceedings of IAU Symposium 266: Star Clusters
RFI Environment at the OVRO LWA: Quantitative Measurements
Creators: name: Larry, D'Addario
name: Hodges, Mark
Publisher: name: Zenodo
Year: 2019
Subjects: radio frequency interference

description: Measurements of the power spectral density of signals received by a few selected OVRO LWA antennas were collected for at least 24 hours over the frequency range 0 to 165 MHz. The objective was to quantify the RFI environment, concentrating primarily on the signals outside the target observing band of 25 to 85 MHz. Those out-of-band signals are subject to suppression by filtering. Significant filtering is practical only after the signals are delivered to the processing shelter, so these results can be used to set the dynamic range requirements for the RF-over-fiber links from outer antennas and for the pre-filtering analog signal processing at the shelter, as well as the amount of filtering needed to keep the signals within the dynamic range of the digitizers. It is found that the total power below 20 MHz (HF communication) is highly variable with peaks about 16 dB above the total power in the observing band, and that the total power above 88 MHz (primarily FM radio) is very stable at about 29 dB above the minimum power in the observing band. Sporadic in-band RFI is also seen.
description: Originally published at http://www.tauceti.caltech.edu/LWA/lwamemos.html.
Sequence Stratigraphy and the Interpretation of Neoproterozoic Earth History
Creators: name: Christie-Blick, Nicholas
name: Dyson, Ian A.
name: Von Der Borch, C. C.
Publisher: name: Columbia University
Year: 1995
Subjects: subject: Geology
subject: FOS: Earth and related environmental sciences
subject: Geomorphology
subject: Physical geography

description: The application of sequence stratigraphy to Neoproterozoic successions is important for improving the resolution of time-correlation within individual sedimentary basins and potentially at a global scale. The methodology is illustrated in this paper by reference to two contrasting examples from the Flinders Ranges (Adelaide geosyncline) of South Australia, where the younger part of the Neoproterozoic to earliest Cambrian succession (∼ 770 Ma to ∼ 540 Ma) has been divided into thirteen unconformity-bounded depositional sequences. One of the most prominent sequence boundaries, at or near the base of the Wonoka Formation, is characterized by a series of buried canyons as much as 1 km deep. High-resolution sequence-stratigraphic studies at Umberatana syncline continue to support the view that the canyons were cut subaerially and filled by fluvial and shallow-water sediments. In contrast to the Wonoka canyons, sequence boundaries interpreted at the base of the Nuccaleena Formation/Seacliff Sandstone and near the top of the ABC Range Quartzite are relatively subtle, with only limited evidence for erosion and valley incision. Four sequence boundaries, at the level of the Sturtian and Marinoan (Varanger?) glacial deposits and in the vicinity of the Precambrian-Cambrian boundary, are thought to correlate with surfaces in the Amadeus basin of central Australia. Other prominent sequence boundaries, including the Wonoka canyons and surfaces within the upper part of the Wonoka Formation and at the base of the Ediacara Member of the Rawnsley Quartzite, correspond with a relatively condensed section in the Amadeus basin, and their lateral persistence beyond the Adelaide geosyncline is therefore difficult to evaluate. Given the lack of precision in biostratigraphy and isotope geochemistry in Neoproterozoic rocks, and in a marked departure from Phanerozoic practice, we recommend placement of a terminal Proterozoic GSSP at a sequence boundary. A prime candidate in Australia is the sequence boundary at the base of the Nuccaleena Formation/Seacliff Sandstone, immediately above the Marinoan glacial rocks in the Adelaide geosyncline, and its likely correlative at or near the base of the Gaylad Sandstone in the Amadeus basin.