Haldane fractional statistics in the fractional quantum Hall effect

We have tested Haldane's ``fractional-Pauli-principle'' description of excitations around the $\nu = 1/3$ state in the FQHE, using exact results for small systems of electrons. We find that Haldane's prediction $\beta = \pm 1/m$ for quasiholes and quasiparticles, respectively, describes our results well with the modification $\beta_{qp} = 2-1/3$ rather than $-1/3$. We also find that this approach enables us to better understand the {\it energetics\/} of the ``daughter'' states; in particular, we find good evidence, in terms of the effective interaction between quasiparticles, that the states $\nu = 4/11$ and 4/13 should not be stable.Comment: 9 pages, 3 Postscript figures, RevTex 3.0. (UCF-CM-93-005

Interpretation at the controller's edge: designing graphical user interfaces for the digital publication of the excavations at Gabii (Italy)

This paper discusses the authors’ approach to designing an interface for the Gabii Project’s digital volumes that attempts to fuse elements of traditional synthetic publications and site reports with rich digital datasets. Archaeology, and classical archaeology in particular, has long engaged with questions of the formation and lived experience of towns and cities. Such studies might draw on evidence of local topography, the arrangement of the built environment, and the placement of architectural details, monuments and inscriptions (e.g. Johnson and Millett 2012). Fundamental to the continued development of these studies is the growing body of evidence emerging from new excavations. Digital techniques for recording evidence “on the ground,” notably SFM (structure from motion aka close range photogrammetry) for the creation of detailed 3D models and for scene-level modeling in 3D have advanced rapidly in recent years. These parallel developments have opened the door for approaches to the study of the creation and experience of urban space driven by a combination of scene-level reconstruction models (van Roode et al. 2012, Paliou et al. 2011, Paliou 2013) explicitly combined with detailed SFM or scanning based 3D models representing stratigraphic evidence. It is essential to understand the subtle but crucial impact of the design of the user interface on the interpretation of these models. In this paper we focus on the impact of design choices for the user interface, and make connections between design choices and the broader discourse in archaeological theory surrounding the practice of the creation and consumption of archaeological knowledge. As a case in point we take the prototype interface being developed within the Gabii Project for the publication of the Tincu House. In discussing our own evolving practices in engagement with the archaeological record created at Gabii, we highlight some of the challenges of undertaking theoretically-situated user interface design, and their implications for the publication and study of archaeological materials

Transonic separated flow predictions based on a mathematically simple, nonequilibrium turbulence closure model

A mathematically simple, turbulence closure model designed to treat transonic airfoil flows even with massive separation is described. Numerical solutions of the Reynolds-averaged, Navier-Stokes equations obtained with this closure model are shown to agree well with experiments over a broad range of test conditions

Expectation values of single-particle operators in the random phase approximation ground state

We developed a method for computing matrix elements of single-particle operators in the correlated random phase approximation ground state. Working with the explicit random phase approximation ground state wavefunction, we derived practically useful and simple expression for a molecular property in terms of random phase approximation amplitudes. The theory is illustrated by the calculation of molecular dipole moments for a set of representative molecules.Comment: Accepted to J.Chem.Phy

Ground winds for Kennedy Space Center, Florida (1978 version)

Ground level runway wind statistics are presented for the Kennedy Space Center, Florida area. Crosswind, headwind, tailwind, and headwind reversal percentage frequencies are given with respect to month and hour for the Kennedy Space Center Space Shuttle runway. This document supersedes NASA CR-128995 and should be used in place of it

On the origin of excess cool gas in quasar host halos

Previous observations of quasar host halos at z=2 have uncovered large quantities of cool gas that exceed what is found around inactive galaxies of both lower and higher masses. To better understand the source of this excess cool gas, we compiled an exhaustive sample of 195 quasars at z=1 with constraints on chemically enriched, cool gas traced by MgII absorption in background quasar spectra from the Sloan Digital Sky Survey. This quasar sample spans a broad range of luminosities from Lbol=10^44.4 to 10^46.8 erg/s and allows an investigation of whether halo gas properties are connected with quasar properties. We find a strong correlation between luminosity and cool gas covering fraction. In particular, low-luminosity quasars exhibit a mean gas covering fraction comparable to inactive galaxies of similar masses, but more luminous quasars exhibit excess cool gas approaching what is reported previously at z=2. Moreover, 30-40% of the MgII absorption occurs at radial velocities of |v|>300 km/s from the quasar, inconsistent with gas bound to a typical quasar host halo. The large velocity offsets and observed luminosity dependence of the cool gas near quasars can be explained if the gas arises from: (1) neighboring halos correlated through large-scale structure at Mpc scales, (2) feedback from luminous quasars, or (3) debris from the mergers thought to trigger luminous quasars. The first of these scenarios is in tension with the lack of correlation between quasar luminosity and clustering while the latter two make distinct predictions that can be tested with additional observations.Comment: 15 pages with 6 figures. Accepted to MNRA

Critical review of the trailing edge condition in steady and unsteady flow. Blade flutter in compressors and fans: Numerical simulation of the aerodynamic loading

Existing interpretations of the trailing edge condition, addressing both theoretical and experimental works in steady, as well as unsteady flows are critically reviewed. The work of Kutta and Joukowski on the trailing edge condition in steady flow is reviewed. It is shown that for most practical airfoils and blades (as in the case of most turbomachine blades), this condition is violated due to rounded trailing edges and high frequency effects, the flow dynamics in the trailing edge region being dominated by viscous forces; therefore, any meaningful modelling must include viscous effects. The question of to what extent the trailing edge condition affects acoustic radiation from the edge is raised; it is found that violation of the trailing edge condition leads to significant sound diffraction at the tailing edge, which is related to the problem of noise generation. Finally, various trailing edge conditions in unsteady flow are discussed, with emphasis on high reduced frequencies

Rheology and ultrasonic properties of Pt57.5Ni5.3Cu14.7P22.5 liquid

The equilibrium and nonequilibrium viscosity and isoconfigurational shear modulus of Pt57.5Ni5.3Cu14.7P22.5 supercooled liquid are evaluated using continuous–strain-rate compression experiments and ultrasonic measurements. By means of a thermodynamically-consistent cooperative shear model, variations in viscosity with both temperature and strain rate are uniquely correlated to the variations in isoconfigurational shear modulus, which leads to an accurate prediction of the liquid fragility and to a good description of the liquid strain-rate sensitivity

Quantum Dots in Strong Magnetic Fields: Stability Criteria for the Maximum Density Droplet

In this article we discuss the ground state of a parabolically confined quantum dots in the limit of very strong magnetic fields where the electron system is completely spin-polarized and all electrons are in the lowest Landau level. Without electron-electron interactions the ground state is a single Slater determinant corresponding to a droplet centered on the minimum of the confinement potential and occupying the minimum area allowed by the Pauli exclusion principle. Electron-electron interactions favor droplets of larger area. We derive exact criteria for the stability of the maximum density droplet against edge excitations and against the introduction of holes in the interior of the droplet. The possibility of obtaining exact results in the strong magnetic field is related to important simplifications associated with broken time-reversal symmetry in a strong magnetic field.Comment: 17 pages, 5 figures (not included), RevTeX 3.0. (UCF-CM-93-002