3,890 research outputs found
The Language of Cruelty: Dialogue Strategies and the Spectator in Gambaro's El desatino and Pinter's The Birthday Party
Planetary image conversion task
The Planetary Image Conversion Task group processed 12,500 magnetic tapes containing raw imaging data from JPL planetary missions and produced an image data base in consistent format on 1200 fully packed 6250-bpi tapes. The output tapes will remain at JPL. A copy of the entire tape set was delivered to US Geological Survey, Flagstaff, Ariz. A secondary task converted computer datalogs, which had been stored in project specific MARK IV File Management System data types and structures, to flat-file, text format that is processable on any modern computer system. The conversion processing took place at JPL's Image Processing Laboratory on an IBM 370-158 with existing software modified slightly to meet the needs of the conversion task. More than 99% of the original digital image data was successfully recovered by the conversion task. However, processing data tapes recorded before 1975 was destructive. This discovery is of critical importance to facilities responsible for maintaining digital archives since normal periodic random sampling techniques would be unlikely to detect this phenomenon, and entire data sets could be wiped out in the act of generating seemingly positive sampling results. Reccomended follow-on activities are also included
Mottness: Identifying the Propagating Charge Modes in doped Mott Insulators
High-temperature superconductivity in the copper-oxide ceramics remains an
unsolved problem because we do not know what the propagating degrees of freedom
are in the normal state. As a result, we do not know what are the weakly
interacting degrees of freedom which pair up to form the superconducting
condensate. That the electrons are not the propagating degrees of freedom in
the cuprates is seen most directly from experiments that show spectral weight
redistributions over all energy scales. Of course, the actual propagating
degrees of freedom minimize such spectral rearrangements. This review focuses
on the range of epxerimental consequences such UV-IR mixings have on the normal
state of the cuprates, such as the pseudogap, mid-infrared band, temperature
dependence of the Hall number, the superfluid density, and a recent theoretical
advance which permits the identification of the weakly interacting degrees of
freedom in a doped Mott insulator. Within this theory, we show how the wide
range of phenomena which typify the normal state of the cuprates arises
including linear resistivity.Comment: To appear as a Colloquium in the April issue of Rev. Mod. Phys
Updated version contains new references and a clarification concerning Fig.
8
A study of ablation effects on antenna performance Final report, 7 Jul. 1965 - 12 Oct. 1966
Dielectric property screening tests, and temperature range tests for determining ablation material effects on Apollo model antennas - simulation of thermal protection syste
Remote sensing of the atmosphere from environmental satellites
Various applications of satellite remote sensing of the earth are reviewed, including (1) the use of meteorological satellites to obtain photographic and radiometric data for determining weather conditions; (2) determination of the earth radiation budget from measurements of reflected solar radiation and emitted long wave terrestrial radiation; (3) the use of microwave imagery for measuring ice and snow cover; (4) LANDSAT visual and near infrared observation of floods and crop growth; and (5) the use of the Nimbus 4 backscatter ultraviolet instrument to measure total ozone and vertical ozone distribution. Plans for future activities are also discussed
Structural properties of electrons in quantum dots in high magnetic fields: Crystalline character of cusp states and excitation spectra
The crystalline or liquid character of the downward cusp states in N-electron
parabolic quantum dots (QD's) at high magnetic fields is investigated using
conditional probability distributions obtained from exact diagonalization.
These states are of crystalline character for fractional fillings covering both
low and high values, unlike the liquid Jastrow-Laughlin wave functions, but in
remarkable agreement with the rotating-Wigner-molecule ones [Phys. Rev. B 66,
115315 (2002)]. The crystalline arrangement consists of concentric polygonal
rings that rotate independently of each other, with the electrons on each ring
rotating coherently. We show that the rotation stabilizes the Wigner molecule
relative to the static one defined by the broken-symmetry
unrestricted-Hartree-Fock solution. We discuss the non-rigid behavior of the
rotating Wigner molecule and pertinent features of the excitation spectrum,
including the occurrence of a gap between the ground and first excited states
that underlies the incompressibility of the system. This leads us to conjecture
that the rotating crystal (and not the static one) remains the relevant ground
state for low fractional fillings even at the thermodynamic limit.Comment: Published version. Typos corrected. REVTEX4. 10 pages with 8
postscript figures (5 in color). For related papers, see
http://www.prism.gatech.edu/~ph274cy
Nonuniform viscosity in the solar nebula and large masses of Jupiter and Saturn
I report a novel theory that nonuniform viscous frictional force in the solar
nebula accounts for the largest mass of Jupiter and Saturn and their largest
amount of H and He among the planets, two outstanding facts that are unsolved
puzzles in our understanding of origin of the Solar System. It is shown that
the nebula model of uniform viscosity does not match the present planet masses.
By studying current known viscosity mechanisms, I show that viscosity is more
efficient in the inner region inside Mercury and the outer region outside
Jupiter-Saturn than the intermediate region. The more efficient viscosity
drives faster radial inflow of material during the nebula evolution. Because
the inflow in the outer region is faster than the intermediate region, the
material tends to accumulate in Jupiter-Saturn region which is between the
outer and intermediate region. It is demonstrated that the gas trapping time of
Jovian planets is longer than the inflow time in the outer region. Therefore
the gas already flows to Jupiter-Saturn region before Uranus and Neptune can
capture significant gas. But the inflow in the Jupiter-Saturn region is so slow
that they can capture large amount of gas before the gas can flow further
inward. Hence they have larger masses with larger H and He content than Uranus
and Neptune. I also extend the discussion to the masses of the terrestrial
planets, especially low mass of Mercury. The advantages of this theory are
discussed.Comment: 4 pages, 1 figure, A&A Letters accepte
Geoeffectiveness of CIR and CME Events: Factors Contributing to Their Differences
Recent work has shown that solar wind-magnetosphere coupling is more efficient for CIR-driven events than for CME-driven events. The study herein looks into the individual physical parameters of Corotating Interaction Regions (CIRs) and Coronal Mass Ejections (CMEs) and looks to isolate particular characteristics that leads to greater coupling of energy from the solar wind into the magnetosphere for certain classes of magnetic storms. While it is clear that these two types of events are distinct in their outcome, it is not known what in the nature of the events leads to these different results. The variation level in the z-component of the Interplanetary Magnetic field (IMF) and the Alfvénic Mach number one hour prior to the onset of a CIR or CME event are investigated as possibly related to the coupling efficiency. While there was no significant correlation between any particular characteristic and energy coupling efficiency, the most promising result came from the Alfvénic Mach number and its effect on the energy efficiency of the storm main phase. The Alfvénic Mach numbers of CIR and CME events had the strongest connection to the main phase energy efficiency. More study is needed on the connection between the Alfvénic Mach number as it relates to energy efficiency. Different or combinations of characteristics of these storms may also shed more light on the necessary conditions for a more geoeffective event
Spin Hall Effect and Spin Transfer in Disordered Rashba Model
Based on numerical study of the Rashba model, we show that the spin Hall
conductance remains finite in the presence of disorder up to a characteristic
length scale, beyond which it vanishes exponentially with the system size. We
further perform a Laughlin's gauge experiment numerically and find that all
energy levels cannot cross each other during an adiabatic insertion of the flux
in accordance with the general level-repulsion rule. It results in zero spin
transfer between two edges of the sample as each state always evolves back
after the insertion of one flux quantum, in contrast to the quantum Hall
effect. It implies that the topological spin Hall effect vanishes with the
turn-on of disorder.Comment: 4 pages, 4 figures final versio
Rapidly Rotating Fermi Gases
We show that the density profile of a Fermi gas in rapidly rotating potential
will develop prominent features reflecting the underlying Landau level like
energy spectrum. Depending on the aspect ratio of the trap, these features can
be a sequence of ellipsoidal volumes or a sequence of quantized steps.Comment: 4 pages, 1 postscript fil
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