1,476,377 research outputs found
Multi-frequency imaging of perfectly conducting cracks via boundary measurements
Imaging of perfectly conducting crack(s) in a 2-D homogeneous medium using
boundary data is studied. Based on the singular structure of the Multi-Static
Response (MSR) matrix whose elements are normalized by an adequate test
function at several frequencies, an imaging functional is introduced and
analyzed. A non-iterative imaging procedure is proposed. Numerical experiments
from noisy synthetic data show that acceptable images of single and multiple
cracks are obtained.Comment: 4 pages, 3 figure
Endless tape transport mechanism Patent
Endless loop tape transport mechanism for driving and tensioning recording medium in magnetic tape recorde
Simulator method and apparatus for practicing the mating of an observer-controlled object with a target
A servo controlled target replica, and a surface bearing a computer generated line drawing of an object are individually viewed by separate television cameras allowing a two-dimensional composite of the target replica and the object to be displayed on a monitor simulating what an observer would see through a window in a spacecraft. The target replica is coded along one self coordinate axis in such a way that the distance of an elemental area on the target along the axis is capable of being remotely readout by a television camera. A third television camera responsive to the code reads out this information by which the Z-coordinate, relative to the observer, can be calculated, on-line with the scan, for the contents of each picture element of the scene televised by the target camera
Dropouts in magnetic tape recording and reproduction
Judicious selection and maintenance of tape and tape transports minimizes dropouts
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Diagnostics for magnetically confined high-temperature plasmas
During the last 20 years, magnetically confined laboratory plasmas of steadily increasing temperatures and densities have been obtained, most notably in tokamak configurations, and now approach the conditions necessary to sustain a fusion reaction. Even more important to the goal of understanding the physics of such systems, remarkable advances in plasma diagnostics, the techniques for determining the properties of such plasmas, have accompanied these developments. More parameters can be determined with greater accuracy and finer spatial and temporal resolution. The magnetic configuration, the primary local thermodynamic quantities (density, temperature, and drift velocity), and other necessary quantities can now be measured with sufficient accuracy to determine particle and energy fluxes within the plasma and to characterize the basic transport processes. These plasmas are far from thermodynamic equilibrium. This deviation manifests itself in a variety of instabilities on several spatial and temporal scales, many of which are aptly described as turbulence. Many aspects of the turbulence can also be characterized. This article reviews the current state of diagnostics from an epistemoiogical perspective: the capabilities and limitations for measuring each important physical quantity are presented.Physic
Automated beam builder
Requirements for the space fabrication of large space structures are considered with emphasis on the design, development, manufacture, and testing of a machine which automatically produces a basic building block aluminum beam. Particular problems discussed include those associated with beam cap forming; brace storage, dispensing, and transporting; beam component fastening; and beam cut-off. Various critical process tests conducted to develop technology for a machine to produce composite beams are also discussed
Jet quenching measurements with ATLAS at LHC
A broad program of measurements is planned for heavy ion collisions in ATLAS.
With up to a factor of 30 increase in collision energy compared to existing
data, significant new insights are anticipated to be obtained with the first
data measured. Global features of the LHC collisions will be accessible with
the early data and will set the stage for the precision measurements to follow.
ATLAS is particularly well suited for exploration of "jet quenching," the
extinction of energetic jets in the hot dense medium. Observations of heavy
quark jet suppression will be possible with unprecedented energy reach and
statistical precision, potentially yielding new insights into the basic
mechanisms involved.Comment: 5 pages, 3 figure
T violation in radiative decay and electric dipole moments
In radiative decay, violation can be studied through a
spin-independent -odd correlation. We consider contributions to this
correlation by beyond the standard model (BSM) sources of -violation,
arising above the electroweak scale. At the same time such sources,
parametrized by dimension-6 operators, can induce electric dipole moments
(EDMs). As a consequence, the manifestations of the -odd BSM physics in
radiative decay and EDMs are not independent. Here we exploit this
connection to show that current EDM bounds already strongly constrain the
spin-independent -odd correlation in radiative decay.Comment: 11 pages, 2 figure
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