43,034 research outputs found
Spin 1 inversion: a Majorana tensor force for deuteron alpha scattering
We demonstrate, for the first time, successful S-matrix to potential
inversion for spin one projectiles with non-diagonal yielding a
interaction. The method is a generalization of the
iterative-perturbative, IP, method. We present a test case indicating the
degree of uniqueness of the potential. The method is adapted, using established
procedures, into direct observable to potential inversion, fitting ,
, , and for d + alpha scattering over
a range of energies near 10 MeV. The interaction which we find is
very different from that proposed elsewhere, both real and imaginary parts
being very different for odd and even parity channels.Comment: 7 pages Revtex, 4 ps figure
The use of Kodak aerochrome infrared color film, type 2443, as a remote sensing tool
An infrared color film, Kodak Aerochrome, type 2443, has replaced the 8443 film. The 2443 has lower contrast than the 8443 film, and allows deeper probing into areas that appear as solid black shadows on the 8443 film. The cyan layer of 2443 is approximately 1 1/2 stops slower, at a density of 1.4, than the yellow and magenta emulsion layers
Locating the pseudogap closing point in cuprate superconductors: absence of entrant or reentrant behavior
Current descriptions of the pseudogap in underdoped cuprates envision a
doping-dependent transition line which descends monotonically towards
zero just beyond optimal doping. There is much debate as to the location of the
terminal point where vanishes, whether or not there is a phase
transition at and exactly how behaves below within the
superconducting dome. One perspective sees cutting the dome and
continuing to descend monotonically to zero at holes/Cu
referred to here as `entrant behavior'. Another perspective derived from
photoemission studies is that intersects the dome near holes/Cu then turns back below , falling to zero again
around referred to here as `reentrant behavior'. By
examining thermodynamic data for BiSrCaCuO we show
that neither entrant nor reentrant behavior is experimentally supported.
Rather, sharply delimits the pseudogap regime and for
the pseudogap is always present, independent of temperature. Similar
results are found for YCaBaCuO. For both
materials is not a temperature but a crossover scale, , reflecting instead the underlying pseudogap energy which
vanishes as .Comment: 20 Pages, 9 Figures, in press Phys. Rev.
Velocity statistics in excited granular media
We present an experimental study of velocity statistics for a partial layer
of inelastic colliding beads driven by a vertically oscillating boundary. Over
a wide range of parameters (accelerations 3-8 times the gravitational
acceleration), the probability distribution P(v) deviates measurably from a
Gaussian for the two horizontal velocity components. It can be described by
P(v) ~ exp(-|v/v_c|^1.5), in agreement with a recent theory. The characteristic
velocity v_c is proportional to the peak velocity of the boundary. The granular
temperature, defined as the mean square particle velocity, varies with particle
density and exhibits a maximum at intermediate densities. On the other hand,
for free cooling in the absence of excitation, we find an exponential velocity
distribution. Finally, we examine the sharing of energy between particles of
different mass. The more massive particles are found to have greater kinetic
energy.Comment: 27 pages, 13 figures, to appear in Chaos, September 99, revised 3
figures and tex
Study of a signal processor employing a synthetic phase isolator
Evaluation of signal data processor employing synthetic phase isolator techniqu
Entanglement enhanced atomic gyroscope
The advent of increasingly precise gyroscopes has played a key role in the
technological development of navigation systems. Ring-laser and fibre-optic
gyroscopes, for example, are widely used in modern inertial guidance systems
and rely on the interference of unentangled photons to measure mechanical
rotation. The sensitivity of these devices scales with the number of particles
used as . Here we demonstrate how, by using sources of entangled
particles, it is possible to do better and even achieve the ultimate limit
allowed by quantum mechanics where the precision scales as 1/N. We propose a
gyroscope scheme that uses ultra-cold atoms trapped in an optical ring
potential.Comment: 19 pages, 2 figure
A Method for the Study of Human Factors in Aircraft Operations
A method for the study of human factors in the aviation environment is described. A conceptual framework is provided within which pilot and other human errors in aircraft operations may be studied with the intent of finding out how, and why, they occurred. An information processing model of human behavior serves as the basis for the acquisition and interpretation of information relating to occurrences which involve human error. A systematic method of collecting such data is presented and discussed. The classification of the data is outlined
Pasteurization of cream for buttermaking
In some European countries the pasteurization of cream for buttermaking is extensively practiced. Butter manufacturers in the United States have long recognized that this is a desirable procedure and they have written numerous letters to the experiment stations seeking information regarding it. In many cases it has been more or less difficult to answer these inquiries because of the comparatively small amount of experimental work which has been done along this line.
The purpose of the experiments herein reported was to determine the value of pasteurization to those engaged in the manufacture of butter. In this connection the effect of pasteurization on the flavor of the butter, on the keeping quality, on the body, on the chemical composition, and on the mechanical losses was considered and an effort was made to determine the relative merits of the various methods of pasteurization
Pool boiling on modified surfaces using R-123
This article has been made available through the Brunel Open Access Publishing Fund.Saturated pool boiling of R-123 was investigated for five horizontal copper surfaces modified by different treatments, namely, an emery-polished surface, a fine sandblasted surface, a rough sandblasted surface, an electron beam-enhanced surface, and a sintered surface. Each 40-mm-diameter heating surface formed the upper face of an oxygen-free copper block, electrically heated by embedded cartridge heaters. The experiments were performed from the natural convection regime through nucleate boiling up to the critical heat flux, with both increasing and decreasing heat flux, at 1.01 bar, and additionally at 2 bar and 4 bar for the emery-polished surface. Significant enhancement of heat transfer with increasing surface modification was demonstrated, particularly for the electron beam-enhanced and sintered surfaces. The emery-polished and sandblasted surface results are compared with nucleate boiling correlations and other published data. © 2014 Syed W. Ahmad, John S. Lewis, Ryan J. McGlen, and Tassos G. Karayiannis Published with license by Taylor & Francis
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