654 research outputs found
Invariant classification and the generalised invariant formalism: conformally flat pure radiation metrics, with zero cosmological constant
Metrics obtained by integrating within the generalised invariant formalism
are structured around their intrinsic coordinates, and this considerably
simplifies their invariant classification and symmetry analysis. We illustrate
this by presenting a simple and transparent complete invariant classification
of the conformally flat pure radiation metrics (except plane waves) in such
intrinsic coordinates; in particular we confirm that the three apparently
non-redundant functions of one variable are genuinely non-redundant, and easily
identify the subclasses which admit a Killing and/or a homothetic Killing
vector. Most of our results agree with the earlier classification carried out
by Skea in the different Koutras-McIntosh coordinates, which required much more
involved calculations; but there are some subtle differences. Therefore, we
also rework the classification in the Koutras-McIntosh coordinates, and by
paying attention to some of the subtleties involving arbitrary functions, we
are able to obtain complete agreement with the results obtained in intrinsic
coordinates. In particular, we have corrected and completed statements and
results by Edgar and Vickers, and by Skea, about the orders of Cartan
invariants at which particular information becomes available.Comment: Extended version of GRG publication, with some typos etc correcte
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ZPPR progress report: February 1988 through April 1988
Results are presented for control rod worth experiments in the axially heterogeneous assembly ZPPR-17, a part of the JUPITER-III program. From the earlier metal-fuel ZPPR-15 program, results are given for measurements and calculations of neutron spectra and sodium voiding in several configurations
Monte-Carlo Event Generators at NLO
A method to construct Monte-Carlo event generators at arbitrarily non-leading
order is explained for the case of a non-gauge theory. A precise and correct
treatment of parton kinematics is provided. Modifications of the conventional
formalism are required: parton showering is not exactly the same as DGLAP
evolution, and the external line prescription for the hard scattering differs
from the LSZ prescription. The prospects for extending the results to QCD are
discussed.Comment: 57 pages, 16 eps figures, revtex
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ANL analysis of ZPPR-13A
The ZPPR-13 experiments provide basic physics data for radial heterogeneous LMFBR cores of approximately 700MWe size. Assemblies ZPPR-13A, ZPPR-13B and ZPPR-13C comprised the JUPITER-II cooperative program between the U.S. Department of Energy (US DOE) and PNC of Japan. The measurements were made between August 1982 and April 1984. The core designs and the measurements were planned jointly by the two parties with substantial input from U.S. industrial interests to ensure coverage of the design requirements. This report describes in detail the results of the Argonne National Laboratory (ANL) analyses of phase 13A
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JUPITER-II Program: ANL analysis of ZPPR-13A and ZPPR-13B
The ZPPR-13 experiments provide basic physics data for radial heterogeneous LMFBR cores of approximately 700MWe size. Assemblies ZPPR-13A, ZPPR-13B and ZPPR-13A comprised the JUPITER-II cooperative program between the U.S. Department of Energy (US DOE) and PNC of Japan. The measurements were made between August 1982 and April 1984. The core designs and the measurements were planned jointly by the two parties with substantial input from U.S. industrial interests to ensure coverage of the design requirements. This report describes in detail the results of the Argonne National Laboratory (ANL) analyses of phases 13A and 13B/1 and includes preliminary results for the later assemblies of phase 13B.
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ZPPR progress report, January 1989 through April 1989
Further results are presented from the large, homogeneous assembly ZPPR-18 in the JUPITER-III program. Reaction rate results are given for ZPPR-18B along with measured gamma ray dose results from ZPPR-18A and 18B. Control rod worth results from the ZPPR-18 assemblies are included. Calculation models, measured and calculated k-effective values and measured sodium worth values, are presented for the ZPPR-19 assemblies of the lo program
Compact SAW aerosol generator
In this work, we discuss and demonstrate the principle features of surface acoustic wave (SAW) aerosol generation, based on the properties of the fluid supply, the acoustic wave field and the acoustowetting phenomena. Furthermore, we demonstrate a compact SAW-based aerosol generator amenable to mass production fabricated using simple techniques including photolithography, computerized numerical control (CNC) milling and printed circuit board (PCB) manufacturing. Using this device, we present comprehensive experimental results exploring the complexity of the acoustic atomization process and the influence of fluid supply position and geometry, SAW power and fluid flow rate on the device functionality. These factors in turn influence the droplet size distribution, measured here, that is important for applications including liquid chromatography, pulmonary therapies, thin film deposition and olfactory displays
On the parabolic equation method in internal wave propagation
A parabolic equation for the propagation of periodic internal waves over
varying bottom topography is derived using the multiple-scale perturbation
method. Some computational aspects of the numerical implementation are
discussed. The results of numerical experiments on propagation of an incident
plane wave over a circular-type shoal are presented in comparison with the
analytical result, based on Born approximation.Comment: Submitted to Coastal Engineering. 16 pages, 5 figures. One figure was
excluded from article because of size problem
Scaling-violation phenomena and fractality in the human posture control systems
By analyzing the movements of quiet standing persons by means of wavelet
statistics, we observe multiple scaling regions in the underlying body
dynamics. The use of the wavelet-variance function opens the possibility to
relate scaling violations to different modes of posture control. We show that
scaling behavior becomes close to perfect, when correctional movements are
dominated by the vestibular system.Comment: 12 pages, 4 figures, to appear in Phys. Rev.
Recoil and Threshold Corrections in Short-distance Cross Sections
We identify and resum corrections associated with the kinematic recoil of the
hard scattering against soft-gluon emission in single-particle inclusive cross
sections. The method avoids double counting and conserves the flow of partonic
energy. It reproduces threshold resummation for high-p_T single-particle cross
sections, when recoil is neglected, and Q_T-resummation at low Q_T, when
higher-order threshold logarithms are suppressed. We exhibit explicit resummed
cross sections, accurate to next-to-leading logarithm, for electroweak
annihilation and prompt photon inclusive cross sections.Comment: minor modifications of the text, some references added. 51 pages,
LaTeX, 6 figures as eps file
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