402 research outputs found
Optimality conditions for the calculus of variations with higher-order delta derivatives
We prove the Euler-Lagrange delta-differential equations for problems of the
calculus of variations on arbitrary time scales with delta-integral functionals
depending on higher-order delta derivatives.Comment: Submitted 26/Jul/2009; Revised 04/Aug/2010; Accepted 09/Aug/2010; for
publication in "Applied Mathematics Letters
Euler-Lagrange equations for composition functionals in calculus of variations on time scales
In this paper we consider the problem of the calculus of variations for a
functional which is the composition of a certain scalar function with the
delta integral of a vector valued field , i.e., of the form
. Euler-Lagrange
equations, natural boundary conditions for such problems as well as a necessary
optimality condition for isoperimetric problems, on a general time scale, are
given. A number of corollaries are obtained, and several examples illustrating
the new results are discussed in detail.Comment: Submitted 10-May-2009 to Discrete and Continuous Dynamical Systems
(DCDS-B); revised 10-March-2010; accepted 04-July-201
Phonon Dispersion Relations in PrBa2Cu3O6+x (x ~ 0.2)
We report measurements of the phonon dispersion relations in
non-superconducting, oxygen-deficient PrBa2Cu3O6+x (x ~ 0.2) by inelastic
neutron scattering. The data are compared with a model of the lattice dynamics
based on a common interaction potential. Good agreement is achieved for all but
two phonon branches, which are significantly softer than predicted. These modes
are found to arise predominantly from motion of the oxygen ions in the CuO2
planes. Analogous modes in YBa2Cu3O6 are well described by the common
interaction potential model.Comment: 4 pages, 3 figures. Minor changes following referees' comment
TEMPERATURE AND LEVEL DENSITY PARAMETER OF EVAPORATION RESIDUES PRODUCED IN THE REACTION 165Ho + 600 MeV 20Ne
Evaporative and preequilibrium neutrons emitted from evaporation residues in the reaction Ho + 600 MeV neon are exploited to deduce the thermal excitation energy E* and temperature T of the residues. From these quantities the level density parameter is deduced at a temperature of 4.1 MeV
A Femtosecond Neutron Source
The possibility to use the ultrashort ion bunches produced by circularly
polarized laser pulses to drive a source of fusion neutrons with sub-optical
cycle duration is discussed. A two-side irradiation of a thin foil deuterated
target produces two countermoving ion bunches, whose collision leads to an
ultrashort neutron burst. Using particle-in-cell simulations and analytical
modeling, it is evaluated that, for intensities of a few ,
more than neutrons per Joule may be produced within a time shorter than
one femtosecond. Another scheme based on a layered deuterium-tritium target is
outlined.Comment: 15 pages, 3 figure
The Effect of Supplementing Mannan Oligosaccharide or Finely Ground Fiber, during the Summer on Body Temperature, Performance, and Blood Metabolites of Finishing Steers
Crossbred beef steers (12 pens, n=96) were used to determine the effect of adding Agrimos or 5% ground (1 in.) wheat straw compared to a control on body temperature, panting score and performance. Th ere were no differences in final BW, ADG, and DMI among treatments. Feed conversion was increased for cattle fed 5% additional ground straw when compared to control and Agrimos. Hot carcass weight, dressing %, LM area, and marbling score were not different among treatments. Cattle fed the control had greater 12th rib fat depth and USDA yield grade than cattle fed straw or Agrimos. Both average and maximum body temperatures were slightly greater for cattle fed Agrimos than for cattle fed control or added straw. Panting scores were decreased slightly for cattle fed the extra straw when compared to control and Agrimos. The addition of Agrimos or wheat straw to the diet had minimal effects on heat stress measures
Nuclear multifragmentation and fission: similarity and differences
Thermal multifragmentation of hot nuclei is interpreted as the nuclear
liquid--fog phase transition deep inside the spinodal region. The experimental
data for p(8.1GeV) + Au collisions are analyzed. It is concluded that the decay
process of hot nuclei is characterized by two size parameters: transition state
and freeze-out volumes. The similarity between dynamics of fragmentation and
ordinary fission is discussed. The IMF emission time is related to the mean
rupture time at the multi-scission point, which corresponds to the kinetic
freeze-out configuration.Comment: 7 pages, 3 Postscript figures, Proceedings of IWM 2005, Catani
Effect of increasing initial implant dosage on feedlot performance and carcass characteristics of long-fed steer and heifer calves1,2
Three experiments evaluated initial implant strategies for finishing cattle. In Exp. 1, heifers (n = 1,405; initial BW = 282 kg) were given (1) Revalor-IH followed by Revalor-200 (REV-IH/200), (2) Revalor-H followed by Revalor-200 (REV-H/200), or (3) Revalor-200 followed by Revalor-200 (REV-200/200). Intake, ADG, and G:F were not affected (P ≥ 0.14) by implant strategies, nor were HCW and LM area (P ≥ 0.16). Percent USDA Choice was greater (P \u3c 0.01) for Rev-IH/200 compared with Rev-H/200 and Rev-200/200. Experiment 2 used steers (n = 1,858; initial BW = 250 kg) given (1) Revalor-IS reimplanted with Revalor-200 (Rev-IS/200), (2) Revalor-XS followed by Revalor-IS (Rev-XS/IS), (3) Revalor-XS followed by Revalor-S (Rev-XS/S), or (4) Revalor-XS followed by Revalor-200 (Rev-XS/200). Implanting strategies did not affect (P ≥ 0.32) DMI or G:F. Carcass traits were not different (P ≥ 0.18) among treatments, except steers implanted with Rev-XS/200 had greater (P \u3c 0.01) LM area. In Exp. 3, steers (n = 1,408; initial BW = 305 kg) were given (1) Rev-IS/200, (2) Rev-200/200, or (3) Rev-XS/200. Gain and G:F did not differ (P ≥ 0.36) among the 3 implant strategies, nor did HCW or marbling score (P ≥ 0.15). Steers given Rev-XS/200 had greater (P \u3c 0.01) LM area and decreased (P ≤ 0.05) 12th-rib fat and YG compared with Rev-200/200 and Rev-IS/200. Using Rev-200/200 and Rev-XS/200 increased (P = 0.03) USDA Select compared with Rev-IS/200. Using greater-initial-dose implant strategies may not affect ADG or G:F but appears to increase leanness
Comparative Analysis of the Mechanisms of Fast Light Particle Formation in Nucleus-Nucleus Collisions at Low and Intermediate Energies
The dynamics and the mechanisms of preequilibrium-light-particle formation in
nucleus-nucleus collisions at low and intermediate energies are studied on the
basis of a classical four-body model. The angular and energy distributions of
light particles from such processes are calculated. It is found that, at
energies below 50 MeV per nucleon, the hardest section of the energy spectrum
is formed owing to the acceleration of light particles from the target by the
mean field of the projectile nucleus. Good agreement with available
experimental data is obtained.Comment: 23 pages, 10 figures, LaTeX, published in Physics of Atomic Nuclei
v.65, No. 8, 2002, pp. 1459 - 1473 translated from Yadernaya Fizika v. 65,
No. 8, 2002, pp. 1494 - 150
Thermal Excitation Energy Distribution of 475 MeV and 2 GeV Proton and 3He Induced Reactions in Heavy Nuclei
The 4pi neutron detector ORION was installed at SATURNE laboratory to perform experiments with high energy light- and heavy- ion beams. The first preliminary results are now available. The thermal excitation energy distribution of nuclei produced in high energy proton induced reactions was measured using almost direct approach. Comparison of the experimental results and predictions of the intranuclear cascade (INC) model is presented. The experimentally observed distributions are in fair agreement with the results of the INC model.</p
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