153,375 research outputs found
Field Evaluation of Trap Components for the Introduced Pine Sawfly, \u3ci\u3eDiprion Similis\u3c/i\u3e (Hymenoptera: Diprionidae)
Three sizes of the Conrel Delta trap, a yellow cardboard tube trap, and the Pherocon II standard trap generally used in detection surveys were evaluated. Tests were run for 41 days in the summer of 1980 and 35 days in the spring of 1981. The lure in all traps was the standard 38-cm cotton dental roll charged with 10 female equivalents of crude virgin female pheromone extract. In 1980, all test traps outperformed the standard Pherocon II model. In 1981, the Pherocon II traps captured more males than any of the others. The catch in the Delta traps appeared to be Toughly proportional to their size. An additional test in 1981 evaluated three types of cigarette filters compared with the dental roll as the pheromone dispenser. After 79 days, the cigarette filter-baited traps were still capturing sawflies whereas the traps baited with the dental rolls stopped catching males after 51 days
Dihadron Fragmentation Functions in the NJL-jet model
The NJL-jet model provides a framework for calculating fragmentation
functions without introducing ad hoc parameters. Here the NJL-jet model is
extended to investigate dihadron fragmentation functions.Comment: 4 pages, 5 figures, Proceedings of 8th Circum-Pan-Pacific Symposium
on High Energy Spin Physic
Minkowski Vacuum Stress Tensor Fluctuations
We study the fluctuations of the stress tensor for a massless scalar field in
two and four-dimensional Minkowski spacetime in the vacuum state. Covariant
expressions for the stress tensor correlation function are obtained as sums of
derivatives of a scalar function. These expressions allow one to express
spacetime averages of the correlation function as finite integrals. We also
study the correlation between measurements of the energy density along a
worldline. We find that these measurements may be either positively correlated
or anticorrelated. The anticorrelated measurements can be interpreted as
telling us that if one measurement yields one sign for the averaged energy
density, a successive measurement with a suitable time delay is likely to yield
a result with the opposite sign.Comment: 24 pages, 5 figures; Some additional comments added in Sect. IIB and
a more compact argument given in App.
On the noncommutative standard model
We propose a pedestrian review of the noncommutative standard model in its
present state.Comment: dedicated to Alain Connes on the occasion of his 60th birthda
Quenched degrees of freedom in symmetric diblock copolymer thin films
We study the effect of monomer immobilization (quenching) on the orientation
of the lamellae in symmetric diblock copolymer thin films with neutrally
wetting surfaces. A small fraction of the monomers immediately next to the
solid substrate is presumed to be quenched. In both the weak segregation limit
and the strong segregation limit, quenching favors the lamellae orienting
perpendicular to the film. Quenching inhibits the order-disorder transition
twice as much for the parallel orientation as for the perpendicular.Comment: 11 page
Brief review related to the foundations of time-dependent density functional theory
The electron density n(\rb,t), which is the central tool of time-dependent
density functional theory, is presently considered to be derivable from a
one-body time-dependent potential V(\rb,t), via one-electron wave functions
satisfying a time- dependent Schr\"{o}dinger equation. This is here related via
a generalized equation of motion to a Dirac density matrix now involving .
Linear response theory is then surveyed, with a special emphasis on the
question of causality with respect to the density dependence of the potential.
Extraction of V(\rb,t) for solvable models is also proposed
Supersonic airplane design optimization method for aerodynamic performance and low sonic boom
This paper presents a new methodology for the optimization of supersonic airplane designs to meet the dual design objectives of low sonic boom and high aerodynamic performance. Two sets of design parameters are used on an existing High Speed Civil Transport (HSCT) configuration to maximize the aerodynamic performance and minimize the sonic boom under the flight track. One set of the parameters perturbs the camber line of the wing sections to maximize the lift-over-drag ratio (L/D). A preliminary optimization run yielded a 3.75 percent improvement in L/D over a baseline low-boom configuration. The other set of parameters modifies the fuselage area to achieve a target F-function. Starting from an initial configuration with strong bow, wing, and tail shocks, a modified design with a flat-top signature is obtained. The methods presented can easily incorporate other design variables and objective functions. Extensions to the present capability in progress are described
Mineralogy and Surface Composition of Asteroids
Methods to constrain the surface mineralogy of asteroids have seen
considerable development during the last decade with advancement in laboratory
spectral calibrations and validation of our interpretive methodologies by
spacecraft rendezvous missions. This has enabled the accurate identification of
several meteorite parent bodies in the main asteroid belt and helped constrain
the mineral chemistries and abundances in ordinary chondrites and basaltic
achondrites. With better quantification of spectral effects due to temperature,
phase angle, and grain size, systematic discrepancies due to non-compositional
factors can now be virtually eliminated for mafic silicate-bearing asteroids.
Interpretation of spectrally featureless asteroids remains a challenge. This
paper presents a review of all mineralogical interpretive tools currently in
use and outlines procedures for their application.Comment: Chapter to appear in the Space Science Series Book: Asteroids IV, 51
pages, 7 figures, 2 table
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