18,603 research outputs found
Additions to fused-fluoride lubricant coatings for reduction of low-temperature friction
Additions to fused-fluoride lubricant coatings for reduction of low temperature frictio
Statics and Dynamics of Vortex Liquid Crystals
Using numerical simulations we examine the static and dynamic properties of
the recently proposed vortex liquid crystal state. We confirm the existence of
a smectic-A phase in the absence of pinning. Quenched disorder can induce a
smectic state even at T=0. When an external drive is applied, a variety of
anisotropic dynamical flow states with distinct voltage signatures occur,
including elastic depinning in the hard direction and plastic depinning in the
easy direction. We discuss the implications of the anisotropic transport for
other systems which exhibit depinning phenomena, such as stripes and electron
liquid crystals.Comment: 4 pages, 4 postscript figure
Pulsation of EE Cam
EE Cam is a previously little studied Delta Scuti pulsator with amplitudes
between those of the HADS (High-Amplitude Delta Scuti stars) group and the
average low-amplitude pulsators. Since the size of stellar rotation determines
both which pulsation modes are selected by the star as well as their
amplitudes, the star offers a great opportunity to examine the astrophysical
connections. Extensive photometric measurements covering several months were
carried out. 15 significant pulsation frequencies were extracted. The dominant
mode at 4.934 cd was identified as a radial mode by examining the phase
shifts at different wavelengths. Medium-dispersion spectra yielded a
value of km s. This shows that EE Cam belongs to the
important transition region between the HADS and normal Delta Scuti stars.Comment: 13 pages, 3 figures, 3 table
Spin-exchange Cross Sections For Hydrogen-atomalkali-metal-atom Collisions
The pseudopotential molecular-structure method has been used to calculate the X1 and a3 interaction potentials for the alkali-metal-atom hydrogen-atom systems. These potentials were then used in a quantum-mechanical calculation to determine the spin-exchange cross sections in the energy range from 2.5x10-4 eV to 2.5 eV. The cross sections follow the general form Q1/2=a-b lnv. However, abundant structure on the cross sections is present due to orbiting resonances induced by the deeply bound well of the X1 molecular state. The spin-exchange cross sections range from 17x10-16 to 25x10-16 cm2 at room temperature for H(F=1) transferring to H(F=0) in collision with unpolarized lithium and cesium, respectively. © 1985 The American Physical Society
Phase space analysis of two-wavelength interferometry
Multiple wavelength phase shifting interferometry is widely used to extend
the unambiguous range (UR) beyond that of a single wavelength. Towards this
end, many algorithms have been developed to calculate the optical path
difference (OPD) from the phase measurements of multiple wavelengths. These
algorithms fail when phase error exceeds a specific threshold. In this paper,
we examine this failure condition. We introduce a "phase-space" view of
multi-wavelength algorithms and demonstrate how this view may be used to
understand an algorithm's robustness to phase measurement error. In particular,
we show that the robustness of the synthetic wavelength algorithm deteriorates
near the edges of its UR. We show that the robustness of de Groot's extended
range algorithm [Appl. Opt. 33, 5948 (1994)] depends on both wavelength and OPD
in a non-trivial manner. Further, we demonstrate that the algorithm developed
by Houairi & Cassaing (HC) [J. Opt. Soc. Am. 26, 2503 (2009)] results in
uniform robustness across the entire UR. Finally, we explore the effect that
wavelength error has on the robustness of the HC algorithm.Comment: 8 pages, 7 figure
CC267 Dairy Producer Waste Guidelines
Campaign Circular 267: This circular is about dairy producer waste guidelines
CC267 Dairy Producer Waste Guidelines
Campaign Circular 267: This circular is about dairy producer waste guidelines
Molecular Treatment Of Charge Transfer In Li+ +Ca Collisions
The perturbed-stationary-state method, appended with electron translation factors, has been applied to charge transfer in Li+ +Ca collisions for energies from 0.1 to 20 keV/amu. The Born-Oppenheimer wave functions and eigenvalues were generated using the pseudopotential technique, which reduced the many-electron system to a simpler two-electron problem. The molecular ground-state X +1 is calculated to be bound and has the potential-well parameters Re=6.20a0, De=1.11 eV, e=235 cm-1, and Be=0.263 cm-1. From the scattering computations, a representative value for the charge-transfer cross section is 4x10-15 cm2 at 5 keV/amu. The cross section decreases rapidly as the energy is reduced below 1 keV/amu. At all energies studied, the dominant electron-capture reaction product is the ground-state Li atom. © 1983 The American Physical Society
Silage Additives
SummaryThrough the years a number of materials have been suggested for incorporation into silage to improve the preservation of nutrients, nutritive value or palatability of the silage. In addition to being called additives, some of these materials are referred to as preservatives or conditioners. Especially during recent years, many commercial preparations have been made available to the farmer, who naturally wonders whether their use will be economically sound. Thorough testing of these materials would require that each be used at several levels, with forages at various moisture contents, under different storage conditions and with many kinds of silage. Therefore, it is highly impractical, if not impossible, to attempt thorough testing of each. However, there is sufficient understanding of the process of silage formation, the requirements for preservation of its nutrients, and the principle of action of the ingredients used in the various additives to make sound decisions as to whether they might be economically worth-while. There is, in addition to this understanding, a rather large amount of research which has been done and reported, and this in its summation justifies the use of what is already known to make judgments. In order to make an appropriate judgment, one should be able to answer certain questions, as follows:1.What happens during the process of silage formation? 2. What does the additive being considered contain and what do its ingredients do?3. What is the value of the silage and what is the cost of the additive?4. How much preservation beyond that afforded by good ensiling procedures can one logically expect from the additive?5.Can one expect to improve the feeding value of a silage by using a particular additive?The discussion that follows deals with these questions
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