30,135 research outputs found
Creation of macroscopic superposition states from arrays of Bose-Einstein condensates
We consider how macroscopic quantum superpositions may be created from arrays
of Bose-Einstein condensates. We study a system of three condensates in Fock
states, all with the same number of atoms and show that this has the form of a
highly entangled superposition of different quasi-momenta. We then show how, by
partially releasing these condensates and detecting an interference pattern
where they overlap, it is possible to create a macroscopic superposition of
different relative phases for the remaining portions of the condensates. We
discuss methods for confirming these superpositions.Comment: 7 pages, 5 figure
Nonlinear acoustic and microwave absorption in glasses
A theory of weakly-nonlinear low-temperature relaxational absorption of
acoustic and electromagnetic waves in dielectric and metallic glasses is
developed. Basing upon the model of two-level tunneling systems we show that
the nonlinear contribution to the absorption can be anomalously large. This is
the case at low enough frequencies, where freqeuency times the minimal
relaxation time for the two-level system are much less than one. In dielectric
glasses, the lowest-order nonlinear contribution is proportional to the wave's
intensity. It is negative and exhibits anomalous frequency and temperature
dependencies. In metallic glasses, the nonlinear contribution is also negative,
and it is proportional to the square root of the wave's intensity and to the
frequency. Numerical estimates show that the predicted nonlinear contribution
can be measured experimentally
Development of Replacement Heifers using Combinations of Three Forage Types and Feed Supplements (with or without Broiler Litter)
The proper management of replacement heifers is an essential component of successful cow/calf operations. The level of management and nutrition applied to replacement heifers as calves and yearlings can impact their subsequent reproductive performance and productivity
Decay of multiply charged vortices at nonzero temperatures
We study the instability of multiply charged vortices in the presence of
thermal atoms and find various scenarios of splitting of such vortices. The
onset of the decay of a vortex is always preceded by the increase of a number
of thermal (uncondensed) atoms in the system and manifests itself by the sudden
rise of the amplitude of the oscillations of the quadrupole moment. Our
calculations show that the decay time gets shorter when the multiplicity of a
vortex becomes higher.Comment: 4 pages, 6 figure
Tangential Touch between the Free and the Fixed Boundary in a Semilinear Free Boundary Problem in Two Dimensions
The main result of this paper concerns the behavior of a free boundary
arising from a minimization problem, close to the fixed boundary in two
dimensions
A Modified Forage System for Stocker Production in the Southern Great Plains, USA
Putting low-cost gain on yearling cattle with forages is an important agricultural activity in the Southern Great Plains. The primary forage system within the area incorporates two forages: winter wheat (Triticum aestivum) for grazing in fall through spring, and warm- season grasses in the summer (Fig. 1). These systems have significant gaps in time when high-quality forage is not available. This study tested the function of introduced cool-season perennial grasses in filling the spring gap, and their capacity as large-scale replacements for winter wheat
Graze-Out Plus: Filling Forage Gaps in the Southern Great Plains, USA
Putting low-cost gain on yearling cattle with forages is a significant agricultural activity in the Southern Great Plains. The primary forage system within the area has two components: winter wheat (Triticum aesitivum) grazed from fall through spring (Redmon et al., 1995), and warm-season perennial grasses for summer grazing. This system has significant gaps (Fig. 1) when high-quality forage is not readily available (September-November and May-June). Introduced cool-season perennial grasses have longer growing seasons than wheat, and could help fill these gaps. This experiment tested the function of an introduced cool-season perennial grass, new to the southern Great Plains, in a stocker production system involving intensive grazing of paddocks
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