1,089 research outputs found
Coupling vortex dynamics with collective excitations in Bose-Einstein Condensates
Here we analyze the collective excitations as well as the expansion of a
trapped Bose-Einstein condensate with a vortex line at its center. To this end,
we propose a variational method where the variational parameters have to be
carefully chosen in order to produce reliable results. Our variational
calculations agree with numerical simulations of the Gross-Pitaevskii equation.
The system considered here turns out to exhibit four collective modes of which
only three can be observed at a time depending of the trap anisotropy. We also
demonstrate that these collective modes can be excited using well established
experimental methods such as modulation of the s-wave scattering length
EBV changes due to different age adjustment factors in the Italian Friesian
Mature equivalent productions are often used as input for breeding values estimation. Adjustment factors can affect genetic trend, thus efforts should be put in order to verily projected production. Adjustment factors used in different countries refer to various ages. EBV changes with adjustment factors projecting lactations to primiparous vs. adjustment factors projecting production to pluriparous were compared. No evident difference was found both in genetic trend and in ranking of sire and cows by changing reference age except for some re-ranking for top 10,000 cows. Effect on genetic trend and EBV variability was found when base parameters of heterogeneity of herd variance were differen
Capture Velocity for a Magneto-Optical Trap in a Broad Range of Light Intensity
In a recent paper, we have used the dark-spot Zeeman tuned slowing technique
[Phys. Rev. A 62, 013404-1, (2000)] to measure the capture velocity as a
function of laser intensity for a sodium magneto optical trap. Due to technical
limitation we explored only the low light intensity regime, from 0 to 27
mW/cm^2. Now we complement that work measuring the capture velocity in a
broader range of light intensities (from 0 to 400 mW/cm^2). New features,
observed in this range, are important to understant the escape velocity
behavior, which has been intensively used in the interpretation of cold
collisions. In particular, we show in this brief report that the capture
velocity has a maximum as function of the trap laser intensity, which would
imply a minimum in the trap loss rates.Comment: 2 pages, 2 figure
Effect of parity in age adjustment factors in the Italian Holstein Friesian cattle breed
Inclusion of parity in multiplicative adjustment factors for age at calving was investigated for the Italian
Holstein Friesian cattle breed. Separated age adjustment factors for first, second, third and later parities are necessary because cows of the same age but different parity have different production. Differences in production were particularly evident for first and second parity cows of same age. If parity is not accounted for, first lactation mature equivalent production can be underestimated. Because progeny testing is based on first lactation production, underestimation of a fraction of mature equivalent records may be reflected in genetic indexes
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