Empirical Determination of Bang-Bang Operations

Strong and fast "bang-bang" (BB) pulses have been recently proposed as a means for reducing decoherence in a quantum system. So far theoretical analysis of the BB technique relied on model Hamiltonians. Here we introduce a method for empirically determining the set of required BB pulses, that relies on quantum process tomography. In this manner an experimenter may tailor his or her BB pulses to the quantum system at hand, without having to assume a model Hamiltonian.Comment: 14 pages, 2 eps figures, ReVTeX4 two-colum

Results of grazing trials on Ladino clover.

Ladino white clover grown under irrigation at the Kokstad Research Station exhibits two major periods of growth, the one in the spring when growth rates reach values of 1 100 kg DM/ha/week and the other in autumn, when a maximum growth rate of 530 kg DM/ha/week was recorded. Quality declined and the dry matter content increased as the season advanced. Lambs performed considerably better in the spring than in summer and at this time (i.e. spring), lamb performance was less sensitive to stocking rate, particularly when continuously grazed. In spring there was a distinct advantage of continuous grazing systems over rotation systems in the seasonally fixed stocking rate treatments but the latter systems allowed for better lamb performance in summer and autumn, so that the average performance for the season was independent of the grazing system adopted. Among the variable stocking rate treatments applied, continuous grazing was superior to rotational grazing.Keywords: clover; continuous grazing; dry matter content; grazing; grazing systems; growth rate; growth rates; irrigation; kokstad agricultural research station; quality; rotational grazing; south africa; stocking rate; white clove

A comparison of grazing management techniques with sheep on Ladino clover pastures.

A comparison of grazing management techniques revealed that, in general, lamb performance under a continuous grazing system was superior to that measured under a rotational grazing system. Lamb performance was also superior at moderate to low levels of pasture dry matter availability using a variable stocking rate ("put and take") continuous grazing system compared to the fixed stocked continuous system. The analysis of lamb performance during periods of uniform dry matter availability revealed a decline in mass gain as the season progressed. There is evidence to suggest that the decline is partly attributable to quantity/quality changes in the pasture and partly to physiological changes in the lambs.Keywords: availability; clover; continuous grazing; dry matter; grazing; grazing management; kokstad agricultural research station; ladino; lambs; mass; pasture; performance; rotational grazing; sheep; south africa; stocking rate; technique