Viscous Brane Cosmology with a Brane-Bulk Energy Interchange Term

We assume a flat brane located at y=0, surrounded by an AdS space, and consider the 5D Einstein equations when the energy flux component of the energy-momentum tensor is related to the Hubble parameter through a constant Q. We calculate the metric tensor, as well as the Hubble parameter on the brane, when Q is small. As a special case, if the brane is tensionless, the influence from Q on the Hubble parameter is absent. We also consider the emission of gravitons from the brane, by means of the Boltzmann equation. Comparing the energy conservation equation derived herefrom with the energy conservation equation for a viscous fluid on the brane, we find that the entropy change for the fluid in the emission process has to be negative. This peculiar effect is related to the fluid on the brane being a non-closed thermodynamic system. The negative entropy property for non-closed systems is encountered in other areas in physics also, in particular, in connection with the Casimir effect at finite temperature.Comment: 12 pages, latex, no figure

Effect of vacuum level on milk flow traits in Mediterranean Italian buffalo cow

The aim of this study was to determine the effects of six different working vacuum levels (range from 37 to 52 kPa) on the milk production, milk flow rate and milking times in Mediterranean Italian buffalo. A total of eight hundred and one milk flow curves were recorded at random from all of the four hundred and fifty animals in different parity and stage of lactation over a period of 12 weeks, with electronic milk flow meters (Lactocorder®). The different vacuum levels tested did not affect significantly the individual milk production per milking (on average 4.02±0.06 kg). When diminishing vacuum level, a decrease in average and peak flow rate occurred (P<0.001), as well as an increase in effective milking time between attaching the teat cup and reaching the value of 0.20 kg/min at the end of milking (P<0.001). The vacuum levels of 37 and 40 kPa showed good milkability conditions, at which plateau phase was longer than decline phase and lag time was not affected by vacuum level.</p