Abstract-

narrower (Table I) so that the separation of energy sublevels along the y-direction is increased. This increases the oscillation period when measuring the conductances as functions of the Fermi energy. On the other hand, the increase of the Fermi energy as a function of the lower gate bias is very significant. In the final conductances versus lower gate bias diagram, Fig. 2, the Fermi energy factor dominates, and the oscillation period in the conductance increases, as indicated in the experiments when the upper gate bias is decreased.The calculated oscillation period increases with increasing lower gate bias in Fig. 2. This is due to the square-well approximation in the y-direction used in the model calculation. When parabolic well is used, the energy separations between sublevels are constant, so becomes the oscillation period. Thus, when real band profile is used in the transport calculation, constant oscillation period is expected. ( 3 )When Q = e and t = 13.1 (silicon), we have V = 1.1,'~ V at the surface of the sphere and 5' = 1.65/a V at the center (a is in the unit of A). It is shown that decreasing the upper gate bias makes the conducting channel created by the lower gate narrower so that the separation of the energy sublevels in the y -direction is increased. However, the decrease of the upper gate bias also greatly reduces the Fermi energy. The total effect of decreasing the upper gate bias is the decrease of the oscillation period in the conductance as functions of the lower gate bias. The calculated oscillation period as a function of the lower and upper gate bias explains very well the experimental data.

We review the guided-wave subcomponents required in the design of high-functionality modulators for advanced modulation formats using the GaAs/AlGaAs material system. In these complex devices, small loss contributions rapidly accumulate unless the substructures are well optimized, not only for low loss but also for process tolerance. Results for an advanced 40-Gb/s DQPSK modulator are presented.

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The aim of this paper was to estimate the prevalence of tail injuries that required veterinary examination in different breeds of dog in Scotland. The study population included all dogs that had visited one of 16 veterinary practices located in Scotland between 2002 and early 2012. The overall prevalence of tail injuries in dogs visiting one of the 16 veterinary practices was 0.59 per cent. The prevalence of tail injuries in dogs of working breeds was estimated to be 0.90 per cent. Working dog breeds that were examined by a veterinary surgeon were at a significantly greater risk of sustaining a tail injury than non-working breeds (P<0.001). To prevent one such tail injury in these working breeds approximately 232 dogs would need to be docked as puppies. To prevent one tail amputation in spaniels, 320 spaniel puppies would need to be docked. Spaniels presented after January 2009 were 2.3 times more likely to have a tail injury than those presented before April 29, 2007 (date of the legislation that banned tail docking in Scotland). Given the results of this and the accompanying paper it may be appropriate to consider changes to the current legislation for specific breeds of working dogs.