26,935 research outputs found
On an atom with a magnetic quadrupole moment in a rotating frame
The quantum description of an atom with a magnetic quadrupole moment in the
presence of a uniform effective magnetic field is analysed. The atom is also
subject to rotation and a scalar potential proportional to the inverse of the
radial distance. It is shown that the spectrum of energy is modified, in
contrast to the Landau-type levels, and there is a restriction on the possible
values of the cyclotron frequency which stems from the influence of the
rotation and scalar potential proportional to the inverse of the radial
distance.Comment: 11 pages. arXiv admin note: text overlap with arXiv:1705.0819
Multiobjective analysis for the design and control of an electromagnetic valve actuator
The electromagnetic valve actuator can deliver much improved fuel efficiency and reduced emissions in spark ignition (SI) engines owing to the potential for variable valve timing when compared with cam-operated, or conventional, variable valve strategies. The possibility exists to reduce pumping losses by throttle-free operation, along with closed-valve engine braking. However, further development is required to make the technology suitable for accept- ance into the mass production market. This paper investigates the application of multiobjective optimization techniques to the conflicting objective functions inherent in the operation of such a device. The techniques are utilized to derive the optimal force–displacement characteristic for the solenoid actuator, along with its controllability and dynamic/steady state performance
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