Currently it is not known how to experimentally measure the contribution of the orbital angular momentum of the quarks to the total spin of the nu-cleon. By examining the quark orbital angular momentum we find that it does not satisfy the standard angular momentum commutation relationships. Thus aside from the experimental difficulty in measuring the quark angular momentum, this indicates that ...

It is shown that in presence of certain external fields a well-defined self-adjoint time operator exists, satisfying the standard canonical commutation relations with Hamiltonian. Examples include uniform electric and gravitational nonrelativistic relativistic Hamiltonians. The physical intepretation these operators proposed terms arrival momentum space.

this paper presents the method of reducing torque ripple of brushless dc (bldc) motor. the commutation torque ripple is reduced by control of the dc link voltage during the commutation time. the magnitude of voltage and commutation time is estimated by a neural network and optimized with an optimization method named particle swarm optimization (pso) algorithm analysis. the goal of optimization ...

This paper presents an original study on the generated torque ripples of phase commutation in the Four-Switch, Three-Phase Inverter (FSTPI) Brushless DC (BLDC) motor drive which is suitable for low cost applications. Analytic values of torque ripple and commutation duration are obtained for different operation conditions. Moreover, limitation on the speed range operation caused from splitti...

The commutation process causes current ripple to be generated in the drive system of brushless DC (BLDC) motor. This, in turn, leads to output torque ripple. Mechanical vibration and acoustic noise are its influences which are undesirable phenomenon in some applications. A new method is presented in this paper which reduces torque ripple and commutation period in the entire range of motor speed...