Parvovirus B19. Parvovirus B19 infections in children present as a viral exanthema, and in adults as a cause of arthralgia and arthritis. The incubation period is 7â10 days with non-specific flu-like symptoms in the first week followed by arthralgias or arthritis in up to 60% of patients in the second week.
Variable Torque Motors - American Made Efficiency. One of the largest down-sides to electric motors is their inherent efficiency range and, in hybrid systems, the drag they can create on the drive train.
A DC motor is usually supplied through slip ring commutator as described above. AC motors' commutation can be either slip ring commutator or externally commutated type, can be fixed-speed or variable-speed control type, and can be synchronous or asynchronous type. Universal motors can run on either AC or DC.