It is well established that light carrying orbital angular momentum (OAM) can be used to induce a mechanical torque causing an object to spin. We consider the complementary scenario: will an observer spinning relative to the beam axis measure a change in OAM as a result of their rotational velocity? Remarkably, although a linear Doppler shift changes the linear momentum of a photon, the angular...

A novel endoscopic optical coherence tomography probe was designed and constructed with a 1.9-mm microelectromechanical system (MEMS) motor. The new MEMS endoscopic probe design eliminates the need to couple the rotational energy from the proximal to the distal end of the probe. Furthermore, the endoscopic probe's sheath and fiber have the advantages of having a much smaller diameter and being ...

Excessive knee joint laxity is often used as an indicator of joint disease or injury such as rupture of the anterior cruciate ligament (ACL). Although the ACL has been shown to contribute to rotational stability of the knee, clinical assessment devices are currently limited to anterior-posterior drawer measurements. The objective of this work was to design a methodology whereby in vivo knee joi...

When Sir William Crookes developed a four-vaned radiometer, also known as the light-mill, in 1873, it was believed that this device confirmed the existence of linear momentum carried by photons, as predicted by Maxwell's equations. Although Reynolds later proved that the torque on the radiometer was caused by thermal transpiration, researchers continued to search for ways to take advantage of t...

Wireless capsule endoscope achieved great success, however, the maneuvering of wireless capsule endoscope is challenging at present. A magnetic driving instrument, including two bar magnets, a stepper motor, a motor driver, a motor controller, and a power supplier, was developed to generate rotational magnetic fields. Permanent magnet ring, magnetized as S and N poles radially and mounted spira...

High rotational torques during baseball pitching are believed to be linked to most overuse injuries at the shoulder. This study investigated the effects of trunk rotation on shoulder rotational torques during pitching. A total of 38 pitchers from the professional, college, high school, and youth ranks were recruited for motion analysis. Professional pitchers demonstrated the least amount of rot...

The configuration of a marine propulsion system is selected with regard to the maximum power resulting from its maximum design speed and displacement. The propulsion systems of high speed vessels use three or even four propellers, and each propulsion unit may be multi-engine. High speed vessels are designed for maximum speeds, but their factual exploitation speed parameters are usually consider...

The measurement of the torque-speed curve is usually done by fixing the cell to a glass slide and tethering a polystyrene bead to the flagellar hook. An optical trap monitor the rotational speed of the bead and the motor torque is calculated from τ = (ξL + ξR)ω ≈ ξLω, where ξR is the drag coefficient due to the internal friction in the motor, ξL is the bead drag coefficient, and ω is the angula...