Crocodilians, including the alligator (Alligator mississippiensis), perform a spinning maneuver to subdue and dismember prey. The spinning maneuver, which is referred to as the ;death roll', involves rapid rotation about the longitudinal axis of the body. High-speed videos were taken of juvenile alligators (mean length=0.29 m) performing death rolls in water after biting onto a pliable target. ...

The purpose of this study was to compare maximal torque exerted about the craniocervical (CC) and cervicothoracic (CT) axes in the sagittal plane using a novel dynamometry device. Maximal voluntary contraction (MVC) recordings in newton-meters (N·m) were measured in 20 males and 20 females for each of 4 tests: CT extension, CT flexion, CC extension, CC flexion. Twenty of the volunteers repeated...

A linear pole-placement technique is presented for magnetic momentum removal of Earth-pointing spacecraft. First probed are the twomost commonly used momentum removal schemes, linear and bang-bangH £ B schemes (whereH is the excess angularmomentumvector andB is the geomagneticŽ eld vector), bothbased on a comparison between a constant disturbance torque and an averaged magnetic control torque a...

Torque smoothness is an essential requirement for high-performance motor drive applications. Synchronous reluctance machines (SyRM) have high torque ripple due to non-linear magnetic circuit and saturation. Typically, in Permanent magnet the active compensation achieved by injecting a compensating current q-axis. For SyRM, injection method cancellation can be used both d-axis Howe...

A frequency response based adaptive control scheme with robust frequency domain specifications for industrial center-driven web winders is presented in this paper. The adaptive control scheme consists of: 1) a self-tuning initialization, 2) an adaptive control, with robust specifications, based on the transfer function estimation from the frequency response, and 3) supervisory monitoring and co...

Rocket technology with water propellant is becoming more popular and as an alternative to be applied education recreation, such industry the military. The use of rockets easy, safe, inexpensive means measuring physical parameters at heights above earth's surface being intensively carried out. One solution aerodynamic rocket equipped a telemetry system. used for test launch made from untested ca...

nowadays, the use of small vehicles is spreading among urban areas and one sort of these vehicles are three-wheeled vehicles (twvs) which can be competitive with four-wheeled urban vehicles (fwvs) in aspects such as smallness, simple manufacturing, and low tire rolling resistance, fuel consumption and so on. the most critical instability associated with twvs is the roll over. in this paper a ti...

Quick phases (QPs) induced by horizontal and vertical sinusoidal vestibular stimulations were studied in rabbits, cats, and humans. In all the animals, large and frequent horizontal QPs were observed following yaw stimulation in prone position. By contrast, QPs were almost absent during roll stimulation in rabbits, and they were small and oblique during pitch stimulation in cats and humans. As ...

An actuator is required to change its speed and force depending on the situation. Using multiple actuators for one driving axis is one of the possible solutions; however, there is an associated problem of output power matching. This study proposes a new active joint mechanism using multiple actuators. Because the actuator is made of a flexible bag, it does not interfere with other actuators whe...

Abstract The angular momentum Jinc of a light beam can be changed by passage through a slab of crystal. When the beam is incident along the optic axis of a biaxial crystal, which may also possess optical activity (chirality), the final angular momentum J can have both orbital (Jorb) and spin (Jsp) contributions, which we calculate paraxially exactly for arbitrary biaxiality and chirality and in...