Motor, wrap. around

The midpiece contains the mitochondria which are wrapped around the proximal part of the flagellum. The beating of the flagellum, and hence the swimming of the sperm involves the motor protein known as dynein, which requires ATP hydrolysis. In some species, the diffusion of energy in the spermatozoa is increased by the presence of the creatine/phosphocreatine shuttle (Chapter 9) that is, phosphocreatine and creatine diffuse throughout the cytosol... 

The reduction of the elementary elastic strip that contracts and relaxes to a rotary motor has been demonstrated by Steinberg et ah In that case, a circular elastic band was constructed. In a continuous manner it was wrapped around a set of pulleys and through a pair of baths, one bath providing the correct chemical energy for contraction and the other for relaxation. In this way a chemomechanical rotary motor was constructed. 

Future direction of gel robots includes polymer robots assisting human with physical interaction muscle suits wrapping around the elders or athletes to support their movements. Artificial muscles will be used for such systems when strength and durability of artificial muscles improve in the future, although existing personal robots and muscle suits are driven by motors or rubber actuators. This study contributes to design and control artificial muscle suits with small numbers of electric wires which enable dexterous and dynamic motions. 

A simple apparatus, which also uses a constant sample length and yields a constant stretch rate, has been described by Ide and White.( 7) it consists of a constant-temperature silicone oil bath, an Instron load cell to which is fastened one end of the polymer sample, and a rotating roll attached to a motor with a speed controller. The polymer filament is stretched by the roll and wraps around it. The stress is determined with the help of the load cell, while the stretch rate is given by the ratio of the linear roll velocity to the filament length. 

In the 1990s, SIEMENS and ABB introduce the concept of the wrap-around motor. 

FIGURE 7-21 SAG mill with wrap-around or ring motor. [Courtesy of Metso Minerals (formerly known as the companies Nordberg and Svedala).]... 

Hybrid thin-film polyimide electrodes integrated in silicone guidance channels have been fabricated as cuffs for electrical stimulation of peripheral nerves [58], Cuff electrodes wrap around a nerve trunk. They are used to record sensory signals from peripheral nerves or stimulate motor fibers to activate muscles [59]. 

The cell body of a mammalian motor neuron has an extended process termed an axon that branches at its tip to make multiple contacts (synapses) with a muscle cell (fig. S1.1). Some axons actually reach lengths of several meters. Much of the axon may be encased in myelin sheaths, which are multilayered membranes formed by other cells that wrap themselves around the neuron. Shorter processes (dendrites) extend from the cell body to make contacts with other neurons. If a motor neuron is stimulated electrically or is triggered by its connecting neurons, an electric signal called an action potential sweeps down the axon and is transmitted to the muscle cell, which then proceeds to contract. Other... 

Godet stand n. A device used in pairs downstream from the extruder when making monofilament and split-film fibers. One stand is placed before, and another following, a conditioning oven, each consisting of a vertical motor housing driving two or more horizontal drums. The filaments are wrapped repeatedly around the drums to... 

The fiber was extruded vertically downward to a nylon guide wheel (8) located about 30 cm below the die, by which point the fiber had been solidified. This guide was mounted on a force transducer to allow measurement of the tension on the fiber. The fiber was wrapped 180° around this guide wheel and directed to a second guide wheel (9) on its way to a pair of take-up rolls (10 and 11). The fiber was wound once around the take-up rolls and was next taken up by a wind-up roll (12). These rolls were 5 cm in diameter and were made of aluminum covered with tape to enhance their grip on the fiber. Only two rolls (10 and 12) were motor-driven having a maximum speed of3,600 rpm, while one roll (11) was free spinning. The maximum take-up speed was therefore about 600 m/min. The motor speed was controlled by a variable transformer (14). 

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