scholarly journals Inter-day session reliability of a novel assessment for rotational power of the pelvis, spine and trunk

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Thomas G. Palmer
Keyword(s):  
Rotational Power

Rotational power losses in amorphous ferromagnets as a function of frequency

1980 ◽  
Vol 16 (5) ◽  
pp. 1218-1220 ◽  
Author(s):  
A. Cecchetti ◽  
F. Masoli ◽  
M. Poppi ◽  
G. Soardo
Keyword(s):  
Power Losses ◽  
Rotational Power ◽  
Amorphous Ferromagnets

A Reliable Method for Assessing Rotational Power

2012 ◽  
Vol 26 (3) ◽  
pp. 720-724 ◽  
Author(s):  
Matthew J Andre ◽  
Andrew C Fry ◽  
Melissa A Heyrman ◽  
Andrea Hudy ◽  
Brady Holt ◽  
...  
Keyword(s):  
Reliable Method ◽  
Rotational Power

Passive wing pitch reversal in insect flight

2007 ◽  
Vol 591 ◽  
pp. 321-337 ◽  
Author(s):  
ATTILA J. BERGOU ◽  
SHENG XU ◽  
Z. JANE WANG
Keyword(s):  
Insect Flight ◽  
Rapid Change ◽  
Force Model ◽  
Fluid Force ◽  
Fluid Forces ◽  
Wing Motion ◽  
Helicopter Flight ◽  
Rotating Blade ◽  
Torsion Axis ◽  
Rotational Power

Wing pitch reversal, the rapid change of angle of attack near stroke transition, represents a difference between hovering with flapping wings and with a continuously rotating blade (e.g. helicopter flight). Although insects have the musculature to control the wing pitch during flight, we show here that aerodynamic and wing inertia forces are sufficient to pitch the wing without the aid of the muscles. We study the passive nature of wing pitching in several observed wing kinematics, including the wing motion of a tethered dragonfly, Libellula pulchella, hovering fruitfly, hovering hawkmoth and simplified dragonfly hovering kinematics. To determine whether the pitching is passive, we calculate rotational power about the torsion axis owing to aerodynamic and wing inertial forces. This is done using both direct numerical simulations and quasi-steady fluid force models. We find that, in all the cases studied here, the net rotational power is negative, signifying that the fluid force assists rather than resists the wing pitching. To further understand the generality of these results, we use the quasi-steady force model to analyse the effect of the components of the fluid forces at pitch reversal, and predict the conditions under which the wing pitch reversal is passive. These results suggest the pitching motion of the wings can be passive in insect flight.

Power Losses Due to Secondary Flow Between Rotating Eccentric Cylinders

1974 ◽  
Vol 96 (1) ◽  
pp. 141-144
Author(s):  
M. A. M. A. Younes ◽  
F. R. Mobbs ◽  
J. E. R. Coney
Keyword(s):  
Axial Flow ◽  
Power Input ◽  
Rotating Cylinder ◽  
Secondary Vortex ◽  
Eccentricity Ratio ◽  
Power Losses ◽  
Pumping Power ◽  
Flow Rates ◽  
Eccentric Cylinders ◽  
Rotational Power

The presence of secondary vortex motions in the flow between eccentric rotating cylinders is shown to increase the power input requirements to the inner rotating cylinder at any eccentricity ratio. The effect of superimposing axial flow is to delay the onset of instability and hence decrease this power input to the system. An evaluation of the rotational power losses due to instability as compared with the pumping power required to introduce the necessary axial flow rates is carried out for three gap-radius ratios.

The measurement of rotational power loss in electrical sheet steel using a vertical yoke system

1992 ◽  
Vol 112 (1-3) ◽  
pp. 91-94 ◽  
Author(s):  
J. Sievert ◽  
H. Ahlers ◽  
M. Enokizono ◽  
S. Kauke ◽  
L. Rahf ◽  
...  
Keyword(s):  
Power Loss ◽  
Sheet Steel ◽  
Rotational Power
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