scholarly journals Are shoulder counter rotation and hip shoulder separation angle representative metrics of three-dimensional spinal kinematics in cricket fast bowling?

2017 ◽  
Vol 36 (15) ◽  
pp. 1763-1767 ◽  
Author(s):  
Billy Senington ◽  
Raymond Y. Lee ◽  
Jonathan Mark Williams
Keyword(s):  
Three Dimensional ◽  
Separation Angle ◽  
Counter Rotation ◽  
Spinal Kinematics ◽  
Shoulder Separation

Non-Dimensional Parameters for Comparing Conventional and Counter-Rotating Turbomachines

2019 ◽  
Author(s):  
J. J. Waldren ◽  
C. J. Clark ◽  
S. D. Grimshaw ◽  
G. Pullan
Keyword(s):  
High Efficiency ◽  
Three Dimensional ◽  
Relative Performance ◽  
Design Parameters ◽  
Blade Design ◽  
Finite Radius ◽  
Counter Rotation ◽  
Dimensional Parameters ◽  
Conventional Machine ◽  
Stage Efficiency

Abstract Counter-rotating turbomachines have the potential to be high efficiency, high power density devices. Comparisons between conventional and counter-rotating turbomachines in the literature make multiple and often contradicting conclusions about their relative performance. By adopting appropriate non-dimensional parameters, based on relative blade speed, the design space of conventional machines can be extended to include those with counter-rotation. This allows engineers familiar with conventional turbomachinery to transfer their experience to counter-rotating machines. By matching appropriate non-dimensional parameters the loss mechanisms directly affected by counter-rotation can be determined. A series of computational studies are performed to investigate the relative performance of conventional and counter-rotating turbines with the same non-dimensional design parameters. Each study targets a specific loss source, highlighting which phenomena are directly due to counter-rotation and which are solely due to blade design. The studies range from two-dimensional blade sections to three-dimensional finite radius stages. It is shown that, at hub-to-tip ratios approaching unity, with matched non-dimensional design parameters, the stage efficiency and work output are identical for both types of machine. However, a counter-rotating turbine in the study is shown to have an efficiency advantage over a conventional machine of up to 0.35 percentage points for a hub-to-tip ratio of 0.65. This is due to differences in absolute velocity producing different spanwise blade designs.

scholarly journals Influence of Carrying Unstable Load on Thoracic Kinematics While Walking on a Curved Path

2021 ◽  
Vol 2071 (1) ◽  
pp. 012013
Author(s):  
D K Ngoc ◽  
A F Salleh ◽  
M S Salim ◽  
N Omar ◽  
K S Basarrudin ◽  
...  
Keyword(s):  
Sagittal Plane ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Axial Rotation ◽  
Heel Strike ◽  
Virtual Lab ◽  
Flexion Extension ◽  
Spinal Kinematics ◽  
Load Intensity ◽  
The Right

Abstract This study investigated the effect of carrying unstable load on thoracic kinematics while walking on a curved path. Three-dimensional spinal kinematics were defined as the rotations between thoracic and the Virtual laboratory coordinate system (Tho/Virtual lab) which consisted of lateral bending (LB), flexion/extension (FE) and axial rotation (AR) in the frontal plane, sagittal plane and transverse plane, respectively. Eight healthy young adults (4 males and 4 females) performed loads carrying and walking on one meter radius curved path. Spinal kinematics was determined at the left leg heel strike and just before the right toe off during the curved path walking. As a result, a significant main effect of load intensity was found only on FE of (Tho/Virtual lab) at both left leg heel strike and right leg toe off. The study concluded that an increase in the load intensity of unstable load from 10% of body weight likely to generate more thorax extension.

scholarly journals Cricket Biomechanics Analysis of Skilled and Amateur Fast Bowling Techniques

2015 ◽  
Vol 49 (4) ◽  
pp. 173-181
Author(s):  
KA Thiagarajan ◽  
Tvisha Parikh ◽  
Anees Sayed ◽  
MB Gnanavel ◽  
S Arumugam
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Three Dimensional ◽  
The Body ◽  
Vertical Ground Reaction Force ◽  
Ball Release ◽  
Equality Of Means ◽  
Counter Rotation ◽  
Vertical Ground ◽  
Release Speed

ABSTRACT Cricket fast bowling action involves complex three-dimensional (3D) motion of the body and poses a high risk of injury more so in schoolboys. It is not known how the bowling technique varies between skilled and less skilled fast bowlers. The aim of this study is to compare the differences in bowling technique between young sub-elite (skilled) and amateur university level cricketers. Twelve players, 6 skilled and six amateur, were attached with 35 retro-reflective markers using the full body Plug-in-Gait marker set and asked to bowl 6 deliveries at a good length. Their bowling action was captured with 12 Vicon 3D cameras and the ground reaction force was measured using AMTI force plates. The best delivery from each bowler was selected. Their bowling action types were classified and parameters like shoulder counter rotation (scr), pelvicshoulder separation angle at back foot contact, trunk lateral flexion, front knee angle, front foot vertical ground reaction force (vGRF) and ball release speed were measured. The results were analyzed with Levene's test for Equality of Variances and a t-test for equality of means. The skilled bowlers showed faster ball release speed and experienced larger vGRF while the other parameters did not show any significant differences. How to cite this article Thiagarajan KA, Parikh T, Sayed A, Gnanavel MB, Arumugam S. Cricket Biomechanics Analysis of Skilled and Amateur Fast Bowling Techniques. J Postgrad Med Edu Res 2015;49(4):173-181.

The Effect of Friction on Load Distribution Around the Hole in Composite Pinned Connections

2007 ◽  
Author(s):  
Vahid Yavari ◽  
Iraj Rajabi ◽  
Mohammad Hassan Kadivar
Keyword(s):  
Contact Area ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Load Level ◽  
Separation Angle ◽  
Surface Separation ◽  
Symmetric Separation ◽  
Dimensional Finite Element ◽  
Pinned Connections ◽  
Three Dimensional Finite Element

This paper presents analyses for computing and evaluating the behavior of the laminated composite plate at the contact area in single lap, mechanically fastened joints. The analyses involve three dimensional finite element models performed by ABAQUS 6.4-PR11 code to evaluate the stress distribution in contact surface, separation angle, the magnitude and location of maximum radial stress. Results are determined for quasi-isotropic model and attempts are made to validate the models with previous works. The variations of separation angles through the thickness are investigated and effects of friction and applied load level are discussed by using different friction coefficients at contact area. Non-symmetric separation about the bearing plane occurs and the separation angle is greater than 90° in some plies.

Three-dimensional flow driven by iso- and counter-rotation of a shallow pool and a disk on the free surface

2009 ◽  
Vol 21 (8) ◽  
pp. 084102 ◽  
Author(s):  
You-Rong Li ◽  
Chun-Mei Wu ◽  
Shuang-Ying Wu ◽  
Lan Peng
Keyword(s):  
Free Surface ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Counter Rotation

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

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