2,645 research outputs found

    Asteroid Belt Meteoroid Hazard Study

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    Mathematical models for probability of successful traverse of asteroid belt or zero penetration of spacecraft shiel

    Surveyor lunar touchdown stability study Final report, Jul. 1965 - Jul. 1966

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    Dynamic analysis and computer simulation of Surveyor lunar landing stabilit

    Elastic constants of 3-, 4- and 6-connected chiral and anti-chiral honeycombs subject to uniaxial in-plane loading

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    Finite Element models are developed for the in-plane linear elastic constants of a family of honeycombs comprising arrays of cylinders connected by ligaments. Honeycombs having cylinders with 3, 4 and 6 ligaments attached to them are considered, with two possible configurations explored for each of the 3- (trichiral and anti-trichiral) and 4- (tetrachiral and anti-tetrachiral) connected systems. Honeycombs for each configuration have been manufactured using rapid prototyping and subsequently characterised for mechanical properties through in-plane uniaxial loading to verify the models. An interesting consequence of the family of 'chiral' honeycombs presented here is the ability to produce negative Poisson's ratio (auxetic) response. The deformation mechanisms responsible for auxetic functionality in such honeycombs are discussed

    General education in the royal air force 1910 - 1961

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    ‘BEND IT LIKE BECKHAM’: BALL ROTATION IN THE CURVED FOOTBALL KICK

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    The objectives of this study were to quantify the 3D angular velocity and spin axes of a curved versus straight kick for goal in football. A 12 camera 250 Hz 3D Vicon motion analysis system recorded 4 semi-professional soccer players, as they performed 5 straight (S) and 10 curved (C) kicks. While the velocity of the ball was similar for both kicks (~20 m.s-1), spin rate was significantly different (S=22.6 rad.s-1; C=36.4 rad.s-1). While the level of spin for the straight kick was surprising, the elevation angle of its spin axis was significantly lower in the straight compared with curved kicks (S=30.4°; C=62.6°

    Public Utility Debt Securities: A Transaction Exempt from the Usury Law

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    The California Public Utilities Commission was recently presented with applications from two public utilities requesting approval of bond offerings carrying an interest rate greater than that prescribed by California\u27s usury laws. The authors comment on the solutions proposed by the utilities to prevent application of the usury laws to their offerings, and discuss the Commission\u27s ruling that the offerings were not subject to the proscriptions of the usury laws

    QUALITATIVE BIOMECHANICS FOR COACHING

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    Session Information: Coaches must apply principles of biomechanics in their qualitative judgments of the technique used by athletes. These judgments can have a major influence on performance and injury risk. This session will focus on the most effective use of qualitative biomechanical analyses and video replay software. Several scholars who have experience teaching qualitative biomechanical analysis to future coaches will present, followed by a question and answer session. Schedule of Presentations: Dr. Knudson will introduce the session and provide a brief overview of qualitative biomechanical analysis. 11:00 – 11:15 Dr. Alderson will present sport injury models as they apply to assessment, intervention and rehabilitation of common injuries in cricket, tennis and running. Relevant qualitative and quantitative 2D features of SiliconCoach that can be utilised by a coach to potentially reduce injury incidence will be presented. 11:15 – 11:45 Dr. Bahamonde will present how qualitative analysis can be used to teach biomechanics concepts to physical education and coaching students. Movement examples from tennis, soccer and track field and meaningful features of Hu-m-an software will be illustrated. Hu-m-an is unique in that it was developed with a specific teaching-learning focus. 11:45 – 12:15 Dr. Bird will present biomechanical core concepts as a “common language” to evaluate and improve all human movements. The core concepts are visually observable, but meaningful features of Dartfish will be illustrated to enhance what is seen by both the coach and the mover. Movement examples from golf, resistance training, basketball, and other sports will be presented. 12:15 – 12:45 Discussion: 12:45 – 13:00 This will provide an opportunity for delegates to ask specific questions relating to any of the presenters
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