1,738 research outputs found

    Smoothed Boundary Method for Solving Partial Differential Equations with General Boundary Conditions on Complex Boundaries

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    In this article, we describe an approach for solving partial differential equations with general boundary conditions imposed on arbitrarily shaped boundaries. A function that has a prescribed value on the domain in which a differential equation is valid and smoothly but rapidly varying values on the boundary where boundary conditions are imposed is used to modify the original differential equations. The mathematical derivations are straight forward, and generically applicable to a wide variety of partial differential equations. To demonstrate the general applicability of the approach, we provide four examples: (1) the diffusion equation with both Neumann and Dirichlet boundary conditions, (2) the diffusion equation with surface diffusion, (3) the mechanical equilibrium equation, and (4) the equation for phase transformation with additional boundaries. The solutions for a few of these cases are validated against corresponding analytical and semi-analytical solutions. The potential of the approach is demonstrated with five applications: surface-reaction diffusion kinetics with a complex geometry, Kirkendall-effect-induced deformation, thermal stress in a complex geometry, phase transformations affected by substrate surfaces, and a self-propelling droplet.Comment: A better smooth algorithm has been developed and tested, will soon replace Eq. 58 in page 16. We have also developed a level-set moving boundary SBM method, and it will replace the Navier-Stokes-Cahn-Hilliard type domain parameter tracking method in Section 5.

    Isolated tracheal injury after whiplash

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    AbstractWhiplash, a sudden acceleration–deceleration movement that can cause diverse symptoms such as neck pain, cervicogenic headache, restricted neck movement, tingling of the arms (central cord syndrome), and dizziness. However, laryngotracheal injuries after whiplash are extremely rare. We report the case of a 25-year-old Taiwanese female who presented to the emergency department with severe posterior midline neck pain after a rear-end motorcycle collision. Her C-spine X-ray showed no definite fracture; furthermore, her neck noncontrast-enhanced CT scan revealed paratracheal free air. She was discharged uneventfully after a 12-h observation period. Laryngotracheal injuries after whiplash, a hyperextension–hyperflexion movement, are potentially life-threatening and could lead to airway obstruction. Such injuries should not be overlooked. To the best of our knowledge, this is the first case report of isolated laryngotracheal injury after whiplash

    Korean-Chinese Person Name Translation for Cross Language Information Retrieval

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    PACLIC 21 / Seoul National University, Seoul, Korea / November 1-3, 200

    INFLUENCE OF APPROACH SPEED AND DISTANCE ON BIOMECHANICS DURING SINGLE-LEGGED RUNNING VERTICAL JUMP

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    The purpose of this study was to look into the kinematics, kinetics and EMG of the single legged running vertical jumps in different approach speed and distance. 12 basketball player performed single-legged running vertical jumps with 2 approach speed and 3 distance randomly. Kinematic and Kinetic data were collected by a force and 11 infrared high speed cameras. EMG data were recorded by Delsys surface EMG system. Two-way repeated measures AMOVA (2 speeds x 3 distance) was used for establishing differences (significance level p< .05). The jump height, jumt moment of lower extremity, knee power and the activation of tibialis anterior and gastrocnemius were found significantly larger in fast approach speed. We suggested using fast approach speed and 9m approach distance to enhance the single-legged running vertical jump ability

    Splint therapy for disc displacement with reduction of the temporomandibular joint. Part I: Modified mandibular splint therapy

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    AbstractThe aims of this preliminary study were to present a modified mandibular splint together with a treatment regimen and to evaluate their effects on the treatment of reciprocal joint sounds of the temporomandibular joint (TMJ). The study participants were recruited from 312 consecutive patients in the temporomandibular disorder clinic of a medical center in Taiwan from January 2003 to December 2003. From among these, 59 cases with typical reciprocal clicking were selected for this study. All participants were treated with a modified mandibular splint and then followed up for 6 months. Successful treatment was defined as leading to the disappearance of the joint sounds of TMJ, as described by patients. Based on clinical evaluation, the overall success rate was 71.2% (42/59) with minimal temporary complications. Patients with clicking at less than 3.5cm of interincisal opening had a success rate of 92.5%, which was higher than the success rate of patients with clicking at a mouth opening of 3.5cm or more. This study showed that a modified mandibular splint can be used to treat reciprocal clicking of the TMJ effectively and encouraged us to conduct further study on the efficacy of this splint to treat disc displacement with reduction of TMJ using magnetic resonance imaging examination
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