• Title/Summary/Keyword: stiffuess

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Design of Air Turbine and Air Bearing for Dental Handpiece

  • Hwang, Pyung;Park, Sang-Shin;Sohn, Jeong-L.;Kwon, Seong-In;Kim, Do-Hyung;Kim, Woo-Seok
    • Tribology and Lubricants
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    • v.23 no.5
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    • pp.240-247
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    • 2007
  • The design process of the dental handpiece is described. The parameters of the high speed air turbine are estimated. The effect of supply hole on the stiffuess and damping of the air bearing for handpiece is studied numerically. The Reynolds equation is solved by using the divergence formulation and the perturbation method. The test rig is built and the test procedure is developed for the turbine rotational speed measurement by using Fourier transform of noise generated by the turbine during steady operation.

Applications of piezoelectric sensors in geotechnical engineering

  • Zeng, Xiangwu
    • Smart Structures and Systems
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    • v.2 no.3
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    • pp.237-251
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    • 2006
  • Piezoelectric sensors have many applications in geotechnical engineering, especially in characterizing soils through measurement of wave velocities. Since mechanical properties of a material are closely associated with wave velocities, piezoelectric sensors provide a reliable and non-destructive method for the determination of soil properties. This paper presents results of recent research on measuring stiffness of a wide range of soils such as clay, sand, and gravel, characterizing anisotropic properties of soil induced by external loading, measuring stiffness of base and subgrade materials in the pavement, determining soil properties in a centrifuge model during the flight of a centrifuge, and understanding wave propagation in granular materials under micro-gravity environment using this technique.