The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
De Zhang - One of the best experts on this subject based on the ideXlab platform.
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Novel propagation direction of quasi-longitudinal leaky surface acoustic wave on quartz and its potential as liquid sensors
Sensors and Actuators A-physical, 1999Co-Authors: Xiaojun Tong, De ZhangAbstract:Abstract In this paper, authors investigate propagation properties of a novel propagation direction of quasi-longitudinal leaky surface acoustic wave (QLLSAW) propagating on the surface of quartz. Experiments show that phase velocity reaches 6992 m/s, propagation attenuation is less than 10 −4 dB/ λ in this proposed direction, with Euler Angle [0°, 124°, 50°]. Particularly, based on this wave mode with longitudinal polarized displacement, SAW sensors to be used in liquid can be realized, and spurious interference from normal SAW and leaky surface acoustic wave can be eliminated.
Satoshi Uda - One of the best experts on this subject based on the ideXlab platform.
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experimental and theoretical analysis of saw properties of the langasite substrate with Euler Angle 0 spl deg 140 spl deg spl phi
Internaltional Ultrasonics Symposium, 1999Co-Authors: A. Bungo, C. Jian, Kunio Yamaguchi, Y. Sawada, R. Kimura, Satoshi UdaAbstract:The numerical calculations using new material constants were in good agreement with the experimental results of the temperature-related SAW properties on the langasite substrate with Euler Angle (0°,140°,φ). The temperature-related SAW properties as a function of the IDT metal thickness were also experimentally investigated. It was revealed that a thicker metal leads to a lower turnover temperature. Furthermore we investigated the NSPUDT (natural single phase unidirectional transducer) properties of langasite with Euler Angle (0°,140°,25°) experimentally. Its directivity was almost equal to one estimated by the calculation based on the coupling of mode (COM) model. This NSPUDT property is a promising feature for the low-loss IF filter.
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Experimental and theoretical analysis of SAW properties of the langasite substrate with Euler Angle (0/spl deg/,140/spl deg/,/spl phi/)
1999 IEEE Ultrasonics Symposium. Proceedings. International Symposium (Cat. No.99CH37027), 1999Co-Authors: A. Bungo, C. Jian, Kunio Yamaguchi, Y. Sawada, R. Kimura, Satoshi UdaAbstract:The numerical calculations using new material constants were in good agreement with the experimental results of the temperature-related SAW properties on the langasite substrate with Euler Angle (0°,140°,φ). The temperature-related SAW properties as a function of the IDT metal thickness were also experimentally investigated. It was revealed that a thicker metal leads to a lower turnover temperature. Furthermore we investigated the NSPUDT (natural single phase unidirectional transducer) properties of langasite with Euler Angle (0°,140°,25°) experimentally. Its directivity was almost equal to one estimated by the calculation based on the coupling of mode (COM) model. This NSPUDT property is a promising feature for the low-loss IF filter.
Ranjan Mukherjee - One of the best experts on this subject based on the ideXlab platform.
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Reconfiguration of a Rolling Sphere: A Problem in Evolute-Involute Geometry
Journal of Applied Mechanics, 2005Co-Authors: Tuhin Das, Ranjan MukherjeeAbstract:This paper provides a new perspective to the problem of reconfiguration of a rolling sphere. It is shown that the motion of a rolling sphere can be characterized by evolute-involute geometry. This characterization, which is a manifestation of our specific selection of Euler Angle coordinates and choice of angular velocities in a rotating coordinate frame, allows us to recast the three-dimensional kinematics problem as a problem in planar geometry. This, in turn, allows a variety of optimization problems to be defined and admits infinite solution trajectories. It is shown that logarithmic spirals form a class of solution trajectories and they result in exponential convergence of the configuration variables.
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Exponential stabilization of the rolling sphere
Automatica, 2004Co-Authors: Tuhin Das, Ranjan MukherjeeAbstract:In this paper we present a non-smooth controller for exponential stabilization of the sphere. This has remained an open problem despite significant progress in nonholonomic systems. Our control design is based on inputs in a rotating coordinate frame that individually produce primitive motions of the sphere along straight lines and circular arcs. The rotating coordinate frame is chosen in concert with Euler Angle description of orientation and placement of the desired configuration at the singularity of the representation. In our paper, we separately establish global stability of the desired configuration and exponential convergence. Our theoretical claims are validated through numerical simulations.
Xiaojun Tong - One of the best experts on this subject based on the ideXlab platform.
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Novel propagation direction of quasi-longitudinal leaky surface acoustic wave on quartz and its potential as liquid sensors
Sensors and Actuators A-physical, 1999Co-Authors: Xiaojun Tong, De ZhangAbstract:Abstract In this paper, authors investigate propagation properties of a novel propagation direction of quasi-longitudinal leaky surface acoustic wave (QLLSAW) propagating on the surface of quartz. Experiments show that phase velocity reaches 6992 m/s, propagation attenuation is less than 10 −4 dB/ λ in this proposed direction, with Euler Angle [0°, 124°, 50°]. Particularly, based on this wave mode with longitudinal polarized displacement, SAW sensors to be used in liquid can be realized, and spurious interference from normal SAW and leaky surface acoustic wave can be eliminated.
Marc De Graef - One of the best experts on this subject based on the ideXlab platform.
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Three-dimensional texture visualization approaches: theoretical analysis and examples
Journal of Applied Crystallography, 2017Co-Authors: Patrick G. Callahan, Saransh Singh, Mclean P. Echlin, Tresa M Pollock, Marc De GraefAbstract:Crystallographic textures are commonly represented in terms of Euler Angle triplets and contour plots of planar sections through Euler space. In this paper, the basic theory is provided for the creation of alternative orientation representations using three-dimensional visualizations. The use of homochoric, cubochoric, Rodrigues and stereographic orientation representations is discussed, and illustrations are provided of fundamental zones for all rotational point-group symmetries. A connection is made to the more traditional Euler space representations. An extensive set of three-dimensional visualizations in both standard and anaglyph movies is available.