The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform

Yanni Zhang - One of the best experts on this subject based on the ideXlab platform.

  • underwater sound scattering and absorption by a Coated infinite Plate with attached periodically located inhomogeneities
    Journal of the Acoustical Society of America, 2015
    Co-Authors: Yanni Zhang, Hai Huang, Jing Zheng
    Abstract:

    This paper extends previous work of Zhang and Pan [J. Acoust. Soc. Am. 133(4), 2082–2096 (2013)] on sound scattering and absorption by an underwater Coated Plate with a single attached distributed-inhomogeneity to that with periodically located distributed-inhomogeneities. A comparison is made among cases of a Plate without inhomogeneities, a Plate with inhomogeneities, and one with inhomogeneities ignoring the mutual coupling. Results show that coupling of the structural waves scattered by the inhomogeneities plays an important role in modifying the sound absorption and scattering of surface sound pressure, especially at low frequencies and/or the resonance frequencies of the trapped modes of the Plate. The sound absorption of the Plate is dependent on the distance between the adjacent inhomogeneities, the length of the inhomogeneity, and the angle of the incident sound. On the surface of the inhomogeneities, the scattered/total sound pressure is generally enhanced. On the surface in between the inhomoge...

  • Underwater sound radiation from an elastically Coated Plate with an embedded and distributed inhomogeneity
    Journal of the Acoustical Society of America, 2015
    Co-Authors: Yanni Zhang
    Abstract:

    This paper studies the effects of an embedded and distributed inhomogeneity on the underwater sound radiation from an elastically Coated Plate. Embedding a signal conditioning Plate (SCP) in the coating material provides an extra parameter for controlling the sound radiation of the Plate, as compared with the previous design with an SCP on the coating surface [Y. Zhang and J. Pan, J. Acoust. Soc. Am. 133(1), 173–185 (2013)]. For such a configuration, the vibration and sound responses of the Coated Plate to a point force excitation are described by three coupled Fredholm integral equations of the second kind. Its acoustical properties are examined by comparing the radiation powers from Plates without an SCP, with a surface SCP, and with an embedded SCP. The differences in the sound powers are explained through resonance and scattering caused by the interaction of the embedded SCP with structural waves. The effects of the depth of the embedded SCP in the coating material on the sound radiation properties of...

  • underwater sound scattering and absorption by a Coated infinite Plate with a distributed inhomogeneity
    Journal of the Acoustical Society of America, 2013
    Co-Authors: Yanni Zhang
    Abstract:

    This paper concerns itself with the scattering and absorption of underwater incident sound by a Coated infinite Plate with an attached distributed inhomogeneity. Its objective is to determine if the distributed inhomogeneity can provide additional local reflection, such that it only increases the signal-to-noise ratio for a hydrophone detector placed on the inhomogeneity without significantly decreasing the overall sound absorption of the Coated Plate.

  • Underwater sound radiation from an elastically Coated Plate with a discontinuity introduced by a signal conditioning Plate
    Journal of the Acoustical Society of America, 2013
    Co-Authors: Yanni Zhang
    Abstract:

    Underwater structural sound radiation and reflection can be reduced by adding an elastic coating to a structure. To increase the signal-to-noise ratio of a detecting hydrophone placed in front of the coating, a signal conditioning Plate (SCP) of finite size placed between the coating and the hydrophone is proposed to increase the local reflection of incoming sound. This paper studies the effects of a SCP as a distributed discontinuity on the general properties of the sound radiation of a Coated Plate. The discontinuity introduced by the SCP changes the vibration and radiated sound power of the Coated Plate by scattering and reflecting structural waves in the coating. The trapped modal response of the structural waves is also observed and found to be responsible for the increase of sound and vibration of the Plate at the corresponding resonance frequencies.

Maria C. Militello - One of the best experts on this subject based on the ideXlab platform.

  • A diamond-like carbon film for wear protection of steel
    Surface and Coatings Technology, 1993
    Co-Authors: Stephen J Harris, Andrew M. Weiner, S. J. Simko, Simon C. Tung, Maria C. Militello
    Abstract:

    We have deposited diamond-like carbon (DLC) and amorphous SiN films on a tool steel coupon. In order to make the DLC adhere to the metal, we used an interlayer of amorphous SiN, taking advantage of the fact that the SiN coating adheres to the metal and the DLC adheres to the SiN. The DLC/SiN-Coated substrate showed a significant reduction in friction compared with either unCoated or SiN-Coated substrates in our laboratory bench tester after lubricated sliding for 30 h. In addition, on the basis of surface profilometry analysis, the DLC/SiN-Coated Plate showed less wear and a much smoother surface. The films were analyzed using X-ray photoelectron spectroscopy and sputter depth profiling. Our results suggest that DLC is a promising coating for wear protection. © 1993.

Keiichi Kamijo - One of the best experts on this subject based on the ideXlab platform.

  • tsh receptor antibody measurement in patients with various thyrotoxicosis and hashimoto s thyroiditis a comparison of two two step assays Coated Plate elisa using porcine tsh receptor and Coated tube radioassay using human recombinant tsh receptor
    Endocrine Journal, 2003
    Co-Authors: Keiichi Kamijo
    Abstract:

    The aim of this study was to compare two two-step assays, a new Coated Plate (CP) ELISA assay (TRAb ELISA) using purified porcine TSH-receptors (pTSH-R) and a Coated tube assay (CT) using recombinant human TSH-receptors (hTSH-R) (DYNOR test TRAK human). The same serum samples were used for the determination by both assays in patients with 100 untreated Graves’ disease (GD), 30 silent thyroiditis (ST), 10 subacute thyroiditis (SAT) and 87 Hashimoto’s thyroiditis (HT). In sera from patients with untreated GD, pTBII and hTBII were positive in nearly all cases except the same one, whereas the thirty sera from the ST had positive values of pTBII in one case and of hTBII in 4 cases. In the one ST case of both pTBII and hTBII positive, hyperthyroidism developed following ST, although the remaining ST cases including the three hTBII-positive cases were not followed by hyperthyroidism after ST attack. A positive value of hTBII was observed in one of 10 patients with SAT, whereas none of them was pTBII positive. In the 87 patients with HT, positive values of pTBII were recognized in 9 patients, whereas hTBII is positive in 10 patients. Serum TSAb and TSBAb activities were analyzed in the hTBII positive 7 patients. As a result, TSAb was all positive except one and TSBAb positive in 4 cases. Since there is no significant difference in the sensitivity and specificity between the two assays in the differentiation of thyrotoxicosis as well as the frequency of finding positive values in patients with HT, it is reasonable to conclude that the clear advantage of sensitivity for clinical application in the new CP and CT assays may be derived from the Coated Plate or Coated tube assay itself, which probably excludes the effect of anti-TSH antibodies and HAMA, and is unrelated to the use of human or porcine TSH-receptors.

Stephen J Harris - One of the best experts on this subject based on the ideXlab platform.

  • A diamond-like carbon film for wear protection of steel
    Surface and Coatings Technology, 1993
    Co-Authors: Stephen J Harris, Andrew M. Weiner, S. J. Simko, Simon C. Tung, Maria C. Militello
    Abstract:

    We have deposited diamond-like carbon (DLC) and amorphous SiN films on a tool steel coupon. In order to make the DLC adhere to the metal, we used an interlayer of amorphous SiN, taking advantage of the fact that the SiN coating adheres to the metal and the DLC adheres to the SiN. The DLC/SiN-Coated substrate showed a significant reduction in friction compared with either unCoated or SiN-Coated substrates in our laboratory bench tester after lubricated sliding for 30 h. In addition, on the basis of surface profilometry analysis, the DLC/SiN-Coated Plate showed less wear and a much smoother surface. The films were analyzed using X-ray photoelectron spectroscopy and sputter depth profiling. Our results suggest that DLC is a promising coating for wear protection. © 1993.

Sherman W. Marcus - One of the best experts on this subject based on the ideXlab platform.

  • Antenna reflector emulation by simplified metamaterial-Coated Plates
    Journal of Electromagnetic Waves and Applications, 2014
    Co-Authors: Sherman W. Marcus
    Abstract:

    The optical transformation has been found to be an exceptional tool for determining the permittivity and permeability tensors e and μ that are required to provide desired patterns of electromagnetic energy flow. In a previous application of the optical transformation, a planar metamaterial-Coated Plate (MMCP) was designed which will scatter waves in the same manner as a three-dimensional parabolic reflector. The required e and μ, however, were not diagonal. A new method is proposed which can be applied to cylindrically symmetric reflectors of general geometry, and which results in e and μ tensors which are diagonal. This is accomplished (a) by dividing the original region into two sub-regions and performing the transformation on each one separately, and (b) by performing the transformation along orthogonal surfaces that include the reflector boundaries. The method is applied to conical, parabolic, and spherical reflectors. The MMCP that is equivalent to each of these geometries is numerically validated fo...

  • Metamaterial-Coated Plates for Emulating Non-Specular Reflection and Antenna Reflectors
    IEEE Transactions on Antennas and Propagation, 2013
    Co-Authors: Sherman W. Marcus
    Abstract:

    The optical transformation is generally used to deform free space in order to obtain novel effects on waves. Such effects can be realized by replacing the deformed region by a “metamaterial” characterized by \mbi e and \mbi μ tensors that are determined by the transformation. A new type of transformation is proposed which not only deforms a free space region, but transforms a non-trivially shaped conducting surface that bounds this region as well. The deformations are designed to map the original region into a planar slab of metamaterial, and to map the conducting surface into a Plate which bounds this slab. Since the fields outside the deformed region-which include the fields scattered by the original conducting surface-are unaffected by the transformation, they can, in effect, be produced by scattering from the planar metamaterial-Coated Plate created from the transformation. This substitution of a non-trivially shaped conducting surface by a planar metamaterial-Coated Plate is applied to (a) a face of a wedge to produce reflection from the planar metamaterial-Coated Plate that is not in the specular direction, and (b) a parabolic reflector antenna to design a planar system which produces the same radiation pattern as the reflector. Both devices are numerically validated.