Orientations of langasite (LGS) with Euler angles (0°, μ, 90°) are potentially useful for applications in wireless SAW sensors because of wide variation of their temperature coefficient of frequency (TCF), between -50 and +50 ppm/°C, combined with high values of electromechanical coupling coefficient, especially if thick electrodes are utilized. The nature and characteristics of shear-horizontally polarized SAWs (SHSAWs) propagating in these orientations are investigated using a combination of numerical techniques: analysis of the BAW slowness surface and its effect on the SH-SAW structure; visualization of displacements that follow wave propagation in the grating; calculation of admittance of infinite periodic gratings; and analysis of SAW dispersion in the gratings, including possible interaction between SH-SAWs and parasitic Rayleigh SAWs. The characteristics of SH-SAWs propagating in symmetric cuts (velocities, localization depth, electromechanical coupling, etc.) are supplemented by analysis of propagation directions deviating from the YZ-plane toward the x-axis of LGS, for the temperature compensated cut with Euler angles (0°, 22°, 90°) and one more orientation for comparison. This extended analysis reveals that in actual devices, the anisotropy may be a reason for strong interaction between SH-SAWs and parasitic Rayleigh SAWs and cause degradation of the device's performance.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1109/TUFFC.2012.2484 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Impact of Convulsive Maternal Seizures on Fetus Dynamics.
Int J Numer Method Biomed Eng
January 2025
The Ferrara Center for Patient Safety and Clinical Simulation, New York Institute of Technology, College of Osteopathic Medicine, New York City, New York, USA.
The study findings demonstrate that the amniotic fluid plays an important role in protecting the fetus during convulsive maternal seizures. The amniotic fluid was found to be an effective buffer, significantly reducing the transfer of kinetic energy to the fetus during these events. This highlights the sufficient protection provided by the amniotic fluid in such circumstances.
View Article and Find Full Text PDFMultiple-quantum magic-angle spinning NMR spectra in the static limit: The I = 3/2 case.
J Chem Phys
December 2024
Department of Chemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
A simplified theoretical description of multiple-quantum excitation and mixing for nuclear magnetic resonance of half-integer quadrupolar nuclei is presented. The approach recasts the multiple-quantum nutation behavior in terms of reduced excitation and mixing curves through a scaling of the first-order offset frequency by the quadrupolar coupling constant. The two-dimensional correlation of the static first-order anisotropic line shape to the second-order anisotropic magic-angle-spinning (MAS) line shape is utilized to transform the three-dimensional integral over the three Euler angles into a single integral over the dimensionless first-order offset parameter.
View Article and Find Full Text PDFCan summary measures of magnitude and structure of trunk movement variability differentiate between people with and without chronic low back pain?
Clin Biomech (Bristol)
December 2024
Dept. of Human Movement Science, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands.
Background: There is inconsistent evidence suggesting that people with chronic low back pain may differ in variability of repeated trunk movements compared to people without chronic low back pain. These inconsistencies may be due to low reliability and task dependence of movement variability measures, which can be addressed using multiple movement tasks and summary measures.
Methods: Participants with and without chronic low back pain were recruited.
Development of a rotary piezoelectric energy harvester using magnetic excitation inspired by the fan blade.
Rev Sci Instrum
December 2024
School of Mechanical Engineering, Northeast Electric Power University, Jilin 132012, China.
This work proposes a new rotary piezoelectric energy harvester using magnetic excitation inspired by the fan blade. The configuration and operating principle of the harvester are introduced. Then, the equivalent nonlinear model of the piezoelectric beam is established based on the Euler-Bernoulli theory and the Rayleigh-Ritz method.
View Article and Find Full Text PDFMicromechanics Modeling on Mechanical Properties in Mg Alloys with Bimodal Grain Size Distribution.
Nanomaterials (Basel)
November 2024
School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
Bimodal grain structure (BGS) Mg alloys containing a high fraction of fine grains (FGs) and a low fraction of coarse grains (CGs) show a good combination of strength and plasticity. Here, taking the ZK60 alloy as an example, the influences of CG size, volume fraction, and texture intensity on mechanical properties and the hetero-deformation-induced (HDI) effect were examined using the Mori-Tanaka mean-field method combined with strain gradient theory of plasticity. The results indicate that the overall mechanical properties decrease with an increase in CG size because the limited HDI effect cannot compensate for the strength and plasticity decrease derived from larger CGs.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!