Based on the first-order shear deformation theory (FSDT) and Kelvin-Voigt viscoelastic model, one derives a wave equation of longitudinal guide waves in viscoelastic orthotropic cylindrical shells, which analytically solves the wave equation and explains the intrinsic meaning of the wave propagation. In the numerical examples, the velocity curves of the first few modes for the elastic cylindrical shell are first calculated, and the results of the available literature are compared to verify the derivation and programming. Furthermore, the phase velocity curves and attenuation coefficient curves of the guide waves for a functionally graded (FG) shell are calculated, and the effects of viscoelastic parameters, material gradient patterns, material volume fractions, and size ratios on the phase velocity curves and attenuation curves are studied. This study can be widely used to analytically model the wave propagating in inhomogeneous viscoelastic composite structures and present a theoretical basis for the excellent service performance of composite structures and ultrasonic devices.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10488484 | PMC |
| http://dx.doi.org/10.3390/ma16175914 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Orientation selectivity properties for the affine Gaussian derivative and the affine Gabor models for visual receptive fields.
J Comput Neurosci
January 2025
Computational Brain Science Lab, Division of Computational Science and Technology, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
This paper presents an in-depth theoretical analysis of the orientation selectivity properties of simple cells and complex cells, that can be well modelled by the generalized Gaussian derivative model for visual receptive fields, with the purely spatial component of the receptive fields determined by oriented affine Gaussian derivatives for different orders of spatial differentiation. A detailed mathematical analysis is presented for the three different cases of either: (i) purely spatial receptive fields, (ii) space-time separable spatio-temporal receptive fields and (iii) velocity-adapted spatio-temporal receptive fields. Closed-form theoretical expressions for the orientation selectivity curves for idealized models of simple and complex cells are derived for all these main cases, and it is shown that the orientation selectivity of the receptive fields becomes more narrow, as a scale parameter ratio , defined as the ratio between the scale parameters in the directions perpendicular to vs.
View Article and Find Full Text PDFRadiogenomic explainable AI with neural ordinary differential equation for identifying post-SRS brain metastasis radionecrosis.
Med Phys
January 2025
Deparment of Radiation Oncology, Duke University, Durham, North Carolina, USA.
Background: Stereotactic radiosurgery (SRS) is widely used for managing brain metastases (BMs), but an adverse effect, radionecrosis, complicates post-SRS management. Differentiating radionecrosis from tumor recurrence non-invasively remains a major clinical challenge, as conventional imaging techniques often necessitate surgical biopsy for accurate diagnosis. Machine learning and deep learning models have shown potential in distinguishing radionecrosis from tumor recurrence.
View Article and Find Full Text PDFThe Value of Lacrimal Gland Ultrasonography and Shear Wave Elastography in the Evaluation of Primary Sjögren's Syndrome: A Cross-Sectional Study.
J Clin Ultrasound
January 2025
Department of Ultrasonography, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Purpose: This study evaluates the effectiveness of lacrimal gland ultrasonography (LGUS) and shear wave elastography (SWE) in distinguishing primary Sjögren's syndrome (PSS) patients from healthy controls and examines their role in assessing disease activity and prognosis.
Methods: A total of 35 PSS patients and 23 age- and gender-matched healthy controls were included. LGUS was used to grade lacrimal gland structure, while SWE assessed gland elasticity.
Recently, the dissipative soliton (DS) generation in the positive fourth-order-dispersion (FOD) fiber laser has been theoretically predicted, namely dissipative pure-quartic soliton (DPQS), featuring a higher energy-scaling ability compared to conventional DS dominated by positive group velocity dispersion. Here, we discover that the formation of spectral sidebands is always accompanying by the stabilized DPQS in the fiber laser, which is different from the conventional DS. Due to the combination of positive FOD and self-phase modulation, low- and high-frequency components are distributed at the leading and trailing edges of the pulse, forming the pedestals that propagate with it.
View Article and Find Full Text PDFGlucagon: a potential protective factor against peripheral nerve compromise in patients with type 2 diabetes and obesity.
Diabetol Metab Syndr
January 2025
Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, No.666 Shengli Road, Nantong, 226001, China.
Background: Increased glucagon levels are now recognized as a pathophysiological adaptation to counteract overnutrition in type 2 diabetes (T2D). This study aimed to elucidate the role of glucagon in peripheral nerve function in patients with T2D with different body mass indices (BMIs).
Methods: We consecutively enrolled 174 individuals with T2D and obesity (T2D/OB, BMI ≥ 28 kg/m), and 480 individuals with T2D and nonobesity (T2D/non-OB, BMI < 28 kg/m), all of whom underwent oral glucose tolerance tests to determine the area under the curve for glucagon (AUC).
Want 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!