This paper presents a Fourier spectral element method (FSEM) to analyze the free vibration of conical-cylindrical-spherical shells with arbitrary boundary conditions. Cylindrical-conical and cylindrical-spherical shells as special cases are also considered. In this method, each fundamental shell component (i.e., cylindrical, conical, and spherical shells) is divided into appropriate elements. The variational principle in conjunction with first-order shear deformation shell theory is employed to model the shell elements. Since the displacement and rotation components of each element are expressed as a linear superposition of nodeless Fourier sine functions and nodal Lagrangian polynomials, the global equations of the coupled shell structure can be obtained by adopting the assembly procedure. The Fourier sine series in the displacement field is introduced to enhance the accuracy and convergence of the solution. Numerical results show that the FSEM can be effectively applied to vibration analysis of the coupled shell structures. Numerous results for coupled shell structures with general boundary conditions are presented. Furthermore, the effects of geometric parameters and boundary conditions on the frequencies are investigated.
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http://dx.doi.org/10.1121/1.4967853 | DOI Listing |
Cogn Affect Behav Neurosci
January 2025
Center for Depression, Anxiety, and Stress Research, McLean Hospital, Belmont, MA, USA.
Post-traumatic stress and major depressive disorders are associated with "overgeneral" autobiographical memory, or impaired recall of specific life events. Interpersonal trauma exposure, a risk factor for both conditions, may influence how symptomatic trauma-exposed (TE) individuals segment everyday events. The ability to parse experience into units (event segmentation) supports memory.
View Article and Find Full Text PDFJ Chin Med Assoc
December 2024
Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
Background: Operative delivery is a technique used during vaginal or cesarean birth to facilitate the patient's labor course through the assistance of a vacuum extractor. This method is increasingly used compared with forceps. This study aimed to investigate the forced effects of vacuum extractors comprising vacuum cups with different thicknesses on the fetal head and the vacuum extractor during vacuum-assisted delivery and to determine the optimal thickness for reducing the failure rate and minimizing neonatal and maternal morbidity.
View Article and Find Full Text PDFPLoS One
January 2025
Faculty of Business, City University of Macau, Macao, China.
Based on the previous studies on the impact of traditional culture on tourists' purchasing intentions, this study aims to further explore the mechanism and boundary conditions regarding the traditional cultural load in tourist souvenir packaging. Through seven simulated experiments (N = 3203), the impact of different degrees of traditional cultural load on tourists' purchasing intentions has been examined, with value perception, cultural identity, and purchase purpose, advancing the research in the field of traditional culture and tourism marketing. The findings provide insights for managers in the industry of tourism and souvenir marketing for their package design.
View Article and Find Full Text PDFJ Chem Inf Model
January 2025
Division of Physics & Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
With remarkable stability and exceptional optoelectronic properties, two-dimensional (2D) halide layered perovskites hold immense promise for revolutionizing photovoltaic technology. Effective data representations are key to the success of all learning models. Currently, the lack of comprehensive and accurate material representations has hindered AI-based design and discovery of 2D perovskites, limiting their potential for advanced photovoltaic applications.
View Article and Find Full Text PDFBackground: The Southern Illinois University Longitudinal Cognitive Aging Study (SIU LCAS) is a community-based, longitudinal cohort study initiated in 1984. LCAS was initially designed to improve the sensitivity of neuropsychological testing to diagnose mild cognitive impairment (MCI) and dementia in individuals residing in central and southern Illinois.
Method: Participants are recruited from the community via newspaper advertisement, word-of-mouth, and community presentations.
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