In this paper, a novel method of numerical computation of the natural frequencies, depending on the most important running parameters for an ultrasonic motor, is described. The analyzed configuration by the Space Division of Alenia Spazio, Rome, within an Italian Space Agency (ASI) development program, is the flexural traveling wave one. The dynamic equations for the stator and the rotors of the ultrasonic motor are assumed into a differential system, whose equations are coupled by terms that represent interface generalized forces. In order to calculate natural frequencies of the motor-coupled terms of the equations are worked out with respect to the variables of the degrees of freedom. Hence, the mass, damping, and stiffness matrix for the whole system are obtained, then resonance frequencies, depending on the most important running parameters such as axial preload of the motor, are calculated. The results are compared with numerical ones, obtained by a finite element modeling (FEM) model, showing a good agreement.
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Eur Spine J
January 2025
Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, China.
Background: Posterior laminectomy is a standard treatment for thoracic ossification of the ligamentum flavum (TOLF), but it often leads to neurological deterioration during surgery. This study aimed to reduce iatrogenic neurological deterioration by using an S8 navigation system combined with an ultrasonic osteotome for three-dimensional real-time dynamic visualization decompression.
Methods: A retrospective analysis was conducted on patients who underwent laminectomy and internal fixation for TOLF in our centre from January 2016 to January 2023.
J Neurochem
January 2025
Department of Pathology, School of Veterinary Medicine, University of São Paulo, Sao Paulo, Brazil.
Autism spectrum disorder (ASD) is a complex developmental disorder characterized by several behavioral impairments, especially in socialization, communication, and the occurrence of stereotyped behaviors. In rats, prenatal exposure to valproic acid (VPA) induces autistic-like behaviors. Previous studies by our group have suggested that the autistic-like phenotype is possibly related to dopaminergic system modulation because tyrosine hydroxylase (TH) expression was affected.
View Article and Find Full Text PDFJ Neurophysiol
January 2025
School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong Province, China.
Parkinson's disease (PD) is a prevalent and challenging neurodegenerative disorder, and may involve impaired autophagy. Nuclear factor erythroid-2-related factor 2 (Nrf2) is crucial for regulating autophagy-related genes, maintaining cellular homeostasis. Electroacupuncture (EA), a complementary and alternative therapy for PD, has gained widespread clinical application.
View Article and Find Full Text PDFJ Mot Behav
December 2024
Department of Vasculocardiology, Chuzhou First People's Hospital, Chuzhou, Anhui Province, China.
This study aimed to compare the effects of electroacupuncture on traditional acupoints and muscle belly of different target muscles against upper limb dysfunction in stroke patients with hemiplegia. A total of thirty-nine stroke patients with subacute hemiplegia were randomly divided into the control group ( = 19) and observation group ( = 20). The control group was treated with physical therapy and normal electroacupuncture, while the observation group was treated with physical therapy and ultrasound-guided electroacupuncture on the muscle belly.
View Article and Find Full Text PDFSensors (Basel)
November 2024
College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
To overcome the problems of the low signal-to-noise ratio and poor performance of wood ultrasonic images caused by ring-down vibrations during the ultrasonic quality detection of wood, a composite pulse excitation technique using a wood air-coupled ultrasonic detection system is proposed. Through a mathematical analysis of the output of the ultrasonic transducer, the conditions necessary for implementing composite pulse excitation were analyzed and established, and its feasibility was verified through COMSOL simulations. Firstly, wood samples with knot and pit defects were used as experimental samples.
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