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In this paper, a simple chain suspension catenary model is constructed. The acting force of pantograph is reduced to a displacement loading. The stress and fatigue life of railway catenary dropper incorporating displacement loading and fluctuating wind load are studied. Through writing a MATLAB code, the vibration equation of the dropper is used to calculate its stress under different conditions using a finite difference method, combining with the initial boundary value conditions obtained by the response equations of the contact wire. Based on the dropper stress, its fatigue life can be obtained. The results show that under the 250 km/h train speed, the stress change process of the dropper experiences three stages: immediate rebound, attenuation vibration, and bending compression. Dropper Ⅳ is most likely to break in a span. Compared with dropper Ⅳ, the fatigue life of dropper Ⅰ is 11 times, and those of droppers Ⅱ, Ⅲ, and Ⅴ are about 2.5 times. Compared with no wind, the fatigue lives of droppers Ⅰ-Ⅳ are reduced by approximately three times at a wind speed of 25 m/s. This work provides a powerful means for the study of dropper stress under actual working condition.
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http://dx.doi.org/10.1177/00368504241311432 | DOI Listing |
Clin Implant Dent Relat Res
October 2025
State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Introduction: This in vitro study evaluated how different forces applied to the dental drill handle during static computer-assisted implant surgery influence surgical guide deformation and implant placement accuracy.
Methods: Twenty-four virtual implants were divided into six groups (0-10 N, in 2 N increments). Surgical guides were scanned under loaded conditions, and deviations were quantified by superimposition with the baseline model.
J Mech Behav Biomed Mater
August 2025
Department of Physical Therapy, School of Health Sciences, Sapporo Medical University, Sapporo, Japan; Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan. Electronic address:
Hamstring strain injuries frequently occur during the late swing phase of running; however, the breaking strength of the human hamstring muscle-tendon complexes remains unclear. This study aimed to determine the breaking strength of human hamstring muscle-tendon complexes. To this end, seven cadaveric specimens preserved using the Thiel's method were examined.
View Article and Find Full Text PDFInt J Exerc Sci
September 2025
School of Health, Science, and Technology, Cornerstone University, Grand Rapids, MI, USA.
Although acutely donning compression garments improves several markers of athletic performance, the effects of training in compression garments remains largely unexplored. Thus, this study aimed to determine the effects of exercise training while donning a novel full-body compression garment on multiple measures of anaerobic performance. Sixteen sedentary males (age: 21±3 y; BMI: 25±3 kg/m) completed 4 weeks of training with (CG; n=8) or without (CON; n=8) a novel full-body compression garment.
View Article and Find Full Text PDFFront Bioeng Biotechnol
August 2025
Department of Mechanical and Electro-Mechanical Engineering, TamKang University, New Taipei City, Taiwan.
Introduction: Patients with hemifacial microsomia exhibit varying degrees of mandibular asymmetry. The commercial plates used during bilateral sagittal split osteotomy (BSSO) surgery are often not tailored to individual patients and may lack sufficient fixation stability, increasing the risk of mandibular relapse. This study proposes a patient-specific plate design by collecting CT images of 30 cases of hemifacial microsomia to statistically analyze mandibular asymmetry.
View Article and Find Full Text PDFJ Biomater Sci Polym Ed
September 2025
Department. of Pharmaceutics, Delhi Pharma Sciences and Research University (DPSRU)Govt of NCT of Delhi, New Delhi, India.
Chronic wounds infected with multidrug-resistant bacteria pose a significant therapeutic challenge, requiring biocompatible and effective interventions. This study presents a novel lignin-based nanoparticle spray for the localized delivery of curcumin, a natural anti-inflammatory and antimicrobial compound. Lignin, a sustainable polyphenolic biopolymer with inherent antioxidant and antimicrobial activities, was used both as a carrier and functional agent.
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