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The tooth width and length of face gear limit control the strength of face gear, and heat treatments are often used to improve the hardness and strength of face gear. However, heat treatments will often cause additional deformations, which will affect the dimensional accuracy of the face gear. In this paper, to effectively control the deformation and ensure the accuracy of the face gear, the finite element method was used to establish the calculation model of the face gear die quenching method, and thus, the influence of die on the gear quenching deformation was analyzed. Next, the accuracy of the calculation model was verified by the pressure quenching experiment. The results demonstrated that the inconsistent phase transformation between the surface and the center of the face gear was the key factor affecting the deformation due to the influence of the carbon content. Compared with die-less quenching, the inner hole-die can effectively limit the radial shrinkage deformation of the face gear. With the increase of the upper-die pressure, the axial and radial deformations of the face gear gradually became stable. In the actual production, the load of dies should be reasonably selected based on the gear accuracy requirements.
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http://dx.doi.org/10.3390/ma16020690 | DOI Listing |
J Craniofac Surg
August 2025
Division of Plastic Surgery, DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, FL.
Introduction: Combat sports, including boxing, wrestling, and martial arts, have surged in popularity across the United States, raising concerns over craniofacial injuries. Despite clinical awareness, large-scale epidemiologic data comparing injury patterns across combat sport disciplines remain limited.
Methods: This study utilized data from the National Electronic Injury Surveillance System (NEISS) spanning 2014 to 2023 to assess craniofacial injuries presenting to US emergency departments.
Front Public Health
August 2025
Office of Occupational Safety and Health, U.S. Food and Drug Administration, U.S. Department of Health and Human Services, Washington, DC, United States.
The Occupational Safety and Health Administration (OSHA) Personal Protective Equipment (PPE) Standard, outlined in 29 CFR 1910 Subpart I states that Protective gear - including personal protective clothing, respiratory equipment, and barriers or shields- must be supplied, properly used, and kept clean and functional whenever there are hazards present. These hazards may arise from processes, environmental conditions, chemicals, radiation, or mechanical sources that could potentially cause injury or harm bodily functions through skin contact, inhalation, or absorption. Employers must supply PPE to their employees as determined by hazard assessments of the workplace and duties performed by employees.
View Article and Find Full Text PDFSci Data
June 2025
School for Environment and Sustainability, University of Michigan, Ann Arbor, USA.
North temperate lakes are an important resource across North America and Eurasia, however, their ecosystems are declining and projected to continue to face further impacts under future land use and climate change. Understanding how lake ecosystems respond to environmental stressors and management actions is critical for identifying resilient lakes and developing adaptation strategies. However, the ability to manage lakes is hampered by a lack of historical information.
View Article and Find Full Text PDFFront Public Health
June 2025
Department of Public Health, College of Health Sciences, Woldia University, Woldia, Ethiopia.
Introduction: Occupational health problems are the major issues of the world, particularly in developing countries. Sanitation workers are facing various health problems with little attention while conducting their day today activities. The review emphasizes the critical need for policies that ensure safety standards, provide proper protective gear, and establish regular health monitoring to protect workers' health and wellbeing.
View Article and Find Full Text PDFFront Public Health
June 2025
Department of Pharmacy, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia.
Background: Edible oil manufacturing is a labor-intensive sector with significant technological demands, where employees face various occupational hazards. The use of personal protective equipment (PPE) is not only a legal obligation but also a key measure for safeguarding workers against job-related injuries and health risks. Despite these challenges, this industry often remains under-researched and overlooked.
View Article and Find Full Text PDF