Search results for "Fracture"
showing 10 items of 873 documents
Improved Planning In-Service Inspections of Fatigued Aircraft Structures Under Parametric Uncertainty of Underlying Lifetime Models
2014
Certain fatigued structures must be inspected in order to detect fatigue damages that would otherwise not be apparent. A technique for obtaining optimal inspection strategies is proposed for situations where it is difficult to quantify the costs associated with inspections and undetected failure. For fatigued structures for which fatigue damages are only detected at the time of inspection, it is important to be able to determine the optimal times of inspection. Fewer inspections will lead to lower fatigue reliability of the structure upon demand, and frequent inspection will lead to higher cost. When there is a fatigue reliability requirement, the problem is usually to develop an inspection…
Critical Fracture Plane Under Multiaxial Random Loading by Means of Euler Angles Averaging
1999
ABSTRACT Several authors have experimentally observed that the position of the fatigue fracture plane strongly depends on the directions of the principal stresses or strains. The expected principal stress directions under multiaxial random loading are obtained herein by averaging the instantaneous values of the three Euler angles through some suitable weight functions, in order to take into account the main factors influencing the fatigue fracture behaviour. Then the correlation between such theoretical principal directions and the experimental fracture plane is examined for some biaxial random fatigue tests.
Effects of Three Interventions Combining Impact or Walking at Intense Pace Training, with or without Calcium and Vitamin Supplements, to Manage Postm…
2022
The purpose was to assess the effects of three interventions on bone mineral density (BMD) to prevent the onset or progression of osteoporosis in postmenopausal women. Specifically, thirty-nine postmenopausal women, diagnosed with osteopenia or osteoporosis, implemented either high-impact training (G1), the same training + calcium and vitamin D intake (G2), or walked at an intense pace + calcium and vitamin D (G3). Baseline change (BC) in BMD was estimated using the femoral neck and lumbar spine T-scores. Participants were classified as having suffered fractures and/or falls before (24-month) and during the 2-year intervention. The participants—aged 61.8 years—were allocated int…
Postmortem Computed Tomography: From Acquisition to Reporting
2019
PMCT in a noninvasive, fast, and quite available method which coroners and forensic experts tend to use more and more often, especially when a crime is suspected. PMCT proved to be an excellent tool for detection and assessment of bone fracture injuries due to sharp trauma and bullet trajectories.
The challenge of open tibial shaft fractures: When tomanage with external fixation and when to useintramedullary nailing?
2020
Treatment of open tibial shaft fractures is challenging. External fixation (EF) is comparatively safe in treating these open injuries with the main advantages of easy application, minimal additional disruption, and convenient subsequent soft tissue repair. Tibial intramedullary nailing (IM) is optimal for the treatment of open tibial fractures. This study aims to report the outcomes of our multi-center experience in the management of open tibial shaft fractures, evaluating the efficacy and safety of using either the external fixation (EF) or intramedullary nailing (IM).In this study, clinical-radiographic results were evaluated in 26 cases of open fractures treated with an external fixator …
Is it possible to change of the duration of consolidation period in the distraction osteogenesis with the repetition of extracorporeal shock waves?
2016
Background In this study we examined the effects of two different repeated Extracorporeal Shock Waves (ESW) on the consolidation period of the distraction osteogenesis (DO) of the rabbit mandible using stereological, radiological and immunohistochemical methods. Material and Methods DO was performed unilaterally in the mandible of 18 New Zealand rabbits (six months old, weighing between 2.5-3 kg). In the consolidation period, rabbits were divided into three groups randomly after the distraction period. The distraction zone of the mandible was received no treatment as controls (E0*2). Group 2 (E 500*2) received ESWT (twice 500 impulses at 14 kV and 0.19 mJ/mm2 energy) in the first and fourth…
Reliability analysis of processes with moving cracked material
2015
Abstract The reliability of processes with moving elastic and isotropic material containing initial cracks is considered in terms of fracture. The material is modelled as a moving plate which is simply supported from two of its sides and subjected to homogeneous tension acting in the travelling direction. For tension, two models are studied: (i) tension is constant with respect to time, and (ii) tension varies temporally according to an Ornstein–Uhlenbeck process. Cracks of random length are assumed to occur in the material according to a stochastic counting process. For a general counting process, a representation of the nonfracture probability of the system is obtained that exploits condi…
Imaging Evaluation of Facial Complex Strut Fractures
2012
High-resolution multidetector computed tomography with multiplanar reformations and 3-D postprocessing often provides the detail necessary for preoperative assessment of facial injuries. Maxillofacial fractures are classified in the following manner: upper face fractures, midface fractures (the most frequent), Le Fort fractures, and lower face or mandible fractures. The facial skeleton is a framework of vertical and horizontal buttresses that ensures a better resistance to trauma, but serves also as reference for maxillofacial surgery to restore facial size and shape. Radiologists should know how to diagnose and report the main types of facial fracture.
Health-related quality of life of patients with zygomatic fracture.
2017
Background: The objective was to evaluate health-related quality of life (HRQoL) before and after surgical treatment of zygomatic complex fracture and assess patients’ perceptions of the aesthetic and functional outcomes of surgery. Material and Methods: A prospective study of 79 adult patients before and after surgery for zygomatic complex fracture was conducted. HRQoL was measured using the generic 15-dimensional (15D) instrument, and patient satisfaction was assessed by an additional questionnaire. Results: The mean preoperative 15D score for patients was lower than for general population that was matched for age and gender (p=0.011). The mean 15D score was lowest on the first postoperat…
Femoral neck's fracture in Fahr's Syndorme
2016
Fahr's syndrome is a rare neurological diseas characterized by the presence of idiopathic deposition of calcium in aeras of the brain that control movements.