58 research outputs found

    Three lateral osteotomy designs for bilateral sagittal split osteotomy: biomechanical evaluation with three-dimensional finite element analysis

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    <p>Abstract</p> <p>Background</p> <p>The location of the lateral osteotomy cut during bilateral sagittal split osteotomy (BSSO) varies according to the surgeon's preference, and no consensus has been reached regarding the ideal location from the perspective of biomechanics. The purpose of this study was to evaluate the mechanical behavior of the mandible and screw-miniplate system among three lateral osteotomy designs for BSSO by using three-dimensional (3-D) finite element analysis (FEA).</p> <p>Methods</p> <p>The Trauner-Obwegeser (TO), Obwegeser (Ob), and Obwegeser-Dal Pont (OD) methods were used for BSSO. In all the FEA simulations, the distal segments were advanced by 5 mm. Each model was fixed by using miniplates. These were applied at four different locations, including along Champy's lines, to give 12 different FEA miniplate fixation methods. We examined these models under two different loads.</p> <p>Results</p> <p>The magnitudes of tooth displacement, the maximum bone stress in the vicinity of the screws, and the maximum stress on the screw-miniplate system were less in the OD method than in the Ob and TO methods at all the miniplate locations. In addition, Champy's lines models were less than those at the other miniplate locations.</p> <p>Conclusions</p> <p>The OD method allows greater mechanical stability of the mandible than the other two techniques. Further, miniplates placed along Champy's lines provide greater mechanical advantage than those placed at other locations.</p

    The Compact Linear Collider (CLIC) - 2018 Summary Report

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    The Compact Linear Collider (CLIC) - 2018 Summary Report

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    The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear e+ee^+e^- collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years

    Double scale numerical FEM-DEM analysis for cohesive-frictional materials

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    ABSTRACT Recently, multi-scale analysis using a numerical approach of the homogenisation of the microstructural behaviour of materials to derive the constitutive response at the macro scale has become a new trend in numerical modelling in geomechanics. Considering rocks as granular media with cohesion between grains, a two-scale fully coupled approach can be defined using FEM at the macroscale, together with DEM at the microscale An implementation of the FEM-DEM method in a well-established, finite strain FEM code is presented, and representative results are discussed, including aspects related to strain localisation in this context. REFERENCES [1] Nitka M., Combe G., Dascalu C., Desrues J. Two-scale modeling of granular materials: a DEM-FEM approach, Granular Matter vol.13 No 3, pp. 277-281, (2011) [2] Nguyen T.K., Combe G., Caillerie D., Desrues J. FEM x DEM modelling of cohesive granular materials: numerical homogenisation and multi-scale simulation, Acta Geophysica vol.62 No 5, pp. 1109-1126 [3] Guo Ning and Zhao Jidong. A coupled FEM/DEM approach for hierarchical multiscale modelling of granular media

    Can calprotectin predict relapse risk in inflammatory bowel disease?

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