Reconstruction of the iliac bone using the homolateral femur after resection for pelvic tumor

AbstractThe authors have treated three patients with extensive involvement of the acetabular and peri-acetabular bone by a malignant tumour. One had a metastasis from a carcinoma of the thyroid, one from a carcinoma of the breast and one a plasmacytoma. In all three cases, the upper part of the femur was unaffected. It was used to replace the resected pelvic bone and fixed to the remaining bone by screws and plates. An acetabular cup was cemented into the transplanted bone, which itself was replaced by a massive femoral prosthesis. This technique allowed the patients to resume weight bearing rapidly. Two patients were alive and walked satisfactorily after two and four years respectively. The third died five months after the surgical procedure

Locked nailing for the treatment of displaced articular fractures of the calcaneus: description of a new procedure with calcanail®

Although open reduction and internal fixation is considered the best method for treating displaced articular fractures of the calcaneus, lateral approach is at high risk for wound healing complications. For this reason, the authors developed a posterior approach and a new implant to perform both intrafocal reduction and internal fixation. The aim of this technical note is to describe this method of treatment for displaced articular fractures of the calcaneus, which offered the following advantages: (a) the creation of a working channel that provides also a significant bone autograft, (b) the intrafocal reduction of the displaced articular surface, (c) the insertion of a locking nail that maintains the reduced articular surface at the right height, (d) the possibility to switch from an ORIF to a reconstruction arthrodesis with the same approach and instrumentation in case of severely damaged posterior facet

Numerical study of the droplet behavior in a thermal diffusion cloud chamber operating with saline water

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Buoyancy-driven convective motion in a thermal diffusion cloud chamber using a water/helium mixture

International audienceThis work is focused on a 2D numerical simulation of a thermal diffusion cloud chamber (TDCC) operating with water-helium mixture. We particularly address the impact of the stability of the vapor-gas mixture with respect to buoyancy-driven convective motion on homogeneous water nucleation rates. A comparison of our model results with Heist and Reiss results of nucleation of water in helium is first proposed. So, no convective fluxes are assumed within the TDCC and the critical supersaturation of water vapor is in agreement as obtained from numerical predictions. However, the influence of wall heating on the critical supersaturation results is found to be significant as obtained when convective transfers is accounted for within the TDCC and the results deviate significantly from those provided by Heist and Reiss. Their approach may lead large differences in terms of temperature, saturation ratio and nucleation profiles as it oversimplifies heat and mass transfer in TDCC compared to a 2D mass heat and momentum, model. Published by Elsevier Masson SAS

Numerical investigation of the motion of a growing droplet in a thermal diffusion cloud chamber

International audienceThe evolution of spherical droplets resulting from the homogeneous condensation of vapor phase diluted in a background gas has been studied numerically. The model was compared with experimental data of dioctylphthalate (DOP) droplets in binary gaseous mixture of DOP-helium and of DOP-hydrogen in a thermal diffusion cloud chamber (TDCC). The motion of droplets due to thermodiffusiophoresis as obtained from numerical predictions is in agreement with the experimental results. Two-dimensional droplet dynamics involving the effect of convection, thermodiffusiophoresis, gravity and condensation has been examined in details for two flow configurations depending on the cloud chamber geometry. When the height of the TDCC is increased, the isothermal patterns and streamlines are similar to those obtained in the case of Rayleigh-Benard instabilities, leading a notable alteration of the droplet behavior. While the thermodiffusiophoresis forces govern the drop motion at low thermal Rayleigh numbers (in conductive regime), the behavior of the droplet is mainly driven by the drag force when the TDCC operates in convective regime (at high Rayleigh numbers). (C) 2003 Elsevier Ltd. All rights reserved

Stable stratification alteration in a thermal diffusion cloud chamber

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Modelling the heat during the injection stretch blowing moulding: Infrared heating and blowing modelling

International audienceThe effects of temperature, initial heating conditions or self heating during the process, are very important during the injection stretch blow moulding (ISBM) process of PET bottles. They control the preform temperature distribution and strongly affect the blowing kinematics via the important influence of temperature on mechanical behaviour. The temperature affects the orientation induced by biaxial stretching, which in turn, affects mechanical properties of PET. Therefore, thermal proprieties are one of the most important variables in the ISBM. In order to achieve accurate simulation of the ISBM process, it is necessary to: (i) measure the initial temperature distribution of the preform when the blowing operation begins; (ii) follow the history of the temperature field and consequently to identify the thermal proprieties of the PET; (iii) to model the behaviour law of PET coupled to the thermal laws. In this work, we modelled the PET behaviour in ISBM strian rate and temperature conditions by a thermo-viscohyperelastic model which has been inspired from Figiel and Buckley 2009 [1] and already presented by Luo et al. 2011 [2]. A procedure is proposed for the identification of the thermal parameters from experimental results of a test where PET sheets are heated using infrared (IR) lamps. The Monte Carlo method is used to provide the parameters best fit from the temperature evolution measured on the face in front of the lamps and from the rear face. The beginning of the temperature evolution gives information on the IR flux and the final stage of the heating gives information on the convection exchange. Difference between the front and the rear faces gives information on the PET conductivity. Using a finite element approach implemented in Matlab, the coupled thermo-visco-hyperelastic model has been used to simulate the ISBM process. The results from the computer simulation can be compared with the temperature profiles measured by thermal imaging

Simplified Modelling of the Infrared Heating Involving the Air Convection Effect before the Injection Stretch Blowing Moulding of PET Preform

International audienceInitial heating conditions and temperature effects (heat transfer with air and mould, self-heating, conduction) have important influence during the ISBM process of PET preforms. The numerical simulation of infrared (IR) heating taking into account the air convection around a PET preform is very time-consuming even for 2D modelling. This work proposes a simplified approach of the coupled heat transfers (conduction, convection and radiation) in the ISBM process based on the results of a complete IR heating simulation of PET sheet using ANSYS/Fluent. First, the simplified approach is validated by comparing the experimental temperature distribution of a PET sheet obtained from an IR camera with the numerical results of the simplified simulation. Second, we focus on the more complex problem of the rotating PET preform heated by IR lamps. This problem cannot be modeled in 2D and the complete 3D approach is out of calculation possibilities actually. In our approach, the IR heating flux coming from IR lamps is calculated using radiative laws adapted to the test geometry. Finally, the simplified approach used on the 2D plane sheet case to model the air convection is applied to the heat transfer between the cylindrical preform and ambient air using a simple model in Comsol where only the preform is meshed. In this case, the effect of the rotation of the preform is taken into account in the radiation flux by a periodic time function. The convection effect is modeled through the thermal boundary conditions at the preform surface using the heat transfer coefficients exported from the simulations of the IR heating of a PET sheet with ANSYS/Fluent. The temperature distribution on the outer surface of the preform is compared to the thermal imaging for validation

Direct testing of subgrid scale models in large-eddy simulation of a non-isothermal turbulent jet

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