Procédé d'étalonnage d'une sonde acoustique au moyen du pendule absolu de pression de radiation

The calibration of an acoustic probe is discussed. The acoustic power is best measured with the help of an absolute pendulum measuring radiation pressure.Dans le procédé connu de détermination du coefficient de proportionnalité de l'indication d'une sonde à la puissance acoustique captée par celle-ci, au moyen d'une intégration graphique du volume caractérisant la répartitron de l'énergie dans une section orthogonale du champ d'un projecteur ultra-sonore et de la mesure de la puissance globale de la source, il y a avantage pour mesurer cette puissance à utiliser un Pendule Absolu de pression de radiation qui, par principe, ne demande pas d'étalonnage

Study of the thermohydraulics of CO2 discharge from a high pressure reservoir

An experimental test set up has been constructed to carry out controlled CO2 release experiments from a high pressure vessel. The test set up is made up of a 500l stainless steel vessel where CO2 can be introduced up to high pressures and where controlled releases can be conducted. The work objective is to get experimental data that help to understand the thermo-hydraulic behavior of CO2 when discharged from a pressurized vessel and to further improve and validate existing and newly developed release and dispersion models. The aim is to get better insight into the fluid behavior in the vessel as well as in the discharged jet, and to understand the relation between the thermodynamic regime inside the high pressure medium and the mass release rate and jet zone characteristics during the release process.In this experimental work, the impact of varying the release orifice diameter and the initial vessel pressure on the CO2 discharge will be examined and analyzed, and the different thermodynamic regimes inside and outside the high pressure medium will be described and interpreted. © 2013 Elsevier Ltd

A diffusion tensor imaging analysis of white matter microstructures in non-operated craniosynostosis patients

Purpose: In 7 to 15-year-old operated syndromic craniosynostosis patients, we have shown the presence of microstructural anomalies in brain white matter by using DTI. To learn more about the cause of these anomalies, the aim of the study is to determine diffusivity values in white matter tracts in non-operated syndromic craniosynostosis patients aged 0–2 years compared to healthy controls. Methods: DTI datasets of 51 non-operated patients with syndromic craniosynostosis with a median [IQR] age of 0.40 [0.25] years were compared with 17 control subjects with a median of 1.20 [0.85] years. Major white matter tract pathways were reconstructed with ExploreDTI from MRI brain datasets acquired on a 1.5 T MRI system. Eigenvalues of these tract data were examined, with subsequent assessment of the affected tracts. Having syndromic craniosynostosis (versus control), gender, age, frontal occipital horn ratio (FOHR), and tract volume were treated as independent variables. Results: ʎ2 and ʎ3 of the tracts genu of the corpus callosum and the hippocampal segment of the cingulum bundle show a ƞ2 > 0.14 in the comparison of patients vs controls, which indicates a large effect on radial diffusivity. Subsequent linear regressions on radial diffusivity of these tracts show that age and FOHR are significantly associated interacting factors on radial diffusivity (p < 0.025). Conclusion: Syndromic craniosynostosis shows not to be a significant factor influencing the major white matter tracts. Enlargement of the ventricles show to be a significant factor on radial diffusivity in the tracts corpus callosum genu and the hippocampal segment of the cingulate bundle

The Influence of Body Contouring Surgery on Weight Control and Comorbidities in Patients After Bariatric Surgery

Introduction: A considerable number of patients experience some long-term weight regain after bariatric surgery. Body contouring surgery (BCS) is thought to strengthen post-bariatric surgery patients in their weight control and maintenance of achieved improvements in comorbidities. Objectives: To examine the impact of BCS on long-term weight control and comorbidities after bariatric surgery. Methods: We performed a retrospective study in a prospective database. All patients who underwent primary Roux-en-Y gastric bypass (RYGB) and presented for preoperative consultation of BCS in the same hospital were included in the study. Linear and logistic mixed-effect model analyses were used to evaluate the longitudinal relationships between patients who were accepted or rejected for BCS and their weight loss outcomes or changes in comorbidities. Results: Of the 1150 patients who underwent primary RYGB between January 2010 and December 2014, 258 patients (22.4%) presented for preoperative consultation of BCS. Of these patients, 126 patients eventually underwent BCS (48.8%). Patients who were accepted for BCS demonstrated significant better ∆body mass index (BMI) on average over time (− 1.31 kg/m2/year, 95% confidence interval (CI) −2.52 − −0.10, p = 0.034) and percent total weight loss (%TWL) was significantly different at 36 months (5.79, 95%CI 1.22 – 10.37, p = 0.013) and 48 months (6.78, 95%CI 0.93 – 12.63, p = 0.023) after body contouring consultation. Patients who were accepted or rejected did not differ significantly in the maintenance of achieved improvements in comorbidities. Conclusion: BCS could not be associated with the maintenance of achieved improvements in comorbidities after bariatric surgery, whereas it could be associated with improved weight loss maintenance at 36 and 48 months after body contouring consultation. This association should be further explored in a large longitudinal study

Black box or hidden abode? The expansion and exposure of platform work managerialism

This Special Issue holds that managerialism is not an abstract, trans-historical category, and this article argues that neither is it hidden within an impenetrable black box. An important new form of managerialism is being revealed which is specific to what Moore and Joyce argue to be a very observable, and also widely contested, platform management model (PMM). Marx’s ‘hidden abode’ is a more appropriate metaphor than a black box, thus, given empirically demonstrable cases of control and resistance. Drawing on insights from labor process theory, the article reveals how control methods are at work, and transversally, how platform managerialism generates considerable levels of worker and union resistance. Despite its seeming inevitability and invincibility, platform managerialism is as knowable and as contestable, indeed, as contested, as other forms