Conception d’un capteur caractérisant la dégradation du fluide dans un embrayage magnétorhéologique

Le monde de l’aéronautique évolue graduellement vers le concept d’aéronefs plus électrique. Dans ce cadre, des systèmes électriques de commande de vol sont à l’étude. De tels systèmes permettraient de réduire le coût de maintenance et l’impact environnemental tout en alliant légèreté fiabilité et performance dynamique. Dans ce but, un système électrique de commande de vol comprenant des embrayages magnétorhéologiques (MR) et des moteurs électriques a été développé à l’Université de Sherbrooke. Un des obstacles principaux au développement de la technologie MR est la capacité de mesurer l’état d’usure du fluide MR en opération. En effet, même si l’état du fluide MR peut déjà être déduit grâce aux performances globales de l’embrayage, une deuxième méthode indépendante de mesure est nécessaire pour assurer une redondance et statuer de manière fiable sur l’état du système. À ce jour, aucunes recherches n’ont été faite pour développer un capteur permettant un suivi direct de l’usure du fluide à partir de l’observation d’une de ses caractéristiques. Le but de cette maitrise est donc de trouver un principe physique pour la mesure de la dégradation du fluide MR, de développer puis de tester sur banc de test un prototype de capteur mesurant la dégradation du fluide de manière directe. Un recensement des différentes propriétés physiques pouvant être affectées par la dégradation a été fait et des expériences simples ont été menées sur chacune d’elles. Les propriétés optiques du fluide ont montré la plus grande sensibilité à la dégradation et ont été choisies comme principe physique de fonctionnement du capteur. Ainsi une corrélation entre l’assombrissement du fluide et son âge a été mise évidence. L’assombrissement du fluide est mesuré par le capteur grâce à une carte RGB. Le prototype développé a ensuite été intégré à un embrayage MR installé sur un banc de test instrumenté afin d’étudier l’assombrissement du fluide au cours de son usure. Pour ce faire, deux types de fluide ont été utilisés: le Lord 140CG, un fluide commercial et le GPL-103, un fluide maison à base de perfluoropolyéther (PFPE). Trois tests ont été faits avec le fluide Lord 140 et ont montré que le fluide s’assombrit de manière régulière jusqu’à devenir 12% plus sombre lors de son usure totale. L’assombrissement apparait alors comme un bon métrique pour mesurer l’état de dégradation du fluide. Les trois tests avec du GPL-103 ont montré une tendance similaire d’assombrissement du fluide, mais avec une corrélation moindre avec la dégradation du fluide à cause de problèmes de blocage de l’écoulement de fluide devant le capteur dû à l’augmentation de la viscosité du fluide. Cela montre que les résultats du capteur sont dépendants du couple embrayage/fluide utilisé et que le capteur doit donc être étalonnés pour chaque nouveau fluide et embrayage

Shoulder flexibility and strength in elite girl tennis players with and without history of shoulder pain

This study aimed at comparing the glenohumeral (GH) range of motion, and shoulder and scapular muscle strength in elite girl tennis players with (group HoSP; n=15) and without (group H; n=16) history of shoulder pain. The GH joint range of motion in internal (IROM) and external rotation (EROM), as well as the maximal isometric strength of eight shoulder and scapular muscles were bilaterally assessed in 31 girl players. The results showed an increased IROM in HoSP, suggesting a laxity, which may contribute to humeral translation motions in the glenoid cavity at critical tennis positions. The HoSP group also presented a weakness in serratus anterior muscle strength, which may create improper motions of the scapula during the tennis strokes. These findings suggested that stretching and strengthening rehabilitative programs may be specifically developed for the young girl athletes involved in an intensive overhead activity practice

PROPHYLACTIC EVALUATION OF SHOULDER PROPRIOCEPTION IN ELITE SWIMMERS

It is suggested that poor shoulder proprioception contributes to shoulder pain in swimmers. However, there is a lack of studies describing the measurement method for shoulder proprioception. The purposes of this preliminary study was to investigate the scapular position depending on arm scaption as a first step in the development of a measurement method for three-dimensional shoulder proprioception. An asymptomatic young adults participated in this study. His scapular rotation were measured as a function of arm position during scaption in two consecutive days. The results showed that scapular rotations are not a reproducible function of humerus elevation. Those findings suggested that the assessement of shoulder proprioception should rely on the evaluation of both gleno-humeral and scapulo-thoracic joints to be valid

Stability of Concentrated Solution of Vancomycin Hydrochloride in Syringes for Intensive Care Units

Abstract Background Vancomycin is increasingly administrated by continuous infusion. But the treatment of patient in intensive care need restricted volume to prevent fluid overload. The aim of the study was to evaluate the physical and chemical stability of solutions of a high concentration of vancomycin hydrochloride in 5 % glucose or 0.9 % NaCl. Methods Eight syringes of 50 mL, containing 41.66 mg/mL of vancomycin hydrochloride four syringes in 5 % glucose and four in 0.9 % NaCl were prepared and stored at ambient temperature during 48 h. Immediately after preparation and during 48 h, vancomycin hydrochloride concentrations were measured by a high-performance liquid chromatography (HPLC). Spectrophotometric absorbance at different wavelengths, pH measurement and microscopic observations were also performed. Results All solutions were physico-chemically stable during the whole period storage at ambient temperature: no color change, turbidity, precipitation or opacity, no significant pH variations or optic densities were observed in the solutions. Any crystals were seen by microscopic analysis. Solutions are considered chemically stable as the lower limit of the 95 % unilateral confidence interval on the mean remained above 90 % of the initial concentration for at least 48 h. Conclusions Solutions of vancomycin hydrochloride 41.66 mg/mL in syringe of 5 % glucose or 0.9 % NaCl are physically and chemically stable for at least 48 h when stored in syringes at ambient temperature. </jats:sec

Contribution d’une démarche quantitative à l’analyse des flux médiatiques d’information

Comment appréhender les flux médiatiques d’information qui fabriquent l’actualité ? Cette contribution propose de restituer à l’information une partie de son sens, en la replaçant dans le flux dont elle procède et qu’elle produit. L’attribution standardisée de descripteurs rédactionnels permet de multiplier les « prises » sur des corpus volumineux de sujets : le matériau, devenu descriptible dans le temps, gagne en intelligibilité par le recours à l’inférence statistique. Une saisie macroscopique et diachronique de l’information est rendue possible, qui invite à découvrir les structures, les dynamiques et les événements saillants à partir desquels se fabrique l’actualité médiatique et, au-delà, l’espace public. Cette méthode est présentée par les résultats qu’elle a fournis pour analyser dix ans d’information sportive dans les journaux télévisés hertziens français. Pour autant, l’outil n’explique pas par lui-même, et suppose de multiplier les questions, de recourir à d’autres savoirs pour rendre intelligible ce qu’il donne à lire autrement. Cette forme de travail ouvre ainsi moins des questions que de nouvelles voies pour produire des indicateurs permettant d’y répondre.How to grasp the media streams of information which make the current events ? This contribution suggests restoring to the information a part of its meaning, by replacing it in the stream of which it proceeds and which it produces. The standardized attribution of editorial descriptors allows to multiply the "grips" on voluminous corpuses of subjects : the material, become descriptible in time, wins in comprehensibility by the appeal to statistical inference. A macroscopic and diachronic seizure of the information is made possible, which invites to discover the structures, the dynamics and the striking events from which are made the media current events and, beyond, the public space. This method is presented by the results that it supplied to analyze ten years of sports information in the French Hertzian television news. For all that, the tool does not explain by itself, and supposes to multiply the questions, to resort to other knowledges to make understandable what it gives to read otherwise. This working shape so opens fewer questions than new ways to produce indicators allowing to answer it

Determinants of COVID-19 vaccine intention in a University population: a serial mediation approach

editorial reviewe

Factors influencing the adoption and participation rate of nursing homes staff in a saliva testing screening programme for COVID-19.

peer reviewedTesting strategies are crucial to prevent and control the spread of covid-19 but suffer from a lack of investment in understanding the human factors that influence their implementation. The aim of this study was to understand the factors that encourage participation and the level of engagement of nursing homes staff in a routine saliva testing programme for COVID-19 In December 2020, nursing homes (n = 571) in Wallonia (Belgium) were invited to participate in a saliva testing programme for their staff. The directors were questioned by telephone at the end of a 3-week pilot phase. 445 nursing homes took part in the evaluation questionnaire, of which 36(8%) answered that they chose not to participate in the testing programme. The average participation rate of nursing staff was 49(±25)%. Perception of the justification of the efforts required for testing and perception of practicability of the procedure were significantly associated with the adoption of the system by the nursing homes directors (OR(95%CI): 5.96(1.97-18.0), p = 0.0016); OR(95%CI): 5.64(1.94-16.4), p = 0.0015 respectively). Staff support, incentives and meetings increased the level of engagement in testing (p<0.05). While the adoption of the programme confirmed the acceptability of salivary testing as a means of screening, the participation rate confirmed the need for studies to understand the factors that encourage health care staff to take part. The results suggested rethinking strategies to consider staff engagement from a health promotion perspective

The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded

Observations of ocean-driven grounding-line retreat in the Amundsen Sea Embayment in Antarctica raise the question of an imminent collapse of the West Antarctic Ice Sheet. Here we analyse the committed evolution of Antarctic grounding lines under the present-day climate. To this aim, we first calibrate a sub-shelf melt parameterization, which is derived from an ocean box model, with observed and modelled melt sensitivities to ocean temperature changes, making it suitable for present-day simulations and future sea level projections. Using the new calibration, we run an ensemble of historical simulations from 1850 to 2015 with a state-of-the-art ice sheet model to create model instances of possible present-day ice sheet configurations. Then, we extend the simulations for another 10 000 years to investigate their evolution under constant present-day climate forcing and bathymetry. We test for reversibility of grounding-line movement in the case that large-scale retreat occurs. In the Amundsen Sea Embayment we find irreversible retreat of the Thwaites Glacier for all our parameter combinations and irreversible retreat of the Pine Island Glacier for some admissible parameter combinations. Importantly, an irreversible collapse in the Amundsen Sea Embayment sector is initiated at the earliest between 300 and 500 years in our simulations and is not inevitable yet – as also shown in our companion paper (Part 1, Hill et al., 2023). In other words, the region has not tipped yet. With the assumption of constant present-day climate, the collapse evolves on millennial timescales, with a maximum rate of 0.9 mm a−1 sea-level-equivalent ice volume loss. The contribution to sea level by 2300 is limited to 8 cm with a maximum rate of 0.4 mm a−1 sea-level-equivalent ice volume loss. Furthermore, when allowing ice shelves to regrow to their present geometry, we find that large-scale grounding-line retreat into marine basins upstream of the Filchner–Ronne Ice Shelf and the western Siple Coast is reversible. Other grounding lines remain close to their current positions in all configurations under present-day climate

University population-based prospective cohort study of SARS-CoV- 2 infection and immunity (SARSSURV-ULiège): a study protocol

peer reviewe

Asthma and COPD Are Not Risk Factors for ICU Stay and Death in Case of SARS-CoV2 Infection

BACKGROUND: Asthmatics and patients with chronic obstructive pulmonary disease (COPD) have more severe outcomes with viral infections than people without obstructive disease. OBJECTIVE: To evaluate if obstructive diseases are risk factors for intensive care unit (ICU) stay and death due to coronavirus disease 2019 (COVID19). METHODS: We collected data from the electronic medical record from 596 adult patients hospitalized in University Hospital of Liege between March 18 and April 17, 2020, for severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. We classified patients into 3 groups according to the underlying respiratory disease, present before the COVID19 pandemic. RESULTS: Among patients requiring hospitalization for COVID19, asthma and COPD accounted for 9.6% and 7.7%, respectively. The proportions of asthmatics, patients with COPD, and patients without obstructive airway disease hospitalized in the ICU were 17.5%, 19.6%, and 14%, respectively. One-third of patients with COPD died during hospitalization, whereas only 7.0% of asthmatics and 13.6% of patients without airway obstruction died due to SARS-CoV2. The multivariate analysis showed that asthma, COPD, inhaled corticosteroid treatment, and oral corticosteroid treatment were not independent risk factors for ICU admission or death. Male gender (odds ratio [OR]: 1.9; 95% confidence interval [CI]: 1.1-3.2) and obesity (OR: 8.5; 95% CI: 5.1-14.1) were predictors of ICU admission, whereas male gender (OR 1.9; 95% CI: 1.1-3.2), older age (OR: 1.9; 95% CI: 1.6-2.3), cardiopathy (OR: 1.8; 95% CI: 1.1-3.1), and immunosuppressive diseases (OR: 3.6; 95% CI: 1.5-8.4) were independent predictors of death. CONCLUSION: Asthma and COPD are not risk factors for ICU admission and death related to SARS-CoV2 infection