Architecture et gestion d'un réseau continu maillé haute-tension pour l'aéronautique

L'objectif de réduction de la consommation en kérosène des avions passant par une plus grande efficacité des systèmes, la distribution électrique devient un moyen privilégié pour satisfaire les besoins. Dans ce cadre, la notion d'avion « plus électrique » implique de revoir les systèmes de distribution et d'étudier, notamment, le passage en haute tension continue (HVDC). Une description générale des systèmes embarqués sur les avions civils est donnée dans ce manuscrit ainsi qu'une description des avantages et inconvénients des différents vecteurs énergétiques permettant de mieux situer les gains envisageables lors du passage à l'électrification des systèmes. Cependant, la mise en place de la distribution HVDC peut entraîner de nouveaux problèmes, notamment de qualité et/ou d'instabilité. Afin de palier ces problèmes, une architecture est proposée dans laquelle les équipements sont reliés entre eux par des coeurs de distribution eux-mêmes liés par des organes de transferts de puissances pouvant maîtriser ces transferts : on parle alors de réseau maillé. Pour pouvoir réaliser ces transferts, deux types d'équipements électroniques de puissance sont proposés : le DCPFC (Direct Current Power Flow Controler) et le MAPFC (Mixed function for Actuation and Power Flow Control). Ces équipements imposent une gestion énergétique spécifique : il faut déterminer les modes de fonctionnement des équipements ainsi que les références des puissances à transférer. Pour cela, une modélisation du réseau sous forme de graphe est effectuée, ceci se traduisant par un algorithme générique permettant de déterminer les équations structurelles du réseau ainsi que deux algorithmes servant à contrôler des grandeurs distinctes : Les grandeurs discrètes sont contrôlées par un système expert détenant un ensemble de règles de fonctionnement ; Les grandeurs continues sont gérées par un algorithme de recherche de flot dans un graphe. Après la mise en place en simulation de l'ensemble du réseau maillé, un banc d'essai expérimental valide les principes décrits théoriquement et permet l'étude de différentes gestions énergétiques (tout autant qu'il permet de tester un équipement seul ou le réseau dans une configuration non-maillée). Finalement, une exploitation des concepts sur un réseau répondant aux normes aéronautiques est développée. Ceci posant notamment des problèmes aux niveaux de la conception des équipements mais également sur l'architecture actuelle des réseaux électriques (connexion du neutre des générateurs, protection des personnes, compatibilité électromagnétique, etc.). ABSTRACT : As the aircraft fuel consumption needs more efficient systems, electrical distribution becomes a favoured way in satisfying those needs. In this context, the “more electrical aircraft” notion implies to deeply refund distribution means. High Voltage Direct Current - HVDC - distribution helps in going this way. A general description of civil aircraft embedded systems is given in this document. Advantages and drawbacks of energetic vectors are described too, allowing a better comprehension of possible improvements due to system electrification. Therefore, the HVDC deployment can lead to new problems, particularly in quality and stability domains. In order to take into account these problems, we propose a new distribution architecture in which equipments are interconnected through power distribution centres, which ones are interconnected through power flow controller equipments. This new architecture is described as a meshed distribution network. Two kinds of equipment are proposed to control the electrical power flow: DCPFC - for Direct Current Power Flow Controller - and MAPFC - Mixed function for Actuation Power Flow Control. As a result, a specific power management is needed. Equipment operating modes and power to transfer references have to be determined. In a first step, a graph based modelling of the electrical network is done, resulting in a generic algorithm which permits to determine network structural equations. In a second step, two algorithms control the network: - Discrete quantities are regulated by an expert system based on a rule set; - Continuous quantities are managed through a flow research algorithm based on the graph modelling; The validation of these concepts is realised through electrical simulations of the whole meshed network. Then, an experimental test bench validates the theoretical principles and allows the operation of equipments and meshed network in multiple configurations. Finally, concepts are extrapolated in an electrical network respecting aeronautic constraints. Those constraints are highlighted at equipment level and network level

How patients perceive the therapeutic communications skills of their general practitioners, and how that perception affects adherence: use of the TCom-skill GP scale in a specific geographical area

To study: (1) the structure and test-retest reliability of a measure of how patients perceive the therapeutic communications skills of their general practitioners (TCom-skill GP), and (2) the associations of that scale with socio-demographic and health-related characteristics, and adherence. Methods: A total of 393 people who lived in the same geographic area and invited to attend a preventive medical centre for a check up were asked to complete a self-administered questionnaire concerning TCom-skill GP (15 items), socio-demographic and health-related characteristics, and to answer two questions on perceived adherence. Results: The average age of respondents was 46.8 years (SD 14), and 50.4% were men. The TCom-skill GP score was one-dimensional, had high internal coherence (Cronbach α 0.92), and good test-retest reliability (intra-class correlation coefficient 0.74). The overall score was positively related to increasing age. Respondents aged 60+ were more likely to be adherent. The higher the score, the higher the probability of adherence. Multivariate analysis showed that the TCom-skill score was associated with advancing age and the number of consultations with the GP during the previous 3 months, but not with gender, living alone, being employed, job category or educational level. Multivariate analysis also showed that adherence was associated with TCom-skill GP score which concealed the association between adherence and advancing age observed in univariate analysis. Conclusion: The TCom-skill GP scale probably has value in assessing the quality of doctor-patient relationships and therapeutic communications. The psychometric properties of the TCom-skill GP scale were appropriate for its use in this context. Adherence related to the TCom-skill GP and the latter related to the age of patients and the number of their previous consultations. The TCom-skill GP scale may be a useful way to assess, in a specific geographical location, the impact of medical professional training on therapeutic communication

A Mixed Function for Actuation and Power Flow Control in Embedded Networks

This paper proposes an original association of a three-phase electrical machine, here a permanent-magnet synchronous motor (PMSM) fed by two inverters, which allows to combine two different functions: actuation and power transfers between two DC buses which supply the inverters. The considered AC machine is an open-end winding PMSM allowing the connection of two inverters supplied by two different DC buses inside a high-voltage DC network. The control part of this system uses the Park’s theory not only to drive the actuator in motor as well as in generator operating modes but also to control the energy transfer from one DC bus to the other. The concept, mixing two main functions, is named MAPFC, for “mixed actuation and power flow control.” It has been particularly developed for aeronautic applications even if other application fields could be targeted. The complete modeling and operation of the system are described. Simulation studies and experimental results are presented, which are validating the proposed concepts

The relationship between traits optimism and anxiety and health-related quality of life in patients hospitalized for chronic diseases: data from the SATISQOL study.

International audienceBACKGROUND: The impact of psychological factors is often taken into account in the evaluation of quality of life. However, the effect of optimism and trait anxiety remains controversial and they are rarely studied simultaneously. We aimed to study the effect of this factor on health-related quality of life (HRQOL) of patients after a hospitalization in relation with their chronic disease. METHODS: Using cross-sectional data from the SATISQOL cohort, we conducted a multicentric study, including patients hospitalized for an intervention in connection with their chronic disease. Six months after hospitalization, patients completed a generic HRQOL questionnaire (SF-36), and the STAI and LOT-R questionnaires to evaluate optimism and trait anxiety. We studied the effect of each trait on HRQOL separately, and simultaneously, taking account of their interaction in 3 models, using an ANOVA. RESULTS: In this study, 1529 patients were included in three participating hospitals and there existed wide diversity in the chronic diseases in our population. The HRQOL score increased for all dimensions of SF36 between 15,8 and 44,5 when the level of anxiety decreased (p < 0.0001) for the model 1, assessing the effect of anxiety on HRQOL and increased for all dimensions of SF36 between 3.1 and 12.7 with increasing level of optimism (< 0.0001) in the model 2 assessing the effect of optimism on HRQOL. In the model 3, assessing the effect of both anxiety and optimism on HRQOL, and their interaction, the HRQOL score for all dimensions of the SF36 increased when the level of anxiety decreased (p < 0.0001). It increased with increasing level of optimism (p < 0.006) in the model for all dimensions of SF36 except the Role Physical dimension. In this model, interaction between anxiety and optimism was significant for the Social Functioning dimension (p = 0.0021). CONCLUSIONS: Optimism and trait anxiety appeared to be significantly correlated with HRQOL. Furthermore, an interaction existed between the trait anxiety and optimism for some dimensions of SF36. Contrary to optimism, it seems essential to evaluate trait anxiety in future studies about HRQOL, since it could represent a confounding factor

Quality of life after the initial treatments of non-small cell lung cancer: a persistent predictor for patients' survival.

International audienceBACKGROUND: Health-related quality of life (HRQoL) before treatment may predict survival of patients with non-small-cell lung cancer (NSCLC). We investigated the predictive role of HRQoL after the initial treatments, on the survival of these patients. METHODS: A prospective multi-center study conducted in northeastern France. The SF-36 and European Organization for Research and Treatment of Cancer, Quality of Life Questionnaire Core-30 (QLQ C-30) were mailed to patients 3 months after the end of the diagnostic process. High scores for functioning dimensions on both questionnaires indicated better QoL, and low scores for symptom dimensions on the QLQ C-30 indicated few symptoms. Cox regression modeling was used to identify predictive factors of survival. RESULTS: In total, 230 (63.5%) patients responded to the SF-36 and QLQ C-30. Before completing the questionnaires, almost 60% of patients had undergone some chemotherapy, about 10% underwent radio/chemotherapy or both and more than 30% underwent surgery or surgery plus chemo/radiotherapy.On SF-36, the highest mean score was for social functioning dimension (55.5 ± 28), and the lowest was for the physical role dimension (17.9 ± 32.2).On QLQ C-30, for the functioning dimensions, the highest mean score was for cognitive functioning (74.6 ± 25.9) and the lowest was for role functioning (47.2 ± 34.1). For symptom dimensions, the lowest score was for diarrhoea (11.5 ± 24.2) and the highest was for fatigue (59.7 ± 27.7).On multivariate analysis, high bodily pain, social functioning and general health scores (SF-36) were associated with a lower risk of death (hazard ratio 0.580; 95% confidence interval [0.400-0.840], p = 0.004; HR 0.652 [0.455-0.935], p < 0.02; HR 0.625 [0.437-0.895] respectively). Better general QoL on QLQ C-30 was related to lower risk of death (HR 0.689 [0.501-0.946], p = 0.02). CONCLUSION: Adding to previous knowledge about factors that may influence patients QoL, this study shows a persisting relationship between better perceived health in HRQoL after the initial treatment of NSCLC and better survival

predictors of flares in infliximab treated children with inflammatory bowel disease

Abstract One third of pediatric IBD patients who initially respond to infliximab (IFX) lose that response over time. This retrospective study, including 62 children treated with IFX from 2004 to 2017, aimed to identify factors associated with clinical flare. Ulcerative colitis, extreme body mass index, and lowest IFX trough levels were associated with clinical flare in the whole population. In Crohn disease patients, perianal disease was pejorative, while location proximal to ligament of Treitz was protective. Underweight patients probably correspond to the most severe cases who are more likely to relapse, with hypoalbuminemia responsible for lower systemic IFX availability. Obesity probably induces higher IFX clearance

Suppression of High-p_T Neutral Pion Production in Central Pb+Pb Collisions at sqrt{s_NN} = 17.3 GeV Relative to p+C and p+Pb Collisions

Neutral pion transverse momentum spectra were measured in p+C and p+Pb collisions at sqrt{s_NN} = 17.4 GeV at mid-rapidity 2.3 < eta_lab < 3.0 over the range 0.7< p_T < 3.5 GeV/c. The spectra are compared to pi0 spectra measured in Pb+Pb collisions at sqrt{s_NN} = 17.3 GeV in the same experiment. For a wide range of Pb+Pb centralities (N_part < 300) the yield of pi0's with p_T > 2 GeV/c is larger than or consistent with the p+C or p+Pb yields scaled with the number of nucleon-nucleon collisions (N_coll), while for central Pb+Pb collisions with N_part > 350 the pi0 yield is suppressed.Comment: 5 pages, 4 figure

Satisfaction with care after total hip or knee replacement predicts self-perceived health status after surgery

<p>Abstract</p> <p>Background</p> <p>Inpatient satisfaction with care is a standard indicator of the quality of care delivered during hospitalization. Total hip and knee replacement (THR/TKR) for osteoarthritis (OA) are among the most successful orthopaedic interventions having a positive impact on health-related quality of life (HRQoL). The aim was to evaluate the effect of satisfaction shortly after hospital discharge on 1-month, 6-month and 1-year Medical Outcomes Study 36-item Short Form (SF-36) scores for OA patients after THR and TKR, controlling for patient characteristics, clinical presentation and preoperative SF-36 scores.</p> <p>Methods</p> <p>A multicenter prospective cohort study recruited 231 patients with OA scheduled to receive THR or TKR. Satisfaction was assessed by the Patients Judgment of Hospital Quality (PJHQ) questionnaire and HRQoL by the SF-36 questionnaire. Linear models for repeated measures assessed the relation between satisfaction (scores were dichotomized) and postoperative SF-36 scores.</p> <p>Results</p> <p>Of 231 participants, 189 were followed up 12 months after discharge (mean age 69 SD = 8; 42.6% male). The mean length of hospital stay was 13.5 (SD = 4) days. After adjustment for preoperative SF-36 scores, sociodemographic and clinical patient characteristics, satisfied patients (PJHQ score > 70) had higher SF-36 scores 1 year after surgery than did less-satisfied patients. Admission, medical care, and nursing and daily care scores mainly predicted bodily pain, mental health, social functioning, vitality and general health scores of the SF-36.</p> <p>Conclusion</p> <p>Besides being a quality-of-care indicator, immediate postoperative patient satisfaction with care may bring a new insight into clinical practice, as a predictor of self-perceived health status after surgery.</p

Determinants of patient satisfaction in ambulatory oncology: a cross sectional study based on the OUT-PATSAT35 questionnaire

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to identify factors associated with satisfaction with care in cancer patients undergoing ambulatory treatment. We investigated associations between patients' baseline clinical and socio-demographic characteristics, as well as self-reported quality of life, and satisfaction with care.</p> <p>Methods</p> <p>Patients undergoing ambulatory chemotherapy or radiotherapy in 2 centres in France were invited, at the beginning of their treatment, to complete the OUT-PATSAT35, a 35 item and 13 scale questionnaire evaluating perception of doctors, nurses and aspects of care organisation. Additionally, for each patient, socio-demographic variables, clinical characteristics and self-reported quality of life using the EORTC QLQ-C30 questionnaire were recorded.</p> <p>Results</p> <p>Among 692 patients included between January 2005 and December 2006, only 6 were non-responders. By multivariate analysis, poor perceived global health strongly predicted dissatisfaction with care (<it>p </it>< 0.0001). Patients treated by radiotherapy (vs patients treated by chemotherapy) reported lower levels of satisfaction with doctors' technical and interpersonal skills, information provided by caregivers, and waiting times. Patients with primary head and neck cancer (vs other localisations), and those living alone were less satisfied with information provided by doctors, and younger patients (< 55 years) were less satisfied with doctors' availability.</p> <p>Conclusions</p> <p>A number of clinical of socio-demographic factors were significantly associated with different scales of the satisfaction questionnaire. However, the main determinant was the patient's global health status, underlining the importance of measuring and adjusting for self-perceived health status when evaluating satisfaction. Further analyses are currently ongoing to determine the responsiveness of the OUT-PATSAT35 questionnaire to changes over time.</p

Observation of direct-photon collective flow in sqrt(s_NN)=200 GeV Au+Au collisions

The second Fourier component v_2 of the azimuthal anisotropy with respect to the reaction plane was measured for direct photons at midrapidity and transverse momentum (p_T) of 1--13 GeV/c in Au+Au collisions at sqr(s_NN)=200 GeV. Previous measurements of this quantity for hadrons with p_T < 6 GeV/c indicate that the medium behaves like a nearly perfect fluid, while for p_T > 6 GeV/c a reduced anisotropy is interpreted in terms of a path-length dependence for parton energy loss. In this measurement with the PHENIX detector at the Relativistic Heavy Ion Collider we find that for p_T > 4 GeV/c the anisotropy for direct photons is consistent with zero, as expected if the dominant source of direct photons is initial hard scattering. However, in the p_T < 4 GeV/c region dominated by thermal photons, we find a substantial direct photon v_2 comparable to that of hadrons, whereas model calculations for thermal photons in this kinematic region significantly underpredict the observed v_2.Comment: 384 authors, 6 pages, 3 figures, and 1 table. Submitted to Phys. Rev. Lett. v2 has minor changes to match the submission version. Plain text data tables for the points plotted in the figures are publicly available at http://www.phenix.bnl.gov/phenix/WWW/info/data/ppg126_data.htm