Mono inverter dual parallel PMSM - Structure and Control strategy

This paper presents a dual parallel connected PMSM fed by a single power inverter. Both motors have to respect the synchronism even if they have different load torque. The rotor position of the two motors that is to say the load applied on each motor are consequently permanently compared. The motor with the highest load is set as the master one and is auto-piloted. The other one which has the same applied voltage has the same electric pulsation and so the same speed rotation. The change of the master choice is done whereas the load applied on the machine is changing so that oscillations appear during this change. The steady state is however rapidly attained and the synchronism stays always observed

Mono inverter multi-parallel permanent magnet synchronous motor:structure and control strategy

This study presents a new and original Mono inverter multi-parallel permanent magnet synchronous motor (PMSM) system. To obtain the stability of such a system, each of the motor synchronisms should always be respected regardless of their load torque. In this case, only one motor, called ‘master motor’, will be self-piloted. If the chosen master motor is the one with the highest applied load torque, synchronism is respected for each of the motors. To find this machine, a solution that compares the rotor positions is thus developed. Experimental results are given for a system with two PMSM plugged in parallel. The proposed solution can, however, be applied to systems whatever the motor numbers; therefore additional simulations are provided for a four-PMSM system

Hydraulic Fracturing Mine Back Trials — Design Rationale and Project Status

Last year, a joint Mining and Oil & Gas industry consortium was established in Canada to conduct hydraulic fracturing (HF) tests accompanied by a mine-back of fractured regions to assess HF models and microseismic monitoring data during controlled experiments. Details about the displacement field, fracture aperture and extent, and micro-seismic parameters could then be verified and used as calibration data for modeling of HF processes in igneous and dense sedimentary rocks

On the injectivity of the global function of a cellular automaton in the hyperbolic plane (extended abstract)

In this paper, we look at the following question. We consider cellular automata in the hyperbolic plane, (see Margenstern, 2000, 2007 and Margenstern, Morita, 2001) and we consider the global function defined on all possible configurations. Is the injectivity of this function undecidable? The problem was answered positively in the case of the Euclidean plane by Jarkko Kari, in 1994. In the present paper, we show that the answer is also positive for the hyperbolic plane: the problem is undecidable

The use of video vignettes to measure health worker knowledge. Evidence from Burkina Faso

The quality of care is a crucial determinant of good health outcomes, but is difficult to measure. Survey vignettes are a standard approach to measuring medical knowledge among health care providers. Given that written vignettes or knowledge tests may be too removed from clinical practice, particularly where “learning by doing” may be an important form of training, we developed a new type of provider vignette. It uses videos presenting a patient visiting the clinic with maternal/early childhood symptoms. We tested these video vignettes with current and future (students) health professionals in Burkina Faso. Participants indicated that the cases used were interesting, understandable and common. Their performance was consistent with expectations. Participants with greater training (medical doctors vs. nurses and midwives) and experience (health professionals vs. students) performed better. The video vignettes can easily be embedded in computers, tablets and smart phones; they are a convenient tool to measure provider knowledge; and they are cost-effective instruction and testing tools

Echocardiographic Changes and Long-Term Clinical Outcomes in Pediatric Patients With Pulmonary Arterial Hypertension Treated With Bosentan for 72 Weeks:A Post-hoc Analysis From the FUTURE 3 Study

FormUlation of bosenTan in pUlmonary arterial hypeRtEnsion (FUTURE) 3 was a 24-week open-label, prospective, and randomized phase 3 study that assessed the pharmacokinetics of bosentan 2 mg/kg b.i.d. or t.i.d. in children with pulmonary arterial hypertension (PAH). We report findings from a post-hoc analysis that explored the prognostic value of echocardiographic changes during FUTURE 3 in relation to clinical outcomes observed during the 24-week core study and 48-week extension. Patients aged ≥3 months to <12 years (n = 64) received oral doses of bosentan 2 mg/kg b.i.d. or t.i.d. (1:1) for 24 weeks, after which they were eligible to enter the extension with continued bosentan administration. Echocardiographic evaluations were performed at baseline, Week 12, and 24 of the core study via central reading, and analyzed post-hoc for correlation with clinical outcomes (time to PAH worsening, time to death, and vital status). Sixty-four patients were randomized in the core study [median (IQR) age 3.8 (1.7–7.8) years]; and 58 patients (90.6%) entered the 48-week extension. Most of the patients (68.8%) were receiving ≥1 PAH medication at baseline. Echocardiographic changes during the core study were small but with high variability. There were statistically significant associations at Week 24 between worsening of the parameters, systolic left ventricular eccentricity index (LVEIS) and E/A ratio mitral valve flow, and the outcomes of time to death and time to PAH worsening. Additional studies that utilize simple and reproducible echocardiographic assessments are needed to confirm these findings and subsequently identify potential treatment goals in pediatric PAH

Hemodynamic and prognostic impact of the diastolic pulmonary arterial pressure in children with pulmonary arterial hypertension-a registry-based analysis

BACKGROUND: Diastolic pulmonary arterial pressure (dPAP) is regarded to be less sensitive to flow metrics as compared to mean PAP (mPAP), and was therefore proposed for the assessment of a precapillary component in patients with postcapillary pulmonary hypertension (PH). To analyze the diagnostic and prognostic impact of dPAP in patients with pure precapillary PH, we purposed to compare the correlation between dPAP and mPAP, as well as hemodynamically-derived calculations [ratio of PAP to systemic arterial pressure (PAP/SAP), pulmonary vascular resistance index (PVRI), transpulmonary gradient (TPG)], using both dPAP and mPAP, at rest and during acute vasoreactivity testing (AVT) in children with idiopathic or heritable pulmonary arterial hypertension (IPAH/HPAH). Furthermore, we aimed to assess the association of these metrics (at baseline and changes after AVT) with transplant-free survival. METHODS: We conducted a retrospective analysis of the TOPP (Tracking Outcomes and Practice in Pediatric Pulmonary Hypertension) registry including 246 IPAH/HPAH patients. Of these, 45 children (18.3%) died, and 13 (5.3%) received lung transplantation during the observation period. RESULTS: dPAP and mPAP-derived variables showed almost linear relationship. Higher mPAP/mSAP, and dPAP-/mPAP-derived PVRI at rest was associated with time to death/transplantation. At maximum AVT-response, the decrease of dPAP and mPAP, diastolic pulmonary gradient (DPG) and TPG, as well as dPAP/dSAP and mPAP/mSAP was associated with time to death/transplantation, showing higher significance than corresponding baseline values. Remarkably, no predictive value was found for PVRI-reduction during AVT, neither dPAP- nor mPAP-derived. CONCLUSIONS: There is a strong relationship between dPAP and mPAP-derived variables. According to our results, hemodynamics during AVT (irrespectively of dPAP- or mPAP-derived) may have more prognostic implications than resting hemodynamics in children with IPAH/HPAH, except for PVRI

Mobiliser et valoriser les données sur les sols forestiers. Compte rendu de l’atelier 4

Une meilleure connaissance des sols forestiers et l’amélioration des référentiels pour interpréter leur fonctionnement est une attente des forestiers comme des acteurs des politiques publiques. Lors de REGEFOR 2013, l’atelier “Mobiliser et valoriser les données sur les sols forestiers” a identifié une ressource importante et sous-exploitée de données au niveau des organismes de développement et des laboratoires de recherche. Des outils existent pour les rendre plus visibles et accessibles sur le réseau internet. Face à la dispersion et à la faible harmonisation des jeux de données, des chantiers importants sont à mettre en oeuvre pour favoriser leur exploitation (exemple : mise en base de données, production de métadonnées et de référentiels sémantiques communs, clarification des droits de propriété, protocoles d’échanges de données entre applications). Dans cette optique, l’atelier a aussi conduit à s’interroger sur les possibilités d’améliorer la coordination entre production et gestion de données, notamment en discutant les intérêts et limites d’une centralisation sous un même système d’information

Variability of Optical properties in perialpine lakes

The aim of the study is to describe how Inherent Optical Properties vary in perialpine lakes and to understand the impact of their vertical variability on the remote sensing signal