•A novel electromechanical structure is proposed for active ground motion isolation.•State of the art disturbance rejection at the subnanometer scale for heavy loads (up to 50kg) is achieved.•A 13dB ...attenuation of the ground motion is obtained between 12Hz and 100Hz.
Vibration isolation is a critical issue in various precision engineering fields. A new design of an active isolation system operating heavy loads (up to 50kg) is presented in this work. This system provides state of the art vibration isolation at the nanometer scale for magnets of a future particle accelerator and is more compact than other studies in this field. The choice of sensors and actuators, the mechanical design and the acquisition electronics are investigated in order to reject ground motion efficiently. A dynamic experimental characterization is performed. Based on the identified model, a specific controller, giving an attenuation between 10Hz and 100Hz was designed and experimentally qualified.
Multiferroics are materials with coexisting magnetic and ferroelectric orders, which show potential for electrically controlled spintronic devices. A common application of ferroelectrics is in ...electro-optical modulators exploiting their electric-field-dependent optical indices. The coupling of optical and magnetic degrees of freedom is attractive for designing multifunctional devices, but to date the electro-optical response of multiferroics has hardly been explored. Here we report a joint experimental and theoretical study of this effect in multiferroic BiFeO3 thin films. We confirm the large birefringence present in single crystals and determine the electro-optic coefficients r13 and r33. We present approaches to increase the obtained oefficients, for instance, by using tetragonal-like BiFeO3, and expand the potential of multiferroics to optical applications.
Sub-nanometer active seismic isolator control Balik, Gael; Caron, Bernard; Allibe, Julie ...
Journal of intelligent material systems and structures,
10/2013, Letnik:
24, Številka:
15
Journal Article
Recenzirano
Odprti dostop
Ambitious projects such as the design of the future Compact Linear Collider require challenging parameters and technologies. Stabilization of the Compact Linear Collider particle beam is one of these ...challenges. Ground motion is the main source of beam misalignment. Beam dynamics controls are, however, efficient only at low frequency (<4 Hz), due to the sampling of the beam at 50 Hz. Hence, ground motion mitigation techniques such as active stabilization are required. This article shows a dedicated prototype able to manage vibration at a sub-nanometer scale. The use of cutting edge sensor technology is, however, very challenging for control applications as they are usually used for measurement purposes. Limiting factors such as sensor dynamics and noise lead to a performance optimization problem. The current state of the art in ground motion measurement and ground motion mitigation techniques is pointed out and shows limits of the technologies. The proposed active device is then described, and a realistic model of the process has been established. A dedicated controller design combining feedforward and feedback techniques is presented, and theoretical results in terms of power spectral density of displacement are compared to real-time experimental results obtained with a rapid control prototyping tool.
Multiferroics are materials with coexisting magnetic and ferroelectric orders, which show potential for electrically controlled spintronic devices. A common application of ferroelectrics is in ...electro-optical modulators exploiting their electric-field-dependent optical indices. The coupling of optical and magnetic degrees of freedom is attractive for designing multifunctional devices, but to date the electro-optical response of multiferroics has hardly been explored. Here we report a joint experimental and theoretical study of this effect in multiferroic BiFeO sub(3) thin films. We confirm the large birefringence present in single crystals and determine the electro-optic coefficients r sub(13) and r sub(33). We present approaches to increase the obtained coefficients, for instance, by using tetragonal-like BiFeO sub(3), and expand the potential of multiferroics to optical applications.
Our primary objective was to validate the French version of the BFI-10, an ultra-short ten-item version of the Big Five Inventory (BFI; John et al., 1991), which allows for a reasonably accurate ...assessment of personality in circumstances in which more in-depth assessment is not possible. In order to reach a thorough evaluation of the external validity, we also aimed to examine the bandwidth of the BFI-10 scales with reference to the study by De Young, Quilty and Peterson (2007) who distinguished between two aspects in each of the Big Five: Assertiveness and Enthusiasm for Extraversion; Compassion and Politeness for Agreeability; Orderliness and Productiveness for Conscientiousness; Withdrawal and Volatility for Negative Emotionality, and finally Openness to Aesthetics and Openness to Ideas for Open-Mindedness. Our concern with regard to bandwidth was to examine whether the BFI-10 scales have strong enough correlations with both aspects of each domain.
Participants. Data from four samples were analysed: Sample 1 comprised 2499 undergraduate students (1654 women) who completed the full BFI in university classes; Sample 2 comprised 13,306 participants (8471 women) who filled out the BFI-10 ten items online via Internet; Sample 3 comprised 143 undergraduate students (115 women) who completed the full BFI twice with a two-week interval; Sample 4 comprised 360 undergraduate students (183 women) who filled out the BFI and NEO PI-R.
The French version of the Big Five Inventory is a 45-item inventory, which measures the five broader domains of personality. The ultrashort Ten-item Big Five Inventory (BFI-10) was developed simultaneously in German and English by Rammstedt and John (2007); it comprises five two-item scales measuring the big five domains. The Neuroticism-Extraversion-Openness Personality Inventory Revised (NEO PI-R; Costa et McCrae, 1992) is a 240-item questionnaire which assesses the big five domains and 30 lower-order facets, i.e. six facets per domain.
Factor structure and reliability of the five two-item scales were first investigated on samples 1 and 3. Confirmatory factor analyses (CFAs) were conducted on samples 1 and 2, and discriminant validity was assessed via comparison with the NEO PI-R (sample 4). In order to examine the bandwidth of the BFI-10 two-item scales, we studied their correlation not only with the NEO PI-R domains but also with the 30 facets.
The CFAs showed the good fit of the five-factor structure, with RMSEA=.077 (.072), CFI=.974 (.956), and SRMR=.029 (.027) in samples 1 and 2 respectively. Multigroup CFA conducted in groups 1 and 2 showed invariance across gender of factor loadings and item intercepts. Test-retest reliability was satisfactory with rs ranging from .68 (Open-Mindedness) to .86 (Extraversion and Negative Emotionality). The comparison of the two-item scales with the NEO PI-R scales showed high correlations not only with the NEO domain scales, but also with several facets: Four BFI-10 two-item scales (Extraversion, Conscientiousness, Negative Emotionality, and Open-Mindedness) were highly correlated with at least three of the six NEO facet scales in each domain. For Agreeableness, the magnitude of correlations was smaller, but the pattern of correlations was the same. All BFI-10 scales had at least moderate correlations with both aspects of each domain, with the exception of Negative Emotionality, which measured the NEO Withdrawal aspect better than Volatility.
The French version of the BFI-10 demonstrated the expected five-factor structure, satisfactory reliability, and broad bandwidth. It could be a valuable tool for the assessment of personality in circumstances in which it is not possible to use a longer and more in-depth instrument, especially when personality is not the main focus of research but one of the variables to be controlled.
BackgroundSwitching biologics is now common practice in severe eosinophilic asthma. After insufficient response to anti–IL-5 or 5 receptor (anti–IL-5/5R), the optimal switch between an anti–IL-4R mAb ...(interclass) or another anti–IL-5/5R drug (intraclass) remains unknown.ObjectiveWe sought to compare the effectiveness of these 2 strategies in asthma control in patients with severe eosinophilic asthma and insufficient response to an anti–IL-5/5R mAb.MethodsWe emulated a target randomized trial using observational data from the Recherche sur les AsthMes SEvèreS (RAMSES) cohort. Eligible patients were switched to an anti–IL-4R mAb or another anti–IL-5/5R drug after insufficient response to an anti–IL-5/5R mAb. The primary outcome was the change in Asthma Control Test score at 6 months.ResultsAmong the 2046 patients in the cohort, 151 were included in the study: 103 switched to an anti–IL-4R mAb and 48 to another anti–IL-5/5R. At 6 months, the difference in Asthma Control Test score improvement was not statistically significant (mean difference groups, 0.82 −0.47 to 2.10, P = .213). The interclass group exhibited greater cumulative reduction in oral corticosteroid dose (Pinter-intra, −1.05 g −1.76 to −0.34, P = .041). The interclass group had a better effect, although not significantly, on reducing exacerbations (Δinter-intra, −0.37 −0.77 to 0.02, P = .124) and increasing lung function (FEV1) (126.8 mL −12.7 to 266.4, P = .124).ConclusionsAfter anti–IL-5/5R mAb insufficient response, switching to dupilumab demonstrated similar improvement in Asthma Control Test scores compared with intraclass switching. However, it appeared more effective in reducing oral corticosteroid use. Larger studies are warranted to confirm these results.
La grippe est une infection respiratoire saisonnière responsable d’une morbidité importante, particulièrement chez les patients âgés et souffrant de maladies chroniques.
Nous avons évalué l’impact ...des épidémies de grippe 2017–2018 et 2018–2019 sur les patients de notre centre d’hémodialyse. Durant la période épidémique 2017–2018, les patients chez qui une grippe était suspectée ont bénéficié d’un Test Rapide d’Orientation Diagnostique (Xpert® Xpress Flu/RSV) associé à une PCR en cas de test positif ou de forte suspicion clinique. En 2018-2019, une PCR a été réalisée systématiquement en première intention. Les données cliniques et biologiques ont été recueillies rétrospectivement.
La grippe saisonnière a touché 5,5 % des patients du centre (13/235) en 2017–2018 avec 41,7 % de grippe A et 58,3 % de grippe B, et 7,1 % des patients (18/255) en 2018–2019 avec 100 % de grippe A. Les patients concernés avaient un âge moyen de 71,5 ans. Un total de 45,1 % ont été hospitalisés, avec une durée moyenne de séjour de 15,1±10,3jours, 32,3 % étaient oxygénorequérants. Deux patients (6,45 %) ont nécessité une prise en charge en réanimation et sont décédés. 45,2 % ont été traités par oseltamivir et 54,8 % ont reçu une antibiothérapie. La présentation clinique et biologique des patients avec une recherche de grippe positive était similaire aux patients négatifs, à l’exception d’une fièvre plus élevée (39,0±0,6°C contre 38,3±0,4°C ; p<0,05) et d’une oxygénorequérance plus fréquente (32,3 % contre 8,3 % ; p<0,05). La couverture vaccinale était de 35,5 % chez les patients atteints contre 22,7 % en moyenne dans notre centre de dialyse (ns).
La grippe a été responsable d’une morbi-mortalité significative chez nos patients hémodialysés. La présentation clinique le plus souvent atypique et la vaccination partiellement efficace incite au dépistage et au traitement précoce devant tout symptôme évocateur en période épidémique.
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