977 resultados para UAM, eVTOL, velivoli elettrici, tilt rotation, batterie
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The purpose of this study was to evaluate skeletal and dental stability in patients who had temporomandibular joint (TMJ) reconstruction and mandibular counterclockwise advancement using TMJ Concepts total join, prostheses (TMJ Concepts Inc. Ventura, CA) with maxillary osteotomies being performed at the same operation. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one surgeon (Wolford). Forty-seven females were studied; the average post-surgical follow-up was 40.6 months. Lateral cephalograms were analyzed to estimate surgical and post-surgical changes. During surgery, the occlusal plane angle decreased 14.9 +/- 8.0 degrees. The maxilla moved forward and upward. The posterior nasal spine moved downward and forward. The mandible advanced 7.9 +/- 3.5 mm at the lower incisor tips, 12.4 +/- 5.4 mm at Point B, 17.3 +/- 7.0 mm at menton, 18.4 +/- 8.5 mm at pogonion, and 11.0 +/- 5.3 mm at gonion. Vertically, the lower incisors moved upward -2.9 +/- 4.0 mm. At the longest follow-up post surgery, the maxilla showed minor horizontal changes while all mandibular measurements remained stable. TMJ reconstruction and mandibular advancement with TMJ Concepts total joint prosthesis in conjunction with maxillary osteotomies for counter-clockwise rotation of the rnaxillo-mandibular complex was a stable procedure for these patients at the longest follow-up.
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The objective of this paper was to analyse the activity of the longissimus dorsi and the iliocostalis lumborum muscles--components of the erector spinae muscle--in order to determine: their action potentials during the use of a plain and a tilt Roman table; 2) to compare the action potentials of the two muscles; 3) to verify if the action potential of these two muscles remain constant during the arc of movement--knee flexion and extension--divided into angle ranges, and 4) to compare the action potentials of the muscles in movements performed in a free manner and against resistance. Twenty-three young volunteers were studied electromyographically and each muscle received a needle electrode (Mise) and a surface electrode. The results showed that the table model did not determine any difference in the action potential of the muscles and that, on average, the iliocostalis lumborum muscle developed a slightly higher action potential than the longissimus dorsi muscle during the free flexion of knees on the plain table. In more than 70% of the cases, there was no difference between the action potential of the muscles over the various angle ranges of knee flexion and extension. Relatively higher action potentials were recorded during knee flexion and extension against resistance than during the same movements performed in a free manner. This shows that the paravertebral musculature responds better to an overload (8 kg) imposed on the knee flexor group, confirming the stabilizing role of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a Roman table.
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Pós-graduação em Fisioterapia - FCT
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This paper presents a mathematical model adapted from literature for the crop rotation problem with demand constraints (CRP-D). The main aim of the present work is to study metaheuristics and their performance in a real context. The proposed algorithms for solution of the CRP-D are a genetic algorithm, a simulated annealing and hybrid approaches: a genetic algorithm with simulated annealing and a genetic algorithm with local search algorithm. A new constructive heuristic was also developed to provide initial solutions for the metaheuristics. Computational experiments were performed using a real planting area and semi-randomly generated instances created by varying the number, positions and dimensions of the lots. The computational results showed that these algorithms determined good feasible solutions in a short computing time as compared with the time spent to get optimal solutions, thus proving their efficacy for dealing with this practical application of the CRP-D.
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Using theoretical arguments, a simple scaling law for the size of the intrinsic rotation observed in tokamaks in the absence of a momentum injection is found: The velocity generated in the core of a tokamak must be proportional to the ion temperature difference in the core divided by the plasma current, independent of the size of the device. The constant of proportionality is of the order of 10 km . s(-1) . MA . keV(-1). When the intrinsic rotation profile is hollow, i.e., it is countercurrent in the core of the tokamak and cocurrent in the edge, the scaling law presented in this Letter fits the data remarkably well for several tokamaks of vastly different size and heated by different mechanisms.
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Internal hip rotation (IHR) is the major cause of intoeing gait in patients with cerebral palsy (CP). Femoral derotation osteotomy (FDO) is the preferred treatment to correct excessive anteversion, however the condition may persist or recur postoperatively. Retrospective clinical and kinematic evaluation of 75 spastic diplegic CP patients was conducted for a mean duration of 22 months following proximal FDO. The patients were divided into two groups depending on the correction or persistence of IHR evident at kinematics after surgery. If corrected, mean patient follow-up was extended to 53 months. Outcomes were analyzed using Two Proportions Equality, Mann-Whitney and Wilcoxon tests. IHR persisted in 33.3% of cases at mean follow-up of 22 months and subtrochanteric femur osteotomy was more frequent in this group (p = 0.033). Thirty-five of the fifty-four patients with first-round gait correction were monitored during the extended follow-up. Those for whom IHR recurred (9.5%) had undergone FDO at a comparatively younger age. Patient gender, operations prior to or at the time of femoral osteotomy, topographic classification, GMFCS level, or the extent of preoperative clinical and kinematic abnormalities had no apparent influence on persistence or recurrence of abnormal gait. (C) 2012 Elsevier B.V. All rights reserved.
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We show that if f is a homeomorphism of the 2-torus isotopic to the identity and its lift (f) over tilde is transitive, or even if it is transitive outside the lift of the elliptic islands, then (0,0) is in the interior of the rotation set of (f) over tilde. This proves a particular case of Boyland's conjecture.
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We study magneto-optical properties of monolayer graphene by means of quantum field theory methods in the framework of the Dirac model. We reveal a good agreement between the Dirac model and a recent experiment on giant Faraday rotation in cyclotron resonance [23]. We also predict other regimes when the effects are well pronounced. The general dependence of the Faraday rotation and absorption on various parameters of samples is revealed both for suspended and epitaxial graphene.
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We evaluated the involvement of paraventricular nucleus (PVN) in the changes in mean arterial pressure (MAP) and heart rate (HR) during an orthostatic challenge (head up tilt, HUT). Adult male Wistar rats, instrumented with guide cannulas to PVN and artery and vein catheters were submitted to MAP and HR recording in conscious state and induction of HUT. The HUT induced an increase in MAP and HR and the pretreatment with prazosin and atenolol blocked these effects. After inhibition of neurotransmission with cobalt chloride (1 mM/100 nl) into the PVN the HR parameters did not change, however we observed a decrease in MAP during HUT. Our data suggest the involvement of PVN in the brain circuitry involved in cardiovascular adjustment during orthostatic challenges. (C) 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.
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Introduction: The aim of the present work was to evaluate the resistance to flexural fatigue of Reciproc R25 nickel-titanium files, 25 mm, used in continuous rotation motion or reciprocation motion, in dynamic assays device. Methods: Thirty-six Reciproc R25 files were divided into 2 groups (n = 18) according to kinematics applied, continuous rotary (group CR) and reciprocation motion (group RM). The files were submitted to dynamic assays device moved by an electric engine with 300 rpm of speed that permitted the reproduction of pecking motion. The files run on a ring's groove of temperate steel, simulating instrumentation of a curved root canal with 400 and 5 mm of curvature radius. The fracture of file was detected by sensor of device, and the time was marked. The data were analyzed statistically by Student's t test, with level of significance of 95%. Results: The instruments moved by reciprocating movement reached significantly higher numbers of cycles before fracture (mean, 1787.78 cycles) when compared with instruments moved by continuous rotary (mean, 816.39 cycles). Conclusions: The results showed that the reciprocation motion improves flexural fatigue resistance in nickel-titanium instrument Reciproc R25 when compared with continuous rotation movement. (J Endod 2012;38:684-687)
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Context. Spectrally resolved long-baseline optical/IR interferometry of rotating stars opens perspectives to investigate their fundamental parameters and the physical mechanisms that govern their interior, photosphere, and circumstellar envelope structures. Aims. Based on the signatures of stellar rotation on observed interferometric wavelength-differential phases, we aim to measure angular diameters, rotation velocities, and orientation of stellar rotation axes. Methods. We used the AMBER focal instrument at ESO-VLTI in its high-spectral resolution mode to record interferometric data on the fast rotator Achernar. Differential phases centered on the hydrogen Br gamma line (K band) were obtained during four almost consecutive nights with a continuous Earth-rotation synthesis during similar to 5h/night, corresponding to similar to 60 degrees position angle coverage per baseline. These observations were interpreted with our numerical code dedicated to long-baseline interferometry of rotating stars. Results. By fitting our model to Achernar's differential phases from AMBER, we could measure its equatorial radius R-eq = 11.6 +/- 0.3 R-circle dot, equatorial rotation velocity V-eq = 298 +/- 9 km s(-1), rotation axis inclination angle i = 101.5 +/- 5.2 degrees, and rotation axis position angle (from North to East) PA(rot) = 34.9 +/- 1.6 degrees. From these parameters and the stellar distance, the equatorial angular diameter circle divide(eq) of Achernar is found to be 2.45 +/- 0.09 mas, which is compatible with previous values derived from the commonly used visibility amplitude. In particular, circle divide(eq) and PA(rot) measured in this work with VLTI/AMBER are compatible with the values previously obtained with VLTI/VINCI. Conclusions. The present paper, based on real data, demonstrates the super-resolution potential of differential interferometry for measuring sizes, rotation velocities, and orientation of rotating stars in cases where visibility amplitudes are unavailable and/or when the star is partially or poorly resolved. In particular, we showed that differential phases allow the measurement of sizes up to similar to 4 times smaller than the diffraction-limited angular resolution of the interferometer.
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In this communication we report results from the application to the study of the rotation of the Moon of the creeping tide theory just proposed (Ferraz-Mello, Cel. Mech. Dyn. Astron., submitted. ArXiv astro-ph 1204.3957). The choice of the Moon for the first application of this new theory is motivated by the fact that the Moon is one of the best observed celestial bodies and the comparison of the theoretical predictions of the theory with observations i may validate the theory or point out the need of further improvements. Particularly, the tidal perturbations of the rotation of the Moon - the physical libration of the Moon - have been detected in the Lunar Laser Ranging measurements (Williams et al. JGR 106, 27933, 2001). The major difficulty in this application comes from the fact that tidal torques in a planet-satellite system are very sensitive to the distance between the two-bodies, which is strongly affected by Solar perturbations. In the case of the Moon, the main solar perturbations - the Evection and the Variation - are more important than most of the Keplerian oscillations, being smaller only than the first Keplerian harmonic (equation of the centre). Besides, two of the three components of the Moon's libration in longitude whose tidal contributions were determined by LLR are related to these perturbations. The results may allow us to determine the main parameter of a possible Moon's creeping tide. The preliminary results point to a relaxation factor (gamma) 2 to 4 times smaller than the one predicted from the often cited values of thr Moon's quality factor Q (between 30 and 40), and points to larger Q values.
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Be stars are known to be fast rotators. At high rotation rates a profound modification of the radiation field reaching the circumstellar environment is expected. The origin of this modification is the decrease of the effective gravity on stellar surface leading to the stellar geometrical flattening and the gravity darkening effect predicted by Von Zeipel. Making use of the radiative transfer code HDUST we discuss the consequences of such stellar rotation on the structure of Be star disks based on the Viscous Decretion Disk model. Observational predictions are also made, as SED, IR-excess and Hydrogen line profiles. The modified illumination of the circumstellar disk generates significant changes in these quantities. Ascertaining these changes is useful to set some of the fundamental parameters of the Be system and to unveil the role of stellar rotation over the stellar evolution.