1000 resultados para COLUMNAR PHASE
Resumo:
PhD in Sciences Specialty in Physics
Resumo:
This paper presents a model predictive current control applied to a proposed single-phase five-level active rectifier (FLAR). This current control strategy uses the discrete-time nature of the active rectifier to define its state in each sampling interval. Although the switching frequency is not constant, this current control strategy allows to follow the reference with low total harmonic distortion (THDF). The implementation of the active rectifier that was used to obtain the experimental results is described in detail along the paper, presenting the circuit topology, the principle of operation, the power theory, and the current control strategy. The experimental results confirm the robustness and good performance (with low current THDF and controlled output voltage) of the proposed single-phase FLAR operating with model predictive current control.
Resumo:
Tese de Doutoramento em Engenharia Civil.
Resumo:
Multiphase flows, hyperbolic model, Godunov method, nozzle flow, nonstrictly hyperbolic
Resumo:
Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2012
Resumo:
Background:In chronic Chagas disease (ChD), impairment of cardiac autonomic function bears prognostic implications. Phase‑rectification of RR-interval series isolates the sympathetic, acceleration phase (AC) and parasympathetic, deceleration phase (DC) influences on cardiac autonomic modulation.Objective:This study investigated heart rate variability (HRV) as a function of RR-interval to assess autonomic function in healthy and ChD subjects.Methods:Control (n = 20) and ChD (n = 20) groups were studied. All underwent 60-min head-up tilt table test under ECG recording. Histogram of RR-interval series was calculated, with 100 ms class, ranging from 600–1100 ms. In each class, mean RR-intervals (MNN) and root-mean-squared difference (RMSNN) of consecutive normal RR-intervals that suited a particular class were calculated. Average of all RMSNN values in each class was analyzed as function of MNN, in the whole series (RMSNNT), and in AC (RMSNNAC) and DC (RMSNNDC) phases. Slopes of linear regression lines were compared between groups using Student t-test. Correlation coefficients were tested before comparisons. RMSNN was log-transformed. (α < 0.05).Results:Correlation coefficient was significant in all regressions (p < 0.05). In the control group, RMSNNT, RMSNNAC, and RMSNNDCsignificantly increased linearly with MNN (p < 0.05). In ChD, only RMSNNAC showed significant increase as a function of MNN, whereas RMSNNT and RMSNNDC did not.Conclusion:HRV increases in proportion with the RR-interval in healthy subjects. This behavior is lost in ChD, particularly in the DC phase, indicating cardiac vagal incompetence.
Resumo:
Two-phase polycrystal, elasto-viscoplastic material model, heterogeneity, anisotropy, flow behaviour, crystallographic texture, strain field
Resumo:
Magdeburg, Univ., Fak. für Naturwiss., Diss., 2009
Resumo:
Magdeburg, Univ., Fak. für Mathematik, Diss., 2010
Resumo:
Magdeburg, Univ., Fak. für Mathematik, Diss., 2010
Resumo:
Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2010
Resumo:
Magdeburg, Univ., Med. Fak., Diss., 2011
Growth of semi-polar GaN on high index silicon (11h) substrates by metal organic vapor phase epitaxy
Resumo:
Magdeburg, Univ., Fak. für Naturwiss., Diss., 2014
Resumo:
Otto-von-Guericke-Universität Magdeburg, Fakultät für Maschinenbau, Univ., Dissertation, 2015
Resumo:
v.38:no.3(1950)