Digital transient torque measurement for rotating or linear AC machines (real time measurement)

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Loudspeakers inherit their directivity from their geometry and dimensions. Enclosed loudspeakers are omnidirectional in the low frequency range, but their directivity depends on frequency for wavelengths smaller than the radiator size, precluding the directional control over the whole bandwidth. Loudspeakers pairs allow achieving simultaneously monopolar (in-phase) and dipolar (out-of-phase) sources, thus allowing directivity control. However, they are limited by their bulkiness, preventing extending contro

The Solid State Transformer (SST) has been gaining tremendous attention, both in academia and industry, promising extraordinary (often hyped) power conversion performances, well beyond the current state of the art converters. Despite well-evidenced efforts, SST as a technology is still somewhat struggling to gain commercial traction and find its place on the market.

Localized corrosion in metallic materials is a stochastic phenomenon that causes irreversible structural failure. Its initiation, which occurs at the solid-liquid interface on the nanometer scale, remains difficult to predict and challenging to characterize. Herein, we describe an experimental platform that exploits advances in electrochemical liquid-phase scanning and transmission electron microscopy (LPSEM and LPTEM) to study pitting corrosion of thin-film pure aluminum in a saline environment in real tim

Visual appearance of objects comes from the interpretation by the human visual system of a light signal issued from the objects. Describing or predicting appearance is therefore a question of light and requires notions about light propagation and measurement. In this paper, we introduce basic laws of optics, the science of light, and radiometry, the science of light measurement, in the context of colored surfaces. We address light spectrum and illuminants, polarization, notions of reflectance and transmitta

This paper presents an automated test bench, based on a rigorous measurement procedure, used to fully characterize vibration energy harvesters including determination of the resonance frequency, impedance, optimal load, and output power as a function of both frequency and acceleration. The potential of this method and the performance of the automated test bench allows systematic data acquisition which is essential for a good comparison of all harvesters. A dedicated automation circuit was designed and fabri

Energy saving becomes more and more important. Therefore different improvements have been made in motor design, electronic devices and software in order to increase the overall efficiency of electronic motor drives. Permanent Magnet Synchronous Motors (PMSM) are widely used in different applications requiring high precision and speed control. Using an inverter stage to create the 3-phase sinusoidal waveform currents causes losses in the switches. The aim of this project is to investigate a possible switchin

This paper introduces a promising technique for detecting the rotor position of a PM motor at standstill. The technique is based on the B-H hysteresis characteristics of the stator iron. Depending on the rotor position, a very particular phenomenon related to B-H hysteresis appears. This phenomenon permits to detect the electrical position of a non-salient rotor.

Piezoelectric ultrasonic motors are superior to electromagnetic micro motors, because their efficiency remains theoretically constant during miniaturization. However, the still relatively recent technology has a considerable unexploited optimisation potential. Numerical structural analysis by the means of the finite element method (FEM) is a common approach for dimensioning piezoelectric motors. Consequently, there is a need for efficient optimisation procedures adapted to the FEM simulation.We developed a

This article presents the analysis of the power efficiency of the inductive links used for remote powering of the biomedical implants by considering the effect of the load resistance on the efficiency. The optimum load condition for the inductive links is calculated from the analysis and the coils are optimized accordingly. A remote powering link topology with a matching network between the inductive link and the rectifier has been proposed to operate the inductive link near its optimum load condition to im

In this paper we propose a new approach to automatic human face detection which employs anisotropic Gaussian filters as local image descriptors. We then show how the paradigm of classifier combination can be used for building a face detector that outperforms the current state of the art systems, while remaining fast enough for being used in real time systems. We report a number of results on some reference datasets and we use an unbiased method for comparing the detectors.

In this paper an objective metric to measure the perceptual quality of watermarked 3D meshes is presented. The metric, which is based on a black-box approach, relies on the measurement of the roughness of 3D meshes before and after the insertion of the watermark. To calibrate the metric and to validate it, a set of psychovisual experiments has been carried out. Due to the lack of prior work in this field, a new methodology for the subjective evaluation of the quality of watermarked 3D objects is introduced.

The control of the current, position and shape of an elongated cross-section tokamak plasma is complicated by the instability of the plasma vertical position. In this case the control becomes a significant problem when saturation of the power supplies is considered. Current saturation is relatively benign due to the integrating nature of the tokamak, resulting in a reasonable time horizon for strategically handling this problem. On the other hand, voltage saturation is produced by the feedback controller it

For describing the E-J relation of high-Tc superconductors (HTS) in power applications, where the applied current I is generally limited by Ic, the critical state model, a piecewise linear generalization, or a simple power-law of the type E=Ec(J/Jc)^n are most often used. The power-law cannot be used for modelling the E-J relation with I>>I_c due to the unbound exponential increase of the electric field for currents above Ic, while in reality the non-linear HTS resistivity is limited by its normal state val

The internal electric field in multilayer organic light-emitting diodes (OLEDs) is investigated using a combination of experimental measurement and numerical device modeling. This approach results in a detailed understanding of the functioning of a multilayer OLED. The method is applied to a standard device structure that has received broad attention in literature. From the experimental part, we have demonstrated that the average electric field inside the hole transport layer is larger than or equal to the

An ac loss experiment on two Nb3Sn cable-in-conduit conductors (CICCs) is carried out in the SULTAN test facility using both magnetization and calorimetric methods to cover a broad range of frequency, from 0.03 Hz to 6 Hz. Loss curves are measured before and after cyclic loading of the samples. The discussion of the results aims to solve the discrepancy observed between the large loss results in the ITER CSMC coil and the low loss observed in former short sample test. The impact of cyclic load on the loss b

For many years, calorimetry has been recognized as a powerful and universal tool for monitoring chem. and biol. processes. A lab.-scale reaction calorimeter (RC1, Mettler-Toledo), initially developed for chem. reaction studies with a sensitivity of 100-150 mW/l, has been improved to enable the monitoring of very low heat prodn. rates (

Pyrochlore free 0.9Pb(Mg1/3Nb2/3)O-3-0.1PbTiO(3) thin films were prepared from alkoxide-based solution precursors. Preferential (111) crystallographic orientation was obtained on TiO2/Pt/TiO2/SiO2/Si substrates by spin coating. Dielectric, electrostrictive, and piezoelectric properties of the films were characterized in detail. Films show relaxor-like behavior, but with dielectric permittivity which is low (around 4300 at peak and at 340 Hz with E-ac=1.6x10(6) V/m) compared to bulk ceramics and single cryst

In recent years, power variations and energy criteria have been the main motivations for developing regenerative drive converters for elevators [1]. A more performant solution for power-smoothing can be easily found by using a supercapacitor based storage device, connected to the intermediary circuit of a Variable Speed Drive system. In this paper, power and energy considerations are made for the design of the storage tank and regarding the maximum power demand from the feeding network. For the power-conver

The oxidn. of benzoic acid has been performed on boron doped diamond electrodes supported on silicon substrate. The voltammetric behavior has shown that during the oxidn. of benzoic acid at 2.7V (RHE), a polymeric film is formed on the electrode surface that is oxidized at higher potential values. Bulk electrolysis of benzoic acid in HClO4, under galvanostatic conditions results in an instantaneous current efficiency(ICE) near 100% at low current densities and high benzoic acid concns. Electrolysis at high

When we achiev a good performance of the field-oriented vector control system, it is necessary to detect the speed and flux of the motor. Usually it is hard to implemment these sensors. Then the sensor-less contro-system techniques using the observer instead of the sensor are being applied. On the other hand, there are also a lot of applications of the linear induction motor into the transportation system because of its simple structure. In these applications, it is required to implement the speed or positi

Digital transient torque measurement for rotating or linear AC machines (real time measurement)

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Achieving Broadband Directivity Control with Dual Corona Discharge Transducers

Inside the Solid State Transformers

Pit Morphology, Dissolution Kinetics, and Gas Generation Monitored in Real Time during Localized Anodic Aluminum Corrosion

Fundamentals of Optics and Radiometry for Color Reproduction

An Automatic Test Bench for Complete Characterization of Vibration-Energy Harvesters

Method for a switching loss reduction in PM drives

Exploitation of a new iron B-H phenomenon for the standstill position detection of PM motors

Finite element method based design and optimisation methodology for piezoelectric ultrasonic motors

Load optimization of an inductive power link for remote powering of biomedical implants

Anisotropic Gaussian Filters for Face Class Modeling

Objective Evaluation of the Perceptual Quality of 3D Watermarking

Enhancing the control of tokamaks via a continuous nonlinear control law

Modelling the E-J relation of high-Tc superconductors in an arbitrary current range

Internal electric field and charge distribution in multilayer organic light-emitting diodes

Coupling currents loss in Nb3Sn cable-in-conduit conductors

Quantitative calorimetric investigation of fed-batch cultures of Bacillus sphaericus 1593M

Dielectric and electromechanical properties of ferroelectric-relaxor 0.9 Pb(Mg1/3Nb2/3)O-3-0.1PbTiO(3) thin films

A Supercapacitor-Based Energy Storage System for Elevators with Soft Commutated Interface

Electrochemical oxidation of benzoic acid on boron doped diamond electrodes

Sensor-less control of linear induction motor considering its asymmetric parameters