Industrial Problems Encountered in the Eddy Current Inspection of Steel

It is anticipated, that through exposing some of the problems encountered in industrial applications of eddy current technology, technical assistance may be generated through the theoretical community. The specific problem examined involves the development, storage\u27and utilization of calibration masters. Although the use of probes versus coils greatly reduces the number of calibration masters in that probes are not sensitive to overall geometry and mass variations, the eddy current response is influenced by near probe geometry variations. At present, an empirically derived algorithm is relied upon to characterize this phenomenon although it is hoped that an appropriate theoretical model will be developed. In addition to geometry, the non-linear permeability present in ferromagnetics, and the microstructural and compositional variations greatly increase the complexity of constructing such a model

Approaches for Improving Lumped Parameter Thermal Networks for Outer Rotor SPM Machines

This work is about the transient modeling of the thermal characteristics of outer rotor SPM machines by considering a lumped parameter thermal network based approach. The machine considered here poses particular challenges for the modeling, e.g., due to the semi-closed stator surrounded by a rotor bell that provides a speed-dependent cooling of the stator coils. Starting from a simpler basic network configuration, model extensions and refinements are presented and discussed. The subsequent parameter identification is done by means of an initial design of experiments based sampling, and a subsequent single-objective and also a multi-objective optimization of error functions for the components' temperatures. Analyzing the therefrom derived Pareto fronts and the consequent tradeoff regarding achievable minimum modeling errors for different system's components gives insights into where and how the modeling can be further improved. All the investigations are based on experimental results obtained through operating a particularly developed test setup

Industrial Problems Encountered in the Eddy Current Inspection of Steel

It is anticipated, that through exposing some of the problems encountered in industrial applications of eddy current technology, technical assistance may be generated through the theoretical community. The specific problem examined involves the development, storage'and utilization of calibration masters. Although the use of probes versus coils greatly reduces the number of calibration masters in that probes are not sensitive to overall geometry and mass variations, the eddy current response is influenced by near probe geometry variations. At present, an empirically derived algorithm is relied upon to characterize this phenomenon although it is hoped that an appropriate theoretical model will be developed. In addition to geometry, the non-linear permeability present in ferromagnetics, and the microstructural and compositional variations greatly increase the complexity of constructing such a model.</p

Industrial Problems Encountered in the Eddy Current Inspection of Steel

It is anticipated, that through exposing some of the problems encountered in industrial applications of eddy current technology, technical assistance may be generated through the theoretical community. The specific problem examined involves the development, storage'and utilization of calibration masters. Although the use of probes versus coils greatly reduces the number of calibration masters in that probes are not sensitive to overall geometry and mass variations, the eddy current response is influenced by near probe geometry variations. At present, an empirically derived algorithm is relied upon to characterize this phenomenon although it is hoped that an appropriate theoretical model will be developed. In addition to geometry, the non-linear permeability present in ferromagnetics, and the microstructural and compositional variations greatly increase the complexity of constructing such a model.</p

Effects of a High-Frequency Augmented Acoustic Environment on Parvalbumin Immunolabeling in the Anteroventral Cochlear Nucleus of BDA/2J and C57BL/6J Mice

Neurons in the anteroventral cochlear nucleus (AVCN) of DBA/2J (D2) and C57BL/6J (B6) mice were immunohistochemically labeled for the calcium binding protein parvalbumin (PV). Prior to this, mice were treated for 12 h nightly with a “high-frequency” augmented acoustic environment (HAAE: repetitive bursts of a 70 dB sound pressure level, half-octave noise band centered at 20 kHz). This was done during the period that hearing loss occurs: pre-weaning to 55 days in D2 mice and weaning to 9 months in B6 mice. After HAAE treatment in D2 mice, high-frequency hearing loss was ameliorated and fewer PV-labeled neurons were found in the AVCN compared to untreated controls. HAAE treatment in B6 mice exacerbated high-frequency hearing loss, yet the number of PV-labeled AVCN neurons in treated mice did not differ significantly from that of control mice. The findings suggest that HAAE treatment provides relief from physiological stress caused by deprivation of auditory input from the impaired cochlea