Thermal and electric effects

Author(s):  
Enrico Gnecco ◽  
Ernst Meyer
Keyword(s):  
Author(s):  
John Silcox

Several aspects of magnetic and electric effects in electron microscope images are of interest and will be discussed here. Clearly electrons are deflected by magnetic and electric fields and can give rise to image detail. We will review situations in ferromagnetic films in which magnetic image effects are the predominant ones, others in which the magnetic effects give rise to rather subtle changes in diffraction contrast, cases of contrast at specimen edges due to leakage fields in both ferromagnets and superconductors and some effects due to electric fields in insulators.


1967 ◽  
Vol 72 (22) ◽  
pp. 5752-5753
Author(s):  
R. B. Harvey ◽  
J. L. Heckscher ◽  
E. A. Lewis
Keyword(s):  

1968 ◽  
Vol 57 (2) ◽  
pp. 419-426 ◽  
Author(s):  
E. Grossetti ◽  
G. Brescia
Keyword(s):  

2021 ◽  
Vol 338 ◽  
pp. 108993
Author(s):  
Wagner Augusto Müller ◽  
Maria Valentina Antúnes Pasin ◽  
Júlia Ribeiro Sarkis ◽  
Ligia Damasceno Ferreira Marczak

2020 ◽  
Vol 10 (14) ◽  
pp. 4927 ◽  
Author(s):  
Martin Angerer ◽  
Michael Zapf ◽  
Benjamin Leyrer ◽  
Nicole V. Ruiter

For breast cancer imaging, ultrasound computer tomography (USCT) is an emerging technology. To improve the image quality of our full 3-D system, a new transducer array system (TAS) design was previously proposed. This work presents a manufacturing approach which realises this new design. To monitor the transducer quality during production, the electro-mechanical impedance (EMI) was measured initially and after each assembly step. To evaluate the measured responses, an extended Krimholtz–Leedom–Matthaei (KLM) transducer model was used. The model aids in interpreting the measured responses and presents a useful tool for evaluating parasitic electric effects and attenuation at resonance. For quality control, the phase angle at thickness resonance φ t was found to be the most specific EMI property. It can be used to verify the functionality of the piezocomposites and allows reliable detection of faults in the acoustic backing. Evaluating the final response of 68 transducers showed 5% variance of the series resonance frequency. This indicates good consistency of derived ultrasound performance parameters.


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