On non‐destructive detection of hidden passive radio‐frequency eavesdroppers

2021 ◽  
Author(s):  
Q. Y. Zhang ◽  
M. L. Liang
Keyword(s):  
Radio Frequency ◽  
Non Destructive

Design of the PTO/PZO Ferroelectric Superlattice Assembly

2012 ◽  
Vol 512-515 ◽  
pp. 1296-1299
Author(s):  
Tuo Hu ◽  
Cheng Zhang ◽  
Na Zhang
Keyword(s):  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Absorption Spectra ◽  
Low Cost ◽  
Radio Frequency Magnetron ◽  
Radio Frequency Magnetron Sputtering ◽  
Non Destructive

A series of ferroelectric superlattice films on ITO substrates have been artificially fabricated by radio frequency magnetron sputtering, starting from the PbZrO3 (PZO) and PbTiO3 (PTO) matrix targets. The design sequence of the layers has been changed via shifting sputtering target in the preparing processes. Diverse systems have been shaped and discussed by XRD, SEM and UV-Vis. UV-Vis absorption spectra have been paid more attention especially, due to the low-cost and non-destructive method to provide the information about the thicknesses of the films.

scholarly journals A Review of the Radio Frequency Non-destructive Testing for Carbon-fibre Composites

2016 ◽  
Vol 16 (2) ◽  
pp. 68-76 ◽  
Author(s):  
Zhen Li ◽  
Zhaozong Meng
Keyword(s):  
Carbon Fibre ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Ultra Wideband ◽  
Electromagnetic Properties ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Cfrp Composites ◽  
Carbon Fibre Composites ◽  
Non Destructive

AbstractThe purpose of this paper is to review recent research on the applications of existing non-destructive testing (NDT) techniques, especially radio frequency (RF) NDT, for carbon-fibre reinforced plastics (CFRP) composites. Electromagnetic properties of CFRP composites that are associated with RF NDT are discussed first. The anisotropic characteristic of the conductivity and the relationship between the penetration depth and conductivity should be paid much attention. Then, the well-established RF NDT including eddy current technique, microwave technique and RF-based thermography are well categorised into four types (i.e. electromagnetic induction, resonance, RF-based thermography and RF wave propagation) and demonstrated in detail. The example of impact damage detection using the induction and resonance methods is given. Some discussions on the development (like industrial-scale automated scanning, three-dimensional imaging, short-range ultra-wideband (UWB) imaging and the radio frequency identification technology (RFID)-based NDT) are presented.

scholarly journals Inductive Imaging of the Concealed Defects with Radio-Frequency Atomic Magnetometers

2020 ◽  
Vol 10 (19) ◽  
pp. 6871
Author(s):  
P. Bevington ◽  
R. Gartman ◽  
W. Chalupczak
Keyword(s):  
Radio Frequency ◽  
Frequency Dependence ◽  
Phase Contrast ◽  
The Self ◽  
Frequency Range ◽  
Background Signal ◽  
Electrically Conductive ◽  
Operational Frequency ◽  
Inductive Measurement ◽  
Non Destructive

We explore the capabilities of the radio-frequency atomic magnetometers in the non-destructive detection of concealed defects. We present results from the systematic magnetic inductive measurement of various defect types in an electrically conductive object at different rf field frequencies (0.4–12 kHz) that indicate the presence of an optimum operational frequency of the sensor. The optimum in the frequency dependence of the amplitude/phase contrast for defects under a 0.5–1.5 mm conductive barrier was observed within the 1–2 kHz frequency range. The experiments are performed in the self-compensated configuration that automatically removes the background signal created by the rf field producing object response.

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Forensic Identifications Aided by Scanning Electron Microscopy of Silicone-Epoxy Microreplicas of Calcified and Cornified Structures

1975 ◽  
Vol 33 ◽  
pp. 678-679 ◽  
Author(s):  
R.F. Sognnaes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Forensic Science ◽  
George Washington ◽  
Epithelial Surface ◽  
Extended Application ◽  
Tissue Surfaces ◽  
Non Destructive ◽  
Scanning Electron ◽  
Surface Changes

Sufficient experience has been gained during the past five years to suggest an extended application of microreplication and scanning electron microscopy to problems of forensic science. The author's research was originally initiated with a view to develop a non-destructive method for identification of materials that went into objects of art, notably ivory and ivories. This was followed by a very specific application to the identification and duplication of the kinds of materials from animal teeth and tusks which two centuries ago went into the fabrication of the ivory dentures of George Washington. Subsequently it became apparent that a similar method of microreplication and SEM examination offered promise for a whole series of problems pertinent to art, technology and science. Furthermore, what began primarily as an application to solid substances has turned out to be similarly applicable to soft tissue surfaces such as mucous membranes and skin, even in cases of acute, chronic and precancerous epithelial surface changes, and to post-mortem identification of specific structures pertinent to forensic science.

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