A fundamental source of error in the scattering method of measuring antenna surface field distributions

2003 ◽  
Author(s):  
D.W. Griffin
Keyword(s):  
Scattering Method ◽  
Field Distributions ◽  
Surface Field ◽  
Antenna Surface ◽  
Measuring Antenna ◽  
Source Of Error

A study of the leakage of surface electromagnetic fields through holes and cracks in metal plates

1989 ◽  
Vol 421 (1860) ◽  
pp. 55-78 ◽  
Keyword(s):  
Skin Surface ◽  
Skin Depth ◽  
Surface Currents ◽  
Surface Laplacian ◽  
Field Distributions ◽  
Surface Field ◽  
Leakage Field ◽  
Metal Plates ◽  
Circular Holes ◽  
Thin Skin

This paper considers the problems of thin-skin surface currents applied to conducting plates that have through holes or through cracks in them. The surface field distributions depend on the parameter m ═ ( μ 0 / μ ) ( l / δ ), where μ 0 / μ is the ratio of the free space to the specimen magnetic permeability and l / δ is the ratio of the flaw length dimension l to the skin depth δ . When m is small the fields are surface Laplacian distributions that can be computed by using methods of conformal mapping. The paper gives these distributions for circular holes and through cracks. Experiments are described for both these geometries, which confirm the incident and the leakage field distributions calculated for the two faces of the plate.

Dynamic Scanning Electron Microscopy of Small Particles

1975 ◽  
Vol 33 ◽  
pp. 280-281
Author(s):  
W. Krakow ◽  
W. C. Nixon
Keyword(s):  
Electron Microscopy ◽  
Low Noise ◽  
Time Sequence ◽  
Field Of View ◽  
Video Tape ◽  
Small Particles ◽  
Polystyrene Spheres ◽  
Field Distributions ◽  
Dynamic Scanning ◽  
Scanning Electron

The scanning electron microscope (SEM) can be run at television scanning rates and used with a video tape recorder to observe dynamic specimen changes. With a conventional tungsten source, a low noise TV image is obtained with a field of view sufficient to cover the area of the specimen to be recorded. Contrast and resolution considerations have been elucidated and many changing specimens have been studied at TV rates.To extend the work on measuring the magnitude of charge and field distributions of small particles in the SEM, we have investigated their motion and electrostatic interaction at TV rates. Fig. 1 shows a time sequence of polystyrene spheres on a conducting grating surface inclined to the microscope axis. In (la) there are four particles present in the field of view, while in (lb) a fifth particle has moved into view.

Phase Separation in Liquid-Crystalline Copolymer/Poly(methyl methacrylate) Blends

1995 ◽  
Vol 60 (11) ◽  
pp. 1869-1874 ◽  
Author(s):  
Anatoly E. Nesterov ◽  
Yuri S. Lipatov ◽  
Vitaly V. Horichko
Keyword(s):  
Phase Separation ◽  
Methyl Methacrylate ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Ethylene Terephthalate ◽  
Crystalline Polymer ◽  
Scattering Method ◽  
Thermally Induced ◽  
Poly Methyl Methacrylate ◽  
Copolymer Poly

The phase separation in the blends of poly(methyl methacrylate) and liquid-crystalline polymer (copolymer of ethylene terephthalate and p-hydroxybenzoic acid) has been studied by the light scattering method and the cloud point curves have been obtained. Simultaneously some morphological features of the blends have been observed. It was found that the initial blends are in the state of forced compatibility and that thermally induced phase separation occurs by the mechanism of spinodal decomposition but presumably in the non-linear regime.

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