Recent Advances in Diffraction Analysis of Reflector Antennas

1991 ◽  
pp. 39-65 ◽  
Author(s):  
Y. Rahmat-Samii
Keyword(s):  
Diffraction Analysis ◽  
Reflector Antennas ◽  
Recent Advances

Diffraction analysis of frequency selective reflector antennas

1993 ◽  
Vol 41 (4) ◽  
pp. 476-487 ◽  
Author(s):  
Y. Rahmat-Samii ◽  
A.N. Tulintseff
Keyword(s):  
Diffraction Analysis ◽  
Reflector Antennas ◽  
Frequency Selective

Recent Advances In Electromagnetic Synthesis And Analysis Of Dual-Shaped Reflector Antennas

1982 ◽  
Author(s):  
Victor Galindo-Israel ◽  
Yahya Rahmat-Samii ◽  
William Imbriale ◽  
Raj Mittra
Keyword(s):  
Reflector Antennas ◽  
Recent Advances

Recent Advances in High Dispersion Spectroscopy of Globular Cluster Stars

1988 ◽  
Vol 132 ◽  
pp. 525-530
Author(s):  
Raffaele G. Gratton
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Dispersion ◽  
Photographic Material ◽  
Recent Advances ◽  
Metal Abundances ◽  
Ccd Detectors ◽  
Major Progress

The use CCD detectors has allowed a major progress in abundance derivations for globular cluster stars in the last years. Abundances deduced from high dispersion spectra now correlates well with other abundance indicators. I discuss some problems concerning the derivation of accurate metal abundances for globular clusters using high dispersion spectra from both the old photographic and the most recent CCD data. The discrepant low abundances found by Cohen (1980), from photographic material for M71 giants, are found to be due to the use of too high microturbulences.

Light Optical Diffraction Studies of Macromolecular Ultrastructure

1970 ◽  
Vol 28 ◽  
pp. 258-259
Author(s):  
Glen B. Haydon
Keyword(s):  
High Resolution ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
Electron Micrographs ◽  
Optical Diffraction ◽  
Electron Micrograph ◽  
Its Analysis ◽  
Resolution Electron ◽  
Diffraction Patterns

Analysis of light optical diffraction patterns produced by electron micrographs can easily lead to much nonsense. Such diffraction patterns are referred to as optical transforms and are compared with transforms produced by a variety of mathematical manipulations. In the use of light optical diffraction patterns to study periodicities in macromolecular ultrastructures, a number of potential pitfalls have been rediscovered. The limitations apply to the formation of the electron micrograph as well as its analysis.(1) The high resolution electron micrograph is itself a complex diffraction pattern resulting from the specimen, its stain, and its supporting substrate. Cowley and Moodie (Proc. Phys. Soc. B, LXX 497, 1957) demonstrated changing image patterns with changes in focus. Similar defocus images have been subjected to further light optical diffraction analysis.

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