Spatial processing techniques for the detection of small targets in IR clutter

Interest in digital image processing techniques dates back to the early 1920's, when digitized pictures of world news events were first transmitted by submarine cable between New York and London. Applications of digital image processing concepts, however, did not become widespread until the middle 1960's, when third-generation digital computers began to offer the speed and storage capabilities required for practical implementation of image processing algorithms. Since then, this area has experienced vigorous growth, having been a subject of interdisciplinary research in fields ranging from engineering and computer science to biology, chemistry, and medicine.

Download Full-text

Digital phase analysis in interference electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106272 ◽

1988 ◽

Vol 46 ◽

pp. 842-843

Author(s):

S. Hasegawa ◽

T. Kawasaki ◽

J. Endo ◽

M. Futamoto ◽

A. Tonomura

Keyword(s):

Magnetic Field ◽

Electron Microscopy ◽

Phase Distribution ◽

Magnetic Recording Media ◽

Electron Wave ◽

Vector Potentials ◽

Weak Magnetic Fields ◽

Leakage Magnetic Field ◽

Optical Reconstruction ◽

Processing Techniques

Interference electron microscopy enables us to record the phase distribution of an electron wave on a hologram. The distribution is visualized as a fringe pattern in a micrograph by optical reconstruction. The phase is affected by electromagnetic potentials; scalar and vector potentials. Therefore, the electric and magnetic field can be reduced from the recorded phase. This study analyzes a leakage magnetic field from CoCr perpendicular magnetic recording media. Since one contour fringe interval corresponds to a magnetic flux of Φo(=h/e=4x10-15Wb), we can quantitatively measure the field by counting the number of finges. Moreover, by using phase-difference amplification techniques, the sensitivity for magnetic field detection can be improved by a factor of 30, which allows the drawing of a Φo/30 fringe. This sensitivity, however, is insufficient for quantitative analysis of very weak magnetic fields such as high-density magnetic recordings. For this reason we have adopted “fringe scanning interferometry” using digital image processing techniques at the optical reconstruction stage. This method enables us to obtain subfringe information recorded in the interference pattern.

Download Full-text

Specific Labeling of Protein Domains with Antibody Fragments

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098587 ◽

1981 ◽

Vol 39 ◽

pp. 416-417

Author(s):

U. Aebi ◽

L.E. Buhle ◽

W.E. Fowler

Keyword(s):

Image Processing ◽

Specific Protein ◽

Antibody Fragments ◽

Supramolecular Organization ◽

Two Dimensional ◽

Ordered Structures ◽

Virus Capsids ◽

Processing Techniques

Many important supramolecular structures such as filaments, microtubules, virus capsids and certain membrane proteins and bacterial cell walls exist as ordered polymers or two-dimensional crystalline arrays in vivo. In several instances it has been possible to induce soluble proteins to form ordered polymers or two-dimensional crystalline arrays in vitro. In both cases a combination of electron microscopy of negatively stained specimens with analog or digital image processing techniques has proven extremely useful for elucidating the molecular and supramolecular organization of the constituent proteins. However from the reconstructed stain exclusion patterns it is often difficult to identify distinct stain excluding regions with specific protein subunits. To this end it has been demonstrated that in some cases this ambiguity can be resolved by a combination of stoichiometric labeling of the ordered structures with subunit-specific antibody fragments (e.g. Fab) and image processing of the electron micrographs recorded from labeled and unlabeled structures.

Download Full-text

A new type of defect structure in 124-superconducting oxide revealed by HREM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100089779 ◽

1991 ◽

Vol 49 ◽

pp. 1092-1093

Author(s):

R. Sharma ◽

B.L. Ramakrishna ◽

N.N. Thadhani ◽

D. Hianes ◽

Z. Iqbal

Keyword(s):

Shock Wave ◽

Defect Structure ◽

Neutron Radiation ◽

Weak Links ◽

Defect Structures ◽

New Materials ◽

New Type ◽

Current Densities ◽

Processing Techniques ◽

Microstructural Studies

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.

Download Full-text

Crystallization of MgO • Al2 • SiO2 • ZrO2 glasses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143778 ◽

1986 ◽

Vol 44 ◽

pp. 440-441

Author(s):

M. A. McCoy

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Powder Processing ◽

Glass Composition ◽

Ceramic Powder ◽

Transformation Toughening ◽

Ceramic Powder Processing ◽

Processing Techniques ◽

Ceramic Matrices

Transformation toughening by ZrO2 inclusions in various ceramic matrices has led to improved mechanical properties in these materials. Although the processing of these materials usually involves standard ceramic powder processing techniques, an alternate method of producing ZrO2 particles involves the devtrification of a ZrO2-containing glass. In this study the effects of glass composition (ZrO2 concentration) and heat treatment on the morphology of the crystallization products in a MgO•Al2•SiO2•ZrO2 glass was investigated.

Download Full-text