THE OCCURRENCE OF ELECTRON SPIN RESONANCE SIGNALS IN BONE GRAFTS STERILIZED WITH HIGH VOLTAGE ELECTRON BEAMS

1962 ◽  
Vol 30 (4) ◽  
pp. 536-537 ◽  
Author(s):  
Ursula T. Slager ◽  
Melvin J. Zucker
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
High Voltage ◽  
Electron Beams ◽  
Bone Grafts ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Spin Resonance

High-resolution charge collection microscopy with high-voltage electron beams

1994 ◽  
Vol 52 ◽  
pp. 954-955
Author(s):  
D. M. Hwang ◽  
Y. A. Tkachenko ◽  
J. C. M. Hwang
Keyword(s):  
Electron Beam ◽  
Spatial Resolution ◽  
High Voltage ◽  
Semiconductor Device ◽  
Field Effect Transistors ◽  
Electron Beams ◽  
Degradation Mechanism ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Probing Depth

Electron-beam-induced-current (EBIC) microscopy has the unique capability of simultaneously providing structural and transport characteristics of semiconductors. However, EBIC is traditionally performed inside an SEM with less than 40 keV electron beam energy. As the result, the applications of traditional EBIC for semiconductor device characterization are limited by either probing depth (0.02 ~0.05 μm with 2 ~5 keV electron beams) or spatial resolution (1-2 um with 20 ~40 keV electron beams). To achieve useful resolution for studying the interface effects critical to today's submicron devices, one would have to prepare the samples by either removing the passivation/metallization layers or making cross sections. In this paper, we report a breakthrough in the art of EBIC using high-voltage electron beams (200 keV and higher) to improve the spatial resolution and probing depth simultaneously. Adopting a JEOL 4000FX AEM for EBIC imaging, a spatial resolution of 0.05 um was demonstrated from structures 0.5 um beneath the surface. Using this technique, we have identified a facet degradation mechanism in strained quantum well laser diodes and hot-electroninduced defects in GaAs metal-semiconductor field-effect transistors (MESFETs).

The Persistence of Electron Spin Resonance in Bone Grafts Sterilized by Ionizing Radiation

1964 ◽  
Vol 22 (3) ◽  
pp. 556 ◽  
Author(s):  
Ursula T. Slager ◽  
Melvin J. Zucker ◽  
Emmett B. Reilly
Keyword(s):  
Electron Spin Resonance ◽  
Ionizing Radiation ◽  
Electron Spin ◽  
Bone Grafts ◽  
Spin Resonance

Test on Resolution of Electron Microscope Applied to Thick Specimens

1968 ◽  
Vol 26 ◽  
pp. 340-341
Author(s):  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Energy Distribution ◽  
High Voltage ◽  
Phase Contrast ◽  
Electron Beams ◽  
Chromatic Aberration ◽  
Lattice Defects ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron

The popularity of the ultra high voltage electron microscope has resulted in a tendency to use thick specimens. R. Uyeda, Y. Kamiya, H. Hashimoto, and V. E. Cosslett reported the results of experiments and calculations determining to what thickness the electron microscope can observe specimens.Generally, in the case of thick specimens, the resolution in the microscope image depends on chromatic ‘aberration and when the energy distribution of electron beams, after being transmitted through the specimen, is measured, the resolution due to chromatic aberration can be obtained byIn practice, however, resolution depends on the position of the objects (e.g., irregularities such as lattice defects) in the specimen. This may be attributable to phase contrast due to interference phenomena and also attributable to the top-bottom effect pointed out by H. Hashimoto.

Uses of Radiation-Induced Paramagnetic Centers in Bone

Physiology ◽  
1989 ◽  
Vol 4 (3) ◽  
pp. 112-116 ◽  
Author(s):  
K Ostrowski ◽  
A Dziedzic-Goclawska
Keyword(s):  
Electron Spin Resonance ◽  
Ionizing Radiation ◽  
Bone Mineral ◽  
Electron Spin ◽  
Biological Markers ◽  
Bone Grafts ◽  
Crystalline Lattice ◽  
Paramagnetic Centers ◽  
Spin Resonance ◽  
Radiation Induced

Ionizing radiation induces stable paramagnetic centers in the crystalline lattice of bone hydroxyapatite. These can be measured by electron-spin resonance spectrometry and can serve as biological markers for evaluation of crystallinity of bone mineral, quantitation of the rebuilding process of radiation-sterilized bone grafts, and estimation of doses of ionizing radiation.

High Voltage Electron Microscopy of Ion-Milled Dental Enamel

1974 ◽  
Vol 32 ◽  
pp. 60-61
Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Third Molar ◽  
Polarized Light ◽  
Dental Enamel ◽  
Longitudinal Section ◽  
Ion Milling ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.

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