Injector for a 100-500 kV Linac Electron Microscopy Source

1967 ◽  
Vol 25 ◽  
pp. 274-275
Author(s):  
John W. Coleman
Keyword(s):  
Electron Microscopy ◽  
Linear Accelerator ◽  
Beam Current ◽  
Ion Trapping ◽  
University Of Virginia ◽  
Electron Injector ◽  
Illumination System ◽  
Radio Corporation Of America ◽  
The University ◽  
Optical Integration

The injector to be described is a component in the Electron Injector-Linear Accelerator—Condenser Module for illumination used on the variable 100-500kV electron microscope being built at the Radio Corporation of America for the University of Virginia.The injector is an independently powered, autonomous unit, operating at a constant 6kV positive with respect to accelerator potential, thereby making beam current independent of accelerator potential. The injector provides for on-axis ion trapping to prolong filament lifetime, and incorporates a derived Einzel lens for optical integration into the overall illumination system for microscopy. Electrostatic beam deflectors for alignment are an integral part of the apparatus. The entire injector unit is cantilevered off a door for side loading, and is topped with a 4-filament turret released electrically but driven by a self-contained Negator spring motor.

The 1-MeV Electron Microscope Installation at the University of Colorado

1973 ◽  
Vol 31 ◽  
pp. 8-9 ◽  
Author(s):  
Mircea Fotino
Keyword(s):  
Electron Microscopy ◽  
Developmental Biology ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
National Institutes Of Health ◽  
Experimental Program ◽  
University Of Colorado ◽  
Transmission Electron ◽  
The University ◽  
Research Resources

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.

Scanning Electron Microscopy of Fish Scales as an Adjunctive Aid in Speciation

1972 ◽  
Vol 30 ◽  
pp. 394-395
Author(s):  
Edward D. DeLamater ◽  
Walter R. Courtenay ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lateral Line ◽  
Species Differences ◽  
Fish Scale ◽  
Fish Scales ◽  
Anterior Border ◽  
The University ◽  
Multiple Holes ◽  
Scanning Electron

Comparative scanning electron microscopy studies of fish scales of different orders, families, genera and species within genera have demonstrated differences which warrant elaboration. These differences in detail appear to be sufficient to act as “fingerprints”, at least, for family differences. To date, the lateral line scales have been primarily studied. These demonstrate differences in the lateral line canals; the pattern of ridging with or without secondary protuberances along the edges; the pattern of spines or their absence on the anterior border of the scales; the presence or absence of single or multiple holes on the ventral and dorsal sides of the lateral line canal covers. The distances between the ridges in the pattern appear likewise to be important.A statement of fish scale structure and a comparison of family and species differences will be presented.The authors wish to thank Dr. Donald Marzalek and Mr. Wallace Charm of the Marine and Atmospheric Laboratory of the University of Miami and Dr. Sheldon Moll and Dr. Richard Turnage of AMR for their exhaustive help in these preliminary studies.

Imaging of polymer single crystals in low-voltage, high-resolution scanning electron microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 1106-1107
Author(s):  
W.W. Adams ◽  
G. Price ◽  
A. Krause
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Single Crystals ◽  
Low Voltage ◽  
Polymer Surface ◽  
Beam Current ◽  
Image Features ◽  
First Results ◽  
Scanning Electron

It has been shown that there are numerous advantages in imaging both coated and uncoated polymers in scanning electron microscopy (SEM) at low voltages (LV) from 0.5 to 2.0 keV compared to imaging at conventional voltages of 10 to 20 keV. The disadvantages of LVSEM of degraded resolution and decreased beam current have been overcome with the new generation of field emission gun SEMs. In imaging metal coated polymers in LVSEM beam damage is reduced, contrast is improved, and charging from irregularly shaped features (which may be unevenly coated) is reduced or eliminated. Imaging uncoated polymers in LVSEM allows direct observation of the surface with little or no charging and with no alterations of surface features from the metal coating process required for higher voltage imaging. This is particularly important for high resolution (HR) studies of polymers where it is desired to image features 1 to 10 nm in size. Metal sputter coating techniques produce a 10 - 20 nm film that has its own texture which can obscure topographical features of the original polymer surface. In examining thin, uncoated insulating samples on a conducting substrate at low voltages the effect of sample-beam interactions on image formation and resolution will differ significantly from the effect at higher accelerating voltages. We discuss here sample-beam interactions in single crystals on conducting substrates at low voltages and also present the first results on HRSEM of single crystal morphologies which show some of these effects.

Re-thinking morbidity and mortality

Diagnosis ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sumner Abraham ◽  
Andrew Parsons ◽  
Brian Uthlaut ◽  
Peggy Plews-Ogan
Keyword(s):  
Cognitive Biases ◽  
Diagnostic Errors ◽  
Dual Process ◽  
Morbidity And Mortality ◽  
Dual Process Theory ◽  
Habits Of Mind ◽  
Thought Processes ◽  
University Of Virginia ◽  
Self Reflection ◽  
The University

AbstractDespite the breadth of patient safety initiatives, physicians talking about their mistakes to other physicians is a difficult thing to do. This difficulty may be exacerbated by a limited exposure to how to analyze and discuss mistakes and respond in a productive way. At the University of Virginia, we recognized the importance of understanding cognitive biases for residents in both their clinical and personal professional development. We re-designed our resident led morbidity and mortality (M&M) conference using a model that integrates dual-process theory and metacognition to promote informed reflection and analysis of cognitive diagnostic errors. We believe that structuring M&M in this way builds a culture that encourages reflection together to learn our most difficult diagnostic errors and to engage in where our thought processes went wrong. In slowly building this culture, we hope to inoculate residents with the habits of mind that can best protect them from harmful biases in their clinical reasoning while instilling a culture of self-reflection.

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