Thermodynamic properties of the nonideal hydrogen plasmas: Comparison of different simulation techniques

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.

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Image Analysis of Intramembrane Particles in Freeze-Fractured Biomembranes Using Computer Simulation Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114694 ◽

1975 ◽

Vol 33 ◽

pp. 214-215

Author(s):

D.J. Benefiel ◽

R.S. Weinstein

Keyword(s):

Membrane Proteins ◽

Freeze Fracture ◽

Integral Membrane Proteins ◽

Systematic Evaluation ◽

Intramembrane Particles ◽

Modeling Methods ◽

Simulation Techniques ◽

Freeze Fracture Electron Microscopy ◽

Fracture Electron ◽

Computer Simulation Techniques

Intramembrane particles (IMP or MAP) are components of most biomembranes. They are visualized by freeze-fracture electron microscopy, and they probably represent replicas of integral membrane proteins. The presence of MAP in biomembranes has been extensively investigated but their detailed ultrastructure has been largely ignored. In this study, we have attempted to lay groundwork for a systematic evaluation of MAP ultrastructure. Using mathematical modeling methods, we have simulated the electron optical appearances of idealized globular proteins as they might be expected to appear in replicas under defined conditions. By comparing these images with the apearances of MAPs in replicas, we have attempted to evaluate dimensional and shape distortions that may be introduced by the freeze-fracture technique and further to deduce the actual shapes of integral membrane proteins from their freezefracture images.

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Σ =13 tilt grain boundary in silicon bicrystal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100175946 ◽

1990 ◽

Vol 48 (4) ◽

pp. 562-563

Author(s):

M.J. Kim ◽

Y.L. Chen ◽

R.W. Carpenter ◽

J.C. Barry ◽

G.H. Schwuttke

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Rotation Axis ◽

Czochralski Method ◽

High Resolution Electron Microscopy ◽

Image Simulation ◽

Simulation Techniques ◽

Resolution Electron ◽

The Common ◽

Tilt Grain Boundary

The structure of grain boundaries (GBs) in metals, semiconductors and ceramics is of considerable interest because of their influence on physical properties. Progress in understanding the structure of grain boundaries at the atomic level has been made by high resolution electron microscopy (HREM) . In the present study, a Σ=13, (510) <001>-tilt grain boundary in silicon was characterized by HREM in conjunction with digital image processing and computer image simulation techniques.The bicrystals were grown from the melt by the Czochralski method, using preoriented seeds. Specimens for TEM observations were cut from the bicrystals perpendicular to the common rotation axis of pure tilt grain boundary, and were mechanically dimpled and then ion-milled to electron transparency. The degree of misorientation between the common <001> axis of the bicrystal was measured by CBED in a Philips EM 400ST/FEG: it was found to be less than 1 mrad. HREM was performed at 200 kV in an ISI-002B and at 400 kv in a JEM-4000EX.

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