A study of visual simulation techniques for astronautical flight training.

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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An Application of the HFACS Method to Aviation Accidents in Africa

Aviation Psychology and Applied Human Factors ◽

10.1027/2192-0923/a000093 ◽

2016 ◽

Vol 6 (1) ◽

pp. 33-38 ◽

Cited By ~ 4

Author(s):

Isaac Munene

Keyword(s):

Human Factors ◽

Physical Environment ◽

Human Factor ◽

Flight Training ◽

African Countries ◽

Causal Factors ◽

Aviation Accidents ◽

Factors Analysis ◽

Adverse Weather ◽

Decision Errors

Abstract. The Human Factors Analysis and Classification System (HFACS) methodology was applied to accident reports from three African countries: Kenya, Nigeria, and South Africa. In all, 55 of 72 finalized reports for accidents occurring between 2000 and 2014 were analyzed. In most of the accidents, one or more human factors contributed to the accident. Skill-based errors (56.4%), the physical environment (36.4%), and violations (20%) were the most common causal factors in the accidents. Decision errors comprised 18.2%, while perceptual errors and crew resource management accounted for 10.9%. The results were consistent with previous industry observations: Over 70% of aviation accidents have human factor causes. Adverse weather was seen to be a common secondary casual factor. Changes in flight training and risk management methods may alleviate the high number of accidents in Africa.

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