Computational study on the positive streamer inception in air at high altitude

Contrast of Filament Bright Rims

International Astronomical Union Colloquium ◽

10.1017/s0252921100025628 ◽

1994 ◽

Vol 144 ◽

pp. 365-367

Author(s):

E. V. Kononovich ◽

O. B. Smirnova ◽

P. Heinzel ◽

P. Kotrč

Keyword(s):

High Altitude ◽

Line Profile ◽

Line Center ◽

Magnetic Structures ◽

The Mean

AbstractThe Hα filtergrams obtained at Tjan-Shan High Altitude Observatory near Alma-Ata (Moscow University Station) were measured in order to specify the bright rims contrast at different points along the line profile (0.0; ± 0.25; ± 0.5; ± 0.75 and ± 1.0 Å). The mean contrast value in the line center is about 25 percent. The bright rims interpretation as the bases of magnetic structures supporting the filaments is suggested.

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Clean Electron Microscope Substrate Films Used for Micrometeorite Collection and Study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100061847 ◽

1967 ◽

Vol 25 ◽

pp. 366-367

Author(s):

D. M. Davies ◽

R. Kemner ◽

E. F. Fullam

Keyword(s):

Thin Film ◽

Electron Microscope ◽

High Altitude ◽

Amyl Acetate ◽

Temperature Variations ◽

Film Forming ◽

Film Specimen ◽

Particulate Contaminants

All serious electron microscopists at one time or another have been concerned with the cleanliness and freedom from artifacts of thin film specimen support substrates. This is particularly important where there are relatively few particles of a sample to be found for study, as in the case of micrometeorite collections. For the deposition of such celestial garbage through the use of balloons, rockets, and aircraft, the thin film substrates must have not only all the attributes necessary for use in the electron microscope, but also be able to withstand rather wide temperature variations at high altitude, vibration and shock inherent in the collection vehicle's operation and occasionally an unscheduled violent landing.Nitrocellulose has been selected as a film forming material that meets these requirements yet lends itself to a relatively simple clean-up procedure to remove particulate contaminants. A 1% nitrocellulose solution is prepared by dissolving “Parlodion” in redistilled amyl acetate from which all moisture has been removed.

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