Features of application of image converter cameras for research on lightning and discharges in long air gaps

2005 ◽  
Author(s):  
Vitaly B. Lebedev ◽  
Grigory G. Feldman ◽  
Boris N. Gorin ◽  
Yuri V. Shcherbacov ◽  
Vladimir S. Syssoev ◽  
...  
Keyword(s):  
Image Converter ◽  
Air Gaps

Application of image converter streak camera FER-14 to investigations of the discharge process pattern in long air gaps

1999 ◽  
Author(s):  
A. R. Koriavin ◽  
O. V. Volkova ◽  
Vitaly B. Lebedev ◽  
A. I. Sitnikova ◽  
A. M. Tolmachev ◽  
...  
Keyword(s):  
Streak Camera ◽  
Discharge Process ◽  
Image Converter ◽  
Air Gaps ◽  
Process Pattern

The development of electrical leader discharges in a point-plane gap in SF 6

1987 ◽  
Vol 412 (1843) ◽  
pp. 285-308 ◽  
Keyword(s):  
High Speed ◽  
Electrical Breakdown ◽  
Step Length ◽  
Schlieren Image ◽  
Image Converter ◽  
Time Resolved ◽  
Atmospheric Air ◽  
Air Gaps ◽  
Breakdown Mechanism ◽  
Corona Charge

Two high-speed image converter cameras and a 600 MHz digital analyser have been used to investigate electrical breakdown of SF 6 in a 20 mm point-plane gap at pressures up to 5 bar (5 × 10 5 Pa). Time-resolved records have been obtained of the schlieren image, the light emitted from the gap and the gap current during the development of impulse breakdown. It has been shown that the breakdown mechanism in a short gap in SF 6 is similar to that observed in atmospheric air gaps of several metres length. A primary corona is followed by the development of a hot leader channel which consists of a series of discrete steps. In this work it has been possible to time-resolve these steps and also to estimate the values of corona charge, leader diameter and step length. From the results obtained some insight has been gained into the mechanisms of leader formation in SF 6 .

A light optical diffractometer for electron microscopical images operating in line

1978 ◽  
Vol 36 (1) ◽  
pp. 86-87
Author(s):  
P. Bonhomme ◽  
A. Beorchia
Keyword(s):  
Electron Microscopy ◽  
Electron Transfer ◽  
Electron Microscope ◽  
Image Converter ◽  
Coherent Light ◽  
Spatial Filters ◽  
Electron Image ◽  
Electron Microscopical ◽  
Working Parameters ◽  
Amorphous Part

We have already described (1.2.3) a device using a pockel's effect light valve as a microscopical electron image converter. This converter can be read out with incoherent or coherent light. In the last case we can set in line with the converter an optical diffractometer. Now, electron microscopy developments have pointed out different advantages of diffractometry. Indeed diffractogram of an image of a thin amorphous part of a specimen gives information about electron transfer function and a single look at a diffractogram informs on focus, drift, residual astigmatism, and after standardizing, on periods resolved (4.5.6). These informations are obvious from diffractogram but are usualy obtained from a micrograph, so that a correction of electron microscope parameters cannot be realized before recording the micrograph. Diffractometer allows also processing of images by setting spatial filters in diffractogram plane (7) or by reconstruction of Fraunhofer image (8). Using Electrotitus read out with coherent light and fitted to a diffractometer; all these possibilities may be realized in pseudoreal time, so that working parameters may be optimally adjusted before recording a micrograph or before processing an image.

A Simple Calculation Method of Flashover Characteristics for Long Air Gaps under Various Discharge Conditions

1993 ◽  
Vol 113 (3) ◽  
pp. 252-258
Author(s):  
Kiyoto Nishijima ◽  
Itaru Tsuneyasu ◽  
Hiraku Nakahodo ◽  
Masaharu Minakami
Keyword(s):  
Calculation Method ◽  
Simple Calculation ◽  
Air Gaps

scholarly journals Acoustic Panels Made of Paper Sludge and Clay Composites

2021 ◽  
Vol 13 (2) ◽  
pp. 637
Author(s):  
Tomas Astrauskas ◽  
Tomas Januševičius ◽  
Raimondas Grubliauskas
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Composite Panel ◽  
Sound Absorption Coefficient ◽  
Core Material ◽  
Paper Sludge ◽  
Frequency Range ◽  
Absorption Properties ◽  
Air Gaps ◽  
The Core

Studies on recycled materials emerged during recent years. This paper investigates samples’ sound absorption properties for panels fabricated of a mixture of paper sludge (PS) and clay mixture. PS was the core material. The sound absorption was measured. We also consider the influence of an air gap between panels and rigid backing. Different air gaps (50, 100, 150, 200 mm) simulate existing acoustic panel systems. Finally, the PS and clay composite panel sound absorption coefficients are compared to those for a typical commercial absorptive ceiling panel. The average sound absorption coefficient of PS-clay composite panels (αavg. in the frequency range from 250 to 1600 Hz) was up to 0.55. The resulting average sound absorption coefficient of panels made of recycled (but unfinished) materials is even somewhat higher than for the finished commercial (finished) acoustic panel (αavg. = 0.51).

Practical Aspects in the Application of Conductive Barriers to Field Controlled Air Gaps

1986 ◽  
Vol 1 (2) ◽  
pp. 169-181 ◽  
Author(s):  
D. Shirmohammadi ◽  
W. Janischewskyj ◽  
D. H. Nguyen ◽  
R. Lanoie
Keyword(s):  
Air Gaps
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