High speed photography

Krypton clathrates have been prepared with hydroquinone and phenol. 85Kr has found recent application in chemical analysis. By imbedding the isotope in various solids, kryptonates are formed. The activity of these kryptonates is sensitive to chemical reactions at the surface. Estimates of the concentration of reactants are therefore made possible. Krypton is used in certain photographic flash lamps for high-speed photography. Uses thus far have been limited because of its high cost. Krypton gas presently costs about 30/1. 

Durand, M. (1984), Use of Optical Fibers for Velocity Measurement by Laser Doppler Interferometry with a Fabry-Perot Interferometer. In High Speed Photography and Photonics, Proc. SPIE, 491 (edited by M. Andre and M. Hugenschmidt), pp. 650-656. 

Documentation of the tests should also be provided by still photography, video camera/recorder systems, and high speed photography. The high speed photography with a minimum speed of 500 frames per second Is necessary to be able to see any flame front exiting a shield. A list of typical Instrumentation used on an operational shield test Is shown on Table II, (see reference A). 

Y. Tsuchiya, H. Suzuki, M. Koishi, K. Kinoshita, T. Nakamura, Infrared sensitive universal streak camera for use in 1.0 to 1.6 micron wavelength region, in High Speed Photography, Videography, and Photonics III, Proc. SPIE 569, 181-188 (1985). 

In the small-scale tests, water was jetted into the salt both from above and below the interface. Explosions were erratic with many tests simply producing water vapor which ejected the salt. In some tests, high-speed photography was employed and, at the highest framing speeds (13,000 fps), the explosion, if it occurred, took place within the time of a single frame, i.e., <77 ju,sec. No definitive conclusions were drawn except that, if an explosion did occur, it was very short in duration and rather destructive. 

Krypton is expensive to produce, which limits its use as an inert gas. It is used in a mixture with argon to fill incandescent light bulbs, fluorescent lamps, lasers, and high-speed photography lamps. Radioactive Kr-85 is used as a source of radiation to measure the thickness of industrial materials. It is also used to test for leakage of scientific instruments. 

Both FEA and experimental impacts were used with high-speed photography to show that the shells could buckle locally under a stud impact. The best guards use complex shaped shells to increase the transverse bending stiffness. 

A. The bursting process as frozen by high-speed photography... 

Shock waves were obtd in Perspex blocks drilled thru with different diameters (Fig 1). The shock wave which developed at the top of the block as well as in the ambient air in contact with the bottom of the same was photographed using the high-speed photography equipment of Cranz Schardin, provided with explosive lamps of which the... 

Berghe,. Proc of 5th Int l Congress on High Speed Photography, Washington, DC (I960), p 49 6) J. Hershkowitz E.W. Dalrymple,... 

Radiography of High-Speed Events. See X-Ray High-Speed Photography in Vol 2, p CI7-R under CAMERAS... 

Combustion Waves Using Methods of High-Speed Photography , Ibid, pp 677-82 88) R.A. Strehlow et al, "Transverse Wave Structure in Detonation , Ibid, pp 683-92 89a) R.I. Soloukhine, "Nonstationary Phenomena in Gaseous Detonation , Ibid, pp 799-807 89b) A.R. Ubbelohde G.M. 

Accdg to our translation from the Russian, the critical density (pc) may be defined as the lowest value of loading density, p, at which a detonation wave will propagate thru full length of expl column at steady rate. Smallest further decrease in p will cause failure of detonation. The lowest deton velocity at this point, as registered by high-speed photography, may be considered as critical velocity and the density as critical pc (Ref 8, pp 292-93)... 

The method is used also as a substitute for high-speed photography where such photography is not feasible because of the obscuration of the projectile by the flash and debris caused by the proj penetrating the target (p IIIB-15 of Ref 39)... 

High-speed photography provides the main observational facility in the study and measurement of explosive phenomena. In Vol 2, pp Cl3-19, many high-speed cameras are described... 

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