High-speed video-camera

Experiments by Schmidli et al. (1990) were focused on the distribution of mass on rupture of a vessel containing a superheated liquid below its superheat-temperature limit. Flasks (50-ml and 100-mI capacity) were partially filled with butane or propane. Typically, when predetermined conditions were reached, the flask was broken with a hammer. Expansion of the unignited cloud was measured by introduction of a smoke curtain and use of a high speed video camera. Large droplets were visible, but a portion of the fuel formed a liquid pool beneath the flask. Figure 6.5 shows that, as superheat was increased, the portion of fuel that... 

Fig. 9.9 Experimental set-up 1 test module, 2 heater, 3 electrical contact, 4 micro-channel, 5 Pyrex, 6 peristaltic pump, 7 and 8 pressure and temperature measurements, 9 cooler, 10 reservoir, 77 IR camera, 72 microscope, 13 high-speed video camera, 14 PC, 75 synchronizer, 16 video recorder. Reprinted from Peles et al. (2001) with permission...

The collision process can be captured by a high speed video camera as shown in Fig. 6 [14]. The slurry is about 50 mm apart away from the solid surface at 0 s (Fig. 6(a)), and reaches the surface at 0.018 s (Fig. 6(b)). Then the slurry reflects at an angle as same as the incidence angle (Fig. 6(c)). As time goes, the reflected liquid beam is divided into two beams, one is in the reflected direction and another is parallel to the solid surface as shown in Fig. 6(d). When time reaches 0.068 s, most of the reflected slurry moves along the solid surface. 

Fig. 3 shows the calculated and experimental results of particle fluidization behaviors in a RFB. A high-speed video camera (FASTCAM MAX, Photoron CO., Ltd.) was used for visualization of actual particle fluidization behavior. The bubbling fluidization behaviors, such as the bubble formation, eruption and particle circulation with rotational motion, could be well simulated, and these behaviors were also observed in the experimental results. 

FIGURE 1.6 High-speed video camera used to visualize bubble nucleation sites in a glass poured with champagne (photograph by Hubert Raguet). 

A type 601A piezio sensor made by Kisler is used as a pressure probe, which leads to a type 5007 change amplifier, and the data are acquired by an R-510 data recorder made by TEAC. A HSV200 high speed video camera (200 frames per second) made by NAC completes the unit. 

A high-speed video camera, recording up to 600 frames per second, can be incorporated in the set-up and erythrocyte velocity in vivo can be measured offline with the line-shift-diagram method [139]. 

In the commercial application, the drop tube method, as mentioned above, is suitable for mass production. The detailed investigations, such as temperature measurement of each small droplet and in situ observation of microstructure formation are not easy to attain because each droplet is in free fall. Here, the levitation method, where an Si droplet with a diameter of mm can be levitated by electromagnetic force using an electro-magnetic levitator (EML), as shown in Fig. 8.5, is a powerful investigation technique because the controlled droplet position enables us to measure the surface temperature of the droplet by pyrometer and to observe the crystallization behavior in situ by a high-speed video camera (HSV) [16-18]. 

For DT, a high-speed video camera (100 frames per second) is used to measure the number of frames the hot bar is in contact with the material. This is performed repeatedly for several days. From this data, the DT standard deviation is estimated to be 0.08 seconds. 

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