Vibration of the Vocal Folds Observed Using a High-speed Movie System with Consumer Digital Video Camera

2009 ◽  
Vol 102 (5) ◽  
pp. 379-384
Author(s):  
Ken-ichi Kaneko ◽  
Koichi Sakaguchi ◽  
Masato Inoue ◽  
Fujinobu Tanaka ◽  
Atsushi Takano ◽  
...  
Author(s):  
H. Kuroda ◽  
M. Iribe ◽  
M. Matsubara ◽  
M. Watanabe ◽  
T. Sanada

Diagnoses of skin diseases are considerably difficult tasks due to the multiply-folded factors. Nailfold capillaroscopy has been developed to diagnosis microvascular disturbances mainly in connective tissue diseases, including systemic sclerosis, dermatomyositis, systemic lupus erythematosus, and Raynaud’s phenomenon. Capillaroscopy is non-invasive, easy to use, low cost and suitable for observation of these typical phenomena. We improved conventional capillaroscopy by constructing “high speed digital video capillaroscopy”, by integrating high speed digital video camera, deep-focus zoom lens, appropriate light source and light collecting adaptor. High speed digital video camera enabled us to observe the individual red blood cell in human nailfold capillary in vivo. The light collecting adaptor is effective for preventing skin from excessive light exposure, which causes serious damage. The first objective of this study is to extract the shape of nailfold capillary quantitatively by using binarization and the level-set method. By using the level-set method, the function, which distinguishes outside from inside of the capillary and also evaluates radius distribution along the capillary center line, is calculated. Based on this mathematical description of capillary shape, more rigorous definition of the capillary red blood cell velocity than the conventional method is obtained. The second objective of this study is to propose the innovative measurement method of red blood cell velocity in nailfold capillary. As plasma gaps show high brightness we trace them and estimate the velocities of blood cells on the center line of capillary. The last objective of this study is to observe the behavior of red blood cell. We evaluate the movement of individual red blood cell, not only in the axial direction but also the lateral direction. We analyze the series of images of red blood cells in capillary and discuss their behavior.


1990 ◽  
Vol 36 (4) ◽  
pp. 3866-3876 ◽  
Author(s):  
A. Morimura ◽  
K. Uomori ◽  
Y. Kitamura ◽  
A. Fujioka ◽  
J. Harada ◽  
...  

2018 ◽  
pp. 199-229
Author(s):  
Mick Hurbis-Cherrier

Author(s):  
Takahiro Arai ◽  
Masahiro Furuya

A high-temperature stainless-steel sphere was immersed into various salt solutions to test film boiling behavior at vapor film collapse. The film boiling behavior around the sphere was observed with a high-speed digital-video camera. Because salt additives enhanced condensation heat transfer, the observed vapor film was thinner. Surface temperature of the sphere was measured. Salt additives increased the quenching (vapor film collapse) temperature, because frequency of direct contact between sphere surface and coolant increased. Quenching temperature rises with increased salt concentration. The quenching temperature, however, approaches a constant value when the slat concentration is close to its saturation concentration. The quenching temperature is well correlated with ion molar concentration, which is a number density of ions, regardless of the type of hydrated salts.


Author(s):  
Kalpak P. Gatne ◽  
Milind A. Jog ◽  
Raj M. Manglik

A study of the normal impact of liquid droplets on a dry horizontal substrate is presented in this paper. The impact dynamics, spreading and recoil behavior are captured using a high-speed digital video camera at 2000 frames per second. A digital image processing software was used to determine the drop spread and height of the liquid on the surface from each frame. To ascertain the effects of liquid viscosity and surface tension, experiments were conducted with four liquids (water, ethanol, propylene glycol and glycerin) that have vastly different fluid properties. Three different Weber numbers (20, 40, and 80) were considered by altering the height from which the drop is released. The high-speed photographs of impact, spreading and recoil are shown and the temporal variations of dimensionless drop spread and height are provided in the paper. The results show that changes in liquid viscosity and surface tension significantly affect the spreading and recoil behavior. For a fixed Weber number, lower surface tension promotes greater spreading and higher viscosity dampens spreading and recoil. Using a simple scale analysis of energy balance, it was found that the maximum spread factor varies as Re1/5 when liquid viscosity is high and viscous effects govern the spreading behavior.


Author(s):  
Tomomichi Nakamura ◽  
Hiroshi Haruguchi ◽  
Hiroyuki Nakajima ◽  
Toyohiro Sawada ◽  
Kozo Sugiyama

The importance of the in-flow oscillation of a single cylinder in cross-flow has been highlighted since an accident in a FBR-type reactor. In-flow oscillations have also been observed in tube arrays. This report is an experimental study on this phenomenon using totally nine cylinders in a water tunnel. Six cases, one single cylinder, two & three cylinders in parallel & in tandem, and a nine cylinder bundle, are examined. Every cylinder can move only in in-flow direction. The motion of cylinders is measured by the strain gages and by a high-speed digital video camera. The results are compared with the visualized vortex motion.


Author(s):  
In-Cheol Chu ◽  
Chul-Hwa Song

A series of experiments were carried out to investigate the bubble nucleation to lift-off phenomena for a subcooled boiling flow in a vertical annulus channel. A high speed digital video camera was used to capture the dynamics of the bubble nucleation to lift-off process. A total of 148 recordings were made, and the bubble lift-off diameter and the bubble nucleation frequency were evaluated for 118 recordings up to now. The basic features of the lift-off diameter and nucleation frequency were addressed based on the present observation. A database for the bubble lift-off diameter was built by gathering and summarizing the data of Prodanovic et al., Situ et al., and the present work. The prediction capability of Unal’s model, Situ et al.’s model, and Prodanovic et al.’s correlation was evaluated against the database. The best prediction results were obtained by modifying the wall superheat correlation in Unal’s model.


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