• Title/Summary/Keyword: Heywood's Diameter

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THE DISTRIBUTION OF DIGESTA PARTICLES AND MEAN PARTICLE SIZE OF DIGESTA OBTAINED FROM THE DIVERSE PARTS OF THE GASTROINTESTINAL TRACT OF RUMINANTS

  • Sekine, J.;Fujikura, T.;Oura, R.;Asahida, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.1
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    • pp.13-18
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    • 1992
  • Three cattle, a sheep and a goat were slaughtered to determine the distribution of digesta particles and mean size of digesta particles. Aliquot samples of digesta in the diverse sites of the digestive tracts were fractionated by a wet sieving technique. Fractionated particles were analyzed by the magnetic grid analyzer system constructed by authors. Results showed that the proportion of particles in digesta was similar among the omasum, abomasums cecum, colon and rectum, but that for the reticulo-ruminal digesta was different from the others. The pattern of the mass base frequency distribution of particles was also similar in the post-ruminal digesta. Average Heywood's diameter (the diameter equivalent to that of a circle with equal area to a projected area of a given particle) was about 1.2 mm in the reticulo-ruminal digesta and decreased to 0.65 mm for cattle or to about 0.35 mm for sheep and goat in the omasal digesta. Average Heywood's diameter was about the same in the post-ruminal digesta. It is concluded that mean particle size and particle distribution in digesta of the rectum or feces reflect those in digesta of the omasum.

Measurement of Carbon Nanotube Agglomerates Size and Shape in Dilute Phase of a Fluidized Bed (유동층 반응기 희박상 내 탄소나노튜브 응집체의 크기 및 형상 측정)

  • Kim, Sung Won
    • Korean Chemical Engineering Research
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    • v.55 no.5
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    • pp.646-651
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    • 2017
  • Size and shape of carbon nanotube (CNT) agglomerates in the dilute phase of a bubbling fluidized bed ($0.15m\;i.d{\times}2.6m\;high$) have been determined by the laser sheet technique. Axial solid holdup distribution of the CNT particles showed S curve with dense phase and dilute phase in bubbling fluidization regime. Heywood diameter and Feret diameter of the CNT agglomerates in the dilute phase of bubbling fluidized bed increased with increasing gas velocity. The CNT particle number in the agglomerates increased with increasing of gas velocity. Aspect ratio increased and circularity, roundness and solidity decreased with increasing of gas velocity. A possible mechanism of agglomerates formation was proposed based on the obtained information.