Studies on the Coulter Counter Part II. Investigations into the Effect of Flow Direction and Angle of Entry of a Particle on both Particle Volume and Pulse Shape

Davies, R.; Karuhn, R.; Graf, J.

doi:10.1016/0032-5910(75)80007-6

Cited by 18 publications

(3 citation statements)

References 6 publications

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“…The nature of particles in lake water and a review of the papers on principles of electronic sizing of particles (e.g. Gsegg and Steidley 1965;Eckhoff 1969;Grover et al 1969;Kubitschek 1969;Thom et al 1969;Zirnrnerman 19741, b;Davies et al 1975;Karuhn et al 1975;KacheE 1976) suggested two possible explanations for poor count overlap. The first hypothesis argues that elongated algae in lake water samples were undersized by the shorter sensing zones of the snaaller aperture tubes.…”

Section: Resultsmentioning

confidence: 97%

Effect of the Algal Length/Aperture Length Ratio on Coulter Analyses of Lake Seston

Vanderploeg¹

1981

Can. J. Fish. Aquat. Sci.

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Great Lakes Environments! ResearchLaboratory, M O M , Ann Arbor, MI 48804, USA VAWDERPLOEG, M. A. 1981. Effect of the algal lengtwaperture length ratio on Coulter analyses of lake seston. Can. J. Fish. Aquat. Sci. 38: 912-916.Experiments on sizing seston and nylon rods in Coulter apertures of different sizes showed that a major difficulty in obtaining a continuous particle-size spectrum for Iake seston is the presence of long, thin algae which are significantly undersized unless their lengths are shorter than aperture length. These fibers affect not only the choice of the largest aperture tube required but also the combination of aperture tubes necessary to obtain a continuous particlesize spectrum. Methods are given for selecting aperture tubes and blending the data obtained from them to give a best estimate of the continusus particle-size spectrum.

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Section: Resultsmentioning

confidence: 97%

Effect of the Algal Length/Aperture Length Ratio on Coulter Analyses of Lake Seston

Vanderploeg¹

1981

Can. J. Fish. Aquat. Sci.

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“…[5] and [6] can be rewritten as Eqs. [12] through [14], in dimensionless form, using cylindrical coordinates (the asterisk has been omitted): tions are zero-slip along and across, and zero electric current flux across, the insulating wall. At the inflow boundary, the following a moving particle, while D/Dt denotes a time derivative following a fluid element.…”

Section: A the Flow Field In The Eszmentioning

confidence: 99%

“…Many theoretical and experimental studies have been carried out on the electrical and hydrodynamic factors involved during the passage of a suspended particle in an aqueous electrolyte medium through an ESZ. [6,7,[10][11][12][13][14] A common feature of all these studies is the assumption that the path followed by the particle does not depend on the electric, but rather the hydrodynamic, field. This is because the electric currents applied in these aqueous systems are very weak, usually on the order of microamperes to milliamperes, as a result of the high electrical resistivity of the electrolyte.…”

Section: Introductionmentioning

confidence: 99%

Numerical studies of the motion of spheroidal particles flowing with liquid metals through an electric sensing zone

Guthrie

2000

Metall Mater Trans B

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A mathematical model has been developed to describe the motion of variously shaped and oriented spheroids entrained in liquid metals passing through a cylindrical electric sensing zone (ESZ) developed for liquid metals cleanliness analyzer (LiMCA) systems. The fluid velocity field within the ESZ was obtained by solving the Navier-Stokes equations, while the trajectories of particles within the ESZ were calculated using the equations of motion for particles. These incorporate forces resulting from drag, added mass, history, and electromagnetic and fluid acceleration balanced against the time rate of changes in a particle momentum. The effects of particle or inclusion shape and orientation were taken into account by including correction factors for drag (R D ), added mass (M A ), history (B), and electromagnetic force (E M ). The numerical results show that particle trajectories are affected by the magnetic pressure number (R H ), the Reynolds number (Re), the blockage ratio (k), and the particlefluid density ratio (␥). In the axial direction, spheroidal particles travel further axially before hitting the wall as the fluid velocity (Re) increases. In the radial direction, the outwardly directed electromagnetic force on nonconducting spheroids increases with radial distance from the axis, with increasing electric current (R H ) and with increasing size (k) of the particle. At low electric currents (low R H ), the competition between the electromagnetic force and the radial fluid acceleration force in the entrance region is predicted to result in particle movements first toward the central axis, before outward motion toward the wall, but directly toward the wall at large currents (high R H ). Spheroidal particles with symmetric axes perpendicular to the transverse axis of the ESZ move faster toward the sidewall as the particle aspect ratio (E ) increases. The dominating increase in the added mass force over the increase in the electromagnetic force with decreasing E makes this effect much stronger for oblates (E Ͻ 1) than for prolates (E Ͼ 1). The stronger drag force on a prolate with its symmetric axis parallel to the axis of the ESZ makes it move slower toward the wall than a prolate with its axis of symmetry perpendicular to the axis of the ESZ. Low-inertia (low-␥) spheroidal particles move faster toward the sidewall than do heavier particles. This effect of ␥ is stronger for prolates than for oblates traversing with their symmetric axes perpendicular to the axis of the ESZ, owing to the decreased added mass effect as E increases, while the effect of ␥ becomes much stronger for a prolate traversing with its symmetric axis perpendicular rather than parallel to the axis of the ESZ, owing to its smaller added mass. The radial particle velocity when approaching the wall is predicted to decrease due to the wall effects. This model has been applied to the movement of spheroidal inclusions within the ESZ of a LiMCA system in molten aluminum, and it was proven from the theoretical point of view that LiMCA systems could be...

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Stream Methods for Characterizing Fineparticles

Kaye

1998

Characterization of Powders and Aerosols

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Studies on the Coulter Counter Part II. Investigations into the Effect of Flow Direction and Angle of Entry of a Particle on both Particle Volume and Pulse Shape

Cited by 18 publications

References 6 publications

Effect of the Algal Length/Aperture Length Ratio on Coulter Analyses of Lake Seston

Effect of the Algal Length/Aperture Length Ratio on Coulter Analyses of Lake Seston

Numerical studies of the motion of spheroidal particles flowing with liquid metals through an electric sensing zone

Stream Methods for Characterizing Fineparticles

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