Results 211 to 220 of about 202,714 (259)

Residence Time Distribution Model for Soil Filters

Water Environment Research, 2004
Pulse tracer tests were carried out to determine the residence time distribution (RTD) in earthworm‐cultured and uncultured, laboratory‐scale soil filters. A two‐parallel‐cell dispersion model for the mixing behavior in soil filters is presented; the model showed excellent fit to experimental data.
PATTANAIK, BR, GUPTA, A, SHANKAR, HS
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RESIDENCE TIME DISTRIBUTIONS AND MICROMIXING

Chemical Engineering Communications, 1981
Abstract This review is concerned primarily with the Lagrangian approach to mixing. First, the concepts of residence time and residence time distribution are introduced and defined. After a general treatment of this topic in the second chapter, the concept of micromixing is discussed in the third chapter with due emphasis on the application to chemical
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Measurement of residence times and residence-time distributions

1986
It is not the intention of this chapter to treat exhaustively the theory of residence-time measurements; there are many excellent textbooks on the subject1,2. A brief review of ideal and non-ideal models, together with an indication of how the more important parameters of the models may be calculated, is sufficient for our purposes.
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Perspectives in residence-time distributions

Chemical Engineering Science, 1983
Abstract A short history is given of the development of interest in residence-time distributions. Attention is concentrated on the role played in this development by Danckwerts' 1953 paper [6]. This defined the residence-time functions in the form now customarily used, and much subsequent development remains based on the approaches laid out in [6 ...
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Determination of residence times and residence time distributions by the integrated pulse method

The International Journal of Applied Radiation and Isotopes, 1968
Abstract It is well-known that residence times and residence time distributions of complicated industrial systems can be determined with the aid of radioactive tracers. Most of the methods in use require accurrate determination of the amount of activity which is injected into the system and good calibration of the detecting equipment.
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RESIDENCE TIME DISTRIBUTIONS IN A JETLOOP REACTOR

Chemical Engineering Communications, 1995
Abstract The effect of residence time, jet position, jet size, catalyst mass and temperature on the recycle ratio in a jetloop reactor using a residence time distribution model is reported. The recycle ratio goes through a maximum as residence time changes. The recycle ratio increases as jet size, catalyst mass and temperature are reduced.
K. P. MOLLER, J. C. Q. FLETCHER, C. T. O'CONNOR, R. J. BECKER   +3 more
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Tracer curves and the residence time distribution

Chemical Engineering Science, 1970
Abstract For a pulse input the shape of the output tracer curve depends on the way tracer is distributed across the flowing fluid, and the way it is measured. This paper properly relates the different curves which may be obtained for flows with negligible cross diffusion, and shows which one of these represents directly the residence time ...
Octave Levenspiel, B.W. Lai, C.Y. Chatlynne   +2 more
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Use of gamma distributed residence times in pharmacokinetics

European Journal of Clinical Pharmacology, 1983
Using a nonclassical statistically based pharmacokinetic concept, a theory is presented which can be applied to the analysis of concentration-time data fitted by power functions of time C = At-ae-bt, which is shown to be equivalent to the assumption of gamma distributed residence times of drugs. The shape and scale parameters a and b, respectively, are
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On the residence time distribution in idealized groundwatersheds

Journal of Hydrology, 1995
The relative cumulative frequency distribution of residence times F(T) is calculated for an entire groundwatershed under steady-state conditions and assuming Dupuit-Forchheimer flow. It appears that F(T) is always the same: F(T) = 1 -exp(−TT), provided that the aquifer recharge rate and T are constant over the groundwatershed.
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Residence time distribution in continuous crystallisers

Journal of Applied Chemistry, 1970
AbstractThe theory of continuous crystallisation (especially of sucrose) in crystallisers connected in series, in which a suspension of growing crystals is fed forward through the system without backmixing, is presented, and the calculation of the minimum coefficient of variation that can be attained under stated conditions is described.
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