In
mass transfer
Mass transfer is the net movement of mass from one location (usually meaning stream, phase, fraction, or component) to another. Mass transfer occurs in many processes, such as absorption, evaporation, drying, precipitation, membrane filtra ...
, the sieving
coefficient
In mathematics, a coefficient is a Factor (arithmetic), multiplicative factor involved in some Summand, term of a polynomial, a series (mathematics), series, or any other type of expression (mathematics), expression. It may be a Dimensionless qu ...
is a measure of
equilibration between the
concentration
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', '' molar concentration'', '' number concentration'', ...
s of two mass transfer streams. It is defined as the
mean
A mean is a quantity representing the "center" of a collection of numbers and is intermediate to the extreme values of the set of numbers. There are several kinds of means (or "measures of central tendency") in mathematics, especially in statist ...
pre- and post-contact concentration of the mass receiving stream divided by the pre- and post-contact concentration of the mass donating stream.
where
* ''S'' is the sieving coefficient
* ''C''
r is the mean concentration mass receiving stream
* ''C''
d is the mean concentration mass donating stream
A sieving coefficient of
unity
Unity is the state of being as one (either literally or figuratively). It may also refer to:
Buildings
* Unity Building, Oregon, Illinois, US; a historic building
* Unity Building (Chicago), Illinois, US; a skyscraper
* Unity Buildings, Liverpoo ...
implies that the concentrations of the receiving and donating stream equilibrate, i.e. the out-
flow concentrations (post-mass transfer) of the mass donating and receiving stream are equal to one another. Systems with sieving coefficient that are greater than one require an external
energy
Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...
source, as they would otherwise violate the
laws of thermodynamics
The laws of thermodynamics are a set of scientific laws which define a group of physical quantities, such as temperature, energy, and entropy, that characterize thermodynamic systems in thermodynamic equilibrium. The laws also use various param ...
.
Sieving coefficients less than one represent a mass transfer process where the concentrations have not equilibrated.
Contact time between mass streams is important in consider in mass transfer and affects the sieving coefficient.
In kidney
In
renal physiology
Renal physiology (Latin language, Latin ''renes'', "kidneys") is the study of the physiology of the kidney. This encompasses all functions of the kidney, including maintenance of acid-base balance; regulation of fluid balance; regulation of sodiu ...
, the glomerular sieving coefficient (GSC) can be expressed as:
sieving coefficient =
clearance /
ultrafiltration rateSieving coefficient in drug clearance
- cuhk.edu.hk
See also
*Heat exchanger
A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contac ...
* Condenser pinch point
*Sieve
A sieve (), fine mesh strainer, or sift is a tool used for separating wanted elements from unwanted material or for controlling the particle size distribution of a sample, using a screen such as a woven mesh or net or perforated sheet m ...
References
Transport phenomena
Chemical engineering
Mechanical engineering