Transport Number


Also found in: Medical.

transport number

[′tranz‚pȯrt ‚nəm·bər]
(physical chemistry)
The fraction of the total current carried by a given ion in an electrolyte. Also known as transference number.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Transport Number

 

(or transference number), a quantity used in electrochemical calculations. It is the ratio of the current carried by a given ionic species through a cross section of an electrolytic solution to the total current passing through the cross section. The transport number is equal to the ratio of the velocity, or mobility, of a given ion to the sum of the velocities, or mobilities, of the cation and anion. It is a characteristic dependent on the mobilities of all the ions in the electrolytic solution, on the concentrations of the ions, and on the temperature of the solution.

The transport number is usually determined by the Hittorf method—that is, by the change in the concentrations of the ions near the electrodes. During electrolysis, ions, owing to solvation, transport not only electric charge but also the solvent in their solvation sheaths. For this reason, transport numbers determined by the Hittorf method are called apparent transport numbers—in contrast to true transport numbers, which take into account only the velocities of the ions.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
where [t.sub.+,CEM] is the transport number of cation in cation exchange membranes and [t.sub.-,AEM] is the transport number of anion in anion exchange membrane.
The first step of algorithm chooses the suppliers and the yearly transport number by paper (Nagy et al., 2003).
Only those ions with a sufficiently high transport number will be efficiently extracted.
where [J.sub.i] is the flux of the ith ion, [t.sub.i] is its transport number, and [z.sub.i] is the valence; F is Faraday's constant; and I is the total current.
The transport numbers ([t.sup.+]) or also known as transference numbers are equivalent to the total contribution of ionic and electronic in solid electrolytes.
The Middle East will record a 7.1% increase in passenger transport numbers annually until the year 2029, while it will be 6.8% annual growth for the freight segment.
The Middle East region will record 7.1 per cent increase in passenger transport numbers annually until the year 2029, while it will be 6.8 per cent annual growth for the freight segment.
With the Metro already leading public transport numbers in Dubai with a daily ridership of 160,000, the new stretch is expected to expand the mass transit culture with an expected initial daily ridership of 100,000 more people.
Among these are the mechanism of current flow in electrolyte solutions, the nature of electrode potentials, and the values of the transport numbers in diffusion layers.
A combination of reduced transport numbers and a less-favorable Medicare fee schedule is causing the department's receipts from ambulance calls to drop by about $450,000 from the $6.2 million collected in the fiscal year that ended June 30.

Full browser ?