# phenol coefficient

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## coefficient

[ko″ĕ-fish´ent]
1. an expression of the change or effect produced by the variation in certain variables, or of the ratio between two different quantities.
2. in chemistry, a number or figure put before a chemical formula to indicate how many times the formula is to be multiplied.
absorption coefficient absorptivity.
Bunsen coefficient the number of milliliters of gas dissolved in a milliliter of liquid at atmospheric pressure (760 mm Hg) and a specified temperature. Symbol, α.
confidence coefficient the probability that a confidence interval will contain the true value of the population parameter. For example, if the confidence coefficient is 0.95, 95 per cent of the confidence intervals so calculated for a large number of random samples would contain the parameter.
correlation coefficient a numerical value that indicates the degree and direction of relationship between two variables; the coefficients range in value from +1.00 (perfect positive relationship) to 0.00 (no relationship) to −1.00 (perfect negative or inverse relationship).
diffusion coefficient see diffusion coefficient.
coefficient of digestibility the proportion of a food that is digested compared to what is absorbed, expressed as a percentage.
dilution coefficient a number that expresses the effectiveness of a disinfectant for a given organism. It is calculated by the equation tcn = k, where t is the time required for killing all organisms, c is the concentration of disinfectant, n is the dilution coefficient, and k is a constant. A low coefficient indicates the disinfectant is effective at a low concentration.
linear absorption coefficient the fraction of a beam of radiation absorbed per unit thickness of absorber.
mass absorption coefficient the linear absorption coefficient divided by the density of the absorber.
phenol coefficient see phenol coefficient.
sedimentation coefficient the velocity at which a particle sediments in a centrifuge divided by the applied centrifugal field, the result having units of time (velocity divided by acceleration), usually expressed in Svedberg units (S), which equal 10−13 second. Sedimentation coefficients are used to characterize the size of macromolecules; they increase with increasing mass and density and are higher for globular than for fibrous particles.

## phenol

[fe´nol]
1. an extremely poisonous compound, used in dilute solution as an antimicrobial, anesthetic, and antipruritic. Ingestion or absorption through the skin causes symptoms including colic, local irritation, corrosion, seizures, cardiac arrhythmias, shock, and respiratory arrest. Phenol should be properly labeled and stored to avoid accidental poisoning. Called also carbolic acid.
2. any of various related organic compounds containing one or more hydroxyl groups attached to an aromatic carbon ring.
phenol coefficient a measure of the bactericidal activity of a chemical compound in relation to phenol. The activity of the compound is expressed as the ratio of dilution in which it kills in 10 minutes but not in 5 minutes under the specified conditions. It can be determined in the absence of organic matter, or in the presence of a standard amount of added organic matter.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

## Rid·e·al-Walk·er co·ef·fi·cient

(rid'ē-ăl wah'kĕr),
a figure expressing the disinfecting power of any substance; it is obtained by dividing the figure indicating the degree of dilution of the disinfectant that kills a microorganism in a given time by that indicating the degree of dilution of phenol that kills the organism in the same space of time under similar conditions.
Farlex Partner Medical Dictionary © Farlex 2012

## Rid·e·al-Walk·er co·ef·fi·cient

(rid'ē-ăl waw'kĕr kō'ĕ-fish'ĕnt)
A figure expressing the disinfecting power of any substance; obtained by dividing the figure indicating the degree of dilution of the disinfectant that kills a microorganism in a given time by the figure, indicating the degree of dilution of phenol that kills the organism in the same amount of time under similar conditions.
Synonym(s): phenol coefficient.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

## Rideal,

Samuel, English chemist and bacteriologist, 1863-1929.
Rideal-Walker coefficient - a figure expressing the disinfecting power of any substance. Synonym(s): hygienic laboratory coefficient; phenol coefficient
Rideal-Walker method