| Rahn-Otis sample | An approximation of alveolar gas continuously provided by a simple device that admits just the latter part of each expiration. (05 Mar 2000) |
|---|---|
| random sample | A group selected randomly, solely by chance. (12 Dec 1998) |
| Haldane-Priestley sample | <physiology> An approximation of alveolar gas obtained from the end of a sudden maximal expiration into a Haldane tube. (05 Mar 2000) |
| probability sample | Each individual in the sample has a known, generally equal, chance of being selected. (05 Mar 2000) |
| sample | 1. A specimen of a whole entity small enough to involve no threat or damage to the whole; an aliquot. 2. A selected subset of a population; a sample may be random or nonrandom (haphazard); representative or nonrepresentative. Origin: M.E. Ensample, fr. L. Exemplum, example (05 Mar 2000) |
| sample, random | A group selected randomly, solely by chance. (12 Dec 1998) |
| sample size | The number of units (persons, animals, patients, specified circumstances, etc.) in a population to be studied. The sample size should be big enough to have a high likelihood of detecting a true difference between two groups. (12 Dec 1998) |
| stratified sample | A subset of a total population, defined by some objective criterion such as age or occupation, is sampled. (05 Mar 2000) |
| end-tidal sample | A sample of the last gas expired in a normal expiration, ideally consisting only of alveolar gas. (05 Mar 2000) |
| atomic number | <chemistry> Symbol Z. The number of protons in the nucleus of an atom and also its characteristic atomic number. The atomic numbers of the known elements form a complete series from 1 (hydrogen) to 103 (lawrencium). (16 Dec 1997) |
| Avogadro's number | <physics> The number of molecules in a mole (gram molecular weight) of a substance, equals 6.02 x 1023 molecules. (09 Oct 1997) |
| Brinell hardness number | A number related to the size of the permanent impression made by a ball indenter of specified size (usually 10 mm in diameter) pressed into the surface of the material under a specified load: where P = applied load in kg, D = diameter of the ball in mm, and d = diameter of the impression in mm. (05 Mar 2000) |
| burst number | The number of viral particles that emerge from a cell after a viralinfection has burst it open. (09 Oct 1997) |
| Mach number | A number representing the ratio between the speed of an object moving through a fluid medium, such as air, and the speed of sound in the same medium. (05 Mar 2000) |
| magnetic mach number | <physics> A dimensionless number equal to the ratio of the velocity of a fluid to the velocity of Alfven waves in that fluid. (13 Nov 1997) |