| farding-bag | The upper stomach of a cow, or other ruminant animal; the rumen. Origin: Of uncertain origin; cf. Fardel. Source: Websters Dictionary (01 Mar 1998) |
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| Abbe limit | <physics> Ernst Abbe's specification for the limit of resolution of a diffraction-limited micro-scope. According to Abbe, a detail with a particular spacing in the specimen is resolved when the numerical aperture of the objective lens is large enough to capture the first-order diffraction pattern produced by the detail at the wavelength employed. See: Rayleigh criterion, Sparrow limit. (05 Aug 1998) |
| beta limit | <radiobiology> if the plasma pressure in a tokamak becomes too high, the so-called ballooning modes become unstable and lead to a loss of confinement (sometimes catastrophic, sometimes not). The exact value at which this occurs depends strongly on the magnetic field B, the plasma minor radius a, and the toroidal plasma current I, such that maximum value of the normalised beta, beta_N=betaBa/I, is around 4% (with B in Teslas, a in metres, and I in Mega-amperes). The exact value depends on details of the plasma shape, the plasma profiles, and the safety factor. Synonym: troyon limit. (09 Oct 1997) |
| visibility, limit of | <microscopy> For the normal eye, the limit of visibility is considerably below the limits of resolution. It depends largely on contrast and intensity of illumination. (05 Aug 1998) |
| central limit theorem | The sum (or average) of n realizations of the same process, provided only that it has a finite variance, will approach the gaussian distribution as n becomes indefinitely large. This theory provides a broad warrant for the use of normal theory even for nongaussian data. In the form stated here, it constitutes the classical version; more general versions allow serious relaxation of the usual assumptions. (05 Mar 2000) |
| permissible exposure limit | An occupational health standard to safeguard workers against dangerous contaminants in the workplace. (05 Mar 2000) |
| control limit | A regulatory value applied to the airborne concentration in the workplace of a potentially poisonous substance which is judged to be reasonably practicable for the whole spectrum of work activities and which must not normally be exceeded. (09 Oct 1997) |
| Hayflick's limit | <cell culture> The limit of human cell division in subcultures; such cells will divide only about 50 times before dying out. (05 Mar 2000) |
| proportional limit | The greatest stress that a material is capable of sustaining without any deviation from proportionality of stress to strain (Hooke's law). (05 Mar 2000) |
| short-term exposure limit | The maximum concentration of a chemical to which workers may be exposed continuously for up to 15 minutes without danger to health or work efficiency and safety. (05 Mar 2000) |
| sparrow limit | <microscopy> The spatial frequency at which the modulation transfer function just becomes 0. See: Abbe limit, Rayleigh criterion. (05 Aug 1998) |
| dextrin limit | The polysaccharide fragments remaining at the end (limit) of exhaustive hydrolysis of amylopectin or glycogen by alpha-1,4-glucan maltohydrolase, which cannot hydrolyze the alpha-1,6 bonds at branch points; accumulates in individuals with type III glycogen storage disease. Synonym: dextrin limit. (05 Mar 2000) |
| quantum limit | The shortest wavelength found in an X-ray spectrum. (05 Mar 2000) |
| threshold limit value | The maximum concentration of a chemical recommended by the American Conference of Government Industrial Hygienists for repeated exposure without adverse health effects on workers. (05 Mar 2000) |
| elastic limit | The greatest stress to which a material may be subjected and still be capable of returning to its original dimensions when the forces are released. (05 Mar 2000) |