| bunsen burner | A small, widely-used piece of laboratory equipment which produces an adjustable gas flame for the purposes of heating chemical reactions and the short-term sterilisation of other small pieces of laboratory equipment. (09 Oct 1997) |
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| Bunsen's solubility coefficient | The milliliters of gas STPD dissolved per milliliter of liquid and per atmosphere (760 mm Hg) partial pressure of the gas at any given temperature. (05 Mar 2000) |
| burner | 1. One who, or that which, burns or sets fire to anything. 2. The part of a lamp, gas fixture, etc, where the flame is produced. <chemistry> Bunsen's burner, a kind of burner, invented by Professor Bunsen of Heidelberg, consisting of a straight tube, four or five inches in length, having small holes for the entrance of air at the bottom. Illuminating gas being also admitted at the bottom, a mixture of gas and air is formed which burns at the top with a feebly luminous but intensely hot flame. Argand burner, Rose burner, etc. See Argand, Rose, etc. Source: Websters Dictionary (01 Mar 1998) |
| burner syndrome | <syndrome> Multiple episodes of upper extremity burning pain, sometimes accompanied by shoulder girdle weakness, experienced during contact sports, especially football, with each forceful blow to the head or shoulder; attributed to an upper trunk brachial plexopathy. (05 Mar 2000) |
| Bunsen, Robert | <person> German chemist and physicist, 1811-1899. See: Bunsen burner, Bunsen's solubility coefficient, Bunsen-Roscoe law. (05 Mar 2000) |
| Bunsen-Roscoe law | In two photochemical reactions, e.g., the darkening of a photographic plate or film, if the product of the intensity of illumination and the time of exposure are equal, the quantities of chemical material undergoing change will be equal; the retina for short periods of exposure obeys this law. Synonym: reciprocity law, Roscoe-Bunsen law. (05 Mar 2000) |
| Roscoe-Bunsen law | In two photochemical reactions, e.g., the darkening of a photographic plate or film, if the product of the intensity of illumination and the time of exposure are equal, the quantities of chemical material undergoing change will be equal; the retina for short periods of exposure obeys this law. Synonym: reciprocity law, Roscoe-Bunsen law. (05 Mar 2000) |
| absorption coefficient | <physics> Measures the degree of wave absorption defined as the fraction of wave energy lost as the wave travels a unit distance. See: absorption. (15 Jan 1998) |
| activity coefficient | <chemistry> The factor by which the value of a concentration of a solute must be multiplied to determine its true thermodynamic activity. (06 May 1997) |
| attenuation coefficient | 1. <radiobiology> Compton: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing as a result of Compton effect interactions. 2. Linear: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing due to all absorption and scattering processes. 3. Pair Production: That fractional decrease in the intensity of a beam of ionising radiation due to pair production in a medium through which it passes. 4. Photoelectric Effect: That fractional decrease in the intensity of a beam of ionising radiation due to photoelectric effect in a medium through which it passes. (16 Dec 1997) |
| biological coefficient | Rarely used term denoting the energy expended by the body at rest. (05 Mar 2000) |
| velocity coefficient | The rate of transformation of a unit mass of substance in a chemical reaction. (05 Mar 2000) |
| recombination coefficient | <radiobiology> The rate of recombination of positive ions with electrons (or negative ions) in a gas, per unit volume, divided by the product of the particle densities of the two species (positive ions and electrons/negative ions) involved. (09 Oct 1997) |
| mass attenuation coefficient | <physics> The mass attenuation coefficient, u/p, of a material for uncharged ionising particles is the quotient of DN/N by pdl, where DN/N is the fraction of particles that experience interactions in traversing a distance dl in a material of density p. (16 Dec 1997) |
| mass energy absorption coefficient | <physics> The mass energy absorption coefficient, uen/p of a material for uncharged ionising particles is the product of the mass energy transfer coefficient, utr/p and (1 - g) where g is the fraction of the energy of secondary charged particles that is lost to bremsstrahlung in the material. (16 Dec 1997) |