| heating curve | <chemistry> A plot of temperature verses time for a substance where energy is added at a constant rate. (09 Jan 1998) |
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| district heating or cooling | A system that involves the central production of hot water, steam, or chilled water and the distribution of these transfer media to heat or cool buildings. (05 Dec 1998) |
| electron cyclotron heating | <physics, radiobiology> Radiofrequency heating scheme that works by injecting electromagnetic wave energy at the electron cyclotron gyration frequency. The electric field of the electromagnetic wave at this frequency looks to a gyrating electron like a static electric field, and thus causes large acceleration of the electron (larger than if the frequency were off the cyclotron frequency and thus, to the electron, appearing to change direction as a function of time). The accelerated electron gains energy, which is then shared with other particles through collisions, resulting in heating. Higher harmonics (multiples) of the cyclotron frequency can also be used in principle. (09 Oct 1997) |
| turbulent heating | <radiobiology> Technique of using turbulence induced by large electric fields to rapidly heat a plasma, the turbulence increases the resistivity of the plasma. (09 Oct 1997) |
| acetyl value | The milligrams of KOH required to neutralise the acetic acid produced by the hydrolysis of 1 g of acetylated fat; a measure of the hydroxy acids present in glycerides; notably high in castor oil. (05 Mar 2000) |
| beta, or beta-value | <radiobiology> Ratio of plasma kinetic pressure to magnetic-field pressure, proportional to the ratio of plasma kinetic energy density to magnetic field energy density. Beta is usually measured relative to the total, local field (loosely called beta toroidal), but sometimes the plasma pressure relative to only the poloidal component of the field (beta poloidal) or relative to some external field (like the maximum field at the magnetic coils) is more useful. There is also a normalised beta (beta_N) of interest when discussing the beta limit. (lots of help from Art Carlson with the above.) Because the cost of a reactor is strongly influenced by the strength of the magnetic field that must be provided, beta values are directly related to the economics of fusion power production. Beta is usually expressed as a percentage, with 5% generally believed to be the minimum value required for an economical fusion reactor. See: pressure, kinetic pressure, magnetic pressure, second stability. (09 Oct 1997) |
| biological value | <nutrition> The nutritional value of a protein, usually measured in comparison to the nutritional value of egg protein, which is the highest possible (BV=0.9 - 1.00). (21 Mar 1998) |
| buffer value | The power of a substance in solution to absorb acid or alkali without change in pH; this is highest at a pH value equal to the pKa value of the acid of the buffer pair. See: buffer capacity. Synonym: buffer index. (05 Mar 2000) |
| buffer value of the blood | The ability of the blood to compensate for additions of acid or alkali without disturbance of the pH. (05 Mar 2000) |
| caloric value | The heat evolved by a food when burnt or metabolised. (05 Mar 2000) |
| value | 1. The property or aggregate properties of a thing by which it is rendered useful or desirable, or the degree of such property or sum of properties; worth; excellence; utility; importance. "Ye are all physicians of no value." (Job xiii. 4) "Ye are of more value than many sparrows." (Matt. X. 31) "Caesar is well acquainted with your virtue, And therefore sets this value on your life." (Addison) "Before events shall have decided on the value of the measures." (Marshall) 2. Worth estimated by any standard of purchasing power, especially by the market price, or the amount of money agreed upon as an equivalent to the utility and cost of anything. "An article may be possessed of the highest degree of utility, or power to minister to our wants and enjoyments, and may be universally made use of, without possessing exchangeable value." (M'Culloch) "Value is the power to command commodities generally." (A. L. Chapin (Johnson's Cys)) "Value is the generic term which expresses power in exchange." (F. A. Walker) "His design was not to pay him the value of his pictures, because they were above any price." (Dryden) In political economy, value is often distinguished as intrinsic and exchangeable. Intrinsic value is the same as utility or adaptation to satisfy the desires or wants of men. Exchangeable value is that in an article or product which disposes individuals to give for it some quantity of labour, or some other article or product obtainable by labour; as, pure air has an intrinsic value, but generally not an exchangeable value. 3. Precise signification; import; as, the value of a word; the value of a legal instrument 4. Esteem; regard. "My relation to the person was so near, and my value for him so great" (Bp. Burnet) 5. The relative length or duration of a tone or note, answering to quantity in prosody; thus, a quarter note has the value of two eighth notes . 6. In an artistical composition, the character of any one part in its relation to other parts and to the whole; often used in the plural; as, the values are well given, or well maintained. 7. Valor. Alternative forms: valew] Value received, a phrase usually employed in a bill of exchange or a promissory note, to denote that a consideration has been given for it. Origin: OF. Value, fr. Valoir, p. P. Valu, to be worth, fr. L. Valere to be strong, to be worth. See Valiant. Source: Websters Dictionary (01 Mar 1998) |
| maturation value | An indicator of the level of maturation attained by vaginal epithelium and used as a factor in cytohormonal evaluation from the maturation index by valuing the parabasal cells at 0.0, the intermediate cells at 0.5, and the superficial cells at 1.0; for special investigations, subtypes of a major cell can be given different values's. (05 Mar 2000) |
| relative value scales | Coded listings of physician or other professional services using units that indicate the relative value of the various services they perform. They take into account time, skill, and overhead cost required for each service, but generally do not consider the relative cost-effectiveness. Appropriate conversion factors can be used to translate the abstract units of the relative value scales into dollar fees for each service based on work expended, practice costs, and training costs. (12 Dec 1998) |
| ceiling value | <pharmacology> The ceiling value is the maximum safe airborne concentration of a potentially toxic substance and is a concentration that should never be exceeded in an area where people are breathing. (26 Mar 1998) |
| gray level also gray value | <microscopy> The brightness of pixels in a digitised video image, commonly expressed in integers ranging from 0 (black) to 255 (white) for an 8-bit digital signal. (05 Aug 1998) |