| higher heating value | (HHV) The maximum potential energy in dry fuel. For wood, the range is 7,600 to 9,600 Btu/lb. (05 Dec 1998) |
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| gross heating value | (GHV) The maximum potential energy in the fuel as received. It reflects the displacement of fibre by water present in the fuel. Expressed as: GHV = HHV (1 - MC / 100) (05 Dec 1998) |
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| heating value | The maximum amount of energy that is available from burning a substance. (05 Dec 1998) |
| net heating value | The potential energy available in the fuel as received, taking into account the energy loss in evapourating and superheating the water in the sample. Expressed as NVH = (HHV x (1- MC / 100)) - (LH(2)O x MC / 100) (05 Dec 1998) |
| lower heating value | (LHV) The potential energy in a fuel if the water vapour from combustion of hydrogen is not condensed. (05 Dec 1998) |
| mean higher high water | <marine biology> The average height of the higher high water over a 19-year period. For shorter periods of observation, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. (09 Oct 1997) |
| higher order conditioning | The use of a previously conditioned stimulus to condition further responses, in much the same way unconditioned stimuli are used. (05 Mar 2000) |
| radio frequency heating | <radiobiology> Process for heating the plasma by transferring energy to ions or electrons using waves generated by an external oscillator at an appropriate frequency. (This is similar to how a microwave oven heats food.) There are various types: See: ECRH, ICRH, and Lower Hybrid. (09 Oct 1997) |
| heating | That heats or imparts heat; promoting warmth or heat; exciting action; stimulating; as, heating medicines or applications. Heating surface, the aggregate surface exposed to fire or to the heated products of combustion, especially. Of all the plates or sheets that are exposed to water on their opposite surfaces. Synonym: fire surface. Source: Websters Dictionary (01 Mar 1998) |
| heating curve | <chemistry> A plot of temperature verses time for a substance where energy is added at a constant rate. (09 Jan 1998) |
| 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) |