| soil pore | An area within soil occupied by either air or water, resulting from the arrangement of individual soil particles. (09 Oct 1997) |
|---|---|
| soil profile | A vertical section of the soil through all its horizons and extending into the parent material. (09 Oct 1997) |
| soil series | A group of soils having horizons similar in differentiating characteristics and arrangements in the soil profile, except for texture of the surface layer. (09 Oct 1997) |
| soil structure | The combination or arrangement of primary soil particles into secondary particles, units or peds. (09 Oct 1997) |
| soil suborder | Second highest taxonomic level of the current U.S. Soil classification system. (09 Oct 1997) |
| soil surface | The upper limits of the soil profile, for mineral soils, the upper limits of the highest mineral horizon (A-horizon), for organic soils, the upper limit of undecomposed organic matter. (09 Oct 1997) |
| soil texture | The relative proportions of the various sizes of particles (silt, sand and clay) in a soil. (09 Oct 1997) |
| somewhat poorly drained soil | <botany> A condition in which water is removed slowly enough that the soil is wet for significant periods during the growing season. (04 Mar 1998) |
| expansive soil | Soils that swell when they absorb water and shrink as they dry. (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) |