| heat instability test | A test for the presence of unstable haemoglobins; fresh red blood cells lysed in distilled water develop a precipitate within one hour at 50캜 if unstable haemoglobin is present. (05 Mar 2000) |
|---|---|
| heat-labile | Destroyed or altered by heat. (05 Mar 2000) |
| heat lamp | A lamp that emits infrared light and produces heat; used to apply topical heat to the skin. Synonym: thermolamp. (05 Mar 2000) |
| heat oedema | Oedema caused by excessively high external temperature. (05 Mar 2000) |
| heat of combustion | The quantity of heat liberated per gram-molecular weight when a substance undergoes complete oxidation. (05 Mar 2000) |
| heat of compression | Heat produced when a gas is compressed. (05 Mar 2000) |
| heat of crystallization | The quantity of heat liberated or absorbed per mol when a substance passes into the crystalline state. (05 Mar 2000) |
| heat of dissociation | The heat (expressed in calories or joules) expended in the dissociation of 1 mol of a substance into specified products. (05 Mar 2000) |
| heat of evaporation | The heat absorbed in the evaporation of water, sweat or other liquid; for water it amounts to 540 cal/g at 100캜. Synonym: heat of vaporization. (05 Mar 2000) |
| heat of formation | The heat (expressed in calories or joules) absorbed or liberated during the (hypothetical) reaction in which a mole of a compound is formed from the necessary elements, in elemental form. (05 Mar 2000) |
| heat of fusion | <chemistry> The enthalpy change that occurs to melt a solid at its melting point. (09 Jan 1998) |
| heat of hydration | <chemistry> The enthalpy change associated with placing gaseous molecules or ions in water. (09 Jan 1998) |
| heat of solution | <chemistry> The enthalpy change associated with dissolving a solute in a solvent. (09 Jan 1998) |
| heat of vaporization | <chemistry> The energy required to vaporise one mole of a liquid at a pressure of one atmosphere. (09 Jan 1998) |
| heat prostration | A form of heat illness that results when the victim is dehydrated (fluid depleted). Common symptoms include: fatigue, lightheadedness, nausea, vomiting, headache, rapid heartbeat and lowered blood pressure. (27 Sep 1997) |