| baseload demand | The minimum demand experienced by an electric utility, usually 30-40% of the utility's peak demand. (05 Dec 1998) |
|---|---|
| biochemical oxygen demand | The amount of oxygen aerobicorganisms need to carry out oxidative metabolism in watercontaining organic matter, such as sewage. (09 Oct 1997) |
| chemical oxygen demand | The amount of dissolved oxygen required to combine with chemicals in wastewater. A measure of the oxygen equivalent of that portion of organic matter that is susceptible to oxidation by a strong chemical oxidizing agent. (05 Dec 1998) |
| health services needs and demand | Health services required by a population or community as well as the health services that the population or community is able and willing to pay for. It includes the identification and assessment of the needs as measured by objective criteria and standards. (12 Dec 1998) |
| demand | A quantity of a substance, commodity, or service wanted or required. (05 Mar 2000) |
| demand pacemaker | A form of artificial pacemaker usually implanted into cardiac tissue because its output of electrical stimuli can be inhibited by endogenous cardiac electrical activity. (05 Mar 2000) |
| demand pulse generator | A generator which suppresses its output in response to natural ventricular activity but which, in the absence of such activity, functions as an asynchronous pulse generator. Synonym: demand pulse generator, standby pulse generator. (05 Mar 2000) |
| anaemic hypoxia | Hypoxia resulting from a decreased concentration of functional haemoglobin or a reduced number of erythrocytes; it is caused by haemorrhage or anaemia of various types, or by poisoning with CO2, nitrites, or chlorates. (05 Mar 2000) |
| cell hypoxia | A condition of decreased oxygen content at the cellular level. (12 Dec 1998) |
| cerebral hypoxia | A lack of oxygen to the cerebral hemispheres (the brain). Depending on the duration and extent of hypoxia, symptoms can be mild (for example lethargy) or serious neurologic damage can result (for example coma, seizures, death). (27 Sep 1997) |
| hypoxia | Reduction of oxygen supply to tissue below physiological levels despite adequate perfusion of the tissue by blood. (cf. Anoxia). (18 Nov 1997) |
| hypoxia-ischemia | See hypoxia. Ischemia refers to blood flow to cells and organs that is not sufficient to maintain their normal function. (12 Dec 1998) |
| hypoxia warning system | A device designed to produce an audio or visual signal at a predetermined level of oxygen partial pressure; ideally, the system would warn of impending hypoxia in time for corrective action to be taken. (05 Mar 2000) |
| hypoxic hypoxia | Hypoxia resulting from a defective mechanism of oxygenation in the lungs; may be caused by a low tension of oxygen, abnormal pulmonary function or respiratory obstruction, or a right-to-left shunt in the heart. (05 Mar 2000) |
| stagnant hypoxia | Tissue hypoxia characterised not by tissue oligaemia (tissue blood volume being normal or even increased), but by intravascular stasis due to impairment of venous outflow or (in some instances) to decreased arterial inflow. (05 Mar 2000) |