| Bohn's nodules | Tiny multiple cysts in newborns. They are found at the junction of the hard and soft palates and along buccal and lingual parts of the dental ridges and are derived from epithelial remnants of mucous gland tissue. (05 Mar 2000) |
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| Bohn, Heinrich | <person> German physician, 1832-1888. See: Bohn's nodules. (05 Mar 2000) |
| Bohr effect | <physiology> Decrease in oxygen affinity of haemoglobin when pH decreases or concentration of carbon dioxide increases. (18 Nov 1997) |
| Bohr's atom | A concept or model of the atom in which the negatively charged electrons move in circular or elliptical orbits around the positively charged nucleus, energy being emitted or absorbed when electrons change from one orbit to another. (05 Mar 2000) |
| Bohr's equation | An equation to calculate the respiratory dead space from the fact that gas expired from the lungs is a mixture of gas from the dead space and gas from the alveoli, i.e., the dead space volume divided by the tidal volume equals the difference between alveolar and mixed expired gas composition, divided by the difference between alveolar and inspired gas composition; gas composition can be expressed in any consistent units of concentration or partial pressure of oxygen or carbon dioxide. (05 Mar 2000) |
| Bohr's theory | That spectrum lines are produced 1) by the quantised emission of radiant energy when electrons drop from an orbit of a higher to one of a lower energy level, or 2) by absorption of radiation when an electron rises from a lower to a higher energy level. (05 Mar 2000) |
| Bohr, Christian | <person> Danish physiologist, 1855-1911. See: Bohr effect, Bohr's equation. (05 Mar 2000) |
| Bohr, Neils | <person> Danish physicist and Nobel laureate, 1885-1962. See: Bohr's atom, Bohr magneton, Bohr's theory. (05 Mar 2000) |
| boidae | A family of snakes comprising the boas, anacondas, and pythons. They occupy a variety of habitats through the tropics and subtropics and are arboreal, aquatic or fossorial (burrowing). Some are oviparous, others ovoviviparous. Contrary to popular opinion, they do not crush the bones of their victims: their coils exert enough pressure to stop a prey's breathing, thus suffocating it. There are five subfamilies: boinae, bolyerinae, erycinae, pythoninae, and tropidophiinae. (goin, goin, and zug, introduction to herpetology, 3d ed, p315-320) (12 Dec 1998) |
| boil | 1. To heat to the boiling point, or so as to cause ebullition; as, to boil water. 2. To form, or separate, by boiling or evaporation; as, to boil sugar or salt. 3. To subject to the action of heat in a boiling liquid so as to produce some specific effect, as cooking, cleansing, etc.; as, to boil meat; to boil clothes. "The stomach cook is for the hall, And boileth meate for them all." (Gower) 4. To steep or soak in warm water. "To try whether seeds be old or new, the sense can not inform; but if you boil them in water, the new seeds will sprout sooner." (Bacon) To boil down, to reduce in bulk by boiling; as, to boil down sap or sirup. 1. To be agitated, or tumultuously moved, as a liquid by the generation and rising of bubbles of steam (or vapor), or of currents produced by heating it to the boiling point; to be in a state of ebullition; as, the water boils. 2. To be agitated like boiling water, by any other cause than heat; to bubble; to effervesce; as, the boiling waves. "He maketh the deep to boil like a pot." (Job xii. 31) 3. To pass from a liquid to an aeriform state or vapor when heated; as, the water boils away. 4. To be moved or excited with passion; to be hot or fervid; as, his blood boils with anger. "Then boiled my breast with flame and burning wrath." (Surrey) 5. To be in boiling water, as in cooking; as, the potatoes are boiling. To boil away, to vaporize; to evaporate or be evaporated by the action of heat. To boil over, to run over the top of a vessel, as liquid when thrown into violent agitation by heat or other cause of effervescence; to be excited with ardor or passion so as to lose self-control. Origin: OE. Boilen, OF. Boilir, builir, F. Bouillir, fr. L. Bullire to be in a bubbling motion, from bulla bubble; akin to Gr, Lith. Bumbuls. Cf. Bull an edict, Budge, v, and Ebullition. A hard, painful, inflamed tumour, which, on suppuration, discharges pus, mixed with blood, and discloses a small fibrous mass of dead tissue, called the core. A blind boil, one that suppurates imperfectly, or fails to come to a head. <medicine> Delhi boil, a peculiar affection of the skin, probably parasitic in origin, prevailing in India (as among the British troops) and especially at Delhi. Origin: Influenced by boil, v. See Beal, Bile. Source: Websters Dictionary (01 Mar 1998) |
| boiler | 1. One who boils. 2. A vessel in which any thing is boiled. The word boiler is a generic term covering a great variety of kettles, saucepans, clothes boilers, evaporators, coppers, retorts, etc. 3. <mechanics> A strong metallic vessel, usually of wrought iron plates riveted together, or a composite structure variously formed, in which steam is generated for driving engines, or for heating, cooking, or other purposes. The earliest steam boilers were usually spheres or sections of spheres, heated wholly from the outside. Watt used the wagon boiler (shaped like the top of a covered wagon) which is still used with low pressures. most of the boilers in present use may be classified as plain cylinder boilers, flue boilers, sectional and tubular boilers. Barrel of a boiler, the cylindrical part containing the flues. Boiler plate, Boiler iron, plate or rolled iron of about a quarter to a half inch in thickness, used for making boilers and tanks, for covering ships, etc. Cylinder boiler, one which consists of a single iron cylinder. Flue boilers are usually single shells containing a small number of large flues, through which the heat either passes from the fire or returns to the chimney, and sometimes containing a fire box inclosed by water. Locomotive boiler, a boiler which contains an inclosed fire box and a large number of small flues leading to the chimney. Multiflue boiler. Same as Tubular boiler, below. Sectional boiler, a boiler composed of a number of sections, which are usually of small capacity and similar to, and connected with, each other. By multiplication of the sections a boiler of any desired capacity can be built up. Tubular boiler, a boiler containing tubes which form flues, and are surrounded by the water contained in the boiler. Source: Websters Dictionary (01 Mar 1998) |
| boiler horsepower | A measure of the maximum rate of heat energy output of a steam generator. One boiler horsepower equals 33,480 Btu/hr output in steam. (05 Dec 1998) |
| boilermaker's deafness | Sensorineural hearing loss due to overexposure to high intensity noise levels. Synonym: boilermaker's deafness, industrial deafness, occupational deafness. (05 Mar 2000) |
| boiling | Heated to the point of bubbling; heaving with bubbles; in tumultuous agitation, as boiling liquid; surging; seething; swelling with heat, ardor, or passion. Boiling point, the temperature at which a fluid is converted into vapor, with the phenomena of ebullition. This is different for different liquids, and for the same liquid under different pressures. For water, at the level of the sea, barometer 30 in, it is 212 deg Fahrenheit; for alcohol.96 deg; for ether.8 deg; for mercury, about 675 deg . The boiling point of water is lowered one degree Fahrenheit for about 550 feet of ascent above the level of the sea. Boiling spring, a spring which gives out very hot water, or water and steam, often ejecting it with much force; a geyser. To be at the boiling point, to be very angry. To keep the pot boiling, to keep going on actively, as in certain games. Source: Websters Dictionary (01 Mar 1998) |
| boiling point | This is the temperature at which the vapor pressure of a given liquid reaches atmospheric pressure (and thus starts to boil). (09 Oct 1997) |