Bismuth is a brittle metal which is silvery in colour with a pink tinge.
Used in recording signals on a magnetic media (tape). As the tape passes the recording head, the head generates a varying magnetic field corresponding to the analogue signal to be recorded.
Bias Current
Current that flows through the base-emitter junction of a transistor and is adjusted to set the operating point of the transistor.
Bias Fabric
A fabric in which warp and fill fibres are at an angle to the length.
Bicarbonate of Ammonia
Alternative name for Ammonium Bicarbonate.
Bichat, Marie
French surgeon and anatomist who recognized that the organs of animals were composed of masses of substance to which the term tissue was applied.
Bi-Concave Lens
Having two outer surfaces that curve inward.
Biconic Geometry
Two cone structure configuration.
Bi-Convex Lens
Having two outer surfaces that curve outward.
Obsolete unit of distance referencing the double prefix micron-micron and equal to 10-12m.
This is an abbreviation for the latin phrase bis in die which translates to "twice a day".
A ligand that has two "teeth" or atoms that coordinate directly to the central atom in a complex.
Bidirectional Array
An array that radiates in opposite directions along the line of maximum radiation.
Bidirectional Laminate
A reinforced plastic laminate in which the fibres are oriented in more than one direction in the plane of the laminate.
Another name for 1,3-Butadiene.
Bifilar Winding
Two conductors wound in parallel.
Bifunctional Monomer
A monomer unit that has two active bonding positions.
Big Bang Theory
A theory that suggests that the universe started with a giant explosion.
Big End
The connection between the conrod and crankshaft in an internal combustion engine.
Big Endian
A byte ordering system where the most-significant byte of a multiple byte number is placed in memory at the lowest address.
Bihexagon Nut
A bolt or screw whose cross section of its head is in the shape of a 12 pointed star.
Another name for Dodecane.
A one-to-one onto transformation.
Abbreviation of billion, a number equal to 109.
Bilayer Lipid Membrane
The structure found in most biological membranes, in which two layers of lipid molecules are so arranged that their hydrophobic parts interpenetrate, whereas their hydrophilic parts form the two surfaces of the bilayer.
Bile Salts
Amphipathic steroid derivatives with detergent properties, participating in digestion and absorption of lipids.
Rectangular or square bar of raw material.
A number equal to 109.
Billion Cubic Feet of Gas Equivalent
This is really an energy unit equal to about 1.091 petajoules (PJ).
An alloy of copper and silver with more than 50% copper.

A unit of time equal to 2 months.
Bimetallic Couple
A joint or union of two dissimilar metals.
Bimetallic Strip
Two metals with different thermal expansion coefficients are bonded together and wound into a spiral.
Unit of time equal to 2000 years.
In the home entertainment context, pertaining to presentations involving the visual and auditory sensory modalities.
Bimolecular Step
Two species are reacting and form the transition state.
A set of emissions standards under the new U.S. Tier 2 emissions program.
Pertaining to a characteristic that involves the selection, choice, or condition in which there are only two possibilities.
Binary Coded Decimal
A number system where each decimal digit is separately represented by a 4-bit binary code.
Binary Coded Digit
A digit of any number system that is represented as a fixed number of binary digits
Binary Compound
A compound that contains two different elements.
Binary Notation
In order to understand how a number in binary notation is constructed, the decimal notation is first discussed.
Binary Number
A number written to base 2.
Binary Operation
An operation that involves two operands.
Binary Point
The radix point that separates powers of two and fractional powers of two in a binary number.
Binary Star
Pair of stars bound together by mutual gravitation and orbiting their common centre of mass.
A situation involving listening with two ears.
Binding Energy
The amount of energy required to take a nucleus apart.
An expression that is the sum of two terms.
Binomial Coefficient
The coefficients of x in the expansion of (x+1)n.
Binomial Distribution
A distribution which gives the probability of observing successes in a fixed number of independent Bernoulli trials.
Binomial Theorem
This gives the form of the expansion of any positive integral power of a binomial (x+a)n as a polynomial.
The individual frequencies at which the amplitudes are calculated, commonly called lines.
Biochemical Conversion
The use of enzymes and catalysts to change biological substances chemically to produce other products.
The chemistry of living things, including the structure and function of biological molecules and the mechanism and products of their reactions.
Chemical substance capable of killing living organisms, usually in a selective way.
The molecule arising from covalent attachment of biotin to a Lys residue via an amide linkage.
Waste materials that can be broken down by organisms.
Diesel fuel derived from renewable lipid feedstocks, such as vegetable oils and animal fats.
Biodiesel B100
100% (neat) biodiesel. The mono alkyl esters of long chain fatty acids derived from renewable lipid feedstocks, such as vegetable oils and animal fats, diesel engines

Biodiesel B20
A blend of biodiesel fuel with petroleum-based diesel where 20% of the volume is biodiesel.
The numbers and relative abundances of different genes, species, and ecosystems in a particular area.
Electrochemistry of biological systems and biological compounds.
A fuel produced from dry organic matter or combustible oils produced by plants.
Biological Corrosion
Deterioration of metals as a result of the metabolic action of micro-organisms.
Lists all the Biology topics
Biology Conversions
Lists all Biology Conversions in the Encyclopaedia
Biology Weblinks
Lists all Biology Weblinks in the Encyclopaedia
Burning wood, crop residues and dung is the most widespread source of energy for heating and cooking in the rural developing world.
A grouping of similar plant and animal communities into broad landscape units that occur under similar environmental conditions.
The recognition of people from characteristics such as fingerprints, facial-geometry, iris patterns or voice.
An enzymatic cofactor derived from pterin and involved in certain oxidation-reduction reactions.
Acronym for basic input/output system, the commands used to tell a CPU how it will communicate with the rest of the computer.
Either a sensor to detect a biological substance or a sensor which incorporates the use of biological molecules such as antibodies or enzymes.
The part of the Earth system comprising all ecosystems and living organisms in the atmosphere, on land, or in the oceans, including derived dead organic matter such as litter, soil organic matter, and oceanic detritus.
Another name for the Abampere.
Biot, Jean-Baptiste
French mathematician and physicist and one of the founders of the theory of electromagnetism.
The animal and plant life of a given region.
The remote measuring and evaluation of life functions.
Commonly known as vitamin H.
Biot-Savart Law
A law describing the magnetic flux density at a distance r away from an electrical conductor.


Notable as a starting material for the production of PCBs, which were once widely used as dielectric fluids and heat transfer agents.

An airplane with two sets of wings, one on top of the other.
A signal that swings both above and below analog ground, thus having positive and negative values.
Bipolar Battery
Design in which the component cells are connected through plates which each, in turn, act as the current-collector for the positive electrode in one cell and for the negative in the adjacent cell.
Bipolar Lead Acid Battery
Design in which the cells are connected through the plates which each, in turn, act as the current-collector for the positive electrode in one cell and for the negative in the adjacent cell.
Biquadratic Equation
A polynomial equation of the 4th degree.
Strong flexible wood that has many uses. Amongst the uses are furniture making, building as well as being used for agricultural implements in the past.
The separation of a beam of light into two beams as it passes through a doubly refracting material or object.
Birmingham Sheet Metal Gauge
This is a numbering system for sheet metal gauge (thickness).
Natural occuring mineral of Magnesium Chloride.
Biscuit Joint
An oval shapped disk that when inserted in a slot with glue swells to form a tight bond. A special tool is required to cut the slot.
Bisect means to cut something in half. For example, to bisect an angle, you would draw a line through the vertex of the angle such that the two angles created are equivalent in measure.
Bismuth is a brittle metal which is silvery in colour with a pink tinge.
Bismuth Chloride


A water soluble crystalline source of bismuth.

Bismuth Germanate


Used in detectors in particle physics and nuclear medicine.

Bismuth Subcarbonate


Chemical compound of bismuth containing both oxide and carbonate.

Bismuth Subgallate


Used in medicine as an internal deodorant.

Circuit that has two stable states.
Bistable Multivibrator
A multivibrator that has two stable states.
Binary Digit - the smallest unit of binary data.
Bit Clock
The synchronizing signal that indicates the rate of individual data bits over a digital audio interface.
Bit Depth
The number of bits used to represent each pixel in an image, determining its colour or tonal range.
Bit Error Rate
The number of bits processed before an erroneous bit is found.
Bit Mapped Display
A display in which each pixel's color and intensity data are stored in a separate memory location.
Bit Rate
The rate or frequency at which bits appear in a bit stream.
Bit Stream
A binary signal without regard to grouping.
An uncompressed graphics file format.
The rate at which the compressed bitstream is delivered from the storage medium to the input of a decoder.
bits per second
A measurement of data transmission speed in a communications system, the number of bits transmitted or received each second.
An ordered series of bits that forms the coded representation of the data.
Bitter Salts
Common name for Magnesium Sulphate.
Waste solution of magnesium salts and bromides from the preparation of salt from sea-water by evaporation.
A name used to describe many different mixtures of hydrocarbons.