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Ba- Ba
- Elemental barium does not occur naturally although it has an abundance within the earth’s crust of 500 ppm.
- BA Threads
- Clearance and tapping drill sizes for BA threads.
- Babbage, Charles
- The British inventor known to some as the Father of Computing.
- Babbitt
- A soft antifriction metal used to line bearings.
- Back Bias
- An external voltage applied to a diode or semiconductor junction to reduce the flow of electrons across the junction.
- Back Electromotive Force
- The emf that opposes the normal flow of current in a circuit.
- Back Gears
- Gears fitted to a machine to increase the number of spindle speeds obtainable with a cone or step pulley belt drive.
- Back Pressure
- Pressure exerted backward; in a field of fluid flow, a pressure exerted contrary to the pressure producing the main flow.
- Back Titration
- Determining the concentration of an analyte by reacting it with a known number of moles of excess reagent.
- Back Weld
- A weld deposited at the back of a single groove weld.
- Back Work Ratio
- The fraction of the gas turbine work used to drive the compressor.
- Background Noise
- Noise from all sources unrelated to a particular sound that is the object of interest.
- Backhand Welding
- A welding technique in which the flame is directed towards the completed weld.
- Backing Strip
- A piece of material used to retain molten metal at the root of the weld.
- Backing Weld
- A weld bead applied to the root of a single groove joint to assure complete root penetration.
- Backlash
- The lost motion or looseness (play) between the faces of meshing gears or threads.
- Backscattering
- Primary radiation deflected or secondary radiation emitted in the general
direction of the incident radiation beam.
- Backstep
- A sequence in which weld bead increments are deposited in a direction opposite to the direction of progress.
- Backup
- An item kept available to replace an item which fails to perform satisfactorily.
- Backward Recognition Masking
- The reduction in the ability to recognize a sound pattern due to the subsequent presentation of another sound pattern with similar information content.
- BaCO3
- Chemical formula for Barium Carbonate.
- Bacon, Francis
- English natural philosopher.
- Bacteria
- A group of small living organisms made of just one cell.
- Bactericide
- A pesticide used to control or destroy bacteria, typically in the home, schools, or hospitals.
- Baekeland, Leo Hendrik
- Belgian-born American chemist who invented Velox photographic paper and Bakelite.
- Baer, Karl Ernst von
- German embryologist who developed the science of comparative embryology.
- Baffle
- A movable barrier used to achieve separation of signals from different sources.
- Baffle Plate
- A metal plate that acts as a baffle.
- Bainite
- An austenitic transformation product found in some steels and cast irons.
- Bakelite
- The first industrial thermoset plastic.
- Baker, Sir Benjamin
- The chief designer of the railway bridge over the Firth of Forth.
- Baker′s Dozen
- Thirteen pieces of something.
- Bakers Salt
- Old name for Ammonium Carbonate.
- Balance Pipe
- A pipe connecting two points of a system to even out pressure fluctuations.
- Balanced Construction
- A method of constructing manufactured wood products so that moisture content changes will be uniformly distributed and therefore will not cause warping.
- Balanced Equation
- A description of a chemical reaction that gives the chemical formulas of the reactants and the products of the reaction, with coefficients introduced so that the number of each type of atom and the total charge is unchanged by the reaction.
- Balancing
- A procedure for adjusting the mass distribution of a rotor so that
vibration of journals, or the forces on the bearings at once-per-revolution, are
reduced or controlled.
- Balconet
- A false balcony constructed with a low railing outside a window.
- Balcony
- A projection from an upper story window or door surrounded by railing.
- Baldachin
- A richly ornamented canopy structure supported by columns, suspended from a roof, or projected from a wall, as over an altar.
- Ball
- A sphere together with its interior.
- Ball Bearing
- A bearing designed to reduce rotational friction and support radial and axial loads.
- Ball Joint
- A flexible joint consisting of a ball in a socket - locks the two parts in translation, but allows all degrees of rotation.
- Ball Lightning
- A relatively rare form of lightning, consisting of a reddish, luminous ball, of the order of 0.3m in diameter, which may move rapidly along solid objects or remain floating in midair.
- Ball Peen Hammer
- A hammer with two ends on the head, one that is round and the other flat.
- Ball Pien Hammer
- A hammer with two ends on the head, one that is round and the other flat.
- Ballast
- Any liquid or solid weight placed in a vehicle to change the weight distribution or trim.
- Ballast Tank
- Tanks at the bottom or sides of a ship which are filled with seawater for ballasting purpose.
- Ballast Tube
- A current-controlling resistance device designed to maintain substantially constant current over a specified range of variation in applied voltage or resistance of a
series circuit.
- Ballistics
- Ignoring the curvature of the Earth, frictional losses and that g is constant it is possible to calculate the trajectory of a projectile that is fired with a given initial velocity and elevation.
- Balloon
- A lighter than air craft. The Montgolfier brothers made the first flight in a hot air balloon in 1783.
- Ballscrew
- A threaded shaft and nut assembly supported by angular contact bearings, normally found on machine tools.
- Ballute
- A cross between a balloon and a parachute, used to brake the free fall of sounding rockets.
- Balmer Series
- A series of lines in the emission spectrum of hydrogen that involve transitions to the n=2 state from states with n>2.
- Balsa Wood
- The wood from Ochroma Lagopus.
- Balsam
- Light oily aromatic extracts from trees which cure into resins.
- Balthazar
- The name of a wine bottle equivalent to the volume of 16 standard bottles or 12 litres.
- Balun
- A transformer circuit that couples a balanced transmission line to an unbalanced transmission line.
- Balusters
- Small turned, square, or flat column that supports a rail; also used to form chair backs.
- Balustrade
- A series of balusters supporting the railing of a stairs or balcony.
- Bamboo
- A natural material with a great strength to weight ratio. It was used in the early construction of aircraft wings and fuselages.
- Band Clamp
- For clamping round, oval and odd-shaped pieces. Consists of nylon band and ratchet mechanism.
- Band Gap Energy
- For semiconductors and insulators, the energies that lie between the valence and conduction bands.
- Band Reject Frequencies
- A tuned circuit that does not pass a specified band of frequencies.
- Band Stop Filter
- An electronic network which passes signals having frequencies above and below
the band-elimination frequency span.
- Bandgap
- The range of energies between existing energy bands where no energy levels exist.
- Bandpass Filter
- An electronic network which transfers through it a specific band of signal frequencies.
- Bandsaw
- A power saw, the blade of which is a continuous, narrow, steel band having teeth on one edge and passing over two large pulley wheels.
- Bandwidth
- The bandwidth of a filter is the separation
between the lower and upper frequencies at which the amplitude of a sinusoidal signal
is attenuated by a factor of 2.
- Bandwidth Time Product
- Used in calculating the confidence limit of a measurement.
- Bannister
- A handrail with supporting posts on a stairway.
- bar
- A derived unit of pressure used in meteorology. 1 bar = 1x105 Pa.
- Bar Chart
- A strong graphical representation of data.
- Bar Clamp
- A tool with a stationary head and a sliding foot for clamping purposes.
- Bar Code
- Coded labels that contain information about the item they are attached to, the information is contained in a numerical code, usually containing 12 digits.
- Bar Stock
- Metal bars of various lengths, made in flat, hexagon, octagon, round, and square shapes from which parts are machined.
- Barany Box
- Clockwork noise generator used when necessary as a masker in tuning fork or clinical speech tests.
- Bargeboard
- The finish board covering the projecting portion of a gable roof.
- Barite
- Most commonly found mineral of Barium Sulphate.
- Barium
- Elemental barium does not occur naturally although it has an abundance within the earth’s crust of 500 ppm.
- Barium Carbonate
BaCO3 Chemical used in rat poison, bricks, ceramic glazes and cement. - Barium Dioxide
- A white toxic powder obtained by heating barium oxide in air.
- Barium Monoxide
- An oxide of barium; a whitish toxic powder.
- Barium Oxide
- An oxide of barium; a whitish toxic powder.
- Barium Peroxide
- A white toxic powder obtained by heating barium oxide in air.
- Barium Protoxide
- An oxide of barium; a whitish toxic powder.
- Barium Sulphate
BaSO4 A white insoluble solid used as a pigment and filler in plastics. Most commonly found as the mineral Barite. - Barium White
- An ancient name for Barium Sulphate.
- Bark
- The Bark is the standard unit corresponding to one critical band width of human hearing.
- Barn
- A unit of nuclear cross section, 1 Barn = 10-28m2.
- Barnard, Christiaan Neethling
- South African heart surgeon who developed surgical procedures for organ transplants, invented new heart valves, and performed the first human heart transplant.
- Barometer
- A device for measuring atmospheric pressure.
- Barometric Pressure
- The total pressure exerted by the atmosphere.
- Baromil
- The unit of length used in graduating a mercury barometer in the centimetre-gram-second system.
- Barrel
- A unit of capacity in the oil industry.
- Barretter
- A type of bolometer characterized by an increase in resistance as the dissipated power rises.
- Barrique
- A large French wine barrel holding 225 litres.
- Bartels Rotation Number
- The serial number assigned to 27-day recurrence periods of solar and geophysical
parameters.
- Barycentre
- This is the centre of gravity of 2 or more masses.
- Barye
- The CGS unit of pressure, equal to 1 dyne per square centimetre.
- Baryon
- A particle with spin 1/2 (or 3/2) which consists of three elementary particles
known as quarks.
- Baryta
- Any of several compounds of barium.
- Basalt
- Dark colored rocks formed by the rapid cooling and hardening of lava flows.
- Bascule Bridge
- The deck is raised with counterweights like a drawbridge.
- Base
- Substance which gives off hydroxide ions (OH-) in solution. In the expression xy, x is called the base and y is the exponent.
- Base Hydrolysis Constant
- The equilibrium constant for the hydrolysis reaction associated with a base.
- Base Metal
- The metal to be welded or cut. In alloys, it is the metal present in the largest proportion.
- Base Oil
- A liquid having a suitable boiling range and viscosity for use in lubricating oils.
- Base Terminal
- That electrode of a transistor which compares generally to the grid of a vacuum tube.
- Base Unit
- Base units are units that are fundamental building blocks in a system of measurement.
- Baseplate
- The surface to which the feet of a machine are attached.
- Basic
- A high-level programming language designed at Dartmouth College as a learning tool.
- Basis Function
- A mathematical function that can be used to build a description of wavefunctions for electrons in atoms or molecules.
- Basis Set
- A set of mathematical functions that are combined to approximate the wavefunctions for electrons in atoms and molecules.
- BaSO4
- Chemical formula for Barium Sulphate.
- Bass
- The lower range of audible frequencies.
- Bass Ratio
- In concert hall acoustics, the ratio of the average reverberation times at 125 and 250 Hz to the average of the RT′s at 500 and 1000 Hz. It is determined only for a hall when fully occupied.
- Bastard
- Threads, parts, tools, and sizes that are not standard.
- Bath Metal
- A cheap bronze made with 21 parts copper and 5 parts zinc. The same as pinchbeck.
- Batten
- The narrow strips of wood nailed vertically over the joints of boards to form board-and-batten siding.
- Batter
- An inclined face of wall; hence battered.
- Batter Boards
- Horizontal boards at exact elevations nailed to posts just outside the corners of a proposed building.
- Battery
- A device for converting chemical energy into electrical energy.
- Battery Acid
- A solution of approximately 6M sulfuric acid used in the lead storage battery.
- Battery Capacity
- The amount of energy available from a battery. Battery capacity is expressed in
ampere-hours.
- Battery Charger
- A device capable of supplying electrical energy to a battery.
- Battery Cycle Life
- How many charge/discharge cycles the battery can endure before it loses its ability to hold a useful charge.
- Baud Rate
- The speed of information being transmitted across a serial interface, expressed
in units of bits per second (bps).
- Bauhaus
- The style of the Bauhaus School, founded in Germany by Walter Gropius in 1919, emphasizing simplicity, functionalism, and craftsmanship.
- Bauxite
- An ore of aluminum consisting of moderately pure hydrated alumina.
- Bay
- A subdivision of the interior space of a building.
- Bay Salt
- Alternative name for Sodium Chloride.
- Bay Window
- A window placed in a projection of an exterior wall of a building is called a bay window when the wall projection extends all the way down to a corresponding projection of the foundation.
- Bayes Rule
- A rule for finding conditional probability.
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