1 Absolute Temperature: The temperature reckoned from the absolute zero temperature.
2 Absolute velocity: The vector sum of the velocity of a fluid parcel relative to the earth and the velocity of the parcel due to the earth's rotation; the east-west component is the only one affected.
3 Absolute Viscosity: Term used interchangeably with viscosity to distinguish it from kinematic viscosity and/or commercial viscosity; occasionally, dynamic viscosity.
4 Absolute zero temperature: Temperature measured from absolute zero (-459.67°F, or -273.16°C).
5 Absorbent: A material which, due to an affinity for certain substances, extracts one or more such substances from a liquid or gaseous medium with which it contacts and which changes physically or chemically, or both, during the process. Calcium chloride is an example of a solid absorbent, while solutions of lithium chloride,lithium bromide, and ethylene glycols are liquid absorbents.
6 Absorber : That part of the low side of an absorption system, used for absorbing vapor refrigerant.
7 Absorption: Act or process of absorbing.
8 Abutment : A concrete support wall constructed at both ends of a bridge or an arch, in order to resist the horizontal force from the bridge or the arch, support the ends of the bridge span and to prevent the bank from sliding under
9 Acid rain: rainwater carrying acidic atmospheric pollutants (nitrous or sulfuric oxides)
10 Acid Rain: Atmospheric precipitation with a pH below 5.6 to 5.7. Burning of fossil fuels for heat and power is the major factor in the generation of oxides of nitrogen and sulfur, which are converted into nitric and sulfuric acids washed down in the rain. (see Atmospheric Corrosion)
11 Acid rain : Atmospheric precipitation with an pH below 5.6 to 5.7.
12 Acre: Unit of land area in the Imperial system; 4840 square yards, or the equivalent of a rectangular field one chain wide and one furlong long, approximately 4047 square metres or 0.4047 hectares.
13 Activation Energy: The energy required for initiating a metallurgical reaction—for example, plastic flow, diffusion, chemical reaction. The activation energy may be calculated from the slope of the line obtained by plotting the natural log of the reaction rate versus the reciprocal of the absolute temperature.
14 Active earth pressure : The horizontal push from earth onto a wall. The active earth force from sand on to a free retaining wall is equivalent to that from a fluid of density 0.25 to 0.30 times that of the sand. The force from sand on to a fixed retaining wall is very much more.
15 Adhesion: The property of a lubricant that causes it to cling or adhere to a solid surface.
16 Adiabatic: Occurring with no addition or loss of heat from the system under consideration.
17 Adiabatic change : A change in the volume, pressure, or temperature of a gas, occurring without a gain of heat or loss of heat.
18 Adiabatic compression: Compressing a gas without removing or adding heat.
19 Adiabatic cooling : A method in which paramagnetic salts are pre-cooled, and then demagnetized, thereby producing further cooling.
20 Admixture or additive : A substance other than aggregate, cement or water, added in small quantities to the concrete mix to alter its properties or those of the hard concrete. The most important admixtures for concrete are accelerators, air-entraining agents, plasticizers and retarders.
21 Admixtures: Materials added to mortar or concrete to achieve particular modifications to the normal properties of the basic material.
22 Adsorbent: A material which has the ability to cause molecules of gases, liquids or solids to adhere to its internal surfaces without changing the adsorbent physically or chemically. In water treatment, a
synthetic resin possessing the ability to attract and to hold charged particles
23 Adsorption: Assimilation of gas, vapor, or dissolved matter by the surface of a solid or liquid.
24 Aeration: Making contact between air and a liquid by spraying liquid into the air or by agitating the liquid to promote absorption of air. Also act of fluffing molding sand.
25 Aeration: Air trapped in the hydraulic fluid. Excessive aeration causes the fluid to appear milky and components to operate erratically.
26 Aerobic: A condition in which "free" or dissolved oxygen is present in water.
27 Aggregate: A mixture of sand and stone and a major component of concrete.
28 Aggregate: The stones and sand (coarse and fine aggregate respectively) used as a filler in concrete, asphalt etc.
29 Aggregate: sand, gravel etcmixed with cement to form concrete.
30 Air brick: Ventilation built into brickwork to provide ventilation through the wall.
31 Air-entrained concrete : A concrete used for constructing roads. It has about 5% air and is therefore less dense than ordinary good concrete, but it has excellent freeze-thaw resistance. The strength loss is roughly 5% for each 1% air entrained. Air entrained concrete produced by adding an admixture to concrete or cement, which drags small bubbles of air (Smaller than 1 mm in diameter) into the concrete mix. The bubbles increase the workability and allowing both sand and water contents to be reduced.
32 Air-Hardening Steel: A steel containing sufficient carbon and other alloying elements to harden fully during cooling in air or other gaseous mediums from a temperature above its transformation range. The term should be restricted to steels that are capable of being hardened by cooling in air in fairly large
sections, about 2 inches or more in diameter.
33 Air-Lift Hammer: A type of gravity drop hammer where the ram is raised for each stroke by an air cylinder. Because length of stroke can be controlled, ram velocity and thus energy delivered to the workpiece can be varied.
34 Alloy: A substance that has metallic properties and is comprised of two or more chemical elements, of which at least one is a metal.
35 Alloy Cast Iron: Highly alloyed cast irons containing more than 3% alloy content. Alloy cast irons may be a type of white iron, gray iron or ductile iron.
36 Alloy Steel: A steel in which a deliberate addition of one or more alloying elements, e.g. Mn, Ni, Cr, Mo,etc. has been made during steel making to enhance the properties of the steel. The amounts of each element that must be present in steel before it is classified as an alloy steel are given in Table 1 in EN 10020:2000. At low levels of addition, the steels may be classified as low alloy. The same standard
classifies steels which do not meet the minimum requirements as 'non-alloy' steels.
37 Altimeter: An instrument used to measure the height above a reference point, such as ground or sea level.
38 Alumina: Aluminum oxide produced fron bauxite by a complicated chemical process. It is a material that looks like granulated sugar. Alumina is an intermediate step in the production of aluminum from bauxite, and is also a valuable chemical on its own.
39 Aluminum: killed steel steel treated with aluminum as an oxidizing agent in order to reduce the oxygen content to such a level that no reaction occurs between carbon and oxygen during solidification.
40 Amalgam: A dental alloy produced by combining mercury with alloy particles of silver, tin, copper and sometimes zinc.
41 Ammeter: An instrument for measuring the magnitude of electric current flow.
42 Amplitude: A measure of floor vibration. It is the magnitude or total distance traveled by each oscillation of the vibration.
43 Amplitude: The maximum instantaneous value of alternating current or voltage. It can be in either a positive or negative direction. The greatest distance through which an oscillating body moves from the mid point.
44 Anchor Bolt: An anchor bolt is a specialized bolt used to attach items to hard surfaces such as concrete, asphalt, brick or stone. Anchor bolts are made up of a threaded end that is turned into the surface of interest and a washer and nut used to carry the load on the bolt. Anchor bolts come in many shapes, sizes, and materials depending on the application and the load requirements.
45 Anchorage: The process of fastening a joist or joist girder to a masonry, concrete, or steel support by either bolting or welding.
46 Anion: A negatively charged ion that migrates through the electrolyte toward the anode under the influence of a potential gradient.(see Cation) (see Ion)
47 Anode: 1. The electrode of an electrolyte cell at which oxidation occurs. Electrons flow away from the anode in the external circuit. It is usually at the electrode that corrosion occurs and metal ions enter solution. 2. The positive (electron-deficient) electrode in an electrochemical circuit. Contrast with
48 Anode: In electrolysis or electrochemical corrosion, a site where metal goes into solution as a cation leaving behind an equivalent of electrons to be transferred to the opposite electron, called the cathode.
49 Anolyte: The electrolyte adjacent to the anode in an electrolytic cell.
50 Antioxidant: An additive to retard oxygen-related deterioration, especially oxidation of lubricants.. (see Inhibitor)
51 Aperature: In an extrusion die, the shaped opening through which the heat-softened metal is forced and which gives the extruded product its cross-sectional shape. Also called the “orifice”.
52 Apex: The highest point of a gable.
53 Apron: Device that the molten slag flows across on its way from the spout to the doughnut. It is cooled by water spray.
54 Aqueduct : a bridge or channel for conveying water, usually over long distances
55 Argon: Argon is a chemical element with symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble or inert gas. Argon is the third most common gas in the Earth's atmosphere, at 0.93% (9,300 ppm).
56 Artesion well : A spring which water flows naturally out of the earth's surface due to pressure placed on the water by an impervious overburden and hydro-static head.
57 ASTM: American Standard of Testing and Materials
58 Axial Impellers: An axial impeller is the rotating component in an axial flow pump. Also known as the rotor, the impeller contains multiple blades to convert the mechanical energy of the shaft into fluid acceleration and pressure rise as the fluid moves through the pump.
59 Backfill: The replacement of excavated earth into a trench around or against a basement /crawl space foundationwall.
60 Backhoe: a rubber tired vehicle with loader bucket in front and small excavator bucket at back.
61 Balcony: A platform, enclosed by a railing or balustrade, projecting from the face of either an inside or outside wall of a building (e.g. a gallery in a theatre).
62 Ball Mill: A method of obtaining a high luster on small parts by rotating them in a wooden-lined barrel with water, burnishing soap and stainless steel shot.
63 Ballast: Framed walls (generally over 10' tall) that run the entire vertical length from the floor sill plate to the roof. This is done to eliminate the need for a gable end truss.
64 Barge board: Horizontal beam rafter that supports shorter rafters.
65 Barometer: To check the atmospheric pressure a device is used called barometer
66 Barrel (Drum): The sequence of abrupt changes in magnetic induction occurring when the magnetizing force acting on a ferromagnetic specimen is varied.
67 Base Plate: A type of mounting where the hoist is mounted to the top side of a horizontal supporting surface.
68 Bat : A half-brick.
69 Batching: Amount or quantity of core or mold sand or other material prepared at one time.
70 Batching Plants: A batching plant is an installation of equipment for mixing bulk components. It typically refers to a remote installation set up for the purpose of mixing concrete on site.
71 Bearing : (1) The supporting section of a beam length or area. (2) The compressive stress between a beam and its support (bearing pressure), particularly on foundations. (3) The horizontal angle turned between a datum direction such as true north and a given line.
72 Bearing Guides: A bearing guide is a mechanical device used to provide a smooth, controlled surface to guide the movement of another component such as a tool bit. The guide is often a set of concentric cylindrical shells with ball or roller element bearings between the two surfaces. An example of a bearing
guide is the small guide often used with router bits in woodworking.
73 Bearing Load: A compressive load supported by a member, usually a tube or collar, along a line where contact is made with a pin, rivet, axle, or shaft.
74 Bearing Test: The shear load on a mechanical joint (such as a pinned or riveted joint) divided by the effective bearing area. The effective bearing area of a riveted joint, for example, is the sum of the diameters of all rivets times the thickness of the loaded member.
75 Bench mark: an elevation reference point.
76 Bernoulli equation : Is an Energy equation for two points along the bottom of an open channel experiencing uniform flow.
77 Bernoulli's Theorem: The simplest aromatic hydrocarbon (C6H6) used in petrochemical processes and as a solvent. It must be used with caution because of its toxicity. For safety considerations, laboratories
have substituted other solvents like toluene in its place.
78 Blacking Hole: Irregular shaped surface cavities in a casting containing carbonaceous matter. Caused by spilling off of the blacking from the mold surface.
79 Blasting: A method of cleaning or of roughening a surface by a forceable stream of sharp angular abrasive.
80 Bleeding: The tendency of a liquid component to separate from a liquid-solid or liquid-semisolid mixture, as oil may separate from a grease.
81 Blister: High-carbon steel produced by carburizing wrought iron. The bar, originally smooth, is covered with small blisters when removed from the cementation (carburizing) furnace.
82 Boiler: Tubes which form part of the heating surface of a boiler, as distinct from super heater tubes. The tubes may contain water and be surrounded by the furnace gases as in a water tube boiler, or they may act as flues and be surrounded by water as in smoke tube boiler.
83 Boom: The lower or bottom horizontal member of a truss.
84 Bore: The angle above or below the horizontal axis of the base boom section.
85 Boulder: pieces of rock larger than 200mm
86 Boulders: rocks larger than 30 an (12 inches) in diameter
87 Box culvert: culvert of rectangular cross section, commonly of precast concrete.
88 Box gutter: A timber gutter lined with lead or some other waterproof material.
89 Brace: A member, usually a diagonal, which resists lateral loads and/or movements of a structure.
90 Bracing : metal that is attached to a fabrication prior to galvanizing in order to provide support so that the steel does not change shape during heating and cooling; can be temporary or permanent
91 Brick: Building unit of a regular size usually made of baked clay. Can also becalcium silicate or concrete. The standard size of metric bricks in the UK is 65 x 102.5 x 215 mm, designed to be used with a 10 mm mortar joint. The equivalent theoretical size of imperial bricks, used with a 3/8 inch joint, is 2 5/8 x
4 3/16 x 8 5/8 inches. Clay bricks are of course of great antiquity as evidenced by archaeology and the bible.
92 Brick guard: Steel mesh panel used on scaffolding to make sure that loose bricks cannot fall off the scaffold.
93 Brick ledge: The metal angle iron that brick rests on, especially above a window, door, or other opening.
94 Brick lintel: Trim used around an exterior door jamb that siding butts to.
95 Brick mold: A small, corrugated metal strip @ 1" X 6"8" long nailed to wall sheeting or studs. They are inserted into the grout mortar joint of the veneer brick, and holds the veneer wall to the sheeted wall behind it.
96 Bridge: The crane movement in a direction parallel to the crane runway.
97 Bull dozer: tracked vehicle with front mounted blade.
98 Bulldozer: The microstructure of malleable or ductile cast iron when graphite nodules are surrounded by a ferrite layer in a pearlitic matrix.
99 Bumper (Buffer): (1) A semirefined alloy containing sufficient precious metal to make recovery profitable. (2) Refined gold or silver, uncoined.
100 Bumping: An energy absorbing device for reducing impact when a moving crane or trolley reaches the end of its permitted travel, or when two moving cranes or trolleys come into contact.
101 Cable : SHIELDEDSpecial cable used with equipment that generates a low voltage output. Used to minimize the effects of frequency "noise" on the output signal.
102 Caisson: An overhang. Where one floor extends beyond and over a foundation wall. For example at a fireplace location or bay window cantilever. Normally, not extending over 2 feet.
103 Calcination: (1) A copper or copper alloy casting rectangular in cross section, used for rolling into sheet or strip. (2) A coalesced mass of unpressed metal powder.
104 Canopy: A projecting member that is supported at one end only.
105 Cantilever: Foundation void material used in unusually expansive soils conditions. This void is "trapezoid" shaped and has vertical sides of 6" and 4" respectively.
106 Cantilever footing : A combined footing that supports an exterior wall or exterior columns.
107 Capillary: The name given to the thin tube attached to the bulb which transmits the bulb pressure changes to the controller or indicator. The cross sectional area of the capillary is extremely small
compared to the cross section of the bulb