Sa

Sabin
The unit of measure of sound absorption in the inch-pound system. A measure of the sound absorption of a surface. One sabin is the equivalent to one square foot of a perfectly absorptive surface.
Sabine Formula
The Sabine formula is derived from the Norris-Eyring formula for small absorption coefficients.
Sabine, Wallace Clement
The Harvard professor honoured as the father of architectural acoustics for his investigations into concert hall sound at the turn of the century.
Saccade
The normal, but largely unnoticed rapid darting of the eyes from one fixed point to another.
Sacrificial Anode
Coupling of a more active metal to a structure resulting in a galvanic current flow through the corroding electrolyte.
SAE Steel
Steel manufactured under the specifications by the Society of Automotive Engineers.
Safety Data Sheet
OSHA has replaced MSDS with SDS in 2013 under 29CFR Part 1910.1200.
Safety Pin
A simple pin that clips shut most commonly used to fasten two pieces of fabric.
Safety Valve
An automatic valve used to release excess pressure within the boiler.
Sag
Deflection due to gravity acting on a cantilevered or otherwise supported object.
Sagging
The tendency of a beam to bend downwards, when acted on by a load, including its own weight.
Sagnac Effect
First discovered in 1913 by Georges Sagnac, it involves sending two beams of light in opposite directions around a closed path and then using a detector to examine the beams when they arrive back at the starting point.
Sail Wing
A propeller having cloth stretched over a metal wire frame which forms an airfoil section.
Sailplane
An unpowered heavier-than-air craft designed primarily for soaring flight.
Sal Ammoniac
Old name for Ammonium Chloride.
Salifiable
Capable of reacting with an acid to form a salt.
Salk, Jonas
American medical researcher and virologist, best known for his discovery and development of the first safe and effective polio vaccine.
Salmanazar
The name of a wine bottle equivalent to the volume of 12 standard bottles or 9 litres.
Salt
Sodium chloride.
Salt Bridge
A tube that allows two solutions to be in electrical contact without mixing in an electrochemical cell.
Salt of Tartar
An old fashioned name for Potassium Carbonate.
Salt of Wormwood
Old fashioned name for Potassium Carbonate.
Salt Spray Test
A test method used to check corrosion resistance of coated samples.
Saltpetre
Old fashioned name for Potassium Nitrate or Sodium Nitrate.
Salts
Ionic compounds that can be formed by replacing one or more of the hydrogen ions of an acid with another positive ion.
Saltspoon
A unit of volume formerly used in U.S. food recipes and equal to 1/4 teaspoon.
Samarium
A relatively stable element in dry air but oxidises on contact with moisture.
Same Side Exterior Angles
Angles located outside a set of parallel lines and on the same side of the transversal.
Same Side Interior Angles
Angles located inside a set of parallel lines and on the same side of the transversal.
Sample
A set of observations, usually considered to have been taken from a much larger population.
Sample and Hold
A circuit that captures and holds an analog signal for a finite period.
Sample Rate Conversion
The process of converting one sample rate to another.
Sample Size
The number of elements in a sample from a population.
Sample Space
The set of all possible outcomes of a given experiment.
Sample Survey
A survey based on the responses of a sample of individuals, rather than the entire population.
Sampling
The process of representing the amplitude of a signal at a particular point in time.
Sampling Frequency
The frequency or rate at which an analog signal is sampled or converted into digital data.
Sampling Theorem
States that a band limited continuous waveform may be represented by a series of discrete samples if the sampling frequency is at least twice the highest frequency contained in the waveform.
Sand
A term generally given to rock with a grain size between 1/16mm and 2mm.
Sand Casting
The formation of shapes by pouring molten metal into a cavity shaped in sand.
Sand Scratches
The marks left in metal or in the old finish by abrasives.
Sandblasting
A process of blowing sand by compressed air with considerable force through a hose against an object.
Sanding
The process of using an abbrasive paper to remove material, create a shape or to smooth and surface.
Sanding Block
A block of rubber or plastic to which the sandpaper is fastened, offering the operator a good grip.
Sandpaper
An abrasive paper used to smooth the rough edges of freshly sawn wood.
Sandwich Construction
A composite construction of alloys, plastics, and other materials consisting of a foam or honeycomb layer and glued between two hard outer sheets.
Sankey Diagram
A specific type of flow diagram, in which the width of the arrows is shown proportionally to the flow quantity.
Sapid
To have a decided, yet pleasant taste.
Saponaceous
To be soapy, slippery, sometimes foaming.
Saponification
The hydrolysis of esters using hot sodium hydroxide solution to produce the salt of a carboxylic acid.
Sapwood
Lighter coloured wood on the outside of a log, this wood is more susceptable to rot than heartwood.
Satellite
An object in an orbit around a planet.
Satellite DNA
Highly repeated, nontranslated segments of DNA whose function is not clear.
Satellite Eclipse
An eclipse where the rays of the sun do not reach the satellite.
Satellite Sun Conjunction
A period when the satellite and sun are close together and the noise from the sun prevents or hampers communications.
Saturable Core Reactor
A coil in which the reactance is controlled by changing the permeability of the core.
Saturated Fat
A lipid that contains no carbon-carbon double bonds.
Saturated Fatty Acid
A fatty acid containing no double bonds.
Saturated Liquid
Purely liquid, but at the saturation temperature any additional heat will cause some vapourisation.
Saturated Solution
A solution which does not dissolve any more solute.
Saturated Vapour
Vapour in equilibrium with its liquid.
Saturation
An overwhelming concentration.
Saturation Pressure
That pressure at which vapour and liquid, or vapour and solid, can coexist in stable equilibrium.
Saturation Temperature
The temperature at which no further moisture can be added to the air water vapour mixture, equal to the dew point temperature.
Saturation Velocity
Maximum velocity which can be obtained in a specific semiconductor.
Saturn
The sixth planet from the sun in our solar system.
Savery, Thomas
English military engineer and inventor who in 1698, patented the first crude steam engine, based on Denis Papin′s Digester or pressure cooker of 1679.
Saw
A tool with a blade or disc with teeth along the edge used to cut metal, wood, plastic and many other materials.
Saybolt Universal Seconds
Another name for Saybolt Universal Viscosity.
Saybolt Universal Viscosity
The time in seconds required for 60 cubic centimeters of a fluid to flow through the orifice of the Standard Saybolt Universal Viscometer at a given temperature under specified conditions.