Abbreviation of Integrated Services Digital Network.
A line of equal or constant entropy.
Of equal or constant entropy with respect to either space or time.
Ishikawa Diagram
Also known as Fish Bone Diagram.
Relates to distributed generation where local generators continue to power a location when power from the electricity grid is no longer present.
Abbreviation of International Organization for Standardization.
ISO Metric Threads
Table of ISO Metric Thread standards.
ISO Paper Sizes
A series is mainly used for standard book print and stationery.
A contour line that corresponds to values measured at identical pressures.
Constant pressure.
A contour line that corresponds to values measured at identical volumes.
Having constant volume.
Time sensitive. Isochronous transmission is time sensitive transmission eg audio and video transmission for a television channel.
A sequence of events is called isochronous if the time separating each pair of successive events is strictly equal.
Refers to a group of atoms or ions having the same number of electrons.
See Isozymes.
Isogonal Conjugate
Isogonal lines of a triangle are cevians that are symmetric with respect to the angle bisector. Two points are isogonal conjugates if the corresponding lines to the vertices are isogonal.
Another name for an Isopleth.
Isolated System
A system which can exchange neither mass nor energy with its surroundings.
The prevention of unwanted interaction or leakage between components.
Isolation Voltage
The voltage that an isolated circuit can normally withstand, usually specified from input to input.


A naturally occuring amino acid with a nonpolar side chain.

Molecules with identical molecular formulas but different structural formulas.
The phenomenon whereby two or more polymer molecules or mer units have the same composition but different structural arrangements and properties.
A chemical change that involves a rearrangement of atoms and bonds within a molecule, without changing the molecular formula.
Isometric Diagram
A diagram showing the outline of a ship, aircraft, or equipment and the location of equipment and cable runs.
A transformation that keeps the same size and shape of a figure but moves it to a new location.
A mapping between objects which shows a relationship between two properties or operations.
On a chart or graph, a line of constant value of a given quantity with respect to either space or time.
Isopropyl Alcohol
The IUPAC name for Propanol.
Isosceles Tetrahedron
A tetrahedron in which each pair of opposite sides have the same length.
Isosceles Triangle
A triangle with two equal sides.
Having identical valence electron configurations.
A type of polymer chain configuration wherein all side groups are positioned on the same side of the chain molecule.
Isotensoid Structure
A filamentary structure in which the filaments are uniformly stressed throughout for the design loading condition.
A contour line that corresponds to values measured at identical temperatures.
Constant temperature.
Isothermal Annealing
Austenitizing a ferrous alloy and then cooling to and holding at a temperature at which austenite transforms to a relatively soft ferrite carbide aggregate.
Isothermal Expansion
The expansion or compression of a gas at constant temperature.
Isothermal Transformation
A change in phase at any constant temperature.
Pertaining to a quality which has equal value in space at a particular time.
Isotomic Conjugate
Two points on the side of a triangle are isotomic if they are equidistant from the midpoint of that side. Two points inside a triangle are isotomic conjugates if the corresponding cevians through these points meet the opposite sides in isotomic points.
One of a group of atoms or ions with nuclei that contain the same number of neutrons but different numbers of protons.
Refers to solutions that have equal osmotic pressure.
Two atoms having the same number of protons but different numbers of neutrons are said to be isotopes of each other.
Isotopic Abundance
The fraction of atoms of a given isotope in a sample of an element.
Isotopic Mass
The mass of a single atom of a given isotope, usually given in daltons.
Having identical values of a property in all crystallographic directions
Isotropic Antenna
A hypothetical loss-less antenna which radiates or receives energy equally in all directions.
Isotropic Radiation
The radiation of energy equally in all directions.
Two or more forms of an enzyme that catalyze the same reaction but differ from each other in their physical properties, such as amino acid sequence, substrate affinity, Vmax, tissue expression or regulatory properties.
Abbreviation of Internet Service Provider.
I Squared R Losses
Losses due to current flowing in a conductor caused by resistance.
Abbreviation of Current Standing Wave Ratio.