Definitions /Dictionary/Glossary - nptel

Negatively Skewed: A distribution is said to be negatively skewed if the distribution is not
symmetric and the longest tail is on the left.
NEO: Abbreviation for the neopentyl glycol type of gel coats.
Nesting: In reinforced plastics, the placing of plies of fabric so that the yarns of one ply lie in the
valleys between the yams of the adjacent ply (nested cloth).
Net Resin Content Prepreg: A prepreg product form that contains the final desired resin
content and does not require resin bleeding during the cure process.
Net Shape: Part fabrication resulting in final dimensions that do not require machining or
cutting.
Node: The bonded portion of adjacent ribbon sheets, double sheets.
Node Adhesive: The adhesive used to bond the honeycomb nodes together.
Nol Ring: A parallel filament wound test specimen used for measuring various mechanical
strength properties of the material by testing the entire ring, or segments of it.
Nomex: Trademark of DuPont for nylon paper-treated material that is commonly made into
honeycomb core.
Nominal Specimen Thickness: The nominal ply thickness multiplied by the number of plies.
Nominal Value: A value assigned for the purpose of a convenient designation. A nominal value
exists in name only.
Non-Air-Inhibited Resin: A resin in which the surface cure will not be inhibited or stopped by
the presence of air. A surfacing agent has been added to exclude air from the surface of the resin.
Non-perforated Core: The standard aluminium honeycomb with no small holes put in the
aluminium foil.
Non-Volatile Material: Portion remaining as solid under specific conditions short of
decomposition.
Nondestructive Inspection (NDI): A process or procedure for determining material or part
characteristics without permanently altering the test subject. Non-destructive testing (NDT) and
non-destructive evaluation (NDE) are broadly considered synonyms with NDI.
Non-Woven Fabric: A textile structure produced by bonding or interlocking of fibers, or both,
accomplished by mechanical, chemical, thermal, or solvent means and combinations thereof.