Contaminated and Hazardous
Waste Site Management Glossary
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Narrative
(SDG narrative): Portion of the data package which includes laboratory, contract,
Case,
and sample number identification, and descriptive documentation of any problems
encountered in processing the samples, along with corrective action taken and
problem resolution. Narrow
Bore Capillary Column: A gas chromatographic column with an internal diameter
(ID) that is smaller than 0.32 mm. Columns with greater diameters are classified
as wide bore capillaries. Neutron
Scattering: Change in neutron direction as a result of collisions with nuclei
in a material. Neutron
Thermalization: See Neutron Scattering, Noise:
Any unwanted signal; a disturbance that is not part of signal from a specified
source. In electrical or induced polarization (IP) surveys, noise may result from
interference of power lines, motor-generators, atmospheric electrical discharges,
etc. See Cultural Noise. Non-Aqueous-Phase-Liquid
(NAPL): Elements or compounds in the liquid phase other than water. This phase
is immiscible in water. Examples include petroleum hydrocarbons, like gasoline,
and solvents such as trichloroethylene. Nonlinear
System: A mathematical system or process is nonlinear if there are at least two
unknown quantities which are dependent on each other. Density- dependent transport
and reactive geochemical transport are common examples. These systems require
more computational effort to solve compared to linear systems. Non-Unique:
In geophysical interpretation and mathematical modelling, a problem for which
two or more subsurface models satisfy the data equally well. Nutrients:
Elements (e.g., nitrogen and phosphorus) and trace elements (including sulfur,
potassium, calcium, and magnesium) that are essential for the growth of organisms.
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