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Nail
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Hard, keratinous, pointed or
more or less oval, epidermal growth at the tip of a finger or
a toe.
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Nail (v); nailing
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Nail leather to frames or boards
to dry.
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Nanofiltration (NF)
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Process based on separation by
membranes which retains particles of between 1 nanometre and
10 nanometres and results in the production of extremely pure
drinking water.
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Nappa
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Soft, full grain gloving or clothing
leather made from unsplit sheep, lamb, goat or kid skins. It
is usually tanned with chromium salts and dyed throughout its
substance.
Note: In France and Germany also
made from side leather for footwear and leather goods purposes.
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Nappalan
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Woolled sheep or lambskins bearing
the characteristics of nappa on the flesh side.
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Natural dyestuff
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Organic dyestuffs obtained from
animal or vegetable matter, with very little, or no chemical
processing.
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Natural feel
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Sensation felt by
handling a material that has no artificial treatment. For example,
a leather without any finishing.
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Natural glue
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Glue made from gelatine extracted
from hides, bones or glue-stock.
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Natural grain
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Grain without any
finishing coat showing its natural design and feel.
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Natural grease
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Natural fatty matter in hides
and skins which is more or less removed during conversion to
leather.
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Near-Infrared Differential (NIR)
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Spectrophotometry
at wavelengths in the near-infrared region of the spectrum.
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Neatsfoot oil
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Oil from the washed split feet
of cattle, as well as sheep and horses.
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Neck
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Part of the hide or skin nearest
to the head.
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Nephelometric Turbidity Unit (NTU)
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Unit used in measuring the scattering
function at various angles of particles suspended in a medium.
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Neutralisation
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Process of raising pH towards
neutral from acidic zone, of a mineral-tanned leather after
tanning by treatment with a solution of alkaline salt or buffer
mixture.
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Neutralise (v); neutralising
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Raise pH towards neutral from
acidic zone, of a mineral-tanned leather after tanning by treatment
with a solution of an alkaline salt or buffer mixture.
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Neutralising agent
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Organic or inorganic alkaline
salt, or alkaline buffer mixture, used to raise the pH of a
mineral-tanned leather after tanning.
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NF
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See: Nanofiltration.
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NIR
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See: Near-Infrared
Differential.
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Nitrate (NO3)
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See: Nitrogen (total).
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Nitrite (NO2)
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See: Nitrogen (total).
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Nitrocellulose finish
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Type of finish in leather production.
The film-forming material is cellulose nitrate dissolved in
organic solvents. Nitrocellulose is made from waste cotton by
treatment with nitric acid. It is also know as collodion.
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Nitrocellulose lacquer
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Finish agents used in solvent-soluble
dye and pigment preparations and as top coats. The basic product
of these agents is nitrocellulose.
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Nitrogen (total)
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Total Nitrogen (TN) applies to
all forms of nitrogen in water including the reduced forms and
the oxidised forms.
· The reduced forms correspond to Kjeldahl
nitrogen (TKN): Organic nitrogen and ammonia nitrogen (-NH4-).
· The oxidised forms correspond to the nitrous
nitrogen (Nitrite NO2) and the nitric (Nitrate NO3).
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NMR
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See: Nuclear
Magnetic Resonance.
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No Observed Acute Effect Concentration (NOAC)
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Acute exposure level at which
there are no statistically or biological significant differences
in the frequency or severity of any effect in the exposed or
control populations. Acute exposures are usually characterised
as lasting no longer than a day, as compared to longer, continuing
exposure over a period of time.
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No Observed Effect Concentration (NOEC)
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Exposure level at which there
are no statistically or biological significant differences in
the frequency or severity of any effect in the exposed or control
populations.
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NO2
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See: Nitrite.
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NO3
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See: Nitrate.
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NOAC
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See: No Observed Acute Effect
Concentration.
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NOEC
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See: No Observed Effect Concentration.
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Non tannin (NT)
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Water soluble constituents of
a vegetable or synthetic tanning material not taken up by the
hide powder in the course of tannin analysis and hence regarded
as incapable of tanning.
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Non-ionic emulsifier
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Emulsifier which, when dissolved
in water, does not ionise.
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Non-ionic surfactant
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Surface active agent which produces
electrically neutral colloid particles in solution.
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Nonyl Phenol Ethoxylate (NPE)
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Chemical compound often found
in emulsifiers and wetting agents.
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NOx
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See: Oxides of nitrogen.
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NPE
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See: Nonyl Phenol Ethoxylate.
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NT
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See: Non tannin.
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NTU
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See: Nephelometric Turbidity
Unit.
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Nubuck
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White or coloured, usually chrome-tanned
leather, mainly used for uppers, made from cattle hides and
calf, and sometimes pig skins, buffed on the grain side to give
a fine, velvety surface.
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Nuclear Magnetic Resonance (NMR)
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Phenomenon exhibited
by a large number of atomic nuclei, in which nuclei in a static
magnetic field absorb energy from a radio-frequency field at
certain characteristic frequencies. It gives information about
the molecular structure.
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