N
From CleanPosts
N-hexane
N-hexane is a chemical made from crude oil. It is used in laboratories,
primarily when it is mixed with similar chemicals to produce solvents. Common
names for these solvents are commercial hexane, mixed hexanes, petroleum ether,
and petroleum naphtha. The major use for solvents containing n-hexane is to
extract vegetable oils from crops such as soybeans, flax, peanuts, and
safflower seed. They are also used as cleaning agents in the textile,
furniture, shoemaking, and printing industries, particularly rotogravure
printing. N-hexane is also an ingredient of special glues that are used in the
roofing, shoe, and leather industries. N-hexane is used in binding books,
working leather, shaping pills and tablets, canning, manufacturing tyres, and
making baseballs. Consumer products that contain small amounts of n-hexane
include petrol, rubber cement, typeover correction fluids, non-mercury
thermometers, alcohol preparations, and aerosols in perfumes. N-hexane is also
a component of preparations such as paint thinners, general purpose solvents,
degreasing agents, or cleaners. N-hexane is a colourless liquid with a slightly
disagreeable odour. It evaporates very easily into the air and dissolves only
sightly in water. It is highly flammable, and its vapors can be explosive. It
may be ignited by heat, sparks, and flames. Flammable vapor may spread away
from a spill. N-hexane can react vigorously with oxidizing materials such as
liquid chlorine, concentrated oxygen, and sodium hypochlorite. It will attack
some forms of plastics, rubber, and coatings. It is insoluble in water and
miscible with alcohol, chloroform, and ether. It is incompatible with strong
oxidizers. N-hexane is also known as hexane and hexyl hydride.
N-Nitrosodiphenylamine
N-Nitrosodiphenylamine is a yellow or orange-brown solid with no odour. It is
soluble in acetone, ethanol, benzene, and ethylene dichloride. Its flash point
and flammability limits are unknown. It is not a naturally occurring substance;
it is a man-made chemical that was used in rubber compounding as a retarder to
prevent premature vulcanization of rubber compounds during mixing and other
processing operations. It was generally used with sulphenamide accelerators in
tyre compounds and other mechanical goods. N-Nitrosodiphenylamine was also used
as an intermediate in the manufacture of p-nitrosodiphenylamine, which was
subsequently used to produced N-phenyl-p-phenylenediamine and other
rubber-processing chemicals. American manufacturers stopped producing
N-nitrosodiphenylamine in the early 1980s because new and more efficient
chemicals were found to replace it. It also had several undesirable side
effects which do not occur with replacement chemicals. N-nitrosodiphenylamine
is also known as diphenylnitrosoamine, N-nitroso-n-phenylaniline,
N-nitroso-n-phenylbenzenamine, N,n-diphenylnitrosoamine, nitrous diphenylamide,
NDPA, and NDPhA.
NACK
Nack (nak) is the 'Negative Acknowledge' character in many data codes;
typically used to indicate receipt of a corrupted message, ordering
retransmission.
Nail
The nail is a unit of the imperial measurement of length equivalent to 1/16
yards.
NAK
see "NACK"
Naphthalene
Naphthalene is a white solid hydrocarbon with a strong smell; is also called
mothballs, moth flakes, white tar, and tar camphor. Naphthalene is a natural
component of fossil fuels such as petroleum and coal; it is also formed when
natural products such as wood or tobacco are burned. The principal use for
naphthalene is as an intermediate in the production of phthalic anhydride,
which is used as an intermediate in the production of phthalate plasticizers,
resins, phthaleins, dyes, pharmaceuticals, insect repellents, and other
materials; other products made from naphthalene are moth repellents, in the
form of mothballs or crystals, and toilet and diaper pail deodorant blocks.
Naphthalene is also used for making leather tanning agents, and the insecticide
carbaryl. There are two common compounds related to naphthalene:
1-methylnaphthalene (C11H10), also called alpha-methylnaphthalene; and
2-methylnaphthalene (C11H10), called beta-methylnaphthalene. Naphthalene
evaporates easily; when its vapors are mixed with air, the mixture can burn
easily. It is soluble in benzene, alcohol, ether, and acetone; it is soluble in
water at 20 degrees C. It is a moderate fire hazard when exposed to heat or
flame; it reacts with oxidizing materials and chromium anhydride. It is a
moderate explosion hazard, in the form of dust, when exposed to heat or flame.
Naphthalene is also known as naphthalin, naphthaline, tar camphor, white tar,
NCI-C52904, albocarbon, and naphthene.
NASA
NASA (National Aeronautics and Space Administration) is an American government
agency founded in 1958 for space flight and aeronautical research. Its
headquarters are in Washington DC. Its main installation is the Kennedy Space
Centre.
Nascent
In chemistry, nascent is the condition of an element that has just been
released in the monatomic state in a chemical reaction.
National Gallery
The National Gallery is an art gallery in London. It was started in 1824 when
the British government purchased the Angerstein collection of 38 pictures for
57,000 pounds. The first exhibition of them took place on the 10th of May 1824
in Pall-mall.
Nature
Nature is a weekly illustrated scientific journal. It first appeared on the 4th
of November 1869 edited by Joseph Norman Lockyer.
Nautical Mile
The Nautical Mile is a unit of measurement used by ships. It is 1852 meters
long.
Nebula
A nebula is a cloud of gas and dust in space. Before the invention of the
telescope, the term nebula was applied to all celestial objects of a diffuse
appearance. As a result, many objects now known to be star clusters or galaxies
were originally called nebulas. Nebulas exist within other galaxies as well as
in our own Milky Way galaxy. They are classified as planetary nebulas,
supernova remnants, and diffuse nebulas, including reflecting, emission, and
dark nebulas. Small, very bright nebulas called Herbig-Haro objects are found
in dense interstellar clouds and are probably the products of gas jets expelled
by new stars in the process of formation. Planetary nebulas, or planetaries,
are so called because many of them superficially resemble planets through
telescopes. They are actually shells of material that an old average star sheds
during a late, red giant stage in its evolution, before becoming a white dwarf.
The Ring nebula of the constellation Lyra, a typical planetary, has a
rotational period of 132,900 years and a mass calculated to be about 14 times
that of the earth's sun. Several thousand planetaries have been discovered in
the Milky Way. More spectacular but fewer in number are nebulas that are the
fragments of supernova explosions, perhaps the most famous of which is the Crab
nebula in Taurus, now fading at the rate of about 0.4 percent per year. Nebulas
of this kind are strong emitters of radio waves, as a result of the explosions
that formed them and the probable pulsar remnants of the original star. Diffuse
nebulas are extremely large structures, often many light-years wide, that have
no definite outline and a tenuous, cloudlike appearance. They are either
luminous or dark. The former shine as a result of the light of neighboring
stars. They include some of the most striking objects in the sky, such as the
Great nebula in Orion. The tremendous streams of matter in the diffuse nebulas
are intermingled in violent, chaotic currents. Many thousands of
uminous nebulas are known. Spectral studies show that light emanating from them
consists of reflected light from stars and also, in so-called emission nebulas,
of stimulated radiation of ionized gases and dust from the nebulas themselves.
Dark, diffuse nebulas are observed as nonluminous clouds or faintly luminous,
obscuring portions of the Milky Way and too distant from the stimulation of
neighboring stars to reflect or emit much light of their own. One of the most
famous dark nebulas is the Horsehead nebula in Orion, so named for the
silhouette of the dark mass in front of a more luminous nebular region. The
longest dark rift observed on photographic plates of the star clouds of the
Milky Way is a succession of dark nebulas. Both dark nebulas and luminous
nebulas are considered likely sites for the processes of dust-cloud
condensation and the formation of new stars.
Nematodes
see "nematode"
Nembutal
see "Phenobarbital"
Neon
Neon is an inert gaseous element with the symbol Ne. It is one of the rare
components of the atmosphere and is used in some forms of discharge tubes and
lamps, in which it gives a characteristic red glow.
Neper
The neper is a unit used for comparing two currents, in a similar way to the
bel or decibel.
Neptunium
Neptunium is an artificial element with the symbol Np produced in nuclear
reactors.
Nerts
The card game of Nerts is also known as Pounce, Racing Demon, Peanuts or
Squeal. It is a competitive patience game for two or more players, using a pack
of cards for each player (or team). The players race to get rid of the cards
from their "Nerts piles" (also kown as "Pounce piles", etc. - depending on what
you call the game) by building them from the ace up onto common foundations.
Neutrino
A neutrino is a short-lived uncharged particle of zero or near zero rest mass.
They occur in certain nuclear reactions.
Neutron
The neutron is a subatomic uncharged particle, of slightly greater mass than a
proton and forming a constituent part of the nucleus of all atoms except
hydrogen atoms, which consist of a single proton. It may be considered as the
equivalent of one proton and one electron.
Neve
In geography, neve is snow which has become a hard crystalline mass, but has
not been compacted into ice.
New English Art Club
The New English Art Club is a British society founded in 1886 by a group of
artists whose progressive work was being largely rejected by the Royal Academy.
Their work was largely influenced by recent French work.
Newmarket
see "Boodle"
Newspaper
A newspaper is a publication reporting and commenting upon news. The first
newspapers were published by the Romans.
Niacin
see "Vitamin B3"
Nickel
Nickel is a metal element with the symbol Ni.
Nickel Silver
Nickel Silver (German Silver, Pack-Fong) is an alloy of copper, nickel and zinc
in different proportions. Sometimes lead is added if the alloy is destined for
making candlesticks or casts.
Nicotine
Nicotine is an alkaloid derived from the leaves of tobacco.
Nicotinic acid
see "Vitamin B3"
Niello
Niello is a black, metal, amalgam of sulphur added to copper, silver or lead
and used for filling engraved lines in metal objects.
Nimbostratus
Nimbostratus is a type of cloud, low, dark grey and trailing.
Nimbus
A nimbus is a bright cloud or halo added to pictures of saints etc. implying
deity.
Nine Card Don
Nine Card Don is a card game and distant relative of All Fours which is played
in parts of England and Wales. According to Arthur Taylor's "Guiness Book of
Traditional Pub Games" published in 1992 it is also known as Big Don, Long Don,
or Welsh Don. The game is normally played in pubs, where there may be more than
four people waiting for a game. In this case, a procedure called 'jacks out' is
used to decide which four people will play. Those who wish to take part (5 to 7
people - because if there were 8 you would have two complete tables) each place
a stake (typically a pound - maybe 5 pounds) on the table, and the cards are
dealt out one at a time, face up to the stakes. When a jack appears, the player
who contributed that stake is in the game, and no further cards are dealt to
that stake. Where the four jacks eventually land, those are the players. All
the stakes, including those of the players who were not selected, form a pool
that goes to the eventual winners of the game.
Partnerships are then determined by cutting cards. In some pubs, people also
bet on whom will be partners.
Ninety Eight
Ninety Eight is a fairly simple drinking card game for two players using a
standard 52-card deck.
Ninety-Nine
Ninety-Nine is a card game that was developed in 1968 by David Parlett in
response to the need for a skilled but easily learnt plain-trick game for three
players. It was first published in 1975 and has since appeared in card-game
books in various countries including Germany, Hungary, Japan and Argentina.
Niobium
Niobium is a metal element with the symbol Nb.
Nisan
see "Abib"
Nitrate
A nitrate is any salt of nitric acid.
Nitric acid
Nitric acid (Aqua fortis) is produced by the oxidation of ammonia.
Nitro Keg
Nitro Keg is a strong copper-coloured dry ale from the Ash Vine brewery at
Frome in Somerset.
Nitro-glycerine
Nitro-glycerine is a powerful explosive produced from nitric acid and glycerol.
Nitrogen
Nitrogen is a colourless, odourless, tasteless, gaseous element which
constitutes 78% of the atmosphere by volume, and occurs as a constituent of all
living tissues in combined form. It has the symbol N.
NLK
NLK is a light-hearted Hungarian card game which is best for about six players.
No*Stop Suprdupe
No*Stop Suprdupe by Nonstop Networks Limited, is a computer program that makes
two drives the same. It "synchronizes" them. It works with any two drives, so
long as the "target" is large enough to hold the data on the "source". It can
make a floppy disk look like a subdirectory of your hard disk, or make your
RAMdrive look like a subdirectory of your hard disk. Scrub a complex data
structure (such as a demo) from your hard disk. Dump important structures and
data to a removable device for backup and safekeeping. It can be used to copy
data only if the date/time, attributes or size are different.
Nobelium
Nobelium is a radioactive metal element with the symbol No.
Noble gases
In chemistry, the noble gases are a family of elements consisting of helium,
neon, argon, krypton, xenon and radon.
Nocardia
Nocardia is a bacteria found in soil which causes nocardiosis.
NoiseKiller
NoiseKiller by Jean-Pierre Menicucci is a computer program to spin IDE drives
down when they are unused. The drives start spinning again as soon as they are
accessed.
Nonelectrolyte
In chemistry, a nonelectrolyte is a compound whose water solution does not
conduct an electric current.
Nones
In the Roman calendar, the nones were the fifth day of each month, excepting
March, May, July and October when the nones fell on the seventh day.
Noose
A noose is a loop with a running knot which tightens as the string is pulled.
Normal solution
In chemistry, a normal solution is a solution which contains 1 gram-equivalent
weight of a solute in 21 litres of solution.
Norse
The term Norse refers to ancient Norway.
North Star
The North Star (polestar) is a conspicuous star in the northern hemisphere,
located closest to the point toward which the axis of the earth is directed,
thus roughly marking the location of the north celestial pole. A polestar has
been used by navigators throughout recorded history for charting navigation
routes and is still used for determining true azimuth and astronomic latitude.
The positions of the celestial poles change as the earth's axis moves with the
earth's precessional motion, and as the north celestial pole assumes different
positions relative to the constellations, different stars become the North
Star. During the past 5000 years the line of direction of the North Pole has
moved from the star Thuban, or Alpha Draconis, in the constellation Draco, to
within one degree of the bright star Polaris in the constellation Ursa Minor,
which is now the North Star.
Nos
Nos is a Dutch domino game for three, four or five players played with a
double-six set of twenty-eight dominoes.
Nova
A nova is a faint star that suddenly erupts in brightness.
Novell Advanced NetWare
Advanced NetWare is a powerful LAN operating system package that lets you link
up to 100 PCs to a file server to share files and network resources such as
printers. With Advanced NetWare installed in an 80286 or better based PC, you
can achieve minicomputer-like performance while you continue to use your
PC-based applications. Advanced NetWare can be configured as either a dedicated
or non-dedicated system upon installation. Taking full advantage of the power
of the processor, this product uses up to 12Mb of RAM and more than 2Mb of hard
disk storage to support up to 100 users per server. Because it is fully
compatible with IBM's NetBIOS, it works with the many multi-user applications
available for the IBM Token-Ring and PC Network. Compatible with over 80
popular network hardware adapters and topologies, the package offers the utmost
in flexibility. For example, if the layout of your building requires multiple
cable-types, you could connect an ARCNET segment in one part of the building,
an Ethernet in another, and a Token-Ring somewhere else. If you already have a
non-Novell network installed, you can switch to Advanced or SFT NetWare and
take advantage of the package's sophisticated security, power, and flexibility.
Advanced NetWare provides operating system support for NetWare for Macintosh, a
VAP (Value Added Process), and offers transparent protocol connectivity between
IPX and Apple's AFP. Using NetWare for Macintosh and Novell NL1000 AppleTalk
network interface card, you can connect any AppleTalk network or network device
(such as Apple LaserWriters) to a Novell file server running NetWare version
2.15.
Novell ELS NetWare
Novell ELS NetWare Level I is Novell's Entry Level Solution non-dedicated
network operating system software for small workgroups or offices. Designed for
those who need the advantages of networking but who are afraid that network
installation is too complex. LAN operations such as file and resource sharing
are supported. Much less expensive and easier to install than Novell's other
LAN software, Novell ELS NetWare Level I is a non-dedicated LAN operating
system that supports up to four network users simultaneously. The package
includes many of the features of Novell's other LAN software, such as
menu-driven operation, print spooling, and a custom menuing program, and
supports up to five network server-attached printers. Novell ELS NetWare Level
II supports up to eight concurrent users. Unlike ELS NetWare Level I, it
includes many key features and network management tools of Novell Advanced
NetWare, such as resource accounting, system security, basic system fault
tolerance, and hardware independence. ELS NetWare Level II offers the choice of
dedicated or non-dedicated 80286 modes of operation. A read-after-write
verification is performed whenever data is written to the network hard disk
insuring that the data is re-readable. If the read-after-write verification
finds a faulty area of the hard disk, Hot Fix labels it as bad, lists it in the
bad block table, and automatically writes data to undamaged areas. ELS NetWare
Level II provides operating system support for NetWare for Macintosh, a VAP
(Value Added Process), and offers transparent protocol connectivity between IPX
Apple's AFF. Using NetWare for Macintosh and Novell NL1000 AppleTalk network
interface card, you can connect any AppleTalk network or network device (such
as Apple LaserWriters) to a Novell file server running NetWare version 2.15.
Nucleic acid
Nucleic acid is a complex organic acid forming the basis of heredity.
Nucleus
The nucleus is the positively charged central part of an atom.
Numismatics
Numismatics is the study of coins and medals.
Nyctophobia
see "Scotophobia"
Nylon
Nylon is a synthetic plastic similar in chemical structure to protein.
o-Toludine Hydrochloride
o-Toludine Hydrochloride is a crystalline, colourless to white sand like
material used to make various dyes and colours fast to acids.
