- PayMaster. Who pays the piper calls the tune.
- Performance Monitoring.
- Permanent Magnet. A ferromagnetic material with an alignment of domains
that produces a net magnetization.
- Phase Modulation.
- Physical Medium.
- Plasma Membrane[s].
- Popular Mechanics. On the cover, underneath the title, the words
Written so you can understand it.
- Post Meridiem (after noon).
- Presentation Manager.
- Preventive Maintainance. The least sexy activity.
- Prime Minister. Catch up on who is the latest Japanese PM here. Read quickly, the page
has a timed fuse.
Say you're standing on a street corner of Main Street, U.S.A., and a fellow
from the ``CBC'' comes up and says he wants to
ask you a few questions. He comes up with a real
obscure one like ``who's the prime minister of Canada?'' You haven't had the time lately to bone up
on your international trivia, and you didn't even realize that Canada had a national church. No problem! Just answer ``Rick
Mercer'' and smile.
- Project Manager.
- (Domain code for) St. Pierre and Miquelon.
- Promethium. Atomic number 61. Named after the titan who gave fire to
man and was punished by having birds pick at his immortal innards.
Eventually he cooperated (became an informer, ratted) with the olympian
authorities to get off that
Learn more, but only about this rare earth (RE)
element and not Greek mythology, at its entry
in WebElements and its
entry at Chemicool.
It's hard to fight the feeling that it ought to be PromethEum.
- Pennsylvania Manufacturers'
- Precision Metalforming Association.
- Produce Marketing Association.
- Property Management Assocation. For example, here's a link to the PMA of Western Michigan,
an NAA affiliate.
- Publishers Marketing Association.
``The largest non-profit trade association representing
independent publishers of books, audio, video and CDs.''
Hey, we're all trying to move product -- apples,
- Petroleum Marketers Association of
America. But see also CSP.
- Precision Metalforming
Association (PMA) Educational Foundation.
- Polymethactylonitrile (polymer).
- Pietermaritzburg. A symbol or initialism used in
- Preliminary Multistate Bar Review.
- Prosopographie de mittelbyzantinischen
Zeit. A five-volume encyclopedia, copyright 2001. They're thick
volumes, but not that thick: PMBZ is the form of the title that appears on the
spine. Even on the cover, mittelbyzantinischen is hyphenated.
- Postmodern Culture. ``An electronic journal of interdisciplinary
criticism, published by North Carolina State University, Oxford University
Press, and the University of Virginia's Institute for Advanced Technology
in the Humanities.''
- (International Conference on the) Performance and Management of Complex
- Physical-Medium-Dependent (sub-layer; layer in the sense of
- Pre-Metal Dielectric.
- Permanent Magnet Direct Current (DC) (motor).
The permanent magnet(s) provide the fixed (external) field surrounding the
rotor. They replace the ``stator'' field windings in a shunt motor.
- Pacific Marine Environmental
Laboratory. A facility of the US NOAA, it
``carries out interdisciplinary scientific investigations in oceanography and
- Professionals, Managers, Executives, and TechnicianS. The acronym is
common in Singapore, and apparently nowhere else, as of February 2009.
(Pi Mu Epsilon)
- National Mathematics
- Pardon Me For Jumping In. Email abbreviation.
PMJI is also used.
- polarization modulation Fourier Transform InfraRed
- PostMaster General.
- PseudoMorphic High Electron Mobility Transistor
- Private Mortgage Insurance.
- Program Management and Integration.
- Project Management Institute. Tests and
certifies project management
- Purchasing Managers' Index.
- Poly Methyl IsoPropenyl Ketone.
- Pardon My Jumping In. Email abbreviation.
PMFJI is also used.
- Perfect Matched Layer (numerical boundary conditions). Scheme for
constructing Absorbing Boundary Conditions (ABC's).
- Progressive Multifocal Leukoencephalopathy. A neuropsychiatric disease
caused by JC-viral infection. Devastating. Occurs
in a few percent (estimates around 5%) of AIDS
patients. Symptoms hard to distinguish from AIDS dementia (q.v.), but
progress (not my choice of word) is more rapid.
- Poly(methyl methacrylate). Common resist for
ion-beam-lithography, and for light-beam photography in energies from
UV to X-rays. Basically, it's a positive resist: the pattern of exposed
polymer is damaged and dissolves more easily in developer solution.
Okay now, we're going to step through the simple organic chemistry of this
plastic in the order dictated by the derivation of its name. This is going
to be so simple, even I could understand it.
[In fact, I might as well warn you, if you know anything about organic
chemistry this will just about make you retch, but it's still better than if
it made you a wretch.]
First off, ``acrylic acid'' is just a
confusing name for propenoic acid.
Now propane is a
three-carbon alkane (a flammable
gas at room temp.); it has only one form:
This is also written H3CCH2CH3 and just plain
It doesn't matter, there's only one stable compound with this formula.
H H H
| | |
H -- C -- C -- C -- H
| | |
H H H
Representing carbons by kinks in, or ends of,
a chain of C-C bonds, omitting to indicate H's,
(In this mode of displaying organic compounds, the precise compound can be
reconstructed by satisfying the valency of all carbons by adding as many hydrogens as necessary. This is a very efficient scheme
for representing organic compounds, since carbon chains and lots of boring
Propene is an alkene, an alkane with a double bond. Since the two
C-C bonds of propane are equivalent, there is no need to indicate which
bond is doubled. The formula is CH2:CHCH3, which we can
H H H
\ | |
C == C -- C -- H
/ | |
H H H
Organic acids are formed by replacing methyl (-CH3) with
carboxyl (-COOH) groups, so propenoic acid can only be
C == C -- C == O
or (in a representation that more closely
approximates the physical conformation)
H C == O
C == C
or (most schematically)
Methacrylic acid is 2-methyl propenoic acid: a methyl (CH3) group
has been substituted for the hydrogen on carbon number 2 (the middle carbon) of
the backbone to yield CH2:C(CH3)COOH. (Really, there's
no need to specify 2-methyl, since putting the methyl group on the only other
available carbon would mean that the molecule should have been designated
butenoic acid. Oh, well, what do I know about IUPAC nomenclature?)
H C == O
C == C H
/ \ /
/ \ /
Up to this point, I reemphasize, the construction has followed the
nomenclature and not the synthesis.
Methyl methacrylate is an ester: methanol has been
reacted with methacrylic acid in what resembles an acid-base reaction.
Methanol was previously known as methyl alcohol; an even older name is
wood alcohol. It is present in minute quantities, and occasionally
not-so-minute quantities, in the cheap stuff winos drink. As is well known,
enough (and not that much) methanol will blind or kill you. In Simon and Garfunkel's song ``Blessed'' (from the
Sounds of Silence album) winos are called
``meth drinkers.'' There were roadblocks and a scandal a couple of decades ago
when cheap table wine imported from Italy to France was found to be contaminated with methanol, but
you'll have to track that old news down yourself. The
SBF offers recipes for a couple of recent-traditional
(Tears of a Komsomol Girl
and Spirit of Geneva).
In esterification, which is a standard synthesis, the OH groups from
the acid and alcohol combine to release one water molecule and leave a single
bond through oxygen. In the present example:
H O -- C -- H
C == C -- C == O
H C -- H
Because this molecule has a carbon-carbon double bond, there is a natural
mechanism for its polymerization. Energy supplied by a photon of UV light
is sufficient to break the double bond and initiate polymerization. This
process tends to continue because the process of bonding to a neighbor
breaks the neighbor's double bond and makes a new carbon reactive. The
resulting chain has the following monomer unit:
H -- C -- H
H C == O
· · ----- C -- C ----- · ·
H C -- H
San Diego Plastics, Inc. serves
a short page of
application-oriented information on PMMA plastic. There's an informative PMMA entry in
PMMA was first discovered in the 1870's, but was first commercialized by
Rohm and Haas in 1935 as Plexiglas. DuPont brought out PMMA as Lucite in
- A copolymer of methyl methacrylate (vide PMMA
supra) and methacrylic acid. A beam resist.
- Paged Memory Management Unit.
- Passive MilliMeter Wave (imaging).
- PolyMorphoNuclear leucocyte.
- PreManufacture Notice. Required by the TSCA,
as noted at the CHEMEST entry.
- Prime Minister's Office.
- pMOS, PMOS
- P-channel MOSFET, which in digital logic
occurs primarily in conjunction with nMOS in CMOS circuits.
There's not much utility for pMOS alone, since everything you can do with
pMOS alone you can do with nMOS alone, but the higher mobility of electrons
than holes in commercial (and indeed most simple) semiconductor materials
gives nMOS a higher gain factor.
- PolyMethylPentene (plastic). (Mitsui Petrochemical Industries, Ltd.:
- Post-Metal Programming. National
Semiconductor (tm) term for the strategy of
using nearly-finished, tested
nMOS NOR ROM to speed the hardware development
process. Generally speaking, nMOS technology is the cheapest basis for ROM that can be programmed before leaving the fab. The
two main types of nMOS ROM are NOR and NAND. From the standpoint of PMP, the crucial
difference is that the bit pattern of NOR core can be written at a late stage
of fabrication, while the bit pattern for NAND core must be written at an early
stage. In detail:
nMOS NAND ROM, zeros and ones are typically implemented by a diffusion or
implantation mask that shifts a transistor threshhold voltage (so the
transistor is always on).
Thus, bit pattern storage must be done relatively early in fabrication,
before metal or polysilicon row lines are deposited (the row line functions
as a gate where it crosses over a bit line -- bit lines are diffused or
implanted). In contrast, nMOS NOR ROM's are encoded at a late stage of
fabrication (the bit pattern is stored by contacting or not contacting
transistor drains to bit lines).
(It can also be performed at a very late stage of fabrication by means of
a high-energy implantation.) Thus, NMOS NOR ROM chips can be pretested
and stored, and large numbers of chips can be available almost immediately
after the ROM program is written.
- Project Management Professional.
- Precision Machined Products
- Pre-Markan Passion Narrative. A document that is either no longer extant
or never existed.
- Prime Minister Question time. An entertainment sponsored by the British
House of Commons. In terms of posturing and bogus news generation, roughly,
comparable to presidential press conferences in the US. Apart from some
linguistic conventions (e.g., the PM answers
for ``the government'' -- the parliamentary party in power), the main
difference in the presumed adversarial position of the questioners: In a US
presidential press conference, the press is nominally neutral, and poses
questions crafted to put the president in the uncomfortable position of having
to make an embarrassing admission or be seen to avoid answering directly. In
stark contrast, in PMQ the questioners are opposition
MP's who pose questions crafted to put the president in the uncomfortable
position of having to make an embarrassing admission or be seen to avoid
- Partido de la Revolución Mexicana. `Party of the Mexican
Revolution.' The revolution was not televised, but a good time was had by all.
Okay, not true. More factish statements at the PRI
- Private Mobile Radio.
- Pest Management Regulatory Agency
of Health Canada.
- Pacific Missile Range Facility.
- Particle Measuring Systems. (Company name.)
- Performance Management System. [Standard avionics.]
- PreMenstrual Syndrome. The non-crime that dares you to speak its name.
Also ``Putting up with Men's S...'' and
``Postal Management Syndrome.''
- Post-Modern Slut.
- PM scholarship
- Papa-Mama SCHOLARSHIP. A euphemism for no scholarship in the ordinary
sense at all. Like a marital
fellowship, it's not an arrangement with a very official status.
- Polymer MicroStructure Waveguide.
- Phiroz Mehta Trust. Phiroz Mehta
(1902-1994) seems to have been a syncretistic guru. I feel transcendent
- PhotoMultiplier Tube. A sensitive photon detector. An evacuated tube with
a number of electrodes of increasing positive voltage onbliquely facing each
other (geometries vary). Any single particle impinging on a low-voltage anode
produces a cascade of increasingly amplified current, as each stage emits more
electrons than it receives (multiplies). It's a photo multiplier tube
because the initial electrode receives a photon and emits one or more electrons
some instructional material from Virginia Tech.
- Prevention of Mother-To-Child Transmission of
(a disease or disease-causing agent). The term is not used to refer to
amniocentesis to detect bad genes. In fact, the term mostly seems to refer to
preventing a human fetus from being infected with
- Physical Mass Unit. The atomic mass unit, according to the definition
favored by physicists, back when chemists and physicists used different
definitions. Read the details at this amu entry.
- Perfluoro(Methyl Vinyl Ether).
- Palestinian Media Watch.
- Pardon Me, You Must Have Mistaken Me For Someone Who Gives A Damn.
A common expression, and an abbreviation that occurs frequently in newsgroup
acronym lists, but never in actual postings. Cf. tanstaafl.
- PM-10, PM10
- Particulate Matter of diameter less than 10 micrometers.
- p-type semiconductor, then n-type semiconductor, together. A
bipolar junction. A homojunction, but not
just any homojunction (it could be n-n+ or n-n-, or
something similar with p).
- Passion Narrative. Described in Christian gospels. One of the many
questions that occur in HJ studies is whether
Mark (see Mk 14-16) invented the PN out of whole
cloth, or whether there was a pre-existing tradition for it (set aside what
actually happened and who might have known).
Disagreements between the Matthean and Lucan PN's (and BN's and resurrection stories), coexisting with a
large number of agreements between the two (sometimes together against Mark),
are the principal motivation for positing a distinct Q document.
- Petri Net.
- (Domain code for) Pitcairn.
- Pottery Neolithic. Later part of the Neolithic period, when clay pottery
was made. Cf. PPN
- Practical Nurse.
- Professional Network. The British electrical engineering organization
(IEE) uses this abbreviation productively,
approximately as the ACM uses
SIG (Special Interest Group) and the IEEE uses ``[technical] society'' and ``council.''
- PseudoNoise. Pseudorandom Number sequence.
Designates a spreading signal used in SS.
- Project for a New American Century. What -- did we use up the previous
American century already? Aren't these things supposed to last, like,
at least 90 years?
PNAC is a Washington, DC, think tank consisting of three thinkers plus, I
think, some support personnel. It plays a major role in the current (2005)
demonology of the US left. In the Boy Scouts, I learned that three of anything
(fires in a line, for example) can be used as a symbol of danger. Maybe that
played a role in the design of the tail-lights on the original Chevy
Caprice/Impala series (two-light Bel Air excluded) and the Ford Mustang.
Detroit must have forgotten, but they're not selling many cars now, are they?
For some stupid remarks on the trilateral commission, another three-headed
monster of legend, see our old conspiracy
- Pageant News Bureau.
Beauty pageant news. Reading this, you get the idea that there
would be enough titles to go around if only they didn't give anyone more
than one or two titles.
- Poly (n-Butyl Acrylic).
- Petri-Net-Based Hypertext.
- People, Networks & Communication © (Conference). Sponsored
- Pacific Northwest Council
for Languages. ``[T]he oldest regional organization [i.e.,
ACTFL regional affiliate] of world-language teachers in the [US].''
- Peaceful Nuclear Explosion Treaty.
When India entered the nuclear club, back in the
seventies, they did not detonate any bomb. Noooo! Indira tested a peaceful
nuclear device. Big difference.
- Proprioceptive Neuromuscular Facilitation.
- Pack 'N' Go. The name of various programs, tools, and options, and
associated data formats (this PNG is not one of
them), that are supposed to simplify data transfer.
- Papua New Guinea.
- Pawnee National
Grassland. In northern Colorado.
- Persona Non Grata. Hey, you gotta go along to get along.
- PNG, .png
- Portable Network Graphics. A graphics format. According to this authoritative page, this PNG is
not related to the others listed around this entry. (English avoids these
homograph confusions by the method of randomized vowel insertion. The
disambiguation symbols can be distinguished from ordinary vowels by the fact
that they have nothing necessarily to do with the pronunciation, just like the
consonants. As you know, English uses a logographic script as Chinese does,
but the logographs are constructed from a finite ``alphabet'' of strokes called
letters. The logograph ``radicals'' of English are borrowed from Swahili and
- Professional Numismatists Guild.
- pnicogen, pnictogen
- An element in the nitrogen group. (group VA American, VB European, 15
IUPAC). From the Greek pnígein, `to choke.' You would choke in
an all-nitrogen atmosphere, I guess, but you would also choke in an all-argon
atmosphere. It only happens that air is about 78% nitrogen and only about 1%
- Batelle (Memorial Institute-operated)
Laboratories of the Department of Energy,
in Richland, WA.
- Planetary-Nebula Luminosity Function. Used to determine distances of
galaxies as far as 100 Mpc away.
- PNM, .pnm
- Portable aNyMap. An image format: MIME-type
Any idea what that means?
- Proton Nuclear Magnetic Resonance (NMR). The
other popular one is based on the C12 nucleus.
- PNNI, P-NNI
- Private Network-to-Network Interface.
- PNP, PnP
- Plug'N'Play. Substantially facilitated by object-oriented coding.
This is different from `pay to play.' In `pay to play,' a citizen (C) makes a
contribution to a political candidate (P), and later the public official (P)
spends public moneys ($) or writes legislation (pork) in a way that benefits
the citizen (C). The ``citizen'' may be a citizen, a corporation, or a
foreign government. In the last case, pay-to-play may be illegal.
- A BJT with net n-doped base and p-doped
collector and emitter. Traditionally, IC manufacture used n-doped substrates
(taking advantage of factor-of-three higher mobility of electrons over holes in
silicon), and was dominated by npn transistors.
- Partido Nacional Revolucionario. `National Revolutionary Party' of
Mexico. Original name of the PRI, q.v.
- The Pakistan News Service. Distributed on the bitnet lists
PAKISTAN@ASUACAD and PAKISTAN@PSUVM, with a bidirectional gateway
(at American University) to a moderated (by the PNS editors) usenet newsgroup <bit.listserv.pakistan>.
A little bit more at .pk entry.
- The Philosophy News Service.
Came into being in June 2004. Of course, if it came into being, then it is
one of those entities that is ever in the process of becoming, and therefore is
not. That's not news, that's Plato. Too bad, it might have useful humor
content, if it existed. There's a mailing list, too.
- Peripheral Nervous System.
- PNS Syndrome
- PIN-Number Syndrome. The term PNS
Syndrome is an instance of an AAP
pleonasm, as is the term AAP pleonasm (an acronym-assisted AAP
pleonasm, in fact). The unconscious use of an AAP pleonasm, or the
conscious use with reckless disregard, is an instance of PNS Syndrome. This
sentence and the last might be examples of
PNS Syndrome. This sentence is not.
Early in the 21st century, The New
Scientist magazine has been doing a number of columns on the
phenomenon, which it calls ``RAS Syndrome.''
- Permanent Normal Trading Relations.
- Programa de las Naciones Unidas para el
Desarrollo. Spanish, `United Nations
Development Program' (UNDP).
- Programme des Nations
Unies pour l'environnement. French for UNEP.