- U Wastes
- A federal list of non-acute hazardous wastes.
- U.S.C.
- United States Code.
- U-AVLIS
- Uranium-Atomic Vapor Laser Isotope Separation (LLNL)
- UAT
- User Acceptance Test. (Computing)
- UA1
- Underground Area 1. The name of a detector, and the related
experiment, at CERN.
- UA2
- Underground Area 2. The name of an experiment, and the
related detector, at CERN.
- UA5
- UA5 detector at CERN.
- UC
- UltraCentrifugation.
- UCN
- UltraCold Neutron
- UCP
- Unique Continuation Property.
- UCPF
- Universal Chiral Partition Function
- UDP
- User Datagram Protocol. A transport protocol in the Internet
suite of protocols. UDP, like TCP, uses IP for delivery; however,
unlike TCP, UDP provides for exchange of datagrams without
acknowledgements or guaranteed delivery.
- UEC
- Users Executive Committee.
- UED
- Ultrafast Electron Diffraction.
- UEL
- Upper Explosive Limit or Upper Flammable Limit (UFL). The
maximum percentage of a substance in air which will ignite. See
also LEL and Flammability Range.
- UEM
- Ultrafast Electron Microscopy.
- UF
- UltraFiltration.
- UFC
- Uniform Fire Code.
- UFC
- UltraFast science Center. (Stanford)
- UFL
- See UEL.
- UFVA
- Unclassified Foreign Visits and Assignments. (DOE)
- UG
- Unified Graphics. (Obsolete)
- UGC
- Uppsala General Catalogue of Galaxies.
- UGPS
- University Grant Program Subpanel.(DOE and NSF)
- UH
- Undulator Hall (LCLS).
- UHE
- Ultra High Energy.
- UHECR
- Ultra High-Energy Cosmic Rays.
- UHF
- Ultra High Frequency. Allocated band of radio frequencies
from 300 Megahertz (MHz) to 3,000 MHz.
- UHV
- Ultra High Vacuum. The vacuum condition below about 10 exp
(-6) TORR. Storage rings operate two to four orders of magnitude
under UHV.
- UI
- User Interface.
- UIC
- Underground Injection Control. (from SDWA)
- UIMS
- User Interface Management System. UIMSes are high-level GUI
building tools. On the same underlying data, you can relatively
easily create different types of user interfaces. UIMSes are also
called GUI builders.
- UKQCD
- United Kingdom Quantum Dynamics Collaboration.
- UL
- Underwriters Laboratory.
- Ultra High Frequency
- See UHF.
- Ultra High Vacuum
- See UHV.
- ULXs
- Ultra-Luminous compact X-ray sources.
- UML
- Unified Modeling Language.
- UN/NA
- United Nations/North American hazardous materials code.
- UND
- UNDulator.
- UND
- UNDer
- Underground Area 1
- See UA1.
- Underground Area 2
- See UA2.
- Undulator
- A permanent magnet, used like a wiggler, to generate more
synchrotron light by causing the beam to bend rapidly back and
forth.
- UNESCO
- United Nations Educational, Scientific, and Cultural
Organization.
- Unibus
- A bus system developed by DEC for the PDPs and other DEC
computers.
- UNID
- Of the 271 Gamma-ray sources detected by the EGRET
instrument onboard the Compton Gamma-Ray Observatory, 172 are
unidentified sources. Possible candidates for these sources
include active galactic nuclei, pulsars, supernova rem
nants, dense molecular clouds, and stellar-mass black holes
within our Galaxy. It is even quite possible that entirely new
phenomena could account for some portion of these unidentified
sources. GLAST will localize the positions of the uni
dentified sources accurately enough to make searches for
counterparts at other wavelengths much more feasible.
Glast Category: ASTRONOMY, operations
- Uninterruptible Power Supply
- See UPS.
- Universities Research Association
- See URA.
- UNIX
- A computer operating system developed by AT&T. It is
available on a wide variety of computing platforms. It is noted
for its portability and interactive software tools.
- Unix to Unix Copy Program
- See UUCP.
- UNP
- Unbounded Nano Particle.
- Unsaturated Zone
- A subsurface zone containing water under pressure less than
that of the atmosphere, including water held by capillarity, and
containing airs or gases generally under atmospheric pressure. It
is limited above by the land surface and below by the water
table. Synonym: Vadose Zone.
- UO
- Users Organization.
- UOEC
- Users Organization Executive Committee.
- UOR
- Unusual Occurrence Report.
- UPK
- User Productivity Kit. (PeopleSoft).
- Upper Explosive Limit
- See UEL.
- Upper Flammable Limit
- See UEL.
- UPS
- Uninterruptible Power Supply. An emergency power supply used
in PPS systems where power must not be interrupted for safety
reasons. Consists of a large bank of batteries and control
circuitry.
- UPSTR
- UPSTReam
- URA
- Universities Research Association. The governing body for
Fermilab and the former SSC.
- URA
- User Research Administration (SSRL, LCLS)
- URI
- Uniform Resource Identifier. The generic term for all types
of names and addresses that refer to objects on the World Wide
Web. A URL is one kind of URI.
- URL
- Uniform Resource Locator. Standardized formatted entities
within hyper-text documents which specify a network service or
document to establish a link.
- URQMD
- UltraRelativistic Quantum Molecualr Dynamic.
- USA
- Unconventional Stellar Aspect satellite experiment.(Group K)
- USAXS
- Ultra Small-Angle X-ray Scattering.
- USC
- Ultrafast Science Center (SLAC)
- USCG
- United States Coast Guard.
- USDA
- United States Department of Agriculture.
- USDW
- Underground Source of Drinking Water.
- USGBC
- U.S. Green Building Council.
- USGS
- United States Geological Survey.
- USI
- Unreviewed Safety Issue.
- USLCSG
- United States Linear Collider Steering Group.
- USN
- United States Navy.
- USPAS
- United States Particle Accelerator School. A twice-yearly
school that rotates among research universities throughout the
U.S. and draws faculty from a variety of institutions to teach
intensive courses on beam science and technology.
- USPCI
- U. S. Pollution Control, Inc.
- USPHS
- United States Public Health Service.
- USR
- Ultimate Storage Ring.(proposed) A light source designed to
produc e brighter X-ray beams than the current synchrotrons can
offer.
- USSKA
- United States Square Kilometer Array Consortium.
- UST
- Underground Storage Tank.
- USTC
- University of Science and Technology of China.
- USW
- United Stanford Workers.
- UT
- Upper Transformer
- UTC
- | A high-precision atomic time standard (also known
Greenwich Mean Time, or as Zulu time) with 24-hour days
conventionally identified using the Gregorian calendar, though
Julian Day Numbers can also be used. Each hour contains 60|
| minutes, but the number of seconds in a minute can vary
slightly. A normal UTC day contains exactly 86,400 seconds, with
exactly 60 seconds in each minute. However, the mean solar day is
slightly longer than 86,400 seconds, resulting in t|
| he occasional inclusion of a leap second in the last minute
of a UTC day, giving it 61 seconds to account for the extra
length of about 2 milliseconds in each of all the mean solar days
since the previous leap second. (These irregular day |
| lengths mean that fractional Julian days do not work
properly with UTC.) Time zones around the world are expressed as
positive or negative offsets from UTC.|
Glast Category: astronomy, operations, SAS
- UTEP
- University of Texas at El Paso. (SSRL Gateway Partner)
- UTIC
- Universal Time Interval Counter.
- UTR
- University Technical Representative.
- UTS
- Ultramedia Tools Series. OS/2, Windows, and DOS multimedia
software products for authoring, graphics, audio, animation, and
video that share common file formats and a similar user
interface.
- UUCP
- Unix to Unix Copy Protocol. A protocol used for copying
files between consenting UNIX systems, and for handling e-mail.
Mostly superseded, but still used in low budget situations.
- UV
- UltraViolet
- UX
- User eXperience.
Send corrections to jmdeken@slac.stanford.edu
or propose new terms for SLACspeak.