ExpertGlossary terms starting with R

2,379 terms

"Repos" (Repurchase Agreements) An agreement to purchase securities from an entity for a specified amount of cash and to resell the securities to the entity at an agreed upon price and…
R Rain
R 2 (1) Recovery and Reconstitution. (2) Reporting Responsibility.
R 2 P 2 Rapid-Retargeting/Precision Pointing (simulator).
R 3 Rotary Reciprocating Refrigerator.
R genes A class of plant genes conferring resistance to a specific strain (or group of strains) of a particular pathogen.
R i Inherent Reliability.
R interface For a basic rate access in an ISDN environment, the interfacing specifications covering pre-ISDN standards (e.g., EIA-232C).
R m Mission Reliability (ILS term).
R&A Reliability and Availability.
R&D Research and Development.
Réplica, contestación La contestación de un demandante a una respuesta del demandado que contiene una reconvención, o contrareclamo.
R-Factor See R-Value.
R-flurbiprofen A substance that is being studied as a treatment for cancer. It belongs to the family of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs).
R-loops Single-stranded DNA regions in RNA -DNA hybrids formed in vitro under conditions where RNA -DNA duplexes are more stable than DNA -DNA duplexes.
R-squared R-squared is a statistical measurement that determines the proportion of a security's return, or the return on a specific portfolio of securities, that…
R-T Real Time.
r-tPA A form of tissue plasminogen activator that is made in the laboratory. It helps dissolve blood clots and is used to treat heart attacks, strokes, and…
R-Value A measure of the capacity of a material to resist heat transfer. The R-Value is the reciprocal of the conductivity of a material (U-Value).
R/ASR Review as Required.
R/C Abbreviation for radio control, radio service.
R/W Read/Write.
R1 The first-generation offspring of a recombinant (genetically modified) organism. Not standard terminology. See: T0, T1, and T2.
R101933 A substance that is being studied for its ability to make cancer cells respond to drugs to which they have become resistant.
R115777 A substance that is being studied in the treatment of acute myeloid leukemia (AML) and other types of cancer.
R1507 A human monoclonal antibody being studied in the treatment of several types of cancer.
R2 The Symmetrix term indicating the remote data copy that is the secondary copy. It is normally read-only by the nodes at the remote site.
R3 Rotary Reciprocating Refrigerator.
RA Rain
RA (Registrant Authority) A Registrant Authority works in conjunction with the Certificate Authority (CA) approving or rejecting requests for certificates of public keys.
RAA Risk Approval Authority.
RAAF Royal Australian Air Force.
rabies A disease of the nervous system caused by the rabies virus. Rabies is marked by an increase in saliva production, abnormal behavior, and eventual…
RACE A distinguishable group of organisms of a particular species. Criteria for distinctness can be one or a combination of geographic, ecological…
race condition See race hazard.
race hazard A situation that arises between multiple threads sharing a resource. A race hazard arises when one thread's assumptions about the state of a resource are…
raceme An inflorescence in which the main axis is elongated but the flowers are borne on pedicels that are about equal in length.
Racetrack bets Also known as 'Call bets'. The racetrack betting area is in front of the croupier on the table used for players wishing to make bets on sections of the…
raceway Within a building, an enclosure, i.e., channel, used to contain and protect wires, cables, or bus bars.
rachilla Shortened axis of a spikelet.
rachis Main axis of a spike; axis of fern leaf (frond) from which pinnae arise; in compound leaves, the extension of the petiole corresponding to the midrib of…
rack A frame upon which one or more units of equipment are mounted. Note: DOD racks are always vertical.
Rack card The typical tourism brochure sized 4” x 9” and used primarily in tourism racks. Also known as a “teaser.”
Rack rate The official cost posted by a hotel, attraction or rental car, but not used by tour operators.
racon See radar beacon.
RAD Radiation Absorbed Dose. The basic unit of an absorbed dose of ionizing radiation.
Rad Hard Radiation Hardened.
rAd/p53 A substance that has been studied in the treatment of some types of cancer. rAd/p53 is a weakened adenovirus that carries the p53 gene into tumor cells…
RADAP II RAdar DAta Processor II, attached to some WSR-57 and WSR-74 radar units. It automatically controls the tilt sequence and computes several radar-derived…
radar Acronym for RAdio Detection And Ranging; a radio device or system for locating an object by means of ultrahigh-frequency radio waves reflected from the…
Radar Beacon A receiver-transmitter combination which sends out a coded signal when triggered by the proper type of pulse, enabling determination of range and bearing…
radar beacon (racon) A transmitter-receiver associated with a fixed navigational mark which, when triggered by a radar, automatically returns a distinctive signal which can…
Radar Beam The straight line that a radar pulse travels along. As the radar beam gets further away from the radar, it gets wider and wider.
radar blind range The range that corresponds to the situation in which a radar transmitter is on and hence the receiver must be off, so that the radar transmitted signal…
radar blind speed The magnitude of the radial component of velocity of an object, i.e., a target, relative to a radar site, that cannot be measured by the radar unit.
Radar Coded Message This is an alphanumeric coded message which will be used in preparation of a national radar summary chart.
Radar Cross Section The area of a fictitious, perfect reflector of electromagnetic waves (e.g., metal sphere) that would reflect the same amount of energy back to the radar…
Radar Cross Section (RCS) Area of an object as scanned by radar; measured in square meters.
Radar Data Acquisition An acronym for Radar Data Acquisition. The RDA is the hardware component of the NEXRAD system that consists of the radar antenna, transmitter, receiver…
radar doppler The power spectrum and moments of the radar signal expressed as a function of Doppler frequency or Doppler velocity.
radar intelligence (RADINT) Intelligence derived from data collected by radar. [JP 1-02]
Radar Meteorology Branch of meteorology that uses radars for weather observations and forecasts.
radar mile The time required for a radar pulse to travel 1 mile (~1.6 km) to an object, i.e., to a target; reflect; and return to the receiver.
Radar Mosaic A radar product that combines information from multiple radars to give a regional or national view of reflectivity or precipitation.
Radar Netting The linking of several radars to a single center to provide integrated target information.
Radar Product Generator (RPG) The RPG is the computer in the NEXRAD system that receives polar-coordinate base radar data from the RDA and processes these data into end-user products.
Radar Range Distance from the radar antenna. The WSR-88D radar has a range for velocity products out to 124 nautical miles and reflectivity products out to 248…
Radar Reflectivity The sum of all backscattering cross-sections (e.g., precipitation particles) in a pulse resolution volume divided by that volume.
Radar Reflectivity Factor (z) z = the sum (over i) of (N_i * D_i^6), where N_i is the number of drops of diameter D_i in a pulse resolution volume.
radar resolution cell The volume of space that is occupied by a radar pulse and that is determined by the pulse duration and the horizontal and vertical beamwidths of the…
radar signature 1. The detailed waveform of a detected radar echo. Note: Radar signatures may be used to identify or distinguish among objects, i.e.
radar xxline-of-sight (LOS) equation An equation that expresses the radar horizon range (RHR), given by where RHRs is the radar horizon range in statute miles, h is the antenna height in…
RADC (1) Region Air Defense Commander. (2) OBSOLETE. Rome Air Development Center. (Now called Rome Laboratory.)
RADEC Radiation Detection Capability.
RADHAZ (1) Electromagnetic Radiation Hazard. (2) Hazards form electromagnetic radiation.
Radial Lines converging at a single center.
Radial gate A pivoted crest gate, the face of which is usually a circular arc, with the center of curvature at the pivot about which the gate swings.
Radial Gate (Tainter Gate) A gate with a curved upstream plate and radial arms hinged to piers or other supporting structures on which the gate pivots.
Radial Velocity Component of motion toward or away from a given location. As "seen" by Doppler radar, it is the component of motion parallel to the radar beam.
radian (rad.) A unit of plane angle measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.
radiance A measure of the intensity of the radiant energy flux emitted by a body in a given direction.
Radiant Barrier A thin, reflective foil sheet that exhibits low radiant energy transmission and under certain conditions can block radiant heat transfer; installed in…
Radiant Ceiling Panels Ceiling panels that contain electric resistance heating elements embedded within them to provide radiant heat to a room.
radiant emittance Radiant power emitted into a full sphere, i.e., 4 sr (steradians), by a unit area of a source, expressed in watts per square meter.
Radiant Energy Energy that transmits away from its source in all directions.
radiant exitance Synonym radiant emittance.
Radiant Exposure The total amount of thermal radiation energy received per unit area of exposed surface; it is usually expressed in calories per square centimeter. 242
Radiant Floor A type of radiant heating system where the building floor contains channels or tubes through which hot fluids such as air or water are circulated.
radiant flux Deprecated synonym for radiant power.
Radiant Heating System A heating system where heat is supplied (radiated) into a room by means of heated surfaces, such as electric resistance elements, hot water (hydronic)…
radiant intensity Radiant power per unit solid angle, usually expressed in watts per steradian.
radiant power The rate of flow of electromagnetic energy, i.e., radiant energy. Note 1: Radiant power is usually expressed in watts, i.e., joules per second.
Radiation (RAY-dee-AY-shun) Energy released in the form of particle or electromagnetic waves.
radiation angle In fiber optics, half the vertex angle of the cone of light emitted at the exit face of an optical fiber.
Radiation Belt Magnetized planets, like Earth, are encircled by zones of particle radiation known as the "Van Allen belts," in which high-energy charged particles spiral…
radiation brachytherapy (RAY-dee-AY-shun BRAY-kee-THAYR-uh-pee) A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed…
radiation dermatitis (RAY-dee-AY-shun DER-muh-TY-tis) A skin condition that is a common side effect of radiation therapy.
radiation efficiency At a given frequency, the ratio of the power radiated to the total power supplied to the radiator.
radiation enteritis (RAY-dee-AY-shun EN-tuh-RY-tis) Inflammation of the small intestine caused by radiation therapy to the abdomen, pelvis, or rectum.
radiation fibrosis (RAY-dee-AY-shun fy-BROH-sis) The formation of scar tissue as a result of radiation therapy.