ExpertGlossary terms starting with P

3,647 terms

pulsating direct current A direct current (dc) that changes in value at regular or irregular intervals. Note: A pulsating direct current may change in value, i.e.
Pulse A short burst of electromagnetic energy that a radar sends out in a straight line to detect a precipitation target.
pulse amplitude The magnitude of a pulse parameter, such as the field intensity, voltage level, current level, or power level.
pulse broadening An increase in pulse duration. Note: Pulse broadening may be specified by the impulse response, the root-mean-square pulse broadening, or the…
pulse carrier An electromagnetic wave that (a) consists of a series of pulses usually of constant length, amplitude, spacing, and repetition rate when not modulated and…
pulse decay time Synonym fall time.
pulse density A measure (or an expression) of the number of "ones" (marks, pulses) in relation to the total number of digit time slots transmitted. [After T1.408-1990]
pulse distortion See distortion.
Pulse Duration The time over which a radar pulse lasts. The pulse duration can be multiplied by the speed of light to determine the pulse length or pulse width.
pulse duty factor In a periodic pulse train, the ratio of the pulse duration to the pulse period.
Pulse Length The linear distance in range occupied by an individual pulse from a radar. h = c * t , where t is the duration of the transmitted pulse, c is the speed of…
pulse link repeater (PLR) A device that interfaces concatenated E&M signal paths. Note 1: A PLR converts a ground, received from the E lead of one signal path, to -48 Vdc, which is…
pulse period The reciprocal of the pulse repetition rate.
Pulse Radar A type of radar, designed to facilitate range (distance) measurements, in which are transmitted energy emitted in periodic, brief transmission.
Pulse Rate The number of times the heart beats per minute.
Pulse Repetition Frequency In radar, the number of pulses the occur each second. Not to be confused with transmission frequency which is determined by the rate at which cycles are…
Pulse Repetition Frequency (PRF) The amount of time between successive pulses, or bursts, of electromagnetic energy that is transmitted by a radar.
pulse repetition rate The number of pulses per unit time.
Pulse Repetition Time (PRT) The time elapsed between pulses by the radar. This is also called the pulse interval.
Pulse Resolution Volume A discrete radar sampling volume, of dimensions (horizontal beamwidth * vertical beamwidth * 1 range gate).
pulse rise time See rise time.
Pulse Severe Thunderstorms Single cell thunderstorms which produce brief periods of severe weather (3/4 inch hail, wind gusts in the excess of 58 miles an hour, or a tornado).
Pulse Storm A thunderstorm within which a brief period (pulse) of strong updraft occurs, during and immediately after which the storm produces a short episode of…
pulse string Synonym pulse train.
pulse stuffing See bit stuffing.
pulse train A series of pulses having similar characteristics. Synonym pulse string.
Pulse Width Same as Pulse Length; the linear distance in range occupied by an individual pulse from a radar.
pulse-address multiple access (PAMA) The ability of a communication satellite to receive signals from several Earth terminals simultaneously and to amplify, translate, and relay the signals…
pulse-amplitude modulation (PAM) Modulation in which the amplitude of individual, regularly spaced pulses in a pulse train is varied in accordance with some characteristic of the…
pulse-code modulation (PCM) Modulation in which a signal is sampled, and the magnitude (with respect to a fixed reference) of each sample is quantized and digitized for transmission…
pulse-duration modulation (PDM) Modulation in which the duration of pulses is varied in accordance with some characteristic of the modulating signal.
pulse-frequency modulation (PFM) Modulation in which the pulse repetition rate is varied in accordance with some characteristic of the modulating signal.
pulse-interval modulation See pulse-position modulation.
pulse-length modulation Deprecated synonym for pulse-duration modulation.
Pulse-Pair Processing Nickname for the technique of mean velocity estimation by calculation of the signal complex covariance argument.
pulse-position modulation (PPM) Modulation in which the temporal positions of the pulses are varied in accordance with some characteristic of the modulating signal.
pulse-repetition-rate modulation Synonym pulse-frequency modulation.
pulse-time modulation (PTM) The general class of pulse-code modulation in which the time of occurrence of some characteristic of the pulsed carrier is varied with respect to some…
pulse-width modulation (PWM) Deprecated synonym for pulse-duration modulation.
Pulse-Width-Modulated (PWM) Wave Inverter A type of power inverter that produce a high quality (nearly sinusoidal) voltage, at minimum current harmonics.
pulsed FM systems A spread spectrum system in which the RF carrier is modulated with a fixed period and fixed duty cycle sequence.
Pulsed Power EMR Radiated fields that have very high instantaneous peak field strengths or power density but significantly lower average values.
pulsed-field gel electrophoresis (Abbreviation: PFGE). A procedure used to separate very large (50 kbp to several Mbp) DNA molecules by alteRNA ting the direction of electric current in a…
pulsing In telephony, the transmission of address information to a switching office by means of pulses, i.e., signals, that originate from the subscriber, i.e.
pulverization A method of destroying records using a device that renders documents into small, random-shaped particles
pumice stone A special foot care tool used to gently file calluses as instructed by your health care team.
Pump See centrifugal pump, diaphragm pump, jetting pump.
pump (pump) A device that is used to give a controlled amount of a liquid at a specific rate.
Pump and dump In a pump and dump scheme, a scam artist manipulates the stock market by buying shares of a low-cost stock and then artificially inflating the price by…
pump frequency The frequency of an oscillator used to provide sustaining power to a device, such as a laser or parametric amplifier, that requires rf or optical power.
Pump Octane Number This number represents the ability of a fuel to resist knocking when ignited in the cylinder of an internal-combustion engine.
Pump-back system A return-flow system in which tailwater is pumped back to the head of an irrigation ditch for reuse.
Pumped Storage Facility A type of power generating facility that pumps water to a storage reservoir during off-peak periods, and uses the stored water (by allowing it to fall…
Pumped-storage plant Powerplant designed to generate electric energy for peakload use by releasing water previously pumped into an elevated storage reservoir, usually during…
Pumping Mechanical transfer of fluids.
Pumping energy Energy required to pump water from the lower reservoir to the upper reservoir of a pumped-storage plant.
Pumping Head Energy given to a fluid by a pump, usually expressed in feet of fluid (foot pounds per pound).
Pumping plant Facility that lifts water up and over hills.
pumpkin A notional "baton" handed around the Perl community indicating who is the lead integrator in some arena of development.
pumpking A "pumpkin" holder, the person in charge of pumping the pump, or at least priming it. Must be willing to play the part of the Great Pumpkin now and then.
Pumplift (pumping lift) The vertical distance that a pump will raise waters. Distance water must be lifted in a well from the pumping level to the ground surface.
punch biopsy (... BY-op-see) Removal of a small disk-shaped sample of tissue using a sharp, hollow device. The tissue is then examined under a microscope.
Punch List A list of items that have not been completed at the time of the final walk through of a newly constructed home.
punctuated equilibrium The occurrence of speciation events in bursts, separated by long intervals of species stability.
punctuation Symbols such as commas and semicolons, which a compiler uses to understand the structure of a program.
Punitive damages Money award given to punish the defendant or wrongdoer.
Punto this is the player.
pupil (PYOO-pil) The round opening in the center of the iris (the colored tissue that makes the "eye color" at the front of the eye).
PUR Program Update Review (OSD term).
Purchase agreement Same or similar to "contract to purchase." See also "contract to purchase" under "mortgage."
Purchase agreement/purchase offer Also, sales agreement. Agreement between buyer and seller of property which sets forth the price and terms of a proposed sale.
Purchase and Sale Agreement A document that details the price and conditions for a transaction. In connection with the sale of a residential property, the agreement typically would…
Purchase APR The APR you will pay for purchases if you carry a balance on your credit card. For many cards, you only have to pay interest on purchases if you carry…
Purchase Money Mortgage A mortgage loan that enables a borrower to acquire a property.
Purchase of Development Rights Programs through which local governments may purchase development rights and dedicate the land for conservation easements, protecting it as open space or…
Purchase Offer A detailed, written document that makes an offer to purchase a property, and that may be amended several times in the process of negotiations.
Purchase Order (PO) A contractual procurement document used primarily to procure supplies and nonpersonal services when the aggregate amount involved in any one transaction…
Purchase price The amount of money paid for the property, including down payment and mortgage, but excluding closing costs and other fees.
Purchased power Normally this type is used to represent the purchase cost of energy for firming up the power supply.
Purchases A purchase is the use of your card to buy or lease products or services. The purchase of cash or cash equivalents, like casino chips or lottery tickets…
pure binary numeration system See binary notation.
pure line A strain in which all members are genetically nearly identical and are indistinguishable by phenotype.
PureTLS http://www.rtfm.com/puretls/
Purge To remove information that has no further value from a file, usually according to a records retention schedule
purging Rendering stored information unrecoverable by laboratory attack. [INFOSEC-99]
purification tag See: affinity tag.
Purine A double-ring, nitrogen-containing base present in nucleic acids . Adenine (A) and guanine (G) are the two purines normally present in DNA and RNA…
Purinethol (PYUR-in-thall) A drug used to treat acute lymphatic leukemia. It belongs to the family of drugs called antimetabolites. Also called mercaptopurine.
purple clover Trifolium pratense. A plant with flowers that has been used in some cultures to treat certain medical problems.
purple coneflower (...KONE-flow-er) An herb native to North America that has been used to prevent and treat the common cold and other respiratory infections.
Purveyor An agency or person that supplies water.
Push Refers to the player and the dealer having the same total. Usually the player's bet is returned when there is a push.
push-down file See last-in first-out.
push-to-talk (PTT) operation In telephone or two-way radio systems, that method of communication over a speech circuit in which the talker is required to keep a switch operated while…
push-to-type operation In telegraph or data transmission systems, that method of communication in which the operator at a station must keep a switch operated in order to send…
Push/Tie When the player and the dealer have hands with the same point total. No money changes hands.
pushbutton dialing Dialing in which (a) pushbuttons or keys are used to actuate and connect audible tone oscillators to a line, (b) each button or key corresponds to a…
pushbutton failover Use of the cmrecovercl command to allow all package recovery groups to start up on the Recovery Cluster following a significant cluster event on the…
Put and take fishery An area where fish are stocked regularly with catchable size fish which are expected to be caught out by fall.
Put option Buying a put option gives you the right to sell the specific financial instrument underlying the option at a specific price, called the exercise or strike…