Science terms starting with D

722 terms

°C - degrees Celsius.
D Dust
D loop Abbreviation for displacement loop. Formed when a short stretch of RNA is paired with one strand of DNA.
D Region In solar-terrestrial terms, a daytime layer of the earth's ionosphere approximately 50 to 90 km in altitude.
dA - dT tailing See complementary homopolymeric tailing.
DAB (Full term: single domain antibody ). Antibodies with only one (instead of two) protein chain derived from only one of the two domains of the normal…
DAF See: DNA amplification fingerprinting.
Daily (or Next-Day) Indexes Published (Platts, NGI, Dow Jones, SNL, ICE, NGW) price indices for commodities (gas or electricity) to be delivered the next day based on transactions…
Daily Climatological Report As the name indicates, this climatological product is issued daily by each National Weather Service office.
Daily Deals Usually transactions done on a day for delivery or settlement or both, the next day.
Daily Flood Peak The maximum mean daily discharge occurring in a stream during a given flood event.
DALR Dry Adiabatic Lapse Rate
Dalton A unit of measurement equal to the mass of a hydrogen atom, 1.67 x 10E-24 gram/L (Avogadro's number).
Dam A structure for impeding and controlling the flow of water in a water course, and which increases the water elevation to create the hydraulic head.
Dam Failure Catastrophic type of failure characterized by the sudden, rapid, and uncontrolled release of impounded water.
Dam failure hydrograph A flood hydrograph resulting from a dam breach prepared for a specific location downstream from the dam.
Dam foundation The excavated surface or undisturbed material upon which a dam is placed.
Dam safety deficiency A physical condition capable of causing the sudden uncontrollable release of reservoir water by partial or complete failure of a dam, appurtenant…
Dam safety issue Dam safety related issues and concerns are those which, if not adequately addressed could/would: 1 - Lead to a failure or malfunction reulting in an…
Dam tender The person responsible for the daily or routine operation and maintenance activities of a dam and its appurtenant structures.
DAMBRK In hydrologic terms, the Dam Break Forecasting Model.
DAMD See: directed amplification of minisatellite DNA.
Damper A movable plate used to control air flow; in a wood stove or fireplace, used to control the amount and direction of air going to the fire.
Damping Resistance which reduces vibration by energy absorption.
Damping ratio The ratio of the actual damping to the critical damping, critical damping being the minimum amount of damping which prevents free oscillatory vibration.
Dansgaard-Oeschger event one of a series of climate changes during the last glacial period that occurred roughly every few thousand years.
DAPM In hydrologic terms, the Data Acquisition Program Manager.
Dark Energy An energy causing the acceleration of the expansion of the universe, detectable through its gravitational effects.
Dark Matter Matter not visible to us because it emits no radiation that we can observe, but it is detectable gravitationally. A small fraction of it is baryonic, e.g.
Dark Surge on Disk (DSD) In solar-terrestrial terms, dark gaseous ejections visible in H-alpha.
Darrius (Wind) Machine A type of vertical-axis wind machine that has long, thin blades in the shape of loops connected to the top and bottom of the axle; often called an…
Dart Leader A faint, negatively charged channel that travels more or less directly and continuously from cloud to ground.
Darwinian cloning Selection of a clone from a large number of essentially random starting points, rather than isolating a natural gene or making a carefully designed…
Data Archive Serves as long-term storage for ARM data to keep data easily accessible. It is located at Oak Ridge National Laboratory.
Data collection platform Electronic equipment device that gathers digital and analog data from monitoring devices and remotely relays that data to a central computer for…
Data Collection Platform (DCP) An electronic device that connects to a river or rainfall gage that records data from the gage and at pre-determined times transmits that data through a…
Data Management Facility (DMF) Manages ARM datastream and provides for the collection, processing, analysis, and delivery of ARM data.
Data Management System (DMS) Controls the data flow and minimizes data loss. Its primary functions are data collection, storage, and processing.
data object description The basic information, definitions, and metadata required to process "raw" measurement data to standard NetCDF files.
Data Point In the context of hydrologic observations, a location on a river/stream for which observed data is input to RFC or WFO hydrologic forecast procedures, or…
Data Quality Assessment Report (DQAR) An assessment report issued by the Data Quality Office and/or instrument mentors based on a data quality inspection.
Data Quality Health and Status (DQ HandS) The Data Quality Office website that displays automatically generated data quality results.
Data Quality Office (DQO) Formed in July 2000 to coordinate ARM's Data Quality Program.
Data Quality Problem Report (DQPR) An ARM infrastructure problem report issued to site operators by the Data Quality Office, instrument mentors, and/or site scientists to report a problem…
Data Quality Program Run by the ARM Program Data Quality Office to help coordinate the continued evolution and implementation of efforts to assure the quality of the data…
Data Quality Report (DQR) Used to identify and document problems with ARM systems, physical infrastructure, or instruments.
Data warehouse A collection of databases, data tables, and mechanisms to access the data on a single subject.
DATACOL The Software System that supports RFC gateway functions.
DATANET Hydrologic Data Network Analysis Software
datastream Similar files that are in a time-sequenced series.
DataWeb DataWeb is an electronic presentation of the Bureau of Reclamation's Project Data book and contains historical, statistical, and technical information on…
dATP Abbreviation for deoxyadenosine 5'-triphosphate. dATP is required for DNA synthesis since it is a direct precursor molecule. See: adenosine, adenylic acid.
datum Any level surface taken as a plane of reference from which to measure elevations.
Daughter A nucleus formed by the radioactive decay of a different (parent) nuclide.
Dawn Same as Civil Dawn; the time of morning at which the sun is 6 degrees below the horizon.
Day Length Duration of the period from sunrise to sunset.
Day-ahead markets Forward markets for electricity to be supplied the following day. This market closes with acceptance by the independent system operator, power exchange…
Day-night average noise level Twenty-four-hour average noise level, obtained after the addition of a 10-dB penalty for environmental noise occurring from 10 p.m. to 7 a.m.
Day-Second Feet Often abbreviated as SDF. See Second-Day Feet.
Daylighting The use of direct, diffuse, or reflected sunlight to provide supplemental lighting for building interiors.
Daytime mean rural background level Daytime (7 a.m. to 10 p.m.) average sound level in the rural environment, from all sources other than a particular noise that is of interest.
DBE - design basis earthquake.
dBZ Nondimensional "unit" of radar reflectivity which represents a logarithmic power ratio (in decibels, or dB) with respect to radar reflectivity factor, Z.
DC See Direct current
DCP (Data Collection Platform) In hydrologic terms, an electronic device that connects to a river or rainfall gage that records data from the gage and at…
dCTP Abbreviation for deoxycytidine 5'-triphosphate. dCTP is required for DNA synthesis since it is a direct precursor molecule. See: cytidine, cytidylic acid.
DD Direct Damage. This is a spell that does all of its damage in one hit rather than spreading its damage over time.
ddNTP Abbreviation for di-deoxynucleotide.
DDS A rare disorder that causes kidney failure before age 3, abnormal development of the sexual organs, and, in most cases, Wilms tumor (a type of kidney…
De Facto MPA Delineated areas of the marine environment where human access is restricted or where specific activities or uses are regulated for reasons other than…
de-differentiation The process, in response to wounding and in tissue cultures, by which plant cells can become unspecialized and start to proliferate by cell division to…
De-energize(d) To disconnect a transmission and/or distribution line; a power line that is not carrying a current; to open a circuit.
de-ionized water Water from which most salts have been removed - with varying degrees of efficiency - by ion exchange.
Dead capacity (dead storage) The reservoir capacity from which stored water cannot be evacuated by gravity.
Dead Storage The volume in a reservoir below the lowest controllable level.
Deaeration Removal of gases from a liquid.
Death phase The final growth phase, during which nutrients have been depleted and cell number decreases. (See Growth phase).
Debris Cloud A rotating "cloud" of dust or debris, near or on the ground, often appearing beneath a condensation funnel and surrounding the base of a tornado.
Debris fan Sloping mass of boulders, cobbles, gravel, sand, silt and clay formed by debris flows at the mouth of a tributary.
Debris flow A mixture of water-saturated rock debris that flows downslope under the force of gravity (also called lahar or mudflow).
Debris flow fans Alluvial fans prone to debris flows; a mixture of water and debris, such as mudslides, mudflows, or debris avalanches.
Debt financing Providing capital by selling bonds, bills, or notes to individuals or institutions.
Decadal Occurring over a 10-year period, such as an oscillation whose period is roughly 10 years ("Pacific Decadal Oscillation").
Decay (radioactive) The change of one radioactive nuclide into a different nuclide by the spontaneous emission of alpha, beta, or gamma rays, or by electron capture.
Deceleration Decreasing the velocity (of expansion).
deceleration phase The phase of declining growth rate, following the linear phase and preceding the stationary phase in most batch-suspension cultures. See: growth phase.
Decentralized (Energy) System Energy systems supply individual, or small-groups, of energy loads.
Decibel A unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 130 for the average level at…
Decibel (dB) A standard unit for measuring the loudness or intensity of sound. In general, a sound doubles in loudness with every increase of 10 decibels.
Decibel, A-weighted (dBA) A measurement of sound approximating the sensitivity of the human ear and used to characterize the intensity or loudness of a sound.
Decibels (dBA) A scale to measure sound levels.
Decidual cells A cellular matrix that first surrounds an implanted embryo and later occupies most of the endometrium.
Deciduous Plants that shed their leaves annually. Not evergreen.
Deciduous trees Trees such as oaks and maples that lose their leaves during part of the year. See coniferous trees.
Decision criteria Set of formal criteria that is used to determine if an event is threatening and what action to implement.
Decision makers Designated personnel responsible for interpreting data that has been collected and determining if an event is threatening enough to issue an alert or…
Decision making The second of five Early Warning System components consisting of the processes and facilities necessary to translate incoming data about the threatening…
Decision notice The written record of a federal agency decision after an environmental assessment.
Decking Separating charges of explosives by inert material which prevents passing of concussion, and placing a primer in each charge.
Declination The angular position of the sun at solar noon with respect to the plane of the equator.