Science — page 37 of 132

13,110 terms including subtopics (0 terms filed directly here)

Subtopics

Science terms

  1. Drop-size Distribution The distribution of rain drops or cloud droplets of specified sizes.
  2. Drosophila melanogaster The fruit fly, used for many years as a model for eukaryotic genetics. Of the nearly 300 disease-causing genes in the human genome, more than half have an…
  3. Drought Climatic condition in which there is insufficient soil moisture available for normal vegetative growth. A prolonged period of below-average precipitation.
  4. Drought Assessments At the end of each month, CPC issues a long-term seasonal drought assessment. On Thursdays of each week, the CPC together with NOAA National Climatic Data…
  5. Drought Index Computed value which is related to some of the cumulative effects of a prolonged and abnormal moisture deficiency.
  6. drug Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition.
  7. drug delivery Method by which a drug is delivered to its site of action. For traditional drugs this is another name for formulation.
  8. Drum gate A movable crest gate in the form of a sector of a cylinder hinged at the centerline.
  9. Dry Adiabat A line of constant potential temperature on a thermodynamic chart.
  10. Dry Adiabatic Lapse Rate The rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere.
  11. dry adiabatic lapse rate (DALR) (DALR) The rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere. The dry adiabatic lapse rate is 5.
  12. Dry Bulb Temperature The temperature of the air as measured by a standard thermometer.
  13. Dry closed-loop cooling See Dry cooling system
  14. Dry cooling See Dry cooling system
  15. Dry cooling system Also known as dry closed-loop cooling; a technology for rejecting heat from the steam condensate of a thermoelectric plant.
  16. Dry Crack Crack visible at the surface but not going right through the ice cover, and therefore it is dry.
  17. Dry Flood proofing A dry flood proofed building is sealed against floodwaters. All areas below the flood protection level are made watertight.
  18. Dry Floodproofing In hydrologic terms, a dry floodproofed building is sealed against floodwaters. All areas below the flood protection level are made watertight.
  19. Dry lake An ephemeral lake of an arid or semiarid region, typically found at low elevation points in desert valleys.
  20. Dry Line A boundary separating moist and dry air masses, and an important factor in severe weather frequency in the Great Plains.
  21. Dry Line Bulge A bulge in the dry line, representing the area where dry air is advancing most strongly at lower levels.
  22. Dry Line Storm Any thunderstorm that develops on or near a dry line.
  23. Dry Microburst A microburst with little or no precipitation reaching the ground; most common in semi-arid regions. They may or may not produce lightning.
  24. Dry Punch [Slang], a surge of drier air; normally a synoptic-scale or mesoscale process. A dry punch at the surface results in a dry line bulge.
  25. Dry Slot A zone of dry (and relatively cloud-free) air which wraps east- or northeastward into the southern and eastern parts of a synoptic scale or mesoscale low…
  26. Dry Steam Geothermal Plants Conventional turbine generators are used with the dry steam resources. The steam is used directly, eliminating the need for boilers and boiler fuel that…
  27. Dry Thunderstorm Generally a high-based thunderstorm when lightning is observed, but little if any precipitation reaches the ground.
  28. Dry Ton 2,000 pounds of material dried to a constant weight.
  29. Dry unit weight The weight of solid particles per unit of total volume. See unit weight.
  30. Dry wash A natural drainage channel that is typically dry, but conveys water following significant rainfall events and is subject to rapid flow during flash…
  31. Dry Weather Flow Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel.
  32. dry weight The weight of tissue obtained following sufficiently prolonged oven-drying at high temperature to remove all water.
  33. Dry well A deep hole, covered, and usually lined or filled with rocks, that holds drainage water until it soaks into the ground.
  34. Dry-adiabatic 1. An adiabatic process in a hypothetical atmosphere in which no moisture is present. 2.
  35. drying Moisture removal from biomass to improve serviceability and utility.
  36. DSA Special Tropical Disturbance Statement
  37. dscDNA See double\-stranded complementary DNA.
  38. dsDNA See: double-stranded DNA.
  39. DSIPT Dissipate
  40. Dst Index A geomagnetic index describing variations in the equatorial ringcurrent
  41. DTRT Deteriorate
  42. dTTP Rarely used but strictly correct abbreviation for deoxythymidine 5'-triphosphate. Required for DNA synthesis since it is a direct precursor molecule.
  43. dual culture A culture made of a plant tissue and one organism (such as a nematode) or an obligate parasite/micro-organism (such as a fungus).
  44. Dual Duct System An air conditioning system that has two ducts, one is heated and the other is cooled, so that air of the correct temperature is provided by mixing varying…
  45. Dual Fuel (or Flex Fuel) Vehicle A vehicle with an engine capable of operating on two different types of fuels.
  46. Dual-fueled (or dual-fired) unit A generating unit that can produce electricity using two or more fuels. In some of these units, only the primary fuel can be used continuously; the…
  47. Duct Fan An axial flow fan mounted in a section of duct to move conditioned air.
  48. Duct(s) The round or rectangular tube(s), generally constructed of sheet metal, fiberglass board, or a flexible plastic-and-wire composite, located within a wall…
  49. Ductility The property of a material that allows it to be formed into thin sections without breaking.
  50. Duff The layer of forest litter.
  51. Dumped A method of compacting soil by dumping the soil into place with no compactive effort.
  52. Dune Mounds of unconsolidated sand grains shaped by wind. Often temporary and nonstationary.
  53. Dunnage Supports for air conditioning and other equipment above the roof of a building.
  54. Duplex DNA Double-stranded DNA.
  55. duplication Multiple occurrence of: 1. A DNA sequence within a defined length of DNA; or 2. A specific segment in the same chromosome or genome.
  56. Duration Curve A cumulative frequency curve that shows the percent of time during which specified units of items (e.g. discharge, head, power, etc.
  57. Duration of Ice Cover The time from freeze-up to break-up of an ice cover.
  58. Duration of Protection Also "Lasting Protection." Site must be established with the intent at the time of designation to provide permanent protection.
  59. Duration of Sunshine The amount of time sunlight was detected at a given point.
  60. DURG During
  61. Duripan A subsurface soil horizon cemented by silica (usually derived from a volcanic source such as ash).
  62. DURN Duration
  63. Dusk Same as Civil Dusk; the time at which the sun is 6 degrees below the horizon in the evening.
  64. Dust Devil A small, rapidly rotating wind that is made visible by the dust, dirt or debris it picks up.
  65. Dust Plume A non-rotating "cloud" of dust raised by straight-line winds. Often seen in a microburst or behind a gust front.
  66. Dust Storm A severe weather condition characterized by strong winds and dust-filled air over an extensive area.
  67. Dust Whirl A rotating column of air rendered visible by dust.
  68. Dutch oven furnace One of the earliest types of furnaces, having a large, rectangular box lined with firebrick (refractory) on the sides and top.
  69. Duty Cycle The duration and periodicity of the operation of a device.
  70. DVA - deficiency verification analysis.
  71. DVLP Develop
  72. DVV Downward Vertical Velocity (sinking air)
  73. DWNDFT Downdraft - A small-scale column of air that rapidly sinks toward the ground, usually accompanied by precipitation as in a shower or thunderstorm.
  74. DWNSLP Downslope
  75. DWPT Dew Point - A measure of atmospheric moisture. It is the temperature to which air must be cooled in order to reach saturation (assuming air pressure and…
  76. Dynamic compaction A method of compacting soil by dropping a heavy weight onto loose soil.
  77. Dynamic equilibrium Condition achieved when the average sand load transported by flowing water is in balance with the sand load being supplied by tributaries.
  78. Dynamic Head The pressure equivalent of the velocity of a fluid.
  79. Dynamic Ice Pressure due to a moving ice cover or drifting ice.
  80. Dynamic Lifting The forced uplifting of air from various atmospheric processes, such as weather fronts, and cyclones.
  81. Dynamic pressure When a pump is operating, the vertical distance from a reference point (such as a pump centerline) to the hydraulic grade line.
  82. Dynamic Wave Routing Model (DWOPER) (DWOPER) A computerized hydraulic routing program whose algorithms incorporate the complete one-dimensional equations of unsteady flow originally developed by…
  83. Dynamics Changes over a length of time.
  84. Dynamo A machine for converting mechanical energy into electrical energy by magneto-electric induction; may be used as a motor.
  85. Dynamometer An apparatus for measuring force or power, especially the power developed by a motor.
  86. Dyne The absolute centimeter-gram-second unit of force; that force that will impart to a free mass of one gram an acceleration of one centimeter per second per…
  87. DZ Drizzle
  88. E East
  89. E REGION In solar-terrestrial terms, a daytime layer of the earth's ionosphere roughly between the altitudes of 85 and 140 km.
  90. E site See: exit site.
  91. E-10 A mixture of 10% ethanol and 90% gasoline based on volume.
  92. E-19, Report on River Gage Station A report to be completed every 5 - 10 years providing a complete history of a river station and all gages that have been used for public forecasts since…
  93. E-19a, Abridged Report on River Gage Sta In hydrologic terms, an abridged version of an E-19, an E-19a updates the E-19 as additional information, or changes occur at the station during the…
  94. E-19a, Abridged Report on River Gage Station An abridged version of an E-19, an E-19a used to be used to update the E-19 as additional information, or changes occur at the station during the…
  95. E-3, Flood Stage Report A form that a Service Hydrologist/ Hydrology Focal Point completes to document the dates in which forecast points are above flood stage, as well as the…
  96. E-5, Monthly Report of River and Flood c In hydrologic terms, a monthly narrative report covering flooding which occurred over the past month.
  97. E-5, Monthly Report of River and Flood conditions A monthly narrative report covering flooding which occurred over the past month.
  98. E-7, Flood Damage Report A report to be completed anytime there is reported flood damage or loss of life as a direct result of flooding.
  99. E-85 A mixture of 85% ethanol and 15% gasoline based on volume.
  100. E. coli See: Escherichia coli.