Science terms starting with S

1,372 terms

  1. Scattering The process in which a beam of light is diffused or deflected by collisions with particles suspended in the atmosphere.
  2. SCE Abbreviation for sister chromatid exchange.
  3. Scenic integrity The degree of "intactness" of a landscape, which is related to the existing amount of visual disturbance present.
  4. Scenic quality A measure of the intrinsic beauty of landform, water form, or vegetation in the landscape, as well as any visible human additions or alterations to the…
  5. Scenic resources The visible physical features on a landscape (e.g., land, water, vegetation, animals, structures, and other features).
  6. Scenic value The importance of a landscape based on human perception of the intrinsic beauty of landform, water form, and vegetation in the landscape, as well as any…
  7. Scheduled outage Shutdown of a generating unit, or other facility, for inspection or maintenance, in accordance with an advance schedule.
  8. Schist A metamorphic rock formed from many types of rocks. Minerals in the rocks include micas, chlorite, talc, hornblende, and garnets.
  9. Schwann cell A type of glial cell of the peripheral nervous system that helps separate and insulate nerve cells.
  10. Science Board An ACRF group made up of the ARM Science Team Executive Committee working group science chairs and climate research community appointees, that ensures…
  11. Science Team Executive Committee (STEC) The committee that provides recommendations, prioritization, coordination of activities, and program vision to the U.S.
  12. Scintillation counter An instrument that detects and measures gamma radiation by counting the light flashes (scintillations) induced by the radiation.
  13. scion A twig or bud used for grafting onto another plant or rootstock.
  14. scion-stock interaction The effect of a rootstock on a scion (and vice versa) in which a particular scion grafted onto a specific s performs differently than it would either on…
  15. sclerenchyma A strengthening tissue in plants, composed of cells with heavily lignified cell walls.
  16. Scoping A first step in the NEPA process and in the river planning process. Scoping is a means of identifying issues and concerns, their significance, and the…
  17. Scoria Congealed lava, usually of mafic composition and red or black in color, with a large number of vesicles formed by gases coming out of solution.
  18. Scour Erosion in a stream bed, particularly if caused or increased by channel changes.
  19. SCP Standing Committee on the Law of Patents
  20. Scrape A nest made from scratching in the ground.
  21. Scraper A stone tool that is modified for the specific task of scraping; for example, to scrape the meat from hides, to remove fat from the underside of a skin…
  22. Scrapie A spongiform encephalopathy disease of sheep. See: proteinaceous infectious particle.
  23. Scree Small, loose, rock debris covering a slope; a slope of loose rock debris at the base of a steep incline or cliff.
  24. screen A screen is a set of criteria against which you measure stocks or other investments to find those that meet your criteria.
  25. screen analysis Method for measuring a proportion of variously sized particles in solid fuels. The sample is passed through a series of screens of known size openings.
  26. Scribing The cutting of a grid pattern of grooves in a semiconductor material, generally for the purpose of making interconnections.
  27. Scrubber A device to clean combustible gas or stack gas by the spraying of water.
  28. Scrubland An area of land that is uncultivated and covered with sparse stunted vegetation.
  29. SCT Scattered
  30. SCUD Small, ragged, low cloud fragments that are unattached to a larger cloud base and often seen with and behind cold fronts and thunderstorm gust fronts.
  31. SDS Abbreviation for sodium dodecyl sulphate.
  32. SDS-PAGE Abbreviation for sodium dodecyl sulphate polyacrylamide gel electrophoresis.
  33. SE Southeast
  34. Sea Breeze A thermally produced wind blowing during the day from a cool ocean surface onto the adjoining warm land, caused by the difference in the rates of heating…
  35. Sea Breeze Convergence Zone The zone at the leading edge of a sea breeze where winds converge. The incoming air rises in this zone, often producing convective clouds.
  36. Sea Breeze Front The leading edge of a sea breeze, whose passage is often accompanied by showers, a wind shift, or a sudden drop in temperature.
  37. Sea Fog Common advection fog caused by transport of moist air over a cold body of water.
  38. Sea Ice Any form of ice found at sea which has originated from the freezing of sea water (sea ice does NOT include superstructure icing).
  39. Sea Level Pressure The sea level pressure is the atmospheric pressure at sea level at a given location.
  40. Sea smoke Sea smoke (arctic sea smoke) Evaporation fog or steam fog which is formed when water vapor is added to air which is much colder than the vapor's source…
  41. Sea surface temperature Sea surface temperature Temperature of the water film at the sea surface.
  42. Sea Surface Temperatures The term refers to the mean temperature of the ocean in the upper few meters.
  43. Sealed Combustion Heating System A heating system that uses only outside air for combustion and vents combustion gases directly to the outdoors.
  44. Seam A layer of rock, coal, or ore.
  45. SEAS Secure Environment Access Solution
  46. Seashore The coastline of a sea or ocean, including the ground between the ordinary high water and low water marks.
  47. Seasonal Energy Efficiency Ratio (SEER) A measure of seasonal or annual efficiency of a central air conditioner or air conditioning heat pump.
  48. Seasonal Performance Factor (SPF) Ratio of useful energy output of a device to the energy input, averaged over an entire heating season.
  49. Seasonal stream. See intermittent stream.
  50. Seasoned Wood Wood, used for fuel, that has been air dried so that it contains 15 to 20 percent moisture content (wet basis).
  51. Secchi depth A measure of water clarity.
  52. Second foot (sec-ft) Shortened term for cubic foot per second (cfs or ft3/s).
  53. Second growth A second generation of timber of merchantable age.
  54. Second Law Efficiency The ratio of the minimum amount of work or energy required to perform a task to the amount actually used.
  55. Second Law of Thermodynamics This law states that no device can completely and continuously transform all of the energy supplied to it into useful energy.
  56. Second-Day Feet The volume of water represented by a flow of one cubic foot per second for 24 hours; equal to 84,000 cubic feet.
  57. Secondary Ambient Air Quality Standards Air quality standards designed to protect human welfare, including the effects on vegetation and fauna, visibility and structures.
  58. secondary antibody In an ELISA or other immunological assay system, the antibody designed to bind to the primary antibody, and to which a label is generally attached.
  59. secondary cell wall The innermost layer of cell wall, giving rigidity to the cells. Characterized by its highly organized microfibrillar structure, and only formed in certain…
  60. Secondary containment A safeguarding method for the prevention of unauthorized releases of toxic or hazardous gases into uncontrolled work areas.
  61. Secondary Embankment Embankment that blocks an area on a reservoiur rim that is lower than the top of the main dam. See also, "Levee".
  62. secondary growth Type of growth characterized by an increase in the thickness of stem and root, and resulting from the formation of secondary s by the vascular cambium.
  63. secondary immune response The rapid immune response that occurs during the second (and subsequent) encounters of the immune system of a mammal with a specific antigen.
  64. secondary messenger A chemical compound within a cell that is responsible for initiating the response to a signal from a chemical messenger (such as a hormone) that cannot…
  65. secondary metabolism The production by living organisms of substances not essential for primary metabolic functions or physiology.
  66. secondary metabolite Product of secondary metabolism.
  67. Secondary oil recovery Injection of water into an oil well after primary oil recovery to force out some of the remaining thicker crude oil.
  68. secondary oocyte See: oocyte.
  69. secondary phloem Phloem tissue formed by the vascular cambium during secondary growth in a vascular plant.
  70. secondary plant product See: secondary metabolite.
  71. Secondary Pollutant Pollutants generated by chemical reactions occurring within the atmosphere. Compare primary pollutant.
  72. secondary root A branch or lateral root.
  73. secondary spermatocyte See: spermatocyte.
  74. secondary structure Localized three dimensional conformations adopted by macromolecules, in particular nucleic acids and polypeptides.
  75. Secondary succession The progression of plant communities following disturbances such as fire, windthrow and timber harvesting. See Succession.
  76. secondary thickening Deposition of secondary cell wall materials which result in an increase in thickness in stems and roots.
  77. secondary vascular tissue Vascular tissue (xylem and phloem ) formed by the vascular cambium during secondary growth in a vascular plant.
  78. secondary xylem See: secondary vascular tissue.
  79. secretion The transport of a molecule from the inside of a cell through the cell membrane.
  80. section An area equal to 640 acres or 1 square mile.
  81. Sector A sector is a segment of the economy that shares distinctive characteristics, such as telecommunications or energy.
  82. Sector Boundary In solar-terrestrial terms, in the solar wind, the area of demarcation between sectors, which are large-scale features distinguished by the predominant…
  83. Sector Visibility The visibility in a specific direction that represents at least a 45º arc of a horizontal circle.
  84. Sectorized Hybrid Scan A single reflectivity scan composed of data from the lowest four elevation scans. Close to the radar, higher tilts are used to reduce clutter.
  85. Secular equilibrium A state of parent-daughter equilibrium which is achieved when the half-life of the parent is much longer than the half-life of the daughter.
  86. Securite A headline within National Weather Service high seas forecasts transmitted via the GMDSS to indicate that no hurricane or hurricane force winds are…
  87. Sedentism A term used to describe the process of settling down to live in groups for periods of time.
  88. Sedge A grasslike plant with a triangular stem often growing in wet areas.
  89. Sediment Any finely divided organic and/or mineral matter deposited by air or water in nonturbulent areas.
  90. Sediment concentration The quantity of sediment relative to the quantity of transporting fluid, or fluid-sediment misture. The concentration may be by weight or by volume.
  91. Sediment discharge Rate at which sediment passes a stream cross-section in a given period of time, expressed in millions of tons per day (mtd).
  92. Sediment load Mass of sediment passing through a stream cross section in a specified period of time, expressed in millions of tons (mt).
  93. Sediment Storage Capacity The volume of a reservoir planned for the deposition of sediment.
  94. Sediment yield Amount of mineral or organic soil material that is in suspension, is being transported, or has been moved from its site of origin.
  95. Sediment yield rate The sediment yield per unit of drainage area.
  96. Sedimentary Rock resulting from the consolidation of loose eroded sediment, remains of organisms, or crystals forming directly from water.
  97. Sedimentary rock Rock formed at or near the Earth's surface from the consolidation of loose sediment that has accumulated in layers through deposition by water, wind, or…
  98. Sedimentation A process in which material carried in suspension by water flows into streams and rivers, increasing turbidity and eventually settling to the bottom.
  99. Seebeck Effect The generation of an electric current, when two conductors of different metals are joined at their ends to form a circuit, with the two junctions kept at…
  100. SEED Botanically, the matured ovule without accessory parts. Colloquially, anything which may be sown; i.e.