Science — page 108 of 132

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

Science terms

Shaft house House at top of the access shaft to gate chamber, which secures access to the gates.
Shaft or Morning Glory Spillway A vertical or inclined shaft into which flood water spills and then is conducted through, under, or around a dam by means of a conduit or tunnel.
Shaft spillway A vertical or inclined shaft into which water spills and then is conveyed through, under, or around a dam by means of a conduit or tunnel.
shake culture An agitated suspension in culture providing adequate aeration for cells in the liquid medium.
shaker A platform, with set or variable speed control, used to agitate vessels containing liquid cell cultures. Also described as a platform shaker.
Shale A rock formed of consolidated mud. Fine-grained sedimentary rock formed from hardened clay and silt that typically splits into thin layers.
Shale (outcrop) A fine-grained sedimentary rock characterized by parallel layering.
Shale oil Slow-flowing, dark brown, heavy oil obtained when kerogen in oil shale is vaporized at high temperatures and then condensed.
Shallow Fog Fog in which the visibility at 6 feet above ground level is 5/8ths statute mile or more and the apparent visibility in the fog layer is less than 5/8ths…
SHARS Subtle Heavy Rainfall Signature
Shear Literally the sliding of one layer across another, with deformation and fracturing in the direction parallel to the movement.
Shear strength Internal resistance to stress (or movement) that comes from friction and cohesion of the sediment.
Shear wall A vertical lateral-force-resisting element in a structure assigned to resist wind or earthquake generated lateral forces.
Shear zone An area where the rock mass has moved along the plane of contact which often becomes a channel for ground water.
Sheathing A construction element used to cover the exterior of wall framing and roof trusses.
Sheepsfoot roller A tamping roller having lugs with feet extending at their outer tips.
Sheet Flow Flow that occurs overland in places where there are no defined channels, the flood water spreads out over a large area at a uniform depth.
Sheet ice Ice formed by the freezing of liquid precipitation or the freezing of melted solid precipitation (see snow depth)
Sheet piling Steel strips shaped to interlock with each other when driven into the ground.
Sheet wash A flow of rainwater that covers the entire ground surface with a thin film and is not concentrated into streams.
SHEFPARS A software decoder for SHEF Data.
Shelf Cloud A low, horizontal wedge-shaped arcus cloud, associated with a thunderstorm gust front (or occasionally with a cold front, even in the absence of…
shell See shoulder.
Shelterbelt A natural or planned barrier of trees or shrubs to reduce erosion and provide shelter from winds or storms.
Sheltering (in-place) A protective action that involves taking cover in upper levels of a building that is able to withstand high flood levels.
Sherds Broken pieces of earthenware/pottery.
SHFT Shift
SHIELD Shield (screen) A screen to shield a rain-gauge from the influence of the wind, or to shield a thermometer against insolation.
Shielding A protective barrier, usually a dense material, which reduces the passage of radiation from radioactive materials to the surroundings.
Shine-Dalgarno sequence A conserved sequence of prokaryotic mRNAs that is complementary to a sequence near the 5' terminus of the 16S ribosomal RNA and is involved in the…
SHLW Shallow
shoot apex See: shoot tip.
shoot differentiation The development of growing points, leaf primordia and finally shoots from a shoot tip, axial bud, or callus surface.
shoot tip The terminal bud (0.1 - 1.0 mm) of a plant, which consists of the apical meristem (0.05 - 0.
shoot-tip graft A shoot tip or meristem tip grafted onto a prepared seedling or micropropagated rootstock in culture.
Shore ice An ice sheet in the form of a long border attached to the bank or shore; border ice.
Shoring Temporary bracing to hold the sides of an excavation from caving.
Short Circuit An electric current taking a shorter or different path than intended.
Short Circuit Current The current flowing freely through an external circuit that has no load or resistance; the maximum current possible.
short interspersed nuclear element (Abbreviation: SINE ). Families of short (150-300 bp), moderately repetitive DNA elements of eukaryotic genomes.
Short position If you sell stock short and have not yet repurchased shares to replace the ones you borrowed, you are said to have a short position in that stock.
Short rotation energy plantation Plantings established and managed under short-rotation intensive culture practices.
Short rotation intensive culture Intensive management and harvesting at 2 to 10 year intervals of cycles of specially selected fast- growing hardwood species for the purpose of producing…
Short Term Forecast A product used to convey information regarding weather or hydrologic events in the next few hours.
Short Ton 2000 pounds. A ton, as commonly used in the U.S. and Canada.
Short Wave Fade (SWF) In solar-terrestrial terms, a particular ionospheric solar flare effect under the broad category of sudden ionospheric disturbances (SIDs) whereby…
short-day plant A plant which will not flower until triggered to do so by exposure to one or a number of dark periods equal to or longer than its critical period.
Short-Fuse Warning A warning issued by the NWS for a local weather hazard of relatively short duration.
Short-throated flumes Short-throated flumes are considered short because they control flow in a region that produces curvilinear flow.
Shortwave Also known as Shortwave Trough; a disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.
shortwave irradiance The rate at which radiant energy, at wavelengths between 0.4 and 4 µm, is being transferred across an area of a surface (real or imaginary) in a…
shortwave net radiation The difference between upwelling and downwelling broadband shortwave radiation.
shortwave radiance A measure of the intrinsic radiant energy flux intensity, at wavelengths between 0.
Shortwave Radiation In solar-terrestrial terms, shortwave radiation is a term used to describe the radiant energy emitted by the sun in the visible and near-ultraviolet…
shortwave spectral irradiance The rate at which radiant energy, at specrally-resolved wavelengths between 0.4 and 4 µm, is being emitted upwards and downwards into a radiation field…
Shortwave Trough Also called Shortwave; A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.
shotgun genome sequencing A strategy for sequencing a whole genome, in which the genomic DNA is initially fragmented into pieces small enough to be sequenced.
Shotgun method Sequencing method that involves randomly sequenced cloned pieces of the genome, with no foreknowledge of where the piece originally came from.
shotgun sequencing An approach used to decode an organism's genome by shredding it into smaller fragments of DNA which can be sequenced individually.
Shoulder (shell) The upstream and downstream parts of the cross section of an embankment dam on each side of the core or core wall.
Showalter Index (Abbrev. SWI) - a stability index used to determine thunderstorm potential. The SWI is calculated by lifting an air parcel adiabatically from 850 mb to…
Shower A descriptor, SH, used to qualify precipitation characterized by the suddenness with which they start and stop, by the rapid changes of intensity, and…
SHRA Rain showers
SHRAS showers
Shrink-swell potential The extent to which soil shrinks or swells with changes in soil moisture content.
Shrinkage Loss of bulk of soil when compacted in a fill.
Shrinkage index (SI) The numerical difference between the plastic and shrinkage limits.
Shrinkage limit (SL) The maximum water content at which a reduction in water content will not cause a decrease in volume of the soil mass.
Shrinkage ratio (R) The ratio of a given volume change, expressed as a percentage of the dry volume, to the corresponding change in moisture content above the shrinkage…
SHRT Short
SHRTWV Shortwave - a disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.
Shrub A plant with persistent woody stems and relatively low growth form; usually produces several basal shoots as opposed to a single bole; differs from a tree…
Shrub-steppe Habitat primarily composed of various shrubs and grasses.
Shrubsteppe obligate A species that is dependent on shrubsteppe habitats to provide food and/or habitat necessary for its survival.
SHSN Snow showers
Shunt Load An electrical load used to safely use excess generated power when not needed for its primary uses.
Shutter An interior or exterior movable panel that operates on hinges or slides into place, used to protect windows or provide privacy.
shuttle vector A plasmid capable of replicating in two different host organisms because it carries two different origins of replication and can therefore be used to…
SHWR Shower
sib-mating The deliberate crossing of siblings. Generally done where self-incompatibility prevents the production of self-fertilized progeny.
Siberian High Siberian High An area of high pressure which forms over Siberia in winter, and which is particularly apparent on mean charts of sea-level pressure.
sickle cell disease (SIH-kul sel dih-ZEEZ) An inherited disease in which the red blood cells have an abnormal crescent shape, block small blood vessels, and do not last as…
Side Channel Spillway A spillway whose crest is roughly parallel to the channel immediately downstream of the spillway.
Side population (SP) stem cell Two examples of multipotent stem cell populations found in bone marrow and skeletal muscle. SPs are not yet fully characterized.
Sidelobe A secondary energy maximum located outside the main radar beam. Typically, it contains a small percentage of energy compared to the main lobe, but it may…
siderophore A low molecular weight entity that binds very tightly to iron. Siderophores are synthesized by a variety of soil micro-organisms to ensure that the…
Siding A construction element applied to the outermost surface of an exterior wall.
sieve cell A long and slender sieve element in vascular plants, characterized by relatively unspecialized sieve areas and tapering end walls that lack sieve plates.
sieve element The phloem cell concerned with longitudinal conduction of food materials.
sieve plate Perforated wall area in a sieve tube element, through which strands connecting sieve tube protoplasts can pass.
sieve tube A tube within the phloem tissue of a plant, composed of joined sieve elements.
sievert (Sv) (Sv) A unit for expressing the equivalent magnitude of an absorbed dose which has been adjusted by a factor that expresses the relative tissue damage potential…
sigma factor The sub-unit of prokaryotic RNA polymerases responsible for the initiation of transcription at specific initiation sequences.
Sigma Heat The sum of sensible heat and latent heat in a substance above a base temperature, typically 32 degrees Fahrenheit.
SIGMET Significant Meteorological Advisory
signal peptide See: signal sequence.
signal sequence A stretch of 15-30 amino acid residues at the N terminus of a protein, which is thought to enable the protein to be secreted (pass through a cell…
signal transduction (SIG-nul trans-DUK-shun) The process by which a cell responds to substances in its environment.
Signal transduction pathways Relay of a signal by the conversion from one physical or chemical form to another.
Signal-to-Noise Ratio A specifically produced response (signal) compared to the response level (noise) when no specific stimulus (activity) is present.