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Sikorsky S-92
The Sikorsky S-92, or S-92 Helibus, is a twin-engine heavy helicopter built by Sikorsky Aircraft that carries up to 19 passengers and first flew in 1998.
Sikorsky S-97 Raider
The Sikorsky S-97 Raider is an American light tactical prototype helicopter built by Sikorsky, using coaxial rotors and a pusher propeller to exceed 200 knots, first flown in 2015.
Sikorsky SH-3 Sea King
The Sikorsky SH-3 Sea King (S-61, H-3 Sea King) is an American twin-engine amphibious anti-submarine helicopter that served as the US Navy's carrier-based submarine hunter from 1961 to 1996.
Sikorsky SH-60 Seahawk
The Sikorsky SH-60 Seahawk is a twin-engine, shipboard multi-mission helicopter developed for the United States Navy from the Army's UH-60 Black Hawk, entering service in 1984.
Sikorsky UH-60 Black Hawk
The Sikorsky UH-60 Black Hawk is a twin-engine utility helicopter, selected by the United States Army in 1976, that has served as its primary medium-lift tactical transport since 1979.
Sikorsky X2
The Sikorsky X2 was an experimental compound helicopter built by Sikorsky Aircraft, using coaxial rotors and a pusher propeller to reach 250 knots in 2010.
Sikorsky–Boeing SB-1 Defiant
The Sikorsky–Boeing SB-1 Defiant is an American high-speed compound helicopter demonstrator, first flown in 2019, that used coaxial rotors and a pusher propulsor to reach 247 knots.
Sila Nanotechnologies
Sila Nanotechnologies, or Sila, is an American battery materials company in Alameda, California, founded in 2011, whose Titan Silicon anode material raises energy density about 20 percent.
Silencer (firearms)
A silencer, also called a suppressor, is a device attached to a firearm that reduces the sound of firing by slowing and cooling propellant gases.
Silent Valley Reservoir
Silent Valley Reservoir is an impounding reservoir in the Mourne Mountains, County Down, Northern Ireland, built between 1923 and 1933 to supply water to Belfast.
SILEX
SILEX (Separation of Isotopes by Laser EXcitation) is a laser-based uranium enrichment technology invented by Silex Systems in the 1990s and commercialized in the United States by Global Laser Enrichment.
Silhouette (clustering)
The silhouette, or silhouette score, is a cluster validity index introduced by Peter J. Rousseeuw in 1987 that measures how well each object fits its cluster versus the nearest other cluster.
Silica aerogel superinsulation
Silica aerogel superinsulation is thermal insulation made from nanoporous silica aerogel, with conductivity of 5 to 20 mW/(m·K), used in buildings, transport, apparel, and electric-vehicle batteries.
Silica fume
Silica fume, also called microsilica, is an amorphous silicon dioxide by-product of silicon and ferrosilicon smelting used in concrete to raise strength, cut permeability, and improve durability.
Silica scaling geothermal
Silica scaling in geothermal power plants is the deposition of solid silica from cooling, depressurized brine on wellbores, piping, and injection wells, often forcing plants to limit output or shut down.
Silicalite-1
Silicalite-1, also called S-1, is a pure-silica MFI zeolite molecular sieve with 10-ring channels, reported in 1978, and used for ethanol/water separation membranes and organic adsorption.
Silicate cement
Silicate cement is a translucent dental restorative material developed in England in 1873 and used mainly in anterior teeth, later replaced by glass-ionomer cement developed in the late 1960s.
Silicidation
Silicidation is a semiconductor fabrication process in which a deposited metal film reacts with silicon at high temperature to form a low-resistivity silicide used on transistor source, drain, and gate regions.
Silicide thermoelectrics
Silicide thermoelectrics are thermoelectric materials based on compounds of silicon with metals, such as Mg2(Si,Sn) and manganese silicide, developed for low-cost waste-heat power generation using abundant, non-toxic elements.
Silicon anode
A silicon anode is a lithium-ion battery electrode using silicon instead of graphite, storing roughly ten times more lithium but limited by its large volume change.
Silicon carbide MOSFET
A silicon carbide MOSFET is a power transistor built on wide-bandgap silicon carbide, giving lower on-resistance and faster switching than silicon, with first commercial devices sold from 2010.
Silicon carbide wafer
A silicon carbide wafer is a thin disc of single-crystal 4H-SiC serving as the substrate for SiC power and radio-frequency devices, which handle higher voltages and temperatures than silicon allows.
Silicon controlled rectifier
The silicon controlled rectifier, also called a thyristor, is a p-n-p-n semiconductor device introduced by General Electric in 1957 that latches on when triggered by a gate current.
Silicon dendritic web and ribbon growth
Silicon dendritic web and ribbon growth are crystal growth methods that pull a thin self-supporting silicon sheet directly from the melt, chiefly to make solar cell wafers without sawing.
Silicon Graphics
Silicon Graphics (SGI) was an American computer company founded in 1982 by James Clark that built high-performance workstations and servers for 3D graphics, used for Hollywood visual effects, and created OpenGL.
Silicon heterojunction solar cell
A silicon heterojunction (SHJ), or HJT, solar cell is a crystalline-silicon cell whose junctions are thin amorphous-silicon films; Kaneka's 26.7% IBC cell set a record certified in 2017.
Silicon ingot
A silicon ingot is a bulk mass of solid silicon, grown as a single crystal or multicrystalline block, that is sliced into wafers for chips and solar cells.
Silicon Integrated Systems
Silicon Integrated Systems (SiS; 矽统科技) is a Taiwanese chip designer founded in 1987 in Hsinchu, known for PC core-logic chipsets and now touch and battery-management ICs.
Silicon interposer
A silicon interposer is a piece of silicon in a 2.5D chip package that provides high-density electrical connections between dies, such as logic chiplets and HBM memory.
Silicon Labs
Silicon Labs is an Austin, Texas semiconductor company founded in 1996 that designs wireless chips and microcontrollers for the Internet of Things; Texas Instruments agreed to acquire it for $7.5 billion in 2026.