All articles starting with S
44,216 articles
S-curve (project management)
An S-curve in project management is a graph of cumulative value, such as cost or work completed, plotted against time, and the standard display for earned value management metrics.
S-curve motion profile
The S-curve motion profile, also called jerk-limited motion, is a trajectory generator in which acceleration changes gradually, producing an S-shaped velocity curve and less vibration.
S-duality
S-duality is a conjectured equivalence in string theory and quantum field theory relating a strongly coupled theory to a weakly coupled one, exchanging electric and magnetic charges.
S-estimator
The S-estimator is a robust regression estimator introduced by Peter Rousseeuw and Victor Yohai in 1984. It minimizes a robust measure of residual scale, withstanding up to 50% data contamination.
S-expression
S-expression (sexp, symbolic expression): the atom-or-parenthesized-list data notation John McCarthy introduced in Lisp (1960), originally the internal representation behind M-expressions; now Lisp syntax and a standalone format used by GnuPG, RFC 9804, and SMT-LIB.
S-expressions
An S-expression (symbolic expression) is a notation for tree-structured data using parenthesized lists, originating in John McCarthy's LISP around 1960 and later standardized as a data format for cryptographic certificates and protocols.
S-glass
S-glass is a high-strength alumino-silicate glass fiber offering higher tensile strength, stiffness, and temperature resistance than E-glass, used chiefly in aerospace, military, and high-performance composites despite its higher cost.
S-I IPVF Holdings, LLC (Shale-Inland / HD Supply IPVF)
S-I IPVF Holdings, LLC was a Houston, Texas holding company created in 2012 when Shale-Inland acquired HD Supply's industrial pipe, valves, and fittings business for $469 million.
S-IVB
The S-IVB, also called Saturn S-IVB, was a Douglas rocket stage powered by one J-2 engine, serving as the Saturn IB's second stage and the Saturn V's third stage.
S-K 1300
S-K 1300 is Subpart 1300 of Regulation S-K, the SEC's mining disclosure rules adopted in 2018 to replace Industry Guide 7, requiring resources, reserves, and technical report summaries.
S-layer protein
S-layer protein (Slp): subunit of S-layers, 2D crystalline protein or glycoprotein lattices forming the outermost cell envelope of many bacteria and most archaea; 5-25 nm periodicity, self-assembling, used in nanobiotechnology, vaccines, biosensing, and ultrafiltration.
S-layer protein B, N-terminal domain
S-layer protein B, N-terminal domain: the β-sandwich N-terminal region of SlaB, the membrane-anchor subunit of the two-component Sulfolobus archaeal S-layer, which binds the SlaA lattice.
S-matrix
The S-matrix, or scattering matrix, is the operator in quantum mechanics and quantum field theory giving transition amplitudes between the incoming and outgoing states of a scattering process.
S-matrix bootstrap
The S-matrix bootstrap is a quantum field theory research program, begun by Chew and Mandelstam in the 1960s and revived numerically around 2016, that derives scattering amplitudes from consistency alone.
S-mine
The S-mine, known to Allied soldiers as the Bouncing Betty, was Germany's standard bounding antipersonnel mine of the Second World War, leaping into the air before bursting.
S-MOS Systems
S-MOS Systems was a San Jose semiconductor company founded in 1983 that designed CMOS chips sold in North America and fabricated by Seiko Epson in Japan.
S-N curve
An S-N curve, also called a Wöhler curve, is a graph of cyclic stress magnitude against the number of cycles to failure, the most common published form of fatigue data.
S-Nitroso-N-acetylpenicillamine
S-Nitroso-N-acetylpenicillamine, abbreviated SNAP, is a synthetic S-nitrosothiol derived from N-acetylpenicillamine that releases nitric oxide and relaxes blood vessels, widely used as an NO donor in research.
S-Nitrosoglutathione
S-Nitrosoglutathione (GSNO) is an S-nitrosothiol formed by nitrosation of the tripeptide glutathione, acting as a nitric oxide reservoir and donor, bronchodilator, and platelet aggregation inhibitor, and tested clinically in asthma and cystic fibrosis.
S-Nitrosothiol
An S-nitrosothiol, also called a thionitrite, is an organosulfur compound in which a nitroso group is covalently bound to the sulfur atom of a thiol, central to nitric oxide signaling.
S-OIL
S-OIL (에쓰오일) is a South Korean oil refining and petrochemical company founded in 1976 and headquartered in Seoul; Saudi Aramco's Aramco Overseas Company holds a 63.4 percent stake.
S-procedure
The S-procedure is a control theory device converting quadratic implications into linear matrix inequality conditions on multipliers, sufficient in general and lossless for a single constraint.
s-process
The s-process, or slow neutron-capture process, is a nucleosynthesis mechanism operating in AGB and massive stars that builds about half of the elements heavier than iron, up to bismuth.
S-scheme heterojunction
The S-scheme heterojunction, also known as the step-scheme heterojunction, is a photocatalytic design joining two semiconductors so low-energy carriers recombine while strong oxidizing and reducing carriers are preserved.
S-stars
S-stars are cool giant stars of spectral class S whose spectra show zirconium oxide bands and enhanced s-process elements, placing them between M giants and carbon stars in evolution.
S-Town
S-Town is a 2017 seven-chapter nonfiction podcast from Serial and This American Life, hosted by Brian Reed, about John B. McLemore of Woodstock, Alabama; released all at once, it drew 40 million downloads in a month and a Peabody Award.
S-train (Copenhagen)
The S-train, or S-tog, is the suburban railway network of Copenhagen, opened in 1934 and operated by DSB on seven lines serving 86 stations, with about 350,000 passengers on a busy weekday.
S-transform
The S-transform, or Stockwell transform, is a linear time-frequency transform with a Gaussian window that narrows at high frequencies, introduced in 1996 and used in power quality and seismic analysis.
S-type asteroid
An S-type asteroid is a stony asteroid of silicate minerals and nickel-iron, making up about 17 percent of asteroids and commonest in the inner main belt.
S-type star
An S-type star is a cool red giant whose spectrum shows zirconium oxide bands from overabundant s-process elements, marking it as transitional between M-type giants and carbon stars.