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  • submaxillary gland (anatomy)

    human digestive system: Salivary glands: …serous type; those of the submandibular glands, of both serous and mucous types, with the serous cells outnumbering the mucous cells by four to one. The acini of the sublingual glands are composed primarily of mucous cells.

  • submerged smelting (metallurgy)

    lead processing: Direct smelting: …divided into two categories: (1) submerged smelting, as in the QSL and Isasmelt processes, in which the refining reactions occur in a liquid (i.e., molten metal, matte, or slag), and (2) suspension smelting, as in the KIVCET process, in which the reactions occur between gases and solids.

  • Submergence (film by Wenders [2017])

    Alicia Vikander: …on a holiday together; and Submergence, Wim Wenders’s romance about a bio-mathematician and an undercover MI6 agent (played by James McAvoy). She later starred as Lara Croft in the 2018 film adaptation of the rebooted video game franchise Tomb Raider. In 2019 Vikander lent her voice to the TV series…

  • submersible (vessel)

    hydrologic sciences: Remote sensing of the oceans: …on special surface vessels and submersibles for direct measurements. It can be very costly to operate either type of vessel on long deep-sea expeditions. Moreover, observations from such craft can provide only a partial picture of oceanic phenomena and processes in terms of both space and time. Consequently, there has…

  • Submillimeter Array (telescope array, Mauna Kea, Hawaii, United States)

    radio telescope: Radio telescope arrays: …Sinica of Taiwan, completed the Submillimeter Array (SMA), located near the summit of Mauna Kea, Hawaii, at an elevation of 4,080 metres (13,385 feet). This is an eight-element array of 6-metre (20-foot) dishes designed to work at wavelengths as short as 0.3 mm (0.01 inch). A major new international facility—under…

  • subminiature camera (photography)

    technology of photography: The ultraminiature or subminiature: This camera takes narrow roll film (16-mm or 9.5-mm) in special cartridges or film disks. The picture size ranges from 8 × 10 mm to 13 × 17 mm. These formats are used for making millions of snapshooting pocket-size cameras; special versions may be…

  • Submission (novel by Houellebecq)

    Michel Houellebecq: Soumission (2015; Submission) was a dystopian work of speculative fiction in which France has become an Islamic state. The novel was published on the day of the attacks on the Paris offices of satirical magazine Charlie Hebdo, which had that week published an issue featuring a caricature…

  • submission (animal)

    Submissive behaviour, form of animal behaviour in which one individual attempts through appeasement displays to avoid injury by a dominant member of its own species. Appeasement displays are commonly found in species that are well armed (e.g., carnivores) and social. The displays, even when

  • Submission of the Clergy, Act of (England [1533])

    Convocations of Canterbury and York: At the Reformation, the Act of Submission of the Clergy (1533) provided that convocation was not to meet without the permission of the king. For the next 140 years the convocations were busy with the Reformation settlement, working with the monarch and Parliament. After the Restoration of Charles II…

  • submissive behaviour (animal)

    Submissive behaviour, form of animal behaviour in which one individual attempts through appeasement displays to avoid injury by a dominant member of its own species. Appeasement displays are commonly found in species that are well armed (e.g., carnivores) and social. The displays, even when

  • submontane plateau (region, Pakistan)

    Pakistan: The submontane plateau: Lying south of the northern mountain rampart, the submontane plateau has four distinct divisions—the Trans-Indus plains, the Potwar Plateau, the Salt Range, and the Sialkot region.

  • submucous plexus (anatomy)

    digestive nerve plexus: …and the submucous plexus (Meissner’s plexus). The myenteric plexus is situated between the circular muscle layer and the longitudinal muscle layer in the lower esophagus, stomach, and intestines. The submucous plexus, as its name implies, is located in the submucosal tissue, which connects the surface mucous membrane lining to…

  • suboptimization, error of (industrial engineering)

    systems engineering: A design example: …a framework is called the error of suboptimization.

  • suborbital space tourism

    space tourism: Suborbital space tourism: Although the orbital space tourism industry garnered much media attention following Tito’s flight, other companies were also hard at work trying to make space tourism a profitable proposition by developing suborbital vehicles designed to take passengers to an altitude of 100 km…

  • subordinated debenture (finance)

    business finance: Long-term debt: …more junior lien is the subordinated debenture, which is secondary (in terms of ability to reclaim capital in the event of a business liquidation) to all other debentures and specifically to short-term bank loans.

  • subordinating construction (linguistics)

    linguistics: Syntax: …constructions fall into two types: subordinating and coordinating. If attention is confined, for simplicity, to constructions composed of no more than two immediate constituents, it can be said that subordinating constructions are those in which only one immediate constituent is of the same form class as the whole construction, whereas…

  • subordinationism (Christianity)

    patristic literature: Late 2nd to early 4th century: …final restoration, and a deeply subordinationist doctrine of the Trinity—i.e., one in which the Son is subordinate to the Father. For his spiritual teaching, with its emphasis on the battle against sin, on freedom from passions, and on the soul’s mystical marriage with the Logos, his Commentary on Canticles provides…

  • suboscine (bird)

    Suboscine, in general, any bird of the suborder Tyranni of the order Passeriformes (perching birds, or passerines) as distinguished from an oscine, or songbird, a member of the suborder Passeri. The term suboscine implies, perhaps rightly, that birds of this group are more primitive in anatomy and

  • Subotica (Serbia)

    Subotica, town in the northern part of the autonomous province of Vojvodina in northern Serbia. It lies along the Belgrade-Budapest railway line near the Hungarian border. Subotica was first mentioned in 1391, and it was included in Austria’s military frontier after the defeat of the Turks in the

  • Subotnik, Morton (American composer)

    electronic music: Music synthesizers: …closely associated with synthesizers is Morton Subotnik, who has produced a series of extended electronic music compositions, starting with Silver Apples of the Moon (1967). These pieces were created on the Buchla synthesizer, and any one of them demonstrates in relatively unmodified form the types of sounds one may obtain…

  • Subpannonia (region, Europe)

    Slovenia: Relief: …the country) is the fertile Subpannonia; it is located in eastern and northeastern Slovenia and includes the valleys of the Sava, Drava, and Mura rivers. Its basins contain the cities of Maribor (on the Drava) and Celje (on the Savinja River, a tributary of the Sava). Subpannonia corresponds in part…

  • subpharyngeal ganglion (anatomy)

    nervous system: Annelids: …the most anterior ganglion, the subpharyngeal ganglion, being the most prominent. Two to five pairs of lateral nerves leave each ganglion to innervate the body wall of that segment. A subepidermal nerve plexus occurs over the whole body. Another plexus, called the enteric, stomodaeal, or sympathetic system, is found in…

  • subpoena (law)

    Subpoena, formal instrument issued by a court, grand jury, legislative body or committee, or duly authorized administrative agency commanding an individual to appear before it at a specific time to give testimony, oral or written, in the matter identified in the document. The subpoena is used only

  • subpoena duces tecum (law)

    evidence: Documentary evidence: …court for a writ of sub poena duces tecum compelling the third party to produce the document in court. If the original is not produced after this, secondhand evidence of its existence is then permitted. In Continental law there is no similar obligation to produce documents. The adversary or third…

  • subpolar glacier

    glacier: Mass balance: …for the entire year; a subpolar (or polythermal) glacier contains ice below the freezing temperature, except for surface melting in the summer and a basal layer of temperate ice; and a temperate glacier is at the melting temperature throughout its mass, but surface freezing occurs in winter. A polar or…

  • subpolar gyre

    Subpolar gyre, an area of cyclonic ocean circulation that sits beneath a persistent region of low atmospheric pressure. In contrast to subtropical gyres, the movement of ocean water within the Ekman layer of subpolar gyres forces upwelling and surface water divergence. In the North Atlantic the

  • subprefect (law)

    China: Unification: …there were district magistrates (subprefects) in charge of areas corresponding roughly in size to counties. The duties of these subprefects were catholic, for they were supposed to see to all aspects of the welfare of the people in their area. This was the lowest level of major direct imperial…

  • subprime lending (finance)

    Subprime lending, the practice of extending credit to borrowers with low incomes or poor, incomplete, or nonexistent credit histories. Subprime mortgage loans, the most common form of subprime lending, are characterized by higher interest rates and more-stringent requirements to compensate lenders

  • subprime mortgage

    Subprime mortgage, a type of home loan extended to individuals with poor, incomplete, or nonexistent credit histories. Because the borrowers in that case present a higher risk for lenders, subprime mortgages typically charge higher interest rates than standard (prime) mortgages. The most common

  • Subprime Mortgages: A Catalyst for Global Chaos

    One version of chaos theory opines that a butterfly flapping its wings in Beijing could produce a change in atmospheric pressure that in turn could cause a tornado in Texas. This “butterfly effect” graphically demonstrates the theory whereby a small change in one area can cause a chain of events

  • subprogram (computer science)

    computer programming language: Control structures: …is an example of a subprogram (also called a procedure, subroutine, or function). A subprogram is like a sauce recipe given once and used as part of many other recipes. Subprograms take inputs (the quantity needed) and produce results (the sauce). Commonly used subprograms are generally in a collection or…

  • Subrahma?ya (Hindu deity)

    Skanda, Hindu god of war who was the firstborn son of Shiva. The many legends giving the circumstances of his birth are often at variance with one another. In Kalidasa’s epic poem Kumarasambhava (“The Birth of the War God”; 5th century ce), as in most versions of the story, the gods wished for

  • Subramaniam, C. (Indian politician)

    C. Subramaniam, Indian politician (born Jan. 30, 1910, Pollachi, near Coimbatore, Tamil Nadu, India—died Nov. 7, 2000, Chennai [formerly Madras], India), was commonly referred to as the “Father of the Green Revolution” after he introduced a new variety of wheat seed that transformed Indian a

  • Subramaniam, Gopala Ratnam (Indian filmmaker)

    Mani Ratnam, Indian filmmaker noted for his popular films in both Tamil and Hindi cinema. Ratnam was the son of film producer Ratnam Iyer. He obtained a management degree at the Jamnalal Bajaj Institute of Management Studies at the University of Bombay (now the University of Mumbai) before foraying

  • subrevolutionary terrorism (violence)

    terrorism: Types of terrorism: Subrevolutionary terrorism is rather less common. It is used not to overthrow an existing regime but to modify the existing sociopolitical structure. Since this modification is often accomplished through the threat of deposing the existing regime, subrevolutionary groups are somewhat more difficult to identify. An…

  • Subroc (missile)

    tactical weapons system: Surface-to-surface systems: Subroc and the Soviet SS-N-15. These missiles break the ocean surface, streak through the air at supersonic speed for about 30 miles (50 km), and then release a nuclear depth bomb that drops back into the water and sinks to the level of the target…

  • subrogation

    insurance: Limits of liability: …element in liability policies is subrogation: the insurer retains the right to bring an action against a liable third party for any loss this third party has caused.

  • subroutine (computer science)

    computer programming language: Control structures: …is an example of a subprogram (also called a procedure, subroutine, or function). A subprogram is like a sauce recipe given once and used as part of many other recipes. Subprograms take inputs (the quantity needed) and produce results (the sauce). Commonly used subprograms are generally in a collection or…

  • subroutine call (programming)

    computer: Central processing unit: A related instruction is the subroutine call, which transfers execution to a subprogram and then, after the subprogram finishes, returns to the main program where it left off.

  • subscapular nerve (anatomy)

    human nervous system: Brachial plexus: thoracodorsal (to latissimus dorsi), and subscapular (to teres major and subscapular). The axillary nerve carries motor fibres to the deltoid and teres minor muscles as well as sensory fibres to the lateral surface of the shoulder and upper arm. The biceps, brachialis, and coracobrachialis muscles, as well as the lateral…

  • subscapularis muscle (anatomy)

    muscle: Tetrapod musculature: …reptiles, and birds and as subscapularis in mammals. It runs from the deep surface of the shoulder girdle to the humerus. In amphibians the dorsalis scapulae arise from the anterior edge of the scapula. The same muscle is known as the deltoideus in reptiles and mammals; in the latter, part…

  • subscription (media)

    Television in the United States: The growth of cable TV: …a monthly fee, cable TV subscribers could receive traditional local broadcast stations, broadcast “superstations” delivered to cable systems by satellite from distant cities, premium movie services, and a wide and growing array of specialized cable-only channels. Originally called “community antenna television,” cable TV had been around almost as long as…

  • subscription library

    library: Subscription libraries: Part public, part private, these libraries enjoyed much popularity from the late 17th to the 19th century. Many of them were set up by associations of scholarly professional groups for the benefit of academies, colleges, and institutions, but their membership was also open…

  • subsea permafrost

    permafrost: Permafrost zones: …is known as subsea or offshore permafrost.

  • subsegment (market segment)

    marketing: Market niches: Segments can be divided into even smaller groups, called subsegments or niches. A niche is defined as a small target group that has special requirements. For example, a bank may specialize in serving the investment needs of not only senior citizens but also senior…

  • subset (mathematics)

    set theory: Equivalent sets: …included in, or is a subset of, a set A (symbolized by B ? A) if every element of B is an element of A. So defined, a subset may possibly include all of the elements of A, so that A can be a subset of itself. Furthermore, the empty…

  • subshell (electronic configuration)

    spectroscopy: Angular momentum quantum numbers: … divides each shell into n subshells consisting of all electrons of the same principal and orbital quantum numbers.

  • subsidence (geology)

    Subsidence, sinking of the Earth’s surface in response to geologic or man-induced causes. When subsidence occurs in great belts, providing troughs for the accumulation of sediments, the resulting features are termed geosynclines; nonlinear subsidence produces basins and irregular depressions.

  • subsidence inversion (meteorology)

    temperature inversion: A subsidence inversion develops when a widespread layer of air descends. The layer is compressed and heated by the resulting increase in atmospheric pressure, and as a result the lapse rate of temperature is reduced. If the air mass sinks low enough, the air at higher…

  • subsidiary (finance)

    accounting: Consolidated statements: …list its investments in its subsidiaries (the companies it owns) as assets; instead, it includes their assets and liabilities with its own.

  • subsidiary motion (law)

    parliamentary procedure: Rules of parliamentary procedure: Subsidiary motions are applicable to other motions for the purpose of modifying the main question or affecting its consideration and disposition. The subsidiary motion to lay on the table is, in American usage, a motion to suspend consideration of the question until such time as…

  • subsidiary rights (publishing)

    history of publishing: Forms of copyright: These subsidiary rights may be briefly summarized. American rights for a British book and British rights for a book of American origin can prove to be exceptionally profitable. Though a book normally has its greatest sale in its country of origin, there are cases in which…

  • subsidiary system (politics)

    India: The government of Lord Wellesley: …to Wellesley’s development of the subsidiary system. In the hands of Clive and Hastings, it was a defensive instrument to safeguard the company’s possessions; in the hands of Wellesley, it became an offensive device with which to subject independent states to British control. The essence of the system was that…

  • Subsidies and Countervailing Duties, Code on (international trade agreement)

    international trade: The General Agreement on Tariffs and Trade: Most notably, a Code on Subsidies and Countervailing Duties was negotiated. This code had two main features: it listed a number of unacceptable subsidy practices, and it introduced a requirement that formal procedures be followed before the imposition of countervailing duties on imports subsidized by foreign nations. Specifically,…

  • subsidy

    Subsidy, a direct or indirect payment, economic concession, or privilege granted by a government to private firms, households, or other governmental units in order to promote a public objective. Identification of a subsidy is often complicated because of the variety of subsidy instruments, the

  • Subsilvan (Swiss dialect)

    Rhaetian dialects: …are two dialects, Sursilvan and Sutsilvan, that constitute the main dialects of the Romansh language. Other Rhaetian dialects are Engadine, Ladin, and Friulian.

  • subsistence economy

    economic system: Prehistoric and preliterate economic systems: …first concerns their level of subsistence, long deemed to have been one of chronic scarcity and want. According to the still controversial findings of the anthropologist Marshall Sahlins, this notion of scarcity is not true. His studies of several preliterate peoples found that they could easily increase their provisioning if…

  • subsistence farming (agriculture)

    Subsistence farming, form of farming in which nearly all of the crops or livestock raised are used to maintain the farmer and the farmer’s family, leaving little, if any, surplus for sale or trade. Preindustrial agricultural peoples throughout the world have traditionally practiced subsistence

  • subsistence theory of wages (economics)

    wage and salary: Subsistence theory: Subsistence theories emphasize the supply aspects of the labour market while neglecting the demand aspects. They hold that change in the supply of workers is the basic force that drives real wages to the minimum required for subsistence (that is, for basic needs…

  • subsocial sequence (behaviour)

    animal social behaviour: Categorizing the diversity of social behaviour: …the parasocial sequence and the subsocial sequence. This classification is based primarily on the involvement of insect parents with their young, whereas classifications of vertebrate sociality are frequently based on spacing behaviour or mating system. Both routes culminate in “eusociality,” a system in which the young are cared for cooperatively…

  • subsoil (geology)

    Subsoil, Layer (stratum) of earth immediately below the surface soil, consisting predominantly of minerals and leached materials such as iron and aluminum compounds. Humus remains and clay accumulate in subsoil, but the teeming macroscopic and microscopic organisms that make the topsoil rich with

  • subsoil plow

    plow: …and packed soils, include the subsoiler and the chisel plow. The subsoiler must be pulled by a heavy tractor, for its steel-pointed shank is capable of penetrating the subsoil to a depth of three feet. The chisel plow, or ripper, has several rigid or spring-toothed shanks with double pointed shovels…

  • subsoiler

    plow: …and packed soils, include the subsoiler and the chisel plow. The subsoiler must be pulled by a heavy tractor, for its steel-pointed shank is capable of penetrating the subsoil to a depth of three feet. The chisel plow, or ripper, has several rigid or spring-toothed shanks with double pointed shovels…

  • subspecies (taxon)

    race: The many meanings of race: …used the term race for subspecies, subdivisions of the human species which were presumed sufficiently different biologically that they might later evolve into separate species.

  • substance (philosophy)

    Christianity: Evidentialist approach: The concept of substance, however, although confidently used throughout the medieval period, was widely questioned by modern thinkers and found little place in distinctively 20th-century streams of philosophy. Consequently, there was a variety of attempts, in which theology and philosophy mingled inextricably, to find an interpretation that would…

  • Substance and Function (work by Cassirer)

    Ernst Cassirer: …work, Substanzbegriff und Funktionsbegriff (1910; Substance and Function), he treated the related topic of concept formation. Attacking the view that a concept is formed by abstracting from a number of particular instances, he argued that the concept, as an instrument in organizing human knowledge, is already pre-existent before any task…

  • substance dualism (philosophy)

    philosophy of mind: Substance dualism and property dualism: Confronted with the problems about identity and explanatory gaps, some philosophers have opted for one version or another of mind-body dualism, the view that mental phenomena cannot in any way be reduced to physical phenomena. In its most radical form,…

  • substance P (hormone)

    human nervous system: Basal ganglia: …in spiny striatal neurons include substance P and enkephalin.

  • substantia compacta (anatomy)

    Compact bone, dense bone in which the bony matrix is solidly filled with organic ground substance and inorganic salts, leaving only tiny spaces (lacunae) that contain the osteocytes, or bone cells. Compact bone makes up 80 percent of the human skeleton; the remainder is cancellous bone, which has a

  • substantia gelatinosa (anatomy)

    pain: Physiology of pain: …in the marginal zone and substantia gelatinosa of the gray matter of the spinal cord. That area is responsible for regulating and modulating the incoming impulses. Two different pathways, the spinothalamic and spinoreticular tracts, transmit impulses to the brainstem and thalamus. Spinothalamic input is thought to effect the conscious sensation…

  • substantia nigra (anatomy)

    dopamine: …with cellular death in the substantia nigra results in Parkinson disease. Dopamine-receptor agonists, which bind to dopamine receptors on dopamine-producing neurons in the neurotransmitter’s absence, can increase dopaminergic activity in the brain, helping to lessen Parkinson symptoms.

  • substantial form (philosophy)

    Aristotle: Form: A substantial form is a second substance (species or kind) considered as a universal; the predicate human, for example, is universal as well as substantial. Thus, Socrates is human may be described as predicating a second substance of a first substance (Socrates) or as predicating a…

  • substantive dye

    Direct dye, any of a class of coloured, water-soluble compounds that have an affinity for fibre and are taken up directly, such as the benzidine derivatives. Direct dyes are usually cheap and easily applied, and they can yield bright colours. Washfastness is poor but may be improved by a

  • substantive Empiricism

    empiricism: Substantive empiricism: …empiricism is that of the substantive empiricists, who are unconvinced by attempts that have been made to interpret formal concepts empirically and who therefore concede that formal concepts are a priori, though they deny that status to categorial concepts and to the theoretical concepts of physics, which they hold are…

  • substantive equal opportunity (political theory)

    equal opportunity: Fairness and equality: …resulting position is often called fair, or substantive, equal opportunity, in contrast to the formal equal opportunity provided by open competition on its own.

  • substantive law

    procedural law: …law is commonly contrasted with substantive law, which constitutes the great body of law and defines and regulates legal rights and duties. Thus, whereas substantive law would describe how two people might enter into a contract, procedural law would explain how someone alleging a breach of contract might seek the…

  • substantive private law

    procedural law: Substantive private law, which deals with the relations between private (i.e., nongovernmental) persons, whether individuals or corporate bodies, has as its corollary the rules of civil procedure. Because the object of judicial proceedings is to arrive at the truth by using the best available evidence,…

  • substantive process (photography)

    motion-picture technology: Film: In a modification called the substantive process, the appropriate dye couplers are suitably embedded in the emulsion in the appropriate colour layers to prevent their moving about during processing and contaminating the colours (an important problem). It is then possible to carry out the second exposure and development on all…

  • substantivity (dyes)

    dye: Dye retention: …such interactions is termed its substantivity. Dyes can be classified by their substantivity, which depends, in part, on the nature of the substituents in the dye molecule.

  • Substanzbegriff und Funktionsbegriff (work by Cassirer)

    Ernst Cassirer: …work, Substanzbegriff und Funktionsbegriff (1910; Substance and Function), he treated the related topic of concept formation. Attacking the view that a concept is formed by abstracting from a number of particular instances, he argued that the concept, as an instrument in organizing human knowledge, is already pre-existent before any task…

  • substation (electronics)

    electric power: …to bulk delivery points, or substations, from which it is distributed to consumers. Transmission is accomplished by an extensive network of high-voltage power lines, including overhead wires and underground and submarine cables. Voltages higher than those suitable for power plant generators are required when transmitting alternating current over long distances…

  • substituted acetylene (chemical compound)

    organometallic compound: Alkene and alkyne ligands: Substituted acetylenes form very stable polymetallic complexes in which the acetylene can be regarded as a four-electron donor. An example is η2-diphenylethynehexacarbonyldicobalt, in which four of the six electrons in the triple bond of the ethyene ligand, R―C≡C―R, are shared with the two cobalt atoms…

  • substitution (prosody)

    Substitution, in Greek or Latin prosody, the replacement of a prosodic element that is required or expected at a given place in a given metre by another which is more or less equivalent in temporal quantity. In modern prosody, substitution refers to the use within a metrical series of a foot other

  • substitution (team sports)

    baseball: Substitutions: The use of a substitute as an offensive tactic most commonly involves sending in a pinch hitter—that is, taking a hitter out of the lineup and substituting another player whose likelihood for driving the ball for a hit or a fly to the deep…

  • substitution (mathematics and logic)

    formal logic: Axiomatization of PC: …axiom”; analogous schemata can be substituted for the other axioms. The number of axioms would then become infinite, but, on the other hand, the rule of substitution would no longer be needed, and modus ponens could be the only transformation rule. This method makes no difference to the theorems that…

  • substitution bone

    human skeleton: Development of cranial bones: …different types of developmental origin—the cartilaginous, or substitution, bones, which replace cartilages preformed in the general shape of the bone; and membrane bones, which are laid down within layers of connective tissue. For the most part, the substitution bones form the floor of the cranium, while membrane bones form the…

  • substitution cipher (cryptology)

    Substitution cipher, data encryption scheme in which units of the plaintext (generally single letters or pairs of letters of ordinary text) are replaced with other symbols or groups of symbols. The ciphertext symbols do not have to be the same as the plaintext characters in a substitution cipher,

  • substitution effect (economics)

    utility and value: Income and substitution effects: …price change is called the substitution effect. The division can be carried out graphically as follows: let the price of X increase so that the price line in Figure 7 moves from PP′ to PR′, and assume an imaginary intermediate price line, LL′, with the slope of PR′ but tangent…

  • substitution mutation (genetics)

    Point mutation, change within a gene in which one base pair in the DNA sequence is altered. Point mutations are frequently the result of mistakes made during DNA replication, although modification of DNA, such as through exposure to X-rays or to ultraviolet radiation, also can induce point

  • substitution of equivalents, rule of (logic)

    formal logic: Logical manipulations in LPC: Because the rule of substitution of equivalents can be shown to hold in LPC, it follows that (?x) may be replaced anywhere in a wff by ~(?x)~, or (?x) by ~(?x)~, and the resulting wff will be equivalent to the original. Similarly, because the law of double…

  • substitution pseudomorph (geology)

    pseudomorph: Pseudomorphs are formed by substitution, deposition, or alteration. In the formation of a pseudomorph by substitution, the original substance has been gradually removed and simultaneously replaced by another. A common example of this is petrified wood, in which all the cellulose fibres have been replaced by silica, even those…

  • substitution reaction (chemical reaction)

    Substitution reaction, any of a class of chemical reactions in which an atom, ion, or group of atoms or ions in a molecule is replaced by another atom, ion, or group. An example is the reaction in which the chlorine atom in the chloromethane molecule is displaced by the hydroxide ion, forming

  • substitution weighing (measurement)

    balance: …than the required precision, the substitution method of weighing may be used. In this method, counterpoise weights are added to one pan to balance the unknown load on the other. Then, known weights are substituted for the unknown load. This method requires only that the two arms of the beam…

  • substitution, rule of (logic)

    formal logic: Axiomatization of LPC: Rules of uniform substitution for predicate calculi, though formulable, are mostly very complicated, and, to avoid the necessity for these rules, axioms for these systems are therefore usually given by axiom schemata in the sense explained earlier (see above Axiomatization of PC). Given the formation…

  • substitution-instance (logic)

    formal logic: Axiomatization of LPC: By an LPC substitution-instance of a wff of PC is meant any result of uniformly replacing every propositional variable in that wff by a wff of LPC. Thus, one LPC substitution-instance of (p ? ~q) ? (q ? ~p) is [?xy ? ~(?x)ψx] ? [(?x)ψx ? ~?xy]. Axiom…

  • substitutional interpretation (logic)

    foundations of mathematics: Boolean local topoi: In particular, quantifiers admit a substitutional interpretation, a desirable property that has been discussed by philosophers (among them, Russell and the American logician Saul Kripke [born 1940])—to wit: if an existential statement is true, then it can be witnessed by a term of appropriate type in the language; and a…

  • substitutional solid solution (chemistry)

    metallurgy: Increasing strength: …case they are known as substitutional elements), or, if they are appreciably smaller than the matrix atoms, they may take up places between regular sites (where they are called interstitial elements).

  • substitutive nomenclature (chemistry)

    organohalogen compound: Nomenclature: …used when naming organohalogen compounds: substitutive and functional class. In substitutive nomenclature the prefix fluoro-, chloro-, bromo-, or iodo- is added to the name of the hydrocarbon framework along with a number (called a locant) identifying the carbon to which the halogen is attached. Substituents, including the halogen, are listed…

  • substorm-wedge current system (atmospheric science)

    geomagnetic field: Expansion phase: The substorm-wedge current system causes sudden changes in the magnetic field at Earth’s surface during substorms. These changes induce very strong localized electric fields. These transient electric fields energize particles to high energy and propel them earthward. Loss of these particles to the atmosphere causes the…

  • substrate (enzymatic reactions)

    acid–base reaction: Acid–base catalysis: …the reacting substance, termed the substrate, with the catalyst being regenerated at a later stage of the reaction. Moreover, knowledge of reaction mechanisms is now sufficient to suggest detailed sequences of reactions for many acid- or base-catalysis reactions, most of these sequences being at least plausible and in many instances…

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