A-Z Browse

Previous Next

Spilornis (bird)
The serpent eagles, or snake eagles, Spilornis (six species, subfamily Circaetinae), eat mostly snakes, including large poisonous ones. They occur in Asia. Other birds called serpent eagles, notably the long-tailed members of the genera Dryotriorchis (e.g., African serpent eagle) and Eutriorchis (e.g., the endangered Madagascar serpent eagle), occur in Africa....
spin (mechanics)
...motion of the centre of mass, acting as if all the body’s mass were concentrated at that point. The quantity Lc in equation (83) is sometimes called the body’s spin, and r × p is called the orbital angular momentum. Any change in the angular momentum of the body is given by the torque equation,...
spin (atomic physics)
in physics, the amount of angular momentum associated with a subatomic particle or nucleus and measured in multiples of a unit called the Dirac h, or h-bar (ℏ), equal to the Planck constant divi...
spin (ice skating)
Spins are generally performed on either the back outside or the back inside edge of the blade. A sit spin is done in sitting position, with the body supported by the leg that controls the spin as the free leg extends beside the bent skating leg. The layback spin, usually performed by women, requires an upright position; the skater arches her back and drops her head and shoulders toward the ice.......
Spin (American publication)
...The Wire, the dance culture-based Mixmag, Germany’s Spex, or American magazines such as Spin (founded in 1985 as a younger, hipper rival to Rolling Stone) and The Village Voice....
spin bath (materials production)
The wet-spinning process is illustrated schematically in Figure 1. During wet spinning the spinnerette is generally (but not always) placed in the spin bath, a coagulation bath in which solvent diffuses out of the extruded material and a nonsolvent, usually water, diffuses into the extrudate. The resulting gel may be oriented by stretching during this stage, as the polymer is coagulated, or the......
spin bowling (cricket)
The primary purpose of the spin is to bring the ball up from the pitch at an angle that is difficult for the batsman to anticipate. The two swerves (curves) are the “inswinger,” which moves in the air from off to leg (into the batsman), and the “away swinger,” or “outswinger,” which swerves from leg to off (away from the batsman). A “googly”....
spin casting (fishing)
Bait casting and spin casting differ essentially in the type of reel, the rod length, and the strength of the line used. Bait casting usually employs a reel with heavier line, often in the 10- to 20-pound (4,500- to 9,000-gram) test range. Most spinning reels are usually spooled with lighter lines in the 6- to 10-pound (2,700- to 4,500-gram) test class. Spinning rods are generally 6–10......
Spīn Ghar Range (mountains, Pakistan-Afghanistan)
mountain range forming a natural frontier between Pakistan and Afghanistan, extending westward for 100 miles (160 km) from the Vale of Peshāwar (Pakistan) to the Lowrah Valley (Afghanistan). The boundary between the two countries runs along the summit of the range, which reaches a height of 15,600 f...
spin guidance (missile control method)
Tail fins can be used to stabilize projectiles. Spin stabilization, provided by rifling, causes gyroscopic wobbling in response to aerodynamic tumbling forces. Insufficient spin permits tumbling, and too much prevents dipping of the shot nose as it traverses the trajectory. Drift of the shot arises from lift, due to yawing, meteorological conditions, and rotation of the Earth....
spin magnetic quantum number (physics)
...angular momenta. The spin quantum number is s = 12, so in the presence of a magnetic field an electron can have one of two orientations corresponding to magnetic spin quantum number ms = ±12. The Pauli exclusion principle requires that no two electrons in an atom have the same......
spin quantum number (physics)
Electrons possess intrinsic magnetic moments that are related to their spin angular momenta. The spin quantum number is s = 12, so in the presence of a magnetic field an electron can have one of two orientations corresponding to magnetic spin quantum number ms = ±12. The Pauli exclusion......
spin stabilization (missile control method)
Tail fins can be used to stabilize projectiles. Spin stabilization, provided by rifling, causes gyroscopic wobbling in response to aerodynamic tumbling forces. Insufficient spin permits tumbling, and too much prevents dipping of the shot nose as it traverses the trajectory. Drift of the shot arises from lift, due to yawing, meteorological conditions, and rotation of the Earth....
spin wave (physics)
...atomic magnet is equivalent to a partial reversal of all the atomic magnets in a group. This partial reversal spreads through the solid as a wave of discrete energy transferal. This wave is called a spin wave, because the magnetism of each atom is produced by the spin of unpaired electrons in its structure. Thus, a magnon is a quantized spin wave....
spin-angular momentum (atomic physics)
in physics, the amount of angular momentum associated with a subatomic particle or nucleus and measured in multiples of a unit called the Dirac h, or h-bar (ℏ), equal to the Planck constant divi...
spin-canted ferromagnetism (physics)
...to that of paramagnetic materials. Above a temperature called the Néel temperature, thermal motions destroy the antiparallel arrangement, and the material then becomes paramagnetic. Spin-canted (anti)ferromagnetism is a special condition which occurs when antiparallel magnetic moments are deflected from the antiferromagnetic plane, resulting in a weak net magnetism. Hematite......
spin-drawing (textile manufacturing)
...called the spinning tower. There the molten polymer is solidified by a blast of cold air, and the numerous fibres are collected, after application of finish, at high speed. In a process known as spin-drawing, fibres may be drawn in-line to several times their original length. Packages may be collected directly from the spinning tower to give what is called continuous filament, or several......
spin-flip Raman laser (instrument)
The development of solid-state diode lasers, F-centre lasers, and spin-flip Raman lasers is providing new sources for infrared spectrometers. These sources in general are not broadband but have high intensity and are useful for the construction of instruments that are designed for specific applications in narrow frequency regions....
spin-flip scattering (physics)
...electrical resistivity. The conduction electrons scatter from the magnetic impurity. Since the conduction electron and the impurity both have spin, they can mutually flip spins while scattering. The spin-flip scattering is strong at low temperatures and actually increases slightly as temperature decreases. This phenomenon is called the Kondo effect after the Japanese theoretical physicist Jun.....
spin-orbit coupling (quantum mechanics)
...group, the palladium group, the platinum group, and the actinoid group. The resonance behaviour of compounds of these elements is conditioned by the relative strength of the ligand field and the spin-orbit coupling. In the lanthanoids, for instance, the ligand field is weak and unable to uncouple the spin and orbital momentum, leaving the latter largely unreduced. In the iron group, on the......
spin-orbit force (physics)
...of its orbital motion within the atom, the electron creates a magnetic field in its vicinity. The interaction of the electron’s magnetic moment with the magnetic field created by its motion (the spin-orbit interaction) modifies its energy and is proportional to the combination of the orbital angular momentum and the spin angular momentum. Small differences in energies of levels arising f...
spin-spin splitting (nuclear magnetic resonance spectroscopy)
...into three distinct peaks, called a triplet. The CH2 peak is split into four peaks, called a quartet. These multiple peaks are caused by nearby hydrogen atoms through a process termed spin-spin splitting. Each set of equivalent hydrogens on a given carbon is split into an n+1 multiplet by adjacent hydrogen atoms that are nonequivalent to the hydrogens of the given carbon.......
spin-statistics theorem (quantum mechanics)
in quantum mechanics, fundamental mathematical proof that subatomic particles having integral values of spin (such as photons and helium-4 atoms) must be described by Bose-Einstein statistics and that subatomic particles having half-integral values of ...
Spina (ancient port, Italy)
ancient Etruscan port on the Adriatic coast of Italy, now about 6 miles (10 km) inland. Spina was founded at the mouth of the Po River toward the end of the 6th century bc and was one of two main ports of entry for the rich Greek commerce with northern Etruria. Soon after 400 bc...
spina bifida (congenital disorder)
congenital cleft of the vertebral column, a form of neural tube defect....
spina bifida occulta (congenital disorder)
In spina bifida occulta, or hidden spina bifida, the vertebrae fail to completely enclose the spinal cord, but the latter is normal in form and is covered by the skin of the back. This form of the defect has no effect on body functions and may go undetected for life....
spinach (plant)
(species Spinacia oleracea), hardy, leafy annual of the goosefoot family (Chenopodiaceae), used as a vegetable. The edible leaves are arranged in a rosette, from which a seedstalk emerges. The leaves are somewhat triangular and may be flat or puckered. Spinach re...
spinach aphid (insect)
The green peach aphid (Myzus persicae), also called the spinach aphid, is pale yellow-green with three dark lines on the back. The life cycle involves two hosts. The female reproduces parthenogenetically during summer and produces sexual males and females in autumn. It is a serious pest, transmitting many plant mosaic diseases....
spinach leaf miner (insect)
...from three to five generations each year. Damage caused by the seed-corn maggot can be reduced by delaying the planting date to avoid times when adults are laying eggs. Another important pest is the spinach leaf miner (Pegomyia hyoscyomi), which produces blotches or linear mines (internal passages) on spinach leaves....
Spinacia oleracea (plant)
(species Spinacia oleracea), hardy, leafy annual of the goosefoot family (Chenopodiaceae), used as a vegetable. The edible leaves are arranged in a rosette, from which a seedstalk emerges. The leaves are somewhat triangular and may be flat or puckered. Spinach re...
spinal anesthesia (pathology)
Spinal anesthesia (sometimes called spinal block) is produced when a local anesthetic agent, such as lidocaine or bivucaine, sometimes mixed with a narcotic, is injected into the cerebrospinal fluid in the lumbar region of the spine. This technique allows the woman to be awake, while producing extensive numbing of the abdomen, legs, and feet. Because it is a single injection, its duration is......
spinal column (anatomy)
in vertebrate animals, the flexible column extending from neck to tail, made of a series of bones, the vertebrae. The major function of the vertebral column is protection of the spinal cord; it also provides stiffening for the body and attachment for the pectoral and pelvic girdles and many muscles. In humans an additional function is to transmit body wei...
spinal cord (anatomy)
major nerve tract of vertebrates, extending from the base of the brain through the canal of the spinal column. It is composed of nerve fibres that mediate reflex actions and that transmit impulses to and from the brain....
spinal cord diseases
major nerve tract of vertebrates, extending from the base of the brain through the canal of the spinal column. It is composed of nerve fibres that mediate reflex actions and that transmit impulses to and from the brain.......
spinal ganglion (anatomy)
...the brain in these more advanced invertebrates, inhibits responses rather than directing them. In vertebrates the ganglion is a cluster of neural bodies outside the central nervous system. A spinal ganglion, for instance, is a cluster of nerve bodies positioned along the spinal cord at the dorsal and ventral roots of a spinal nerve. The dorsal root ganglia contain the cell bodies of......
spinal meningitis (pathology)
the bacterium Neisseria meningitidis, which causes meningococcal meningitis in humans, who are the only natural hosts in which it causes disease. The bacteria are spherical, ranging in diameter from 0.6 to 1.0 μみゅーm (micrometre; 1 μみゅーm = 10-6 metre); they frequently occur in pairs, with adjacent sides flattened. They are strongly gram-negative. These bacte...
spinal muscular atrophy (pathology)
Hereditary motor neuropathies (also known as spinal muscular atrophies and as Werdnig-Hoffman or Kugelberg-Welander diseases) are a diverse group of genetic disorders in which signs of ventral-horn disease occur in babies or young people. The usual symptoms of muscle atrophy and weakness progress more slowly if the disease begins at a later age (5 to 15 years); at later ages the disease may......
spinal nerve (anatomy)
in vertebrates, any one of many paired peripheral nerves that arise from the spinal cord. In humans there are 31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Each pair connects the spinal cord with a specific region of the body. Near the spinal cord each spinal nerve branches into two roots. One, composed of sensory fibres, enters the s...
spinal polio (pathology)
...paralyzed, affecting posture. The neck muscles may become weak, so that the head cannot be raised. Paralysis of the face muscles may cause twisting of the mouth or drooping eyelids. In some types of spinal polio, the virus damages the upper part of the spinal cord, with resulting difficulties in breathing. In bulbar polio the virus attacks the brainstem, and the nerve centres that control......
spinal reflex (physiology)
...measures of mental phenomena and higher nervous activity. He sought analogies between the conditional (commonly though incorrectly translated as “conditioned”) reflex and the spinal reflex....
spinal root (physiology)
The symptoms and signs of damage to the spinal roots are the same as for peripheral-nerve damage except that the area of involvement is restricted to the area supplied by the spinal roots rather than the nerves. Also, generalized symmetrical sensory loss is not seen in spinal root damage....
spinal tap (medical procedure)
direct aspiration (fluid withdrawal) of cerebrospinal fluid (CSF) through a hollow needle. The needle is inserted in the lower back, usually between the third and fourth lumbar vertebrae, into the subarachnoid space of the spinal cord, where the CSF is located....
spinal-accessory nerve (anatomy)
The accessory nerve is formed by fibres from the medulla oblongata (known as the cranial root) and by fibres from cervical levels C1–C4 (known as the spinal root). The cranial root originates from the nucleus ambiguus and exits the medulla below the vagus nerve. Its fibres join the vagus and distribute to some muscles of the pharynx and larynx via pharyngeal and......
spinalis muscle (anatomy)
any of the deep muscles of the back near the vertebral column that, as part of the erector spinae (sacrospinalis) muscle group, assist in extension (e.g., bending backward), lateral flexion (bending to the side), and rotation of the spine. The ...
Spinden, Herbert Joseph (American archaeologist)
...system of the Maya calendar with the Gregorian calendar, are the most generally accepted; but there is a slight chance that a rival correlation espoused by the American archaeologist Herbert J. Spinden may be correct, which would make these dates 260 years earlier.)...
spindle (receptor)
Changes in the length of a muscle affect the force it can produce when stimulated. Generally there is a length at which the force generated is maximal. Receptors, called spindles, in the respiratory muscles measure muscle length and increase motor discharge to the diaphragm and intercostal muscles when increased stiffness of the lung or resistance to the movement of air caused by disease......
spindle (yarn production tool)
...to weaving cloth from those fibres that do not have extreme length. From early times through the Middle Ages, spinning was accomplished with the use of two implements, the distaff and the spindle. The distaff was a stick on which the mass of fibres was held. The drawn-out length of fibre was fastened to the weighted spindle, which hung free. The spinner whirled the spindle, causing it......
spindle and whorl (device)
Earliest device for spinning fibres into thread or yarn. The spinster lets the spindle fall to draw out the fibres while the whorl keeps it rotating to apply the necessary twist. The spindle and whorl was replaced by the spinning wheel....
spindle bomb (volcanic ejecta)
...molten lava ejected during a volcanic eruption, partly solidifying during flight. The final shape is determined by the initial size, viscosity, and flight velocity of the lava bomb. Some, called spindle bombs, are shaped like a football or spindle of thread; others, called cow-dung or pancake bombs, are flattened on landing; and still others are ribbon-shaped. If bombs are still molten or......
spindle, mitotic (biochemistry)
...chromatids is divided between the two daughter cells during mitosis, or division of the nucleus, a process in which the chromosomes are propelled by attachment to a bundle of microtubules called the mitotic spindle....
spindle tree, common (plant)
The winged spindle tree (E. alata), also called burning bush (q.v.), is a handsome shrub with corky winged stems. The common spindle tree (E. europaea), which grows to 6 m (20 feet), keeps its pink and orange fruits after the leaves fall. In eastern Europe gutta-percha resin is extracted from this plant. The wood is used for pegs and spindles. Several varieties of the......
Spindler, Michael (American businessman)
Sculley was replaced by Michael Spindler in 1993. Spindler’s most notable achievements as CEO were the successful migration of the Mac OS to the PowerPC microprocessor and the initiation of a shift away from Apple’s proprietary standards. Nevertheless, Apple struggled with marketing projections, accumulating large unsalable inventories of some models while simultaneously being unable...
spine (anatomy)
in vertebrate animals, the flexible column extending from neck to tail, made of a series of bones, the vertebrae. The major function of the vertebral column is protection of the spinal cord; it also provides stiffening for the body and attachment for the pectoral and pelvic girdles and many muscles. In humans an additional function is to transmit body wei...
spine (plant structure)
Stipules often develop before the rest of the leaf; they protect the young blade and then are often shed when the leaf matures. Spines are also modified leaves. In cacti, spines are wholly transformed leaves that protect the plant from herbivores, radiate heat from the stem during the day, and collect and drip condensed water vapour during the cooler night. In the many species of the spurge......
spine, curvature of the (pathology)
any of a group of deviations of the normal spinal curvature, including scoliosis, lordosis, and kyphosis....
spine, dendritic (anatomy)
...axons and are unmyelinated. Dendrites are thought to form receiving surfaces for synaptic input from other neurons. In many dendrites these surfaces are provided by specialized structures called dendritic spines, which, by providing discrete regions for the reception of nerve impulses, isolate changes in electrical current from the main dendritic trunk....
spine, tuberculosis of the
disease caused by infection of the spinal column, or vertebral column, by the tuberculosis bacillus, Mycobacterium tuberculosis. Pott disease is characterized by softening and collapse of the vertebrae, often resulting in a hunchback ...
spine-tailed swift (bird)
...Apodidae (sometimes Micropodidae), in the order Apodiformes, which also includes the hummingbirds. The family is divided into the subfamilies Apodinae, or soft-tailed swifts, and Chaeturinae, or spine-tailed swifts. Almost worldwide in distribution, swifts are absent only from polar regions, southern Chile and Argentina, New Zealand, and most of Australia....
spinefoot
any of about 25 species of fishes constituting the family Siganidae (order Perciformes), found in shallow tropical marine waters from the Red Sea to Tahiti. They live in areas near shore or around reefs and graze on algae and other plants. Most rabbitfish are olive or brown in colour and have sharp, poisonous spines on several of their fins. They seldom attain lengths greater than 30 cm (1 foot)....
spinel (mineral)
mineral composed of magnesium aluminum oxide (MgAl2O4) or any member of a group of rock-forming minerals, all of which are metal oxides with the general composition AB2O4, in which A may be magnesium, iron, zinc, manganese, or nickel; B may be aluminum...
spinel group (mineralogy)
...the general composition AB2O4, in which A may be magnesium, iron, zinc, manganese, or nickel; B may be aluminum, chromium, or iron; and O is oxygen. The spinel group is divided into three immiscible series: the spinel (aluminum-spinel) series, in which B is aluminum; the chromite (chromium-spinel) series, in which B is chromium; and the.....
spinel series (mineralogy)
...in which A may be magnesium, iron, zinc, manganese, or nickel; B may be aluminum, chromium, or iron; and O is oxygen. The spinel group is divided into three immiscible series: the spinel (aluminum-spinel) series, in which B is aluminum; the chromite (chromium-spinel) series, in which B is chromium; and the magnetite (iron-spinel) series, in which B is......
spinel structure (mineral)
...ferric iron ion is trivalent, and the oxygen ion accepts two electrons. Actually M can also be divalent iron, forming magnetite (Fe3O4). The crystal structure is called spinel, which is the mineral name for MgAl2O4. Ferrites are electrical insulators with magnetic ordering. Their insulating quality makes them useful as magnetic cores. When......
Spinelli, Altiero (Italian resistance leader)
...the papers produced by its distinguished supporters, including work by Lord Lothian and Lionel Robbins, found their way to another group of activists in the Italian Resistance, led by, among others, Altiero Spinelli. One of the most stubborn of Mussolini’s political prisoners, he was freed in 1943 from confinement on an island off the coast between Rome and Naples. Admiring what he calle...
Spinello Aretino (Italian painter)
late Gothic Italian painter noteworthy for his vigorous narrative sense. His style anticipates the realistic painting of the early Renaissance of the 15th century. Early in his career he came under the influence of Orcagna and Nardo di Cione, whose style shows in his first major work, a fresco cycle in San Francesco...
Spinello di Luca Spinelli (Italian painter)
late Gothic Italian painter noteworthy for his vigorous narrative sense. His style anticipates the realistic painting of the early Renaissance of the 15th century. Early in his career he came under the influence of Orcagna and Nardo di Cione, whose style shows in his first major work, a fresco cycle in San Francesco...
spinet (piano)
...plane of the strings run vertically, perpendicular to the keyboard, thus taking up less floor space than the normal grand piano. Upright pianos are made in various heights; the shortest are called spinets or consoles, and these are generally considered to have an inferior tone resulting from the shortness of their strings and their relatively small soundboards. The larger upright pianos were......
spinet (harpsichord)
small form of the harpsichord, generally wing-shaped, with a single set of strings placed at an oblique angle to the keyboard. The wing-shaped spinet may have originated in Italy during the 16th century; later it became known in France and England....
Spinicaudata (crustacean)
...show a great diversity of form. In the Laevicaudata, for example, the number of trunk segments remains constant; there are 12 pairs of trunk limbs in the female and 10 pairs in the male. In the Spinicaudata, however, the number of paired trunk segments varies among its members from 12 up to 32 in some species. A carapace is present in the infraorders Ctenopoda and Anomopoda, but it encloses......
Spink, Alfred H. (American author)
Both Alfred H. Spink’s The National Game (1910) and A.G. Spalding’s America’s National Game (1911), generally regarded as the first attempts at writing a standard history of baseball, cite Casey at the Bat as the best baseball poem ever written. Spalding goes so far as to proclaim that “Love ha...
Spinks, Leon (American boxer)
American boxer who won an Olympic gold medal in 1976 and was the world heavyweight champion in 1978. He and Michael Spinks became the first brothers to win gold medals in the same sport at the same Olympics and, as professional champions, the first brothers in boxing history to win world titles....
Spinks, Michael (American boxer)
American boxer who was both the light heavyweight (1981–85) and heavyweight (1985–88) world champion and an Olympic gold medalist (1976). He and Leon Spinks became the first brothers to win gold medals in the same sport at the same Olympics and the first brothers to win world titles as professional boxers....
spinner (game piece)
form of top having usually 4, 6, 8, or 12 sides marked with distinctive symbols. A teetotum is used for playing games, mostly of the gambling variety, and serves in place of dice. The hexagonal (six-sided) teetotum was known to the ancient Greeks and Romans. A common gambling game with a teetotum played since medieval times is put and take, in which the various sides have symbols instructing the p...
spinner shark
...any of several species with dark fin tips. Two Atlantic species are the small blacktip (Carcharhinus limbatus), which grows to about 2.5 m, and the somewhat larger large blacktip, or spinner shark (C. maculipinnis). One small species, C. melanopterus, is found in shallow Indo-Pacific waters....
spinneret (zoology)
The silkworm caterpillar builds its cocoon by producing and surrounding itself with a long, continuous fibre, or filament. Liquid secretions from two large glands within the insect emerge from the spinneret, a single exit tube in the head, hardening upon exposure to air and forming twin filaments composed of fibroin, a protein material. A second pair of glands secretes sericin, a gummy......
spinneret (fibre manufacturing)
in the spinning of man-made fibre, small, thimble-shaped, metal nozzle having fine holes through which a spinning solution is forced to form a filament. The viscous or syrupy solution, prepared by melting or chemically dissolving raw material, emerges from the spinneret as long fibres that are then solidified by coagulation, evaporation, or cooling....
spinnerette (fibre manufacturing)
in the spinning of man-made fibre, small, thimble-shaped, metal nozzle having fine holes through which a spinning solution is forced to form a filament. The viscous or syrupy solution, prepared by melting or chemically dissolving raw material, emerges from the spinneret as long fibres that are then solidified by coagulation, evaporation, or cooling....
Spinney, Caroll (American actor and puppeteer)
...12 Sesame Street. A running character on the TV program, Big Bird debuted in 1969. Big Bird’s characteristics and mannerisms were created by actor and puppeteer Caroll Spinney, who at the program’s inception and for many years thereafter was the sole performer in the Big Bird role....
spinning (fishing)
Bait casting and spin casting differ essentially in the type of reel, the rod length, and the strength of the line used. Bait casting usually employs a reel with heavier line, often in the 10- to 20-pound (4,500- to 9,000-gram) test range. Most spinning reels are usually spooled with lighter lines in the 6- to 10-pound (2,700- to 4,500-gram) test class. Spinning rods are generally 6–10......
spinning (metalwork)
In metalwork, a technique for making hollow metal utensils and artifacts. Developed in the 19th century, the method can be used for most metals. A metal disk is set on a lathe behind an appropriately shaped metal or wooden chuck; while the lathe is rotating, the metal is pressed onto the chuck with a tool. A typical modern spun object is the aluminum saucepan....
spinning (yarn manufacturing)
in textiles, process of drawing out fibres from a mass and twisting them together to form a continuous thread or yarn. In man-made fibre production the name is applied to the extrusion of a solution to form a fibre, a process similar to the method by which silkworms and similar insect larvae produce filament to make their cocoons from a viscous fluid...
spinning frame (textiles)
Machine for drawing, twisting, and winding yarn. Invented in the 1730s by Lewis Paul and John Wyatt, the spinning machine operated by drawing cotton or wool through pairs of successively faster rollers. It was eventually superseded by R. Arkwright’s ...
spinning jenny (textiles)
Early multiple-spindle machine for spinning wool or cotton. The hand-powered spinning jenny was patented by James Hargreaves in 1770. The development of the spinning wheel into the spinning jenny was a significant factor in the industrialization of the textile industry, though its product was inferior to...
spinning mule (textiles)
Multiple-spindle spinning machine invented by Samuel Crompton (1779), which permitted large-scale manufacture of high-quality thread for the textile industry. Crompton’s machine made it possible for a single operator to work more than 1,000 spindles simultaneously, and was capable of spinning fine as well as coarse yarn....
spinning reel (fishing)
...spread the line evenly as it was wound. The next significant tackle development took place in 1905, when English textile magnate Holden Illingworth filed the first patent on the fixed-spool, or spinning, reel. In this kind of reel, the spool permanently faces toward the tip of the rod, and the line peels off during the cast. The increased casting distance afforded by the spinning......
spinning top (toy)
a toy having a body of conical, circular, or oval shape, often hollow, with a point or peg on which it turns or is made to whirl. If given a knock, a spinning top will go around in a circle at a slant; if spun with a slant at the start, it will quickly stand upright until halted by friction. Its physical properties are simi...
spinning tower (textiles)
In dry spinning, the solution of polymer is pushed through a spinnerette into a heated column called the spinning tower, where the solvent evaporates, leaving a fibre. The emerging fibre may contain solvent that may have to be removed by further heating or by washing. This operation is followed by stretching, application of finish, and either take-up on a spindle or cutting to staple....
spinning wheel (textiles)
early machine for turning fibre into thread or yarn, which was then woven into cloth on a loom. The spinning wheel was probably invented in India, though its origins are obscure. It reached Europe via the Middle East in the European Middle Ages. It replaced the earlier method of hand spinning, in which the individual fibres...
spinocerebellar degeneration (pathology)
Spinocerebellar degenerations are genetically determined conditions characterized by dysfunction of the dorsal columns or of the corticospinal and spinocerebellar tracts of the spinal cord. These conditions usually appear in the first 20 years of life and cause position sensation, gait, limb power, balance, and coordination disturbances. (For further discussion, see below The cerebellum:......
spinocerebellar tract (anatomy)
Impulses from stretch receptors are carried by fibres that synapse upon cells in deep laminae of the dorsal horn or in lamina VII. The posterior spinocerebellar tract arises from the dorsal nucleus of Clarke and ascends peripherally in the dorsal part of the lateral funiculus. The anterior spinocerebellar tract ascends on the ventral margin of the lateral funiculus. Both tracts transmit signals......
spinochrome (biochemistry)
...importance are the K vitamins. Another series within the naphthoquinone class manifests conspicuous red, purple, or sometimes green colours in a few animal types. These are the echinochromes and spinochromes, so named because they are conspicuous in tissues and in the calcareous tests (shells) of echinoids, or sea urchins....
spinodal mechanism (chemistry)
...more disordered glassy phases that eventually are quenched in as glass inside glass when the substance becomes rigid. Two distinct mechanisms of phase separation exist, the nucleated droplet and the spinodal; the microstructures produced by these two mechanisms, as revealed by electron microscopy, are shown in Figure 4. In Figure 4A the interfac...
Spinola, Ambrogio di Filippo, marqués de los Balbases (Spanish military officer)
an outstanding military commander in the service of Spain and one of the ablest soldiers of his time. Though he won fame in the wars against the Dutch Republic in the early 17th century, he was ultimately unable to break Dutch military power....
Spínola, António Sebastião Ribeiro de (president of Portugal)
Portuguese military officer who briefly served as his country’s president following the military coup that toppled dictator Marcelo Caetano and set Portugal on the road to democracy (b. April 11, 1910--d. Aug. 13, 1996)....
Spinola family (Italian family)
one of the noble families that dominated the history of Genoa, Italy, during the city-state’s great period, from the 12th to the 14th century....
Spinola, Oberto (Italian noble)
In 1270 Andrea’s grandson Oberto Doria (died 1295) and Oberto Spinola, member of another great Genoese family, inaugurated a series of two-man governments headed by their families, with dictatorial powers as captains of the people. Ruling for 15 years during what has been termed the golden age of the Genoese medieval commune, Oberto Doria was a hero of the decisive Battle of Meloria (1284)....
Spinone Italiano (breed of dog)
In 1270 Andrea’s grandson Oberto Doria (died 1295) and Oberto Spinola, member of another great Genoese family, inaugurated a series of two-man governments headed by their families, with dictatorial powers as captains of the people. Ruling for 15 years during what has been termed the golden age of the Genoese medieval commune, Oberto Doria was a hero of the decisive Battle of Meloria (1284)....
spinor (mathematics)
...of Benjamin Peirce of Harvard and exhibiting a subalgebra of the German mathematician Ferdinand Georg Frobenius. In 1912 Cartan became a professor at the Sorbonne, and a year later he discovered the spinors, complex vectors that are used to transform three-dimensional rotations into two-dimensional representations....
spinoreticular tract (anatomy)
...different pathways, the spinothalamic and spinoreticular tracts, transmit impulses to the brainstem and thalamus. Spinothalamic input is thought to effect the conscious sensation of pain, and the spinoreticular tract is thought to effect the arousal and emotional aspects of pain....
Spinosaurus (dinosaur)
a genus of theropod dinosaurs belonging to the family Spinosauridae, known from incomplete North African fossils that date to Cenomanian times (roughly 100 to 94 million years ago). Spinosaurus, or “spined reptile,” was named for its “sail-back” feature, created by tall...