Encyclopædia Britannica Australia -

Encyclopedias since 1768

0-9

introverted quatrain ... ion-exchange resin

introverted quatrain: a quatrain having an enclosed rhyme. An example of an introverted quatrain is the In Memoriam stanza (named for the poem by Alfred, Lord Tennyson), which has an abba rhyme scheme. An introverted stanza may also be called an envelope. ...
intuition: in philosophy, the power of obtaining knowledge that cannot be acquired either by inference or observation, by reason or experience. As such, intuition is thought of as an original, independent source of knowledge, since it is designed to account for ...
intuitionism: school of mathematical thought introduced by the 20th-century Dutch mathematician L.E.J. Brouwer that contends the primary objects of mathematical discourse are mental constructions governed by self-evident laws. Intuitionists have challenged many of the oldest principles of mathematics as being nonconstructive ...
intussusception: telescoping of a segment of the intestine into an adjacent segment, producing a mechanical obstruction of the alimentary canal. Primary intussusception is sometimes congenital and rarely appears later than the third year of life; it arises in the course of ...
Inugsuk culture: Eskimo culture that developed from the Thule culture (q.v.) in northern Greenland during the 12th and 13th centuries. It was distinguished by an increased dependence on hunting by means of a kayak (a one-man skin boat) and implements associated with ...
Inuit: the Eskimo (q.v.) of Canada and Greenland.
Inuit language: the northeastern division of the Eskimo languages, spoken in northern Alaska, Canada, and Greenland.
Inukai Tsuyoshi: Japanese politician and prime minister whose assassination marked the end of party participation in the Japanese government in the period preceding World War II.
inulin: polysaccharide that is a commercial source of the sugar fructose. It occurs in many plants of the family Asteraceae (Compositae), particularly in such roots and tubers as the dahlia and the Jerusalem artichoke. Inulin forms a white, crystalline powder that ...
inulin clearance: procedure by which the filtering capacity of the glomeruli (the main filtering structures of the kidney) is determined by measuring the rate at which inulin, the test substance, is cleared from blood plasma. Inulin is the most suitable and accurate ...
Inuvik: northwestern region of the Northwest Territories, Canada. Inuvik region was created in the early 1970s by the territorial government and was formerly part of Mackenzie and Franklin districts. It extends from Wrigley northward along the middle reaches of the Mackenzie ...
Inuvik: town, Inuvik region, Northwest Territories, Canada. It lies along the East Channel of the Mackenzie River delta, just east of the northernmost point of the Yukon. Planned as a model community by the Canadian government, with an Inuit (Eskimo) name ...
Invar: alloy of iron that expands very little when heated; it contains 64 percent iron and 36 percent nickel. Invar was formerly used for absolute standards of length measurement and is now used for surveying tapes and in watches and various ...
invention: in music, any of a number of markedly dissimilar compositional forms dating from the 16th century to the present. While its exact meaning has never been defined, the term has often been affixed to compositions of a novel, progressive character-i.e., ...
inventory: in business, any item of property held in stock by a firm, including finished goods ready for sale, goods in the process of production, raw materials, and goods that will be consumed in the process of producing goods to be ...
Inveraray: royal burgh (town), Argyll and Bute council area, historic county of Argyllshire, Scotland, on Loch Fyne on the Atlantic coast near the mouth of the River Aray. It was made a royal burgh in 1648. Inveraray was the ancestral seat ...
Invercargill: city, Southland local government region, South Island, New Zealand. The city lies along the Waihopai River near its confluence with the New River estuary and is the southernmost city of South Island. The surrounding area was bought from the Maoris ...
Inverclyde: council area, west-central Scotland, lying entirely within the historic county of Renfrewshire. Inverclyde extends along the River Clyde and the Firth of Clyde on the north and encompasses an area of hills and valleys to the south. Its economy historically ...
Inverell: town, northeastern New South Wales, Australia, at the junction of the Swanbrook and Macintyre rivers in the Western Slopes district. Established in 1848 as a stock station, it was declared a town in 1858 and a municipality in 1872, when ...
Invergordon: small North Sea port, Highland council area, historic county of Ross-shire, historic region of Ross and Cromarty, Scotland, on the deep sheltered waters of the Cromarty Firth. Situated on one of the deepest and safest harbours in Great Britain, Invergordon ...
Inverness: royal burgh (town), Highland council area, historic county of Inverness-shire, Scotland. It is the long-established centre of the Highlands and lies at the best crossing place of the River Ness, which flows from Loch Ness at the east end of ...
Inverness-shire: historic county of northern Scotland. It is Scotland's largest historic county and includes a section of the central Highlands, Glen Mor, and a portion of the Highlands to the north. It also encompasses several islands of the Inner and Outer ...
inversion: in music, rearrangement of the top-to-bottom elements in an interval, a chord, a melody, or a group of contrapuntal lines of music. The inversion of chords and intervals is utilized for various purposes, e.g., to create a melodic bass line ...
inversion: in literary style and rhetoric, the syntactic reversal of the normal order of the words and phrases in a sentence, as, in English, the placing of an adjective after the noun it modifies ("the form divine"), a verb before its ...
inversion: in chemistry, the spatial rearrangement of atoms or groups of atoms in a dissymmetric molecule, giving rise to a product with a molecular configuration that is a mirror image of that of the original molecule.
invertebrate: any animal that lacks a vertebral column, or backbone, in contrast to vertebrates, all of which possess some form of cartilaginous or bony internal skeleton. More than 90 percent of living animals are invertebrates. Worldwide in distribution, they range in ...
Investigator Strait: channel, about 60 mi (100 km) long and nearly 30 mi wide, between Yorke Peninsula to the north and Kangaroo Island to the south, leading eastward from the Indian Ocean into Gulf St. Vincent, South Australia. It merges (east) with ...
Investiture Controversy: conflict during the late 11th and the early 12th century involving the monarchies of what would later be called the Holy Roman Empire (the union of Germany, Burgundy, and much of Italy; see Researcher's Note), France, and England on the ...
investment: process of exchanging income during one period of time for an asset that is expected to produce earnings in future periods. Thus, consumption in the current period is foregone in order to obtain a greater return in the future.
investment bank: firm that originates, underwrites, and distributes new security issues of corporations and government agencies. Unlike a savings bank, an investment bank is a commercial bank that does not accept deposits. The investment (or merchant) banking house operates by purchasing all ...
investment casting: precision-casting technique for forming metal shapes. A typical process for bronze castings involves six steps:
investment credit: tax incentive that permits businesses to deduct a specified percentage of certain investment costs from their tax liability, in addition to the normal allowances for depreciation (q.v.). Investment credits are similar to investment allowances, which permit businesses to deduct a ...
investment trust: financial organization that pools the funds of its shareholders and invests them in a diversified portfolio of securities. It differs from the mutual fund, or unit trust, which issues units representing the diversified holdings rather than shares in the company ...
invisible trade: in economics, the exchange of physically intangible items between countries. Invisible trade can be distinguished from visible trade, which involves the export, import, and reexport of physically tangible goods. Basic categories of invisible trade include services (receipts and payments arising ...
invocation: a convention of classical literature and of epics in particular, in which an appeal for aid (especially for inspiration) is made to a muse or deity, usually at or near the beginning of the work. Homer's Odyssey, for instance, beginsTell ...
inyoite: a colourless and transparent borate mineral (CaB₃O₃(OH)₅·4H₂O) that occurs as massive granular or sperulitic aggregates in borate deposits. The structure of the mineral consists of two BO₂(OH)₂ tetrahedrons and a BO₂OH triangle linked by calcium and hydroxyl-hydrogen bonds. Inyoite alters ...
Io: in Greek mythology, daughter of Inachus, the river god of Argos. Under the name of Callithyia, Io was regarded as the first priestess of Hera, the wife of Zeus. Zeus fell in love with her and, to protect her from ...
Io: innermost of the four large moons (Galilean satellites) discovered around Jupiter by the Italian astronomer Galileo in 1610. It was probably also discovered independently that same year by the German astronomer Simon Marius, who named it after Io of Greek ...
Ioannina: city and capital, nomos (department) of Ioannina, in the Epirus (Ipiros) region of northwestern Greece. It is located on a plateau on the western side of Lake Ioannina (ancient Pambotis), facing the gray limestone mass of Mount Mitsikeli.
iodine: (I), chemical element, a member of the halogen elements, or Group VIIa of the periodic table.
iodine deficiency: condition in which iodine is insufficient or is not utilized properly. Iodine is an element that directly affects thyroid gland secretions, which themselves to a great extent control heart action, nerve response to stimuli, rate of body growth, and metabolism.
iodine value: in analytical chemistry, measure of the degree of unsaturation of an oil, fat, or wax; the amount of iodine, in grams, that is taken up by 100 grams of the oil, fat, or wax. Saturated oils, fats, and waxes take ...
iodized salt: table salt with small amounts of iodine added, usually as potassium iodide, to ensure against dietary deficiency of iodine. Where iodized salt is used, particularly in Switzerland and the United States, endemic goitre has disappeared.
iodoform: a yellow, crystalline solid belonging to the family of organic halogen compounds, used as an antiseptic component of medications for minor skin diseases.
Iol: ancient seaport of Mauretania, located west of what is now Algiers in Algeria. Iol was originally founded as a Carthaginian trading station, but it was later renamed Caesarea and became the capital of Mauretania in 25 BC. The city was ...
Iolaus: ancient Greek hero, the nephew, charioteer, and assistant of Heracles. He was the son of Iphicles, himself mortal half brother of Heracles by the same mother.
ion: any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions, anions. Ions are formed by the addition of electrons to, or the removal of electrons ...
ion pair: in physics and chemistry, a duplex of charged particles (ordinarily charged atoms or molecules), one positive, the other negative. An ion pair, for the physicist, is the positively charged particle (positive ion) and the negatively charged particle (negative ion) simultaneously ...
ion-exchange capacity: measure of the ability of an insoluble material to undergo displacement of ions previously attached and loosely incorporated into its structure by oppositely charged ions present in the surrounding solution. Zeolite minerals used in water softening, for example, have a ...
ion-exchange reaction: any of a class of chemical reactions between two substances (each consisting of positively and negatively charged species called ions) that involves an exchange of one or more ionic components.
ion-exchange resin: any of a wide variety of organic compounds synthetically polymerized and containing positively or negatively charged sites that can attract an ion of opposite charge from a surrounding solution. The resins commonly consist of a styrene-divinylbenzene copolymer (high molecular weight ...