Despite the various English dialects spoken from country to country and within different regions of the same country, there are only slight regional variations in English orthography , the two most notable variations being British and American spelling. Many of the differences between American and British or Commonwealth English date back to a time before spelling standards were developed. For instance, some spellings seen as "American" today were once commonly used in Britain, and some spellings seen as "British" were once commonly used in the United States.
161-429: A tire ( British spelling : tyre ) is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on
322-434: A body-centered cubic (bcc) crystal structure . As it cools further to 1394 °C, it changes to its γ-iron allotrope, a face-centered cubic (fcc) crystal structure, or austenite . At 912 °C and below, the crystal structure again becomes the bcc α-iron allotrope. The physical properties of iron at very high pressures and temperatures have also been studied extensively, because of their relevance to theories about
483-430: A nuclear spin (− 1 ⁄ 2 ). The nuclide Fe theoretically can undergo double electron capture to Cr, but the process has never been observed and only a lower limit on the half-life of 4.4×10 years has been established. Fe is an extinct radionuclide of long half-life (2.6 million years). It is not found on Earth, but its ultimate decay product is its granddaughter, the stable nuclide Ni . Much of
644-499: A supernova for their formation, involving rapid neutron capture by starting Fe nuclei. In the far future of the universe, assuming that proton decay does not occur, cold fusion occurring via quantum tunnelling would cause the light nuclei in ordinary matter to fuse into Fe nuclei. Fission and alpha-particle emission would then make heavy nuclei decay into iron, converting all stellar-mass objects to cold spheres of pure iron. Iron's abundance in rocky planets like Earth
805-439: A wheelwright , would cause the tire to expand by heating it in a forge fire, placing it over the wheel, and quenching it, causing the metal to contract back to its original size to fit tightly on the wheel. The first patent for what appears to be a standard pneumatic tire appeared in 1847 and was lodged by Scottish inventor Robert William Thomson . However, this idea never went into production. The first practical pneumatic tire
966-490: A 1968 article in an influential American magazine, Consumer Reports , highlighting the superiority of radial construction. The US tire industry lost its market share to Japanese and European manufacturers, which bought out US companies. Tires may be classified according to the type of vehicle they serve. They may be distinguished by the load they carry and by their application, e.g. to a motor vehicle, aircraft, or bicycle. Light-duty tires for passenger vehicles carry loads in
1127-629: A bias tire are many, including longer tread life, better steering control, lower rolling resistance , improved fuel economy, more uniform wear, higher heat resistance, fewer blowouts, and a steadier, more comfortable ride at speed. Disadvantages, besides a higher cost than that of bias tires, are a harder ride at low speeds and generally worse performance on rough terrain. Radial tires are also seldom seen in diameters of greater than 42 inches, as such tires are difficult to make. Bias tire (bias-ply, or cross-ply) construction utilizes body ply cords that extend diagonally from bead to bead, usually at angles in
1288-767: A body. The tread provides traction while the body provides containment for a quantity of compressed air . Before rubber was developed, tires were metal bands fitted around wooden wheels to hold the wheel together under load and to prevent wear and tear. Early rubber tires were solid (not pneumatic). Pneumatic tires are used on many vehicles, including cars , bicycles , motorcycles , buses , trucks , heavy equipment , and aircraft . Metal tires are used on locomotives and railcars , and solid rubber (or other polymers) tires are also used in various non-automotive applications, such as casters , carts , lawnmowers , and wheelbarrows . Unmaintained tires can lead to severe hazards for vehicles and people, ranging from flat tires making
1449-691: A consonant followed by an unstressed -re (pronounced /ə(r)/ ). In modern American English, most of these words have the ending -er . The difference is most common for words ending in -bre or -tre : British spellings calibre , centre , fibre , goitre , litre , lustre , manoeuvre , meagre , metre (length) , mitre , nitre , ochre , reconnoitre , sabre , saltpetre , sepulchre , sombre , spectre , theatre (see exceptions ) and titre all have -er in American spelling. In Britain, both -re and -er spellings were common before Johnson's 1755 dictionary
1610-475: A distinctive set of Canadian English spellings is viewed by many Canadians as one of the unique aspects of Canadian culture (especially when compared to the United States). In Australia, -or endings enjoyed some use throughout the 19th century and in the early 20th century. Like Canada, though, most major Australian newspapers have switched from " -or " endings to " -our " endings. The " -our " spelling
1771-454: A distorted sodium chloride structure. The binary ferrous and ferric halides are well-known. The ferrous halides typically arise from treating iron metal with the corresponding hydrohalic acid to give the corresponding hydrated salts. Iron reacts with fluorine, chlorine, and bromine to give the corresponding ferric halides, ferric chloride being the most common. Ferric iodide is an exception, being thermodynamically unstable due to
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#17327719728531932-495: A emium , and a enigma . In others, it is kept in all varieties: for example, phoenix , and usually subpoena , but Phenix in Virginia . This is especially true of names: Aegean (the sea), Caesar , Oedipus , Phoebe , etc., although "caesarean section" may be spelled as "cesarean section". There is no reduction of Latin -ae plurals (e.g., larv ae ); nor where the digraph <ae>/<oe> does not result from
2093-466: A eon , an a emia , an a esthesia , c a ecum , c a esium , c o eliac , diarrh o ea , encyclop a edia , f a eces , f o etal , gyn a ecology , h a emoglobin , h a emophilia , leuk a emia , o esophagus , o estrogen , orthop a edic , pal a eontology , p a ediatric , p a edophile . Oenology is acceptable in American English but is deemed
2254-553: A macroscopic piece of iron will have a nearly zero overall magnetic field. Application of an external magnetic field causes the domains that are magnetized in the same general direction to grow at the expense of adjacent ones that point in other directions, reinforcing the external field. This effect is exploited in devices that need to channel magnetic fields to fulfill design function, such as electrical transformers , magnetic recording heads, and electric motors . Impurities, lattice defects , or grain and particle boundaries can "pin"
2415-532: A minor variant of enology , whereas although archeology and ameba exist in American English, the British versions amoeba and archaeology are more common. The chemical haem (named as a shortening of h a emoglobin ) is spelled heme in American English, to avoid confusion with hem . Canadian English mostly follows American English in this respect, although it is split on gynecology (e.g. Society of Obstetricians and Gynaecologists of Canada vs.
2576-569: A mistaken etymology. The etymologically correct original spelling fetus reflects the Latin original and is the standard spelling in medical journals worldwide; the Oxford English Dictionary notes that "In Latin manuscripts both fētus and foetus are used". The Ancient Greek diphthongs <αι> and <οι> were transliterated into Latin as <ae> and <oe>. The ligatures æ and œ were introduced when
2737-475: A mixture of O 2 /Ar. Iron(IV) is a common intermediate in many biochemical oxidation reactions. Numerous organoiron compounds contain formal oxidation states of +1, 0, −1, or even −2. The oxidation states and other bonding properties are often assessed using the technique of Mössbauer spectroscopy . Many mixed valence compounds contain both iron(II) and iron(III) centers, such as magnetite and Prussian blue ( Fe 4 (Fe[CN] 6 ) 3 ). The latter
2898-471: A result, mercury is traded in standardized 76 pound flasks (34 kg) made of iron. Iron is by far the most reactive element in its group; it is pyrophoric when finely divided and dissolves easily in dilute acids, giving Fe . However, it does not react with concentrated nitric acid and other oxidizing acids due to the formation of an impervious oxide layer, which can nevertheless react with hydrochloric acid . High-purity iron, called electrolytic iron ,
3059-532: A result, modern English orthography varies only minimally between countries and is far from phonemic in any country. In the early 18th century, English spelling was inconsistent. These differences became noticeable after the publication of influential dictionaries . Today's British English spellings mostly follow Johnson's A Dictionary of the English Language (1755), while many American English spellings follow Webster's An American Dictionary of
3220-477: A separate inner tube . Semi-pneumatic tires have a hollow center, but they are not pressurized. They are lightweight, low-cost, puncture-proof, and provide cushioning. These tires often come as a complete assembly with the wheel and even integral ball bearings . They are used on lawn mowers , wheelchairs , and wheelbarrows . They can also be rugged, typically used in industrial applications, and are designed to not pull off their rim under use. An airless tire
3381-667: A suffix for agentive ( reader , user , winner ) and comparative ( louder , nicer ) forms. One outcome is the British distinction of meter for a measuring instrument from metre for the unit of length. However, while " poetic metre " is often spelled as -re , pentameter , hexameter , etc. are always -er . Many other words have -er in British English. These include Germanic words, such as anger , mother , timber and water , and such Romance-derived words as danger , quarter and river . The ending -cre , as in acre , lucre , massacre , and mediocre ,
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#17327719728533542-439: A system of circumferential grooves, lateral sipes, and slots for road tires or a system of lugs and voids for tires designed for soft terrain or snow. Grooves run circumferentially around the tire and are needed to channel away water. Lugs are that portion of the tread design that contacts the road surface. Grooves, sipes, and slots allow tires to evacuate water. The design of treads and the interaction of specific tire types with
3703-523: A thin layer of brass, various additives will also be added to the rubber to improve binding, such as resorcinol / HMMM mixtures. The elastomer, which forms the tread and encases the cords to protect them from abrasion and hold them in place, is a key component of pneumatic tire design. It can be composed of various composites of rubber material – the most common being styrene-butadiene copolymer – with other chemical compounds such as silica and carbon black . Optimizing rolling resistance in
3864-455: A type of rock consisting of repeated thin layers of iron oxides alternating with bands of iron-poor shale and chert . The banded iron formations were laid down in the time between 3,700 million years ago and 1,800 million years ago . Materials containing finely ground iron(III) oxides or oxide-hydroxides, such as ochre , have been used as yellow, red, and brown pigments since pre-historical times. They contribute as well to
4025-505: A variety of profiles and carry loads in the range of 4,000 to 5,500 pounds (1,800 to 2,500 kg) on the drive wheel. These are typically mounted in tandem on the drive axle. Aircraft, bicycles, and a variety of industrial applications have distinct design requirements. Tire construction spans pneumatic tires used on cars, trucks, and aircraft, but also includes non-automotive applications with slow-moving, light-duty, or railroad applications, which may have non-pneumatic tires. Following
4186-435: A very large coordination and organometallic chemistry : indeed, it was the discovery of an iron compound, ferrocene , that revolutionalized the latter field in the 1950s. Iron is sometimes considered as a prototype for the entire block of transition metals, due to its abundance and the immense role it has played in the technological progress of humanity. Its 26 electrons are arranged in the configuration [Ar]3d 4s , of which
4347-683: A whole, providing the main advantage of this construction, better traction and smoother motion on uneven surfaces, with a greater tendency to conform to rocky ground and throw off mud and clay, especially because the rubber is usually of a softer compound than that used on radial tires. However, this conformity increases a bias tire's rolling resistance, and its stiffness allows less control, traction , and comfort at higher speeds, while shear between its overlapping plies causes friction that generates heat. Still, bias tires benefit from simpler structure and so cost less than like-size radials, and they remain in use on heavy equipment and off-road vehicles, although
4508-432: Is - /s/ for the noun and - /z/ for the verb). For licence / license or practice / practise , British English also keeps the noun–verb distinction graphically (although phonetically the two words in each pair are homophones with - /s/ pronunciation). On the other hand, American English uses license and practice for both nouns and verbs (with - /s/ pronunciation in both cases too). American English has kept
4669-823: Is a chemical element ; it has the symbol Fe (from Latin ferrum 'iron') and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table . It is, by mass, the most common element on Earth , forming much of Earth's outer and inner core . It is the fourth most abundant element in the Earth's crust , being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching 1,500 °C (2,730 °F), about 500 °C (932 °F) higher than that required to smelt copper . Humans started to master that process in Eurasia during
4830-557: Is a non-pneumatic tire that is not supported by air pressure. They are most commonly used on small vehicles, such as golf carts, and on utility vehicles in situations where the risk of puncture is high, such as on construction equipment. Many tires used in industrial and commercial applications are non-pneumatic, and are manufactured from solid rubber and plastic compounds via molding operations. Solid tires include those used for lawnmowers, skateboards, golf carts, scooters , and many types of light industrial vehicles, carts, and trailers. One of
4991-429: Is a term used for a tire that failed inspection during manufacturing - but only for superficial/cosmetic/aesthetic reasons. For example, a tire with white painted lettering which is smudged or incomplete might be classified as a "blem". Blem tires are fully functional and generally carry the same warranty as flawless tires - but are sold at a discount. The materials of modern pneumatic tires can be divided into two groups,
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5152-675: Is almost identical to British spelling, except in the word fiord (instead of fjord ) . There is an increasing use of macrons in words that originated in Māori and an unambiguous preference for -ise endings (see below). Most words ending in an unstressed ‑our in British English (e.g., behaviour , colour , favour , flavour , harbour , honour , humour , labour , neighbour , rumour , splendour ) end in ‑or in American English ( behavior , color , favor , flavor , harbor , honor , humor , labor , neighbor , rumor , splendor ). Wherever
5313-646: Is also rarely found in basalts that have formed from magmas that have come into contact with carbon-rich sedimentary rocks, which have reduced the oxygen fugacity sufficiently for iron to crystallize. This is known as telluric iron and is described from a few localities, such as Disko Island in West Greenland, Yakutia in Russia and Bühl in Germany. Ferropericlase (Mg,Fe)O , a solid solution of periclase (MgO) and wüstite (FeO), makes up about 20% of
5474-407: Is considered to be resistant to rust, due to its oxide layer. Iron forms various oxide and hydroxide compounds ; the most common are iron(II,III) oxide (Fe 3 O 4 ), and iron(III) oxide (Fe 2 O 3 ). Iron(II) oxide also exists, though it is unstable at room temperature. Despite their names, they are actually all non-stoichiometric compounds whose compositions may vary. These oxides are
5635-399: Is dropped for other derivations, for example, central , fibrous , spectral . However, the existence of related words without e before the r is not proof for the existence of an -re British spelling: for example, entry and entrance come from enter , which has not been spelled entre for centuries. The difference relates only to root words; -er rather than -re is universal as
5796-499: Is due to its abundant production during the runaway fusion and explosion of type Ia supernovae , which scatters the iron into space. Metallic or native iron is rarely found on the surface of the Earth because it tends to oxidize. However, both the Earth's inner and outer core , which together account for 35% of the mass of the whole Earth, are believed to consist largely of an iron alloy, possibly with nickel . Electric currents in
5957-474: Is experimentally well defined for pressures less than 50 GPa. For greater pressures, published data (as of 2007) still varies by tens of gigapascals and over a thousand kelvin. Below its Curie point of 770 °C (1,420 °F; 1,040 K), α-iron changes from paramagnetic to ferromagnetic : the spins of the two unpaired electrons in each atom generally align with the spins of its neighbors, creating an overall magnetic field . This happens because
6118-502: Is generally preferred over oe and often over ae , but oe and ae are sometimes found in academic and scientific writing as well as government publications (for example, the fee schedule of the Ontario Health Insurance Plan ) and some words such as palaeontology or aeon . In Australia, it can go either way, depending on the word: for instance, medieval is spelled with the e rather than ae , following
6279-443: Is in Earth's crust only amounts to about 5% of the overall mass of the crust and is thus only the fourth most abundant element in that layer (after oxygen , silicon , and aluminium ). Most of the iron in the crust is combined with various other elements to form many iron minerals . An important class is the iron oxide minerals such as hematite (Fe 2 O 3 ), magnetite (Fe 3 O 4 ), and siderite (FeCO 3 ), which are
6440-527: Is key in achieving safety and fuel efficiency in the transportation sector. The most common elastomer material used today is a styrene - butadiene copolymer. It combines the properties of polybutadiene , which is a highly rubbery polymer ( Tg = -100 °C) having high hysteresis and thus offering good wet grip properties, with the properties of polystyrene , which is a glassy polymer ( Tg = 100 °C) having low hysteresis and thus offering low rolling resistance in addition to wear resistance. Therefore,
6601-601: Is known as the Pacific Parlour car, not Pacific Parlor . Proper names such as Pearl Harbor or Sydney Harbour are usually spelled according to their native-variety spelling vocabulary. The name of the herb savory is spelled thus everywhere, although the related adjective savo(u)ry , like savo(u)r , has a u in the UK. Honor (the name) and arbor (the tool) have -or in Britain, as mentioned above, as does
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6762-618: Is largely rubber but reinforced with fabric or steel cords that provide for tensile strength and flexibility. The sidewall contains air pressure and transmits the torque applied by the drive axle to the tread to create traction but supports little of the weight of the vehicle, as is clear from the total collapse of the tire when punctured. Sidewalls are molded with manufacturer-specific detail, government-mandated warning labels, and other consumer information. Sidewall may also have sometimes decorative ornamentation that includes whitewall or red-line inserts as well as tire lettering . The shoulder
6923-401: Is not like that of Mn with its weak, spin-forbidden d–d bands, because Fe has higher positive charge and is more polarizing, lowering the energy of its ligand-to-metal charge transfer absorptions. Thus, all the above complexes are rather strongly colored, with the single exception of the hexaquo ion – and even that has a spectrum dominated by charge transfer in the near ultraviolet region. On
7084-407: Is possible, but nonetheless the sequence does effectively end at Ni because conditions in stellar interiors cause the competition between photodisintegration and the alpha process to favor photodisintegration around Ni. This Ni, which has a half-life of about 6 days, is created in quantity in these stars, but soon decays by two successive positron emissions within supernova decay products in
7245-495: Is predicted to reach 2,665 million tires by 2027. As of 2011, the top three tire manufacturing companies by revenue were Bridgestone (manufacturing 190 million tires), Michelin (184 million), Goodyear (181 million); they were followed by Continental , and Pirelli . The Lego group produced over 318 million toy tires in 2011 and was recognized by Guinness World Records as having the highest annual production of tires by any manufacturer. A tire comprises several components:
7406-613: Is sometimes used. The ratio between -ise and -ize stood at 3:2 in the British National Corpus up to 2002. The spelling -ise is more commonly used in UK mass media and newspapers, including The Times (which switched conventions in 1992), The Daily Telegraph , The Economist and the BBC . The Government of the United Kingdom additionally uses -ise , stating "do not use Americanisms" justifying that
7567-548: Is somewhat different). Pieces of magnetite with natural permanent magnetization ( lodestones ) provided the earliest compasses for navigation. Particles of magnetite were extensively used in magnetic recording media such as core memories , magnetic tapes , floppies , and disks , until they were replaced by cobalt -based materials. Iron has four stable isotopes : Fe (5.845% of natural iron), Fe (91.754%), Fe (2.119%) and Fe (0.282%). Twenty-four artificial isotopes have also been created. Of these stable isotopes, only Fe has
7728-714: Is standard worldwide and complection is rare. However, the adjective complected (as in "dark-complected"), although sometimes proscribed, is on equal ground in the U.S. with complexioned. It is not used in this way in the UK, although there exists a rare alternative meaning of complicated . In some cases, words with "old-fashioned" spellings are retained widely in the U.S. for historical reasons (cf. connexionalism ). Many words, especially medical words, that are written with ae/æ or oe/œ in British English are written with just an e in American English. The sounds in question are /iː/ or /ɛ/ (or, unstressed, /i/ , /ɪ/ or /ə/ ). Examples (with non-American letter in bold ):
7889-442: Is such a strong oxidizing agent that it oxidizes ammonia to nitrogen (N 2 ) and water to oxygen: The pale-violet hex aquo complex [Fe(H 2 O) 6 ] is an acid such that above pH 0 it is fully hydrolyzed: As pH rises above 0 the above yellow hydrolyzed species form and as it rises above 2–3, reddish-brown hydrous iron(III) oxide precipitates out of solution. Although Fe has a d configuration, its absorption spectrum
8050-502: Is supposed to have an orthorhombic or a double hcp structure. (Confusingly, the term "β-iron" is sometimes also used to refer to α-iron above its Curie point, when it changes from being ferromagnetic to paramagnetic, even though its crystal structure has not changed. ) The inner core of the Earth is generally presumed to consist of an iron- nickel alloy with ε (or β) structure. The melting and boiling points of iron, along with its enthalpy of atomization , are lower than those of
8211-607: Is taught in schools nationwide as part of the Australian curriculum. The most notable countrywide use of the -or ending is for one of the country's major political parties, the Australian Labor Party , which was originally called "the Australian Labour Party" (name adopted in 1908), but was frequently referred to as both "Labour" and "Labor". The "Labor" was adopted from 1912 onward due to
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#17327719728538372-434: Is that part of the tire at the edge of the tread as it makes the transition to the sidewall. Plies are layers of relatively inextensible cords embedded in the rubber to hold its shape by preventing the rubber from stretching in response to the internal pressure. The orientations of the plies play a large role in the performance of the tire and are one of the main ways that tires are categorized. Blem (short for "blemished")
8533-424: Is the part of the tire that contacts the rim on the wheel. This essential component is constructed with robust steel cables encased in durable, specially formulated rubber designed to resist stretching. The precision of the bead's fit is crucial, as it seals the tire against the wheel, maintaining air pressure integrity and preventing any loss of air. The bead's design ensures a secure, non-slip connection, preventing
8694-482: Is the usual form of the male given name, as a surname both the spellings Peter and Petre (the latter notably borne by a British lord ) are found. For British accoutre , the American practice varies: the Merriam-Webster Dictionary prefers the -re spelling, but The American Heritage Dictionary of the English Language prefers the -er spelling. More recent French loanwords keep
8855-418: Is thus very important economically, and iron is the cheapest metal, with a price of a few dollars per kilogram or pound. Pristine and smooth pure iron surfaces are a mirror-like silvery-gray. Iron reacts readily with oxygen and water to produce brown-to-black hydrated iron oxides , commonly known as rust . Unlike the oxides of some other metals that form passivating layers, rust occupies more volume than
9016-451: Is used as the traditional "blue" in blueprints . Iron is the first of the transition metals that cannot reach its group oxidation state of +8, although its heavier congeners ruthenium and osmium can, with ruthenium having more difficulty than osmium. Ruthenium exhibits an aqueous cationic chemistry in its low oxidation states similar to that of iron, but osmium does not, favoring high oxidation states in which it forms anionic complexes. In
9177-484: Is used in both British and American English to show that the c is pronounced /k/ rather than /s/ . The spellings euchre and ogre are also the same in both British and American English. Fire and its associated adjective fiery are the same in both British and American English, although the noun was spelled fier in Old and Middle English. Theater is the prevailing American spelling used to refer to both
9338-437: Is used in chemical actinometry and along with its sodium salt undergoes photoreduction applied in old-style photographic processes. The dihydrate of iron(II) oxalate has a polymeric structure with co-planar oxalate ions bridging between iron centres with the water of crystallisation located forming the caps of each octahedron, as illustrated below. Iron(III) complexes are quite similar to those of chromium (III) with
9499-591: The -meter suffix (from Ancient Greek - μέτρον métron , via French -mètre ) normally had the -re spelling from earliest use in English but were superseded by -er . Examples include thermometer and barometer . The e preceding the r is kept in American-inflected forms of nouns and verbs, for example, fibers , reconnoitered , centering , which are fibres , reconnoitred , and centring respectively in British English. According to
9660-560: The -ise form as an alternative. Publications by Oxford University Press (OUP)—such as Henry Watson Fowler 's A Dictionary of Modern English Usage , Hart's Rules , and The Oxford Guide to English Usage —also recommend -ize . However, Robert Allan's Pocket Fowler's Modern English Usage considers either spelling to be acceptable anywhere but the U.S. American spelling avoids -ise endings in words like organize , realize and recognize . British spelling mostly uses -ise ( organise , realise , recognise ), though -ize
9821-687: The -ise form is preferred in Australian English at a ratio of about 3:1 according to the Macquarie Dictionary . In Canada, the -ize ending is more common, although the Ontario Public School Spelling Book spelled most words in the -ize form, but allowed for duality with a page insert as late as the 1970s, noting that, although the -ize spelling was in fact the convention used in the OED ,
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#17327719728539982-439: The -ise variation, once more common amongst older Canadians, is employed less and less often in favour of the -ize spelling. (The alternate convention offered as a matter of choice may have been due to the fact that although there were an increasing number of American- and British-based dictionaries with Canadian Editions by the late 1970s, these were largely only supplemental in terms of vocabulary with subsequent definitions. It
10143-450: The -re spelling in American English. These are not exceptions when a French-style pronunciation is used ( /rə/ rather than /ə(r)/ ), as with double entendre , genre and oeuvre . However, the unstressed /ə(r)/ pronunciation of an -er ending is used more (or less) often with some words, including cadre , macabre , maître d' , Notre Dame , piastre , and timbre . The -re endings are mostly standard throughout
10304-568: The 2nd millennium BC and the use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event is considered the transition from the Bronze Age to the Iron Age . In the modern world , iron alloys, such as steel , stainless steel , cast iron and special steels , are by far the most common industrial metals, due to their mechanical properties and low cost. The iron and steel industry
10465-495: The Canadian Medical Association 's Canadian specialty profile of Obstetrics/gynecology ). Pediatrician is preferred roughly 10 to 1 over paediatrician , while foetal and oestrogen are similarly uncommon. Words that can be spelled either way in American English include a esthetics and arch a eology (which usually prevail over esthetics and archeology ), as well as pal a estra , for which
10626-548: The OED , centring is a "word ... of 3 syllables (in careful pronunciation)" (i.e., /ˈsɛntərɪŋ/ ), yet there is no vowel in the spelling corresponding to the second syllable ( /ə/ ). The OED third edition (revised entry of June 2016) allows either two or three syllables. On the Oxford Dictionaries Online website, the three-syllable version is listed only as the American pronunciation of centering . The e
10787-663: The Organisation for Economic Co-operation and Development ). The European Union 's style guides require the usage of - ise . Proofreaders at the EU's Publications Office ensure consistent spelling in official publications such as the Official Journal of the European Union (where legislation and other official documents are published), but the -ize spelling may be found in other documents. Iron Iron
10948-524: The radial tire method of construction. Michelin had bought the bankrupt Citroën automobile company in 1934 to utilize this new technology. Because of its superiority in handling and fuel economy, use of this technology quickly spread throughout Europe and Asia. In the US, the outdated bias-ply tire construction persisted until the Ford Motor Company adopted radial tires in the early 1970s, following
11109-432: The supernova remnant gas cloud, first to radioactive Co, and then to stable Fe. As such, iron is the most abundant element in the core of red giants , and is the most abundant metal in iron meteorites and in the dense metal cores of planets such as Earth . It is also very common in the universe, relative to other stable metals of approximately the same atomic weight . Iron is the sixth most abundant element in
11270-543: The theatre spelling. (The word "theater" in American English is a place where both stage performances and screenings of films take place, but in British English a "theatre" is where stage performances take place but not film screenings – these take place in a cinema, or "picture theatre" in Australia.) In the United States, the spelling theatre is sometimes used when referring to the art form of theatre, while
11431-491: The trans - chlorohydridobis(bis-1,2-(diphenylphosphino)ethane)iron(II) complex is used as a starting material for compounds with the Fe( dppe ) 2 moiety . The ferrioxalate ion with three oxalate ligands displays helical chirality with its two non-superposable geometries labelled Λ (lambda) for the left-handed screw axis and Δ (delta) for the right-handed screw axis, in line with IUPAC conventions. Potassium ferrioxalate
11592-519: The u has since been dropped: ambassadour , emperour , errour , governour , horrour , inferiour , mirrour , perturbatour , superiour , tenour , terrour , tremour . Johnson, unlike Webster, was not an advocate of spelling reform, but chose the spelling best derived, as he saw it, from among the variations in his sources. He preferred French over Latin spellings because, as he put it, "the French generally supplied us". English speakers who moved to
11753-435: The u : In American usage, derivatives and inflected forms are built by simply adding the suffix in all cases (for example, favorite , savory etc.) since the u is absent to begin with. American usage, in most cases, keeps the u in the word glamour , which comes from Scots , not Latin or French. Glamor is sometimes used in imitation of the spelling reform of other -our words to -or . Nevertheless,
11914-466: The universe , and the most common refractory element. Although a further tiny energy gain could be extracted by synthesizing Ni , which has a marginally higher binding energy than Fe, conditions in stars are unsuitable for this process. Element production in supernovas greatly favor iron over nickel, and in any case, Fe still has a lower mass per nucleon than Ni due to its higher fraction of lighter protons. Hence, elements heavier than iron require
12075-463: The vulcanization of natural rubber using sulfur, as well as the development of the "clincher" rim for holding the tire in place laterally on the wheel rim. Synthetic rubbers were invented in the laboratories of Bayer in the 1920s. Rubber shortages in the United Kingdom during WWII prompted research on alternatives to rubber tires with suggestions including leather, compressed asbestos, rayon, felt, bristles, and paper. In 1946, Michelin developed
12236-604: The ‑our/or group do not have a Latin counterpart that ends in ‑or ; for example, armo(u)r , behavio(u)r , harbo(u)r , neighbo(u)r ; also arbo(u)r , meaning "shelter", though senses "tree" and "tool" are always arbor , a false cognate of the other word. The word arbor would be more accurately spelled arber or arbre in the US and the UK, respectively, the latter of which is the French word for "tree". Some 16th- and early 17th-century British scholars indeed insisted that ‑or be used for words from Latin (e.g., color ) and ‑our for French loans; however, in many cases,
12397-418: The " Polyglas " trademark tire featuring a polyester carcass with belts of fiberglass. The "belted" tire starts two main plies of polyester, rayon, or nylon annealed as in conventional tires, and then placed on top are circumferential belts at different angles that improve performance compared to non-belted bias tires. The belts may be fiberglass or steel. Tubeless tires are pneumatic tires that do not require
12558-441: The 17th and 18th centuries, whereas there are thousands of examples of their -our counterparts. One notable exception is honor . Honor and honour were equally frequent in Britain until the 17th century; honor only exists in the UK now as the spelling of Honor Oak , a district of London, and of the occasional given name Honor . In derivatives and inflected forms of the -our/or words, British usage depends on
12719-549: The 1840s when the English began shrink-fitting railway car wheels with malleable iron. Nevertheless, many publishers continued using tire . The Times newspaper in London was still using tire as late as 1905. The spelling tyre began to be commonly used in the 19th century for pneumatic tires in the UK. The 1911 edition of the Encyclopædia Britannica states that "The spelling 'tyre' is not now accepted by
12880-477: The 1968 Consumer Reports announcement of the superiority of the radial design, radial tires began an inexorable climb in market share, reaching 100% of the North American market in the 1980s. Radial tire technology is now the standard design for essentially all automotive tires, but other methods have been used. Radial (or radial-ply) tire construction utilizes body ply cords extending straight across
13041-615: The 1970s, but had by then been overtaken by connection in regular usage (for example, in more popular newspapers). Connexion (and its derivatives connexional and connexionalism ) is still in use by the Methodist Church of Great Britain to refer to the whole church as opposed to its constituent districts, circuits and local churches, whereas the US-majority United Methodist Church uses Connection . Complexion (which comes from complex )
13202-570: The 3d and 4s electrons are relatively close in energy, and thus a number of electrons can be ionized. Iron forms compounds mainly in the oxidation states +2 ( iron(II) , "ferrous") and +3 ( iron(III) , "ferric"). Iron also occurs in higher oxidation states , e.g., the purple potassium ferrate (K 2 FeO 4 ), which contains iron in its +6 oxidation state. The anion [FeO 4 ] with iron in its +7 oxidation state, along with an iron(V)-peroxo isomer, has been detected by infrared spectroscopy at 4 K after cocondensation of laser-ablated Fe atoms with
13363-743: The American National Theatre was referred to by The New York Times as the "American National Theater ", but the organization uses "re" in the spelling of its name. The John F. Kennedy Center for the Performing Arts in Washington, D.C. has the more common American spelling theater in its references to the Eisenhower Theater, part of the Kennedy Center. Some cinemas outside New York also use
13524-413: The American usage along with numerous other words such as eon or fetus , while other words such as oestrogen or paediatrician are spelled the British way. The Macquarie Dictionary also notes a growing tendency towards replacing ae and oe with e worldwide and with the exception of manoeuvre, all British or American spellings are acceptable variants. Elsewhere, the British usage prevails, but
13685-587: The Anglo-French spelling for defense and offense , which are defence and offence in British English. Likewise, there are the American pretense and British pretence ; but derivatives such as defensive , offensive , and pretension are always thus spelled in both systems. Australian and Canadian usages generally follow British usage. The spelling connexion is now rare in everyday British usage, its use lessening as knowledge of Latin attenuates, and it has almost never been used in
13846-668: The British usage of -our . This coincided with a renewed interest in Canadian English, and the release of the updated Gage Canadian Dictionary in 1997 and the first Canadian Oxford Dictionary in 1998. Historically, most libraries and educational institutions in Canada have supported the use of the Oxford English Dictionary rather than the American Webster's Dictionary . Today, the use of
14007-471: The Commonwealth. The -er spellings are recognized as minor variants in Canada, partly due to United States influence. They are sometimes used in proper names (such as Toronto's controversially named Centerpoint Mall ). For advice / advise and device / devise , American English and British English both keep the noun–verb distinction both graphically and phonetically (where the pronunciation
14168-603: The Earth's surface. Items made of cold-worked meteoritic iron have been found in various archaeological sites dating from a time when iron smelting had not yet been developed; and the Inuit in Greenland have been reported to use iron from the Cape York meteorite for tools and hunting weapons. About 1 in 20 meteorites consist of the unique iron-nickel minerals taenite (35–80% iron) and kamacite (90–95% iron). Native iron
14329-607: The English Language ("ADEL", "Webster's Dictionary", 1828). Webster was a proponent of English spelling reform for reasons both philological and nationalistic. In A Companion to the American Revolution (2008), John Algeo notes: "it is often assumed that characteristically American spellings were invented by Noah Webster. He was very influential in popularizing certain spellings in the United States, but he did not originate them. Rather [...] he chose already existing options such as center, color and check for
14490-488: The Greek-style ligature as, for example, in maelstrom or toe ; the same is true for the British form aeroplane (compare other aero- words such as aerosol ) . The now chiefly North American airplane is not a respelling but a recoining, modelled after airship and aircraft . The word airplane dates from 1907, at which time the prefix aero- was trisyllabic, often written aëro- . In Canada, e
14651-518: The US: the more common connection has become the standard worldwide. According to the Oxford English Dictionary , the older spelling is more etymologically conservative, since the original Latin word had -xio- . The American usage comes from Webster , who abandoned -xion and preferred -ction . Connexion was still the house style of The Times of London until the 1980s and was still used by Post Office Telecommunications for its telephone services in
14812-575: The United Kingdom had little effect on today's American spellings and vice versa. For the most part, the spelling systems of most Commonwealth countries and Ireland closely resemble the British system. In Canada, the spelling system can be said to follow both British and American forms, and Canadians are somewhat more tolerant of foreign spellings when compared with other English-speaking nationalities. Australian English mostly follows British spelling norms but has strayed slightly, with some American spellings incorporated as standard. New Zealand English
14973-497: The United States took these preferences with them. In the early 20th century, H. L. Mencken notes that " honor appears in the 1776 Declaration of Independence , but it seems to have been put there rather by accident than by design". In Jefferson 's original draft it is spelled "honour". In Britain, examples of behavior , color , flavor , harbor , and neighbor rarely appear in Old Bailey court records from
15134-423: The United States use Centre in their names. Examples include the villages of Newton Centre and Rockville Centre , the city of Centreville , Centre County and Centre College . Sometimes, these places were named before spelling changes but more often the spelling serves as an affectation. Proper names are usually spelled according to their native-variety spelling vocabulary; so, for instance, although Peter
15295-617: The adjective glamorous often drops the first "u". Saviour is a somewhat common variant of savior in the US. The British spelling is very common for honour (and favour ) in the formal language of wedding invitations in the US. The name of the Space Shuttle Endeavour has a u in it because the spacecraft was named after British Captain James Cook 's ship, HMS Endeavour . The (former) special car on Amtrak 's Coast Starlight train
15456-542: The best English authorities, and is unrecognized in the US" , while Fowler's Modern English Usage of 1926 describes that "there is nothing to be said for 'tyre', which is etymologically wrong, as well as needlessly divergent from our own [sc. British] older & the present American usage". However, over the 20th century, tyre became established as the standard British spelling. The earliest tires were bands of leather , then iron (later steel ) placed on wooden wheels used on carts and wagons . A skilled worker, known as
15617-450: The brown deposits present in a sizeable number of streams. Due to its electronic structure, iron has a very large coordination and organometallic chemistry. Many coordination compounds of iron are known. A typical six-coordinate anion is hexachloroferrate(III), [FeCl 6 ] , found in the mixed salt tetrakis(methylammonium) hexachloroferrate(III) chloride . Complexes with multiple bidentate ligands have geometric isomers . For example,
15778-518: The building itself, as noted above, generally is spelled theater . For example, the University of Wisconsin–Madison has a "Department of Theatre and Drama", which offers courses that lead to the "Bachelor of Arts in Theatre ", and whose professed aim is "to prepare our graduate students for successful 21st Century careers in the theatre both as practitioners and scholars". Some placenames in
15939-456: The choice to spell such words in the -ise form was a matter of personal preference ; however, a pupil having made the decision, one way or the other, thereafter ought to write uniformly not only for a given word, but to apply that same uniformity consistently for all words where the option is found. Just as with -yze spellings, however, in Canada the ize form remains the preferred or more common spelling, though both can still be found, yet
16100-426: The close historic, economic, and cultural relationship with the United States, -or endings are also sometimes used. Throughout the late 19th and early to mid-20th century, most Canadian newspapers chose to use the American usage of -or endings, originally to save time and money in the era of manual movable type . However, in the 1990s, the majority of Canadian newspapers officially updated their spelling policies to
16261-661: The color of various rocks and clays , including entire geological formations like the Painted Hills in Oregon and the Buntsandstein ("colored sandstone", British Bunter ). Through Eisensandstein (a jurassic 'iron sandstone', e.g. from Donzdorf in Germany) and Bath stone in the UK, iron compounds are responsible for the yellowish color of many historical buildings and sculptures. The proverbial red color of
16422-448: The compacted snow to improve braking and cornering performance. Wear bars (or wear indicators) are raised features located at the bottom of the tread grooves that indicate the tire has reached its wear limit. When the tread lugs are worn to the point that the wear bars connect across the lugs, the tires are fully worn and should be taken out of service, typically at a remaining tread depth of 1.6 millimetres (0.063 in). The tire bead
16583-416: The cords that make up the ply and the elastomer which encases them. The cords, which form the ply and bead and provide the tensile strength necessary to contain the inflation pressure, can be composed of steel , natural fibers such as cotton or silk , or synthetic fibers such as nylon or kevlar . Good adhesion between the cords and the rubber is important. To achieve this the steel cords are coated in
16744-464: The cores of the Earth and other planets. Above approximately 10 GPa and temperatures of a few hundred kelvin or less, α-iron changes into another hexagonal close-packed (hcp) structure, which is also known as ε-iron . The higher-temperature γ-phase also changes into ε-iron, but does so at higher pressure. Some controversial experimental evidence exists for a stable β phase at pressures above 50 GPa and temperatures of at least 1500 K. It
16905-401: The domains in the new positions, so that the effect persists even after the external field is removed – thus turning the iron object into a (permanent) magnet . Similar behavior is exhibited by some iron compounds, such as the ferrites including the mineral magnetite , a crystalline form of the mixed iron(II,III) oxide Fe 3 O 4 (although the atomic-scale mechanism, ferrimagnetism ,
17066-403: The dramatic arts and buildings where stage performances and screenings of films take place (i.e., " movie theaters "); for example, a national newspaper such as The New York Times would use theater in its entertainment section. However, the spelling theatre appears in the names of many New York City theatres on Broadway (cf. Broadway theatre) and elsewhere in the United States. In 2003,
17227-479: The earlier 3d elements from scandium to chromium , showing the lessened contribution of the 3d electrons to metallic bonding as they are attracted more and more into the inert core by the nucleus; however, they are higher than the values for the previous element manganese because that element has a half-filled 3d sub-shell and consequently its d-electrons are not easily delocalized. This same trend appears for ruthenium but not osmium . The melting point of iron
17388-399: The earthmoving market has shifted to radials. A belted bias tire starts with two or more bias plies to which stabilizer belts are bonded directly beneath the tread. This construction provides a smoother ride that is similar to the bias tire, while lessening rolling resistance because the belts increase tread stiffness. The design was introduced by Armstrong, while Goodyear made it popular with
17549-420: The elastomer material is a key challenge for reducing fuel consumption in the transportation sector. It is estimated that passenger vehicles consume approximately 5~15% of their fuel to overcome rolling resistance, while the estimate is understood to be higher for heavy trucks. However, there is a trade-off between rolling resistance and wet traction and grip: while low rolling resistance can be achieved by reducing
17710-715: The ending became ‑our to match the later Old French spelling. The ‑our ending was used not only in new English borrowings, but was also applied to the earlier borrowings that had used ‑or . However, ‑or was still sometimes found. The first three folios of Shakespeare 's plays used both spellings before they were standardised to ‑our in the Fourth Folio of 1685. After the Renaissance , new borrowings from Latin were taken up with their original ‑or ending, and many words once ending in ‑our (for example, chancellour and governour ) reverted to ‑or . A few words of
17871-499: The environment. Moreover, the regular use of tires produces micro-plastic particles that contain these chemicals that both enter the environment and affect human health. The word tire is a short form of attire , from the idea that a wheel with a tire is a dressed wheel. Tyre is the oldest spelling, and both tyre and tire were used during the 15th and 16th centuries. During the 17th and 18th centuries, tire became more common in print. The spelling tyre did not reappear until
18032-406: The etymology was not clear, and therefore some scholars advocated ‑or only and others ‑our only. Webster's 1828 dictionary had only -or and is given much of the credit for the adoption of this form in the United States. By contrast, Johnson's 1755 (pre-U.S. independence and establishment) dictionary used -our for all words still so spelled in Britain (like colour ), but also for words where
18193-406: The exception of iron(III)'s preference for O -donor instead of N -donor ligands. The latter tend to be rather more unstable than iron(II) complexes and often dissociate in water. Many Fe–O complexes show intense colors and are used as tests for phenols or enols . For example, in the ferric chloride test , used to determine the presence of phenols, iron(III) chloride reacts with a phenol to form
18354-484: The first pneumatic tires. Cyclist Willie Hume demonstrated the supremacy of Dunlop's tires in 1889, winning the tire's first-ever races in Ireland and then England. In Dunlop's tire patent specification dated 31 October 1888, his interest is only in its use in cycles and light vehicles. In September 1890, he was made aware of an earlier development, but the company kept the information to itself. In 1892, Dunlop's patent
18515-462: The global stock of iron in use in society is 2,200 kg per capita. More-developed countries differ in this respect from less-developed countries (7,000–14,000 vs 2,000 kg per capita). Ocean science demonstrated the role of the iron in the ancient seas in both marine biota and climate. Iron shows the characteristic chemical properties of the transition metals , namely the ability to form variable oxidation states differing by steps of one and
18676-682: The grooves to escape sideways and mitigate hydroplaning . Different tread designs address a variety of driving conditions. As the ratio of tire tread area to groove area increases, so does tire friction on dry pavement, as seen on Formula One tires , some of which have no grooves. High-performance tires often have smaller void areas to provide more rubber in contact with the road for higher traction, but may be compounded with softer rubber that provides better traction, but wears quickly. Mud and snow (M&S) tires employ larger and deeper slots to engage mud and snow. Snow tires have still larger and deeper slots that compact snow and create shear strength within
18837-685: The influence of the American labor movement and King O'Malley . On top of that, some place names in South Australia such as Victor Harbor , Franklin Harbor or Outer Harbor are usually spelled with the -or spellings. Aside from that, -our is now almost universal in Australia but the -or endings remain a minority variant. New Zealand English , while sharing some words and syntax with Australian English , follows British usage. In British English, some words from French, Latin or Greek end with
18998-453: The liquid outer core are believed to be the origin of the Earth's magnetic field . The other terrestrial planets ( Mercury , Venus , and Mars ) as well as the Moon are believed to have a metallic core consisting mostly of iron. The M-type asteroids are also believed to be partly or mostly made of metallic iron alloy. The rare iron meteorites are the main form of natural metallic iron on
19159-446: The literature, this mineral phase of the lower mantle is also often called magnesiowüstite. Silicate perovskite may form up to 93% of the lower mantle, and the magnesium iron form, (Mg,Fe)SiO 3 , is considered to be the most abundant mineral in the Earth, making up 38% of its volume. While iron is the most abundant element on Earth, most of this iron is concentrated in the inner and outer cores. The fraction of iron that
19320-407: The major ores of iron . Many igneous rocks also contain the sulfide minerals pyrrhotite and pentlandite . During weathering , iron tends to leach from sulfide deposits as the sulfate and from silicate deposits as the bicarbonate. Both of these are oxidized in aqueous solution and precipitate in even mildly elevated pH as iron(III) oxide . Large deposits of iron are banded iron formations ,
19481-775: The metal and thus flakes off, exposing more fresh surfaces for corrosion. Chemically, the most common oxidation states of iron are iron(II) and iron(III) . Iron shares many properties of other transition metals, including the other group 8 elements , ruthenium and osmium . Iron forms compounds in a wide range of oxidation states , −4 to +7. Iron also forms many coordination compounds ; some of them, such as ferrocene , ferrioxalate , and Prussian blue have substantial industrial, medical, or research applications. The body of an adult human contains about 4 grams (0.005% body weight) of iron, mostly in hemoglobin and myoglobin . These two proteins play essential roles in oxygen transport by blood and oxygen storage in muscles . To maintain
19642-612: The meteorites Semarkona and Chervony Kut, a correlation between the concentration of Ni, the granddaughter of Fe, and the abundance of the stable iron isotopes provided evidence for the existence of Fe at the time of formation of the Solar System . Possibly the energy released by the decay of Fe, along with that released by Al , contributed to the remelting and differentiation of asteroids after their formation 4.6 billion years ago. The abundance of Ni present in extraterrestrial material may bring further insight into
19803-458: The most common applications for solid tires is for material handling equipment (forklifts). Such tires are installed utilizing a hydraulic tire press. Wooden wheels for horse-drawn vehicles usually have a wrought iron tire. This construction was extended to wagons on horse-drawn tramways, rolling on granite setts or cast iron rails . The wheels of some railway engines and older types of rolling stock are fitted with railway tires to prevent
19964-414: The nature of the suffix used. The u is kept before English suffixes that are freely attachable to English words (for example in humourless , neighbourhood , and savoury ) and suffixes of Greek or Latin origin that have been adopted into English (for example in behaviourism , favourite , and honourable ). However, before Latin suffixes that are not freely attachable to English words,
20125-559: The necessary levels, human iron metabolism requires a minimum of iron in the diet. Iron is also the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals. At least four allotropes of iron (differing atom arrangements in the solid) are known, conventionally denoted α , γ , δ , and ε . The first three forms are observed at ordinary pressures. As molten iron cools past its freezing point of 1538 °C, it crystallizes into its δ allotrope, which has
20286-422: The need to replace the entirety of a wheel. The tire, usually made of steel, surrounds the wheel and is primarily held in place by interference fit . Aircraft tires may operate at pressures that exceed 200 pounds per square inch (14 bar ; 1,400 kPa ). Some aircraft tires are inflated with nitrogen to "eliminate the possibility of a chemical reaction between atmospheric oxygen and volatile gases from
20447-436: The orbitals of those two electrons (d z and d x − y ) do not point toward neighboring atoms in the lattice, and therefore are not involved in metallic bonding. In the absence of an external source of magnetic field, the atoms get spontaneously partitioned into magnetic domains , about 10 micrometers across, such that the atoms in each domain have parallel spins, but some domains have other orientations. Thus
20608-539: The origin and early history of the Solar System . The most abundant iron isotope Fe is of particular interest to nuclear scientists because it represents the most common endpoint of nucleosynthesis . Since Ni (14 alpha particles ) is easily produced from lighter nuclei in the alpha process in nuclear reactions in supernovae (see silicon burning process ), it is the endpoint of fusion chains inside extremely massive stars . Although adding more alpha particles
20769-444: The other hand, the pale green iron(II) hexaquo ion [Fe(H 2 O) 6 ] does not undergo appreciable hydrolysis. Carbon dioxide is not evolved when carbonate anions are added, which instead results in white iron(II) carbonate being precipitated out. In excess carbon dioxide this forms the slightly soluble bicarbonate, which occurs commonly in groundwater, but it oxidises quickly in air to form iron(III) oxide that accounts for
20930-581: The oxidizing power of Fe and the high reducing power of I : Ferric iodide, a black solid, is not stable in ordinary conditions, but can be prepared through the reaction of iron pentacarbonyl with iodine and carbon monoxide in the presence of hexane and light at the temperature of −20 °C, with oxygen and water excluded. Complexes of ferric iodide with some soft bases are known to be stable compounds. The standard reduction potentials in acidic aqueous solution for some common iron ions are given below: The red-purple tetrahedral ferrate (VI) anion
21091-497: The past work on isotopic composition of iron has focused on the nucleosynthesis of Fe through studies of meteorites and ore formation. In the last decade, advances in mass spectrometry have allowed the detection and quantification of minute, naturally occurring variations in the ratios of the stable isotopes of iron. Much of this work is driven by the Earth and planetary science communities, although applications to biological and industrial systems are emerging. In phases of
21252-414: The principal ores for the production of iron (see bloomery and blast furnace). They are also used in the production of ferrites , useful magnetic storage media in computers, and pigments. The best known sulfide is iron pyrite (FeS 2 ), also known as fool's gold owing to its golden luster. It is not an iron(IV) compound, but is actually an iron(II) polysulfide containing Fe and S 2 ions in
21413-400: The range of 30 to 40 degrees from the direction of travel. Successive plies are laid at opposing angles, forming a crisscross pattern to which the tread is applied. Such a design is resistant to sidewall deformation and punctures (and to punctures’ expansion, or “torque splitting”) and therefore durable in severe use. Since the tread and sidewalls share their casing plies, the tire body flexes as
21574-637: The range of 550 to 1,100 pounds (250 to 500 kg) on the drive wheel. Light-to-medium duty trucks and vans carry loads in the range of 1,100 to 3,300 pounds (500 to 1,500 kg) on the drive wheel. They are differentiated by speed rating for different vehicles, including (starting from the lowest speed to the highest): winter tires, light truck tires, entry-level car tires, sedans and vans, sport sedans, and high-performance cars. Apart from road tires, there are special categories: Other types of light-duty automotive tires include run-flat tires and race car tires: Heavy-duty tires for large trucks and buses come in
21735-528: The ratio of the two monomers in the styrene-butadiene copolymer is considered key in determining the glass transition temperature of the material, which is correlated to its grip and resistance properties. Non-exhaust emissions of particulate matter, generated by the wearing down of brakes, clutches, tires, and road surfaces, as well as by the suspension of road dust, constitute a little-known but rising share of emissions from road traffic and significantly harm public health. Associated components of tires include
21896-403: The roadway surface affects roadway noise , a source of noise pollution emanating from moving vehicles. These sound intensities increase with higher vehicle speeds. Tires treads may incorporate a variety of distances between slots ( pitch lengths ) to minimize noise levels at discrete frequencies. Sipes are slits cut across the tire, usually perpendicular to the grooves, which allow the water from
22057-437: The second half of the 3d transition series, vertical similarities down the groups compete with the horizontal similarities of iron with its neighbors cobalt and nickel in the periodic table, which are also ferromagnetic at room temperature and share similar chemistry. As such, iron, cobalt, and nickel are sometimes grouped together as the iron triad . Unlike many other metals, iron does not form amalgams with mercury . As
22218-608: The simplicity, analogy or etymology". William Shakespeare 's first folios , for example, used spellings such as center and color as much as centre and colour . Webster did attempt to introduce some reformed spellings, as did the Simplified Spelling Board in the early 20th century, but most were not adopted. In Britain, the influence of those who preferred the Norman (or Anglo-French ) spellings of words proved to be decisive. Later spelling adjustments in
22379-475: The simplified form palestra is described by Merriam-Webster as "chiefly Brit[ish]." This is a reverse of the typical rule, where British spelling uses the ae / oe and American spelling simply uses e . Words that can be spelled either way in British English include cham a eleon , encyclop a edia , hom o eopathy , medi a eval (a minor variant in both AmE and BrE ), f o etid and f o etus . The spellings f o etus and f o etal are Britishisms based on
22540-410: The sounds became monophthongs , and later applied to words not of Greek origin, in both Latin (for example, cœli ) and French (for example, œuvre ). In English, which has adopted words from all three languages, it is now usual to replace Æ/æ with Ae/ae and Œ/œ with Oe/oe . In many words, the digraph has been reduced to a lone e in all varieties of English: for example, o economics , pr
22701-695: The spelling "is often seen as such". The -ize form is known as Oxford spelling and is used in publications of the Oxford University Press, most notably the Oxford English Dictionary , and of other academic publishers such as Nature , the Biochemical Journal and The Times Literary Supplement . It can be identified using the IETF language tag en-GB-oxendict (or, historically, by en-GB-oed ). In Ireland, India, Australia, and New Zealand -ise spellings strongly prevail:
22862-608: The spellings with just e are increasingly used. Manoeuvre is the only spelling in Australia, and the most common one in Canada, where maneuver and manoeuver are also sometimes found. The -ize spelling is often incorrectly seen in Britain as an Americanism. It has been in use since the 15th century, predating the -ise spelling by over a century. The verb-forming suffix -ize comes directly from Ancient Greek -ίζειν ( -ízein ) or Late Latin -izāre , while -ise comes via French -iser . The Oxford English Dictionary ( OED ) recommends -ize and lists
23023-564: The surface of Mars is derived from an iron oxide-rich regolith . Significant amounts of iron occur in the iron sulfide mineral pyrite (FeS 2 ), but it is difficult to extract iron from it and it is therefore not exploited. In fact, iron is so common that production generally focuses only on ores with very high quantities of it. According to the International Resource Panel 's Metal Stocks in Society report ,
23184-406: The surface. Tires provide a footprint, called a contact patch , designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface. The materials of modern pneumatic tires are synthetic rubber , natural rubber , fabric, and wire, along with carbon black and other chemical compounds. They consist of a tread and
23345-424: The tire from rotating independently from the wheel during vehicle motion. Additionally, the interplay between the bead's dimensions and the wheel's width significantly influences the vehicle's steering responsiveness and stability, as it helps to maintain the tire’s intended shape and contact with the road. The sidewall is that part of the tire, or bicycle tire , that bridges between the tread and bead. The sidewall
23506-486: The tire inner liner producing a tire explosion". Pneumatic tires are manufactured in about 450 tire factories around the world. Tire production starts with bulk raw materials such as rubber, carbon black, and chemicals and produces numerous specialized components that are assembled and cured. Many kinds of rubber are used, the most common being styrene-butadiene copolymer . Forecasts for the global automotive tire market indicate continued growth through 2027. Estimates put
23667-505: The tread from bead to bead—so that the cords are laid at approximately right angles to the centerline of the tread, and parallel to one another—as well as stabilizer belts directly beneath the tread. The plies are generally made of nylon, polyester, or steel, and the belts of steel, fiberglass, or Kevlar . The tire’s footprint, wider than a bias tire’s, and flexible sidewalls provide a better grip in turns, and its circumferential belts stabilize it. The advantages of this construction over that of
23828-414: The tread, bead, sidewall, shoulder, and ply. The tread is the part of the tire that comes in contact with the road surface. The portion that is in contact with the road at a given instant in time is the contact patch . The tread is a thick rubber, or rubber/composite compound formulated to provide an appropriate level of traction that does not wear away too quickly. The tread pattern is characterized by
23989-527: The value of worldwide sales volume around $ 126 billion in 2022, it is expected to reach the value of over $ 176 billion by 2027. Production of tires is also experiencing growth. In 2015, the US manufactured almost 170 million tires. Over 2.5 billion tires are manufactured annually, making the tire industry a major consumer of natural rubber. It was estimated that for 2019 onwards, at least 3 billion tires would be sold globally every year. However, other estimates put worldwide tire production of 2,268 million in 2021 and
24150-590: The vehicle inoperable to blowouts , where tires explode during operation and possibly damage vehicles and injure people. The manufacture of tires is often highly regulated for this reason. Because of the widespread use of tires for motor vehicles, tire waste is a substantial portion of global waste. There is a need for tire recycling through mechanical recycling and reuse, such as for crumb rubber and other tire-derived aggregate , and pyrolysis for chemical reuse, such as for tire-derived fuel . If not recycled properly or burned , waste tires release toxic chemicals into
24311-467: The viscoelastic properties of the rubber compound (low tangent (δ) ), it comes at the cost of wet traction and grip, which requires hysteresis and energy dissipation (high tangent (δ)). A low tangent (δ) value at 60 °C is used as an indicator of low rolling resistance, while a high tangent (δ) value at 0 °C is used as an indicator of high wet traction. Designing an elastomer material that can achieve both high wet traction and low rolling resistance
24472-455: The volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO 3 ; it also is the major host for iron in the lower mantle. At the bottom of the transition zone of the mantle, the reaction γ- (Mg,Fe) 2 [SiO 4 ] ↔ (Mg,Fe)[SiO 3 ] + (Mg,Fe)O transforms γ-olivine into a mixture of silicate perovskite and ferropericlase and vice versa. In
24633-412: The vowel is unreduced in pronunciation (e.g., devour , contour , flour , hour , paramour , tour , troubadour , and velour ), the spelling is uniform everywhere. Most words of this kind came from Latin, where the ending was spelled ‑or . They were first adopted into English from early Old French , and the ending was spelled ‑our , ‑or or ‑ur . After the Norman conquest of England ,
24794-454: The wheel on which it is mounted, the valve stem through which air is introduced, and, for some tires, an inner tube that provides the airtight means for maintaining tire pressure. American and British English spelling differences#Miscellaneous spelling differences A "British standard" began to emerge following the 1755 publication of Samuel Johnson 's A Dictionary of the English Language , and an "American standard" started following
24955-428: The word pallor . As a general noun, rigour / ˈ r ɪ ɡ ər / has a u in the UK; the medical term rigor (sometimes / ˈ r aɪ ɡ ər / ) does not, such as in rigor mortis , which is Latin. Derivations of rigour / rigor such as rigorous , however, are typically spelled without a u , even in the UK. Words with the ending -irior , -erior or similar are spelled thus everywhere. The word armour
25116-407: The work of Noah Webster and, in particular, his An American Dictionary of the English Language , first published in 1828. Webster's efforts at spelling reform were effective in his native country, resulting in certain well-known patterns of spelling differences between the American and British varieties of English. However, English-language spelling reform has rarely been adopted otherwise. As
25277-696: Was declared invalid because of the prior art by forgotten fellow Scot Robert William Thomson of London (patents London 1845, France 1846, USA 1847). However, Dunlop is credited with "realizing rubber could withstand the wear and tear of being a tire while retaining its resilience". John Boyd Dunlop and Harvey du Cros worked through the ensuing considerable difficulties. They employed inventor Charles Kingston Welch and acquired other rights and patents, which allowed them some limited protection of their Pneumatic Tyre business's position. Pneumatic Tyre would become Dunlop Rubber and Dunlop Tyres . The development of this technology hinged on myriad engineering advances, including
25438-410: Was made in 1888 on May Street, Belfast , by Scots-born John Boyd Dunlop , owner of one of Ireland's most prosperous veterinary practices. It was an effort to prevent the headaches of his 10-year-old son Johnnie while riding his tricycle on rough pavements. His doctor, John, later Sir John Fagan, had prescribed cycling as an exercise for the boy and was a regular visitor. Fagan participated in designing
25599-666: Was not until the mid-1990s that Canadian-based dictionaries became increasingly common.) Worldwide, -ize endings prevail in scientific writing and are commonly used by many international organizations, such as United Nations Organizations (such as the World Health Organization and the International Civil Aviation Organization ) and the International Organization for Standardization (but not by
25760-428: Was once somewhat common in American usage but has disappeared except in some brand names such as Under Armour . The agent suffix -or ( separator , elevator , translator , animator , etc.) is spelled thus both in American and British English. Commonwealth countries normally follow British usage. Canadian English most commonly uses the -our ending and -our- in derivatives and inflected forms. However, owing to
25921-929: Was published. Following this, -re became the most common usage in Britain. In the United States, following the publication of Webster's Dictionary in the early 19th century, American English became more standardized, exclusively using the -er spelling. In addition, spelling of some words have been changed from -re to -er in both varieties. These include September , October , November , December , amber, blister , cadaver , chamber , chapter , charter , cider , coffer , coriander , cover , cucumber , cylinder , diaper , disaster , enter , fever , filter , gender , leper , letter , lobster , master , member , meter (measuring instrument) , minister , monster , murder , number , offer , order , oyster , powder , proper , render , semester , sequester , sinister , sober , surrender , tender , and tiger . Words using
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