Iron

One element of the medical approach is a specific chelating agent called deferoxamine, used to bind and expel excess iron from the body in case of iron toxicity. These will consist of between 6 and 12 workstations, each with their own oven, sink and kitchen utensils. The medical management of iron toxicity is complex. In Schools where Home Economics (HE) or Food technology (previously known as Domestic science) is taught, there will be a series of kitchens with multiple equipment (similar in some respects to laboratories) solely for the purpose of teaching. Blood donors are at special risk of low iron levels and are often recommended to supplement their iron intake. Military camps and similar temporary settlements of nomads may have dedicated kitchen tents. For this reason, people should not take iron supplements unless they suffer from iron deficiency and have consulted a doctor. Outdoor areas in which food is prepared are generally not considered to be kitchens, although an outdoor area set up for regular food preparation, for instance when camping, might be called an "outdoor kitchen".

Iron overload disorders require a genetic inability to regulate iron uptake; however, many people have a genetic susceptibility to iron overload without realizing it and without knowing a family history of the problem. The astronauts' food is generally completely prepared, dehydrated, and sealed in plastic pouches, and the kitchen is reduced to a rehydration and heating module. If iron intake is excessive iron overload disorders can sometimes result, such as hemochromatosis. aboard a Space Shuttle (where it is also called the "galley") or the International Space Station. For children under fourteen years old the UL is 40 mg/day. An extreme form of the kitchen occurs in space, e.g. The DRI lists the Tolerable Upper Intake Level (UL) for adults as 45 mg/day. On passenger airplanes, the kitchen is reduced to a mere pantry, the only function reminiscent of a kitchen is the heating of in-flight meals (where they haven't been "optimized" away altogether) delivered by a catering company.

Humans experience iron toxicity above 20 milligrams of iron for every kilogram of weight, and 60 milligrams per kilogram is a lethal dose.[3] Over-consumption of iron, often the result of children eating large quantitities of ferrous sulfate tablets intended for adult consumption, is the most common toxicological cause of death in children under six. On yachts, galleys are often cramped, with one or two gas burners fuelled by a gas bottle, but kitchens on cruise ships or large warships are comparable in every respect with restaurants or canteen kitchens. This can cause serious problems, including the potential of death from overdose, and long-term organ damage in survivors. Galleys are kitchens aboard ships (although the term galley is also often used to refer to a railroad dining car's kitchen). Once there, it causes damage to cells in the heart, liver and elsewhere. Especially in the early history of the railway this required flawless organization of processes; in modern times, the microwave oven and prepared meals have made this task a lot easier. However, too much ingested iron can damage the cells of the gastrointestinal tract directly, and may enter the bloodstream by damaging the cells that would otherwise regulate its entry. The kitchens in railway dining cars present special challenges: space is constrained, and nevertheless the personnel must be able to serve a great number of meals quickly.

Iron uptake is tightly regulated by the human body, which has no physiologic means of excreting iron and regulates iron solely by regulating uptake. There is a trend for restaurants to only "finish" delivered convenience food or even just re-heat completely prepared meals, maybe at the utmost grilling a hamburger or a steak. In excess, uncontrollable quantities of free radicals are produced. The fast food and convenience food trends have also changed the way restaurant kitchens operate. Iron becomes toxic when it exceeds the amount of transferrin needed to bind free iron. (As of 2004, steamers—not to be confused with a pressure cooker—are beginning to find their way into domestic households, sometimes as a combined appliance of oven and steamer.). Excessive iron is toxic to humans, because excess ferrous iron reacts with peroxides in the body, producing free radicals. Some special appliances are typical for professional kitchens, such as large installed deep fryers, steamers, or a Bain Marie.

Also note the section below on precautions. Professional kitchens are often equipped with gas stoves, as these allow cooks to regulate the heat quicker and more finely than electrical stoves. The RDA for iron varies considerably based on the age, gender, and source of dietary iron (heme-based iron has higher bioavailability)[2]. Today's western restaurant kitchens typically have tiled walls and floors and use stainless steel for other surfaces (workbench, but also door and drawer fronts) because these materials are durable and easy to clean. Iron provided by dietary supplements is often found as Iron (II) fumarate. For instance, Benjamin Thompson's "energy saving stove", an early 19th century fully-closed iron stove using one fire to heat several pots, was designed for large kitchens; another thirty years passed before they were adapted for domestic use. Good sources of dietary iron include meat, fish, poultry, lentils, beans, leaf vegetables, tofu, chickpeas, black-eyed pea, strawberries and farina. Canteen kitchens (and castle kitchens) were often the places where new technology was used first.

A lengthier article on the system of human iron regulation can be found in the article on human iron metabolism. They are inspected periodically by public-health officials, and forced to close if they don't meet hygienic requirements mandated by law. [1]. Restaurant and canteen kitchens found in hotels, hospitals, army barracks and similar establishments are generally (in developed countries) subject to public health laws. There it gets by an as yet unknown mechanism incorporated into target proteins. Kitchens with enough space to eat in are sometimes called "eat-in kitchens". The iron absorbed from the duodenum binds to transferrin, and is carried by blood to different cells. Such areas are called "breakfast areas", "breakfast nooks" or "breakfast bars" if the space is integrated into a kitchen counter.

Iron distribution is heavily regulated in mammals, both as a defense against bacterial infection as well as the potential biological toxicity of iron. Modern kitchens often have enough informal space to allow for people to eat in it without having to use the formal dining room. When the body is fighting a bacterial infection, the body sequesters iron inside of cells (mostly stored in the storage molecule ferritin) so that it cannot be used by bacteria. This observation led to a few common kitchen forms, commonly characterized by the arrangement of the kitchen cabinets and sink, stove, and refrigerator:. A class of non-heme iron proteins is responsible for a wide range of functions within several life forms, such as enzymes methane monooxygenase (oxidizes methane to methanol), ribonucleotide reductase (reduces ribose to deoxyribose; DNA biosynthesis), hemerythrins (oxygen transport and fixation in marine invertebrates) and purple acid phosphatase (hydrolysis of phosphate esters). A natural arrangement is a triangle, with the refrigerator, the sink, and the stove at a vertex each. Inorganic iron involved in redox reactions is also found in the iron-sulfur clusters of many enzymes, such as nitrogenase (involved in the synthesis of ammonia from nitrogen and hydrogen) and hydrogenase. It was there that the notion of the "kitchen work triangle" was formalized: the three main functions in a kitchen are storage, preparation, and cooking (which Catherine Beecher had already recognized), and the places for these functions should be arranged in the kitchen in such a way that work at one place does not interfere with work at another place, the distance between these places is not unnecessarily large, and no obstacles are in the way.

Many animals incorporate iron into the heme complex, an essential component of cytochromes, which are proteins involved in redox reactions (including but not limited to cellular respiration), and of oxygen carrying proteins hemoglobin and myoglobin. In the U.S., the "Small Homes Council", since 1993 the "Building Research Council", of the School of Architecture of the University of Illinois at Urbana-Champaign was founded in 1944 with the goal to improve the state of the art in home building, originally with an emphasis on standardization for cost reduction. Iron binds avidly to virtually all biomolecules so it will adhere nonspecifically to cell membranes, nucleic acids, proteins etc. Nevertheless, kitchen design was mostly ad-hoc following the whims of the architect. To say that iron is free doesn't mean that it is free floating in the bodily fluids. While this "work kitchen" and variants derived from it were a great success for tenement buildings, home owners had different demands and didn't want to be constrained by a 6.4 m² kitchen. It is mostly stably incorporated in the inside of metalloproteins, because in exposed or in free form it causes production of free radicals that are generally toxic to cells. A social housing project in Frankfurt (the Römerstadt of architect Ernst May) realized in 1927/28 was the breakthrough for her Frankfurt kitchen, which embodied this new notion of efficiency in the kitchen.

Iron is essential to all organisms, except for a few bacteria. Her ideas were taken up in the 1920s by architects in Germany and Austria, most notably Bruno Taut, Erna Meyer, and Margarete Schütte-Lihotzky. For this reason, ⁵⁷Fe has application as a spin isotope in chemistry and biochemistry. Christine Frederick published from 1913 a series of articles on "New Household Management" in which she analyzed the kitchen following Taylorist priciples, presented detailed time-motion studies, and derived a kitchen design from them. Of the stable isotopes, only ⁵⁷Fe has a nuclear spin (−1/2). Beecher even separated the functions of preparing food and cooking it altogether by moving the stove into a compartment adjacent to the kitchen. The abundance of ⁶⁰Ni present in extraterrestrial material may also provide further insight into the origin of the solar system and its early history. The design included regular shelves on the walls, ample work space, and dedicated storage areas for various food items.

Possibly the energy released by the decay of ⁶⁰Fe contributed, together with the energy released by decay of the radionuclide ²⁶Al, to the remelting and differentiation of asteroids after their formation 4.6 billion years ago. Beecher's "model kitchen" propagated for the first time a systematic design based on early ergonomics. In phases of the meteorites Semarkona and Chervony Kut a correlation between the concentration of ⁶⁰Ni, the daughter product of ⁶⁰Fe, and the abundance of the stable iron isotopes could be found which is evidence for the existence of ⁶⁰Fe at time formation of solar system. The first ideas to optimize the work in the kitchen go back to Catherine Beecher's A Treatise on Domestic Economy (1843, revised and republished together with her sister Harriet Beecher Stowe as The American Woman's Home in 1869). This is not true, as both ⁶²Ni and ⁵⁸Fe are more stable. Domestic kitchen design per se is a relatively recent discipline. A common misconception is that this isotope represents the most stable nucleus possible, and that it thus would be impossible to perform fission or fusion on ⁵⁶Fe and still liberate energy. For others, who followed the "cooking as a social act" trend, the open kitchen had the advantage that they could be with their guests while cooking, and for the "creative cooks" it might even become a stage for their cooking performance.

The isotope ⁵⁶Fe is of particular interest to nuclear scientists. Whereas in the 1950s most cooking started out with raw ingredients and a meal had to be prepared for real, the advent of frozen meals and pre-prepared convenience food changed the cooking habits of many people, who consequently used the kitchen less and less. Much of the past work on measuring the isotopic composition of Fe has centered on determining ⁶⁰Fe variations due to processes accompanying nucleosynthesis (i.e., meteorite studies) and ore formation. Another reason for the trend back to open kitchens (and a foundation of the "kitchen object" philosophy) is changes in how food is prepared. ⁶⁰Fe is an extinct radionuclide of long half-life (1.5 million years). However, like their precursor, Colani's "kitchen satellite", such futuristic designs are exceptions. Naturally occurring iron consists of four isotopes: 5.845% of radioactive ⁵⁴Fe (half-life: >3.1E22 years), 91.754% of stable ⁵⁶Fe, 2.119% of stable ⁵⁷Fe and 0.282% of stable ⁵⁸Fe. Some architects have capitalized on this "object" aspect of the kitchen by designing freestanding "kitchen objects".

Iron carbide Fe₃C is known as cementite. The enhanced status of cooking also made the kitchen a prestige object for showing off one's wealth or cooking professionalism. Note that despite the chemical formula, the iron in the common pyrite is not in the +4 oxidation state; the sulfur is in the -1 oxidation state. Besides, many families also appreciated the trend towards open kitchens, as it made it easier for the parents to supervise the kids while cooking. Common oxidation states of iron include:. The re-integration of the kitchen and the living area went hand in hand with a change in the perception of cooking: increasingly, cooking was seen as a creative and sometimes social act instead of work, especially in upper social classes. The 1100Mt of iron ore was used to produce approximately 572Mt of pig iron. The extractor hood made it possible to build open kitchens in apartments, too, where both high ceilings and skylights were not possible.

While ore production occurs in 48 countries, the five largest producers were China, Brazil, Australia, Russia and India, accounting for 70% of world iron ore production. Both had open kitchens, with high ceilings (up to the roof) and were aired by skylights. Approximately 1100Mt (million tons) of iron ore was produced in the world in 2000, with a gross market value of approximately 25 billion US dollars. Examples are Frank Lloyd Wright's House Willey (1934) and House Jacobs (1936). The iron, once cooled, is called pig iron, while the slag can be used as a material in road construction or to improve mineral-poor soils for agriculture. Before that, only a few earlier experiments, typically in newly built upper middle class family homes, had open kitchens. In the bottom of the furnace, the molten slag floats on top of the more dense liquid iron, and spouts in the side of the furnace may be opened to drain off either the iron or the slag. Starting in the 1980s, the perfection of the extractor hood allowed an open kitchen again, integrated more or less with the living room without causing the whole apartment or house to smell.

The slag melts in the heat of the furnace, which silicon dioxide would not have. The kitchen was reduced to the max and the "work kitchen" paradigm taken to its extremes: in East Germany for instance, the standard tenement block of the model "P2" had tiny 4 m² kitchens in the inside of the building (no windows), connected to the dining and living room of the 55 m² apartment and separated from the latter by a pass-through or a window. Then calcium oxide combines with silicon dioxide to form a slag. Also, housing had to be built at low costs and quickly, which led directly to the standardized apartment block using prefabricated slabs. In the heat of the furnace the limestone flux decomposes to calcium oxide (quicklime):. In the former Eastern bloc countries, the official doctrine viewed cooking as a mere necessity, and women should work "for the society" in factories, not at home. Other fluxes may be used depending on the impurities that need to be removed from the ore. Such extravaganzas remained outside the norm, though.

Common fluxes include limestone (principally calcium carbonate) and dolomite (magnesium carbonate). General technocentric enthusiasm even led some designers to take the "work kitchen" approach even further, culminating in futuristic designs like Luigi Colani's "kitchen satellite" (1969, commissioned by the German high-end kitchen manufacturer Poggenpohl for an exhibit), in which the room was reduced to a ball with a chair in the middle and all appliances at arm's length, an optimal arrangement maybe for "applying heat to food", but not necessarily for actual cooking. The flux is present to melt impurities in the ore, principally silicon dioxide sand and other silicates. There, the kitchens usually were somewhat larger, suitable for everyday use as a dining room, but otherwise the ongoing technicalization was the same, and the use of unit furniture became a standard also in this market sector. The carbon monoxide reduces the iron ore (in the chemical equation below, hematite) to molten iron, becoming carbon dioxide in the process:. Parallel to this development in tenement buildings went the evolution of the kitchen in homeowner's houses. In the furnace, the coke reacts with oxygen in the air blast to produce carbon monoxide:. Following the end of World War II, massive demand in Europe for low-price, high-tech consumer goods led to Western European kitchens being designed to accommodate new appliances such as refrigerators and electric/gas cookers.

In a blast furnace, iron ore, carbon in the form of coke, and a flux such as limestone are fed into the top of the furnace, while a blast of heated air is forced into the furnace at the bottom. A trend began in the 1940s in the United States to equip the kitchen with electrified small and large kitchen appliances such as blenders, toasters, and later also microwave ovens. Industrially, iron is extracted from its ores, principally hematite (nominally Fe₂O₃) and magnetite (Fe₃O₄) by a carbothermic reaction (reduction with carbon) in a blast furnace at temperatures of about 2000°C. Soon the concept was amended by the use of smooth synthetic door and drawer fronts, first in white, recalling a sense of cleanliness and alluding to sterile lab or hospital settings, but soon after in lively, friendly colors, too. Iron is also one of the least reactive metals, and therefore, it is sometimes found pure in nature. The concept was refined in the "Swedish kitchen" using unit furniture with wooden fronts for the kitchen cabinets. Although rare, these are the major form of natural metallic iron on the earth's surface. Not much later, the refrigerator was added as a standard item.

About 5% of the meteorites similarly consist of iron-nickel alloy. The equipment used remained a standard for years to come: hot and cold water on tap and a kitchen sink and an electrical or gas stove and oven. The earth's core is believed to consist largely of a metallic iron-nickel alloy. The idea of standardized dimensions and layout developed for the Frankfurt kitchen took hold. Most of this iron is found in various iron oxides, such as the minerals hematite, magnetite, and taconite. Practical reasons also played a role in this development: just as in the bourgeois homes of the past, one reason for separating the kitchen was to keep the steam and smells of cooking out of the living room. Iron is one of the most common elements on Earth, making up about 5% of the Earth's crust. The kitchen once more was seen as a work place that needed to be separated from the living areas.

This innovation by Abraham Darby supplied the energy for the Industrial Revolution. Too small to live or dine in, it was soon criticized as "exiling the women in the kitchen", but the post-World War II conservatism coupled with economic reasons prevailed. In 18th century England, wood supplies ran down and coke, a fossil fuel, was used as an alternative. But the Frankfurt kitchen embodied a standard for the rest of the 20th century in rental apartments: the "work kitchen". Early iron smelting (as the process is called) used charcoal as both the heat source and the reducing agent. The initial reception was heavily critical: people were not accustomed to the changed processes also designed by Schütte-Lihotzky; it was so small that only one person could work in it; some storage spaces intended for raw loose food ingredients such as flour were reachable by children. In any event, by the late fourteenth century, a market for cast iron goods began to form, as a demand developed for cast iron cannonballs. It was built in some 10,000 apartments in a social housing project of architect Ernst May in Frankfurt.

There are suggestions by scholars that the practice may have followed the Mongols across Russia to these sites, but there is no clear proof of this hypothesis. The design, created by Margarete Schütte-Lihotzky, was the result of detailed time-motion studies and heavily influenced by the railway dining car kitchens of the period. Some of the earliest casting of iron in Europe occurred in Sweden, in two sites, Lapphyttan and Vinarhyttan, between 1150 and 1350 AD. It was built for two purposes: to optimize kitchen work to reduce cooking time (so that women would have more time for the factory) and to lower the cost of building decently-equipped kitchens. Through a good portion of the Middle Ages, in Western Europe, iron was still being made by the working of sponge iron into wrought iron. Developed in 1926, this kitchen measured 1.9m by 3.4m (approximately 6'2" by 11'2"), with a standard layout. Cast iron development lagged in Europe, as the smelters could only achieve temperatures of about 1000 K. Social housing projects led to the next milestone: the "Frankfurt kitchen".

Iron, however, remained a pedestrian product, used by farmers for hundreds of years, and did not really affect the nobility of China until the Qin dynasty (ca 221 BC). Working class women frequently worked in factories to ensure the family's survival, as the men's wages often did not suffice. The vast majority of Chinese iron manufacture, from the Zhou dynasty onward, was of cast iron. These ideas also spilled over into domestic kitchen architecture due to a growing trend that called for a professionalization of household work, started in the mid-19th century by Catharine Beecher and amplified by Christine Frederick's publications in the 1910s. This product is strong, can be cast into intricate shapes, but is too brittle to be worked, unless the product is decarburized to remove most of the carbon. Taylorism was born, and time-motion studies were used to optimize processes. If iron ores are heated with carbon to 1420–1470 K, a molten liquid is formed, an alloy of about 96.5% iron and 3.5% carbon. In industry, it was the phase of rationalisation, where work processes were attempted to be streamlined.

The famous iron pillar in the Qutb complex in Delhi is made of very pure iron (98%) and has not rusted or eroded till this day. The trend to increasing gasification and electrification continued at the turn of the 20th century. Iron was used in India as early as 250 BCE. Gas and water pipes were first installed in the big cities; small villages were connected only much later. Producing blast furnaces capable of temperatures exceeding 1300 K, the Chinese developed the manufacture of cast, or pig iron. In rural areas, the older technology using coal or wood stoves or even brick-and-mortar open fireplaces remained common throughout. In the later years of the Zhou Dynasty (ca 550 BC), a new iron manufacturing capability began because of a highly developed kiln technology. Where workers' apartments were equipped with a gas stove, gas distribution would go through a coin meter.

These items were made of wrought iron, created by the same processes used in the Middle East and Europe, and were thought to be imported by non-Chinese people. Gas was more expensive than coal, though, and thus the new technology first was installed in the wealthier homes. In China the first irons used were also meteoric iron, with archeological evidence for items made of wrought iron appearing in the northwest, near Xinjiang, in the 8th century BC. Gas pipes were laid only in the late 19th century, and gas stoves started to replace the older coal-fired stoves. The resulting product, which had a surface of steel, was harder and less brittle than the bronze it began to replace. Besides a cupboard to store the kitchenware, there were a table and chairs, where the family would dine, and sometimes—if space allowed—even a fauteuil or a couch. The people of the Middle East found that a much harder product could be created by the long term heating of a wrought iron object in a bed of charcoal, which was then quenched in water or oil. Because of this, these middle-class kitchens often were more homely than those of the upper class, where the kitchen was a work-only room occupied only by the servants.

Wrought iron was very low in carbon content and was not easily hardened by quenching. The study or living room was saved for special occasions such as an occasional dinner invitation. Iron was recovered as sponge iron, a mix of iron and slag with some carbon and/or carbide, which was then repeatedly hammered and folded over to free the mass of slag and oxidise out carbon content, so creating the product wrought iron. Living in smaller apartments, the kitchen was the main room—here, the family lived. Concurrent with the transition from bronze to iron was the discovery of carburization, which was the process of adding carbon to the irons of the time. The middle class tried to imitate the luxurious dining styles of the upper class as best as it could. A common alchemical symbol for iron, the metal of weapons, was that of Mars, the god of war. A large table served as a workbench; there were at least as many chairs as there were servants, for the table in the kitchen also doubled as the eating place for the servants.

This period of transition, which occurred at different times in different parts of the world, is the ushering in of an age of civilization called the Iron Age. The kitchen floors were tiled; kitchenware was neatly stored in cupboards to protect them from dust and steam. The critical factor in this transition does not appear to be the sudden onset of a superior ironworking technology, but instead the disruption of the supply of tin. For the servants the kitchen continued to serve also as a sleeping room; they slept either on the floor, or later in narrow spaces above a lowered ceiling, for the new stoves with their smoke outlet no longer required a high ceiling in the kitchen. In the period from the 12th to 10th century BC, there was a rapid transition in the Middle East from bronze to iron tools and weapons. The kitchen became a much cleaner space with the advent of "cooking machines", closed stoves made of iron plates and fired by wood and increasingly charcoal or coal, and that had flue pipes connected to the chimney. By 1600 BC to 1200 BC, iron was used increasingly in the Middle East, but did not supplant the dominant use of bronze. In some houses, water pumps were installed, and some even had kitchen sinks and drains (but no water on tap yet, except for some feudal kitchens in castles).

Some resources (see the reference What Caused the Iron Age? below) suggest that iron was being created then as a by-product of copper refining, as sponge iron, and was not reproducible by the metallurgy of the time. The kitchen, located in the basement or the ground floor, continued to be operated by servants. In the Iliad, weaponry is mostly bronze, but iron ingots are used for trade. In contrast, there were no dramatic changes for the upper classes. However, their use appears to be ceremonial, and iron was an expensive metal, more expensive than gold. Pots and kitchenware typically were stored on open shelves, and parts of the room could be separated from the rest using simple curtains. By 3500 BC to 2000 BC, increasing numbers of smelted iron objects (distinguishable from meteoric iron by the lack of nickel in the product) appear in Mesopotamia, Anatolia, and Egypt. Brick-and-mortar stoves fired with coal remained the norm until well into the second half of the century.

Because meteorites fall from the sky some linguists have conjectured that the English word iron (OE īsern), which has cognates in many northern and western European languages, derives from the Etruscan aisar which means "the gods". Water pipes were laid only towards the end of the 19th century, and then often only with one tap per building or per story. The first signs of use of iron come from the Sumerians and the Egyptians, where around 4000 BC, a few items, such as the tips of spears, daggers and ornaments, were being fashioned from iron recovered from meteorites. Water had to be fetched from wells and heated on the stove. Steel is the best known alloy of iron, and some of the forms that iron takes include:. The kitchen in such an apartment was often used as a living and sleeping room, and even as a bathroom. Its combination of low cost and high strength make it indispensable, especially in applications like automobiles, the hulls of large ships, and structural components for buildings. Sometimes, they shared apartments with "night sleepers", unmarried men that paid for a bed at night.

Iron is the most used of all the metals, comprising 95 percent of all the metal tonnage produced worldwide. Whole families lived in small one or two-room apartments in tenement buildings up to six stories high, badly aired and with insufficient lighting. Some cosmological models with an open universe predict that there will be a phase where as a result of slow fusion and fission reactions, everything will become iron. The new factory working class in the cities was housed under generally poor conditions. This leads to a supernova. Industrialization also caused social changes. When a very large star contracts at the end of its life, internal pressure and temperature rise, allowing the star to produce progressively heavier elements, despite these being less stable than the elements around mass number 60 (the "iron group"). The first electrical stove had been presented in 1893 at the Chicago world fair, but it wasn't until the 1930s that the technology was stable enough and began to take off.

Although a further tiny energy gain could be extracted by synthesizing ⁶²Ni, conditions in stars are not right for this process to be favoured. But like the gas stove, the electrical stove had a slow start. This is formed by nuclear fusion in the stars. At the turn of the 20th century, electricity had been mastered well enough to become a commercially viable alternative to gas and slowly started replacing the latter. The universally most abundant of the highly stable nucleides is, however, ⁵⁶Fe. Gas pipes were laid; gas was used first for lighting purposes, but once the network had grown sufficiently, it became available also for heating and cooking on gas stoves. Nuclei of iron have some of the highest binding energies per nucleon, superseded only by the nickel isotope ⁶²Ni. Out of sheer necessity, cities began planning and building water distribution pipes into homes, and built canalisations to deal with the waste water.

Iron is used in the production of steel, which is not an element but an alloy, a solution of different metals (and some non-metals, particularly carbon). The urbanization in the second half of the 19th century induced other significant changes that ultimately would also change the kitchen. In order to obtain elemental iron, the impurities must be removed by chemical reduction. patent on a gas stove was granted in 1825, it wasn't until the late 19th century that using gas for lighting and cooking became commonplace in urban areas. Iron is a metal extracted from iron ore, and is hardly ever found in the free (elemental) state. Although the first gas street lamps were installed in Paris, London, and Berlin at the beginning of the 1820s and the first U.S. Iron is also the most abundant (by mass, 34.6%) element making up the Earth; the concentration of iron in the various layers of the Earth ranges from high at the inner core to about 5% in the outer crust; it is possible the Earth's inner core consists of a single iron crystal although it is more likely to be a mixture of iron and nickel; the large amount of iron in the Earth is thought to contribute to its magnetic field. These stoves were still fired with wood or coal.

Iron is the most abundant metal on Earth, and is believed to be the tenth most abundant element in the universe. in 1834 and became a commercial success with some 90,000 units sold over the next 30 years. . The "Oberlin stove" was a refinement of the technique that resulted in a size reduction; it was patented in the U.S. It is therefore the most abundant heavy metal in the universe. However, his stove was designed for large kitchens; it was too big for domestic use. Iron is notable for being the final element produced by stellar nucleosynthesis, and thus the heaviest element which does not require a supernova or similarly cataclysmic event for its formation. This stove was much more energy efficient than earlier stoves; it used one fire to heat several pots, which were hung into holes on top of the stove and were thus heated from all sides instead of just from the bottom.

Iron is a group 8 and period 4 metal. Benjamin Thompson in England designed his "Rumford stove" around 1800. Iron is a chemical element with the symbol Fe (L.: Ferrum) and atomic number 26. Early models included the Franklin stove around 1740, which was a furnace stove intended for heating, not for cooking. Los Alamos National Laboratory — Iron. Iron stoves, which enclosed the fire completely and were more efficient, appeared. the Iron(VI) state, Fe⁶⁺ is also known, if rare, in potassium ferrate. Technological advances during industrialization brought major changes to the kitchen.

peroxidases). Completely separated "summer kitchens" also developed on larger farms further north to avoid that the main house was heated by the preparation of the meals for the harvest workers or tasks like canning. the Iron(IV) state, Fe⁴⁺, previously ferryl, stabilized in some enzymes (e.g. In addition, the area's warm climate made operating a kitchen quite unpleasant, especially in the summer. the Iron(III) state, Fe³⁺, previously ferric, is also very common, for example in rust. In southern estates, the kitchen was often relegated to an outhouse, separated from the mansion, for much of the same reasons as in the feudal kitchen in medieval Europe: the kitchen was operated by slaves, and their working place had to be separated from the living area of the masters by the social standards of the time. the Iron(II) state, Fe²⁺, previously ferrous is very common. The development in the southern states was quite different, but then, so were the climate and sociological conditions.

the Iron(I) state, [Fe(H₂O)₅NO]²⁺. Later, the kitchen did become a separate room, but remained within the building. the Iron(0) state, Fe(CO)₅, Fe(PF₃)₅. The early settlers in the north often had no separate kitchen; a fireplace in a corner of the cabin served as the kitchen space. Fe(CO)₄^2-,Fe(CO)₂(NO)₂. In the Colonial American kitchen, the same distinction as for the medieval European kitchen is visible. the Iron(-II) state, Fe^2- (e.g. The smoke then rose more or less freely, warming the upstairs rooms and protecting the woodwork from vermin.

They are often mixed with other compounds, and retain their magnetic properties in solution. These houses often had no chimney, but only a smoke hood above the fireplace, made of wood and covered with clay, and used to smoke meat. Iron(III) oxides are used in the production of magnetic storage in computers. In a few European farmhouses, the smoke kitchen was in regular use until the middle of the 20th century. Recent developments in ferrous metallurgy have produced a growing range of microalloyed steels, also termed 'HSLA' or high-strength, low alloy steels, containing tiny additions to produce high strengths and often spectacular toughness at minimal cost. The medieval smoke kitchen remained common, especially in rural farmhouses and generally in poorer homes, until much later. They are used for structural purposes, as their alloy content raises their cost and necessitates justification of their use. Poorer homes often did not have a separate kitchen yet; they kept the one-room arrangement where all activities took place, or at the most had the kitchen in the entrance hall.

Alloy steels contain varying amounts of carbon as well as other metals, such as chromium, vanadium, molybdenum, nickel, tungsten, etc. In the upper classes, cooking and the kitchen were the domain of the servants, and the kitchen was set apart from the living rooms, sometimes even far from the dining room. Wrought iron is characterised, especially in old samples, by the presence of fine 'stringers' or filaments of slag entrapped in the metal. Freed from smoke and dirt, the living room thus began to serve as an area for social functions and increasingly became a showcase for the owner's wealth and was sometimes prestigiously furnished. If honed to an edge, it loses it quickly. The living room was now heated by tiled stoves, operated from the kitchen, which offered the huge advantage of not filling the room with smoke. It has a very small amount of carbon, a few tenths of a percent. Beginning in the late middle ages, kitchens in Europe lost their home-heating function even more and were increasingly moved from the living area into a separate room.

It is a tough, malleable product, not as fusible as pig iron. Using open fire for cooking (and heating) was risky; fires devastating whole cities occurred frequently. Wrought iron contains less than 0.2% carbon. This kind of system was widely used in wealthier homes. Carbon steel contains between 0.4% and 1.5% carbon, with small amounts of manganese, sulfur, phosphorus, and silicon. Leonardo da Vinci invented an automated system for a rotating spit for spit-roasting: a propeller in the chimney made the spit turn all by itself. A newer variant of grey iron, referred to as 'ductile iron' is specially treated with trace amounts of magnesium to alter the shape of graphite to sheroids, or nodules, vastly increasing the toughness and strength of the material. The temperature was controlled by hanging the pot higher or lower over the fire, or placing it on a trivet or directly on the hot ashes.

In 'grey' cast iron, the carbon exists free as fine flakes of graphite , and also, renders the material brittle due to the stress-raising nature of the sharp edged flakes of graphite. Pots made of iron, bronze, or copper started to replace the pottery used earlier. The broken surface of a white cast iron is full of fine facets of the broken carbide, a very pale, silvery, shiny material, hence the appellation. The fire was lit on top of the construction; a vault underneath served to store wood. This hard, brittle compound dominates the mechanical properties of white cast irons, rendering them hard, but unresistant to shock. With the advent of the chimney, the hearth moved from the center of the room to one wall, and the first brick-and-mortar hearths were built. 'White' cast irons contain their carbon in the form of cementite, or iron carbide. In Japanese homes, the kitchen started to become a separate room within the main building at that time.

Its mechanical properties vary greatly, dependant upon the form carbon takes in the alloy. In castles and monasteries, the living and working areas were separated; the kitchen was moved to a separate building, and thus couldn't serve anymore to heat the living rooms. It has a melting point in the range of 1420–1470 K, which is lower than either of its two main components, and makes it the first product to be melted when carbon and iron are heated together. In wealthy homes, the ground floor was often used as a stable while the kitchen was located on the floor above, like the bedroom and the hall. Contaminants present in pig iron that negatively affect the material properties, such as sulfur and phosphorus, have been reduced to an acceptable level. In European medieval cities around the 10th to 12th centuries, the kitchen still used an open fire hearth in the middle of the room. Cast iron contains 2% – 4.0% carbon , 1% – 6% silicon , and small amounts of manganese. European medieval kitchens were dark, smokey, and sooty places, whence their name "smoke kitchen".

Its only significance is that of an intermediate step on the way from iron ore to cast iron and steel. The kitchen remained largely unaffected by architectural advances throughout the middle ages; open fire remained the only method of heating food. Pig iron has 4% – 5% carbon and contains varying amounts of contaminants such as sulfur, silicon and phosphorus. A kamado was used to cook the staple food, for instance rice, while irori served both to cook side dishes and as a heat source. A kind of open fire pit fired with charcoal, called irori, remained in use as the secondary stove in most homes until the Edo period (17th to 19th century). Like in Europe, the wealthier homes had a separate building which served for cooking.

This type of stove remained in use for centuries to come, with only minor modifications. These stoves, called kamado, were typically made of clay and mortar; they were fired with wood or charcoal through a hole in the front and had a hole in the top, into which a pot could be hanged by its rim. The earliest findings are from the Kofun period (3rd to 6th century). The first known stoves in Japan date from about the same time.

In the larger homesteads of European nobles, the kitchen was sometimes in a separate sunken floor building to keep the main building, which served social and official purposes, free from smoke. A similar design can be found in the Iroquois longhouses of North America. Besides cooking, the fire also served as a source of heat and light to the single-room building. In place of a chimney, these early buildings had a hole in the roof through which some of the smoke could escape.

The "kitchen area" was between the entrance and the fireplace. Early medieval European longhouses had an open fire under the highest point of the building. There were no chimneys. The fireplace was typically on the floor, placed at a wall--sometimes raised a little bit--such that one had to kneel to cook.

In a Roman villa, the kitchen was typically integrated into the main building as a separate room, set apart for practical reasons of smoke and sociological reasons of the kitchen being operated by slaves. Wealthy Romans had relatively well-equipped kitchens. Some had small mobile bronze stoves, on which a fire could be lit for cooking. In the Roman Empire, common folk in cities often had no kitchen of their own; they did their cooking in large public kitchens.

In such houses, there was often a separate small storage room in the back of the kitchen used for storing food and kitchen utensils. Homes of the wealthy had the kitchen as a separate room, usually next to a bathroom (so that both rooms could be heated by the kitchen fire), both rooms being accessible from the court. In many such homes, a covered but otherwise open patio served as the kitchen. The houses in Ancient Greece were commonly of the atrium-type: the rooms were arranged around a central courtyard.

Water on tap only became gradually available during industrialization; before, water had to be collected from the nearest well and heated in the kitchen. When technical advances brought new ways to heat food in the 18th and 19th centuries, architects took advantage of newly-gained flexibility to bring fundamental changes to the kitchen. Until the 18th century, open fire was the sole means of heating food, and the architecture of the kitchen reflected this. The development of the kitchen has been intricately and intrinsically linked with the development of the cooking range or stove.

. Sometimes, it is the most comforting room in a house, where family and visitors tend to congregate. The kitchen may also be the place where the family eats, provided it is large enough. If a washing machine is present, washing and drying laundry is also done in the kitchen.

Although the main function of a kitchen is cooking, it can be the center of other activities as well, especially within homes, depending on its size, furnishing, and equipment. Some installations to store food usually also are present, either in the form of an adjacent pantry or more commonly cabinets and a refrigerator. Modern kitchens often also feature a dishwasher. A modern kitchen is typically equipped with a stove or microwave oven and has a sink with water on tap for cleaning food and dishwashing.

A kitchen is a room used for food preparation. Daidokoro - the kitchen in Japan. Online edition of Nicolas Cahill's Household and City Organization at Olynthus (ISBN 0-300-08495-1), which has some information about the kitchens in ancient Greek times. E.: Encyclopedia of Kitchen History; Fitzroy Dearborn Publishers; (November 2004); ISBN 1-579-58380-6.

Snodgrass, M. In English. The introduction is available online. A.: The Bathroom, the Kitchen, and the Aesthetics of Waste, Princeton Architectural Press; 1996; ISBN 1-568-98096-5.

and Miller, J. Lupton, E. Harrison, M.: The Kitchen in History, Osprey; 1972; ISBN 0-850-45068-3; out of print. The text is vailable at Project Gutenberg at [1].

and Beecher Stowe, H.: The American Woman's Home, 1869. E. Beecher, C. In German; out of print.

(Ed.): Oikos: Von der Feuerstelle zur Mikrowelle, Anabes, Giessen 1992; ISBN 3-870-38669-X. Andritzky, M. Both in German. Gang" (PDF file, 5 Mb).

Two collections of architecture students' works on the kitchen: "Küchen" (PDF file, 3 Mb) and "Küchen, 2. In German. (Ed.): Die Küche — Zur Geschichte eines architektonischen, sozialen und imaginativen Raums, Verlag Böhlau, Vienna 1999; ISBN 3-205-99076-5. et al.

Miklautz, E. Japanese kitchens. In a closed room, this doesn't make much sense, but in an open kitchen, it makes the stove accessible from all sides such that two persons can cook together, and allows for contact with guests or the rest of the family, for the cook doesn't face the wall anymore. Here, the stove or both the stove and the sink are placed where an L or U kitchen would have a table, in a freestanding "island", separated from the other cabinets.

The block kitchen is a more recent development, typically found in open kitchens. This is a typical work kitchen, too, unless the two other cabinet rows are short enough to place a table at the fourth wall. A U-kitchen has cabinets along three walls, typically with the sink at the base of the "U". Again, the work triangle is preserved, and there may even be space for an additional table at a third wall, provided it doesn't intersect the triangle.

In the L-kitchen, the cabinets occupy two adjacent walls. This is the classical work kitchen. The double file kitchen (also known as galley or corridor) has two rows of cabinets at opposite walls, one containing the stove and the sink, the other the refrigerator. This is not optimal, but often the only solution if space is restricted.

A single file kitchen has all of these along one wall; the work triangle degenerates to a line.