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Medium-density fibreboard

Medium-density fibreboard (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibre, often in a defibrator, combining it with wax and a resin binder, and forming it into panels by applying high temperature and pressure. MDF is generally denser than plywood. It is made up of separated fibre but can be used as a building material similar in application to plywood. It is stronger and denser than particle board.

The name derives from the distinction in densities of fibreboard. Large-scale production of MDF began in the 1980s, in both North America and Europe.

Over time, the term "MDF" has become a generic name for any dry-process fibreboard.

Physical properties
MDF is typically made up of 82% wood fibre, 9% urea-formaldehyde resin glue, 8% water, and 1% paraffin wax. The density is typically between 500 and 1,000 kg/m3. The range of density and classification as light-, standard-, or high-density board is a misnomer and confusing. The density of the board, when evaluated in relation to the density of the fibre that goes into making the panel, is important. A thick MDF panel at a density of 700 – may be considered as high density in the case of softwood fibre panels, whereas a panel of the same density made of hardwood fibres is not regarded as so. The evolution of the various types of MDF has been driven by differing need for specific applications.

Types
The different kinds of MDF (sometimes labeled by colour) are:
 * Ultralight MDF plate (ULDF)
 * Moisture-resistant board is typically green
 * Fire retardant MDF is typically red or blue

Although similar manufacturing processes are used in making all types of fibreboard, MDF has a typical density of 600–800 kg/m3 or 0.022–0.029 lb/in3, in contrast to particle board (500–800 kg/m3) and to high-density fibreboard (600–1,450 kg/m3).

Manufacturing
In Australia and New Zealand, the main species of tree used for MDF is plantation-grown radiata pine, but a variety of other products have also been used, including other woods, waste paper, and fibres. Where moisture resistance is desired, a proportion of eucalypt species may be used, making use of the endemic oil content of such trees.

Chip production
The trees are debarked after being cut. The bark can be sold for use in landscaping or used as biomass fuel in on-site furnaces. The debarked logs are sent to the MDF plant, where they go through the chipping process. A typical disk chipper contains four to 16 blades. Any resulting chips that are too large may be rechipped; undersized chips may be used as fuel. The chips are then washed and checked for defects. Chips may be stored in bulk, as a reserve for manufacturing.

Fibre production
Compared to other fibre boards, such as Masonite, MDF is characterised by the next part of the process, and how the fibres are processed as individual, but intact, fibres and vessels, manufactured through a dry process. The chips are then compacted into small plugs using a screw feeder, heated for 30–120 seconds to soften the lignin in the wood, then fed into a defibrator. A typical defibrator consists of two counter-rotating discs with grooves in their faces. Chips are fed into the centre and are fed outwards between the discs by centrifugal force. The decreasing size of the grooves gradually separates the fibres, aided by the softened lignin between them.

From the defibrator, the pulp enters a blowline, a distinctive part of the MDF process. This is an expanding circular pipeline, initially 40 mm in diameter, increasing to 1500 mm. Wax is injected in the first stage, which coats the fibres and is distributed evenly by the turbulent movement of the fibres. A urea-formaldehyde resin is then injected as the main bonding agent. The wax improves moisture resistance and the resin initially helps reduce clumping. The material dries quickly in the final heated expansion chamber of the blowline and expands into a fine, fluffy and lightweight fibre. The glue and the other components (hardener, dye, urea, and so on) can be injected into blowline even at a high pressure (100 bar) and the drying process continues inside a long pipe to the exit cyclones, that is connected to the heating chamber. This fibre may be used immediately, or stored.

Sheet forming
Dry fibre gets sucked into the top of a "pendistor", which evenly distributes fibre into a uniform mat below it, usually of 230–610 mm thickness. The mat is precompressed and either sent straight to a continuous hot press or cut into large sheets for a multiple-opening hot press. The hot press activates the bonding resin and sets the strength and density profile. The pressing cycle operates in stages, with the mat thickness being first compressed to around 1.5 times the finished board thickness, then compressed further in stages and held for a short period. This gives a board profile with zones of increased density, thus mechanical strength, near the two faces of the board and a less dense core.

After pressing, MDF is cooled in a star dryer or cooling carousel, trimmed, and sanded. In certain applications, boards are also laminated for extra strength.

The environmental impact of MDF has greatly improved over the years. Today, many MDF boards are made from a variety of materials. These include other woods, scrap, recycled paper, bamboo, carbon fibres and polymers, forest thinnings, and sawmill off-cuts.

As manufacturers are being pressured to come up with greener products, they have started testing and using nontoxic binders. New raw materials are being introduced. Straw and bamboo are becoming popular fibres because they are a fast-growing, renewable resource.

Comparison with natural woods
MDF does not contain knots or rings, making it more uniform than natural woods during cutting and in service. However, MDF is not entirely isotropic since the fibres are pressed tightly together through the sheet. Typical MDF has a hard, flat, smooth surface that makes it ideal for veneering, as no underlying grain is available to telegraph through the thin veneer as with plywood. A so-called "premium" MDF is available that features more uniform density throughout the thickness of the panel.

MDF may be glued, doweled, or laminated. Typical fasteners are T-nuts and pan-head machine screws. Smooth-shank nails do not hold well, and neither do fine-pitch screws, especially in the edge. Special screws are available with a coarse thread pitch, but sheet-metal screws also work well. MDF is not susceptible to splitting when screws are installed in the face of the material, but due to the alignment of the wood fibres, may split when screws are installed in the edge of the board without pilot holes.

Advantages

 * Denser than plywood and chipboard
 * Consistent in strength and size
 * Shapes well
 * Stable dimensions (less expansion and contraction than natural wood)
 * Takes paint well
 * Takes wood glue well
 * High screw pull-out strength in the face grain of the material
 * Flexible

Disadvantages

 * Low-grade MDF may swell and break when saturated with water
 * May warp or expand in humid environments if not sealed
 * May release formaldehyde, which is a known human carcinogen and may cause allergy, eye and lung irritation when cutting and sanding
 * Dulls blades more quickly than many woods: Use of tungsten carbide-edged cutting tools is almost mandatory, as high-speed steel dulls too quickly.
 * Though it does not have a grain in the plane of the board, it does have one into the board. Screwing into the edge of a board will generally cause it to split in a fashion similar to delaminating.

Applications
MDF is often used in school projects because of its flexibility. Slatwall panels made from MDF are used in the shop fitting industry. MDF is primarily used for indoor applications due to its poor moisture resistance. It is available in raw form, or with a finely sanded surface, or with a decorative overlay.

MDF is also usable for furniture such as cabinets, because of its strong surface.

MDF's density makes it a useful material for the walls of pipe-organ chambers, allowing sound, particularly bass, to be reflected out of the chamber into the hall.

Safety concerns
When MDF is cut, a large quantity of dust particulate is released into the air.

Formaldehyde resins are commonly used to bind together the fibres in MDF, and testing has consistently revealed that MDF products emit free formaldehyde and other volatile organic compounds that pose health risks at concentrations considered unsafe, for at least several months after manufacture. Urea-formaldehyde is always being slowly released from the edges and surface of MDF. When painting, coating all sides of the finished piece is a good practice to seal in the free formaldehyde. Wax and oil finishes may be used as finishes, but they are less effective at sealing in the free formaldehyde.

Whether these constant emissions of formaldehyde reach harmful levels in real-world environments is not fully determined. The primary concern is for the industries using formaldehyde. As far back as 1987, the United States Environmental Protection Agency classified it as a "probable human carcinogen", and after more studies, the World Health Organization's International Agency for Research on Cancer (IARC), in 1995, also classified it as a "probable human carcinogen". Further information and evaluation of all known data led the IARC to reclassify formaldehyde as a "known human carcinogen" associated with nasal sinus cancer and nasopharyngeal cancer, and possibly with leukaemia in June 2004.

According to International Composite Board Emission Standards, three European formaldehyde classes are used, E0, E1, and E2, based on the measurement of formaldehyde emission levels. For instance, E0 is classified as having less than 3 mg of formaldehyde out of every 100 g of the glue used in particleboard and plywood fabrication. E1 and E2 are classified as having 9 and 30 g of formaldehyde per 100 g of glue, respectively. All around the world, variable certification and labeling schemes are there for such products that can be explicit to formaldehyde release, such as that of Californian Air Resources Board.

Veneered MDF
Veneered MDF provides many of the advantages of MDF with a decorative wood veneer surface layer. In modern construction, spurred by the high costs of hardwoods, manufacturers have been adopting this approach to achieve a high-quality finishing wrap covering over a standard MDF board. One common type uses oak veneer. Making veneered MDF is a complex procedure, which involves taking a slice of hardwood about 1–2 mm thick and then, through high pressure and stretching methods, wrapping them around the profiled MDF boards. This is possible only with simple profiles; otherwise, when the thin wood layer dries, it breaks at bends and angles.

title: Medium-density fibreboard


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Homo ergaster

Homo ergaster is an extinct species or subspecies of archaic humans who lived in Africa in the Early Pleistocene. Whether H. ergaster constitutes a species of its own or should be subsumed into H. erectus is an ongoing and unresolved dispute within palaeoanthropology. Proponents of synonymisation typically designate H. ergaster as "African Homo erectus" or "Homo erectus ergaster". The name Homo ergaster roughly translates to "working man", a reference to the more advanced tools used by the species in comparison to those of their ancestors. The fossil range of H. ergaster mainly covers the period of 1.7 to 1.4 million years ago, though a broader time range is possible. Though fossils are known from across East and Southern Africa, most H. ergaster fossils have been found along the shores of Lake Turkana in Kenya. There are later African fossils, some younger than 1 million years ago, that indicate long-term anatomical continuity, though it is unclear if they can be formally regarded as H. ergaster specimens. As a chronospecies, H. ergaster may have persisted to as late as 600,000 years ago, when new lineages of Homo arose in Africa.

Those who believe H. ergaster should be subsumed into H. erectus consider there to be too little difference between the two to separate them into distinct species. Proponents of keeping the two species as distinct cite morphological differences between the African fossils and H. erectus fossils from Asia, as well as early Homo evolution being more complex than what is implied by subsuming species such as H. ergaster into H. erectus. Additionally, morphological differences between the specimens commonly seen as constituting H. ergaster might suggest that H. ergaster itself does not represent a cohesive species. Regardless of their most correct classification, H. ergaster exhibit primitive versions of traits later expressed in H. erectus and are thus likely the direct ancestors of later H. erectus populations in Asia. Additionally, H. ergaster is likely ancestral to later hominins in Europe and Africa, such as modern humans and Neanderthals.

Several features distinguish H. ergaster from australopithecines as well as earlier and more basal species of Homo, such as H. habilis. Among these features are their larger body mass, relatively long legs, obligate bipedalism, relatively small jaws and teeth (indicating a major change in diet) as well as body proportions and inferred lifestyles more similar to modern humans than to earlier and contemporary hominins. With these features in mind, some researchers view H. ergaster as being the earliest true representative of the genus Homo.

H. ergaster lived on the savannah in Africa, a unique environment with challenges that would have resulted in the need for many new and distinct behaviours. Earlier Homo probably used counter-attack tactics, like modern primates, to keep predators away. By the time of H. ergaster, this behaviour had probably resulted in the development of true hunter-gatherer behaviour, a first among primates. H. ergaster was an apex predator. Further behaviours that might first have arisen in H. ergaster include male-female divisions of foraging and true monogamous pair bonds. H. ergaster also marks the appearance of more advanced tools of the Acheulean industry, including the earliest known hand axes. Though undisputed evidence is missing, H. ergaster might also have been the earliest hominin to master control of fire.

Research history
The systematics and taxonomy of Homo in the Early to Middle Pleistocene is one of the most disputed areas of palaeoanthropology. In early palaeoanthropology and well into the twentieth century, it was generally assumed that Homo sapiens was the end result of gradual modifications within a single lineage of hominin evolution. As the perceived transitional form between early hominins and modern humans, H. erectus, originally assigned to contain archaic human fossils in Asia, came to encompass a wide range of fossils covering a large span of time (almost the entire temporal range of Homo). Since the late twentieth century, the diversity within H. erectus has led some to question what exactly defines the species and what it should encompass. Some researchers, such as palaeoanthropologist Ian Tattersall in 2013, have questioned H. erectus since it contains an "unwieldly" number of fossils with "substantially differing morphologies".

In the 1970s, palaeoanthropologists Richard Leakey and Alan Walker described a series of hominin fossils from Kenyan fossil localities on the eastern shore of Lake Turkana. The most notable finds were two partial skulls; KNM ER 3733 and KNM ER 3883, found at Koobi Fora. Leakey and Walker assigned these skulls to H. erectus, noting that their brain volumes (848 and 803 cc respectively) compared well to the far younger type specimen of H. erectus (950 cc). Another significant fossil was a fossil mandible recovered at Ileret and described by Leakey with the designation KNM ER 992 in 1972 as "Homo of indeterminate species".

In 1975, palaeoanthropologists Colin Groves and Vratislav Mazák designated KNM ER 992 as the holotype specimen of a distinct species, which they dubbed Homo ergaster. The name (ergaster being derived from the Ancient Greek ἐργαστήρ, ergastḗr, 'workman') roughly translates to "working man" or "workman". Groves and Mazák also included many of the Koobi Fora fossils, such as KNM ER 803 (a partial skeleton and some isolated teeth) in their designation of the species, but did not provide any comparison with the Asian fossil record of H. erectus in their diagnosis, inadvertently causing some of the later taxonomic confusion in regards to the species.

A nearly complete fossil, interpreted as a young male (though the sex is actually undetermined), was discovered at the western shore of Lake Turkana in 1984 by Kenyan archaeologist Kamoya Kimeu. The fossils were described by Leakey and Walker, alongside paleoanthropologists Frank Brown and John Harris, in 1985 as KNM-WT 15000 (nicknamed "Turkana Boy"). They interpreted the fossil, consisting of a nearly complete skeleton, as representing H. erectus. Turkana Boy was the first discovered comprehensively preserved specimen of H. ergaster/erectus found and constitutes an important fossil in establishing the differences and similarities between early Homo and modern humans. Turkana Boy was placed in H. ergaster by paleoanthropologist Bernard Wood in 1992, and is today, alongside other fossils in Africa previously designated as H. erectus, commonly seen as a representative of H. ergaster by those who support H. ergaster as a distinct species.

Classification
H. ergaster is easily distinguished from earlier and more basal species of Homo, notably H. habilis and H. rudolfensis, by a number of features that align them, and their inferred lifestyle, more closely to modern humans than to earlier and contemporary hominins. As compared to their relatives, H. ergaster had body proportions more similar to later members of the genus Homo, notably relatively long legs which would have made them obligately bipedal. The teeth and jaws of H. ergaster are also relatively smaller than those of H. habilis and H. rudolfensis, indicating a major change in diet. In 1999, palaeoanthropologists Bernard Wood and Mark Collard argued that the conventional criteria for assigning species to the genus Homo were flawed and that early and basal species, such as H. habilis and H. rudolfensis, might appropriately be reclassified as ancestral australopithecines. In their view, the true earliest representative of Homo was H. ergaster.

Since its description as a separate species in 1975, the classification of the fossils referred to H. ergaster has been in dispute. H. ergaster was immediately dismissed by Leakey and Walker and many influential researchers, such as palaeoanthropologist G. Philip Rightmire, who wrote an extensive treatise on H. erectus in 1990, continued to prefer a more inclusive and comprehensive H. erectus. Overall, there is no doubt that the group of fossils composing H. erectus and H. ergaster represent the fossils of a more or less cohesive subset of closely related archaic humans. The question is instead whether these fossils represent a radiation of different species or the radiation of a single, highly variable and diverse, species over the course of almost two million years. This long-running debate remains unresolved, with researchers typically using the terms H. erectus s.s. (sensu stricto) to refer to H. erectus fossils in Asia and the term H. erectus s.l. (sensu lato) to refer to fossils of other species that may or may not be included in H. erectus, such as H. ergaster, H. antecessor and H. heidelbergensis.

For obvious reasons, H. ergaster shares many features with H. erectus, such as large forward-projecting jaws, large brow ridges and a receding forehead. Many of the features of H. ergaster are clearly more primitive versions of features later expressed in H. erectus, which somewhat obscures the differences between the two. There are subtle, potentially significant, differences between the East African and East Asian fossils. Among these are the somewhat higher-domed and thinner-walled skulls of H. ergaster, and the even more massive brow ridges and faces of Asian H. erectus.

The question is made more difficult since it regards how much intraspecific variation can be exhibited in a single species before it needs to be split into more, a question that in and of itself does not have a clear-cut answer. A 2008 analysis by anthropologist Karen L. Baab, examining fossils of various H. erectus subspecies, and including fossils attributed to H. ergaster, found that the intraspecific variation within H. erectus was greater than expected for a single species when compared to modern humans and chimpanzees, but fell well within the variation expected for a species when compared to gorillas, and even well within the range expected for a single subspecies when compared to orangutans (though this is partly due to the great sexual dimorphism exhibited in gorillas and orangutans). Baab concluded that H. erectus s.l. was either a single but variable species, several subspecies divided by time and geography or several geographically dispersed but closely related species. In 2015, paleoanthropologists David Strait, Frederick Grine and John Fleagle listed H. ergaster as one of the seven "widely recognized" species of Homo, alongside H. habilis, H. rudolfensis, H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens, noting that other species, such as H. floresiensis and H. antecessor, were less widely recognised or more poorly known.

Variation in the fossil material
Comparing various African fossils attributed to H. erectus or H. ergaster to Asian fossils, notably the type specimen of H. erectus, in 2013, Ian Tattersall concluded that referring to the African material as H. ergaster rather than "African H. erectus" was a "considerable improvement" as there were many autapomorphies distinguishing the material of the two continents from one another. Tattersall believes it to be appropriate to use the designation H. erectus only for eastern Asian fossils, disregarding its previous use as the name for an adaptive grade of human fossils from throughout Africa and Eurasia. Though Tattersall concluded that the H. ergaster material represents the fossils of a single clade of Homo, he also found there to be considerable diversity within this clade; the KNM ER 992 mandible accorded well with other fossil mandibles from the region, such as OH 22 from Olduvai and KNM ER 3724 from Koobi Fora, but did not necessarily match with cranial material, such as KNM ER 3733 and KNM ER 3883 (since neither preserves the jaw), nor with the mandible preserved in Turkana Boy, which has markedly different dentition.

The most "iconic" fossil of H. ergaster is the KNM ER 3733 skull, which is sharply distinguished from Asian H. erectus by a number of characteristics, including that the brow ridges project forward as well as upward and arc separately over each orbit and the braincase being quite tall compared to its width, with its side walls curving. KNM ER 3733 can be distinguished from KNM ER 3883 by a number of features as well, notably in that the margins of KNM ER 3883's brow ridges are very thickened and protrude outwards but slightly downwards rather than upwards. Both skulls can be distinguished from the skull of Turkana Boy, which possesses only slightly substantial thickenings of the superior orbital margins, lacking the more vertical thickening of KNM ER 3883 and the aggressive protrusion of KNM ER 3733. In addition to this, the facial structure of Turkana Boy is narrower and longer than that of the other skulls, with a higher nasal aperture and likely a flatter profile of the upper face. It is possible that these differences can be accounted for through Turkana Boy being a subadult, 7 to 12 years old. Furthermore, KNM ER 3733 is presumed to have been the skull of a female (whereas Turkana Boy is traditionally interpreted as male), which means that sexual dimorphism may account for some of the differences.

The differences between Turkana Boy's skull and KNM ER 3733 and KNM ER 3883, as well as the differences in dentition between Turkana Boy and KNM ER 992 have been interpreted by some, such as paleoanthropologist Jeffrey H. Schwartz, as suggesting that Turkana Boy and the rest of the H. ergaster material does not represent the same taxon. Schwartz also noted none of the fossils seemed to represent H. erectus either, which he believed was in need of significant revision. In 2000, French palaeoanthropologist Valéry Zeitoun suggested that KNM ER 3733 and KNM ER 3883 should be referred to two separate species, which she dubbed H. kenyaensis (type specimen KNM ER 3733) and H. okotensis (type specimen KNM ER 3883), but these designations have found little acceptance.

Evolution and temporal range
Although frequently assumed to have originated in East Africa, the origins of H. ergaster are obscured by the fact that the species marks a radical departure from earlier species of Homo and Australopithecus in its long limbs, height and modern body proportions. Though a large number of Pleistocene tools have been found in East Africa, it can not be fully ascertained that H. ergaster originated there without further fossil discoveries. It is assumed that H. ergaster evolved from earlier species of Homo, probably H. habilis. Though populations of H. ergaster outside of Africa have been inferred based on the geographical distribution of their descendants and tools matching those in East Africa, fossils of the species are mainly from East Africa in the time range of 1.8 to 1.7 million years ago. Most fossils have been recovered from around the shores of Lake Turkana in Kenya.

The oldest known specimen of H. erectus s.l. in Africa (i.e. H. ergaster) is DNH 134, a skull recovered in the Drimolen Palaeocave System in South Africa, dated to 2.04 to 1.95 million years ago. The skull is also the oldest known H. erectus s.l. specimen overall, showing clear similarities to KNM ER 3733, and demonstrates that early H. ergaster coexisted with other hominins such as Paranthropus robustus and Australopithecus sediba.

There are also younger specimens of H. ergaster; notably, Turkana Boy is dated to about 1.56 million years ago. A handful of even younger African skulls make the case for long-term anatomical continuity, though it is unclear if they can appropriately be formally regarded as H. ergaster specimens; the "Olduvai Hominid 9" skull from Olduvai Gorge is dated to about 1.2 to 1.1 million years ago and there are also skulls from Buia (near the coast of Eritrea, dated to ~1 million years old), the Bouri Formation in Ethiopia (dated to between 1 million and 780,000 years old) and a fragmentary skull from Olorgesailie in Kenya (dated to between 970,000 and 900,000 years ago). The Olduvai skull is similar to Asian H. erectus in its massive brow ridge, but the others only show minor differences to earlier H. ergaster skulls.

The H. erectus in Asia, as well as later hominins in Europe (i. e. H. heidelbergensis and H. neanderthalensis) and Africa (H. sapiens) are all probably lineages descended from H. ergaster. Because H. ergaster is thought to have been ancestral to these later Homo, it might have persisted in Africa until around 600,000 years ago, when brain size increased rapidly and H. heidelbergensis emerged.

Expansion out of Africa
Traditionally, H. erectus was seen as the hominin that first left Africa to colonise Europe and Asia. If H. ergaster is distinct from H. erectus, this role would apply to H. ergaster instead. Very little concrete information is known on when and which Homo first appeared in Europe and Asia, since Early Pleistocene fossil hominins are scarce on both continents, and that it would have been H. ergaster (or "early H. erectus") that expanded, as well as the particular manner in which they did, remains conjecture. The presence of H. erectus fossils in East Asia means that a human species, most likely H. ergaster, had left Africa before 1 million years ago, the assumption historically having been that they first migrated out of Africa around 1.9 to 1.7 million years ago. Discoveries in Georgia and China push the latest possible date further back, before 2 million years ago, also casting doubt on the idea that H. ergaster was the first hominin to leave Africa.

The main reason for leaving Africa is likely to have been an increasing population periodically outgrowing their resource base, with splintering groups moving to establishing themselves in neighboring, empty territories over time. The physiology and improved technology of H. ergaster might have allowed them to travel to and colonise territories that no one had ever occupied before. It is unclear if H. ergaster was truly uniquely capable of expanding outside Africa; australopithecines had likely colonised savannah grasslands throughout Africa by 3 million years ago and there are no clear reasons as to why they would not have been able to expand into the grasslands of Asia before H. ergaster.

The general assumption is that hominins migrated out of the continent either across the southern end of the Red Sea or along the Nile Valley, but there are no fossil hominins known from either region in the Early Pleistocene. The earliest Homo fossils outside Africa are the Dmanisi skulls from Georgia (dated to 1.77–1.85 million years old, representing either early H. ergaster or a new taxon, H. georgicus), three incisors from Ubeidiya in Israel (about 1.4 to 1 million years old) and the fossils of Java Man (H. erectus erectus, more than five thousand miles away). The dating of key Asian H. erectus specimens (including Java Man) is not entirely certain, but they are all likely to be 1.5 million years old or younger. Ubeidiya is also the oldest firmly confirmed site of Acheulean tools (one of the tool industries associated with H. ergaster) outside Africa, the tools recovered there closely resembling older tools discovered in East Africa.

The earliest fossil evidence of Homo in Asia are the aforementioned Dmanisi skulls, which share many traits with H. ergaster in Africa, suggesting that H. ergaster might have expanded out of Africa as early as 1.7–1.9 million years ago. In addition to H. ergaster-like traits, the Dmanisi skulls possess a wide assortment of other traits, some of which are similar to traits in earlier hominins such as H. habilis, and the site notably lacks preserved hand axes (otherwise characteristic of H. ergaster), which means that hominins might have spread out of Africa even earlier than H. ergaster. The skull D2700 (Dmanisi skull 3) in particular resembles H. habilis in the small volume of its braincase (600 cc), the form of the middle and upper face and the lack of an external nose. The mixture of skulls at Dmanisi suggests that the definition of H. ergaster (or H. erectus) might most appropriately be expanded to contain fossils that would otherwise be assigned to H. habilis or that two separate species of archaic humans left Africa early on. In addition to the Dmanisi fossils, stone tools manufactured by hominins have been discovered on the Loess Plateau in China and dated to 2.12 million years old, meaning that hominins must have left Africa before that time.

An alternative hypothesis historically has been that Homo evolved in Asia from earlier ancestors that had migrated there from Africa, and then expanded back into Europe, where it gave rise to H. sapiens. This view was notably held by Eugène Dubois, who first described H. erectus fossils in the 19th century and considered the fossils of Java Man, at the time undeniably the earliest known hominin fossils, as proof of the hypothesis. Though the discovery of australopithecines and earlier Homo in Africa meant that Homo itself did not originate in Asia, the idea that H. erectus (or H. ergaster) in particular did, and then expanded back into Africa, has occasionally resurfaced. Various fossil discoveries have been used to support it through the years, including a massive set of jaws from Indonesia which were perceived to be similar to those of australopithecines and dubbed Meganthropus (now believed to be an unrelated hominid ape). The discovery of H. floresiensis in 2003, which preserved primitive foot and wrist anatomy reminiscent of that of H. habilis and Australopithecus again led to suggestions of pre-erectus hominins in Asia, though there are no known comparable foot or wrist bones from H. erectus which makes comparisons impossible. The idea that H. ergaster/H. erectus first evolved in Asia before expanding back into Africa was substantially weakened by the dating of the DNH 134 skull as approximately 2 million years old, predating all other known H. ergaster/H. erectus fossils.

Build and appearance
The only well-preserved post-cranial remains of H. ergaster come from the Turkana Boy fossil. Unlike the australopithecines, Turkana Boy's arms were not longer relative to their legs than the arms of living people and the cone-shaped torso of their ancestors had evolved into a more barrel-shaped chest over narrow hips, another similarity to modern humans. The tibia (shin bone) of Turkana Boy is relatively longer than the same bone in modern humans, potentially meaning that there was more bend in the knee when walking. The slim and long build of Turkana Boy may be explained by H. ergaster living in hot and arid, seasonal environments. Through thinning of the body, body volume decreases faster than skin area and greater skin area means more effective heat dissipation.

H. ergaster individuals were significantly taller than their ancestors. Whereas Lucy, a famous Australopithecus fossil, would only have been about 1 m tall at her death, Turkana Boy was about 1.62 m tall and would probably have reached 1.82 m or more if he had survived to adulthood. Adult H. ergaster are believed to have ranged in size from about 1.45 to 1.85 m tall.

Because of being adapted to a hot and arid climate, H. ergaster might also have been the earliest human species to have nearly hairless and naked skin. If instead H. ergaster had an ape-like covering of body hair, sweating (the primary means through which modern humans prevent their brains and bodies from overheating) would not have been as efficient. Though sweating is the generally accepted explanation for hairlessness, other proposed explanations include a reduction of parasite load and sexual selection. It is doubtful if australopithecines and earlier Homo were sufficiently mobile to make hair loss an advantageous trait, whereas H. ergaster was clearly adapted for long-distance travel and noted for inhabiting lower altitudes (and open, hot savannah environments) than their ancestors. Australopithecines typically inhabited colder and higher altitudes 1,000–1,600 m (3,300–5,200 ft), where nighttime temperatures would have gotten significantly colder and insulating body hair may have been required.

Alternatively and despite this, the loss of body hair could have occurred significantly earlier than H. ergaster. Though skin impressions are unknown in any extinct hominin, it is possible that human ancestors were already losing their body hair around 3 million years ago. Human ancestors acquired pubic lice from gorillas about 3 million years ago, and speciation of human from gorilla pubic lice was potentially only possible because human ancestors had lost most of their body hair by this early date. It is also possible that the loss of body hair occurred at a significantly later date. Genetic analysis suggests that high activity in the melanocortin 1 receptor, which produces dark skin, dates back to about 1.2 million years ago. This could indicate the evolution of hairlessness around this time, as a lack of body hair would have left the skin exposed to harmful UV radiation.

Skull and face
Differences to modern humans would have been readily apparent in the face and skull of H. ergaster. Turkana Boy's brain was almost fully grown at the time of his death, but its volume (at 880 cc) was only about 130 cc greater than the maximum found in H. habilis, about 500 cc below the average of modern humans. The 130 cc increase from H. habilis becomes much less significant than what could be presumed when the larger body size of Turkana Boy and H. ergaster is considered. With all H. ergaster skulls considered, the brain volume of the species mostly varied between 600 and 910 cc, with some small examples only having a volume of 508–580 cc. Since their brain was smaller than that of modern humans, the skull of H. ergaster immediately narrowed behind the eye sockets (post-orbital constriction).

The brain case was long and low, and Turkana Boy's forehead was flat and receding, merging at an angle with the brow ridge above their eyes. A noticeable difference between Turkana Boy and the australopithecines and H. habilis would have been their nose, which would have been similar to that of modern humans in projecting forwards and having nostrils oriented downwards. This external nose may have also been an adaptation towards a warmer climate, since the noses of modern humans are usually cooler than their central bodies, condensing moisture that would otherwise have been exhaled and lost during periods of increased activity. The face of Turkana Boy would have been longer from top to bottom than that of modern humans, with the jaws projecting farther outwards (prognathism). Though the jaws and teeth were smaller than those of the average australopithecine and H. habilis, they were still significantly larger than those of modern humans. Since the jaw slanted sharply backwards, it is probable that they were chinless.

The overall structure of Turkana Boy's skull and face is also reflected in other H. ergaster skulls, which combine large and outwardly projecting faces with brow ridges, receding foreheads, large teeth and projecting nasal bones. Though Turkana Boy would have been no more than 12 years old when he died, their stature is more similar to that of a modern 15-year-old and the brain is comparable to that of a modern 1-year-old. By modern standards, H. ergaster would thus have been cognitively limited, though the invention of new tools prove that they were more intelligent than their predecessors.

Body mass and sexual dimorphism
H. ergaster possessed a significantly larger body mass in comparison to earlier hominins such as early Homo, Australopithecus and Paranthropus. Whereas australopithecines typically ranged in weight from 29–48 kg (64–106 lbs), H. ergaster typically ranged in weight from 52–63 kg (115–139 lbs). It is possible that the increased body size was the result of life in an open savannah environment, where increased size gives the ability to exploit broader diets in larger foraging areas, increases mobility and also gives the ability to hunt larger prey. The increased body mass also means that parents would have been able to carry their children to an older age and larger mass.

Though reduced sexual dimorphism has often been cited historically as one of the radical differences between H. ergaster and earlier Homo and australopithecines, it is unclear whether australopithecines were significantly more sexually diamorphic than H. ergaster or modern humans. Skeletal evidence suggests that sexes in H. ergaster differed no more in size than sexes in modern humans do, but a 2003 study by palaeoanthropologists Philip L. Reno, Richard S. Meindl, Melanie A. McCollum and C. Owen Lovejoy suggested that the same was also true for the significantly earlier Australopithecus afarensis. Sexual dimorphism is difficult to measure in extinct species since the sex of fossils is usually not determinable. Historically, scientists have typically measured differences between the extreme ends (in terms of size and morphology) of the fossil material attributed to a species and assumed that the resulting ratio applies to the mean difference between male and female individuals.

Growth and development
The dimensions of a 1.8 million years old adult female H. ergaster pelvis from Gona, Ethiopia suggests that H. ergaster would have been capable of birthing children with a maximum prenatal (pre-birth) brain size of 315 cc, about 30–50 % of adult brain size. This value falls intermediately between that of chimpanzees (~40 %) and modern humans (28%). Further conclusions about the growth and development in early Homo can be drawn from the Mojokerto child, a ~1.4–1.5 million year old ~1-year old Asian H. erectus, which had a brain at about 72–84% the size of an adult H. erectus brain, which suggests a brain growth trajectory more similar to that of other great apes than of modern humans. Both the Gona pelvis and the Mojokerto child suggest that the prenatal growth of H. ergaster was similar to that of modern humans but that the postnatal (post-birth) growth and development was intermediate between that of chimpanzees and modern humans. The faster development rate suggests that altriciality (an extended childhood and a long period of dependency on your parents) evolved at a later stage in human evolution, possibly in the last common ancestor of Neanderthals and modern humans. The faster development rate might also indicate that the expected lifespan of H. ergaster and H. erectus was lower than that of later and modern humans.

Diet and energetics
It is frequently assumed that the larger body and brain size of H. ergaster, compared to its ancestors, would have brought with it increased dietary and energy needs. In 2002, palaeoanthropologists Leslie C. Aiello and Jonathan C. K. Wells stated that the average resting metabolic requirements of H. ergaster would have been 39% higher than those of Australopithecus afarensis, 30% higher in males and 54% higher in females. However, the torso proportions of H. ergaster implies a relatively small gut, which means that energy needs might not necessarily have been higher in H. ergaster than in earlier hominins. This is because the earlier ape (and australopithecine) gut was large and energy-expensive since it needed to synthesize fat through fermenting plant matter, whereas H. ergaster likely ate significantly more animal fat than their predecessors. This would have allowed more energy to be diverted to brain growth, increasing brain size while maintaining the energy requirements of earlier species.

If they had increased energy requirements, H. ergaster would have needed to eat either vastly more food than australopithecines, or would have needed to eat food of superior quality. If they ate the same type of foods as the australopithecines, feeding time would then have had to be dramatically increased in proportion to the extra calories required, reducing the time H. ergaster could use for resting, socialising and travelling. Though this would have been possible, it is considered unlikely, especially since the jaws and teeth of H. ergaster are reduced in size compared to those of the australopithecines, suggesting a shift in diet away from fibrous and difficult-to-chew foods. Regardless of energy needs, the small gut of H. ergaster also suggests a more easily digested diet composed of food of higher quality.

It is likely that H. ergaster consumed meat in higher proportions than the earlier australopithecines. Meat was probably acquired through a combination of ambushes, active hunting and confrontational scavenging. H. ergaster must not only have possessed the ability of endurance running, but must also have been able to defend themselves and the carcasses of their prey from the variety of contemporary African predators. It is possible that a drop in African carnivoran species variety around 1.5 million years ago can be ascribed to competition with opportunistic and carnivorous hominins.

On its own, meat might not have been able to fully sustain H. ergaster. Modern humans can not sufficiently metabolize protein to meet more than 50% of their energy needs and modern humans who heavily rely on animal-based products in their diet mostly rely on fat to sustain the rest of their energy requirements. Multiple reasons make a fully meat-based diet in H. ergaster unlikely, the most prominent being that African ungulates (the primary prey available) are relatively low in fat and that high meat diets demand increased intake of water, which would have been difficult in an open and hot environment. Modern African hunter-gatherers who rely heavily on meat, such as the Hadza and San peoples, also use cultural means to recover the maximum amount of fat from the carcasses of their prey, a method that would not have been available to H. ergaster.

H. ergaster would thus likely have consumed large quantities of meat, vastly more than their ancestors, but would also have had to make use of a variety of other food sources, such as seeds, honey, nuts, invertebrates, nutritious tubers, bulbs and other underground plant storage organs. The relatively small chewing capacity of H. ergaster, in comparison to its larger-jawed ancestors, means that the meat and high quality plant food consumed would likely have required the use of tools to process before eating.

Social structure and dynamics
H. ergaster lived on the African savannah, which during the Pleistocene was home to a considerably more formidable community of carnivorans than the present savannah. Hominins could probably only have adapted to life on the savannah if effective anti-predator defense behaviours had already evolved. Defense against predators would likely have come through H. ergaster living in large groups, possessing stone (and presumably wooden) tools and effective counter-attack behaviour having been established. In modern primates that spend significant amounts of time on the savannah, such as chimpanzees and savannah baboons, individuals form large, multi-male, groups wherein multiple males can effectively work together to fend off and counter-attack predators, occasionally with the use of stones or sticks, and protect the rest of the group. It is possible that similar behaviour was exhibited in early Homo. Based on the male-bonded systems within bonobos and chimpanzees, and the tendency towards male bonding in modern foragers, groups of early Homo might have been male-bonded as well. Because of the scarcity of fossil material, group size in early Homo cannot be determined with any certainty. Groups were probably large, it is possible groups were above the upper range of known group sizes among chimpanzees and baboons (c. 100 individuals or more). In 1993, palaeoanthropologists Leslie C. Aiello and R. I. M. Dunbar estimated that the group size of H. habilis and H. rudolfensis, based on neocortex size (as there is a known relationship between neocortex size and group size in modern non-human primates), would have ranged from about 70–85 individuals. With the additional factor of bipedalism, which is energetically cheaper than quadrupedalism, the maximum ecologically tolerable group size may have been even larger. Aiello's and Dunbar's group size estimate in regards to H. ergaster was 91–116 individuals.

Social and counter-attack behaviour of earlier Homo probably carried over into H. ergaster, where they are likely to have developed even further. H. ergaster was probably the first primate to move into the niche of social carnivore (i. e. hunter-gatherer). Such behaviour would probably have been the result of counter-attacks in the context of competition over nutritious food with other carnivores and would probably have evolved from something akin to the opportunistic hunting sometimes exhibited by chimpanzees. The switch to predation in groups might have triggered a cascade of evolutionary changes which changed the course of human evolution. Cooperative behaviours such as opportunistic hunting in groups, predator defense and confrontational scavenging would have been critical for survival which means that a fundamental transition in psychology gradually transpired. With the typical "competitive cooperation" behaviour exhibited by most primates no longer being favored through natural selection and social tendencies taking its place, hunting, and other activities, would have become true collaborative efforts. Because counter-attack behaviour is typically exhibited in males of modern primates, social hunting in archaic humans is believed to have been a primarily male activity. Females likely conducted other types of foraging, gathering food which did not require hunting (i.e. fruits, nuts, eggs etc.).

With hunting being a social activity, individuals probably shared the meat with one another, which would have strengthened the bonds both between the hunters themselves and between the hunters and the rest of the H. ergaster group. Females likely shared what they had foraged with the rest of the group as well. This development could have led to the development of male-female friendships into opportunistic monogamous pair bonds. Since sexual selection from females probably favored males that could hunt, the emerging social behaviour resulting from these new behaviours would have been carried over and amplified through the generations.

The only direct evidence of H. ergaster group composition comes from a series of sites outside of Ileret in Kenya, where 97 footprints made around 1.5 million years ago by a group of at least 20 individuals have been preserved. Based on the size of the footprints, one of the trackways appears to have been a group entirely composed of males, possibly a specialised task group, such as a border patrol or a hunting or foraging party. If this assessment is correct, this would further suggest a male-female division of responsibilities. In modern hunter-gatherer societies who target large prey items, male parties are typically dispatched to bring down these high-risk animals, and, due to the low success rate, female parties tend to focus on more predictable foods.

Tool production
Early H. ergaster inherited the Oldowan culture of tools from australopithecines and earlier Homo, though quickly learnt to strike much larger stone flakes than their predecessors and contemporaries. By 1.65 million years ago, H. ergaster had created the extensively flaked artefacts and early hand axes that mark the Acheulean culture, and by 1.6–1.4 million years ago, the new tool industry was widely established in East Africa. Acheulean tools differ from Oldowan tools in that the core forms of the tools were clearly deliberate. Whereas the shape of the core forms in Oldowan tools, which were probably used mostly as hammers to crack bones for marrow, appears to not have mattered much, the hand axes of the Acheulean culture demonstrate an intent to produce narrow and sharp objects, typically in teardrop, oval or triangular shapes. Once in place, the Acheulean industry remained unchanged throughout H. ergaster 's existence and later times, with tools produced near its end about 250,000 years ago not being significantly different from tools produced 1.65 million years ago. The oldest Acheulean assemblages also preserve core forms similar to those in Oldowan tools, but there are no known true intermediate forms between the two, suggesting that the appearance of Acheulean tools was an abrupt and sudden development. The most significant development that led to the Acheulean tools was likely early hominins learning the ability to strike large flakes, up to 30 cm (1 ft) or more in length, from larger boulders, from which they could manufacture new tools such as hand axes. Though "hand axe" implies that all hand axes were used for chopping and were hand-held, they came in a variety of different shapes and size and probably served several different functions. Carefully shaped and symmetric examples may have been hurled at prey akin to modern discuses, more casually made examples may simply have served as portable sources for sharp flakes and some could have been used for scraping or chopping wood. Additionally, hand axes are effective butchering tools and were possibly also used for dismembering carcasses of large animals.

There are preserved hand axes that are too unwieldy and large to be used for any apparent practical purpose. The use of these larger hand axes, and for some discovered collections of hundreds of hand axes without obvious signs of use, is speculative and conjectural. An idea that has been popular in the popular press, and frequently cited in academia, is that large and impressive hand axes might have been emblems used for attracting mates, with makers of large axes showing strength, coordination and determination, qualities that may have been regarded as attractive. Palaeoanthropologists April Nowell and Melanie Lee Chang noted in 2009 that though this theory is "both intriguing and emotionally appealing", there is little evidence for it and it is untestable. They considered it more probable that variations in hand axe morphology over the course of hundreds of thousands of years was the result of various different factors rather than a single, overarching factor in sexual selection.

Fire
As Homo migrated into open savannah environments, encounters with natural fires must have become more frequent and significant. It is possible that H. ergaster were the earliest humans to master the control of fire, which they may have used for cooking purposes. Cooking renders both meat and plant foods more digestible, which might have been important since the guts of H. ergaster were reduced in size compared to those of their ancestors. Though H. ergaster/H. erectus is frequently assumed to have been the earliest Homo to control fire, concrete evidence is somewhat lacking in the fossil record, perhaps partly due to the difficulty for actual evidence of fire usage to be preserved. Two of the earliest sites commonly claimed to preserve evidence of fire usage are FxJj20 at Koobi Fora and GnJi 1/6E near Lake Baringo, both in Kenya and both dated as up to 1.5 million years old. The evidence at FxJj20 consists of burned sediments and heat-altered stone tools, whereas GnJi 1/6E preserves large clasts of baked clay, associated with stone tools and faunal remains. Though it is difficult to exclude a natural origin for the fire residue evidenced, the sites remain strong candidates for early fire use.

Several sites, preserving more widely accepted evidence of fire usage, have been dated to 1 million years ago or younger, postdating the emergence and last generally accepted record of H. ergaster. These sites include cave sites, such as Wonderwerk and Swartkrans in South Africa, and open sites, such as Kalambo Falls in Zambia. The site Gesher Benot Ya’aqov in Israel, dated to about 700,000 years ago, preserves widely accepted evidence of fire usage through burnt materials and burnt flint microartefacts being preserved at numerous levels. From around 400,000 years ago and onwards, traces of fire become even more numerous in sites across Africa, Europe and Asia.

Language
The spinal cord of Turkana Boy would have been narrower than that of modern humans, which means that the nervous system of H. ergaster, and their respiratory muscles, may not have been developed enough to produce or control speech. In 2001, anthropologists Bruce Latimer and James Ohman concluded that Turkana Boy was afflicted by skeletal dysplasia and scoliosis, and thus would not have been representative of the rest of his species in this respect. In 2006, when anthropologist Marc Meyer and colleagues described a H. erectus s.l. specimen from Dmanisi, Georgia, dated to 1.78 million years old. The fossil preserves the oldest known Homo vertebrae and the spine found falls within the range of modern human spines, suggesting that the individual would have been capable of speech. Meyer and colleagues concluded that speech was probably possible within Homo very early on and that Turkana Boy probably suffered from some congenital defect, possibly spinal stenosis.

In 2013 and 2014, anthropologist Regula Schiess and colleagues concluded that there was no evidence of any congenital defects in Turkana Boy, and, in contrast to the 2001 and 2006 studies, considered the specimen to be representative of the species.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Homo ergaster


text:
L3 Technologies

L3 Technologies, formerly L-3 Communications Holdings, was an American company that supplied command and control, communications, intelligence, surveillance and reconnaissance (C3ISR) systems and products, avionics, ocean products, training devices and services, instrumentation, aerospace, and navigation products. Its customers included the Department of Defense, Department of Homeland Security, United States Intelligence Community, NASA, aerospace contractors, and commercial telecommunications and wireless customers. In 2019, it merged with Harris Corporation to form L3Harris Technologies.

L3 was headquartered in Murray Hill, Manhattan, New York City.

History
L3 was formed as L-3 Communications in 1997 to acquire certain business units from Lockheed Martin that had previously been part of Loral Corporation. These units had belonged to Lockheed Corporation and Martin Marietta, which had merged three years before in 1993. The company was founded by (and named for) Frank  L anza and Robert  L aPenta in partnership with  L ehman Brothers. Lanza and LaPenta had both served as executives at Loral and Lockheed.

Acquisitions

 * 1997
 * Paramax Systems Corporation from Lockheed Martin. Loral had acquired Paramax in 1995
 * 2000
 * Training & Simulation Division of Raytheon Systems Co., based in Arlington, Texas. This company was formerly known as Hughes Training, Inc., and part of the Hughes Aircraft Defense Group purchased by Raytheon from General Motors two years earlier. The division traces its ancestry to the original company formed by Edwin Link, inventor of the Link Trainer airplane simulator, and accordingly was renamed Link Simulation and Training (now known as Link Training and Simulation).
 * 2001
 * KDI Precision Products, Batavia, Ohio. Electronic fuzing, safe and arm devices.
 * Litton Electron Devices from Northrop Grumman (renamed L3 Electron Devices)
 * 2002
 * Raytheon Aircraft Integration Systems (renamed L3 Integrated Systems; the Greenville, Texas facility is now known as L3 Mission Integration Division, while the Waco, Texas facility is now known as L3 Platform Integration Division)
 * SyColeman Corporation, which came about from the joining of Sy Technologies and Coleman Research Corporation.
 * PerkinElmer Detection Systems from PerkinElmer which became L-3 Security & Detection Systems.
 * Wescam (currently named L3 Harris Wescam) developer of gyro-stabilized, EO-IR imaging systems.
 * 2003
 * Ship Analytics, Inc.
 * BF Goodrich Avionics
 * L-3 Communication MAS from Bombardier Aerospace.
 * 2004
 * Cincinnati Electronics, Mason, Ohio. Infrared detectors & systems, space avionics.
 * Raytheon Commercial Infrared, Richardson Texas. Infrared detectors.
 * 2005
 * Titan Corp., after a failed buyout attempt by Lockheed Martin.
 * L-3 Communication Combat Propulsion Systems, previously owned by General Dynamics Land Systems.
 * L-3 Communications MAPPS, previously CAE's Marine Controls unit
 * Electron Dynamic Devices from Boeing Satellite Systems.
 * Applied Signal & Image Technology, Linthicum Heights, MD. Geo-location systems for RF emitters.
 * Sonoma Design Group, Santa Rosa, CA. Stabilized EO/IR sensors.
 * 2006
 * Advanced System Architectures, a company based in Fleet, Hampshire, United Kingdom. L-3 ASA has core capabilities in the development and through-life management of complex information systems, data fusion and tracking solutions, and interoperable secure communications systems.
 * Crestview Aerospace, a company based in northwest Florida. Crestview Aerospace provides aircraft structures, major airframe assemblies, and military aircraft modifications for leading prime contractors and OEMs in the aerospace industry. (Sold in 2017 along with Vertex Aerospace and TCS.)
 * Nautronix and MariPro, based in Fremantle, Australia and Santa Barbara, California, respectively, from Nautronix Plc in Aberdeen, Scotland. Nautronix and MariPro provide acoustic ranges and hydrographics to commercial and defense markets.
 * TRL Technology, a specialist defense electronics company based in Gloucestershire, UK. TRL Technology is internationally known for development and innovation in the fields of interception, surveillance, electronic warfare, and communications.
 * 2010
 * Insight Technology, a company based in Londonderry, New Hampshire. Insight develops and builds optics, from night-vision goggles to weapon-mounted sights and lasers.

 * 2012
 * Thales Training and Simulation (partial), a multinational company which manufactures civil and military full flight simulators and provides related training and support services – a wholly owned subsidiary of the Thales Group. In August 2012, L-3 acquired Thales Group's civil fixed-wing flight simulation business, to form L-3 Link Simulation & Training UK.

 * 2015
 * CTC Aviation Limited (rebranded in May 2017 as L3 Airline Academy ) a company based in Southampton providing training and resourcing to many international airlines.

 * 2016
 * MacDonald Humfrey (Automation), a Luton, UK–based checkpoint security and automation company.
 * ExMac (Automation), a Droitwich, UK based automated material handling company.

 * 2017
 * Open Water Power, a Somerville, Massachusetts–based battery startup spun out of MIT. Its novel aluminum-water battery technology promises a tenfold improvement in the endurance of Unmanned Underwater Vehicles.
 * Ocean-Server Technology, a Fall River, Massachusetts–based small business specializing in lithium-ion battery, sensor, and robotic mini-sub (UUV) products
 * ASV Global, a Lafayette, Louisiana–based business with international offices in Portchester specializing in Autonomous Surface Vehicles for commercial and defense markets.

 * 2018
 * In October 2018, L3 announced an all-stock "merger of equals" with Florida-based Harris Corporation, to be closed (subject to approvals) in mid-2019. The merger was completed on June 29, 2019, and the new company, L3Harris Technologies, Inc., is based in Melbourne, Florida, where Harris was headquartered.

Business organization
As of 2017, L3 was organized under four business segments:
 * Electronic Systems
 * Advanced Programs
 * Aviation Products and Security
 * Power and Propulsion Systems
 * Precision Engagement and Training
 * Aerospace Systems
 * Aircraft Systems
 * ISR Systems
 * MAS
 * Vertex Aerospace
 * Communication Systems
 * Advanced Communications
 * Broadband Communications
 * Space and Power
 * Tactical SATCOM
 * Sensor Systems
 * Space & Sensor Systems
 * Maritime Sensor Systems
 * Worldwide Surveillance & Targeting Missions
 * Warrior Sensor Systems

Management
Frank Lanza, CEO and co-founder, died on June 7, 2006. CFO Michael T. Strianese was named as interim CEO, and was later appointed Chairman, President and CEO of the company on October 23, 2006. In 2015, former Lockheed Martin executive Christopher E. Kubasik was named president and COO, with Strianese remaining as chairman and CEO. On July 19, 2017, Strianese announced that he would retire as CEO on December 31, 2017, to be succeeded by Kubasik, but would remain as board chairman. As of January 1, 2018, Christopher E. Kubasik became chief executive officer and president of L3 Technologies.

Naming
L3 Technologies was originally named L-3 Communications for the last initials of its founders Frank Lanza, Robert LaPenta, and Lehman Brothers. Despite the similarity in naming, there is no corporate connection between L3 Technologies, formerly known as L-3 Communications, and networking provider Level 3 Communications, whose name is often abbreviated "L3" in informal industry communication.

On December 31, 2016, the company changed its name from L-3 Communications Holdings, Inc. to L3 Technologies, Inc. to better reflect the company's wider focus since its founding in 1997. The company's website changed from L-3com.com to L3T.com, but the company's NYSE ticker symbol of LLL remained the same.

Products

 * L-3 ProVision, Millimeter Wave Airport Passenger Screening System
 * L-3 eXaminer SX, 3DX, and XLB, Airport baggage scanning systems
 * L-3 OptEX, Trace level explosive detection system
 * AVCATT, a mobile aviation training simulator
 * Orchid, Total Development & Simulation Environment (Power, Marine)
 * EOTech, Holographic weapon sights
 * L-3 Sonoma EO, Electro Optical Imaging Systems, 1508M Dragon Eyes, 1205MD, 2111X, 2514X, & 2711G
 * OMNI, an encryption device that adds secure voice and secure data to a standard analog telephone or modem connected computer, made in "Standard" model with a 56 kbit/s limit and "OMNIxi" with a 15 Mbit/s limit

Federal contract suspension
In 2010, it was announced that L3's Special Support Programs Division had been suspended by the United States Air Force from doing any contract work for the US federal government. A US Department of Defense investigation had reportedly found that the company had, "used a highly sensitive government computer network to collect competitive business information for its own use." A US federal criminal investigation ended the temporary suspension on July 27, 2010.

Counterfeit parts
On November 4, 2010, L3 issued a part purge notification to prevent future use of Chinese counterfeit parts, but did not notify its customers whose display systems suffered from much higher than expected failure rates.

EOTech defective holographic sights lawsuit
In 2015, L3 Technologies agreed to pay $25.6 million to settle a lawsuit with the U.S. Government. L3 was accused of knowingly providing the U.S. military with optics that failed in extreme temperatures and humid weather conditions. These sights were provided to infantry and special operations forces operating in Afghanistan and Iraq, as well as civilians and law enforcement.

The civil fraud lawsuit was filed by Preet Bharara, in the Southern District of New York. The lawsuit alleged L3 officials have known since 2006 that the holographic sights being sent to Iraq and Afghanistan failed to perform as advertised in extreme temperature ranges. The lawsuit alleges that the FBI independently discovered the thermal drift defect, where the point-of-aim would shift when the sights were exposed to temperature extremes, in March 2015 and presented EOTech with "the very same findings that the company had documented internally for years. Shortly thereafter, EOTech finally disclosed the thermal drift defect to the DoD." According to court documents, EOTech had advertised that its sights performed in temperatures ranging from -40 degrees to 140 degrees Fahrenheit, and in humid conditions.

title: L3 Technologies


text:
Zuni people

The Zuni (formerly spelled Zuñi) are Native American Pueblo peoples native to the Zuni River valley. The Zuni people today are federally recognized as the Zuni Tribe of the Zuni Reservation, New Mexico, and most live in the Pueblo of Zuni on the Zuni River, a tributary of the Little Colorado River, in western New Mexico, United States. The Pueblo of Zuni is 55 km south of Gallup, New Mexico. The Zuni tribe lived in multi level adobe houses. In addition to the reservation, the tribe owns trust lands in Catron County, New Mexico, and Apache County, Arizona. The Zuni call their homeland Halona Idiwan’a or Middle Place. The word Zuni is believed to derive from the Western Keres language (Acoma) word sɨ̂‧ni, or a cognate thereof.

History
Archaeology suggests that the Zuni have been farmers in the general area for 3,000 to 4,000 years. It is now thought that the Ancestral Zuni people inhabited the Zuni River valley from the last millennium B.C., when they began using irrigation to farm maize on at least household-sized plots.

Zuni culture is associated with Mogollon and Ancestral Pueblo peoples cultures, who lived in the deserts of New Mexico, Arizona, Utah, and southern Colorado for over two millennia. White Mound was one such settlement of pit houses, farming, and storerooms, built around 700 A.D., followed by the village of Kiatuthlanna around 800 A.D., and Allantown around 1000 A.D. These Mogollon villages included kivas. Likewise, Zuni ancestors were in contact with the Ancestral Puebloans at Chaco Canyon around 1100. The Zuni settlement called Village of the Great Kivas, was built around 1100, and included nine kivas. The Zuni region, however, was probably only sparsely populated by small agricultural settlements until the 12th century when the population and the size of the settlements began to increase. The large villages of Heshot Ula, Betatakin, and Kiet Siel were established by 1275. By the 13th century villages were built on top of mesas, including Atsinna on Inscription Rock. In the 14th century, the Zuni inhabited a dozen pueblos containing between 180 and 1,400 rooms, while the Anasazi abandoned larger settlements for smaller ones, or established new ones along the Rio Grande. The Zuni did move from the eastern portion of their territory to the western side, and built six new villages, Halona, Hawikuh, Kiakima, Matsaki, Kwakina, and Kechipaun. Halona was located 97 km north Zuni Salt Lake, and the Zuni traded in salt, corn and turquoise. Hawikuh was claimed by Niza to be one of the Seven Cities of Cibola, a legendary 16th century wealthy empire.

In 1539, Moorish slave Estevanico led an advance party of Fray Marcos de Niza's Spanish expedition. Sponsored by Antonio de Mendoza who wanted Niza to "explain to the natives of the land that there is only one God in heaven, and the Emperor on earth to rule and govern it, whose subjects they all must become and whom they must serve." The Zuni reportedly killed Estevanico as a spy, or for being "greedy, voracious and bold". This was Spain's first contact with any of the Pueblo peoples. Francisco Vásquez de Coronado expedition followed in the wake of Niza's Seven Cities of Cibola claim. Sponsored once again by Mendoza, Coronado led 230 soldiers on horseback, 70 foot soldiers, several Franciscan priests and Mexican natives. The Spanish met 600 Zuni warriors near Hawikuh in July 1540, inflicting several casualties, and capturing the village. Coronado continued to the Rio Grande, but several priests and soldiers stayed an additional two years. The Chamuscado and Rodríguez Expedition followed in 1581, and Antonio de Espejo in 1583. Juan de Oñate visited Zuni territory in 1598 and 1604 looking for copper mines, but without success. Francisco Manuel de Silva Nieto established a mission at Hawikuh in 1629 with two Franciscan priests. They completed a church compound in 1632, and established a second mission in Halona. Shortly afterwards, the Zuni destroyed the missions, killing two priests, and then retreated to Dowa Yalanne, where they remained for the next three years. The Spanish built another mission in Halona in 1643.

Before the Pueblo Revolt of 1680, the Zuni lived in six villages. After the revolt, until 1692, they took refuge in a defensible position atop Dowa Yalanne, a steep mesa 5 km (3.1 miles) southeast of the present Pueblo of Zuni; Dowa means "corn", and yalanne means "mountain". After the establishment of peace and the return of the Spanish, the Zuni relocated to their present location, returning to the mesa top only briefly in 1703. By the end of the 17th century, only Halona was still inhabited of the original six villages. Yet, satellite villages were settled around Halona, and included Nutria, Ojo Caliente, and Pescado.

Of the three Zuni missions, only the church at Halona was rebuilt after the reconquest. According to Nancy Bonvillain, "Indeed, by the late eighteenth century, Spanish authorities had given up hope of dominating the Zuni and other western Pueblo Indians, and in 1799 only seven Spanish people were recorded as living among the Zuni.". In 1821, the Franciscans ended their missionary efforts.

In 1848, U.S. Army Lt. Col. Henderson P. Boyakin signed a treaty with Zuni and Navajo leaders stating the Zuni "shall be protected in the full management of all their rights of Private Property and Religion...[by] the authorities, civil and military, of New Mexico and the United States." Observing the Zuni in the 1850s, Balduin Möllhausen noted "In all directions, fields of wheat and maize, as well as gourds and melons, bore testimony to their industry."

The Zuni Reservation was created by the United States federal government in 1877, and enlarged by a second Executive order in 1883.

Frank Hamilton Cushing, an anthropologist associated with the Smithsonian Institution, lived with the Zuni from 1879 to 1884. He was one of the first non-native participant-observers and ethnologists at Zuni. In 1979, it was reported that some members of the Pueblo consider he had wrongfully documented the Zuni way of life, exploiting them by photographing and revealing sacred traditions and ceremonies.

During the early 2000s, the Zuni opposed the development of a coal mine near the Zuni Salt Lake, a site sacred to the Zuni and under Zuni control. The mine would have extracted water from the aquifer below the lake and would also have involved construction between the lake and the Zuni. The plan was abandoned in 2003 after several lawsuits.

Culture
The Zuni traditionally speak the Zuni language, a language isolate that has no known relationship to any other Native American language. Linguists believe that the Zuni have maintained the integrity of their language for 6,000-to-7,000 years. The Zuni do, however, share a number of words from Keresan, Hopi, and Pima pertaining to religion. The Zuni continue to practice their traditional religion with its regular ceremonies and dances, and an independent and unique belief system.

The Zuni were and are a traditional people who live by irrigated agriculture and raising livestock. Gradually the Zuni farmed less and turned to sheep and cattle herding as a means of economic development. Their success as a desert agri-economy is due to careful management and conservation of resources, as well as a complex system of community support. Many contemporary Zuni also rely on the sale of traditional arts and crafts. Some Zuni still live in the old-style Pueblos, while others live in modern houses. Their location is relatively isolated, but they welcome respectful tourists.

The Zuni Tribal Fair and rodeo is held the third weekend in August. The Zuni also participate in the Gallup Inter-Tribal Ceremonial, usually held in early or mid-August. The A:shiwi A:wan Museum and Heritage Center is a tribal museum that showcases Zuni history, culture, and arts.

Ethnobotany
The Zuni utilize many local plants in their culture. For an extensive list, see the main article, "Zuni ethnobotany". Zuni have developed knowledge of local plants that are used for medical practices and religious rites.

Pottery

Traditionally, Zuni women made pottery for storing food and water. They used symbols of their clans for designs. Clay for the pottery is sourced locally. Prior to its extraction, the women give thanks to the Earth Mother (Awidelin Tsitda) according to ritual. The clay is ground, sifted, mixed with water, rolled into a coil, shaped into a vessel or other design, and scraped smooth with a scraper. A thin layer of finer clay, called slip, is applied to the surface for extra smoothness and color. The vessel is polished with a stone after it dries. It is painted with home-made organic dyes, using a traditional yucca brush. The shape and painted images depend on the intended purpose of the pottery. To fire the pottery, the Zuni used animal dung in traditional kilns. Today, Zuni potters might use electric kilns. While the firing was usually a community enterprise, silence or communication in low voices was considered essential in order to maintain the original "voice" of the "being" of the clay, and the purpose of the end product. Sales of pottery and traditional arts provide a major source of income for many Zuni people today. An artisan may be the sole financial support for her immediate family as well as others. Many women make pottery or, more rarely, clothing or baskets. Brown, black and red ornamentation can be found on traditional Zuni pots that are first covered with white slip. Common motifs are spiral scrolls edged with triangles, deer, as well as frogs, dragonflies and other symbols associated with rain and water. In addition to pots, Zuni produce owl figurines that are covered with white slip and painted with black and red motifs before firing.

Carving and silversmithing
Zuni also make fetishes and necklaces for the purpose of rituals and trade, and more recently for sale to collectors.

The Zuni are known for their fine lapidary work. Zuni jewelers set hand-cut turquoise and other stones in silver. Today jewelry-making thrives as an art form among the Zuni. Many Zuni have become master stone-cutters. Techniques used include mosaic and channel inlay to create intricate designs and unique patterns.

Two specialties of Zuni jewelers are needlepoint and petit point. In making needlepoint, small, slightly oval-shaped stones with pointed ends are set in silver bezels, close to one another and side by side to create a pattern. The technique is normally used with turquoise, sometimes with coral and occasionally with other stones in creating necklaces, bracelets, earrings and rings. Petit point is made in the same fashion as needlepoint, except that one end of each stone is pointed, and the other end is rounded.

Religion
Religion is central to Zuni life. Their traditional religious beliefs are centered on the three most powerful of their deities: Earth Mother, Sun Father, and Moonlight-Giving Mother. The religion is katsina-based, and ceremonies occur during winter solstice, summer, harvest, and again in winter.

Priesthood includes three priests (north, above and below), and Pekwin (the above priest) determines the religious calendar. A religious society is associated with each of the six kivas, and each boy is initiated into one of these societies.

Shalako
Shalako is a series of ceremonial dances that take place throughout the night on or around the winter solstice. They are closed to non-native individuals unless there is a personal invitation by a tribal member. The ceremony also blesses the houses that were built during the year. The blessing takes the form of singing that accompanies six dancers who are dressed in Shalako outfits. These outfits can be as high as eight feet; the dancers wearing them represent "couriers of the rain deities come to bless new homes". The dancers move from house to house throughout the night; at dawn Saiyatasha performs a final prayer and the ceremony is complete.

In popular culture
In the novel Brave New World, a Zuni native named John comes to grip with sexual realities in the New State and how they differ from his own culture.

Notable Zuni people

 * Emily Pinto, painter
 * Percy Tsisete Sandy (Kai-Sa [Red Moon]), painter
 * We'wha, weaver

title: Zuni people


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Talk:Wave period

Merge this article?
Does this page really need to exist? All it says is that period is the inverse of frequency, which is already stated in the period article. The rest of the article is a list of formulas like "period = 1 / frequency" and "frequency = 1 / period" which are the same formula restated and can be found in the reciprocal article, talk about some SI units (Hertz and seconds), and another list of formulas like "wavelength / time = velocity" that are restated 6 times. Seems like a pointless article to me. Opinions? HN 22:10 24 Jul 2003 (UTC)

 * It is fairly light, content-wise. Conceiveably it could be revised to change that, but I'm not up to it today. Michael Hardy 22:13 24 Jul 2003 (UTC)

 * I agree with HN. It should be merged into Frequency.  Also, as an electronics engineer, I've never actually heard the term 'wave period', it's always just 'period'.  If this is a term specific to ocean surface waves, it should be so stated.  -- Chetvorno TALK 21:44, 26 January 2008 (UTC)

 * Added merger proposal tag -- Chetvorno TALK 22:31, 26 January 2008 (UTC)

 * I agree with the proposed merge into Frequency. I also notified the merge proposal on Proposed_mergers. Kraaiennest (talk) 18:06, 29 January 2008 (UTC)

 * I disagree with the merger. Studying wave forms and energy in a coastal geomporhology sense, listing wave period separately helps people looking for information in the context of coastal geomorphology.  If it is joined into its physics roots, it becomes harder to find.  Wikipeadia is so good because it aligns information with disciplines, and coastal geomorphology is its own discipline.  Pushing things into master disciplines is going to water down the strength of Wikipedia. (I hope I have done this right) Peter Drescher (talk) 02:32, 13 November 2012 (UTC)

- It's totally useless to show all possible permutations of a formula...must be changed IMHO. dave 04:26 25 Jul 2003 (UTC)

 * I've made a lot of changes. I hope it doesn't tick anyone off, but there was a ton of redundancy in the article as it was.  dave 04:40 25 Jul 2003 (UTC)

How about this lot for ocean waves if tidied up and equations sorted out?: Subsea (talk) 17:22, 17 December 2007 (UTC)

Period estimators

Mean zero up-crossing period, TZ or Tm0,2

When recordings were first taken this was onto charts and simple counts could be made. First the charts were zero-meaned (the average and trend calculated and drawn through the plot to provide a new axis for measuring) and then the number of times the wave record crossed the mean going up (or sometimes down) was counted and this gave the number of waves and, as a time measure, the zero-crossing period. The parameter is estimated by taking the mean of these periods for a given wave record. For wave records on paper the mean level is found by eye and Tvisual is estimated from the record length and the number of zero up-crossings counted on the record. This method can also be applied to digitised data using a computer but if the wave records are available in machine readable form it is preferable to estimate from the moments of the spectrum using,

Tz=$$sqrt(m0/m2)$$

where the mi values are spectral moments. The alternative symbol of Tm0,2 is derived from the moment equation. It can be seen that TZ is very dependent on the higher frequency end of the spectrum and although TZ is the most commonly used period estimator it is not very stable.

Significant wave period, Ts

The significant wave period is the mean of the zero up-crossing periods associated with the highest one third of the waves. It is sometimes denoted by Ts. Note that this parameter cannot be obtained directly from the wave spectrum. It is not very useful, but sometimes is used!

Spectral peak period, Tp

The spectral peak period is the inverse of the frequency at which the value of the frequency spectrum is a maximum. It cannot be defined satisfactorily in multi-peaked spectra. fp is very important in characterising spectra.

Period associated with the most likely highest wave, Tmax

The most likely height of the highest wave in a record of duration 3 hours is Hmax and Tmax is its period. It is often obtained indirectly from Tz or Tp using empirical relationships, or from Hmax and steepness assumptions – usually to obtain a range of possible associated periods. These methods should be applied only in the water depth for which the empirical relationships have been found, usually deep water (i.e. depth >1/2 wavelength). It should be possible to use the steepness method in shallow water provided that refraction is minimal and that allowance can be made for shoaling effects. It cannot, however, be derived directly from the wave spectrum.

Energy period, Te

This period is important for power estimation and is used in wave power design as a preferred comparator. The most appropriate way to consider energy period is as the period of the regular wave that has the same significant height and the same power density as the sea-state under consideration. It is defined as,

Te=$$(m-1/m0)$$

Because of the relationship with power it is worth giving the expression for time averaged power associated with a spectrum,

power = rho g^2 m0 Te / 4Pi

Hence we can find an expression for Te as follows,

Te=(64 Pi Power)/ rho g^2 Hs^2

Average wave period, Tav This is the inverse of the average frequency calculated from the mean of all component sine waves weighted by the spectral energy. It cannot be measured in the time domain unless the waves are simple sine curves.

Average crest period, Tc

Defined as, Tc=$$sqrt{(m2/m4)}$$

This is equivalent to dividing the length of the wave record by the number of crests where a crest is any point either side of which the surface elevation decreases. Crests are not necessarily associated with zero up-crossings. Clearly this is very much influenced by the ‘tail’ of the spectrum through the fourth moment.

title: Talk:Wave period


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Wind chill (disambiguation)

Wind chill is a meteorological effect.

Windchill may refer to:

 * Wind Chill (film), 2007 horror film
 * Windchill (software), PLM application
 * Windchill (G.I. Joe), a fictional character in the G.I. Joe universe

title: Wind chill (disambiguation)


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Seitan

Seitan (, ; セイタン) is a food made from gluten, the main protein of wheat. It is also known as miànjīn, fu (麩), milgogi (밀고기), wheat meat, gluten meat, or simply gluten. It is made from vital wheat gluten, a flour-like substance primarily consisting of gluten extracted from wheat flour.

Wheat gluten is an alternative to soybean-based foods, such as tofu, which are sometimes used as a meat alternative. Some types of wheat gluten have a chewy or stringy texture that resembles meat more than other substitutes. Wheat gluten is often used instead of meat in Asian, vegetarian, vegan, Buddhist, and macrobiotic cuisines. Mock duck is a common use.

Wheat gluten first appeared during the 6th century as an ingredient for Chinese noodles. It has historically been popular in the cuisines of China, Japan and other East and Southeast Asian nations. In Asia, it is commonly found on the menus of restaurants catering primarily to Buddhist customers who do not eat meat.

Production
Gluten is traditionally extracted from wheat flour. A dough is washed in water until most of the starch granules have been removed, leaving behind the sticky, insoluble gluten as an elastic mass. This mass is cooked in a variety of ways and eaten.

The separated gluten can alternatively be dried and ground into a powder, so-called "vital wheat gluten". The powder can be rehydrated into a mass of gluten ("seitan") and cooked in the same way as the original product.

There are several industrial methods for separating gluten from starch.

History
Called miànjīn (麵筋), this way of preparing wheat gluten has been documented in China since the 6th century. It is widely consumed by the Chinese as a substitute for meat, especially among monastic and lay adherents of Chinese Buddhism. The oldest reference to wheat gluten appears in the Qimin Yaoshu, a Chinese agricultural encyclopedia written by Jia Sixie in 535. The encyclopedia mentions noodles prepared from wheat gluten called bótuō (餺飥). Wheat gluten was known as miànjīn (麵筋) by the Song dynasty (960–1279). Traditionally food is perceived as kitchen medicine within Chinese culture, gluten is part of traditional Chinese food therapy called shí liáo (食療), and was prescribed by traditional Chinese medicinal physicians to treat a wide range of illnesses and disease. Wheat gluten arrived in the West by the 18th century. De Frumento, an Italian treatise on wheat written in Latin by Bartolomeo Beccari in 1728 and published in Bologna in 1745, describes the process of washing wheat flour dough to extract the gluten. John Imison wrote an English-language definition of wheat gluten in his Elements of Science and Art published in 1803. By the 1830s, Western doctors were recommending wheat gluten in diets for diabetics. In the United States, the Seventh-day Adventists promoted the consumption of wheat gluten from the late 19th century. Sanitarium Foods, a company affiliated with John Harvey Kellogg's Battle Creek Sanitarium, advertised wheat gluten in 1882.

Etymology of seitan
The word seitan is of Japanese origin and was coined in 1961 by George Ohsawa, a Japanese advocate of the macrobiotic diet, to refer to a wheat gluten product created by Ohsawa's student Kiyoshi Mokutani. In 1962, wheat gluten was sold as seitan in Japan by Marushima Shoyu K.K. It was imported to the West in 1969 by the American company Erewhon. The etymology of seitan is uncertain, but it is believed to come from combining the characters 生 (sei, "fresh, raw") and 蛋 (tan, from 蛋白 (tanpaku, "protein")).

Chinese
Wheat gluten, called miànjīn in Chinese (traditional: 麵筋, simplified: 面筋, literally "dough tendon"; also spelled mien chin in Latin script) is believed to have originated in ancient China, as a meat substitute for adherents of Buddhism, particularly some Mahayana Buddhist monks, who are strict vegetarians (see Buddhist cuisine). One story attributes the invention of imitation meat to chefs who made it for Chinese emperors who traditionally observed a week of vegetarianism each year. Miànjīn is often deep fried before being further cooked in Chinese cuisine, which confers a crispy rind that enhances the texture of the gluten. There are three primary Chinese forms of wheat gluten.

Oil-fried gluten (油麵筋, yóumiànjīn) is raw gluten that has been torn into small bits, and then deep-fried into puffy balls of 3 to 5 cm in diameter and sold as "imitation abalone". They are golden brown, and cooked by braising or boiling in a savory soup or stew. They are frequently paired with xiānggū (black mushrooms). Larger fried balls of gluten, called miànjīnqiú (麵筋球) or miànjīnpào (麵筋泡), which may be up to 5 in in diameter, are sometimes seen in Asian supermarkets, often stuffed with meat or tofu mixtures and served as a dish called "gluten meatballs" (麵筋肉丸, Miànjīn roùwán) or "gluten stuffed with meat" (麵筋塞肉, miànjīn saī roù).

Steamed gluten (蒸麵筋, zhēngmiànjīn), is raw gluten that has been wrapped around itself to form a long sausage shape which is then steamed. This type of gluten has a dense texture and ranges from off-white to light greenish grey in color. It is torn open into strips and used as a cooking ingredient. When this sausage-shaped gluten is thickly sliced into medallions, the resulting form is called miànlún (麵輪, "gluten wheels"). Larger blocks of steamed gluten are sometimes colored pink and sold as vegetarian "mock ham." Steamed gluten is also a well-known food in Xi'an. Steamed gluten can be served with bean sprouts and cucumbers as a cold dish, or served with liángpí (凉皮).

Baked spongy gluten is similar in texture to a sponge, kaofu (sometimes labeled in English as "bran puff") is made by leavening raw gluten, and then baking or steaming it. These are sold as small blocks in Chinese markets, and are diced and cooked. This type of gluten absorbs its cooking liquid like a sponge and is enjoyed for its "juicy" character. Chinese kaofu has a different texture from its Japanese counterpart, yaki-fu, due to the relatively larger air bubbles it contains. Kaofu is available fresh, frozen, dehydrated, and canned.

Miànjīn is also available in Asian grocery stores in cans and jars, often marinated in combination with peanuts or mushrooms. Such canned and jarred gluten is commonly eaten as an accompaniment to congee (boiled rice porridge) as part of a traditional Chinese breakfast. Depending on its method of preparation and ingredients used, both fresh and preserved miànjīn can be used to simulate pork, poultry, beef, or seafood.

Miànjīn can also refer to latiao, a modern Chinese snack food consisting of a strip of miànjīn (in the gluten sense), generally with a spicy and savory flavoring.

Japanese
In Japanese cuisine, the traditional type of wheat gluten is called (麩, "gluten"), deriving from the Wu Chinese pronunciation of 麩, fu. In Japan, the two main types of fu are most widely used in Buddhist vegetarian cooking (Shōjin ryōri) and tea ceremony cuisine (cha-kaiseki). There are two main forms of fu, the raw nama-fu, and dry-baked yaki-fu.

Raw (nama-fu 生麩) is solid gluten which is mixed with glutinous rice flour and millet and steamed in large blocks. It may be shaped and colored in a variety of ways, using ingredients such as mugwort. Popular shapes include autumn-colored maple leaves and bunnies. Such shapes and colors enhance the attractiveness of the cooked product since steamed gluten has an unappealing grey hue. Nama-fu is an important ingredient in Shōjin-ryōri, the Buddhist vegetarian cuisine of Japan. It may also be used as an ingredient in wagashi, Japanese confectionery. Fu-manjū (麩まんじゅう) is a type of manjū made from nama-fu. Solid gluten is sweetened and filled with various sweet fillings such as red bean paste. They are then wrapped in leaves and steamed in a manner similar to that used to prepare Chinese zongzi.

Dry baked (yaki-fu 焼き麩 or sukiyaki-fu すき焼き麩) is gluten leavened with baking powder and baked into long bread-like sticks. It is often sold in cut form, as hard dry discs resembling croutons or bread rusk. Yaki-fu is typically added to miso soup and sukiyaki, where it absorbs some of the broth and acquires a fine texture that is lighter and fluffier than its Chinese equivalent. It is the most commonly available type of fu in Japanese supermarkets.

In Japan, seitan, initially a rather salty macrobiotic seasoning that gradually evolved into a food, is not well known or widely available, despite the macrobiotic diet's Japanese origins. When used, the terms for this food are rendered in katakana as グルテンミート (Romanized "gurutenmīto", from the English "gluten meat"), or, rarely, セイタン ("seitan"). Outside macrobiotic circles, these terms are virtually unknown in Japan, and they do not typically appear in Japanese dictionaries.

Along with tofu and Abura-age, fu can be used as a substitute for meat in Japanese cuisine.

Vietnamese
In Vietnam, wheat gluten is called mì căng or mì căn, and is prepared in a similar fashion to Chinese miàn jīn. Along with tofu, it is a part of the Buddhist cuisine of Vietnam.

Macrobiotic
The meaning of the word "seitan" has undergone a gradual evolution. The initial product, imported from Japan in 1969 was a very salty seasoning, the color of soy sauce, sold in a small glass jar or plastic pouch, to be used as a seasoning for brown rice. The name gradually came to refer to any wheat gluten seasoned with soy sauce. The people most responsible for this change were Nik and Joanne Amartseff, who introduced Tan Pups in 1972, and John Weissman, who in 1974 introduced Wheatmeat (first meatballs then cutlets made of seitan) in Boston. All worked for years to popularize these products at the Erewhon retail store, and developed a trademark on the Wheatmeat name.

While wheat gluten itself is rather flavorless, it holds a marinade very well and is usually simmered in a dashi (broth) made from soy sauce, kombu, ginger, and sometimes also sesame oil.

Western
Since the mid-20th century, wheat gluten (usually called seitan) has been increasingly adopted by vegetarians in Western nations as a meat alternative. It is sold in block, strip and shaped forms in North America, where it can be found in some supermarkets, Asian food markets, health food stores and cooperatives.

The block form of seitan is often flavored with shiitake or portobello mushrooms, fresh coriander or onion, or barbecue sauce, or packed in a vegetable-based broth. In strip form, it can be packed to be eaten right out of the package as a high-protein snack. Shaped seitan products, in the form of "ribs" and patties, are frequently flavored with barbecue, teriyaki, or other savory sauces.

In North America, several brand-name meat alternatives are used in the restaurant and food service markets.

Wheat gluten is also used in many vegetarian products in various countries, for example by The African Hebrew Israelites of Jerusalem, a Black vegan religious sect in Israel, that operates a chain of restaurants, to produce vegetarian sandwiches.

Vital wheat gluten
A powdered form of wheat gluten is produced and sold as an additive for baking or used to make seitan. When used to make seitan, wheat gluten is often flavored with liquid smoke, smoked paprika and garlic powder. Vital wheat gluten is nearly all gluten and almost no starch. When used as an additive in baking, its purpose is to add elasticity to flours that would otherwise be low in gluten, such as whole wheat flour or rye. Very little is required: generally about 1 tablespoon (15ml) per 2–3 cups (480–720 ml) of flour. It improves the rise of the raw dough and also improves the texture and chewiness of the final product.

Vital wheat gluten is made by hydrating hard wheat flour to activate the gluten and then processing the hydrated mass to remove the starch, leaving only the gluten. The gluten is then dried and ground back into a powder.

Animal feed
Wheat gluten is used both as a protein source and binding ingredient in pet foods. Wheat gluten imported from China adulterated with melamine used in pet foods was considered to have caused harm in many countries in 2007.

title: Seitan