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72-531: There is evidence that indicates the hill was settled even in prehistoric times. Pieces of pottery from the Michelsberg culture have also been found here. Excavations in the vicinity of the present-day collegiate church have revealed traces of ditches, ramparts and posts. Radio carbon dating points to their origin in the pre-Roman Iron Age . In addition the wooden posts were made from trees that can be dated to between 420 and 370 B.C. Earlier research viewed

144-505: A few hundred ohms . The major advantage of these is that they can dissipate a lot of energy, and they self-reset; after the voltage across the device drops below the threshold, its resistance returns to being high. This makes them ideal for surge-protection applications; as there is control over the threshold voltage and energy tolerance, they find use in all sorts of applications. The best demonstration of their ability can be found in electrical substations , where they are employed to protect

216-514: A finer examination of the composition of ceramic artifacts and sherds to determine the source of the material and, through this, the possible manufacturing site. Key criteria are the composition of the clay and the temper used in the manufacture of the article under study: the temper is a material added to the clay during the initial production stage and is used to aid the subsequent drying process. Types of temper include shell pieces, granite fragments, and ground sherd pieces called ' grog '. Temper

288-422: A furnace, a pyroelectric crystal allowed to cool under no applied stress generally builds up a static charge of thousands of volts. Such materials are used in motion sensors , where the tiny rise in temperature from a warm body entering the room is enough to produce a measurable voltage in the crystal. In turn, pyroelectricity is seen most strongly in materials that also display the ferroelectric effect , in which

360-669: A glassy surface, making a vessel less pervious to water. Ceramic artifacts have an important role in archaeology for understanding the culture, technology, and behavior of peoples of the past. They are among the most common artifacts to be found at an archaeological site, generally in the form of small fragments of broken pottery called sherds . The processing of collected sherds can be consistent with two main types of analysis: technical and traditional. The traditional analysis involves sorting ceramic artifacts, sherds, and larger fragments into specific types based on style, composition, manufacturing, and morphology. By creating these typologies, it

432-523: A pathway were found in the East of the site. Michelsberg pottery is characterised by undecorated pointy-based tulip beakers. Finds of barley and emmer indicate an agricultural economy. Animal husbandry is indicated by bones of domesticated cattle , pig , sheep and goat . Domestic dogs have also been identified. Bones of deer and fox suggest that the MK diet was supplemented by hunting . There

504-565: A rampart. A large tumulus (burial mound) was built at the centre of the settlement between 4200–4100 BC, indicating the influence of the Castellic culture in Brittany, where giant burial mounds containing megalithic tombs (such as Tumiac and Saint-Michel ) were built c. 4500 BC for elite males described by some researchers as 'divine kings'. The Castellic mounds contained large quantities of jade axes (the jade originally imported from

576-492: A rotation process called "throwing"), slip casting , tape casting (used for making very thin ceramic capacitors), injection molding , dry pressing, and other variations. Many ceramics experts do not consider materials with an amorphous (noncrystalline) character (i.e., glass) to be ceramics, even though glassmaking involves several steps of the ceramic process and its mechanical properties are similar to those of ceramic materials. However, heat treatments can convert glass into

648-434: A semi-crystalline material known as glass-ceramic . Traditional ceramic raw materials include clay minerals such as kaolinite , whereas more recent materials include aluminium oxide, more commonly known as alumina . Modern ceramic materials, which are classified as advanced ceramics, include silicon carbide and tungsten carbide . Both are valued for their abrasion resistance and are therefore used in applications such as

720-423: A signal). The unit of time measured is the natural interval required for electricity to be converted into mechanical energy and back again. The piezoelectric effect is generally stronger in materials that also exhibit pyroelectricity , and all pyroelectric materials are also piezoelectric. These materials can be used to inter-convert between thermal, mechanical, or electrical energy; for instance, after synthesis in

792-533: A single individual and two containing several. The age profile of those buried is very striking, as it is limited to children under the age of seven and adults over 50 (a considerable age in Neolithic Europe). In other words, humans of the ages that must have dominated the active social and economic life of the settlement are absent. It has been suggested that their bodies may not have received formal burial, but were disposed of by excarnation , in which case

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864-418: A stable electric dipole can be oriented or reversed by applying an electrostatic field. Pyroelectricity is also a necessary consequence of ferroelectricity. This can be used to store information in ferroelectric capacitors , elements of ferroelectric RAM . The most common such materials are lead zirconate titanate and barium titanate . Aside from the uses mentioned above, their strong piezoelectric response

936-479: Is about 4 km southeast of modern Bruchsal , near the suburb of Untergrombach. The hill rises steeply 160m above the Kraichgau plain, its overall height above sea level is 272m. As the hill is defined by steep slopes on three sides, it is a naturally protected or defensible site. The first discoveries of prehistoric material took place in 1884, systematic excavation began in 1889. Further works took place in

1008-671: Is any of the various hard, brittle , heat-resistant , and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay , at a high temperature. Common examples are earthenware , porcelain , and brick . The earliest ceramics made by humans were fired clay bricks used for building house walls and other structures. Other pottery objects such as pots, vessels, vases and figurines were made from clay , either by itself or mixed with other materials like silica , hardened by sintering in fire. Later, ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through

1080-467: Is employed. Ice templating allows the creation of macroscopic pores in a unidirectional arrangement. The applications of this oxide strengthening technique are important for solid oxide fuel cells and water filtration devices. To process a sample through ice templating, an aqueous colloidal suspension is prepared to contain the dissolved ceramic powder evenly dispersed throughout the colloid, for example Yttria-stabilized zirconia (YSZ). The solution

1152-468: Is exploited in the design of high-frequency loudspeakers , transducers for sonar , and actuators for atomic force and scanning tunneling microscopes . Temperature increases can cause grain boundaries to suddenly become insulating in some semiconducting ceramic materials, mostly mixtures of heavy metal titanates . The critical transition temperature can be adjusted over a wide range by variations in chemistry. In such materials, current will pass through

1224-498: Is no indication of organised burial grounds, as known from the earlier Linear pottery (LBK) and Rössen cultures. Human skeletal remains, frequently disarticulated, have been found inside pits and ditches in many MK earthworks and have had considerable influence on the interpretation of such structures. Their discussion is closely connected with that of similar remains in the ditches of British Causewayed enclosures . The MK settlement of Aue yielded eight pit graves, six containing

1296-480: Is not understood, but there are two major families of superconducting ceramics. Piezoelectricity , a link between electrical and mechanical response, is exhibited by a large number of ceramic materials, including the quartz used to measure time in watches and other electronics. Such devices use both properties of piezoelectrics, using electricity to produce a mechanical motion (powering the device) and then using this mechanical motion to produce electricity (generating

1368-491: Is possible to distinguish between different cultural styles, the purpose of the ceramic, and the technological state of the people, among other conclusions. Besides, by looking at stylistic changes in ceramics over time, it is possible to separate (seriate) the ceramics into distinct diagnostic groups (assemblages). A comparison of ceramic artifacts with known dated assemblages allows for a chronological assignment of these pieces. The technical approach to ceramic analysis involves

1440-568: Is responsible for such diverse optical phenomena as night-vision and IR luminescence . Thus, there is an increasing need in the military sector for high-strength, robust materials which have the capability to transmit light ( electromagnetic waves ) in the visible (0.4 – 0.7 micrometers) and mid- infrared (1 – 5 micrometers) regions of the spectrum. These materials are needed for applications requiring transparent armor, including next-generation high-speed missiles and pods, as well as protection against improvised explosive devices (IED). In

1512-589: Is suggested by the recent discovery of MK burials in the Blätterhof cave near Hagen , Westphalia . Here, a full age profile appears to be represented. An unusual burial was found at Rosheim ( Bas-Rhin , France ). Here, the fill of a pit contained the crouched remains of an adult woman, her legs leaning against a quernstone. She appeared to have been laid onto a carefully placed packing of clay lumps, mixed with pottery and bones. Her death had been caused by some blunt impact on her skull. Beau et al. 2017 examined

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1584-425: Is then cooled from the bottom to the top on a platform that allows for unidirectional cooling. This forces ice crystals to grow in compliance with the unidirectional cooling, and these ice crystals force the dissolved YSZ particles to the solidification front of the solid-liquid interphase boundary, resulting in pure ice crystals lined up unidirectionally alongside concentrated pockets of colloidal particles. The sample

1656-475: Is then heated and at the same the pressure is reduced enough to force the ice crystals to sublime and the YSZ pockets begin to anneal together to form macroscopically aligned ceramic microstructures. The sample is then further sintered to complete the evaporation of the residual water and the final consolidation of the ceramic microstructure. During ice-templating, a few variables can be controlled to influence

1728-472: Is typically somewhere between the minimum wavelength of visible light and the resolution limit of the naked eye. The microstructure includes most grains, secondary phases, grain boundaries, pores, micro-cracks, structural defects, and hardness micro indentions. Most bulk mechanical, optical, thermal, electrical, and magnetic properties are significantly affected by the observed microstructure. The fabrication method and process conditions are generally indicated by

1800-399: Is usually identified by microscopic examination of the tempered material. Clay identification is determined by a process of refiring the ceramic and assigning a color to it using Munsell Soil Color notation. By estimating both the clay and temper compositions and locating a region where both are known to occur, an assignment of the material source can be made. Based on the source assignment of

1872-473: Is virtually lossless. Optical waveguides are used as components in Integrated optical circuits (e.g. light-emitting diodes , LEDs) or as the transmission medium in local and long haul optical communication systems. Also of value to the emerging materials scientist is the sensitivity of materials to radiation in the thermal infrared (IR) portion of the electromagnetic spectrum . This heat-seeking ability

1944-596: The Irminsul , a pagan religious site here or in the vicinity, destroyed. In 779, he charged the Fulda abbot , Sturmius , with mission service in this area and directed him to this location. As early as 784/785 Charlemagne overwintered at Eresburg and had a church built, probably on the site of the former Saxon temple. Pope Leo III is supposed to have stayed at the Eresburg in 799 on his way to Paderborn . In 915 there

2016-552: The Italian Alps ), as well jewellery made from callaïs (variscite and turquoise) imported from south-western Spain. Jade axes have similarly been found at the Kappellenberg, attesting to an exchange network of prestige goods associated with elites as well as the trade in salt. The Kappellenberg tumulus and jade axes indicate that "a socio-political hierarchisation process linked to the emergence of high-ranking elites"

2088-636: The Saxons . The wording of the Royal Frankish Annals in 772 suggests that the Irminsul might have been located either at the Eresburg itself or in the near vicinity. The Annales Petaviani states: "He conquered the Eresburg and found the place which is called Ermensul, and set these places on fire." On the one hand, therefore, Charlemagne captured the Eresburg and, on the other, "pervenit ad locum, qui dicitur Ermensul" , i. e. he found

2160-437: The 1950s and 1960s. The summit plateau, measuring ca 400 x 250m, contained a Neolithic settlement, enclosed by a curvilinear earthwork. Such earthworks have since been recognised as one of the most widespread and typical types of MK monument. The Michelsberg site itself was unusually well-preserved, its interior yielded numerous settlement-related pits. The architecture consisted of daub -covered wooden structures. Remains of

2232-886: The 1960s, scientists at General Electric (GE) discovered that under the right manufacturing conditions, some ceramics, especially aluminium oxide (alumina), could be made translucent . These translucent materials were transparent enough to be used for containing the electrical plasma generated in high- pressure sodium street lamps. During the past two decades, additional types of transparent ceramics have been developed for applications such as nose cones for heat-seeking missiles , windows for fighter aircraft , and scintillation counters for computed tomography scanners. Other ceramic materials, generally requiring greater purity in their make-up than those above, include forms of several chemical compounds, including: For convenience, ceramic products are usually divided into four main types; these are shown below with some examples: Frequently,

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2304-741: The Central European Late Neolithic. Its distribution covered much of West Central Europe, along both sides of the Rhine . A detailed chronology, based on pottery , was produced in the 1960s by the German archaeologist Jens Lüning. The Michelsberg culture emerges in northeastern France c. 4400 BC. Genetic evidence suggests that it originated through a migration of peoples from the Paris Basin . Its people appear to trace their origins to Mediterranean farmers expanding from

2376-606: The Eresburg as a border castle of the Cherusci tribe and a fortress of Prince Segestes , who was supposed to have held his daughter, Thusnelda , prisoner here. However, there are no records supporting that theory. Thanks to its favourable position on the border, the castle was repeatedly attacked and hard fought for before being conquered in 772 A.D. during the Saxon Wars by the Frankish king , Charlemagne . Charlemagne had

2448-532: The Hall-Petch equation, hardness , toughness , dielectric constant , and the optical properties exhibited by transparent materials . Ceramography is the art and science of preparation, examination, and evaluation of ceramic microstructures. Evaluation and characterization of ceramic microstructures are often implemented on similar spatial scales to that used commonly in the emerging field of nanotechnology: from nanometers to tens of micrometers (µm). This

2520-674: The Irminsul site in the days that followed. The question over the location of the Irminsul is however, probably, misleading; because there may have been several of them. Michelsberg culture The Michelsberg culture ( German : Michelsberger Kultur (MK) ) is an important Neolithic culture in Central Europe . Its dates are c. 4400–3500 BC. Its conventional name is derived from that of an important excavated site on Michelsberg (short for Michaelsberg) hill near Untergrombach, between Karlsruhe and Heidelberg ( Baden-Württemberg ), Germany. The Michelsberg culture belongs to

2592-614: The Michelsberg expansion was accompanied by violence. The Michelsberg culture has strong affinities to the Chasséen culture of central France. Archaeological evidence strongly suggests that colonists from the Michelsberg culture played an instrumental role in establishing the Funnelbeaker culture of Northern Europe , which brought agriculture to southern Scandinavia . The Michelsberg culture also displays close affinities to

2664-654: The Middle Neolithic. Lipson et al. 2017 examined the remains of 4 individuals buried c. 4000–3000 BC at the Blätterhöhle site in modern-day Germany, ascribed to the Michelsberg culture and its successor, the Wartberg culture . The 3 samples of Y-DNA extracted belonged to the paternal haplogroups R1b1 , R1 and I2a1 , while the 4 samples of mtDNA extracted belonged to the maternal haplogroups U5b2a2 , J1c1b1 , H5 and U5b2b2 . The individuals carried

2736-582: The area would not have easily supported agriculture any more, forcing human communities (and their livestock) to relocate. Prehistoric settlement patterns in Central Europe are generally quite volatile. The abandonment of a settlement may be part of a broader economic and social system. Thus, the Bruchsal area appears to contain several earthworks from different phases within MK. Formal Michelsberg burials have only been recognised rarely. There

2808-494: The artifact, further investigations can be made into the site of manufacture. The physical properties of any ceramic substance are a direct result of its crystalline structure and chemical composition. Solid-state chemistry reveals the fundamental connection between microstructure and properties, such as localized density variations, grain size distribution, type of porosity, and second-phase content, which can all be correlated with ceramic properties such as mechanical strength σ by

2880-513: The brightness and contrast of a digital image. Guided lightwave transmission via frequency selective waveguides involves the emerging field of fiber optics and the ability of certain glassy compositions as a transmission medium for a range of frequencies simultaneously ( multi-mode optical fiber ) with little or no interference between competing wavelengths or frequencies. This resonant mode of energy and data transmission via electromagnetic (light) wave propagation , though low powered,

2952-418: The ceramic family. Highly oriented crystalline ceramic materials are not amenable to a great range of processing. Methods for dealing with them tend to fall into one of two categories: either making the ceramic in the desired shape by reaction in situ or "forming" powders into the desired shape and then sintering to form a solid body. Ceramic forming techniques include shaping by hand (sometimes including

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3024-471: The chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand very high temperatures, ranging from 1,000 °C to 1,600 °C (1,800 °F to 3,000 °F). The crystallinity of ceramic materials varies widely. Most often, fired ceramics are either vitrified or semi-vitrified, as is the case with earthenware, stoneware , and porcelain. Varying crystallinity and electron composition in

3096-534: The class of ceramic matrix composite materials, in which ceramic fibers are embedded and with specific coatings are forming fiber bridges across any crack. This mechanism substantially increases the fracture toughness of such ceramics. Ceramic disc brakes are an example of using a ceramic matrix composite material manufactured with a specific process. Scientists are working on developing ceramic materials that can withstand significant deformation without breaking. A first such material that can deform in room temperature

3168-606: The cultures of the Neolithic British Isles . The spread of agriculture into the British Isles by colonists from the continent happens at almost exactly the same time as in Scandinavia, suggesting that the two events are connected. The Michelsberg culture ends about c. 3500 BC. It is succeeded in its core area by the Wartberg culture , with which it displays strong signs of continuity. Since 2008

3240-457: The electrical properties that show grain boundary effects. One of the most widely used of these is the varistor. These are devices that exhibit the property that resistance drops sharply at a certain threshold voltage . Once the voltage across the device reaches the threshold, there is a breakdown of the electrical structure in the vicinity of the grain boundaries, which results in its electrical resistance dropping from several megohms down to

3312-568: The fortified settlement of Kapellenberg near Hofheim and Frankfurt (one of the largest of the Michelsberg culture) has been investigated by the Römisch-Germanisches Zentralmuseum, Leibniz Archaeological Research Institute . The settlement has been described as representing "the beginnings of urbanism", already in 4000 BC. The overall site was 45 hectares in size with an internal settlement covering 26 hectares, containing numerous rectangular houses and surrounded by

3384-460: The group as a whole. General properties such as high melting temperature, high hardness, poor conductivity, high moduli of elasticity , chemical resistance, and low ductility are the norm, with known exceptions to each of these rules ( piezoelectric ceramics , low glass transition temperature ceramics, superconductive ceramics ). Composites such as fiberglass and carbon fiber , while containing ceramic materials, are not considered to be part of

3456-589: The high amount of about 40–50% Western Hunter-Gatherer (WHG) ancestry, with one individual displaying as much as c. 75% Brunel et al. 2020 examined the remains of 18 individuals ascribed to the Michelsberg culture. The 2 samples of Y-DNA belonged to the paternal haplogroup I , while the 16 samples of mtDNA extracted belonged to types of the maternal haplogroups H (3 samples), K (9 samples), X (1 sample), T (2 samples) and U (1 sample). 49°05′16″N 8°33′42″E  /  49.08778°N 8.56167°E  / 49.08778; 8.56167 Ceramic A ceramic

3528-632: The infrastructure from lightning strikes. They have rapid response, are low maintenance, and do not appreciably degrade from use, making them virtually ideal devices for this application. Semiconducting ceramics are also employed as gas sensors . When various gases are passed over a polycrystalline ceramic, its electrical resistance changes. With tuning to the possible gas mixtures, very inexpensive devices can be produced. Under some conditions, such as extremely low temperatures, some ceramics exhibit high-temperature superconductivity (in superconductivity, "high temperature" means above 30 K). The reason for this

3600-468: The ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators (researched in ceramic engineering ). With such a large range of possible options for the composition/structure of a ceramic (nearly all of the elements, nearly all types of bonding, and all levels of crystallinity), the breadth of the subject is vast, and identifiable attributes ( hardness , toughness , electrical conductivity ) are difficult to specify for

3672-486: The material near its critical temperature, the dielectric effect remains exceptionally strong even at much higher temperatures. Titanates with critical temperatures far below room temperature have become synonymous with "ceramic" in the context of ceramic capacitors for just this reason. Optically transparent materials focus on the response of a material to incoming light waves of a range of wavelengths. Frequency selective optical filters can be utilized to alter or enhance

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3744-445: The material until joule heating brings it to the transition temperature, at which point the circuit will be broken and current flow will cease. Such ceramics are used as self-controlled heating elements in, for example, the rear-window defrost circuits of automobiles. At the transition temperature, the material's dielectric response becomes theoretically infinite. While a lack of temperature control would rule out any practical use of

3816-410: The mechanical performance of materials and components. It applies the physics of stress and strain , in particular the theories of elasticity and plasticity , to the microscopic crystallographic defects found in real materials in order to predict the macroscopic mechanical failure of bodies. Fractography is widely used with fracture mechanics to understand the causes of failures and also verify

3888-412: The microstructure. The root cause of many ceramic failures is evident in the cleaved and polished microstructure. Physical properties which constitute the field of materials science and engineering include the following: Mechanical properties are important in structural and building materials as well as textile fabrics. In modern materials science , fracture mechanics is an important tool in improving

3960-718: The pore size and morphology of the microstructure. These important variables are the initial solids loading of the colloid, the cooling rate, the sintering temperature and duration, and the use of certain additives which can influence the microstructural morphology during the process. A good understanding of these parameters is essential to understanding the relationships between processing, microstructure, and mechanical properties of anisotropically porous materials. Some ceramics are semiconductors . Most of these are transition metal oxides that are II-VI semiconductors, such as zinc oxide . While there are prospects of mass-producing blue LEDs from zinc oxide, ceramicists are most interested in

4032-448: The realms of cult or ritual , as are specific depositions of offerings in some of the ditches, especially at the settlements of Aue and Scheelkopf. Here, ditches contained carefully placed complete vessels, well-preserved quern-stones and the horns of aurochs . The latter had been neatly separated from the skulls, perhaps reflecting a special symbolic significance ascribed to that animal. A hitherto unknown aspect to MK burial practice

4104-434: The region, suggesting that the Michelsberg culture emerged through a migration of people from west. They displayed genetic links to other farmers of Western Europe, and carried substantial amounts of hunter-gatherer ancestry. The authors of the study proposed that migrations of people associated with the Michelsberg culture may have been responsible for the resurgence of hunter-gatherer ancestry observed in Central Europe during

4176-433: The remains 22 Michelsberg people buried at Gougenheim , France. The 21 samples of mtDNA extracted belonged to the maternal haplogroups H (7 samples), K (4 samples), J (2 samples), W (1 samples), N (1 sample), U (3 samples) and T (2 samples). The examined individuals displayed genetic links to earlier farming populations of the Paris Basin , and were genetically very different from previous post-LBK cultures of

4248-694: The root ceram- is the Mycenaean Greek ke-ra-me-we , workers of ceramic, written in Linear B syllabic script. The word ceramic can be used as an adjective to describe a material, product, or process, or it may be used as a noun, either singular or, more commonly, as the plural noun ceramics . Ceramic material is an inorganic, metallic oxide, nitride, or carbide material. Some elements, such as carbon or silicon , may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, and weak in shearing and tension. They withstand

4320-509: The site that was called Irminsul. The writer calls the site of the Eresburg, Erisburgo , i.e. not Ermensula . The third part of the sentence runs "et succendit ea loca" , i. e. he set "these places" (plural) on fire, possibly implying that Charlemagne moved on from the Eresburg to the Irminsul. According to other sources, Charlemagne stayed near the Bullerborn, an intermittent spring near Altenbeken , before he conquered and destroyed

4392-569: The skeletal remains from rubbish pits may be the result of such activity. The same may apply to human bones found in the fills of enclosure ditches around MK settlements. It has also been suggested (hypothetically) that partially articulated remains found in such ditches may indicate that graves were placed on the surfaces adjacent to them and later washed into the ditches due to erosion. Occasionally, earthwork ditches contain more structured deposits of human bone, e.g. adult skeletons surrounded by those of children. Such burials are probably connected to

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4464-559: The southwest and of the Linear Pottery culture of Central Europe. Shortly after its emergence in northeastern France, the Michelsberg culture expands rapidly throughout central Germany, northeastern France, eastern Belgium, and the southwestern Netherlands. These areas had previously been occupied by cultures derived from the Linear Pottery culture (LBK), with whom the Michelsberg culture shares surprisingly little cultural or genetic affinity. Archaeological evidence suggests that

4536-453: The theoretical failure predictions with real-life failures. Ceramic materials are usually ionic or covalent bonded materials. A material held together by either type of bond will tend to fracture before any plastic deformation takes place, which results in poor toughness in these materials. Additionally, because these materials tend to be porous, the pores and other microscopic imperfections act as stress concentrators , decreasing

4608-460: The toughness further, and reducing the tensile strength . These combine to give catastrophic failures , as opposed to the more ductile failure modes of metals. These materials do show plastic deformation . However, because of the rigid structure of crystalline material, there are very few available slip systems for dislocations to move, and so they deform very slowly. To overcome the brittle behavior, ceramic material development has introduced

4680-565: The use of glassy, amorphous ceramic coatings on top of the crystalline ceramic substrates. Ceramics now include domestic, industrial, and building products, as well as a wide range of materials developed for use in advanced ceramic engineering, such as semiconductors . The word ceramic comes from the Ancient Greek word κεραμικός ( keramikós ), meaning "of or for pottery " (from κέραμος ( kéramos )  'potter's clay, tile, pottery'). The earliest known mention of

4752-446: The wear plates of crushing equipment in mining operations. Advanced ceramics are also used in the medical, electrical, electronics, and armor industries. Human beings appear to have been making their own ceramics for at least 26,000 years, subjecting clay and silica to intense heat to fuse and form ceramic materials. The earliest found so far were in southern central Europe and were sculpted figures, not dishes. The earliest known pottery

4824-598: Was a bloody feud at the Eresburg between the Saxon Duke Henry the Fowler and the East Francian king, Conrad . The Bishop of Paderborn, Theoderic is also supposed to have participated personally in the battle. Also in 915 at Eresburg the invading Hungarians defeated a German army. Eresburg may have been the site of the Irminsul , a sort of pillar or tree, and one of the chief pagan religious sites of

4896-425: Was found in 2024. If a ceramic is subjected to substantial mechanical loading, it can undergo a process called ice-templating , which allows some control of the microstructure of the ceramic product and therefore some control of the mechanical properties. Ceramic engineers use this technique to tune the mechanical properties to their desired application. Specifically, the strength is increased when this technique

4968-503: Was made by mixing animal products with clay and firing it at up to 800 °C (1,500 °F). While pottery fragments have been found up to 19,000 years old, it was not until about 10,000 years later that regular pottery became common. An early people that spread across much of Europe is named after its use of pottery: the Corded Ware culture . These early Indo-European peoples decorated their pottery by wrapping it with rope while it

5040-467: Was no indication of a destruction of the site; nor were there any finds suggesting humans meeting a violent end. Some pits contained the remains of food stores. Thus, the abandonment of the site may have had environmental reasons . A common suggestion is the drying up of the Rhine's arms which used to flow by the bottom of the hill, due to an extensive dry period . As the result of such a change in climate ,

5112-528: Was still wet. When the ceramics were fired, the rope burned off but left a decorative pattern of complex grooves on the surface. The invention of the wheel eventually led to the production of smoother, more even pottery using the wheel-forming (throwing) technique, like the pottery wheel . Early ceramics were porous, absorbing water easily. It became useful for more items with the discovery of glazing techniques, which involved coating pottery with silicon, bone ash, or other materials that could melt and reform into

5184-510: Was underway in the Rhine valley at the same time as similar developments were occurring in Brittany ( Castellic culture ) and the Paris basin ( Cerny culture ). The settlement at Schierstein might have housed up to several thousand inhabitants. Research so far tends to characterise MK as a culture that avoided or rejected the use of copper , but occasional finds, e.g. at Heilbronn -Klingenberg, do indicate use of that metal. Michelsberg hill

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