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Chamotte Clay
Grog, also known as firesand and chamotte, is a raw material usually made from crushed and ground potsherds, reintroduced into crude clay to temper it before making ceramic ware. It has a high percentage of silica and alumina. It is normally available as a powder or chippings, and is an important ingredient in Coade stone. Production It can be produced by firing selected fire clays to high temperatures before grinding and screening to specific particle sizes. An alternate method of production uses pitchers. The particle size distribution is generally coarser in size than the other raw materials used to prepare clay bodies. It tends to be porous and have low density. Properties Grog is composed of 40% minimum alumina, 30% minimum silica, 4% maximum iron(III) oxide, up to 2% calcium oxide and magnesium oxide combined.. Its melting point is approximately . Its water absorption is maximum 7%. Its thermal expansion coefficient is 5.2 mm/m and thermal conductivity is 0.8 W/( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grog - Ground Potsherds
Grog is a term used for a variety of alcoholic beverages. Origin and history Popularization of rum and invention of grog Following England's conquest of Jamaica in 1655, rum gradually replaced beer and brandy as the drink of choice for the Royal Navy. The prior ration of eight pints of beer was replaced with a ration of one half-pint of spirits. In 1740, to minimise the subsequent illness, drunkenness, and disciplinary problems, British Vice-Admiral Edward Vernon ordered that the daily rum issue of of rum be mixed with of water, a water-to-rum ratio of 4:1, with half issued before noon and the remainder after the end of the working day. This both diluted its effects and accelerated its spoilage, preventing hoarding of the allowance. The mixture of rum and water became known as a "grog". This procedure became part of the official regulations of the Royal Navy in 1756 until the reduction of the ration to the "tot" in 1850. Sailors were given of rum daily, or 17.5 imperial o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength and low raw material cost, steel is one of the most commonly manufactured materials in the world. Steel is used in structures (as concrete Rebar, reinforcing rods), in Bridge, bridges, infrastructure, Tool, tools, Ship, ships, Train, trains, Car, cars, Bicycle, bicycles, Machine, machines, Home appliance, electrical appliances, furniture, and Weapon, weapons. Iron is always the main element in steel, but other elements are used to produce various grades of steel demonstrating altered material, mechanical, and microstructural properties. Stainless steels, for example, typically contain 18% chromium and exhibit improved corrosion and Redox, oxidation resistance versus its carbon steel counterpart. Under atmospheric pressures, steels generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typology (archaeology)
In archaeology, a typology is the result of the classification of things according to their physical characteristics. The products of the classification, i.e. the classes, are also called types. Most archaeological typologies organize portable artifacts into types, but typologies of larger structures, including buildings, field monuments, fortifications or roads, are equally possible. A typology helps to manage a large mass of archaeological data. According to Doran and Hodson, "this superficially straightforward task has proved one of the most time consuming and contentious aspects of archaeological research". Philosophical background Typology is based on a view of the world familiar from Plato's metaphysics called essentialism. Essentialism is the idea that the world is divided into real, discontinuous and immutable "kinds". This idea is the basis for most typological constructions particularly of stone artefacts where essential forms are often thought of as "mental templates" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze Age
The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of the three-age system, following the Stone Age and preceding the Iron Age. Conceived as a global era, the Bronze Age follows the Neolithic, with a transition period between the two known as the Chalcolithic. The final decades of the Bronze Age in the Mediterranean basin are often characterised as a period of widespread societal collapse known as the Late Bronze Age collapse (), although its severity and scope are debated among scholars. An ancient civilisation is deemed to be part of the Bronze Age if it either produced bronze by smelting its own copper and alloying it with tin, arsenic, or other metals, or traded other items for bronze from producing areas elsewhere. Bronze Age cultures were the first to History of writing, develop writin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceramic
A ceramic 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 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 (), meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeology
Archaeology or archeology is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of Artifact (archaeology), artifacts, architecture, biofact (archaeology), biofacts or ecofacts, archaeological site, sites, and cultural landscapes. Archaeology can be considered both a social science and a branch of the humanities. It is usually considered an independent academic discipline, but may also be classified as part of anthropology (in North America – the four-field approach), history or geography. The discipline involves Survey (archaeology), surveying, Archaeological excavation, excavation, and eventually Post excavation, analysis of data collected, to learn more about the past. In broad scope, archaeology relies on cross-disciplinary research. Archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pizza Stone
A baking stone is a portable cooking surface used in baking. It may be made of ceramic, stone or, more recently, salt. Food is put on the stone, which is then placed in an oven, though sometimes the stone is heated first. Baking stones are used much like cookie sheets, but may absorb additional moisture for crispier food. A pizza stone is a baking stone designed for cooking pizza. Overview Due to the thermal mass of baking stones and the material's property as a poor heat conductor, food is less likely to burn when one uses a baking stone instead of metal or glass bakeware. Baking stones are a variation on hot stone cooking, which is one of the oldest cooking techniques known. Some cooks recommend sprinkling corn meal or flour on the baking stone to prevent the crust from sticking or using parchment paper atop the stone. Baking "stones" may be purchased as unglazed ceramic tiles, unglazed fired clay tiles and quarried tiles, from tile shops and hardware stores. To prevent frac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Europe
Southern Europe is also known as Mediterranean Europe, as its geography is marked by the Mediterranean Sea. Definitions of southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Gibraltar, Greece, Italy, Kosovo, Malta, Monaco, Montenegro, North Macedonia, Portugal, San Marino, Serbia, Slovenia, southern France, southern Romania, Spain, Turkey, and Vatican City. Southern Europe is focused on the three peninsulas located in the extreme south of the European continent. These are the Iberian Peninsula, the Italian Peninsula, and the Balkan Peninsula. These three peninsulas are separated from the rest of Europe by towering mountain ranges, respectively by the Pyrenees, the Alps and the Balkan Mountains. The location of these peninsulas in the heart of the Mediterranean Sea, as well as their mountainous reliefs, provide them with very different types of climates (mainly subtropical Mediterranean) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Europe
Central Europe is a geographical region of Europe between Eastern, Southern, Western and Northern Europe. Central Europe is known for its cultural diversity; however, countries in this region also share some historical and cultural similarities. The region is variously defined, but it’s minimum definition could be considered of consisting of Austria, Bosnia and Herzegovina, Croatia, the Czech Republic, eastern France, Germany, Liechtenstein, Luxembourg, Poland, Slovakia, Slovenia and Switzerland. But also the Baltic States, the Alsace in north-east France, and South Tyrol, northern Belluno , and Friuli-Venezia Giulia in north-east Italy are culturally usually considered to be part of Central Europe. From the early 16th century until the early 18th century, parts of Croatia and Hungary were ruled by the Ottoman Empire. During the 17th century, the empire also occupied southern parts of present-day Slovakia. During the Early Modern period, the territories of Poland and Lithuani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as mica, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Shock
Thermal shock is a phenomenon characterized by a rapid change in temperature that results in a transient mechanical load on an object. The load is caused by the differential expansion of different parts of the object due to the temperature change. This differential expansion can be understood in terms of strain, rather than stress. When the strain exceeds the tensile strength of the material, it can cause cracks to form, and eventually lead to structural failure. Methods to prevent thermal shock include: * Minimizing the thermal gradient by changing the temperature gradually * Increasing the thermal conductivity of the material * Reducing the coefficient of thermal expansion of the material * Increasing the strength of the material * Introducing compressive stress in the material, such as in tempered glass * Decreasing the Young's modulus of the material * Increasing the toughness of the material through crack tip blunting or crack deflection, utilizing the process of pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesh (scale)
Mesh is a measurement of particle size often used in determining the particle-size distribution of a granular material A granular material is a conglomeration of discrete solid, macroscopic scale, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would be friction when granulation, grains collide). T .... For example, a sample from a truckload of peanuts may be placed atop a mesh with 5 mm openings. When the mesh is shaken, small broken pieces and dust pass through the mesh while whole peanuts are retained on the mesh. A commercial peanut buyer might use a test like this to determine if a batch of peanuts has too many broken pieces. This type of test is common in some industries, and, to facilitate uniform testing methods, several standardized mesh series have been established. Metal surfaces mechanically polished are designated as having a mechanical finish related to the abrasive used. Many mesh siz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
