1.
Olaf II of Norway
–
Olaf II Haraldsson, later known as St. Olaf, was King of Norway from 1015 to 1028. He was posthumously given the title Rex Perpetuus Norvegiae and canonised in Nidaros by Bishop Grimkell and his remains were enshrined in Nidaros Cathedral, built over his burial site. He is also a saint of the Eastern Orthodox Church. The exact position of Saint Olafs grave in Nidaros has been unknown since 1568, Saint Olaf is symbolised by the axe in Norways coat of arms, and the Olsok is still his day of celebration. Many Christian institutions with Scandinavian links and Norways Order of St. Olav, are named after him, modern historians generally agree that Olaf was inclined to violence and brutality, and they accuse earlier scholars of neglecting this side of Olafs character. Especially during the period of Romantic Nationalism, Olaf was a symbol of independence and pride. Olaf IIs Old Norse name is Ólafr Haraldsson, during his lifetime he was known as Olaf the fat or the stout or simply as Olaf the big. In Norway today, he is referred to as Olav den hellige or Heilage-Olav in honour of his sainthood. Olaf Haraldsson had the given name Óláfr in Old Norse, Olav is the modern equivalent in Norwegian, formerly often spelt Olaf. His name in Icelandic is Ólafur, in Faroese Ólavur, in Danish Oluf, Olave was the traditional spelling in England, preserved in the name of medieval churches dedicated to him. Other names, such as Oláfr hinn helgi, Olavus rex and he is sometimes referred to as Rex Perpetuus Norvegiae, a designation which goes back to the thirteenth century. The term Ola Nordmann as epithet of the archetypal Norwegian may originate in this tradition and his mother was Åsta Gudbrandsdatter, and his father was Harald Grenske, great-great-grandchild of Harald Fairhair, the first king of Norway. Harald Grenske died when Åsta Gudbrandsdatter was pregnant with Olaf and she later married Sigurd Syr, with whom she had other children including Harald Hardrada, who would reign as a future king of Norway. There are many texts giving information concerning Olaf Haraldsson, the oldest source that we have is the Glælognskviða or Sea-Calm Poem, composed by Þórarinn loftunga, an Icelander. It praises Olaf and mentions some of the miracles attributed to him. Olaf is also mentioned in the Norwegian synoptic histories and these include the Ágrip af Nóregskonungasögum, the Historia Norwegiae and a Latin text, Historia de Antiquitate Regum Norwagiensium by Theodoric the Monk. Icelanders also wrote extensively about Olaf and we also have several Icelandic sagas about him, the famous Heimskringla, written by Snorri Sturluson, largely bases its account of Olaf on the earlier Fagrskinna. We also have the important Oldest Saga of St. Olaf, finally, there are many hagiographic sources describing St. Olaf, but these focus mostly on miracles attributed to him and cannot be used to accurately recreate his life
Olaf II of Norway
–
Coin of Olaf dated 1023–28.
Olaf II of Norway
–
Olav den Helliges død Peter Nicolai Arbo (1859)
Olaf II of Norway
–
St Olaf with his axe on a
bishop's crozier, walrus ivory, Norway c 1375–1400 (
Victoria and Albert Museum)
Olaf II of Norway
–
Modern wrought-iron vignettes of Olaf's life on the door of a
stave church in
Hardemo,
Nerike, where Olaf baptized locals during his escape
2.
Ductility
–
In materials science, ductility is a solid materials ability to deform under tensile stress, this is often characterized by the materials ability to be stretched into a wire. Malleability, a property, is a materials ability to deform under compressive stress. Both of these properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Also, these properties are dependent on temperature and pressure. Ductility and malleability are not always coextensive – for instance, while gold has high ductility and malleability, lead has low ductility, the word ductility is sometimes used to encompass both types of plasticity. Ductility is especially important in metalworking, as materials that crack, break or shatter under stress cannot be manipulated using metal-forming processes such as hammering, rolling, malleable materials can be formed cold using stamping or pressing, whereas brittle materials may be cast or thermoformed. High degrees of ductility occur due to bonds, which are found predominantly in metals. In metallic bonds valence shell electrons are delocalized and shared between many atoms, the delocalized electrons allow metal atoms to slide past one another without being subjected to strong repulsive forces that would cause other materials to shatter. Ductility can be quantified by the fracture strain ε f, which is the strain at which a test specimen fractures during a uniaxial tensile test. Another commonly used measure is the reduction of area at fracture q, the ductility of steel varies depending on the alloying constituents. Increasing levels of carbon decrease ductility, many plastics and amorphous solids, such as Play-Doh, are also malleable. The most ductile metal is platinum and the most malleable metal is gold, DBTT is important since, once a material is cooled below the DBTT, it has a much greater tendency to shatter on impact instead of bending or deforming. For example, zamak 3 exhibits good ductility at room temperature, DBTT is a very important consideration in selecting materials that are subjected to mechanical stresses. A similar phenomenon, the transition temperature, occurs with glasses and polymers. In some materials the transition is sharper than others and typically requires a temperature-sensitive deformation mechanism and this can be problematic for steels with a high ferrite content. This famously resulted in serious hull cracking in Liberty ships in colder waters during World War II, DBTT can also be influenced by external factors such as neutron radiation, which leads to an increase in internal lattice defects and a corresponding decrease in ductility and increase in DBTT. The most accurate method of measuring the DBTT of a material is by fracture testing, typically four point bend testing at a range of temperatures is performed on pre-cracked bars of polished material. For experiments conducted at higher temperatures, dislocation activity increases, the temperature at which this occurs is the ductile–brittle transition temperature
Ductility
–
Tensile test of an
AlMgSi alloy. The local necking and the cup and cone fracture surfaces are typical for ductile metals.
Ductility
–
This tensile test of a
nodular cast iron demonstrates low ductility.
Ductility
–
Gold leaf can be produced owing to gold's malleability.
3.
Metal
–
A metal is a material that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible and ductile, about 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms, astrophysicists use the term metal to collectively describe all elements other than hydrogen and helium, the simplest two, in a star. The star fuses smaller atoms, mostly hydrogen and helium, to larger ones over its lifetime. In that sense, the metallicity of an object is the proportion of its matter made up of all chemical elements. Many elements and compounds that are not normally classified as metals become metallic under high pressures, the atoms of metallic substances are typically arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, and hexagonal close-packed. In bcc, each atom is positioned at the center of a cube of eight others, in fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layers differs. Some metals adopt different structures depending on the temperature, atoms of metals readily lose their outer shell electrons, resulting in a free flowing cloud of electrons within their otherwise solid arrangement. This provides the ability of metallic substances to easily transmit heat, while this flow of electrons occurs, the solid characteristic of the metal is produced by electrostatic interactions between each atom and the electron cloud. This type of bond is called a metallic bond, Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales. Examples,4 Na + O2 →2 Na2O2 Ca + O2 →2 CaO4 Al +3 O2 →2 Al2O3, the transition metals are slower to oxidize because they form a passivating layer of oxide that protects the interior. Others, like palladium, platinum and gold, do not react with the atmosphere at all, some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades. The oxides of metals are generally basic, as opposed to those of nonmetals, exceptions are largely oxides with very high oxidation states such as CrO3, Mn2O7, and OsO4, which have strictly acidic reactions. Painting, anodizing or plating metals are good ways to prevent their corrosion, however, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. Water and the two form an electrochemical cell, and if the coating is less reactive than the coatee. Metals in general have high conductivity, high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving, in terms of optical properties, metals are shiny and lustrous. Sheets of metal beyond a few micrometres in thickness appear opaque, although most metals have higher densities than most nonmetals, there is wide variation in their densities, lithium being the least dense solid element and osmium the densest
Metal
–
Gallium crystals
Metal
–
Hot metal work from a
blacksmith.
Metal
–
Zinc, a base metal, reacting with an acid
Metal
–
A gold nugget
4.
Alloy
–
An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character, an alloy may be a solid solution of metal elements or a mixture of metallic phases. Intermetallic compounds are alloys with a stoichiometry and crystal structure. Zintl phases are sometimes considered alloys depending on bond types. Alloys are used in a variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties, in other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, solder, brass, pewter, duralumin, bronze, the alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the arrangement that forms the alloy. They can be classified as homogeneous, or heterogeneous or intermetallic. An alloy is a mixture of elements, which forms an impure substance that retains the characteristics of a metal. Alloys are made by mixing two or more elements, at least one of which is a metal and this is usually called the primary metal or the base metal, and the name of this metal may also be the name of the alloy. The other constituents may or may not be metals but, when mixed with the base, they will be soluble. The mechanical properties of alloys will often be different from those of its individual constituents. A metal that is very soft, such as aluminium, can be altered by alloying it with another soft metal. Although both metals are soft and ductile, the resulting aluminium alloy will have much greater strength. Adding a small amount of carbon to iron trades its great ductility for the greater strength of an alloy called steel. Due to its strength, but still substantial toughness, and its ability to be greatly altered by heat treatment, steel is one of the most useful. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel
Alloy
–
Liquid
bronze, being poured into molds during casting.
Alloy
–
Wire rope made from
steel, which is a metal alloy whose major component is
iron, with
carbon content between 0.02% and 2.14% by mass.
Alloy
–
A
brass lamp.
Alloy
–
A gate valve, made from
Inconel.
5.
Tin
–
Tin is a chemical element with symbol Sn and atomic number 50. It is a metal in group 14 of the periodic table. It is obtained chiefly from the mineral cassiterite, which contains tin dioxide, Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, metallic tin is not easily oxidized in air. The first alloy used on a scale was bronze, made of tin and copper. After 600 BC, pure metallic tin was produced, pewter, which is an alloy of 85–90% tin with the remainder commonly consisting of copper, antimony, and lead, was used for flatware from the Bronze Age until the 20th century. In modern times, tin is used in alloys, most notably tin/lead soft solders. Another large application for tin is corrosion-resistant tin plating of steel, inorganic tin compounds are rather non-toxic. Because of its low toxicity, tin-plated metal was used for packaging as tin cans. However, overexposure to tin may cause problems with metabolizing essential trace elements such as copper and zinc, Tin is a soft, malleable, ductile and highly crystalline silvery-white metal. When a bar of tin is bent, a sound known as the tin cry can be heard from the twinning of the crystals. Tin melts at the low temperature of about 232 °C, the lowest in group 14, the melting point is further lowered to 177.3 °C for 11 nm particles. β-tin, which is stable at and above room temperature, is malleable, in contrast, α-tin, which is stable below 13.2 °C, is brittle. α-tin has a cubic crystal structure, similar to diamond. α-tin has no properties at all because its atoms form a covalent structure in which electrons cannot move freely. It is a dull-gray powdery material with no common uses other than a few specialized semiconductor applications and these two allotropes, α-tin and β-tin, are more commonly known as gray tin and white tin, respectively. Two more allotropes, γ and σ, exist at temperatures above 161 °C, in cold conditions, β-tin tends to transform spontaneously into α-tin, a phenomenon known as tin pest. Commercial grades of tin resist transformation because of the effect of the small amounts of bismuth, antimony, lead
Tin
–
left: white, beta, β; right: gray, alpha, α
Tin
–
Droplet of solidified molten tin
Tin
–
Ceremonial giant bronze
dirk of the Plougrescant-Ommerschans type, Plougrescant, France, 1500–1300 BC.
Tin
–
Sample of cassiterite, the main
ore of tin.
6.
Copper
–
Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
Copper
–
Native copper (~4 cm in size)
Copper
–
A copper disc (99.95% pure) made by
continuous casting;
etched to reveal
crystallites.
Copper
–
Copper just above its melting point keeps its pink luster color when enough light outshines the orange
incandescence color.
Copper
–
Unoxidized copper wire (left) and oxidized copper wire (right).
7.
Antimony
–
Antimony is a chemical element with symbol Sb and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite, Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name, kohl. Metallic antimony was known, but it was erroneously identified as lead upon its discovery. In the West, it was first isolated by Vannoccio Biringuccio, for some time, China has been the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan. The industrial methods for refining antimony are roasting and reduction with carbon or direct reduction of stibnite with iron, the largest applications for metallic antimony is an alloy with lead and tin and the lead antimony plates in lead–acid batteries. Alloys of lead and tin with antimony have improved properties for solders, bullets, Antimony compounds are prominent additives for chlorine and bromine-containing fire retardants found in many commercial and domestic products. An emerging application is the use of antimony in microelectronics, Antimony is in a pnictogen and has an electronegativity of 2.05. In accordance with periodic trends, it is more electronegative than tin or bismuth, Antimony is stable in air at room temperature, but reacts with oxygen if heated to produce antimony trioxide, Sb2O3. Antimony is resistant to attack by acids, four allotropes of antimony are known, a stable metallic form and three metastable forms. Elemental antimony is a brittle, silver-white shiny metalloid, when slowly cooled, molten antimony crystallizes in a trigonal cell, isomorphic with the gray allotrope of arsenic. A rare explosive form of antimony can be formed from the electrolysis of antimony trichloride, when scratched with a sharp implement, an exothermic reaction occurs and white fumes are given off as metallic antimony forms, when rubbed with a pestle in a mortar, a strong detonation occurs. Black antimony is formed upon cooling of antimony vapor. It has the crystal structure as red phosphorus and black arsenic, it oxidizes in air. At 100 °C, it transforms into the stable form. The yellow allotrope of antimony is the most unstable and it has only been generated by oxidation of stibine at −90 °C. Above this temperature and in ambient light, this metastable allotrope transforms into the more stable black allotrope, elemental antimony adopts a layered structure in which layers consist of fused, ruffled, six-membered rings. The nearest and next-nearest neighbors form an octahedral complex, with the three atoms in each double layer slightly closer than the three atoms in the next. This relatively close packing leads to a density of 6.697 g/cm3
Antimony
–
Antimony, 51 Sb
Antimony
–
Native antimony with
oxidation products
Antimony
–
Stibnite
Antimony
–
The Italian metallurgist Vannoccio Biringuccio described the first procedure of how to isolate antimony.
8.
Bismuth
–
Bismuth is a chemical element with the symbol Bi and atomic number 83. Bismuth, a pentavalent post-transition metal and one of the pnictogens, chemically resembles its lighter homologs arsenic, elemental bismuth may occur naturally, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead and it is a brittle metal with a silvery white color when freshly produced, but surface oxidation can give it a pink tinge. Bismuth is the most naturally diamagnetic element, and has one of the lowest values of thermal conductivity among metals, Bismuth metal has been known since ancient times, although it was often confused with lead and tin, which share some physical properties. Bismuth was long considered the element with the highest atomic mass that is stable, because of its tremendously long half-life, bismuth may still be considered stable for almost all purposes. Bismuth compounds account for half the production of bismuth. They are used in cosmetics, pigments, and a few pharmaceuticals, notably bismuth subsalicylate, bismuths unusual propensity to expand upon freezing is responsible for some of its uses, such as in casting of printing type. Bismuth has unusually low toxicity for a heavy metal, as the toxicity of lead has become more apparent in recent years, there is an increasing use of bismuth alloys as a replacement for lead. The name bismuth dates from around the 1660s, and is of uncertain etymology and it is one of the first 10 metals to have been discovered. Bismuth appears in the 1660s, from obsolete German Bismuth, Wismut, Wissmuth, the New Latin bisemutum is from the German Wismuth, perhaps from weiße Masse, white mass. The element was confused in early times with tin and lead because of its resemblance to those elements, Bismuth has been known since ancient times, so no one person is credited with its discovery. Agricola, in De Natura Fossilium states that bismuth is a metal in a family of metals including tin. This was based on observation of the metals and their physical properties, miners in the age of alchemy also gave bismuth the name tectum argenti, or silver being made, in the sense of silver still in the process of being formed within the Earth. Bismuth was also known to the Incas and used in a bronze alloy for knives. Bismuth is a metal with a white, silver-pink hue, often occurring in its native form. The spiral, stair-stepped structure of crystals is the result of a higher growth rate around the outside edges than on the inside edges. The variations in the thickness of the layer that forms on the surface of the crystal causes different wavelengths of light to interfere upon reflection. When burned in oxygen, bismuth burns with a blue flame and its toxicity is much lower than that of its neighbors in the periodic table, such as lead, antimony, and polonium
Bismuth
–
Bismuth, 83 Bi
Bismuth
–
Bismuth crystal illustrating the many iridescent refraction hues of its oxide surface
Bismuth
–
Artificially grown bismuth crystal illustrating the stairstep crystal structure, with a 1 cm 3 cube of bismuth metal
Bismuth
–
Bismite mineral
9.
Lead
–
Lead is a chemical element with atomic number 82 and symbol Pb. When freshly cut, it is bluish-white, it tarnishes to a dull gray upon exposure to air and it is a soft, malleable, and heavy metal with a density exceeding that of most common materials. Lead has the second-highest atomic number of the stable elements. Lead is a relatively unreactive post-transition metal and its weak metallic character is illustrated by its amphoteric nature and tendency to form covalent bonds. Compounds of lead are found in the +2 oxidation state. Exceptions are mostly limited to organolead compounds, like the lighter members of the group, lead exhibits a tendency to bond to itself, it can form chains, rings, and polyhedral structures. Lead is easily extracted from its ores and was known to people in Western Asia. A principal ore of lead, galena, often bears silver, Lead production declined after the fall of Rome and did not reach comparable levels again until the Industrial Revolution. Nowadays, global production of lead is about ten million tonnes annually, Lead has several properties that make it useful, high density, low melting point, ductility, and relative inertness to oxidation. In the late 19th century, lead was recognized as poisonous, Lead is a neurotoxin that accumulates in soft tissues and bones, damaging the nervous system and causing brain disorders and, in mammals, blood disorders. A lead atom has 82 electrons, arranged in a configuration of 4f145d106s26p2. The combined first and second ionization energies—the total energy required to remove the two 6p electrons—is close to that of tin, leads upper neighbor in group 14. This is unusual since ionization energies generally fall going down a group as an elements outer electrons become more distant from the nucleus, the similarity is caused by the lanthanide contraction—the decrease in element radii from lanthanum to lutetium, and the relatively small radii of the elements after hafnium. The contraction is due to shielding of the nucleus by the lanthanide 4f electrons. The combined first four ionization energies of lead exceed those of tin, for this reason lead, unlike tin, mostly forms compounds in which it has an oxidation state of +2, rather than +4. Relativistic effects, which become particularly prominent at the bottom of the periodic table, as a result, the 6s electrons of lead become reluctant to participate in bonding, a phenomenon called the inert pair effect. A related outcome is that the distance between nearest atoms in crystalline lead is unusually long, the lighter group 14 elements form stable or metastable allotropes having the tetrahedrally coordinated and covalently bonded diamond cubic structure. The energy levels of their outer s- and p-orbitals are close enough to allow mixing into four hybrid sp3 orbitals
Lead
–
Lead, 82 Pb
Lead
–
A sample of freshly solidified lead (from molten state)
Lead
–
World lead production peaking in the
Roman period and the rising
Industrial Revolution
Lead
–
Lead
ingots from
Roman Britain on display at the
Wells and Mendip Museum
10.
Silver
–
Silver is a metallic element with symbol Ag and atomic number 47. The symbol Ag stems from Latin argentum, derived from the Greek ὰργὀς, a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earths crust in the pure, free form, as an alloy with gold and other metals. Most silver is produced as a byproduct of copper, gold, lead, Silver is more abundant than gold, but it is much less abundant as a native metal. Its purity is measured on a per mille basis, a 94%-pure alloy is described as 0.940 fine. As one of the seven metals of antiquity, silver has had a role in most human cultures. Silver has long valued as a precious metal. Silver metal is used in many premodern monetary systems in bullion coins, Silver is used in numerous applications other than currency, such as solar panels, water filtration, jewelry, ornaments, high-value tableware and utensils, and as an investment medium. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings, Silver compounds are used in photographic film and X-rays. Dilute silver nitrate solutions and other compounds are used as disinfectants and microbiocides, added to bandages and wound-dressings, catheters. Silver is similar in its physical and chemical properties to its two neighbours in group 11 of the periodic table, copper and gold. This distinctive electron configuration, with an electron in the highest occupied s subshell over a filled d subshell. Silver is a soft, ductile and malleable transition metal. Silver crystallizes in a cubic lattice with bulk coordination number 12. Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a covalent character and are relatively weak and this observation explains the low hardness and high ductility of single crystals of silver. Silver has a brilliant white metallic luster that can take a polish. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm, at wavelengths shorter than 450 nm, silvers reflectivity is inferior to that of aluminium and drops to zero near 310 nm. The electrical conductivity of silver is the greatest of all metals, greater even than copper, during World War II in the US,13540 tons of silver were used in electromagnets for enriching uranium, mainly because of the wartime shortage of copper
Silver
–
Electrolytically refined silver
Silver
–
Silver 1000
oz t (~31 kg) bullion bar
Silver
–
Cessna 210 equipped with a silver iodide generator for
cloud seeding
Silver
–
A Canadian 50 cent piece from 1951, with King George the 6th on the obverse and Canada's (now former) coat of arms on the reverse. It is made of 80% silver and 20% copper.
11.
Melting point
–
The melting point of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure. At the melting point the solid and liquid phase exist in equilibrium, the melting point of a substance depends on pressure and is usually specified at standard pressure. When considered as the temperature of the change from liquid to solid. Because of the ability of some substances to supercool, the point is not considered as a characteristic property of a substance. For most substances, melting and freezing points are approximately equal, for example, the melting point and freezing point of mercury is 234.32 kelvins. However, certain substances possess differing solid-liquid transition temperatures, for example, agar melts at 85 °C and solidifies from 31 °C to 40 °C, such direction dependence is known as hysteresis. The melting point of ice at 1 atmosphere of pressure is close to 0 °C. In the presence of nucleating substances the freezing point of water is the same as the melting point, the chemical element with the highest melting point is tungsten, at 3687 K, this property makes tungsten excellent for use as filaments in light bulbs. Many laboratory techniques exist for the determination of melting points, a Kofler bench is a metal strip with a temperature gradient. Any substance can be placed on a section of the strip revealing its thermal behaviour at the temperature at that point, differential scanning calorimetry gives information on melting point together with its enthalpy of fusion. A basic melting point apparatus for the analysis of crystalline solids consists of an oil bath with a transparent window, the several grains of a solid are placed in a thin glass tube and partially immersed in the oil bath. The oil bath is heated and with the aid of the melting of the individual crystals at a certain temperature can be observed. In large/small devices, the sample is placed in a heating block, the measurement can also be made continuously with an operating process. For instance, oil refineries measure the point of diesel fuel online, meaning that the sample is taken from the process. This allows for more frequent measurements as the sample does not have to be manually collected, for refractory materials the extremely high melting point may be determined by heating the material in a black body furnace and measuring the black-body temperature with an optical pyrometer. For the highest melting materials, this may require extrapolation by several hundred degrees, the spectral radiance from an incandescent body is known to be a function of its temperature. An optical pyrometer matches the radiance of a body under study to the radiance of a source that has been previously calibrated as a function of temperature, in this way, the measurement of the absolute magnitude of the intensity of radiation is unnecessary. However, known temperatures must be used to determine the calibration of the pyrometer, for temperatures above the calibration range of the source, an extrapolation technique must be employed
Melting point
–
Melting points (in blue) and boiling points (in pink) of the first eight
carboxylic acids (°C)
Melting point
–
Kofler bench with samples for calibration
Melting point
–
Automatic digital melting point meter
Melting point
–
Pressure dependence of water melting point
12.
Zinc
–
Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table, in some respects zinc is chemically similar to magnesium, both elements exhibit only one normal oxidation state, and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earths crust and has five stable isotopes, the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States, Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century, the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, alchemists burned zinc in air to form what they called philosophers wool or white snow. The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746, work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the application for zinc. Other applications are in batteries, small non-structural castings. A variety of compounds are commonly used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide. Zinc is an essential mineral perceived by the public today as being of exceptional biologic and public health importance, Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency, Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C, above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a conductor of electricity. For a metal, zinc has relatively low melting and boiling points, the melting point is the lowest of all the transition metals aside from mercury and cadmium. Many alloys contain zinc, including brass, Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium
Zinc
–
Zinc, 30 Zn
Zinc
–
Sphalerite (ZnS)
Zinc
–
Zinc acetate
Zinc
–
Zinc chloride
13.
Bronze Age
–
The Bronze Age is a historical period characterized by the use of bronze, proto-writing, and other early features of urban civilization. The Bronze Age is the principal period of the three-age Stone-Bronze-Iron system, as proposed in modern times by Christian Jürgensen Thomsen. An ancient civilization is defined to be in the Bronze Age either by smelting its own copper and alloying with tin, arsenic, or other metals, or by trading for bronze from production areas elsewhere. Copper-tin ores are rare, as reflected in the fact there were no tin bronzes in Western Asia before trading in bronze began in the third millennium BC. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition, although the Iron Age generally followed the Bronze Age, in some areas, the Iron Age intruded directly on the Neolithic. Bronze Age cultures differed in their development of the first writing, according to archaeological evidence, cultures in Mesopotamia and Egypt developed the earliest viable writing systems. The overall period is characterized by use of bronze, though the place and time of the introduction. Human-made tin bronze technology requires set production techniques, tin must be mined and smelted separately, then added to molten copper to make bronze alloy. The Bronze Age was a time of use of metals. The dating of the foil has been disputed, the Bronze Age in the ancient Near East began with the rise of Sumer in the 4th millennium BC. Societies in the region laid the foundations for astronomy and mathematics, the usual tripartite division into an Early, Middle and Late Bronze Age is not used. Instead, a division based on art-historical and historical characteristics is more common. The cities of the Ancient Near East housed several tens of thousands of people, ur in the Middle Bronze Age and Babylon in the Late Bronze Age similarly had large populations. The earliest mention of Babylonia appears on a tablet from the reign of Sargon of Akkad in the 23rd century BC, the Amorite dynasty established the city-state of Babylon in the 19th century BC. Over 100 years later, it took over the other city-states. Babylonia adopted the written Semitic Akkadian language for official use, by that time, the Sumerian language was no longer spoken, but was still in religious use. Elam was an ancient civilization located to the east of Mesopotamia, in the Old Elamite period, Elam consisted of kingdoms on the Iranian plateau, centered in Anshan, and from the mid-2nd millennium BC, it was centered in Susa in the Khuzestan lowlands. Its culture played a role in the Gutian Empire and especially during the Achaemenid dynasty that succeeded it
Bronze Age
–
Chalcolithic copper mine in
Timna Valley,
Negev Desert,
Israel.
Bronze Age
–
Diffusion of metallurgy in
Europe and
Asia Minor. The darkest areas are the oldest.
Bronze Age
–
A
Shang Dynasty two-handled bronze gefuding gui (1600–1046 BC).
Bronze Age
–
Spring and Autumn Period pu bronze vessel with interlaced
dragon design (722–481 BC)
14.
Near East
–
The Near East is a geographical term that roughly encompasses Western Asia. Despite having varying definitions within different academic circles, the term was applied to the maximum extent of the Ottoman Empire. The term has fallen into disuse in English and has replaced by the terms Middle East. The Food and Agriculture Organization of the United Nations defines the region similarly, but also includes Afghanistan while excluding the countries of North Africa and the Palestinian territories. Up until 1912 the Ottomans retained a band of territory including Albania, Macedonia and Southern Thrace, the Ottoman Empire, believed to be about to collapse, was portrayed in the press as the sick man of Europe. The Balkan states, with the exception of Bosnia and Albania, were primarily Christian. Starting in 1894 the Ottomans struck at the Armenians on the grounds that they were a non-Muslim people. The Hamidian Massacres aroused the indignation of the entire Christian world, in the United States the now aging Julia Ward Howe, author of the Battle Hymn of the Republic, leaped into the war of words and joined the Red Cross. Relations of minorities within the Ottoman Empire and the disposition of former Ottoman lands became known as the Eastern Question and it now became relevant to define the east of the eastern question. In about the middle of the 19th century Near East came into use to describe part of the east closest to Europe. The term Far East appeared contemporaneously meaning Japan, China, Korea, Indonesia, near East applied to what had been mainly known as the Levant, which was in the jurisdiction of the Ottoman Porte, or government. Those who used the term had little choice about its meaning and they could not set foot on most of the shores of the southern and central Mediterranean from the Gulf of Sidra to Albania without permits from the Ottoman Empire. Some regions beyond the Ottoman Porte were included, one was North Africa west of Egypt. It was occupied by piratical kingdoms of the Barbary Coast, de facto independent since the 18th century, formerly part of the empire at its apogee. Iran was included because it could not easily be reached except through the Ottoman Empire or neighboring Russia, in the 1890s the term tended to focus on the conflicts in the Balkan states and Armenia. The demise of the man of Europe left considerable confusion as to what was to be meant by Near East. It is now used only in historical contexts, to describe the countries of Western Asia from the Mediterranean to Iran. There is, in short, no universally understood fixed inventory of nations and they appear together in the journals of the mid-19th century
Near East
–
The Near East as defined as the
Ottoman Empire at the beginning of "
the eastern question ".
Near East
–
Inhabitants of the Near East, late 19th century
Near East
–
Ottoman Porte, 1767, gateway to trade with the Levant. Painting by
Antoine de Favray.
Near East
–
British troops, Crimea, 1855.
15.
Ancient Egypt
–
Ancient Egypt was a civilization of ancient Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. It is one of six civilizations to arise independently, Egyptian civilization followed prehistoric Egypt and coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh Narmer. In the aftermath of Alexander the Greats death, one of his generals, Ptolemy Soter and this Greek Ptolemaic Kingdom ruled Egypt until 30 BC, when, under Cleopatra, it fell to the Roman Empire and became a Roman province. The success of ancient Egyptian civilization came partly from its ability to adapt to the conditions of the Nile River valley for agriculture, the predictable flooding and controlled irrigation of the fertile valley produced surplus crops, which supported a more dense population, and social development and culture. Its art and architecture were widely copied, and its antiquities carried off to far corners of the world and its monumental ruins have inspired the imaginations of travelers and writers for centuries. The Nile has been the lifeline of its region for much of human history, nomadic modern human hunter-gatherers began living in the Nile valley through the end of the Middle Pleistocene some 120,000 years ago. By the late Paleolithic period, the climate of Northern Africa became increasingly hot and dry. In Predynastic and Early Dynastic times, the Egyptian climate was less arid than it is today. Large regions of Egypt were covered in treed savanna and traversed by herds of grazing ungulates, foliage and fauna were far more prolific in all environs and the Nile region supported large populations of waterfowl. Hunting would have been common for Egyptians, and this is also the period when many animals were first domesticated. The largest of these cultures in upper Egypt was the Badari, which probably originated in the Western Desert, it was known for its high quality ceramics, stone tools. The Badari was followed by the Amratian and Gerzeh cultures, which brought a number of technological improvements, as early as the Naqada I Period, predynastic Egyptians imported obsidian from Ethiopia, used to shape blades and other objects from flakes. In Naqada II times, early evidence exists of contact with the Near East, particularly Canaan, establishing a power center at Hierakonpolis, and later at Abydos, Naqada III leaders expanded their control of Egypt northwards along the Nile. They also traded with Nubia to the south, the oases of the desert to the west. Royal Nubian burials at Qustul produced artifacts bearing the oldest-known examples of Egyptian dynastic symbols, such as the crown of Egypt. They also developed a ceramic glaze known as faience, which was used well into the Roman Period to decorate cups, amulets, and figurines. During the last predynastic phase, the Naqada culture began using written symbols that eventually were developed into a system of hieroglyphs for writing the ancient Egyptian language. The Early Dynastic Period was approximately contemporary to the early Sumerian-Akkadian civilisation of Mesopotamia, the third-century BC Egyptian priest Manetho grouped the long line of pharaohs from Menes to his own time into 30 dynasties, a system still used today
Ancient Egypt
–
The
Great Sphinx and the
pyramids of Giza are among the most recognizable symbols of the civilization of ancient Egypt.
Ancient Egypt
–
A typical Naqada II jar decorated with gazelles. (Predynastic Period)
Ancient Egypt
–
The
Narmer Palette depicts the unification of the Two Lands.
16.
Tableware
–
Tableware is the dishes or dishware used for setting a table, serving food and dining. It includes cutlery, glassware, serving dishes and other items for practical as well as decorative purposes. The quality, nature, variety and number of objects according to culture, religion, number of diners, cuisine. For example, Middle Eastern, Indian or Polynesian food culture and cuisine sometimes limits tableware to serving dishes, special occasions are usually reflected in higher quality tableware. Sets of dishes are referred to as a service, dinner service or service set. Table settings or place settings are the dishes, cutlery and glassware used for formal and informal dining, in Ireland such items are normally referred to as delph, the word being an English language phonetic spelling of the word delft, the town from which so much delftware came. Silver service or butler service are methods for a butler or waiter to serve a meal, Setting the table refers to arranging the tableware, including individual place settings for each diner at the table as well as decorating the table itself in a manner suitable for the occasion. Tableware and table decoration is more elaborate for special occasions. Unusual dining locations demand tableware be adapted, dishes are usually made of ceramic materials such as earthenware, stoneware, faience, bone china or porcelain. However, they can be made of materials such as wood, pewter, silver, gold, glass. Before it was possible to purchase mass-produced tableware, it was fashioned from available materials, industrialisation and developments in ceramic manufacture made inexpensive washable tableware available. It is sold either by the piece or as a set for a number of diners, normally four, six, eight. Large quantities are purchased for use in restaurants, individual pieces, such as those needed as replacement pieces for broken dishes, can be procured from open stock inventory at shops, or from antique dealers if the pattern is no longer in production. Possession of tableware has to a large extent been determined by individual wealth, the greater the means, the higher was the quality of tableware that was owned and the more numerous its pieces. In the London of the 13th century, the more affluent citizens owned fine furniture and silver, while those of straiter means possessed only the simplest pottery and kitchen utensils. By the later 16th century, even the poorer citizens dined off pewter rather than wood and had plate, jars, the nobility often used their arms on heraldic china. Table decoration may be ephemeral and consist of items made from confectionery or wax - substances commonly employed in Roman banqueting tables of the 17th century, in modern times, ephemeral table decorations continue to be made from sugar or carved from ice. In wealthy countries such as 17th century France, table decorations for the aristocracy were made of silver
Tableware
–
Formal dining table laid for a large private dinner party at
Chatsworth House
Tableware
–
Table laid for six
Royal Castle, Warsaw, (18th-19th century)
Tableware
–
Table laid for one
Tableware
–
Pewter and old glass tableware
17.
Holloware
–
Holloware is constructed to last a long time. It differs from some other silverplated items in being made with thicker walls, dining car holloware is a type of railroad collectible. The relative value of pieces depends on their scarcity, age and condition, holloware is the traditional gift in the UK and the modern gift in the US for the 16th wedding anniversary. Holloware is the gift for jubilee or wedding in Russia
Holloware
–
Creamer and sugar bowl from
ATSF service, made by Harrison & Howson for dining car service
18.
Redox
–
Redox is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a process and a complementary oxidation process, two key concepts involved with electron transfer processes. Redox reactions include all chemical reactions in which atoms have their oxidation state changed, in general, the chemical species from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. It can be explained in terms, Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom. Reduction is the gain of electrons or a decrease in state by a molecule, atom. As an example, during the combustion of wood, oxygen from the air is reduced, the reaction can occur relatively slowly, as in the case of rust, or more quickly, as in the case of fire. Redox is a portmanteau of reduction and oxidation, the word oxidation originally implied reaction with oxygen to form an oxide, since dioxygen was historically the first recognized oxidizing agent. Later, the term was expanded to encompass oxygen-like substances that accomplished parallel chemical reactions, ultimately, the meaning was generalized to include all processes involving loss of electrons. The word reduction originally referred to the loss in weight upon heating a metallic ore such as an oxide to extract the metal. In other words, ore was reduced to metal, antoine Lavoisier showed that this loss of weight was due to the loss of oxygen as a gas. Later, scientists realized that the atom gains electrons in this process. The meaning of reduction then became generalized to all processes involving gain of electrons. Even though reduction seems counter-intuitive when speaking of the gain of electrons, it help to think of reduction as the loss of oxygen. Since electrons are charged, it is also helpful to think of this as reduction in electrical charge. The electrochemist John Bockris has used the words electronation and deelectronation to describe reduction and oxidation processes respectively when they occur at electrodes and these words are analogous to protonation and deprotonation, but they have not been widely adopted by chemists. The term hydrogenation could be used instead of reduction, since hydrogen is the agent in a large number of reactions. But, unlike oxidation, which has been generalized beyond its root element, the word redox was first used in 1928. The processes of oxidation and reduction occur simultaneously and cannot happen independently of one another, the oxidation alone and the reduction alone are each called a half-reaction, because two half-reactions always occur together to form a whole reaction
Redox
–
Rusting iron
Redox
–
A
bonfire
Redox
–
Oxides, such as
iron(III) oxide or
rust, which consists of hydrated
iron(III) oxides Fe 2 O 3 · n H 2 O and
iron(III) oxide-hydroxide (FeO(OH), Fe(OH) 3), form when oxygen combines with other elements
Redox
–
Iron rusting in
pyrite cubes
19.
Malaysia
–
Malaysia is a federal constitutional monarchy located in Southeast Asia. Peninsular Malaysia shares a land and maritime border with Thailand and maritime borders with Singapore, Vietnam, East Malaysia shares land and maritime borders with Brunei and Indonesia and a maritime border with the Philippines and Vietnam. The capital city is Kuala Lumpur, while Putrajaya is the seat of the federal government, with a population of over 30 million, Malaysia is the 44th most populous country. The southernmost point of continental Eurasia, Tanjung Piai, is in Malaysia, located in the tropics, Malaysia is one of 17 megadiverse countries on earth, with large numbers of endemic species. Malaysia has its origins in the Malay kingdoms present in the area which, from the 18th century, the first British territories were known as the Straits Settlements, whose establishment was followed by the Malay kingdoms becoming British protectorates. The territories on Peninsular Malaysia were first unified as the Malayan Union in 1946, Malaya was restructured as the Federation of Malaya in 1948, and achieved independence on 31 August 1957. Malaya united with North Borneo, Sarawak, and Singapore on 16 September 1963 to become Malaysia, less than two years later in 1965, Singapore was expelled from the federation. The country is multi-ethnic and multi-cultural, which plays a role in politics. About half the population is ethnically Malay, with minorities of Malaysian Chinese, Malaysian Indians. The constitution declares Islam the state religion while allowing freedom of religion for non-Muslims, the government system is closely modelled on the Westminster parliamentary system and the legal system is based on common law. The head of state is the king, known as the Yang di-Pertuan Agong and he is an elected monarch chosen from the hereditary rulers of the nine Malay states every five years. The head of government is the prime minister, since its independence, Malaysia has had one of the best economic records in Asia, with its GDP growing at an average of 6. 5% per annum for almost 50 years. The economy has traditionally been fuelled by its resources, but is expanding in the sectors of science, tourism, commerce. Today, Malaysia has a newly industrialised market economy, ranked third largest in Southeast Asia, the name Malaysia is a combination of the word Malay and the Latin-Greek suffix -sia/-σία. The word melayu in Malay may derive from the Tamil words malai and ur meaning mountain and city, land, malayadvipa was the word used by ancient Indian traders when referring to the Malay Peninsula. Whether or not it originated from these roots, the word melayu or mlayu may have used in early Malay/Javanese to mean to steadily accelerate or run. This term was applied to describe the current of the river Melayu in Sumatra. The name was adopted by the Melayu Kingdom that existed in the seventh century on Sumatra
Malaysia
–
"Malaysia" used as a label for the
Malay Archipelago on a 1914 map from a United States atlas
Malaysia
–
Flag
Malaysia
–
The Dutch fleet battling with the Portuguese armada as part of the
Dutch–Portuguese War in 1606 to gain control of
Malacca.
Malaysia
–
Statue of
Francis Light in the
Fort Cornwallis of Penang, marking the first step of
British expansion in the 18th century over the Malay Archipelago.
20.
Singapore
–
Singapore, officially the Republic of Singapore, sometimes referred to as the Lion City or the Little Red Dot, is a sovereign city-state in Southeast Asia. It lies one degree north of the equator, at the tip of peninsular Malaysia. Singapores territory consists of one island along with 62 other islets. Since independence, extensive land reclamation has increased its size by 23%. During the Second World War, Singapore was occupied by Japan, after early years of turbulence, and despite lacking natural resources and a hinterland, the nation developed rapidly as an Asian Tiger economy, based on external trade and its workforce. Singapore is a global commerce, finance and transport hub, the country has also been identified as a tax haven. Singapore ranks 5th internationally and first in Asia on the UN Human Development Index and it is ranked highly in education, healthcare, life expectancy, quality of life, personal safety, and housing, but does not fare well on the Democracy index. Although income inequality is high, 90% of homes are owner-occupied, 38% of Singapores 5.6 million residents are permanent residents and other foreign nationals. There are four languages on the island, Malay, Mandarin, Tamil. English is its language, most Singaporeans are bilingual. Singapore is a multiparty parliamentary republic, with a Westminster system of unicameral parliamentary government. The Peoples Action Party has won every election since self-government in 1959, however, it is unlikely that lions ever lived on the island, Sang Nila Utama, the Srivijayan prince said to have founded and named the island Singapura, perhaps saw a Malayan tiger. There are however other suggestions for the origin of the name, the central island has also been called Pulau Ujong as far back as the third century CE, literally island at the end in Malay. In 1299, according to the Malay Annals, the Kingdom of Singapura was founded on the island by Sang Nila Utama and these Indianized Kingdoms, a term coined by George Cœdès were characterized by surprising resilience, political integrity and administrative stability. In 1613, Portuguese raiders burned down the settlement, which by then was part of the Johor Sultanate. The wider maritime region and much trade was under Dutch control for the following period, in 1824 the entire island, as well as the Temenggong, became a British possession after a further treaty with the Sultan. In 1826, Singapore became part of the Straits Settlements, under the jurisdiction of British India, prior to Raffles arrival, there were only about a thousand people living on the island, mostly indigenous Malays along with a handful of Chinese. By 1860 the population had swelled to over 80,000, many of these early immigrants came to work on the pepper and gambier plantations
Singapore
–
Raffles Square around 1900.
Singapore
–
Flag
Singapore
–
Victorious Japanese troops marching through Singapore City after the British capitulation at the
Battle of Singapore in 1942.
Singapore
–
A cheering crowd welcome the return of British forces, 1945
21.
Thailand
–
Thailand, officially the Kingdom of Thailand, formerly known as Siam, is a country at the centre of the Indochinese peninsula in Southeast Asia. With a total area of approximately 513,000 km2, Thailand is the worlds 51st-largest country and it is the 20th-most-populous country in the world, with around 66 million people. The capital and largest city is Bangkok, Thailand is a constitutional monarchy and has switched between parliamentary democracy and military junta for decades, the latest coup being in May 2014 by the National Council for Peace and Order. Its capital and most populous city is Bangkok and its maritime boundaries include Vietnam in the Gulf of Thailand to the southeast, and Indonesia and India on the Andaman Sea to the southwest. The Thai economy is the worlds 20th largest by GDP at PPP and it became a newly industrialised country and a major exporter in the 1990s. Manufacturing, agriculture, and tourism are leading sectors of the economy and it is considered a middle power in the region and around the world. The country has always been called Mueang Thai by its citizens, by outsiders prior to 1949, it was usually known by the exonym Siam. The word Siam has been identified with the Sanskrit Śyāma, the names Shan and A-hom seem to be variants of the same word. The word Śyâma is possibly not its origin, but a learned, another theory is the name derives from Chinese, Ayutthaya emerged as a dominant centre in the late fourteenth century. The Chinese called this region Xian, which the Portuguese converted into Siam, the signature of King Mongkut reads SPPM Mongkut King of the Siamese, giving the name Siam official status until 24 June 1939 when it was changed to Thailand. Thailand was renamed Siam from 1945 to 11 May 1949, after which it reverted to Thailand. According to George Cœdès, the word Thai means free man in the Thai language, ratcha Anachak Thai means kingdom of Thailand or kingdom of Thai. Etymologically, its components are, ratcha, -ana- -chak, the Thai National Anthem, written by Luang Saranupraphan during the extremely patriotic 1930s, refers to the Thai nation as, prathet Thai. The first line of the anthem is, prathet thai ruam lueat nuea chat chuea thai, Thailand is the unity of Thai flesh. There is evidence of habitation in Thailand that has been dated at 40,000 years before the present. Similar to other regions in Southeast Asia, Thailand was heavily influenced by the culture and religions of India, Thailand in its earliest days was under the rule of the Khmer Empire, which had strong Hindu roots, and the influence among Thais remains even today. Voretzsch believes that Buddhism must have been flowing into Siam from India in the time of the Indian Emperor Ashoka of the Maurya Empire, later Thailand was influenced by the south Indian Pallava dynasty and north Indian Gupta Empire. The Menam Basin was originally populated by the Mons, and the location of Dvaravati in the 7th century, the History of the Yuan mentions an embassy from the kingdom of Sukhothai in 1282
Thailand
–
The ruins of
Wat Chaiwatthanaram at
Ayutthaya.
Thailand
–
Flag
Thailand
–
Stupas,
Ayutthaya Historical Park.
Thailand
–
Pottery discovered near
Ban Chiang in Udon Thani Province, the earliest dating to 2100 BCE.
22.
Middle Ages
–
In the history of Europe, the Middle Ages or Medieval Period lasted from the 5th to the 15th century. It began with the fall of the Western Roman Empire and merged into the Renaissance, the Middle Ages is the middle period of the three traditional divisions of Western history, classical antiquity, the medieval period, and the modern period. The medieval period is subdivided into the Early, High. Population decline, counterurbanisation, invasion, and movement of peoples, the large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the seventh century, North Africa and the Middle East—once part of the Byzantine Empire—came under the rule of the Umayyad Caliphate, although there were substantial changes in society and political structures, the break with classical antiquity was not complete. The still-sizeable Byzantine Empire survived in the east and remained a major power, the empires law code, the Corpus Juris Civilis or Code of Justinian, was rediscovered in Northern Italy in 1070 and became widely admired later in the Middle Ages. In the West, most kingdoms incorporated the few extant Roman institutions, monasteries were founded as campaigns to Christianise pagan Europe continued. The Franks, under the Carolingian dynasty, briefly established the Carolingian Empire during the later 8th, the Crusades, first preached in 1095, were military attempts by Western European Christians to regain control of the Holy Land from Muslims. Kings became the heads of centralised nation states, reducing crime and violence, intellectual life was marked by scholasticism, a philosophy that emphasised joining faith to reason, and by the founding of universities. Controversy, heresy, and the Western Schism within the Catholic Church paralleled the conflict, civil strife. Cultural and technological developments transformed European society, concluding the Late Middle Ages, the Middle Ages is one of the three major periods in the most enduring scheme for analysing European history, classical civilisation, or Antiquity, the Middle Ages, and the Modern Period. Medieval writers divided history into periods such as the Six Ages or the Four Empires, when referring to their own times, they spoke of them as being modern. In the 1330s, the humanist and poet Petrarch referred to pre-Christian times as antiqua, leonardo Bruni was the first historian to use tripartite periodisation in his History of the Florentine People. Bruni and later argued that Italy had recovered since Petrarchs time. The Middle Ages first appears in Latin in 1469 as media tempestas or middle season, in early usage, there were many variants, including medium aevum, or middle age, first recorded in 1604, and media saecula, or middle ages, first recorded in 1625. The alternative term medieval derives from medium aevum, tripartite periodisation became standard after the German 17th-century historian Christoph Cellarius divided history into three periods, Ancient, Medieval, and Modern. The most commonly given starting point for the Middle Ages is 476, for Europe as a whole,1500 is often considered to be the end of the Middle Ages, but there is no universally agreed upon end date. English historians often use the Battle of Bosworth Field in 1485 to mark the end of the period
Middle Ages
–
The
Cross of Mathilde, a
crux gemmata made for
Mathilde, Abbess of Essen (973–1011), who is shown kneeling before the Virgin and Child in the
enamel plaque. The body of Christ is slightly later. Probably made in
Cologne or
Essen, the cross demonstrates several medieval techniques:
cast figurative sculpture,
filigree, enamelling, gem polishing and setting, and the reuse of Classical
cameos and
engraved gems.
Middle Ages
–
A late Roman statue
depicting the four Tetrarchs, now in
Venice
Middle Ages
–
Coin of
Theodoric
Middle Ages
–
Mosaic showing
Justinian with
the bishop of
Ravenna, bodyguards, and courtiers
23.
Porcelain
–
Porcelain /ˈpɔːrsəlᵻn, ˈpɔːrslᵻn/ is a ceramic material made by heating materials, generally including kaolin, in a kiln to temperatures between 1,200 and 1,400 °C. Porcelain was first developed in China around 2,000 years ago, then spread to other East Asian countries, and finally Europe. It combines well with both glazes and paint, and can be modelled very well, allowing a range of decorative treatments in tablewares, vessels. It also has uses in technology and industry. The European name, porcelain in English, come from the old Italian porcellana because of its resemblance to the translucent surface of the shell, Porcelain is also referred to as china or fine china in some English-speaking countries, as it was first seen in imports from China. Porcelain has been described as being completely vitrified, hard, impermeable, white or artificially coloured, translucent, however, the term porcelain lacks a universal definition and has been applied in a very unsystematic fashion to substances of diverse kinds which have only certain surface-qualities in common. Terms such as porcellaneous or near-porcelain may be used in such cases, a high proportion of modern porcelain is made of the variant bone china. Kaolin is the material from which porcelain is made, even though clay minerals might account for only a small proportion of the whole. The word paste is an old term for both the unfired and fired material, a more common terminology these days for the unfired material is body, for example, when buying materials a potter might order an amount of porcelain body from a vendor. The composition of porcelain is highly variable, but the mineral kaolinite is often a raw material. Other raw materials can include feldspar, ball clay, glass, bone ash, steatite, quartz, petuntse, the clays used are often described as being long or short, depending on their plasticity. Long clays are cohesive and have high plasticity, short clays are cohesive and have lower plasticity. Clays used for porcelain are generally of lower plasticity and are shorter than many other pottery clays and they wet very quickly, meaning that small changes in the content of water can produce large changes in workability. Thus, the range of content within which these clays can be worked is very narrow. The following section provides information on the methods used to form, decorate, finish, glaze. Many types of glaze, such as the iron-containing glaze used on the wares of Longquan, were designed specifically for their striking effects on porcelain. Porcelain wares may be decorated under the glaze using pigments that include cobalt and copper or over the glaze using coloured enamels. Like many earlier wares, modern porcelains are often biscuit-fired at around 1,000 °C, coated with glaze, another early method is once-fired where the glaze is applied to the unfired body and the two fired together in a single operation
Porcelain
–
Porcelain wares, such as those similar to these Yongle-era porcelain flasks, were often presented as trade goods during the 15th-century
Chinese maritime expeditions. (British Museum)
Porcelain
–
Soft-paste porcelain Swan
tureen, 1752-6,
Chelsea.
Porcelain
–
Flower centrepiece, 18th century, Spain.
Porcelain
–
Ming Dynasty Xuande Archaic Porcelain Vase
24.
East Asia
–
East Asia is the eastern subregion of the Asian continent, which can be defined in either geographical or ethno-cultural terms. Geographically and geopolitically, it includes China, Taiwan, Mongolia, Korea and Japan, it covers about 12,000,000 km2, or about 28% of the Asian continent, the East Asian people comprise more than 1.5 billion people. About 38% of the population of Asia and 22%, or over one fifth, the overall population density of the region is 133 inhabitants per square kilometre, about three times the world average of 45/km2. Historically, societies in East Asia have been part of the Chinese cultural sphere, major religions include Buddhism, Confucianism or Neo-Confucianism, Taoism, Chinese folk religion in China and Taiwan, Shinto in Japan, Korean shamanism in Korea. Shamanism is also prevalent among Mongolians and other populations of northern East Asia. The Chinese calendar is the root from which many other East Asian calendars are derived, Chinese Dynasties dominated the region in matters of culture, trade, and exploration as well as militarily for a very long time. There are records of tributes sent overseas from the kingdoms of Korea. There were also considerable levels of cultural and religious exchange between the Chinese and other regional Dynasties and Kingdoms, as connections began to strengthen with the Western world, Chinas power began to diminish. Around the same time, Japan solidified itself as a nation state, throughout World War II, Korea, Taiwan, much of eastern China, Hong Kong, and Vietnam all fell under Japanese control. Culturally, China, Japan, Korea, Taiwan and Vietnam are commonly seen as being encompassed by cultural East Asia, there are mixed debates around the world whether these countries or regions should be considered in East Asia or not. Vietnam Siberia in Russia Sovereignty issues exist over some territories in the South China Sea, however, in this context, the term Far East is often more appropriate which covers ASEAN countries and the countries in East Asia. However, being a Eurocentric term, Far East describes the geographical position in relation to Europe rather than its location within Asia. Alternatively, the term Asia Pacific Region is often used in describing East Asia and this usage, which is seen in economic and diplomatic discussions, is at odds with the historical meanings of both East Asia and Northeast Asia. The Council on Foreign Relations defines Northeast Asia as Japan and Korea, the military and economic superpower of China became the largest economy in the world in 2014, surpassing the United States of America. Currently in East Asia, trading systems are open, and zero or low duties on imports of consumer and capital goods etc. have considerably helped stimulate cost-efficiency. Free and flexible labor and other markets are important factors making for high levels of business-economic performance. East Asian populations have demonstrated highly positive work ethics, there are relatively large and fast-growing markets for consumer goods and services of all kinds. The culture of East Asia has been influenced by the civilisation of China, East Asia, as well as Vietnam, share a Confucian ethical philosophy, Buddhism, political and legal structures, and historically a common writing system
East Asia
–
Tokyo is the largest city in the world, both in
metropolitan population and
economy.
East Asia
–
East Asia
East Asia
–
Seoul is the capital and largest city of South Korea (ROK), and is a leading global technology hub.
East Asia
–
Kaohsiung is the second largest city in Taiwan.
Kaohsiung Harbor is one of the largest harbors in the world.
25.
Ancient Rome
–
In its many centuries of existence, the Roman state evolved from a monarchy to a classical republic and then to an increasingly autocratic empire. Through conquest and assimilation, it came to dominate the Mediterranean region and then Western Europe, Asia Minor, North Africa and it is often grouped into classical antiquity together with ancient Greece, and their similar cultures and societies are known as the Greco-Roman world. Ancient Roman civilisation has contributed to modern government, law, politics, engineering, art, literature, architecture, technology, warfare, religion, language and society. Rome professionalised and expanded its military and created a system of government called res publica, the inspiration for modern republics such as the United States and France. By the end of the Republic, Rome had conquered the lands around the Mediterranean and beyond, its domain extended from the Atlantic to Arabia, the Roman Empire emerged with the end of the Republic and the dictatorship of Augustus Caesar. 721 years of Roman-Persian Wars started in 92 BC with their first war against Parthia and it would become the longest conflict in human history, and have major lasting effects and consequences for both empires. Under Trajan, the Empire reached its territorial peak, Republican mores and traditions started to decline during the imperial period, with civil wars becoming a prelude common to the rise of a new emperor. Splinter states, such as the Palmyrene Empire, would divide the Empire during the crisis of the 3rd century. Plagued by internal instability and attacked by various migrating peoples, the part of the empire broke up into independent kingdoms in the 5th century. This splintering is a landmark historians use to divide the ancient period of history from the pre-medieval Dark Ages of Europe. King Numitor was deposed from his throne by his brother, Amulius, while Numitors daughter, Rhea Silvia, because Rhea Silvia was raped and impregnated by Mars, the Roman god of war, the twins were considered half-divine. The new king, Amulius, feared Romulus and Remus would take back the throne, a she-wolf saved and raised them, and when they were old enough, they returned the throne of Alba Longa to Numitor. Romulus became the source of the citys name, in order to attract people to the city, Rome became a sanctuary for the indigent, exiled, and unwanted. This caused a problem for Rome, which had a large workforce but was bereft of women, Romulus traveled to the neighboring towns and tribes and attempted to secure marriage rights, but as Rome was so full of undesirables they all refused. Legend says that the Latins invited the Sabines to a festival and stole their unmarried maidens, leading to the integration of the Latins, after a long time in rough seas, they landed at the banks of the Tiber River. Not long after they landed, the men wanted to take to the sea again, one woman, named Roma, suggested that the women burn the ships out at sea to prevent them from leaving. At first, the men were angry with Roma, but they realized that they were in the ideal place to settle. They named the settlement after the woman who torched their ships, the Roman poet Virgil recounted this legend in his classical epic poem the Aeneid
Ancient Rome
–
Senātus Populus que Rōmānus
Ancient Rome
–
Roman Republic
Ancient Rome
–
According to legend,
Rome was founded in 753 BC by
Romulus and Remus, who were raised by a she-wolf.
Ancient Rome
–
This bust from the
Capitoline Museums is traditionally identified as a portrait of
Lucius Junius Brutus.
26.
Tankard
–
A tankard is a form of drinkware consisting of a large, roughly cylindrical, drinking cup with a single handle. Tankards are usually made of silver, pewter, or glass, a tankard may have a hinged lid, and tankards featuring glass bottoms are also fairly common. Tankards are shaped and used similarly to beer steins, the word tankard originally meant any wooden vessel and later came to mean a drinking vessel. The earliest tankards were made of staves, similar to a barrel. A 2000-year-old wooden tankard of approximately four-pint capacity has been unearthed in Wales, metal tankards often come with a glass bottom. The legend is that the glass bottomed tankard was developed as a way of refusing the Kings shilling, the drinker could see the coin in the bottom of the glass and refuse the drink, thereby avoiding conscription. However, this is likely to be a myth, for the Navy could press by force, rendering deception unnecessary. In a bar fight, the first punch was thrown while the recipient had the tankard raised to his mouth, a further story is that the glass bottom merely allowed the drinker to judge the clarity of their drink while forgoing the expense of a fragile pint glass. Glass bottoms are sometimes retrofitted to antique tankards, reducing their value, covered tankards fell out of fashion in 19th century England resulting in a number of them being converted to other roles such as jugs. Metal and ceramic tankards are still manufactured, but are regarded as speciality or novelty items, modern metal tankards are often engraved to commemorate some occasion. Glass tankards—that is, straight-sided or inward-sloping glass vessels with strap handles—are still in everyday use, in previous centuries, the pewter used to make tankards often contained lead, which exposed the drinker to medical effects ranging from heavy metal poisoning to gout. This effect was exacerbated in cider drinking areas such as Somerset, UK, clay tankards became prevalent in this area. A 1970s TV advertising campaign for Whitbread beer features a pub landlord spinning a tale to an American tourist. Beer stein Kronkåsa Maß An ancient Middle Eastern tankard at the British Museum
Tankard
–
A wooden tankard found on board the 16th century
carrack Mary Rose.
Tankard
–
Little ceramic tankard with lid
Tankard
–
Pewter tankard
27.
Porringer
–
A porringer is a shallow bowl, between 4 and 6 inches in diameter, and 1½ to 3 deep, the form originates in the medieval period in Europe and they were made in wood, ceramic, pewter and silver. Porringers resembled the smaller quaich, a Scottish drinking vessel, one can discern authentic pewter porringers in much the same way that silver can be authenticated from the touch marks that were stamped either into the bowl of the porringer or on its base. Wooden porringers are occasionally found from excavations, e. g. 16th-century example from Southwark, the most famous colonial porringers are probably those made by Paul Revere. In more modern times, some manufacturers of porringers have produced them without handles and these types of porringers appear to be deep bowls, with the sides being nearly totally flat. Porringers are also used less and less, as a bowl will suffice for most people, porringers, however, are still circulated, a second, modern usage, for the term porringer is a double saucepan similar to a bain-marie used for cooking porridge. The porridge is cooked gently in the saucepan, heated by steam from boiling water in the outer saucepan. This ensures the porridge does not burn and allows a longer cooking time so that the oats can absorb the water or milk in which they are cooked more completely. Also the porridge does not need stirring during the process, which means the oats maintain their structural integrity. The lower heat may also degrade less of the beta-glucan in the oats, porringers were also made out of red earthenware clay in a type of pottery that is called redware today but called earthen during colonial and Early America. These would have the typical, strap or pulled handle that is familiar on mugs, some collectors or materials historians also call what resembles the pewter porringer a bleeding cup. Grabit One-handled Porringer picture from the Brooklyn Museum Two-handled Porringer picture from Learn NC Definition of porringer from Britannica online
Porringer
–
A silver porringer created by
John Coney, c. 1710,
Birmingham Museum of Art
28.
Beer stein
–
Beer stein, or simply stein, is an English neologism for either traditional beer mugs made out of stoneware, or specifically ornamental beer mugs that are usually sold as souvenirs or collectibles. In German, the word stein means stone and is not used to refer to a beverage container. Such Steins may be out of stoneware, pewter, porcelain, or even silver, wood or crystal glass. Steins usually come in sizes of a half litre or a full litre, like decorative tankards, they are often decorated in a nostalgic manner, but with allusions to Germany or Bavaria. It is believed by some that the lid was implemented during the age of the Black Plague, stein is an abbreviation of German Steinzeug stoneware, the common material for beer mugs before the introduction of glass. The word alone is not used within Germany, rather Krug or Steinkrug are used, the word stein could have also originated from the German word Steinzeugkrug, meaning stoneware jug or tankard. By common usage, stein refers to a container with a handle. Bierstein in German means beerstone – i. e. beer scale – a hard residue of calcium oxalate, protein, in the latter half of the 19th century, stein makers found different advantages within the different materials. The advantage in using stoneware to make steins was that molds could be used to mass-produce elaborately carved steins. In using glass, not only could one produce multiple glass mugs, porcelains advantage was that a stein fabricator could use molds to make character steins, steins that had a particular shape modeled after an item or a person. Throughout the 1900s, collecting antique and replicated beer steins became very popular not only among individual people. Production of beer steins has become large in America. The most traditional area of beer production is the Kannenbäckerland in the Westerwald region in Germany. This unique German potters region has been creating beer steins for centuries and is famous among the collectors as the original German beer stein producer, on the 21st of September 2014, Oliver Strumpfel broke the record for most beer steins carried over 40 metres without spilling managing 25 steins. Beer steins were made primarily with pewter in many areas across Europe, but many steins were known to be made of glass, porcelain, Steins have also been known to have been made out of wood, earthenware, and crystal. Ordinary German beer mugs have been out of glass for hygienic reasons since the introduction of glass mugs to the 1892 Oktoberfest. Modern beer mugs, except again decorative or luxury versions, do not have a lid, beer mugs are typical for beer gardens and especially the Oktoberfest, where they are popular for their robustness. In other settings,0.33 and 0.5 litre beer glasses are also popular, the lids on beer mugs serve as a sanitary measure especially to keep insects out of the beer
Beer stein
–
Earthenware beer steins.
Beer stein
–
A typical half-litre German Humpen (beer mug).
Beer stein
–
An unusually large German beer stein (31.99 litre capacity; weighs 15.88 kg when empty).
Beer stein
–
Beer stein made in Poland.
29.
Fashion
–
Fashion is a popular style or practice, especially in clothing, footwear, accessories, makeup, body, or furniture. Fashion is a distinctive and often constant trend in the style in which a person dresses and it is the prevailing styles in behaviour and the newest creations of textile designers. Although aspects of fashion can be feminine or masculine, some trends are androgynous, early Western travelers, traveling whether to Persia, Turkey, India, or China, would frequently remark on the absence of change in fashion in the respective places. The Japanese Shoguns secretary bragged to a Spanish visitor in 1609 that Japanese clothing had not changed in over a thousand years, however, there is considerable evidence in Ming China of rapidly changing fashions in Chinese clothing. Changes in costume took place at times of economic or social change, as occurred in ancient Rome. In 8th-century Moorish Spain, the musician Ziryab introduced to Córdoba sophisticated clothing-styles based on seasonal and daily fashions from his native Baghdad, modified by his own inspiration. Similar changes in fashion occurred in the 11th century in the Middle East following the arrival of the Turks, who introduced clothing styles from Central Asia, the beginning in Europe of continual and increasingly rapid change in clothing styles can be fairly reliably dated. This created the distinctive Western outline of a tailored top worn over leggings or trousers, the pace of change accelerated considerably in the following century, and women and mens fashion, especially in the dressing and adorning of the hair, became equally complex. Art historians are able to use fashion with confidence and precision to date images, often to within five years. These national styles remained very different until a counter-movement in the 17th to 18th centuries imposed similar styles once again, in the 16th century, national differences were at their most pronounced. Ten 16th century portraits of German or Italian gentlemen may show ten entirely different hats, albrecht Dürer illustrated the differences in his actual contrast of Nuremberg and Venetian fashions at the close of the 15th century. Though textile colors and patterns changed from year to year, the cut of a gentlemans coat, by 1800, all Western Europeans were dressing alike, local variation became first a sign of provincial culture and later a badge of the conservative peasant. The Haute house was the established by government for the fashion houses that met the standards of industry. Since then, the idea of the designer as a celebrity in his or her own right has become increasingly dominant. The impact of unisex expands more broadly to various themes in fashion including androgyny, mass-market retail. Fashion weeks are held in cities, where designers exhibit their new clothing collections to audiences. Modern Westerners have a number of choices available in the selection of their clothes. What a person chooses to wear can reflect his or her personality or interests, when people who have high cultural status start to wear new or different clothes, a fashion trend may start
Fashion
–
In Following the Fashion (1794),
James Gillray caricatured a figure flattered by the short-
bodiced gowns then in fashion, contrasting it with an imitator whose figure is not flattered.
Fashion
–
Albrecht Dürer 's drawing contrasts a well turned out bourgeoise from
Nuremberg (left) with her counterpart from
Venice. The Venetian lady's high
chopines make her look taller.
Fashion
–
Marie Antoinette, wife of Louis XVI, was a leader of fashion. Her choices, such as this 1783 white
muslin dress called a chemise a la Reine, were highly influential and widely worn.
Fashion
–
For other uses, see
Fashion (disambiguation).
30.
Electroplating
–
Electroplating is a process that uses electric current to reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode. The term is used for electrical oxidation of anions onto a solid substrate. Electroplating is primarily used to change the properties of an object. The process used in electroplating is called electrodeposition and it is analogous to a galvanic cell acting in reverse. The part to be plated is the cathode of the circuit, in one technique, the anode is made of the metal to be plated on the part. Both components are immersed in a solution called an electrolyte containing one or more dissolved metal salts as well as other ions that permit the flow of electricity. A power supply supplies a direct current to the anode, oxidizing the metal atoms that it comprises, at the cathode, the dissolved metal ions in the electrolyte solution are reduced at the interface between the solution and the cathode, such that they plate out onto the cathode. The rate at which the anode is dissolved is equal to the rate at which the cathode is plated, in this manner, the ions in the electrolyte bath are continuously replenished by the anode. Other electroplating processes may use a non-consumable anode such as lead or carbon, in these techniques, ions of the metal to be plated must be periodically replenished in the bath as they are drawn out of the solution. The most common form of electroplating is used for creating coins such as pennies, the cations associate with the anions in the solution. These cations are reduced at the cathode to deposit in the metallic, for example, for copper plating, in an acid solution, copper is oxidized at the anode to Cu2+ by losing two electrons. The Cu2+ associates with the anion SO42− in the solution to form copper sulfate, at the cathode, the Cu2+ is reduced to metallic copper by gaining two electrons. The result is the transfer of copper from the anode source to a plate covering the cathode. The plating is most commonly a metallic element, not an alloy. However, some alloys can be electrodeposited, notably brass and solder, many plating baths include cyanides of other metals in addition to cyanides of the metal to be deposited. These free cyanides facilitate anode corrosion, help to maintain a constant metal ion level, additionally, non-metal chemicals such as carbonates and phosphates may be added to increase conductivity. When plating is not desired on certain areas of the substrate, typical stop-offs include tape, foil, lacquers, and waxes. The ability of a plating to cover uniformly is called throwing power, initially, a special plating deposit called a strike or flash may be used to form a very thin plating with high quality and good adherence to the substrate
Electroplating
–
Copper electroplating machine for layering
PCBs
Electroplating
–
Nickel plating
Electroplating
–
Boris Jacobi developed electroplating,
electrotyping and
galvanoplastic sculpture in
Russia
Electroplating
–
Galvanoplastic sculpture on
St. Isaac's Cathedral in
Saint Petersburg.
"Pewter". Encyclopædia Britannica (11th ed.). 1911.
"
