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Blue
Blue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The term ''blue'' generally describes colours perceived by humans observing light with a dominant wavelength that's between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective. Blue has been an important colour in art and decoration since ancient times. The semi-precious stone lapis lazuli was used in ancient Egypt for jewellery and ornament and later, in the Renaissance, to make the pigment ultr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Militsiya (Ukraine)
The Militsiya (, ) was a type of domestic law enforcement agency (''militsiya'') that existed in various forms in Ukraine from 1919 until 2015. The Militsiya was originally formed while Ukraine was governed by the Ukrainian Soviet Socialist Republic, part of the Soviet Union, and it continued to serve as a national police service in post-Soviet Ukraine until it was replaced by the National Police of Ukraine on 7 November 2015. The Militsiya was under the direct control of the Ministry of Internal Affairs (Ukraine), Ministry of Internal Affairs (known by the Ukrainian language, Ukrainian acronym MVS and by the Russian language, Russian acronym MVD), and it was widely seen as corrupt and inconsiderable to the demands of the Ukrainian public. During Euromaidan, the Militsiya was accused of brutality against protestors as well as kidnapping Automaidan activists, leading to the reputation of the Militsiya being irreversibly damaged. This resulted in its replacement under the post-Maid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azure (color)
Azure ( , ) is the color between cyan and blue on the visible spectrum, spectrum of visible light. It is often described as sky blue, the color of the sky on a clear day. On the :File:RGB color wheel.svg, RGB color wheel, "azure" (Web colors#Hex triplet, hexadecimal #0080FF) is defined as the color at 210 degrees, i.e., the hue halfway between Shades of blue#Blue (RGB) (X11 blue), blue and cyan. In the RGB color model, used to create all the colors on a television or computer screen, azure is created by adding a 50% of green light to a 100% of blue light. In the X11 color names, X11 color system, which became a model for early web colors, azure is depicted as a pale cyan or white cyan. Etymology and history The color azure ultimately takes its name from the vivid-blue gemstone lapis lazuli, a metamorphic rock. ' is the Latin word for "stone" and ' is the genitive form of the Medieval Latin ', which is taken from the Arabic ''lāzaward'' (), itself from the Persian lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indigo Dye
Indigo dye is an organic compound with a distinctive indigo, blue color. Indigo is a natural dye obtained from the leaves of some plants of the Indigofera#Uses, ''Indigofera'' genus, in particular ''Indigofera tinctoria''. Dye-bearing ''Indigofera'' plants were once common throughout the world. It is now produced via chemical routes. Blue colorants are rare. Since indigo is insoluble, it is also referred to as a pigment (C.I. Pigment Blue 66, C.I.). Most indigo dye produced today is chemical synthesis, synthetic, constituting around 80,000 tonnes each year, as of 2023. It is most commonly associated with the production of denim cloth and jeans, blue jeans, where its properties allow for effects such as stone washing and stone washing#Acid-washed jeans, acid washing to be applied quickly. Uses The primary use for indigo is as a dye for cotton yarn, mainly used in the production of denim cloth suitable for blue jeans; on average, a pair of blue jeans requires to of dye. Smal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woad
''Isatis tinctoria'', also called woad (), dyer's woad, dyer's-weed, or glastum, is a flowering plant in the family Brassicaceae (the mustard family) with a documented history of use as a blue dye and medicinal plant. Its genus name, ''Isatis'', derives from the ancient Greek word for the plant, . It is occasionally known as Asp of Jerusalem. Woad is also the name of a blue dye produced from the leaves of the plant. Woad is native to the steppe and desert zones of the Caucasus, Central Asia to Eastern Siberia and Western Asia but is now also found in South-Eastern and Central Europe and western North America. Since ancient times, woad was an important source of blue dye and was cultivated throughout Europe, especially in Western and Southern Europe. In medieval times, there were important woad-growing regions in England, Germany and France. Towns such as Toulouse became prosperous from the woad trade. Woad was eventually replaced by the more colourfast ''Indigofera tinctoria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathedral
A cathedral is a church (building), church that contains the of a bishop, thus serving as the central church of a diocese, Annual conferences within Methodism, conference, or episcopate. Churches with the function of "cathedral" are usually specific to those Christian denominations with an episcopal hierarchy, such as the Catholic Church, Catholic, Eastern Orthodox Church, Eastern Orthodox, Anglicanism, Anglican, and some Lutheranism, Lutheran churches.''New Standard Encyclopedia'', 1998 by Standard Educational Corporation, Chicago, Illinois; page B-262c. Church buildings embodying the functions of a cathedral first appeared in Italy, Gaul, Spain, and North Africa in the 4th century, but cathedrals did not become universal within the Western Catholic Church until the 12th century, by which time they had developed architectural forms, institutional structures, and legal identities distinct from parish churches, monastery, monastic churches, and episcopal residences. The cathedra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery. 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 itself subdivided into the Early, High, and Late Middle Ages. Population decline, counterurbanisation, the collapse of centralised authority, invasions, and mass migrations of tribes, which had begun in late antiquity, continued into the Early Middle Ages. 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 7th century, North Africa and the Middle East—once part of the Byzantine Empire� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue And White Porcelain
"Blue and white pottery" () covers a wide range of white pottery and porcelain decorated underglaze, under the glaze with a blue pigment, generally cobalt(II) oxide, cobalt oxide. The decoration was commonly applied by hand, originally by brush painting, but nowadays by stencilling or by transfer-printing, though other methods of application have also been used. The cobalt pigment is one of the very few that can withstand the highest firing temperatures that are required, in particular for porcelain, which partly accounts for its long-lasting popularity. Historically, many other colours required overglaze decoration and then a second firing at a lower temperature to fix that. The origin of the blue glazes is thought to lie in Iraq, when craftsmen in Basra sought to imitate imported white Chinese stoneware with their own tin-glazed, white pottery and added decorative motifs in blue glazes. Such Abbasid Caliphate, Abbasid-era pieces have been found in present-day Iraq dating to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt Blue
Cobalt blue is a blue pigment made by sintering cobalt(II) oxide with aluminium(III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl2O4. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue. It is extremely stable, and has historically been used as a coloring agent in ceramics (especially Chinese porcelain), jewelry, and paint. Transparent glasses are tinted with the silica-based cobalt pigment "smalt". Historical uses and production Ores containing cobalt have been used since antiquity as pigments to give a blue color to porcelain and glass. Cobalt blue in impure forms had long been used in Chinese porcelain. In 1742, Swedish chemist Georg Brandt showed that the blue color was due to a previously unidentified metal, cobalt. The first recorded use of ''cobalt blue'' as a color name in English was in 1777. It was independently discovered as an alumina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renaissance
The Renaissance ( , ) is a Periodization, period of history and a European cultural movement covering the 15th and 16th centuries. It marked the transition from the Middle Ages to modernity and was characterized by an effort to revive and surpass the ideas and achievements of classical antiquity. Associated with great social change in most fields and disciplines, including Renaissance art, art, Renaissance architecture, architecture, politics, Renaissance literature, literature, Renaissance exploration, exploration and Science in the Renaissance, science, the Renaissance was first centered in the Republic of Florence, then spread to the Italian Renaissance, rest of Italy and later throughout Europe. The term ''rinascita'' ("rebirth") first appeared in ''Lives of the Artists'' () by Giorgio Vasari, while the corresponding French word was adopted into English as the term for this period during the 1830s. The Renaissance's intellectual basis was founded in its version of Renaiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lapis Lazuli
Lapis lazuli (; ), or lapis for short, is a deep-blue metamorphic rock used as a semi-precious stone that has been prized since antiquity for its intense color. Originating from the Persian word for the gem, ''lāžward'', lapis lazuli is a rock composed primarily of the minerals lazurite, pyrite and calcite. As early as the 7th millennium BC, lapis lazuli was mined in the Sar-i Sang mines,David Bomford and Ashok Roy, ''A Closer Look- Colour'' (2009), National Gallery Company, London, () in Shortugai, and in other mines in Badakhshan province in modern northeast Afghanistan. Lapis lazuli artifacts, dated to 7570 BC, have been found at Bhirrana, which is the oldest site of Indus Valley civilisation. Lapis was highly valued by the Indus Valley Civilisation (3300–1900 BC). Lapis beads have been found at Neolithic burials in Mehrgarh, the Caucasus, and as far away as Mauritania. It was used in the funeral mask of Tutankhamun (1341–1323 BC). By the end of the Middle A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerial Perspective
Aerial perspective, or atmospheric perspective, is the effect the atmosphere has on the appearance of an object as viewed from a distance. As the distance between an object and a viewer increases, the contrast between the object and its background decreases, and the contrast of any markings or details within the object also decreases. The colours of the object also become less saturated and shift toward the background colour, which is usually bluish, but may be some other colour under certain conditions (for instance, reddish around sunrise or sunset). History Atmospheric perspective was used in Pompeian Second Style frescos, one of the Pompeian Styles, dating as early as 30 BCE. Notable examples include the Garden Room Fresco from the Villa of Livia in Prima Porta, Italy, and the first century Pompeian fresco ''Paris on Mount Ida''. With varying degrees of accuracy, explanations of the effects of atmospheric perspective were written by polymaths such as Leon Battista ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Color
Eye color is a polygene, polygenic phenotypic trait determined by two factors: the pigmentation of the eye's Iris (anatomy), iris and the frequency-dependence of the scattering of light by the Turbidity, turbid medium in the Stroma of iris, stroma of the iris. In humans, the pigmentation of the Iris (anatomy), iris varies from light brown to black, depending on the concentration of melanin in the iris pigment epithelium (located on the back of the iris), the melanin content within the iris stroma (located at the front of the iris), and the cellular density of the stroma. The appearance of blue, green, and hazel eyes results from the Tyndall effect, Tyndall scattering of light in the stroma, a phenomenon similar to Rayleigh scattering which accounts for the blue sky. Neither blue nor green pigments are present in the human iris or vitreous humour. This is an example of structural color, which depends on the lighting conditions, especially for lighter-colored eyes. The brightly c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
