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Raking Illumination
Raking light, the illumination of objects from a light source at an oblique angle or almost parallel to the surface, provides information on the surface topography and relief of the artefact thus lit. It is widely used in the examination of works of art. Examination of paintings Using raking light, the effects of impasto and the surface texture of a painting are accentuated by the increased illumination of surfaces facing the light source and the exaggeration of shadows on surfaces facing away from the light source. In some instances, raking light may help reveal pentimenti (changes in an artist's intention). In the case of wall paintings, raking light helps show preparatory techniques such as incisions in the plaster support. Conservation Conservators examine objects under raking light during a visual inspection and for condition recording. In the examination of easel paintings, raking light may help document craquelure, paint cupping, uneven tension in a canvas, or warp i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condition Recording
Condition or conditions may refer to: In philosophy and logic * Material conditional, a logical connective used to form "if...then..." statements * Necessary and sufficient condition, a statement which is true if and only if another given statement is true In science and technology In computer science * Exception handling#Condition systems, a generalization of exceptions in exception handling * Condition (SQL), a filtering mechanism in relational database queries * Condition variable, a synchronization primitive in concurrent programming In medicine * Medical condition, as a synonym for disease * Medical state or condition, a patient's clinical status in a hospital In numerical analysis * Condition number, a measure of a matrix in digital computation In arts and entertainment * ''Condition'' (film), a 2011 film * ''Conditions'' (album), 2009 debut album by Australian rock band The Temper Trap * ''Conditions'' (magazine), an annual lesbian feminist literary magazine * Cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imaging
Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of an image). Imaging technology is the application of materials and methods to create, preserve, or duplicate images. Imaging science is a multidisciplinary field concerned with the generation, collection, duplication, analysis, modification, and visualization of images,Joseph P. Hornak, ''Encyclopedia of Imaging Science and Technology'' (John Wiley & Sons, 2002) including imaging things that the human eye cannot detect. As an evolving field it includes research and researchers from physics, mathematics, electrical engineering, computer vision, computer science, and perceptual psychology. ''Imager, Imagers'' are imaging sensors. Imaging chain The foundation of imaging science as a discipline is the "imaging chain" – a conceptual model describing all of the factors which must be considered when developing a system for creating visual renderings (image ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delamination
Delamination is a mode of failure where a material fractures into layers. A variety of materials, including Lamination, laminate Composite material, composites and concrete, can fail by delamination. Processing can create layers in materials, such as steel formed by Rolling (metalworking), rolling and plastics and metals from 3D printing which can fail from layer separation. Also, surface coatings, such as paints and films, can delaminate from the coated substrate. In Lamination, laminated composites, the adhesion between layers often fails first, causing the layers to separate. For example, in Fibre-reinforced plastic, fiber-reinforced plastics, sheets of high strength reinforcement (e.g., Carbon fibers, carbon fiber, fiberglass) are bound together by a much weaker polymer matrix (e.g., epoxy). In particular, loads applied perpendicular to the high strength layers, and shear loads can cause the polymer matrix to fracture or the fiber reinforcement to debond from the polymer. Del ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt (chemistry)
In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions ( anions), which results in a compound with no net electric charge (electrically neutral). The constituent ions are held together by electrostatic forces termed ionic bonds. The component ions in a salt can be either inorganic, such as chloride (Cl−), or organic, such as acetate (). Each ion can be either monatomic, such as sodium (Na+) and chloride (Cl−) in sodium chloride, or polyatomic, such as ammonium () and carbonate () ions in ammonium carbonate. Salts containing basic ions hydroxide (OH−) or oxide (O2−) are classified as bases, such as sodium hydroxide and potassium oxide. Individual ions within a salt usually have multiple near neighbours, so they are not considered to be part of molecules, but instead part of a continuous three-dimensional network. Salts usually form crystalline structures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Efflorescence
In chemistry, efflorescence (Derived from the Latin verb 'efflorescere' roughly meaning 'to flower') is the migration of a salt to the surface of a porous material, where it forms a coating. The essential process involves the dissolving of an internally held salt in water or occasionally, in another solvent. The water, with the salt now held in solution, migrates to the surface, then evaporates, leaving a coating of the salt. In what has been described as "primary efflorescence", the water is the invader and the salt was already present internally, and a reverse process, where the salt is originally present externally and is then carried inside in solution, is referred to as "secondary efflorescence". Efflorescences can occur in natural and built environments. On porous construction materials it may present a cosmetic outer problem only (primary efflorescence causing staining), but can sometimes indicate internal structural weakness (migration/degradation of component materials ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murals
A mural is any piece of graphic artwork that is painted or applied directly to a wall, ceiling or other permanent substrate. Mural techniques include fresco, mosaic, graffiti and marouflage. Word mural in art The word ''mural'' is a Spanish adjective that is used to refer to what is attached to a wall. The term ''mural'' later became a noun. In art, the word began to be used at the beginning of the 20th century. In 1906, Dr. Atl issued a manifesto calling for the development of a monumental public art movement in Mexico; he named it in Spanish ''pintura mural'' (English: ''wall painting''). In ancient Roman times, a mural crown was given to the fighter who was first to scale the wall of a besieged town. "Mural" comes from the Latin ''muralis'', meaning "wall painting". This word is related to ''murus'', meaning "wall". History Antique art Murals of sorts date to Upper Paleolithic times such as the cave paintings in the Lubang Jeriji Saléh cave in Borneo (40,000–52,0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamilton Kerr Institute
The Hamilton Kerr Institute is a branch of the Fitzwilliam Museum in Cambridgeshire, England, dedicated to the study and conservation of easel paintings. It is also part of the University of Cambridge. Facilities and logistics The institute was founded in 1976 through grants from the Baring Foundation, the Esmée Fairbairn Trust, the Gulbenkian Foundation, the Isaac Wolfson Foundation, the Monument Trust, and the Pilgrim Trust, and continues to finance itself through income from its work and its endowment fund. It is housed in a riverside property, donated by Hamilton Kerr, seven miles south of Cambridge in the village of Whittlesford. The premises consist of a mid-eighteenth century house and converted mill buildings, containing offices and a scientific laboratory, restoration studios, studios for panel treatment and the relining of canvases, and studios for photography. In 1980, the institute opened a studio in London. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panel Painting
A panel painting is a painting made on a flat panel of wood, either a single piece or a number of pieces joined together. Until canvas became the more popular support medium in the 16th century, panel painting was the normal method, when not painting directly onto a wall ( fresco) or on vellum (used for miniatures in illuminated manuscripts). Wood panels were also used for mounting vellum paintings. History Panel painting is very old; it was a very prestigious medium in Greece and Rome, but only very few examples of ancient panel paintings have survived. A series of 6th century BC painted tablets from Pitsa (Greece) represent the oldest surviving Greek panel paintings. Most classical Greek paintings that were famous in their day seem to have been of a size comparable to smaller modern works – perhaps up to a half-length portrait size. However, for a generation in the second quarter of the fifth-century BC there was a movement, called the "new painting" and led by Polygnotus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood Warping
Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree, it performs a mechanical-support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients among the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fibers. Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the productio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canvas
Canvas is an extremely durable Plain weave, plain-woven Cloth, fabric used for making sails, tents, Tent#Marquees and larger tents, marquees, backpacks, Shelter (building), shelters, as a Support (art), support for oil painting and for other items for which sturdiness is required, as well as in such fashion objects as handbags, electronic device cases, and shoes. It is popularly used by artists as a painting surface, typically stretched across a wooden frame. Although historically made from hemp, modern canvas is usually made of cotton, linen, or sometimes polyvinyl chloride (PVC). It differs from other heavy cotton fabrics, such as denim, in being plain weave rather than Twill, twill weave. Canvas comes in two basic types: plain and Cotton duck, duck. The threads in duck canvas are more tightly woven. The term ''duck'' comes from the Dutch language, Dutch word for cloth, ''doek''. In the United States, canvas is classified in two ways: by weight (ounces per square yard) and by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tension (physics)
Tension is the pulling or stretching force transmitted axially along an object such as a string, rope, chain, rod, truss member, or other object, so as to stretch or pull apart the object. In terms of force, it is the opposite of ''compression''. Tension might also be described as the action-reaction pair of forces acting at each end of an object. At the atomic level, when atoms or molecules are pulled apart from each other and gain potential energy with a restoring force still existing, the restoring force might create what is also called tension. Each end of a string or rod under such tension could pull on the object it is attached to, in order to restore the string/rod to its relaxed length. Tension (as a transmitted force, as an action-reaction pair of forces, or as a restoring force) is measured in newtons in the International System of Units (or pounds-force in Imperial units). The ends of a string or other object transmitting tension will exert forces on the objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
