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Damar Gum
Dammar, also called dammar gum, or damar gum, is a resin obtained from the tree family Dipterocarpaceae in India and Southeast Asia, principally those of the genera ''Shorea'' or ''Hopea'' (synonym ''Balanocarpus''). The resin of some species of ''Canarium'' may also called dammar. Most is produced by tapping trees; however, some is collected in fossilised form on the ground. The gum varies in colour from clear to pale yellow, while the fossilised form is grey-brown. Dammar gum is a triterpenoid resin, containing many triterpenes and their oxidation products. Many of them are low molecular weight compounds (dammarane, dammarenolic acid, oleanane, oleanonic acid, etc.), which easily oxidizes and photoxidizes. Types * ''Damar mata kucing'' ('cat's eye damar') is a crystalline resin, usually in the form of round balls. ''Shorea javanica'' is an important source in Indonesia. * ''Damar batu'' ('stone damar') is stone or pebble-shaped, opaque dammar collected from the ground. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dammar
Dammar, also called dammar gum, or damar gum, is a resin obtained from the tree family Dipterocarpaceae in India and Southeast Asia, principally those of the genera '' Shorea'' or '' Hopea'' (synonym ''Balanocarpus''). The resin of some species of '' Canarium'' may also called dammar. Most is produced by tapping trees; however, some is collected in fossilised form on the ground. The gum varies in colour from clear to pale yellow, while the fossilised form is grey-brown. Dammar gum is a triterpenoid resin, containing many triterpenes and their oxidation products. Many of them are low molecular weight compounds ( dammarane, dammarenolic acid, oleanane, oleanonic acid, etc.), which easily oxidizes and photoxidizes. Types * ''Damar mata kucing'' ('cat's eye damar') is a crystalline resin, usually in the form of round balls. '' Shorea javanica'' is an important source in Indonesia. * ''Damar batu'' ('stone damar') is stone or pebble-shaped, opaque dammar collected from the g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shorea Javanica
''Anthoshorea javanica'' is a species of flowering plant in the family Dipterocarpaceae. It is a tree native to southern Sumatra and Java in Indonesia. It is one of several dipterocarp species commonly known as white meranti. . Retrieved 22 September 2024. It is a large tree, growing up to 40 or 50 meters tall. It generally flowers in January and is pollinated by insects. Seeds are dispersed by the wind. Seedlings can tolerate shade, but the best propagation is in forest clearings. The plant has a very restricted range, with the larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be used: \rho = \frac, where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate this quantity is more specifically called specific weight. For a pure substance, the density is equal to its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium is the densest known element at standard conditions for temperature and pressure. To simplify comparisons of density across different systems of units, it is sometimes replaced by the dimensionless quantity "relative den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melting Point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state of matter, state from solid to liquid. At the melting point the solid and liquid phase (matter), phase exist in Thermodynamic equilibrium, equilibrium. The melting point of a substance depends on pressure and is usually specified at a Standard temperature and pressure, standard pressure such as 1 Atmosphere (unit), atmosphere or 100 Pascal (unit), kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of substances to Supercooling, supercool, the freezing point can easily appear to be below its actual value. When the "characteristic freezing point" of a substance is determined, in fact, the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice, that is, the #Melting point measurements, melting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Microscopy
Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy. Optical microscopy and electron microscopy involve the diffraction, reflection, or refraction of electromagnetic radiation/electron beams interacting with the specimen, and the collection of the scattered radiation or another signal in order to create an image. This process may be carried out by wide-field irradiation of the sample (for example standard light microscopy and transmission electron microscopy) or by scanning a fine beam over the sample (for example confocal laser scanning microscopy and scanning electron microscopy). Scanning probe microscopy involves the interaction of a scanning probe with the surface of the object of interest. The de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canada Balsam
Canada balsam, also called Canada turpentine or balsam of fir, is the oleoresin of the balsam fir tree (''Abies balsamea'') of boreal North America. The resin, dissolved in essential oils, is a viscous, sticky, colourless or yellowish liquid that turns to a transparent yellowish mass when the essential oils have been allowed to evaporate. Canada balsam is amorphous when dried. It has poor thermal and solvent resistance. Uses left, Slide of a holotype specimen of a flatworm (''Lethacotyle fijiensis)'' permanently mounted in Canada balsam in 1953 Due to its high optical quality and the similarity of its refractive index to that of crown glass (optics), crown glass (''n'' = 1.52), purified and filtered Canada balsam was traditionally used in optics as an invisible-when-dry glue for glass, such as lens elements. Other optical elements can be cemented with Canada balsam, such as two prisms bonded to form a beam splitter. Canada balsam was also commonly used for making perman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encaustic Painting
Encaustic painting, also known as hot wax painting, is a form of painting that involves a heated wax medium to which colored pigments have been added. The molten mix is applied to a surface—usually prepared wood, though canvas and other materials are sometimes used. The simplest encaustic medium could be made by adding pigments to wax, though recipes most commonly consist of beeswax and damar resin, potentially with other ingredients. For pigmentation, dried powdered pigments can be used, though some artists use pigmented wax, inks, oil paints or other forms of pigmentation. Metal tools and special brushes can be used to shape the medium as it cools. Also, heated metal tools, including spatulas, knives and scrapers, can be used to manipulate the medium after it has cooled onto the surface. Additionally, heat lamps, torches, heat guns, and other methods of applying heat are used by encaustic artists to fuse and bind the medium. Because encaustic medium is thermally malleable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraffin Wax
Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and melting point, begins to melt above approximately , and its boiling point is above . Common applications for paraffin wax include lubrication, electrical insulation, and candles; dyed paraffin wax can be made into crayons. Un-dyed, unscented paraffin candles are odorless and bluish-white. Paraffin wax was first created by Carl Reichenbach#Scientific contributions, Carl Reichenbach in Germany in 1830 and marked a major advancement in candlemaking technology, as it burned more cleanly and reliably than tallow candles and was cheaper to produce. In chemistry, ''paraffin'' is used synonymously with ''alkane'', indicating hydrocarbons with the general formula C''n''H2''n''+2. The name is derived from Latin ''parum'' ("very little") + ''affinis'', meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batik
Batik is a dyeing technique using wax Resist dyeing, resist. The term is also used to describe patterned textiles created with that technique. Batik is made by drawing or stamping wax on a cloth to prevent colour absorption during the dyeing process. This creates a patterned negative when the wax is removed from the dyed cloth. Artisans may create intricate coloured patterns with multiple cycles of wax application and dyeing. Patterns and motifs vary widely even within countries. Some patterns hold symbolic significance and are used only in certain occasions, while others were created to satisfy market demand and fashion trends. Resist dyeing using wax has been practised since ancient times, and it is attested in several world cultures, such as Egypt, southern China (especially among hilltribes like the Miao people, Miao, Bouyei people, Bouyei, and Gejia peoples), India, Indonesia, Malaysia, Nigeria, and Sri Lanka. The technique developed Batik in Indonesia, in Indonesia (es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Painting
Oil painting is a painting method involving the procedure of painting with pigments combined with a drying oil as the Binder (material), binder. It has been the most common technique for artistic painting on canvas, wood panel, or oil on copper, copper for several centuries. The advantages of oil for painting images include "greater flexibility, richer and denser color, the use of layers, and a wider range from light to dark". The oldest known oil paintings were created by Buddhism, Buddhist artists in Afghanistan, and date back to the 7th century AD. Oil paint was later developed by Europeans for painting statues and woodwork from at least the 12th century, but its common use for painted images began with Early Netherlandish painting in Northern Europe, and by the height of the Renaissance, oil painting techniques had almost completely replaced the use of egg tempera paints for panel paintings in most of Europe, though not for Orthodox icons or wall paintings, where tempera a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
