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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] [Amazon] |
Dammarane
Dammarane is a tetracyclic triterpene found in sapogenins (forming triterpenoid saponins) like those of ginseng (ginsenosides: panaxatriol Panaxatriol is an organic compound that is an aglycone of ginsenosides, a group of steroid glycosides. It is a dammarane-type tetracyclic triterpene sapogenin found in ginseng (''Panax ginseng'') and in notoginseng (''Panax pseudoginseng''). It ... and protopanaxadiol). Compounds of the series were first isolated from and named after dammar resin, a natural resin from the tropical trees of the dipterocarp family. Mills J.S. (1956) "The Constitution of the Neutral, Tetracyclic Triterpenes of Dammar Resin" ''Journal of the Chemical Society'' 2196-2202 References External links Numbering of dammarane according to IUPAC Recommendations Steroids Triterpenes {{steroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Shorea
Fruit of a ''Shorea'' species ''Shorea'' is a genus of about 47 species of mainly rainforest trees in the family Dipterocarpaceae. The timber of trees of the genus is sold under the common names lauan, luan, lawaan, meranti, seraya, balau, bangkirai, and Philippine mahogany. Description The tallest documented tropical angiosperm is a '' Shorea faguetiana'' found in the Danum Valley Conservation Area, in Sabah, Malaysia (Borneo). In Sabah's Tawau Hills National Park, at least five other species of the genus have been measured to be over tall: '' S. argentifolia'', '' S. gibbosa'', '' S. johorensis'', '' S. smithiana'', and '' S. superba''. Borneo is also the hotspot of ''Shorea'' diversity with 138 species, of which 91 are endemic to the island.Ashton, P. S. "Dipterocarpaceae". In ''Tree Flora of Sabah and Sarawak,'' Volume 5, 2004. Soepadmo, E.; Saw, L. G. and Chung, R. C. K. eds. Government of Malaysia, Kuala Lumpur, Malaysia. Reproduction The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Canarium
''Canarium'' is a genus of about 120 species of tropical and subtropical trees, in the family Burseraceae. They grow naturally across tropical Africa, south and southeast Asia, Indochina, Malesia, Australia and western Pacific Islands; including from southern Nigeria east to Madagascar, Mauritius, Sri Lanka and India; from Burma, Malaysia and Thailand through the Malay Peninsula and Vietnam to south China, Taiwan and the Philippines; through Borneo, Indonesia, Timor and New Guinea, through to the Solomon Islands, Vanuatu, New Caledonia, Fiji, Samoa, Tonga and Palau. ''Canarium'' species grow up to large evergreen trees of tall, and have alternately arranged, pinnate leaves. They are dioecious, with male and female flowers growing on separate trees. Species As of January 2024, Plants of the World Online accepts 121 species. The brief species distribution information was sourced from '' Flora Malesiana'', the ''Flora of China'' (series), the ''Australian Tropical Rainforest Pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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] [Amazon] |
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] [Amazon] |
Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc. An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through). When light strikes an interface between two substances, in general, some may be reflected, some absorbed, some scattered, and the rest transmitted (also see refraction). Reflection can be diffuse, for example light reflecting off a white wall, or specular, for example light reflecting off a mirror. An opaque substance transmits no light, and therefore reflects, scatters, or absorbs all of it. Other categories of visual appearance, related to the perception of regular or diffuse reflection and transmission of light, have been organized under the concept of cesia in an order sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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] [Amazon] |
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] [Amazon] |
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] [Amazon] |
