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Ash |
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ash, in botanyash, in botany, any plant of the genus Fraxinus of the family Oleaceae (olive olive, common name for the Oleaceae, a family of trees and shrubs (including climbing forms) of warm temperate climates and of the Old World tropics, especially Asia and the East Indies...... Click the link for more information. family), trees and shrubs mainly of north temperate regions. The ashes are characterized by small clusters of greenish flowers and by fruits with long "wings" to aid in wind dispersal. The most valuable of the species used for hardwood timber is the white ash (F. americana), ranging from Nova Scotia to Minnesota and Texas. Its strong, durable wood is used for sporting goods, furniture, tool handles, and oars. The bark of the blue ash (F. quadrangulata) yields a blue dye; the Mediterranean flowering ash (F. ornus) is the source of commercial manna manna , in the Bible, edible substance provided by God for the people of Israel in the wilderness. In the Book of Exodus it is compared to coriander seed and described as fine, white, and flaky, with the taste of honey and wafer. ..... Click the link for more information. . The name flowering ash is also applied to a shrubby species (F. cuspidata) of the California canyon chaparral and to the fringe tree (genus Chionanthus of the same family) of North America and China. The mountain ash mountain ash, name for any species of the genus Sorbus of the family Rosaceae (rose family), hardy ornamental trees and shrubs native to the Northern Hemisphere, not related to the true ashes. ..... Click the link for more information. and prickly ash prickly ash, name for two deciduous shrubs or small trees (Zanthoxylum americanum and Z. clava-herculis) of the family Rutaceae (rue family). They are native to E North America and have prickly twigs and foliage similar to that of the unrelated ash tree. ..... Click the link for more information. are not true ashes. Ashes are classified in the division Magnoliophyta Magnoliophyta , division of the plant kingdom consisting of those organisms commonly called the flowering plants, or angiosperms. The angiosperms have leaves, stems, and roots, and vascular, or conducting, tissue (xylem and phloem). ..... Click the link for more information. , class Magnoliopsida, order Scrophulariales, family Oleaceae. ash, in chemistryash, in chemistry, solid residue of combustion. The chemical composition of an ash depends on that of the substance burned. Wood ash contains metal carbonates (e.g., potassium carbonate) and oxides formed from metals originally compounded in the wood. Coal ash usually has a high content of minerals and is sometimes contaminated with rock; during combustion the mineral matter may become partially fused, forming cinders or clinker. Bone ash is largely made up of calcium phosphate. Seaweed ash (called kelp or varec) contains sodium carbonate, potassium carbonate, and iodine that can be extracted. Fly ash is very fine ash produced during the combustion of many materials.ashAny tree of the genus Fraxinus, in the olive family. The genus includes about 70 species of trees and shrubs found mostly in the Northern Hemisphere. The U.S. boasts 18 species of ash, 5 of which furnish most of the ash cut as lumber. Most important are the white ash (F. americana) and the green ash (F. pennsylvanica), which yield wood that is stiff, strong, and resilient, yet lightweight. This “white ash” is used for baseball bats, hockey sticks, paddles and oars, tennis and other racket frames, and the handles of agricultural tools. Black ash (F. nigra), blue ash (F. quadrangulata), and Oregon ash (F. latifolia) produce wood of comparable quality that is used for many more purposes, including furniture, interior paneling, and barrels. ash1 1. the nonvolatile products and residue formed when matter is burnt 2. any of certain compounds formed by burning 3. fine particles of lava thrown out by an erupting volcano 4. a light silvery grey colour, often with a brownish tinge ash2 1. any oleaceous tree of the genus Fraxinus, esp F. excelsior of Europe and Asia, having compound leaves, clusters of small greenish flowers, and winged seeds 2. the close-grained durable wood of any of these trees, used for tool handles, etc. 3. any of several trees resembling the ash, such as the mountain ash 4. Austral any of several Australian trees resembling the ash, esp of the eucalyptus genus ash [ash] (botany) A tree of the genusFraxinus,deciduous trees of the olive family (Oleaceae) characterized by opposite, pinnate leaflets. Any of various Australian trees having wood of great toughness and strength; used for tool handles and in work requiring flexibility. (chemistry) The incombustible matter remaining after a substance has been incinerated. (engineering) An undesirable constituent of diesel fuel whose quantitative measurement indicates degree of fuel cleanliness and freedom from abrasive material. (geology) Volcanic dust and particles less than 4 millimeters in diameter. ash A hard, strong, straight-grained hardwood of the eastern US having good shock resistance and bending qualities; used as flooring, trim, and decorative veneer.
Ash an incombustible residue that is formed by the inorganic impurities in fuel after its complete combustion. The ash content of coal and lignite is 1–45 percent or more; that of combustible shales, 50–80 percent; that of fuel peat, 2–30 percent; that of firewood, usually less than 1 percent; that of other kinds of plant fuels, 3–5 percent; and that of mazut, usually up to 0.15 percent, but sometimes higher. The upper limit of the inorganic impurity content determines the technological possibility and economic feasibility of using a particular mineral as a fuel. The presence of ash reduces the relative amount of combustibles in a fuel. Upon combustion of a fuel, part of the heat is lost with the ash. In boiler installations molten ash is deposited on the tubes of the furnace baffles, shields, and other parts as a sintered slag. The deposition of ash on heating surfaces inhibits the transfer of heat from furnace gases to the water or stem and increases the boiler’s aerodynamic resistance. Fly ash abrades boiler tubes and flue gas pumps, and ash pollutes the air when it is carried away with the flue gases. In the building-materials industry ashes are used for making certain kinds of concrete. Rare and trace elements, such as germanium and gallium, are extracted from the ash of certain coals. In agriculture, ash is widely used as a fertilizer containing potassium in the form of potash (K2CO3), which is readily soluble in water and available to plants. Other inorganic substances that are essential for plants (phosphorus, calcium, magnesium, sulfur, boron, and manganese); as well as other macroelements and trace elements, are present in ash. The high calcium carbonate content of shale and peat ash makes possible their use to reduce soil acidity. The average percentages in ash of compounds containing the main nutritive elements of plants are given in Table 1.
Ash is added to all soils and crops, but its use is most expedient with tobacco, potatoes, buckwheat, leguminous plants, flax, and fruit crops. It is introduced with the plowing, when turning over the soil under the crowns of trees (4–15 centners per hectare), and in planting potatoes, cabbage, and tomatoes (3–5 centners per hectare), as well as to fertilize meadows and cultivated and grain crops (3–5 centners per hectare). Ash must not be mixed with organic and ammonia fertilizers (to avoid loss of ammonia) or with superphosphate and other water-soluble phosphorus fertilizers (it causes retrogradation, reducing the ability of plants to assimilate phosphates). REFERENCESAgrokhimiia. Edited by V. M. Klechkovskii and A. V. Peterburgskii. Moscow, 1967.Khimizatsiia sel’skogo khoziaistva: Nauchno-tekhnicheskii slovar’-spravochnik, 2nd ed. Edited by L. L. Balashev and S. I. VoPfkovich. Moscow, 1968. A. V. PETERBURGSKII How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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