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Definição e significado de sand

Definição

sand (n.)

1.fortitude and determination"he didn't have the guts to try it"

2.a loose material consisting of grains of rock or coral

Sand (n.)

1.French writer known for works concerning women's rights and independence (1804-1876)

2.(MeSH)Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.

sand (v. trans.)

1.rub with sandpaper"sandpaper the wooden surface"

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Merriam Webster

SandSand (?), n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. �.]
1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent when wet.

That finer matter, called sand, is no other than very small pebbles. Woodward.

2. A single particle of such stone. [R.] Shak.

3. The sand in the hourglass; hence, a moment or interval of time; the term or extent of one's life.

The sands are numbered that make up my life. Shak.

4. pl. Tracts of land consisting of sand, like the deserts of Arabia and Africa; also, extensive tracts of sand exposed by the ebb of the tide. “The Libyan sands.” Milton. “The sands o' Dee.” C. Kingsley.

5. Courage; pluck; grit. [Slang]

Sand badger (Zoöl.), the Japanese badger (Meles ankuma). -- Sand bag. (a) A bag filled with sand or earth, used for various purposes, as in fortification, for ballast, etc. (b) A long bag filled with sand, used as a club by assassins. -- Sand ball, soap mixed with sand, made into a ball for use at the toilet. -- Sand bath. (a) (Chem.) A vessel of hot sand in a laboratory, in which vessels that are to be heated are partially immersed. (b) A bath in which the body is immersed in hot sand. -- Sand bed, a thick layer of sand, whether deposited naturally or artificially; specifically, a thick layer of sand into which molten metal is run in casting, or from a reducing furnace. -- Sand birds (Zoöl.), a collective name for numerous species of limicoline birds, such as the sandpipers, plovers, tattlers, and many others; -- called also shore birds. -- Sand blast, a process of engraving and cutting glass and other hard substances by driving sand against them by a steam jet or otherwise; also, the apparatus used in the process. -- Sand box. (a) A box with a perforated top or cover, for sprinkling paper with sand. (b) A box carried on locomotives, from which sand runs on the rails in front of the driving wheel, to prevent slipping. -- Sand-box tree (Bot.), a tropical American tree (Hura crepitans). Its fruit is a depressed many-celled woody capsule which, when completely dry, bursts with a loud report and scatters the seeds. See Illust. of Regma. -- Sand bug (Zoöl.), an American anomuran crustacean (Hippa talpoidea) which burrows in sandy seabeaches. It is often used as bait by fishermen. See Illust. under Anomura. -- Sand canal (Zoöl.), a tubular vessel having a calcareous coating, and connecting the oral ambulacral ring with the madreporic tubercle. It appears to be excretory in function. -- Sand cock (Zoöl.), the redshank. [Prov. Eng.] -- Sand collar. (Zoöl.) Same as Sand saucer, below. -- Sand crab. (Zoöl.) (a) The lady crab. (b) A land crab, or ocypodian. -- Sand crack (Far.), a crack extending downward from the coronet, in the wall of a horse's hoof, which often causes lameness. -- Sand cricket (Zoöl.), any one of several species of large terrestrial crickets of the genus Stenophelmatus and allied genera, native of the sandy plains of the Western United States. -- Sand cusk (Zoöl.), any ophidioid fish. See Illust. under Ophidioid. -- Sand dab (Zoöl.), a small American flounder (Limanda ferruginea); -- called also rusty dab. The name is also applied locally to other allied species. -- Sand darter (Zoöl.), a small etheostomoid fish of the Ohio valley (Ammocrypta pellucida). -- Sand dollar (Zoöl.), any one of several species of small flat circular sea urchins, which live on sandy bottoms, especially Echinarachnius parma of the American coast. -- Sand drift, drifting sand; also, a mound or bank of drifted sand. -- Sand eel. (Zoöl.) (a) A lant, or launce. (b) A slender Pacific Ocean fish of the genus Gonorhynchus, having barbels about the mouth. -- Sand flag, sandstone which splits up into flagstones. -- Sand flea. (Zoöl.) (a) Any species of flea which inhabits, or breeds in, sandy places, especially the common dog flea. (b) The chigoe. (c) Any leaping amphipod crustacean; a beach flea, or orchestian. See Beach flea, under Beach. -- Sand flood, a vast body of sand borne along by the wind. James Bruce. -- Sand fluke. (Zoöl.) (a) The sandnecker. (b) The European smooth dab (Pleuronectes microcephalus); -- called also kitt, marysole, smear dab, town dab. -- Sand fly (Zoöl.), any one of several species of small dipterous flies of the genus Simulium, abounding on sandy shores, especially Simulium nocivum of the United States. They are very troublesome on account of their biting habits. Called also no-see-um, punky, and midge. -- Sand gall. (Geol.) See Sand pipe, below. -- Sand grass (Bot.), any species of grass which grows in sand; especially, a tufted grass (Triplasis purpurea) with numerous bearded joints, and acid awl-shaped leaves, growing on the Atlantic coast. -- Sand grouse (Zoöl.), any one of many species of Old World birds belonging to the suborder Pterocletes, and resembling both grouse and pigeons. Called also rock grouse, rock pigeon, and ganga. They mostly belong to the genus Pterocles, as the common Indian species (P. exustus). The large sand grouse (P. arenarius), the painted sand grouse (P. fasciatus), and the pintail sand grouse (P. alchata) are also found in India. See Illust. under Pterocletes. -- Sand hill, a hill of sand; a dune. -- Sand-hill crane (Zoöl.), the American brown crane (Grus Mexicana). -- Sand hopper (Zoöl.), a beach flea; an orchestian. -- Sand hornet (Zoöl.), a sand wasp. -- Sand lark. (Zoöl.) (a) A small lark (Alaudala raytal), native of India. (b) A small sandpiper, or plover, as the ringneck, the sanderling, and the common European sandpiper. (c) The Australian red-capped dotterel (Ægialophilus ruficapillus); -- called also red-necked plover. -- Sand launce (Zoöl.), a lant, or launce. -- Sand lizard (Zoöl.), a common European lizard (Lacerta agilis). -- Sand martin (Zoöl.), the bank swallow. -- Sand mole (Zoöl.), the coast rat. -- Sand monitor (Zoöl.), a large Egyptian lizard (Monitor arenarius) which inhabits dry localities. -- Sand mouse (Zoöl.), the dunlin. [Prov. Eng.] -- Sand myrtle. (Bot.) See under Myrtle. -- Sand partridge (Zoöl.), either of two small Asiatic partridges of the genus Ammoperdix. The wings are long and the tarsus is spurless. One species (A. Heeji) inhabits Palestine and Arabia. The other species (A. Bonhami), inhabiting Central Asia, is called also seesee partridge, and teehoo. -- Sand picture, a picture made by putting sand of different colors on an adhesive surface. -- Sand pike. (Zoöl.) (a) The sauger. (b) The lizard fish. -- Sand pillar, a sand storm which takes the form of a whirling pillar in its progress in desert tracts like those of the Sahara and Mongolia. -- Sand pipe (Geol.), a tubular cavity, from a few inches to several feet in depth, occurring especially in calcareous rocks, and often filled with gravel, sand, etc.; -- called also sand gall. -- Sand pride (Zoöl.), a small British lamprey now considered to be the young of larger species; -- called also sand prey. -- Sand pump, in artesian well boring, a long, slender bucket with a valve at the bottom for raising sand from the well. -- Sand rat (Zoöl.), the pocket gopher. -- Sand rock, a rock made of cemented sand. -- Sand runner (Zoöl.), the turnstone. -- Sand saucer (Zoöl.), the mass of egg capsules, or oöthecæ, of any mollusk of the genus Natica and allied genera. It has the shape of a bottomless saucer, and is coated with fine sand; -- called also sand collar. -- Sand screw (Zoöl.), an amphipod crustacean (Lepidactylis arenarius), which burrows in the sandy seabeaches of Europe and America. -- Sand shark (Zoöl.), an American shark (Odontaspis littoralis) found on the sandy coasts of the Eastern United States; -- called also gray shark, and dogfish shark. See Illust. under Remora. -- Sand skink (Zoöl.), any one of several species of Old World lizards belonging to the genus Seps; as, the ocellated sand skink (Seps ocellatus) of Southern Europe. -- Sand skipper (Zoöl.), a beach flea, or orchestian. -- Sand smelt (Zoöl.), a silverside. -- Sand snake. (Zoöl.) (a) Any one of several species of harmless burrowing snakes of the genus Eryx, native of Southern Europe, Africa, and Asia, especially E. jaculus of India and E. Johnii, used by snake charmers. (b) Any innocuous South African snake of the genus Psammophis, especially P. sibilans. -- Sand snipe (Zoöl.), the sandpiper. -- Sand star (Zoöl.), an ophiurioid starfish living on sandy sea bottoms; a brittle star. -- Sand storm, a cloud of sand driven violently by the wind. -- Sand sucker, the sandnecker. -- Sand swallow (Zoöl.), the bank swallow. See under Bank. -- Sand trap, (Golf) a shallow pit on a golf course having a layer of sand in it, usually located near a green, and designed to function as a hazard, due to the difficulty of hitting balls effectively from such a position. -- Sand tube, a tube made of sand. Especially: (a) A tube of vitrified sand, produced by a stroke of lightning; a fulgurite. (b) (Zoöl.) Any tube made of cemented sand. (c) (Zoöl.) In starfishes, a tube having calcareous particles in its wall, which connects the oral water tube with the madreporic plate. -- Sand viper. (Zoöl.) See Hognose snake. -- Sand wasp (Zoöl.), any one of numerous species of hymenopterous insects belonging to the families Pompilidæ and Spheridæ, which dig burrows in sand. The female provisions the nest with insects or spiders which she paralyzes by stinging, and which serve as food for her young.

SandSand (?), v. t. [imp. & p. p. Sanded; p. pr. & vb. n. Sanding.]
1. To sprinkle or cover with sand.

2. To drive upon the sand. [Obs.] Burton.

3. To bury (oysters) beneath drifting sand or mud.

4. To mix with sand for purposes of fraud; as, to sand sugar. [Colloq.]

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Definiciones (más)

definição - Wikipedia

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George Sand • Sand Baths • Sand Dollars • Sand Flies • Sand-Dollar • Western sand cherry • rough-sand • sand badger • sand bar • sand berry • sand blackberry • sand blast • sand blasting • sand boa • sand bucket • sand cast • sand cat • sand cherry • sand crack • sand cricket • sand dab • sand devil's claw • sand dollar • sand down • sand drift • sand dropseed • sand dune • sand dune fixation • sand dune plantation • sand eel • sand filter • sand flea • sand fly • sand gecko • sand goby • sand grouse • sand hopper • sand lance • sand launce • sand leek • sand lizard • sand martin • sand myrtle • sand painting • sand phlox • sand pit • sand quarry • sand rat • sand reed • sand sage • sand sedge • sand shark • sand silting • sand slinger • sand snake • sand sole • sand spurry • sand stargazer • sand tiger • sand trap • sand tumor • sand verbena • sand viper • sand wedge • sand-bank • sand-blasting • sand-blind • sand-coloured • sand-crack • sand-dune • sand-eel • sand-lance • sand-storm • sea sand • silver sand

Dicionario analógico

Sand (n.)

écrivain français. (fr)[ClasseParExt.]

baronne. (fr)[ClasseParExt.]


Sand (n.) [MeSH]






Wikipedia

Sand

From Wikipedia, the free encyclopedia

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Close-up of sand from a beach in Vancouver, showing a surface area of (approximately) between 1-2 square centimetres.
Heavy minerals (dark) in a quartz beach sand (Chennai, India).

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.

As the term is used by geologists, sand particles range in diameter from 0.0625mm (or 116 mm, or 62.5 micrometers) to 2 millimeters. An individual particle in this range size is termed a sand grain. The next larger size class above sand is gravel, with particles ranging from 2 mm up to 64 mm (see particle size for standards in use). The next smaller size class in geology is silt: particles smaller than 0.0625 mm down to 0.004 mm in diameter. The size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A 1938 specification of the United States Department of Agriculture was 0.05 mm.[1] Sand feels gritty when rubbed between the fingers (silt, by comparison, feels like flour).

ISO 14688 grades sands as fine, medium and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is commonly divided into five sub-categories based on size: very fine sand (116 - 18 mm diameter), fine sand (18 mm - 14 mm), medium sand (14 mm - 12 mm), coarse sand (12 mm - 1 mm), and very coarse sand (1 mm - 2 mm). These sizes are based on the Krumbein phi scale, where size in Φ = -log base 2 of size in mm. On this scale, for sand the value of Φ varies from -1 to +4, with the divisions between sub-categories at whole numbers.

Contents

Constituents

File:PismoBeachSand.JPG
Sand from Pismo Beach, California. Components are primarily quartz, chert, igneous rock and shell fragments. Scale bar is 1.0 mm.
Close up of black volcanic sand from Perissa, in Santorini, Greece
The most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica (silicon dioxide, or SiO2), usually in the form of quartz, which, because of its chemical inertness and considerable hardness, is the most common mineral resistant to weathering.

The composition of sand is highly variable, depending on the local rock sources and conditions. The bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material.[2] The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from the weathering and erosion of a (usually nearby) granitic rock outcrop. Some sands contain magnetite, chlorite, glauconite or gypsum. Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are typically green in color, as are sands derived from basaltic (lava) with a high olivine content. Many sands, especially those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones.

Environments

Sand is transported by wind and water and deposited in the form of beaches, dunes, sand spits, sand bars and related features. In environments such as gravel-bed rivers and glacial moraines it often occurs as one of the many grain sizes that are represented. Sand-bed rivers, such as the Platte River in Nebraska, USA, have sandy beds largely because there is no larger source material that they can transport. Dunes, on the other hand, are sandy because larger material is generally immobile in wind, and are a distinctive geographical feature of desert environments.

Study

An electron micrograph showing grains of sand
File:CoralPinkSandDunesSand.JPG
Sand from Coral Pink Sand Dunes State Park, Utah. These are grains of quartz with a hematite coating providing the orange color. Scale bar is 1.0 mm.

The study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is recently weathered from granite or gneiss quartz crystals will be angular. It is called grus in geology or sharp sand in the building trade where it is preferred for concrete, and in gardening where it is used as a soil amendment to loosen clay soils. Sand that is transported long distances by water or wind will be rounded, with characteristic abrasion patterns on the grain surface. Desert sand is typically rounded.

People who collect sand as a hobby are known as arenophiles or psammophiles.

Uses

At 300 km/h, an ICE 3 (DB class 403) releases sand from several bogies to the rails.
Sand sorting tower at a gravel extraction pit.
  • Agriculture: Sandy soils are ideal for crops such as watermelons, peaches, and peanuts and their excellent drainage characteristics make them suitable for intensive dairy farming.
  • Aquaria: Sand makes a low cost aquarium base material which some[who?] believe is better than gravel for home use.[why?]
  • Artificial reefs: Geotextile bagged sand can serve as the foundation for new reefs.
  • Beach nourishment: Governments move sand to beaches where tides, storms or deliberate changes to the shoreline erode the original sand.[3]
  • Brick: Manufacturing plants add sand to a mixture of clay and other materials for manufacturing bricks.
  • Car Engine Disablement Sand is also used in addition to Sodium Silicate to inexpensively, quickly, and permanently disable automobile engines.
  • Cob: Coarse sand makes up as much as 75% of cob.
  • Concrete: Sand is often a principal component of this critical construction material.
  • Glass: Sand is the principal component in common glass.
  • Landscaping: Sand makes small hills and slopes (for example, in golf courses).
  • Paint: Mixing sand with paint produces a textured finish for walls and ceilings or non-slip floor surfaces.
  • Railroads: Train operators use sand to improve the traction of wheels on the rails.
  • Roads: Sand improves traction (and thus traffic safety) in icy or snowy conditions.
  • Sand animation: Performance artists draw images in sand. Makers of animated films use the same term to describe their use of sand on frontlit or backlit glass.
  • Sand casting: Casters moisten or oil molding sand, also known as foundry sand and then shape it into molds into which they pour molten material. This type of sand must be able to withstand high temperatures and pressure, allow gases to escape, have a uniform, small grain size and be non-reactive with metals.
  • Sand castles: Shaping sand into castles or other miniature buildings is a popular beach activity.
  • Sandbags: These protect against floods and gun fire. The inexpensive bags are easy to transport when empty, and unskilled volunteers can quickly fill them with local sand in emergencies.
  • Sandblasting: Graded sand serves as an abrasive in cleaning, preparing, and polishing.
  • Water filtration: Media filters use sand for filtering water.
  • Zoanthid "skeletons": Animals in this order of marine benthic cnidarians related to corals and sea anemones, incorporate sand into their mesoglea for structural strength, which they need because they lack a true skeleton.

Hazards

A stingray about to bury itself in sand

While sand is generally non-toxic, sand-using activities such as sandblasting require precautions. Bags of silica sand used for sandblasting now carry labels warning the user to wear respiratory protection to avoid breathing the resulting fine silica dust. Material safety data sheets (MSDS) for silica sand state that "excessive inhalation of crystalline silica is a serious health concern".[4]

In areas of high pore water pressure sand and salt water can form quicksand, which is a colloid hydrogel that behaves like a liquid. Quicksand produces a considerable barrier to escape for creatures caught within, who often die from exposure (not from submersion) as a result.

Environmental Issues

Sand's many uses require a significant dredging industry, raising environmental concerns over fish depletion, landslides, and flooding. Countries such as China, Indonesia, Malaysia and Cambodia ban sand exports, citing these issues as a major factor.[5]

See also

References

  1. ^ Urquhart, Leonard Church, "Civil Engineering Handbook" McGraw-Hill Book Company (1959) p.8-2
  2. ^ Seaweed also plays a role in the formation of sand
  3. ^ Importing Sand, Glass May Help Restore Beaches : NPR
  4. ^ Simplot
  5. ^ "The hourglass effect". October 8, 2009. http://www.economist.com/world/asia/displaystory.cfm?story_id=14588255. Retrieved October 14, 2009. 

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