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Hypertufa
Hypertufa is an anthropic rock made from various aggregates bonded together using Portland cement. Hypertufa is intended as a manufactured substitute for natural tufa, which is a slowly precipitated limestone rock; being very porous, it is favorable for plant growth. Hypertufa is popular for making garden ornaments, pots and land forms. It is relatively light compared with terracotta or traditional concrete and can withstand harsh winters, at least down to . Hypertufa was invented for use in alpine gardens. Alpine gardeners formerly used antique animal watering troughs, which became rare and expensive. Composition Aggregates are generally ''Sphagnum'' (peat moss), sand, and perlite or vermiculite. Coconut coir is coming to take the place of sphagnum moss, as the latter is a very slowly renewing natural resource and the former is a ready byproduct of the coconut industry— it has all of the advantages of the moss but without the environmental costs. To increase structural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tufa
Tufa is a variety of limestone formed when carbonate minerals precipitate out of water in unheated rivers or lakes. Geothermally heated hot springs sometimes produce similar (but less porous) carbonate deposits, which are known as travertine. Tufa is sometimes referred to as (meteogene) travertine. It should not be confused with hot spring (thermogene) travertine. Tufa, which is calcareous, should also not be confused with tuff, a porous volcanic rock with a similar etymology that is sometimes also called "tufa". Classification and features Modern and fossil tufa deposits abound with wetland plants; as such, many tufa deposits are characterised by their large macrobiological component, and are highly porous. Tufa forms either in fluvial channels or in lacustrine environments. Ford and Pedley (1996) provide a review of tufa systems worldwide. Fluvial deposits Deposits can be classified by their depositional environment (or otherwise by vegetation or petrographically). Pedle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4 Tufe
4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures. In mathematics Four is the smallest composite number, its proper divisors being and . Four is the sum and product of two with itself: 2 + 2 = 4 = 2 x 2, the only number b such that a + a = b = a x a, which also makes four the smallest squared prime number p^. In Knuth's up-arrow notation, , and so forth, for any number of up arrows. By consequence, four is the only square one more than a prime number, specifically three. The sum of the first four prime numbers two + three + five + seven is the only sum of four consecutive prime numbers that yields an odd prime number, seventeen, which is the fourth super-prime. Four lies between the first proper pair of twin primes, three and five, which are the first two Fermat primes, like seventeen, which is the third. On the other han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coir
Coir (), also called coconut fibre, is a natural fibre extracted from the outer husk of coconut and used in products such as floor mats, doormats, brushes, and mattresses. Coir is the fibrous material found between the hard, internal shell and the outer coat of a coconut. Other uses of brown coir (made from ripe coconut) are in upholstery padding, sacking and horticulture. White coir, harvested from unripe coconuts, is used for making finer brushes, string, rope and fishing nets. It has the advantage of not sinking, so can be used in long lengths in deep water without the added weight dragging down boats and buoys. Coir must not be confused with coir pith, which is the powdery and spongy material resulting from the processing of the coir fibre. Coir fibre is locally named 'coprah' in some countries, adding to confusion. Pith is chemically similar to coir, but contains much shorter fibers. The name coco peat may refer either to coir or the pith or a mixture, as both have go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papercrete
Papercrete is a building material that consists of re-pulped paper fiber with Portland cement or clay and/or other soil added. First patented in 1928, it was revived during the 1980s. Although perceived as an environmentally friendly material due to the significant recycled content, this is offset by the presence of cement. The material lacks standardisation, and proper use therefore requires care and experience. Eric Patterson and Mike McCain, who have been credited with independently "inventing" papercrete (they called it "padobe" and "fibrous cement"), have both contributed considerably to research into machinery to make it and ways of using it for building. Manufacture The paper to be used can come from a variety of sources, including newspaper, junk mail, magazines, books. A mixer is used to pulp the mix. Depending on the type of mixer, the paper may be soaked in water beforehand. Standardization and commercial acceptance As of 2007, papercrete lacks approval from the Inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkalinity
Alkalinity (from ar, القلوي, al-qaly, lit=ashes of the saltwort) is the capacity of water to resist acidification. It should not be confused with basicity, which is an absolute measurement on the pH scale. Alkalinity is the strength of a buffer solution composed of weak acids and their conjugate bases. It is measured by titrating the solution with an acid such as HCl until its pH changes abruptly, or it reaches a known endpoint where that happens. Alkalinity is expressed in units of concentration, such as meq/L (milliequivalents per liter), μeq/kg (microequivalents per kilogram), or mg/L CaCO3 (milligrams per liter of calcium carbonate). Each of these measurements corresponds to an amount of acid added as a titrant. Although alkalinity is primarily a term used by oceanographers, it is also used by hydrologists to describe temporary hardness. Moreover, measuring alkalinity is important in determining a stream's ability to neutralize acidic pollution from rainfall or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distressing
Distressing (or weathered look) in the decorative arts is the activity of making a piece of furniture or object appear aged and older, giving it a "weathered look". There are many methods to produce an appearance of age and wear. Distressing is viewed as a refinishing technique although it is the opposite of finishing in a traditional sense. In distressing, the object's finish is intentionally destroyed or manipulated to look less than perfect, such as with sandpaper or paint stripper. For example, the artisan often removes some but not all of the paint, leaving proof of several layers of paint speckled over wood grain underneath. This becomes the "finished" piece. Distressing has become a popular design style and decorative art form. The artisan attempts a rustic, attractive, one-of-a-kind appearance or vintage look. The final appearance is often called the patina. Distressing can be applied to a variety of surfaces and materials such as wood, glass, metal, plastic, stone, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curing (chemistry)
Curing is a chemical process employed in polymer chemistry and process engineering that produces the toughening or hardening of a polymer material by cross-linking of polymer chains. Even if it is strongly associated with the production of thermosetting polymers, the term "curing" can be used for all the processes where a solid product is obtained from a liquid solution, such as with PVC plastisols. Curing process During the curing process, single monomers and oligomers, mixed with or without a curing agent, react to form a tridimensional polymeric network. In the very first part of the reaction branches of molecules with various architectures are formed, and their molecular weight increases in time with the extent of the reaction until the network size is equal to the size of the system. The system has lost its solubility and its viscosity tends to infinite. The remaining molecules start to coexist with the macroscopic network until they react with the network creating other c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molding (process)
Molding (American English) or moulding (British and Commonwealth English; see spelling differences) is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix. This itself may have been made using a pattern or model of the final object. A mold or mould is a hollowed-out block that is filled with a liquid or pliable material such as plastic, glass, metal, or ceramic raw material. The liquid hardens or sets inside the mold, adopting its shape. A mold is a counterpart to a cast. The very common bi-valve molding process uses two molds, one for each half of the object. Articulated molds have multiple pieces that come together to form the complete mold, and then disassemble to release the finished casting; they are expensive, but necessary when the casting shape has complex overhangs. Piece-molding uses a number of different molds, each creating a section of a complicated object. This is generally only used for larger a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mortar (masonry)
Mortar is a workable paste which hardens to bind building blocks such as stones, bricks, and concrete masonry units, to fill and seal the irregular gaps between them, spread the weight of them evenly, and sometimes to add decorative colors or patterns to masonry walls. In its broadest sense, mortar includes pitch, asphalt, and soft mud or clay, as those used between mud bricks, as well as cement mortar. The word "mortar" comes from Old French ''mortier'', "builder's mortar, plaster; bowl for mixing." (13c.). Cement mortar becomes hard when it cures, resulting in a rigid aggregate structure; however, the mortar functions as a weaker component than the building blocks and serves as the sacrificial element in the masonry, because mortar is easier and less expensive to repair than the building blocks. Bricklayers typically make mortars using a mixture of sand, a binder, and water. The most common binder since the early 20th century is Portland cement, but the ancient binder lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decorative Concrete
Decorative concrete is the use of concrete as not simply a utilitarian medium for construction but as an aesthetic enhancement to a structure, while still serving its function as an integral part of the building itself such as floors, walls, driveways, and patios. The transformation of concrete into decorative concrete is achieved through the use of a variety of materials that may be applied during the pouring process or after the concrete is cured, these materials and/or systems include but are not limited to stamped concrete, acid staining, decorative overlays, polished concrete, concrete countertops, vertical overlays and more. Concrete statues Concrete statues are made by pouring concrete into a latex mold. Often painted and sold for garden ornaments. Most popular designs are bird baths and garden gnomes. Stamped concrete As a modern technique, stamped concrete is the process of adding texture and color to concrete to make it resemble stone, brick, slate, cobblestone an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but 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. Calcium carbonate is the second most common type of sand, for example, aragonite, which has mostly been created, over the past 500million years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Somewhat more rarely, sand may be composed of calciu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiberglass
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinyl ester resin—or a thermoplastic. Cheaper and more flexible than carbon fiber, it is stronger than many metals by weight, non- magnetic, non-conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, orthopedic casts, surfboards, and external door skins. Other common names for fiberglass are glass-reinforced plastic (GRP), glass-fiber reinforced plastic (GFRP) or GF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
