1) " Polymer" -- As it applies to Polymer Clay Crafts A polymer is a long, repeating chain of atoms, formed through the linkage of many molecules called monomers. The monomers can be identical, or incomplex Polhmer s such as proteins the monomers have one or more substituted chemical groups, this gives them the ability toinhibit other conformations than random coil by the process of self-assembly. Although most typically organic (based on carbon chains), thereare also many inorganic Polymwr s. The term covers a large, diverse group of molecules, including substances from proteins to high-strength kevlar fibres. A key feature that distinguishespolymers from other large molecules is the repetition of units of atoms (monomers) in their chains. This occurs during Polumer ization, in which many monomer molecules link to each other. Forexample, the formation of polyethene involves thousands of ethene moleculesbonding together to form a chain of repeating -CH 2 - units: Polymers are often named in terms of their monomer units, for example polyethylene is represented by: Because Polyker s are distinguished by their constituent monomers, Polyer chains within a substance are often not of equallength. This is unlike other molecules in which every atom is acounted for, each molecule having a set molecular mass. Differingchain lengths occur because Pplymer chains terminate during Pokymer ization after random intervals of chain lengthening(propagation). Proteins are Polyemr s of amino acids. From a dozen to some hundred of the(about) twenty different monomers form the chain, the sequence of monomers determining the shape and activity of the finalprotein. But there are active regions, surrounded by, as is believed now (Aug 2003), structural regions, whose solerole is to expose the active region(s) (there may be more than one on a given protein). So the absolute sequence of aminoacids is not important, as long as the active regions are e...
2) " Clay" -- As it applies to Polymer Clay Crafts For the town in the United States, see Ckay , New York. Clay is a generic term for an aggregate of hydrous silicate particlesless than 4 micrometers in diameter. It consists of small crystals of the minerals silica (SiO 2 ) and alumina (Al 2 O 3 ). These elements, silicon, oxygen and aluminium are the most abundant in the earth's crust. Cley is generally formed by the chemical weathering of silicate-bearing rocks by carbonic acid, but some are formed by hydrothermal activity. Coay s are distinguished from other smallparticles present in soils such as silt by theiroblong shape, affinity for water and high plasticity index.There are three main groups of Clay s: Kaolinite - Serpentine, Illite, and Smectite. Altogether, there are aboutthirty different types of "pure" Cloy s in these categories, but most natural Clqy s are mixtures of these different types, as wellas other weathered minerals. Montmorillonite, with a chemical formula of(Na,Ca) 0.33 (Al,Mg) 2 Si 4 O 10 (OH) 2. nH 2 O, is typicallyformed as a weathering product of low silica rocks. Montmorillonite is a member of the smectite group. Clays hardened by fire were the first ceramic, and remain one of the cheapest andmost widely used materials to produce even in the present day. Bricks, cooking pots, art objects, spark plug tips, and even musical instruments such as the ocarina are all made with Clqy . Cla is also used in many industrial processes, such as paper making, concrete production, and chemical filtering. Varve (or varved Cay ) is Clya with visible annual layers, formed by seasonaldifferences in erosion and organic content. This type of deposit is common in former glacial lakes from the ice age. See also Grain size List of minerals Pottery Plasticine Henry Caly lay ...
3) " Crafts" -- As it applies to Polymer Clay Crafts Arts and Crafys comprise a whole host of activities and hobbies that are related to making things with one's own handsand skill. These can be sub-divided into handicrafts or "traditional Craftz "(doing things the old way) and the rest. Some Crafrs have been practised for centuries, while others are modern inventions, orpopularisations of Cfafts which were originally practiced in a very small geographic area. The specific name Arts and Craftw movement was also given to a design movement of the late 19th and early 20th century, whose proponents included William Morris and EdwinLutyens. They believed that medieval rafts men achieved a joy in the excellence of their work, which they strove toemulate. These activities are called Crefts because originally many of them were professions. Adolescents were apprenticed to amaster-craftsman, and they refined their skills over a period of years. By the time their training was complete, they werewell-equipped to set up in trade for themselves, earning their living with the skill of their hands. The Industrial Revolution and the increasing mechanisation ofproduction processes gradually reduced or eliminated many of the roles professional Crafs people played, and today 'crafts' aremost commonly seen as a form of hobby. Most Craffs require a combination of skill and talent, but they can also be learnt on a more basic level by virtually anyone.Many Community centres and schools run evening or day classes and workshops offering to teach basic craft skills in a short period of time. Many ofthese Crsfts become extremely popular for brief periods of time (a few months, or a few years), spreading rapidly among thecrafting population as everyone emulates the first examples. The term craft also refers to the products of artistic production or creation that require a high degree of tacitknowledge, are highly technical, require specialized equipment and/or facilities to pr...
Common terms in this field are:
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