Although brittle, silicate glass is extremely durable, and many examples of glass fragments exist from early glass-making cultures. All rights reserved.The American Heritage® Idioms Dictionary

For other uses, see Wilde, H. "Technologische Innovationen im 2. Vitrification (from Latin vitreum, "glass" via French vitrifier) is the transformation of a substance into a glass, that is to say, a non-crystalline amorphous solid.In the production of ceramics, vitrification is responsible for its impermeability to water.. Vitrification is usually achieved by heating materials until they liquidize, then cooling the liquid, often rapidly, so that it passes through the glass transition to form a …

Published by Houghton Mifflin Harcourt Publishing Company.a hard, brittle, noncrystalline, more or less transparent substance produced by fusion, usually consisting of mutually dissolved silica and silicates that also contain soda and lime, as in the ordinary variety used for windows and bottles.any artificial or natural substance having similar properties and composition, as fused borax, obsidian, or the like.something made of such a substance, as a windowpane.a tumbler or other comparatively tall, handleless drinking container.a device to compensate for defective vision or to protect the eyes from light, dust, and the like, consisting usually of two glass or plastic lenses set in a frame that includes a nosepiece for resting on the bridge of the nose and two sidepieces extending over or around the ears (usually used with a hard brittle transparent or translucent noncrystalline solid, consisting of metal silicates or similar compounds. The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. However, the term "glass" is often defined in a broader sense, to describe any non-crystalline solid that exhibits a glass transition when heated towards the liquid state.Glass is an amorphous solid.Although the atomic-scale structure of glass shares characteristics of the structure of a supercooled liquid, glass exhibits … The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. The United States Federal Glass Ceiling Commission defines the glass ceiling as "the unseen, yet unbreachable barrier that keeps minorities and women from rising to the upper rungs of the corporate ladder, regardless of their qualifications or achievements." "Glass ceiling" means an invisible upper limit in corporations and other organizations, above which it is difficult or impossible for women to rise in the ranks.

This artificial variety is made from sheets of glass that are cut up and placed in an acid bath or a rock tumbler. Artificial sea glass, on the other hand, can be formed in a workshop, factory or even a rock tumbler (very rare). de Jong, "Glass"; in "Ullmann's Encyclopedia of Industrial Chemistry"; 5th edition, vol.

A glass ceiling …

Glass used for decorative purposes often has iron in it to alter its optical properties. Glass definition, a hard, brittle, noncrystalline, more or less transparent substance produced by fusion, usually consisting of mutually dissolved silica and silicates that also contain soda and lime, as in the ordinary variety used for windows and bottles. Other types of glass are made by adding other chemical compounds. Common glass is generally composed of a silicate (such as silicon oxide, or quartz) combined with an alkali and sometimes other substances.

It is made from a fused mixture of oxides, such as lime, silicon dioxide, etc, and is used for making windows, mirrors, bottles, etcany compound that has solidified from a molten state into a noncrystalline formsomething made of glass, esp a drinking vessel, a barometer, or a mirrorto hit (someone) in the face with a glass or a bottleAny of a large class of materials with highly variable mechanical and optical properties that solidify from the molten state without crystallization, are typically made by silicates fusing with boric oxide, aluminum oxide, or phosphorus pentoxide, are generally hard, brittle, and transparent or translucent, and are considered to be supercooled liquids rather than true solids.Something usually made of glass, such as a window, mirror, or drinking vessel.A pair of lenses mounted in a light frame, used to correct faulty vision or protect the eyes.A device, such as a monocle or spyglass, containing a lens or lenses and used as an aid to vision.A usually transparent or translucent material that has no crystalline structure yet behaves like a solid. In the laboratory mostly pure Colour in glass may be obtained by addition of homogenously distributed electrically charged ions (or Different oxide additives produce the different colours in glass: Four-colour Roman glass bowl, manufactured circa 1st century B.C.

The "glass ceiling" metaphor has also been used to describe the limits and barriers experienced by … David Cotter and colleagues defined four distinctive characteristics that must be met to conclude that a glass ceiling exists. Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. The negative Silica-free glasses may often have poor glass forming tendencies.

Structural glazing systems represent one of the most significant architectural innovations of modern times, where glass buildings now often dominate Glass is an essential component of tableware and is typically used for water, Glass is an important material in scientific laboratories for the manufacture of experimental apparatus because it is relatively cheap, readily formed into required shapes for experiment, easy to keep clean, can withstand heat and cold treatment, is generally non-reactive with many The 19th century saw a revival in ancient glass-making techniques including This article is about the material. Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company.

Zur Verwendung und Verbreitung neuer Werkstoffe im ostmediterranen Raum". See more.