The soft ones are made from high-water-content polymers like hydroxyethylmethacrylate
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Hydrogel Lenses - The College of Optometrists  hydrophilic polymers. Polymers are solid materials made from high-molecular- ... Materials made from one monomer are termed homopolymers ... That material was poly(hydroxyethyl methacrylate) or PHEMA. ... Hydrocurve thin lens (Soft Lenses, Inc.) in 1977 and subsequently ... water content was similar to that of PHEMA.
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HYDROGEL LENS MATERIALS - University of Missouri-St. Louis  Also called a soft contact lens. II. ... Lenses may also be made of different polymers which are related to HEMA. B. Water Content 1. Water content = weight of water in lens X 100 /total weight of lens 2. Range ... Group 4 - ionic polymers, high water (poly HEMA & hydrophilic monomers & increased levels of MAA, no NVP) e.
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Water properties of soft contact lens materials. - NCBI  The properties of water in soft contact lenses such as the water content, ... Specifically, lenses made from the following eight materials (and nominal water contents) ... [HEMA = 2-hydroxy-ethyl methacrylate, VP = vinyl pyrrolidone, MMA = methyl ... the other hand, medium and high water content materials exhibited multiple...
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Modern Contact Lens Materials: A Clinical Performance Update  Sep 1, 2002 ... High-water content soft lenses need to be made thicker than their low-water ... All contact lens materials are polymers, which are either ... material (poly-2-hydroxyethyl methacrylate or polyHEMA) developed by Otto ... One approach to achieve this goal incorporates of two "phases" into the materials.
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Contact Lens Polymers - School of Engineering and Applied Sciences  During this time Otto Wichterle discovered poly(hydroxyethyl methacrylate), ... HEMA is a hydrogel that could be made into contacts using a simply and efficient spin cast method. ..... In soft contact lenses the water content affect many things. ... make hydrogels from silicone based polymers like polydimethylsiloxane (PDMS).
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Materials - Colosseum  Tiles and bricks were produced with clay mixed with water and often with sand, straw ... Roman Cement (most of the info from Benjamin Herring "The secrets of ... One was made with simple lime and river sand, mixed at a ratio of three parts ... The other type used pozzolana instead of river sand and was mixed at a ratio of...
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U.S. Synthetic Rubber Program - National Historic Chemical ...  Today 70 percent of the rubber used in manufacturing processes is synthetic and a ... solvent, laminated sticky rubber cloth and fabric together to make raincoats. ... for goods made from this waterproof gum, but the "rubber fever" ended abruptly ... It was Charles Goodyear who discovered a way to cure natural rubber to...
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Hygloss Wet & Set Plaster Roll, 4" x 180" - Walmart.com  Buy Hygloss Wet & Set Plaster Roll, 4" x 180" at Walmart.com. ... 10-Piece Ultimate Pumpkin Carving Set. $7.84. 10-Piece Ultimate Pumpkin Carving Set.
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Jeo 19 - 4 Flashcards | Quizlet  The stiff-mud process is a way of combining water & clay to make these pieces ... The Caucasus Mountains straddle the border between Russia & this country, y'all? ... The name of this smooth, closely woven cotton cloth used in bedsheets is from a ... To avoid storms, planes will often fly in this relatively peaceful atmosphere...
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At what temperature does plastic melt? | Reference.com  Sturdy plastics can typically hold boiling water, which is at 212 degrees Fahrenheit, while soft plastics like plastic bags would melt if they came into contact with...
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Natural vs Synthetic Polymers-Gelfand - Carnegie Mellon University  There are two types of polymers: synthetic and natural. ... Examples of synthetic polymers include nylon, polyethylene, polyester, Teflon, and epoxy. ... in various proportions resulting in a wide range of physical, mechanical, and chemical properties. ... In the plant/fruit, pectin is the material that joins the plant cells together.
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Polyamides - The Essential Chemical Industry  Polyamides are polymers which contain repeating amide, -CO-NH-, linkages. ... and resilience, make them very important in the manufacture of clothing and carpets. ... Figure 1 The children's clothing is made of polyamide 6, impregnated with ... One of the monomers, hexanedioic acid is also produced from KA mixed oil...
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How Paper Is Made - Evergreen Packaging  Paper Pressing. The wet sheet is picked up on a moving belt made of felt. The felt carries the sheet through the press section, which squeezes out more water...
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DIY: 50 fabulous fixes every home owner should know - Telegraph  Jul 6, 2008 ... Scrunched into a handy cleaning ball, newspaper is more effective, and ... Most glass scratches are caused by careless use of sandpaper ... It dries to a hard, water-resistant seal, so it's also ideal for worktops. ... or Pollyfilla (the powder type that you mix with water, not the pre-mix, ..... this is so silly. honest.
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HAMMERS - Snap-on  Products 1 - 28 of 114 ... soft face  ... 1.5-Ounce Soft Hammer Head (Blue-Point), HSPI6KT2 ... 16 oz Dead Blow Ball Peen Soft Grip Hammer, HBBD16.
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Manila paper - Wikipedia  Manila paper is a relatively inexpensive type of paper, generally made through a less refined ... Manila paper was originally made out of old Manila Hemp ropes which were extensively used on ships, having replaced true hemp. It was made...
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Contents 2. Cellulose-based plastics: celluloid and rayon 3. Bakelite ...  include particulate fillers, fibres and gases, the last resulting in foams. Dispersion .... much current use as the substance of toy figurines and novelties. PVC has...
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Rubber Materials, Silicone, EPDM, Neoprene, Natural Rubber ...  Silicone, EPDM, Natural Rubber, Neoprene. ... and most mineral acids, this high performance synthetic rubber also has excellent temperature resistance. It also...
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jeopardy/2878_Qs.txt at master  jedoublen/jeopardy  GitHub  ANATOMY | Each of these is made up of 4 kinds of tissue: pulp, dentin, enamel & cementum | .... THE SPORTING NEWS | Now officially made by Inglasco for the pros, these were originally made from frozen cow dung in Canada | hockey pucks.
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Polymers in the Orchestra Polymers in the Piano Caring for ...  Since Clara is an old clarinet from the classical period, she also knows a lot about ... The keys of a piano were once made of the protein ivory, but now they are ... Newer pianos have quite a few plastic parts, even some of the action parts can ... In many cases synthetic polymers have been used to replace wood, which is a...
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Toxic Dentures  Merrilyn Hope's Blog  Oct 20, 2010 ... They use this soft plastic because it is easy to mould: It can be heated and ... That tests were also assisted by a group of dentists of which the leader was ... Although I often wonder if your teeth can regrow or fix its own cavities, ...... be able to stay,to do so,meaning all 6 removed at once&full upper denture