NBR – Nitrile rubber (NBR), also called nitrile-butadiene rubber, an oil-resistant synthetic rubber produced from a copolymer of acrylonitrile and butadiene. Its main applications are in fuel hoses, gaskets, rollers, and other products in which oil resistance is required.
NBR is the polymerization of Acrylonitrile (CH2=CHCN) and Butadiene (CH2CH-CH=CH2) into one large multiple-unit chains. The amount of Acrylonitrile is varied to provide different range of oil resistance the base polymer will have. … As the Acrylonitrile increase the polymer will have greater oil and fuel resistance.
Nitrile butadiene rubber (NBR) is a non-toxic synthetic rubber material. Yoga mats made of NBR are usually thick, about 10 mm or more, thus making it more suitable for people with sensitive or injured joints.
NBS – The National Bureau of Standards (NBS) was established by an act of Congress on March 3, 1901. The Bureau’s overall goal is to strengthen and advance the Nation’s science and technology and facilitate their effective application for public benefit.
In 1934, the word “national” was affixed again to its name. For more than 50 years it remained the National Bureau of Standards, or NBS. It became the National Institute of Standards and Technology, or NIST, in 1988.
NMR – Nuclear Magnetic Resonance (NMR) spectroscopy is an analytical chemistry technique used in quality control and research for determining the content and purity of a sample as well as its molecular structure. For example, NMR can quantitatively analyze mixtures containing known compounds. For unknown compounds, NMR can either be used to match against spectral libraries or to infer the basic structure directly. Once the basic structure is known, NMR can be used to determine molecular conformation in solution as well as studying physical properties at the molecular level such as conformational exchange, phase changes, solubility, and diffusion. In order to achieve the desired results, a variety of NMR techniques are available.
NR– Natural rubber is obtained from latex, a milky liquid present in either the latex vessels (ducts) or in the cells of rubber-producing plants. Around 20,000 species of plants produce latex, but only 2,500 species have been found to contain rubber in their latex.
The major commercial source of natural rubber latex is the Amazonian rubber tree (Hevea brasiliensis), a member of the spurge family, Euphorbiaceae. This species is preferred because it grows well under cultivation. A properly managed tree responds to wounding by producing more latex for several years.
Natural rubber is extracted by method called tapping, by making incisions into the bark and collecting the fluid into vessels attached to the rubber trees. The liquid is a sticky, milky sap called latex, and requires a couple of steps before it will be sold as natural rubber.
There are 2 types of rubber Natural and Synthetic. Natural rubber is an elastic hydrocarbon polymer known as an elastomer that was originally derived from latex which is a milky colloidal suspension, found in the sap of some plants.
NECKING – The Tuscan entablature was simply a wood architrave supporting the deeply overhanging roof, but Renaissance authors show the entablature with its typical three parts of architrave, frieze and cornice. In some treatises the architrave is shown split into two fasciae, and in others, only one.
Both column styles are simple, without carvings or ornaments. … A Doric column is stocky and usually without a base. Also, the shaft of a Tuscan column is usually smooth, while a Doric column usually has flutes (grooves).
NEOPRENE – Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range.
neoprene is commonly used to mass-produce reliable gaskets, cable jackets, tubing, Orings, seals, tire-sidewalls, gasoline hoses, wetsuits, and orthopaedic braces.
The fabric, neoprene, is used for wetsuits, drink koozies, seat covers and more. It’s a synthetic rubber that is a good insulator. … Neoprene lunch bags are highly washable. Just as you’d wash a wetsuit, for example, you can wash neoprene lunch bags.
NERVE – A 10 mm gap of rat sciatic nerve was created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes filled with an extracellular gel containing collagen, laminin and fibronectin. Empty silicone rubber tubes were used as controls. Six weeks after implantation, all extracellular elements were completely degraded and absorbed, and 90% of the animals from the extracellular gel group exhibited regeneration across the nerve gaps, whereas only 60% in the control group. Both qualitative and quantitative histology of the regenerated nerves revealed a more mature ultrastructural organization with 28% larger cross-sectional area and 28% higher number of myelinated axons in the extracellular gel group than the controls. These results showed that the gel mixture of collagen, laminin and fibronectin could offer a suitable growth medium for the regeneration of axons.
NITRILE RUBBER– Nitrile rubber is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene that you may know better under trade names like Nipol, Krynac and Europrene N. Why might you consider specifying nitrile for your application? Let’s find out, with a closer inspection of this rubber material.
NBR is used in the automotive and aeronautical industry to make fuel and oil handling hoses, seals, grommets, and self-sealing fuel tanks. It is used in the nuclear industry to make protective gloves.
The Glove Company’s nitrile gloves also have strong chemical resistance. Nitrile is derived from rubber so it is naturally waterproof.
Acrylonitrile-butadiene, commonly known as nitrile or NBR, has excellent chemical resistance, similar to silicone. However, the two materials differ in many of other properties.
NON-FILL– The most common cause of non-fill is insufficient material being injected into the mold, caused by not enough material in the hopper. … The material will push slowly into the mold and the flow fronts that form will not be hot enough to complete the filling of the mold.
Defects typically related to material use or storage. Injection molding defects can often originate from the material itself or how the manufacturer stores and handles the material prior to the production process. These defects can range from minor aesthetic issues to compromised strength of the finished component.
NON-STAINING – According to Family Handyman, dish detergent, water and a soft-bristle scrubbing brush can do the job of ridding most rubber products of minor stains and surface dirt. Using chemicals such as bleach or ammonia may wear them down quickly by causing them to degrade or break.
Natural ventilation – Ventilation of a mine without the aid of fans or furnaces.
Nip – Device at the end of the trailing cable of a mining machine used for connecting the trailing cable to the trolley wire and ground.