Additive


Also found in: Dictionary, Thesaurus, Medical, Legal, Wikipedia.

additive

[′ad·əd·iv]
(materials)
A substance added to another to strengthen or otherwise alter it for the purpose of improving the performance of the finished product.
(mathematics)
Pertaining to addition.
(statistics)
That property of a process in which increments of the dependent variable are independent for nonoverlapping intervals of the independent variable.

Additive

 

in metallurgy, a material introduced into a liquid metal to change the composition and properties of the metal or slag. A distinction is made among slag-forming additives (lime, fluorspar, and bauxite and their combinations or substituents), carbonizing additives (ground coke, cast iron, and metal carbides), oxidizing additives (ores, clinker, and metal oxides), and alloying additives (ferroalloys, hardeners, and industrial-grade chemical elements). Additives are introduced into the melting unit, ladle, or casting mold.


Additive

 

in petrochemistry, a substance that is added in small amounts to fuels and industrial oils to improve their working properties. Liquid fuels and oils usually do not contain more than a few hundredths or tenths of a percent additives by weight, and only certain additives are used in concentrations of about 1-2 percent or greater.

Additives in fuels improve the efficiency of combustion processes, storage life, and the ability of a fuel to maintain its original properties during shipment and use. They also reduce the harmful effects of fuels on machinery and improve performance at low temperatures. The most common additives are antiknocks, for example, tetraethyllead, which reduce detonation of engine fuels. Other widely used additives act as antioxidants (para-oxydiphenylamine and naphthol), chemical inhibitors, modifiers, metal deactivators, stabilizers, and antifouling agents.

Additives for petroleum oils and synthetic oils are classified on the basis of their use. High-viscosity additives increase the viscosity and improve the viscothermal properties of oils, while pour-point depressants lower the pour point of oils. Antioxidants protect an oil from oxidation by atmospheric oxygen; anticorrosives reduce the decay of a metal in aggressive mediums; and antiwear and antiscuff agents improve the lubricating properties of oils. Antifoaming agents reduce foam, detergents prevent deposition of solids on mechanical parts, and multipurpose additives simultaneously improve several working properties of oils. Also used as additives for oils are various hydrocarbons and compounds that consist of organic molecules and certain elements, including low-molecular surfactants and polymers.

REFERENCES

Nefteprodukty: Svoistva, kachestvo, primenenie. Spravochnik Edited by B. V. Losikov. Moscow, 1966.
Kuliev, A. M. Khimiia i tekhnologiia prisadok k maslam i toplivam. Moscow, 1972.

L. A. SHITS

additive

A material, used in very small quantity, to modify a specific property of another material or otherwise improve its characteristics; used in paints, plasters, mortars, etc.

additive

(mathematics)
A function f : X -> Y is additive if

for all Z <= X f (lub Z) = lub { f z : z in Z }

(f "preserves lubs"). All additive functions defined over cpos are continuous.

("<=" is written in LaTeX as \subseteq, "lub" as \sqcup ).
References in periodicals archive ?
Vice President and General Manager of GE Additive, Mohammad Ehteshami, said, GE and Stryker share a similar vision and both of us understand the transformative power of additive design and manufacturing.
Even at the green grocery store, harmful food additives lurk behind innocent-looking labels.
This company offers over 600 process or resin specific process aid additives and external release agents.
Colorwel custom color concentrates and dry colors for all thermoplastics include custom additive packages and specialty colors (pearlescents, fluorescents, phosphorescents, and metallics).
Lau says young children may be especially at risk for the type of toxicity observed in the nerve-cell cultures, because effects were seen at concentrations of additives she says are theoretically achievable in plasma by eating foods and drinks typically consumed by children--for example, a snack of corn chips, which may contain MSG, and a fruit juice drink, which may contain aspartame.
Additive Cost Reduction: A fourdrinier paper machine making offset printing papers with a sheet ash of 15 % was using a single component cationic flocculant for retention.
Other researchers have suggested that changes in engine temperature or chemical interactions between the additive and metal surfaces trigger a lubricant's function.
Water-based technologies consumed two-thirds of the additive volume, and a 2% annual rate of increase is projected.
The additive also improved the cumulative mulling effect of the return sand by increasing the water bonding capabilities.
Also, before the merger even took place, DuPont Protein Technologies reached out to mainstream consumers, positioning Solae as a "good tasting" as well as nutritious additive.
Lubricant Additives (published 07/2000, 168 pages) is available for $3,500 from The Freedonia Group, Inc.
Even so, some people seem to be additive-sensitive, and for others, additives may be downright dangerous.