Additive

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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 ?
The additivity of ATTD of P values for pigs may depend on the property of component ingredients of the experimental diets, such as anti-nutritional factors [26,31].
However, the variation of o-Ps lifetime ([tau.sub.3]) in nylon 6/PAN-CF reinforced polymer composite shows negative deviation from linear additivity relation.
Liebman, "A group Additivity approach for the estimation of heat capacities of organic liquids and solids," Structural Chemistry, vol.
For the additivity axiom again we follow exactly the argument from Theorem 3.2.
In other words, as argued by Bohner et al., (2008) and Bohner & Dickel (2011), future persuasion research should explore closely the potential interplay of pieces of information similar to the HSM's additivity, bias, attenuation, and contrast hypotheses instead of the controversy between dual- and single-process approaches.
The distance between the fittest optima and the other optima is minimal indicating good mutational additivity and a well-tuned landscape.
This discrepancy arises from the fact that the CSLS decomposition does not satisfy exact additivity; see the discussion in Section II.
Some limitations of the study should be highlighted, the sample size may have affected the power of the study, hypothesis tests for additivity has low power when applied to traditional sample sizes, which is reflected in the poor accuracy of the corresponding estimates, as RERI (10).
All these parameters are determined according to the additivity rule.
In addition, results from maximality and additivity studies may be interpreted in terms of differential histories of responding to the stimuli in the compound either separately (elemental responding), or as a unique stimulus configuration (configural responding; Glautier, 2002; Livesey & Boakes, 2004; Melchers, Lachnit, Ungor, & Shanks, 2008).
TAGUCHI'S ADDITIVITY MODEL An additive model (also called superposition model or variable separable model) is used to approximate the relationship between the response variable and factor levels.
* Paolo Bertoletti, University of Pavia; Federico Etro, Ca' Foscari University of Venice; and Ina Simonovska, University of California, Davis, and NBER, "International Trade with Indirect Additivity"