Admixtures definition

CEN EN 934-2 2009+Al. 2012. Admixtures for concrete, mortar and grout - Part 2 Concrete admixtures. Definitions, requirements, conformity, marking and labeling. Brussels CEN. 

It is difficult to prepare a definitive synopsis of the effect that the various classes of admixtures will have on the volume deformations of concrete because of the conflicting results between workers and different types of test methods used, but the points given below should enable some guidelines to be set. 

Another issue is that many primary care physicians have difficulty distinguishing between depressive and anxiety disorders. This has led to the impression that patients in a general medical setting are more likely to have an admixture of symptoms, rather than a clearly defined condition. That depressed patients have anxiety symptoms and anxiety-disordered patients have depressive symptoms, as assessed by the Flamilton scales, are used to support this clinical impression, which ignores the fact that these scales were developed to quantitate symptoms only after a definitive syndromic diagnosis had been made. 

Rubber articles often contain admixtures of various substances introduced either to give them certain definite characters or as adulterants. 

Admixtures are 1-2% nitrogen and NO, which can be removed by passing bivalent iron sulfate through the solution. Moreover, N20 is also produced by nitrates and nitrites reduction under definite conditions or by hyponitrite decomposition. 

The definitions given in Webster s dictionary for authentic and genuine are authentic implies being fully trustworthy as according with fact or actuality genuine implies accordance with an original or a type without counterfeiting, admixture, or adulteration. 

If solid solutions are formed, one may not get a depression in melting point of the two substances on admixture. This depends on the particular system with which one is concerned and again indicates that in the determination of mixed melting points the only definite indication is a depression in melting point and that the observation of no depression proves nothing. However, in probably more than 90 per cent of the cases a depression will be noted, particularly if two mixtures of different compositions are prepared, and this remains a fairly reliable method of establishing the identity of two samples. 

Trinitr4maphtha(tn . This was used to some extent during the war in admixture with picnc acid, etc. It is a mixture of various isomerx and has no definite melting point. The melting points of the individual constituents are 1 3 8 (aiS ), 1 2 5 = 5 5... 

The second point can be considered a semantic one, and it relates to the definition of the test and reference item. In all those cases, where the test item is applied in a vehicle, the respective vehicle may also be applied to the test system in the property of the reference (or control) item, and therefore, a sample of the vehicle should then also be retained. In the case of toxicity studies involving the admixture of the test item to the feed, the feed therefore becomes the reference item, and thus samples of the respective feed batches will have to be retained for analytical purposes , e.g. for later ascertainment that the reference feed did neither contain traces of the test item, nor that it was contaminated in any other way which could have influenced the study. 

The knock rating of a gasoline is expressed as octane number and is the percentage by volume of o-octane (octane number 100, by definition) in admixture with normal heptane (octane number 0, by definition) that has the same knock characteristics as the gasoline being assessed. 

Thus this model maps density over atoms rather than spatial coordinates. If overlap is included some other definition of charge density such as Mulliken s17 may be employed. Eq. (30) and (31) are then used with this wave function to calculate the hyperfine constants as a function of the pn s. If symmetry is high enough, there will be enough hyperfine constants to determine all the p s, otherwise additional approximations may be necessary. For transition metal complexes, where spin-orbit effects are appreciable, it is necessary to include admixtures of excited-state configurations that are mixed with the ground state by the spin-orbit operator. To determine the extent of admixture, we must know the value of the spin-orbit constant X and the energy of the excited states. 

The first of these types of processes may be operated either in batches or continuously. Both methods require eflicient distilling columns, which may be of perforateiji plate or bell-cap design or even of the packed t3q>e. In every case, it is now customary to employ a catalyst, which is usually sulfuric acid, in admixture with the alcohol and acid that are to react. In making ethyl acetate industrially, ethyl alcohol of 95 per cent by volume and acetic acid of 80 per cent or less concentration are generally used. There being no definite lower limit of acid concentration, it is merely a matter of economic balance as to how far the exhaustion of the acetic acid may be carried. In a continuous process such as that of Backhaus, the concentration of the acetic acid may be reduced to 1 per cent. 

There is much precedent but no particular justification for omitting the core orbitals from the molecular calculation. To determine the consequences of (6) separating the core orbitals and electrons, we divide the set of atomic orbitals into two classes, Xp, core orbitals with energies Ep, and valence orbitals for which we retain the symbol . Unlike the Crrti, the coefficients of the core orbitals are not free for variation to minimize the energy but are determined by requiring that arbitrary admixture of the core orbitals in the valence molecular orbitals do not change the energy of the latter. The final matrix equation (6) is of the order of the number of valence orbitals, but the definitions of the S and H matrix elements are modified ... 

Although pozzolans, ground granulated slag and finely divided mineral powders fall within the above definition of admixtures they are generally treated separately and are not included in this publication. 

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