Fraction by mass

Among minor constituents some 0- and S-heterocycles and their alkyl derivatives were detected. No non-PAH-type compound or polar derivatives of PAHs (e.g., quinones) were detected in this fraction by mass spectrometry indicating the effectiveness of the isolation procedure. 

Peng, J., Kim, M. J., Cheng, D., Duong, D. M., Gygi, S. P., Sheng, M. Semiquan-titative proteomic analysis of rat forebrain postsynaptic density fractions by mass spectrometry. /. Biol. Chem. 2004, 279 21003-21011. 

F + D l-F) where the superscript i has been dropped for clarity, Cq is the concentration in the bulk system, and F is the melt fraction by mass. For highly incompatible elements, which are characterized by very low partition coefficients, so that D [Pg.766]

Moisture content (also water content ) is in principle very simple to measure it is the quantity of water in a unit mass of bulk powder, as a percentage or fraction by mass (or weight). The confusion arises whether the mass of bulk powder includes moisture or not. The moisture content may, therefore, be either on a dry basis (i.e. per unit mass of dry powder) or on a wet basis, the former being more frequently used such as in soil mechanics for example16. 

TABLE 16-4. MOLECULAR SIZE DISTRIBUTION IN OIL FRACTIONS BY MASS SPECTROGRAPHY... 

Another fundamental chemical observation is summarized as the law of definite (or constant) composition no matter what its source, a particular compound is composed of the same elements in the same parts (fractions) by mass. The fraction by mass (mass fraction) is that part of the compound s mass contributed by the element. It is obtained by dividing the mass of each element by the total mass of compound. The percent by mass (mass percent, mass %) is the fraction by mass expressed as a percentage. 

The fitting of the kinetic model calculated to the experimental results is shown in Figures 1 and 2, where the evolution with time on stream of the mass fraction (by mass unit of organic components in reaction medium) of each lump of the kinetic scheme has been plotted. As is observed in Figure 1, deactivation attenuates as water content in the feed increases, at 350 °C. 

Karaca, E, Morgan, T.J., George, A., Bull, I.D., Herod, A.A., Millan, M., Kandiyoti, R. (2009) Molecular mass ranges of coal tar pitch fractions by mass spectrometry and size exclusion chromatography. Rapid Commun. Mass Spectrom., 23,2087-2098. 

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