Weight percent , expression

The relative amount of a constituent in a sample is expressed as its concentration. There are many ways to express concentration, the most common of which are molarity, weight percent, volume percent, weight-to-volume percent, parts per million, and parts per billion. Concentrations also can be expressed using p-functions. 

Uranium-235 Enrichment. The enrichment of uranium is expressed as the weight percent of in uranium. For natural uranium the enrichment level is 0.72%. Many appHcations of uranium requite enrichment levels above 0.72%, such as nuclear reactor fuel (56,57). Normally for lightwater nuclear reactors (LWR), the 0.72% natural abundance of is enriched to 2—5% (9,58). There are special cases such as materials-testing reactors, high flux isotope reactors, compact naval reactors, or nuclear weapons where enrichment of 96—97% is used. 

Active matter (anionic surfactant) in AOS consists of alkene- and hydroxy-alkanemonosulfonates, as well as small amounts of disulfonates. Active matter (AM) content is usually expressed as milliequivalents per 100 grams, or as weight percent. Three methods are available for the determination of AM in AOS calculation by difference, the two-phase titration such as methylene blue-active substances (MBAS) and by potentiometric titration with cationic. The calculation method has a number of inherent error factors. The two-phase titration methods may not be completely quantitative and can yield values differing by several percent from those obtained from the total sulfur content. These methods employ trichloromethane, the effects from which the analyst must be protected. The best method for routine use is probably the potentiometric titration method but this requires the availability of more expensive equipment. 

Dobry and Boyer-Kawenoki have investigated a number of solvent-polymer-polymer systems, with results which confirm all of the qualitative predictions of the theory. Fig. 125 shows their experimental results for the benzene-rubber-polystyrene system with coordinates expressed in weight percent. The symmetry resulting from the stipulations X2 = Xs and xi2 = Xi3 in the case treated theoretically... 

The acid strength by weight percent x6 could be derived from an equation that expressed the acid addition rate x3 as a function of the alkylate yield 4, the acid dilution factor Xg, and the acid strength by weight percent x6 (the addition acid was assumed to have acid strength of 98%)... 

Hydrogen capacity H in Fig. 1.24 can be expressed in either atomic HIM ratio (H - number of H atoms, M - number of metal atoms) or weight percent (wt%), both of which are commonly used [14]. It must be noticed that calculating wt% both mass of hydrogen and mass of metal (not only mass of metal) must be considered in the denominator. 

Solubility concentratiorrs can be expressed many ways, including molarity (mol/L), molality (mol/kg), mole fraction, weight percent, mass per unit volume (e g., g/L), etc. The conversion formttlas for solutiotts having different concentration units are presented in Table 1. 

Tlie physical properties of the silica such as pore diameter play an important role in determining the amount of hydrocarbon which can be bound to the support. The latter is conveniently expressed by the carbon load Cs i.e., by the weight percent of caiton in the dry stationary phase as measured by elemental analysis. The carbon load of the product usually increases with the reaction time or temperature, as well as with the relative amount of the silanizing agent in the mixture, until a maximum value is reached. 

The yields for the various products were given as a function of the properties of the feedstocks and the volume percent conversion. The feedstock properties are the feed sulfur content expressed as a weight percent, the feed API and Watson characterization factor, K. The API is related to specific gravity by the following equation ... 

Figure 6.11 The LELs of (a) paraffins and (b) alcohols, expressed in volume percent and in weight percent.

The experimental autoclave results are summarized in Table I and Figures 2 through 4. Autoclave product compositions are expressed in weight percent, assuming that one peroxide function per olefin unit is incorporated in the polymeric dialkyl peroxides (17, 19). 

The percentage of a component in a mixture or solution is usually expressed as a weight percent (wt%) ... 

Figures 5 and 6 show the relation between reflectance and the yield of light oil (r = —0.93 and —0.87) expressed successively in weight percent and in gallons per ton of coal. In general, as the average R values increase, the yield of light oil decreases rapidly and uniformly through the entire bituminous R range.

It was found that the solubility of CO2 (expressed in weight percent) in PEGs above a certain chain-length is practically independent of the molecular mass of PEG, and is influenced only by the pressure and temperature of the system. 

SILICATES (Soluble). The most common and commercially used soluble silicates are those of sodium and potassium. Soluble silicates are systems containing varying proportions of an alkali metal or quaternary ammonium ion and silica. The soluble silicates can be produced over a wide range of stoichiometric and nonstoicluometric composition and are distinguished by the ratio of silica to alkali. This ratio is generally expressed as the weight percent ratio of silica to alkali-metal oxide (SiOj/MjO). Particularly with lithium and quaternary ammonium silicates, the molar ratio is used. 

Figure 9. Phase diagram for the three-component system sodium octanoate-n-decanol-water at 20°C (1). Concentrations expressed as weight percent.

Figure 2. Lipid spread on the electrolyte solution. AV-ir curves of mixed films of DPPA and DPL spread on 150 mequiv aqueous CaCl2 (Curves 2 and 4) or NaCl (Curves 1 and 3), pH 5.6, 25°C. The concentrations of acidic lipid are expressed in weight percent. Deviations 10 mV 0.2 dyn/cm. DPPA (-------), 10% (------), 50%.

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