Concentrations reported

Aqueous Solution Viscosity. A special solution preparation method is used for one type of measurement of aqueous solution viscosity (96). The appropriate amount of poly(ethylene oxide) resin is dispersed in 125 mL of anhydrous isopropyl alcohol by vigorous stirring. Because the resin is insoluble in anhydrous isopropyl alcohol, a slurry forms and the alcohol wets the resin particles. An appropriate amount of water is added and stirring is slowed to about 100 rpm to avoid shear degradation of the polymer. In Table 4, the nominal resin concentration reported is based on the amount of water present and ignores the isopropyl alcohol. 

Sorenson and Arlt Liquid-Liquid Equilihiium Data Collection, DECHEMA, Frankfurt, Germany, 1979) report several sets of liquid-liquid equilibrium data for the system acetone-water-chloroform, but the lowest solute concentrations reported at 25 C were. 3 weight percent acetone in the water layer in equilibrium with 9 weight percent acetone in the chloroform layer. This gives a partition ratio K of, 3.0. 

Component A = feed solvent, component B = solute, and component S = extraction solvent. K is the partition ratio in weight-fraction solute if/x for the tie line of lowest solute concentration reported. Ordinarily, K will approach unity as the solute concentration is increased. 

Fig. 1 Concentrations reported for opiods and cannabinoids in surface water of different European countries. MOR morphine Nor-MOR nor-morphine 6ACM 6-monoacetyl morphine HER heroin MET methadone EDDP 2-ethylidene-l,5-dimethyl-3,3 diphenylpyrrolidine THC A9-tetrahydro-cannabinol THC-COOH 11-nor 9-carboxy-THC N/A Values not availabe, not measured...

Butyltin compounds, in contrast, are produced only anthropogenically. Besides the applications covered in this CICAD, there exist other applications of butyltin compounds that may represent a significant source of these substances in the environment. In particular, the use of tributyltin compounds in antifouling coatings represents a significant source of these substances in the marine and freshwater environments. Hence, many of the measured concentrations reported will relate predominantly to this use. 

Sampling time of 5 minutes, whereas the average concentrations reported in the table are related to the whole study period. 

Number of Projects Reporting Number of Projects with Last MTBE Concentration Range Initial MTBE Concentrations Reported MTBE Concentrations... 

MTBE Concentration Range Initial MTBE Concentrations Reported MTBE Concentrations... 

Arvela, H. and K. Winqvist, Influence of source type and air exhange on variations of indoor radon concentration. Report STUK-A51, Finnish Centre for Radiation and Nuclear Safety, Helsinki (1986). 

As Hem (1985) notes, a chemical analysis with concentrations reported to two or three, and sometimes four or five, significant figures can be misleadingly authoritative. Analytical accuracy and precision are generally in the range of 2 to 10%, but depend on the technique used, the skill of the analyst, and on whether or not the constituent was present near the detection limit of the analytical method. The third digit in a reported concentration is seldom meaningful, and confidence should not necessarily be placed on the second. 

Fig. 6.4. Effects of the pore size of filter paper used during fluid sampling on the analytical concentrations reported for aluminum and iron (Kennedy el al., 1974). Samples were acidified, stored for 19 ( ) or 94 ( ) days, and analyzed by standard wet chemical methods. Dotted lines show dissolved concentrations determined by a solvent extraction technique.

Second, the total barium concentration in solution, which is constrained by equilibrium with barite, is 6.6 qmolal or 0.68 mg kg-1. The concentration reported by chemical analysis (Table 6.8) is 0.9 mg kg-1, in close agreement with the calculation. Considering the uncertainties in the calculation, these values are probably fortuitously similar. 

Yen, T., and Bulatovic, S., Investigation for the Improvement of Concentrate Grades and Metal Recoveries from Western Group of Concentrators, Report of Investigation No. 4 LR2550, 1985. 

Blacet [4], who carried out experiments in high 02 concentrations, reported that ozone and S03 appear to be the only products of the photochemically induced reaction. The following essential steps were postulated ... 

Witherup S, Cleveland FP, Shaffer FE, et al. 1955. The physiological effects of the introduction of heptachlor into the diet of experimental animals in varying levels of concentration Report of Experiment No. 2. U.S. Environmental Protection Agency, Freedom of Information Office, MRID No. 00062599. 

Seasonal and interannual trends in atmospheric carbon dioxide concentrations reported as mole fraction in dry air. (a) Monthly mean values at Mauna Loa Observatory, Hawaii. Data are also presented as 6-month running average to eliminate the seasonal effects and (b) three-dimensional representation of latitudinal distributions of monthly mean values. Source After P. Tans and T. Conway, NOAA/ESRL Global Monitoring Division (www.esrl.noaa.gov/gmd/ccgg/trends). (See companion website for color version.)... 

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