Site averaging

Some elevated outdoor air levels of triehloroethylene reported are associated with waste disposal sites. Average trichloroethylene levels of 0.08-2.43 ppb were detected in ambient air at six landfill sites in New Jersey the maximum concentration was 12.3 ppb (Harkov et al. 1985). Levels between 3.0 and 3.2 pg/m (0.56 ppb and 0.60 ppb) were found at a distance of 0.5-1.5 meters above the surface of a landfill known to contain halogenated volatile organic compounds in Germany (Koenig et al. 1987). 

Seven-coordination is found among bidentate 1.1-dithiolate complexes248 of mono-organotin, [RSn(S2CY)3], where R is alkyl or phenyl and Y is commonly NR 2 or OR. The distorted pentagonal bipyramids have R and one S in axial sites (average values Sn-S = 249 pm, CSnS = 165°) with the remaining S equatorial and more distant (Sn-S = 260-282 pm). 

In the derivation of the mean-field partition function, it is necessary to know the probability for inserting a chain molecule in a given conformation into the system. The classical way to compute this quantity is by approximating it by a product of the local volume fractions of an unoccupied site (averaged over lattice layers). It was realised that, besides the density information, information on the bond distributions is also available. The bond distribution gives information on the average local order. Using this information, it becomes possible to more accurately access the vacancy probability. 

Table 2 - Percent of At in tetrahedral sites, average long-range order coefficient Sj, average S and Si/Al ratio for zeolites with an ideal Si/Al=1.0.

Table 3 - Percent of A1 in tetrahedral sites, "average long-range order coefli-cient S, and Si/Al ratio for zeolite A.

Deposition doses in the human respiratory system were estimated based on the roadside PNCs in various locations. These showed the similar trend to the roadside PNCs since the dose estimates did not take into account the size distributions of particles at each site. Average deposition doses over all the considered locations were found to be 3.61 0.17 x 1010 h 1 for male subjects, with exceptionally high values (1.61 0.08 x 1011 h ) for site at Birmingham where the study was carried out along the roadside about 15 years ago (i.e. in 1996-1997). 

The DNMR spectra of A1(I1I) and Co(III) require a computer fit for this conclusion whereas the Ga(III) spectra clearly show the site averaging pattern (Fig. 8). 

The soil-water partition coefficients were obtained using three different soils from different locations from the PPI sites at several depths with four harbinger compounds (1,4-dichlorobenzene, 1,2 dichloroethane, 1,1,2,2-tetrachloroethane, and 1,1,2-trichloroethane). The soils provided a broad horizon and chemicals are major ones of concern at the sites. Average values were calculated from triplicate samples and used in plots mentioned above to determine log Koc and log Kmin, which were correlated to log Kow to arrive at the general predictive equation for PPI soils given below [7] ... 

Total Available Binding Sites Average Binding Constant Free Energy of Binding... 

Data are presented as mean standard deviation. When data from a given site were reported with several averages and standard deviations, the data were pooled for an overall site average and a new estimate of the standard deviation was calculated using propogation of errors. Negative rates indicate uptake by the sediment. Rates are confined to those measured in situ in papers published since 1990 for a summary of earlier rates see Burdige (2006). 

Figure 7 Normative spinel Iherzolite mineral abundances (wt.%) versus rock Mg for a set of reconstructed abyssal peridotite compositions. Reconstructions were made using mineral modes and phase composition data (see text Niu et al. (1997), Baker and Beckett (1998), and Asimow (1999) for details). Circles are from Baker and Beckett (1998), and filled circles are reconstructions based on site-averages, whereas open circles are reconstructions based on single thin section modes. Crosses are from Asimow (1999), and are reconstructions based on single thin section modes after the method of Niu et al (1997).

Figure 21 shows site-averaged and grand-average compositions for oceanic, off-craton, and cratonic mantle on plots of normative garnet Iherzolite minerals versus rock Mg. Also shown... 

Figure 1 Average Error Data for Each Site. Average error was calculated for each site as described in Materials and Methods. Numbers below each bar correspond to 4 digit identifier codes provides by each respondent. The type of derivatization chemistry used is indicated by the shading of each bar. Note the different scales on the two plots.

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