R correlation coefficient

Fig. 7. Toxicity of chlorine to aquatic organisms, (a) Time-dependent mortaUty (50%) of four example species in various levels of total residual chlorine in the laboratory, where for A, A.losa aestivalis and B, Salmogairdnerii r (correlation coefficient of the curve) = —0.96 and for C, P/euroneetesplatessa and D, Salmo trutta r = —0.98. (b) A summary of chlorine toxicity to freshwater species, indicating overall no-effect thresholds for acute and chronic exposures. Numbers indicate where more than one test yielded the same result. A different summary figure appHes to marine organisms because of differences in the...

Table I. Simple regression of TOW-ISO data and time for Campeche PCGM coastal test station in a period of 2 years. Equation t = a + b TOW-ISO, r = correlation coefficient, r2 = percentage of variation explained by the independent variable, P = Statistical...

Symbols p— Raman depolarization ratio, r - correlation coefficient... 

Sc = water solubility of crystalline dye in mol/m3 mp = melting point in degrees C R = correlation coefficient... 

The online statistical calculations can be performed at http //members.aol.com/ johnp71/javastat.html. To carry out linear regression analysis as an example, select Regression, correlation, least squares curve-fitting, nonparametric correlation, and then select any one of the methods (e.g., Least squares regression line, Least squares straight line). Enter number of data points to be analyzed, then data, x and y . Click the Calculate Now button. The analytical results, a (intercept), b (slope), f (degrees of freedom), and r (correlation coefficient) are returned. 

Tab. 3.2 Statistical parameters (n, number of data points r, correlation coefficient s, standard error) of regression equations relating bioactivity data [6] to experimental hydro-phobicity parameters. (Reprinted from Tab. 4 of ref. 5, with permission from Elsevier Science)...

Note r = correlation coefficient n = number of compounds analyzed, p = net charge on P, Kcorr = hydrolysis rate corrected for fraction of compound sorbed to sediment. K"corr represents a sediment-catalyzed transformation and rates of hydrolysis in the overlying water phase will be much lower than predicted using these QSARs. 

Figure 7.17 Estimated accretion rates of intertidal salt marshes on the coast of Rhode Island (USA). Despite having well-developed exponential decay curves of excess 210Pb in most marsh sediment cores, indicating a relatively a constant rate of sediment accretion, some variations in the log excess 210Pb indicate that accretion may not have been constant through time. R = correlation coefficient, I = inventories of excess 210Pb (dpm cm-2) (Benninger, 1979 Olsen et al., 1985). (Modified from Bricker-Urso et al., 1989.)...

Solvent, 50E, a (v/v) mixture of 50% aqueous-50% EtOH, 80E a (v/v) mixture of 20% aqueous-80% EtOH. R, correlation coefficient SD, standard deviation n, number of substituents included in the correlation. Correlation (overall p) for three aryl-substituents, Yukawa et al. (1966) data taken from Deno and Evans (1957), Deno and Schriesheim (1955), Deno etal. (1955,1959). Fujio et al. (1997c). Murata et al. (1990a). 

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