1. The effect of the pH on the germicidal action of soaps has been studied. The lower members of the series were found to be most active in acid solution; the higher members, in alkaline. The point of transition varied with the test organism used. 2. This is probably due to the effect of the pH on the dissociation residue and on the solubility of the soap. The dissociation residue may affect th...

Mechanistic bioaccumulation models for fish and piscivorous food-webs are widely used to assess the environmental hazard and risk of commercial chemicals, develop water quality criteria and remediation objectives, and conduct exposure assessment of pesticides in aquatic systems. Similar models for mammals and terrestrial food-webs are largely absent. As a result, the hazards and risks of bioacc...

Five widely used metrics of bioaccumulation in fish are defined and discussed, namely the octanol-water partition coefficient (KOW ), bioconcentration factor (BCF), bioaccumulation factor (BAF), biomagnification factor (BMF), and trophic magnification factor (TMF). Algebraic relationships between these metrics are developed and discussed using conventional expressions for chemical uptake from w...

The sorption of organic electrolytes to soil was investigated. A dataset consisting of 164 electrolytes, composed of 93 acids, 65 bases, and six amphoters, was collected from literature and databases. The partition coefficient log Kow of the neutral molecule and the dissociation constant pKa were calculated by the software ACD/Labs. The Henderson-Hasselbalch equation was applied to calculate di...

Pesticide runoff research relies heavily on rainfall simulation experiments. Most are conducted at a constant intensity, i.e., at a fixed rainfall rate; however, large differences in natural rainfall intensity is common. To assess implications we quantified runoff of two herbicides, fluometuron and pendimethalin, and applied preemergence after planting cotton on Tifton loamy sand. Rainfall at c...

Gross primary production (GPP) is a parameter of significant importance for carbon cycle and climate change research. Remote sensing combined with other climate and meteorological data offers a convenient tool for large scale GPP estimation. This paper presents a study of GPP estimation using three methods with in situ measurements of canopy reflectance, LAI, and the photosynthetically active r...

Using replica density functional theory and Monte Carlo computer simulations we investigate a system of annealed hard spherocylinders adsorbed in a matrix of quenched hard spheres. Theoretical predictions for the partition coefficient, defined as the ratio of density of rods in the matrix and that in a reservoir, agree well with simulation results. Theory predicts the isotropic-nematic transiti...

The recent paper of Williamson and Craig (1) should advance the use of counter-current extraction processes as a potent laboratory implement. The general usefulness of the method in research laboratories is due to the work of Martin and Synge (2), who showed that the process could be expressed mathematically as a binomial expansion, and to the development of the method and a compact apparatus b...