Description: This article discusses enthalpy of solvation correlations for gaseous solutes dissolved in dimethyl sulfoxide and propylene carbonate based on the Abraham model. Abstract: Data have been assembled from the published literature on the enthalpies of solvation for more than 100 compounds in dimethyl sulfoxide and propylene carbonate. It is shown that an Abraham solvation equation with five descriptors can be used to correlate the experimental solvation enthalpies to within standard deviations of 2.80 and 2.61 kJ/mol for dimethyl sulfoxide and propylene carbonate, respectively. The derived correlations provide very accurate mathematical descriptions of the measured enthalpy of solvation data at 298 K, which in the case of dimethyl sulfoxide span a range of about 92 kJ/mol. Division of the experimental values into a training set and a test set shows that there is no bias in predictions, and that the predictive capability of the correlations is better than 3.6 kJ/mol.

Description: This article discusses the correlation and prediction of partition coefficient between the gas phase and water, and the solvents dry methyl acetate, dry and wet ethyl acetate, and dry and wet butyl acetate. Abstract: Experimental partition coefficient data have been compiled from the published literature for the water/methyl acetate, water/ethyl acetate and water/butyl acetate partition systems, log P data, and for the gas/methyl acetate, gas/ethyl acetate and gas/butyl acetate partition systems, log K data. Application of the Abraham solvation parameter model to the sets of partition coefficients leads to equations that correlate the log P data and log K data to 0.18 log units for the three dry alkyl acetate solvents. Slightly larger deviations were noted for solute partition into both wet ethyl acetate and wet butyl acetate. The derived correlations were validated using training set and test set analyses.

Description: This article discusses the evaluation of WEPP for runoff and sediment yield prediction on natural gas well sites. Abstract: Natural gas exploration and production requires land-disturbing construction activities that have the potential to accelerate soil loss due to land cover modifications, increased slopes, and flow concentration. In the U.S., nearly 30,000 new gas wells are drilled each year. Erosion modeling has been successfully used for decades to predict soil loss and conservation effects on agricultural fields, rangelands, and forests, although much less research has been conducted on the application of erosion models for disturbed construction site conditions. The objective of this research was to evaluate Water Erosion Prediction Project (WEPP) runoff and sediment yield predictions relative to measured data from two natural gas well sites (referred to as GW1 and GW2) in north central Texas. Model parameters were adjusted from WEPP default parameters based on available literature and model observations. A low effective hydraulic conductivity value (0.75 mm h⁻¹) resulted in successful runoff predictions. Agreement between predicted and measured sediment yields was accomplished by increasing rill and interrill erodibility values and decreasing critical shear stress values from default values. WEPP performance was evaluated with the Nash-Sutcliffe efficiency (NSE), root mean ...

Description: This article discusses chemical toxicity correlations for several fish species based on the Abraham solvation parameter model. Abstract: The Abraham solvation parameter model is used to construct mathematical correlations for describing the nonspecific aquatic toxicity of organic compounds to the fathead minnow, guppy, bluegill, goldfish, golden orfe, and high-eyes medaka. The derived mathematical correlations describe the observed published toxicity data to within an overall average standard deviation of approximately 0.28 log units. In the case of ester solutes, the descriptions were improved by introducing an indicator variable into the basic model. Derived correlations can be used to estimate aquatic toxicities of organic chemicals to the six fish species studied and to help in identifying compounds whose toxic mode of action might involve chemical specific reactivity, rather than nonpolar or polar narcosis. A principle component analysis of the correlation equations shows that the water-octanol system is a poor model for nonspecific aquatic toxicity but that the water-isobutanol and water-pentanol systems are much better models.

Description: This article discusses Salman Rushdie and reading the postcolonial texts in the era of empire. Using the first three novels of Salman Rushdie, this essay articulates a different conceptual framework for reading the postcolonial texts. It is a known fact that in most metropolitan readings of the global periphery, the text is made to stand in for an entire culture. Inundation, a technique introduced in this essay, ensures a more complex reading by inserting silenced knowledge and histories in our reading to challenge any reductive representations of the global periphery. An inundated text, the author suggests, becomes a better tool in teaching the complexities of the postcolony to the metropolitan audiences, while also taking the reader beyond the politics of representation. It is hoped that this essay will invite other scholars to expand on this concept (inundation), for a new mode of reading is absolutely necessary in the politically charged world of today's empire.