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Six hundred and seventy-five measurements of dynamic viscosity and density have been used to assess the prediction error of the Arrhenius blending rule for kinematic viscosity of hydrocarbon mixtures. Major trends within the data show that mixture complexity–binary to hundreds of components—and temperature are more important determinants of prediction error than differences in molecular size or hydrogen saturation between the components of the mixtures. Over the range evaluated, no correlation between prediction error and mole fractions was observed, suggesting the log of viscosity truly is linear in mole fraction, as indicated by the Arrhenius blending rule. Mixture complexity and temperature also impact molar volume and its prediction. However, a linear regression between the two model errors explains less than 20% of the observed variation, indicating that mixture viscosity and/or molar volume are not linear with respect to temperature and/or mixture complexity. Extensive discussion of the intermolecular forces and the geometric arrangement of molecules and vacancies in liquids, which ultimately determines its viscosity, is brought into context with the implicit approximations behind the Arrhenius blending rule. The complexity of this physics is not compatible with a simple algebraic correction to the model. However, sufficient data is now available to determine confidence intervals around the prediction of fuel viscosity based on its component mole fractions and viscosities. At −40°C, when all identified components are pure molecules the modeling error is 13.2% of the predicted (nominal) viscosity times the root mean square of the component mole fractions.

When an extensive amount of oil or gas exploration is projected for a homogenous area which apparently contains a low cultural resource density, a sample survey of the area can be utilized to identify and define environmental variables associated with cultural site presence. Through the implementation of a large scale sampling study, the archeologist can determine those topographic features and vegetation zones containing high to low resource density and can provide the developer with archeological clearance recommendations based upon the site sensitivity of specific environments. This procedure can reduce the need for archeological evaluations in the area by concentrating future examinations in those localities where environmental factors indicate a moderate to high potential for cultural site presence. The Archeological-Environmental Research Corporation (AERC) has successfully utilized this technique on several large areas in the overthrust belt region of northeastern Utah.