The predictive capability of the Vignes equation is limited, with considerable deviations encountered in a number of systems. A modification of this expression is developed accounting for solution viscosity. Comparison with data for a large number of known systems shows that this modified version improves the over-all predictability. The concept of segmental diffusion is used to explain the results for mixtures of n-alkanes.
Nomenclature C = total molar concentration C , GREEK LETTERS CY Yz AD A,, X A , AB, A 0 = characteristic distance for viscous process x A, w* 7 = solution viscosity 7L SUBSCRIPTS 1, 2, 3 SUPERSCRIPT = thermodynamic factor defined by Equation 4 = activity coefficient of species i = characteristic distance for diffusion process = characteristic distance applicable to diffusion = characteristic distance for pure species i = chemical potential of species i = viscosity of species i = component 1, 2, 3 = infinite dilution of indicated species or viscous process 0 literature Cited The modification of the Vignes equation, proposed and demonstrated for binary liquid systems by Leffler and Cullinan, is extended to the case of a dilute species diffusing in a mixture of two solvents. Experimental results are reported for the three dilute limits of the systems hexane-benzene-cyclohexane, acetonebenzene-cyclohexane, and acetone-hexane-carbon tetrachloride. These data and previous results are used to test the proposed predictive equation. Agreement is generally good. VOL. 9 NO. I FEBRUARY 1970 l&EC FUNDAMENTALS 89
The manufacture and inspection of porcelain-enameled bathing surface friction in the United States has relied on tribometry since 1979; in modernizing the standards for testing bathing surface friction, tribometry is an obvious candidate. However, although bathing surface standards allow a range of bathing surface contours and curvatures (e.g., concavity) for facilitating drainage, it is currently unknown whether tribometer measurements may be sensitive to these features. This preliminary study sought to determine the influence of bathing surface concavity on tribometer measurements. Four different tribometer models were used to assess the available friction of a porcelain-enameled bathing surface under wet conditions and five different radii of concavity. The results indicate that varying concavities may affect the available friction measurements differently for different tribometer models. Based on our preliminary findings, we recommend a more robust study be undertaken.
In Personal Injury And Fatality Cases, Particularly Those Involving Biomechanics, It Can Occasionally Be Difficult To Evaluate Causation Scenarios Without The Use Of A Human Tape Measure, More Commonly Known As A Surrogate. In These Cases, For The Incident To Happen In The Manner Alleged, Certain Bodily Positions, Configurations And Movements Would Be Necessary. A Surrogate Provides Tangible, Real-World Dimensional And Range-Of-Motion References That Can Assist Both The Causation Analysis And The Triers Of Fact. Three Case Studies Will Illustrate The Benefits Of Using Human Surrogates: A Vehicle Crash Injury, An Alleged Ramp Slip-And-Fall, And A Tractor/Mower Fatality.
A forensic case involved an allegation of defective minivan brake repairs. On a wet two-lane road, the minivan left the road while stopping, and impacted a telephone pole. The plaintiff driver’s complaints implied a dragging brake, and the plaintiff ’s expert reported a bent lower caliper bolt. This forensic investigation involved instrumented exemplar analysis of the effects on caliper drag that could be caused by a bent caliper bolt. The investigation methodology was chosen (in part) based on significant evidence spoliation on the part of the plaintiff ’s expert. This paper will also discuss the effects of the spoliation and resulting limitations on the scope of the analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.