A screening test used to help select surfactant systems potentially effective for oil recovery is to identify those formulations that yield middle-phase microemulsions when mixed with sufficient quantities of oil and brine. A correlation is presented to link these variables regarding their contributions to middle-phase formation: structure of the sulfonated surfactant, alkane carbon number (ACN...

This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR) process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous B. subtilis and indigenous microbial populations. The ex...

This paper finds and analyzes a formula for the total variation distance between iterations of riffle shuffles and iterations of “cut and then riffle shuffle”. This allows one to obtain information about the convergence rate of permutation statistics (such as the length of the longest increasing subsequence or position of a given card) under these processes. Similar results are given for affine...

Abstract. We compute the limit distribution for (centered and scaled) length of the longest increasing subsequence of random colored permutations. The limit distribution function is a power of that for usual random permutations computed recently by Baik, Deift, and Johansson (math.CO/9810105). In two–colored case our method provides a different proof of a similar result by Tracy and Widom about...

Enhanced oil recovery (EOR) has been identified as a method of sequestering CO2 recovered from power plants. In CO2flood EOR, CO2 is injected into an oil reservoir to reduce oil viscosity, reduce interfacial tension, and cause oil swelling which improves oil recovery. Previous studies suggest that substantial amounts of CO2 from power plants could be sequestered in EOR projects, thus reducing t...

Dietary fish oils, rich in (n-3) PUFA, including eicosapentaenoic acid and docosahexaenoic acid, have been shown to have antiinflammatory properties. Although the antiinflammatory properties of fish oil may be beneficial during a chronic inflammatory illness, the same antiinflammatory properties can suppress the inflammatory responses necessary to combat acute viral infection. Given that (n-3) ...

Biosurfactants are extracellular surface active compounds produced by bacteria, fungi and yeast. Most microbial surfactants are complex molecules, comprising different structures that include lipopeptides, glycolipids, polysaccharide protein complexes, fatty acids and phospholipids. In the past two decades, biosurfactants have gained increasing attention due to their useful properties such as b...