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Full-Text Articles in Physical Sciences and Mathematics
Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee
Using Nitrate, Chloride, Sodium, And Sulfate To Calculate Groundwater Age, Kimm Crawford, Terry Lee
Sinkhole Conference 2015
Regression analysis is used to identify monotonic trends to assign water age using ion data from two large well water databases from southeast Minnesota (SE MN). Nitrate (NO3-N), chloride (Cl), sodium (Na), and sulfate (SO4) ions in the commonly used aquifers in SE MN can be used as groundwater tracers since they are either entirely or partly anthropogenic in their sources, their loading occurs on a regional scale, and they are almost entirely conserved. Ion concentrations over time are used to establish six trend patterns. Two patterns are unchanging (background and stable above background), and four are changing (linear up, …
L-Lactide And Ε-Caprolactone Ring Opening Polymerization By Binary Catalysts Systems That Include Bis-Ligated Magnesium Complexes, Reile M. Slattery, Arnold L. Rheingold, Joseph M. Fritsch
L-Lactide And Ε-Caprolactone Ring Opening Polymerization By Binary Catalysts Systems That Include Bis-Ligated Magnesium Complexes, Reile M. Slattery, Arnold L. Rheingold, Joseph M. Fritsch
Seaver College Research And Scholarly Achievement Symposium
A series of bis-ligated magnesium complexes supported by tridentate ketoiminates containing electron-donating and electron-withdrawing groups were prepared. The complexes were characterized with 1H, 13C, and 19F NMR, absorbance spectroscopy, and x-ray crystallography. The complexes were assessed for their ring opening polymerization activity with L-lactide (L-lac) and ϵ-caprolactone (eCL) in binary catalyst systems with 4-fluorophenol at 100 °C. The magnesium complexes supported by ketoiminates bearing electron-donating groups yielded greater percentage conversions from monomers to polymers than those containing electron-withdrawing groups for both L-lac and eCL. The magnesium complexes were more efficient at polymerizing L-lac than eCL, and …