Utility Acid Precipitation Study

In order to determine the importance of chemical changes introduced by the longer sampling period, a collocated sampling study was implemented from October 1983 to October 1984 at three sites of the Utility Acid Precipitation Study Program (UAPSP) network. The sites were selected to represent the southeastern, central (west of the Mississippi River) and northeastern regions of the United States. 

Precipitation Study Program (UA""SP). UAPSP 104" Utility Acid Precipitation Study Program ashington, D.C., 1983. 

Topol, L.E. "Plan for Controlling the Quality of Measurements and Data Base in the Utility Acid Precipitation Study Program (UAPSP)" Environmental Monitoring Services, Inc., January 1982. 

Other workers (115-124 for example) have also centered their efforts on the role of phytic acid on zinc and iron bioavailabiliy from both soy and wheat products. It has been suggested (120) that the phytate-to-zinc molar ratio could be used to predict zinc bioavailability in high-phytate foods. Several groups (115, 117), including ours (113), 1 least partially supporT this hypothesis. However, recent work from our laboratory (112) involving soy protein of similar phytate-to-zinc molar ratios clearly demonstrates that zinc bioavailability is also altered by food processing. In this study, zinc from neutralized soy concentrates and isolates was shown to be less available to the rat than was the corresponding acid-precipitated products. This is unfortunate as alkaline conditions are commonly utilized for soy and other plant proteins to obtain beneficial functional properties. 

Monomers Polymerizable by Plasma Initiation. Polymerization data for all of the vinyl monomers utilized in this study are summarized in Table 1. As shown previously, methyl methacrylate is readily polymerizable (, ). Methacrylic acid (MAA) and acrylic acid (AA) are polymerized immediately upon exposure to the plasma. Because the resulting polymers are insoluble in their monomers, the products are precipitated out and conversion is low despite prolonged post-polymerization. However, if water is now added as solvent, polymerization becomes homogeneous and high conversions can be readily achieved with post-polymerization. For example, after a 15 second plasma initiation period more than 80% yield was obtained for a 75% aqueous solution of MAA. The molecular weight, determined by intrinsic viscosity measurements, was found to be 4.5 X 10 gm/mole. 

Human serum a-L-fucosidase has been purified 240 000 fold with 35 % yield by an affinity chromatographic procedure utilizing agarose-immobilized 2-amino-2-deoxy-L-fucose. Isoelectric focusing of the purified enzyme indicated the presence of several forms (major form p/ 5.0). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of the enzyme (mol. wt. 2.96 0.30 X 10 by gel filtration) indicated that the presence of two subunits with similar molecular weights (5.65 x 10 and 5.40 x 10 ). Using the 4-nitro-phenyl substrate (Xm value 0.52 mM) the enzyme displayed a broad pH optimum centred round pH 4.8 with a second minor optimum at pH 6.1. The enzyme was shown to contain 1.7% neuraminic acid quantitative immuno-precipitation studies were also conducted on the enzyme. 

Amic acids (AA) were prepared by two different methods. Stirring appropriate mixtures of amine and anhydride overnight in NMP yielded solutions of the desired amic acid suitable for F-NMR studies, hi order to discern a crude isomer composition, -C-NMR was performed on compounds prepared by a literature procedure utilizing chloroform as a solvent." This technique gave very high yields of very high-purity monoamic acid as the materials precipitated from the reaction mixture. 

Salem et al. [48] reported simple and accurate methods for the quantitative determination of flufenamic, mefenamic and tranexamic acids utilizing precipitation reactions with cobalt, cadmium and manganese. The acidic drugs were precipitated from their neutral alcoholic solutions with cobalt sulfate, cadmium nitrate or manganese chloride standard solutions followed by direct determination of the ions in the precipitate or indirect determination of the ions in the filtrate by atomic absorption spectroscopy (AAS). The optimum conditions for precipitation were carefully studied. The molar ratio of the reactants was ascertained. Statistical analysis of the results compared to the results of the official methods revealed equal precision and accuracy. The suggested procedures were applied for determining flufenamic, mefenamic and... 

Recent studies at the Iron Mountain acid mine-drainage site in California suggest that the main role of A. ferrooxidans is to oxidize iron downstream from the principal acid-generating site, and that the primary effect is to enhance the precipitation of iron oxyhydroxides (Banfield and Welch, 2000). Other iron-oxidizing bacteria (e.g., L. ferrooxidans) and archeal (e.g., Thermoplasmales) species have been observed proximal to the sulfide ore (Edwards et al., 2000). The utilization of energy derived from iron or sulfur oxidation in other prokaryotes remains unclear, but it can be surmised that the mechanism involved could be broadly similar to that determined for A. ferrooxidans (Banfield and Welch, 2000). 

The polymerization of vinyl monomers in liquid and supercritical CO2 has been studied extensively. Patents were issued in 1968 to the Sumitomo Chemical Company [81] and in 1970 to Fukui et al. [82] for the preparation of homopolymers of polystyrene, poly(vinyl chloride), poly(acrylonitrile) (PAN), poly-(acrylic acid) (PAA), and poly(vinyl acetate) (PVAc), as well as the random copolymers PS-co-PMMA and PVC-co-PVAc. Additionally, a patent was issued in 1995 to Bayer AG [83] for the preparation of styrene/acrylonitrile copolymers in SCCO2. In 1986, the BASF Corporation was issued a Canadian patent for the precipitation polymerization of 2-hydroxyethylacrylate and various N-vinylcarboxamides in compressed carbon dioxide [84]. In 1988, Terry et al. attempted to homopolymerize ethylene, 1-octene, and 1-decene in SCCO2 for the purpose of increasing the viscosity of CO2 for enhanced oil recovery [85]. These reactions utilized free-radical initiation with benzoyl peroxide and r-butylperoctoate at 71 °C and 100-130 bar for 24-48 h. Although the resulting polymers were not well characterized, they were found to be relatively... 

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