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Full-Text Articles in Physical Sciences and Mathematics
A Study Of The Chlorination Products Of Methionine In Model Solutions And In Wastewater, D. Scott Winters
A Study Of The Chlorination Products Of Methionine In Model Solutions And In Wastewater, D. Scott Winters
Chemistry & Biochemistry Theses & Dissertations
Model solutions of the amino acid methionine were chlorinated to seven chlorine-to-nitrogen (Cl2/N) molar ratios. After 30 minutes, the solutions were analyzed by high performance liquid chromatography (HPLC). At a Cl2/N molar ratio of 1, methionine sulfoxide was found to be the main product. At Cl2/N molar ratios ≥ 2, a mixture of methionine sulfoxide, methionine sulfone, an unidentified sulfoxide (product 1), and N-chloro-3-(methylsulfonyl) propionaldimine are formed. These products were identified by comparison to synthesized standards which were characterized by 1H-NMR and 13C-NMR nuclear magnetic resonance spectroscopy, ion trap mass spectroscopy, …
Chlorination Products Of Glycylphenylalanine In Model Solutions And A Wastewater, Daniel J. Keefe
Chlorination Products Of Glycylphenylalanine In Model Solutions And A Wastewater, Daniel J. Keefe
Chemistry & Biochemistry Theses & Dissertations
Model solutions of the dipeptide glycylphenylalanine were chlorinated to five different chlorine-to-amino nitrogen (Cl/N) mole ratios and analyzed after 30 min by high performance liquid chromatography. At mole ratios of ≤ 1, N-chloroglycylphenylalanine (I) appeared to be the only major product. At a mole ratio ≤ 2, N, N-dichloroglycylphenylalanine (II) was the only product. Compound II decomposes in model solutions (t1/2= 6.4 hr) at pH 7.0 to form a compound tentatively identified as an H-chloroaldimine (III). Compound III in turn decomposes (t1/2= 36 hr) in model solutions at pH 7. o to (IV) . From 13 …
Changes In The Sea-Ice Brine Community During The Spring-Summer Transition, Mcmurdo Sound, Antarctica .2. Phagotrophic Protists, Diane K. Stoecker, Kurt R. Buck, Mary Putt
Changes In The Sea-Ice Brine Community During The Spring-Summer Transition, Mcmurdo Sound, Antarctica .2. Phagotrophic Protists, Diane K. Stoecker, Kurt R. Buck, Mary Putt
OES Faculty Publications
The land-fast sea-ice brine contains a diverse phagotrophic protist assemblage consisting of < 5 mum heterotrophic flagellates, Cryothecomonas spp., heterotrophic dinoflagellates, and heterotrophic and mixotrophic ciliates. Fine-scale horizontal spatial variability is a feature of this assemblage; samples taken within 1 m of each other can be dominated by different heterotrophic protists. Many of the larger heterotrophic protists found in the brine are also found in the water column. The photosynthetic ciliate Mesodinium rubrum is also common. In mid to late austral spring, the heterotrophic assemblage accounts for ca 10% of the total protist biomass in the brine and is dominated by Cryothecomonas spp. This flagellate …
Benthic Microalgal Production At Stellwagen Bank, Massachusetts Bay, Usa, Lawrence B. Cahoon, Guy R. Beretich Jr., Carrie J. Thomas, Amy M. Mcdonald
Benthic Microalgal Production At Stellwagen Bank, Massachusetts Bay, Usa, Lawrence B. Cahoon, Guy R. Beretich Jr., Carrie J. Thomas, Amy M. Mcdonald
OES Faculty Publications
Benthic microalgal chlorophyll a and production were measured at 3 sites at Stellwagen Bank, a cold temperate continental shelf habitat in Massachusetts Bay, USA, during August 1991. Benthic microalgal chlorophyll a averaged 39.8 Mg M-2, vs average integrated phytoplankton chlorophyll a of 25.9 mg m-2. Gross benthic microalgal production, measured by oxygen exchange in clear and opaque benthic chambers, averaged 20.9 mg C m-2 h-1. This production was supported by average daily light fluxes to the bottom that never exceeded 1 % of surface incident radiation and were as low as 4.7 μE …