A5011384486- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Hydrocarbon exploration and reservoir analysis
- Isotope Analysis in Ecology
- Atmospheric and Environmental Gas Dynamics
- Marine and coastal ecosystems
- Marine and environmental studies
- Geological Studies and Exploration
- Marine Biology and Ecology Research
- Metabolomics and Mass Spectrometry Studies
- Mass Spectrometry Techniques and Applications
- Oceanographic and Atmospheric Processes
- Radioactive contamination and transfer
- Offshore Engineering and Technologies
- Coal Combustion and Slurry Processing
- Toxic Organic Pollutants Impact
- Identification and Quantification in Food
- Climate variability and models
- Marine and Offshore Engineering Studies
- Proteoglycans and glycosaminoglycans research
- Groundwater and Isotope Geochemistry
- Metabolism and Genetic Disorders
- Chemical and Physical Properties in Aqueous Solutions
- Analytical Chemistry and Chromatography
- Geological Modeling and Analysis
International Isotopes (United States)
2001-2024
Pfizer (United States)
2000
University of Hawaiʻi at Mānoa
1997
Indiana University Bloomington
1989-1994
Woods Hole Oceanographic Institution
1984-1993
Massachusetts Institute of Technology
1988
The carbon isotopic fractionation accompanying formation of biomass by alkenone‐producing algae in natural marine environments varies systematically with the concentration dissolved phosphate. Specifically, if is expressed є P ≈ δ e − p , where and are 13 C values for CO 2 algal (determined analysis 37 alkadienones), respectively, μmol kg −1 then b = 38 + 160*[PO 4 ], [PO ] phosphate, μM, (25 ) . correlation found between due to effects linking nutrient levels growth rates cellular budgets...
The geological record encodes the relationship between climate and atmospheric carbon dioxide (CO 2 ) over long short timescales, as well potential drivers of evolutionary transitions. However, reconstructing CO beyond direct measurements requires use paleoproxies herein lies challenge, proxies differ in their assumptions, degree understanding, even reconstructed values. In this study, we critically evaluated, categorized, integrated available to create a high-fidelity transparently...
Carbon isotopically based estimates of CO 2 levels have been generated from a record the photosynthetic fractionation 13 C (≡ ε p ) in central equatorial Pacific sediment core that spans last ∼255 ka. Contents phytoplanktonic biomass were determined by analysis 37 alkadienones. These compounds are exclusive products Prymnesiophyte algae which at present grow most abundantly depths 70–90 m Pacific. A isotopic compostion dissolved was constructed analyses planktonic foraminifera...
The sedimentary record of a ratio (UK37) long chain (C 37 ) unsaturated alkenones is useful indicator glacial‐interglacial climatic change in the Late Quaternary northern Gulf Mexico where planktonic foraminiferal δ 18 O‐CaCO 3 complicated by meltwater and/or fluvial events (Williams and Kohl, 1986). Application laboratory temperature calibration UK37 (Prahl Wakeham, 1987) to Pigmy Basin hydraulic piston core (Deep Sea Drilling Project 619) suggested that minimum glacial surface mixed layer...
At least three methods of calculating the random errors or variance molecular isotopic data are presently in use. The major components differentiated and quantified here into to four individual components. measurement error analyte relative a working (whether an internal external) standard is via statistical pooled estimate error. A method for total associated with difference two compositions from isotope laboratories given, including variances laboratory (secondary) standards, as well those...
Molecular carbon isotopic ( 13 C/ 12 C) ratios of a selected marine organic biomarker compound (a C 37 alkadienone) from the Pigmy Basin (Deep Sea Drilling Program Hole 619) in northern Gulf Mexico varied by 5.3‰ sychrony with last ∼100 ka glacial‐interglacial cycle. This (δ variation is likely due to effect climatically linked variations concentrations CO 2 (aq) on photosynthetic fractionation isotopes phytoplankton. Measurement δ alkadienone 37:2 ) reconstruct composition total permits...
Process patent protection via the analysis of natural-abundance stable isotopes has been demonstrated as an approach to extend effective life bio/pharmaceutical patents. The high specificity isotope ratio compared other approaches (for example, concentrations organic impurities or trace metals) allows isotopic differentiate processes that were not previously resolvable by less precise analytical methods. Here we summarize rationale for, and some selected case studies of, this emerging field....
Techniques for the gas and liquid chromatographic separation of complex mixtures triglycerides have evolved over past two decades, as reviewed in detail by Huang et al. (J. Agric. Food Chem. 1995, 43, 1834-1844; J. 1997, 45, 1770-1778). A novel method quantitative partitioning into functionally related groups is developed applied to a low-calorie triglyceride mixture [namely, Benefat S or Salatrim plus mid-chain (C(6,8,10,12)) fatty acids]. The based on nonlinear calibration retention times...
Molecular Isotopic Engineering (MIE) is the directed stable-isotopic synthesis of chemical products for reasons product identification and security, also intellectual property considerations. We report here a generally excellent correspondence between observed predicted stable carbon-isotopic (δ<sup>13</sup>C) results successful racemic mixture from its immediate precursors. The are readily explained by laws mass balance isotope balance. Oxygen- hydrogen isotopic which require an...