United States Coast Guard Academy

About: United States Coast Guard Academy is a education organization based out in New London, Connecticut, United States. It is known for research contribution in the topics: Gas chromatography & Curriculum. The organization has 270 authors who have published 375 publications receiving 17109 citations. The organization is also known as: USCGA & Revenue Cutter Service School of Instruction.

An index of factorial simplicity

Abstract: An index of factorial simplicity, employing the quartimax transformational criteria of Carroll, Wrigley and Neuhaus, and Saunders, is developed. This index is both for each row separately and for a factor pattern matrix as a whole. The index varies between zero and one. The problem of calibrating the index is discussed.

Bounded error adaptive control

Abstract: Identification and control when plant output is corrupted with disturbance and when plant parameters vary with time are considered. It is shown how the error model can be described by a non-homogeneous differential equation. Subject to bounded disturbance and parameter variation and sufficiently rich input the parameter error vector remains bounded and explicit bounds are derived. For inputs that are not sufficiently rich some sufficient conditions for stability and some examples of instability are given. Finally, a non-linear adaptation algorithm is presented for the control problem that insures the boundedness of the parameter error vector and all signals in the system.

Resolving the unresolved complex mixture in petroleum-contaminated sediments.

Abstract: Comprehensive two-dimensional gas chromatography (GC x GC) was used to investigate the chemical composition of the unresolved complex mixture (UCM) of hydrocarbons in petroleum-contaminated marine sediments. The UCM hydrocarbons were extracted and separated with silica and silver-impregnated silica gel chromatography to yield four fractions (branched alkanes and cycloalkanes, monoaromatics, naphthalenes, and multi-ring PAHs) prior to GC x GC analysis. GC x GC separations used a poly-(dimethylsiloxane) stationary phase for volatility selectivity on the first dimension and a 14% cyanopropylphenyl polysiloxane phase for polarity selectivity on the second dimension to fully resolve monoaromatic, naphthalene, and multi-ring PAH compounds from the UCM. A chiral gamma-cyclodextrin phase was used for shape selectivity on the second GC x GC dimension to resolve individual branched alkanes and cycloalkanes in the saturates fraction of the UCM. The ability of GC x GC to resolve thousands of individual chemical components from the UCM will facilitate an understanding of the sources, weathering, and toxicity of UCM hydrocarbons.

The West Falmouth oil spill after thirty years: the persistence of petroleum hydrocarbons in marsh sediments.

Abstract: The long-term fate of petroleum hydrocarbons in marsh sediments (West Falmouth, MA) contaminated in 1969 by the spill of the barge Florida was investigated. A 36-cm-long sediment core was collected in August 2000, and sediment extracts were analyzed by gas chromatography (GC) and comprehensive two-dimensional gas chroma tography (GC×GC). The latter technique is capable of separating 1 order of magnitude more compounds than the former and was used to observe whether any compositional changes in the unresolved complex mixture (UCM) occurred. No evidence of petroleum residues was detected in the top 6 cm (0−6 cm) and the lower 8 cm (28−36 cm) of the core. However, the central sections (6−28 cm) were dominated by a UCM in the boiling range of n-C13−n-C25 alkanes, consistent with a No. 2 fuel oil source. The 12−14- and 14−16-cm sections had the highest concentrations of UCM (∼8 mg g-1). These values are similar to concentrations observed shortly after the spill. Initial GC×GC analysis revealed that only the n-...