Scott Ramos - Academia.edu (original) (raw)

2000's Publications by Scott Ramos

Aapg Bulletin, 2007

2007.03

Papers by Scott Ramos

AAPG Bulletin, 2013

Chemometric analyses of geochemical data for 165 crude oil samples from the San Joaquin Basin ide... more Chemometric analyses of geochemical data for 165 crude oil samples from the San Joaquin Basin identify genetically distinct oil families and their inferred source rocks and provide insight into migration pathways, reservoir compartments, and filling histories. In the first part of the study, 17 source-related biomarker and stable carbon-isotope ratios were evaluated using a chemometric decision tree (CDT) to identify families. In the second part, ascendant hierarchical clustering was applied to terpane mass chromatograms for the samples to compare with the CDT results. The results from the two methods are remarkably similar despite differing data input and assumptions. Recognized source rocks for the oil families include the (1) Eocene Kreyenhagen Formation, (2) Eocene Tumey Formation, (3-4) upper and lower parts of the Miocene Monterey Formation (Buttonwillow depocenter), and (5-6) upper and lower parts of the Miocene Monterey Formation (Tejon depocenter). Ascendant hierarchical clustering identifies 22 oil families in the basin as corroborated by independent data, such as carbon-isotope ratios, sample location, reservoir unit, and thermal maturity maps from a three-dimensional basin and petroleum system model. Five families originated from the Eocene Kreyenhagen Formation source rock, and three families came from the overlying Eocene Tumey Formation. Fourteen families migrated from the upper and lower parts of the Miocene Monterey Formation source rocks within the Buttonwillow and Tejon depocenters north and south of the Bakersfield arch. The Eocene and Miocene families show little cross-stratigraphic migration because of seals within and between the source rocks.

Regression transfer of calibration (TOC) problems are well-studied. Similar difficulties may aris... more Regression transfer of calibration (TOC) problems are well-studied. Similar difficulties may arise when a multivariate classification model is created with independent variable data from one instrument and applied to data collected on another instrument. Between- instrument differences (e.g., in mass spectral tuning or wavelength registration) can sig- nificantly reduce model reliability. Details of TOC for classification models are dis- cussed.

Journal of Natural Products, 1984

Alpinia speciosa (Wendl.) Schum. is cultivated around the cities of Manaus and BelCm in the Amazo... more Alpinia speciosa (Wendl.) Schum. is cultivated around the cities of Manaus and BelCm in the Amazon, but it is a foreign plant brought from the Eastern Hemisphere. It is used in the Amazon as acardiovascular agent and hypotonic (1). Rengalmiafiribunda K. Sch. grows wild in the state of Amazonas, Brazil. Both

Analytical Chemistry, 1986

Analytical procedures including materials, water, sewage sludge, biota, sediment, extract filtrat... more Analytical procedures including materials, water, sewage sludge, biota, sediment, extract filtration and preliminary clean up, liquid chromatography, gas chromatography (GC) and mass spectrometry (MS) are reported. More than 250 samples of the New York Bight were analyzed. Selected samples, representing 10 substrates, were intensively analyzed by GC/MS for whatever additional compounds could be identified. Results are tabulated.

Fuel

Abstract Ultrafast gas chromatography (UFGC) along with supervised and unsupervised chemometric m... more Abstract Ultrafast gas chromatography (UFGC) along with supervised and unsupervised chemometric methods were utilized for evaluation of biodiesel-diesel blended fuels. A variety of biodiesel feedstocks (soybean, tallow, canola, safflower, sunflower, camelina, flaxseed, etc.) and concentrations (1–20%) were evaluated. The method, which uses a short nonpolar column, falls within ASTM D7798 requirements for diesel and extends the method to include biodiesel-diesel blended fuels. Using Principal Components Analysis (PCA), samples clustered based on concentration and diesel type, and differences in plant and animal feedstocks were apparent. Biodiesel concentration was accurately assessed using Partial Least Squares (PLS) on a training set for B0–B20, while predictions were made with some success on a set of commercial and lab unknowns. k Nearest Neighbors (kNN) was used to describe and predict concentration, plant versus animal feedstock, and to identify biodiesel blends. The combination of chemometric methods alongside UFGC proves an effective and fast technique for the analysis of biodiesel source and composition in biodiesel-diesel blended fuels.

Acta Amazonica

RESUMODuas variedades químicas de Hyptis mutabilis foram estudadas. Uma delas, a variedade A, con... more RESUMODuas variedades químicas de Hyptis mutabilis foram estudadas. Uma delas, a variedade A, contém α e β-pineno, α e β-feladreno e β-cariofileno como os principais constituintes de seu óleo essencial. A outra variedade B, apresentou α-cimeno , 1,8-cineol, timol, β-cariofileno e β-elemeno como os seus principais componentes.

AAPG Bulletin, 2016

The prolific Los Angeles basin in California may be the most petroliferous province on Earth per ... more The prolific Los Angeles basin in California may be the most petroliferous province on Earth per volume of sedimentary fill. However, because most exploration in the basin occurred prior to the advent of modern geochemical methods, genetic relationships among the various petroleum accumulations and their source rocks have remained speculative. A training set of 24 source-related biomarker and stable carbon isotope ratios for 111 non-or mildly biodegraded oil samples from the basin was used to construct a chemometric (multivariate statistics) decision tree. The decision tree allows genetic classification of additional oil or source-rock extract samples that might be collected. The decision tree identifies 6 tribes and a total of 12 genetically distinct oil families. The families have different bulk properties, such as API gravity and sulfur content, which were previously explained as resulting from secondary processes, including thermal maturity or biodegradation. However, the chemometric assignments are based on genetic properties that reflect distinct organofacies. The oil families occur in different locations and reservoir intervals in the basin, consistent with their origins from different organofacies of active source rock. The source-rock depositional environment for each oil family can be inferred using biomarker and isotope ratios. The samples show stable carbon isotope ratios for saturate and aromatic hydrocarbons that indicate different organofacies of Miocene marine source rocks. Tribes 1 and 2 straddle the central trough, mainly occur east of the Newport-Inglewood fault zone (NIFZ), and show evidence of proximal, clay-rich source rock deposited under suboxic conditions with elevated angiosperm input. Tribes 3-6 occur west of the NIFZ and show evidence of more distal, clay-poor source rock deposited under anoxic conditions.

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ABSTRACT

The 37 raw FIDs were processed using the macro and batch processing functions of ProcessIt TM NMR... more The 37 raw FIDs were processed using the macro and batch processing functions of ProcessIt TM NMR and MineIt TM modules in the KnowItAll system. The macro contains commands for correction of DC offset, zero-filling, Lorentzian apodization, Fourier Transform, automatic phase correction, baseline correction, and reference setting. The processed spectra were automatically imported into a database, and the sample properties were manually added. The spectra were inspected and manually adjusted when necessary.

Journal of Clinical Microbiology

Current methods for identifying mycobacteria by high-performance liquid chromatography (HPLC) req... more Current methods for identifying mycobacteria by high-performance liquid chromatography (HPLC) require a visual assessment of the generated chromatographic data, which often involves time-consuming hand calculations and the use of flow charts. Our laboratory has developed a personal computer-based file containing patterns of mycolic acids detected in 45 species of Mycobacterium, including both slowly and rapidly growing species, as well as Tsukamurella paurometabolum and members of the genera Corynebacterium, Nocardia, Rhodococcus, and Gordona. The library was designed to be used in conjunction with a commercially available pattern recognition software package, Pirouette (Infometrix, Seattle, Wash.). Pirouette uses the K-nearest neighbor algorithm, a similarity-based classification method, to categorize unknown samples on the basis of their multivariate proximities to samples of a preassigned category. Multivariate proximity is calculated from peak height data, while peak heights are named by retention time matching. The system was tested for accuracy by using 24 species of Mycobacterium. Of the 1,333 strains evaluated, .97% were correctly identified. Identification of M. tuberculosis (n = 649) was 99.85% accurate, and identification of the M. avium complex (n = 211) was .98% accurate; .95% of strains of both double-cluster and single-cluster M. gordonae (n = 47) were correctly identified. This system provides a rapid, highly reliable assessment of HPLC-generated chromatographic data for the identification of mycobacteria.

Retention time alignment is often required to improve the precision of gas chromatographic data. ... more Retention time alignment is often required to improve the precision of gas chromatographic data. Metrics for evaluating alignment performance include the correlation coefficient and the correlation coefficient with the Wallis Filter [J. Chromatogr. A, 1998, 805, 17-35]. Filtering the data before evaluating the correlation coefficient removes much of the chemical differences and improves the relationship between retention time uncertainty (peak shifting) and the correlation coefficient. The metric only requires inputs for the target and the sample to be aligned to the target. Therefore, this metric can be used to optimize parameters for on-line analysis. Targets and alignment parameters are optimized in real-time using the optimized metrics. Improvements to metric and target selection and parameter optimization are shown to improve classification with Principal Component Analysis (PCA) and a windowed version of PCA, Windowed Factor Analysis (WFA) [Anal. Chim. Acta, 2007, 584, 370-378...

Journal of clinical microbiology, 1996

Mycobacterium genavense, a fastidious opportunist in patients with AIDS, cannot be identified by ... more Mycobacterium genavense, a fastidious opportunist in patients with AIDS, cannot be identified by conventional biochemical methods. Computerized mycolic acid analysis by high-performance liquid chromatography offers an alternative that distinguishes the mycolic acid profile of M. genavense from those of all other organisms in the database developed at the Centers for Disease Control and Prevention.

Journal of clinical microbiology, 1994

American biotechnology laboratory, 1992

Mycobacteria include a number of respiratory and non-respiratory pathogens for humans, such as M.... more Mycobacteria include a number of respiratory and non-respiratory pathogens for humans, such as M. tuberculosis, the causative agent of the disease for which it is named. Identification of the responsible bacterium is, therefore, a critical first step in public health regulation or medical treatment.

The Circum-Arctic is one of the last major frontiers in petroleum exploration. As part of the Wor... more The Circum-Arctic is one of the last major frontiers in petroleum exploration. As part of the World Energy Consortium organized by the U.S. Geological Survey, source-and age-related biomarker and isotopic data were measured for more than 1000 crude oil and seep samples collected above 55 degrees N latitude. A unique, multi-tiered decision tree consisting of many chemometric (multivariate statistical) models created using Pirouette (super R) allowed detailed classification of genetically related oil groups. The results show that our new chemometric approach is more versatile than conventional methods for oil-oil and oil-source rock correlation. Using 622 'training set' samples, an automated protocol was created using InStep (super TM) to classify newly acquired samples of crude oils, seeps, and source-rock extracts, and assign corresponding confidence limits. The geochemical data were also used to infer the age, lithology, organic matter input, and depositional environment of the source rock for each oil sample. Twenty-one oil groups were identified, mapped, and linked to their source rocks; examples include Upper Jurassic distal marine shale (West Siberia), Lower-Middle Jurassic paralic-deltaic marine shale (West Siberia), Triassic marine marl (North Slope), Devonian fluvial lacustrine shale (Scotland), Devonian marine carbonate (Western Canada Basin), and Precambrian marine marl (East Siberia). To better assess the original and present-day distributions of each petroleum system, paleo-latitudes and paleo-longitudes of the samples were reconstructed using PointTracker and located on paleogeographic maps using Earth System History-GIS (PALEOMAP Project, C. Scotese). These paleomaps can be used to predict the physiochemical properties of discoveries within the mapped areal extent of each petroleum system, including sulfur content, API gravity, and gas-to-oil ratio.