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1
Jernigan, Jonathan. "Mathematical Modeling of Convective Heat Transfer in Mammoth Cave." TopSCHOLAR®, 1997. http://digitalcommons.wku.edu/theses/787.
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Around two centuries ago, changes were made to the entrances of Mammoth Cave and its passages. Today the Historic Entrance to Mammoth Cave is enlarged and the passage just beyond the entrance known as Houchins' Narrows has been cleared of rubble and filled with sediments. These enlargements have resulted in an increase in airflow throughout the Historic Section of the cave causing environmental conditions such as air temperature and airflow to fluctuate. These fluctuations have negatively impacted inhabitants and contents of the cave system. To restore natural conditions within the cave, Science and Resource Management personnel at Mammoth Cave National Park have been collecting large data sets on atmospheric conditions inside the cave. The author has access to data from eight sites within the cave. In this thesis, the author provides a brief introduction to the effects of the increase in airflow as well as a short discussion of the data gathered by Science and Resource Management. The author then proposes a natural cause for airflow (i.e., convection) in Mammoth Cave, constructs empirical models with this as the underlying driving force, and uses atmospheric data to verify the validity of the claim of convection as the force driving airflow in Mammoth Cave. Data from the site in Houchins' Narrows is used to predict atmospheric data at other locations in the cave. The author concludes this thesis with time series analysis on data from Houchins' Narrows.
2
Subedi, Suresh Chandra. "A Functional Trait Approach to Examine Plant Community Dynamics in South Florida Hardwood Hammock Forests." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3373.
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The tropical hardwood forests of south Florida persist as well-drained patches of broadleaf forest separated by brackish water swamp, marsh, or pineland. In this dissertation, a functional trait approach was used to understand the structure and dynamics of these communities and their responses to abiotic and biotic variation. Twenty-seven permanent plots (20 x 20 m2) were established across the south Florida landscape, representing four sub-regions: Everglades marsh, Long Pine Key, Upper Keys, and Lower Keys. Community weighted mean trait values for four of six selected traits showed significant inter-sub-regional variation. Out of them, three traits (specific leaf area, tree height, and leaf phosphorus) increased significantly from dry and low productivity Florida Keys in the south to the moist and productive areas on the south Florida mainland, while wood density showed the opposite pattern. Trait variance ratios (T-statistic metrics) was used to explore internal filtering (processes that operate within a community) and external filtering (processes that operate at larger scale than that of the individual population or community) on community structure. Both external and internal filtering in the functional composition of south Florida hardwood hammock forest were important for local communities differing in freshwater accessibility, or that occupy different positions along strong edaphic or climatic gradients.
To understand the underlying mechanisms that drive species assembly during forest succession in Florida dry sub-tropical forest, 13 leaf, stem, reproductive, and architectural traits of resident tree species across the successional gradient were measured. Tests of null models showed that younger communities are shaped by environmentally driven processes, while mature communities are shaped by competitively driven processes. The overall trait similarities among species present in North Key Largo tropical dry forest suggest that tree species are specialists on the local environment, and their ability to survive and grow in a stressful environment may be more important than competition for resources at larger scale. Moreover, tree species in these forests may exhibit specialization or trait plasticity in coping with drought by changes in their stomatal morphology or activity, allowing for a balance between gas exchange and water loss in a periodically stressful environment. A significant negative correlation between stomatal density and size, and a positive correlation between leaf δ13C and stomatal density were observed across habitat gradient for one of the dominant hardwood hammock species (Bursera simaruba). Small and densely distributed stomates in tandem seems to represent a strategy that allows hammock species to conserve water under physiological drought. Furthermore, findings from this work also showed both intra- and inter-specific trait variation at regional and local scales influence community assembly patterns in hardwood hammock communities in South Florida.
3
Gao, Zimin. "Phase Relationships in the System CaO-MgO-Al2O3-SiO2 in Plagioclase Lherzolite Field." FIU Digital Commons, 1991. http://digitalcommons.fiu.edu/etd/3615.
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Unreversed phase equilibrium studies were carried out in a model mantle composition CaO-MgO-Al2O3-SiO2 (CMAS) system at 5-9 kb and 12 7 0-13 3 CPC. The experiments provide a set of data which narrowly constraints the position of the solidus in the system CMAS in the plagioclase lherzolite field. All runs were conducted in a 2.54 cm core-diameter piston-cylinder apparatus with salt-cell pressure medium. The equilibrium compositions of the mineral phases and glass were analyzed with an electron microprobe. The A12O3 contents in orthopyroxene and clinopyroxene coexisting with olivine and plagioclase increase with pressure. The deduced alumina isopleths in orthopyroxene and clinopyroxene have higher slope in P-T space than those of theoretical calculations. An empirical pyroxene geobarometer has been developed and applied to the plagioclase lherzolite xenoliths in Hawaiian basalt.
4
Robison, Robert M. "The Surficial Geology and Neotectonics of Hansel Valley, Box Elder County, Utah." DigitalCommons@USU, 1986. https://digitalcommons.usu.edu/etd/4865.
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Hansel Valley, located at the north end of the Great Salt Lake in Box Elder County, Utah, has exposures of the lacustrine sediments of the Little Valley, Bonneville, and Gilbert lake cycles. A 1:50,000 scale map was constructed of the surface geology. Although no trenches were dug for this study, about 240m of logs were compiled in an arroyo in lake bottom sediments. Sediments from at least three lake cycles were found in this gully: 1) compact bottom deposits from the Little Valley cycle; 2) bottom sediments from an intermediate cycle (the Hansel Valley cycle); and 3) beach gravel and bottom sediments from the Bonneville cycle. Evidence gathered indicates that a previously undescribed lake, the Hansel Val ley cycle, which reached a maximum elevation of about 1342 m (4400 feet). Thermoluminescence (TL) dating, supplemented by ostracode identification and stratigraphic position, dates the Hansel Valley cycle at about 80 ka (late Oxygen Isotope Stage 5).
Hansel Valley is seismically very active and the site of the largest and only historic earthquake to rupture the ground surface in Utah. Scarp heights up to 50 em were measured from the 1934 M6.6 event, which was contiguous with an older 6 km long scarp that crosses Lake Bonneville recessional shoreline s. Scarp heights range from 1.6 m to 9.0 m and control recessional shorelines (instead of simply displacing them). This morphologic evidence suggests that a portion of the scarp was formed underwater, and that slumping occurred along the trace of the fault. The fault scarp intersects the gully mentioned above and reveals highly fractured sediments with 11 main faults within a 240 m zone. Movement on individual faults ranges from 0.1 to 2.5 m, with a net displacement of 1.3 m down to the east, which agrees with the offset measured on the scarp on both sides of the gully. Most faults offset Little Val ley, and transgressive Bonneville shoreline sediments, but are not continuous through intensely convoluted Bonneville lake bottom sand, silt and clay. Two units of Bonneville bottom sediments show convolutions, features and slump blocks. roll structures, liquefaction Fault scarps, liquefaction features, and subsurface faults indicate one pre-BonneviIIe, possibly two Bonneville, and one post-Bonneville-age large earthquakes.
5
Rasmusson, Eric A. "The Influence of Small Displacement Faults on Seal Integrity and Lateral Movement of Fluids." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4886.
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In the subsurface, faults can act as conduits for seal bypass or as lateral barriers to subsurface fluid flow. Recent reservoir modeling shows that the area where a reservoir-seal interface is in contact with a fault—the fault-interface corner—can be a site of high pore-fluid pressure that may cause seal failure. This can have negative implications for industries dependent on the quality of that seal, for example, petroleum, CO2 sequestration, waste fluid injection, and nuclear waste storage industries.
In order to better understand the fault-interface corner and improve models, we examined five mesoscale (cm- to m- scale) normal-slip faults that juxtapose medium cross-bedded sandstone (1-2 m thick beds) against red or green siltstone or mudstone (~1 m thick beds) in the San Rafael Swell, Utah. Outcrop observations, X-ray diffraction mineralogy, whole-rock geochemistry, petrography, fractured grain density, and porosity data were used to gain insight into past fluid compositions, cross-cutting relationships, and fault seal qualities in order to better define the fault-interface corner models and identify new fault elements previously not considered in the models.
Fault elements documented here include shale injection into faults, fault-bounded shale blocks, entrained sand blocks, and reactivated joints. Faults with shale injection have almost double the seal thickness and mineralization along the bottom slip surface of the injected shale bed. Step-over faults on either side of fault-bounded shale blocks replace overly simplified single plane faults in previous models. Geochemical alteration and mineralization includes calcite precipitation and clay development in several faults. These faults have varying spatial relationships with the zone of deformation bands. A fault with reactivated joints represents an endmember example of the fault-interface corner models with a large opening mode fracture allowing seal bypass.
6
VanDenburg, Colby J. "Cenozoic Tectonic and Paleogeographic Evolution of the Horse Prairie Half-graben, Southwest Montana." DigitalCommons@USU, 1997. https://digitalcommons.usu.edu/etd/4690.
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The Horse Prairie basin (HPB) of southwestern Montana is a complex, east dipping half-graben that contains three angular unconformity-bounded sequences of Tertiary lacustrine, paludal, and fluvial sediments overlying middle Eocene volcanic rocks. The basin is near the eastern edge of the Cordilleran thrust belt, and represents the western half of a larger Paleogene rift basin. Geologic mapping within the Everson Creek and Bannock Pass 7.5 minute quadrangles indicates that five temporally and geometrically distinct episodes of extension characterize the late Mesozoic (?) to Cenozoic tectonic evolution of the upper HPB.
The first episode of extension occurred prior to emplacement of middle Eocene volcanic rocks on an enigmatic, low-angle, southeast-dipping fault. Pre-volcanic extension (?) may reflect gravitational collapse of the Sevier thrust belt beginning in the lateMesozoic. The second episode of extension occurred in middle Eocene time on northwestdipping syn-volcanic normal faults. Syn-volcanic faults can be attributed to extension of the Challis volcanic arc, and typically accommodate less than I km of dip-slip separation. The third generation of normal faulting occurred on the low-angle, south-southwest- and west-dipping Lemhi Pass and Maiden Peak fault systems, respectively. Slip may have initiated during the waning phases of Challis volcanism, but these late to post-volcanic normal faults probably reflect continued gravitational collapse of the Sevier thrust belt, because they generally parallel contractional structures in the region. Late to post-volcanic normal faults accommodate the bulk of extensional strain in the study area, and are responsible for the deposition and preservation of the majority of basin-fill deposits in the HPB. Two episodes of middle Miocene and younger extension also occur within the study area; however, structural and basin analysis indicates the HPB experienced only minor extension in the last 17 m.y.
Spatial and temporal relationships between magmatism and extension suggest that large magnitude extension in the HPB (episodes I and 3) was not associated with magmatism, and that extension in this portion of the Basin and Range province initiated due to gravitational instabilities imparted on the crust during the Sevier orogeny.
7
Bailey, Elizabeth A. "Testing models of ultra-fast India-Asia convergence : new paleomagnetic results from Ladakh, Western Himalaya." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90648.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mathematics, 2014.Author received an S.B. from the Department of Mathematics, but her thesis was submitted to the Department of Earth, Atmospheric and Planetary Sciences for the degree of S.B. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 29-32).
Rapid India-Asia convergence has led to a major continental collision and formation of the Himalayas, the highest mountain range on Earth. Knowledge of the paleolatitude of the Kohistan-Ladakh Arc (KLA), an intermediate tectonic unit currently situated between the converging Indian and Eurasian continents in Western Himalaya, would constrain the tectonic history and dynamics of Himalayan orogenesis. We present new paleomagnetic data from the Khardung volcanic rocks of the Shyok-Nubra valley region of Ladakh, western Himalaya. Samples from all four sites (KP1-KP4) display high-temperature components indicating a roughly equatorial paleolatitude, with the average of site mean directions implying a paleolatitude of 5'N. We interpret results of a positive baked contact test at one site (KP3) to imply that the high-temperature components in the distal volcanic bedrock predate bedding tilt and dike formation. Previous studies of the Khardung unit (Bhutani 2009, Dunlap 2002) have measured 40Ar-39Ar and U-Pb dates of -52-67 Ma. Assuming these ages apply to our samples, our results support the two-stage collision model of Jagoutz and Royden (in prep), which indicates an approximately equatorial India-KLA collision at 50 Ma.
by Elizabeth A. Bailey.
S.B.
8
Carroll, Bryan P. "Paleolimnological investigation of recent sediments from Lake Monroe, Florida, USA." FIU Digital Commons, 2005. http://digitalcommons.fiu.edu/etd/2059.
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Sediments recovered in October 2003 from Lake Monroe, a hypereutrophic lake in central Florida, have been sub-sampled and analyzed for δ13C, δ15N, TC, TIC, TOC, and TN. A chronology of bulk sediment and nutrient accumulation was established by radiometric analyses (210Pb, 137Cs, and 14C), to aid in evaluating spatial and temporal patterns within the lake since development in the watershed began. A continuous 100- year sediment record from Lake Monroe shows significant changes in production, sedimentation, and nutrient abundance following land settlement in the mid 1800's. Sediment nutrient and isotopic analyses demonstrate an increasing trend in nutrients, δ-values, and sediment accumulation relative to pre-disturbance deposits. The sediment geochemical record suggests increased production, possible nutrient limitation, and shifts in primary producer communities through time. The data demonstrates that these historic increases are a direct result of watershed development, land use alterations, and increased nutrient loading within the basin.
9
Callahan, Joshua. "Erosion and Trail Building: A Case Study of the East Tennessee State University Trail System." Digital Commons @ East Tennessee State University, 2008. https://dc.etsu.edu/etd/1952.
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Natural and accelerated erosion from trail users affects the sustainability of trail systems. Designing and building sustainable trail systems will greatly decrease the effect that erosion has on a trail. Trails that allow multiple types of users, such as hiking and mountain biking, must be able to sustain both groups. At East Tennessee State University the trail system was originally designed for hiking. Mountain bikers have become the main user group on the trail system leading to erosion problems on certain areas of the trail due to trail design flaws. The study seeks to identify the problem areas of trail and make recommendations towards correcting the trail in order for the trail system to adequately sustain both hikers and mountain bikers on the East Tennessee State University trail system.
10
Gelnaw, William B. "On The Cranial Osteology of Eremiascincus and Its Use For Identification." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1294.
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A persistent problem for Australian paleontology has been a lack of diagnostic characters for identifying lizard fossils. Eremiascincus is one of the most widespread genera in Australia, so it was examined for distinguishing features and how it fits into a model of skink evolution. Skulls of Eremiascincus were examined within five separate contexts: 1) a description of the cranial osteology, 2) a qualitative comparison of individual cranial elements of Eremiascincus to closely related Ctenotus, 3) a description of the cranial allometry in Eremiascincus using linear morphometrics, 4) using cranial morphometrics of skinks to deduce their phylogeny, and 5) using geometric morphometrics to distinguish between individual elements of Eremiascincus and Ctenotus. Although linear morphometrics is adept at describing allometric changes to the skull during ontogeny, it only displayed a phylogenetic signal for small, closely related groups. Also, geometric morphometrics was just as capable distinguishing Eremiascincus from Ctenotus as qualitative characters.
11
Binda, Nkongho Collins. "Study of Metal Tolerance / Accumulation in Festuca arundinacea Schreb. From a Serpentine Site in North Carolina." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1448.
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The prevailing conditions in metalliferous soils are usually hostile for plant growth, but some plant species are still able to thrive in these substrates. Festuca arundinacea Schreb. plants were found to thrive on serpentine soils containing high concentrations of Cr and Ni. These plants contained higher concentrations of Ni in their roots than in their shoots. Hydroponic growth experiments with 350 µM and 650 µM Ni singularly and in combination revealed that more Cr was accumulated at the roots. The opposite was the case for Ni. The same experiments showed no difference between plants from serpentine and control soils in terms of growth and metal uptake. Ni was found to be toxic to control Festuca arundinacea plants at concentrations of at least 50 µM. The uptake of Ni in Festuca arundinacea was increased by an increase in the concentration of Ni and a decrease the pH of the substrate.
12
Ray, Darrell. "Patterns of Sulfur Deposition in the Wood of Pinus Echinatia Mill. from the Cumberland Plateau in Kentucky." TopSCHOLAR®, 1988. https://digitalcommons.wku.edu/theses/2749.
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Air pollution and acid precipitation have long had an influence on plant and animal life. In this study, the level of sulfur in the stem tissue of Pinus echinata Mill. was measured in trees from various sites along the western edge of the Cumberland Plateau to determine the presence and pattern of sulfur deposition in this species. Overall, a 40.28% increase in sulfur levels was observed from four sites along the plateau with levels increasing from 0.072 mgS/gdwt in the 1962-66 growth increment to 0.101 mg in the 1982-86 increment. According to a computer generated analysis of variance, the differences observed are a function of increasing levels through time and are less related to geographic differences. Significant differences were measured in the sulfur content of saplings and mature trees from the Rock Creek collection site; no changes were detected in the levels of carbon, hydrogen and nitrogen from Rock Creek between 1957-1962. A preliminary study of sulfur uptake in seedlings resulted in no conclusive results. While the effects of pollutants on plant health has been intensely studied, long term effects including pollutant influences on wood product quality are less well documented. The pattern of increased deposition seen in the current study indicates that more work is needed to understand all of the impacts and implications of sulfur deposition in important forest species such as Pinus echinata.
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Giesler, Amanda K. "A Systematic and Taphonomic Analysis of Late Pleistocene Cervid Remains and Isotopic Paleoecology of Herbivores from Guy Wilson Cave, Southern Appalachians, Tennessee." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1502.
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The paleoecology of Guy Wilson Cave is based on 1) systematic identification of cervid material, 2) taphonomic analysis of cervids with a focus on carnivore utilization, and 3) carbon isotopes from cervid and herbivore tooth enamel (δ13C). Systematic identification reveals that there are at least three cervid species in the cave fauna based on fossil remains: Odocoileus virginianus, Rangifer tarandus, and either Cervalces scotti or Alces alces. Separation of Cervalces and Alces based on the dental material was not possible. Taphonomic analysis of gnawing and tooth markings showed alterations by a canid predator, and the overall pattern suggests full-heavy utilization and possible scavenging activity by the dire wolf, Canis dirus. δ13C analysis of the herbivore community showed that taxa were feeding in a dominantly C3 environment, likely a relatively dense forest. Odocoileus showed no dietary shift from the late Pleistocene to today, also suggesting a forested environment in the past.
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Bredehoeft, Keila Elaine. "A Re-Evaluation of the Pleistocene Hellbender, Cryptobranchus guildayi, and an Overview of Cryptobranchus Remains from Appalachian Caves." Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etd/1701.
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Cryptobranchus guildayi is described as an extinct species of large salamander that is closely related to the hellbender, Cryptobranchus alleganiensis. The validity of this extinct taxon has been questioned, so an expanded osteological sample of modern hellbenders was used for comparative purposes with the C. guildayi fossil material. Based on this analysis, all supposed distinguishing morphological characteristics used to define C. guildayi can be observed in specimens of C. alleganiensis, or are based on misidentifications. Therefore, Cryptobranchus guildayi is considered to be conspecific with C. alleganiensis and taxonomically should be considered a junior synonym of the latter. The reassignment of the C. guildayi specimens to C. alleganiensis and examination of undescribed fossil specimens from the same region expands the prehistoric range of the species to the Potomac River and its tributaries and also extends the age of the species to the Irvingtonian North American land mammal age.
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Boardman, Grant Stanley. "Salamanders of the Mio-Pliocene Gray Fossil Site, Washington County, Tennessee." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1790.
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Screening efforts at the Gray Fossil Site, Washington County, Tennessee, have yielded a unique and diverse salamander fauna for the southern Appalachian Mio-Pliocene; including at least five taxa from three modern families (Ambystomatidae, Plethodontidae, and Salamandridae) supporting the woodland-pond interpretation of the site. All specimens represent the earliest record of their respective families in the Appalachian Mountains; with the Notophthalmus sp. vertebrae being the only Mio-Pliocene skeletal fossil known for the family Salamandridae in North America. Three types of plethodontid salamander are present, with one type representing the earliest known desmognathine. The desmognathine fossils lend credence to the 'Appalachian' origin of the clade in the Mio-Pliocene. The GFS salamander fauna is predominated by plethodontids; competition is inferred by the presence of several similarly large-sized taxa and is invoked to explain the presence of neotenic individuals in an otherwise amicable terrestrial environment.
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Carr, Megan. "Detection and Purification of a Novel Natural Inhibitory Compound from an Isolated Strain of Rhodococcus Using an Agar Extraction Method." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1479.
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The soil bacterium Rhodococcus has a wide array of secondary metabolic pathways such as production of pigments, siderophores, and antibiotics that makes it an organism of interest for the production of novel natural products. Analysis of the genome sequence of Rhodococcus indicates the presence of 24 non-ribosomal peptide synthases and 7 polyketide synthases possibly involved in production of secondary metabolites. The use of a solid agar extraction method to screen soil isolates of Rhodococcus for compounds with inhibitory activity against other bacteria resulted in the discovery of a promising candidate molecule. The Rhodococcus strain KCHXC3, isolated from eastern Tennessee soil, produces a substance that inhibits the growth of several Gram-negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia and Gram-positive bacteria such as Micrococcus luteus and, Staphylococcus aureus. After bulk extraction of this compound with ethyl acetate from agar plates, the material was partially purified through different chromatography processes.
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Baker, Scott Edward. "Power Distribution and Probabilistic Forecasting of Economic Loss and Fatalities due to Hurricanes, Earthquakes, Tornadoes, and Floods in the United States." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1462540615.
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Hawkins, Patrick Lawrence. "Variation in the Modified First Metatarsal of a Large Sample of Tapirus polkensis and the Functional Implications for Ceratomorphs." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1241.
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The Mio-Pliocene age Gray Fossil Site of northeastern Tennessee has the largest collection of tapir postcranial skeletons in the world. Though representing a single species, a few localized structures show high variability. This paper deals with variation of the first metatarsal, which in tapirs was reduced as an early adaptation for running and then retrofitted to serve as a special origin for flexors and adductors of the proximal phalanges. The first metatarsal connects the medial ankle with a posterior process of the third metatarsal in tapiroids. In Tapirus indicus, T. webbi, and 6 out of 31 T. polkensis feet at Gray, it extends more laterally to articulate with the fourth metatarsal. This condition is too variable for species distinction but is correlated with a decrease in the metatarsophalangeal joint facet, suggesting a mobility reduction likely related to the increased range and feeding strategy seen in extant T. indicus.
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Abernethy, Aaron Randall. "Extreme Variation in the Sagittal Crest of Tapirus polkensis (Mammalia Perissodactyla) at the Gray Fossil Site Northeastern TN." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1348.
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The preservation and quantity of fossil tapirs (Tapirus polkensis) from the Gray Fossil Site in northeastern Tennessee provides a unique opportunity for comparison and analysis of skeletal characters. Intraspecifically, modern tapirs show little to no variation in the morphology of the sagittal crest. However, several different morphologies exist within the sample at Gray. No osteological evidence of sexual dimorphism exists for tapirs, and no correlation between crest shape and sex was observed. Several juveniles display well defined crests, while some adults have only minor thickening of the temporal ridges; therefore, no distinct correlation between age and crest state could be established. Three different patterns of wear exist within the sample, but there is no correlation between these and crest morphology. No cranial pathologies were found to be associated with a crest type. Despite some correlations the sagittal crest could simply be a variable character due to intraspecific variation.
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Taylor, Andrew W. "Sedimentology, Facies Architecture, and Reservoir Characterization of Lacustrine Rocks, Eocene Green River and Colton Formations, Uinta Basin, Utah." DigitalCommons@USU, 2002. https://digitalcommons.usu.edu/etd/6780.
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Outcrop and petrographic studies of the Eocene Green River and Colton formations in the Uinta basin, Utah, document the facies architecture and heterogeneity characteristic of lacustrine reservoirs. A southwest-northeast transect of Eocene strata in the Uinta basin records three main marginal lacustrine depositional environments: fluvial, deltaic, and wave-dominated. Heterogeneity exists between and within individual depositional systems.
Reservoir rocks of Outcrops One and Two (the flu vial facies of the Colton Formation and the deltaic facies of the Green River Formation, respectively) consist of 2 to 18 m thick lenticular, tabular, or undulatory channel-fill, distributary channel, and distributary mouth bar deposits that are partially to entirely compartmentalized, or encased, by mudstone units. These reservoir analog intervals are dominated by large scale heterogeneity, in that sand bodies show a variety of connectivity and lateral continuity. Small-scale heterogeneity exists within these sand bodies in the form of mud chip lag surfaces, large mud clast horizons, and discontinuous finer-grained beds. These features add complexity to the systems by reducing flow transmissibility or acting as flow baffles. The complex heterogeneity characteristic of these reservoir analogs confirms the need for detailed reservoir characterization studies on all scales in order to improve exploration and production efficiency in such systems.
Outcrop Three (the wave-dominated facies of the Green River Formation) is dominated by thinner (2 to 4 m) tabular and laterally extensive offshore bar deposits that are compartmentalized by mudstone units. Large-scale heterogeneity is minimized in these reservoir analogs, in that sand bodies exhibit excellent lateral continuity and less complex amalgamation. Therefore, documentation of the smaller-scale heterogeneities (similar to those mentioned in the previous two outcrops) is necessary to better address exploration and production potential in these types of reservoirs.
Data collected in this study were utilized in geostatistical simulations and fluid flow models in an attempt to document the effects of reservoir heterogeneity on hydrocarbon exploration and production efficiency in lacustrine basins. Further studies of this type are necessary if predictable classification systems and hierarchies of bounding surfaces are to be derived for lacustrine reservoirs. (152 pages)
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Rucker, Justin Thomas. "3D wavelet-based algorithms for the compression of geoscience data." Master's thesis, Mississippi State : Mississippi State University, 2005. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.
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Reid, Fiona J. L. "Velocity and attenuation structure of the mantle : constraints from differential properties of shear waves." Thesis, University of Oxford, 1999. http://ora.ox.ac.uk/objects/uuid:83796f01-c45f-4d84-9c4c-04e084ac135f.
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Although much progress has been made in determining the three dimensional distribution of seismic wave velocities in the Earth, substantially less is known about the three dimensional distribution of intrinsic attenuation. In this study variations in attenuation and shear velocity of the Earth's mantle are constrained using measurements of differential travel time and attenuation. The data are broadband displacement SH seismograms filtered to have energy in the period range 8 to 20 s. Broadband data are used as they should allow a more accurate estimation of body wave attenuation to be made. The seismograms are obtained from over 600 globally distributed earthquakes of magnitude, Mw, 5.5 or greater. Two new methods for determining differential travel times and differential t* values from multiple S phases are presented. The first of these, referred to as the "waveform fitting method" is used to analyse approximately 4300 SS and S waveforms and around 1000 SSS and SS waveforms resulting in differential SS-S and SSS-SS travel times, and corresponding values of differential attenuation represented by t*. The second method, referred to as the "spectral ratio method" is used to analyse approximately 3200 SS and S and around 900 SSS and SS waveforms. The differential travel times and t* values are inverted to obtain models of the lateral variation of shear velocity and lateral variation of q(mu) where q(mu) =1/Q(mu). The models explain the data well but have limited depth resolution. The velocity models show good correlation with previous studies, in particular, low velocities are observed underlying spreading ridges and convergent margins and high velocities are observed under continental regions. The q(mu) model shows shield regions to be less attenuating than PREM, with ridges appearing as highly attenuating features. Models of shear velocity and attenuation are also obtained by combining the body wave dataset of this study with the surface wave datasets of Van Heijst (1997) and Selby (1998).
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Schirmer, Tad William. "Sequential Thrusting Beneath the Willard Thrust Fault, Wasatch Mountains, Ogden, Utah." DigitalCommons@USU, 1985. https://digitalcommons.usu.edu/etd/4516.
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The downstructure of viewing geologic maps, balanced and cross sections, and hanging-wall-sequence diagrams are applied to produce the first comprehensive synthesis of the structure below the willard thrust sheet.
Development of the duplex beneath the Willard thrust may be explained with a "piggyback" thrust model where younger thrust slices form below and fold an older, overlying thrust sheet. Progressive failure of the footwall ramp of the Willard thrust sheet extended the sole thrust eastward and produced a duplex consisting of thrust slices (horses) which adhered to the overriding thrust sheet where it ramped from a lower sole thrust to an upper decollement horizon. The resulting structural culmination produced a distinct antiform in the Willard thrust sheet. The duplex is here named the Ogden duplex.
Frontal folds (formed at ramps perpendicular to transport) and lateral folds (formed at ramps parallel to transport) mark the margin of Individual horses within the duplex. Folded thrusts, thrust-splay relationships, and lateral overlap of horses help determine the sequence of thrusting.
The involvement of cratonic foreland basement rocks (Farmington Canyon Complex) in thrust slices within the Ogden duplex is similar to the Moine thrust belt in northern Scotland and pinpoints this area within zone III of Boyer and Elliott's (1982) model of a thrust system dominated by a major thrust sheet.
The basement rocks form the core of several horses which moved a minimum of 9.6 km. Total shortening within the Ogden duplex is estimated at 8 to 12 km.
The sequence of thrusting is proposed from higher to lower: the willard thrust fault moved first, then the Ogden thrust fault and, finally, the Taylor and Weber thrust system (here named). Striking similarities between the Ogden thrust fault, the Weber-Taylor thrust system, and the Durst thrust fault geometries suggest that they are all part of the same system.
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Atkinson, Trevor Alex. "Geochemical Characterization of the Mountain Home Geothermal System." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4599.
Full textAbstract:
The Mountain Home (MH) geothermal system of the western Snake River Plain (SRP) magmatic province was discovered in 2012 by the Snake River Geothermal Drilling Project. Artesian flowing water with a temperature of 150°C was encountered at a depth of 1745 m below ground surface (mbgs) and extensive mineralized fracture networks of pectolite-prehnite, calcite, and laumontite were discovered in the recovered core. The objectives of this study are to: 1) describe the thermal and compositional history of past geothermal fluids, and 2) compare these fluids to modern fluids in order to characterize the evolution of the MH geothermal system and the geothermal potential of the western SRP. Core observations, thin section petrography, X-ray diffraction, and Electron Microprobe analyses were performed in order to describe mineral parageneses of various alteration zones. Carbon and oxygen stable isotope ratios along with temperatures of homogenization from fluid inclusions in hydrothermally precipitated calcite were measured along ~100 m of basalt core from 1709-1809 mbgs. The d13CPDB values in calcite range from -7.2 to -0.43 ‰ and d18OPDB values range between -20.5 and -15.9 ‰. An anomalous zone from 1722-1725 m depth displays a range in d13CPDB and d18OPDB of -1.9 to +0.88 ‰ and -17.1 to -8.1 ‰, respectively, suggesting non-equilibrium fractionation due to boiling. Carbon isotopic ratios suggest a mixture of deep-seated mantle derived and meteoric fluids. Fluid inclusion microthermometry has identified primary inclusions with trapping temperatures ranging from 168-368°C. A calcite-water geothermometer used to calculate paleo-fluid oxygen isotopic composition (-0.43 to +7.2 ‰ SMOW) and a comparison with present-day fluid oxygen isotopic composition (-3.2 ‰ SMOW) reveals a cooling trend with potential mixing of meteoric waters and deeply derived fluid. The MH geothermal system has cooled over time and reflects potentially less, if any magmatic fluid input presently into the system as there was in the past.
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Reeder, Philip. "The Use of Down-Hole Video to Evaluate Parameters Affecting Removal of Storm Water Runoff into a Karst Aquifer in Bowling Green, Kentucky." TopSCHOLAR®, 1988. http://digitalcommons.wku.edu/theses/1991.
Full textAbstract:
Due to recent land use changes, runoff has greatly increased In Bowling Green, necessitating the drilling of nearly 600 drainage wells to direct storm water into the Lost River Karst Aquifer. Research was conducted to (1) differentiate areas of the city as optimal for removal of storm water runoff, (2) correlate lithologic features between wells, and (3) determine optimal depths to which new drainage wells should be drilled. This was accomplished using maximum capacity tests, correlation of lithologic features between wells and comparing void density to depth below the land surface.
It was only possible to develop general trends in the areal distribution of voids throughout the city, hence: specific optimal areas for removal of storm water runoff could not be differentiated. The correlation of voids between wells was possible alone both the regional dip and strike of the beds. It was also determined that the greatest potential for intersecting voids was in the first 6 meters of borehole, but no clear cut depth criteria were developed, although recommendations were made pertaining to drilling new wells to an optimal, functional depth.
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Nye, April Season. "Pleistocene Peccaries from Guy Wilson Cave, Sullivan County, Tennessee." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etd/2115.
Full textAbstract:
Descriptive and taphonomic analyses of undescribed Pleistocene Tayassuidae from Guy Wilson Cave within the East Tennessee State University and McClung Museum collections revealed a MNI of 16 Platygonus compressus and 2 Mylohyus from left femora and isolated teeth, respectively. Linkage between upper dentition and species identification is suggested by comparing Mylohyus fossilis to M. nasutus from other Pleistocene-aged sites. Long-bone NISP and age profiles show a predominance of Platygonus adults. Tayassuidae upper canines, likely Platygonus, suggest sexual dimorphism. Long bones were analyzed for carnivore damage and utilization revealing light utilization similar to that caused by modern wolves. Long bone weathering is predominantly light and suggests limited exposure prior to burial. Results indicate the cave was likely used as a carnivore den, possibly from dire wolf, for a period of time. No stratigraphical excavation data were available for either collection; therefore, additional excavations are needed to confirm these findings.
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Christine, Joel Alvin. "Landmark Analysis of Musteloid Carnassials Applied to Taxonomic Identification and Examination of Sexual Dimorphism and Regional Morphotypes." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1452.
Full textAbstract:
Guy Wilson Cave (GWC) in Sullivan County, Tennessee holds many late Pleistocene mammal fossils. Based on visual morphology, several partial mandibles with lower carnassial from GWC appeared to be musteloids. Geometric morphometrics has been successfully used to identify fragmentary fossils, so a landmark based, 2 dimensional technique was applied to identify the GWC musteloids using the lower carnassial. Digital images of several GWC fossils and of extant reference musteloids were combined using morphometric programs tpsDIG1, tpsUtil, and tpsSuper. Statistical data analysis was performed in PASW Statistics. Results successfully separated Mephitis mephitis (striped skunk) from M. macroura (hooded skunk) and Martes americana (American marten) from M. pennanti (fisher). Sex-based and geographical patterns were also found in the data. Sex separated all three species via the lower carnassial. Geographic divisions were found for Mephitis mephitis, Martes americana and M. pennanti populations that hint at interestingly unique biogeographical histories for each taxon.
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Olsen, Aric Alan. "Discharge Monitoring, Chemical Characterization, and Source Identification of Springs Along the East Side of Southern Cache Valley, Utah." DigitalCommons@USU, 2007. https://digitalcommons.usu.edu/etd/6760.
Full textAbstract:
Discharge monitoring and water sampling of springs in the southeastern portion of Cache Valley, Utah was performed in order to determine recharge sources and the cause of decreasing flows for some springs. The discharges of 43 springs were measured monthly from May or June of 2005 through March of 2006. Water samples from 36 of these springs plus an additional 10 were analyzed for major ions and trace metals. Twenty-one of the springs were analyzed for deuterium and oxygen-18 and 10 of these were analyzed for tritium. The springs were divided into groups based on when they had their peak discharge. Peak discharges in the summer months suggest recharge from excess irrigation water and/or canal water, whereas peak discharges in winter months suggest recharge from rivers, and peak discharges in spring months suggest recharge by precipitation and/or river water recharge. Multiple discharge peaks suggest multiple recharge sources. The chemical data collected in the study were compared with data from previous investigations to determine potential spring sources, including: shallow ground water, deep ground water, irrigation (river/canal) water, and precipitation. Spring water is characterized by calcium, magnesium, and bicarbonate, similar to deep ground water and river water. However, most of the 21 springs analyzed for deuterium and oxygen-18 displayed an evaporative signature; thus, chemically, the shallow, unconfined aquifer that recharges these springs appears to be recharged in part by excess irrigation water and/or canal water. Several of the springs have high chloride levels indicating the shallow, unconfined aquifer recharging those springs has surface runoff infiltrating into it. Because of the evaporative signature in the stable isotopes, the similarity of major ion and trace metal values, and the discharge trends observed throughout the year, it seems unlikely that the springs are directly connected hydraulically with the deep, confined aquifer, from which most of the wells in the valley withdraw their water. Thus, the recent drought, rather than increased pumping, probably has been responsible for decreases in spring discharges.
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Pirbudak, Ozan. "Reconstruction of Radar Images by Using Spherical Mean and Regular Radon Transforms." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7889.
Full textAbstract:
The goal of this study is the recovery of functions and finite parametric distributions from their spherical means over spheres and designing a general formula or algorithm for the reconstruction of a function f via its spherical mean transform. The theoretical study is and supported with a numerical implementation based on radar data. In this study, we approach the reconstruction problem in two different way. The first one is to show how the reconstruction problem could be converted to a Prony-type system of equations. After solving this Prony-type system of equations, one can extract the parameters that describe the corresponding functions or distributions efficiently. The second way is to solve this problem via a backprojection procedure.
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McConnell, Shannon M. "The Occurrence of an Abdominal Fauna in an Articulated Tapir (Tapirus polkensis) Recovered from the Miocene Gray Fossil Site Northeast Tennessee." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1313.
Full textAbstract:
The analysis of samples recovered from the abdominal area of an articulated tapir from the Late Miocene (4.5-7 million bp) Gray Fossil Site, revealed a rich palyno-fauna comprised of about 94% egg/oocyst-like structures and 6% pollen and other palynomorphs. In addition, a tight grouping of six hickory nuts (Carya) was recovered from the same area suggesting that the samples represent the abdominal contents. The analysis of a sample from immediately outside the tapir produced a sample with 98% pollen and less than 0.5% egg-like structures. The size, shape, and general morphology of egg-like structures were analyzed with light and scanning electron microscopy and were compared to a variety of intestinal eggs found in extant ungulates, and in particular the Perissodactyla. We also compared the fossil structures to the numbers and kind of intestinal parasites recovered from fecal samples from the Baird's tapir (Tapirus bairdii) in Costa Rica and from samples collected from the Lowland tapir (T. terrestris) from Ecuador to assess their similarity to our fossil sample. Based on these data we discuss what role parasites may have played in the biology of T. polkensis during the late Miocene-early Pliocene.
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Stout, Jeremy Brett. "Cranial Morphology and Systematics of Late Pliocene Alligator from Florida, with Notes on Alligator Evolution and Distribution." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1786.
Full textAbstract:
Alligator mississippiensis is only distantly related to the other extant alligator (A. sinensis), with much closer relatives known from the geologic past of North America. While A. mississippiensis is well known from the early Pleistocene and later, no Alligator was known from the middle and late Pliocene until the discovery of Haile 7C and 7G late Pliocene (~2 Ma) sites from Florida. These specimens were analyzed using a diagnostic character matrix along with systematic analyses of the results. This research upholds A. mefferdi as a valid taxon, and the utility of the species in fossil identification is further established. The Haile material cannot be placed within either of the aforementioned taxa, and a new species description is planned in a later publication. Furthermore, the systematic analysis used in this research suggests that the line leading to A. sinensis diverged before the earliest known Alligator. An Eocene dispersal of the genus into Asia is plausible.
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Gibson, Matthew L. "Population Structure Based on Age-Class Distribution of Tapirus polkensis from the Gray Fossil Site Tennessee." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1267.
Full textAbstract:
Individuals of Tapirus polkensis from the Gray Fossil Site exhibit an excellent level of preservation. Intact skulls collected from the site were arranged in a rough age class system separated into 7 categories based on the teeth present and amount of dental wear. Such an eruption series is useful for general comparisons amongst the individual tapirs; however, the classes do not represent an age in years due to a lack of data on living tapirs. Consequently, it is possible that some age classes may contain several years of a tapirs life, or comparatively only a few months. In this study I placed ages on individuals of T. polkensis from the Gray Fossil Site based on age data taken from The Baird's Tapir Project of Costa Rica (Baird's Tapirs, T. bairdii) ranging from several months to 7 years in age. As eruption data is only useful for aging tapirs up to 7 years, this study also took dental wear into account for adult tapirs. After aging all possible individuals in the sample, the sample was compared to other studies on perissodactyl population structure. Interestingly, the T. polkensis sample is remarkably similar to modern populations of Diceros bicornis.
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Schattauer, Sarah Ann. "Non-Ranid Anurans of the Mio-Pliocene Gray Fossil Site, Tennessee." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1454.
Full textAbstract:
Researchers at the GFS, Washington County, Tennessee through the wet screening of nearly 100%of the sediment excavated at the site, recovered an extensive collection of anuran fossil elements. Until recently, these specimens have not been analyzed. The purpose here is the examination, description, and identification of all non-ranid anuran (frogsand toads) material using the following elements: ilium, urostyle, maxilla, frontoparietal, and last sacral vertebra. Anurans identified include Scaphiopus wardorum(extinct spadefoot toad), Bufo terrestris(southern toad), B. cf. B. marinus(giant neotropical toad), three morphotypes of Hyla(tree frogs), and Pseudacris cf. P. brachyphona(mountain chorus frog). Occurrence of these Anura support a paleoecological environment described as warm, moist, and wooded.
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Allen, Eric B. "Dendrochronology in Northern Utah: Modeling Sensitivity and Reconstructing Logan River Flows." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1716.
Full textAbstract:
Semi-arid valleys in northern Utah are home to the majority of the state population and are dependent upon winter snowpack in surrounding mountains for water for irrigation, hydropower and municipal use. Water is delivered to the urban areas in the spring as discharge in rivers draining the mountains. Understanding the natural variability and cycles of wet and dry periods enables water managers to make informed water allocations. However, the complex regional climate teleconnections are not well understood and the shortness of the instrumental period does not allow for a full understanding of natural variability. Paleo proxies can be used to extend the instrumental record and better capture natural variability. This study uses dendrochronology to reconstruct streamflows of the Logan River in northern Utah over the last several centuries to provide water managers with a better understanding of natural variability. This reconstruction involved sampling and creating three Douglas-fir, one limber pine and two Rocky Mountain juniper chronologies in northern Utah. Combined with existing chronologies, three flow reconstructions of the Logan River were created: one using only within basin chronologies, one using all considered chronologies and one long chronology. Employing regional chronologies resulted in the most robust models, similar to other findings. Results indicate that the last several centuries exhibited greater variability and slightly higher mean annual flows than in the instrumental record (1922-2011). These reconstructions were created using species well established within the dendroclimatology literature such as of Douglas-fir and limber pine and the lesser used Rocky Mountain juniper. The success of Rocky Mountain juniper suggests that it can be a useful species for dendroclimatology in other areas lacking more widely recognized species in semi-arid climates (e.g., pinyon pine).
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Tressler, Christopher. "From Hillslopes to Canyons, Studies of Erosion at Differing Time and Spatial Scales Within the Colorado River Drainage." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1109.
Full textAbstract:
This thesis includes two different studies in an attempt to investigate and better understand the key characteristics of landscape evolution. In the first study, the rate of surface particle creep was investigated through the use of Terrestrial lidar at an archaeological site in Grand Canyon National Park. The second study developed ways to quantify metrics of the Colorado River drainage and reports the role of bedrock strength in the irregular profile of the trunk Colorado River drainage.
Archaeological sites along the Colorado River corridor in Grand Canyon National Park are eroding due to a variety of surficial processes. The nature of surface particle creep is difficult to quantify and managers of this sensitive landscape wish to know the rates of erosion in order to make timely decisions regarding preservation. In the first study, two scans of a single convex hillslope were collected over the span of 12 months through the use of a ground-based lidar instrument. The scans were used to track the movement of rock clasts. This study, with a relatively small data set, did not show the expected positive relations of creep rate to slope or clast size, but did not preclude the existence of these relations either.
The remarkably irregular long profile of the Colorado River has inspired several questions about the role of knickpoint recession, tectonics, and bedrock in the landscape evolution of Grand Canyon and the region. Bedrock resistance to erosion has a fundamental role in controlling topography and surface processes. In this second study, a data set of bedrock strength data was compiled and presented, providing relations of bedrock strength to hydraulicdriving forces of the trunk Colorado River drainage.
Results indicate that rock strength and topographic metrics are strongly correlated in the middle to lower reaches of the plateau drainage. In the upper reaches of the drainage, intact-rock strength values are ~25% higher without a matching increase in stream power. As more tensile strength samples are analyzed and appropriately scaled with respect to fracturing and shale content, we believe we will see a clearer and more consistent pattern in the upper reaches.
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Land, Timothy. "FM Radio Signal Propagation Evaluation and Creating Statistical Models for Signal Strength Prediction in Differing Topographic Environments." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etd/3423.
Full textAbstract:
Radio wave signal strength and associated propagation models are rarely analyzed across individual geographic provinces. This study evaluates the effectiveness of the Radio Mobile model to predict radio wave signal strength in the Blue Ridge and Valley and Ridge physiographic provinces. A spectrum analyzer was used on 19 FM transmitters to determine model accuracy. Statistical analysis determined the significance between different terrain factors and signal strength. Field signal strength was found to be related to test site elevation, transmitter azimuth, elevation angle, transmitter elevation, path loss, and distance. Using 76 signal strength receiver sites, Ordinary Least Square regression models predicted signal strength with 60% of variability explained in the Valley and Ridge province model and 43% of variability explained in the Blue Ridge province model. Region-specific statistical models were more accurate in determining a region’s transmitter placement and level of power for broadcasting compared to generic computer models.
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Whittington, Kayla Lee. "How Does a Next Generation Science Standard Aligned, Inquiry Based, Science Unit Impact Student Achievement of Science Practices and Student Science Efficacy in an Elementary Classroom?" PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3942.
Full textAbstract:
This study examined the impact of an inquiry based Next Generation Science Standard aligned science unit on elementary students' understanding and application of the eight Science and Engineering Practices and their relation in building student problem solving skills. The study involved 44 second grade students and three participating classroom teachers. The treatment consisted of a school district developed Second Grade Earth Science unit: What is happening to our playground? that was taught at the beginning of the school year. Quantitative results from a Likert type scale pre and post survey and from student content knowledge assessments showed growth in student belief of their own abilities in the science classroom. Qualitative data gathered from student observations and interviews performed at the conclusion of the Earth Science unit further show gains in student understanding and attitudes. This study adds to the existing literature on the importance of standard aligned, inquiry based science curriculum that provides time for students to engage in science practices.
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Lynch, Eric Randally. "Cursorial Adaptations in the Forelimb of the Giant Short-Faced Bear, Arctodus simus, Revealed by Traditional and 3D Landmark Morphometrics." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1477.
Full textAbstract:
The paleobiology of the Pleistocene North American giant short-faced bear, Arctodus simus, has eluded paleontologists for decades. Its more gracile form has led past researchers to myriad intepretations of the locomotion and feeding ecology of this species. While earlier studies have focused on craniodental morphology and simple postcranial indices, it is forelimb morphology that represents a direct compromise between locomotor and foraging behavior. The study here uses traditional and 3D landmark morphometrics to more completely compare the 3-dimensional shape of the major forelimb elements and their muscle attachment sites between A. simus, extant ursids, and other carnivorans. Results herein agree well with previous studies and provide additional evidence for reduced abductor/adductor and supinator/pronator musculature, more restricted parasagittal motion, increased stride length, and lighter and more packed distal elements. Forelimb skeletal morphology therefore supports the hypothesis that A. simmus represents a bear in the early stages of cursorial evolution.
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Gong, Fade. "Vitis Seeds (Vitaceae) from the Late Neogene Gray Fossil Site, Northeastern Tennessee, USA." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1819.
Full textAbstract:
This study focuses on the morphometric and systematic studies of fossil vitaceous seeds recently recovered from the Gray Fossil Site (7-4.5 Ma, latest Miocene-earliest Pliocene) northeastern Tennessee. Morphologically, all fossil seeds correspond to the extant subgenus Vitis (genus Vitis) of the Vitaceae based on the smooth dorsal surface with a centrally positioned chalaza connected with a conspicuous chalaza-apex groove and short linear ventral infolds that are slightly diverged apically. A multivariate analysis based on 11 measured characters from 76 complete seeds identified three types of seeds, each representing a distinct morphotaxon. Based on comparison with modern and fossil vitaceous specimens, three new species were recognized: Vitis grayana sp. nov., Vitis lanatoides sp. nov., and Vitis latisulcata sp.nov. The close resemblance between the first two fossil grapes (Vitis grayana and Vitis lanatoides) with extant eastern Asian Vitis provides further evidence that the eastern Asian floristic elements existing in the southeastern North American flora continued to as late as late Neogene.
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Holte, Sharon Elizabeth. "Description of Jefferson’s Ground Sloth (Megalonyx jeffersonii) from Acb-3 Cave, Colbert County, Alabama, with Comments on Ontogeny, Taphonomy, Pathology, and Paleoecology." Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1436.
Full textAbstract:
Excavations of ACb-3 Cave have uncovered the remains of at least seven individual Megalonyx jeffersonii, providing the most complete ontogenetic sequence of the taxon from one locality. Four individuals representing four distinct age classifications (infant, juvenile, subadult, and adult) were described and examined for pathologies. Cranial and major forelimb elements depict a change in morphology (trending from robust and stout to gracile and elongate) through ontogeny. Pathologies on the scapula and radius of the adult ground sloth indicate a potential attack from fighting or mating. The presence of infant and juvenile sloths suggests this cave may have been used as a maternity den. The nearly complete adult (RMM 5353) was compared to Megalonyx from other North American localities. Bivariate plots, created using linear measurements, showed that RMM 5353 was within the size range of M. jeffersonii and further supports the concept of Megalonyx chronospecies.
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Cole, Timothy. "Physical Properties of Tar Sand Tailings that Influence Their Ability to Sustain Plant Growth." TopSCHOLAR®, 1985. http://digitalcommons.wku.edu/theses/1900.
Full textAbstract:
The mining of bituminous sandstone rock for the purpose of extracting bitumen has created a need for reclamation. One such mine is located in northern Logan County. Their mining operation involves removing large sections of sandstone, which is impregnated with bitumen, and crushing it to sand-sized material. The sand-sized material is then mixed with organic solvents which extract the bitumen. Once separated, the bitumen is stored for future refinement and the spent sand is stockpiled for later disposal.
The spent sands or waste material are referred to as tar sand tailings. These tailings have particular properties which make reclamation efforts difficult. One restrictive property is the 30 percent swell factor, which prevents replacement of the tailings into their respective mined area. Another property is the tailings’ hydrophobicity. This water repellence prevents merely spreading the tailings onto the surface.
Experiments were conducted at Western Kentucky University during 1984 and 1985 to determine methods to lessen the hydrophobic tendencies and allow for reclamation. These experiments included mixing the tailings with the existing soil and adding surfactants to the tailings. Water holding capacities, infiltration rates, and the ability to sustain plant life were determined and evaluated.
It appears that the residual bitumen not removed by the extraction process causes the hydrophobic tendencies of the tailings. This conclusion was based on a comparison of pure tailings and tailings which were subjected to 500°C temperatures for 24 hours which could destroy all organic material, specifically the residual bitumen. The pure tar sand tailing held 0.44 percent moisture and the tailings with the organic material removed held 27.48 percent moisture.
Mixtures of tailings and Zanesville soil were also evaluated and compared to the tailings with and without organic material. The percent moisture of the soil was not significantly different from the tailings without organic material. All mixtures were significantly lower than the soil or the tailings without organic material and significantly higher than the pure tar and tailings. However, the mixtures apparently can hold sufficient moisture for plant growth.
Water infiltration rates through various mixtures of tailings and soil with and without surfactants were also evaluated. It was concluded that a tailings/soil mixture of 75/25 percent with and without surfactant and 90/10 percent mixture with surfactant allowed the fastest water infiltration. The rate of infiltration is important since the Logan County topography is favorable for runoff erosion.
Rye (secale cereale) was grown in various mixtures of tailings and soil with and without surfactants to determine phytotoxic effects. Visual observations of the growing plants indicated no phytotoxic effects due to the bitumen or surfactants. However, dry matter yields of the plants differed significantly. The lower yield of some plants could be attributed to a lack of moisture since the lowest yields were in the pure tailings with and without surfactant.
In conclusion, the results of this study revealed that tar sand tailings do have hydrophobic tendencies apparently due to residual bitumen. These tendencies can be buffered by mixing the waste material with an existing soil or by complete combustion of the residual organic material. Also it was concluded that vegetation could be established on the mixtures of tailings and soil and thus, the land reclaimed.
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Veni, George. "Effects of Urbanization on the Quantity and Quality of Storm Water Runoff Recharging Through Caves into the Edwards Aquifer, Bexar County, Texas." TopSCHOLAR®, 1985. http://digitalcommons.wku.edu/theses/1842.
Full textAbstract:
Eighty-nine caves and sinkholes were investigated in the Edwards Aquifer recharge zone in Bexar County, Texas. The study examined their hydrogeologic and topographic origins and distribution, relationships to major fracture traces, quantity of recharge into the aquifer and degree of sensitivity towards degradation of the aquifer’s water quality. Groundwater traces were attempted to determine aquifer flow routes, time of groundwater travel, groundwater volume within conduits, and the aquifer’s capacity for dilution and dispersion of recharged contaminants. Trends in water quality were examined to quantify the volume and variety of contaminants recharged into the aquifer and to determine the effects of urbanization upon the Edwards Aquifer. The Edwards recharge zone was hydrogeologically assessed to rate the sensitivity of its areas. Socio-political impacts on recharge zone development were also examined.
Based on the results of the above outlined research method, the conclusions of this investigation are that caves and sinkholes contribute substantial recharge into the Edwards Aquifer, rapidly transmit that recharge to the aquifer and are sensitive sites for potential contamination. The entire recharge zone was determined to be very sensitive to contamination. No significant differences were found between areas within the recharge zone to scale their degree of sensitivity. Major conduit flow networks were found to exist within the aquifer and their groundwater flow paths could be traced. Urban development of the Edwards recharge zone was shown to decrease the volume of recharge and degrade the aquifer’s water quality. No significant detrimental effects on the aquifer were observed. The volume of diminished recharge and the concentration of recharged contaminants that were necessary to produce significant adverse effects on the aquifer were not determined due to lack of precipitation during the study period and inconclusive groundwater tracings. It was recommended that further development of the recharge zone be suspended until the effects of urbanization are quantified.
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Feeney, Thomas. "Mechanisms Responsible for Sinkhole Flooding on an Urbanized Karst Terrain: South Sunrise / Media Drive, Bowling Green, Kentucky." TopSCHOLAR®, 1986. http://digitalcommons.wku.edu/theses/2006.
Full textAbstract:
Sinkhole flooding on the urban karst area of Bowling Green, Kentucky, was studied by investigating past flood events in the South Sunrise/Media Drive Sinkhole. The actual flood levels of four floods were compared to levels calculated by an empirical runoff determination method. Outflow capacity tests and dye tracing revealed the nature of drainage within the karst depression.
The Soil Conservation Service runoff determination method and the three-hour maximum rainfall event were used to estimate the level of flooding. Three of the four flood events studied provided deviations between the actual and calculated flood levels of less than 0.26 feet (0.08 meters). The fourth event produced a deviation of 1.45 feet (0.44 meters) which was explained by the intense nature of the precipitation event.
Analysis of the data resulted in the conclusion that surface storm water runoff exceeded the outflow capacity of the sinkhole drains during all four flood events and that the peak flood elevations were not related to the level of the water table in the area. Evidence also suggested that drainage from the base of the South Sunrise/Media Drive Sinkhole occurs through interconnecting voids associated with a cave roof breakdown pile, and not through an efficient system of solution conduits.
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Baker, Jordan David. "A Phylogenetic Analysis of Species Relationships in Hemlocks, the Genus Tsuga (Pinaceae)." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1791.
Full textAbstract:
The genus Tsuga is comprised of eight extant species found in North America and East Asia and four species represented by fossils from Europe and Japan. This study presents the first phylogenetic analysis based on structural, biochemical, and molecular sequence data. Characters obtained from published and unpublished literature were combined with new morphological characters from seeds, seedlings, and leaf cuticle material. Results from parsimony analyses of these characters differed from the published molecular based phylogeny. The non-molecular based phylogeny resolves two separate clades, a North American and an Asian, but did not group the western North American species, as in the molecular based analysis. Character states were traced on the trees to interpret character evolution. The combined analysis resulted in a phylogeny that differed from the previously published molecular tree by resolving a clade between T. caroliniana and T. diversifolia and placing T. dumosa outside of the Asian clade.
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Kyrke-Smith, Teresa Marie. "Ice-stream dynamics : the coupled flow of ice sheets and subglacial meltwater." Thesis, University of Oxford, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.629515.
Full textAbstract:
Ice sheets are among the key controls on global climate and sea level. A detailed understanding of their dynamics is crucial to make accurate predictions of their future mass balance. Ice streams are the dominant negative component in this balance, accounting for up to 90% of the Antarctic ice flux into ice shelves and ultimately into the sea. Despite their importance, our understanding of ice-stream dynamics is far from complete. A range of observations associate ice streams with meltwater. Meltwater lubricates the ice at its bed, allowing it to slide with less internal deformation. It is believed that ice streams may appear due to a localisation feedback between ice flow, basal melting and water pressure in the underlying sediments. This thesis aims to address the instability of ice-stream formation by considering potential feedbacks between the basal boundary and ice flow. Chapter 2 considers ice-flow models, formulating a model that is capable of capturing the leading-order dynamics of both a slow-moving ice sheet and rapidly flowing ice streams. Chapter 3 investigates the consequences of applying different phenomenological sliding laws as the basal boundary condition in this ice-flow model. Chapter 4 presents a model of subglacial water flow below ice sheets, and particularly below ice streams. This provides a more physical representation of processes occurring at the bed. Chapter 5 then investigates the coupled behaviour of the water with the sediment, and Chapter 6 the coupled behaviour of the water with the ice flow. Under some conditions this coupled system gives rise to ice streams due to instability of the internal dynamics.
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Beck, Chase W. "The Analysis of Palaeobotanical Remains from Native American Sites in the Tennessee Region of the Upper Cumberland Plateau." Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etd/1731.
Full textAbstract:
Sediment samples were collected from 3 rock shelter sites and one natural pond on the Upper Cumberland Plateau. Samples were processed to quantitatively and qualitatively evaluate pollen and charcoal abundance as well as other palaeobotanicals. The analysis was to determine when prehistoric Native Americans began controlled burns to enhance resources acquisition. Samples were also analyzed for the presence of pollen to determine vegetation changes that may accompany the use of controlled burns and to determine the onset of horticulture. The Upper Cumberland Plateau is often considered a marginal area used only seasonally by Native Americans; however, management practices may have been highly refined to maximize resources acquisition. Results show evidence of overt land management and usage of the area by Native Americans over several thousand years. Remains indicate reliance upon nut producing trees. This reliance led to land management practices designed to maximize availability of said resources.
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Yang, Xin-She. "Mathematical modelling of compaction and diagenesis in sedimentary basins." Thesis, University of Oxford, 1997. http://ora.ox.ac.uk/objects/uuid:0bdc6c43-4534-4f08-97e2-8a33d6b13e61.
Full textAbstract:
Sedimentary basins form when water-borne sediments in shallow seas are deposited over periods of millions of years. Sediments compact under their own weight, causing the expulsion of pore water. If this expulsion is sufficiently slow, overpressuring can result, a phenomenon which is of concern in oil drilling operations. The competition between pore water expulsion and burial is complicated by a variety of factors, which include diagenesis (clay dewatering), and different modes (elastic or viscous) of rheological deformation via compaction and pressure solution, which may also include hysteresis in the constitutive behaviours. This thesis is concerned with models which can describe the evolution of porosity and pore pressure in sedimentary basins. We begin by analysing the simplest case of poroelastic compaction which in a 1-D case results in a nonlinear diffusion equation, controlled principally by a dimensionless parameter lambda, which is the ratio of the hydraulic conductivity to the sedimentation rate. We provide analytic and numerical results for both large and small lambda in Chapter 3 and Chapter 4. We then put a more realistic rheological relation with hysteresis into the model and investigate its effects during loading and unloading in Chapter 5. A discontinuous porosity profile may occur if the unloaded system is reloaded. We pursue the model further by considering diagenesis as a dehydration model in Chapter 6, then we extend it to a more realistic dissolution-precipitation reaction-transport model in Chapter 7 by including most of the known physics and chemistry derived from experimental studies. We eventually derive a viscous compaction model for pressure solution in sedimentary basins in Chapter 8, and show how the model suggests radically different behaviours in the distinct limits of slow and fast compaction. When lambda << 1, compaction is limited to a basal boundary layer. When lambda >> 1, compaction occurs throughout the basin, and the basic equilibrium solution near the surface is a near parabolic profile of porosity. But it is only valid to a finite depth where the permeability has decreased sufficiently, and a transition occurs, marking a switch from a normally pressured environment to one with high pore pressures.
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CHAOUCHE, Keltoum. "Approche multifractale de la modélisation stochastique en hydrologie." Phd thesis, ENGREF (AgroParisTech), 2001. http://tel.archives-ouvertes.fr/tel-00005781.
Full textAbstract:
La plupart des séries d'observations hydrologiques possèdent des caractéristiques peu communes (grande variabilité sur une large gamme d'échelles spatiales et temporelles, périodicité, corrélation temporelle à faible décroissance), difficiles à mesurer (séries tronquées et intégrées sur des pas de temps qui ne respectent pas la nature du phénomène) et compliquées à intégrer dans un modèle stochastique classique (ARMA, Markov). Le modélisateur doit aussi faire face aux problèmes liés à l'échelle : en hydrologie (et en météorologie) où les données sont issues de pas de temps très divers, il est particulièrement intéressant de disposer de modèles à la fois capable d'intégrer des données à pas de temps différents et de fournir des résultats à un pas de temps différent de celui des entrées (désagrégation ou agrégation de séries temporelles).Ce travail de thèse explore les possibilités d'application d'un nouveau type de modèle, les modèles multifractals, qui traduisent le plus simplement possible des propriétés d'invariance de certains paramètres (invariance spatiale, temporelle ou spatio-temporelle). En particulier, dans les modèles de cascades multifractales de générateur algébrique, c'est le coefficient de décroissance algébrique qui est un invariant d'échelle. Des résultats issus de la théorie probabiliste des valeurs extrêmes sont dès lors très utiles pour estimer ce paramètre. L'élaboration d'un outil statistique capable de détecter un comportement algébrique et d'estimer le paramètre de décroissance algébrique constitue une étape préalable au développement de cette thèse. Il est aussi montré dans ce travail, que la forme de dépendance (longue ou courte) des modèles en cascade multifractale diffère selon le générateur de la cascade.L'étude exploite une base de données de 232 séries annuelles de divers sites, de nombreuses séries de pluie à divers pas de temps (mois, jour, heure, minute) ainsi que quelques séries de débits. Elle conduit aux résultats suivants :
- Les lois de type algébrique sont adaptées à la modélisation des grandes périodes de retour des séries de pluie étudiées.
- Sur ces mêmes séries, le coefficient de décroissance algébrique est un paramètre invariant d'échelle (sur des gammes d'échelles supérieures à l'heure).
- L'estimation de ce coefficient en divers sites à travers le monde est très peu variable.
- La propriété de longue dépendance est décelable au sein de certaines séries de débits, notamment des séries de rivières sur craie.
Ces résultats incitent donc à l'emploi de cascades multifractales pour la modélisation des séries de pluie, bien qu'un travail concernant la détection et l'estimation de longue dépendance reste à accomplir pour que le choix du générateur respecte la forme de dépendance de la série.
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van, den Bremer T. S. "The induced mean flow of surface, internal and interfacial gravity wave groups." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:e735afe7-a77d-455d-a560-e869a9941f69.
Full textAbstract:
Although the leading-order motion of waves is periodic - in other words backwards and forwards - many types of waves including those driven by gravity induce a mean flow as a higher-order effect. It is the induced mean flow of three types of gravity waves that this thesis examines: surface (part I), internal (part II) and interfacial gravity waves (part III). In particular, this thesis examines wave groups. Because they transport energy, momentum and other tracers, wave-induced mean flows have important consequences for climate, environment, air traffic, fisheries, offshore oil and other industries. In this thesis perturbation methods are used to develop a simplified understanding of the physics of the induced mean flow for each of these three types of gravity wave groups. Leading-order estimates of different transport quantities are developed. For surface gravity wave groups (part I), the induced mean flow consists of two compo- nents: the Stokes drift dominant near the surface and the Eulerian return flow acting in the opposite direction and dominant at depth. By considering subsequent orders in a separation of scales expansion and by comparing to the Fourier-space solutions of Longuet-Higgins and Stewart (1962), this thesis shows that the effects of frequency dis- persion can be ignored for deep-water waves with realistic bandwidths. An approximate depth scale is developed and validated above which the Stokes drift is dominant and below which the return flow wins: the transition depth. Results are extended to include the effects of finite depth and directional spreading. Internal gravity wave groups (part II) do not display Stokes drift, but a quantity analogous to Stokes transport for surface gravity waves can still be developed, termed the “divergent- flux induced flow” herein. The divergent-flux induced flow it itself a divergent flow and induces a response. In a three-dimensional geometry, the divergent-flux induced flow and the return flow form a balanced circulation in the horizontal plane with the former transporting fluid through the centre of the group and the latter acting in the opposite direction around the group. In a two-dimensional geometry, stratification inhibits a balanced circulation and a second type of waves are generated that travel far ahead and in the lee of the wave group. The results in the seminal work of Bretherton (1969b) are thus validated, explicit expressions for the response and return flow are developed and compared to numerical simulations in the two-dimensional case. Finally, for interfacial wave groups (part III) the induced mean flow is shown to behave analogously to the surface wave problem of part I. Exploring both pure interfacial waves in a channel with a closed lid and interacting surface and interfacial waves, expressions for the Stokes drift and return flow are found for different configurations with the mean set-up or set-down of the interface playing an important role.
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Faure, Olivier. "Simulation du mouvement brownien et des diffusions." Phd thesis, Ecole Nationale des Ponts et Chaussées, 1992. http://tel.archives-ouvertes.fr/tel-00523258.
Full textAbstract:
L'objet de cette thèse est l'étude de la simulation numérique de certains processus stochastiques, les diffusions, dont le mouvement brownien est un exemple typique. Nous commençons par quelques rappels sur le mouvement brownien au chapitre 1. Il s'agit d'une présentation élémentaire, qui s'appuie sur la simulation numérique, et permet de rappeler quelques propriétés classiques. Puis nous présentons au chapitre 2 une simulation alternative du mouvement brownien, en un sens plus naturelle, qui s'attache davantage à son comportement spatial que les méthodes traditionnelles. Le mouvement brownien est simulé à des instants aléatoires qui gouvernent son comportement; ce sont les temps de sortie de certaines "boîtes noires". En choisissant la taille et la position de ces boîtes noires dans l'espace, et sous réserve qu'elles se chevauchent, on peut ainsi simuler très précisément une trajectoire brownienne. La suite de la thèse est consacrée à l'analyse numérique des équations différentielles stochastiques (E.D.S) et à la simulation informatique de leur solution. Nous commençons au chapitre 3 par une introduction qui rappelle ce que sont les E.D.S, cite quelques unes de leurs propriétés et applications classiques dans les sciences de l'ingénieur. Au chapitre 4 nous présentons un résultat de convergence trajectorielle du schéma d'Euler en en précisant l'ordre de convergence. Un résultat similaire est présenté pour le schéma de Milshtein au chapitre 5. Comme on peut s'y attendre, ce schéma est plus performant que le schéma d'Euler, quand la condition classique de commutativité est vérifiée. Ceci améliore partiellement un résultat de Denis Talay. On étudie ensuite au chapitre 6 une classe de schémas de discrétisation à pas variables permettant une approximation spatiale des diffusions dans l'esprit du chapitre 2. Nous commençons par un résultat assez général de convergence d'un schéma d'Euler défini le long d'une subdivision aléatoire. Dans le cas où cette subdivision est gouvernée par les temps de passage successifs du mouvement brownien, nous retrouvons et étendons partiellement des travaux de Nigel Newton. Dans le cas où cette subdivision de façon à ce que les accroissements du schéma de discrétisation soient constants, nous étudions un schéma de discrétisation originalement présenté par Bichteler. Nous précisons sa vitesse de convergence et donnons une méthode de simulation numérique. Le chapitre 7 est un panorama des travaux existants sur la discrétisation des équations différentielles stochastiques. Sans prétendre être exhaustif, nous présentons au contraire une relecture des travaux existants dans l'optique de la simulation numérique. Enfin le chapitre 8 s'attache à quelques questions ou problèmes non résolus qui représentent un intérêt évident pour les applications. Nous suggérons pour chacune de ces questions quelques commencements de réponse.