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STRUCTURAL EVOLUTION OF AN INTRACRATONIC RIFT SYSTEM; MISSISSIPPI VALLEY GRABEN, ROUGH CREEK GRABEN, AND ROME TROUGH OF KENTUCKY, USAHickman, John Bibb, Jr. 01 January 2011 (has links)
As indicated by drilling and geophysical data, the Mississippi Valley Graben, the Rough Creek Graben, together with the Rome Trough of eastern Kentucky and West Virginia, are fault-bounded graben structures filled with as much as 27,000 feet of Early to Middle Cambrian sediments. Detailed regional mapping of Cambrian and younger strata within and surrounding these structures indicates that they formed contemporaneously. The proximity of these structures suggests they developed within the same regional stress fields and tectonic environments. These three structures are mechanically and kinematically connected, and formed part of a single continent-scale rift system produced during the breakup of Rodinia and the separation of Laurentia from Amazonia.
Data including stratigraphic tops from 1,764 wells, interpretations of 106 seismic profiles, aeromagnetic and gravity survey analysis, and mapped surface geology and structures were used within this project. Seven stratigraphic packages resolvable in both geophysical well logs and reflection seismic profiles were mapped in the subsurface across parts of Kentucky, Ohio, Indiana, Illinois, Missouri, and Tennessee. These stratigraphic units were then analyzed through structure maps, isopachous maps, and across 12 regional well-based cross sections.
Detailed analysis of thickness patterns of seven major stratigraphic packages was used to identify the locations and timing of major fault movements within the study area. The regional patterns of fault movements through time were used to investigate how the structures evolved in response to the tectonic episodes in southeastern Laurentia during the Cambrian through Devonian Periods.
Active rifting of the Precambrian crystalline bedrock began by the Early Cambrian, and resulted in a thick deposit of Reelfoot Arkose and Eau Claire Formation within the Mississippi Valley and Rough Creek Grabens, and the Rome Formation and Conasauga Group within the Rome Trough. Major tectonic extension ended by the Late Cambrian, prior to the deposition of the Knox Supergroup. Counter-clockwise rotation of the regional sigma-1 stress field between the Middle Ordovician and Early Mississippian (Taconic through Acadian Orogenies) resulted in the reactivation of varying sets of preexisting faults through time. The locations, orientations, and timing of these active faults relate to the deep architecture of the rift system.
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Monitoring and modelling mire hydrology for conservation managementMacAlister, Charlotte Rachel January 2001 (has links)
The functional hydrological components of the ombrotrophic mire water balance are, considered in terms of their ecological relevance. It is proposed that numerical models provide a suitable framework for mire hydro-systems and their potential as quantitative tools for mire restoration and conservation management is demonstrated. Existing models previously applied to mires are reviewed. The USGS 3-D groundwater model MODFLOW is selected and a new shallow surface and groundwater model GSHAW5 is developed for application to mires. Extensive ecohydrological case studies are undertaken at two mire sites and the models are tested using data collected at the sites. Field studies at Wedholme Flow, Cumbria, extended over four years and the data collected were combined with historical records to form a 10-year hydrological data set. Studies at Trough End Bog, Northumbria, extended over a 3-year period. Topographic, soil and vegetation surveys were carried out at both sites. Watertable fluctuation was recorded manually on a weekly basis and electronically at a 20-minute interval along with automatic meteorological records. New hydrometric techniques were developed in the Surface Water Monitoring Plot, SWaMP, constructed at Trough End to record hydrological exchanges within the hummock-hollow complex of the mire acrotelm. The models operate on very different spatial and temporal scales. GSHAW5 is applied to reproduce ground and surface exchanges in the acrotel. MODFLOW is used to simulate large-scale exchanges in undisturbed areas and between regenerating and active peat cutting areas. Predictive MODFLOW simulations are used to examine the impact of different peat cutting regimes on mire hydrology and potential regeneration. Both models produce simulations strongly correlated to observed hydrological exchanges. The usefulness of numerical models as tools for mire management is considered in light of the model test results from both case studies. It is concluded that both models provide insight and quantitative estimates of hydrological exchanges not possible by other means. MODFLOW simulations reveal considerable water loss from the Wedholme Flow mire reserve to an active peat cutting area. Simulations of Trough End bog reveal hydrological acrotelm processes strongly related to vegetation assemblages. An extensified GSHAW5 acrotelm model is recommended for the simulation of intact ombrotrophic mires.
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Structural restoration and application of dynamic Coulomb wedge theory to the Nankai Trough accretionary wedge toeStuder, Melody A January 2007 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 66-78). / x, 78 leaves, bound ill. (some col.), map 29 cm
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Analyzing automatic cow recordings to detect the presence of outliers in feed intake data recorded from dairy cows in Lovsta farmKogo, Gloria January 2016 (has links)
Outliers are a major concern in data quality as it limits the reliability of any data. The objective of our investigation was to examine the presence and cause of outliers in the system for controlling and recording the feed intake of dairy cows in Lovsta farm, Uppsala Sweden. The analyses were made on data recorded as a timestamp of each visit of the cows to the feeding troughs from the period of August 2015 to January 2016. A three step methodology was applied to this data. The first step was fitting a mixed model to the data then the resulting residuals was used in the second step to fit a model based clustering for Gaussian mixture distribution which resulted in clusters of which 2.5% of the observations were in the outlier cluster. Finally, as the third step, a logistic regression was then fit modelling the presence of outliers versus the non-outlier clusters. It appeared that on early hours of the morning between 6am to 11.59am, there is a high possibility of recorded values to be outliers with odds ratio of 1.1227 and this is also the same time frame noted to have the least activity in feed consumption of the cows with a decrease of 0.027 kilograms as compared to the other timeframes. These findings provide a basis for further investigation to more specifically narrow down the causes of the outliers.
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INITIAL MICROSEISMIC RECORDINGS AT THE ONSET OF UNCONVENTIONAL HYDROCARBON DEVELOPMENT IN THE ROME TROUGH, EASTERN KENTUCKYHolcomb, Andrew 01 January 2017 (has links)
The Cambrian Rogersville Shale is a part of a hydrocarbon system in the Rome Trough of eastern Kentucky and West Virginia that can only be produced unconventionally. In Kentucky, the Rogersville Shale ranges in depth from ~1,800 to ~3,700 m below the surface with the crystalline basement ~1,000 m lower than the formation’s base. Baseline Rome Trough microseismicity data were collected, focusing on wastewater injection wells and recently completed and planned unconventional hydrocarbon test wells in the Rogersville Shale, using thirteen broadband seismic stations installed between June, 2015 and June, 2016 and existing University of Kentucky and central and eastern United States network stations. In addition, the network’s minimum detection threshold, the magnitude at which the theoretical signal exceeds the noise by a factor of 3 between 1 and 20 Hz for at least 4 stations, was estimated for the project area. Thirty-eight local and regional events were located and magnitudes were calculated for each event. No events were proximal to operating disposal or hydrocarbon test wells, nor did any occur in the eastern Kentucky’s Rome Trough. The minimum detection threshold varies between 0.4 and 0.7 Mw from 0000-1100 UTC and 0.6 to 0.9 Mw from 1100-2300 UTC.
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Approches physiologiques et génomiques d'une archée thermo-piézophile Thermococcus piezophilus / Physiological and genomic approaches of a thermo-piezophile archeon involved in the sulfur cycleDalmasso, Cécile 09 December 2016 (has links)
Suite à la découverte récente des sources hydrothermales les plus profondes de la planète au niveau de laFosse des Caïmans, des échantillons hydrothermaux y ont été prélevés en vue de cultiver des microorganismes de ce site encore peu documenté. Des cultures d’enrichissement ont été réalisées à partir de ces échantillons en vue d’isoler de nouveaux taxons microbiens ayant des métabolismes clés des cycles biogéochimiques du soufre et du carbone ou une physiologie particulière (piézophilie). Parmi les isolats obtenus, il y avait notamment une nouvelle archée hyperthermophile anaérobie sulfo-réductrice, désignée comme CDGST, qui provenait du champ hydrothermal Beebe, à 4964 m de profondeur. Cette souche, affiliée au genre Thermococcus, présentait une certaine plasticité physiologique et se démarquait de ses plus proches parents du point de vue de sa physiologie.Elle a été caractérisée en détails aux niveaux métabolique, physiologique et génomique. Cette souche estpiézophile et possède la plus large gamme de pression de croissance jamais décrite pour un organisme. Elle se développe de manière optimale à 75°C, pH 6,0 et sous une pression hydrostatique de 50 MPa, la pression in situ de son habitat naturel. Elle appartient à une nouvelle espèce qui a été appelée Thermococcus piezophilus sp.nov. Son génome a été séquencé et annoté.La croissance de ce nouvel isolat est efficace de pression atmosphérique jusqu’à au moins 120 MPa, et la souche croît avec plus de difficultés jusqu'à 130 MPa. Aucun autre microorganisme, qu’il soit psychrophile, mésophile ou hyperthermophile ne possède une telle gamme de pression de croissance. Pour cette raison, les mécanismes d’adaptation de cette souche à la pression ont été étudiés par une approche de transcriptomique.Cette souche s’adapte aux variations de pression notamment en modulant sa production et sa conversion d’énergie (transporteurs, hydrogénases, etc.) en fonction de la pression. / Following the recent discovery of the world’s deepest hydrothermal vents at the Cayman Trough, hydrothermal samples were taken for culturing microorganisms of this site still poorly documented. Enrichment cultures were performed using these samples to isolate new microbial taxa having key metabolisms of biogeochemical cycles of carbon and sulfur or a particular physiology (piezophily). Among the isolates, there was a new hyperthermophilic and anaerobic sulfur-reducing archaea, designated as CDGST, originating from the hydrothermal field Beebe, at 4964 m depth. This strain belonged to the Thermococcus genus. It exhibited some physiological plasticity and was distinguishable from its closest relatives from the point of view of its physiology. It has been characterized in great details at metabolic, physiological and genomics levels. This strain is piezophilic and has the broadest range pressure for growth ever described for an organism. It grows optimally at 75°C, pH 6.0 and under a hydrostatic pressure of 50 MPa, the in situ pressure of its natural habitat. It belongs to a new species that was called Thermococcus piezophilus sp. nov. Its genome has been sequenced and annotated.The growth of this new isolate is effective from atmospheric pressure to at least 120 MPa, and the strain grows with more difficulties up to 130 MPa. No other organism, whether psychrophilic, mesophilic or hyperthermophilic has such a range of growth pressure. For this reason, the adaptation mechanisms to pressure of the strain were studied by a transcriptomic approach. This strain adapts to pressure variations, by modulating notably its energy production and energy conversion (carriers, hydrogenases, etc.) depending on the pressure.
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3D Regional Geological Modelling in Structurally Complex Environments: Gaining Geological Insight for the Northern Labrador TroughMontsion, Rebecca January 2017 (has links)
3D geological modelling is becoming an effective tool for communication and development of geological understanding. This is due to increased computer performance and availability of improved geological modelling software. 3D geological modelling technology has reached the stage where it can be implemented in regionally extensive and geologically complex settings, with the ability to achieve geological insight beyond what could otherwise have been gained through 2D investigations alone. Insight includes better constrained fault and horizon topologies, refined fold geometries, improved understanding of tectonic processes, and characterization of deformational events. By integrating field observations, aeromagnetic maps, and 3D modelling techniques in the northern Labrador Trough, a regionally extensive and structurally complex geological environment, regional faults geometries and topological relationships were refined. Additionally, a new fault, the Ujaralialuk Fault, and two shear zones were interpreted. During modelling, several challenges were identified, including higher computational costs for regionally extensive models, sparse 3D constraints, algorithmic limitations related to complex geometries, and the large investment of time and effort required to produce a single model solution. A benefit of this investigation is that new insight was also gained for a greenfields region which may assist future exploration efforts. Developing 3D models in challenging environments allows for better definition of future workflow requirements, algorithm enhancements, and knowledge integration. These are needed to achieve a geologically reasonable modelling standard and gain insight for poorly constrained geological settings.
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Tracing Wyville Thomson Ridge overflow water in the Rockall TroughJohnson, Clare January 2012 (has links)
Although it has long been known that cold dense waters from the Nordic Seas overflow the Wyville Thomson Ridge, the water masses' subsequent pathways and fate have been uncertain. This study conclusively places Wyville Thomson Ridge Overflow Water (WTOW) as an important water mass in the eastern subpolar North Atlantic for the first time. Using a variety of chemical tracer s (chlorofluorocarbons, oxygen, nutrients and aluminium) in conjunction with temperature and salinity, WTOW is traced southwards into the northern and central Rockall Trough as well as into the channels between the western banks. The overflow water has a clear temperature, salinity and chlorofluorocarbon (CFC-11 and CFC-12) signature. Additionally, levels of aluminium are elevated in WTOW suggesting that this element is potentially a useful and novel water mass tracer. The lower oxygen layer complicates the use of dissolved oxygen and nitrate as tracers in the mid water column. However, higher and lower concentrations respectively in the western trough reveal the presence of WTOW in this area. The overflow water does not appear to have a silicate or phosphate signature. Two branches of WTOW exist in the Rockall Trough: a slow-moving indistinct intermediate branch (600-1200 m) f ound in both the east and west of the basin; and a coherent deep branch (> 1200 m) that flows southward along the western banks of the trough. As well as having a large spatial footprint within the Rockall Trough, intermediate a nd deep WTOW are temporally persistent being present 65-75 % of the time between 1975 and 2008. The signature of WTOW at intermediate depths is absent from the Ellett Line record in the mid-1980s and early-1990s. As deep WTOW is still observed during these periods flow over the Wyville Thomson Ridge cannot have ceased. Instead, it is proposed that the strength of the Subpolar Gyre is an important driver in the temporal distribution of intermediate WTOW within the Rockall Trough. When the gyre is strong, such as in the mid-1980s and early-1990s, the mid water column is dominated by waters originating from the west which block the southward flow of intermediate WTOW. In contrast, when the gyre is weak, such as in the late-1990s and 2000s, subpolar waters lie further west enabling intermediate waters within the Rockall Trough to be dominated by the southern orig inating Mediterranean Overflow Water and the northern water mass of WTOW.
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Dynamic process modelling of the HPS2 solar thermal molten salt parabolic trough test facilityTemlett, Robert 10 May 2019 (has links)
In recent years power generation from renewable energy has grown substantially both in South Africa and around the world. This growth is set to continue as there is more pressure to reduce the burning of fossil fuels. However, renewable energy power generation suffers from unpredictability, which causes problems when it comes to managing power grids. Concentrated Solar Power (CSP) plants offer a practical solution to store power in the form of thermal energy storage (TES). Thus, the plant can run when there is no solar energy available, leading to a more stable power supply. Unfortunately, CSP plants cost more than other renewables such as photovoltaic and wind power. Thus, there is a need for research into how to bring down the cost of CSP plants. One of the most proven types of CSP is the parabolic trough plant. The most recent innovation is to try and use molten salt as the heat transfer fluid which would reduce the cost of the plant. However, this new technology has not been implemented on a full scale CSP plant and little testing has been done to prove the technology. The HPS2 is a test facility aimed at testing the use of molten salt as a heat transfer fluid (HTF). This test facility, located in Evora Portugal, is being developed by an international consortium led by the German DLR institute of Solar Research. It is one of the first test facilities of its kind where experiments will be conducted to demonstrate the validity of using molten salt as a HTF and a storage medium in a parabolic trough CSP plant. The HPS2 test facility is not yet operational and there is a need for a dynamic thermofluid process model to better understand and predict both its steady state and transient operational behaviour. This dissertation reports on the development of such a dynamic thermofluid process model and the results obtained from it. The process model developed primarily focuses on the steam cycle with the TES incorporated into the model. The physical geometry of each of the components are employed to construct discretized elements for which the conservation of mass, energy, and momentum are applied in a one-dimensional network approach. The economizer and evaporator combined has a helical coil geometry and uses molten salt as a heat transfer fluid, which is unique. Thus, correlations had to be adjusted for the flow characteristics found in the economizer/evaporator. Results from the steady state simulations of the steam cycle show that the molten salt mass flowrate through the steam generation system will have to be reduced from the initially expected value to meet operational requirements. Results of the dynamic simulations show that the test facility will be able to produce a constant power supply despite transient solar conditions and highlights key dynamic responses for operators to be aware of.
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Numerické modelování proudění v bezpečnostním přelivu vybraného vodního díla / Modelling of Flow over Spillway of a DamDesatová, Martina January 2020 (has links)
This thesis deals with mathematical modelling of water flow through the safety object. It explains the principle of mathematical modelling and its laws. There is also present-ed the mathematical models used by numerical modelling. The results of mathemati-cal model Koryčany are included in this thesis compared with hydraulic calculations and physical model.
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