The ultimate goal of this project is to comprehensively investigate induced seismicity potential by studying the behavior of fault shear zones during high pressure CO2 injection for utilization and storage operations. Seismicity induced by fluid injection is one of the major concerns associated with recent energy technologies such as Carbon capture and storage (CCS) projects. CO2 injection increases reservoir pore pressure and decreases the effective stress causing deformation that can degrade the storage integrity by creating new fractures and reactivating faults. The first consequence is that reactivation of faults and fractures create a pathway for upward CO2 migration. The increased seismic activity is the second consequence, which raises the public concern despite the small magnitudes of such earthquakes. Changes in pore fluid pressure within the injection zone can induce low-magnitude seismic events. However, there are multiple involved Thermo-Hydro-Mechanical (THM) processes during and after fault slip that influences pore pressure and fault strength. Flash heating and thermal pressurization are two examples of such processes that can weaken the fault and decrease frictional resistance along the fault. The proposed study aims to use a multi-physics numerical simulation to analyze the fault shear zone mechanics and capture the involved THM processes during CO2 injection. In one study, a coupled THM model is performed to simulate stress and pore pressure changes in the fault and ultimately measuring the maximum induced magnitude. The other study investigates the response of the fault shear zone during CO2 injection with and without considering the thermal pressurization (TP) effect. In the third part, the realistic behavior of friction was studied by using a rate-and-state friction theory to capture the full earthquake rupture sequence. The outcome of the proposed project can significantly increase the efficiency and public acceptance of CCS technology by addressing the major concerns related to the induced seismicity due to CO2 injection.

Mississippi River affects the carbon dynamics in the northern Gulf of Mexico (N-GoM) significantly. Hence, total alkalinity (TA) algorithms developed for major ocean basins produce inaccurate estimations for this region. A TA algorithm was developed, which addresses the local effects of coastal processes and complex spatial influences. In-situ data collected during numerous previous research cruises in the N-GoM were compiled and used to calculate the efficiency of an existing TA algorithm that uses Sea-Surface-Temperature (SST) and Sea-Surface-Salinity (SSS) as explanatory variables. To improve this algorithm, statistical analyses were performed to improve the coefficients and functional form of this algorithm. Then, chlorophyll-a (Chla) was included as an additional explanatory variable. Chla worked as a proxy for addressing the organic carbon pump’s pronounced effects on coastal waters. Finally, a Geographically Weighted Regression (GWR) algorithm was developed to address spatial non-stationarity, which apparently could not be addressed in the previously developed global algorithm.

This thesis investigates the utilization of hydrodynamic models as tools for assessing factors impacting water quality in the Ross Barnett Reservoir. The primary focus is development of a hydrodynamic model that provides transport information to subsequent application of a water quality model. Environmental Fluid Dynamics Code (EFDC) is a complex, dynamic, multi-dimensional computer model used to simulate hydrology in water bodies. The secondary focus is on data acquisition and manipulation methods for completing the hydrodynamic modeling. Monitoring was completed to create modern bathymetry of Ross Barnett Reservoir to provide accurate model cell grid representation. Temperature and dissolved oxygen profile monitoring occurred to provide data for model output comparison. The EFDC model successfully predicted lake stratification and subsequent mixing based on changes in observed meteorological conditions.

The Abstract Data Model (ADM) was developed by Sanderson [19] to model and predict semantic loss in data translation between computer languages. In this work, the ADM was applied to eight languages that were not considered as part of the original work. Some of the languages were found to support semantic features, such as the restriction semantics for inheritance found in languages like XML Schemas and Java, which could not be represented in the ADM. A proposal was made to extend the ADM to support these semantic features, and the requirements and implications of implementing that proposal were considered.

This research effort first characterizes the trucks traveling along US highways by analyzing data from Interstate 81. It is hypothesized that I-81 is typical of US highways and thus can provide some insight into typical truck characteristics. These truck characteristics are important for the development of an exhaustive vehicle performance procedure. Analysis was done based on data collected at the Troutville weigh station. The characterization involves an analysis of vehicle class distribution, GVW (Gross Vehicle Weight) distribution, vehicle volume distribution, Average Weight on Tractive Axle (AWTA), and typical weight-to-power ratios. The thesis then assembles a database of systematic field data that can be utilized for the validation of vehicle performance models. This database is unique because it was conducted in a controlled field environment where the vehicle is only constrained by its dynamics. Using the assembled field database, a simple constant power vehicle dynamics model for estimating maximum vehicle acceleration levels based on a vehicle's tractive effort and aerodynamic, rolling, and grade resistance forces was tested and validated. In addition, typical model input parameters for different vehicle, pavement, and tire characteristics are included in the thesis. The model was found to predict vehicle speeds at the conclusion of the travel along the section to within 5 km/h (3.1 mi/h) of field measurements, thus demonstrating the validity and applicability of the model. Finally, the research effort introduces the concept of variable power in order to enhance current state-of-the-art vehicle dynamics models and capture the build-up of power as a vehicle engages in gearshifts at low travel speeds. The proposed enhancement to the current state-of-practice vehicle dynamics model allows the model to reflect typical vehicle acceleration behavior more accurately. Subsequently, the model parameters are calibrated using field measurements along a test roadway facility. / Master of Science

3D models have been widely used in many areas since decades ago. When BIM (Building Information Modelling) and VR (Virtual Reality) become popular recent years, 3D model, as an essential part of it has been frequently asked or even required, which is both a challenge and opportunity to a surveying engineer.   Through investigation of three different alternatives to create 3D models: image based, terrestrial laser scanning based and airborne laser scanning based modelling, the author aims to help a surveying engineer to choose the proper method and tool. Workflows, costs and applications have been discussed for each approach and the results show that image based modeling is most time and cost efficient but with lower accuracy which is suitable for visualization while thanks to the high resolution of data capture, terrestrial laser scanning based modeling can be utilized for detailed as-built modeling or BIM. The weakness of such method is the high initial cost and much time demanded; for large area city modeling, the airborne laser scanning approach is the most efficient way with limitations of the low level of details and expensive equipment.   However, it should be critical to understand that there is no automatic way to reconstruct a controllable 3D object at present. Due to the limited accessibility of equipment, the photogrammetric 3D building reconstruction method is not included in this study and thus, a future study may continue with this method. 3D object may be converted to a format that can be used in BIM, such kind of format exchange can be an interesting topic for further study.

Fluvial flooding has long been recognized as one of the most frequently occurring natural disasters worldwide, with consequences as large economic losses from damages on infrastructure and agriculture, as well as severe impacts on human health. A less known and explored type of flooding is groundwater flooding. A flood type that for instance can arise in river-connected floodplains when groundwater levels rise to the ground surface due to increased river stages in the watercourse. Although groundwater flooding in general is a poorly understood phenomenon, it has become more recognized since its inclusion in the European Floods Directive (2007/60/EC) in 2007. Sweden has however excluded pure groundwater flooding as a separate flood type in its interpretation of the directive, but recognizes groundwater as a component which together with soil water and river water can influence the appearance of a flood event. One of the difficulties regarding groundwater floods that occur in connection to a river is that they typically are hard to differentiate from inundations of fluvial or pluvial origin. It is however important to address the role of groundwater in the inundation of these settings, since traditional flood protection strategies like levees might be circumvented by flows through the subsurface. The aim of this study has been to investigate the role of groundwater in the flooding of a river-connected floodplain by setting up a groundwater model in the integrated hydrological modeling tool MIKE SHE and couple it to an existing MIKE 11 river model, developed by DHI. The study area is a floodplain located along the river Silverån, a tributary to the river Emån, located in the south eastern part of Sweden. By running the model using four different sub-scenarios, regarding initial groundwater level and amount of precipitation, flood extent and contribution of groundwater to the inundation, in relation to other flood sources, has been investigated for different river discharges. A scenario with artificial levees constructed along parts of the river was also examined as levees have been found to have little effect on groundwater floods. As the model provides a simplified and generalized representation of reality it possesses several uncertainties, and so does the results. In summary, the results are in line with what is stated in the Swedish interpretation of the European Floods directive. It has not been possible to demonstrate pure groundwater flooding, but the results suggest that an elevated groundwater level in the beginning of a flood event will increase the extent of the inundation and result in a larger contribution of groundwater to the total amount of flood water. This suggests that there, in some cases, might be a value in integrating groundwater processes in flood risk mapping. Something that is not included in the conventional hydraulic 1D and 2D models, which traditionally are used in flood mapping. As could be expected, the results indicate that groundwater only accounts for a minor part of the flood water added to the total floodplain, while the major sources are river water and surface runoff. A delimited floodplain section that was investigated more in detail, as an increased flow from groundwater to overland water was detected along it, did however show larger contributions from groundwater. This river reach was less vulnerable to fluvial flooding, which in total resulted in a less severe flood, but also enabled a larger amount of groundwater to seep up to the floodplain surface. These conditions did also result in that the river section experienced a worsened inundation at the sub-scenario of high precipitation and high initial groundwater level, as levees were constructed along the river. Most likely because a lot of surface runoff, otherwise able to drain to the river along this section, got trapped outside the levees since it was unable to drain both to the river and to the saturated ground. These results support the theory that levees have little impact on groundwater flooding and stresses the importance 0f surveying and understanding the governing processes in the inundation of a floodplain when planning which type of flood protection scheme to use. / Översvämning utmed vattendrag, så kallad fluvial översvämning, har länge varit känd som en av de vanligast förekommande naturkatastroftyperna världen över, med konsekvenser i form av stora ekonomiska förluster, skador på infrastruktur och jordbruk samt allvarlig påverkan på människors hälsa. En mindre känd och utforskad översvämningstyp är grundvattenöversvämning. En typ av översvämning som kan uppstå i svämplanet längs ett vattendrag då grundvattennivån går upp i markytan till följd av förhöjda nivåer i vattendraget. Trots att grundvattenöversvämning generellt sett är ett outforskat fenomen har det blivit mer uppmärksammat sedan det inkluderades i det europeiska översvämningsdirektivet (2007/60/EG) som antogs 2007. I Sverige har man dock valt att exkludera renodlade grundvattenöversvämningar ur sin tolkning av direktivet och sagt att sådana inte förekommer i Sverige. Istället ser man grundvattnet som en av delarna i ett samverkande system, där det tillsammans med markvatten och ytvatten kan ha påverkan då ett vattendrag översvämmas. En svårighet med grundvattenöversvämningar som inträffar i anslutning till vattendrag är att de kan vara svåra att skilja från översvämningar med fluvialt eller pluvialt ursprung. Det är dock viktigt att uppmärksamma grundvattnets roll i den här typen av översvämningar då traditionella åtgärder som sätts in mot översvämningar, såsom invallningar, kan kringgås av flöden genom marken. Syftet med den här studien har varit att undersöka grundvattnets roll vid en översvämning utmed ett vattendrag genom att konstruera en grundvattenmodell i det integrerade hydrologiska modellverktyget MIKE SHE och koppla denna till en befintlig MIKE 11 vattendragsmodell, utvecklad av DHI. Modellområdet som studerats är beläget längs Silverån, ett av biflödena till Emån i sydöstra Sverige. Genom att undersöka fyra olika delscenarion, avseende initial grundvattenyta och nederbördsmängd, har översvämningsutbredning samt grundvattnets bidrag till översvämningen utvärderats för olika vattenflöden. Ett scenario där invallningar konstruerats längs delar av vattendraget har också undersökts, eftersom invallningar visat sig ha begränsad effekt på grundvattenöversvämningar. Eftersom modellen utgör en förenklad och generaliserad representation av verkligheten har den flertalet osäkerheter, något som även gäller för modellresultaten. Sammanfattningsvis kan sägas att resultaten är i linje med den svenska tolkningen av det europeiska översvämningsdirektivet. Det har inte varit möjligt att påvisa renodlade grundvattenöversvämningar. Däremot pekar resultaten på att en förhöjd grundvattennivå under inledningen av ett översvämningstillfälle kommer att bidra till en ökad översvämningsutbredning, samt ett större bidrag av grundvatten till den totala mängden översvämningsvatten. Detta indikerar att det i vissa fall skulle kunna finnas en mening i att inkludera grundvattenprocesser vid översvämningskartering. Något som inte finns med i de konventionella hydrauliska 1D- och 2D-modeller som traditionellt används vid översvämningskarteringen. Som väntat visar resultaten på att grundvattnet står för en mycket liten del av det vatten som totalt översvämmar det undersökta svämplanet, och att de främsta källorna är vatten från vattendraget tillsammans med ytavrinning. Längs en avgränsad sträcka av svämplanet som undersöktes mer i detalj, då ett ökat flöde från grundvatten till vatten på markytan påträffades längs denna, återfanns dock ett större bidrag från grundvattnet. Denna del av svämplanet var mindre känsligt för fluvial översvämning, något som på det hela taget resulterade i en mindre allvarlig översvämning, men också tillät en större mängd grundvatten att tränga upp på markytan. Dessa förhållanden ledda också till att den aktuella delen av svämplanet kom att få en förvärrad översvämning då vallar konstruerades för delscenariot med hög nederbörd och initialt hög grundvattenyta. Detta till följd av att en stor mängd ytavrinning, som tidigare kunnat dräneras till den här delen av vattendraget, fastnade utanför vallarna istället för att avledas till vattendraget eller infiltrera den mättade marken. Dessa resultat kan sägas stödja teorin kring att invallningar har liten påverkan på grundvattenöversvämningar och visar på vikten av att undersöka och förstå styrande processer kring översvämningen av ett svämplan då åtgärder mot översvämning planeras.

<p dir="ltr">The Cascadia margin in the Pacific Northwest of US is characterized by the subduction of the young and warm Juan De Fuca beneath the North American plate. This region shows strong correlations in spatial heterogeneities in geophysical observations such as thickness of low shear wave velocity zones in the lower crust, tremors distribution, intraslab seismicity, topography, uplift rates, and Bouguer gravity anomalies. In this thesis, both 3D and 2.5D forward gravity modeling have been conducted to understand the composition of the materials at ~20-40 km along the Cascadia subduction margin, that can explain the spatial heterogeneities by linking them together.</p>

The United Nations have declared the effects of climate change as the “defining issue of our time” (United Nations, 2019). As a result of increased industrialization in the last century to keep up with the demands of a growing global population, the global output of greenhouse emissions has rocketed, which is linked to the shifting and abnormal weather patterns of the planet. Electricity and heat production alone are attributed to generating 25% of greenhouse gas emissions (Edenhofer, et al.). To alleviate the increasing levels of carbon emission there is an effort to transition in green energy power generation sources like wind energy that is abundantly available in the midwestern United States. This study aims to implement the Blade Element Method derived modeling methods for predicting the performance of a wind turbine. The experimental results obtained from the MEXICO project is employed as the validation source for the research.

Hybrid organic-inorganic nanocomposites have received considerable attention during the last five years due to their unexpected properties. This work incorporated nanodispersed organically modified montmorillonite clay into polydicyclopentadiene resin matrices. Montmorillonite consists of 1 nm platelet sheets with a 2:1 structure, consisting of an alumina octahedral layer sandwiched between two silica tetrahedral layers. The relative weak forces between platelets allow small molecules like water, solvents and monomers as well as polymers, to enter into the interlayer spacings between the platelet sheets. In-situ polymerization of highly delaminated clay/dicyclopentadiene(DCPD) dispersions was used to prepare clay/polydicyclopentadiene (polyDCPD) nanocomposites. Highly delaminated composites were characterized using X-ray diffraction, X-ray scattering and high resolution TEM. Composites with 0.5-1 weight percent of clay had higher Tg values and flexural moduli. The flow properties of the organically-modified montmorillonite/DCPD liquid dispersions were examined using a co-rotating viscometer. The dispersions with clay concentrations higher than 0.5wt% clay in DCPD showed thixotropic flow behavior. Small angle neutron scattering (SANS) experiments were performed to obtain anisotropic scattering of highly delaminated clay in DCPD due to the orientation of clay platelets and tactoids in the shear field. No anisotropic scattering was observed. The reason for this unexpected result is not yet understood. Highly delaminated organically-modified clay composites were examined using small angle neutron scattering (SANS) and ultra small angle neutron scattering (USANS). The SANS data from 0.5, 1 and 2wt% clay/polyDCPD composites with 2 different types of clay were fitted to the stacked disk model. The average number of clay layers per tactoid was predicted by fitting the experimental data to the stacked disk model. Extensive high-resolution TEM analyses were performed on the same samples to obtain the average numbers of clay layers per tactoid. Two finite element models, one for the intercalated clay/polyDCPD nanocomposite and one for the exfoliated clay/polyDCPD nanocomposite, were developed. The effects of these different dispersion geometries for seven platelets in the polyDCPD matrix on the stress distributions were examined. The exfoliated platelet model showed reduced deformations and uniform stress distributions. The highest stress concentrations were found on the platelets? surfaces and where platelets were in close proximity.