Geological Engineering Commons^™

Joint Diagonalization Applied To The Detection And Discrimination Of Unexploded Ordnance, Fridon Shubitidze, Juan Pablo Fernández, Irma Shamatava, Benjamin Barrowes, Kevin O’Neill

Dartmouth Scholarship

Efforts to discriminate buried unexploded ordnance from harmless surrounding clutter are often hampered by the uncertainty in the number of buried targets that produce a given detected signal. We present a technique that helps determine that number with no need for data inversion. The procedure is based on the joint diagonalization of a set of multistatic response (MSR) matrices measured at different time gates by a time-domain electromagnetic induction sensor. In particular, we consider the Naval Research Laboratory’s Time-Domain Electromagnetic Multisensor Towed Array Detection System (TEMTADS), which consists of a 5×5 square grid of concentric transmitter/receiver pairs. The diagonalization process …

Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob

Michigan Tech Publications

The effects of future land use and land cover change on the chemical composition of the atmosphere and air quality are largely unknown. To investigate the potential effects associated with future changes in vegetation driven by atmospheric CO 2 concentrations, climate, and anthropogenic land use over the 21st century, we performed a series of model experiments combining a general circulation model with a dynamic global vegetation model and an atmospheric chemical-transport model. Our results indicate that climate-and CO 2-induced changes in vegetation composition and density between 2100 and 2000 could lead to decreases in summer afternoon surface ozone of up …

Imaging The Subsurface In Karst Terrain Using Electrical Resistivity Tomography, Evgeniy V. Torgashov

Doctoral Dissertations

"Five electrical resistivity tomography (resistivity) case studies are presented. The first case study, entitled "Springfield Underground", includes ERT data acquired with the purpose of imaging the ceiling of an limestone aggregate mine following simultaneous localized roof failure. The interpretation of the ERT data indicates roof rock failure occurred at the intersection of two previously unmapped near-vertical solution-widened fractures.

At the "Chesterfield Dam" site, resistivity data were acquired to identify the zone of seepage through an earthfill dam. The seepage pathway beneath the dam is interpreted as through a solution-widened fracture, the top of which constituted a segment of the original …

Capture Zone Modeling For Photovoltaic Microgrid Powered Pump And Treat Remediation, John Patrick Conroy

Masters Theses

"Remediation systems protect human health and the environment by removing harmful contaminants from the environment. Pump and treat groundwater remediation systems typically rely on utility power to continuously pump contaminated groundwater to an above ground treatment unit. However, the use of renewable energy (solar and wind) for a pump and treat remediation system can reduce the output of harmful greenhouse gases and the need for coal-based utility power.

This paper describes a hypothetical renewable energy powered pump and treat remediation system that uses an off-grid photovoltaic array to power a submersible solar water pump. The pump operates on an intermittent …

Analyses Of Surface Wave Seismic Data And Supplemental Borehole And Electrical Resistivity Tomography Control, Mengxing Li

Masters Theses

"Multichannel analyses of surface wave (MASW) data and electrical resistivity tomography (ERT) control were acquired at two test sites in central Missouri. Limestone bedrock existed at both test sites at variable depths. The ground surface at both test sites was relatively flat.

The primary objective was to map the variable depth to the top of the rock based on shear-wave velocity contrasts. ERT data and borehole control were acquired at each site in order to constrain the interpretation of the MASW data.

The MASW method proved to be more effective than the ERT method in terms of mapping soil layers …

Surface Expressions Of Discontinuities, And The Estimation Of Their 3-D Orientations Using Combined Lidar And Optical Imaging, James Nii Aboh Otoo

Doctoral Dissertations

"The importance of the collection and analysis of data on discontinuities cannot be overemphasized. Problems which include sampling difficulties, risks, limited access to rock faces and exposures, and the delay in data collection has led to a high need for data collection tools and analysis techniques that can overcome these problems.

Discontinuities manifest themselves as either traces or as facets. Traces are linear features that intersect with both the discontinuity and the rock cut. Facets are the actual discontinuity surfaces that are exposed in the rock cut. Facets can be natural or induced. Identifying a facet as either natural or …

Influence Of Capillary Heterogeneity On Leakage Of Co2 From A Borehole, Frank Roecker

Electronic Theses and Dissertations

We used a modified invasion percolation (MIP) model to examine the effect of capillary heterogeneity, buoyancy forces, and viscous forces on the surface area and saturation of a CO2 plume leaking into a shallow aquifer. The purpose of this study is to provide a better understanding of how CO 2 migrates from a borehole, which is essential in implementing effective simulation and monitoring regimes to accurately detect CO2 leakage from sequestration sites. The MIP model approach will simulate invasion of a light non-wetting fluid (e.g., CO2) into a medium initially saturated with a dense wetting fluid (water). The style of …

The Use Of Electrical Resistivity Tomography (Ert) To Delineate Water-Filled Vugs Near A Bridge Foundation, Jeremiah Chukwunonso Obi

Masters Theses

"A structural support was needed to strengthen the load-bearing capacity of an unnamed bridge foundation in Laclede County in South-Central Missouri due to increasing traffic volume and age of the bridge. This area is characterized by karstic features such as losing streams, underground caves and sinkholes. During the construction of a drilled shaft for the substructure, a few feet north of the north footing of the pier, voids were noted beneath a roughly 2 foot thick cap of dolomite rock. Because of this, there were concerns about the integrity of the rock beneath the existing bridge foundation. Consequently, subsurface investigation …

Visualizing And Modeling Interior Spaces Of Dangerous Structures Using Lidar, Norbert H. Maerz, T. K. Assebaum, Dustin J. Williams, K. Shea, Yongjian Xi, Xiaoling Li, Ye Duan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

LIght Detection and Ranging (LIDAR) scanning can be used to safely and remotely provide intelligence on the interior of dangerous structures for use by first responders that need to enter these structures. By scanning into structures through windows and other openings or moving the LIDAR scanning into the structure, in both cases carried by a remote controlled robotic crawler, the presence of dangerous items or personnel can be confi rmed or denied. Entry and egress pathways can be determined in advance, and potential hiding/ambush locations identifi ed. This paper describes an integrated system of a robotic crawler and LIDAR scanner. …

Performance Characterization And Optimization Of Microgrid-Based Energy Generation And Storage Technologies, Joe D. Guggenberger Ii

Doctoral Dissertations

"Renewable energy-powered microgrids have proven to be a valuable technology for self-contained (off-grid) energy systems. Characterizing microgrid system performance pre-deployment would allow the system to be appropriately sized to meet all required electrical loads at a given renewable source operational time frequency. A vanadium redox battery was empirically characterized to determine operating efficiency as a function of charging characteristics and parasitic load losses. A model was developed to iteratively determine system performance based on known weather conditions and load requirements. A case study was performed to compare modeled system performance to measurements taken during operation of the microgrid system. Another …

Saturation Effects On Mechanical Excavatability Of Roubidoux Sandstone Under Selected Rock Cutting Tools, Muhammad Zubair Abu Bakar

Doctoral Dissertations

"This study investigated the differences in the cutting performance of two rock cutting tools in dry and saturated rock. For this purpose, a permeable quartzose sandstone was subjected to a series of full scale linear rock cutting tests, in both dry and saturated conditions, using a constant cross-section (CCS) disc cutter and a radial drag pick at a constant cutting speed.

In this rock, saturation with water reduced the forces acting on the disc cutter by 27-48% (significant at 90% confidence), but also reduced the chip yield by nearly as much. Even though the specific energy of fragmentation went down …

Measuring The Orientations Of Hidden Subvertical Joints In Highways Rock Cuts Using Ground Penetrating Radar In Combination With Lidar, Adnan Mohammed Aqeel

Doctoral Dissertations

"Mapping discontinuities in rock cuts and measuring their orientations is crucial in assessing the stability of rock masses. This can be done usually using manual methods such as scanline or advanced techniques such as LIDAR. However, these methods are used only to map exposed discontinuities which may cause underestimation for slope stability. Accordingly, ground penetrating radar (GPR) has been recently used to detect such hidden discontinuities.

The used 400 MHz monostatic GPR antenna was significantly able to detect and map hidden subvertical joints within 4 m depths in five sandstone highways rock cuts and within 3 m depths in two …