Engineering Commons^™

Novel Uses Of Distributed Optical Fiber Sensing For Geo-Mechanical Monitoring, Samuel Vincent Nowak

Doctoral Dissertations

"Rock mass monitoring in underground excavations is crucial for ensuring workplace safety and efficiency. As mines become deeper and more complex, the need to monitor larger volumes of rock during mining becomes impractical with existing instruments due to high costs. Distributed Optical Fiber Sensing (DOFS) is a powerful technology with advantages like long sensor length, real-time measurement capabilities, ease of installation, low cost, and distributed measurement. However, its application in rock mass monitoring is limited, especially in the mining industry. This study addresses a major gap in DOFS technology, specifically the inability of long-range distributed optical fiber strain sensors to …

Optimization Of Fire Emergency Preparedness In Underground Mining Environments: An Agent-Based Evacuation Approach, Oluwafemi Babatunde Salami

Doctoral Dissertations

"Underground mining environments present a complex interplay of thermal and non-thermal hazards, with fires constituting a significant risk due to the release of heat smoke from incomplete combustion. The propagation of these hazards through the ventilation networks underscores the critical need for understanding fire scenarios and their interaction with the underground environment. Existing knowledge regarding past mine fire disasters, and quantification of associated hazards and risks are insufficient for optimizing emergency evacuation strategies in the event of an underground fire emergency.

This research endeavors to bridge this gap by developing advanced quantitative risk assessment and evacuation models tailored specifically for …

Monitoring And Control Of Coal Dust Exposure Using Low-Cost Pm Sensors And Computational Fluid Dynamics, Nana Kobina Amoako Amoah

Doctoral Dissertations

"Overexposure to respirable coal mine dust has been linked to causing serious health problems including coal workers pneumoconiosis (CWP) and chronic massive fibrosis. The prevalence of these health problems has been on the increase since the 2000s due to increased exposure levels with roof bolter operators having the highest exposure levels. The currently used PDM3700 is too expensive, heavy and bulky which limits their use only for regulatory monitoring failing to measure miners’ personal exposure levels. Also, since roof bolter operators are more prone to elevated coal dust levels, the canopy air curtain (CAC) was developed to protect then high …

Investigating Detonation Parameters Through The Plate Dent Test: A Novel Approach For Characterizing Detonation Curvature And Thickness, Emily Michelle Johnson

Doctoral Dissertations

Detonation is the driving factor behind how an explosive, used in an array of applications, performs. Understanding and measuring detonation parameters of an explosive is key in explosive charge design and application. Currently, determining parameters is costly as the instrumentation needed is expensive in terms of price, maintenance, and personnel. This research examines two methods of determining detonation parameters through measurement of secondary material response to the detonation wave in an effort to provide an alternate, simple, and inexpensive method of measurement. The first of these studies focuses on the Gurney Model and demonstrates that the model's accuracy was diminished …

Effects Of Downwash When Measuring Gas Concentration With Uav-Mounted Gas Sensors, Jacob Lane Brinkman

Doctoral Dissertations

"This research concludes that the downwash region of a rotary-wing unmanned aerial vehicle (UAV) does not produce pressure variations substantial enough to cause significant changes in density-based gas concentration measurements. US regulations evaluate gas concentration as a function of gas density, and accurate concentration measurements are critical for protecting health and safety, which means evaluation of actual downwash effects on measured gas concentration is essential.

During experimentation, the UAV was fixed to a stand in a sealed chamber filled with NOx (NO and NO₂) of constant concentration. The UAV rotors ran at hovering speeds, and gas concentrations were …

Depression Of Pyrite In Polymetallic Sulfide Flotation Using Chitosan-Grafted-Polyacrylamide Polymers, Keitumetse Cathrine Monyake

Doctoral Dissertations

“In this work, Chitosan-grafted-Polyacrylamides (Chi-g-PAMs) were studied, for the first time, as selective depressants of pyrite in the flotation of base metal sulfides. Fundamental studies of the adsorption behavior of Chi-g-PAM on model sulfide minerals indicated that Chi-g-PAM was more selective to pyrite’s surfaces as compared to base metal sulfides. Results suggested that the adsorption of Chi-g-PAM at pyrite-water interface was a chemisorption in nature which involved the amine, amide, and hydroxyl groups of Chi-g-PAM. Batch flotation studies of complex sulfide ore of Mississippi Valley Type (MVT) showed that Chi-g-PAM outperformed other pyrite’s depressants at producing less pyrite-diluted concentrates. Statistical …

Investigation Of Anomalous Data Trends During Coal Dust Explosibilty Testing, Jacob Lee Miller

Doctoral Dissertations

Coal dust explosibility is a health and safety concern that has been a recognized hazard for over 100 years. Initial testing by the Author using a Siwek 20L apparatus recorded a secondary maximum pressure at higher dust concentrations (1,000-7,000g/m³) with Pulverized Pittsburgh Coal (PCC). Higher dust concentrations are beyond the typical ASTM E1226 testing procedure but are possible in mining and processing scenarios. No reference documents have been discovered that show a secondary maximum pressure at higher dust concentrations. Literature reviewed identified that once a coal dust concertation generates a peak pressure, the pressure remains constant or decreases …

Using Similitude Theory And Discrete Element Modeling To Understand The Effects Of Digging Parameters On Excavation Performance For Rubber Tire Loaders, Atta Ur Rehman

Doctoral Dissertations

"The large sizes of mining equipment pose challenges for analysis using experiments or simulation. While scaled physical and simulation models can address this challenge, no previous work has explored how similitude theory and modeling can provide valid analysis of large equipment such as rubber tire loaders. The objective of this research was to apply similitude theory and discrete element modeling (DEM) to study the effect of different digging parameters on the penetration and the draft on the buckets of rubber tire loaders. The work sought to (1) test the hypothesis that the geometry of a rubber tire loader bucket and …

Computational Intelligent Impact Force Modeling And Monitoring In Hislo Conditions For Maximizing Surface Mining Efficiency, Safety, And Health, Danish Ali

Doctoral Dissertations

"Shovel-truck systems are the most widely employed excavation and material handling systems for surface mining operations. During this process, a high-impact shovel loading operation (HISLO) produces large forces that cause extreme whole body vibrations (WBV) that can severely affect the safety and health of haul truck operators. Previously developed solutions have failed to produce satisfactory results as the vibrations at the truck operator seat still exceed the “Extremely Uncomfortable Limits”. This study was a novel effort in developing deep learning-based solution to the HISLO problem.

This research study developed a rigorous mathematical model and a 3D virtual simulation model to …

Relating Detonation Parameters To The Detonation Synthesis Of Nanomaterials, Martin Langenderfer

Doctoral Dissertations

“This research investigates the physical and chemical processes that contribute to the detonation synthesis of silicon carbide nanoparticles. Bulk production of SiC nanoparticles through detonation is possible due to pressures achieved over 20 GPa and temperatures over 2000 K as well as quenching rates in excess of 13 billion K/second. These conditions catalyze reaction and bottom-up molecular growth while retaining particles < 100 nm in diameter. In this work, detonation synthesis of SiC was demonstrated by incorporation of polycarbosilane, an SiC precursor material, into an RDX/TNT explosive matrix prior to detonation. Detonation Synthesis of SiC was also accomplished by reacting elemental silicon with carbon liberated by the detonation of negatively oxygen balanced TNT. Hydrodynamic simulation of a 60:40 mass ratio RDX/TNT detonation created conditions thermodynamically suitable to produce cubic silicon carbide within the first 500 nanoseconds after the passage of the detonation wave while carbon remains chemically reactive for molecular formation. Simulations and experimental tests indicated that loading configuration and impedance mismatch of the precursor additives used in detonation synthesis results in conditions in the additives that exceed the accepted detonation pressure of the explosive by greater than three times. Finally, a full factorial experimental design showed increasing silicon concentration, reducing silicon size, and reducing oxygen balance by adjusting the ratio of RDX to TNT decreased the explosives detonation pressure by 20% and increased the soot yield and concentration of SiC observed in the detonation products by 82% and 442% respectively”--Abstract, page iv.

Evaluation Of Excavated Surface Irregularities And Hardness Of Mechanical Excavations And Their Relationship With Excavator Performance, Prosper Evaristus Akansah Ayawah

Doctoral Dissertations

"This research involved lab and numerical excavation of a clastic sedimentary rock (Roubidoux Sandstone) using a long-bladed disc cutter in a Linear Rock Cutting Machine (LCM) with the aim of establishing relationships between the cutting parameters, excavated surface parameters (underbreaks, overbreaks and hardness), and performance parameters (specific energy and cutting rate). Three-dimensional cutting forces were recorded during the linear cutting. A structured laser imaging system was used to image the excavated surfaces for the estimation of the irregularities (ridge volumes (RV) and overbreak volumes (OV)). The excavated surface hardness was measured using the N-type Schmidt hammer. The numerical simulation was …

Mining Haul Road Defect Detection -- Advancement In Automated Road Extent And Response Calibration For Improved Maintenance, Alexander David Douglas

Doctoral Dissertations

Mine haul roads degrade rapidly due to extremely heavy loads on sub optimal construction materials. This research tests two methods of defect detection to determine limitations to current technology: optical detection and vehicle vibration response. Optical defect detection was found to have the least significant limitations for surface defect detection and vehicle vibration response modeling has the least significant limitations for subsurface defects. This research proposes novel methods to eliminate the critical limitations of both technologies.

Unmanned Aerial Vehicles (UAV) equipped with GPS and a high-resolution camera is used to create a 3-D point cloud using a structure-from-motion algorithm. This …

Investigating The Focusing Effect Of Charge Geometry With Computer Simulations, Witness Plates, And High-Speed Videography, Kelly Ray Williams

Doctoral Dissertations

"Scaled distance is used to calculate a safe standoff radius from the detonation of a known mass of an explosive. It has been shown that varying only the geometry of the charge significantly overdrives regions of the blast wave potentially resulting in hazardous overpressure levels at scaled distance safe radii. Pressure transducers are used to measure overpressure surrounding spherical, cylindrical, and cubic charges to determine if bridge waves were formed at the edges between flat sides as seen in published studies of cylindrical charges. In the fireball field a witness plate is used to evaluate radial energy distribution with a …

Assessment Of Rib Failure Mechanisms Using Discontinuum Mechanics Based Modeling Approach, Maurice Nuonituo Sunkpal

Doctoral Dissertations

"Coal mine rib failures are major safety and health challenge for coal mines worldwide. The need for clear procedures to evaluate mine rib behavior and to provide an efficient, reliable, and consistent rib control protocol is needed. Understanding coal rib geomechanics is essential for improving rib stability and eliminating fatality and injury trends due to rib failures. This knowledge is also vital to determine support requirements.

The rib control practices used in the 21st Century in most countries originated in roof control techniques. Understandably, applying roof control methods to coal rib does not yield desirable results. The geology of structures …

Application Of Geophysics And Remote Sensing Techniques For Economic Mineral Exploitation In Libya, Awad Abdussalam Henish Lemnifi

Doctoral Dissertations

“This study investigates crustal thickness and properties within the north central Africa region. Results obtained from 15 seismic stations belonging to the Libyan Center for Remote Sensing and Space Science are reported, in addition to 3 seismic stations publically available, using receiver functions, the first P-to-S receiver function investigation of the 410 km and 660 km depth discontinuities bounding the mantle transition zone (MTZ), and P wave tomography methods. The results from the first method show crustal thicknesses ranging from 24 km to 36 km (with uncertainties ranging between ±0.10 km and ±0.90 km). More specifically, crustal thickness ranges from …

Modeling And Optimization Of Froth Flotation Of Low-Grade Phosphate Ores: Experiments And Machine Learning, Ashraf Alsafasfeh

Doctoral Dissertations

”In this research work, bench-scale and micro-scale flotation tests were conducted to separate “minerals from silicate minerals using direct and reverse flotation approaches, respectively. Experiments were conducted at different flotation conditions including reagents’ type, reagents’ dosages, pulp’s pH, and flotation time.

In the direct flotation process, two polymers were selected to promote the depression of silicates: hybrid polyacrylamide-based polymers (Hy-PAM) and chitosan. Results indicated that the highest recovery of P₂O₅ (86.82%) was obtained when the Hy-PAM polymer was used compared with 66.7% and 40% when chitosan and commercial inorganic depressant were used, respectively. The experimental datasets obtained …

Pressure Versus Impulse Graph For Blast-Induced Traumatic Brain Injury And Correlation To Observable Blast Injuries, Barbara Rutter

Doctoral Dissertations

"With the increased use of explosive devices in combat, blast induced traumatic brain injury (bTBI) has become one of the signature wounds in current conflicts. Animal studies have been conducted to understand the mechanisms in the brain and a pressure versus time graph has been produced. However, the role of impulse in bTBIs has not been thoroughly investigated for animals or human beings.

This research proposes a new method of presenting bTBI data by using a pressure versus impulse (P-I) graph. P-I graphs have been found useful in presenting lung lethality regions and building damage thresholds. To present the animal …

The Mechanics Of Precision Presplitting, Anthony Joseph Konya

Doctoral Dissertations

"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.

This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested …

Improving Base Metal Electrowinning, Charles Ebenezer Abbey

Doctoral Dissertations

"In zinc electrowinning, Mn oxidizes to form MnO₂ on Pb-Ag anodes, cell walls and pipes. MnO₂ reduces anode corrosion but also leads to short circuits and maintenance issues. MnO₂ is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb-Ag anodes. Increasing the average Mn/Cl^- ratio from ~7:1 to ~11:1 reduced the anode corrosion rate. Anode scales produced with Mn/Cl …

Investigating Blast Fume Propagation, Concentration And Clearance In Underground Mines Using Computational Fluid Dynamics (Cfd), Raymond Ninnang Tiile

Doctoral Dissertations

"Blasting activities using standard industry explosives is an essential component of underground hard rock mining operations. Blasting operations result in the release of noxious gases, presenting both safety and productivity threats. Overestimation of post-blast re-entry time results in production losses, while underestimation leads to injuries and fatalities. Research shows that most underground mines simply standardize post-blast re-entry times based on experiences and observations. Few underground mines use theoretical methods for calculating post-blast re-entry time. These theoretical methods, however, are unable to account for the variations in the blasting conditions. Literature review shows that: (i) there is currently no means of …

The Behavior Of Suas Under Explosive Loading Conditions And Implications For Safe Operating Procedures, Ashok Em Sudhakar

Doctoral Dissertations

"Drones are increasingly being used for tasks previously unimagined and the beneficial uses are evolving. The United States Congress has envisioned the possible uses of drones for both combating and conveying explosive threats and other harmful and destructive activities. Congress' intent is reflected in new laws (2018) and policies (2019).

All civilian available Small Unmanned Aerial Systems sUASs (Drones), weighing less than 55 pounds, in the current market are not designed for operations in explosive environments. This first of a kind research focuses on further understanding of sUASs response to explosive loading and the public policy implications. This research measured …

Characterization Of Aerosols In An Underground Mine, Arash A. Habibi

Doctoral Dissertations

“Diesel-powered engines are a common source of submicron carbon-rich particles. Characterizing morphological and physical attributes of diesel agglomerates is therefore of great importance to be able to identify the source and improve removal technology. Size-segregated sampling was conducted in two phases of underground experiments. Scanning transmission electron microscopy and fast mobility particle sizers were used to determine the size distribution of agglomerates based on particle mobility and projected area diameter. Controlled zone sampling test results were used to determine the morphological characteristics of agglomerates for specific types of diesel equipment both with and without removal strategies. Changes in fractal dimension, …

Multi-Body Dynamic And Finite Element Modeling Of Ultra-Large Dump Truck - Haul Road Interactions For Machine Health And Haul Road Structural Integrity, Bruno Ayaga Kansake

Doctoral Dissertations

"Haul truck capacities have increased due to their economies of scale in large-scale surface mine production systems. Ultra-large trucks impose high dynamic loads on haul roads. The dynamic loads are exacerbated by road surface roughness and truck over-loading. The dynamic forces also subject trucks to high torsional stresses, which affect truck health. Current haul road response models are 2D and use static truckloads for low capacity trucks. Existing 3D models consider the road as a two-layer system. No models capture the truck dynamic effects on haul roads and predict strut pressures during haulage.

Lagrangian mechanics was used to formulate the …

Computational Dynamics And Virtual Dragline Simulation For Extended Rope Service Life, Muhammad Wardeh

Doctoral Dissertations

"The dragline machinery is one of the largest equipment for stripping overburden materials in surface mining operations. Its effectiveness requires rigorous kinematic and dynamic analyses. Current dragline research studies are limited in computational dynamic modeling because they eliminate important structural components from the front-end assembly. Thus, the derived kinematic, dynamic and stress intensity models fail to capture the true response of the dragline under full operating cycle conditions. This research study advances a new and robust computational dynamic model of the dragline front-end assembly using Kane's method. The model is a 3-DOF dynamic model that describes the spatial kinematics and …

Mitigation Of Environmental Hazards Of Sulfide Mineral Flotation With An Insight Into Froth Stability And Flotation Performance, Muhammad Badar Hayat

Doctoral Dissertations

"Today's major challenges facing the flotation of sulfide minerals involve constant variability in the ore composition; environmental concerns; water scarcity and inefficient plant performance. The present work addresses these challenges faced by the flotation process of complex sulfide ore of Mississippi Valley type with an insight into the froth stability and the flotation performance. The first project in this study was aimed at finding the optimum conditions for the bulk flotation of galena (PbS) and chalcopyrite (CuFeS₂) through Response Surface Methodology (RSM). In the second project, an attempt was made to replace toxic sodium cyanide (NaCN) with the biodegradable chitosan …

A New Signal Processing Method For Acoustic Emission/Microseismic Data Analysis, Charles Mborah

Doctoral Dissertations

"The acoustic emission/microseismic technique (AE/MS) has emerged as one of the most important techniques in recent decades and has found wide applications in different fields. Extraction of seismic event with precise timing is the first step and also the foundation for processing AE/MS signals. However, this process remains a challenging task for most AE/MS applications. The process has generally been performed by human analysts. However, manual processing is time consuming and subjective. These challenges continue to provide motivation for the search for new and innovative ways to improve the signal processing needs of the AE/MS technique. This research has developed …

Discrete Element And Artificial Intelligence Modeling Of Rock Properties And Formation Failure In Advance Of Shovel Excavation, Muhammad Waqas

Doctoral Dissertations

"Rock tests are performed before the start of every mining or civil engineering project as part of a detailed feasibility study. The feasibility study is costly and it comprises drilling, sample collection, sample handling and laboratory testing. Numerical modeling techniques, such as Particle Flow Code (PFC), can be used to provide reliable estimates of rock strength values. The numerical models for unconfined compressive strength (UCS), direct tension, and Brazilian tests were developed in PFC, and validated using data from literature. A particle size range of 3-5 mm with D_max/D_min = 1.67 gave the best results. The numerical …

The Effect Of Overloading On Reliability Of Wheel Loader Structural Components, Eric Raymond Achelpohl

Doctoral Dissertations

"This research attempts to provide a fundamental understanding into the relationship between the productivity of material handling equipment, specifically wheel loaders, and their ability to operate reliably when subjected to high overload conditions. The overall aim is to determine the effect of overloading the bucket on wheel loader reliability. The specific objectives of the research are to: 1) evaluate the effect of overloading the bucket on wheel loader productivity; 2) examine the effect of overloading the bucket on hydraulic pressures in the hoist cylinders (used as a proxy for forces on a wheel loader); and 3) investigate the effect of …

Imaging And Mitigating Karst Features, Kenneth Joseph Bansah

Doctoral Dissertations

"Over the last three years, a comprehensive subsurface investigation that combines both conventional and geophysical techniques has been conducted near Springfield in southwest Missouri, United States. This study, which forms part of the comprehensive subsurface investigation, aimed to (1) image and characterize the subsurface, (2) map variations in engineering properties of soil/rock, (3) map variable depth to top of rock, (4) explore the utility of the geophysical techniques, (5) determine the factors contributing to karst processes, and (6) propose karst mitigation. Electrical resistivity tomography (ERT) and multichannel analysis of surface waves (MASW) were employed for the acquisition of subsurface geophysical …

Correlation Between Delay Time And Measured Concentration And Concentration Uncertainty By Neutron Activation Analysis, James Thomas Seman

Doctoral Dissertations

"For the last several decades, it has been apparent that new methods of identifying explosives can help investigators trace their origins. One way to identify an explosive is through the use of taggants: materials added to a product that encodes information about the product such as when it was manufactured.

This research investigates the survivability of a new identification taggant called the Nuclear Barcode that overcomes some of the downfalls that have been identified in prior taggants. The Nuclear Barcode encodes information as a unique combination of concentrations of rare earths (Ho, Eu, Sm, Lu, and Dy) and precious metals …