Engineering Commons^™

Acoustic Emission And Guided Wave Modeling And Experiments For Structural Health Monitoring And Non-Destructive Evaluation, Roshan Prakash Joseph

Theses and Dissertations

This dissertation is organized into major parts. In Part I of the dissertation, plate guided waves due to an acoustic emission (AE) event are analytically studied in the context of seismic moment tensor sources. The guided wave propagation elastodynamic equation corresponding to a point source applied to the plate in an arbitrary direction is modified in order to describe the case when the source is a seismic moment tensor of various tensor components. This part of the dissertation also discusses the analytical modeling of AE test sources such as pencil lead break, hammer hit excitation, etc.

In Part II of …

Eliminating Rebar Splicing In Transverse Joints Of Precast Full Depth Bridge Deck Panels, David Gee

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This study looks at the removal of longitudinal rebar splicing when sufficient longitudinal post-tensioning is provided for full-depth precast deck panels for simply supported bridges. Full-depth precast prestressed concrete deck panels are high quality plant produced pretensioned panels. They are often post-tensioned at the site to provide an average net compression in the joint of at least 250 psi due to effective prestress. This is to ensure adequate transfer of load as truck wheels pass over the joint. This net compression on the transverse joint is not explicitly clear by the AASHTO LRFD Bridge Design Specifications. Based on this section, …

Electric Vehicle-Grid Integration With Voltage Regulation In Radial Distribution Networks, Chong Cao, Zhouquan Wu, Bo Chen

Michigan Tech Publications, Part 1

In this paper, a vehicle-grid integration (VGI) control strategy for radial power distribution networks is presented. The control schemes are designed at both microgrid level and distribution level. At the VGI microgrid level, the available power capacity for electric vehicle (EV) charging is optimally allocated for charging electric vehicles to meet charging requirements. At the distribution grid level, a distributed voltage compensation algorithm is designed to recover voltage violation when it happens at a distribution node. The voltage compensation is achieved through a negotiation between the grid-level agent and VGI microgrid agents using the alternating direction method of multipliers. In …

The Viability And Simplicity Of 3d-Printed Construction: A Military Case Study, Jeneé A. Jagoda, Brandy Diggs-Mcgee, Megan Kreiger, Steven J. Schuldt

Faculty Publications

In November 2019, U.S. Marines, Air Force, and Army Corps of Engineers personnel demonstrated the viability and simplicity of three-dimensionally (3D)-printed construction in a controlled environment at the U.S. Army Engineer Research and Development Center—Construction Engineering Research Laboratory in Champaign, Illinois. The tri-service exercise spanned three days and culminated in the construction of three 1 m × 1 m × 1 m (3 ft × 3 ft × 3 ft) concrete dragon’s teeth (square pyramid military fortifications used to defend against tanks and armored vehicles) and several custom-designed objects. The structural components were printed using a custom-built, gantry-style printer called …

Cfd Simulations Of A Propeller-Wing Interaction, Asim Oktay Akdeniz

Mechanical & Aerospace Engineering Theses & Dissertations

In this study, 3-D turbulent flows around a propeller driven aircraft model placed in a subsonic wind tunnel were computationally simulated for qualitative investigation of near field wakes. The geometry of the model was created using commercial mesh generation software, GRIDGEN, and then simulations were performed using a commercial finite volume Reynolds-Averaged Navier-Stokes (RANS) solver FLUENT.

Initial runs were performed to validate the boundary conditions and setup of the problem where a hybrid mesh consisting of multi-blocks was in use. Sliding mesh concept used in the computations. Laminar flow simulation have been utilized and tested besides Spalart-Allmaras and k-ω SST …

Prediction Of Tunnel Wall Convergences For Natm Tunnels Which Are Excavated In Weak-To-Fair-Quality Rock Masses Using Decision-Tree Technique And Rock Mass Strength Parameters, Özgür Satici, Tamer Topal

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Tunnel wall convergences should be predicted before the excavation and should be determined accurately in order to ensure safe and economic tunnel excavation media. For this to be possible, rock mass behaviors in the tunnel should also be estimated prior to excavation. This could be ensured by site investigation studies, numerical models and predictive statistics. In this study, the development of convergences during a tunnel excavation in Turkey, excavated by NATM technique, was evaluated by using statistical prediction techniques for weak-to-fair-quality rock masses. For this aim, actual tunnel wall convergence data and rock mass strength parameters were used. For prediction …

Social Justice Mitigation In Transportation Projects: Why And How Lexington Fayette Urban County Government Can Support The Lexington Community Land Trust’S Path To Self-Sustainability, Pamela Clay-Young, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The city of Lexington has reached a critical shortage of affordable housing available to families earning 80% - 50% of area median income (AMI). This study focuses on how to grow the Lexington CLT into self-sustainability while also narrowing the affordable housing gaps in Fayette County. Current research offers support for the city’s affordable housing program to adopt the community land trust model (CLT). The research recommends using tools such as the Lexington CLT, the Lexington-Fayette Urban County Landbank Authority (LFUCLA), and Lexington’s Affordable Housing Trust Fund, along with new development incentives, to develop a housing strategy that is cost …

Long-Term Dynamic Simulation Of Power Systems Using Python, Agent Based Modeling, And Time-Sequenced Power Flows, Thad Haines

Graduate Theses & Non-Theses

Automated controls facilitate reliable and efficient operation of modern power systems. Engineers employ computer simulations to develop, analyze, and tune such controls. Short-term dynamic, or transient, power system simulation is a useful and standardized power industry tool. Researchers have developed effective long-term dynamic (LTD) simulators, but there is not yet an industry standard computational method or software package for LTD simulation.

This work introduces a novel LTD simulation tool and provides examples of various engineering applications. The newly created software tool, Power System Long-Term Dynamic Simulator (PSLTDSim), uses a time-sequenced power flow (TSPF) technique to simulate LTD events. The TSPF …

Assessing The Energy Management Culture Of Global Leading Mining Companies: Curbing Carbon Emissions In A World Of Growing Climate Change Concerns, Irene Ateng

Graduate Theses & Non-Theses

Industries such as the oil, mining and chemical industry have been under a lot of pressure from governments and certain organizations worldwide to reduce their carbon footprint. The United Nations (UN), the International Council on Mining and Metals (ICMM) and other organizations, have mapped out policies and recommendations that can be used to achieve this. Mining companies all over the world have adopted sustainability commitments based on recommendations by the United Nations Intergovernmental Panel on Climate Change and have set targets for managing their energy use and GHG emissions. This research assessed the energy management culture of twenty (20) leading …

A Novel Method For Making Titanium Dioxide For Photocatalytic Applications, Gary Wilson

Graduate Theses & Non-Theses

Titanium dioxide possesses near-ideal properties for large-scale application as a photocatalyst. It is cheap and abundant, nontoxic, and environmentally safe. However, it still suffers from logistical problems preventing its application in industry: namely, rapid electron-hole recombination and inability to utilize visible light. For nearly five decades researchers in this booming field have made numerous attempts to address these problems, doping and combining titanium dioxide with a wide range of materials. A novel ambient-temperature approach to synthesis and doping/modification of anatase-form titanium dioxide was attempted using both oxygen-rich and oxygen deprived synthetic routes. Reactants were exposed to various wavelengths of ultraviolet …

Nadir And Oblique Uav Photogrammetry Techniques For Quantitative Rock Fall Evaluation In The Rimrocks Of South-Central Montana, Micah Gregory-Lederer

Graduate Theses & Non-Theses

As our cities expand into geologically sensitive areas across the greater Rocky Mountain region and beyond, quantitative methods of assessment are increasingly critical for the development of evidence-based alternatives to avoid or mitigate geologic hazards. Unmanned Aerial Vehicle (UAV) photogrammetry can improve these geologic investigations by enabling remote visual inspection, measurement, and spatial analysis while eliminating many of the physical access limitations that contribute to field sampling bias and human error. UAV photogrammetry technology was employed to evaluate fragmental rock fall hazards at two locations in the Rimrocks region of south-central Montana, Zimmerman Trail Road and Phipps Park. At these …

Design, Assessment, And Comparison Of Antagonistic, Cable-Driven, Variable Stiffness Actuators, Ryan P. Moore

Master's Theses (2009 -)

This thesis presents the designs and test results for two antagonistic, cable-driven, variable stiffness actuator designs. Each of these variable stiffness actuators is compact, has a large range of controllable stiffness, and limits the inertia at the robotic link it is controlling. Each design consists of a cable running through a set of three pulleys. Tension on the cable displaces a linear spring, which moves along a path designed to achieve quadratic spring behavior. One design uses a variable radius path to achieve the nonlinear elastic behavior while the other uses a fixed radius (lever) path.A quasi-static model of …

Energy Storage Systems For Traction And Renewable Energy Applications, Hamad Abdullah Aldawsari

Master's Theses (2009 -)

Energy storage systems are the set of technologies used to store various forms of energy, and by necessity, can be discharged. Energy storage technologies have a wide range of characteristics and specifications. Like any other technology, each type of energy storage has its pros and cons. Depending on the application, it is crucial to perform a tradeoff study between the various energy storage options to choose the optimal solution based on the key performance objectives and various aspects of those technologies. The purpose of this thesis is to present a thorough literature review of the various energy storage options highlighting …

Trajectory Simulation With Battery Modeling For Electric Powered Unmanned Aerial Vehicles, Ege Konuk

Mechanical & Aerospace Engineering Theses & Dissertations

Fixed wing electric powered unmanned aerial vehicles (UAVs) has been widely adopted for the last decade in a great number of applications. One of the primary advantages to fixed wing versus multi-rotor designs is the efficiency in forward flight with best possible range and endurance capabilities. In electrically powered air vehicles range and endurance are monitored by the State-of-Charge (SOC) of the battery. To understand the capabilities of the battery, discharge experiments can be conducted in lab environments; however, sometimes the results are difficult to integrate in flight simulations.

In this thesis, a trajectory simulation is developed that can estimate …

Symmetry Versus Balance In Balancing Networks For Dipolar Antennas, James Mclean, Heinrich D. Foltz

Electrical and Computer Engineering Faculty Publications

Imperfect balancing networks (baluns) have been identified as a source of error in emission and site attenuation measurements. For this reason performance tests have been developed to characterize the symmetry of baluns. We draw a distinction between symmetry and balance as they relate to baluns and describe both quantitatively in terms of 3-port network parameters. It is shown that a symmetric balun alone does not necessarily eliminate common-mode (CM) current on the feed transmission line. Common-mode current on the feed transmission line is minimized by use of a current balun. However, for a given implementation such as a transmissionline transformer, …

Ionic Conductivity And Electrochemical Properties Of Alginate–Nn4no3-Based Biopolymer Electrolytes For Edlc Application, Norfatihah Binti Mazuki, Nur Muhitul Jalilah Rasali, Bouchta Sahraoui, Ahmad Salihin Samsudin

Makara Journal of Technology

In this work, alginate doped with various contents of ammonium nitrate (NH4NO3) as a solid biopolymer electrolyte (SBE) was prepared via casting by using distilled water as a solvent. Impedance studies on alginate–NH4NO3 SBE films were conducted via impedance spectroscopy. The lowest bulk resistance (Rb) showed that the maximum ionic conductivity of the sample containing 25 wt.% NH4NO3 at ambient temperature (303 K) was 5.56 × 10−5 S cm−1. The temperature dependence of ionic conductivity was evaluated, and results confirmed that electrolytes followed an Arrhenius behavior. The highest conducting sample was fabricated into an electrical double-layer capacitor and characterized in …

Current Status Of Hydrothermal Treatment For Energy And Material Recovery Toward A Sustainable Post-Consumer Material Cycle, Baskoro Lokahita, Muhammad Aziz, Fumitake Takahashi

Makara Journal of Technology

The demand for energy-efficient and environmentally friendly municipal solid waste (MSW) processing has increased in developing countries. The thermochemical process offers a fast and reliable solution to reutilize or reduce the volume of MSW. Hydrothermal treatment is a novel MSW treatment technology that is compatible with high-moisture-content feedstock. It involves the thermal degradation of MSW in pressurized water or steam, which promotes the disintegration of cellulosic and polymer materials. Recent advances have shown effective MSW conversion into homogenous solid hydrochar with higher energy density. Alkali and chlorine content, which causes issues in combustors, was successfully removed due to the washing …

Heavy Civil Estimating Module For Cm 314, Everett A. Roberts

Construction Management

In the past, through engagement with students that have gone through the Heavy Civil class, it has been found that student understanding of typical heavy civil operations is subpar. Through an updated course module that focuses on estimating the four major operations, Earthwork, Underground, Asphalt, and Concrete, students will gain a deeper understanding of the heavy civil field of construction. The module consists of four assignments that pertain to the previously mentioned operations. Each contain a lecture detailing typical crew compositions and cycle times, reference material and resources the student can use when completing the assignments. This new module will …

Structural Design Of Pool House In The City Of Columbia, Nathan F. Gates

Senior Theses

This report presents a structural design for a one-story pool house in the City of Columbia. The most important part of the project was determining critical horizontal and vertical loads, and designing each member in accordance to those governing loads. The loads we analyzed were dynamic, dead, live and seismic. By means of the LRFD method, the greatest possible load combination was calculated, combining the previously mentioned loads. These load combinations were different for each analysis, as the loading pressures will change depending on what structural system is being analyzed. This comprises the large part of the report and of …

Fluid Power Vehicle Challenge, Jacob Torrey, Kayla Londono, Bryson Chan, Aaron Trujillo

Mechanical Engineering

The FPVC combines mechanical engineering disciplines to design and manufacture a vehicle that utilizes hydraulic power. The FDR covers the final manufacturing process and verification processes developed during the front end of research and analysis built upon the Critical Design Review (CDR) and the PDR (Preliminary Design Review). This report showcases the design decisions and extensive research that supports the continuing efforts by the Team Pump My Ride, to build upon the accomplishments of Cal Poly’s previous team, The Incompressibles. The FDR presents how Team Pump My Ride produced the design changes from the CDR and PDR to achieve improvements …

Differentially Private Online Task Assignment In Spatial Crowdsourcing: A Tree-Based Approach, Qian Tao, Yongxin Tong, Zimu Zhou, Yexuan Shi, Lei Chen, Ke Xu

Research Collection School Of Computing and Information Systems

With spatial crowdsourcing applications such as Uber and Waze deeply penetrated into everyday life, there is a growing concern to protect user privacy in spatial crowdsourcing. Particularly, locations of workers and tasks should be properly processed via certain privacy mechanism before reporting to the untrusted spatial crowdsourcing server for task assignment. Privacy mechanisms typically permute the location information, which tends to make task assignment ineffective. Prior studies only provide guarantees on privacy protection without assuring the effectiveness of task assignment. In this paper, we investigate privacy protection for online task assignment with the objective of minimizing the total distance, an …

Incorporating A Reverse Logistics Scheme In A Vehicle Routing Problem With Cross-Docking Network: A Modelling Approach, Audrey Tedja Widjaja, Aldy Gunawan, Panca Jodiawan, Vincent F. Yu

Research Collection School Of Computing and Information Systems

Reverse logistics has been implemented by various companies because of its ability to gain more profit and maintain the competitiveness of the company. However, extensive studies on the vehicle routing problem with cross-docking (VRPCD) only considered the forward flow instead of the reverse flow. Motivated by the ability of a VRPCD network to minimize the distribution cost in the forward flow, this research incorporates the reverse logistics scheme in a VRPCD network, namely the VRP with reverse cross-docking (VRP-RCD). We propose a VRP-RCD mathematical model for a four-level supply chain network that involves suppliers, cross-dock, customers, and outlets. The main …

How To And How Much? Teaching Ethics In An Interaction Design Course, Bimlesh Wadhwa, Eng Lieh Ouh, Benjamin Gan

Research Collection School Of Computing and Information Systems

How much is sufficient and how should one teach ethics in an Interaction Design curriculum in undergraduate computing program has been a point of dilemma for many HCI educators. We conducted a preliminary study using a mixed method to gather perception on ethics in our interaction design courses at two of the leading Singapore Universities. We answer three research questions specific to an undergraduate HCI course: Is there a need for ethics? Is there sufficient ethics coverage? and how to teach ethics? We surveyed 140 students and interviewed six teachers in two Singapore Universities. Our findings suggest that 92% of …

Design And Control Of An Arrayed Infrared (Mat-Ir) Heater For Accurate Heating Control During Automated Fiber Placement, Benjamin L. C. Greenberg

Theses and Dissertations

Automated Fiber Placement (AFP) is the primary method for manufacturing of large and complex primary composite structures in the aerospace industry. Predominantly, AFP use infrared heaters to ensure appropriate tackiness between the different composite layers. The task of accurately detecting and obtaining a set uniform temperature, across the nip point/line, has proven to be difficult. Traditional AFP heat processes are mostly open-loop controlled, which can lead to issues with ensuring accurate and uniform heat distributions. The latter need to be obtained to allow for proper material consolidation to occur. Uneven heating could cause degradation at the center or at the …

Kinetic And Multidimensional Transport Coupled Numerical Investigation Of Nox Formation During Syngas And Natural Gas Combustion, Sheikh Farhan Ahmed

Theses and Dissertations

The primary objective of this thesis work is focused on the chemical kinetic modeling of the formation of Oxides of Nitrogen (collectively termed as NOx), regarded as a major pollutant emitted by combustion devices, and the application of that model to simulate transport coupled multidimensional distribution of NOx in a reacting flow. The underlying motivation of this kinetic modeling is the noted discrepancies among the existing models, which become critical in selecting the correct model in advanced gas turbine and engine research. The first part of this work is the performance evaluation and comparison of the existing models. Based on …

Using Human Granulosa Cells To Select The Most Competent Embryos For Uterine Transfer In In Vitro Fertilization Cycles, Richard John Kordus

Theses and Dissertations

Infertility is a worldwide epidemic often treated with in vitro fertilization. The success of in vitro fertilization is directly dependent upon the quality of oocytes produced during the controlled stimulation of the patient’s ovaries. There is a need for improved methods to allow embryologists to select the most viable embryos with the highest probability of leading to live births since in vitro fertilization success is far from optimal.

Oocyte and subsequent embryo quality are intimately influenced by the granulosa cells which surround the oocyte during follicular maturation. The oocytes require proper signaling and energy production form the surrounding granulosa cells …

The Role Of Acute And Chronic Neuroinflammation In Depression: Uncovering The Relationship Between Histamine And Serotonin Transmission, Melinda Hersey

Theses and Dissertations

Depression is the leading cause of disability worldwide. Disorders of the brain, including depression, are notoriously difficult to treat because the basic pathology underlying behavioral outcomes remains undefined. Robust chemical biomarkers of these diseases have not been identified, nor are there reliable methods to measure brain chemicals. Depression is associated with chemical and inflammatory changes in the brain that are predicted to contribute to the pathology. By studying the serotonin and histamine systems we aim to better define the neurochemical basis of depression. Serotonin has long been hypothesized to play a role in depression since selective serotonin reuptake inhibitors (SSRIs) …

Effect Of Cannabinoid Treatment On Immune Cell Functions During Acute Lung Injury, Amira Kamil Mohammed

Theses and Dissertations

Staphylococcal enterotoxin B (SEB) is a highly potent CDC select agent that can trigger acute lung injury (ALI) via robust T cell proliferation and differentiation, and massive cytokine and chemokine release. Δ9-Tetrahydrocannabinol (THC) is a psychoactive ingredient found in Cannabis sativa. In the current study, we investigated the effects of treatment with THC on SEB-induced acute lung injury. To this end, acute lung injury was induced by a dual dose of SEB in C3H/HeJ mice, which were then treated with vehicle or THC. THC-treatment led to survival of all the SEB-administered mice when compared to vehicle-treated. This corroborated with THC-induced …

The Evolution Of The Southeastern North American Margin From Integrated Analyses Of Potential Field Data: Continent-Continent Collision And Rifting, Patrick D. Duff

Theses and Dissertations

The southeastern North American margin (SENAM) is one of the world’s oldest intact passive margins, containing the ancient southern Appalachian Mountains, the South Georgia Rift (SGR), and the Central Atlantic Magmatic Province (CAMP).

Potential field data is used in combination with seismic imaging, borehole data, and surface geology to better constrain the lithospheric configuration created by Appalachian orogenesis and Atlantic rifting. In combination with filtering techniques, maps and 2D potential field forward models, and Euler inverse modeling are used to illuminate the pre-Cretaceous basement including basement faults, shear zones, and granites in the hinterland of the southern Appalachians, and rift …

The Manufacturing And Characterization Of Pseudo-Woven Carbon Fiber Composite Architectures For Enhanced Damage Tolerance, Cyrus Vakili Rad

Theses and Dissertations

Traditional unidirectional carbon fiber reinforced polymer matrix composites exhibit brittle failure, limited toughness, and poor damage tolerance often resulting in the overdesign of composite systems. This work focuses on the automated fiber placement (AFP) manufacturing and characterization of a new family of pseudo-woven (PW) laminate architectures aimed to enhance impact resistance and damage tolerance. The PW laminate architecture uses a specialized in situ AFP process implementing tow skips to produce its laminate architecture. This results in a heterogeneous architecture possessing spatially variable in-plane material properties unlike traditional laminated composites. This heterogeneity is associated with topological variations in the fiber orientations …