Engineering Commons^™

Understanding The State Agency Policies Toward Rap Usage In The United States: State Of Practice, Ayman Ali, Venkatsushanth Revelli

Henry M. Rowan College of Engineering Faculty Scholarship

The usage of Reclaimed Asphalt Pavement (RAP) material is a highly resource-conservative, economical, and sustainable practice in flexible pavement construction. However, its usage in hot mix asphalt (HMA) is capped at 25% by the majority of state transportation agencies due to its aging levels, stiffness characteristics, and handling capabilities, which may result in early-age pavement distress. Though researchers suggest methodologies to increase RAP usage, higher RAP percentages in asphalt pavements require the support of state authorities. The main objective of this paper is to provide information on how different states design their mixtures with high RAP percentages. This study reviewed …

Optimal Method To Obtain Soil Strength Properties In Sands For Laterally Loaded Pile Analysis In Lpile, Troy Roger Washburn

Theses and Dissertations

One common software program developed for analyzing single laterally loaded piles is called LPILE. Soil properties are required as input into LPILE. For sands, the soil properties required are effective soil unit weight, γ’; subgrade modulus, k; and the internal friction angle, ϕ’. There are two commonly used methods to obtain ϕ’ and subsequently k: the API method and Bolton method. Fourteen different pile test sites were used in the analysis of the API and Bolton methods to obtain soil strength properties in sands for laterally loaded single pile tests. Between the fourteen pile test sites, a total of 26 …

Characterization Of Friction At The Tool/Material Interface In Friction Stir Welding, Bryan Gonzalo Ramos Gonzales

Theses and Dissertations

Friction Stir Welding (FSW) process development is very costly, and it is still experimental. A predictive model would optimize the weld by changing parameters and obtaining results that reflect the physical process. Friction is the primary adjustable parameter in FSW modeling. Currently, friction model selection is not physic-based. It is based on what is available and contributes to the best fit between the model and experimental data. The research objective is to characterize the interface tool/base material by studying the effect of tool friction coefficient and thermal properties. This is accomplished by changing welding parameters such as force, rpm, and …

Functionalized Thermoplastic Polyurethane Nanofibers: An Innovative Triboelectric Energy Generator, Julia I. Salas, Diego De Leon, Sk Shamim Hasan Abir, Mohammed Jasim Uddin, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

A triboelectric nanogenerator (TENG) is one of the most significantly innovative microdevices for built-in energy harvesting with wearable and portable electronics. In this study, the forcespinning technology was used to synthesize a nanofiber (NF) mat-based TENG. Polyvinylidene fluoride (PVDF) membrane was used as the negative triboelectric electrode/pole, and chemically designed and functionalized thermoplastic polyurethane (TPU) was used as the positive electrode/pole for the TENG. The electronic interference, sensitivity, and gate voltage of the synthesized microdevices were investigated using chemically modified bridging of multi-walled carbon nanotubes (MWCNT) with a TPU polymer repeating unit and bare TPU-based positive electrodes. The chemical functionality …

Experimental Study On Shear Properties Of Fault Gouge With Different Mineral Compositions, Li-Huan Xie, He-Juan Liu, Sheng-Nan Ban, Hai-Jun Mao, De-Bin Xia, Yu-Jia Song, Rong-Chen Tong, Qi-Qi Ying

Rock and Soil Mechanics

The strength parameters of fault gouge is significant for the fault sealing of underground gas storage. In this paper, direct shear tests are performed for fault gouge composed of different contents of kaolinite(K), montmorillonite(M) and quartz(Q), thus obtaining the shear strength parameters (cohesion c and internal friction angle ) of various types of fault gouge. The results reveal that: (1) the cohesion of fault gouge is positively correlated with the content of montmorillonite and negatively correlated with the content of quartz. The cohesion of fault gouge specimens with high content of montmorillonite (≥40%) is positively correlated with the content of …

Experimental Study Of Capillary Water Rising In Aeolian Sand Using A Moisture Field Testing Technique Based On Image Rgb Information, Sheng-Kui Tian, Guan-Shi Liu, Qing-Song Zhao, Guo-Fang Xu, Ming-Xuan Cai

Rock and Soil Mechanics

Capillary action has an important impact on the deformation and stability of various geotechnical engineering structures. It is challenging to accurately monitor the dynamic changes in the capillary water rising process by traditional methods. In this study, the relationship between RGB (red, green, blue) information and water content of aeolian sand images was firstly investigated. The methodology and technology for measuring water content and obtaining centimeter-level resolution moisture fields via image RGB information were developed. According to this method, the spatial-temporal variation of water content during capillary water rising in aeolian sand was further explored, and the wetting front profile …

Experimental Investigation On Quantitative Evaluation Of Rock Hardness Based On Impact Energy Dissipation Index, Rui-Lang Cao, Yu-Jie Wang, Bo Xing, Yu-Fei Zhao, Qiang Shen

Rock and Soil Mechanics

Rock hardness is an important indicator reflecting the relative hardness, drillability, and blastability of rock formation. Accurate interpretation of the response of percussion drilling tools can provide new possibilities for in-situ, rapid, and quantitative evaluation of rock hardness. High-precision digital displacement, hydraulic pressure, and rotational speed sensors were used to monitor the key transmission parts of the percussion drill, and a digital monitoring system for the drilling process was then established. Rock hardness measurement and orthogonal tests of percussion drilling were parallelly carried out, and a standard database containing response data of the drill when drilling various types of rocks …

Multi-Directional Cyclic Simple Shear Behaviour Of Loose Sand Under Complex Initial Stress States, Yao Li, Jia-Ping Li

Rock and Soil Mechanics

Loose sand is highly susceptible to liquefaction, and small changes in stress state can affect its liquefaction characteristics. Based on multi-directional cyclic simple shear tests, this study conducted cyclic simple shear tests on loose sand under different magnitudes and directions of static shear stress, and complex shear paths. The cyclic simple shear characteristics of loose sand under complex initial stress states are studied. The main conclusions are drawn as follows: (1) As the static shear stress ratio increases, the peak shear stress of the specimen increases, the increment of pore water pressure in the first cycle increases, and the specimen …

Characteristics And Mechanism Of Soil Heave At The Bottom Of Ultra-Deep Circular Shafts In Soft Soil Areas, Ya-Fei Qiao, Kai Yan, Teng-Teng Zhao, Wen-Qi Ding

Rock and Soil Mechanics

Based on an ultra-deep circular shaft project in Shanghai, the field data of soil heave at the bottom of the pit during the construction were collected, and the vertical distribution pattern, evolution law and main influencing factors of soil heave at the bottom of the pit were summarized. An axisymmetric numerical model was then built and verified to investigate the effect of the excavation-induced unloading, dewatering, diaphragm wall and soil mechanical properties on the soil heave, then the mechanism of soil heave was revealed. Soil heave was the combined result of the soil mechanical response under the excavation-induced unloading, dewatering, …

Numerical Simulation Of Three-Dimensional Rock Fragmentation By Disc Cutters Of Tunnel Boring Machine Using Peridynamics, Jian Zhou, Xiao-Nan Shang, Fu-Shen Liu, Jun-Yi Shen, Xing-Chuan Liao

Rock and Soil Mechanics

Peridynamics is a non-local mesh-free numerical method which has great advantages in simulating dynamic damage and fracture. This work proposes to use the peridynamics to simulate rock fragmentation by TBM disc cutters and seven tests are simulated to verify this idea. The feasibility of peridynamics in simulating rock fragmentation by TBM disc cutters is demonstrated by comparisons with the punch indentation tests. A nonlinear short-range force contact model is proposed to better reflect the variation of the disc cutter normal force with respect to indentation depth, and can also calculate the changing contact area between the disc cutter and the …

Shaking Table Test Study On The Influence Of Seismic History On Liquefaction Resistance Of Soils At Different Depths, Xiao-Lei Wang, Li-Teng Liu, Run Liu, Li-Bo Liu, Lin Dong, Hai Ren

Rock and Soil Mechanics

Earthquake-induced liquefaction can cause significant damage to geotechnical structures, and the aftershocks accompanying the earthquakes may cause the sandy soils to liquefy again. To investigate the effect of free-field subsurface seismic history on the liquefaction resistance of saturated sandy soils at various depths, a series of shaking table tests was designed and conducted. Four shaking events with different accelerations, subdivided into seven smaller events, were input to the sandy soil in the tests. The excess pore pressure ratio, acceleration response, and soil settlement were calculated and compared for each vibration event to investigate the variation laws of soil liquefaction resistance …

Cost Minimization For Charging Electric Bus Fleets, Daniel Mortensen, Jacob Gunther, Greg Droge, Justin Whitaker

Electrical and Computer Engineering Student Research

Recent attention for reduced carbon emissions has pushed transit authorities to adopt battery electric buses (BEBs). One challenge experienced by BEB users is extended charge times, which create logistical challenges and may force BEBs to charge when energy is more expensive. Furthermore, BEB charging leads to high power demands, which can significantly increase monthly power costs and may push the electrical infrastructure beyond its present capacity, requiring expensive upgrades. This work presents a novel method for minimizing the monthly cost of BEB charging while meeting bus route constraints. This method extends previous work by incorporating a more novel cost model, …

Volumetric Imaging Using The Pupil-Matched Remote Focusing Technique In Light-Sheet Microscopy, Sayed Hassan Dibaji Foroushani

Optical Science and Engineering ETDs

ABSTRACT

The dissertation explores innovative techniques in light sheet microscopy, a pivotal tool in biomedical imaging, to enhance its speed, resolution, and efficiency in capturing dynamic biological processes. Light sheet microscopy allows for quick 3D imaging of biological specimens ranging from cells to organs with high spatiotemporal resolution, large field-of-view, and minimal damage, making it vital for in vivo imaging.

The first project introduces a novel optical concept designed to optimize Axially Swept Light Sheet Microscopy (ASLM). This technique is crucial for imaging specimens ranging from live cells to chemically cleared organs due to its versatility across different immersion media. …

A Symbiotic Content Caching Approach In Next-Generation Information-Centric Networks Based On Game Theory, Aisha B Rahman

Electrical and Computer Engineering ETDs

The continuous growth of mobile data traffic with strict time requirements calls for the development of sustainable edge content caching solutions. This becomes more prominent in the setting of Information-Centric Networking (ICN) architectures, where different ICNs are leasing caching slices to the available content providers (CPs), who in turn offer their services to the users. In this thesis, we introduce a novel symbiotic content caching framework that provides the necessary economic benefits to the ICNs and the CPs to mutualistically collaborate among each other. The corresponding mutualistic interactions among the ICNs and CPs are studied under the prism of two …

Colloid Fabrication For Biomedical Engineering Applications Through Droplet Microfluidics, Lewis I. Larsen

Biomedical Engineering ETDs

The goal of this work was to leverage soft colloid fabrication through droplet microfluidics to improve the biomedical fields of radiotracer microspheres for selective internal radiation therapy (SIRT) and 3D hydrogel tissue constructs for cell culture with future potential as a platform to study liver diseases and drug response. The importance of positron emission tomography (PET) imaging microspheres infused with positron-emitting radioisotopes such as Ga-68, Cu-64, and F-18 is that they accurately map tumor-to-liver uptake (TLR) ratio and lung shunting factor of hepatocellular carcinoma. These pretreatment radiotracers model the intravascular accumulation behavior of radioactive therapeutic Y-90 SIRT microspheres. Qualifying patients, …

Series Aperture Coupled Fed Phased Array Antenna, Guang Yang

Electrical Engineering Theses and Dissertations

Phased arrays are employed in a wide range of civil and Military contexts, including RADAR, cellular communications, and satellite communications. However, modern phased-array antennas require complex design and bulky structure at high costs, hindering their implementation in many applications. The critical aspect of a phased array design lies in power splitting with a proper phase to each radiating element. Conventional power splitters such as quarter-wavelength or Wilkinson power splitters suffer problems associated with complex array network and high power dissipation. Furthermore, popular phase shifters such as MEMS switch, ferrite-based or PIN diode have drawbacks of low power-handling capability, expensive packaging, …

Essays In Robust Optimization With Applications To Finance And Renewable Energy, Hao Jiang

Operations Research and Engineering Management Theses and Dissertations

Real-world optimization problems are often sensitive to uncertainties caused by estimation errors, forecasting inaccuracy, and imprecise data information. These uncertainties bring significant challenges to decision-making in many areas. Robust optimization (RO) is a tool for addressing the challenges of parameter uncertainty. In this dissertation, we focus on the studies of RO on two problems. (1) In the study of finance, we proposed a tractable RO model for a Mean-Variance portfolio selection problem. We consider Markowitz's Mean-Variance Optimization when stock returns are modeled using Sharpe's single-index framework, but the model coefficients Alpha and Beta, are not precisely known. This study assumes …

Early-Age Strength And Failure Characteristics Of 3d Printable Polymer Concrete: Numerical Modelling And Experimental Testing, Mohammad Amin Dehghani Najvani

Civil Engineering ETDs

The time-dependent rheological and early-age strength parameters of Polymer concrete (PC) were investigated. PC flow decreased, and the static yield stress and thixotropy increased as the specimen aged, while the dynamic yield stress remained unchanged. The study found that the Herschel-Bulkley model can accurately describe the PC’s rheological behavior over time. The change in cohesion strength and internal friction angle over time was observed using uniaxial unconfined compression and direct shear tests of fresh PC. A time-dependent MohrCoulomb failure criterion was established. Temperature analysis was used to determine the gel time and explain the evolution of the time-dependent early-age strength …

A Bio-Inspired Alternative Positioning, Navigation, And Timing Approach Based On A Potential Game-Theoretic Model, Md Sadman Siraj

Electrical and Computer Engineering ETDs

This thesis addresses the challenge of designing of alternative Positioning, Navigation, and Timing (PNT) solutions. Inspired by the evolution of biological ecosystems, we introduce a novel symbiotic PNT solution, based on the principles of Game Theory and the exploitation of Reconfigurable Intelligent Surfaces (RISs). A set of actors, consisting of anchor nodes and RISs with known coordinates, collaborator nodes having a rough estimate of their positions, and targets of unknown positions, are cooperating to accurately determine the targets’ positioning and timing. The key objective is to minimize the estimation error of each target and collaborator node, as well as of …

Location Aware Task Offloading Framework For Edge Computing Empowered By Reconfigurable Intelligent Surfaces, Md Sahabul Hossain

Electrical and Computer Engineering ETDs

In this thesis, an energy efficient task offloading mechanism in a multi-access edge computing (MEC) environment is introduced, based on the principles of Contract Theory. The technology of Reconfigurable Intelligent Surfaces (RIS) is adopted and serves as the enabler for the energy efficient task offloading, from the perspective of location-awareness and improved communication environment. Initially a novel positioning, navigation, and timing solution is designed, based on the RIS technology and an artificial intelligent method that selects a set of RISs to perform the multilateration technique and determine the Internet of Things (IoT) nodes’ positions in an efficient and accurate manner …

Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan

Civil Engineering ETDs

Asphalt Concrete (AC) is a cross-anisotropic viscoelastic material. This study has developed a methodology to backcalculate the cross-anisotropic properties of the AC layer from the Falling Weight Deflectometer (FWD) sensor and pavement response data from embedded sensors inside a pavement section. This study has also developed a two-way coupled Multiscale Finite Element Model (MsFEM) with Phase Field Fracture (PFF) to study the microstructural heterogeneity and damage of the AC layer based on the actual field loadings. A Finite Difference Time Domain (FDTD) and Machine learning-based backcalculation algorithm were developed to determine the layer thickness and dielectric constant from air-coupled Ground …

Aerodynamic Dimpling For The Nose Cone Of A High-Power Competition Rocket, Graham Geoffrey Monroe

Mechanical Engineering ETDs

This thesis investigates nose cone dimpling for the reduction of the aerodynamic drag of a Level 3 High-Power amateur rocket. Two rocket launches were conducted. The first used a COTS nose cone with a smooth surface. A dimple distribution was created according to dimensions calculated by Sandia National Laboratories’ proprietary Right- Size Dimple Evaluator. A dimpled nose cone, designed with geometry matching the COTS component, was 3D printed. Axial acceleration and barometric pressure data, recorded by an onboard flight computer, were used to calculate and plot the drag coefficient as a function of the Reynolds number for the smooth and …

Physical Properties Of Copper Niobium Nanolamellar Composites Fabricated By Accumulative Roll Bonding, Jared Justice

Nuclear Engineering ETDs

Nanolamellar composites with high interface density have increased strength due to interfaces serving as barriers to dislocation movement and high radiation damage resistance. However, these interfaces also serve as barriers to electron motion, reducing the electrical resistivity and thermal conductivity. This work seeks to understand the inherent tradeoff between strength and physical properties of nanolamellar composites produced by accumulative roll bonding with layer thickness ranging from 25 nm to 193 nm. The electrical resistivity was investigated over temperatures ranging from 2 K to 300 K. The effect of longitudinal rolling and cross rolling was also investigated. Electrical resistivity results were …

Screw Dislocations In A Holed Wedge, Gregory T. Whiteside

Mechanical Engineering ETDs

A numerical code has been designed and implemented to find the stress at any material point in a holed-wedge material due to any number of crystal or real screw dislocations in the wedge. The code implements the image dislocation method together with the collocation point method to find stresses at any material point. We demonstrate that the combined analytical-numerical method (analytical with the image dislocations and numerical with the collocation-point method) is valid in that it produces stress fields giving rise to zero traction on free surfaces as well at an arbitrary number of collocation points on void surfaces. Additionally, …

Control Of Fully-Actuated Aerial Manipulators And Omni-Directional Multirotors, Riley M. Mccarthy

Mechanical Engineering ETDs

This thesis details the system modeling, design, control, simulation, construction, and
testing of both a fully-actuated and omni-directional multirotor aerial system created
for the primary purpose of performing active tasks with their environment. This work
verifies the capabilities of both systems through empirical testing, and demonstrates
how through the use of new control methods and physical designs multirotors can
expand their purpose from passive inspection based tasks to active contact based
tasks. These systems take advantage of newly implemented control allocation features present in the PX4 flight control software, version 1.14. The use of which makes designing controllers for such …

Design, Fabrication And Characterization Of Zero Power Sensor/Harvester For Smart Grid Applications, Zeynel Guler

Mechanical Engineering ETDs

This study presents a flexible sensor/harvester device to be used in both electromagnetic sensing and energy harvesting applications for smart grids. When a current passes through a wire, the sensor detects the magnetic field created by that current. The sensor magnet interacts with the wire magnetic field resulting in a transfer of energy through the piezoelectric cantilever. Piezoelectric, conductive, magnetic, and magnetostrictive composite thin films were prepared to fabricate this device.

Initially, the magnet of the cantilever was optimized considering its shape, thickness, length, taper angle etc. via both simulations and experiments. Peak to peak voltage versus cantilever position graph …

Main Effects Screening Study Of Fe/Kclo4 Thermal Battery Heat Pellet Resistive Activation, Bryan T. Steiner

Mechanical Engineering ETDs

Thermal battery iron-potassium perchlorate (Fe/KClO₄) heat pellets are often ignited by explosive igniters or heat paper. An alternative direct electrical ignition method via resistive heating is explored, which could improve thermal battery manufacturability and design flexibility. A main effects screening experiment was performed with the goal of confirming prior observed trends under more realistic test conditions and ranking the importance of design factors, to optimize future experiments and develop knowledge of the performance space. Relevant literature is examined to advance a theoretical understanding of resistive activation. Ignition sensitivity (go/no-go and time to ignition) and ignition energy are primary …

Investigation Of Thermofluid Processes In A Pcm Based Thermal Storage Module, Luca M. Crnjac

Electronic Thesis and Dissertation Repository

Latent heat thermal energy storage systems can capture and store solar thermal energy, enhancing the reliability of solar energy by facilitating a continuous and consistent energy supply. However, phase change materials used in these systems suffer from low thermal conductivities making it difficult to achieve suitable charging and discharging rates. The present research investigated this issue using computational and experimental approaches to improve the design of a thermal storage module through heat transfer enhancement. Various heat transfer enhancements including a finned honeycomb structure, and metal wool were incorporated into a thermal storage module to analyze their effect on charging and …

Socially Engaged Engineering: A Framework For K-8 Education, Christine M. Cunningham, Gregory J. Kelly, Ashwin Mohan

Journal of Pre-College Engineering Education Research (J-PEER)

Socially engaged engineering provides for student learning of the design, analysis, and practices of engineering as well as the ways that engineering is situated in sociocultural contexts. This paper provides a conceptual framework regarding socially engaged engineering for K-8 educators, researchers, and curriculum designers. The framework identifies ways to support youth learning of engineering and considerations of technical, social, environmental, and ethical dimensions of engineering. As engineering enters K-8 educational settings, it is important to introduce the discipline in equity-oriented ways. We draw from the field of engineering for social justice to build this framework for examining engineering at the …

A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng

Journal of Marine Science and Technology

Ocean Thermal Energy Conversion (OTEC) requires a large amount of cold seawater. The traditional rigid pipe, semi-rigidly fixed onto the ship bottom is not easy to install and disassemble, so the Floating Flexible Cold Water Pipe (FFCWP) flexibly connected to the ship is proposed. A small FFCWP was designed, fabricated, and successfully installed and recovered in the sea. The flexible pipe adopts commercially available fire ventilation snake pipe. The pipe wall material strength must be improved in the future. Assuming that the drag coefficient Cd value is 1.5, a numerical calculation is employed to simulate the FFCWP attitude from the …