Engineering Commons^™

Displacement Measurement Using A Laser Doppler Vibrometer Mounted On An Unmanned Aerial Vehicles, Piyush Garg

Electrical and Computer Engineering ETDs

The railroad network in the united states is one of the best in the world, handling around 40 percent of all US freight movement. To maintain the serviceability and cost-effective operation of the railway infrastructure, regular monitoring is essential. Bridges are a critical part of the railway infrastructure and their timely maintenance and repair are important. Measuring transverse bridge displacement under train loading can assist to determine the bridge condition. The traditional methods available for transverse displacement measurement include Linear Variable Differential Transducers (LVDT). However, irregular terrain, remote and inaccessible locations, and the height of railroad bridges make implementation of …

Spatial Transferability Assessment Of A Composite Walkability Index: The Pedestrian Index Of The Environment (Pie), Gabriel Lefebvre-Ropars, Catherine Morency, Patrick A. Singleton, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

This paper analyzes the transferability of a composite walkability index, the Pedestrian Index of the Environment (PIE), to the Greater Montréal Area (GMA). The PIE was developed in Portland, Oregon, and is based on proprietary data. It combines six urban form variables into a score ranging from 20 to 100. The measure introduces several methodological refinements which have not been applied concurrently in previous efforts: a wide coverage of the different dimensions of the urban form, together with the use of a distance-based decay function and modelling-based weighing of the variables.

Micro-Architectured Metamaterials: Design And Analysis, Li Ai

Mechanical Engineering Research Theses and Dissertations

Metamaterials are engineered materials with unusual properties deriving mainly from their micro-architectures rather than composition. They have attracted increasing attention owing to their tailorable multi-functional properties that cannot be exhibited by naturally-occurring or traditionally-manufactured materials. Materials with a negative Poisson’s ratio (PR) and materials with a non-positive coefficient of thermal expansion (CTE) are examples of mechanical metamaterials. In this dissertation, metamaterials with negative Poisson’s ratios and negative coefficients of thermal expansion are designed using both heuristic approaches and topology optimization methods.

Firstly, based on a star-shaped re-entrant structure, three two-dimensional (2-D) periodic cellular materials are developed, which can be tailored …

Material State Awareness For Composites Part I: Precursor Damage Analysis Using Ultrasonic Guided Coda Wave Interferometry (Cwi), Subir Patra, Sourav Banerjee

Faculty Publications

Detection of precursor damage followed by the quantification of the degraded material properties could lead to more accurate progressive failure models for composite materials. However, such information is not readily available. In composite materials, the precursor damages—for example matrix cracking, microcracks, voids, interlaminar pre-delamination crack joining matrix cracks, fiber micro-buckling, local fiber breakage, local debonding, etc.—are insensitive to the low-frequency ultrasonic guided-wave-based online nondestructive evaluation (NDE) or Structural Health Monitoring (SHM) (~100–~500 kHz) systems. Overcoming this barrier, in this article, an online ultrasonic technique is proposed using the coda part of the guided wave signal, which is often neglected. Although …

A Low Power High Speed Mobile Memory I/O Interface Using Reconfigurable Multi-Band Multi-Modulation Signaling, Yue Yu

Electrical Engineering Theses and Dissertations

This research mainly focuses on the design of a novel memory I/O interface with high bandwidth and high energy-efficient for mobile computing systems in order to dramatically enhance the circuit and system bandwidth and power efficiency. The proposed memory I/O interface, exploiting multi-modulation and multi-band signaling, is capable of supporting simultaneous bidirectional data transition of 4 separate data streams across a single-ended off-chip transmission line to achieve both high speed data rate and low power consumption. This multi-band multi-modulation interface (MMI) consists of multiple RF-band transceivers which utilize ASK modulation, and baseband transceivers which utilize 4-PAM modulation to increase the …

Design, Fabrication, And Demonstration Of Square Holey Dielectric Thz Waveguides, Nafiseh Aflakian

Electrical Engineering Theses and Dissertations

A variety of novel dielectric THz waveguides were demonstrated to increase a channel capacity in a chip-to-chip communication system. Square holey cladding dielectric THz waveguides were designed, fabricated, and characterized. The single material holey cladding waveguide is low loss and easy to fabricate compared to doped core fibers. The square geometry supports two states of polarization with minimum cross-talk for polarization division multiplexing applications. Simulations show the waveguide supports two states of polarization across the frequency range of 180 GHz to 360 GHz. In addition, simulations show good mode isolation and low bending losses. Holey cladding square waveguide was fabricated …

Implementation Of Switching Circuit Models As Vector Space Transformations, David Kebo Houngninou

Computer Science and Engineering Theses and Dissertations

Modeling of switching circuits is the foundation for many Electronic Design Automation (EDA) tasks and is commonly used at various phases of the design flow for tasks such as simulation, justification, and other analyses. State-of-the-art simulation tools are based on discrete event algorithms using switching algebraic models and are highly optimized and mature. Symbolic simulation may also be implemented using a discrete event approach, or other approaches based on extracted functional models. The common foundation of modern simulation tools is that of a switching or Boolean algebraic model that may be augmented with timing information. Justification using switching circuit models …

Moving Bed Biofilm Reactors: Evaluation Of Geometry, Attachment Surface Material And Biofilm Populations On The Uptake Of Ammonia And Synthetic Organic Contaminants In Wastewater., Patrick D. Mclee

Civil Engineering ETDs

Plastic biofilm carriers are used in biological wastewater treatment to encourage the attachment and retention of microorganisms that metabolize pollutants. The following research was conducted to better understand how different characteristics of the biofilm carrier affect the treatment performance of the attached biofilms in moving bed bioreactors. Lab scale reactors were used in this study to grow nitrifying biofilms in reactors with contrasting and controlled conditions. The effect of surface geometry on nitrification performance was evaluated by testing commercially available moving bed bioreactor media that contrast in physical design, and by varying operational parameters. Additionally, mature biofilm from a similar …

Brain Motion, Deformation, And Potential Injury During Soccer Heading, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Working Papers

This paper addresses the problem of what is happening physically inside the skull during head-ball contact. Mathematical models based upon Newton’s laws of motion and numerical methods are used to create animations of brain motion and deformation inside the skull.

Initially a 1 cm gap filled with cerebrospinal fluid (CSF) separates the brain from the rigid skull in adults and older children. Whole head acceleration induces a pulse of artificial gravity within the skull. Because brain density differs slightly from that of CSF, the brain accelerates and strikes the inner aspect of the skull, undergoing viscoelastic deformation, ranging from 1 …

Quantifying The Effect Of Construction Site Factors On Concrete Quality, Costs And Production Rates, Jorge L. Santamaria

Civil Engineering ETDs

Factors affecting concrete can be categorized as structured factors or unstructured factors. The first group of factors consists of those related to the production process of concrete including water-cement ratio, properties of raw materials and mix proportions. Unstructured factors or construction site factors are related to labor skills and local conditions during the construction process of a project. Concrete compressive strength as a quality metric, costs and production rates may be affected significantly by such factors while performing concrete operations at the jobsite. Several prior studies have investigated the effect of structured factors on concrete. However literature is limited regarding …

Outer Space: A Steam Voyage, Jancy Mcphee

The Transdisciplinary STEAM+ Journal

SciArt Exchange offers multi-disciplinary art contests, artwork events, consulting, training and community resources to support science and technology education, collaboration, and innovation. Using a science-integrated- with-art approach, SciArt Exchange supports, prepares, and convenes people of all ages, backgrounds and affiliations to discuss and potentially solve space, science, and technology challenges. This field note shares the Humans in Space Art Program and the Project Mars Competition.

3d Printing – An Insider’S Perspective, Siddharth Sah

The Transdisciplinary STEAM+ Journal

The 3D printing market globally is still at its infancy, - or some might argue that there isn’t really a market yet. The knowledge of 3D printing design is still largely limited to engineering design – not product design. At MakeWhale, we are constantly pushing the boundaries of the application of 3D printing technology to consumer products resulting in a beautiful mix of technology and art.

Mitochondrial Dynamics And Respiration Within Cells With Increased Open Pore Cytoskeletal Meshes, David H. Jang, Sarah C. Seeger, Martha E. Grady, Frances S. Shofer, David M. Eckmann

Mechanical Engineering Faculty Publications

The cytoskeletal architecture directly affects the morphology, motility, and tensional homeostasis of the cell. In addition, the cytoskeleton is important for mitosis, intracellular traffic, organelle motility, and even cellular respiration. The organelle responsible for a majority of the energy conversion for the cell, the mitochondrion, has a dependence on the cytoskeleton for mobility and function. In previous studies, we established that cytoskeletal inhibitors altered the movement of the mitochondria, their morphology, and their respiration in human dermal fibroblasts. Here, we use this protocol to investigate applicability of power law diffusion to describe mitochondrial locomotion, assessment of rates of fission and …

Development Of A Curriculum Analysis And Simulation Library With Applications In Curricular Analytics, Michael S. Hickman

Electrical and Computer Engineering ETDs

Higher education institutions are currently investing significant resources in attempts to improve student success by improving instruction quality, implementing tutoring programs, and providing other services to help students. While these are all worth- while, one area that tends to be overlooked is the structure of the curricula that are offered. When viewing curricula as data, or more specifically, a graph, it is intuitive to see how its structure can influence a student’s ability to move through it. How- ever, there are currently no tools to analyze a curriculum’s structural properties and how they might affect student success. This thesis describes …

The Effect Of Z-Binding Yarns On The Electrical Properties Of 3d Woven Composites, Mohamed Nasr Saleh, Arief Yudhanto, Gilles Lubineau, Constantinos Soutis

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electrical resistance monitoring (ERM) has been used to study the effect of the z-binding yarns on the initial electrical resistance (ER) and its change of three architectures of 3D woven carbon fiber composites namely (orthogonal "ORT", layer-to-layer "LTL" and angle interlock "AI") when tested in tension. Specimens are loaded in on-axis "warp" and off-axis "45°" directions. In situ ERM is achieved using the four-probe technique. Monotonic and cyclic "load/unload" tests are performed to investigate the effect of piezo-resistivity and residual plasticity on resistance variation. The resistance increases for the off-axis loaded specimens (∼90%) is found to be higher than that …

The Future Of Nuclear Security: A Medical Physicist’S Perspective, Katharine E. Thomson

International Journal of Nuclear Security

Planning for the future of nuclear security is a vital and complex task, requiring cooperation and contribution from many disciplines and industries. This diversity of expertise should include the medical sector, which faces many of the same challenges as the nuclear industry: controlling access to dangerous material, creating a strong security culture, cooperating with the wider world and engaging the public.

Medical physicists, of which the author is one, oversee all aspects of small-scale radiation use. This paper discusses three key areas increasingly important to both medical and nuclear uses of radioactive materials: public engagement, prevention of nuclear and radiological …

The Future Of Nuclear Security In Moroccan Territory After The Creation Of The New Moroccan Agency Of Nuclear And Radiological Safety And Security: Opportunities And Challenges, Amal Touarsi, Amina Kharchaf

International Journal of Nuclear Security

Nowadays, a security regime for protecting nuclear and radiological material—providing an intelligent national regulatory institution and establishing national security laws—is necessary in order for a state to ensure security of nuclear and radiological materials used within its borders.

This paper focuses on discussing the opportunities and challenges facing the future of nuclear security after the creation of the new Moroccan Agency of Nuclear and Radiological Safety and Security.

Characterization Of Structural Dynamics Of The Human Head Using Magnetic Resonance Elastography, Andrew Arun Badachhape

McKelvey School of Engineering Graduate Student Theses & Dissertations

In traumatic brain injury (TBI), the skull-brain interface, composed of three meningeal layers: the dura mater, arachnoid mater, and pia mater, along with cerebrospinal fluid (CSF) between the layers, plays a vital role in transmitting motion from the skull to brain tissue. Magnetic resonance elastography (MRE) is a noninvasive imaging modality capable of providing in vivo estimates of tissue motion and material properties. The objective of this work is to augment human and phantom MRE studies to better characterize the mechanical contributions of the skull-brain interface to improve the parameterization and validation of computational models of TBI. Three specific aims …

Image Reconstruction Of The Speed Of Sound And Initial Pressure Distributions In Ultrasound Computed Tomography And Photoacoustic Computed Tomography, Thomas Paul Matthews

McKelvey School of Engineering Graduate Student Theses & Dissertations

Ultrasound computed tomography (USCT) and photoacoustic computed tomography (PACT) are two emerging imaging modalities that have a wide range of potential applications from pre-clinical small animal imaging to cancer screening in human subjects. USCT is typically employed to measure acoustic contrasts, including the speed of sound (SOS) distribution, while PACT typically measures optical contrasts or some related quantity such as the initial pressure distribution. Their complementary contrasts and similar implementations make USCT and PACT a natural fit for a hybrid imaging system. Still, much work remains to realize this promise. First, USCT image reconstruction methods based on the acoustic wave …

Impact Of Flow Direction On Local Flow Behavior In Biologically-Inspired Flow Passages, Derrick Dewayne Herrin

Honors College Theses

ABSTRACT

A computational fluid dynamics model was utilized to study the effect of flow direction on local flow behavior in biologically-inspired microscale flow networks. Biologically-inspired flow networks have been found to offer numerous advantages when compared with parallel flow networks, particularly in thermal management applications. Flow behavior was examined for a range of bifurcation angles and laminar inlet Reynolds numbers. The computational model was validated with existing theoretical solutions and verified for grid independence. As the bifurcation angle increased, the pressure drop, and thus pumping power, across the biologically-inspired flow networks increased. In addition, as the inlet Reynolds number increased, …

Assessing And Enhancing Nuclear Safety And Security Culture For Small Facilities That Handle Radioactive Material, Solymosi Máté

International Journal of Nuclear Security

The use of radioactive sources is expanding all over the world and abreast the necessity of the enhancement of its safe and secure application is increasing too. In the nuclear industry, the safety and security are top priorities since decades. They share the same goal, to protect humans from the negative affect of the ionizing radiation. The human component of them is a significant factor and technical solutions can protect us so far and thus the culture for safety and security become a major focus. On the other hand, there are still some contradiction between recommendations and international guidance of …

Strength Analysis For The Rudders Of Power-Free Underwater Vehicle In Kuroshio Subjected To Typhoon Waves, Chuan-Tsung Lee, Ray-Yeng Yang, Huang Hsing Pan, Li-An Kuo

Journal of Marine Science and Technology–Taiwan

In this study, a 1/25 hydraulic model of a power-free vehicle was developed. Typhoon waves and Kuroshio current flow in a wave-current flume (200 x 2 x 2 m3 ) were applied to the model for determining the net flow velocity and mooring forces. Through hydraulic experiments with a wave period of 16 s, wave height of 10 m, and ocean current speed of 1.0 m/s, a net flow velocity of up to 3.81 m/s was measured. The maximum lift and drag forces acting on each rudder were calculated through computational fluid dynamics as -245.6 and 151.6 kN, respectively, when …

Cascaded Uuv Trajectory Tracking Control Based On Model Predictive And Sliding Mode Control, Bing Sun, Wenyang Gan, Man Mei, Daqi Zhu, Simon X Yang

Journal of Marine Science and Technology–Taiwan

This paper describes a cascaded dynamic trajectory tracking control approach based on model predictive control (MPC) and sliding mode control for unmanned underwater vehicles (UUVs). The proposed method combines kinematic and dynamic controllers to achieve robust control. First, MPC is employed to realize tracking control kinematically. The MPC algorithm is proposed as a solution to the speed jump problem. Considering the computational burden for nonlinear UUV dynamic models, the MPC method is used in conjunction with sliding mode control to achieve dynamic tracking control, which solves problems of modeling uncertainty and external disturbances. Experimental results showed that the proposed method …

Investigation Of Effects Of Wave Directions On Hull Wave Loads By Hydroelastic Experimental Method, Zhanyang Chen, Jialong Jiao

Journal of Marine Science and Technology–Taiwan

This paper focuses on the hydroelastic responses of ultralarge vessels under different wave directions. Segmented ship model experiments provide an invaluable tool in naval applications. However, most model tests are performed on heading waves. Therefore, a segmented model with variable cross-section steel backbones was designed and the oblique wave tests were performed in a comprehensive test tank. The oblique wave test system was introduced in detail. Time histories of bending moments in oblique waves were given. In order to analyze the influence of structural elastic effect on hydroelastic responses, the number of segments of the model was changed, and the …

A Comparison Of The Aerodynamic Centers For Panel Code Compressible Corrections And Openfoam 5 For Mach 0.1 To 0.8, Dustin Weaver

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

It is known that the aerodynamic center changes from quarter chord to half chord from incompressible to compressible flows on airfoils. Compressible corrections are derived and implemented in a vortex panel code. These results will be used to find the aerodynamic centers for the specified Mach range of 0.1 to 0.8 in 0.1 increments within - 6 to 6 degrees angle of attack. OpenFOAM 5 cases will be created with specific meshes and settings. The results calculated from OpenFOAM 5 will be compared to the results obtained from the compressible corrections.

Determination Of Vertical Datum Level For Tidal Bench Mark Using Gnss Buoy Observations, Jae Young Roh, Kyung Wan Yoo, Yong Cheol Suh, Moon Seung Shin, Dong Ha Lee

Journal of Marine Science and Technology–Taiwan

Coastal areas are the most vulnerable areas to sea level fluctuations. Such areas comprise approximately 4% of South Korea's total land; therefore, monitoring these fluctuations is crucial. The present study determined the vertical datum level using a global navigation satellite system (GNSS). Unlike traditional sea level measurements, which are performed using fixed-type gauge observations, a GNSS has an accuracy of a few millimetres and no spatiotemporal constraints. For this purpose, a set of buoys containing GNSS devices was installed in coastal waters, and observations were performed for more than 8 h. The processed GNSS buoy data were compared with tidal …

Development Of Design Equations For Drilled Shafts In Granular Dense Soils Using Dem Simulations, Sadia Faiza

Civil Engineering ETDs

Drilled shafts have proven to be cost-effective, excellent performing, deep foundation systems where large loads and lateral resistance are major factors. The available design methods that are recommended by FHWA (2010) for drilled shafts are mostly empirical and are developed based on generalized data which sometimes can be conservative for a particular soil. The main objective of this study is to develop a design methodology for estimating the side resistance of an axially loaded drilled shaft based on the current and the unique properties of the soil. The objective was met through using the discrete element method (DEM) to investigate …

Characterization And Modeling Of Asphalt Concrete For Dynamic Properties And Performances, A S M A. Rahman

Civil Engineering ETDs

The recently developed mechanistic-empirical pavement design guide (MEPDG, also known as Pavement M-E design method) uses the nationally calibrated, binder viscosity-based dynamic modulus predictive model for the design and analysis of asphalt pavements. In this study, this model is assessed for its appropriateness for asphalt-aggregate mixtures typically used in New Mexico. In essence, this study investigates the predictability issue of complex modulus of New Mexico mixes. A total of 54 Superpave mixes with different aggregate gradations, air voids, and binder grades were collected from the mixing plants and from the pavement construction sites. The loose asphalt mixtures were then compacted, …

Next Generation Sequencing Technologies For Real-Time Genotyping And Targeted Sequencing For Precision Medicine, Priyanka Rawat

Biomedical Engineering ETDs

Astounding success of Human genome project and accelerating success of sequencing technologies have enabled $ 1000 genome goals possible. But, this is still far-fetched from the reach of many resource refrained populations with high genetic variations causing lethal genetic diseases. Based on present technology principles, I have developed prototypes for affordable, scalable and customizable point-of-care genotyping and targeted sequencing. Ion-sensitive field effect transistors with novel read-out and signal amplification techniques are used for laying foundation of possible ISFET based allele-arrays. Sequencing-by-synthesis based full-fledge sequencer is made with novel immobilization, flow-cell and data acquisition methods for massive sequenciing.

The Processing And Polarization Reversal Dynamics Of Thin Film Poly(Vinylidene) Fluoride, Noel Mayur Dawson

Nanoscience and Microsystems ETDs

Many ferroelectric devices benefit from the ability to deposit thin ferroelectric layers. Poly(vinylidene) fluoride (PVDF) is the prototypical ferroelectric polymer, but processing of thin film ferroelectric PVDF remains a challenge due to the formation of large voids in the film during traditional thin film processing. The research described in this dissertation starts by investigating the origin of these voids. The cause of these voids is found to be caused by vapor induced phase separation (VIPS). Guided by the thermodynamics of VIPS, a process is then designed to produce void-free ferroelectric PVDF thin films on polar and non-polar substrates. The films …