Engineering Commons^™

Diffuse Damage Repair Mechanism In Bone, Leila Mehraban Alvandi

Dissertations and Theses

Bone microdamage is a result of fatigue, creep or ‘wear and tear’ caused by physiological activities and largely contributes to bone fragility. Bone, unlike engineered materials, has the ability to repair the microscopic cracking or microdamage through targeted, osteoclast-mediated bone remodeling. This capability is crucial for preservation of its structural integrity and quality; failure of the skeleton to effectively repair microdamage leads to accumulation of damage, which is one of the main contributors to bone fragility. Linear microcracks (50-100 µm) and diffuse damage (Dif.Dx) (sub-micron) are the two types of microdamage. Recent studies show that Dif.Dx repairs without bone remodeling, …

Characterization Of Bone Pathology In Sickle Cell Disease And Therapeutic Strategies, Mykel D. Green

Dissertations and Theses

Sickle cell disease (SCD) is a genetic hemoglobinopathy that has grown into a global health concern. While the advances in medical treatment and management of SCD during childhood have drastically improved the overall survival of children, the transition from pediatric to adult services is significantly inadequate in comparison. Life expectancies of patients with SCD in first world countries such as the United States are shortened to averages of 42 and 48 years for men and women, respectively. Despite the increasing number of people living with SCD, remarkably, few detailed studies have described the clinical course and complications of the disease …

Adapting To Extreme Heat: Social, Atmospheric, And Infrastructure Impacts Of Air Conditioning In Megacities - The Case Of New York City, Harold Gamarro

Dissertations and Theses

Extreme heat events are becoming more frequent and intense in most large cities. Built-up surfaces also limit cooling mechanisms, leading to warmer conditions in cities, a phenomenon called the Urban Heat Island (UHI). This presents major challenges to reduce adverse health effects of hot weather, particularly in vulnerable populations like the elderly and low-income communities. Here we explore the overall impacts of increasing air conditioning (AC) system adoption in residences as an adaptive measure to reduce human health risks under heat waves, with New York City (NYC) as a case study. This study uses AC adoption data from the 2017 …

Investigation Of Asphaltene Adsorption At Liquid-Liquid And Liquid-Solid Interfaces, Fang Liu

Dissertations and Theses

Asphaltenes, as indigenous components in crude oils, are believed to play an important role in the petroleum production and processing industry. For example, asphaltene molecules can adsorb onto the water / oil interface like the amphiphiles and hinder water droplet coalescence, resulting in the stabilization of water-in-oil emulsions. Also, in the upstream production, depending on the temperature and pressure, asphaltenes can precipitate and deposit onto the reservoir rocks, the wellbores and the pipelines, leading to the change in reservoir rocks’ surface wettability and the blockage of the production facilities. Hence, it is crucial to understand the mechanism of asphaltenes adsorption …

Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas

Dissertations and Theses

Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …

Decision-Making In Reuse Of Highway Bridge Foundations, Ehssan Hoomaan

Dissertations and Theses

According to the 2019 National Bridge Inventory data from Federal Highway Administration, the average age of highway bridges in the U.S.A. is 45 years, with almost 43% of existing highway bridges being older than 50 years, and eight percent of all U.S. national highway bridges being in poor condition. Foundation and substructure of existing highway bridges (over land and water) may have significant functional values even after being under service for decades. Reusing an existing bridge foundation during the reconstruction of a bridge (e.g., major rehabilitation, retrofitting, replacement of superstructure and substructure, and addition/removal of a span) has the potential …

Attention Strongly Modulates Reliability Of Neural Response To Naturalistic Narrative Stimuli, Jason Ki

Dissertations and Theses

Attentional engagement is a major determinant of how effectively we gather information through our senses. Alongside the sheer growth in the amount and variety of information content we are presented with through modern media, there is increased variability in the degree to which we ‘absorb’ that information. Traditional research on attention has illuminated the basic principles of sensory selection to isolated features or locations, but it provides little insight into the neural underpinnings of our attentional engagement with modern naturalistic content. Here, we show in human subjects that the reliability of an individual's neural responses with respect to a larger …

Recuperation Of Regenerative Braking Energy In Electric Rail Transit Systems, Mahdiyeh Khodaparastan

Dissertations and Theses

Electric rail transit systems are large consumers of energy. In trains with regenerative braking capability, a fraction of the energy used to power a train is regenerated during braking. This regenerated energy, if not properly captured, is typically dumped in the form of heat to avoid overvoltage. Finding a way to recuperate regenerative braking energy can result in substantial economic as well as technical benefits. Regenerative braking energy can be effectively recuperated using wayside energy storage, reversible substations, or hybrid storage/reversible substation systems. In this research study, we compare these recuperation techniques and investigate their application in New York City …

Influence Graphs For Modeling Of Cascading Failures In Electric Distribution Networks, Muhammad S. Bhatti

Dissertations and Theses

Power Grids are one of the most intricate systems and greatly affect economic, political, and social aspects of contemporary life. A well-operated power system consists of many control devices and protection methods to prevent the interruption of power to consumers. However, such systems are highly vulnerable to severe events; for instance, natural disasters, cyber-attacks, mal-function of control devices, etc. The occurrence of these odd events may lead to cascading failures, which are prominent contributors to blackouts.

This paper focuses on the development of a cascade model in a distribution network using Newton-Raphson’s power flow method to study the impact of …

Toward Closing The Urban Surface Energy Balance Using Satellite Remote Sensing, Joshua Hrisko

Dissertations and Theses

The energy exchanges at the Earth’s surface are responsible for many of the processes that govern weather, climate, human health, and energy use. This exchange, commonly known as the surface energy balance (SEB), determines the near-surface thermodynamic state by partitioning the available energy into surface fluxes. The net all-wave radiation is often the primary energy source, while the heat storage and sensible and latent heat fluxes account for the majority of energy distributed elsewhere. While the SEB of various natural environments(trees, crops, soils) has been well-observed and modeled, the urban surface energy balance remains elusive. This is due to the …

Effects Of Weak Electric Fields On Long-Term Synaptic Plasticity, Gregory Kronberg

Dissertations and Theses

Transcranial direct current stimulation (tDCS) is a technique where a weak direct electrical current is applied to the scalp with the goal of stimulating the brain. There is tremendous interest in the use of tDCS for treating brain disorders and improving brain function. However, the effects of tDCS have been highly variable across studies, leading to a debate over its efficacy. A major challenge is therefore to design tDCS protocols that yield predictable effects, which will require a better understanding of its basic mechanisms of action. One commonly discussed mechanism is that tDCS may alter synaptic plasticity, but the biophysics …

Dynamics And Phase Behavior Of Mixed Antibody-Excipient Adsorption At An Air/Water Interface, Ankit D. Kanthe

Dissertations and Theses

Monoclonal antibodies (mAbs) have become a leading candidate for oncological therapeutics due to their unparalleled selectivity. Monoclonal antibodies are amphiphilic, containing polar and nonpolar amino acid residues on their biomolecular surfaces. Their amphiphilic nature drives mAbs to strongly adsorb to air/water interfaces. Interfacial adsorption presents a central problem to the production and use of antibody-based pharmaceuticals. Air/water interfaces are frequently generated during the manufacture (filtration and chromatography) and production (freezing, thawing, filtration and filling) of the drug product. Moreover, air/water interfaces are present during the storage, transportation and administration of the therapeutics. When an air/water interface is created, the antibodies …

Computational Fluid Dynamics Simulation Of Rain-Wind-Induced Vibration Of Stay Cables, Hongfan Wang

Dissertations and Theses

Due to the large amplitude, frequent occurrence and severe consequences, the rain-wind induced vibration (RWIV) of stay cables in cable-stayed bridges has been investigated extensively by researchers around the world. However, the underlying excitation mechanism is still unclear. Recently, computational fluid dynamics (CFD) simulation has been widely applied in the research on structure vibrations due to dynamic wind loads, with great potential as an alternative tool for wind tunnel testing. It has also been adopted to investigate the RWIV, but only a few studies have been conducted so far. Furthermore, most of the CFD simulations reported in literatures are two-dimensional, …

Unique Image Representation As A Tensor, Bharat Rosanlall

Dissertations and Theses

This thesis presents a two dimensional orthonormal transform that represents an image as coefficients in 4 independent channels. The salient feature of these coefficients is that they contain complete position spatial frequency information about the image, in a sense that the original image can be reconstructed from these coefficients with negligible error. These coefficients can be used in various machine learning, AI , and other tasks where data features are used. Popular convolutional layer used in various neural networks reduces information and can not reconstruct original image. In this thesis , we present several examples where these coefficients are used …

Adaptive Effort Classifiers: A System Design For Partitioned Edge/Cloud Inference, Divya Sankar

Dissertations and Theses

The massive growth in availability of real-world data from connected devices and the overwhelming success of Deep Neural Networks (DNNs) in many ArtificialIntelligence (AI) tasks have enabled AI-based applications and services to become commonplace across the spectrum of computing devices from edge/Internet-of-Things (IoT) devices to data centers and the cloud. However, DNNs incur high computational cost (compute operations, memory footprint and bandwidth),which far outstrip the capabilities of modern computing platforms. Therefore improving the computational efficiency of DNNs wide-spread commercial deployment and success.In this thesis, we address the computational efficiency challenge in the context ofAI inference applications executing on edge/cloud systems, …

Using Statistical Learning Approaches To Understand Trends And Variability Of Tornadoes Across The Continental United States, Niloufar Nouri

Dissertations and Theses

The annual frequency of tornadoes during 1950-2018 across the major tornado-impacted states were examined and modeled using anthropogenic and large-scale climate covariates in a hierarchical Bayesian inference framework. Anthropogenic factors include increases in population density and better detection systems since the mid-1990s. Large-scale climate variables include El Niño Southern Oscillation (ENSO), Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), Arctic Oscillation (AO), and Atlantic Multi-decadal Oscillation (AMO). The model provides a robust way of estimating the response coefficients by considering pooling of information across groups of states that belong to Tornado Alley, Dixie Alley, and Other …

Motion Of Janus And Patchy Particles Near Various Boundaries, Zohreh Jalilvand

Dissertations and Theses

Colloidal particles with anisotropic surface properties are an emergent class of novel materials that have been indicated to possess a remarkable potential to still be fully exploited. Among anisotropic colloids, Janus and patchy particles with different compositions and functionalities recently have drawn significant attention in the field of colloid science. They are known as promising candidates to address challenges in various fields such as emulsion stabilization, oil recovery, drug delivery, biosensors and environmental remediation. A majority of the envisioned applications require Janus and patchy particles to operate near boundaries, i.e., a wall or a fluid/liquid interface, which significantly affect the …

On The Energy Sustainability Of Active And Passive Building Integrated Technologies In The Context Of A Changing Climate For Tropical Coastal Cities, Rabindra Pokhrel

Dissertations and Theses

Caribbean Sea surface temperatures have been rising at an alarming rate of 0.020C/year. The effect of rising sea surface temperatures is reflected in increasing in 2m air temperature over the Caribbean. The rise in extreme temperatures increases human discomfort and energy demands for air conditioning (AC) putting both the population and energy infrastructure at higher risk of vulnerability. This vulnerability is amplified in compact cities where anthropogenic heat removal from the built environment further increases the temperature of the urban canyon with feedback on human comfort and energy demands. Although there has been prior work reported on mitigating energy demands …

V-Slam And Sensor Fusion For Ground Robots, Ejup Hoxha

Dissertations and Theses

In underground, underwater and indoor environments, a robot has to rely solely on its on-board sensors to sense and understand its surroundings. This is the main reason why SLAM gained the popularity it has today. In recent years, we have seen excellent improvement on accuracy of localization using cameras and combinations of different sensors, especially camera-IMU (VIO) fusion. Incorporating more sensors leads to improvement of accuracy,but also robustness of SLAM. However, while testing SLAM in our ground robots, we have seen a decrease in performance quality when using the same algorithms on flying vehicles.We have an additional sensor for ground …

Influence Of Droplet Velocity, Spacing, And Inter-Arrival Time On Line Formation And Saturation In Binder Jet Additive Manufacturing, Trenton Colton, Nathan B. Crane

Faculty Publications

Binder Jetting (BJ) is a low-cost Additive Manufacturing (AM) process that uses inkjet technology to selectively bind particles in a powder bed. BJ relies on the ability to control, not only the placement of binder on the surface but also its imbibition into the powder bed. This is a complex process in which picoliter-sized droplets impact powder beds at velocities of 1-10 m/s. However, the effects of printing parameters such as droplet velocity, size, spacing, and inter-arrival time on saturation level (fraction of pore space filled with binder) and line formation (merging of droplets to form a line) are unknown. …

Reinventing High School: Understanding The Challenges And Successes Of Transforming Education To Meet Student, Society, And Industry Needs, Scott R. Bartholomew, Greg J. Strimel, Anne M. Lucietto, Mesut Akdere

Faculty Publications

Efforts to revamp existing educational systems and approaches result in various new models in STEM education. Accordingly, a new urban public charter school, located in a Midwest state in the United States, was established in partnership with the state’s land-grant university to create a transformed integrated STEM educational environment characterized by industry-focused and design-based learning to help prepare students for the future of work and learning. This article presents findings from an exploratory study that examined the experiences of teachers and administrative staff of this innovative high school (IHS) during the first year of school operation. A purposive sample of …

Optimizing Router Performance, Bradley Newton, Radon Rosborough, Miles President, Hakan Alpan

CMC Senior Theses

To support its development of networking hardware and software, Juniper Networks conducts research into enhancements to the protocols used on the Internet, in coordination with standards bodies such as the Internet Engineering Task Force. We helped Juniper Networks with two specific research objectives. The first was to design and implement an improved algorithm by which Internet hosts can establish the appropriate packet size to maximize bandwidth while avoiding packet fragmentation. We produced a working implementation of the improved algorithm in the Linux kernel. The second objective was to measure the effect of different Internet Protocol extension headers (specifically, Routing Header …

Slender Frp Elements As Discrete Reinforcement For Concrete, Yuan Tian

Dissertations and Theses

This dissertation presents a study that led to the development of slender elements that look like fibers used for reinforcing concrete but with a very different reinforcing mechanism. These elements, referred to as “Needles” are very rigid and strong; when intersected by growing cracks in concrete under heavy and increasing loads, they do not break and deform minimally. In the present work major steps were taken to understand the reinforcing mechanism of Needles. In addition, to investigate the influence of Needles on the mechanical performance of concrete incorporating Needles, at both material and structural levels, a series of laboratory experiments …

Object Identification In Radar Imaging Via The Reciprocity Gap Method, Matthew Charnley, Aihua W. Wood

Faculty Publications

In this paper, we present an experimental method for locating and identifying objects in radar imaging, specifically problems that could arise in physical situations. The data for the forward problem are generated using a discretization of the Lippmann‐Schwinger equation, and the inverse problem of object location is solved using the reciprocity gap approach to the linear sampling method. The main new development in this paper is an exploration of determining the permittivity of the object from the back‐scattered data, utilizing another discretization of the Lippmann‐Schwinger equation.
Abstract © AGU.

Order Fulfillment Errors And Military Aircraft Readiness, Michael Weber, Daniel Steeneck, William Cunningham

Faculty Publications

This paper aims to measure the effect of supply discrepancy reports (SDRs) on military aircraft readiness metrics, including aircraft availability, not mission capable supply (NMCS) hours, cannibalizations and mission-impaired capability awaiting parts (MICAP) hours.

Monthly SDR, NMCS, aircraft cannibalizations and MICAP data from 2009 to 2018 are analyzed using linear regression and independent samples t-tests to examine whether discrepant shipments negatively impact aircraft readiness.

Research In Defense Logistics: Where Are We And Where Are We Going?, George A. Zsidisin, Amanda Bresler, Benjamin T. Hazen, Keith F. Schneider, Taylor H. Wilkerson

Faculty Publications

The purpose of this paper is to provide insight on high-interest areas of research in defense-related logistics and supply chain management and opportunities for advancing theory and practice in this domain.

A Scenario-Based Parametric Analysis Of The Army Personnel-To-Assignment Matching Problem, Matthew D. Ferguson, Raymond R. Hill, Brian J. Lunday

Faculty Publications

This study aims to compare linear programming and stable marriage approaches to the personnel assignment problem under conditions of uncertainty. Robust solutions should exhibit reduced variability of solutions in the presence of one or more additional constraints or problem perturbations added to some baseline problems.
Several variations of each approach are compared with respect to solution speed, solution quality as measured by officer-to-assignment preferences and solution robustness as measured by the number of assignment changes required after inducing a set of representative perturbations or constraints to an assignment instance. These side constraints represent the realistic assignment categorical priorities and limitations …

Comparison Of Pyrolysis Of Live Wildland Fuels Heated By Radiation Vs. Convection, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

During wildland fires, which include both planned (prescribed fire) and unplanned (wildfire) fires, live and dead plants may be subject to both radiative and convective heat transfer mechanisms. In this study, the pyrolysis of 14 live plant species native to the forests of the southern United States was investigated using a flat-flame burner (FFB) apparatus under three heating modes in order to mimic pyrolysis of plants during wildland fires. The heating modes were: (1) radiation-only, where the plants were pyrolyzed under a moderate heating rate of 4 °C s−1 (radiative flux of 50 kW m−2); (2) convection-only, where the FFB …

The Effects And Analysis Of Implant Type And Surgical Approach In Total Hip Arthroplasty Dislocation Resistance, Brittany Marshall

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most successful orthopaedic surgeries performed, in which the hip joint is reconstructed to decrease pain and to improve the functionality to the joint. Although these surgeries are very successful, there still remain areas for improvement, such as failures due to instability and dislocation of the implanted joint. The purpose of this thesis is to investigate the effect of surgical entrance approach on dislocation, the effect of implant type, and the effect of capsule repair and closure. The need to quantify the resistance to dislocation is important in understanding the effect that each …

Transcatheter Mitral Valve Replacement: Structural And Hemodynamic Analysis, Saba Ravaghi

Electronic Theses and Dissertations

Transcatheter mitral valve replacement (TMVR) is being developed to become a substitute therapy for surgery in prohibitive or high surgical risk patients to treat severe mitral regurgitation. A limited number of TMVR systems are under clinical evaluation. However, transcatheter mitral valve (TMV) long-term durability and hemodynamic performance is not known. TMV durability and hemodynamics must match with that of surgical bioprostheses for potential commercialization of TMVR. Experimental and computational approaches were used to find the leaflets’ three-dimensional anisotropic mechanical properties in a transcatheter Edwards SAPIEN 3 valve and a surgical Carpentier-Edwards PERIMOUNT Magna mitral valve and finite element (FE) simulations …