Engineering Commons^™

The Professional Constructor, Full Issue, Volume 45, Number 01

The Professional Constructor

No abstract provided.

Neural Network Pruning For Ecg Arrhythmia Classification, Isaac E. Labarge

Master's Theses

Convolutional Neural Networks (CNNs) are a widely accepted means of solving complex classification and detection problems in imaging and speech. However, problem complexity often leads to considerable increases in computation and parameter storage costs. Many successful attempts have been made in effectively reducing these overheads by pruning and compressing large CNNs with only a slight decline in model accuracy. In this study, two pruning methods are implemented and compared on the CIFAR-10 database and an ECG arrhythmia classification task. Each pruning method employs a pruning phase interleaved with a finetuning phase. It is shown that when performing the scale-factor pruning …

Geopolitics And The Digital Domain: How Cyberspace Is Impacting International Security, Georgia Wood

Independent Study Project (ISP) Collection

The digital domain is the emerging environment for which the internet and data connectivity exists. This new domain is challenging the traditional place for geopolitics to exist, and creating new challenges to international relations. The use of cyberweapons through direct cyberattacks, such as the possibility of an attack on the U.S. power grid, or misinformation campaigns, such as the one launched by Russia against the 2016 U.S. Presidential election, can expand the international threat landscape. While these new threats increase, states are widely not prepared to address the new challenges in the digital domain. This paper will use three primary …

El Artista Está En Línea: E-Performance En El Tiempo De Covid-19, Ezequiel N. González

Independent Study Project (ISP) Collection

Esta investigación propone una lectura detallada y comparativa de varias e-performances creadas por el artista visual uruguayo Ernesto Rizzo y la performer argentina Susy Shock, trazando un corpus de trabajo creado durante la crisis de COVID-19 y compartido en Instagram desde finales de marzo a finales de mayo de 2020. Al centrarse en el giro digital del arte de performance debido a las particularidades de la cuarentena, esta investigación busca distinguir este momento de "e-performance", entendiendo cuáles serán sus ramificaciones para el/la artista y el arte de performance en general. Así, a través de una reflexión teórica sobre el terreno …

La Minería Del Litio En Salinas Grandes: Un Análisis De Diferentes Narrativas En Torno A La Extracción De Litio Desde 2010 Hasta El Presente / Lithium Mining In The Salinas Grandes: An Analysis Of Different Narratives Surrounding The Extraction Of Lithium From 2010 Until The Present, Sofia Perrotto

Independent Study Project (ISP) Collection

El litio ha ocupado una posición muy interesante y controvertida dentro del movimiento ambiental desde su descubrimiento en 2010. Entre los muchos usos de este metal precioso está la fabricación de baterías, que es un componente esencial para la transición hacia una "economía verde". Los vehículos eléctricos y las unidades de almacenamiento de energía que funcionan con baterías de litio son dos tecnologías importantes para este movimiento, y como resultado, la demanda de litio está aumentando en el mercado global. En las Salinas Grandes, la cuestión de la extracción de litio involucra a una variedad de actores que tienen diferentes …

Optimization Of Vehicle To Grid System In A Power System With Unit Commitment, Charles Uko

Theses and Dissertations

This thesis provides a comprehensive overview and analysis of the benefits of using plug-in electric vehicles (PEVs) in solving the unit commitment problem. PEVs are becoming more attractive and a rapid replacement of conventional fuel vehicles due to their environmental-friendly operation. Through collective control by an aggregator, PEVs batteries can also provide ancillary services such as load leveling and frequency regulation to improve the quality of power supplied in the power grid and reduce the cost of power generation. This study presents the modeling, simulation, and analysis of a vehicle-to-grid (V2G) system connected to a smart power grid. The model …

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 …

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 …

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 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 …

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 …

Structural Evolution Of La Florida And Guavio Anticlines, Fractures, And Petroleum Systems In A Foreland Fold Belt, Eastern Cordillera Foothills, Colombia, Ziyad Albesher

Theses and Dissertations

Geological structures and petroleum systems associated with La Florida anticline and the Cusiana fault system in the Llanos foothills and the Guavio anticline and the Guaicaramo fault system in the Medina basin were interpreted based on 3D seismic data from La Florida anticline in the foothills, 2D seismic data in the Medina basin and Guavio anticline, well, and surface geology maps. Unlike previous interpretations of the Guavio anticline and Medina basin area, our interpretation shows that thin-skinned thrusting on the Guaicaramo fault preceded thick-skinned basement thrusting. Late Miocene thin-skinned ramp thrusting was followed by a Pliocene thick-skinned fault-bend fold ramping …

Effects Of Material Characteristics And Equipment Configuration On Profilometry Scanning Results For Error Mitigation In Automated Fiber Placement, Jacob Ondeck

Theses and Dissertations

The Automated Fiber Placement manufacturing process is a method for constructing layered composite parts. This is done by placing tapes of material on a tool using a compaction roller and heat to tackify the material [1]. This manufacturing process is not new, but latest equipment generations can still introduce randomly occurring defects, presenting often as tow twists, gaps, unintentional overlaps and even missing tows during the layup process. These defects deviate the manufactured structure from the as-designed structure, and have been proven to introduce stress concentration sources, which can ultimately undermine the performance of a structure [2]. To detect and …

Advanced Geometric Analyses In Vascular Disease And Interventions, Dara Ahmadi Azar

Theses and Dissertations

The central function of the vascular system is the transportation and distribution of blood throughout the body. Occurrence of various forms of vascular disease, in which this central function is compromised, is associated with high mortality and morbidity rates. Vascular disease is an active and multifactorial process causing changes in local hemodynamics and blood vessel wall mechanics. The work presented here aims to advance the current knowledge on the role of local geometrical parameters in vascular disease and endovascular intervention modalities. In our first set of studies, we develop a computational framework to understand the role of aortic geometry in …

An Overlay Architecture For Pattern Matching, Rasha Elham Karakchi

Theses and Dissertations

Deterministic and Non-deterministic Finite Automata (DFA and NFA) comprise the fundamental unit of work for many emerging big data applications, motivating recent efforts to develop Domain-Specific Architectures (DSAs) to exploit fine-grain parallelism available in automata workloads.

This dissertation presents NAPOLY (Non-Deterministic Automata Processor Over- LaY), an overlay architecture and associated software that attempt to maximally exploit on-chip memory parallelism for NFA evaluation. In order to avoid an upper bound in NFA size that commonly affects prior efforts, NAPOLY is optimized for runtime reconfiguration, allowing for full reconfiguration in 10s of microseconds. NAPOLY is also parameterizable, allowing for offline generation of …

Strain Components In Friction Stir Extrusion, Megan Ryan

Theses and Dissertations

Friction stir extrusion is a solid state process that uses a rotating die to perform extrusions. This process can be used to directly recycle waste from machining processes and has been shown to produce wires with desirable mechanical properties. In order to better understand the friction stir extrusion process, the effect of the process parameters on the strain distribution in the wires needs to be understood. The process parameters evaluated in this work are die advance rate, die rotational seed, and die geometry. A total of 16 wires were extruded using different combinations of these process parameters. Marker wires were …

Assessing The Impacts Of Greenhouse Gasses On Upwelling And Surface Temperature In The California Current System, Kevin Mcgee

LMU Theses and Dissertations

The California Current system (CCS) is home to a vast and diverse marine coastal ecosystem. Upwelling is an oceanic phenomenon wind-driven displacement of surface water brings cold nutrient-rich water from the ocean bottom to surface waters. Along the coast in the CCS, upwelling occurs via the advection of water perpendicular to the shoreline northerly winds, a phenomenon called “Ekman Transport”. In the open ocean. Wind stress curl causes disruption of normal currents, resulting in small pockets of upwelled or downwelled water (downwelling is the movement of water downward in the ocean, the opposite of upwelling). This process is called “Ekman …

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, …

Occurrence And Persistence Of Antibiotics Administered To Cattle In A Newly Established Feedlot, Brittany Trejo

Department of Environmental Engineering: Theses and Other Student Research

The common practice of using therapeutic antibiotics in livestock farming is a worldwide phenomenon. Over the last decade, there has been a growing concern of antibiotics entering the environment via animal manure. Similar studies have focused on the occurrence and biological effects of antibiotics in land-applied animal feedlots; however, limited research has been conducted on the occurrence and persistence of antibiotics in animal feedlots. A study was conducted to investigate the occurrence and persistence of four injected antibiotics (ceftiofur enrofloxacin, florfenicol, and tulathromycin) and two continuously fed antibiotics (monensin and tylosin) in feedlot sediment, runoff, and sediment runoff. For antibiotics …

Activated Carbon Nanofibers From Renewable (Lignin) And Waste Resources (Recycled Pet) And Their Adsorption Capacity Of Refractory Sulfur Compounds From Fossil Fuels, Efstratios Svinterikos

Dissertations

The development of advanced engineering materials such as carbon nanofibers from low-cost, renewable and/or waste resources is a key aspect of sustainability. In addition, escalating concerns related to the presence of noxious sulfur compounds in commercial fuels are driving the need to develop more efficient desulfurization technologies. In this PhD dissertation research, activated carbon nanofibers were produced from a blend of lignin with recycled poly(ethylene terephthalate) (r-PET) and they were successfully tested for the adsorption of refractory sulfur compounds from a model diesel fuel. Starting from different lignin/r-PET mass ratios, precursor nanofibers of different morphologies were initially prepared using the …

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 …

Seismic Attribute Fracture Analysis And Thin And Thick-Skinned Structural Controls On The Evolution Of A Foreland Basin - Parrando And Guavio Anticlines, Eastern Cordillera Foothills, Colombia, Ibraheem Khalil Hafiz

Theses and Dissertations

The Parrando and Guavio anticlines are located in the Llanos foothills on the eastern flank of the Eastern Cordillera of Colombia. This study presents new 3D horizon maps, seismic and stratigraphic interpretations, and 1D burial models based on a 3D seismic volume, 2D seismic lines, and well logs. The Guavio anticline was formed by overlapping Miocene-Pliocene fault-bend folds and inversion of the Guaicaramo normal fault. Unlike previous models, the basement fold is interpreted as formed by a ramp from pre-Cretaceous basement to a double wedge fault probably preceded by a thin-skinned bedding plane thrust fault. A new 1D burial model …

Tow-Path Characterization For Automated Fiber Placement, Roudy Wehbe

Theses and Dissertations

Automated Fiber Placement (AFP) is a manufacturing process used to fabricate large composite structures for aerospace applications. During the process, the machine head deposits multiple bands of composite material named tows over a prescribed path. Temperature, speed, and compaction pressure can be varied to obtain a good layup quality. For conventional laminated plate structures manufactured using the AFP process, fibers are laid at constant angles (0°, 90°, ±45°) in straight paths. However, to manufacture complex shell structures or variable stiffness plates, curved paths are necessary in the design leading to a length mismatch between the parallel edges of the towpath. …

Geophysical Study Of Gold Mineralized Zones In The Carolina Terrane Of South Carolina, Saad Saud Alarifi

Theses and Dissertations

T

he goal of this study was to calibrate and test geophysical methods for the detection of geological structural and disseminated sulfides in the area of the four largest gold deposits in the Southern Appalachian of South Carolina. The Coastal plain sediments, vegetation and saprolite covering the mining areas remain the most challenging in this region. The work focused on the calibration of high-resolution gravity, and helicopter electromagnetic (EM) and magnetic data provided by OceanaGold over the Haile and Brewer Mines; then calibrating the regional gravity and aeromagnetic data over the four gold mines in South Carolina. Observed geophysical fields …

A Machine Learning Based Approach To Accelerate Catalyst Discovery, Asif Jamil Chowdhury

Theses and Dissertations

Computational catalysis, in contrast to experimental catalysis, uses approximations such as density functional theory (DFT) to compute properties of reaction intermediates. But DFT calculations for a large number of surface species on variety of active site models are resource intensive. In this work, we are building a machine learning based predictive framework for adsorption energies of intermediate species, which can reduce the computational overhead significantly. Our work includes the study and development of appropriate machine learning models and effective fingerprints or descriptors to predict energies accurately for different scenarios. Furthermore, Bayesian inverse problem, that integrates experimental catalysis with its computational …

Parsimonious Sociology Theory Construction: From A Computational Framework To Semantic-Based Parsimony Analysis, Mingzhe Du

Theses and Dissertations

In the social sciences, theories are used to explain and predict observed phenomena in the natural world. Theory construction is the research process of building testable scientific theories to explain and predict observed phenomena in the natural world. Conceptual new ideas and meanings of theories are conveyed through carefully chosen definitions and terms.

The principle of parsimony, an important criterion for evaluating the quality of theories (e.g., as exemplified by Occam’s Razor), mandates that we minimize the number of definitions (terms) used in a given theory.

Conventional methods for theory construction and parsimony analysis are based on heuristic approaches. However, …

Design And Testing Of A Supercritical Carbon Dioxide Plasma Reactor, Gregory Belk

Theses and Dissertations

The objective of this project was to design, build, and test a plasma reactor capable of operating in the supercritical conditions. The reactor allows for the initiation of a plasma discharge in different fluids driven by a direct current (DC) power supply operating either in steady state mode or pulsing mode. The reactor was specifically designed for igniting plasmas within supercritical carbon dioxide, which has a pressure of 72.9 atm and 31.1 degrees Celsius.

A series of runs were conducted for varying pressures and inter-electrode separation, which allowed testing the operation regimes of the reactors. Finally, plasma experiments were conducted …

Automation Of Process Planning For Automated Fiber Placement, Joshua A. Halbritter

Theses and Dissertations

Process planning represents an essential stage of the Automated Fiber Placement (AFP) workflow. It develops useful and efficient machine processes based upon the working material, composite design, and manufacturing resources. The current state of process planning requires a high degree of interaction from the process planner and could greatly benefit from increased automation. Therefore, a list of key steps and functions are created to identify the more difficult and time-consuming phases of process planning. Additionally, a set of metrics must exist by which to evaluate the effectiveness of the manufactured laminate from the machine code created during the Process Planning …

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 …