Engineering Commons^™

Modeling The Effects Of Parameter Changes On Heating And Pressure At The Weld Interface And Joint Strength In Friction Bit Joining, Adam Hartly Wagner

Theses and Dissertations

Joining of dissimilar metals is a process that is of interest in many fields, especially the automotive industry where lightweighting of the body structure is important. However, creating strong joints between dissimilar metals can be challenging. Friction bit joining (FBJ) is a solid-state method that uses a consumable bit to create a strong joint between dissimilar metals such as aluminum and steel. The purpose of this research is to gain understanding of how adjusting FBJ parameters affects the heating and pressure at the weld interface using a modeling approach, in order to better understand the bonding process. The questions guiding …

Sustainable Underground Reactive Barrier To Attenuate Contaminants From Agricultural Drainage, Yuchuan Fan

Doctoral Dissertations

Denitrifying bioreactor (DNBR) has become a popular edge-of-field practice applied to reduce nitrate over the Mississippi river and to prevent a downstream hypoxic zone occurring at the Gulf of Mexico. Despite widespread field and laboratory studies, fewer investigations have been directed toward a systematic means of evaluating the nitrate removal performance achieved by various filling materials, abiotic factors, and other critical parameters. Our ultimate goal is to improve the nitrate removal by choosing the optimum fill materials and operate under optimal conditions, meanwhile, modeling the DNBR by critical variables. This study begins by establishing a global database. Forty filling materials …

Development And Validation Of An Analytical Modeling Tool For Solar Borehole Heat Exchangers, Adam Ornelles

All Theses

Current numerical modeling solutions used for subsurface heat flow, such as the Berkeley TOUGH codes, are often difficult to use and time-consuming compared to analytical modeling methods. However, current analytical modeling methods for subsurface heat flow and groundwater cannot accurately model the subsurface in 3 dimensions, a feature paramount to the planning and installation of thermal borehole heat exchangers used in environmental remediation.

This research developed a novel 3-dimensional analytical modeling tool for solar-powered borehole heat exchangers. The analytical modeling tool can plan thermal remediation systems while being more straightforward to operate than current numerical modeling software. By creating a …

Investigation Of Control Parameters, Strategies, And Transport Modeling For Effective Electrokinetic Nanoparticle Treatment Of Cementitious Materials, Huayuan Zhong

Doctoral Dissertations

Various deleterious chemical species (including sulfates, chlorides, and others) contaminate concrete structures which are inherently porous and thus suffer from compromised durability. Several technologies have been developed for repairing concrete or enhancing the service life. Nevertheless, their efficiency, practicability, and cost can vary widely. Compared with chemical grout, fiber wrap, and traditional repair technology, electrokinetic nanoparticle treatment (EN) has been found to provide remarkable benefits for strength restoration and mitigation of durability problems via porosity reduction. Nanoparticle instability and over dosage issues can arise and lead to problems during treatments. In many cases, these treatment processes have been accompanied by …

Metabolic Modeling Of Cystic Fibrosis Airway Microbiota From Patient Samples, Arsh Vyas

Masters Theses

Cystic Fibrosis (CF) is a genetic disorder, found with higher prevalence in the Caucasian population, affecting > 30,000 individuals in the United States and > 70,000 worldwide. Due to the astoundingly high rate of mortality among CF patients being attributed to respiratory failure brought on by chronic bacterial infections and subsequent airway inflammation, there has been a lot of focus on systematically analyzing CF lung airway communities. While it is observed traditionally that Pseudomonas aeruginosa is the most threatening and persistent CF colonizer due to high antibiotic resistance, recent studies have elicited the roles of other pathogens and it has been widely …

Spatiotemporal Metabolic Modeling Of Pseudomonas Aeruginosa Biofilm Expansion, Robert Sourk

Masters Theses

Spatiotemporal metabolic modeling of microbial metabolism is a step closer to achieving higher dimensionalities in numerical studies (in silico) of biofilm maturation. Dynamic Flux Balance Analysis (DFBA) is an advanced modeling technique because this method incorporates Genome Scale Metabolic Modeling (GSMM) to compute the biomass growth rate and metabolite fluxes. Biofilm thickness is pertinent because this variable of biofilm maturation can be measured in a laboratory (in vitro). Pseudomonas aeruginosa (P. aeruginosa) is the model bacterium used in this computational model based on previous research conducted by Dr. Michael Henson, available GSMMs, and the societal significance of patients suffering from …

Development Of A Multi-Scale Mechano-Electrochemical Battery Model, Drew J. Pereira

Theses and Dissertations

As the automotive industry moves towards large format electric vehicles, such as trucks and SUVs, the need for highly efficient, energy-dense electrodes rapidly increases. Several promising active materials have been studied and proposed, however, many of these materials undergo significant volume change upon lithiation and de-lithiation. Cell and pack designers struggle to understand and predict how active material volume change at the particle scale will affect mechano-electrochemical behavior on the electrode, cell, and pack scales. Additionally, many of these active materials suffer in their cycle life due to a mechanically-driven degradation of the electrode matrix. Therefore, the focus of this …

Development Of Predictive Equations For Thermal Conductivity Of Compost Bedding, Flávio A. Damasceno, Joseph L. Taraba, George B. Day V, Randi A. Black, Jeffrey M. Bewley, Tales J. Fernandes, Carlos E. A. Oliveira, Rafaella R. Andrade, Matteo Barbari, Patrícia F. P. Ferraz, Lorenzo Leso

Biosystems and Agricultural Engineering Faculty Publications

Among animal facilities, compost-bedded pack (CBP) barns have attracted a lot of attention from milk producers and the scientific community. Systematic investigation of the main thermal properties utilizing sawdust in CBP barns is of environmental and economic relevance. In this paper, the aim was to (a) develop predictive equations for the thermal conductivity (k) of compost bedding as a function of moisture content (MC), the degree of compaction (DC_o), and particle size (PS); and (b) investigate the links between k and depth within bedding material. Samples of compost bedding materials were collected from 42 commercial CBP …

Thermal Vacuum Chamber Modification, Testing, And Analysis, Jared C. Lehmann

Master's Theses

This work discusses the modification and analysis of the Blue Thermal Vacuum Chamber (TVAC) located at the Space Environments Lab at California Polytechnic State University, San Luis Obispo. The modified design has a cylindrical test section and can accommodate 6U Cubesats or larger for educational or research purposes. The sizing process for the modified shroud cooling system and modular heating plates is discussed. The modified cooling system uses existing nitrogen plumbing into the chamber and control systems with a new copper shroud. The modified heating system uses modular heater plates, which utilize the existing three heater strips. The modified system …

Digital Cutting Force Modeling For Milling Operations, Timothy T. No

Doctoral Dissertations

Process improvement in milling through improved understanding of machining dynamics is an on-going research endeavor. The objective of this project is to advance digital modeling of the milling process by incorporating tool-specific geometry in the machining analysis. Structured light scanning will be used to perform tool geometry measurements and produce a 3D model. The 3D model data will include the spatial location of the cutting edges, as well as the rake and relief profiles from the tool cross section. The rake and relief profiles will be imported, together with the work material flow stress model, into a finite element analysis …

Nonlinear Model Development And Validation For Ball And Plate Control System, Zachary Richter

Master's Theses

Ball and plate balancing control systems are commonly studied due to the complex dynamics associated with the instability of the system in open-loop. For simplicity, mathematical models describing the ball and plate dynamics are often linearized and the effects of complex motion are assumed to be negligible. These assumptions are rarely backed with evidence or explanations validating the simplified form of the dynamical equations of motion. This thesis focuses on developing a nonlinear model that more accurately defines the dynamics of the system, in order to quantify the error of linear and nonlinear models when compared to a Simscape physical …

Effects Of Acid Deposition And Changing Climate On The Hydrochemistry And Critical Loads Of Watersheds In The Adirondack Region Of New York, Shuai Shao

Dissertations - ALL

Despite decreases in acidic deposition since the 1970s, the recovery of surface waters from acidification has been limited primarily due to the depletion of exchangeable base cations, net mineralization of organic sulfur and nitrogen and release of previously retained SO42- and NO3-, and increases in concentrations of naturally occurring organic acids from soil. The future recovery of stream chemistry from acidic deposition may be altered by projected increases in temperature and precipitation associated with a changing climate. The goals of this study were to conduct a modeling analysis of the response of soils and streams in the Adirondack Park, New …

Developing A Lab-Scale Fluidized Bed Dryer System To Enhance Rough Rice Drying Process, Kaushik Luthra

Graduate Theses and Dissertations

For more than half of the world's population, rice (Oryza sativa L.) is a staple meal. However, rice growers encounter difficulties supplying this demand, particularly in developing nations, where rice is susceptible to spoilage if the moisture content is not lowered to a safe level soon after harvest. As a result, traditional drying methods, such as sun drying and natural air drying, are commonly used by rice growers, particularly in underdeveloped nations. However, these procedures are time-consuming and can lead to rice spoilage. On the other hand, fluidized bed drying is a well-established technology that might give rice growers a …

Development Of Experimental And Numerical Methods For Investigations Of High-Octane Fuels In Heavy-Duty Applications, Jared James Zeman

Master's Theses (2009 -)

Increasingly stringent emissions regulations has threatened the existence of the internal combustion (IC) engine. In some transportation sectors, non-IC engine powertrains have the potential to be a logical solution. However, in the heavy-duty sector, the IC engine is predicted to remain the dominant propulsion method for the foreseeable future. With ever-increasing demand for heavy-duty power generation platforms, the primary focus for the development of the future heavy-duty IC engine needs to be on increasing engine efficiency and the adoption of lowlife-cycle carbon, clean burning fuels, e.g. methanol. The fuel ignition properties of these fuels, e.g. high octane, cause difficulties when …

Creation And Application Of Various Tools For The Reconstruction, Curation, And Analysis Of Genome-Scale Models Of Metabolism, Wheaton L. Schroeder

Department of Chemical and Biomolecular Engineering: Theses and Student Research

Systems biology uses mathematics tools, modeling, and analysis for holistic understanding and design of biological systems, allowing the investigation of metabolism and the generation of actionable hypotheses based on model analyses. Detailed here are several systems biology tools for model reconstruction, curation, analysis, and application through synthetic biology. The first, OptFill, is a holistic (whole model) and conservative (minimizing change) tool to aid in genome-scale model (GSM) reconstructions by filling metabolic gaps caused by lack of system knowledge. This is accomplished through Mixed Integer Linear Programming (MILP), one step of which may also be independently used as an additional curation …

Rapid Development Technology Of Virtual Maintenance Training Simulation Model For Aviation Equipment, Rongqiang Li, Aibing Wen, Bin Hua, Jiajun Li, Jiang Bing

Journal of System Simulation

Abstract: Taking the practical application of the aircraft virtual maintenance training as the demand, the basic development process and technical means of the aircraft virtual maintenance training simulation model are analyzed, which solves the technical bottleneck in the popularization and application of the large-scale engineering. Aiming at the crucial problems such as the low efficiency in the development of maintenance training simulation model and the difficulties in updating the model, a rapid development process to support the large-scale engineering applications is proposed. The principles and implementation ways of three key technologies supporting the rapid development of virtual maintenance training simulation …

Selective Neural Stimulation By Leveraging Electrophysiological Diversity And Using Alternative Stimulus Waveforms, Bemin Ghobreal

Dissertations

Efforts on finding the principle mechanism for selective neural stimulation have concentrated on segregating the neurons based on their size and other geometric factors. However, neuronal subtypes found in different parts of the nervous system also differ in their electrophysiological properties. The primary objective of this study is to investigate the feasibility of selective activation of neurons by leveraging the diversity seen in passive and active membrane properties.

Using both a local membrane model and an axon model based on the CRRSS, the diversity of electrophysiological properties is simulated by varying four model parameters (membrane leakage-Gleak and capacitance-Cm, temperature coefficient-Ktemp, …

Computational Design Of Nonlinear Stress-Strain Of Isotropic Materials, Askhad M.Polatov, Akhmat M. Ikramov, Daniyarbek Razmukhamedov

Chemical Technology, Control and Management

The article deals with the problems of numerical modeling of nonlinear physical processes of the stress-strain state of structural elements. An elastoplastic medium of a homogeneous solid material is investigated. The results of computational experiments on the study of the process of physically nonlinear deformation of isotropic elements of three-dimensional structures with a system of one- and double-periodic spherical cavities under uniaxial compression are presented. The influence and mutual influence of stress concentrators in the form of spherical cavities, vertically located two cavities and a horizontally located system of two cavities on the deformation of the structure are investigated. Numerical …

Modeling And Monitoring Of Water Quantity And Quality In Permeable Pavement Systems Using Geophysical Equipment, Abby Klimowicz

Honors Scholar Theses

Permeable pavements are a type of low impact development (LID) that reduces runoff by increasing the permeability of developed surfaces. Less runoff helps protect the surrounding ecosystems from erosion and pollution. Without pools of accumulating runoff, the potential for the development of ice on roads and parking lots is also decreased. However, sufficient research on the movement of water and the ions dissolved in it through the permeable pavement system has not been completed. In this study, geophysical equipment was used to observe how moisture, measured as volumetric water content (VWC), and ions, approximated by electrical conductivity, pass through constructed …

A Review Of Harmful Algal Bloom Prediction Models For Lakes And Reservoirs, Jade Snyder Echard

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

Anthropogenic activity has led to eutrophication in water bodies across the world. This eutrophication promotes blooms, cyanobacteria being among the most notorious bloom organisms. Cyanobacterial blooms (more commonly referred to as harmful algal blooms (HABs)) can devastate an ecosystem. Cyanobacteria are resilient microorganisms that have adapted to survive under a variety of conditions, often outcompeting other phytoplankton. Some species of cyanobacteria produce toxins that ward off predators. These toxins can negatively affect the health of the aquatic life, but also can impact animals and humans that drink or come in contact with these noxious waters. Although cyanotoxin’s effects on humans …

3d Printable And Computational Models Of The Bone Marrow Mechanical Environment, Alexander Regner

Boise State University Theses and Dissertations

Aged individuals and astronauts experience bone loss despite rigorous physical activity. Bone mechanoresponse is in part regulated by mesenchymal stem cells (MSCs). We reported that daily low intensity vibration (LIV) restores MSC proliferation in senescence and simulated microgravity models, suggesting reduced mechanical signal delivery to MSCs likely contributes to declining bone mechanoresponse. To this end, we have developed a 3D bone marrow analog which controls trabecular geometry, marrow mechanics and external stimuli.

Finite element (FE) models of hydrogels, representing bone marrow, were generated using instantaneous compression (1000% strain/s, 20% strain) and relaxation experiments (100s) of both gelatin and hyaluronin-based hydrogels. …

Characterizing Students’ Engineering Design Strategies Using Energy3d, Jasmine Singh, Viranga Perera, Alejandra Magana, Brittany Newell

Discovery Undergraduate Interdisciplinary Research Internship

The goals of this study are to characterize design actions that students performed when solving a design challenge, and to create a machine learning model to help future students make better engineering design choices. We analyze data from an introductory engineering course where students used Energy3D, an open source computer-aided design software, to design a zero-energy home (i.e. a home that consumes no net energy over a period of a year). Student design actions within the software were recorded into text files. Using a sample of over 300 students, we first identify patterns in the data to assess how students …

Modeling Considerations For Built-Up Compression Members In Communication Towers, Ghada M. El-Mahdy P.Eng., Ceng, Amro A. Alawamry

Civil Engineering

It is a well-established fact that built-up compression members exhibit extra flexibility than their equivalent solid members due to the shear action which effects the overall stability. This is usually taken into consideration by using a modified slenderness ratio for buckling modes that involve relative deformation of the interconnectors. Built-up members are often used as space truss members in communication towers. When modeling communication towers in structural analysis programs like SAP2000, the built-up member is usually defined as a single member element with a double section cross section. This does not catch the increase in deflection in the member due …

Vascular Endothelial Dysfunction And Effects On Arterial Wall Microstructure, Jeffrey Thomas Rodgers

Theses and Dissertations

Vascular endothelial cell dysfunction (ECD) is a disease characterized by the inability of the vascular endothelial cells to transmit signaling molecules, namely nitric oxide (NO), in response to changes in blood flow rate. This disease is shown to be incident in the onset of more severe vascular disease such as hypertension, atherosclerosis, and heart failure. Long-term ECD is shown to cause long-term remodeling such as decreased flow-mediated dilation, increased pulse-wave velocity, intimal-medial thickening, and increased wall stiffness due to collagen deposition. We used second harmonic generation (SHG) microscopy to analyze this change in the collagen microstructure of the arterial extracellular …

Coal Pyrolysis Models For Use In Massively Parallel Oxyfuel-Fired Boiler Simulations, Andrew Perry Richards

Theses and Dissertations

Accurately modeling key aspects of coal combustion allows for the virtual testing and application of new technologies and processes without the need for investments in lab- and pilot-scale facilities, since such facilities may only be used for a few small tests. However, modeling of subprocesses must not only be accurate but computationally efficient. Modeling of coal devolatilization reactions and processes are one of the important parts of large-scale simulations of coal combustion systems. The work presented here details efforts to improve the modeling of coal devolatilization processes in massively-parallel simulations of coal combustors, including: (1) devolatilization rate/yield models, (2) modeling …

Integrated Approach For Diversion Route Performance Management During Incidents, Rajib Chandra Saha

FIU Electronic Theses and Dissertations

Non-recurrent congestion is one of the critical sources of congestion on the highway. In particular, traffic incidents create congestion in unexpected times and places that travelers do not prepare for. During incidents on freeways, route diversion has been proven to be a useful tactic to mitigate non-recurrent congestion. However, the capacity constraints created by the signals on the alternative routes put limits on the diversion process since the typical time-of-day signal control cannot handle the sudden increase in the traffic on the arterials due to diversion. Thus, there is a need for proactive strategies for the management of the diversion …

Strength, Fracture Evolution, And Permeability Changes From Confined Brazilian Tests On Sandstone, Tyler Louis Hagengruber

Civil Engineering ETDs

This research reports on confined Brazilian strength tests and concurrent permeability testing on sandstone. The majority of the tests measured permeability during loading to failure in the confined extension region. Additional testing includes unloading and reloading cycles to detect the development of microcracks and the dependence of permeability on mixed stress conditions. Further testing characterizes fracture networks by observing porosity changes due to microcrack interactions before peak load. All tests involve 5 cm diameter disk-shaped, jacketed samples that are subjected to confining stresses while they are diametrically loaded. Specially designed end caps allow for gas flow measurements. The test configuration …

Development Of A Hurricane Recovery Function And Resilience Model For Single-Family Residential Homes, Uriel Robert Donald Clark

Theses and Dissertations

The resilience of communities, infrastructure, and the environment in the face of hurricanes has increasingly become of public interest in the wake of recent natural disasters and environmental activism. Previous methodologies have attempted to quantify resilience for various structures and scenarios. Many studies have primarily investigated the robustness of critical infrastructure (e.g., bridges, emergency facilities, and water systems) which are essential to the function of a community. However, few studies have applied this approach to individual residential buildings. Therefore, this research aimed to adapt the most recent recovery functions developed for residential homes by considering measurable factors that are known …

Architecture Design Of An Emergency Command Simulation Exercise Platform Based On Tena, Peng Zhang, Qinfu Li

Journal of System Simulation

Abstract: Based on the analysis of the current situation and development needs of the emergency command simulation exercise platform and the common characteristics of most emergency command case scenarios, an emergency command simulation exercise platform architecture based on TENA (Test and Training Enabling Architecture) is designed and put forward, which can expand various simulation models such as disaster accidents, disaster-bearing subjects, higher-lower linkage command organizations, rescue forces, natural environment, etc. in a multi-granularity and modular manner, and interface with various exercise support and analysis evaluation tools, as well as heterogeneous systems such as external three-dimensional simulation, virtual reality/augmented reality equipment …

Modeling Emergence Of Network Radar Countermeasure System, Huang Chen, Jianqing Qi, Fangzheng Liu

Journal of System Simulation

Abstract: Network radar countermeasure system (NRCS) is a new kind of integrated electronic warfare system with the integrated network developing trend of radar and EW equipment, and emergence is the typical complex feature of NRCS. The connotation and composition of the NRCS emergence was interpreted. Four sources of the NRCS emergence were analyzed: composition effect, structural effect, interaction effect and environmental effect. The conceptual models and mathematical models of the NRCS emergence were built from three aspects: system reconnaissance detection emergence, system target identification emergence and system jamming emergence. Simulation results coincide with the NRCS emergence source analysis, which verifies …