Engineering Commons^™

Designing And Evaluating Of Mimo Systems For Millimeter-Wave Communications, Mojtaba Ahmadi Almasi

Boise State University Theses and Dissertations

The fifth generation (5G) of wireless communications will integrate all existing technologies while bringing its own to the system. Amongst these technologies, millimeter-wave (mmWave) is emerging as a promising solution for 5G systems. However, to fully harness the potential of mmWave communications, obstacles such as severe path loss, channel sparsity, and hardware complexity should be overcome. The existing cost-effective systems can considerably reduce the hardware complexity and partially severe path loss, while channel sparsity still remains a main problem. Other factors such as transmission reliability and coverage area should be considered in 5G mmWave communications. Non-orthogonal multiple access (NOMA) is …

In Vitro Method To Quantify And Visualize Volumetric Wear In Meniscus Subjected To Joint Loading Using A 3d Optical Scanner, Kate J. Benfield

Boise State University Theses and Dissertations

The menisci are fibrocartilaginous soft tissues that act to absorb and distribute load across the surface of the knee joint. As a result of mechanical wear and large repetitive loading, meniscus tissue can begin to breakdown, or degenerate. Meniscus degeneration increases the risk of tearing, weakened tissue integrity, and the progression of osteoarthritis. Therefore, it is imperative to understand the wear behavior of whole human meniscus to identify conditions that may significantly increase the risk of degeneration.

The objective of this study is to develop and validate an in vitro methodology for characterizing volumetric wear behavior in whole human meniscus …

A One‐Dimensional Model For Turbulent Mixing In The Benthic Biolayer Of Stream And Coastal Sediments, Stanley B. Grant, Jesus D. Gomez‐Velez, Marco Ghisalberti, Ian Guymer, Fulvio Boano, Kevin Roche, Judson Harvey

Civil Engineering Faculty Publications and Presentations

In this paper, we develop and validate a rigorous modeling framework, based on Duhamel's Theorem, for the unsteady one‐dimensional vertical transport of a solute across a flat sediment‐water interface (SWI) and through the benthic biolayer of a turbulent stream. The modeling framework is novel in capturing the two‐way coupling between evolving solute concentrations above and below the SWI and in allowing for a depth‐varying diffusivity. Three diffusivity profiles within the sediment (constant, exponentially decaying, and a hybrid model) are evaluated against an extensive set of previously published laboratory measurements of turbulent mass transfer across the SWI. The exponential diffusivity profile …

Defect Evolution In High-Temperature Irradiated Nuclear Graphite, Steve Johns

Boise State University Theses and Dissertations

Graphite has historically been used as a moderator material in nuclear reactor designs dating back to the first man-made nuclear reactor to achieve criticality (Chicago Pile 1) in 1942. Additionally, graphite is a candidate material for use in the future envisioned next-generation nuclear reactors (Gen IV); specifically, the molten-salt-cooled (MSR) and very-high-temperature reactor (VHTR) concepts. Gen IV reactor concepts will introduce material challenges as temperature regimes and reactor lifetimes are anticipated to far exceed those of earlier reactors. Irradiation-induced defect evolution is a fundamental response in nuclear graphite subjected to irradiation. These defects directly influence the many property changes of …

Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez

Boise State University Theses and Dissertations

The growing demand for clean water supplies is driving the need for an innovative approach of water desalination. Developing a method for treating water with high salinities is possible with membrane distillation (MD). Additionally, MD is very attractive for pairing with solar energy due to the low temperature requirements. The integration of a membrane distillation system with a photovoltaic (PV) system will result in the co-production of electricity and clean water, thereby improving the economics of MD. Such a hybrid system will directly absorb thermal energy in the membrane for desalination while taking advantage of the spectrally selective nature of …

Heat Transfer Modeling And Optimization Of A Carbonized Microvascular Solar Receiver, Taylor Brown

Boise State University Theses and Dissertations

Concentrating solar power is an emerging renewable energy source. The technology can collect and store thermal energy from the sun over long durations, generating electricity as needed at a later time. Current CSP systems are limited to a maximum operational temperature due to constraints of the working fluid, which limits the maximum possible efficiency of the system. One proposed pathway forward is to utilize a gas phase for the working fluid in the system such as supercritical carbon dioxide.

A composite gas phase modular receiver is being developed by researchers at Boise State University and the University of Tulsa. The …

Constitutive Modeling Of Force-Controlled Fatigue Testing In Human Meniscus Tissue, Bradley Scott Henderson

Boise State University Theses and Dissertations

The meniscus is a wedge-shaped fibrocartilaginous tissue located between the femur and tibia that helps stabilize the knee and protect the underlying cartilage. There are 2.5 million reported knee injuries each year, making it the most injured joint in the human body. Nearly twenty percent of these injuries are due to a torn meniscus, leading to over half a million meniscus surgeries performed in the United States annually. Therefore, it is critical to understand the failure modes of meniscus tissue to prevent these debilitating injuries. A failure mode that accounts for one-third of all meniscus injuries is repeated exposure to …

Additive Manufacturing Of Graphene-Based Devices For Flexible Hybrid Electronics, Twinkle Pandhi

Boise State University Theses and Dissertations

In this work, I investigate and enhance the fundamental sensing properties of printed electronic nanomaterials (e.g., graphene) in real-world environments while decreasing weight, cost, and power consumption. The dissertation addresses this issue with the following foci in mind: (1) developing a straightforward and repeatable process to synthesize graphene ink which is also compatible with Inkjet-printing (IJP) and Aerosol Jet printing (AJP). (2) Tuning additive manufacturing printing (IJP and AJP) parameters to establish a repeatable manufacturing process and print high performing (graphene-based) electrodes and interconnects, compatible with the underlying substrate. (3) Investigate power dissipation and electrical breakdown in AJP printed graphene …

In-Situ Fluid Injections To Achieve Bio-Stimulated Calcite Precipitation In Expansive Soils, Anish Pathak

Boise State University Theses and Dissertations

Expansive soils undergo vast changes in volume when subject to change in water contents and cause damages to infrastructures across the world. Traditional methods of tackling the problem of expansive soils using cement or lime are environmentally unfriendly and expensive. Microbial Induced Calcite Precipitation (MICP) is a new method which uses bacteria in the soil to precipitate CaCO3 (calcite) and improve the engineering properties of soils. Various laboratory studies have shown that this method can be applied successfully to treat expansive soils, but the field application of the method have barely been studied.

To study the applicability of MICP in …

Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, Joshua Gunderson

Boise State University Theses and Dissertations

The J-integral is used to develop an alternative double cantilever beam (DCB) test method for the Mode I fracture toughness suitable for both small and large displacements. The current focus is the experimental determination of the Mode I interlaminar fracture toughness of composite materials, but the method is generally applicable to other similar tests and material systems, such as to the Mode I fracture toughness of adhesives. A series of five identical specimens are tested to compare the linear-elastic fracture mechanics method recommended by ASTM, which makes use of linear beam theory with root rotation, large displacement, and end …

A Resilience Metric For Modern Power Distribution Systems, Tyler Bennett Phillips

Boise State University Theses and Dissertations

Modern society has become increasingly reliant on the functioning of critical infrastructure. It is considered so vital that its incapacitation or destruction would have debilitating effects on the global economy, national security, and public health and safety. The electrical power system is uniquely positioned, as it is essential for all other sectors of critical infrastructure to operate as intended. However, it is constantly at risk due to factors such as natural disasters, climate change, aging infrastructure, and cyber threats. Thus, ensuring the efficient and continuous supply of electricity is of utmost importance and the topic of this dissertation.

The work …

Novel Memristor Based True Random Number Generator, Scott Stoller

Boise State University Theses and Dissertations

Random numbers are an important, but often overlooked part of the modern computing environment. They are used everywhere around us for a variety of purposes, from simple decision making in video games such as a coin toss, to securing financial transactions and encrypting confidential communications. They are even useful for gambling and the lottery.

Random numbers are generated in many ways. Pseudo random number generators (PRNGs) generate numbers based on a formula. True random number generators (TRNGs) capture entropy from the environment to generate randomness. As our society and our devices become more connected in the digital world, it is …

Understanding Mesoscopic Chemo-Mechanical Distress And Mitigation Mechanisms Of Concrete Subject To Asr, Md Asif Rahman

Boise State University Theses and Dissertations

Alkali-silica reaction (ASR) is one of the common sources of concrete damage worldwide. The surrounding environment, namely, temperature and humidity greatly influence the alkali-silica reaction induced expansion. Global warming (GW) has caused frequent change in the climate and initiated extreme weather events in recent years. These extreme events anticipate random change in temperature and humidity, and convey potential threats to the concrete infrastructure. Moreover, external loading conditions also affect the service life of concrete. Thus, complex mechanisms of ASR under the impact of seasonal change and global warming require a precise quantitative assessment to guide the durable infrastructure materials design …

Low-Intensity Vibration Restores Nuclear Yap Levels And Acute Yap Nuclear Shuttling In Mesenchymal Stem Cells Subjected To Simulated Microgravity, Matthew Thompson, Kali Woods, Joshua Newberg, Julia Thom Oxford, Gunes Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Reducing the musculoskeletal deterioration that astronauts experience in microgravity requires countermeasures that can improve the effectiveness of otherwise rigorous and time-expensive exercise regimens in space. The ability of low-intensity vibrations (LIV) to activate force-responsive signaling pathways in cells suggests LIV as a potential countermeasure to improve cell responsiveness to subsequent mechanical challenge. Mechanoresponse of mesenchymal stem cells (MSC), which maintain bone-making osteoblasts, is in part controlled by the “mechanotransducer” protein YAP (Yes-associated protein), which is shuttled into the nucleus in response to cyto-mechanical forces. Here, using YAP nuclear shuttling as a measurement outcome, we tested the effect of 72 h …

Effects Of Ca Doping On Structural And Optical Properties Of Pzt Nanopowders, K. H. Omran, M. Mostafa, M. S. Abd El-Sadek, O. M. Hemeda, R. Ubic

Materials Science and Engineering Faculty Publications and Presentations

The influence of the addition of calcium ions (Ca²⁺) in the Pb_(1-x)Ca_xZr_0.52Ti_0.48O₃ system (PCZT) for x = 0.05, 0.10, 0.15, 0.20, and 0.25 on the structural and optical properties was systematically studied. The compositions were synthesized through a polymerized-complex approach based on the Pechini polymeric precursor route. The solubility limit of calcium ions within the PCZT lattice is in between x = 0.10 and x = 0.15, at which a CaTiO₃ secondary phase is detected. The Goldschmidt tolerance factors, modified tolerance factors, and the effective vacancy sizes were …

Aerosol Jet Printed Capacitive Strain Gauge For Soft Structural Materials, Kiyo T. Fujimoto, Jennifer K. Watkins, Timothy Phero, Takoda Bingham, Kshama Lakshmi Ranganatha, Benjamin C. Johnson, Zhangxian Deng, Brian Jaques, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Soft structural textiles, or softgoods, are used within the space industry for inflatable habitats, parachutes and decelerator systems. Evaluating the safety and structural integrity of these systems occurs through structural health monitoring systems (SHM), which integrate non-invasive/non-destructive testing methods to detect, diagnose, and locate damage. Strain/load monitoring of these systems is limited while utilizing traditional strain gauges as these gauges are typically stiff, operate at low temperatures, and fail when subjected to high strain that is a result of high loading classifying them as unsuitable for SHM of soft structural textiles. For this work, a capacitance based strain gauge (CSG) …

Annual Simulation Of Photovoltaic Retrofits Within Existing Parabolic Trough Concentrating Solar Powerplants, Nipun Goel, Hannah O'Hern, Matthew Orosz, Todd Otanicar

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Solar power for electricity production comes from either photovoltaics or concentrating solar power plants. The former has seen rapid growth and expansion due to the rapid fall in global prices, while the latter has seen moderate growth due to ability to cheaply store thermal energy for later use. Hybridization, or combining photovoltaics with concentrating solar power represents a potential way for lowering cost while enabling long term storage. Over 5 GW of capacity exist worldwide using parabolic trough style technology for concentrating solar power which presents a unique option for optimization in the form of a photovoltaic retrofit. While it …

General-Purpose Coarse-Grained Toughened Thermoset Model For 44dds/Dgeba/Pes, Michael M. Henry, Stephen Thomas, Mone’T Alberts, Carla E. Estridge, Brittan Farmer, Olivia Mcnair, Eric Jankowski

Materials Science and Engineering Faculty Publications and Presentations

The objective of this work is to predict the morphology and material properties of crosslinking polymers used in aerospace applications. We extend the open-source dybond plugin for HOOMD-Blue to implement a new coarse-grained model of reacting epoxy thermosets and use the 44DDS/DGEBA/PES system as a case study for calibration and validation. We parameterize the coarse-grained model from atomistic solubility data, calibrate reaction dynamics against experiments, and check for size-dependent artifacts. We validate model predictions by comparing glass transition temperatures measurements at arbitrary degree of cure, gel-points, and morphology predictions against experiments. We demonstrate for the first time in molecular simulations …

Basis Set Truncation Further Clarifies Vibrational Coherence Spectra, Daniel B. Turner, Paul C. Arpin

Materials Science and Engineering Faculty Publications and Presentations

Coherent vibrational oscillations in femtosecond transient-absorption spectra have been interpreted since the 1990s using a model based on Gaussian wavepacket dynamics. The oscillations are often studied using probe-wavelength dependent plots of the oscillation amplitude and phase that are known as vibrational coherence spectra. Here we show that restricting the basis of the wavepacket to a small number of eigenstates clarifies several features in vibrational coherence spectra. Improving the understanding of vibrational coherence signatures will help distinguish them from signatures of electronic coherence that arise from measurements of strongly coupled excitonic states in molecular aggregates and light-harvesting proteins.

High-Performance Flexible Bismuth Telluride Thin Film From Solution Processed Colloidal Nanoplates, Madhusudan Kongara, Tony Varghese, Karthik Chinnathambi, Jesse Schimpf, Josh Eixenberger, Paul H. Davis, Yaqiao Wu, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Thermoelectric generators are an environmentally friendly and reliable solid‐state energy conversion technology. Flexible and low‐cost thermoelectric generators are especially suited to power flexible electronics and sensors using body heat or other ambient heat sources. Bismuth telluride (Bi₂Te₃) based thermoelectric materials exhibit their best performance near room temperature making them an ideal candidate to power wearable electronics and sensors using body heat. In this report, Bi₂Te₃ thin films are deposited on a flexible polyimide substrate using low‐cost and scalable manufacturing methods. The synthesized Bi₂Te₃ nanocrystals have a thickness of 35 ± …

Wildfires Force Thousands To Evacuate Near Los Angeles: Here’S How The 2020 Western Fire Season Got So Extreme, Mojtaba Sadegh, Ata Akbari Asanjan, Mohammad Reza Alizadeh

Civil Engineering Faculty Publications and Presentations

Two wildfires erupted on the outskirts of cities near Los Angeles, forcing more than 100,000 people to evacuate their homes Monday as powerful Santa Ana winds swept the flames through dry grasses and brush. With strong winds and extremely low humidity, large parts of California were under red flag warnings.

High fire risk days have been common this year as the 2020 wildfire season shatters records across the West.

More than 4 million acres have burned in California – 4% of the state’s land area and more than double the previous annual record. Five of the state’s six largest historical …

The Year The West Was Burning: How The 2020 Wildfire Season Got So Extreme, Mojtaba Sadegh, Ata Akbari Asanjan, Mohammad Reza Alizadeh

Civil Engineering Faculty Publications and Presentations

More than 4 million acres of California went up in flames in 2020 – about 4% of the state’s land area and more than double its previous wildfire record. Five of the state’s six largest fires on record were burning this year.

In Colorado, the Pine Gulch fire broke the record for that state’s largest wildfire, only to be surpassed by two larger blazes, the Cameron Peak and East Troublesome fires.

Oregon saw one of the most destructive fire seasons in its recorded history, with more than 4,000 homes destroyed.

What caused the 2020 fire season to become so extreme?

Fully Inkjet-Printed Multilayered Graphene-Based Flexible Electrodes For Repeatable Electrochemical Response, Twinkle Pandhi, Kiyo Fujimoto, Pete Barnes, Jasmine Cox, Hui Xiong, Paul H. Davis, Harish Subbaraman, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Graphene has proven to be useful in biosensing applications. However, one of the main hurdles with printed graphene-based electrodes is achieving repeatable electrochemical performance from one printed electrode to another. We have developed a consistent fabrication process to control the sheet resistance of inkjet-printed graphene electrodes, thereby accomplishing repeatable electrochemical performance. Herein, we investigated the electrochemical properties of multilayered graphene (MLG) electrodes fully inkjet-printed (IJP) on flexible Kapton substrates. The electrodes were fabricated by inkjet printing three materials – (1) a conductive silver ink for electrical contact, (2) an insulating dielectric ink, and (3) MLG ink as the sensing material. …

Mechanochemical Conversion Kinetics Of Red To Black Phosphorus And Scaling Parameters For High Volume Synthesis, Samuel V. Pedersen, Florent Muramutsa, Joshua D. Wood, Chad Husko, David Estrada, Brian J. Jaques

Materials Science and Engineering Faculty Publications and Presentations

Adopting black phosphorus (BP) as a material in electronic and optoelectronic device manufacturing requires the development and understanding of a large-scale synthesis technique. To that end, high-energy planetary ball milling is demonstrated as a scalable synthesis route, and the mechanisms and conversion kinetics of the BP phase transformation are investigated. During the milling process, media collisions rapidly compress amorphous red phosphorus (RP) into crystalline, orthorhombic BP flakes, resulting in a conversion yield of ≈90% for ≈5 g of bulk BP powder. Milling conversion kinetics, monitored via ex situ x-ray diffraction, manifest a sigmoidal behavior best described by the Avrami rate …

Using Schema Training To Facilitate Students' Understanding Of Challenging Engineering Concepts In Heat Transfer And Thermodynamics, Dazhi Yang, Ruth Streveler, Ronald L. Miller, Inanc Senocak, Jim Slotta

Educational Technology Faculty Publications and Presentations

Background: Chi and colleagues have argued that some of the most challenging engineering concepts exhibit properties of emergent systems. However, students often lack a mental framework, or schema, for understanding emergence. Slotta and Chi posited that helping students develop a schema for emergent systems, referred to as schema training, would increase the understanding of challenging concepts exhibiting emergent properties.

Purpose: We tested the effectiveness of schema training and explored the nature of challenging concepts from thermodynamics and heat transfer. We investigated if schema training could (a) repair misconceptions in advanced engineering students and (b) prevent them in beginning engineering students. …

Increasing Concurrence Of Wildfire Drivers Tripled Megafire Critical Danger Days In Southern California Between 1982 And 2018, Mohammad Sadegh Khorshidi, Philip E. Dennison, Mohammad Reza Nikoo, Amir Aghakouchak, Charles H. Luce, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Wildfire danger is often ascribed to increased temperature, decreased humidity, drier fuels, or higher wind speed. However, the concurrence of drivers—defined as climate, meteorological and biophysical factors that enable fire growth—is rarely tested for commonly used fire danger indices or climate change studies. Treating causal factors as independent additive influences can lead to inaccurate inferences about shifting hazards if the factors interact as a series of switches that collectively modulate fire growth. As evidence, we show that in Southern California very large fires and 'megafires' are more strongly associated with multiple drivers exceeding moderate thresholds concurrently, rather than direct relationships …

A Review Of Inkjet Printed Graphene And Carbon Nanotubes Based Gas Sensors, Twinkle Pandhi, Ashita Chandnani, Harish Subbaraman, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

Graphene and carbon nanotube (CNT)-based gas/vapor sensors have gained much traction for numerous applications over the last decade due to their excellent sensing performance at ambient conditions. Inkjet printing various forms of graphene (reduced graphene oxide or modified graphene) and CNT (single-wall nanotubes (SWNTs) or multiwall nanotubes (MWNTs)) nanomaterials allows fabrication onto flexible substrates which enable gas sensing applications in flexible electronics. This review focuses on their recent developments and provides an overview of the state-of-the-art in inkjet printing of graphene and CNT based sensors targeting gases, such as NO₂, Cl₂, CO₂, NH_{3 …}

Data And Analysis Toolbox For Modeling The Nexus Of Food, Energy, And Water, Mojtaba Sadegh, Arvin Farid

Civil Engineering Faculty Publications and Presentations

Energy, water, and food resources are highly interdependent. Agricultural irrigation accounts for 84% of global consumptive freshwater use, the food supply chain demands up to 30% of global primary energy use, and roughly 80% of global electricity generation depends on water for cooling (an average of nearly 100 L of water withdrawn per kWh). Improving understanding of the complex interactions of this resource nexus is, therefore, a top priority for human well-being, sustainable development, and policymaking. Here, we present an interactive analysis toolbox, Nexus of Food, Energy, and Water (NeFEW), that synthesizes available global data to …

Impact Of Arsenic Species On Self-Assembly Of Triangular And Hexagonal Tensile-Strained Gaas(111)A Quantum Dots, Christopher F. Schuck, Kevin D. Vallejo, Trent Garrett, Qing Yuan, Ying Wang, Baolai Liang, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

We use dimeric arsenic (As₂) or tetrameric arsenic (As₄) during molecular beam epitaxy to manipulate the structural and optical properties of GaAs(111)A tensile-strained quantum dots (TSQDs). Choice of arsenic species affects nucleation and growth behavior during TSQD self-assembly. Previously, epitaxial GaAs(111)A TSQDs have been grown with As₄, producing TSQDs with a triangular base, and 'A-step' edges perpendicular to the three 1̅1̅2 directions. We demonstrate that using As₂ at low substrate temperature also results in triangular GaAs(111)A TSQDs, but with 'B-step' edges perpendicular to the three 112̅ directions. We can therefore invert the crystallographic …

A Century Of Observations Reveals Increasing Likelihood Of Continental-Scale Compound Dry-Hot Extremes, Mohammad Reza Alizadeh, Jan Adamowski, Mohammad Reza Nikoo, Amir Aghakouchak, Philip Dennison, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Using over a century of ground-based observations over the contiguous United States, we show that the frequency of compound dry and hot extremes has increased substantially in the past decades, with an alarming increase in very rare dry-hot extremes. Our results indicate that the area affected by concurrent extremes has also increased significantly. Further, we explore homogeneity (i.e., connectedness) of dry-hot extremes across space. We show that dry-hot extremes have homogeneously enlarged over the past 122 years, pointing to spatial propagation of extreme dryness and heat and increased probability of continental-scale compound extremes. Last, we show an interesting shift between …