Engineering Commons^™

The Fractionation Of Woody Biomass With Bifunctional Aryl Sulfonic Acids At Mild Conditions, Duo He

Dissertations

Fractionation of lignocellulose is a fundamental step in the valorization of cellulose, hemicelluloses, and lignin to produce various sustainable fuels, materials, and chemicals. Over the years, most fractionation processes are cellulose centered or lignin-first. However, regardless of the fractionation strategy, the previous reported fractionation processes either need high temperature and high pressure or intensive size reduction of lignocellulose prior to the process. Therefore, there is a need to develop low energy and rapid delignification with simplistic recovery of chemicals for advanced utilization of renewable and biodegradable lignocelluloses for the future biobased economy.

To address this need, an innovative and scalable …

Creep Behavior Of A Ti-Based Multi-Principal Element Alloy, Benjamin Elbrecht

All Theses

Abstract

The understanding of microstructural damage mechanisms is the foundation of better understanding existing materials and future material development. There are significant challenges to measuring these damage mechanisms in-situ as continuous observation of the state of the microstructure is difficult or impossible for many experimental setups. This thesis presents a method for measuring grain boundary sliding (GBS) and local strain concentrations in-situ via a Heaviside function based algorithm. GBS is the shearing of two grains along their shared grain boundary and is a common damage mechanism in creep which presents as a discontinuity that can be measured with a Heaviside …

Characterization Of Thermal Gelation Properties In Bioresorbable Thermally Activated Hydrogel Polymers For Hernia Surgery Applications, Alexander Mayfield

All Theses

Hydrogel adhesives are a new class of materials with excellent biocompatibility, which makes them very attractive for biomaterial applications. It has been previously shown that Tetronic T1107, a four-arm poly (propylene oxide)-poly (ethylene oxide) (PPO-PEO) block copolymer, is useful as a chemical crosslinking thermo-responsive hydrogel for bioadhesive applications. The end groups of this polymer are modified with acrylate and N-hydroxysuccinimide (NHS) functional groups. The acrylate end group gives the polymer cohesive properties with long-range chemical crosslinking using dithiothreitol (DTT), while the NHS end group gives the polymer adhesive properties through bonding with amines found in organic tissue. It was found …

Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Poor workability is a common feature of calcium sulfoaluminate (CSA) cement paste. Multiple chemical admixtures, such as set retarders and dispersants, are frequently employed to improve the workability and delay the setting of CSA cement paste. A quantitative assessment of the compatibility, efficiency, and the effects of the admixtures on cement paste workability is critical for the design of an appropriate paste formulation and admixture proportioning. Very limited studies are available on the quantitative rheology-based method for evaluating the workability of calcium sulfoaluminate cement pastes. This study presents a novel and robust time-dependent rheological method for quantifying the workability of …

3d Printed Multicomponent Polymer Based Materials Via Hybrid Filaments: Fabrication And Characterization, Erik Antonio

All Dissertations

Additive manufacturing, also known as 3D printing, promises a manufacturing revolution for both industry and academic circles. One of the most widely used method of 3D printing is Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF), which requires a thermoplastic filament to be directed towards a heating block and then deposited via extrusion layer by layer to produce a finished part. However, there are significant issues with this technology, mainly a limitation on the materials available for use and mechanical property deficiencies when compared to traditional manufacturing. These issues are brought about by the temperature limited nature of the …

Understanding Charge Effects On Marked Ball Wear Rates – A Corrosion Study, John Bailey Fletcher

Masters Theses

"To measure the wear rates of grinding balls within a ball mill, marked ball wear tests (MBWTs) have been used extensively. Using the wear rates from a MBWT, operators select the most cost-effective media for their grinding application. One factor that a MBWT does not account for is the possible interaction between different media materials which could affect their corrosion rates. Galvanic coupling between dissimilar metals can cause significant changes in their corrosion rates. While galvanic interactions between minerals and grinding media have been studied, the interaction between dissimilar media has not. Corrosion rates and potentials of modern high carbon …

Effect Of Boron In Cast Iron, Suyash Durendra Pawaskar

Masters Theses

"Boron, mostly considered a residual element, has started to cause issues in the cast iron foundries by causing a decrease in the strength of pearlitic gray and ductile iron castings. Because of the increase in the use of boron-added steel scrap from automotive steel and a lack of agreement on the critical levels of boron in cast iron, foundries are facing difficulties in controlling the microstructure of gray iron castings when boron is present. The current investigation was designed to analyze the effects of boron in cast irons and predict a mechanism to understand its effects with a vision of …

Shape Memory Alloys Via Halide-Activated Pack Equilibration, Andrew S. King, Ryan D. Dempsey, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of shape memory alloy (SMA) components based on NiTi is challenging due to the precision with which elemental composition and microstructure must be controlled during processing to achieve desired shape memory behavior. Herein, a method to control chemistry in an NiTi SMA via halide-activated pack equilibration (SHAPE) against a constant chemical potential reservoir is described. To demonstrate the efficacy of the SHAPE process, an initially titanium-deficient specimen (pure nickel foam) has been equilibrated against an excess of an intimately mixed two-phase pack (NiTi + Ti2Ni) in the presence of a vapor phase transport agent (iodine). The two-phase pack regulates …

Recent Advances In Microwave Synthesis For Photoluminescence And Photocatalysis, Rajagopalan Krishnan, Sini Nanadath Shibu, Dirk Poelman, Ankush Kumar Badyal, Arup K. Kunti, Hendrik C. Swart, Samvit G. Menon

Cappa Publications

This review provides a comprehensive discussion on the microwave-assisted synthesis of various materials for photoluminescence and photocatalytic applications. In the past decade, because of its ability to synthesize nanomaterials through faster, cleaner and more cost-effective routes compared to conventional heating, microwave techniques have gained significant importance for the synthesis of metal oxides, fluorides, sulphides, and quantum dots. Additionally, due to the uniqueness of its heating mechanism, the synthesis of materials in various nanostructured forms through microwave-assisted methods has been of great interest and is widely pursued. The materials thus synthesized have been applied as sensing elements in gas sensors, luminescent …

Modeling Phase Behavior And Agglomeration In Polymer Systems Incorporating Complex Architectures: From Bottlebrush To Lysozyme, Sidong Tu

All Dissertations

Using computational modeling, we focus on the phase behavior of multicomponent systems incorporating enzyme and bottlebrush polymers where the agglomeration of multiple components occurs. We start with all-atom molecular dynamics (MD) simulations of lysozyme and polyethylene glycol (PEG) based polymer mixture to understand the mechanisms of preservation of lysozyme bioactivity at high temperatures with addition of PEG-derived bottlebrushes. We show that the PEG part of bottlebrushes phase separates at high temperature and shells the access of water to lysozyme, resulting in the preservation of lysozyme secondary structures. We then developed a coarse-grained model using a Dissipative Particle Dynamics approach to …

Modeling Pattern Formation And Morphology Development In Polymer Networks, Yao Xiong

All Dissertations

Topography and morphology have considerable impacts on the functionalities of soft materials in an entire range of applications from smart optics to tissue engineering. Adapting theoretical and computational approaches, we focus on the dynamics of pattern formation and morphology development in polymer networks. This dissertation starts with studying the dynamical control of pattern formation in confined thermo-responsive poly(N-isopropylacrylamide) (PNIPAAm) gel films. The patterns are formed due to mechanical instabilities. We perform a linear stability analysis and identify the limits of this analysis in predicting pattern formation in gels. We then study the restructuring between patterns and hysteresis phenomena …

Subwavelength Engineering Of Silicon Photonic Waveguides, Farhan Bin Tarik

All Dissertations

The dissertation demonstrates subwavelength engineering of silicon photonic waveguides in the form of two different structures or avenues: (i) a novel ultra-low mode area v-groove waveguide to enhance light-matter interaction; and (ii) a nanoscale sidewall crystalline grating performed as physical unclonable function to achieve hardware and information security. With the advancement of modern technology and modern supply chain throughout the globe, silicon photonics is set to lead the global semiconductor foundries, thanks to its abundance in nature and a mature and well-established industry. Since, the silicon waveguide is the heart of silicon photonics, it can be considered as the core …

Quantum-Mechanical Evaluation Of Defects In Uranium-Bearing Materials, Megan Hoover

All Dissertations

Quantum-mechanical calculations using density functional theory with the generalized gradient approximation were employed to investigate the effects dopants have on the uranium dioxide (UO₂) structure. Uraninite is a common U⁴⁺ mineral in the Earth's crust and an important material used to produce energy and medical isotopes. Though the incorporation mechanism remains unclear, divalent cations are known to incorporate into the uranium dioxide system. Three charge-balancing mechanisms were evaluated to achieve a net neutral system, including the substitution of (1) a divalent cation for a tetravalent uranium atom and oxygen atom; (2) two divalent cations for a tetravalent …

Manufacturing And Characterization Of Continuous Nanofiber-Reinforced Composites, Lucas Barry

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fiber-reinforced composite laminates are some of the most advanced structural materials available. However, delamination remains a critical challenge due to its prevalence in structures and ability to cause catastrophic failure. Recently, high-temperature composites are at the forefront of polymer-matrix composites research, but they are prone to microcracking followed by delamination. Nanoreinforcement of interfaces by continuous nanofibers has been proposed earlier at UNL and produced increased interlaminar fracture resistance in conventional advanced composites. However, no studies have yet been conducted on emerging high-temperature composites. Also, there is insufficient information on the translatability of observed modes I and II interlaminar fracture toughness …

Crack Control And Bond Performance Of Alternative Coated Reinforcements In Concrete, Sachin Sreedhara

All Dissertations

Concrete cracking in structures is a ubiquitous problem which can lead to the deterioration of the structure. Other than affecting the strength aspect of a structure, cracking impacts the serviceability criteria as well. Although cracking phenomenon in any structure is highly inevitable, it has to be minimized in order to maintain a structure’s life effectively. Cracking in reinforced concrete structures is related to the bond strength developed between the bar and the concrete. It also depends on an ability of the bar to resist the stresses due to shrinkage to minimize the crack. Another important aspect is the resistance offered …

Computational Characterization Of Nonwoven Fibrous Materials: Transport And Wetting Properties, Fang Wang

All Dissertations

Nonwoven fibrous materials represent a platform of flexible material substrates. Nonwovens are widely used in the production of napkins, paper, filters, wound covers and face masks. In addition, for many applications, nonwoven materials interact with fluids. For example, in filtration applications, nonwoven materials are used to clean fluids containing solid particles or emulsified droplets. The filtration performance is affected not only by the geometrical arrangement of fibers in non-woven materials but also wettability of fibers. Understanding the transport properties of nonwoven materials and interactions between the dispersed droplets and solid substrate is crucial for the design and optimization of filter …

Controlled Manipulation Of Droplets On Fibers: Fundamentals And Printing Applications, Yueming Sun

All Dissertations

In this dissertation, the drop interactions with a single fiber is discussed under an application angle for the development on new Drop-on-Demand (DOD) printhead using a fiber-in-a-tube platform[1] to print highly viscous materials[2]. To control the drop formation and manipulation on fiber, one needs to know how the fiber wetting properties and the fiber diameter influence drop formation. And then, one needs to know the effects of fiber movement in the device on drop formation. These two questions constitute the main theme of this dissertation.

Before this study, it was accepted that the liquids could not form axisymmetric droplets if …

Open-Source Workflows For Reproducible Molecular Simulation, Jenny W. Fothergill

Boise State University Theses and Dissertations

We apply molecular simulation to predict the equilibrium structure of organic molecular aggregates and how these structures determine material properties, with a focus on software engineering practices for ensuring correctness. Because simulations are implemented in software, there is potential for authentic scientific reproducibility in such work: An entire experimental apparatus (codebase) can be given to another investigator who should be able to use the same processes to find the same answers. Yet in practice, there are many barriers which stand in the way of reproducible molecular simulations that we address through automation, generalization, and software packaging. Collaboration on and application …

Reproducible Prediction Of Organic Semiconductor Properties Through Open Source Software Development, James Rushing

Boise State University Theses and Dissertations

Semiconducting materials made from carbon-based molecules are potential replacements for inorganic semiconductors, but with lower costs of processing. Devices made from organic semiconductors can be produced at scale by inkjet printing and roll-to-roll manufacturing of these molecules in solution or melt phases. The efficiency of these organic devices is dependent on the structure of the active layer, so controlling the morphology of organic molecules through self-assembly during manufacturing is a key challenge to realizing their utility. Molecular self-assembly depends on the chemical structure of the molecules, how key moieties interact with each other and with any solvent present, and the …

Study As Form-Of-Life: Meditations On Schooling, Enjoyment, And The Inoperative Life, Bryan K. Weeks

Boise State University Theses and Dissertations

The aim of this thesis is to explore what potential that the concept of 'inoperativity' has in the philosophy and theory of education. I will discuss the method of critique used which aims to think through the problems in existing theory rather than discard good thinking when problems are found. The strengths and weaknesses of deschooling and democratic approaches will be at the center of this critique. As a response to the weaknesses of both, the philosophy of Emmanuel Levinas, focusing on the way that interiority and enjoyment are essential concepts for the philosophy of education, as well as Giorgio …

Solution Synthesis And Additive Manufacturing Of Bismuth Telluride Nanoflakes For Flexible Energy Harvesting, Ariel E. Weltner

Boise State University Theses and Dissertations

Flexible thermoelectric generators (TEGs) are energy harvesting devices which convert temperature differences into electrical power. These devices require no moving parts and offer silent and autonomous operation. The variety of suitable materials covering a broad range of operating temperatures positions TEGs as a promising renewable energy source using waste heat recovery, especially for space and microgravity applications. Conventional manufacturing of flexible electronic and thermoelectric devices requires complicated and relatively expensive processing, which limits the capabilities of in-space manufacturing. Additive manufacturing (AM) expands the use of flexible electronics to new surfaces, applications, and recently, low gravity conditions. Plasma jet printing (PJP) …

Xps And Ipe Determination Of Band Offsets Of Germanium Based Materials, Justin Michael Rudie

Graduate Theses and Dissertations

Germanium tin and silicon germanium tin are group IV semiconductor alloys that have gained significant interest in recent years for their potential use in optoelectrical devices. While silicon and germanium are indirect bandgap materials on their own, alloying them with tin in sufficient quantities leads to a transition to direct bandgap alloys. Direct gap performance opens the door for efficient light emitting and detecting devices fabricated entirely on group IV materials that are compatible with the industry standard CMOS manufacturing techniques. Germanium tin and silicon germanium tin have bandgaps that respond to light in the mid to near infrared spectrum …

Hierarchically Structured Photoelectrodes Via Atomic Layer Deposition, Justin Rowan Reed Demoulpied

Graduate Theses and Dissertations

In the search for a sustainable method to meet increasing energy needs, solar energy emerges as an underutilized, plentiful resource. Solar intermittency and requirements for transportation necessitate storing solar energy in the form of chemical bonds via artificial photosynthesis. Photoelectrochemical (PEC) water splitting generates hydrogen fuel from solar energy and water. A semiconducting material that successfully meets the complex requirements for building an industrially scalable PEC device has yet to emerge. This is leading to a reevaluation of materials previously overlooked within PEC research, mainly materials with limitations such as minimal charge carrier mobility and propensity to corrosion under illumination …

Fabrication And Non-Covalent Functionalization And Characterization Of Graphene-Based Devices On Novel Substrate Cadmium Trithiophosphate (Iv) — Cdps, Abayomi Omotola Omolewu

Graduate Theses and Dissertations

With graphene at the center of several application areas such as sensing, circuits, high-frequency devices for communication systems, etc., it is crucial to understand how the intrinsic properties of devices made from graphene and other materials like platinum and palladium nanoparticles affect the performance of such devices for the specific application area. Many graphene-based devices for different application areas have focused mainly on the material composition of the graphene-based devices and how it affects performance parameters for the specific application. However, it would be insightful to understand how the intrinsic electrical properties of the graphene devices for different applications affect …

Study Of Single-Photon Wave-Packets With Atomically Thin Nonlinear Mirrors, Christopher Klenke

Graduate Theses and Dissertations

A novel controlled phase gate for photonic quantum computing is proposed by exploiting the powerful nonlinear optical responses of atomically thin transition metal dichalcogenides (TMDs) and it is shown that such a gate could elicit a π-rad phase shift in the outgoing electric field only in the case of two incident photons and no other cases. Firstly, the motivation for such a gate is developed and then the implementation of monolayer TMDs is presented as a solution to previous realization challenges. The single-mode case of incident photons upon a TMD is derived and is then used to constrain the more …

Study Of Thin Gan/Ingan/Gan Double Graded Structures For Future Photovoltaic Application, Mirsaeid Sarollahi

Graduate Theses and Dissertations

Indium gallium nitride (In_x Ga_(1-x) N) materials have displayed great potential for photovoltaic and optoelectronic devices due to their optical and electrical properties. Properties such as direct bandgap, strong bandgap absorption, thermal stability and high radiation resistance qualify them as great materials for photovoltaic devices. The tunable bandgap which absorbs the whole solar spectrum is the most significant feature which became attractive for scientists. The bandgap for these materials varies from 0.7 eV for InN to 3.4 eV for GaN covering from infrared to ultraviolet. In_x Ga_(1-x) N wurtzite crystal is grown on GaN buffer layer by Molecular Beam Epitaxy …

Etching Process Development For Sic Cmos, Weston Reed Renfrow

Graduate Theses and Dissertations

Silicon Carbide (SiC) is an exciting material that is growing in popularity for having qualities that make it a helpful semiconductor in extreme environments where silicon devices fail. The development of a SiC CMOS is in its infancy. There are many improvements that need to be made to develop this technology further. Photolithography is the most significant bottleneck in the etching process; it was studied and improved upon. Etching SiC can be a challenge with its reinforced crystal structure. Chlorine-based inductively coupled plasma (ICP) etching of intrinsic SiC and doped SiC, SiO2, and Silicon has been studied. A baseline chlorine …

Development Of Smart Wearable Sensory Systems On Flexible And Fabric Platforms For Health Monitoring Applications, Simin Masihi

Dissertations

Wearable sensing technology has recently received an increased attention in both research and commercialization phases and has moved from a vision of science fiction to reality with a wide variety of applications. This incredible growth can be attributed to several factors, such as affordability and ergonomics provided by advances in flexible electronics. The other factors that realized wearable sensing technology include a critical need for more accessible health care services experienced during the recent COVID pandemic, integration to the Internet of Things (IoT), and a growing consumer desire for health awareness. This dissertation presents the fulfillment of three main projects …

Role Of Structural Hierarchy In Multiscale Material Systems, Siavash Sattar

Mechanical & Aerospace Engineering Theses & Dissertations

Multiscale material systems derive their effective mechanical properties through a hierarchical organization of their structural elements and components. The hierarchy of a material is related to its effective properties, material processing, and composition. The hierarchy can be defined as an identifiable structural component with a specific size scale, such as the individual fibers collimated into platelets arranged randomly and producing a complex composite system or the lamellar structure in freeze-casted ceramic with the variation of in-plane orientation. In this study, the role of the structural hierarchy on the effective mechanical response and failure behavior of three complex material systems was …

A Comparison Of Uniaxial Compressive Response And Inelastic Deformation Mechanisms In Freeze Cast Alumina-Epoxy Composites Without And With Rigid Confinement, Tareq Aljuhari

Mechanical & Aerospace Engineering Theses & Dissertations

Cellular ceramics have an array of improved mechanical properties that make them incredibly desired for different applications such as armor systems, aircraft structures, automobiles bumpers, and biomedical implants. It is also desirable that porous architecture could be shaped into bulk complicated shapes and easy to scale-up with low manufacturing cost. Despite several efficient techniques to fabricate cellular ceramics, some limitations are preventing us from meeting the high demand of the after mentioned applications. For that, freeze casting, also called ice-templating, is technique of solidifying an aqueous ceramic suspension under the effect of unidirectional temperature gradient. In this study, Ice-templated porous …