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Full-Text Articles in Engineering

Degredation Of Organic Pollutants In Flocculated Liquid Digestate Using Photocatalytic Titanate Nanofibers: Mechanism And Response Surface Optimization, Yiting Xiao, Yang Tian, Yuanhang Zhan, Jun Zhu Sep 2023

Degredation Of Organic Pollutants In Flocculated Liquid Digestate Using Photocatalytic Titanate Nanofibers: Mechanism And Response Surface Optimization, Yiting Xiao, Yang Tian, Yuanhang Zhan, Jun Zhu

Biological and Agricultural Engineering Faculty Publications and Presentations

Titanate nanofibers (TNFs) were synthesized using a hydrothermal method and were employed for the first time in this study to photocatalytically degrade organic pollutants found in flocculated liquid digestate of poultry litter. The photocatalytic performance of TNFs, with a bandgap of 3.16 eV, was tested based on degradation of organic pollutants and removal of color. Five combinations of pollutant concentration and pH were examined (0.2 to 1.3 g·L−1 at pH 4 to 10). Central composite design (CCD) and response surface methodology (RSM) were applied in order to optimize the removal rates of volatile fatty acids (VFA) and chemical oxygen …


Investigation Of Deformation Behavior Of Additively Manufactured Aisi 316l Stainless Steel With In Situ Micro-Compression Testing, Fei Teng, Ching-Heng Shiau, Cheng Sun, Robert C. O'Brien, Michael D. Mcmurtrey Sep 2023

Investigation Of Deformation Behavior Of Additively Manufactured Aisi 316l Stainless Steel With In Situ Micro-Compression Testing, Fei Teng, Ching-Heng Shiau, Cheng Sun, Robert C. O'Brien, Michael D. Mcmurtrey

Materials Science and Engineering Faculty Publications and Presentations

Additive manufacturing techniques are being used more and more to perform the precise fabrication of engineering components with complex geometries. The heterogeneity of additively manufactured microstructures deteriorates the mechanical integrity of products. In this paper, we printed AISI 316L stainless steel using the additive manufacturing technique of laser metal deposition. Both single-phase and dual-phase substructures were formed in the grain interiors. Electron backscatter diffraction and energy-dispersive X-ray spectroscopy indicate that Si, Mo, S, Cr were enriched, while Fe was depleted along the substructure boundaries. In situ micro-compression testing was performed at room temperature along the [001] orientation. The dual-phase substructures …


Intrinsic And Atomic Layer Etching Enhanced Area-Selective Atomic Layer Deposition Of Molybdenum Disulfide Thin Films, Jake Soares, Wesley Jen, John D. Hues, Drew Lysne, Jesse Wensel, Steven M. Hues, Elton Graugnard Sep 2023

Intrinsic And Atomic Layer Etching Enhanced Area-Selective Atomic Layer Deposition Of Molybdenum Disulfide Thin Films, Jake Soares, Wesley Jen, John D. Hues, Drew Lysne, Jesse Wensel, Steven M. Hues, Elton Graugnard

Materials Science and Engineering Faculty Publications and Presentations

For continual scaling in microelectronics, new processes for precise high volume fabrication are required. Area-selective atomic layer deposition (ASALD) can provide an avenue for self-aligned material patterning and offers an approach to correct edge placement errors commonly found in top-down patterning processes. Two-dimensional transition metal dichalcogenides also offer great potential in scaled microelectronic devices due to their high mobilities and few-atom thickness. In this work, we report ASALD of MoS2 thin films by deposition with MoF6 and H2S precursor reactants. The inherent selectivity of the MoS2 atomic layer deposition (ALD) process is demonstrated by growth …


Optimizing Mn-Al Permanent Magnet Performance Through Control Of The Phase Transformation, Ternary Element Addition, And Advanced Processing, Thomas R. Keller Sep 2023

Optimizing Mn-Al Permanent Magnet Performance Through Control Of The Phase Transformation, Ternary Element Addition, And Advanced Processing, Thomas R. Keller

Dartmouth College Ph.D Dissertations

The growing need for electrical power in machines and vehicles brings with it a growing need for critical materials. The current high-performance permanent magnets (PMs) based on rare-earth (RE) elements Nd and Sm cannot escape the problem of raw material cost, geographic scarcity in the earth’s crust, and lack of circular global supply chains. This poses a problem of industrial ecology: can PMs be made from inexpensive, more abundant materials while still meeting sufficient performance criteria? PMs based on the magnetic τ phase of Mn-Al offer a possible alternative to REPMs. However, years of innovation have not yet achieved real-world …


Data-Driven 2d Materials Discovery For Next-Generation Electronics, Zeyu Zhang Aug 2023

Data-Driven 2d Materials Discovery For Next-Generation Electronics, Zeyu Zhang

Dissertations

The development of material discovery and design has lasted centuries in human history. After the concept of modern chemistry and material science was established, the strategy of material discovery relies on the experiments. Such a strategy becomes expensive and time-consuming with the increasing number of materials nowadays. Therefore, a novel strategy that is faster and more comprehensive is urgently needed. In this dissertation, an experiment-guided material discovery strategy is developed and explained using metal-organic frameworks (MOFs) as instances. The advent of 7r-stacked layered MOFs, which offer electrical conductivity on top of permanent porosity and high surface area, opened up new …


Challenges In Optimization For The Performance On Sustainability Dimensions In Reverse Logistics Social Responsibility, Sumarsono Sudarto, Katsuhiko Takahashi, Mochammad Dewo Aug 2023

Challenges In Optimization For The Performance On Sustainability Dimensions In Reverse Logistics Social Responsibility, Sumarsono Sudarto, Katsuhiko Takahashi, Mochammad Dewo

Makara Journal of Technology

Reverse logistics social responsibility is preferred as the most acceptable solution for addressing the challenges in stakeholders’ debate regarding social responsibility in supply chains because it involves as many actors as possible in the supply chain to perform social responsibility to achieve sustainability. This paper explores the challenges in achieving optimal policies in sustainability dimensions for collection and recycling facilities in reverse logistics. Sustainability dimensions include economic, environmental, and social aspects. The reverse logistics is modeled on System Dynamics, and a simplified statistical analysis using a contour chart is employed in numerical experiments. Results show a narrow area of optimal …


Investigating The Rheological Behavior Of A Simple Yield Stress Fluid Under Shear Flows, Francesco Accetta Aug 2023

Investigating The Rheological Behavior Of A Simple Yield Stress Fluid Under Shear Flows, Francesco Accetta

Theses

Many soft materials display unique and complex rheological behavior characterized by a transition from a solid-like to a fluid-like state upon the application of a force that exceeds the threshold to flow, known as the yield stress. Yield stress fluids are found in a wide range of commonly encountered materials including microgels, emulsions, and foams, and have been widely studied by rheologists over the last several decades. Carbopol is a popular polymeric microgel system as it displays simple, non-thixotropic rheological behavior and is typically seen as an ideal yield stress fluid. Previous research has demonstrated the reproducible behavior of shear …


Large-Scale Cascading Of First-Order Fbg Array In A Highly Multimode Coreless Fiber Using Femtosecond Laser For Distributed Thermal Sensing, Farhan Mumtaz, Bohong Zhang, Ronald J. O'Malley, Jie Huang Aug 2023

Large-Scale Cascading Of First-Order Fbg Array In A Highly Multimode Coreless Fiber Using Femtosecond Laser For Distributed Thermal Sensing, Farhan Mumtaz, Bohong Zhang, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research focuses on the performance analysis and characterization of a fiber Bragg gratings (FBGs) array, consisting of 10 first order FBGs inscribed by a femtosecond (FS) laser in a highly multimode coreless fiber. The study evaluates the FBG array's ability to function as a distributed thermal sensing (DTS) platform, with the coreless fiber chosen as the sensing element due to its immunity to dopant migration at high temperatures. The design of a large cascaded first-order FBG array effectively eliminates unwanted harmonic peaks across a wide spectrum range. In contrast, higher-order FBGs introduce limitations due to the overlapping of Bragg …


Effects Of Traps On Photo-Induced Interfacial Charge Transfer Of Ag-Tio2: Photoelectrochemical, Electrochemical And Spectroscopic Characterizations, Zhi-Hao Liang, Jia-Zheng Wang, Dan Wang, Jian-Zhang Zhou, De-Yin Wu Aug 2023

Effects Of Traps On Photo-Induced Interfacial Charge Transfer Of Ag-Tio2: Photoelectrochemical, Electrochemical And Spectroscopic Characterizations, Zhi-Hao Liang, Jia-Zheng Wang, Dan Wang, Jian-Zhang Zhou, De-Yin Wu

Journal of Electrochemistry

In the field of metal-semiconductor composites based plasmon-mediated chemical reactions, a clear and in-depth understanding of charge transfer and recombination mechanisms is crucial for improving plasmonic photocatalytic efficiency. However, the plasmonic photocatalytic reactions at the solid-liquid interface of the electrochemical systems involve complex processes with multiple elementary steps, multiple time scales, and multiple controlling factors. Herein, the combination of photoelectrochemical and electrochemical as well as spectroscopic characterizations has been successfully used to study the effects of traps on the photo-induced interfacial charge transfer of silver-titanium dioxide (Ag-TiO2). The results show that the increase of surface hydroxyl groups may …


Synthesis And Evaluation Of Organic Additives For Copper Electroplating Of Interconnects, Yue-Hui Zhai, Yi-Xiao Peng, Yan Hong, Yuan-Ming Chen, Guo-Yun Zhou, Wei He, Peng-Ju Wang, Xian-Ming Chen, Chong Wang Aug 2023

Synthesis And Evaluation Of Organic Additives For Copper Electroplating Of Interconnects, Yue-Hui Zhai, Yi-Xiao Peng, Yan Hong, Yuan-Ming Chen, Guo-Yun Zhou, Wei He, Peng-Ju Wang, Xian-Ming Chen, Chong Wang

Journal of Electrochemistry

Copper interconnects are essential to the functionality, performance, power efficiency, reliability, and fabrication yield of electronic devices. They are widely found in chips, packaging substrates and printed circuit boards, and are often produced by copper electroplating in an acidic aqueous solution. Organic additives play a decisive role in regulating copper deposition to fill microgrooves, and micro-vias to form fine lines and interlayer interconnects. Generally, an additive package consists of three components (brightener, suppressor, and leveler), which have a synergistic effect of super-filling on electroplating copper when the concentration ratio is appropriate. Many works of literature have discussed the mechanism of …


Effect Of Amine Additives On Thermal Runaway Inhibition Of Sic||Ncm811 Batteries, Bo-Wen Hou, Long He, Xu-Ning Feng, Wei-Feng Zhang, Li Wang, Xiang-Ming He Aug 2023

Effect Of Amine Additives On Thermal Runaway Inhibition Of Sic||Ncm811 Batteries, Bo-Wen Hou, Long He, Xu-Ning Feng, Wei-Feng Zhang, Li Wang, Xiang-Ming He

Journal of Electrochemistry

The high energy density of NCM batteries with high nickel content is a key advantage in replacing fossil fuels and promoting clean energy development, at the same time, is also a fundamental cause of serious safety hazards in batteries. Primary and secondary amines can lead to ring-opening polymerization of common ethylene carbonate electrolytes, resulting in an isolation layer between the cathode and the anode, and improving the thermal safety of the battery. In this work, the safety of batteries is considered both at the material level and at the cell level, based on the chemical reactions between amines and the …


Retracted: Fabrication And Characterization Of Wood Fiber Reinforced Polymer Composites, Firoz Ahmed, Omar Faroque, Saif Hasan, Khan Rajib Hossain, Rezaul Karim Sheikh Aug 2023

Retracted: Fabrication And Characterization Of Wood Fiber Reinforced Polymer Composites, Firoz Ahmed, Omar Faroque, Saif Hasan, Khan Rajib Hossain, Rezaul Karim Sheikh

Al-Bahir

Wood-polymer composites (WPCs) combine the properties of wood and polymers. Creating composites involves adding plant or wood fibers as fillers to a polymer matrix. This study used mahogany and mango wood sawdust as reinforcement materials, while high-density polyethylene (HDPE) and polyvinyl chloride (PVC) were used as matrices. The investigated data in this study comprises four different (10, 20, 30, and 40) weight percentages (wt%) of mahogany and mango sawdust paired with corresponding wt% (90, 80, 70, and60) of HDPE and PVC matrices. The extrusion method produced composites with different amounts of sawdust and polymer matrices. Wood polymer composites were characterized …


Mechanochemical Esterification Of Cellulose Nanofibers Lyophilized From Eutectic Water–Tert-Butanol Mixtures, Miran Mavlan, Taehoo Chang, Rudan Feng, Jake R. Wilkinson, Robert J. Nicholas, Nosa B. Idahagbon, Jeffrey Youngblood, Alexander Wei Aug 2023

Mechanochemical Esterification Of Cellulose Nanofibers Lyophilized From Eutectic Water–Tert-Butanol Mixtures, Miran Mavlan, Taehoo Chang, Rudan Feng, Jake R. Wilkinson, Robert J. Nicholas, Nosa B. Idahagbon, Jeffrey Youngblood, Alexander Wei

Department of Chemistry Faculty Publications

Freeze-dried CNFs can be modified by mechanochemical (MC) processes with minimal use of auxiliary solvents, however aggregation of nanofibers during lyophilization compromises their granularity and reaction efficiency. Adding 10 wt% tert-butanol (TBA) to aqueous slurries of wood-derived CNF creates a eutectic mixture that reduces hornification during lyophilization, resulting in well-formed aerogels with minimal shrinkage in volume. CNFs lyophilized from mixtures containing at least 10 wt% TBA exhibit an order of magnitude increase in specific surface area relative to CNFs freeze-dried from water alone. The amount of TBA and input energy needed for lyophilization can be reduced considerably by dewatering …


Design, Synthesis, And Characterization Of Peptide Amphiphile Biomaterials, Huihua Xing Aug 2023

Design, Synthesis, And Characterization Of Peptide Amphiphile Biomaterials, Huihua Xing

Theses & Dissertations

Self-assembled peptide amphiphiles (PAs) have gained significant attention in recent years due to their ability to form various supramolecular nanostructures with unique physical and chemical properties. These amphiphilic molecules consist of a hydrophobic tail and a peptide domain, allowing for the formation of nanoscale assemblies in aqueous environments. The PA supramolecular structures have a wide range of potential applications, including drug delivery, tissue engineering, and regenerative medicine.

By manipulating the driving forces (e.g., hydrophobic interactions, hydrogen bonds, and electrostatic interactions) involved in the self-assembly, researchers can tune the self- assembly properties (size, shape, stability, and surface character) and, consequently, the …


Elucidating Self-Assembly Of Semiconducting Polymers In The Presence Of A Low Molecular Weight Gelator, Madhubhashini Lakdusinghe Aug 2023

Elucidating Self-Assembly Of Semiconducting Polymers In The Presence Of A Low Molecular Weight Gelator, Madhubhashini Lakdusinghe

Theses and Dissertations

Semiconducting polymers with a conjugated backbone are important for energy storage, conversion, and biomedical field applications. The self-assembly process of these polymers in solutions depends on the polymer concentration and quality of the solvent. The electrical properties of thin films obtained from the solution phase depend on the self-assembled process. Thin films of conjugated polymer gels with percolating networks of self-assembled structures display improved electrical conductivities. In this dissertation, we studied the impact of the secondary gel matrix formed by a low molecular weight gelator, on the self-assembly of conjugated polymers, the preservation of assembled structures in dried gel films …


Development Of Preservative-Treated Cross-Laminated Timber And Lignin-Reinforced Polyurethane-Adhesive For Glued Laminated Timber, Samuel Oluwafemi Ayanleye Aug 2023

Development Of Preservative-Treated Cross-Laminated Timber And Lignin-Reinforced Polyurethane-Adhesive For Glued Laminated Timber, Samuel Oluwafemi Ayanleye

Theses and Dissertations

Interest in the use of mass timber in building and construction is growing worldwide, this is due to the structural integrity and reduced environmental footprint of timber-based structures. Concerns associated with the biological and environmental degradation of mass timber necessitate the development of adequate protection strategies to ensure the durability of these products. Preservative treatment is a proven technique that increases the durability and performance of wood in-service and can also be applied to large-sized timber panels such as cross-laminated timber (CLT). Therefore, this study focused on investigating the feasibility of treating prefabricated 3- and 5-layer CLT panels with Copper-azole …


Investigations Of Dual-Electrolyte Layer Protonic Ceramic Fuel Cells For Enhanced Electrochemical Performance And Longevity, Abdul-Sommed Hadi Aug 2023

Investigations Of Dual-Electrolyte Layer Protonic Ceramic Fuel Cells For Enhanced Electrochemical Performance And Longevity, Abdul-Sommed Hadi

Graduate Theses & Non-Theses

A cermet anode comprising of yttria-doped barium zirconate, BZY and nickel, Ni is now the preferred choice of materials for use in proton conducting fuel cell (PCFC) anodes because of their influence on anode oxidation kinetics. The Ni grains, being in a solid solution with the BZY support, helps improve on the catalytic activity and conductivity, in addition to the relative stability of BZY in steam and hydrocarbon reforming environments, as well as BZY’s excellent protonic conductivity.

Ni-BZY based anodes, sintered onto a ~600-micron electrolyte-supported substrates of BZY, BCZY (yttria- and ceria-doped barium zirconate), and a BZY/BCZY dual electrolyte-layer substrate, …


Leveraging Steric Moieties For Kinetic Control Of Dna Strand Displacement Reactions, Drew Lysne, Tim Hachigian, Chris Thachuk, Jeunghoon Lee, Elton Graugnard Aug 2023

Leveraging Steric Moieties For Kinetic Control Of Dna Strand Displacement Reactions, Drew Lysne, Tim Hachigian, Chris Thachuk, Jeunghoon Lee, Elton Graugnard

Materials Science and Engineering Faculty Publications and Presentations

DNA strand displacement networks are a critical part of dynamic DNA nanotechnology and are proven primitives for implementing chemical reaction networks. Precise kinetic control of these networks is important for their use in a range of applications. Among the better understood and widely leveraged kinetic properties of these networks are toehold sequence, length, composition, and location. While steric hindrance has been recognized as an important factor in such systems, a clear understanding of its impact and role is lacking. Here, a systematic investigation of steric hindrance within a DNA toehold-mediated strand displacement network was performed through tracking kinetic reactions of …


Influence Of Forming Forces On Torsional, Tensile, And Compressive Deformation Of Paperboard Packages, Arvo Niini, Panu Tanninen, Juha Varis, Ville Leminen Aug 2023

Influence Of Forming Forces On Torsional, Tensile, And Compressive Deformation Of Paperboard Packages, Arvo Niini, Panu Tanninen, Juha Varis, Ville Leminen

Journal of Applied Packaging Research

Paperboard packages were tested mechanically to investigate influence of forming forces on torsional, tensile, and compressive deformation. The packages were paperboard trays which were press formed with different pressing forces and blank holder forces. Deformation of the trays was observed with torsion, compression, and tensile tests. A statistical analysis of test results was conducted to derive optimal forming forces. Increased pressing force yielded desirable deformation characteristics with the trays. Blank holder force had largest impact on the compressive deformation. Interaction of the pressing force and the blank holder force influenced the torsional and the compressive deformation. The optimal forming forces …


Thermomechanical Properties Of Neutron Irradiated Al3Hf-Al Thermal Neutron Absorber Materials, Donna Post Guillen, Mychailo B. Toloczko, Ramprashad Prabhakaran, Yuanyuan Zhu, Yu Lu, Yaqiao Wu Aug 2023

Thermomechanical Properties Of Neutron Irradiated Al3Hf-Al Thermal Neutron Absorber Materials, Donna Post Guillen, Mychailo B. Toloczko, Ramprashad Prabhakaran, Yuanyuan Zhu, Yu Lu, Yaqiao Wu

CAES Energy Policy Institute Faculty Publications and Presentations

A thermal neutron absorber material composed of Al3Hf particles in an aluminum matrix is under development for the Advanced Test Reactor. This metal matrix composite was fabricated via hot pressing of high-purity aluminum and micrometer-size Al3Hf powders at volume fractions of 20.0, 28.4, and 36.5%. Room temperature tensile and hardness testing of unirradiated specimens revealed a linear relationship between volume fraction and strength, while the tensile data showed a strong decrease in elongation between the 20 and 36.5% volume fraction materials. Tensile tests conducted at 200 °C on unirradiated material revealed similar trends. Evaluations were then …


Fatigue And Fracture Of Electron Beam Melting Ti-6al-4v, William A. Grell Aug 2023

Fatigue And Fracture Of Electron Beam Melting Ti-6al-4v, William A. Grell

Electronic Theses and Dissertations

For applications in the aerospace field, selection of materials for a given design requires an understanding of critical properties, like fatigue and fracture, in addition to static mechanical and physical properties. With the ongoing advancements in metallic additive manufacturing techniques and the interest in applying the process to aerospace applications, there is a clear need to fully characterize properties. Arguably, the most attractive alloy for applications in aerospace is the Ti-6Al-4V alloy. The current dissertation examines the mechanical properties of the alloy, made by the Electron Beam Melting (EBM) Powder Bed Fusion (PBF) method. As illustrated in this work, the …


A Transport Property-Based Assessment Of Triple Ionic-Electronic Conductors As Cathodes For Protonic Ceramic Fuel Cells, Jack Harrison Duffy Aug 2023

A Transport Property-Based Assessment Of Triple Ionic-Electronic Conductors As Cathodes For Protonic Ceramic Fuel Cells, Jack Harrison Duffy

All Dissertations

Triple ionic-electronic conductors (TIECs) are a widely studied class of materials for electrodes in ceramic electrochemical devices such as protonic ceramic fuel cells. These ceramics are perovskite-based and exhibit concurrent conductivity of protons, oxide ions, and electrons at elevated temperatures. Despite their numerous references in literature, few studies have systematically probed the fundamental surface- and bulk-level properties of TIECs. In this dissertation, dopant levels are systematically altered in the BaCo0.4Fe0.4Zr0.1Y0.1O3-δ-type perovskite TIEC to reveal the effects on structure, transport properties, and durability of each material. The results of this work …


Glass Bubbles Grafted With Polymer Brushes For Liquid Hydrocarbon Fire Extinguishment, Randall Snipes Aug 2023

Glass Bubbles Grafted With Polymer Brushes For Liquid Hydrocarbon Fire Extinguishment, Randall Snipes

All Dissertations

The current most efficient solution to fighting liquid pool fires involves the use of firefighting foams containing fluorinated surfactants. The physiochemical properties of these foams are considerably different to all other currently available firefighting foams. Fluorinated surfactants lower the surface tension to a point where the foam solution draining from the foam structure forms a continuous aqueous film on the surface of a volatile hydrocarbon fuel, adding an additional barrier to fuel vapor diffusion to the burning fire. For this reason, these foams qualify as aqueous film forming foams (AFFFs). However, fluorinated compounds are extremely harmful for the environment due …


Life Cycle Energy Assesment Of Advanced Fiber Reinforced Composite Design And Manufacturing Methodologies, Urjit Lad Aug 2023

Life Cycle Energy Assesment Of Advanced Fiber Reinforced Composite Design And Manufacturing Methodologies, Urjit Lad

All Theses

Automotive industry at large is focused on vehicle light-weighting since a 6%-8% increase in fuel efficiency can be achieved with a 10% reduction in vehicle weight [1]. With the growing demand for cost-effective and sustainable light weighting of automobile structures, interest has increased in the application of fiber reinforced plastic (FRP) composites for use in the Body-in-White (BiW), which can account for up to 40% of the total vehicle weight. Traditional FRP composite manufacturing processes like vacuum assisted resin transfer molding, autoclave consolidation or use of automated fiber placement have been successfully used for marine and aerospace applications. However, these …


Magnesium-Based Nanocomposites: A Review From Mechanical, Creep And Fatigue Properties, S. Abazari, A. Shamsipur, H. R. Bakhsheshi-Rad, J. W. Drelich, J. Goldman, S. Sharif, A. F. Ismail, M. Razzaghi Aug 2023

Magnesium-Based Nanocomposites: A Review From Mechanical, Creep And Fatigue Properties, S. Abazari, A. Shamsipur, H. R. Bakhsheshi-Rad, J. W. Drelich, J. Goldman, S. Sharif, A. F. Ismail, M. Razzaghi

Michigan Tech Publications

The addition of nanoscale additions to magnesium (Mg) based alloys can boost mechanical characteristics without noticeably decreasing ductility. Since Mg is the lightest structural material, the Mg-based nanocomposites (NCs) with improved mechanical properties are appealing materials for lightweight structural applications. In contrast to conventional Mg-based composites, the incorporation of nano-sized reinforcing particles noticeably boosts the strength of Mg-based nanocomposites without significantly reducing the formability. The present article reviews Mg-based metal matrix nanocomposites (MMNCs) with metallic and ceramic additions, fabricated via both solid-based (sintering and powder metallurgy) and liquid-based (disintegrated melt deposition) technologies. It also reviews strengthening models and mechanisms that …


Carbon Fibers From Athabasca Oil-Sand Asphaltenes, Blake Reardon Aug 2023

Carbon Fibers From Athabasca Oil-Sand Asphaltenes, Blake Reardon

All Theses

Carbon fibers possess ultra-high specific strength and modulus. Therefore, the material is popular in aerospace, automotive, and sports industries. Approximately 95% of all carbon fibers are spun from a high-cost precursor, polyacrylonitrile (PAN). There is a need for a cheaper grade of carbon fiber for low-cost applications because about half of carbon fiber cost is associated with precursor cost. A promising alternative to the high-cost PAN precursor is petroleum-based asphaltene. Asphaltenes are highly aromatic and have a high carbon content but lack the purity of the PAN precursor. Processes like the molten- sodium desulfurization upgrading have been used to harvest …


Poly(Alkyl Aldehyde)S: A New Class Of Closed-Loop Recyclable Plastics, Kyle Arnold Nogales Aug 2023

Poly(Alkyl Aldehyde)S: A New Class Of Closed-Loop Recyclable Plastics, Kyle Arnold Nogales

Boise State University Theses and Dissertations

This dissertation will describe a new class of closed-loop recyclable, self-immolative polymers that undergo selective, complete, and rapid depolymerization in the solid state when triggered. Self-immolative poly(alkyl aldehyde)s are synthesized efficiently in approximately 60% yield using anionic polymerization, which provides access to polymers in accessible lengths ranging from short (Mn value of 2 kDa) to long polymers (Mn value of 5,000 kDa). The physical and thermal properties of the polymers can be tuned rationally by appropriate choice of the aldehyde monomer, with some of the polymers displaying mechanical properties that are similar to traditional plastics. The polymers depolymerize …


Photophysical Studies Of Electronic Structure And Excited-State Dynamics Of Dna-Templated Cyanine Dye Aggregates, Jonathan Samuel Huff Aug 2023

Photophysical Studies Of Electronic Structure And Excited-State Dynamics Of Dna-Templated Cyanine Dye Aggregates, Jonathan Samuel Huff

Boise State University Theses and Dissertations

The invention and widespread adoption of the digital computer in the last century has led to an era of rapid technological advancement that has continued to the present day. This advancement has been sustained to a large degree by continued miniaturization of the electronic components in microprocessors, which results in increased computing power and energy efficiency. In recent years, this strategy has produced diminishing returns because the cost for each incremental size reduction increases as engineers approach the fundamental scaling limits of silicon-based semiconductor devices. Meanwhile, breakthroughs in DNA nanotechnology hold great promise for a new generation of self-assembled nanodevices …


Transformation Pathways Of Lanthanide-Free Mn-Al-Ga-X Alloys Where X = Co, Fe, And Ni, Shane L. Palmer Aug 2023

Transformation Pathways Of Lanthanide-Free Mn-Al-Ga-X Alloys Where X = Co, Fe, And Ni, Shane L. Palmer

Boise State University Theses and Dissertations

Ubiquitous rare-earth, (i.e. lanthanide) permanent magnets (PMs) composed of Nd-Fe-B are the strongest PMs on the market. However, limited mineral sources, complex elemental separation, and supply chain volatility have shifted the lanthanides to critical material status. Inexpensive, readily available materials are sought to fill an energy product performance gap to reduce dependency on lanthanide PMs. Frequently, lanthanide PMs are used in applications where their energy products are excessively high. Mn-Al based permanent magnets offer a potential substitute for PM applications which do not require the high energy product of a lanthanide PM. MnAl alloys form a metastable ferromagnetic tetragonal …


Chemical And Physical Interaction Mechanisms And Multifunctional Properties Of Plant Based Graphene In Carbon Fiber Epoxy Composites, Daniel W. Mulqueen Aug 2023

Chemical And Physical Interaction Mechanisms And Multifunctional Properties Of Plant Based Graphene In Carbon Fiber Epoxy Composites, Daniel W. Mulqueen

Mechanical & Aerospace Engineering Theses & Dissertations

Graphene has generated substantial interest as a filler due to its exceptional strength, flexibility, and conductivity but faces obstacles in supply and implementation. A renewable, plant-based graphene nanoparticle (pGNP) presents a more accessible and sustainable filler with the same properties as mineral graphenes. In this study, the mechanisms of graphene reinforcement in carbon fiber reinforced plastic (CFRP) were examined, along with the resulting improvements to mechanical strength, resistance to crack propagation, electrical and thermal conductivity at elevated temperatures. pGNP, produced from renewable biomass, was shown to have a graphitic structure with flakes 3-10 layers thick and a median lateral size …