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Articles 1 - 30 of 265
Full-Text Articles in Engineering
Progress In Energy: Usa–Canada Special Issue On Energy, Yun Hang Hu
Progress In Energy: Usa–Canada Special Issue On Energy, Yun Hang Hu
Michigan Tech Publications, Part 2
No abstract provided.
Thermo-Photo Catalytic Anode Process For Carbonate-Superstructured Solid Fuel Cells, Hanrui Su, Yun Hang Hu
Thermo-Photo Catalytic Anode Process For Carbonate-Superstructured Solid Fuel Cells, Hanrui Su, Yun Hang Hu
Michigan Tech Publications, Part 2
Converting hydrocarbons and greenhouse gases (i.e., carbon dioxide, CO2) directly into electricity through fuel cells at intermediate temperatures (450 to 550 °C) remains a significant challenge, primarily due to the sluggish activation of C-H and C=O bonds. Here, we demonstrated a unique strategy to address this issue, in which light illumination was introduced into the thermal catalytic CO2reforming of ethane in the anode as a unique thermo-photo anode process for carbonate-superstructured solid fuel cells. The light-enhanced fuel activation led to excellent cell performance with a record-high peak power density of 168 mW cm-2at an intermediate temperature of 550 °C. Furthermore, …
Heating Capacity And Biocompatibility Of Hybrid Nanoparticles For Magnetic Hyperthermia Treatment, Aline Alexandrina Gomes, Thalita Marcolan Valverde, Vagner De Oliveira Machado, Emanueli Do Nascimento Da Silva, Daniele Alves Fagundes, Fernanda De Paula Oliveira, Erico Freitas, José Domingos Ardisson, José Maria Da Fonte Ferreira, Junnia Alvarenga De Carvalho Oliveira, Eliza Rocha Gomes, Caio Fabrini Rodrigues, Alfredo Miranda De Goes, Rosana Zacarias Domingues, Ângela Leão Andrade
Heating Capacity And Biocompatibility Of Hybrid Nanoparticles For Magnetic Hyperthermia Treatment, Aline Alexandrina Gomes, Thalita Marcolan Valverde, Vagner De Oliveira Machado, Emanueli Do Nascimento Da Silva, Daniele Alves Fagundes, Fernanda De Paula Oliveira, Erico Freitas, José Domingos Ardisson, José Maria Da Fonte Ferreira, Junnia Alvarenga De Carvalho Oliveira, Eliza Rocha Gomes, Caio Fabrini Rodrigues, Alfredo Miranda De Goes, Rosana Zacarias Domingues, Ângela Leão Andrade
Michigan Tech Publications, Part 2
Cancer is one of the deadliest diseases worldwide and has been responsible for millions of deaths. However, developing a satisfactory smart multifunctional material combining different strategies to kill cancer cells poses a challenge. This work aims at filling this gap by developing a composite material for cancer treatment through hyperthermia and drug release. With this purpose, magnetic nanoparticles were coated with a polymer matrix consisting of poly (L-co-D,L lactic acid-co-trimethylene carbonate) and a poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) triblock copolymer. High-resolution transmission electron microscopy and selected area electron diffraction confirmed magnetite to be the only iron oxide in the sample. Cytotoxicity …
Improving Cast Steel Rail Coupler Fatigue Resistance Through Local Wire-Arc Additive Manufacturing, Andrew M. Bunge
Improving Cast Steel Rail Coupler Fatigue Resistance Through Local Wire-Arc Additive Manufacturing, Andrew M. Bunge
Dissertations, Master's Theses and Master's Reports
Every year, thousands of cast-steel railcar couplers suffer from corrosion-initiated fatigue cracking in similar areas of the coupler’s knuckle; between 2015 and 2018 about 90,000 knuckles were replaced, otherwise these couplers would have been at risk for unexpected failures. These types of couplers have been common in industrial use as early as 1932, hence it is desirable for a countermeasure to the fatigue cracking that does not involve significantly altering the geometry or casting process. Wire arc additive manufacturing (WAM) is a developing technology which boasts the ability to produce complex near-net-shape components; however, less attention has been paid to …
Nickel Superalloy Composition And Process Optimization For Weldability, Cost, And Strength, Sophie A. Mehl
Nickel Superalloy Composition And Process Optimization For Weldability, Cost, And Strength, Sophie A. Mehl
Dissertations, Master's Theses and Master's Reports
To advance sustainability efforts, electric power plants have reduced specific carbon dioxide emissions by increasing operating temperatures and pressures to improve power generation efficiency. The latest improvements are utilized in advanced ultra-supercritical power generation. To meet these operating conditions, nickel superalloys are used in the highest temperature components; however, they are expensive and present weldability challenges. This project aims to experimentally optimize a nickel superalloy to improve material weldability and decrease cost without compromising strength. Three optimized compositions were developed, and their microstructures and mechanical properties were compared to Nimonic 263, a common nickel superalloy in electric power plants. The …
The Influence Of Boron (B), Tin (Sn), Copper (Cu), And Manganese (Mn) On The Microstructure Of Spheroidal Graphite Irons, A. V. Bugten, P. Sanders, C. Hartung, R. Logan, M. Di Sabatino, L. Michels
The Influence Of Boron (B), Tin (Sn), Copper (Cu), And Manganese (Mn) On The Microstructure Of Spheroidal Graphite Irons, A. V. Bugten, P. Sanders, C. Hartung, R. Logan, M. Di Sabatino, L. Michels
Michigan Tech Publications, Part 2
Most spheroidal graphite irons (SGIs) have a matrix consisting of ferrite, pearlite, or a mix of the two. To achieve the desired matrix composition, pearlite promoters such as Mn, Cu, or Sn, are added to the molten metal. Among these elements, Sn is the most potent pearlite promoter. However, each has a different impact on the solidification, graphite precipitation, eutectoid transformation, and ultimately the final structure of the material. Research has shown that B promotes ferrite in fully pearlitic grades where Cu and Mn were used to promote pearlite. The present work investigates the effect of B in SGI with …
Modification Strategies For Development Of 2d Material-Based Electrocatalysts For Alcohol Oxidation Reaction, Haichang Fu, Zhangxin Chen, Xiaohe Chen, Fan Jing, Hua Yu, Dan Chen, Binbin Yu, Yun Hang Hu, Yanxian Jin
Modification Strategies For Development Of 2d Material-Based Electrocatalysts For Alcohol Oxidation Reaction, Haichang Fu, Zhangxin Chen, Xiaohe Chen, Fan Jing, Hua Yu, Dan Chen, Binbin Yu, Yun Hang Hu, Yanxian Jin
Michigan Tech Publications, Part 2
2D materials, such as graphene, MXenes (metal carbides and nitrides), graphdiyne (GDY), layered double hydroxides, and black phosphorus, are widely used as electrocatalyst supports for alcohol oxidation reactions (AORs) owing to their large surface area and unique 2D charge transport channels. Furthermore, the development of highly efficient electrocatalysts for AORs via tuning the structure of 2D support materials has recently become a hot area. This article provides a critical review on modification strategies to develop 2D material-based electrocatalysts for AOR. First, the principles and influencing factors of electrocatalytic oxidation of alcohols (such as methanol and ethanol) are introduced. Second, surface …
Modification Strategies For Development Of 2d Material-Based Electrocatalysts For Alcohol Oxidation Reaction, Haichang Fu, Zhangxin Chen, Xiaohe Chen, Fan Jing, Hua Yu, Dan Chen, Binbin Yu, Yun Hang Hu, Yanxian Jin
Modification Strategies For Development Of 2d Material-Based Electrocatalysts For Alcohol Oxidation Reaction, Haichang Fu, Zhangxin Chen, Xiaohe Chen, Fan Jing, Hua Yu, Dan Chen, Binbin Yu, Yun Hang Hu, Yanxian Jin
Michigan Tech Publications, Part 2
2D materials, such as graphene, MXenes (metal carbides and nitrides), graphdiyne (GDY), layered double hydroxides, and black phosphorus, are widely used as electrocatalyst supports for alcohol oxidation reactions (AORs) owing to their large surface area and unique 2D charge transport channels. Furthermore, the development of highly efficient electrocatalysts for AORs via tuning the structure of 2D support materials has recently become a hot area. This article provides a critical review on modification strategies to develop 2D material-based electrocatalysts for AOR. First, the principles and influencing factors of electrocatalytic oxidation of alcohols (such as methanol and ethanol) are introduced. Second, surface …
Acute Exposure To Two Biocides Causes Morphological And Molecular Changes In The Gill Ciliary Epithelium Of The Invasive Golden Mussel Limnoperna Fortunei (Dunker, 1857), Amanda Maria Siqueira Moreira, Erico Freitas, Mariana De Paula Reis, Júlia Meireles Nogueira, Newton Pimentel De Ulhôa Barbosa, André Luiz Martins Reis, Afonso Pelli, Paulo Ricardo Da Silva Camargo, Antonio Valadão Cardoso, Rayan Silva De Paula, Erika Cristina Jorge
Acute Exposure To Two Biocides Causes Morphological And Molecular Changes In The Gill Ciliary Epithelium Of The Invasive Golden Mussel Limnoperna Fortunei (Dunker, 1857), Amanda Maria Siqueira Moreira, Erico Freitas, Mariana De Paula Reis, Júlia Meireles Nogueira, Newton Pimentel De Ulhôa Barbosa, André Luiz Martins Reis, Afonso Pelli, Paulo Ricardo Da Silva Camargo, Antonio Valadão Cardoso, Rayan Silva De Paula, Erika Cristina Jorge
Michigan Tech Publications, Part 2
Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L−1) and NaDCC (1.5 mg L−1) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an …
Evolution Of Glassy Carbon Derived From Pyrolysis Of Furan Resin, Josh Kemppainen, Ivan Gallegos, Aaron Krieg, Jacob R. Gissinger, Kristopher E. Wise, Margaret Kowalik, Julia A. King, S. Gowtham, Adri Van Duin, Gregory Odegard
Evolution Of Glassy Carbon Derived From Pyrolysis Of Furan Resin, Josh Kemppainen, Ivan Gallegos, Aaron Krieg, Jacob R. Gissinger, Kristopher E. Wise, Margaret Kowalik, Julia A. King, S. Gowtham, Adri Van Duin, Gregory Odegard
Michigan Tech Publications, Part 2
Glassy carbon (GC) material derived from pyrolyzed furan resin was modeled by using reactive molecular dynamics (MD) simulations. The MD polymerization simulation protocols to cure the furan resin precursor material are validated via comparison of the predicted density and Young's modulus with experimental values. The MD pyrolysis simulations protocols to pyrolyze the furan resin precursor is validated by comparison of calculated density, Young's modulus, carbon content, sp carbon content, the in-plane crystallite size, out-of-plane crystallite stacking height, and interplanar crystallite spacing with experimental results from the literature for furan resin derived GC. The modeling methodology established in this work can …
Establishing Physical And Chemical Mechanisms Of Polymerization And Pyrolysis Of Phenolic Resins For Carbon-Carbon Composites, Ivan Gallegos, Josh Kemppainen, Jacob R. Gissinger, Malgorzata Kowalik, Adri Van Duin, Kristopher E. Wise, S. Gowtham, Gregory Odegard
Establishing Physical And Chemical Mechanisms Of Polymerization And Pyrolysis Of Phenolic Resins For Carbon-Carbon Composites, Ivan Gallegos, Josh Kemppainen, Jacob R. Gissinger, Malgorzata Kowalik, Adri Van Duin, Kristopher E. Wise, S. Gowtham, Gregory Odegard
Michigan Tech Publications, Part 2
The complex structural and chemical changes that occur during polymerization and pyrolysis critically affect material properties but are difficult to characterize in situ. This work presents a novel, experimentally validated methodology for modeling the complete polymerization and pyrolysis processes for phenolic resin using reactive molecular dynamics. The polymerization simulations produced polymerized structures with mass densities of 1.24 ± 0.01 g/cm3 and Young's moduli of 3.50 ± 0.64 GPa, which are in good agreement with experimental values. The structural properties of the subsequently pyrolyzed structures were also found to be in good agreement with experimental X-ray data for the phenolic-derived carbon …
Carbohydrates Generated Via Hot Water As Catalyst For Co2 Reduction Reaction, Yang Yang, Heng Zhong, Jiong Cheng, Yun Hang Hu, Richard Lee Smith Jr, Fangming Jin
Carbohydrates Generated Via Hot Water As Catalyst For Co2 Reduction Reaction, Yang Yang, Heng Zhong, Jiong Cheng, Yun Hang Hu, Richard Lee Smith Jr, Fangming Jin
Michigan Tech Publications, Part 2
Combining terrestrial biomass with submarine-type hydrothermal environments for CO2 reduction is a possible approach for realizing new energies while achieving sustainable circulation of carbon. Herein, carbohydrateenabled CO2 reduction based on NaHCO3 conversion to formate revealed that hydrothermal environments facilitated direct hydrogen transfer from carbohydrates (glucose, cellulose) to CO2/NaHCO3 with hot water (250–300 °C, 5–20 MPa) acting as homogeneous catalyst in absence of any conventional catalysts giving CO2/ NaHCO3 reduction efficiencies as high as 76% for cellulose. Time-resolved operando hydrothermal DRIFTS spectra of glycolaldehyde in hot water (250 °C, autogenous pressure) verified that water catalyzed NaHCO3 reduction by converting the -CHO …
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
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, Part 2
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 …
Conventional Platinum Metal Implants Provoke Restenosis Responses In Atherogenic But Not Healthy Arteries, Lea M. Morath, Roger J. Guillory Ii, Alexander A. Oliver, Shu Q. Liu, Martin L. Bocks, Galit Katarivas Levy, Jaroslaw Drelich, Jeremy Goldman
Conventional Platinum Metal Implants Provoke Restenosis Responses In Atherogenic But Not Healthy Arteries, Lea M. Morath, Roger J. Guillory Ii, Alexander A. Oliver, Shu Q. Liu, Martin L. Bocks, Galit Katarivas Levy, Jaroslaw Drelich, Jeremy Goldman
Michigan Tech Publications
Platinum-containing stents are commonly used in humans with hypercholesterolemia, whereas preclinical stent evaluation has commonly been performed in healthy animal models, providing inadequate information about stent performance under hypercholesterolemic conditions. In this investigation, we used an ApoE−/− mouse model to test the impact of hypercholesterolemia on neointima formation on platinum-containing implants. We implanted 125 μm diameter platinum wires into the abdominal aortas of ApoE−/− and ApoE+/+ mice for 6 months, followed by histological and immunofluorescence examination of neointimal size and composition. It was found that ApoE−/− mice developed neointimas with four times larger area and ten times greater thickness than …
Material Design And Performance Of Carbon Monoxide-Fueled Solid Oxide Fuel Cells: A Review, Wei Zhang, Yun Hang Hu
Material Design And Performance Of Carbon Monoxide-Fueled Solid Oxide Fuel Cells: A Review, Wei Zhang, Yun Hang Hu
Michigan Tech Publications
Solid oxide fuel cells (SOFCs) are electrochemical energy conversion devices with fuel flexibility. Since carbon monoxide (CO) is a major product of SOFC anodes operating with hydrocarbon fuels, direct utilization of CO as a fuel is expected for more efficient operation of SOFCs. A review on CO-fueled SOFC technologies is imperative to promote research activities in this important field, but it has not been published. In this review, we summarize and comment on literatures in this field, with respect to (1) materials developed for three fundamental components (anode, cathode, and electrolyte), (2) power output and stabilization strategies, and (3) critical …
Turning Dead Leaves Into An Active Multifunctional Material As Evaporator, Photocatalyst, And Bioplastic, Siyuan Fang, Xingyi Lyu, Tian Tong, Aniqa Ibnat Lim, Tao Li, Jiming Bao, Yun Hang Hu
Turning Dead Leaves Into An Active Multifunctional Material As Evaporator, Photocatalyst, And Bioplastic, Siyuan Fang, Xingyi Lyu, Tian Tong, Aniqa Ibnat Lim, Tao Li, Jiming Bao, Yun Hang Hu
Michigan Tech Publications
Large numbers of leaves fall on the earth each autumn. The current treatments of dead leaves mainly involve completely destroying the biocomponents, which causes considerable energy consumption and environmental issues. It remains a challenge to convert waste leaves into useful materials without breaking down their biocomponents. Here, we turn red maple dead leaves into an active three-component multifunctional material by exploiting the role of whewellite biomineral for binding lignin and cellulose. Owing to its intense optical absorption spanning the full solar spectrum and the heterogeneous architecture for effective charge separation, films of this material show high performance in solar water …
Austenite Formation And Manganese Partitioning During Double Soaking Of An Ultralow Carbon Medium-Manganese Steel, Josh J. Mueller, Alexandra G. Glover, David K. Matlock, John G. Speer, Emmanuel De Moor
Austenite Formation And Manganese Partitioning During Double Soaking Of An Ultralow Carbon Medium-Manganese Steel, Josh J. Mueller, Alexandra G. Glover, David K. Matlock, John G. Speer, Emmanuel De Moor
Michigan Tech Publications
Double soaking (DS) is a thermal processing route intended to produce austenite–martensite microstructures in steels containing austenite-stabilizing additions and consists of intercritical annealing (primary soaking), followed by heating and brief isothermal holding at an increased temperature (secondary soaking), and quenching. Herein, experimental dilatometry during DS of a medium-manganese (Mn) steel with nominally 7 wt% Mn and an ultralow residual carbon concentration, in combination with phase-field simulations of austenite formation during secondary soaking, is presented. The feasibility of maintaining heterogeneous Mn distributions during DS is demonstrated and insight is provided on the effects of the secondary soaking temperature and prior Mn …
Can Grid-Tied Solar Photovoltaics Lead To Residential Heating Electrification? A Techno-Economic Case Study In The Midwestern U.S., Nelson Sommerfeldt, Joshua M. Pearce
Can Grid-Tied Solar Photovoltaics Lead To Residential Heating Electrification? A Techno-Economic Case Study In The Midwestern U.S., Nelson Sommerfeldt, Joshua M. Pearce
Michigan Tech Publications
This study aims to quantify the techno-economic potential of using solar photovoltaics (PV) to support heat pumps (HP) towards the replacement of natural gas heating in a representative North American residence from a house owner's point of view. For this purpose, simulations are performed on: (1) a residential natural gas-based heating system and grid electricity, (2) a residential natural gas-based heating system with PV to serve the electric load, (3) a residential HP system with grid electricity, and (4) a residential HP+PV system. Detailed descriptions are provided along with a comprehensive sensitivity analysis for identifying specific boundary conditions that enable …
Temperature, Pressure, And Adsorption Dependent Redox Potentials: Iii. Processes Of Co Conversion To Value-Added Compounds, Siyuan Fang, Yun Hang Hu
Temperature, Pressure, And Adsorption Dependent Redox Potentials: Iii. Processes Of Co Conversion To Value-Added Compounds, Siyuan Fang, Yun Hang Hu
Michigan Tech Publications
Carbon monoxide (CO) is a primary air pollutant and a poisonous species for human beings, animals, and some catalytic reactions. Meanwhile, CO is also a versatile feedstock in the chemical industry to produce high‐value chemicals and clean fuels, which has stimulated extensive research interests in exploiting efficient CO conversion processes. Redox potential is a key thermodynamic quantity in these processes whereas only standard reduction potentials at 25°Cand 1 atm are currently available. Herein, it is the first time to report the effects of temperature (0–1000°C), pressure (1–100 atm), and adsorption on the redox potentials of 18 CO conversion reactions to …
Conductive 3d Nano-Biohybrid Systems Based On Densified Carbon Nanotube Forests And Living Cells, Roya Bagheri, Alicia K. Ball, Masoud Kasraie, Aparna Chandra, Xinqian Chen, Ibrahim Miskioglu, Zhiying Shan, Parisa Pour Shahid Saeed Abadi
Conductive 3d Nano-Biohybrid Systems Based On Densified Carbon Nanotube Forests And Living Cells, Roya Bagheri, Alicia K. Ball, Masoud Kasraie, Aparna Chandra, Xinqian Chen, Ibrahim Miskioglu, Zhiying Shan, Parisa Pour Shahid Saeed Abadi
Michigan Tech Publications, Part 2
Conductive biohybrid cell-material systems have applications in bioelectronics and biorobotics. To date, conductive scaffolds are limited to those with low electrical conductivity or 2D sheets. Here, 3D biohybrid conductive systems are developed using fibroblasts or cardiomyocytes integrated with carbon nanotube (CNT) forests that are densified due to interactions with a gelatin coating. CNT forest scaffolds with a height range of 120–240 µm and an average electrical conductivity of 0.6 S/cm are developed and shown to be cytocompatible as evidenced from greater than 89% viability measured by live-dead assay on both cells on day 1. The cells spread on top and …
Size Distribution, Elemental Composition And Morphology Of Nanoparticles Separated From Respirable Coal Mine Dust, Shoeleh Assemi, Lei Pan, Xuming Wang, Titilayo Akinseye, Jan D. Miller
Size Distribution, Elemental Composition And Morphology Of Nanoparticles Separated From Respirable Coal Mine Dust, Shoeleh Assemi, Lei Pan, Xuming Wang, Titilayo Akinseye, Jan D. Miller
Michigan Tech Publications
Nanoparticles, defined as particles with one dimension below 100 nm, contribute little to the total mass concentration in respirable coal mine dust (RCMD) toxicological studies, but they could have a considerable part in the adverse health effects by RCMD inhalation. It has been shown that inhaled nanoparticles can penetrate deep into the lung and could plausibly contribute to acute and chronic pulmonary diseases by triggering oxidative stress formation and inducing inflammation. RCMD nanoparticles from samples collected in an underground mine in the United States were analyzed by a particle separation technique, field-flow fractionation (FFF), for size, morphology, and elemental composition. …
Molecular Dynamics Modeling Of Polymers For Aerospace Composites, Swapnil Sambhaji Bamane
Molecular Dynamics Modeling Of Polymers For Aerospace Composites, Swapnil Sambhaji Bamane
Dissertations, Master's Theses and Master's Reports
Polymer matrix composite materials are widely used as structural materials in aerospace and aeronautical vehicles. Resin/reinforcement wetting and the effect of polymerization on the thermo-mechanical properties of the resin are key parameters in the manufacturing of aerospace composite materials. Determining the contact angle between combinations of liquid resin and reinforcement surfaces is a common method for quantifying wettability. It is challenging to determine contact angle values experimentally of high-performance resins on CNT materials such as CNT, graphene, bundles or yarns, and BNNT surfaces. It is also experimentally difficult to determine the effect of polymerization reaction on material properties of a …
Effect Of Sc On Recrystallization Resistance Of Aa7050, Keaton Schmidt
Effect Of Sc On Recrystallization Resistance Of Aa7050, Keaton Schmidt
Dissertations, Master's Theses and Master's Reports
The extrusion process involves high temperatures and strains that can result in undesirable microstructures, especially along the surface. Extruded alloys tend to exhibit surface recrystallization during heat treating at regions of higher strains, which can lead to reduced fatigue strength and corrosion resistance. By adding Sc to AA7050, nano-sized dispersoids are formed with Sc cores and Zr shells that restrict recrystallization more than the base alloy that only utilizes Zr. Billets with varying Sc content and a control with only Zr were cast, and extrusions were made in order to compare surface microstructures at varying strains in the as-extruded and …
Stability Of Linicoal-Oxide Electrode Material Under High-Temperature Ceramic Fuel Cell Conditions, Wei Zhang
Stability Of Linicoal-Oxide Electrode Material Under High-Temperature Ceramic Fuel Cell Conditions, Wei Zhang
Dissertations, Master's Theses and Master's Reports
LiNi0.8Co0.15Al0.05O2 (LNCA) is an important cathode material for room-temperature operation of lithium-ion batteries (LIBs). As an emerging research area, LNCA was recently applied as electrodes (both cathode and anode) for high-temperature ceramic fuel cells (CFCs) with impressive performances. However, the stability of LNCA electrode material under CFC operating conditions (i.e., reactive atmospheres and high temperatures) remains unknown. In this dissertation: (1) The stability of LNCA in air and H2 atmospheres was systematically evaluated at elevated temperatures (i.e., the operating electrode environments of H2-fueled CFCs). It was found that LNCA exhibited excellent stability in air within a wide temperature range from …
Quantifying The Evolution Of Strengthening Mechanisms For Commercially Produced Niobium And Titanium Hsla Steel Sheet, Isabella M.W. Jaszczak
Quantifying The Evolution Of Strengthening Mechanisms For Commercially Produced Niobium And Titanium Hsla Steel Sheet, Isabella M.W. Jaszczak
Dissertations, Master's Theses and Master's Reports
Strength uniformity along the coil length of commercially produced high-strength, low-alloy (HSLA) steel hot-rolled sheet is crucial to avoid the downgrading of product that does not meet strength specifications. In addition to contributing to precipitation strengthening through the growth of niobium-titanium carbides ((Nb,Ti)-C), niobium hinders austenite recrystallization and refines ferrite grain size. The potency of these strengthening mechanisms relies heavily on the austenite to ferrite transformation kinetics of the hot-rolling process. While niobium’s effect on precipitation strengthening, Hall-Petch strengthening, dislocation strengthening, and solute strengthening have all been studied in literature independently, the interactions of these mechanisms with each other and …
Optimizing The Extrudability Of 6082 Aluminum By Varying The Magnesium And Silicon Concentration, Eli A. Harma
Optimizing The Extrudability Of 6082 Aluminum By Varying The Magnesium And Silicon Concentration, Eli A. Harma
Dissertations, Master's Theses and Master's Reports
Alloy 6082 aluminum is used for high-volume manufacturing in the automotive industry due to its high strength, impact performance, and corrosion resistance. However, given these improved properties, the alloy has decreased formability compared to other 6xxx series alloys, especially in the extrusion process. Controlling the dynamic recovery and recrystallization properties by changing the additions of Mg and Si can improve the hot deformation properties. Five alloys of varying Mg and Si concentrations between 0.6 to 1.2wt% Mg and 0.7 to 1.3wt% Si were made with constant concentrations of Cr, Fe, and Mn and the same homogenization heat treatment. The proposed …
Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad
Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad
Dissertations, Master's Theses and Master's Reports
There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …
Fluid Droplet Spreading And Adhesion Studied With A Microbalance: A Review, Youhua Jiang, Jaroslaw Drelich
Fluid Droplet Spreading And Adhesion Studied With A Microbalance: A Review, Youhua Jiang, Jaroslaw Drelich
Michigan Tech Publications
A contact angle observed for a liquid–solid system is not necessarily a unique value, and a few contact angles need to be considered carefully in relation to liquid spreading, adhesion and phase separation. Understanding of the significance of different contact angles has improved in the last few years through direct measurements of interactive forces between droplets/bubbles and solids together with the simultaneous visualization of the changes in their shapes. A microelectronic balance system is employed to measure the force of spreading after either liquid droplet or gas bubble attachment to a substrate surface and the droplet/bubble–substrate adhesion forces after droplet/bubble …
Carbonate-Superstructured Solid Fuel Cells With Hydrocarbon Fuels, Hanrui Su, Wei Zhang, Yun Hang Hu
Carbonate-Superstructured Solid Fuel Cells With Hydrocarbon Fuels, Hanrui Su, Wei Zhang, Yun Hang Hu
Michigan Tech Publications
A basic requirement for solid oxide fuel cells (SOFCs) is the sintering of electrolyte into a dense impermeable membrane to prevent the mixing of fuel and oxygen for a sufficiently high open-circuit voltage (OCV). However, herein, we demonstrate a different type of fuel cell, a carbonate-superstructured solid fuel cell (CSSFC), in which in situ generation of superstructured carbonate in the porous samarium-doped ceria layer creates a unique electrolyte with ultrahigh ionic conductivity of 0.17 S.cm21 at 550 °C. The CSSFC achieves unprecedented high OCVs (1.051 V at 500 °C and 1.041 V at 550 °C) with methane fuel. Furthermore, the …
Development Of High-Performance Fiber Cement: A Case Study In The Integration Of Circular Economy In Product Design, Parinya Chakartnarodom, Sarunya Wanpen, Wichit Prakaypan, Edward A. Laitila, Nuntaporn Kongkajun
Development Of High-Performance Fiber Cement: A Case Study In The Integration Of Circular Economy In Product Design, Parinya Chakartnarodom, Sarunya Wanpen, Wichit Prakaypan, Edward A. Laitila, Nuntaporn Kongkajun
Michigan Tech Publications
A new fiber cement (FC) is designed with the integration of circular economy (CE) concepts, in particular a product that is recyclable yet maintains performance. The FC samples were prepared from the mixtures of ordinary Portland cement (OPC), sand, and cellulose fibers, and required an inclusion compound (IC) and water. From the heat of hydration tests, the most effective IC, IC1, was prepared from lithium silicate, sodium thiocyanate, alkylbenzene sulfonate, and hydrochloric acid. The FC samples were recycled by crushing and grinding, then used as sand replacement in varying amounts to produce new FC samples. The results from the mechanical …