Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Missouri University of Science and Technology

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2221 - 2250 of 21777

Full-Text Articles in Engineering

Atomic Layer Deposited Pt/Tio2-Sio2 And Pt/Zro2-Sio2 For Sequential Adsorption And Oxidation Of Vocs, Busuyi O. Adebayo, Han Yu, Ali A. Rownaghi, Xinhua Liang, Fateme Rezaei Sep 2022

Atomic Layer Deposited Pt/Tio2-Sio2 And Pt/Zro2-Sio2 For Sequential Adsorption And Oxidation Of Vocs, Busuyi O. Adebayo, Han Yu, Ali A. Rownaghi, Xinhua Liang, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, Pt nanoparticles were loaded on SiO2, TiO2-thin-film-modified SiO2 (TiO2-SiO2), or ZrO2-thin-film-modified SiO2 (ZrO2-SiO2) particles and the composites were investigated for sequential adsorption and desorption/catalytic oxidation of benzene. The SiO2 was prepared via sol–gel method, while TiO2-SiO2 and ZrO2-SiO2 were synthesized via atomic layer deposition (ALD) thin film coating of TiO2 or ZrO2 on SiO2 particles substrate. In the sequential capture-reaction tests, the materials were first exposed to ca. 500 ppmv benzene …


Effects Of Radiation Reabsorption On The Laminar Flame Speed And No Emission During Aviation Kerosene Combustion At Elevated Pressures, Shu Zheng, Hao Liu, Qing Li, Jiajian Zhu, Mingbo Sun, Bo Zhou, Ran Sui, Qiang Lu Sep 2022

Effects Of Radiation Reabsorption On The Laminar Flame Speed And No Emission During Aviation Kerosene Combustion At Elevated Pressures, Shu Zheng, Hao Liu, Qing Li, Jiajian Zhu, Mingbo Sun, Bo Zhou, Ran Sui, Qiang Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Increasing attention has been paid on combustion stability and pollution emission of aviation kerosene due to the emerging interests on supersonic combustion scramjets. Whereas the vitiation component H2O introduced by hydrogen-fueled heaters in high-enthalpy vitiated air during ground experiments has a considerable influence on kerosene combustion, especially through its radiation effect, which needs to be further investigated. In this paper, the radiation reabsorption effects on laminar flame speeds and NO emissions during RP-3/H2O/O2/N2 combustion was assessed numerically over a wide range of equivalence ratio and pressure (ϕ = 0.7–1.4 and P = 1–15 atm) using detailed chemical and radiation models. …


Reliability Of Bridge Inspection Technologies, Glenn A. Washer Sep 2022

Reliability Of Bridge Inspection Technologies, Glenn A. Washer

INSPIRE Archived Webinars

This presentation will discuss the reliability of inspection technologies used for the condition assessment of highway bridges. Data from condition assessments are critical to asset management and decision-making. The methodologies used to assess condition are usually subjective methods, such as visual inspections, that can vary as a result of human factors and differences in training and interpretation of inspection procedures. Nondestructive evaluation technologies (NDE) are implemented on a more limited basis and rely on indirect measurements to infer the presence of damage, and these assessments are affected by environmental factors, materials variability, and limitations in the interpretation of the resulting …


Ionic Liquid Pilocarpine Analog As An Antiglaucoma Drug Candidate, Juan Wang, Boxuan Li, Jing Tang, Li Qiu, Xin Qiao, Na Xu, Hu Yang Sep 2022

Ionic Liquid Pilocarpine Analog As An Antiglaucoma Drug Candidate, Juan Wang, Boxuan Li, Jing Tang, Li Qiu, Xin Qiao, Na Xu, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ionic liquid pilocarpine analog [Pilo-OEG]Cl, the first-of-its-kind ionic liquid antiglaucoma drug candidate, is synthesized and reported. To synthesize [Pilo-OEG]Cl, pilocarpine was reacted with the oligo-polyethylene glycol chloride, 2-[2-(2-chloroethoxy)ethoxy] ethanol, to form an ionic liquid molecule with an imidazole cation and a chloride anion. The chemical structure of [Pilo-OEG]Cl was confirmed with 1H NMR spectroscopy. Compared with pilocarpine (Pilo) and pilocarpine hydrochloride (PiloHCl), [Pilo-OEG]Cl has improved structural stability according to pH measurements and LC-MS analysis. The corneal permeability coefficient of [Pilo-OEG]Cl is 2-fold higher than that of Pilo and 8-fold higher than that of PiloHCl. [Pilo-OEG]Cl does not show apparent toxicity …


Study Of Asymptotic Velocity In The Bondi–Hoyle Accretion Flows In The Domain Of Kerr And 4-D Einstein–Gauss–Bonnet Gravities, Orhan Donmez, Fatih Dogan, Tuba Sahin Sep 2022

Study Of Asymptotic Velocity In The Bondi–Hoyle Accretion Flows In The Domain Of Kerr And 4-D Einstein–Gauss–Bonnet Gravities, Orhan Donmez, Fatih Dogan, Tuba Sahin

Materials Science and Engineering Faculty Research & Creative Works

Understanding the physical structures of the accreted matter very close to a black hole in quasars and active galactic nucleus (AGN) is an important milestone to constrain the activities occurring in their centers. In this paper, we numerically investigate the effects of the asymptotic velocities on the physical structures of the accretion disk around the Kerr and Einstein–Gauss–Bonnet (EGB) rapidly rotating black holes. The Bondi–Hoyle accretion is considered with a falling gas towards the black hole in an upstream region of the computational domain. Shock cones are naturally formed in the downstream part of the flow around both black holes. …


Some New Insights For Inferring Diapycnal (Irreversible) Diffusivity In Stably Stratified Turbulence, Amrapalli Garanaik, Subhas Karan Venayagamoorthy Sep 2022

Some New Insights For Inferring Diapycnal (Irreversible) Diffusivity In Stably Stratified Turbulence, Amrapalli Garanaik, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

New insight for inferring diapycnal diffusivity in stably stratified turbulent flows is obtained based on physical scaling arguments and tested using high-resolution direct numerical simulation data. It is shown that the irreversible diapycnal diffusivity can be decomposed into a diapycnal length scale that represents an inner scale of turbulence and a diapycnal velocity scale. Furthermore, it is shown that the diapycnal length scale and velocity scale can be related to the measurable Ellison length scale (LE) that represents outer scale of turbulence and vertical turbulent velocity scale (w ′) through a turbulent Froude number scaling analysis. The turbulent Froude number …


A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas, Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li Sep 2022

A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas, Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Ordos block of the north China craton and its surrounding regions are affected by the India-Eurasia collision to the southwest and the subduction of the Pacific beneath the Eurasian plates to the east. To provide the foundation for delineating lithospheric deformation and asthenospheric flow beneath this tectonically diverse region, we have created a database of individual shear-wave splitting (SWS) parameters by applying a uniform set of data processing procedures. After automatic data processing and manual checking, a total of 16,228 pairs of well-defined PKS, SKKS, and SKS splitting parameters (fast orientations and splitting times) are obtained from 1023 broadband …


Crustal Structure And Subsidence Mechanisms Of The Williston Basin: New Constraints From Receiver Function Imaging, Jianguo Song, Stephen S. Gao, Kelly H. Liu, Muchen Sun, Youqiang Yu, Fansheng Kong, Kevin Mickus Sep 2022

Crustal Structure And Subsidence Mechanisms Of The Williston Basin: New Constraints From Receiver Function Imaging, Jianguo Song, Stephen S. Gao, Kelly H. Liu, Muchen Sun, Youqiang Yu, Fansheng Kong, Kevin Mickus

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Mechanisms responsible for the long-term subsidence of intracontinental basins such as the Williston Basin in North America remain enigmatic, partly due to the thick sedimentary layer commonly found in the basins that prevents reliably imaging the deep crustal and upper mantle structures using some of the most-commonly employed seismic methods such as receiver function analysis. In this study, we used receiver functions recorded by 274 USArray and other stations in the Williston Basin and adjacent areas to investigate the layered structure of the crust in the hydrocarbon-rich intracontinental basin. After the removal of strong reverberations on the receiver functions associated …


Investigation On Chloride Binding Capacity And Stability Of Friedel's Salt In Graphene Oxide Reinforced Cement Paste, Wu Jian Long, Xuanhan Zhang, Gan Lin Feng, Jing Xie, Feng Xing, Biqin Dong, Jinrui Zhang, Kamal Khayat Sep 2022

Investigation On Chloride Binding Capacity And Stability Of Friedel's Salt In Graphene Oxide Reinforced Cement Paste, Wu Jian Long, Xuanhan Zhang, Gan Lin Feng, Jing Xie, Feng Xing, Biqin Dong, Jinrui Zhang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chloride binding capacity is one of the important factors affecting chloride induced rebar corrosion in reinforced concrete structures. Moreover, the stability of Friedel's salt will also affect the chloride binding capacity of cement-based materials. This study investigates the effect of graphene oxide (GO) on the chloride binding capacity of cement paste and stability of Friedel's salt under different pH conditions. Experiments of X-ray diffraction (XRD), Thermogravimetric analyzer (TGA), Scanning electron microscope (SEM) and Energy dispersive spectroscopy (EDS) were performed to analyze the phase assemblage, micro morphology, element ratio and the enhanced mechanisms. Results showed that the 0.2 wt% GO addition …


A Heuristic Approach To Predict The Tensile Strength Of A Non-Persistent Jointed Brazilian Disc Under Diametral Loading, Mostafa Asadizadeh, Nima Babanouri, Taghi Sherizadeh Sep 2022

A Heuristic Approach To Predict The Tensile Strength Of A Non-Persistent Jointed Brazilian Disc Under Diametral Loading, Mostafa Asadizadeh, Nima Babanouri, Taghi Sherizadeh

Mining Engineering Faculty Research & Creative Works

The mechanical response of rock bridges plays a key role in the stability of concrete and rock structures. In particular, the tensile failure of non-persistent discontinuities can result in their coalescence and the failure of rock or concrete engineering structures. The effect of non-persistent joint parameters on rock structures' failure under tensile mode has not been investigated by many researchers yet. Many non-persistent jointed Brazilian concrete discs are tested under diametral loading in this work, to study the influence of joint spacing, joint continuity factor, loading direction with regard to joint angle, and bridge angle on their tensile behavior. Heuristic …


Wettability Alteration Process At Pore-Scale During Engineered Waterflooding Using Computational Fluid Dynamics, Yongqiang Chen, Ping Chang, Guang Xu, Quan Xie Sep 2022

Wettability Alteration Process At Pore-Scale During Engineered Waterflooding Using Computational Fluid Dynamics, Yongqiang Chen, Ping Chang, Guang Xu, Quan Xie

Mining Engineering Faculty Research & Creative Works

Engineered waterflooding modifies chemistry of injected brine to efficiently and environmentally friendly enhance oil recovery. The common practice of engineered waterflooding includes low salinity waterflooding (LSW) and carbonated waterflooding. Among these oil recovery methods, wettability alteration has been perceived as a critical physicochemical process for additional oil recovery. While extensive work has been conducted to characterize the wettability alteration, the existing theory cannot explain the conflict oil recovery between secondary mode (injecting engineered water at the very beginning of flooding) and tertiary mode (injecting engineered water after conventional waterflooding), where secondary engineered waterflooding always gives a greater incremental oil recovery …


Products Pricing And Return Strategies For The Dual Channel Retailers, Jian Liu, Xinyue Sun, Yanyan Liu Sep 2022

Products Pricing And Return Strategies For The Dual Channel Retailers, Jian Liu, Xinyue Sun, Yanyan Liu

Electrical and Computer Engineering Faculty Research & Creative Works

This paper analyzed how different return strategies and return rates affect dual-channel retailers' profits and channel pricings. Return can stimulate sales; however, the return has presented significant challenges to retailers. The return has long been studied to maximize profit and pricing; however, the different return strategies for dual-channel retailers affect channel both. This paper aimed to study whether or not dual-channel retailers should allow customers to return items in two channels and whether or not the retailer should contract with the manufacturers and pay extra fees to return products. This study indicated when the retailer should allow customers' returns to …


Effects Of Drying Temperature On Preparation Of Pectin Polysaccharide Thin Film For Resistive Switching Memory, Poh Liang Yap, Kuan Yew Cheong, Hooi Ling Lee, Feng Zhao Sep 2022

Effects Of Drying Temperature On Preparation Of Pectin Polysaccharide Thin Film For Resistive Switching Memory, Poh Liang Yap, Kuan Yew Cheong, Hooi Ling Lee, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

Commercially purchased pectin powder was formulated and processed into a thin film with different drying temperatures (60 °C–180 °C) and subsequently, sandwiched between Ag and ITO as top and bottom electrodes, respectively, for resistive switching memory study. Chemical functional groups, surface roughness, elemental chemical composition, and cross-sectional morphology of the dried pectin thin film were investigated via Fourier transform infrared spectroscopy, atomic force microscopy, and high-resolution transmission electron microscopy-energy dispersive X-ray spectroscopy. The higher the drying temperature, the rougher the surface with less residual moisture and more defect sites within the thin film was observed. Current–voltage measurements together with the …


Estimating Flashpoints Of Fuels And Chemical Compounds Using Hybrid Machine-Learning Techniques, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi, Abdoulmohammad Gholamzadeh Chofreh, Feybi Ariani Goni, Jiří Jaromír Klemeš Sep 2022

Estimating Flashpoints Of Fuels And Chemical Compounds Using Hybrid Machine-Learning Techniques, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi, Abdoulmohammad Gholamzadeh Chofreh, Feybi Ariani Goni, Jiří Jaromír Klemeš

Chemical and Biochemical Engineering Faculty Research & Creative Works

Flashpoint of organic materials is a crucial physical property in industrial applications and laboratory experiments, which provides information on safety standards and needed precautions in handling various organic materials. Proposed methods to determine the flashpoint of an organic material suffer from dependency on other physical properties of the chemical or demand complicated calculations which are time-consuming. In this work, a direct system model is proposed to anticipate the flashpoints of organic materials for a wide range of chemical compounds. The following models of genetic algorithm-adaptive neuro-fuzzy inference system, the least-squares version of the support vector machine, particle swarm optimization-adaptive neuro-fuzzy …


Metallization Of Polymers And Composites: State-Of-The-Art Approaches, Ruslan Melentiev, Arief Yudhanto, Ran Tao, Todor Vuchkov, Gilles Lubineau Sep 2022

Metallization Of Polymers And Composites: State-Of-The-Art Approaches, Ruslan Melentiev, Arief Yudhanto, Ran Tao, Todor Vuchkov, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Polymers and their composites are widely used for designing structures in aerospace, automotive, electronic, sport industries due to their lightweight, cost, and processing advantages. However, the surface of polymeric materials typically exhibits intrinsic deficiencies, limiting their durability and functionalities, e.g., low wear resistance, low thermal and electrical conductivity, low adhesion, low bioactivity, low reflectiveness, and weak photochemical resistance. Polymer metallization is an emerging concept that addresses these deficiencies by forming a metallic skin on polymeric surfaces. Herein, the working principles, recent advances, challenges, functional capabilities, and applications of the state-of-the-art polymer metallization methods in the fields of additive manufacturing, coating …


Improved Additive Manufacturing Of Silicon Carbide Parts Via Pressureless Electric Field-Assisted Sintering, Adam Bratten, Ruoyu Chen, Joshua Rittenhouse, Ming-Chuan Leu, Haiming Wen Sep 2022

Improved Additive Manufacturing Of Silicon Carbide Parts Via Pressureless Electric Field-Assisted Sintering, Adam Bratten, Ruoyu Chen, Joshua Rittenhouse, Ming-Chuan Leu, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

High solids loading silicon carbide (SiC)-based aqueous slurries containing only.5 wt. % organic additives were utilized to create specimens of various geometries via an extrusion-based additive manufacturing (AM) technique. Pressure less electric field-assisted sintering was performed to densify each specimen without deformation. The combination of these techniques produced parts with >98% relative density despite containing only 5 wt.% oxide sintering additives. After sintering, specimens contained only the α-SiC and yttrium aluminum perovskite phases. This suggests the evolution of a nonequilibrium yttrium aluminate phase, as well as transformation from β-SiC to α-SiC. The fabrication method presented in this work has advantages …


Accelerated Bs/Ms Program In Electrical And Computer Engineering, Robert S. Woodley, Steve Eugene Watkins Sep 2022

Accelerated Bs/Ms Program In Electrical And Computer Engineering, Robert S. Woodley, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

The Electrical and Computer Engineering Department at Missouri University of Science and Technology implemented an Accelerated BS/MS Program in 2019. This program is designed to encourage and facilitate undergraduate majors in electrical and computer engineering to pursue a masters program. It is similar to engineering programs at other institutions that are identified with titles such as accelerated masters, combined BS/MS, and 4+1 options. It reduces the time needed for undergraduates to earn a graduate degree and exposes these students to research work. It provides a route for faculty to obtain quality graduate students and it builds enrollment for the department. …


Improved A-Efie System For Electromagnetic Simulation In Low Frequency Regime, Wen Jing Chen, Sheng Sun, Yang Liu, Lijun Jiang, Jun Hu Sep 2022

Improved A-Efie System For Electromagnetic Simulation In Low Frequency Regime, Wen Jing Chen, Sheng Sun, Yang Liu, Lijun Jiang, Jun Hu

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, the quasi-Helmholtz projectors are applied to address numerical cancellation of augmented electric field integral equation (A-EFIE). The projectors rescale the term overline {bf V} cdot i{k}_0{bf j} and right-hand side to guarantee that the solution is stable at very low frequency. The improved system is full rank without removing the singularity caused by charge neutrality. Compared to the EFIE with quasi-Helmholtz projectors, this letter presents a better convergence performance and takes less computational cost. The numerical results show that the solution of both scattering problems and circuit problems can ensure the accuracy in the low-frequency regime.


Online Optimal Adaptive Control Of Partially Uncertain Nonlinear Discrete-Time Systems Using Multilayer Neural Networks, Rohollah Moghadam, Pappa Natarajan, Sarangapani Jagannathan Sep 2022

Online Optimal Adaptive Control Of Partially Uncertain Nonlinear Discrete-Time Systems Using Multilayer Neural Networks, Rohollah Moghadam, Pappa Natarajan, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This article intends to address an online optimal adaptive regulation of nonlinear discrete-time systems in affine form and with partially uncertain dynamics using a multilayer neural network (MNN). The actor-critic framework estimates both the optimal control input and value function. Instantaneous control input error and temporal difference are used to tune the weights of the critic and actor networks, respectively. The selection of the basis functions and their derivatives are not required in the proposed approach. The state vector, critic, and actor NN weights are proven to be bounded using the Lyapunov method. Our approach can be extended to neural …


Study On Apparent Permeability Model For Gas Transport In Shale Inorganic Nanopores, Shuda Zhao, Hongji Liu, Enyuan Jiang, Nan Zhao, Chaohua Guo, Baojun Bai Sep 2022

Study On Apparent Permeability Model For Gas Transport In Shale Inorganic Nanopores, Shuda Zhao, Hongji Liu, Enyuan Jiang, Nan Zhao, Chaohua Guo, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Inorganic nanopores occurring in the shale matrix have strong hydrophilicity and irreducible water (IW) film can be formed on the inner surface of the pores making gas flow mechanisms in the pores more complex. In this paper, the existence of irreducible water (IW) in inorganic pores is considered, and, based on the Knudsen number (K (Formula presented.)) correction in shale pores, a shale gas apparent permeability model of inorganic nano-pores is established. The effect of the K (Formula presented.) correction on the apparent permeability, the ratio of flow with pore radius and the effect of IW on the apparent permeability …


Fabrications And Applications Of Micro/Nanofluidics In Oil And Gas Recovery: A Comprehensive Review, Junchen Liu, Yandong Zhang, Mingzhen Wei, Xiaoming He, Baojun Bai Sep 2022

Fabrications And Applications Of Micro/Nanofluidics In Oil And Gas Recovery: A Comprehensive Review, Junchen Liu, Yandong Zhang, Mingzhen Wei, Xiaoming He, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Understanding fluid flow characteristics in porous medium, which determines the development of oil and gas oilfields, has been a significant research subject for decades. Although using core samples is still essential, micro/nanofluidics have been attracting increasing attention in oil recovery fields since it offers direct visualization and quantification of fluid flow at the pore level. This work provides the latest techniques and development history of micro/nanofluidics in oil and gas recovery by summarizing and discussing the fabrication methods, materials and corresponding applications. Compared with other reviews of micro/nanofluidics, this comprehensive review is in the perspective of solving specific issues in …


High-Entropy Boride–Carbide Ceramics By Sequential Boro/Carbothermal Synthesis, Steven M. Smith, Lun Feng, William Fahrenholtz, Greg Hilmas, Tieshu Huang Sep 2022

High-Entropy Boride–Carbide Ceramics By Sequential Boro/Carbothermal Synthesis, Steven M. Smith, Lun Feng, William Fahrenholtz, Greg Hilmas, Tieshu Huang

Materials Science and Engineering Faculty Research & Creative Works

A dual-phase high-entropy boride (HEB)/carbide (HEC) ceramic with a fine grain size was synthesized by a sequential boro/carbothermal process. In the first step, an Hf–Nb–Ta–Ti–Zr-containing carbide was synthesized by a carbothermal reduction of oxides followed by the reaction of the carbide with B4C and ZrH2 to convert part of the carbide to boride. The resulting composition was ∼29 vol% HEB with an average grain size of ∼1.1 μm. Solid solution formation occurred at the densification temperature of 1900°C resulting in a relative density higher than 99%. The Vickers hardness was 26.5 ± 1.4 GPa. This is the first report of …


Effect Of Rolling Process On Magnetic Properties Of Fe-3.3 Wt% Si Non-Oriented Electrical Steel, Yizhou Du, Ronald J. O'Malley, Mario F. Buchely, Paul Kelly Sep 2022

Effect Of Rolling Process On Magnetic Properties Of Fe-3.3 Wt% Si Non-Oriented Electrical Steel, Yizhou Du, Ronald J. O'Malley, Mario F. Buchely, Paul Kelly

Materials Science and Engineering Faculty Research & Creative Works

In this study, the influence of the rolling process on magnetic properties of Fe-3.3 wt% Si non-oriented electrical steel was investigated. The strip samples were cast using a high solidification cooling rate vacuum sampling method to simulate the solidification conditions of the industrial twin roll thin strip casting (TRSC) process. As-cast samples were subjected to various thermo-mechanical processing routes with different levels of hot-rolling (HR) and cold-rolling (CR). The influence of carbon and sulfur (C&S) contents in the steel were also investigated. Core loss (P1.5/50, P1.5/60, P1.0/50, P1.0/60) and magnetic induction (B25, B50) of the final annealed strip samples were …


Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas Sep 2022

Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

ZrB2 was mixed with 0.5 wt% carbon and up to 10 vol% ZrC and densified by hot-pressing at 2000 °C. All compositions were > 99.8% dense following hot-pressing. The dense ceramics contained 1–1.5 vol% less ZrC than the nominal ZrC addition and had between 0.5 and 1 vol% residual carbon. Grain sizes for the ZrB2 phase decreased from 10.1 µm for 2.5 vol% ZrC to 4.2 µm for 10 vol% ZrC, while the ZrC cluster size increased from 1.3 µm to 2.2 µm over the same composition range. Elastic modulus was ~505 GPa and toughness was ~2.6 MPa·m½ for all compositions. …


Global Tellurium Supply Potential From Electrolytic Copper Refining, Nedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. Hayes Sep 2022

Global Tellurium Supply Potential From Electrolytic Copper Refining, Nedal T. Nassar, Haeyeon Kim, Max Frenzel, Michael S. Moats, Sarah M. Hayes

Materials Science and Engineering Faculty Research & Creative Works

The transition towards renewable energy requires increasing quantities of nonfuel mineral commodities, including tellurium used in certain photovoltaics. While demand for tellurium may increase markedly, the potential to increase tellurium supply is not well-understood. In this analysis, we estimate the quantity of tellurium contained in anode slimes generated by electrolytic copper refining by country between 1986 and 2018, including uncertainties. For 2018, the results indicate that 1930 (1500-2700, 95% confidence interval) metric tons of tellurium were contained in anode slimes globally. This is nearly quadruple the reported tellurium production for that year. China has the greatest potential to increase tellurium …


Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant Sep 2022

Ultrafast Stiffening Of Concentrated Thermoresponsive Mineral Suspensions, Sharu Bhagavathi Kandy, Iman Mehdipour, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Samanvaya Srivastava, Torben Gaedt, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Extrusion-based 3D printing with rapidly hardening polymeric materials is capable of building almost any conceivable structure. However, concrete, one of the most widely used materials for large-scale structural components, is generally based on inorganic binder materials like Portland cement. Unlike polymeric materials, a lack of precise control of the extent and rate of solidification of cement-based suspensions is a major issue that affects the ability to 3D-print geometrically complex structures. Here, we demonstrate a novel method for controllable-rapid solidification of concentrated mineral suspensions that contain a polymer binder system based on epoxy and thiol precursors as well as one or …


Mechanical Activation And Cation Site Disorder In Mgal2o4, Cole A. Corlett, Matthias D. Frontzek, Nina Obradovic, Jeremy Lee Watts, William Fahrenholtz Sep 2022

Mechanical Activation And Cation Site Disorder In Mgal2o4, Cole A. Corlett, Matthias D. Frontzek, Nina Obradovic, Jeremy Lee Watts, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The synthesis and crystallographic site occupancy were investigated for MgAl2O4 with and without mechanical activation of the precursor powders. Heating to 1200 °C or higher resulted in the formation of a single spinel phase regardless of whether the powders were mechanically activated or not. Neutron diffraction analysis was used to determine cation site occupancy and revealed that mechanical activation resulted in a lower degree of cation site inversion compared to the nonactivated materials, which indicated that the powders were closer to thermodynamic equilibrium. This is the first study to characterize the effects of mechanical activation on crystallographic site occupancy in …


A Hybridizable Discontinuous Galerkin Time-Domain Method With Robin Transmission Condition For Transient Thermal Analysis Of 3-D Integrated Circuits, Xuan Zhang, Ping Li, Xiao Chun Li, Li (Lijun) Jun Jiang, Jun Fa Mao Sep 2022

A Hybridizable Discontinuous Galerkin Time-Domain Method With Robin Transmission Condition For Transient Thermal Analysis Of 3-D Integrated Circuits, Xuan Zhang, Ping Li, Xiao Chun Li, Li (Lijun) Jun Jiang, Jun Fa Mao

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, a discontinuous Galerkin time-domain (DGTD) method hybridized with Robin transmission condition (RTC-DGTD) is proposed for the transient thermal analysis of 3-D integrated circuits (ICs). As a kind of domain decomposition method (DDM), the DGTD method employs a term named numerical flux for the information exchange of solutions between neighboring subdomains. The numerical flux is a function of both temperature T and heat flux q, and thus for the heat equation, apart from T, the variable q has to be solved as well. To reach this, the traditional DGTD method decomposes the second-order partial-differential thermal equation into two …


In-Situ Measurements Of Temperature And Emissivity During Msw Combustion Using Spectral Analysis And Multispectral Imaging Processing, Shu Zheng, Weiguang Cai, Ran Sui, Zixue Luo, Qiang Lu Sep 2022

In-Situ Measurements Of Temperature And Emissivity During Msw Combustion Using Spectral Analysis And Multispectral Imaging Processing, Shu Zheng, Weiguang Cai, Ran Sui, Zixue Luo, Qiang Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

By using a novel multispectral imaging technology, the 2-D distributions of flame temperature and emissivity were measured in a 16 MW incinerator to co-fire municipal solid waste (MSW) and municipal sludge. A way to establish the relationship between the multispectral flame images and the temperature was proposed by combing the Newton iteration method and Hottel emissivity model. The results showed that the measured temperatures at different locations varied by 31.25% with a fixed steam evaporation rate, and 11.76% with different steam evaporation rates at a given port. The temperatures and emissivities decreased at upper locations due to the lower local …


Machine Learning Mosa Monitoring System, Aditya G. Manjunath, Sabahudin Vrtagic, Fatih Dogan, Milan Dordevic, Mileta Zarkovic, Jasmin Kevric, Goran Dobric Aug 2022

Machine Learning Mosa Monitoring System, Aditya G. Manjunath, Sabahudin Vrtagic, Fatih Dogan, Milan Dordevic, Mileta Zarkovic, Jasmin Kevric, Goran Dobric

Materials Science and Engineering Faculty Research & Creative Works

This research paper deals with the problem of Metal-Oxide Surge Arrester (MOSA) condition monitoring and a new methodology in surge arrester monitoring and diagnostics is presented. A machine learning algorithm (back propagation regression) is used to estimate the non-linearity coefficient of the surge arrester, based on operating voltage and leakage current of the arrester. Using a simulated system, this research investigates the possibility of application and efficiency of machine learning. It is shown that the applied learning algorithm results are competitive with the model results parameters calculated as R2 = 0.999 and mean absolute real error computed as 0.005 which …