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Articles 4261 - 4290 of 21795

Full-Text Articles in Engineering

System Of Systems (Sos) Architecture For Digital Manufacturing Cybersecurity, Lirim Ashiku, Cihan H. Dagli Aug 2019

System Of Systems (Sos) Architecture For Digital Manufacturing Cybersecurity, Lirim Ashiku, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Technology advancements of real time connectivity and computing powers has evolved the way people manage activities triggering heavy reliance on smart devices. This has reshaped the ability to memorize crucial information, instead accumulate the information into devices allowing real-time fingertip access when needed. Inability to access such information when needed is routinely assumed with device malfunctioning bypassing the probability of compromise, but what if the information is now being accessed by adversaries depriving the data-owner access to crucial information? Cyber manufacturing systems are not immune from these issues. It is possible to approach this problem as generating SoS meta-architecture. In …

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Bioactive Glass Fiber Fabrication Via A Combination Of Sol-Gel Process With Electro-Spinning Technique, Malvika Nagrath, Adel Alhalawani, Alireza Rahimnejad Yazdi, Mark R. Towler Aug 2019

Bioactive Glass Fiber Fabrication Via A Combination Of Sol-Gel Process With Electro-Spinning Technique, Malvika Nagrath, Adel Alhalawani, Alireza Rahimnejad Yazdi, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

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Cyber-Enabled Product Lifecycle Management: A Multi-Agent Framework, Vishwa V. Kumar, Avimanyu Sahoo, Frank W. Liou Aug 2019

Cyber-Enabled Product Lifecycle Management: A Multi-Agent Framework, Vishwa V. Kumar, Avimanyu Sahoo, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Trouble free use of a product and its associated services for a specified minimum period of time is a major factor to win the customer's trust in the product. Rapid and easy serviceability to maintain its functionalities plays a key role in achieving this goal. However, the sustainability of such a model cannot be promised unless the current health status of the product is monitored and condition-based maintenance is exercised. Internet of Things (IoT), an important connectivity paradigm of recent times, which connects physical objects to the internet for real-time information exchange and execution of physical actions via wired/wireless protocols. …

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Predictive Model For Thermal And Stress Field In Selective Laser Melting Process -- Part I, Lan Li, Lei Yan, Wenyuan Cui, Yitao Chen, Tan Pan, Xinchang Zhang, Aaron Flood, Frank W. Liou Aug 2019

Predictive Model For Thermal And Stress Field In Selective Laser Melting Process -- Part I, Lan Li, Lei Yan, Wenyuan Cui, Yitao Chen, Tan Pan, Xinchang Zhang, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During the part forming in laser powder bed fusion process, thermal distortion is one big problem due to the thermal stress which is caused by the high cooling rate and temperature gradient. Therefore, it is important to know the effect of process parameters on thermal and stress evolution in the melt zone. In this paper, a 3D finite element model for Selective Laser Melting (SLM) process based on sequentially coupled thermo-mechanical field analysis was developed for accurately predicting thermal history and surface features, like distortion and residual stress. Temperature dependent material properties for performed material 304L stainless steel are incorporated …

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Computational Fluid Dynamic Simulation Of Inhaled Radon Dilution By Auxiliary Ventilation In A Stone-Coal Mine Laneway And Dosage Assessment Of Miners, Bin Zhou, Ping Chang, Guang Xu Aug 2019

Computational Fluid Dynamic Simulation Of Inhaled Radon Dilution By Auxiliary Ventilation In A Stone-Coal Mine Laneway And Dosage Assessment Of Miners, Bin Zhou, Ping Chang, Guang Xu

Mining Engineering Faculty Research & Creative Works

Inhaled radon status in the laneways of some Chinese stone-coal mines is a cause of concern. In this study, computational fluid dynamics simulations were employed to investigate three flowrates of the dilution gas (2.5, 5, and 7.5 m3/s) and radon distributions at realistic breathing levels (1.6, 1.75, and 1.9 m). The results showed that there are obvious jet-flow, backflow, and vortex zones near the heading face, and a circulation flow at the rear of the laneway. A high radon concentration area was found to be caused by the mining machinery. As the ventilation rate increased, the radon concentrations …

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Probing Surface Characteristics Of Rare Earth Minerals Using Contact Angle Measurements, Atomic Force Microscopy, And Inverse Gas Chromatography, Mostafa Khodakarami, Lana Z. Alagha, Daniel J. Burnett Aug 2019

Probing Surface Characteristics Of Rare Earth Minerals Using Contact Angle Measurements, Atomic Force Microscopy, And Inverse Gas Chromatography, Mostafa Khodakarami, Lana Z. Alagha, Daniel J. Burnett

Mining Engineering Faculty Research & Creative Works

Rare earth minerals (REMs) such as bastnaesite, monazite, and xenotime are of considerable significance since they are the main commercial sources for rare earth elements (REEs) with cutting-edge applications. Fundamental understanding of surface properties of REMs is essential to identify the reactions taking place at different interfaces to develop more robust technologies for the recovery of REEs. The goal of this study is to provide a comprehensive investigation on the surface energy characteristics of bastnaesite and xenotime, as the primary sources of light and heavy rare earth elements, respectively. Crystal's orientation of REMs was identified using surface X-ray diffraction analysis, …

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Cascaded Fabry-Pérot Interferometers With Vernier Effect For Gas Pressure Measurement, Hongfeng Lin, Yanyan Xu, Farhan Mumtaz, Yutang Dai, Ai Zhou Aug 2019

Cascaded Fabry-Pérot Interferometers With Vernier Effect For Gas Pressure Measurement, Hongfeng Lin, Yanyan Xu, Farhan Mumtaz, Yutang Dai, Ai Zhou

Electrical and Computer Engineering Faculty Research & Creative Works

A sensitivity enhanced gas pressure sensor with Vernier effect is proposed in this paper. The sensor is a cascade configuration which includes two Fabry-Pérot interferometers (FPIs) with different free spectrum range (FSR). Each Fabry-Pérot interferometer is fabricated by inserting a piece of hollow core fiber (HCF) in between two sections of single mode fiber (SMF). Femtosecond laser is applied for drilling an opening on the HCF of sensing FPI to make the air hole interact with outside environment, while the air hole of the reference FPI is kept closed. Gas pressure response is measured by monitoring the wavelength shift of …

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Generalizing Multiple Access Wiretap And Wiretap Ii Channel Models: Achievable Rates And Cost Of Strong Secrecy, Mohamed Nafea, Aylin Yener Aug 2019

Generalizing Multiple Access Wiretap And Wiretap Ii Channel Models: Achievable Rates And Cost Of Strong Secrecy, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, new two-user multiple access wiretap channel models are studied. First, the multiple access wiretap channel II with a discrete memoryless main channel under different wiretapping scenarios is introduced. The wiretapper, as in the classical wiretap channel II model, chooses a fixed-size subset of the channel uses, in which it obtains noise-free observations of one of the codewords: a deterministic function, e.g., superposition, of the two codewords or each of the two codewords. A fourth wiretapping scenario is considered, in which the wiretapper, in each position it chooses, decides to observe either one of the codewords or both …

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Joint Manufacturing And Onsite Microgrid System Control Using Markov Decision Process And Neural Network Integrated Reinforcement Learning, Wenqing Hu, Zeyi Sun, Y. Zhang, Y. Li Aug 2019

Joint Manufacturing And Onsite Microgrid System Control Using Markov Decision Process And Neural Network Integrated Reinforcement Learning, Wenqing Hu, Zeyi Sun, Y. Zhang, Y. Li

Mathematics and Statistics Faculty Research & Creative Works

Onsite microgrid generation systems with renewable sources are considered a promising complementary energy supply system for manufacturing plant, especially when outage occurs during which the energy supplied from the grid is not available. Compared to the widely recognized benefits in terms of the resilience improvement when it is used as a backup energy system, the operation along with the electricity grid to support the manufacturing operations in non-emergent mode has been less investigated. In this paper, we propose a joint dynamic decision-making model for the optimal control for both manufacturing system and onsite generation system. Markov Decision Process (MDP) is …

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Remote Sensing Of Explosives-Induced Stress In Plants: Hyperspectral Imaging Analysis For Remote Detection Of Unexploded Threats, Paul V. Manley, Vasit Sagan, Felix B. Fritschi, Joel Gerard Burken Aug 2019

Remote Sensing Of Explosives-Induced Stress In Plants: Hyperspectral Imaging Analysis For Remote Detection Of Unexploded Threats, Paul V. Manley, Vasit Sagan, Felix B. Fritschi, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Explosives contaminate millions of hectares from various sources (partial detonations, improper storage, and release from production and transport) that can be life-threatening, e.g., landmines and unexploded ordnance. Exposure to and uptake of explosives can also negatively impact plant health, and these factors can be can be remotely sensed. Stress induction was remotely sensed via a whole-plant hyperspectral imaging system as two genotypes of Zea mays, a drought-susceptible hybrid and a drought-tolerant hybrid, and a forage Sorghum bicolor were grown in a greenhouse with one control group, one group maintained at 60% soil field capacity, and a third exposed to …

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Machine Learning Methodology Review For Computational Electromagnetics, He Ming Yao, Lijun Jiang, Huan Huan Zhang, Wei E.I. Sha Aug 2019

Machine Learning Methodology Review For Computational Electromagnetics, He Ming Yao, Lijun Jiang, Huan Huan Zhang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

While machine learning is revolutionizing every corner of modern technologies, we have been attempting to explore whether machine learning methods could be used in computational electromagnetic (CEM). In this paper, five efforts in line with this direction are reviewed. They include forward methods such as the method of moments (MoM) solved by the artificial neural network training process, FDTD PML (perfectly matched layer) using the hyperbolic tangent basis function (HTBF), etc. There are also inverse problems that use the deep ConvNets for the effective source reconstruction and subwavelength imaging in the far-field. Benchmarks are provided to demonstrate the feasibility of …

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Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li Aug 2019

Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on developing high performance magnesium phosphate cement (MPC) composite bipolar plates for fuel cells. The MPC composite bipolar plates composed of MPC with partial replacement of fly ash as the binding matrix phase and multiple carbon-based materials (including graphite, carbon fiber and multi-walled carbon nanotubes) as the conductive phase. A simple hot-press process was applied to produce the MPC composite. After the optimization on the formula and the structure of the MPC composite and the processing parameters, all the US DOE 2015 technical targets, including electrical conductivity, flexural strength, corrosion resistance were …

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A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou Aug 2019

A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

A novel adaptive displacement-controlled test setup was developed for fatigue testing on mini specimens. In property characterization of additive manufacturing materials, mini specimens are preferred due to the specimen preparation, and manufacturing cost but mini specimens demonstrate higher fatigue strength than standard specimens due to the lower probability of material defects resulting in fatigue. In this study, a dual gauge section Krouse type mini specimen was designed to conduct fatigue tests on additively manufactured materials. The large surface area of the specimen with a constant stress distribution and increased control volume as the gauge section may capture all different types …

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A Framework Of Integrating Manufacturing Plants In Smart Grid Operation: Manufacturing Flexible Load Identification, Md. Monirul Islam, Zeyi Sun, Wenqing Hu, Cihan H. Dagli Aug 2019

A Framework Of Integrating Manufacturing Plants In Smart Grid Operation: Manufacturing Flexible Load Identification, Md. Monirul Islam, Zeyi Sun, Wenqing Hu, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

In the deregulated electricity markets run by Independent System Operator (ISO), a two-settlement (day-ahead and real-time) process is typically used to determine the electricity price to the end-use customers at different buses. In the day-ahead settlement, the demand is predicted at each bus based on the previous consumption behavior of the consumers and thus, Locational Marginal Price (LMP) can be determined and shared to the consumers. A significant gap is usually observed between the planned and real-time demands due to the uncertainties of the weather (temperature, wind-speed etc.), the intensity of business, and everyday activities. Therefore, a large price variation …

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Infrared Glass–Ceramics With Multidispersion And Gradient Refractive Index Attributes, Laura Sisken, Myungkoo Kang, Johann M. Veras, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Devon Mcclane, Cesar Blanco, Clara Rivero-Baleine, Theresa S. Mayer, Kathleen A. Richardson Aug 2019

Infrared Glass–Ceramics With Multidispersion And Gradient Refractive Index Attributes, Laura Sisken, Myungkoo Kang, Johann M. Veras, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Devon Mcclane, Cesar Blanco, Clara Rivero-Baleine, Theresa S. Mayer, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

Infrared (IR) glass–ceramics (GCs) hold the potential to dramatically expand the range of optical material solutions available for use in bulk and planar optical systems in the IR. Current material solutions are limited to single- or polycrystalline materials and traditional IR-transparent optical glasses. GCs that can be processed with spatial control and extent of induced crystallization present the opportunity to realize an effective refractive index variation, enabling arbitrary gradient refractive index elements with tailored optical function. This work discusses the role of the parent glass composition and morphology on nanocrystal phase formation in a multicomponent chalcogenide glass. Through a two-step …

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Ionic Conductivity Behavior By Activated Hopping Conductivity (Ahc) Of Barium Aluminoborosilicate Glass–Ceramic System Designed For Sofc Sealing, M. J. Da Silva, W. M. Pontuschka, J. F. Bartolomé, P. Jasinski, J. Karczewski, Signo Tadeu Dos Reis Aug 2019

Ionic Conductivity Behavior By Activated Hopping Conductivity (Ahc) Of Barium Aluminoborosilicate Glass–Ceramic System Designed For Sofc Sealing, M. J. Da Silva, W. M. Pontuschka, J. F. Bartolomé, P. Jasinski, J. Karczewski, Signo Tadeu Dos Reis

Materials Science and Engineering Faculty Research & Creative Works

Non-conducting BaO-B2O3 -Al2O3 -SiO2 parent glasses designed for solid oxide fuel cell (SOFC) sealing applications were prepared using the melt-quenching technique. The glass formation region was determined according to phase equilibrium relations and was found to be in the composition range 70BaO-(x) Al2O3 -(10−x) B2O3 -20SiO2 where 3.0 < x < 6.0 wt.%. The conductivity values obtained conductivity ranged from 10 −5 to 10 −10 S/cm at temperatures between 600 and 850 °C. The batch compositions presented a threshold of dc conductivity near 70BaO wt% with a quasi linear behavior with the decrease of the BaO content. Different values of conduction activation energy were observed at temperatures above the glass transition temperature (T g ) (up to 700 °C), which were attributed to the thermal bond-breaking of non-bridging oxygen (NBO) defects. The experimental results of the electrochemical characterization by impedance spectroscopy of glass–ceramic interfaces with yttria-stabilized zirconia (YSZ) acting as solid ionic conductor electrolyte are presented and discussed.

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Detection Of Sensor Attacks In Uncertain Stochastic Linear Systems, Chandreyee Bhowmick, S. Jagannathan Aug 2019

Detection Of Sensor Attacks In Uncertain Stochastic Linear Systems, Chandreyee Bhowmick, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel attack detection scheme is developed for linear discrete-time systems with unknown dynamics that are subject to the additive process and output measurements noise. A novel stochastic adaptive observer is proposed to estimate the state vector in the presence of noisy sensor measurements and uncertain dynamics, and also to generate the innovation signal to detect attacks using a modified $\chi2} $ detector. It has been shown that the innovation signal, which is defined as the difference between the measured and the estimated output from the observer, has a Gaussian distribution with non-zero mean. The modified $\chi^ {2} $ detector …

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Attack Detection In Linear Networked Control Systems By Using Learning Methodology, Haifeng Niu, A. Sahoo, C. Bhowmick, S. Jagannathan Aug 2019

Attack Detection In Linear Networked Control Systems By Using Learning Methodology, Haifeng Niu, A. Sahoo, C. Bhowmick, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel learning-based attack detection scheme for linear networked control systems (NCS) is introduced. The class of attacks considered here tends to increase network induced delays and packet losses which affects the physical system dynamics. For the network side, an adaptive observer is proposed to generate the attack detection residual, which in turn is utilized to determine the onset of an attack when it exceeds a predefined threshold. The uncertain stochastic physical system dynamics as a result of network-induced delays of packet losses require an optimal Q-learning based event-triggered controller that optimizes the control policy and the event-triggering instants simultaneously. …

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Fabrication And Characterization Of Alₓcrcufeni₂ High-Entropy Alloys Coatings By Laser Metal Deposition, Wenyuan Cui, Xinchang Zhang, Lan Li, Yitao Chen, Tan Pan, Frank W. Liou Aug 2019

Fabrication And Characterization Of Alₓcrcufeni₂ High-Entropy Alloys Coatings By Laser Metal Deposition, Wenyuan Cui, Xinchang Zhang, Lan Li, Yitao Chen, Tan Pan, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

High-entropy alloys (HEAs) are becoming new hot spots in the metallic materials community, which are defined to contain equiatomic or close-to-equiatomic compositions. HEAs can possess many interesting mechanical properties, and in particular, they have the great potential to be used as coating materials requiring high hardness and wear resistance. In this study, the feasibility of fabrication AlₓCrCuFeNi₂ (x=0,0.75) HEAs was investigated via laser metal deposition from elemental powders. The microstructure, phase structure, and hardness were studied by an optical microscope, scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), electron backscatter diffraction (EBSD) and Vickers hardness tester. The bonding between the …

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Predictive Model For Thermal And Stress Field In Selective Laser Melting Process -- Part Ii, Lan Li, Lei Yan, Yitao Chen, Tan Pan, Xinchang Zhang, Wenyuan Cui, Aaron Flood, Frank W. Liou Aug 2019

Predictive Model For Thermal And Stress Field In Selective Laser Melting Process -- Part Ii, Lan Li, Lei Yan, Yitao Chen, Tan Pan, Xinchang Zhang, Wenyuan Cui, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Finite Element Analysis (FEA) is used to predict the transient thermal cycle and optimize process parameters to analyze these effects on deformation and residual stresses. However, the process of predicting the thermal history in this process with the FEA method is usually time-consuming, especially for large-scale parts. In this paper, an effective predictive model of part deformation and residual stress was developed for accurately predicting deformation and residual stresses in large-scale parts. An equivalent body heat flux proposed from the single layer laser scan model was imported as the thermal load to the layer by layer model. The hatched layer …

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Action Recognition In Manufacturing Assembly Using Multimodal Sensor Fusion, Md. Al-Amin, Wenjin Tao, David Doell, Ravon Lingard, Zhaozheng Yin, Ming-Chuan Leu, Ruwen Qin Aug 2019

Action Recognition In Manufacturing Assembly Using Multimodal Sensor Fusion, Md. Al-Amin, Wenjin Tao, David Doell, Ravon Lingard, Zhaozheng Yin, Ming-Chuan Leu, Ruwen Qin

Computer Science Faculty Research & Creative Works

Production innovations are occurring faster than ever. Manufacturing workers thus need to frequently learn new methods and skills. In fast changing, largely uncertain production systems, manufacturers with the ability to comprehend workers' behavior and assess their operation performance in near real-time will achieve better performance than peers. Action recognition can serve this purpose. Despite that human action recognition has been an active field of study in machine learning, limited work has been done for recognizing worker actions in performing manufacturing tasks that involve complex, intricate operations. Using data captured by one sensor or a single type of sensor to recognize …

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Distributed Energy Storage System, Jonghyun Park, Mohammed Abdulkhabeer Al-Yasiri Jul 2019

Distributed Energy Storage System, Jonghyun Park, Mohammed Abdulkhabeer Al-Yasiri

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An energy storage system reaction cell configured for distribution throughout a transport system. The length of the reaction cell is substantially greater than its width and is looped throughout the transport system in a serpentine configuration. A membrane within the reaction cell has a length substantially equal to the length of the reaction cell such that surface area of the membrane is maximized relative to volume of the reaction cell to increase electrical power provided to an electrical load of the transport system.

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Braze For Ceramic And Ceramic Matrix Composite Components, Sean E. Landwehr, Scott Nelson, Jeremy Lee Watts, Greg Hilmas, William Fahrenholtz, Derek Scott King Jul 2019

Braze For Ceramic And Ceramic Matrix Composite Components, Sean E. Landwehr, Scott Nelson, Jeremy Lee Watts, Greg Hilmas, William Fahrenholtz, Derek Scott King

Materials Science and Engineering Faculty Research & Creative Works

In some examples, a technique may include positioning a first part comprising a ceramic or ceramic matrix composite and a second part comprising a ceramic or a CMC adjacent to each other to define a joint region at the interface of the first part and the second part. In some examples, the joint region may be heated using at least one of a laser or a plasma arc source to heat the joint region to an elevated temperature. The first and second parts may be pressed together and cooled to join the first and second parts at the joint region. …

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Methods Of Use And Manufacture Of Silver-Doped, Nano-Porous Hydroxyapatite, Cheol-Woon Kim, Richard K. Brow Jul 2019

Methods Of Use And Manufacture Of Silver-Doped, Nano-Porous Hydroxyapatite, Cheol-Woon Kim, Richard K. Brow

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A silver-doped, nano-porous hydroxyapatite material is provided that can be utilized to capture radioactive iodine, 129I. Methods of using the silver-doped, nano-porous hydroxyapatite material to remove radioactive iodine, and methods of manufacturing the material are also provided.

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Microwave Reflectometry For Physical Inspections, Mohammad Tayeb Ahmad Ghasr, R. Zoughi, Satyajeet Shinde, Sasi Jothibasu Jul 2019

Microwave Reflectometry For Physical Inspections, Mohammad Tayeb Ahmad Ghasr, R. Zoughi, Satyajeet Shinde, Sasi Jothibasu

Electrical and Computer Engineering Faculty Research & Creative Works

Utilizing microwave reflections to compare a reference device with counterfeit and/or aging devices under test. The reflection from the device under test varies based on certain properties, which results in each device having a unique and intrinsic electromagnetic signature. Comparisons of the electromagnetic signature of the device under test to the electromagnetic signature of a reference device enable evaluating the acceptability of the device under test.

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Interactions Of Bacteria With Monolithic Lateral Silicon Nanospikes Inside A Microfluidic Channel, Lei Li, Feng Tian, Hao Chang, Jie Zhang, Cheng Wang, Wei Rao, Huan Hu Jul 2019

Interactions Of Bacteria With Monolithic Lateral Silicon Nanospikes Inside A Microfluidic Channel, Lei Li, Feng Tian, Hao Chang, Jie Zhang, Cheng Wang, Wei Rao, Huan Hu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a new strategy of integrating lateral silicon nanospikes using metal-assisted chemical etching (MacEtch) on the sidewall of micropillars for on-chip bacterial study. Silicon nanospikes have been reported to be able to kill bacteria without using chemicals and offer a new route to kill bacteria and can prevent the overuse of antibiotics to reduce bacteria. We demonstrated a new methodology to fabricate a chip with integrated silicon nanospikes onto the sidewalls of micropillars inside the microfluidic channel and attested its interactions with the representative gram-negative bacteria Escherichia coli. The results of colony-forming unit (CFU) calculation showed that 80% …

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Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin Jul 2019

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti3C2Tx and Ti2CTx) with a SiO2 coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account …

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The Dependence Of Breakdown Field Upon Breakdown Delay Time In Adiabatically Compressed Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase Jul 2019

The Dependence Of Breakdown Field Upon Breakdown Delay Time In Adiabatically Compressed Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase

Mining Engineering Faculty Research & Creative Works

The ability of ferroelectric materials to generate high voltage under mechanical stress is widely used in transducer applications. The high strain-rate adiabatic compression of poled ferroelectrics results in their complete depolarization, the release of surface charges, and the generation of up to hundreds of kilovolts of electric potential that is an order of magnitude higher than in the low-strain piezoelectric mode. Electric breakdown within adiabatically compressed ferroelectric specimens is one of the factors that affect the generation of a high voltage by ferroelectric materials under extreme stress. We report herein the results of experimental investigations of the generation of high …

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The Blue Emission At 2.8 Ev In Strontium Titanate: Evidence For A Radiative Transition Of Self-Trapped Excitons From Unbound States, Miguel L. Crespillo, Joseph T. Graham, Fernando Agullo-Lopez, Y. Zhang, William J. Weber Jul 2019

The Blue Emission At 2.8 Ev In Strontium Titanate: Evidence For A Radiative Transition Of Self-Trapped Excitons From Unbound States, Miguel L. Crespillo, Joseph T. Graham, Fernando Agullo-Lopez, Y. Zhang, William J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The origin of the blue emission in SrTiO3 has been investigated as a function of irradiation fluence, electronic excitation density, and temperature using a range of ion energies and masses. The emission clearly does not show correlation with the concentration of vacancies generated by irradiation but is greatly enhanced under heavy-ion irradiation. The intensity ratio of the 2.8 and 2.5 eV bands is independent of fluence at all temperatures, but it increases with excitation rate. The 2.8 eV emission is proposed to correspond to a transition from conduction band states to the ground state level of the self-trapped exciton …

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Load Distribution Of A Prestressed Self-Consolidating Concrete Bridge, Eli S. Hernandez, John J. Myers Jul 2019

Load Distribution Of A Prestressed Self-Consolidating Concrete Bridge, Eli S. Hernandez, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bridge A7957 is the first Missouri Department of Transportation (MoDOT) large-scale project using self-consolidating concrete (SCC) and high-strength self-consolidating concrete (HS-SCC). The objective of this research was to monitor the initial in-service behavior of the precast-prestressed concrete primary elements of Bridge A7957 and to obtain the load distribution of the bridge using field and finite element models (FEM) data. An initial series of diagnostic load tests was conducted on the bridge superstructure. Embedded sensors recorded strain variations at different section of the instrumented girders for different load configurations. An automated total station (ATS) collected the vertical deflection of the girders …

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