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 2251 - 2280 of 21777

Full-Text Articles in Engineering

Anti-Washout Concrete: An Overview, Hao Lu, Xiao Sun, Hongyan Ma Aug 2022

Anti-Washout Concrete: An Overview, Hao Lu, Xiao Sun, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Anti-washout concrete (AWC) is a special cement-based material that can be directly employed in underwater environments without dispersion. It was developed around 50 years ago, and more than 150 journal articles and technical reports have been published. This paper provides a holistic review about the basic fresh-state and hardened-state properties of the AWC, such as water (washout) resistance, consistency, bleeding and segregation resistance, mechanical properties, and durability, as well as relevant testing methods. The discrepancies between AWC's characteristics and those of conventional concrete are clearly presented. The mixture compositions, supplementary cementitious materials (SCMs), and other conditions that affect AWC's performance …

Go to article

Machine Learning Assisted High-Sensitivity And Large-Dynamic-Range Curvature Sensor Based On No-Core Fiber And Hollow-Core Fiber, Chen Zhu, Yiyang Zhuang, Jie Huang Aug 2022

Machine Learning Assisted High-Sensitivity And Large-Dynamic-Range Curvature Sensor Based On No-Core Fiber And Hollow-Core Fiber, Chen Zhu, Yiyang Zhuang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Simultaneously Increasing the Sensitivity and Dynamic Range of an Optical Fiber Sensor is Desired and Yet Challenging. in This Article, We Demonstrate an Optical Fiber Curvature Sensor based on a No-Core Fiber (NCF) Cascaded with a Hollow-Core Fiber (HCF), Realizing Simultaneously High Sensitivity and a Large Dynamic Range with the Assistance of Machine Learning Analysis. the Sensor is Fabricated by Simply Fusion Splicing a Section of NCF and HCF to Two Single-Mode Fibers (SMFs), Forming the SMF-NCF-HCF-SMF Hybrid Structure. It is Shown that the Multimode Interference in the NCF Can Increase the Sensitivity of the Device for Curvature Measurements, Compared …

Go to article

Sensitivity-Enhanced Fiber-Optic Sensor In A Microwave Photonics Fiber Loop Ringdown System, Chen Zhu, Yiyang Zhuang, Jie Huang Aug 2022

Sensitivity-Enhanced Fiber-Optic Sensor In A Microwave Photonics Fiber Loop Ringdown System, Chen Zhu, Yiyang Zhuang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In This Article We Report a Microwave Photonics Fiber Loop Ringdown (MWP-FLRD) Interrogated Fiber-Optic Sensor with Enhanced Sensitivity. a Section of a Single-Mode Fiber in the Fiber Loop is Macro-Bent into a Circular Ring as the Element Responsive to Displacement. When the Circular Ring is Subjected to External Displacement, the Transmission Loss of the Loop Changes, Resulting in a Change in the Ringdown Time of the MWP-FLRD System. to Enhance the Measurement Sensitivity, a Multi-Turn Structure is Proposed and Experimentally Demonstrated. Compared to the Traditional Time-Domain FLRD System, the MWP-FLRD System Employs a Frequency Domain Measurement, Showing a High Signal-To-Noise …

Go to article

Advancing Water Resource Assessment With Insar Data And Subsidence Models, Ryan G. Smith Aug 2022

Advancing Water Resource Assessment With Insar Data And Subsidence Models, Ryan G. Smith

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Over the past three decades, Interferometric Synthetic Aperture Radar (InSAR) has grown from a tool for monitoring earthquakes and other massive signature deformation events to tracking the subtle, slow deformation processes associated with changes in groundwater storage. Improvements in time-series processing and noise reduction, as well as improved models of deformation, have enabled this advancement. InSAR has proven to be a valuable tool for characterizing elastic deformation in regions experiencing little long-term storage loss, as well as inelastic deformation in over-stressed aquifers.

Go to article

The Use Of Gpr To Investigate The Effect Of Steel Fiber Distribution On The Mechanical Behavior Of Frc, Paola Machado Barreto Manhães, José Tavares Araruna Júnior, Genda Chen, Neil Lennart Anderson, Erik Valloti Pereira, Flávio De Andrade Silva Aug 2022

The Use Of Gpr To Investigate The Effect Of Steel Fiber Distribution On The Mechanical Behavior Of Frc, Paola Machado Barreto Manhães, José Tavares Araruna Júnior, Genda Chen, Neil Lennart Anderson, Erik Valloti Pereira, Flávio De Andrade Silva

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The present work focuses on the steel fiber distribution in self-consolidating concrete short beams. The objective is to assess the feasibility of the ground penetrating radar (GPR) in evaluating the homogeneity of fibers within concrete materials, for use in testing laboratories to study the modes of placing and compaction employed for preparing specimens during quality control or material development. Self-consolidating concrete beams were cast, tested, and evaluated. A GPR survey employing a concrete scanning system with a shielded 1.2 GHz center frequency was performed on self-consolidating casted short beams just before a monotonic four-point bending test was carried out. After …

Go to article

Two-Step Flotation And Reverse Flotation Circuits Of Iron Oxide And Its Process Minerology, Ying Hou, Song Lin, Guohui Fu, Zhuang Gai, Guang Yang, Ahmed Sobhy Aug 2022

Two-Step Flotation And Reverse Flotation Circuits Of Iron Oxide And Its Process Minerology, Ying Hou, Song Lin, Guohui Fu, Zhuang Gai, Guang Yang, Ahmed Sobhy

Mining Engineering Faculty Research & Creative Works

Mining operations usually provide ore of varying characteristics. Similarly, for Donganshan Sintering Plant, the charges in iron oxide ore especially prior flotation process were investigated by conducting mineral liberation analyzer “MLA”. This in-deep study of process mineralogy explored and analyzed the mechanism of difficulty to obtain high-efficient flotation process. The MLA analysis results showed also that the main useful minerals in this ore are magnetite/hematite, and the main gangue minerals is quartz, followed by chlorite and ankerite. In addition, two-step “direct then reverse” and one step “reverse” flotation experiments were carried out and produced iron oxide concentrates of 48.91% and …

Go to article

Nbt (No-Boundary Thinking): Needed To Attend To Ethical Implications Of Data And Ai, Joan Peckham, Andy Perkins, Tayo Obafemi-Ajayi, Xiuzhen Huang Aug 2022

Nbt (No-Boundary Thinking): Needed To Attend To Ethical Implications Of Data And Ai, Joan Peckham, Andy Perkins, Tayo Obafemi-Ajayi, Xiuzhen Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In this era of Big Data and AI, expertise in multiple aspects of data, computing, and the domains of application is needed. This calls for teams of experts with different training and perspectives. Because data analysis can have serious ethical implications, it is important that these teams are well and deeply integrated. No-Boundary Thinking (NBT) teams can provide support for team formation and maintenance, thereby attending to the many dimensions of the ethics of data and analysis. In this NBT workshop session, we discuss the ethical concerns that arise from the use of data and AI, and the implications for …

Go to article

Team Building Without Boundaries, Andy Perkins, Joan Peckham, Tayo Obafemi-Ajayi, Xiuzhen Huang Aug 2022

Team Building Without Boundaries, Andy Perkins, Joan Peckham, Tayo Obafemi-Ajayi, Xiuzhen Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Team building can be challenging when participants are from the same discipline or sub-discipline, but needs special attention when participants use a different vocabulary and have different cultural views on what constitutes viable problems and solutions. Essential to No Boundary Thinking (NBT) teams is proper formulation of the problem to be solved, and a basic tenant is that the NBT team must come together with diverse perspectives to decide the problem before solutions can be considered. Given that participants come with different views on problem formulation and solution, it is important to consider a robust process for team formation and …

Go to article

2022 Technical Program, Inspire - University Transportation Center Aug 2022

2022 Technical Program, Inspire - University Transportation Center

INSPIRE-UTC Annual Meetings

INSPIRE University Transportation Center 2022 Annual Meeting
August 1-2, 2022

Go to article

Llam-Mdcnet For Detecting Remote Sensing Images Of Dead Tree Clusters, Zongchen Li, Ruoli Yang, Weiwei Cai, Yongfei Xue, Yaowen Hu, Liujun Li Aug 2022

Llam-Mdcnet For Detecting Remote Sensing Images Of Dead Tree Clusters, Zongchen Li, Ruoli Yang, Weiwei Cai, Yongfei Xue, Yaowen Hu, Liujun Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Clusters of dead trees are forest fires-prone. To maintain ecological balance and realize its protection, timely detection of dead trees in forest remote sensing images using existing computer vision methods is of great significance. Remote sensing images captured by Unmanned aerial vehicles (UAVs) typically have several issues, e.g., mixed distribution of adjacent but different tree classes, interference of redundant information, and high differences in scales of dead tree clusters, making the detection of dead tree clusters much more challenging. Therefore, based on the Multipath dense composite network (MDCN), an object detection method called LLAM-MDCNet is proposed in this paper. First, …

Go to article

A Numerical Thermal Analysis Of A Battery Pack In An Electric Motorbike Application, Mohammad Shahjalal, Tamanna Shams, Sadat Bin Hossain, Probir Kumar Roy, Arafat Alam Jion, Mominul Ahsan, Jahedul Islam Chowdhury, Md Rishad Ahmed, Syed B. Alam, Julfikar Haider Aug 2022

A Numerical Thermal Analysis Of A Battery Pack In An Electric Motorbike Application, Mohammad Shahjalal, Tamanna Shams, Sadat Bin Hossain, Probir Kumar Roy, Arafat Alam Jion, Mominul Ahsan, Jahedul Islam Chowdhury, Md Rishad Ahmed, Syed B. Alam, Julfikar Haider

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Today, electric driven motorbikes (e-motorbikes) are facing multiple safety, functionality and operating challenges, particularly in hot climatic conditions. One of them is the increasing demand for efficient battery cooling to avoid the potential thermal stability concerns due to extreme temperatures and the conventional plastic enclosure of the battery pack. A reliable and efficient thermal design can be formulated by accommodating the battery within an appropriate battery housing supported by a cooling configuration. The proposed design includes a battery pack housing made of high conductive materials, such as copper (Cu) and aluminum (Al), with an adequate liquid cooling system. This study …

Go to article

Professional And Organizational Leadership Role In Ethics Management: Avoiding Reliance On Ethical Codification And Nurturing Ethical Culture, Islam H. El-Adaway, Marianne Jennings Aug 2022

Professional And Organizational Leadership Role In Ethics Management: Avoiding Reliance On Ethical Codification And Nurturing Ethical Culture, Islam H. El-Adaway, Marianne Jennings

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The engineering profession has experienced some ethical cases that were rarely reported, scrutinized, or discussed because: they did not necessarily represent violations of existing codes even if they breached ethical principles; those within the organization were not prepared to take steps to address the issues or impose sanction; an/or some of the personnel associated with these cases resorted to silence to avoid being labeled as trouble-makers in their organizations and, perhaps, more broadly, in society. The goal of this paper is to heighten managerial awareness of ethical issues, interrelated ethical lapses, and appropriate responsive actions within professional engineering communities. As …

Go to article

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan Aug 2022

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rockfalls and unstable slopes pose a serious threat to people and property along roads/highways in the southwestern mountainous regions of Saudi Arabia. In this study, the application of terrestrial light detection and ranging (LiDAR) technology was applied aiming to propose a strategy to analyze and accurately depict the detection of rockfall changes, calculation of rockfall volume, and evaluate rockfall hazards along the Habs Road, Jazan Region, Saudi Arabia. A series of temporal LiDAR scans were acquired at three selected sites. Our results show that these three sites have different degrees of hazard due to their geological differences. The mean volume …

Go to article

The Use Of Alkaline Co2 Solvent For The Co2 Curing Of Blast-Furnace Slag Mortar, Seong Ho Han, Yubin Jun, Jae Hong Kim Aug 2022

The Use Of Alkaline Co2 Solvent For The Co2 Curing Of Blast-Furnace Slag Mortar, Seong Ho Han, Yubin Jun, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Moving toward carbon neutrality in the construction industry involves utilizing CO2 to produce construction materials. CO2 curing of cement-based materials induces carbonation at an early age, which enhances strength and performance. A new process for the CO2 curing is proposed using CO2-dissolved curing water, which needs no massive CO2-gas chamber encasing cement-based materials in mild pressure. Gaseous CO2 was dissolved in 1 M aqueous KOH solution beforehand, and mortar samples made with ground-granulated blast furnace slag were submerged and cured. The CO2-water curing for 3 days carbonated the samples but …

Go to article

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan Aug 2022

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rockfalls and unstable slopes pose a serious threat to people and property along roads/highways in the southwestern mountainous regions of Saudi Arabia. In this study, the application of terrestrial light detection and ranging (LiDAR) technology was applied aiming to propose a strategy to analyze and accurately depict the detection of rockfall changes, calculation of rockfall volume, and evaluate rockfall hazards along the Habs Road, Jazan Region, Saudi Arabia. A series of temporal LiDAR scans were acquired at three selected sites. Our results show that these three sites have different degrees of hazard due to their geological differences. The mean volume …

Go to article

A Novel Approach To Estimate Rock Strength Parameters From Multistage Triaxial Tests (The A-Has Method), Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Munir Aldin, Sudarshan Govindarajan Aug 2022

A Novel Approach To Estimate Rock Strength Parameters From Multistage Triaxial Tests (The A-Has Method), Abo Taleb T. Al-Hameedi, Husam H. Alkinani, Shari Dunn-Norman, Munir Aldin, Sudarshan Govindarajan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rock strength parameters are vital to creating robust geomechanical models for wellbore stability, sand production, and hydraulic fracturing. Static rock strength parameters can be estimated from single stage triaxial tests (SST) or multistage triaxial tests (MST). Although SST tests are the most accurate way to estimate rock strength parameters, SST tests require at least four to five core plugs to estimate rock strength parameters. Thus, MST tests are used as an alternative method to estimate rock strength parameters from only one core plug to overcome the limitation of materials and save time and money. However, the currently used method to …

Go to article

Enhanced Supervised Descent Learning Technique For Electromagnetic Inverse Scattering Problems By The Deep Convolutional Neural Networks, He Ming Yao, Rui Guo, Maokun Li, Lijun Jiang, Michael Kwok Po Ng Aug 2022

Enhanced Supervised Descent Learning Technique For Electromagnetic Inverse Scattering Problems By The Deep Convolutional Neural Networks, He Ming Yao, Rui Guo, Maokun Li, Lijun Jiang, Michael Kwok Po Ng

Electrical and Computer Engineering Faculty Research & Creative Works

This work proposes a novel deep learning (DL) framework to solve the electromagnetic inverse scattering (EMIS) problems. The proposed framework integrates the complex-valued deep convolutional neural network (DConvNet) into the supervised descent method (SDM) to realize both off-line training and on-line 'imaging' prediction for EMIS. The offline training consists of two parts: 1) DConvNet training: the training dataset is created, and the proposed DConvNet is trained to realize the EM forward process and 2) SDM training: the trained DConvNet is integrated into the SDM framework, and the average descent directions between the initial prediction and the true label of SDM …

Go to article

Huber Kalman Filter For Wi-Fi Based Vehicle Driver's Respiration Detection, Yang Yang, Yunlong Luo, Alex Qi, Ge Shi, Miao Miao, Jun Fan, Jianhua Ma, Yihong Qi Aug 2022

Huber Kalman Filter For Wi-Fi Based Vehicle Driver's Respiration Detection, Yang Yang, Yunlong Luo, Alex Qi, Ge Shi, Miao Miao, Jun Fan, Jianhua Ma, Yihong Qi

Electrical and Computer Engineering Faculty Research & Creative Works

The use of breath detection in vehicles can reduce the number of vehicular accidents caused by drivers in poor physical condition. Prior studies of contactless respiration detection mainly targeted a static person. However, there are emerging applications to sense a driver, with emphasis on contactless methods. For example, being able to detect a driver's respiration while driving by using a vehicular Wi-Fi system can significantly enhance driving safety. The sensing system can be mounted on the back of the driver's seat, and it can sense the tiny chest displacement of the driver via Wi-Fi signals. The body displacement and car …

Go to article

Coupled Effect Of Fiber And Granular Skeleton Characteristics On Packing Density Of Fiber-Aggregate Mixtures, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat Aug 2022

Coupled Effect Of Fiber And Granular Skeleton Characteristics On Packing Density Of Fiber-Aggregate Mixtures, Naimeh Nouri, Masoud Hosseinpoor, Ammar Yahia, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The addition of fiber to cementitious materials enhances mechanical performance but can reduce workability of the fiber-reinforced concrete (FRC) mixtures. This can be due to the negative effect of fibers on packing density (PD) of the fiber-coarse aggregate (F-A) combination. The performance of FRC, as a diphasic suspension, is dependent on the characteristics of both F-A (suspended-solid skeleton) and mortar (suspending liquid) phases. PD can reflect the voids within the F-A skeleton to be filled with mortar. An adequate optimization of the characteristics of the F-A skeleton can modify the performance of FRC in fresh and hardened states. The F-A …

Go to article

Optimization Of High-Speed Channel For Signal Integrity With Deep Genetic Algorithm, Huan Huan Zhang, Zhao Sheng Xue, Xin Yi Liu, Ping Li, Lijun Jiang, Guang Ming Shi Aug 2022

Optimization Of High-Speed Channel For Signal Integrity With Deep Genetic Algorithm, Huan Huan Zhang, Zhao Sheng Xue, Xin Yi Liu, Ping Li, Lijun Jiang, Guang Ming Shi

Electrical and Computer Engineering Faculty Research & Creative Works

A deep genetic algorithm (GA) is proposed to optimize the high-speed channel for signal integrity. In the traditional genetic algorithm-based high-speed channel optimization method, the eye height and eye width of the eye diagram are obtained by eye diagram simulation based on the full-wave algorithm, which is computationally expensive. In this letter, a deep neural network (DNN) is trained to predict the eye diagram information corresponding to a set of given design parameters of the high-speed channel. This DNN is embedded into the genetic algorithm to carry out the evaluation operation, which can greatly accelerate the evaluation process. A high-speed …

Go to article

Estimation Of Coal Density Using A 3d Imaging System: Rhovol, F. Nakhaei, Q. P. Campbell, M. Le Roux, S. Botlhoko Aug 2022

Estimation Of Coal Density Using A 3d Imaging System: Rhovol, F. Nakhaei, Q. P. Campbell, M. Le Roux, S. Botlhoko

Mining Engineering Faculty Research & Creative Works

The results of coal sink and float tests are plotted as washability curves. Analysis of these curves indicates the most effective method by which the coal can be cleaned. Sink and float experiments are sampling-dependent, destructive, and use toxic chemicals. The present research introduces an alternative method based on a 3D imaging system called RhoVol, in which the density of individual particles is determined from mass and volume measurements. A quantitative error analysis was conducted on coal sample density measurements obtained by RhoVol, and the main factors influencing the errors identified and investigated. The results show that the drawback of …

Go to article

Advances In Energy Hybridization For Resilient Supply: A Sustainable Approach To The Growing World Demand, Haider Al-Rubaye, Joseph D. Smith, Mohammed H.S. Zangana, Prashant Nagapurkar, Yishu Zhou, Gregory M. Gelles Aug 2022

Advances In Energy Hybridization For Resilient Supply: A Sustainable Approach To The Growing World Demand, Haider Al-Rubaye, Joseph D. Smith, Mohammed H.S. Zangana, Prashant Nagapurkar, Yishu Zhou, Gregory M. Gelles

Chemical and Biochemical Engineering Faculty Research & Creative Works

Energy poverty, defined as a lack of access to reliable electricity and reliance on traditional biomass resources for cooking, affects over a billion people daily. The World Health Organization estimates that household air pollution from inefficient stoves causes more premature deaths than malaria, tuberculosis, and HIV/AIDS. Increasing demand for energy has led to dramatic increases in emissions. The need for reliable electricity and limiting emissions drives research on Resilient Hybrid Energy Systems (RHESs), which provide cleaner energy through combining wind, solar, and biomass energy with traditional fossil energy, increasing production efficiency and reliability and reducing generating costs and emissions. Microgrids …

Go to article

Elevated Temperature Thermal Properties Of Zrb2-B4c Ceramics, Eric W. Neuman, Matthew Thompson, William Fahrenholtz, Gregory E. Hilmas Aug 2022

Elevated Temperature Thermal Properties Of Zrb2-B4c Ceramics, Eric W. Neuman, Matthew Thompson, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The elevated temperature thermal properties of zirconium diboride ceramics containing boron carbide additions of up to 15 vol% were investigated using a combined experimental and modeling approach. The addition of B4C led to a decrease in the ZrB2 grain size from 22 µm for nominally pure ZrB2 to 5.4 µm for ZrB2 containing 15 vol% B4C. The measured room temperature thermal conductivity decreased from 93 W/m·K for nominally pure ZrB2 to 80 W/m·K for ZrB2 containing 15 vol% B4C. The thermal conductivity also decreased as temperature increased. For nominally pure ZrB2, the thermal conductivity was 67 W/m·K at 2000 °C …

Go to article

Transient Response Of Esd Protection Devices For A High-Speed I/O Interface, Jianchi Zhou, Yang Xu, Sergej Bub, Steffen Holland, Javad Soleiman Meiguni, David Pommerenke, Daryl G. Beetner Aug 2022

Transient Response Of Esd Protection Devices For A High-Speed I/O Interface, Jianchi Zhou, Yang Xu, Sergej Bub, Steffen Holland, Javad Soleiman Meiguni, David Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

System-efficient electrostatic discharge (ESD) design (SEED) models of a diode and transient voltage suppressor (TVS) were developed to study their transient response in a high-speed input/output interface. Previously reported SEED models were improved to strengthen their convergence stability and facilitate accurate predictions over a wide range of conditions. These improvements were required to accurately capture the race conditions between the TVS and on-chip diode, where the diode's turn on may prevent turn on of the TVS. Simulations and measurements were performed to demonstrate the impact of the ESD pulse's rise time on race conditions. During a race, results showed the …

Go to article

Superhard Single-Phase (Ti,Cr)B2 Ceramics, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Laura Silvestroni Aug 2022

Superhard Single-Phase (Ti,Cr)B2 Ceramics, Lun Feng, William Fahrenholtz, Gregory E. Hilmas, Laura Silvestroni

Materials Science and Engineering Faculty Research & Creative Works

A nominally pure and dense (Ti0.9Cr0.1)B2 ceramic was produced by spark plasma sintering of powders synthesized by boro/carbothermal reduction of oxides. The synthesized powders were a single phase and had an average particle of 0.4 ± 0.1 μm and an oxygen content of 1.2 wt%. Average Vickers hardness values of the resulting ceramics increased from 25.9 ± 0.8 GPa at a load of 9.81 N, to 46.3 ± 0.8 GPa at a load of 0.49 N. Compared to the nominally pure TiB2 ceramic obtained under the same processing conditions, the (Ti0.9Cr0.1)B2 ceramic had higher values under the same load due …

Go to article

Quantifying The Workability Of Calcium Sulfoaluminate Cement Paste Using Time-Dependent Rheology, Sukanta K. Mondal, Adam Welz, Carrie Clinton, Kamal Khayat, Aditya Kumar, Monday Uchenna Okoronkwo Aug 2022

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

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

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

Go to article

Source Reconstruction Of Electronic Circuits In Shielding Enclosures Based On Numerical Green's Function And Application In Electromagnetic Interference Estimation, Zi An Wang, Zhi Fei Xiao, Jun Fa Mao, Li (Lijun) Jun Jiang, Hakan Bagci, Ping Li Aug 2022

Source Reconstruction Of Electronic Circuits In Shielding Enclosures Based On Numerical Green's Function And Application In Electromagnetic Interference Estimation, Zi An Wang, Zhi Fei Xiao, Jun Fa Mao, Li (Lijun) Jun Jiang, Hakan Bagci, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, to characterize the radiated emission from electronic circuits in shielding enclosure, an improved electric dipole-based source reconstruction method (SRM) is developed. Moreover, by resorting to this reconstructed equivalent source, the estimation of electromagnetic interference (EMI) between different circuit modules in the enclosure can be conveniently and accurately evaluated. Different from the free-space SRM, the equivalent dipoles of the proposed SRM are directly placed over the shielding box enclosed circuit board, and the numerical Green's function (NGF) is developed to bridge the connection between the equivalent dipoles and the planar scanned magnetic near-field. With the NGF strategy, the …

Go to article

A Millimeter-Wave Frequency-Reconfigurable Fabry-Pérot Cavity Antenna, Min Li, Muhammad Yasir Jamal, Xiaoqiang Li, Kwan Lawrence Yeung, Lijun Jiang, Tatsuo Itoh, Ross Murch Aug 2022

A Millimeter-Wave Frequency-Reconfigurable Fabry-Pérot Cavity Antenna, Min Li, Muhammad Yasir Jamal, Xiaoqiang Li, Kwan Lawrence Yeung, Lijun Jiang, Tatsuo Itoh, Ross Murch

Electrical and Computer Engineering Faculty Research & Creative Works

This letter introduces a method for implementing a frequency-reconfigurable Fabry-Pérot cavity (FPC) antenna utilizing polarization standing waves (PSWs). The PSW is supported by two metasurfaces (MSs) at cavity ends. The resonant condition allows the antenna to have frequency-reconfigurable characteristic by mechanically rotating the top MS around the center and relative to the bottom MS, without adjusting the physical dimension. The antenna is prototyped at 60 GHz for millimeter-wave applications. Simulated and measured results demonstrate that a tunable frequency range of 60.8-66.2 GHz with a maximum boresight gain of around 22.2 dBi can be attained, verifying the antenna concept.

Go to article

Analytical Method For Joint Optimization Of Ffe And Dfe Equalizations For Multi-Level Signals, Nana Dikhaminjia, Mikheil Tsiklauri, Zurab Kiguradze, Jiayi He, Arun Chada, Bhyrav Mutnury, James L. Drewniak Aug 2022

Analytical Method For Joint Optimization Of Ffe And Dfe Equalizations For Multi-Level Signals, Nana Dikhaminjia, Mikheil Tsiklauri, Zurab Kiguradze, Jiayi He, Arun Chada, Bhyrav Mutnury, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Channel equalization is the efficient method for recovering distorted signal and correspondingly reducing bit error rate (BER). Different type of equalizations, like feed forward equalization (FFE) and decision feedback equalization (DFE) are canceling channel effect and recovering channel response. Separate optimization of tap coefficients for FFE and DFE does not give optimal result. In this case FFE and DFE tap coefficients are found separately and they are not collaborating. Therefore, the final equalization result is not global optimal. In the present paper new analytical method for finding best tap coefficients for FFE and DFE joint equalization is introduced. The proposed …

Go to article

A Spice-Compatible Model To Simulate Rfi-Induced Buzz Noise Problem In A Camera, Wei Zhang, Shengxuan Xia, Xin Fang, Xu Wang, Takashi Enomoto, Hideki Shumiya, Kenji Araki, Chulsoon Hwang Aug 2022

A Spice-Compatible Model To Simulate Rfi-Induced Buzz Noise Problem In A Camera, Wei Zhang, Shengxuan Xia, Xin Fang, Xu Wang, Takashi Enomoto, Hideki Shumiya, Kenji Araki, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposed a SPICE-compatible model to fast simulate the buzz noise problem in a camera device. Based on the reciprocity theorem, the proposed SPICE-compatible model consists of cascaded scattering (S) parameters extracted from the field coupling. It can provide an accurate estimation of the buzz noise transfer function (TFtotal) between the radio-frequency antenna and the audio system within an average error of 1 dB. Besides, the proposed model allows for coupling decomposition by separating the audio system into different regions, fast buzz noise mitigation by adding filtering circuits, and fast antenna evaluation/selection by characterizing the TFtotal with different antenna …

Go to article

First Prev Next Last