Engineering Commons^™

Dual Light Emission Of Cssni3-Based Powders Synthesized Via A Mechanochemical Process, Xuan Huang, Xiaobing Tang, Xiyu Wen, Yuebin Charles Lu, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Lead toxicity has hindered the wide applications of lead halide perovskites in optoelec- tronics and bioimaging. A significant amount of effort has been made to synthesize lead-free halide perovskites as alternatives to lead halide perovskites. In this work, we demonstrate the feasibility of synthesizing CsSnI3-based powders mechanochemically with dual light emissions under ambi- ent conditions from CsI and SnI2 powders. The formed CsSnI3-based powders are divided into CsSnI3-dominated powders and CsSnI3-contained powders. Under the excitation of ultraviolet light of 365 nm in wavelength, the CsSnI3-dominated powders emit green light with a wavelength centered at 540 nm, and the CsSnI3-contained powders …

Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe

Markey Cancer Center Faculty Publications

Werner syndrome (WS) is an autosomal recessive disease caused by loss of function of WRN. WS is a segmental progeroid disease and shows early onset or increased frequency of many characteristics of normal aging. WRN possesses helicase, annealing, strand exchange, and exonuclease activities and acts on a variety of DNA substrates, even complex replication and re- combination intermediates. Here, we review the genetics, biochemistry, and probably physiological functions of the WRN protein. Although its precise role is unclear, evidence suggests WRN plays a role in pathways that respond to replication stress and maintain genome stability particularly in telomeric regions.

Best Practices For Maintenance Of Traffic On Interstate Pavement Rehabilitation Projects, Catherine Keathley, Ryan Griffith, Rachel Catchings

Kentucky Transportation Center Research Report

Across the United States, aging roadway infrastructure has led state departments of transportation (DOTs) to increase their focus on pavement rehabilitation projects. These projects upgrade existing infrastructure to meet the needs of current levels of vehicle use. On interstate rehabilitation projects, maintenance of traffic (MOT) is an especially important consideration. Having a good MOT plan for completing construction work is critical for maintaining facility capacity while ensuring the safety of the traveling public and roadway construction staff. This study explores on behalf of the Kentucky Transportation Cabinet (KYTC) best practices for MOT on interstate pavement rehabilitation projects. Based on a …

Accommodating Innovative Uses Of Public Right Of Way, Travis Thompson, David Moses, Candice Wallace, Pam Clay-Young, Arlen Sandlin

Kentucky Transportation Center Research Report

State departments of transportation (DOTs) are embracing the use of clean energy and connectivity (CEC) applications along publicly owned right of way (ROW). Applications such as wind and solar power installations, broadband lines, small cell wireless equipment, electric vehicle charging stations, and technologies related to connected and automated vehicles (CAVs) hold considerable promise for conferring environmental benefits, energy savings, and generating much-needed revenue for DOTs. This report explores innovative uses of state-owned ROW that the Kentucky Transportation Cabinet (KYTC) could implement. Although Kentucky may not be currently situated for all clean energy applications, opportunities in solar do currently exist and …

Development Of A Sms Rollout Plan And Evaluation, Gabriel Dadi, Hala Nassereddine, Farshid Taherpour, Salena Pham

Kentucky Transportation Center Research Report

Many state transportation agencies have introduced safety management systems (SMSs) to improve employee safety and health programs. These systems let employees quickly access safety and health policies, procedures, training, responsibilities, resources, and incident reporting tools, often electronically. Instituting a SMS is a critical step in adopting a proactive, data-driven approach to organizational safety. The Kentucky Transportation Cabinet Secretary’s Office of Safety (SOS) worked with Kentucky Transportation Center (KTC) to acquire, adapt, and rollout the Boosting Occupational Outcomes in Transportation Safety (BOOTS) system, a new SMS. Researchers assisted KYTC by conducting pre-rollout focus groups, helping to bring the system online, providing …

Using Knowledge Of Human Factors To Strengthen Highway Design, Chris Van Dyke, Jeff Jasper, Jill Asher, Steve Waddle

Kentucky Transportation Center Research Report

Transportation practitioners recognize that leveraging knowledge of human factors in road design is critical for delivering safe mobility to the full spectrum of multimodal road users (motorists, pedestrians, micromobility users, transit users). Understanding how psychology, cognition, and behavioral tendencies shape the ways in which different road users interact with one another and the road environment itself is critical for creating design solutions that promote safe and efficient movement. NCHRP Report 600 (Human Factors Guidelines for Road Systems) provides guidance on integrating knowledge of human factors into design practice. While the report is a valuable resource, it appears to …

Coordinated Controls Of Residential Ev Chargers Considering High Power Appliances, Steven B. Poore, Rosemary E. Alden, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

In addition to electric vehicle (EV) adoption, the electricity demand of the modern grid is also under change from the replacement of resistive electric water heaters (EWHs) with high-efficiency heat pump electric water heaters (HPWH). Typical load of a HPWH has two parts: a low power compressor and a backup high power resistive boosting element. Within this paper, residential load from a large field demonstration for over one thousand homes is simulated in virtual power plant (VPP) operation with realistic HPWH and EV synthetic modules based on big data from the latest CBECC-Res and National Household Travel Survey (NHTS). Simultaneous …

Comparative Analysis Of Motors With Inner And Outer Reluctance Rotors And Pm Stators, Oluwaseun A. Badewa, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents a comparison of special outer and inner reluctance rotor motor topologies with permanent magnet (PM) stators having toroidal AC windings. A systematic approach is taken to study and discuss the design geometries, the respective impact on performance, and adoption of technological advancements such as stator-only cooling and hair-pin winding for high slot fill factor. Parametric FEA models are developed for both topologies, and design of experiments (DoE)-based sensitivity analysis is used to study the effect of independent variables on specific performance metrics such as torque, motor loss, torque ripple, and power factor. Inner and outer rotor topologies …

Sensorless Control Of Low Inductance Coreless Afpm Machines For Fault-Tolerant Operation Of Propulsion Systems, Yaser Chulaee, Ali Mohammadi, Aaron M. Cramer, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

In motor-drive systems utilized in safety-critical applications and demanding conditions like electric aircraft propulsion systems, the reliability of the system is greatly affected by position sensors, given their susceptibility within the motor drive system. Consequently, there is a need to eliminate sensors in vector-controlled motor drives to decrease overall hardware complexity and expenses, bolster the mechanical durability and dependability of the drive system. In this paper, a fault-tolerant sensorless control system for low inductance coreless axial flux PM (AFPM) machines, integrated into electric aircraft propulsion systems, is introduced. The proposed control system spans a wide operating range, from zero to …

Fault-Tolerant Axial Flux Coreless Pm Machines With Independent Phase Modules, Yaser Chulaee, Ali Mohammadi, Dan M. Ionel, Matin Vatani

Electrical and Computer Engineering Graduate Research

In this paper, a fault-tolerant two-phase high power coreless axial flux PM (AFPM) machine with a modular structure is introduced. The performance of this machine, in terms of torque, power density, and efficiency, is compared with its three-phase counterpart configuration based on finite element analysis (FEA) and experimental results. The fault tolerance of these two configurations, considering the control systems, is also compared. A detailed power loss breakdown for the prototype two-phase and three-phase printed circuit board (PCB) stator coreless AFPM machines derived from experiments is presented, showcasing that the introduced fault-tolerant two-phase machine has comparable performance and efficiency, while …

High-Power Polyphase Pcb-Type Inductive Coupler For Wireless Electric Vehicle Charging, Donovin D. Lewis, Omer Onar, Lucas Gastineau, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

The cost and manufacturing difficulty of traditionally wound coils for wireless charging of electric vehicles has led to the exploration of alternative manufacturing for scalable deployment at a range of rated powers. A rotating-field polyphase wireless coupler is developed with balanced fully pitched coils which are not possible with conventional Litz wire. The usage of printed circuit board (PCB) technology is proposed for the innovative construction at large dimensions due to reduced cost, increased ease of manufacturability, and potential geometric customization compared to would coils. Design considerations specific to PCBs are detailed for wireless power transfer coils including advantages such …

Comparative Analysis Of Vernier Machines With Spoke, Surface Mounted, And Halbach Pm Rotors For In-Wheel Traction, Ali Mohammadi, Aaron M. Cramer, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Axial-flux Permanent Magnet (AFPM) machines are well-suited for in-wheel traction in electric vehicles due to their compact structure and higher torque density. This paper presents a large-scale design optimization of an axial-flux permanent magnet vernier machine (PMVM) of the MAGNUS type with a double stator configuration. The active stator features double layer wound coils, while the passive stator is unwound but has a similar profile. The reference design employs a rotor with permanent magnets (PMs) arranged in a spoke-type field intensifying pattern, providing high flux concentration. Design optimization was performed using 3-D electromagnetic Finite Element Analysis (FEA) and the Differential …

On The Optimal Design Of Coreless Afpm Machines With Halbach Array Rotors For Electric Aircraft Propulsion, Matin Vatani, Yaser Chulaee, Ali Mohammadi, David R. Stewart, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents and evaluates the optimal design of a coreless axial flux permanent magnet (AFPM) motor for electric aircraft propulsion. Ferromagnetic cores are entirely removed from the machine’s structure to improve the specific power density and efficiency. An approach for envelope design optimization of the proposed motor is introduced, considering the polarity as an independent variable and employing an evolutionary algorithm and 3D Finite Element Analysis (FEA). In addition to the proposed electric motor’s electromagnetic performance, fault-tolerant capability and thermal management are considered in the optimization procedure. The optimization results and similar studies from power electronic and thermal management …

Ultra‐Fast Finite Element Analysis Of Coreless Axial Flux Permanent Magnet Synchronous Machines, Yaser Chulaee, Dan Ionel

Power and Energy Institute of Kentucky Faculty Publications

Large‐scale design optimisation techniques enable the design of high‐performance electric machines. Electromagnetic 3D finite element analysis (FEA) is typically employed in optimisation studies for accurate analysis of axial flux permanent magnet(AFPM) machines, which require extensive computational resources. To reduce the computational burden, a FEA‐based mathematical method relying on the geometric and magnetic symmetry of coreless AFPM machines is proposed to estimate the machine performance indicators using the least number of FEA solutions, thereby significantly lowering the running time. This method is generally applicable to AFPM machines with low saturation effects and cogging torque as exemplified for a printed circuit board …

Design Optimization Of A Direct-Drive Wind Generator With A Reluctance Rotor And A Flux Intensifying Stator Using Different Pm Types, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Donovin D. Lewis, Somasundaram Essakiappan, Madhav Manjrekar, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

This paper presents a large-scale multi-objective design optimization for a direct-drive wind turbine generator concept that is based upon an experimentally validated computational model for a small-scale prototype motor of the same type. By integrating an outer reluctance-type rotor and a segmented stator with toroidally wound single-coil modules containing spoke-type PMs, the design optimization aims to minimize losses, active mass, and torque ripple while adhering to a power factor constraint. The AC windings and PMs are positioned in the stator and this concept enhances flux concentration, enabling the use of more affordable high energy non-rare-earth (special type) magnets. The exterior …

Free And Forced Vibrations Of Elastically Restrained Cantilever With Lumped Oscillator, Alireza Babaei, Johné Parker, Paria Moshaver

Earth and Environmental Sciences Faculty Publications

The efficiency assessment of cantilever-based energy harvesters relies on vibrational analysis, which necessitates modi- fications aimed at enhancing efficiency. These modifications involve manipulating the fundamental frequency to lower values and encompassing a wider range of resonances within a specified bandwidth. Consequently, this paper introduces an original analytical-numerical exploration into the vibratory response of a cantilever with a novel boundary condi- tion involving an elastically restrained oscillator-spring arrangement. At the microbeam’s tip, an oscillator is elastically confined by a linear spring, resulting in a novel set of coupled governing equations and a distinct shearing boundary condition. Microbeam equations is derived from …

Developing Guidelines For The Use Of Lightweight Materials In Culvert Preservation, Charlie Sun, Kean H. Ashurst Jr.

Kentucky Transportation Center Research Report

This study addresses challenges that arise during highway embankment construction on road widening projects when additional fill is placed above existing culverts. Researchers conducted reduced-scale model laboratory tests to simulate culvert behavior under different loading conditions and to determine how well lightweight materials (LWMs) perform when subjected to changing loads. Testing showed that proximity of LWM to the culvert’s top surface strongly influences the magnitude of strain reductions or increases. Placing LWMs with relatively low elastic modulus closer to the culvert’s top surface led to reduced culvert ceiling strain and increased culvert wall strain. LWMs with relatively high elastic modulus …

Addressing Multimodal Transportation Needs Through Complete Streets Implementation, Eirini Stavropoulou, Nikiforos Stamatiadis, William Staats, Teng Wang, Reginald Souleyrette

Kentucky Transportation Center Research Report

Since the early 2000s, over 1,600 transportation agencies in the United States have adopted Complete Streets policies. Recently, the Kentucky Transportation Cabinet (KYTC) published its Complete Streets, Roads, and Highways Manual, which aims to implement a safe and equitable transportation system throughout the state, as well as a Complete Streets policy. The manual and policy offer guidance on integrating Complete Streets principles into road design, however, KYTC currently lacks tools or methods to evaluate how well specific projects address Complete Streets goals. This is problematic because systematic assessments are needed to effectively prioritize projects and allocate scarce funding. Based …

Estimation Of Benefits From Pedestrian And Bicycle Improvements, Dionysios Tzamakos, Nikiforos Stamatiadis, William Staats, Teng Wang, Reginald Souleyrette

Kentucky Transportation Center Research Report

Delivering safe mobility for all users of the transportation system is a key priority of the Kentucky Transportation Cabinet (KYTC). Because many system users rely on pedestrian and bicycle facilities, it is critical for KYTC to balance pedestrian and bicycle facility accommodations with those for motorized users. Currently, the Strategic Highway Investment Formula for Tomorrow (SHIFT) — the Cabinet’s systematic approach to scoring and prioritizing proposed roadway projects — awards up to five points (out of a possible total of 100) for pedestrian and bicycle projects. But the agency lacks a robust method for estimating the benefits of pedestrian and …

Balancing Environmental Clearances With Construction Work Zone Needs, Chris Van Dyke, Steve Waddle, Ying Li

Kentucky Transportation Center Research Report

On small, single-span bridge projects (< 100 feet), the Kentucky Transportation Cabinet (KYTC) during project development works to establish an environmentally clear area (ECA) large enough to accommodate contractor operations. An adequately sized ECA gives contractors sufficient room to have materials delivered, park vehicles, store materials, and maneuver equipment around the project site (e.g., cranes, drill rig). If a contractor finds an ECA is too small to support their operations, they are responsible for obtaining additional environmental clearances. Clearing additional areas following the project award can slow down project delivery. To reduce the likelihood of contractors needing to enlarge an ECA, this report includes four documents KYTC can implement immediately to streamline and clarify the environmental clearances process. They include a checklist that project managers can use to coordinate the work of project team members and verify environmental clearances are on track, a combined environmental clearances workflow and best practices document for use by environmental subject-matter experts (SMEs), proposed language that can be inserted into project proposals that describes the environmental clearance process and specifies materials the Cabinet will hand off to contractors showing the location of the ECA, and a one-page explainer for contractors describing the environmental clearances process. Taken together, these deliverables emphasize the importance of early and ongoing coordination among project team members, clearing as much area as practical in and around bridges, and being transparent with contractors about their responsibilities.

Effects Of Ferrite And Graphite Phases On Scratch Characteristics Of Nodular Cast Iron, Zhitong Xu, Ming Liu, Chenghui Gao, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this work, we conduct micro-scratch tests of nodular cast iron with Vickers indenter under constant normal load and investigate the effects of individual phases (i.e., ferrite and graphite phases) on the scratch charac- teristics of nodular cast iron. Using a bimodal Gaussian model to fit the experimental data of penetration depth, residual depth, elastic recovery rate, and scratch hardness, we calculate the contribution percentages of indi- vidual phases to scratch variables. The scratch variables are independent of the scratch speed used in this work, while the penetration depth increases linearly with increasing the normal load. There exists a large …

A Mechanical Model For Stress Relaxation Of Polylactic Acid/Thermoplastic Polyurethane Blends, Yi-Sheng Jhao, Hao Ouyang, Chien-Chao Huang, Fuqian Yang, Sanboh Lee

Chemical and Materials Engineering Faculty Publications

Polylactic acid (PLA) is considered a promising biodegradable polymer alternative. Due to its high brittleness, composite materials made by melt blending thermoplastic polyurethane (TPU) with PLA can enhance the toughness of PLA. To understand the forced aging caused by stress relaxation in polymer materials, this study explains the stress relaxation experiments of PLA/TPU blends with different mass ratios under applied strain through mechanical model simulations. The Kelvin representation of the standard linear solid model (SLSM) is used to analyze the stress relaxation data of TPU/PLA blends, successfully explaining that the Young’s moduli (E1 and E2) of springs decrease with increasing …

Rethinking Wind In Kentucky, Lawrence E. Holloway, Aron Patrick, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Recent analyses and developments suggest that wind energy could play a role in Kentucky's future power generation mix. This recent change in outlook for Kentucky wind has been driven by three factors: (1) improved wind turbine technologies, (2) improved economics, and (3) recent analyses showing improved grid reliability due to wind's complementarity to solar power generation.

Guidebook For Project Management, Jill Asher, Keith Caudill, Travis Thompson, Jeff Jasper, Chris Van Dyke, Samantha Wright, Bryan Gibson, Pam Clay-Young, Candice Wallace

Kentucky Transportation Center Research Report

For the Kentucky Transportation Cabinet’s (KYTC) Department of Highways, project development encompasses all the work activities needed to move a transportation project from concept and project initiation to construction letting. Developing projects efficiently requires the adoption of sound project management practices. Although KYTC has a long track record of executing complex projects, doing so is increasingly challenging due to staff attrition and the attendant loss of institutional knowledge. Today’s entry- and mid-level project managers have more responsibilities than ever but lack a trusted source of guidance to help them manage projects from development through completion. The objective of this study …

Reducing Vehicle Licensing And Titling Fraud, Mallory Brown, Andrew Martin, Jeeyen Koo, Jennifer Walton

Kentucky Transportation Center Research Report

This study reviews Kentucky’s vehicle licensing and registration program, evaluates methods of motor vehicle title fraud, examines current anti-fraud mechanisms in Kentucky, reports on vehicle titling and anti-fraud efforts in other states, assesses Ohio’s vehicle inspection program, and develops a proposal for a new Kentucky rebuilt title inspection program. Researchers developed the proposal based on historical Kentucky vehicle registration and titling data, a survey of other states, and other information provided by Kentucky’s Division of Motor Vehicle Licensing and other agency partners. Kentucky historical data revealed consistently high numbers of salvage title applications as well as spatial concentration in rebuilt …

Shorting At Long Duration: Impact Of Extended Discharge Capacity On Battery Solid Electrolytes, Ryan C. Hill, Amanda S. Peretti, Leo J. Small, Erik D. Spoerke, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

Long-duration energy storage (LDES) is critical to a stable, resilient, and decarbonized electric grid. While batteries are emerging as important LDES devices, extended, high-power discharges necessary for cost-competitive LDES present new materials challenges. Focusing on a new generation of low-temperature molten sodium batteries, we explore here unique phenomena related to long-duration discharge through a well-known solid electrolyte, NaSICON. Specifically, molten sodium symmetric cells at 110 ° C were cycled at 0.1 A cm−2 for 1–23 h discharges. Longer discharges led to unstable overpotentials, reduced resistances, and decreased electrolyte strength, caused by massive sodium penetration not observed in shorter duration discharges. …

Western Science And Eastern Zen To Seek The Origin Of Truth: Philosophical Background Of Scale Modeling, Kozo Saito

Progress in Scale Modeling, an International Journal

This article was written to introduce philosophical background of scale modeling, where Zen philosophy was applied to overcome the limitation of logical thinking and hypotheses-driven deductive science. Three specific reasons are as follows. The first is related to the law approach in scale modeling; it uses the kufu principle, originated in Zen Buddhism, together with the other three scientific methods: experimental, theoretical, and computational. The second reason is because scale modeling seeks relativistic understanding by attempting to realize similarity; the concept is closer to Eastern philosophy rather than absolute understanding cultivated by deductive science. The third is in the educational …

Online Instructional Tools For Motor Carriers, Brian Howell, Jennifer Walton, Paul Ross, Andrew Martin

Kentucky Transportation Center Research Report

Commercial motor carrier customers on Kentucky highways must register and pay taxes for licensing and credentialing requirements. The Kentucky Transportation Cabinet (KYTC) provides an online Motor Carrier Portal that offers information and instructions on meeting these requirements, but customers have increasingly resorted to calling into KYTC’s motor carrier help desk, thereby straining limited personnel resources. The Kentucky Transportation Center (KTC) coordinated with KYTC to develop a series of online instructional videos that can better assist customers with applying for and meeting credentialing requirements.

KTC researchers used a three-phase approach to determine the feasibility and requirements for instructional videos. First, they …

Impact Of The New Context Functional Classifications For Kytc, Arlen Sandlin, Jill Asher, Nikiforos Stamatiadis, Jeff Jasper, Rachel Catchings, Chris Van Dyke

Kentucky Transportation Center Research Report

State transportation agencies are adopting an expanded context classification system to inform project development and delivery. This system classifies roadways into one of five categories based on factors such as level of development, building densities and setbacks, multimodal user patterns and requirements, network permeability, and speed. Compared to functional classification, context classification better captures the types of mobility, travel patterns, and user mixes observed in specific contexts. The expanded context classification system is found in AASHTO’s A Policy on Geometric Design of Highways and Streets (7^th Edition). The forthcoming 8^th edition will deepen integration of context classification throughout …

Pl 43 Traffic Forecasting Report 2023, Mei Chen, Xu Zhang, Eugene Antwi

Kentucky Transportation Center Research Report

This document is the seventh edition of the Traffic Forecasting Report (TFR) for the state of Kentucky. TFR data are important for multiple engineering applications that involve analyzing temporal and spatial variability in traffic distributions and volumes. Most of the metrics discussed in the report were computed using data from 2019, 2021, and 2022 — excluded from consideration were 2020 data because they exhibited anomalous traffic patterns tied to shutdowns associated with the COVID-19 pandemic. Data summarized in this report include average daily traffic, annual average daily truck traffic, travel activity by vehicle type, weekday and weekend hourly volume percentages, …