Engineering Commons^™

Desorption From Hot Scandate Cathodes: Effects On Vacuum Device Interior Surfaces After Long-Term Operation, Mujan N. Seif, Thomas John Balk, Matthew J. Beck

Chemical and Materials Engineering Faculty Publications

Scandate cathodes have exhibited superior emission properties compared to current state-of-the-art “M-type” thermionic cathodes. However, their integration into vacuum devices is limited in part by a lack of knowledge regarding their functional lifespan and behavior during operation. Here, we consider thermal desorption from scandate cathodes by examining the distribution of material deposited on interior surfaces of a sealed vacuum device after ~26,000 h of cathode operation. XPS, EDS, and TEM analyses indicate that on the order of 1 wt.% of the initial impregnate is desorbed during a cathode’s lifetime, Ca does not desorb uniformly with time, and little to no …

3d Cfd Analysis Of Natural Ventilation In Reduced Scale Model Of Compost Bedded Pack Barn For Dairy Cows, Flávio A. Damasceno, Joseph L. Taraba, George B. Day V, Felipe A. O. Vega, Keller S. O. Rocha, Randi A. Black, Jeffrey M. Bewley, Carlos E. A. Oliveira, Matteo Barbari

Biosystems and Agricultural Engineering Faculty Publications

Compost bedded pack (CBP) barns have been receiving increased attention as an alternative housing system for dairy cattle. To create a satisfactory environment within CBP barns that promotes a good composting process, an adequate air movement and minimal temperature fluctuations throughout the building are required. Therefore, a study based on compost barn structure model employing techniques of dimensional analysis for naturally ventilated buildings was developed. Three-dimensional computational fluid dynamic (CFD) simulations of compost barns with different ridge designs and wind direction, along with the visual demonstration of the impact on airflow through structure were performed. The results showed that the …

Effects Of Laser Power And Substrate On The Raman Shift Of Carbon-Nanotube Papers, Fuqian Yang, Shanshan Wang, Yuling Zhang

Chemical and Materials Engineering Faculty Publications

The progress in the fabrication of carbon-nanotube-based structures has made it possible to use Raman spectroscopy to measure the deformation states of carbon nanotubes and abutting materials. In this work, we investigate the effects of laser power and surrounding materials on the Raman shift of carbon-nanotube (CNT) papers for the laser intensity in a range of 0.071 to 1.415 kW/mm² without action of mechanical loading. Two different configurations of the CNT papers are used in the Raman measurement; one uses a suspended CNT paper, and the other places a CNT paper on a glass or aluminum substrate. The experimental …

Cost Minimization Of Battery-Supercapacitor Hybrid Energy Storage For Hourly Dispatching Wind-Solar Hybrid Power System, Pranoy Roy, Jiangbiao He, Yuan Liao

Electrical and Computer Engineering Faculty Publications

This study demonstrates a dispatching scheme of wind-solar hybrid power system (WSHPS) for a one-hour dispatching period for an entire day utilizing battery and supercapacitor hybrid energy storage subsystem (HESS). A frequency management approach is deployed to extend the longevity of the batteries through extensively utilizing the high energy density property of batteries and the high power density property of supercapacitors in the HESS framework. A low-pass filter (LPF) is employed to decouple the power between a battery and a supercapacitor (SC). The cost optimization of the HESS is computed based on the time constant of the LPF through extensive …

Recent Advances In Reducing Food Losses In The Supply Chain Of Fresh Agricultural Produce, Daniel I. Onwude, Guangnan Chen, Nnanna Eke-Emezie, Abraham Kabutey, Al Fadhl Yahya Al Khaled, Barbara Sturm

Biosystems and Agricultural Engineering Faculty Publications

Fruits and vegetables are highly nutritious agricultural produce with tremendous human health benefits. They are also highly perishable and as such are easily susceptible to spoilage, leading to a reduction in quality attributes and induced food loss. Cold chain technologies have over the years been employed to reduce the quality loss of fruits and vegetables from farm to fork. However, a high amount of losses (≈50%) still occur during the packaging, transportation, and storage of these fresh agricultural produce. This study highlights the current state-of-the-art of various advanced tools employed to reducing the quality loss of fruits and vegetables during …

Atmospheric Measurements With Unmanned Aerial Systems (Uas), Marcelo I. Guzman

Chemistry Faculty Publications

This Special Issue provides the first literature collection focused on the development and implementation of unmanned aircraft systems (UAS) and their integration with sensors for atmospheric measurements on Earth. The research covered in the Special Issue combines chemical, physical, and meteorological measurements performed in field campaigns as well as conceptual and laboratory work. Useful examples for the development of platforms and autonomous systems for environmental studies are provided, which demonstrate how careful the operation of sensors aboard UAS must be to gather information for remote sensing in the atmosphere. The work serves as a key collection of articles to introduce …

Nmr Spectroscopy Analysis Reveals Differential Metabolic Responses In Arabidopsis Roots And Leaves Treated With A Cytokinesis Inhibitor, Thomas E. Wilkop, Minmin Wang, Angelo Heringer, Jaideep Singh, Florence Zakharov, Viswanathan V. Krishnan, Georgia Drakakaki

Physiology Faculty Publications

In plant cytokinesis, de novo formation of a cell plate evolving into the new cell wall partitions the cytoplasm of the dividing cell. In our earlier chemical genomics studies, we identified and characterized the small molecule endosidin-7, that specifically inhibits callose deposition at the cell plate, arresting late-stage cytokinesis in arabidopsis. Endosidin-7 has emerged as a very valuable tool for dissecting this essential plant process. To gain insights regarding its mode of action and the effects of cytokinesis inhibition on the overall plant response, we investigated the effect of endosidin-7 through a nuclear magnetic resonance spectroscopy (NMR) metabolomics approach. In …

An Overview Of Methods And A New Three-Dimensional Fea And Analytical Hybrid Technique For Calculating Ac Winding Losses In Pm Machines, Narges Taran, Dan M. Ionel, Vandana Rallabandi, Greg Heins, Dean Patterson

Power and Energy Institute of Kentucky Faculty Publications

This article proposes a new hybrid analytical and numerical finite element (FE) based method for calculating ac eddy current losses in wire windings and demonstrates its applicability for axial flux permanent magnet electric machines. The method takes into account three-dimensional (3-D) field effects in order to achieve accurate results and yet greatly reduce computational efforts. The new 3-D FE-based method is advantageous as it employs minimum simplifications and considers the end turns in the eddy current path, the magnetic flux density variation along the effective length of coils, and the field fringing and leakage, which ultimately increases the accuracy of …

A User Study Of A Wearable System To Enhance Bystanders’ Facial Privacy, Alfredo J. Perez, Sherali Zeadally, Scott Griffith, Luis Y. Matos Garcia, Jaouad A. Mouloud

Information Science Faculty Publications

The privacy of users and information are becoming increasingly important with the growth and pervasive use of mobile devices such as wearables, mobile phones, drones, and Internet of Things (IoT) devices. Today many of these mobile devices are equipped with cameras which enable users to take pictures and record videos anytime they need to do so. In many such cases, bystanders’ privacy is not a concern, and as a result, audio and video of bystanders are often captured without their consent. We present results from a user study in which 21 participants were asked to use a wearable system called …

Design Optimization And Comparison Of Direct-Drive Outer-Rotor Srms Based On Fast Current Profile Estimation And Transient Fea, Vandana Rallabandi, Peng Han, Jie Wu, Aaron M. Cramer, Dan M. Ionel, Ping Zhou

Power and Energy Institute of Kentucky Faculty Publications

Outer-rotor switched reluctance machines (SRMs) have drawn much attention as promising candidates for in-wheel direct-drive motors of future electric vehicles. This article presents a systematic performance comparison of three outer-rotor SRM topologies for in-wheel traction applications in terms of the specific torque, electromagnetic efficiency, torque ripple, radial force, and mechanical aspects. A generalized design optimization framework for SRMs is proposed to enable the fast evaluation of large numbers of designs generated from the differential evolution by incorporating an analytical current profile estimation into the transient finite element analysis. The relationship between the saliency ratio and converter volt-ampere rating is also …

Potential Of Zero Charge-Based Capacitive Deionization, Xin Gao, Ayokunle Omosebi, James Richardson Landon, Kunlei Liu

Center for Applied Energy Research Faculty Patents

The invention is a capacitive, aka electrostatic, deionization apparatus and method that solves the problem of short lifetime of conventional capacitive deionization (CDI) and of membrane capacitive deionization (MCDI) devices and methods by shifting the Potential of Zero Charge of electrode surfaces through surface modifications. Such electrode surface modifications provide very long lifetime capacitive deionization devices and methods.

Evaluation Of Bearing Voltage Reduction In Electric Machines By Using Insulated Shaft And Bearings, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Bearing voltages and corresponding currents in electric machines driven by pulse width modulation (PWM) converters with fast switching and high dv/dt can cause premature bearing failures. This paper evaluates the bearing voltage reduction by using insulated shafts and bearings. An equivalent circuit representation of electric machines taking into account high-frequency effects is developed to show the production mechanism of bearing voltage, based on which simulations are performed with detailed finite element models for transient and simplified equivalent circuit for steady-state analysis. The steady-state equivalent circuit is then calibrated, by combined numerical calculations and experimental measurements, and used to predict the …

Combined Numerical And Experimental Determination Of Ball Bearing Capacitances For Bearing Current Prediction, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel

Electrical and Computer Engineering Faculty Publications

High-frequency voltages across the steel ball bearings and the corresponding currents can cause premature bearing failures in electric machines driven by PWM converters. The bearing voltage, one of the most commonly-used failure indicators, depends heavily on the bearing capacitance. This paper presents a combined numerical and experimental approach for the calculation of ball bearing capacitances to address the uncertainty introduced by lubricant property, lubrication status and other metal parts, such as seals and ball retainers. Based on the obtained capacitance breakdown, the influences of temperature, speed and bearing load (radial, axial or combined) on the capacitance are studied. Measurements and …

Electric Drives With Wide Bandgap Devices For Two-Phase Very Low Inductance Machines, Yibin Zhang, Damien Lawhorn, Peng Han, Aaron M. Cramer, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Slotless and coreless machines with low inductance and low core losses are attractive for high speed and high power density applications. With the increase in fundamental frequency, typical drive implementations using conventional silicon-based devices are performance limited and also produce large current and torque ripples. This paper presents a systematic study of proposed drive configurations implemented with wide bandgap (WBG) devices in order to mitigate such issues for 2-phase very low inductance machines. Two inverter topologies, i.e., a dual H-bridge inverter with maximum redundancy and survivability and a 3-leg inverter for reduced cost, are considered. Feasible modulation schemes are derived …

Kentucky Traffic Collision Facts 2019, Eric R. Green, Paul A. Ross, Christopher L. Blackden, Michael A. Fields, Kenneth R. Agent

Kentucky Transportation Center Research Report

KENTUCKY’S TRAFFIC COLLISION FACTS report is based on collision reports submitted to the Kentucky State Police Records Branch. As required by Kentucky Revised Statutes 189.635:

“Every law enforcement agency whose officers investigate a vehicle accident of which a report must be made...shall file a report of the accident...within ten days after investigation of the accident upon forms supplied by the bureau.”

The stated purpose of this requirement is to utilize data on traffic collisions for such purposes as will improve the traffic safety program in the Commonwealth.

Cdl Data Quality Assessment, Valerie Keathley-Helil, Mallory Brown, Andrew Martin, Amir E. Najarzadeh, Brian K. Howell, Jennifer R. Walton

Kentucky Transportation Center Research Report

Quality issues related to commercial driver license (CDL) data present ongoing challenges to state and federal transportation agencies. This study highlights several problems with CDL data, including a lack of standardization for state-specific traffic infractions; process and workflow difficulties that degrade the accuracy, validity, and timeliness of data; adjudication procedures that can potentially mask serious violations from CDL driver history records; inadequate recordkeeping in state law enforcement citation and court case management software applications; outdated mainframe systems in urgent need of upgrades; IT personnel who are not paid enough; and insufficient reporting requirements for federal agencies that issue traffic citations. …

Optimal Study Of A High Specific Torque Vernier-Type Axial-Flux Pm Machine With Two Different Stators And A Single Winding, Murat G. Kesgin, Peng Han, Narges Taran, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

This paper presents the optimal study of a verniertype axial-flux permanent-magnet (AFPM) machine, which has a high-polarity spoke-type PM rotor, a wound stator with a low number of coils, and a profiled stator. Both stators have profiled teeth to enhance the magnetic interaction between the rotor PM array and stator windings for torque production. Compared to the topology with two wound stators, the studied one has a smaller total axial length and is expected more suitable for applications where the space is limited in axial direction. Both topologies are optimized through 3-dimensional (3D) finite element analysis (FEA) by the combined …

Demand Response Of Hvacs In Large Residential Communities Based On Experimental Developments, Huangjie Gong, Evan S. Jones, Rosemary E. Alden, Andrew G. Frye, Donald G. Colliver, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Heating, ventilation, and air-conditioning (HVAC) systems contribute the largest electricity usage for a residential community. Modeling of the HVAC systems facilitate the study of demand response (DR) at both the residential and the power system level. In this paper, the equivalent thermal model of a reference house was proposed. Parameters for the reference house were determined based on the systematic study of experimental data obtained from fully instrumented field demonstrators. The aggregated HVAC load was modeled based on the reference house while considering a realistic distribution of HVAC parameters derived from data that was provided by one of the largest …

Electric Power System Studies For A Multi-Mw Pv Farm And Large Rural Community With Net Zero Energy And Microgrid Capabilities, Evan S. Jones, Oluwaseun M. Akeyo, Keith Waters, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Solar photovoltaic (PV) systems are currently being deployed at an accelerated rate because of their cost-competitiveness and environmental benefits, which make them a prime candidate for local renewable energy generation in communities. Microgrids can help accommodate for the problems that accompany PV systems, such as intermittency due to weather, by coordinating different distributed energy resources (DERs), while islanded or by drawing power from the utility while in grid-connected mode. An islanding option is also important for resilience and grid fault mitigation, even if other DERs are not present within the system. This paper studies the potential benefits that a multi-MW …

Design Optimization Of Coreless Axial-Flux Pm Machines With Litz Wire And Pcb Stator Windings, Murat G. Kesgin, Peng Han, Narges Taran, Damien Lawhorn, Donovin Lewis, Dan M. Ionel

Electrical and Computer Engineering Faculty Publications

Coreless axial-flux permanent-magnet (AFPM) machines may be attractive options for high-speed and high-power-density applications due to the elimination of core losses. In order to make full use of the advantages offered by these machines and avoid excessive eddy current losses in windings, advanced technologies for winding conductors need to be employed to suppress the eddy effect, such as the Litz wire and printed circuit board (PCB). In this paper, the best practices for designing Litz wire/PCB windings are discussed and a brief survey of state of the art PCB winding technology is provided. Three coreless AFPM machines are mainly considered. …

Analysis Of Traffic Crash Data In Kentucky 2015-2019, Eric R. Green, Paul A. Ross, Christopher L. Blackden, Michael A. Fields, William Nicholas Staats

Kentucky Transportation Center Research Report

Executive Summary and Introduction

This report documents an analysis of traffic crash data in Kentucky. A primary objective of this study was to determine average crash statistics for Kentucky highways. Where used, rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.

Average and critical numbers, SPFs, and rates of crashes were calculated for various types of highways in rural and urban areas. These use crashes identified on highways where Annual Average Daily Traffic (AADT) volumes were available. The data in this report may be used to help identify problem areas. …

Determination Of Steels In Kentucky Bridges, Theodore Hopwood Ii, Christopher Goff, Sudhir Palle

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) maintains over two hundred steel bridges constructed with types of steel which are unknown. Kentucky Transportation Center (KTC) researchers have developed a procedure for determining steel tensile properties (0.2% yield strength and ultimate tensile strength) which can be used to help identify unknown steels. The procedure involves extracting small coupons from the lower flanges of steel deck girder bridges. Coupons are then machined into sub-sized tensile testing specimens and suitable shapes for chemical analyses. Sub-sized tensile tests returned values generally comparable to those provided in mill certifications of steels purchased for laboratory trials. Several analytical …

Rare Earth-Bearing Particles In Fly Ash Carbons: Examples From The Combustion Of Eastern Kentucky Coals, James C. Hower, John G. Groppo Jr.

Center for Applied Energy Research Faculty and Staff Publications

Graphitic carbons from the combustion of bituminous coals and, perhaps, other coal ranks, tend to capture iron and a number of hazardous elements, including As, Hg, and Se. Rare earth elements in fly ashes occur in minerals, such as monazite, xenotime, and davidite. They also occur in sub-nm particles, probably in a mineral form, within the Al–Si glass on the investigated fly ashes. Just as graphitic carbons can capture Fe and hazardous elements, the carbons surrounding the fly ash glass and magnetic particles captures or encapsulates a broad suite of rare earth elements.

Survey Of Dc-Dc Non-Isolated Topologies For Unidirectional Power Flow In Fuel Cell Vehicles, Mahajan Sagar Bhaskar, Vigna K. Ramachandaramurthy, Sanjeevikumar Padmanaban, Frede Blaabjerg, Dan M. Ionel, Massimo Mitolo, Dhafer Almakhles

Power and Energy Institute of Kentucky Faculty Publications

The automobile companies are focusing on recent technologies such as growing Hydrogen (H2) and Fuel Cell (FC) Vehicular Power Train (VPT) to improve the Tank-To-Wheel (TTW) efficiency. Benefits, the lower cost, `Eco' friendly, zero-emission and high-power capacity, etc. In the power train of fuel cell vehicles, the DC-DC power converters play a vital role to boost the fuel cell stack voltage. Hence, satisfy the demand of the motor and transmission in the vehicles. Several DC-DC converter topologies have proposed for various vehicular applications like fuel cell, battery, and renewable energy fed hybrid vehicles etc. Most cases, the DC-DC power converters …

Classifying Reflectance Targets Under Ambient Light Conditions Using Passive Spectral Measurements, Ali Hamidisepehr, Michael P. Sama, Joseph S. Dvorak, Ole O. Wendroth, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

Collecting remotely sensed spectral data under varying ambient light conditions is challenging. The objective of this study was to test the ability to classify grayscale targets observed by portable spectrometers under varying ambient light conditions. Two sets of spectrometers covering ultraviolet (UV), visible (VIS), and near−infrared (NIR) wavelengths were instrumented using an embedded computer. One set was uncalibrated and used to measure the raw intensity of light reflected from a target. The other set was calibrated and used to measure downwelling irradiance. Three ambient−light compensation methods that successively built upon each other were investigated. The default method used a variable …

100% Renewable Energy Grid For Rural Electrification Of Remote Areas: A Case Study In Jordan, Loiy Al-Ghussain, Mohammad Abujubbeh, Adnan Darwish Ahmad, Ahmad M. Abubaker, Onur Taylan, Murat Fahrioglu, Nelson K. Akafuah

Institute of Research for Technology Development Faculty Publications

Many developing countries suffer from high energy-import dependency and inadequate electrification of rural areas, which aggravates the poverty problem. In this work, Al-Tafilah in Jordan was considered as a case study, where the technical, economic, and environmental benefits of a decentralized hybrid renewable energy system that can match 100% of the city demand were investigated. A tri-hybrid system of wind, solar, and hydropower was integrated with an energy storage system and optimized to maximize the match between the energy demand and production profiles. The optimization aimed at maximizing the renewable energy system (RES) fraction while keeping the levelized cost of …

Measurement Of Three-Dimensional Welding Torch Orientation For Manual Arc Welding Process, Yuming Zhang, Weijie Zhang

Electrical and Computer Engineering Faculty Patents

Methods and systems are provided herein for measuring 3D apparatus (e.g., manual tool or tool accessory) orientation. Example implementations use an auto-nulling algorithm that incorporates a quaternion-based unscented Kalman filter. Example implementations use a miniature inertial measurement unit endowed with a tri-axis gyro and a tri-axis accelerometer. The auto-nulling algorithm serves as an in-line calibration procedure to compensate for the gyro drift, which has been verified to significantly improve the estimation accuracy in three-dimensions, especially in the heading estimation.

Lstm Forecasts For Smart Home Electricity Usage, Rosemary E. Alden, Huangjie Gong, Cristinel Ababei, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

With increasing of distributed energy resources deployment behind-the-meter and of the power system levels, more attention is being placed on electric load and generation forecasting or prediction for individual residences. While prediction with machine learning based approaches of aggregated power load, at the substation or community levels, has been relatively successful, the problem of prediction of power of individual houses remains a largely open problem. This problem is harder due to the increased variability and uncertainty in user consumption behavior, which make individual residence power traces be more erratic and less predictable. In this paper, we present an investigation of …

Lessons Learned From Six Different Structural Health Monitoring Systems On Highway Bridges, Abheetha Peiris, Charlie Sun, Issam E. Harik

Kentucky Transportation Center Faculty and Researcher Publications

Structural health monitoring has been utilized in numerous ways to investigate the performance and integrity of highway bridges. This paper highlights the use of six structural health monitoring systems, which were deployed to monitor distinct behaviors on six bridges in Kentucky. The structural health monitoring systems are as follows: (1) Over-height truck impact detection and monitoring on the I-64 over US 60 bridge, (2) Barge impact detection and monitoring on northbound US 41 over the Ohio River, (3) effectiveness of carbon fiber-reinforced polymer retrofit evaluation based on prestressed concrete I-girder crack movement on the I-65 elevated expressway in Louisville, (4) …

Crash Data Analysis Tool: Research Report + User Guide, Eric R. Green, Paul Ross

Kentucky Transportation Center Research Report

This manual describes the Crash Data Analysis Tool (CDAT), which can be used by KYTC staff and the agency’s work partners to securely access crash datasets. CDAT users can query and download data using flags stored during post-processing. Unlike KyOPS, however, CDAT’s location data are validated using geographic coordinates and several of county, route, and milepoint fields to ensure crashes are properly geocoded. CDAT grants access to data and information that can be used in conjunction with KYTC’s Data Driven Safety Analysis (DDSA) Implementation Guide to conduct highway safety analysis numerous KYTC processes. Historically, the Cabinet’s Division of Traffic Operations …