Engineering Commons^™

Fast Diffusion Of Silver In Tio2 Nanotube Arrays, Wanggang Zhang, Yiming Liu, Diaoyu Zhou, Hui Wang, Wei Liang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

Using magnetron sputtering and heat treatment, Ag@TiO₂ nanotubes are prepared. The effects of heat-treatment temperature and heating time on the evolution of Ag nanofilms on the surface of TiO₂ nanotubes and microstructure of Ag nanofilms are investigated by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Ag atoms migrate mainly on the outmost surface of the TiO₂ nanotubes, and fast diffusion of Ag atoms is observed. The diffusivity for the diffusion of Ag atoms on the outmost surface of the TiO₂ nanotubes at 400 °C is 6.87 × 10⁻¹⁸ m²/s, …

2016 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green, Michael A. Fields

Kentucky Transportation Center Research Report

The use of safety belts and child safety seats is a proven means of reducing injuries to motor vehicle occupants involved in traffic crashes. There have been various methods used in efforts to increase safety belt and safety seat usage. Past efforts have included public information campaigns, local and statewide legislation, and enforcement of the legislation.

The objective of the survey summarized in this report was to establish a statewide safety belt usage rate in Kentucky for 2016. This rate can be compared to those determined from previous surveys. The 2016 statewide survey documents the continued increase in usage associated …

Synthesis Of Kentucky’S Traveler Information Systems, Christopher W. Van Dyke, Jennifer R. Walton, James Ballinger

Kentucky Transportation Center Research Report

After the United States Department of Transportation (USDOT) petitioned the Federal Communications Commission (FCC) to establish a dedicated phone number for real-time travel information services, the abbreviated 511 dialing code was founded in July 2000. The FCC reasoned that 511 services could reduce traffic congestion, air pollution, and the inefficient use of fossil fuels. 511 would, in turn, improve traveler safety. In 2010, the Federal Highway Administration (FHWA) mandated a set of requirements for systems that deliver real-time traffic information to the public. States DOTs were asked to comply with this mandate by November 2014. Many states, in addition to …

Self-Similar Random Process And Chaotic Behavior In Serrated Flow Of High Entropy Alloys, Shuying Chen, Liping Yu, Jingli Ren, Xie Xie, Xueping Li, Ying Xu, Guangfeng Zhao, Peizhen Li, Fuqian Yang, Yang Ren, Peter K. Liaw

Chemical and Materials Engineering Faculty Publications

The statistical and dynamic analyses of the serrated-flow behavior in the nanoindentation of a high-entropy alloy, Al_0.5CoCrCuFeNi, at various holding times and temperatures, are performed to reveal the hidden order associated with the seemingly-irregular intermittent flow. Two distinct types of dynamics are identified in the high-entropy alloy, which are based on the chaotic time-series, approximate entropy, fractal dimension, and Hurst exponent. The dynamic plastic behavior at both room temperature and 200 °C exhibits a positive Lyapunov exponent, suggesting that the underlying dynamics is chaotic. The fractal dimension of the indentation depth increases with the increase of temperature, and …

The Confounding Effects Of Particle Size And Substrate Bulk Density On Phanerochaete Chrysosporium Pretreatment On Panicum Virgatum, Amanda N. Hickman, Sue E. Nokes, William S. Sympson, Mathew J. Ruwaya, Michael D. Montross, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

Phanerochaete chrysosporium treatment is less effective as a biological pretreatment on feedstock with larger particle sizes. We hypothesized that the improved effectiveness of the pretreatment when smaller particle sizes are used may be due to the inherently higher bulk density with smaller particle sizes. The effects of substrate bulk density and particle size on the efficacy of P. chrysosporium pretreatment of switchgrass (Panicum virgatum) was tested experimentally. Phanerochaete chrysosporium was grown on senesced switchgrass (2 different particle sizes) with various bulk densities. In all treatments, the fungal-pretreated samples released more glucose during enzymatic saccharification than the control sample. …

Large-Scale Optimization Of Synchronous Reluctance Machines Using Ce-Fea And Differential Evolution, Yi Wang, Dan M. Ionel, Vandana Rallabandi, Minjie Jiang, Steven Stretz

Power and Energy Institute of Kentucky Faculty Publications

A novel automated design optimization procedure based on the application of an ultrafast computationally efficient finite-element analysis (CE-FEA) for current-regulated synchronous reluctance machines supplied from power electronic converters is proposed. The CE-FEA uses only a minimum number of magnetostatic solutions in order to comprehensively evaluate performance, including ripple torque and core losses. The optimization algorithm is based on differential evolution, and uses as independent variables the torque angle and ratios for a generic rotor topology with four flux barriers. Two problems, one with two and the other with three objectives, are studied and results are compared. Global performance indices and …

Physicochemical And Functional Properties Of Extruded Sorghum‐Based Bean Analog, Akinbode A. Adedeji, Michael V. Joseph, Brian Platter, Sajid Alavi

Biosystems and Agricultural Engineering Faculty Publications

The objective of this study was to develop and evaluate the physicochemical and functional properties of a bean like product made from cold extrusion of sorghum, soy and wheat flours. Formulated samples comprised of sorghum (25–70%), wheat (0–35%) and soy (30–50%) flours. The degree of gelatinization ranged from 54.1 to 93.6%. Pasting curves showed minimal starch damage with peak and final viscosities in the range of 456.0–1138.5 and 297–584 cP, respectively. Textural properties of the extrudates were significantly impacted by starch content and cooking time. There was significant cooking loss due to poor binding properties of the extrudates. Cooking the …

Estimation Of Average Daily Traffic On Local Roads In Kentucky, Reginald R. Souleyrette, Brian K. Howell, Eric R. Green, William Nicholas Staats

Kentucky Transportation Center Research Report

Kentucky Transportation Cabinet (KYTC) officials use annual average daily traffic (AADT) to estimate intersection performance across the state maintained highway system. KYTC currently collects AADTs for state maintained roads but frequently lacks this information on local roads. A method is needed to estimate local road AADTs in a cost-effective and reasonable manner. Kentucky Transportation Center (KTC) researchers conducted a literature review on U.S. AADT models but found that none of them were suitable to Kentucky. Therefore, KTC developed an AADT model using non-linear regression to estimate AADTs on approaches to those intersections.

KTC developed a Poisson distributed, non-linear regression model …

Development Of An Improved Method For Determining Advisory Speeds On Horizontal Curves, Eric R. Green, Kenneth R. Agent, Erin Lammers-Staats

Kentucky Transportation Center Research Report

Horizontal curves are an integral part of the highway alignment. However, a disproportionately high number of severe crashes occur on them. One method transportation agencies use to reduce the number crashes at horizontal curves is the installation of curve warning signs which post an appropriate advisory speed. Appropriate curve advisory speeds can be determined using several methods. Some of these methods are time-consuming to perform and are error-prone. The purpose of this research was to find the most efficient and accurate data collection method for determining curve advisory speeds. Several processes were developed and tested. They were then validated against …

Green Synthesis Nanocomposite Membranes, Dibakar Bhattacharyya, Vasile Smuleac, Rajender S. Varma, Subhas K. Sikdar

Chemical and Materials Engineering Faculty Patents

A nanocomposite membrane includes a macroporous polymer membrane having a plurality of pores. A plurality of metal nanoparticles are synthesized and immobilized within those plurality of pores. The nanoparticles are reduced and capped with a green reducing and capping agent such as green tea extract.

On-Farm Integrated High-Solids Processing System For Biomass, Sue E. Nokes, Bert C. Lynn, Stephen E. Rankin, Barbara L. Knutson, Michael D. Montross, Michael D. Flythe

Biosystems and Agricultural Engineering Faculty Patents

A method for on-farm processing a biomass feedstock into a useful industrial chemicals includes the steps of (a) delignifying the biomass feedstock to produce a delignified biomass, (b) subjecting the deliguified biomass to cellulase production, (c) subjecting the deliguified biomass with attached cellulase to simultaneous cellulolytic and solventogenic reactions to produce useful industrial chemicals (d) collecting and separating the useful industrial chemical from the fermentation broth and (e) collecting the fermentation residues.

Simultaneous Metal-Insulator And Antiferromagnetic Transitions In Orthorhombic Perovskite Iridate Sr0.94Ir0.78O2.68 Single Crystals, Hao Zheng, Jsaminka Terzic, Feng Ye, X. G. Wan, D. Wang, Jinchen Wang, Xiaoping Wang, P. Schlottmann, Shujuan Yuan, Gang Cao

Center for Advanced Materials Faculty Publications

The orthorhombic perovskite SrIrO₃ is a semimetal, an intriguing exception in iridates where the strong spin-orbit interaction coupled with electron correlations tends to impose an insulating state. We report results of our investigation of bulk single-crystal S_r0.94Ir_0.78O_2.68 or Ir-deficient, orthorhombic perovskite SrIrO₃. It retains the same crystal structure as stoichiometric SrIrO₃ but exhibits a sharp, simultaneous antiferromagnetic (AFM) and metal-insulator (MI) transition occurring in the basal-plane resistivity at 185 K. Above it, the basal-plane resistivity features an extended regime of almost linear temperature dependence up to 800 K but the strong …

Observation Of Metallic Surface States In The Strongly Correlated Kitaev-Heisenberg Candidate Na2Iro3, Nasser Alidoust, Chang Liu, Su-Yang Xu, Ilya Belopolski, Tongfei Qi, Minggang Zeng, Daniel S. Sanchez, Hao Zheng, Guang Bian, Madhab Neupane, Yu-Tzu Liu, Stephen D. Wilson, Hsin Lin, Arun Bansil, Gang Cao, M. Zahid Hasan

Center for Advanced Materials Faculty Publications

We report high-resolution angle-resolved photoemission spectroscopy measurements on the honeycomb iridate Na₂IrO₃. Our measurements reveal the existence of a metallic surface band feature crossing the Fermi level with nearly linear dispersion and an estimated surface carrier density of 3.2 x 10¹³ cm^-2, which has not been theoretically predicted or experimentally observed, and provides the first evidence for metallic behavior on the boundary of this material, whereas the bulk bands exhibit a robust insulating gap. We further show the lack of theoretically predicted Dirac cones at the M¯ points of the surface Brillouin …

Evolution Of The Automotive Body Coating Process—A Review, Nelson K. Akafuah, Sadegh Poozesh, Ahmad Salaimeh, Gabriela Patrick, Kevin Lawler, Kozo Saito

Mechanical Engineering Faculty Publications

Automotive coatings and the processes used to coat automobile surfaces exemplify the avant-garde of technologies that are capable of producing durable surfaces, exceeding customers’ expectations of appearance, maximizing efficiency, and meeting environmental regulations. These accomplishments are rooted in 100 years of experience, trial-and-error approaches, technique and technology advancements, and theoretical assessments. Because of advancements directed at understanding the how, why, when, and where of automobile coatings, the progress in controlling droplets and their deposition attributes, and the development of new technologies and paint chemistries, a comprehensive and up-to-date review of automobile coatings and coating technologies was considered to be of …

Anisotropic Softening Of Magnetic Excitations In Lightly Electron-Doped Sr2Iro4, X. Liu, M. P. M. Dean, Z. Y. Meng, M. H. Upton, T. Qi, T. Gog, Y. Cao, J. Q. Lin, D. Meyers, H. Ding, Gang Cao, J. P. Hill

Center for Advanced Materials Faculty Publications

The magnetic excitations in electron-doped (Sr_1−xLa_x)₂IrO₄ with x = 0.03 were measured using resonant inelastic x-ray scattering at the Ir L₃ edge. Although much broadened, well defined dispersive magnetic excitations were observed. Comparing with the magnetic dispersion from the undoped compound, the evolution of the magnetic excitations upon doping is highly anisotropic. Along the antinodal direction, the dispersion is almost intact. On the other hand, the magnetic excitations along the nodal direction show significant softening. These results establish the presence of strong magnetic correlations in electron-doped (Sr_1−xLa_{x …}

Aqueous Photochemistry Of Glyoxylic Acid, Alexis J. Eugene, Sha-Sha Xia, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging …

Microstructural Properties And Four-Point Bend Fatigue Behavior Of Ti-6.5al-2zr-1mo-1v Welded Joints By Electron Beam Welding, Peng Liu, Tongguang Zhai, Yuanbin Zhang

Chemical and Materials Engineering Faculty Publications

With the help of a four-point-bend of fatigue rig, high-cycle fatigue tests were carried out on an Ti–6.5Al–2Zr-1Mo-1V titanium alloy at room temperature, 20 Hz and R = 0.1 in ambient air. The test results indicated that the fatigue strength of base metal, 888 MPa, is about 120% of yield strength. The fatigue strength of joints is 814 MPa. It is about 110% of yield strength of base metal. When the loading stress is higher, the fatigue failure region is located in middle weld zone of weld face, which the cracks are propagated along coarse β phase’s grain boundary. When …

Evaluation Of Alternatives To Provide Wet-Nighttime Delineation, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to compare the performance of various types of materials, devices, and procedures that can potentially delineate roadways during wet, nighttime conditions. Snowplowable markers provide the most effective wet-nighttime delineation. Durability issues associated with the steel casting marker make the recessed marker preferable over the life of the pavement. Wet reflective tape placed in a groove provided both dry and wet-nighttime delineation and remained durable. The performance of thermoplastic material installed on the pavement surface supports its future use but will not provide wet-nighttime delineation. Inconsistent performance of inlaid tape argues against its expanded use. …

Cost Benefit Analysis: Applications And Future Opportunities, Bryan Gibson, Candice Y. Wallace

Kentucky Transportation Center Research Report

Cost Benefit Analysis (CBA or Benefit Cost Analysis — BCA) is an evaluation tool that state transportation agencies can use to compare infrastructure project options across transportation modes and gauge if the discounted value of benefits exceed the costs. CBA lets policymakers compare alternative project proposals to a baseline scenario, or status quo case, under which no investments are made. CBA is used to select which proposal is the most sensible investment—ideally, the project that maximizes benefits while minimizing costs should be chosen. As the use of CBA to evaluate projects and grant applications (e.g., TIGER Discretionary Grants) continues to …

Evaluation Of The Use Of Painted And Unpainted Weathering Steel On Bridges, Theodore Hopwood Ii, Sudhir Palle, Bobby W. Meade, Rick Younce

Kentucky Transportation Center Research Report

KTC researchers studied the use of unpainted weathering steel on bridges, using findings of inspections performed on Kentucky Transportation Cabinet (KYTC) bridges constructed with both painted and unpainted weathering steel as well as laboratory testing. Laboratory tests were conducted on test panels of conventional and weathering grades of steel to determine the performance of barrier and zinc-based coatings over abrasive-blasted substrates of those steel types in both the new and corroded conditions. The report provides the following recommendations for the use of painted and unpainted weathering steel on Kentucky bridges based upon both the field and laboratory findings:

• KYTC should …

Size Effect On The Magnetic Phase In Sr4Ru3O10, Yan Liu, Jiyong Yang, Weike Wang, Haifeng Du, Wei Ning, Langsheng Ling, Wei Tong, Zhe Qu, Zhaorong Yang, Minling Tian, Gang Cao, Yuheng Zhang

Center for Advanced Materials Faculty Publications

High quality Sr₄Ru₃O₁₀ nanoflakes are obtained by the scotch tape-based micro-mechanical exfoliation method. The metamagnetic transition temperature T_m^flake is found to decrease in line with the decrease of thickness, while the ferromagnetic (FM) phase, the ordinary, and anomalous Hall effects (OHE and AHE) are independent on the thickness of the flake. Analysis of the data demonstrates that the AHE reflects the FM nature of Sr₄Ru₃O₁₀, and the decrease of thickness favors the Ru moments aligned in the ab-plane, which induces a decrease of the metamagnetic transition …

Cardiac Remodeling And Dysfunction In Childhood Obesity: A Cardiovascular Magnetic Resonance Study, Linyuan Jing, Cassi M. Binkley, Jonathan D. Suever, Nivedita Umasankar, Christopher M. Haggerty, Jennifer Rich, Christopher D. Nevius, Gregory J. Wehner, Sean M. Hamlet, David K. Powell, Aurelia Radulescu, H. Lester Kirchner, Frederick H. Epstein, Brandon K. Fornwalt

Pediatrics Faculty Publications

Background: Obesity affects nearly one in five children and is associated with increased risk of premature death. Obesity-related heart disease contributes to premature death. We aimed to use cardiovascular magnetic resonance (CMR) to comprehensively characterize the changes in cardiac geometry and function in obese children.

Methods and results: Forty-one obese/overweight (age 12 ± 3 years, 56 % female) and 29 healthy weight children (age 14 ± 3 years, 41 % female) underwent CMR, including both standard cine imaging and displacement encoded imaging, for a complete assessment of left ventricular (LV) structure and function. After adjusting for age, LV mass index …

Mobile Device-Based Location Services Accuracy, Hasan Seyyedhasani, Joseph S. Dvorak, Michael P. Sama, Tim S. Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

The objective of this study was to characterize the expected position accuracy when using popular mobile devices for location-based agricultural decision-making activities. This study utilized Android-based Nexus 7 tablets and tested the operation of the three location services available on this system in a 24-h fixed location test and a shorter duration multiple location field test. In the 24-h test, the “network” location system had a measured error of 37.19 m while reporting an accuracy of 55.56 m. The “gps” location system had a measured error of 2.57 m and a reported accuracy of 3.20 m. Multiple tests were conducted …

2016 Maintenance Customer Survey, R. Clark Graves, David L. Allen

Kentucky Transportation Center Research Report

The Kentucky Transportation Center, with the assistance of the University of Kentucky’s Survey Research Center, administered a telephone survey to 1,221 licensed drivers throughout the state to gauge their opinion of the Kentucky Transportation Cabinet’s (KYTC) maintenance activities. Survey respondents were distributed throughout KYTC’s 12 highway districts. The survey focused on five areas of highway maintenance: roadside features, pavement surfaces, shoulders, drainage and signs/markings. Respondents indicated they were most satisfied with the current maintenance of signs, guardrail, and striping. Pavement surfaces and potholes, and shoulders and roadway drainage, received the lowest rankings — given that the driving public is very …

Effects Of Vocal Fold Nodules On Glottal Cycle Measurements Derived From High-Speed Videoendoscopy In Children, Rita R. Patel, Harikrishnan Unnikrishnan, Kevin D. Donohue

Electrical and Computer Engineering Faculty Publications

The goal of this study is to quantify the effects of vocal fold nodules on vibratory motion in children using high-speed videoendoscopy. Differences in vibratory motion were evaluated in 20 children with vocal fold nodules (5–11 years) and 20 age and gender matched typically developing children (5–11 years) during sustained phonation at typical pitch and loudness. Normalized kinematic features of vocal fold displacements from the mid-membranous vocal fold point were extracted from the steady-state high-speed video. A total of 12 kinematic features representing spatial and temporal characteristics of vibratory motion were calculated. Average values and standard deviations (cycle-to-cycle variability) of …

Hallmarks Of The Mott-Metal Crossover In The Hole-Doped Pseudospin-1/2 Mott Insulator Sr2Iro4, Yue Cao, Qiang Wang, Justin A. Waugh, Theodore J. Reber, Haoxiang Li, Xiaoqing Zhou, Stephen Parham, S. -R. Park, Nicholas C. Plumb, Eli Rotenberg, Aaron Bostwick, Jonathan D. Denlinger, Tongfei Qi, Michael A. Hermele, Gang Cao, Daniel S. Dessau

Physics and Astronomy Faculty Publications

The physics of doped Mott insulators remains controversial after decades of active research, hindered by the interplay among competing orders and fluctuations. It is thus highly desired to distinguish the intrinsic characters of the Mott-metal crossover from those of other origins. Here we investigate the evolution of electronic structure and dynamics of the hole-doped pseudospin-1/2 Mott insulator Sr₂IrO₄. The effective hole doping is achieved by replacing Ir with Rh atoms, with the chemical potential immediately jumping to or near the top of the lower Hubbard band. The doped iridates exhibit multiple iconic low-energy features previously observed …

Wet Grain Delivery Advice: A Previously Impossible Extension Challenge Solved Through App Technology, Joseph S. Dvorak, Sam Mcneill, Clint Hardy

Biosystems and Agricultural Engineering Faculty Publications

The delivery of wet grain during harvest is a complex and constantly changing problem about which Extension professionals have been unable to offer more than general advice. By capitalizing on important characteristics of mobile devices, a new app enables producers to fully benefit from detailed information universities have generated on grain drying and costs associated with delivery of grain to different locales. Development of such an app demonstrates the power of apps and mobile devices in allowing Extension to deliver previously unattainable services to its clientele.

Spatio-Temporal Linear Stability Analysis Of Stratified Planar Wakes: Velocity And Density Asymmetry Effects, Benjamin Emerson, Swapnil Jagtap, J. Mathew Quinlan, Michael W. Renfro, Baki M. Cetegen, Tim Lieuwen

Mechanical Engineering Faculty Publications

This paper explores the hydrodynamic stability of bluff body wakes with non-uniform mean density, asymmetric mean density, and velocity profiles. This work is motivated by experiments [S. Tuttle et al., “Lean blow off behavior of asymmetrically-fueled bluff body-stabilized flames,” Combust. Flame 160, 1677 (2013)], which investigated reacting wakes with equivalence ratio stratification and, hence, asymmetry in the base flow density profiles. They showed that highly stratified cases exhibited strong, narrowband oscillations, suggestive of global hydrodynamic instability. In this paper, we present a local hydrodynamic stability analysis for non-uniform density wakes that includes base flow asymmetry. The results show …

Notes On Contributions To The Science Of Rare Earth Element Enrichment In Coal And Coal Combustion Byproducts, James C. Hower, Evan J. Granite, David B. Mayfield, Ari S. Lewis, Robert B. Finkelman

Center for Applied Energy Research Faculty and Staff Publications

Coal and coal combustion byproducts can have significant concentrations of lanthanides (rare earth elements). Rare earths are vital in the production of modern electronics and optics, among other uses. Enrichment in coals may have been a function of a number of processes, with contributions from volcanic ash falls being among the most significant mechanisms. In this paper, we discuss some of the important coal-based deposits in China and the US and critique classification systems used to evaluate the relative value of the rare earth concentrations and the distribution of the elements within the coals and coal combustion byproducts.

X-Ray Absorption Spectroscopy Study Of The Effect Of Rh Doping In Sr2Iro4, C. H. Sohn, Deok-Yong Cho, C. -T. Kuo, L. J. Sandilands, Tongfei Qi, Gang Cao, T. W. Noh

Center for Advanced Materials Faculty Publications

We investigate the effect of Rh doping in Sr₂IrO₄ using X-ray absorption spectroscopy (XAS). We observed appearance of new electron-addition states with increasing Rh concentration (x in Sr₂Ir_1−xRh_xO₄) in accordance with the concept of hole doping. The intensity of the hole-induced state is however weak, suggesting weakness of charge transfer (CT) effect and Mott insulating ground states. Also, Ir J_eff = 1/2 upper Hubbard band shifts to lower energy as x increases up to x = 0.23. Combined with optical spectroscopy, these results suggest a hybridisation-related mechanism, in …