Engineering Commons^™

Inductance Testing According To The New Ieee Std 1812-Application And Possible Extensions For Ipm Machines, Vandana Rallabandi, Narges Taran, Dan M. Ionel, Ping Zhou

Power and Energy Institute of Kentucky Faculty Publications

Equivalent circuit parameters are very important for permanent magnet synchronous machines since they serve as the basis for performance estimation and implementation of power electronic drives controls. Specified in the newly approved IEEE Std 1812, a short-circuit test can be employed, in combination with an open-circuit measurement, in order to determine the back emf and the synchronous inductance. In this paper, it is shown that for interior permanent magnet (IPM) machines this approach can be used only to determine the d-axis inductance and additional and separate measurements are required for the q-axis inductance. In this respect, one method widely used …

Safety Concepts For Workers From An Osha Perspective, Zamaan Al-Shabbani, Roy E. Sturgill Jr., Gabriel B. Dadi

Kentucky Transportation Center Research Report

Highway construction and maintenance workers face numerous hazards on job sites, many of which are unique by industry standards. Despite the exposure of state transportation agency employees and contractors to these hazards, there are few safety standards, regulations, programs that directly target the sector aimed at prevention and mitigation. To help the Kentucky Transportation Cabinet (KYTC) improve employee safety, researchers at the Kentucky Transportation Center (KTC) analyzed the frequency and causes of workplace injuries for 10 essential Cabinet maintenance operations. Most incidents were attributable to human factors or ergonomics. Based on this analysis, the leading causes of incidents, and a …

Tuning Properties Of Poly(Ethylene Glycol)-Block-Poly(Simvastatin) Copolymers Synthesized Via Triazabicyclodecene, Theodora A. Asafo-Adjei, Thomas D. Dziubla, David A. Puleo

Biomedical Engineering Faculty Publications

Simvastatin was polymerized into copolymers to better control drug loading and release for therapeutic delivery. When using the conventional stannous octoate catalyst in ring-opening polymerization (ROP), reaction temperatures ≥ 200 °C were required, which promoted uncontrollable and undesirable side reactions. Triazabicyclodecene (TBD), a highly reactive guanidine base organocatalyst, was used as an alternative to polymerize simvastatin. Polymerization was achieved at 150 °C using 5 kDa methyl-terminated poly(ethylene glycol) (mPEG) as the initiator. ROP reactions with 2 kDa or 550 Da mPEG initiators were also successful using TBD at 150 °C instead of stannous octoate, which required a higher reaction temperature. …

Orientation Dependent Compression Behavior Of Co35Ni35Al30 Single Crystals, Peizhen Li, Haluk E. Karaca, Yury I. Chumlyakov

Mechanical Engineering Faculty Publications

The shape memory effect (SME) and superelasticity (SE) behavior of homogenized Co₃₅Ni₃₅Al₃₀ single crystals were systematically characterized along the [100], [110] and [111] orientations under compression. The shape memory behavior of CoNiAl was found to be highly orientation and stress/temperature dependent. Maximum compressive recoverable strains were 3.98 % in [110], 3 % in [100] and 0.30 % in [111] orientations, respectively. The Co₃₅Ni₃₅Al₃₀ demonstrated a very high superelastic temperature window of more than 350 °C along the [100] and [110] orientations. Moreover, two-way shape memory effect with very low thermal …

Optical And Electronic Properties Of Femtosecond Laser-Induced Sulfur-Hyperdoped Silicon N+/P Photodiodes, Ting Zhang, Bohan Liu, Waseem Ahmad, Yaoyu Xuan, Xiangxiao Ying, Zhijun Liu, Zhi David Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

Impurity-mediated near-infrared (NIR) photoresponse in silicon is of great interest for photovoltaics and photodetectors. In this paper, we have fabricated a series of n⁺/p photodetectors with hyperdoped silicon prepared by ion-implantation and femtosecond pulsed laser. These devices showed a remarkable enhancement on absorption and photoresponse at NIR wavelengths. The device fabricated with implantation dose of 10¹⁴ ions/cm² has exhibited the best performance. The proposed method offers an approach to fabricate low-cost broadband silicon-based photodetectors.

Truck Routing Issues, Kenneth R. Agent

Kentucky Transportation Center Research Report

Commercial vehicle drivers selecting inappropriate routes where the handling characteristics (e.g., off-tracking) and dimensions of their trucks are not consistent with a roadway’s cross section and geometrics can damage the vehicle, harm adjacent property, or result in crashes. Analysis of crashes that involve the use of inappropriate routes indicate a significant number are caused by drivers receiving faulty directions from in-truck GPS units or adhering to incorrect directions provided by their companies. The Kentucky Transportation Center (KTC) investigated strategies to ensure truck drivers are given correct directions when traveling on Kentucky roadways. As part of this effort, this report reviews …

Cfrp Strengthening Of Ky 583 Over The Bluegrass Parkway Bridge In Hardin Country, Abheetha Peiris, Issam E. Harik

Kentucky Transportation Center Research Report

The report details the planning, design, and construction of the retrofit measure on the KY 583 Bridge (047B00072N), which traverses the Bluegrass Parkway in Hardin County, Kentucky. Reinforced concrete girders within the span over the eastbound Bluegrass Parkway of the bridge had cracks that led to concrete delamination and deterioration of the girders.

To remedy the problem, triaxial carbon fiber reinforced polymer (CFRP) fabric sheets were selected to perform a retrofit due to their strength, conformability, and flexibility. The concrete surface, over which the fabric sheets were applied, were first prepared by removing all spalling and deteriorated concrete, which exposed …

Kytc Maintenance Overview And Budget Analysis, Nancy Albright, Bryan Gibson, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) manages over 27,500 miles of the state’s roadways and is responsible for preserving many assets in a good state of repair, including bridges, traffic signals, lighting features, traffic signs, and guardrails. The Cabinet’s Maintenance function, which encompasses maintenance (e.g., patching potholes, repainting roadway lines and markings, cleaning bridges, mowing) and operations (e.g., plowing and salting roadways; keeping signs, traffic signals, and roadway signals functional), had a budget in FY 2018 of roughly $350 million. This report describes core maintenance functions and reviews their importance for preserving Kentucky’s roadway network and analyzes trends in KYTC’s maintenance …

Quantifying Roadside Assessment For Highway Safety, Reginald R. Souleyrette, Michael A. Fields, Heather Hunt

Kentucky Transportation Center Research Report

Many of Kentucky’s two-lane rural roads pose an above average risk for fixed object crashes. In Kentucky, run-off-road (ROR) collisions with fixed objects account for 18.9% of all crashes and 41.6% of fatal crashes. Accordingly, ROR crashes are a significant public safety hazard that must be addressed through judicious investments in safety improvements. Until recently, transportation engineers and planners have mostly leveraged qualitative metrics to prioritize safety investments, however, qualitative methodologies are problematic because they may rely excessively on subjective opinion and intuition. This study applied methodologies and software from the U.S. Road Assessment Program (usRAP) to develop quantitative, objective …

Long-Term Corrosion Protection Of Bridge Elements Reinforcing Materials In Concrete, Christopher W. Van Dyke, Bobby W. Meade, Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Research Report

Preventing or mitigating the corrosion of reinforcing steel in bridge decks is a major challenge for state transportation agencies. With agency budgets stretched thinner every year, they must implement strategies to extend the service lives of bridges and other critical structures. As such, it is imperative for them to adopt cost effective materials and maintenance practices to delay the onset of bridge corrosion. To assist the Kentucky Transportation Cabinet (KYTC) in its efforts to improve the condition of its bridges as well as its construction and maintenance practices, researchers at the Kentucky Transportation Center (KTC) investigated the use and performance …

Kytc Sidewalk And Curb Ramp Inventory For Ada Compliance, Reginald R. Souleyrette, Brian K. Howell, William Nicholas Staats

Kentucky Transportation Center Research Report

The Americans with Disabilities Act of 1990 (ADA) requires that all public and private organizations providing services to the public ensure their facilities and infrastructure comply with regulations set forth therein. The ADA requires that a transition plan “identify physical obstacles in the public entity’s facilities that limit the accessibility of its programs or activities to individuals with disabilities.” In the first phase of Kentucky’s transition plan to become ADA compliant, KTC researchers inventoried sidewalks along all state-maintained roads in Kentucky to determine the presence or absence of pedestrian facilities. This sidewalk inventory was used to query Kentucky’s intersection database …

Analysis Of Traffic Crash Data In Kentucky (2012-2016), Eric R. Green, Kenneth R. Agent, Jerry G. Pigman, Paul A. Ross

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 2012 through 2016. A primary objective of this study was to determine average crash statistics for Kentucky highways. Rates were calculated for various types of highways and for counties and cities. Difference criteria were used for exposure.

The other primary objective of this study was to provide data that can be used in the preparation of the problem identification portion of Kentucky’s Annual Highway Safety Plan. County and city crash statistics were analyzed. A summary of results and recommendations in several problem identification areas is …

Application Of Ihsdm: Ky 30 Case Study, William Nicholas Staats, Adam J. Kirk

Kentucky Transportation Center Research Report

A section of KY 30 in Jackson and Owsley Counties is targeted for redesign to provide a safer and more efficient corridor that will support economic activity in eastern Kentucky. Data for the existing KY 30 alignment and eight alternative alignments developed by HMB Professional Engineers Inc. were provided to researchers at the Kentucky Transportation Center (KTC). KTC researchers also developed a new alternative that modified the existing alignment to improve the safety of various locations. Researchers applied safety analysis procedures from Part C of the Highway Safety Manual (HSM) to the existing and alternative alignments of KY 30 using …

Streamlined Project Closeout For Construction At Kytc, Tyler A. Johnson, Dominic A. Michaels, Roy E. Sturgill, Timothy R. B. Taylor

Kentucky Transportation Center Research Report

Project closeout is the period between the end of construction and when a contract is finalized. During closeout, resources are held in encumbered funds intended for the project and in the contractor’s bonding capacity. Although the Kentucky Transportation Cabinet’s (KYTC) stated goal is to close out projects within 240 days of their ending, in 2016 the average duration of project closeout was 366 days. This report analyzes the Cabinet’s project closeout procedures, summarizes project closeout best practices adopted by other state transportation agencies, and recommends ways to improve KYTC’s practices. Streamlining project closeouts would free up sufficient funds to resurface …

Improving The Thermal Stability Of Cellobiohydrolase Cel7a From Hypocrea Jecorina By Directed Evolution, Frits Goedegebuur, Lydia Dankmeyer, Peter Gualfetti, Saeid Karkehabadi, Henrik Hansson, Suvamay Jana, Vicky Huynh, Bradley R. Kelemen, Paulien Kruithof, Edmund A. Larenas, Pauline J. M. Teunissen, Jerry Ståhlberg, Christina M. Payne, Colin Mitchinson, Mats Sandgren

Chemical and Materials Engineering Faculty Publications

Secreted mixtures of Hypocrea jecorina cellulases are able to efficiently degrade cellulosic biomass to fermentable sugars at large, commercially relevant scales. H. jecorina Cel7A, cellobiohydrolase I, from glycoside hydrolase family 7, is the workhorse enzyme of the process. However, the thermal stability of Cel7A limits its use to processes where temperatures are no higher than 50 °C. Enhanced thermal stability is desirable to enable the use of higher processing temperatures and to improve the economic feasibility of industrial biomass conversion. Here, we enhanced the thermal stability of Cel7A through directed evolution. Sites with increased thermal stability properties were combined, and …

High Resolution Imaging Of The Mitral Valve In The Natural State With 7 Tesla Mri, Sam E. Stephens, Serguei Liachenko, Neil B. Ingels, Jonathan F. Wenk, Morten O. Jensen

Mechanical Engineering Faculty Publications

Imaging techniques of the mitral valve have improved tremendously during the last decade, but challenges persist. The delicate changes in annulus shape and papillary muscle position throughout the cardiac cycle have significant impact on the stress distribution in the leaflets and chords, thus preservation of anatomically accurate positioning is critical. The aim of this study was to develop an in vitro method and apparatus for obtaining high-resolution 3D MRI images of porcine mitral valves in both the diastolic and systolic configurations with physiologically appropriate annular shape, papillary muscle positions and orientations, specific to the heart from which the valve was …

Pulsed Laser Beam Welding Of Pd43Cu27Ni10P20 Bulk Metallic Glass, Ling Shao, Amit Datye, Jiankang Huang, Jittisa Ketkaew, Sung Woo Sohn, Shaofan Zhao, Sujun Wu, Yuming Zhang, Udo D. Schwarz, Jan Schroers

Electrical and Computer Engineering Faculty Publications

We used pulsed laser beam welding method to join Pd₄₃Cu₂₇Ni₁₀P₂₀ (at.%) bulk metallic glass and characterized the properties of the joint. Fusion zone and heat-affected zone in the weld joint can be maintained completely amorphous as confirmed by X-ray diffraction and differential scanning calorimetry. No visible defects were observed in the weld joint. Nanoindentation and bend tests were carried out to determine the mechanical properties of the weld joint. Fusion zone and heat-affected zone exhibit very similar elastic moduli and hardness when compared to the base material, and the weld joint shows high …

Catalytic Oxidation And Depolymerization Of Lignin In Aqueous Ionic Liquid, Lalitendu Das, Siquan Xu, Jian Shi

Biosystems and Agricultural Engineering Faculty Publications

Lignin is an integral part of the plant cell wall, which provides rigidity to plants, also contributes to the recalcitrance of the lignocellulosic biomass to biochemical and biological deconstruction. Lignin is a promising renewable feedstock for aromatic chemicals; however, an efficient and economic lignin depolymerization method needs to be developed to enable the conversion. In this study, we investigated the depolymerization of alkaline lignin in aqueous 1-ethyl-3-methylimidazolium acetate [C₂C₁Im][OAc] under oxidizing conditions. Seven different transition metal catalysts were screened in presence of H₂O₂ as oxidizing agent in a batch reactor. CoCl₂ and …

Reducing Equifinality Using Isotopes In A Process-Based Stream Nitrogen Model Highlights The Flux Of Algal Nitrogen From Agricultural Streams, William I. Ford, James F. Fox, Erik Pollock

Biosystems and Agricultural Engineering Faculty Publications

The fate of bioavailable nitrogen species transported through agricultural landscapes remains highly uncertain given complexities of measuring fluxes impacting the fluvial N cycle. We present and test a new numerical model named Technology for Removable Annual Nitrogen in Streams For Ecosystem Restoration (TRANSFER), which aims to reduce model uncertainty due to erroneous parameterization, i.e., equifinality, in stream nitrogen cycle assessment and quantify the significance of transient and permanent removal pathways. TRANSFER couples nitrogen elemental and stable isotope mass‐balance equations with existing hydrologic, hydraulic, sediment transport, algal biomass, and sediment organic …

Endothelial Function Is Associated With White Matter Microstructure And Executive Function In Older Adults, Nathan F. Johnson, Brian T. Gold, Christopher A. Brown, Emily F. Anggelis, Alison L. Bailey, Jody L. Clasey, David K. Powell

Physical Therapy Faculty Publications

Age-related declines in endothelial function can lead to cognitive decline. However, little is known about the relationships between endothelial function and specific neurocognitive functions. This study explored the relationship between measures of endothelial function (reactive hyperemia index; RHI), white matter (WM) health (fractional anisotropy, FA, and WM hyperintensity volume, WMH), and executive function (Trail Making Test (TMT); Trail B - Trail A). Participants were 36 older adults between the ages of 59 and 69 (mean age = 63.89 years, SD = 2.94). WMH volume showed no relationship with RHI or executive function. However, there was a positive relationship between RHI …

Enhancements In Mass Transfer For Carbon Capture Solvents Part I: Homogeneous Catalyst, Leland R. Widger, Moushumi Sarma, Jonathan J. Bryant, David S. Mannel, Jesse G. Thompson, Cameron A. Lippert, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

The novel small molecule carbonic anhydrase (CA) mimic [Co^III(Salphen-COO⁻)Cl]HNEt₃ (1), was synthesized as an additive for increasing CO₂ absorption rates in amine-based post-combustion carbon capture processes (CCS), and its efficacy was verified. 1 was designed for use in a kinetically slow but thermally stable blended solvent, containing the primary amines 1-amino-2-propanol (A2P) and 2-amino-2-methyl-1-propanol (AMP). Together, the A2P/AMP solvent and 1 reduce the overall energy penalty associated with CO₂ capture from coal-derived flue gas, relative to the baseline solvent MEA. 1 is also effective at increasing absorption kinetics of kinetically fast solvents, such …

2017 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green, Erin Lammers-Staats

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. The objective of the survey summarized in this report was to establish a statewide safety belt usage rate in Kentucky for 2017. This rate can be compared to those determined from previous surveys. The 2017 statewide survey documents the continued increase in usage associated with the change in the law to allow primary enforcement and related education and enforcement.

Snow And Ice Removal Route Optimization In Kentucky, Benjamin L. Blandford, Erin Lammers-Staats, Eric R. Green

Kentucky Transportation Center Research Report

Each year the Kentucky Transportation Cabinet (KYTC) spends $40-$80 million removing snow and ice from the state’s roadways. Snow and ice removal are accomplished through a system of snow and ice removal routes that are designed to account for location and the attributes of trucks, facilities, materials, and roadways. To identify strategies that will improve and optimize KYTC’s snow and ice removal operations, Kentucky Transportation Center (KTC) researchers used ArcGIS and its Network Analyst extension to study the performance of the Cabinet’s current routing procedures. Building from this investigation, researchers developed optimized snowplow routings for four counties located in KYTC …

Analysis And Modeling Of The Growth Of Intermetallic Compounds In Aluminum–Steel Joints, Gang Zhang, Manjiao Chen, Yu Shi, Jiankang Huang, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

In this work, we experimentally and numerically studied the microstructures and growth of intermetallic compounds (IMCs) formed in Al–Fe (aluminum–steel) joints welded by a pulsed double electrode gas metal arc welding (DE-GMAW)-brazing method. The IMCs consist of Fe₂Al₅ and FeAl₃, with Fe₂Al₅ being the main compound in the joints. The thickness of an IMC layer increases with an increase of the welding current (heat input) into the base metal. EBSD measurement suggests that the preferred crystal orientation of the Fe₂Al₅ IMC likely provides the necessary path for Al atoms …

Glucose Recovery From Different Corn Stover Fractions Using Dilute Acid And Alkaline Pretreatment Techniques, D. Aboagye, N. Banadda, R. Kambugu, Jeffrey Seay, N. Kiggundu, A. Zziwa, I. Kabenge

Chemical and Materials Engineering Faculty Publications

Background: Limited availability of corn stover due to the competing uses (organic manure, animal feed, bio-materials, and bioenergy) presents a major concern for its future in the bio-economy. Furthermore, biomass research has exhibited different results due to the differences in the supply of enzymes and dissimilar analytical methods. The effect of the two leading pretreatment techniques (dilute acid and alkaline) on glucose yield from three corn stover fractions (cob, stalk, and leaf) sourced from a single harvest in Uganda were studied at temperatures 100, 120, 140, and 160 °C over reaction times of 5, 10, 30, and 60 min.

Results: …

Suppression Of Magnetism In Ba5Alir2O11: Interplay Of Hund's Coupling, Molecular Orbitals, And Spin-Orbit Interaction, Sergey V. Streltsov, Gang Cao, Daniel I. Khomskii

Center for Advanced Materials Faculty Publications

The electronic and magnetic properties of Ba₅AlIr₂O₁₁ containing Ir-Ir dimers are investigated using the generalized gradient approximation (GGA) and GGA + spin-orbit coupling (SOC) calculations. We found that the strong suppression of the magnetic moment in this compound recently found by Terzic et al. [Phys. Rev. B 91, 235147 (2015)] is not due to charge ordering but is related to the joint effect of the spin-orbit interaction and strong covalency, resulting in the formation of metal-metal bonds. They conspire and act against the intraatomic Hund's rule exchange interaction to reduce total magnetic moment of the …

A Brief Review Of Opt101 Sensor Application In Near-Infrared Spectroscopy Instrumentation For Intensive Care Unit Clinics, Ting Li, Fulin Zhong, Boan Pan, Zebin Li, Chong Huang, Zishan Deng

Biomedical Engineering Faculty Publications

The optoelectronic sensor OPT101 have merits in advanced optoelectronic response characteristics at wavelength range for medical near-infrared spectroscopy and small-size chip design with build-in trans-impedance amplifier. Our lab is devoted to developing a series of portable near-infrared spectroscopy (NIRS) devices embedded with OPT101 for applications in intensive care unit clinics, based on NIRS principle. Here we review the characteristics and advantages of OPT101 relative to clinical NIRS instrumentation, and the most recent achievements, including early-diagnosis and therapeutic effect evaluation of thrombus, noninvasive monitoring of patients' shock severity, and fatigue evaluation. The future prospect on OPT101 improvements in noninvasive clinical applications …

Real-Time Sensing Of Single-Ligand Delivery With Nanoaperture-Integrated Microfluidic Devices, W. Elliott Martin, Ning Ge, Bernadeta R. Srijanto, Emily Furnish, C. Patrick Collier, Christine A. Trinkle, Christopher I. Richards

Chemistry Faculty Publications

The measurement of biological events on the surface of live cells at the single-molecule level is complicated by several factors including high protein densities that are incompatible with single-molecule imaging, cellular autofluorescence, and protein mobility on the cell surface. Here, we fabricated a device composed of an array of nanoscale apertures coupled with a microfluidic delivery system to quantify single-ligand interactions with proteins on the cell surface. We cultured live cells directly on the device and isolated individual epidermal growth factor receptors (EGFRs) in the apertures while delivering fluorescently labeled epidermal growth factor. We observed single ligands binding to EGFRs, …

Band Offsets At The Interface Between Crystalline And Amorphous Silicon From First Principles, Karol Jarolimek, E. Hazrati, R. A. De Groot, D. A. De Wijs

Center for Applied Energy Research Faculty and Staff Publications

The band offsets between crystalline and hydrogenated amorphous silicon (a−Si∶H) are key parameters governing the charge transport in modern silicon heterojunction solar cells. They are an important input for macroscopic simulators that are used to further optimize the solar cell. Past experimental studies, using x-ray photoelectron spectroscopy (XPS) and capacitance-voltage measurements, have yielded conflicting results on the band offset. Here, we present a computational study on the band offsets. It is based on atomistic models and density-functional theory (DFT). The amorphous part of the interface is obtained by relatively long DFT first-principles molecular-dynamics runs at an elevated temperature …

The Effect Of Conditioning On The Flotation Of Pyrrhotite In The Presence Of Chlorite, Yanfei Chen, Qing Shi, Qimeng Feng, Yiping Lu, Wencai Zhang

Mining Engineering Faculty Publications

The influence of conditioning on the flotation of pyrrhotite in the presence of chlorite was investigated through flotation tests, sedimentation tests, and X-ray photoelectron spectroscopy (XPS) analysis. The flotation results show that chlorite slimes dramatically impair the flotation of pyrrhotite. Sedimentation and flotation tests reveal that conditioning can effectively remove chlorite slimes from pyrrhotite surfaces, resulting in an enhanced flotation recovery of pyrrhotite. When mixed minerals were conditioned under the natural atmosphere, a faster conditioning speed and longer conditioning time decreased the flotation recovery of pyrrhotite. However, when mixed minerals were conditioned under a nitrogen atmosphere, a more intensive conditioning …