Engineering Commons^™

Subcontracting And The Survival Of Plants In The Road Construction Industry: A Panel Quantile Regression Analysis, Dakshina G. De Silva, Georgia Kosmopoulou, Carlos Lamarche

Economics Faculty Publications

This paper investigates how subcontracting parts of contracted work shapes entrants’ success and survival. We find that newly developed quantile regression approaches can be adapted to study survival of firms competing for government contracts in road construction. The method is applied on a data set that includes patterns of firm entry, exit and auction related information. We find an apparent increase in the business life of firms who subcontract out part of their projects. In Texas, these subcontracting effects appear to be more pronounced for firms with few or no options outside the industry, and among firms who contract out …

On The Effect Of Design Tolerances On The Performance Of Synchronous Pm Machines Evaluated According To The Ieee Std 1812, Narges Taran, Vandana Rallabandi, Dan M. Ionel, Ping Zhou

Power and Energy Institute of Kentucky Faculty Publications

In the process of designing an electric machine, the systematic study of tolerances for the design variables and material properties is of the utmost importance. This paper proposes a method by which possible variations of the design variables and material properties can be distinguished. The design of experiments (DOE) technique, open-circuit and short-circuit tests, with minimum instrumentation requirements, have been employed. Virtual tests are conducted based on the recently approved IEEE 1812 testing guide for PM synchronous machines. As a case study, a 100 hp 16-pole 18-slot spoke-type PM machine is discussed. It is shown that variation in magnet remanence, …

Axial-Flux Pm Synchronous Machines With Air-Gap Profiling And Very High Ratio Of Spoke Rotor Poles To Stator Concentrated Coils, Vandana Rallabandi, Narges Taran, Dan M. Ionel, Ion G. Boldea

Power and Energy Institute of Kentucky Faculty Publications

Permanent magnet machines including a magnetic gearing effect are attractive for low-speed high-torque applications. This paper proposes a dual-stator axial-flux machine topology with a high ratio for the number of rotor poles to concentrated stator coils. The stator consists of a relatively small number of teeth, with each tooth including multiple smaller/auxiliary teeth. The rotor employs spoke-type permanent magnets, which result in high flux concentration, thereby further improving the torque density. The paper discusses the principle of operation of the proposed machine topology. Finite element results on example designs with 6 stator teeth, each having 2 and 3 auxiliary teeth, …

Synthesis Of Graphene Oxide Membranes And Their Behavior In Water And Isopropanol, Ashish Aher, Yuguang Cai, Mainak Majumder, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

Graphene oxide (GO) membrane has been synthesized on commercial polysulfone ultrafiltration membranes (Pore size: 17 nm) using the drop casting method followed by baking at 90 C for 24 h. Baking resulted in the reduction of GO and removal of bulk water intercalated in the GO sheets. Deposited GO film showed high stability under shear stress variation. This work shows that water adsorption on the GO membrane determines its permeation performance. Despite the higher viscosity of isopropyl alcohol (IPA), its permeability was 7 times higher than water through the baked (“dry”) GO membranes, which were never contacted with water. However, …

Mapping And Integrating Value Creation Factors With Life-Cycle Stages For Sustainable Manufacturing, P. Bilge, S. Emec, G. Seliger, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Instead of implementing each element individually, engineers must be aware of multiple interactions among all major value creation factors and their life-cycle stages. Interactions are analyzed by a set of factors and hierarchical levels within a production system based on empirical observations and described in analytical models. Such analyses and missing information about the current condition of the system and its parts remain limited to addressing specific aspects of interactions among factors and stages for multiple decision making. To build a case-based scope addressing the interactions among a set of factors and life-cycle stages, a comprehensive approach for mapping and …

Expression And Reception: An Analytic Method For Assessing Message Production And Consumption In Cmc, Kang Namkoong, Dhavan V. Shah, Bryan Mclaughlin, Ming-Yuan Chih, Tae Joon Moon, Shawnika Hull, David H. Gustafson

Community & Leadership Development Faculty Publications

This article presents an innovative methodology to study computer-mediated communication (CMC), which allows analysis of the multi-layered effects of online expression and reception. The methodology is demonstrated by combining the following three data sets collected from a widely tested eHealth system, the Comprehensive Health Enhancement Support System (CHESS): (1) a flexible and precise computer-aided content analysis; (2) a record of individual message posting and reading; and (3) longitudinal survey data. Further, this article discusses how the resulting data can be applied to online social network analysis and demonstrates how to construct two distinct types of online social networks—open and targeted …

Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …

Clinical Applications Of Near-Infrared Diffuse Correlation Spectroscopy And Tomography For Tissue Blood Flow Monitoring And Imaging, Yu Shang, Ting Li, Guoqiang Yu

Biomedical Engineering Faculty Publications

Objective. Blood flow is one such available observable promoting a wealth of physiological insight both individually and in combination with other metrics.

Approach. Near-infrared diffuse correlation spectroscopy (DCS) and, to a lesser extent, diffuse correlation tomography (DCT), have increasingly received interest over the past decade as noninvasive methods for tissue blood flow measurements and imaging. DCS/DCT offers several attractive features for tissue blood flow measurements/imaging such as noninvasiveness, portability, high temporal resolution, and relatively large penetration depth (up to several centimeters).

Main results. This review first introduces the basic principle and instrumentation of DCS/DCT, followed by presenting …

In-Service Evaluation Of High Tension Cable Barrier Systems, Brian K. Howell, Kenneth R. Agent, Jeff Jasper, William Nicholas Staats

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet has installed hundreds of miles of high-tension cable median barrier (CMB) as a safety innovation. The usage of CMB aids in the prevention of crossover crashes, where a vehicle departs the roadway on the left shoulder, crosses the median, and enters the opposing lane(s) of traffic. KYTC officials have questioned whether all three barrier products perform similarly. Some installed cable barrier systems have lost tension across the entire cable length after a single vehicle impact. If a second vehicle were to strike the cable barrier system in a location other than the damaged area of the …

White Matter Hyperintensity Associations With Cerebral Blood Flow In Elderly Subjects Stratified By Cerebrovascular Risk, Ahmed A. Bahrani, David K. Powell, Guoqiang Yu, Eleanor S. Johnson, Gregory A. Jicha, Charles D. Smith

Biomedical Engineering Faculty Publications

Objective: This study aims to add clarity to the relationship between deep and periventricular brain white matter hyperintensities (WMHs), cerebral blood flow (CBF), and cerebrovascular risk in older persons. Methods: Deep white matter hyperintensity (dWMH) and periventricular white matter hyperintensity (pWMH) and regional gray matter (GM) and white matter (WM) blood flow from arterial spin labeling were quantified from magnetic resonance imaging scans of 26 cognitively normal elderly subjects stratified by cerebrovascular disease (CVD) risk. Fluidattenuated inversion recovery images were acquired using a high-resolution 3-dimensional (3-D) sequence that reduced partial volume effects seen with slicebased techniques. Results: dWMHs but not …

Enhanced Performance Of Planar Perovskite Solar Cells Using Low-Temperature Solution-Processed Al-Doped Sno2 As Electron Transport Layers, Hao Chen, Detao Liu, Yafei Wang, Chenyun Wang, Ting Zhang, Peng Zhang, Hojjatollah Sarvari, Zhi Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

Lead halide perovskite solar cells (PSCs) appear to be the ideal future candidate for photovoltaic applications owing to the rapid development in recent years. The electron transport layers (ETLs) prepared by low-temperature process are essential for widespread implementation and large-scale commercialization of PSCs. Here, we report an effective approach for producing planar PSCs with Al³⁺ doped SnO₂ ETLs prepared by using a low-temperature solution-processed method. The Al dopant in SnO₂ enhanced the charge transport behavior of planar PSCs and increased the current density of the devices, compared with the undoped SnO₂ ETLs. Moreover, the enhanced electrical …

An Experimental Investigation Of Wing-Tip Vortex Decay In Turbulence, Hai G. Ghimire, Sean C. C. Bailey

Mechanical Engineering Faculty Publications

Particle image velocimetry measurements were conducted for a wing-tip vortex decaying in free-stream turbulence. The vortex exhibited stochastic collapse with free-stream turbulence present, with the breakdown initiating earlier for higher levels of turbulence. An increased rate of decay of the vortex tangential velocity was also observed, increasing with increasing free-stream turbulence. The decay of the vortex tangential velocity without the free-stream turbulence was well represented by viscous diffusion, resulting in an increase in the core radius and decrease in the peak tangential velocity. With the addition of free-stream turbulence, the rate of decay of the peak tangential velocity of the …

Electronic Properties Of A New All-Inorganic Perovskite Tlpbi3 Simulated By The First Principles, Zhao Liu, Ting Zhang, Yafei Wang, Chenyun Wang, Peng Zhang, Hojjatollah Sarvari, Zhi Chen, Shibin Li

Electrical and Computer Engineering Faculty Publications

All-inorganic perovskites have been recognized as promising photovoltaic materials. We simulated the perovskite material of TlPbI₃ using ab initio electronic structure calculations. The band gap of 1.33 eV is extremely close to the theoretical optimum value. Compared TlPbI₃ with CsPbI₃, the total energy (−3980 eV) of the former is much lower than the latter. The partial density of states (PDOS) of TlPbI₃ shows that a strong bond exists between Tl and I, resulting in the lower total energy and more stable existence than CsPbI₃.

Chemically Stable Artificial Sei For Li-Ion Battery Electrodes, Qinglin Zhang, Lei Han, Jie Pan, Zhi Chen, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

The importance of coating's chemical stability in lithium-ion batteries has been demonstrated by this study. It is well known that the mechanical properties determine the cycle life, and chemical stability or chemical degradation rate determines the calendar life. In this study, we used HfO₂ coatings prepared by atomic layer deposition as an example to show the chemical stability of the coatings for lithium ion battery electrodes.

Focused Electron Beam Induced Deposition Of Copper With High Resolution And Purity From Aqueous Solutions, Samaneh Esfandiarpour, Lindsay Boehme, J. Todd Hastings

Electrical and Computer Engineering Faculty Publications

Electron-beam induced deposition of high-purity copper nanostructures is desirable for nanoscale rapid prototyping, interconnection of chemically synthesized structures, and integrated circuit editing. However, metalorganic, gas-phase precursors for copper introduce high levels of carbon contamination. Here we demonstrate electron beam induced deposition of high-purity copper nanostructures from aqueous solutions of copper sulfate. The addition of sulfuric acid eliminates oxygen contamination from the deposit and produces a deposit with ~95 at% copper. The addition of sodium dodecyl sulfate (SDS), Triton X-100, or polyethylene glycole (PEG) improves pattern resolution and controls deposit morphology but leads to slightly reduced purity. High resolution nested lines …

Session 1c (Source Water Protection), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• The Pleasant Grove Spring Non-Point Source Pollution Study: An Underused Data Set, James Currens, Kentucky Geological Survey
• Kentucky’s Source Water Protection Program, Robert Blair, Kentucky Division of Water
• Assistance Program for Source Water Protection: Success in Kentucky, Laura Norris and Allan Shingleton, Kentucky Division of Water

Session 2c (Sediment And Nutrients), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Real-Time Continuous Monitoring of Nutrients and Biological Parameters in Kentucky’s Rivers and Lakes, Mac Cherry, USGS Indiana-Kentucky Water Science Center
• Sediment Transport Modeling using Dynamic (Dis)connectivity to Assess Sediment Impacts on Water Quality, Tyler Mahoney and others, Dept. of Civil Engineering, University of Kentucky
• Sediment Nitrogen and Nitrate Dynamics of a Fluviokarst System in the Bluegrass Region: Isotopic and Numerical Modeling Investigation, Admin Husic and others, Dept. of Civil Engineering, University of Kentucky

Poster Session 2, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

1. GIS as a Tool to Inform Field Studies and Reduce Human Health Exposure Risks, Evan Willett and others, Dept. of Civil Engineering, University of Kentucky
2. The Use of Environmental DNA to Detect Bacterial Molecular Markers in the Triplett Creek Watershed, Rowan County, Kentucky, Rachel Brown and others, Dept. Biology and Chemistry, Morehead State University
3. Detection of Percopsis ominsomaycus (TROUT-PERCH) using eDNA in Eastern Kentucky Streams, Ben Brammell and others, Dept. of Natural Sciences, Asbury University
4. Seasonal Fluctuations in Salamander eDNA in Central Kentucky Streams, Ronald Sams and others, Dept. Natural Sciences, Asbury University
5. Virtual 3D Septic …

Session 2b (Biology), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Microscale Electrokinetics for Phytoplankton Analysis, Stuart Williams, Mechanical Engineering Dept., University of Louisville and Susan Hendricks, Hancock Biological Station, Murray State University
• Selenium Reduction by a Co-Culture of Pantoea vagans strain EWB32213-2 and Shigella fergusonii strain TB42616, Yuxia Ji and Yi-tin Wang, Dept. of Civil Engineering, University of Kentucky
• Effects of Temperature and Macronutrient Ratios (N:P) on Microcystis aeruginosa Toxin Production and Growth, Brandon Yates and Brian Reeder, Dept. of Biology and Chemistry, Morehead State University

Session 1b (Agriculture And Water), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Feathered or Four-Legged: Working Together to Manage Manure in Kentucky, Amanda Gumbert and others, College of Agriculture, Food, and Environment, University of Kentucky
• There’s a Purple Cow in My MS4, Steve Higgins, College of Agriculture, Food and Environment, University of Kentucky
• Field Scale Characterization of Soil Hydraulic Conductivity and its Implication for Irrigation Management, Xi Zhang and Ole Wendroth, Dept. Plant and Soil Sciences, University of Kentucky

Session 1a (Soils And Geology), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Potential Mechanism Contributing to the Development of Cover Collapse in Kentucky, James Currens, Kentucky Geological Survey
• Preliminary Assessment of the Geothermal Potential of the Alluvial Aquifer Beneath Louisville, Kentucky Created by Rising Groundwater Levels and Temperatures, Mike and K.G. Unthank, USGS Indiana- Kentucky Water Science Center
• Influence of Land Use on Soil Bulk Density, Infiltration, and NRCS Runoff Curve Number, Samuel Austen and others, Dept. of Biosystems and Agricultural Engineering, University of Kentucky

Session 2a (Climate Change/Data Platform), Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Assessing Climate Change and Impacts on Future Water Availability and Droughts in the Kentucky River Basin, Som Chattopadhyay and Dwayne Edwards, Dept. of Biosystems and Agricultural Engineering, University of Kentucky
• Variance Decomposition of Maxima Extreme Streamflow Forecasted with Global Climate Models, Nabil Al Aamery and Jimmy Fox, Dept. of Civil Engineering, University of Kentucky
• Aquavit: A HUBzero-Based Collaboration Portal for the AFI and SENSE Projects, Jack Smith and Justin Chapman, Marshall University

Poster Session 1, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

1. Sensing and Educating the Nexus to Sustain Ecosystems (SENSE): A Kentucky-West Virginia Partnership, Susan Hendricks and others, Hancock Biological Station, Murray State University
2. Using OpenNSPECT to Model Riparian Buffer Effectiveness for Mitigating Sediment Accumulation in Small Order Agricultural Streams, Lee Moser, College of Agriculture, Food and Environment, University of Kentucky
3. The Benefits of Staying Local – the Kentucky Section of the American Society of Agricultural and Biological Engineers, Carmen Agouridis and Michael Sama, Dept. of Biosystems and Agricultural Engineering, University of Kentucky
4. Overview of Groundwater Sampling Conducted in an Unconventional Oil and Gas Play Area of eastern …

Plenary Session, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Assessing Public Drinking Water Systems in Kentucky, Caroline Chan and Russell Neal, Kentucky Division of Water
• Bankfull Regional Curves and Hydraulic Geometry Curves for the Eastern Kentucky Coalfields, Ashlan Berry and Carmen Agrouridis, Dept. Biosystems and Agricultural Engineering, University of Kentucky
• Quasi-Three-Dimensional Hydrodynamic Model Development for Two-Phase Flow Applied to Geyser Phenomena in Urban Storm Sewers, Richard Shook and others, Dept. of Civil Engineering, University of Kentucky
• Curve Numbers for Urban Watersheds: A Problem and an Interim Solution, Robert Peterson and Lindell Ormsbee, Dept. of Civil Engineering, University of Kentucky

Proceedings Of 2017 Kentucky Water Resources Annual Symposium, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

This symposium was planned and conducted as a part of the state water resources research institute annual program that is supported by Grant/Cooperative Agreement Number G16AP00055 from the United States Geological Survey. The contents of this proceedings document and the views and conclusions presented at the symposium are solely the responsibility of the individual authors and presenters and do not necessarily represent the official views of the USGS or of the symposium organizers and sponsors. This publication is produced with the understanding that the United States Government is authorized to reproduce and distribute reprints for government purposes. Mention of trade …

Strategies For Value Creation Through Sustainable Manufacturing, Fazleena Badurdeen, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Making the business case and establishing strategic directions for sustainable manufacturing requires a collaborative effort. Strategic capabilities that can help create sustainable value for all stakeholders must be identified. Technologies and methodologies to provide these capabilities for implementation must then be developed, through public-private partnerships. This paper presents major business imperatives and strategic capabilities necessary to enable value creation through sustainable manufacturing identified based on extensive engagement with business leaders and industry professionals as well as academic experts and government agency representatives. The paper also presents a future vision for sustainable products, processes and systems that can be derived from …

Sustainable Manufacturing Performance Evaluation: Integrating Product And Process Metrics For Systems Level Assessment, Aihua Huang, Fazleena Badurdeen

Mechanical Engineering Faculty Publications

This paper builds on the previously developed product sustainability index (ProdSI) and process sustainability index (ProcSI), and presents a framework for sustainable manufacturing performance evaluation at the systems level. The framework is then used to propose a comprehensive set of metrics for the enterprise level following a five-stage metrics hierarchy (individual metrics, sub-clusters, clusters, sub-index and index). The 6R concept (reduce, reuse, recycle, recover, redesign and remanufacture), total life-cycle emphasis, and triple bottom line (TBL) are considered for selecting relevant metrics. Finally, the metrics are integrated to develop an index for enterprise level sustainability assessment and …

A Fast And Efficient Python Library For Interfacing With The Biological Magnetic Resonance Data Bank, Andrey Smelter, Morgan Astra, Hunter N. B. Moseley

Center for Environmental and Systems Biochemistry Faculty Publications

Background: The Biological Magnetic Resonance Data Bank (BMRB) is a public repository of Nuclear Magnetic Resonance (NMR) spectroscopic data of biological macromolecules. It is an important resource for many researchers using NMR to study structural, biophysical, and biochemical properties of biological macromolecules. It is primarily maintained and accessed in a flat file ASCII format known as NMR-STAR. While the format is human readable, the size of most BMRB entries makes computer readability and explicit representation a practical requirement for almost any rigorous systematic analysis.

Results:To aid in the use of this public resource, we have developed a package called …

Synthesis And Catalytic Applications Of Non-Metal Doped Mesoporous Titania, Syed Z. Islam, Suraj R. Nagpure, Doo Young Kim, Stephen E. Rankin

Chemical and Materials Engineering Faculty Publications

Mesoporous titania (mp-TiO₂) has drawn tremendous attention for a diverse set of applications due to its high surface area, interfacial structure, and tunable combination of pore size, pore orientation, wall thickness, and pore connectivity. Its pore structure facilitates rapid diffusion of reactants and charge carriers to the photocatalytically active interface of TiO₂. However, because the large band gap of TiO₂ limits its ability to utilize visible light, non-metal doping has been extensively studied to tune the energy levels of TiO₂. While first-principles calculations support the efficacy of this approach, it is challenging to …