Engineering Commons^™

A Tensile Deformation Model For In-Situ Dendrite/Metallic Glass Matrix Composites, J. W. Qiao, T. Zhang, Fuqian Yang, P. K. Liaw, S. Pauly, B. S. Xu

Chemical and Materials Engineering Faculty Publications

In-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti₄₆Zr₂₀V₁₂Cu₅Be₁₇ exhibit ultimate tensile strength of 1510 MPa and fracture strain of about 7.6%. A tensile deformation model is established, based on the five-stage classification: (1) elastic-elastic, (2) elastic-plastic, (3) plastic-plastic (yield platform), (4) plastic-plastic (work hardening), and (5) plastic-plastic (softening) stages, analogous to the tensile behavior of common carbon steels. The constitutive relations strongly elucidate the tensile deformation mechanism. In parallel, the simulation results by a finite-element method (FEM) are in good agreement with the experimental findings and theoretical calculations. The present study gives a mathematical model to clarify …

Repair Of I-65 Expressway Bridges Using Carbon Fiber Reinforced Polymer (Cfrp) Composites, Ching Chiaw Choo, Abheetha Peiris, Issam E. Harik

Kentucky Transportation Center Research Report

This report documents the repair of five locations along the I-65 Expressway in Jefferson County, KY. The repair involved: (1) the precast prestressed concrete girder spans between Jacob Street and Gray Street, (2) the reinforced concrete bearing pads of Bridge Pier 4 at the intersection of Jefferson Street and Preston Street, (3) the reinforced concrete bearing pads of Bridge Pier 6 near the intersection of Main Street and Hancock Street, (4) the precast prestressed concrete girder spans between Chestnut Street and Gray Street and (5) the reinforced concrete pier column on East Muhammad Ali Blvd.

The precast prestressed concrete girders …

Kentucky's Prism-Based Automated Ramp Screening System Evaluation, Jerry Kissick, David Q. Hunsucker, Andrew Martin, Jennifer Walton, Mark Bell

Kentucky Transportation Center Research Report

In 2010, Kentucky implemented a Performance Registration Information Systems and Management (PRISM) based automated ramp screening system (PARSS) at the Boone County inspection station on southbound I-71. The purpose of the PARSS is to identify and screen every vehicle that enters the Boone County inspection station. The system provides automated screening of trucks based on the license plate number and the USDOT number displayed on the vehicle. If it is determined that the vehicle should be stopped for inspection, that decision is communicated to the truck driver via the existing directional arrows that direct drivers to the static scale for …

Tools For Applying Constructability Concepts To Project Development (Design), Nikiforos Stamatiadis, Paul Goodrum, Emily Shocklee, Roy Sturgill, Chen Wang

Kentucky Transportation Center Research Report

The purpose of this report is to document the activities of Phases I and II of the research effort and present the findings of the work accomplished. Phase I developed the Constructability Review Database for the Kentucky Transportation Cabinet and Phase II conducted a benefit analysis of the constructability review process. The database provides the basis for entry and collection of constructability reviews and allows for the identification of trends leading to potential improvements of the process. The database can be used to summarize activities, generate reports for a project, and be capable of quantifying the benefits from the process. …

Repair Using Steel Fiber Reinforced Polymer On Us 150 Bridges, Ching Chiaw Choo, Abheetha Peiris, Issam E. Harik

Kentucky Transportation Center Research Report

The report details the pre-construction monitoring, planning and design, and construction of the retrofit measures on the US150 bridge over Beech Fork River in Nelson County, KY and Cartwright Creek bridge on the border of Washington-Nelson County, KY. All reinforced concrete girders of the five-span Beech Fork River bridge and three-span Cartwright Creek bridge of deck-girder construction had developed diagonal cracks near or at the transition of the variable-and-constant depth regions.

To remedy the problem steel fiber reinforced polymer (SFRP) sheets were selected as the means of retrofit due to their strength and stiffness, as well as conformability and flexibility. …

2013 Driver Attitudes And Awareness Survey, Kenneth R. Agent, Eric R. Green, Ronald E. Langley

Kentucky Transportation Center Research Report

A basic set of questions was developed that could be used in periodic surveys that track drivers attitudes and awareness concerning impaired driving, seat belt use, and speeding issues. The objective of the survey was to learn the knowledge, views, and behaviors of drivers in these areas. This report documents the results of the 2013 survey with a comparison to the 2011 and 2012 surveys as well as the 2010 baseline survey.

The method used to conduct the survey was a telephone survey. In addition to questions for the three major highway safety areas of impaired driving, seat belt use, …

Enzymatic Hydrolysis Of Biomass At High-Solids Loadings – A Review, Alicia A. Modenbach, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

Enzymatic hydrolysis is the unit operation in the lignocellulose conversion process that utilizes enzymes to depolymerize lignocellulosic biomass. The saccharide components released are the feedstock for fermentation. When performed at high-solids loadings (≥ 15% solids, w/w), enzymatic hydrolysis potentially offers many advantages over conversions performed at low- or moderate-solids loadings, including increased sugar and ethanol concentrations and decreased capital and operating costs.

The goal of this review is to provide a consolidated source of information on studies using high-solids loadings in enzymatic hydrolysis. Included in this review is a brief discussion of the limitations, such as a lack of available …

Analysis Of Traffic Crash Data In Kentucky (2008-2012), Eric R. Green, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 200 8 through 201 2 . A primary objective of this study was to determine average crash statistics for Kentucky highways. Average and critical numbers and rates of crashes were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky’s procedure to identify locations that have abnormal rates or numbers of crashes.

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 …

Controlled Magnetic Reversal In Permalloy Films Patterned Into Artificial Quasicrystals, Vinayak Shantaram Bhat, J. Sklenar, B. Farmer, J. Woods, Jeffrey Todd Hastings, S. J. Lee, J. B. Ketterson, Lance E. De Long

Physics and Astronomy Faculty Publications

We have patterned novel Permalloy thin films with quasicrystalline Penrose P2 tilings and measured their dc magnetization and ferromagnetic resonance absorption. Reproducible anomalies in the hysteretic, low-field data signal a series of abrupt transitions between ordered magnetization textures, culminating in a smooth evolution into a saturated state. Micromagnetic simulations compare well to experimental dc hysteresis loops and ferromagnetic resonance spectra and indicate that systematic control of magnetic reversal and domain wall motion can be achieved via tiling design, offering a new paradigm of magnonic quasicrystals.

Experimental Investigation Of Blowing Effects On Turbulent Flow Over A Rough Surface, Mark A. Miller, Alexandre Martin, Sean C. C. Bailey

Mechanical Engineering Faculty Publications

A high Reynolds number turbulent channel flow facility was used to study the combined effects of roughness and flow injection on the mean flow and turbulence characteristics. It was found that the additional momentum injection through the surface enhanced the roughness effects and for the mean flow the effect of blowing was indistinguishable from that of increased roughness. However, for the turbulence statistics, this analogy broke down in that the addition of blowing resulted in behavior which did not follow that predicted by Townsend’s hypothesis. This was observed as a reduction of outer-scaled Reynolds stress well into the outer layer. …

Utilization Of Mobile Lidar To Verify Bridge Clearance Heights On The Western Kentucky Parkway, Brad Rister, Levi Mcintosh, Joe Whelan

Kentucky Transportation Center Research Report

Bridge clearances can vary from lane-to-lane beneath overpasses, and can often be difficult to measure due to high traffic volumes. Therefore, a mobile LiDAR unit was utilized in this project to obtain the bridge clearance heights on the Western Kentucky Parkway. The LiDAR information was collected at 400,000 points-per-second at a driving speed of 30 mph. Hand measurements were also taken on each bridge to assist in quantifying the potential error between field measurements and LiDAR measurements. The results of the collected LiDAR data appear to be less than 1.2 inches, which appears to be in line with both manufactures …

Assessment Of Kentucky’S Road Fund, Bryan Gibson, Dwight V. Denison, Candice Y. Wallace, Christopher Jepsen, Doug Kreis, Joseph D. Crabtree

Kentucky Transportation Center Research Report

Kentucky’s Road Fund serves as the primary source of funds for the state’s roadway system. Motor fuels taxes and motor vehicle usage taxes are the two main components of Road Fund revenues. In recent years, there has been concern about the ability of the Road Fund, as currently constituted, to provide sufficient revenue to meet the funding needs for Kentucky’s transportation system. This study first analyzed the sources of Road Fund revenue, utilizing historical data to provide context for how past revenues have been generated and where those revenues were spent. In addition to examining revenues, the study also examined …

2013 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green, Tony Fields

Kentucky Transportation Center Research Report

The objective of the survey summarized in this report was to establish a statewide safety belt usage rate in Kentucky for 2013. This rate can be compared to those determined from previous surveys. The 2013 statewide survey continues to document the increase in usage associated with the change in the law to allow primary enforcement and related evaluation and enforcement.

Method And Apparatus For Characterizing Microscale Formability Of Thin Sheet Materials, Nasr A. Shuaib, Marwan K. Khraisheh

Mechanical Engineering Faculty Patents

A method of predicting sheet formability at a microscale level includes the steps of providing a grid pattern on a test sheet, bulging the test sheet to a hemispherical shape until a crack is initiated on the surface of the test sheet, detecting the initiation of the crack, acquiring two images of the surface adjacent to the crack and calculating surface strains on the test sheet.

The Use Of Co-Culturing In Solid Substrate Cultivation And Possible Solutions To Scientific Challenges, Wanying Yao, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

This perspective systematically summarizes the use of solid substrate co‐cultures in agriculture, food, plant, and industrial biotechnology applications. The summarization is organized by organism, i.e. fungus, bacteria, yeast and then co‐cultivation of either two or three organisms. Generally, in solid substrate co‐culture, the organisms synergistically penetrate and degrade the solid substrate, thereby increasing product yield and productivity over a monoculture. Efforts to increase co‐culture performance include optimizing process parameters (pH, temperature, moisture, and oxygen demand) and defining the acceptable types of substrate. Scientific challenges exist in understanding the interactions between microbial stains, such as viability, suite of products, and bio‐transformations. …

Horizontal Pressures In Cylindrical Metal Silos And Comparison With Different International Standards, José W. B. Do Nascimiento, José P. Lopes Neto, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

The focus of this research was to evaluate the horizontal pressures on a cylindrical metal silo of corrugated walls and flat bottom with 1.82m diameter and 5.4m high, and to compare the values with those obtained theoretically by the ISO 11697, EP 433 and AS 3774 standards. The silo was symmetrically filled and constant speed with wheat cv. soft red for two different height/diameter ratios (H/D) and was unloaded through three orifices with a diameter of 71.6mm, one concentric and two eccentrics. Horizontal pressures were measured on the walls of the silo at three positions using hydraulic type pressure cells. …

Metal-Based Nanoparticle Interactions With The Nervous System: The Challenge Of Brain Entry And The Risk Of Retention In The Organism, Robert A. Yokel, Eric A. Grulke, Robert C. Macphail

Pharmaceutical Sciences Faculty Publications

This review of metal-based nanoparticles focuses on factors influencing their distribution into the nervous system, evidence they enter brain parenchyma, and nervous system responses. Gold is emphasized as a model metal-based nanoparticle and for risk assessment in the companion review. The anatomy and physiology of the nervous system, basics of colloid chemistry, and environmental factors that influence what cells see are reviewed to provide background on the biological, physical–chemical, and internal milieu factors that influence nervous system nanoparticle uptake. The results of literature searches reveal little nanoparticle research included the nervous system, which about equally involved in vitro and in …

Evaluation Of Mechanically Stabilized Earth Walls For Bridge Ends In Kentucky; What Next?, Charlie Sun, Clark Graves

Kentucky Transportation Center Research Report

This report summarizes the nationwide survey results on MSE wall abutment status. Many of handy features on MSE Wall Abutment Inspection/Rating In KY web application are highlighted, and various graphical user interfaces of the web application are illustrated and described. The inspection/rating results for fifty-six (56) existing MSE wall abutments are presented and discussed.

Observations Of Peak Strength Behavior In Csa Cement Mortars, Joshua V. Brien, Kevin R. Henke, Kamyar C. Mahboub

Civil Engineering Faculty Publications

The purpose of this study was to assess the mechanical property performance behavior of calcium sulfoaluminate (CSA) cement mortar when cured at ambient laboratory temperature of ~23°C (73°F) and constant 50% relative humidity for an extended period of time. Four CSA cement mortars were tested. Three CSA cement mortars contained equivalent mass amounts of calcium sulfate; whereas, the fourth mortar contained double the amount of calcium sulfate. The three CSA cement mortars containing constant mass amounts of calcium sulfate differed as the specific type of calcium sulfate varied across the three formulations—one mortar containing solely anhydrite, one mortar contained half …

Effects Of Hinged Dowel System On The Performance Of Concrete Pavement Joints, Alireza Zeinali, Kamyar C. Mahboub, Herbert F. Southgate

Civil Engineering Faculty Publications

Concrete joint failure is a major distress mode in rigid pavements. Improving the joint performance in concrete pavements could yield substantial savings in terms of reduced maintenance and rehabilitation costs. The newly developed Hinged Dowel System (HDS) is a means for transferring loads across the concrete pavement joints. The HDS was patented as a new invention by the United States Patent and Trademark Office, and it is envisioned that it could significantly reduce the potential for joint failure in concrete pavements. The HDS assembly comprises a number of dowel bars and a collective hinge provided at the mid-length of the …

Influence Of Media Composition On The Growth Rate Of Chlorella Vulgaris And Scenedesmus Acutus Utilized For Co2 Mitigation, Czarena L. Crofcheck, Xinyi E, Aubrey Shea, Michael D. Montross, Mark Crocker, Rodney Andrews

Biosystems and Agricultural Engineering Faculty Publications

Atmospheric carbon dioxide levels have increased since the industrial revolution due to increasing combustion of fossil fuels. One possible CO₂ mitigation strategy is the use of microalgae for mitigation of CO₂. This paper focuses on the influence of media composition on the growth rate of two microalgae strains, Chlorella vulgaris and Scenedesmus actus. A KNO₃ based medium was found to work better for Chlorella, while a urea based equivalent worked better for Scenedesmus. The urea based media investigated here resulted in growth similar to that found with previously reported KNO₃ based media. …

On Electric Conduction Of Amorphous Silicon Carbonitride Derived From A Polymeric Precursor, Yaohan Chen, Fuqian Yang, Linan An

Chemical and Materials Engineering Faculty Publications

A long-existing problem that the conductivity of amorphous silicon carbonitrides derived from polymeric precursor increases significantly with pyrolysis temperature is investigated. We show that the conductivity exhibited an Arrhenius dependence on pyrolysis temperature, with the activation energy of ∼3.41 eV. Structural analysis using Raman spectroscopy reveals that the free carbon within the material undergoes a sp³-to-sp² transition as pyrolysis temperature increases, with the activation energy of ∼3.6 eV. We conclude that the pyrolysis-temperature induced increase in the conductivity is mainly due to the increase in the conductivity of the free carbon. A simple model is proposed to …

Coupled Flow Field Simulations Of Charring Ablators With Nonequilibrium Surface Chemistry, Hicham Alkandry, Iain D. Boyd, Alexandre Martin

Mechanical Engineering Faculty Publications

This paper describes the coupling of a Navier-Stokes solver to a material response code to simulate nonequilibrium gas-surface interactions. The Navier-Stokes solver used in this study is LeMANS, which is a three-dimensional computational fluid dynamics code that can simulate hypersonic reacting flows including thermo-chemical nonequilibrium effects. The material response code employed in this study is MOPAR, which uses the one-dimensional control volume nite-element method to model heat conduction and pyrolysis gas behavior. This coupling is demonstrated using a test case based on the Stardust sample return capsule. Coupled simulations are performed at three different trajectory conditions. The effects of the …

A New Approach To Light-Weight Ablators Analysis: From Micro-Tomography Measurements To Statistical Analysis And Modeling, Nagi N. Mansour, Francesco Panerai, Alexandre Martin, Dilworth Y. Parkinson, Alastair A. Macdowell, Abdelmoula Haboub, Timothy A. Sandstrom, Tony Fast, Gerard L. Vignoles, Jean Lachaud

Mechanical Engineering Faculty Publications

The morphology characteristics and ablation behavior of a highly porous carbon fiber preform are studied using a combined experimental/numerical approach. Morphological characterization of the three-dimensional structure of the material is performed by hard X-rays synchrotron micro-tomography at the Advanced Light Source of Lawrence Berkeley National Laboratory. The resulting micro-tomography voxels are used to compute geometrical properties of the carbon preform, like porosity, specific surface area and tortuosity, that are otherwise indirectly measured through experimental techniques. The reconstructed volumes are used to build a computational grid for numerical simulations of the fibers' ablation. By modeling the diffusion of oxygen through the …

Volume Averaged Modeling Of The Oxidation Of Porous Carbon Fiber Material, Alexandre Martin

Mechanical Engineering Faculty Publications

Charring ablators remain the premium choice for space exploration missions that involve atmospheric re-entry. This type of ablative material is composed of a carbon matrix, usually made of fibers, which is then impregnated with a resin. During re-entry, the high heat flux produced by convective heating causes the material to chemically react. First, the resin pyrolyzes, and is vaporized into a gas that travels through the material, and is eventually ejected at the surface. Then, as the temperature rises, the surface of the porous matrix recess through ablative processes. For re-entry conditions typical of space exploration missions, this is mainly …

Flow-Tube Oxidation Experiments On The Carbon Preform Of Pica, Francesco Panerai, Alexandre Martin, Nagi N. Mansour, Steven A. Sepka, Jean Lachaud

Mechanical Engineering Faculty Publications

Oxidation experiments on the carbon preform of a phenolic-impregnated carbon ablator were performed in the NASA Ames ow-tube reactor facility, at temperatures between 700 and 1300 K, under dry air gas at pressures between 103 and 104 Pa. Mass loss, volumetric recession and density changes were measured at different test conditions. An analysis of the diffusion/reaction competition within the porous material, based on the Thiele number, allowed us to identify low temperature and low pressure conditions to be dominated by in-depth volume oxidation. Experiments above 1000 K were found at transition conditions, where diffusion and reaction occur at similar scales. …

Multi-Dimensional Modeling Pyrolysis Gas Flow Inside Charring Ablators, Haoyue Weng, Alexandre Martin

Mechanical Engineering Faculty Publications

Using an ablative thermal/material response code, the importance of three-dimensionality for modeling ablative test-article is addressed. In particular, the simulation of the pyrolysis gas flow inside a porous material is presented, using two different geometries. The effects of allowing the gas to flow out of the side wall are especially highlighted. Results show that the flow inside the test-article is complex, and that the 0D or 1D assumption made in most Material Response (MR) codes might not be valid for certain geometries.

Evaluation Of Alternative Snowplowable Markers And Snowplowing Procedures, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objectives of this study were to investigate viable alternatives to the currently approved snowplowable raised pavement marker and alternative methods and equipment used to snowplow roadways. The study included evaluating any potential durable and effective pavement marker that is not disruptive to snowplowing operations and alternative snowplowing procedures and equipment that do not damage pavement delineation and pavements. Implementation possibilities resulting from the research project include a recessed snowplowable marker and improved/alternative snowplowing procedures and equipment.

The alternative snowplowable markers included in the evaluation were the current steel casting marker and a recessed marker. The evaluations confirmed past research …

Evaluation Of Wet-Nighttime Delineation, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of the research was to evaluate the alternative methods which could potentially provide effective and durable delineation of roadways during wet-nighttime conditions. Following is a summary of conclusions for future procedures and materials which should be considered as a method to provide effective lane delineation during wet-nighttime conditions.

• Snowplowable raised pavement markers should continue to be used on interstates and parkways. The installation process must ensure the markers are not placed on or adjacent to the pavement joint.
• Lenses in the steel casting raised pavement markers should be replaced on a three-year cycle. The condition of the castings …

Compressive Response Of Polycrystalline Nicomnga High-Temperature Meta-Magnetic Shape Memory Alloys, H. E. Karaca, A. S. Turabi, B. Basaran, A. K. Pathak, I. Dubenko, N. Ali, Y. I. Chumlyakov, P. Li

Mechanical Engineering Faculty Publications

The effects of the addition of quaternary element, Co, to polycrystalline NiMnGa alloys on their magnetic and shape memory properties have been investigated. NiCoMnGa polycrystalline alloys have been found to demonstrate good shape memory and superelasticity behavior under compression at temperatures greater than 100 °C with about 3% transformation strain and low-temperature hysteresis. It is also possible to train the material to demonstrate a large two-way shape memory effect.