Engineering Commons^™

A 3d Model For Earthquake-Induced Liquefaction Triggering And Post-Liquefaction Response, Arash Khosravifar, Ahmed Elgamal, Jinchi Lu, John Li

Civil and Environmental Engineering Faculty Publications and Presentations

A constitutive soil model that was originally developed to model liquefaction and cyclic mobility has been updated to comply with the established guidelines on the dependence of liquefaction triggering to the number of loading cycles, effective overburden stress (Kσ), and static shear stress (Kα). The model has been improved with new flow rules to better capture contraction and dilation in sands and has been implemented as PDMY03 in different computational platforms such as OpenSees finite-element, and FLAC and FLAC3D finite-difference frameworks. This paper presents the new modified framework of analysis and describes a guideline to calibrate the input parameters of …

Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou

Materials Science and Engineering Faculty Research & Creative Works

A new nonlinear hysteretic model with considering the loading, unloading, and reloading processes is developed based on Drucker—Prager yield criterion and finite-element analysis. This model can be used for multiple repeated elastic—plastic normal direction contact problems between two identical spherical geomaterials. After examining the influence of material properties, strain hardening, and loading histories, we found that the hysteretic phenomena (represented by residual displacement and plastic work) become weak after the first cycle, and the subsequent cycles step into elastic shakedown state eventually. A critical number of cycles can be used to estimate the state of ratchetting, plastic shakedown, as well …

Holmium And Samarium Detectability In Post-Blast Residue, James Seman, Catherine E. Johnson, Carlos Henry Castano Giraldo

Mining Engineering Faculty Research & Creative Works

The creation of an identification taggant that survives detonation and can easily be recovered would prove invaluable in situations such as a terrorist attack where the explosives have been detonated and need to be traced by law enforcement. This paper shows that traces of two elements, samarium (Sm) and holmium (Ho), can be identified from explosive post-blast residue. This is the first step to creating a viable taggant system that survives detonation. The two elements were introduced to the explosive before detonation, and the post-blast residue was analyzed by neutron activation analysis (NAA). These data indicate the presence of these …

Detonation Synthesis Of Alpha-Variant Silicon Carbide, Martin Langenderfer, Catherine E. Johnson, William Fahrenholtz, Vadym Mochalin

Mining Engineering Faculty Research & Creative Works

A recent research study has been undertaken to develop facilities for conducting detonation synthesis of nanomaterials. This process involves a familiar technique that has been utilized for the industrial synthesis of nanodiamonds. Developments through this study have allowed for experimentation with the concept of modifying explosive compositions to induce synthesis of new nanomaterials. Initial experimentation has been conducted with the end goal being synthesis of alpha variant silicon carbide (α-SiC) in the nano-scale. The α-SiC that can be produced through detonation synthesis methods is critical to the ceramics industry because of a number of unique properties of the material. Conventional …

Microwave-Assisted Synthesis Of Palladium Nanoparticles Supported On Copper Oxide In Aqueous Medium As An Efficient Catalyst For Suzuki Cross-Coupling Reaction, Hany A. Elazab, M. A. Sadek, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report here a reliable green method for the synthesis of palladium nanoparticles supported on copper oxide as a highly active and efficient catalyst for Suzuki cross-coupling reaction. The experimental synthetic approach is based on microwave-assisted chemical reduction of an aqueous mixture of palladium and copper salt simultaneously using hydrazine hydrate as reducing agent. The catalyst was fully characterized using various techniques showing well-dispersed palladium nanoparticles. The catalytic activity and recyclability of the prepared catalyst were experimentally explored in the ligand-free Suzuki cross-coupling reaction with a diverse series of functionalized substrates. The synthesized Pd/CuO catalyst shows many advantages beside its …

Understanding Transit System Performance Using Avl-Apc Data: An Analytics Platform With Case Studies For The Pittsburgh Region, Xidong Pi, Mark Egge, Jackson Whitmore, Amy Silbermann, Zhen Sean Qian

Journal of Public Transportation

This paper introduces a novel transit data analytics platform for public transit planning, assessing service quality and revealing service problems in high spatiotemporal resolution for public transit systems based on Automatic Passenger Counting (APC) and Automatic Vehicle Location (AVL) technologies. The platform offers a systematic way for users and decision makers to understand system performance from many aspects of service quality, including passenger waiting time, stop-skipping frequency, bus bunching level, bus travel time, on-time performance, and bus fullness. The AVL-APC data from September 2012 to March 2016 were archived in a database to support the development of a user-friendly web …

Material Properties Of Laser Powder Bed Fusion Processed 316l Stainless Steel, Steven Keckler

Graduate Theses & Non-Theses

Laser powder bed fusion additive manufactured 316L stainless steel specimens were evaluated to establish a baseline for future research in determining an optimized energy density and build orientation. Test specimens were printed at various energy densities. At each energy density, tensile and fatigue specimens were printed at 0o (longitudinal), 45o, and 90o (transverse) orientation to the build plate. Tensile and high cycle fatigue tests were performed then representative fracture surfaces were analyzed. The apparent melt track and dendrite size were evaluated using grain analysis software. Static loading of the tensile specimens showed a marginal difference in UTS for specimens with …

Us 31w Jefferson County Pavement Surface Treatment Evaluation, Tim C. Scully Jr.

Kentucky Transportation Center Research Report

Reflective cracking inevitably occurs when asphaltic concrete (AC) is placed over an existing unfractured Portland cement concrete (PCC) pavement. However, manufacturers state their products will mitigate reflective cracking, therefore extending the pavement life cycle.

To evaluate the performance of each manufacturer’s product, an experimental test section consisting of a southbound and northbound segment was established on US 31W in Louisville, Kentucky. The funding for this project will help track the performance of each product from the construction phase through the long-term monitoring phase. Hall Construction performed all work.

The Effect Of Destoning And Enzymatic Pretreatments On The Biofuel Production From Olive Cake, Patrick Tai

Master's Theses

More than 16,000 tons of olive cake was produced in the United States in 2017. Olive cake is a by-product of olive oil extraction, which has limited animal feed potential, and poses an environmental threat when landfilled due to its high organic load and polyphenol content. This residue has potential for biofuel (bioethanol and biomethane) production because it is rich in polysaccharides such as pectin, hemicellulose, and cellulose. Yet, olive cake contains olive stones that can impede its conversion to biofuel. Therefore, two methods of destoning, centrifugation and screening by horizontal screw press, were first compared. Both methods removed an …

Power Electronics Powertrain Architectures For Hybrid And Solar Electric Airplanes With Distributed Propulsion, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Distributed propulsion in aircraft has been shown to increase reliability and benefit aerodynamic performance. This paper discusses power electronic architectures and proposes control schemes suitable for distributed propulsion in hybrid and electric airplanes. Hybrid electric airplanes include permanent magnet synchronous generators driven by jet engines. The output of the generators is connected to the propulsion motors through back to back voltage source converters. Batteries, connected to the DC bus through buck-boost converters, are used to provide additional power to the propulsion motors during take off and climb. In the case of electric airplanes, the jet engine-permanent magnet generator system is …

Non-Linear Deformation Analysis Of An Embankment Dam, Silas T. Sanderson

Civil and Environmental Engineering Master's Project Reports

Non-linear deformation analysis (NDA) of embankment dams is becoming more common as geotechnical engineers seek to better understand how critical infrastructure will perform under high seismic loading. In order to perform this type of analysis, site specific ground motions and engineering properties of the embankment dam are required. The NDA modeling effort consists of a static and seepage analysis to establish an initial stress state followed by a dynamic analysis to simulate the embankment response to ground motions. Using this approach, a two dimensional NDA was performed on an embankment dam using the NDA program FLAC. This report discusses the …

Smart Bandage For Monitoring And Treatment Of Chronic Wounds, Pooria Mostafalu, Ali Tamayol, Rahim Rahimi, Manuel Ochoa, Akbar Khalilpour, Gita Kiaee, Iman K. Yazdi, Sara Bagherifard, Mehmet R. Dokmeci, Babak Ziaie, Sameer R. Sonkusale, Ali Khademhosseini

Department of Mechanical and Materials Engineering: Faculty Publications

Chronic wounds are a major health concern and they affect the lives of more than 25 million people in the United States. They are susceptible to infection and are the leading cause of nontraumatic limb amputations worldwide. The wound environment is dynamic, but their healing rate can be enhanced by administration of therapies at the right time. This approach requires real-time monitoring of the wound environment with on-demand drug delivery in a closed-loop manner. In this paper, a smart and automated flexible wound dressing with temperature and pH sensors integrated onto flexible bandages that monitor wound status in real-time to …

Super Hydrophobicity Of Sputtered Ptfe Films On Nanotextured Aluminum Surface, S Lumjeak, T Lertvanithpo, P Limnonthakul, M Horprathum, P Songsirirtthigul

Journal of Metals, Materials and Minerals

In this research, the superhydrophobic surface was prepared by using the polytetrafluoroethylene (PTFE) thin films which deposited on aluminum (Al) nanotextures. The Al nanotextures have been prepared under different alkaline-treatment concentrations, and deposited with the PTFE thin films by the RF magnetron sputtering technique. During the alkaline treatments, the Al surface was immersed in the potassium hydroxide (KOH) solution with the concentrations of 1 mM to 0.10 mM. Then, the samples of PTFE films were deposited on Al nanotextures were characterized; the crystal structures, chemical compositions, physical morphologies, and surface roughness by photoelectron spectroscopy (PES), field-emission scanning electron microscopy (FE-SEM) …

Aluminium-Sic Composite: Study Of Its Mechanical Properties, D Sánchez-García, A Herrera-Vázquez, J Hinojosa-Torres

Journal of Metals, Materials and Minerals

Cylindrical specimens with geometries and sizes, in agreement with the standard of American Society for Testing Materials (ASTM), they were used to characterize the tension behaviour of the composite. A significant effect of the SiC shape/size on the tensile behaviour of aluminium-based composite was observed, caused by the differences between the superheat (993 K) and the mould temperatures (333 K, 473 K, 623 K) in the melting practice. Ultimate tensile stress and Fracture Toughness factor for the composite showed a numerical advantage over the corresponding ones to the aluminium at a solidification speed of 82.5 K·s-1. At the mould temperature …

A Comparative Study Of Nanofibrillated Cellulose And Microcrystalline Cellulose As Reinforcements In All-Cellulose Composites, S Tanpichai

Journal of Metals, Materials and Minerals

The reinforcing abilities of nanofibrillated cellulose (NFC) and microcrystalline cellulose (MCC) in composites were investigated and compared. All-cellulose composites were prepared using the dissolved MCC as the matrix, and NFC and MCC were introduced as the reinforcing phase. With the addition of MCC, tensile strength of the composites decreased; on the other hand, the higher tensile strength of the composites with NFC was found with increasing a NFC content. Strong interfacial interaction between the matrix and reinforcing phase could be obtained at a low content of the reinforcement was observed. At a higher content of the reinforcement the fiber pull-out …

Effect Of Tempering Temperature On Microstructure And Mechanical Properties Of Low Alloy Steel In Quenched Tempered Conditions, V Yadav, A K. Singh, G Sahoo

Journal of Metals, Materials and Minerals

The effect of tempering temperature on the microstructure and mechanical properties of a low alloy steel has been investigated using optical microscopy, hardness testing and Charpy V-notch impact testing at -20°C, -40°C and -60°C. At first, the laboratory based study revealed that tempering the specimens at 650°C resulted in lowest hardness with highest impact energy. Based on this, the heat-treated industrial steel showed sufficiently high toughness after Charpy V-notch impact testing at -40°C. Fractography after impact testing showed predominately ductile dimple rupture in the sample tempered at 650°C. The presence of decomposed martesitic laths in prior austenite was noticed in …

Wear Properties Of Boron Added High Strength Low Alloy (Hsla) Sae 8620 Steel, M Musa, A G. Mohammed, A Muhammad

Journal of Metals, Materials and Minerals

The High Strength Low Alloy (HSLA) SAE 8620 steel with different contents of boron in ppm rate used in bearings, automotive gearing and automotive body components applications were studied. We report the relationship between wear properties, microstructural characterization and hardness properties of the steel. The steel chemical composition is selected to obtain relatively high mechanical properties with different boron contents. Increasing the normalization temperature and boron content, shows ferrite grain-size becomes larger when compared to lower normalization temperatures and boron content. With differences in boron content, only 2 HBN were measured from the average hardness of 3.3 ppm and 13.5 …

Crystalline Silica In Compressed Rice Hull Coke Ash, T Okutani, E Ichikawa, H Nagai, T Hashimoto, T Makihata

Journal of Metals, Materials and Minerals

Compressed rice hull coke was produced by compressing rice hulls ground to less than 200 µm diameter at 1.22x106 N/m2 and 310˚C with an oxygen deficient atmosphere. The compressed rice hull coke had a 5 cm outer diameter, a 1.5 cm inner diameter and 35 cm length. The density of the coke is 1.2, and, the heat value is 16570 kJ·kg-1. In this study, 2 kg coke was combusted at the average temperature of 850˚C for 104 min with a maximum temperature of 860˚C. The ash was colored black-grey, and the form remained coke. The ash contained 95.4% silica with …

Investigation Of Erosive Wear Behaviour Of Tungsten Carbide Cobalt Coated Metal Matrix Composites Using Ann, M Pasha, M Kaleemulla

Journal of Metals, Materials and Minerals

An artificial neural network (ANN) model was employed on erosive wear result of aluminium 7034 T6 reinforced with different weight percentage of Al2O3 and SiC with tungsten carbide cobalt (WC-Co) coated composites. WC-Co in the form of powder was pretreated before coating, to identify the inflence of pretreatment on the substrate. The WC-Co coating was deposited with high velocity oxy fuel (HVOF) sparay method. The microstructural examination was carried through scanning electron microscope (SEM) and to identify the elemental composition of coated specimens, energy dispersive X-ray analysis (EDX) was used. These material charecterisation shows that pretreated WC-Co coated Al 7034 …

Starch Consolidation Of Porous Fused Silica Ceramics, K Kanlai, T Wasanapiarnpong, B Wiratphinthu, K Serivalsatit

Journal of Metals, Materials and Minerals

Starch consolidation is a forming technique, in which ceramic suspension is consolidated by gelatinization of starch under suitable temperature. This technique is promising for fabricating porous ceramics because starch can act as a binder as well as a pore former. In this study, porous fused silica ceramics were prepared by starch consolidation using glutinous rice flour as a gelling agent. The 29 vol% solid loading of fused silica slurries with the addition of glutinous rice flour were prepared. After mixing the slurries were poured into a plastic mold and kept in an oven at 75ºC for an hour. The green …

Carboxymethylchitosan-Based Hydrogels Crosslinked With Polydimethylsiloxane, N Rodkate, N Deepuppha, B Rutnakornpituk, M Rutnakornpituk

Journal of Metals, Materials and Minerals

Synthesis and properties of hydrophilic carboxymethylchitosan (CMC) hydrogels containing hydrophobic polydimethylsiloxane (PDMS) were herein presented. Fourier transform infrared spectroscopy indicated that PDMS can covalently bound to CMC chains with the use of hexamethylene-1,6-di-(aminocarboxysulfonate) (HDA), a water soluble crosslinker. Also, according to scanning electron microscopy, PDMS microphases with the size of 0.2-0.5 µm in diameter were thoroughly dispersed in CMC matrix. Addition of PDMS improved properties of the CMC hydrogels including increasing water vapor permeability and water swellability, improving tensile properties and increasing surface hydrophobicity. PDMS with different amounts (1-20 wt%) and molecular weights (2,000 and 8,000 g·mol-1) were added into …

Simple And Rapid Preparation Of Cuo Film Using Silar Process For Application As Hole-Transporting Layer In P-I-N Perovskite Solar Cell, S Wongrerkdee, K Hongsith, S Choopun, K Lohawet, P Kumno

Journal of Metals, Materials and Minerals

Copper oxide (CuO) films are considered to be an alternative metal oxide semiconductor for hole-transporting layer application in p-i-n perovskite solar cells due to their unique properties including intrinsic p-type materials and energy band level matching. The films can be synthesized using several methods such as sputtering, solution process and spin-coating processes. However, using the successive ionic layer adsorption and reaction (SILAR) process to prepare a CuO hole-transporting layer in p-i-n perovskite solar cells is still underreported. Thus, this study prepared the SILAR processed CuO films and applied as a hole-transporting layer in p-i-n perovskite solar cells. The results showed …

Influence Of Blt Content On Phase Structure And Electrical Properties Of (1-X)Bt-Xblt Ceramic, N Thongmee, R Sumang, S Pojprapai, T Klaytae

Journal of Metals, Materials and Minerals

(1-x)BaTiO3-x(Bi3.25La0.75)Ti3O12; (1-x)BT-xBLT ceramics with x = 0-0.20 wt.% were prepared by a solid-state reaction method. The BaTiO3 (BT) and (Bi3.25La0.75)Ti3O12 (BLT) powders were, respectively, calcined at 1100°C and 750°C for 4 h. The (1-x)BT-xBLT samples were sintered between 1250°C and 1350°C. The structure exhibited a transformation from tetragonal to orthorhombic with increasing in BLT contents. The average grain size increased with increasing BLT contents. The maximum density and relative density about 6.19 ± 0.07 g/cm3and 99.3% were obtained for the composition of 0.95BT-0.05BLT. The Curie temperature (Tc) continuously decreased with increase in BLT contents. The dielectric constant showed a broad …

Eggshell Waste: An Effective Source Of Hydroxyapatite For Photocatalyst, S Ummartyotin, H Manuspiya

Journal of Metals, Materials and Minerals

Interest in eggshell waste and its modification has been increasing rapidly. The outstanding property of eggshell waste is its high calcium carbonate content. This can be transformed to calcium oxide, and can provide a source of hydroxyapatite. As interest in clean technology has grown, the use of eggshell waste has become a focus of research. The objective of this review article is to characterize eggshell waste, describe the preparation of hydroxyapatite from eggshell waste and its modification, and discuss the use of hydroxyapatite as a photocatalyst.

Recent Developments In The Field Of Metal Foam-Polymer Hybrid Materials: A Brief Overview, A Chaturvedi

Journal of Metals, Materials and Minerals

In this paper, a brief overview of the various techniques employed for the preparation of metal foam-polymer hybrid/composite materials including infiltration/penetration and adhesive joining is given. Scanning electron microscopy (SEM) micro structural characterization method and various dependent mechanical properties such as stress-strain diagram, energy absorption etc is described. In addition, some possible applications of such materials are discussed. The paper intends to inform as well as educate the reader about the various aspects of this emerging field in a lucid manner.

Arrhenius Rate Chemistry-Informed Inter-Phase Source Terms (Arciist), Matthew J. Schwaab, Robert B. Greendyke, Bryan J. Steward

Faculty Publications

Currently, in macro-scale hydrocodes designed to simulate explosive material undergoing shock-induced ignition, the state of the art is to use one of numerous reaction burn rate models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these burn rate models are largely based on empirical data and must be recalibrated for every new material being simulated. We propose that the use of Arrhenius Rate Chemistry-Informed Interphase Source Terms (ARCIIST) in place of empirically derived burn models will improve the accuracy for these computational codes. A reacting chemistry model of this form was developed for the cyclic …

Privacy-Preserving Mining Of Association Rule On Outsourced Cloud Data From Multiple Parties, Lin Liu, Jinshu Su, Rongmao Chen, Ximeng Liu, Xiaofeng Wang, Shuhui Chen, Ho-Fung Fung Leung

Research Collection School Of Computing and Information Systems

It has been widely recognized as a challenge to carry out data analysis and meanwhile preserve its privacy in the cloud. In this work, we mainly focus on a well-known data analysis approach namely association rule mining. We found that the data privacy in this mining approach have not been well considered so far. To address this problem, we propose a scheme for privacy-preserving association rule mining on outsourced cloud data which are uploaded from multiple parties in a twin-cloud architecture. In particular, we mainly consider the scenario where the data owners and miners have different encryption keys that are …

Soa Maturity Influence On Digital Banking Transformation, Alan Megargel, Venky Shankararaman, Terence P. C. Fan

Research Collection School Of Computing and Information Systems

Digital Banking is an evolution of online banking, where the banks attempt to further enhance customer experience by integrating digital technologies such as mobile technology, social media and analytics. Traditional banks have the highest barriers to entry into the digital banking market due to the presence of legacy core banking systems. These legacy systems while still high performing and reliable, are inflexible to change and are not easily integrated to the modern application systems needed for delivering digital banking services across multiple online banking channels. One solution that is widely adopted in the industry to overcome this obstacle is the …

Adopt: Combining Parameter Tuning And Adaptive Operator Ordering For Solving A Class Of Orienteering Problems, Aldy Gunawan, Hoong Chuin Lau, Kun Lu

Research Collection School Of Computing and Information Systems

Two fundamental challenges in local search based metaheuristics are how to determine parameter configurations and design the underlying Local Search (LS) procedure. In this paper, we propose a framework in order to handle both challenges, called ADaptive OPeraTor Ordering (ADOPT). In this paper, The ADOPT framework is applied to two metaheuristics, namely Iterated Local Search (ILS) and a hybridization of Simulated Annealing and ILS (SAILS) for solving two variants of the Orienteering Problem: the Team Dependent Orienteering Problem (TDOP) and the Team Orienteering Problem with Time Windows (TOPTW). This framework consists of two main processes. The Design of Experiment (DOE) …

Characterizing Common And Domain-Specific Package Bugs: A Case Study On Ubuntu, Xiaoxue Ren, Qiao Huang, Xin Xia, Zhenchang Xing, Lingfeng Bao, David Lo

Research Collection School Of Computing and Information Systems

Ubuntu is an open source software platform that runs everywhere from the smartphone, the tablet and the PC to the server and the cloud. In Ubuntu, there are many self-contained or third-party software packages for different use, and a bug report in Ubuntu could affect one or more packages simultaneously. Identifying the common package bugs in Ubuntu can help both developers and users better understand the packages they are developing or using, and also provide further guidelines to developers of similar packages in the future. In this paper, we perform a large-scale empirical study of common package bugs on Ubuntu …