Engineering Commons^™

Continuous Flow Process For Recovery Of Metal Contaminants From Industrial Wastewaters With Magnetic Nanocomposites, David Hutchins

Graduate Theses & Non-Theses

Remediation of metal-containing industrial effluents presents both a technical challenge and an economic opportunity. Many industrial waste streams contain low levels of metal ions requiring treatment prior to discharge. Existing treatment technologies are frustrated by disparate compositions and low metal concentrations. Chemical precipitation is effective; however, it requires excessive reagents and discourages selective recovery. Ion-exchange enables recovery, but requires a batch process with extensive operational and maintenance demands, and is rarely implemented in large-scale applications. A continuous flow process capable of selective recovery would present many advantages over existing technologies.

This research examines and develops a continuous flow process for …

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 …

Identification Of Transportation Infrastructure At Risk Due To Sea Level Rise And Subsidence Of Land In Coastal Louisiana, Sanjay Tewari, Wesley Palmer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The coast of Louisiana is under threat because of sea level rise and land subsidence. Sea water is encroaching deeper inland and as a result Louisiana is losing at an alarming rate. The combined effect of sea level rise and land subsidence is variable spatially. This paper focuses on this combined effect in identifying the transportation infrastructure that is at risk of getting affected by the sea-water inundation of the land.

This paper is an attempt of taking account of land elevation data monitored continuously at various locations along the coast of Louisiana and combining it with local sea level …

The Use Of Recommender Systems In Web Applications – The Troi Case, Donjeta Mulaj

Theses and Dissertations

Avoiding digital marketing, surveys, reviews and online users behavior approaches on digital age are the key elements for a powerful businesses to fail, there are some systems that should preceded some artificial intelligence techniques. In this direction, the use of data mining for recommending relevant items as a new state of the art technique is increasing user satisfaction as well as the business revenues. And other related information gathering approaches in order to our systems thing and acts like humans. To do so there is a Recommender System that will be elaborated in this thesis. How people interact, how to …

Performanca E Makinave Kerkuese Duke Perdorur Cloud Shërbimet “Elasticsearch” Dhe “Algolia”, Besnik Korça

Theses and Dissertations

Ueb Aplikacionet me data-set të mëdha në kohën e tanishme janë shumë më të përhapura. Kërkimet e të dhënave në data-set të tilla për shkak të performances bëhen duke përdorur makinat kërkuese. Provider të ndryshëm ofrojnë makina kërkuese si Software as a Service(SaaS) shërbime të cilat kanë për avantazh konfigurimin minimal që duhet bërë makinave kërkuese për t’i vënë në funksion. Nëpërmjet këtij punimi synohet që së pari të analizohen shërbimet cloud computing që ofrohen nga provider të ndryshem. Pastaj pasi që fokusi i makinave kërkuese ndodhet në “information retrieval” është bë analizimi i disa teknikave të “information retrieval”. Makinat …

Modelimi Dhe Kontrolli I Sistemit Të Mikrorrjetit Me Fotovoltaik/Turbina Me Erë, Kadri Krasniqi

Theses and Dissertations

Mikrorrjetet çdo ditë e më tepër janë duke u bërë faktorë më të rendësishëm për të ardhmen e sistemeve të energjisë. Në këtë temë janë marrë në konsideratë dy burime të Energjisë: Energjinë diellore dhe atë të erës. Këto dy burime të ripërtritshme të Energjisë janë të lidhura paralel në sistemin e mikrorrjetit, në menyrë që të marrim performancë më të mirë nga mikrorrjeti. Mikrorrjeti është koncept që integron një sasi të madhe të burimeve të vogla duke mos ndërprerë operimin e rrjetit kryesorë. Ky rrjet hibrid përbëhet nga panelet fotovoltaike dhe turbina të erës për rrjetet DC respektivisht për …

Struktura Nga Druri Monolit (Objekt Me Destinim Ekonomik, Zona Industriale Gjakovë), Çlirim Qarri

Theses and Dissertations

Motivi për këtë hulumtim bazohet në cilësitë pozitive të drurit monolit si material ndërtimor. Objekti i trajtuar në këtë punim është projektuar si objekt me destinim ekonomik dhe lokacioni i tij është menduar në zonën industriale, Gjakovë. Problematikë kryesore e realizimit të objekteve ekonomike është krijimi i hapësirave të mëdha mes mbajtësve, në mënyrë që të mos pengohet procesi teknologjik. Përcaktimi i distancës mes mbajtësve shpesh kufizohet nga pesha vetjake e materialit të mbajtësve, prandaj për këtë punim është përzgjedhur druri monolit si material me peshë vetjake katër herë më të vogël se betoni. Pesha e vogël vetjake e materialit …

Punimet Tokësore Për Ndërtimin E Infrastrukturës Rrugore, Gëzim Fetahu

Theses and Dissertations

Historia e lindje së rrugëve është e vjetër po aq sa është edhe shfaqja e njeriut në Tokë. Rruga lindi si kërkesë e njeriut për të siguruar mirëqenien e tij etj. Mbulimi me rrjetin e infrastrukturës rrugore për një vendi, territori, rajoni, zone etj., ka një rëndësi të veçantë dhe është e domosdoshme për një standard jetësor sa më cilësor. Si në të kaluarën, edhe sot rrejti rrugor, respektivisht infrastruktura rrugore ka luajtur dhe luan rolin dominant në zhvillimin e përgjithshëm social dhe ekonomik. Ndërtimi i rrugëve ballafaqohet me ndërhyrje të shumta të cilat realizohen përmes punimeve tokësore siç janë: …

Sloped And Mitered Concrete Headwalls, Kean H. Ashurst Jr., Brad W. Rister, Eileen Grady, Jason K. Ward

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) currently uses several pipe culvert end treatments, including standard headwalls, slope and flared headwalls, sloped and parallel headwalls, and safety metal ends. These treatments, however, can pose a safety hazard to motorists and those performing landscaping work (e.g., mowing). Crash statistics from 2012 through 2016 for Kentucky reveal that 49 fatalities and 148 incapacitating injuries occurred in incidents where culverts/headwalls were coded as the first harmful event on the police report. One solution to the safety hazards associated with standard pipe culvert headwalls is to use sloped and mitered concrete headwalls instead. To evaluate the …

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 …

Computational Fluid Dynamics Modeling And In Situ Physics-Based Monitoring Of Aerosol Jet Printing Toward Functional Assurance Of Additively-Manufactured, Flexible And Hybrid Electronics, Roozbeh (Ross) Salary

Graduate Dissertations and Theses

Aerosol jet printing (AJP)—a direct-write, additive manufacturing technique—has emerged as the process of choice particularly for the fabrication of flexible and hybrid electronics. AJP has paved the way for high-resolution device fabrication with high placement accuracy, edge definition, and adhesion. In addition, AJP accommodates a broad range of ink viscosity, and allows for printing on non-planer surfaces. Despite the unique advantages and host of strategic applications, AJP is a highly unstable and complex process, prone to gradual drifts in machine behavior and deposited material. Hence, real-time monitoring and control of AJP process is a burgeoning need. In pursuit of this …

Use Of A Triboelectric Generator For A Tunable Wideband Energy Harvester And A Threshold Shock Sensor, Daniel S. Nelson

Graduate Dissertations and Theses

The prevalence of triboelectricity as a transduction mechanism has increased rapidly in recent years. We will discuss two uses for triboelectric generators. One design is a tunable wideband energy harvester. An axial force and amplitude limiter work together to create an energy harvester that can accommodate various frequency sources and have a large operating bandwidth. The addition of the compressive axial force also softens the system, which allows for higher voltage outputs. A proof of concept of a threshold shock sensor is proposed that incorporates bi-stability along with the triboelectric effect. A clamped-clamped buckled beam will switch stable states when …

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 …

A Representation Of Tactical And Strategic Precursors Of Supply Network Resilience Using Simulation Based Experiments, Yaneth C. Correa-Martinez

Engineering Management & Systems Engineering Theses & Dissertations

Modern supply chains are becoming increasingly complex and are exposed to higher levels of risk. Globalization, market uncertainty, mass customization, technological and innovation forces, among other factors, make supply networks more susceptible to disruptions (both those that are man-made and/or ones associated with natural events) that leave suppliers unavailable, shut-down facilities and entail lost capacity.

Whereas several models for disruption management exist, there is a need for operational representations of concepts such as resilience that expand the practitioners’ understanding of the behavior of their supply chains. These representations must include not only specific characteristics of the firm’s supply network but …

Solid Oxide Electrochemical Cells For High Temperature Hydrogen Production: Theory, Fabrication And Characterization, Can Zhou

Mechanical & Aerospace Engineering Theses & Dissertations

In this dissertation, the concept of water splitting using solid oxide photoelectrochemical cells (SOPCs) at high temperature was introduced and experimentally investigated. High temperature photoelectrochemical water splitting physically broadens the selection of potential applicable semiconductor materials and enables more visible sunlight absorption. This newly conceived concept provides a unique pathway for solar hydrogen production, as compared to conventional photoelectrochemical cells (PECs) that use wide band gap semiconductors in aqueous environments. The theoretical framework of SOPC was elaborated, followed by the experimental investigation to search for appropriate high temperature materials. Selected high temperature Schottky and p-n junction diodes, which were expected …

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 …

Adaptive Spaceship Cockpit Architecture, Ondřej Doule

Theses and Dissertations

This research project is focused on a system design theory and practice of the most complex environment that a human-system architect can ever encounter. It is the environment of the spaceship cockpit or cabin that is affected by forces of propulsion and gravity accelerations and freefall while the direction and magnitude of gravity change during the flight. Furthermore, the hyperbaric, restrictive environment of Intra Vehicular Activity spacesuit adds another layer of complexity. In off-nominal or emergency situations, these environmental effects combine, which results in specific human-system interaction requirements. Considering human-system integration requirements on safety, comfort and efficiency of communication between …

Economic Development In Nonmetropolitan Nebraska: Internet Use, Nature-Based Tourism, Federal Tax Policy And Workforce Development: 2018 Nebraska Rural Poll Results, Rebecca J. Vogt, Cheryl A. Burkhart-Kriesel, Randolph L. Cantrell, Bradley Lubben, L. J. Mcelravy, Timothy Meyer

Rural Futures Institute: Publications

Conclusion

The proportion of rural Nebraskans accessing the Internet using their cell phone has increased compared to two years ago. But, the proportion subscribing to high-speed Internet service at home remained stable during the past two years. Persons living in or near the smallest communities are less likely than persons living in or near larger communities to have high-speed Internet service at home.

Not many rural Nebraskans report significant limitations from their home Internet service on their ability to do most tasks. At least one in ten report being limited significantly or not being able to play real time video …

A Nonlinear Crack Model For Concrete Structure Based On An Extended Scaled Boundary Finite Element Method, Jian-Bo Li, Xin Gao, Xing-An Fu, Chenglin Wu, Gao Lin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fracture mechanics is one of the most important approaches to structural safety analysis. Modeling the fracture process zone (FPZ) is critical to understand the nonlinear cracking behavior of heterogeneous quasi-brittle materials such as concrete. In this work, a nonlinear extended scaled boundary finite element method (X-SBFEM) was developed incorporating the cohesive fracture behavior of concrete. This newly developed model consists of an iterative procedure to accurately model the traction distribution within the FPZ accounting for the cohesive interactions between crack surfaces. Numerical validations were conducted on both of the concrete beam and dam structures with various loading conditions. The results …

Control Laws For Autonomous Landing On Pitching Decks, Kendrick Buchala

Theses and Dissertations

This thesis addresses the problem of landing a quadcopter onto the pitching deck of a ship, as a partial simulation of a shipboard landing during high seas. The deck is modeled to pitch with a sinusoidal motion. While shipboard landing consists of many stages, only the final landing is simulated in this research. Other ship motions, such as roll and heave, are likewise not considered. The goal is to land the quadcopter in the center of the deck with minimal position and pitch error, where position error measures how far fore or aft of the center of the landing pad …

Development Of A Small Diameter Rapid Pressuremeter Test For Unbound Pavement Layer Evaluations, Thaddeus Joseph Misilo Iii

Theses and Dissertations

Six inch and 12 inch long small diameter pressuremeter (SDPMT) probes were developed and tested extensively to determine in situ stress-strain properties of unbound pavement layers. They were deployed in the same hole as the one made during nuclear density testing. The stress strain response of conventional or incremental and continuous or rapid strain controlled tests in unbound pavement layers were evaluated at four sites in Brevard County, Florida. One test site was A-1-b base material, one was A-3 subgrade and two were compacted A-3 fill of subgrade quality. The SDPMT results were compared with nuclear density dry and wet …

The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Non-equilibrium molecular dynamics simulations are performed to investigate the dynamic behavior of three-dimensional binary glasses prepared via an instantaneous quench across the glass transition. We found that with increasing strain amplitude up to a critical value, the potential energy approaches lower minima in steady state, whereas the amplitude of shear stress oscillations becomes larger. Below the yielding transition, the storage modulus dominates the mechanical response, and the gradual decay of the potential energy over consecutive cycles is accompanied by reduction in size of transient clusters of atoms with large nonaffine displacements. In contrast, above the yield strain, the loss modulus …