Engineering Commons^™

Strengthening Qc Relaxations Of Optimal Power Flow Problems By Exploiting Various Coordinate Changes, Mohammad Rasoul Narimani

Doctoral Dissertations

"Motivated by the potential for improvements in electric power system economics, this dissertation studies the AC optimal power flow (AC OPF) problem. An AC OPF problem optimizes a specified objective function subject to constraints imposed by both the non-linear power flow equations and engineering limits. The difficulty of an AC OPF problem is strongly connected to its feasible space's characteristics. This dissertation first investigates causes of nonconvexities in AC OPF problems. Understanding typical causes of nonconvexities is helpful for improving AC OPF solution methodologies.

This dissertation next focuses on solution methods for AC OPF problems that are based on convex …

Experimental And Modeling Studies Using Packed Bed Reactors: Liquid Phase Ethylene Production By Hydrogenation Of Acetylene, Humayun Shariff

Doctoral Dissertations

"Gas-phase catalytic hydrogenation of acetylene to produce ethylene, commonly practiced in industries, has green oil formation, which leads to catalyst deactivation and sometimes reactor runaway risks due to high exothermicity. To overcome these issues as well as to increase the selectivity and conversion, liquid-phase hydrogenation of acetylene was investigated in packed bed reactors (PBR) using a commercial catalyst. The reactor performance of two-phase flow PBRs was assessed experimentally complemented by a validated mathematical model at different scales.

The selective hydrogenation of acetylene in the liquid phase over a commercial 0.5 wt% Pd/Al₂O₃ catalyst was investigated in a …

Minimizing The Detrimental Effects Of Hydro-Peaking On Riverbank Instability: The Lower Osage River Case, Wesam Sameer Mohammed-Ali

Doctoral Dissertations

"The fluctuation of water level downstream from dams due to hydropower flow releases negatively affects the riverbank stability. Therefore, this research aims to examine the feasibility of using an optimization technique to mitigate the riverbank instability resulting from the outflow variation of hydropower plants. The effects of the water releases from the Bagnell Dam were investigated by computing a series of safety factors for 78 cross sections along the 81-mile stretch of the lower Osage River in relation to outflow events by using the integrated BSTEM model incorporated into the HEC-RAS model. The 1-D sediment transport and unsteady flow in …

Design Of X-Ray Source For Real-Time Computed Tomography, Wesley William Tucker

Doctoral Dissertations

"The reduction of motion blur in computed tomography (CT) drives the current research for multisource CT. Due to their compact nature, the current multisource systems utilize stationary angled anodes. Unfortunately, these configurations neither simplify the imaging geometry, nor satisfy the need for managing the high thermal loads demanded by real-time CT (30 acquisition frames per second). To add to the current field of knowledge, two x-ray tube concepts are presented in this dissertation. First, a simulation of transient thermal analysis was performed on a compact transmission-type x-ray tube anode operating in pulse-mode. A correlation was found between deposited beam power …

Characterization And Recyclability Of 304l Stainless Steel Powder For Use In The Selective Laser Melting Process, Austin Taylor Sutton

Doctoral Dissertations

"Powder-bed fusion refers to a subset of additive manufacturing (AM) methods which successively melts and solidifies selected regions within a powder bed on a layer-by-layer basis to construct components directly from computer-aided design files. Laser Powder-Bed Fusion (L-PBF) is a process among the powder-bed fusion techniques that utilizes a laser to consolidate particles into a material with little porosity. During the L-PBF process, the large energy input from the laser causes the production of ejecta in the form of laser spatter and condensate, both of which have the potential to settle in the surrounding powder bed compromising its reusability. In …

System Si/Pi Modeling And Analysis, Biyao Zhao

Doctoral Dissertations

"A physics-based circuit modeling methodology for 3D IC/packages is proposed here. The method is based on partial element equivalent circuit (PEEC) and layered Green's function (LGF). The LGFs are calculated from discrete complex image method (DCIM) with three terms, direct coupling, complex images, and surface wave, extracted to analyze the wave behavior. The dominate terms for LGFs are analyzed for four stack-ups in 3D IC/packages. Analytical formulas that include the contribution of complex images are proposed for partial capacitance calculation, with the complex image extracted from LGFs. A chip PDN geometry is used to illustrate the use of LGF in …

Trajectory Control Of A Wheeled Robot Using Interaction Forces For Intuitive Overground Human-Robot Interaction, George Leno Holmes Jr.

Doctoral Dissertations

"Effective and intuitive physical human robot interaction (pHRI) requires an understanding of how humans communicate movement intentions with one another. It has been suggested that humans can guide another human by hand through complex tasks using force information only. However, no clear and applicable paradigm has been set forth to understand these relationships. While the human partner can readily understand and adhere to this expectation, it would be difficult for anyone to explain their intuitive motions with strict rules, algorithms, or steps. Uncovering such a procedural framework for the control of robotic systems to execute expected performance simply from force …

Modeling A Nuclear Research Reactor And Radiation Dose Estimation In An Accident Scenario, Abdulaleem Abdulmajeed Bugis

Doctoral Dissertations

“A detailed, flexible three-dimensional (3D) model of the Missouri S&T Reactor (MSTR) with a heterogeneous core geometry was developed using the Standardized Computer Analyses for Licensing Evaluation (SCALE). A Graphical User Interface (GUI) was developed for SCALE, which allows the user to generate an input file automatically. The SCALE model was validated with a Monte Carlo N-Particle Transport (MCNP) model of the MSTR. The validation process was based on the criticality calculations using the Criticality Safety Analysis Sequence (CSAS6). Three geometrical models were examined. The SCALE model that has the full detailed geometry showed a good agreement with the MCNP …

Development Of Radiation Transport Techniques For Modelling A High-Resolution Multi-Energy Photon Emission Tomography System, Seth Kilby

Doctoral Dissertations

”Nondestructive characterization techniques such as gamma tomography represent powerful tools for the analysis and quantification of physical defects and radionuclide concentrations within nuclear fuel forms. Gamma emission tomography, in particular, has the ability to utilize the inherent radiation within spent nuclear fuel to provide users with information about the migration and concentration of fission and activation products within the fuel form. Idaho National Laboratory is interested in using this technology to analyze new nuclear fuel forms for potential use in next generation nuclear reactors. In this work, two aspect of the system are analyzed. The first is a semi-analytic radiation …

Development Of Tools For Water Management In The Hatra Watershed (Northwestern Iraq) Using Satellite Technologies, Majid S. Mohamod

Doctoral Dissertations

“All around the world the demand for water is increasing, especially in arid and semi-arid regions, including Iraq which subject to continuous desertification that is worsening, more importantly the Jezira region in northwestern Iraq. Thus, it’s crucial to have a better strategy for water management. One of these strategies is to promote groundwater recharge for restoring the aquifer depletion. The successful groundwater recharge is limited by some potential data such as the annual water budge and precipitation measurements. The atomospheric and hydrological observations are limited by sparse population which tends to be less in arid and semi-arid regions. Therefore, an …

Integrating Resilience Into Military Infrastructure Mission Assurance Assessments And Decision Making, John Richards

Doctoral Dissertations

“This research created the Mission Assurance Resilience Matrix, a decision framework that integrates existing infrastructure assessment methods with emerging resilience research to model resilience under uncertainty as part of a detailed infrastructure management system. This framework enables military decision makers to easily visualize deficiencies in infrastructure resilience and assess where to most efficiently allocate resources. This research further extends results by including modules on training and education as a component of the scope of work.

There are three significant contributions of this research. The first identifies the gaps of how and where modeling under uncertainty, infrastructure systems management, and resilient …

Coordinated Container Migration And Base Station Handover In Mobile Edge Computing, Mao V. Ngo, Tie Luo, Hieu T. Hoang, Q. S. Tony Quek

Computer Science Faculty Research & Creative Works

Offloading computationally intensive tasks from mobile users (MUs) to a virtualized environment such as containers on a nearby edge server, can significantly reduce processing time and hence end-to-end (E2E) delay. However, when users are mobile, such containers need to be migrated to other edge servers located closer to the MUs to keep the E2E delay low. Meanwhile, the mobility of MUs necessitates handover among base stations in order to keep the wireless connections between MUs and base stations uninterrupted. In this paper, we address the joint problem of container migration and base-station handover by proposing a coordinated migration-handover mechanism, with …

Continuous-Flow Synthesis Of Fine Chemicals And Pharmaceutical Compounds Over Intelligent Organocatalysts With Bifunctional Reactivity, Abdo-Alslam Alwakwak

Doctoral Dissertations

“Many biological systems that utilize organic active sites to catalyze reactions under mild conditions invoke cooperative catalytic pathways, whereby two or more active sites work together to activate the reactant(s). The use of cooperative (bifunctional) catalysts and continuous flow chemistry (a reaction within the narrow channels of a micro‐ or microfluidic reactor) are commonplace in sustainable chemical transformation and attract a great deal of interest with respect to economic and environmentally-sustainable production of fine chemicals, pharmaceuticals, and agrochemicals, water treatment, as well as upgrading of biomass feedstocks. Although, some methods have been developed for immobilization of bifunctional catalysts for cooperative …

Comprehensive Study Of Bio-Diesel Continuous Flow Synthesis, Aso A. Hassan

Doctoral Dissertations

“Energy has become an indispensable factor in preserving economic growth since the commencement of the industrial revolution. In recent years, biodiesel has gained acceptance as a notable alternative to the widely used petroleum-derived diesel fuel because it is biodegradable, non-toxic, and generates fewer exhaust pollutants. Recently, biodiesel studies have focused on the development of process intensification technologies to resolve some technical challenges facing biodiesel production, such as long residence times and catalyst sensitivity. These intensification technologies enhance process mass/heat transfer to achieve a continuous, scalable process that can be easily transported to utilize locally available feed stocks. Five phases have …

System Efficient Esd Design Concept For Soft Failures, Giorgi Maghlakelidze

Doctoral Dissertations

"This research covers the topic of developing a systematic methodology of studying electrostatic discharge (ESD)-induced soft failures. ESD-induced soft failures (SF) are non-destructive disruptions of the functionality of an electronic system. The soft failure robustness of a USB3 Gen 1 interface is investigated, modeled, and improved. The injection is performed directly using transmission line pulser (TLP) with varying: pulse width, amplitude, polarity. Characterization provides data for failure thresholds and a SPICE circuit model that describes the transient voltage and current at the victim. Using the injected current, the likelihood of a SF is predicted. ESD protection by transient voltage suppressor …

Hydrokinetic Turbine Composite Blades And Sandwich Structures: Damage Evaluation And Numerical Simulation, Mokhtar Fal

Doctoral Dissertations

“Composite materials are gaining interest due to their high strength to weight ratio. This study deals with both experimental and numerical approaches to cover the aspects of the failure of composite materials in hydrokinetic turbine applications. In Part I, the location and magnitude of failure in the horizontal axis water turbine carbon fiber-reinforced polymer (CFRP) composite blades with different laminate stacking sequences were investigated. Two lay-up orientations were adopted for this work ([0⁰]₄ and [0⁰/90⁰]_2s). A finite element analysis model was generated to examine the stresses along the blade. Five angles were introduced to study the effect …

Transition Metal Chalcogenide Hybrid Systems As Catalysts For Energy Conversion And Biosensing, Siddesh Umapathi

Doctoral Dissertations

"Generation of hydrogen and oxygen through catalyst-aided water splitting which has immense applications in metal air batteries, PEM fuel cells and solar to fuel energy production, has been one of the critical topics in recent times. The state of art oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) catalysts are mostly comprised of precious metals. The current challenge lies in replacing these precious metal-based catalysts with non-precious earth-abundant materials without compromising catalytic efficiency.

This research explores mixed metal selenides containing Fe-Ni, Fe-Co and RhSe which were hydrothermally synthesized and/or electrodeposited and tested for OER and ORR …

Application Of Geophysics And Remote Sensing Techniques For Economic Mineral Exploitation In Libya, Awad Abdussalam Henish Lemnifi

Doctoral Dissertations

“This study investigates crustal thickness and properties within the north central Africa region. Results obtained from 15 seismic stations belonging to the Libyan Center for Remote Sensing and Space Science are reported, in addition to 3 seismic stations publically available, using receiver functions, the first P-to-S receiver function investigation of the 410 km and 660 km depth discontinuities bounding the mantle transition zone (MTZ), and P wave tomography methods. The results from the first method show crustal thicknesses ranging from 24 km to 36 km (with uncertainties ranging between ±0.10 km and ±0.90 km). More specifically, crustal thickness ranges from …

Analysis And Modeling Of Power Supply Induced Jitter For High Speed Driver And Low Dropout Voltage Regulator, Yin Sun

Doctoral Dissertations

”With the scaling of power supply voltage levels and improving trans-conductance of drivers, the sensitivity of drivers to power supply induced delays has increased. The power supply induced jitter (PSIJ) has become one of the major concerns for high-speed system. In this work, the PSIJ analysis and modeling method are proposed for high speed drivers and the system with on-die low dropout (LDO) voltage regulator. In addition, a jitter-aware target impedance concept is proposed for power distribution network (PDN) design to correlate the PSIJ with PDN parasitic.

The proposed PSIJ analysis model is based on the driver power supply rejection …

Cyclic Regeneration Of Nanostructured Composites For Catalytic Applications, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

A catalyst obtained by first preparing a cermet material with the general formula ABOx, wherein A is selected from the group consisting of Co, Cu, Ni, Ti, and combinations thereof, wherein B is selected from the group consisting of Mo, W, Ce, and combinations thereof, wherein A and B are different elements, and wherein x is a nonzero number ranging from 3 to 7 and represents the moles of O. Next, the cermet is activated in a reducing atmosphere to yield metal particles dispersed within and/or on the cermet.

Fundamental Limits To The Transfer Of Energy Harvested From Ferroelectric Materials Under Shock Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase

Mining Engineering Faculty Research & Creative Works

Ferroelectrics are capable of producing megawatt power levels under shock loading due to stress-induced phase transformations, resulting in depolarization of the ferroelectric materials. This power can be used for generation of high voltages, high currents, or ultrahigh-power electromagnetic radiation. The results are reported herein on an experimental study of limitations on energy harvested from shocked Pb_0.99(Zr_0.95Ti_0.05)_0.98Nb_0.02O₃ and PbZr_0.52Ti_0.48O₃ ferroelectrics and transferred to external electrical systems. The experimental results indicate that one of the limits to the energy transfer is electric breakdown that occurs within …

Neutronic Investigation Of Alternative & Composite Burnable Poisons For The Soluble-Boron-Free And Long Life Civil Marine Small Modular Reactor Cores, Syed B. Alam, Bader Almutairi, Tuhfatur Ridwan, Dinesh Kumar, Cameron S. Goodwin, For Full List Of Authors, See Publisher's Website.

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Concerns about the effects of global warming provide a strong case to consider how best nuclear power could be applied to marine propulsion. Currently, there are persistent efforts worldwide to combat global warming, and that also includes the commercial freight shipping sector. In an effort to decarbonize the marine sector, there are growing interests in replacing the contemporary, traditional propulsion systems with nuclear propulsion systems. The latter system allows freight ships to have longer intervals before refueling; subsequently, lower fuel costs, and minimal carbon emissions. Nonetheless, nuclear propulsion systems have remained largely confined to military vessels. It is highly desirable …

Impact Of Isolated Atmospheric Aging Processes On The Cloud Condensation Nuclei Activation Of Soot Particles, Franz Friebel, Prem Lobo, David Neubauer, Ulrike Lohmann, Saskia Drossaart Van Dusseldorp, Evelyn Mühlhofer, Amewu A. Mensah

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The largest contributors to the uncertainty in assessing the anthropogenic contribution in radiative forcing are the direct and indirect effects of aerosol particles on the Earth's radiative budget. Soot particles are of special interest since their properties can change significantly due to aging processes once they are emitted into the atmosphere. Probably the largest obstacle for the investigation of these processes in the laboratory is the long atmospheric lifetime of 1 week, requiring tailored experiments that cover this time span. This work presents results on the ability of two types of soot, obtained using a miniCAST soot generator, to act …

Bubble Pinch-Off In Turbulence, Daniel J. Ruth, Wouter Mostert, Stephane Perrard, Luc Deike

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Although bubble pinch-off is an archetype of a dynamical system evolving toward a singularity, it has always been described in idealized theoretical and experimental conditions. Here, we consider bubble pinch-off in a turbulent flow representative of natural conditions in the presence of strong and random perturbations, combining laboratory experiments, numerical simulations, and theoretical modeling. We show that the turbulence sets the initial conditions for pinch-off, namely the initial bubble shape and flow field, but after the pinch-off starts, the turbulent time at the neck scale becomes much slower than the pinching dynamics: The turbulence freezes. We show that the average …

Diffusion And Uniformity Of Recycled Asphalt In Pavements, Baoshan Huang

Abbett Distinguished Seminar Series

Asphalt pavements covers over 93 percent of the paved roads in the United States. The use of recycled asphalt into pavement maintenance and construction has been a common practice. However the lack of understanding of the interaction between recycled and virgin asphalt poses a change on the efficient use of recycled asphalt, and often causes pavement premature failures. The present study addressed some fundamental aspects associated with the beneficial use of recycled asphalt into asphalt paving mixtures: 1) how much recycled asphalt can be mobilized into a uniform asphalt coating in the mixture? and 2) will the mobilized old asphalt …

Simulation Training And Route Optimization For Bridge Inspection, Sushil Louis

INSPIRE Archived Webinars

Since the 1970s, simulation training has developed opera­tional trainers for a variety of complex systems from pilot flight simulations to cultural awareness training simulations. When connected to the real world, such simulation training interfaces can drive real vehicles and systems. We have been building a Simulation Training And Control System (STACS) for autonomous bridge inspection that uses a simulated world to train inspectors to control a heterogeneous group of robots. The objective is that, once trained, inspectors can use the same STACS interface used in training to control multiple real robots simultaneously during a bridge inspection task. We first built …

The Bridge Newsletter Winter 2019, Missouri University Of Science And Technology

The Bridge Newsletter

-Dehghani joins S&T
-Life after death of solar panels
-Civil engineering senior studies in Hong Kong
-Planning for future climate changes in the Artic

Better Beware: Comparing Metacognition For Phishing And Legitimate Emails, Casey I. Canfield, Baruch Fischhoff, Alex Davis

Engineering Management and Systems Engineering Faculty Research & Creative Works

Every electronic message poses some threat of being a phishing attack. If recipients underestimate that threat, they expose themselves, and those connected to them, to identity theft, ransom, malware, or worse. If recipients overestimate that threat, then they incur needless costs, perhaps reducing their willingness and ability to respond over time. In two experiments, we examined the appropriateness of individuals' confidence in their judgments of whether email messages were legitimate or phishing, using calibration and resolution as metacognition metrics. Both experiments found that participants had reasonable calibration but poor resolution, reflecting a weak correlation between their confidence and knowledge. These …

Analysis And Introduction Of Effective Permeability With Additional Air-Gaps On Wireless Power Transfer Coils For Electric Vehicle Based On Sae J2954 Recommended Practice, Dongwook Kim, Hongseok Kim, Anfeng Huang, Qiusen He, Hanyu Zhang, Seungyoung Ahn, Yuyu Zhu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

The wireless power transfer (WPT) method for electric vehicles (EVs) is becoming more popular, and to ensure the interoperability of WPT systems, the Society of Automotive Engineers (SAE) established the J2954 recommended practice (RP). It includes powering frequency, electrical parameters, specifications, testing procedures, and other contents for EV WPT. Specifically, it describes the ranges of self-inductances of the transmitting coil, the receiving coil, and coupling coefficient (k), as well as the impedance matching values of the WPT system. Following the electrical parameters listed in SAE J2954 RP is crucial to ensure the EV wireless charging system is interoperable. This paper …

Multifunctional Lightweight Aggregate Containing Phase Change Material And Water For Damage Mitigation Of Concrete, Wenyu Liao, Aditya Kumar, Kamal Khayat, Hongyan Ma

Materials Science and Engineering Faculty Research & Creative Works

This paper presents an innovative concept of multifunctional lightweight aggregate, which is produced by loading phase change material (PCM) into the interior of lightweight sand (LWS) and sealing the surface pores using water. The PCM loaded in the LWS functionalizes it as a temperature management agent in concrete, and the water in surface pores enables internal curing. It has been found that the particle shape and pore structure of crushed expanded shale LWS makes it an ideal carrier for PCM, loading sufficient PCM and maintaining better (compared to natural sand) mechanical interlocking. When coupled with the internal curing effect, the …