Engineering Commons^™

Pd-Fe3o4/Rgo: A Highly Active And Magnetically Recyclable Catalyst For Suzuki Cross Coupling Reaction Using A Microfluidic Flow Reactor, Hany A. Elazab, Ali R. Siamaki, B. Frank Gupton, M. Samy El-Shall

Chemical and Biochemical Engineering Faculty Research & Creative Works

There are several crucial issues that need to be addressed in the field of applied catalysis. These issues are not only related to harmful environmental impact but also include process safety concerns, mass and heat transfer limitations, selectivity, high pressure, optimizing reaction conditions, scale-up issues, reproducibility, process reliability, and catalyst deactivation and recovery. Many of these issues could be solved by adopting the concept of micro-reaction technology and flow chemistry in the applied catalysis field. A microwave assisted reduction technique has been used to prepare well dispersed, highly active Pd/Fe₃O₄ nanoparticles supported on reduced graphene oxide nanosheets …

Hydrothermal Synthesis Of Graphene Supported Pd/Fe 3 O 4 Nanoparticles As Efficient Magnetic Catalysts For Suzuki Cross – Coupling, Hany A. Elazab, Mamdouh A. Gadalla, Mohamed A. Sadek, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

This research reports a reproducible, reliable, and efficient method for preparing palladium nanoparticles dispersed on a composite of Fe₃O₄ and graphene as an active catalyst with high efficiency for being used in Suzuki cross – coupling reactions. Graphene supported Pd/Fe₃O₄ nanoparticles (Pd/Fe₃O₄ /G) exhibit a remarkable catalytic performance towards Suzuki coupling reactions. Moreover, the prepared catalyst recyclability was up to nine times without losing its high catalytic activity. The catalyst was prepared using hydrothermal synthesis; the prepared catalyst is magnetic in order to facilitate catalyst separation out of the reaction medium …

Extraction Rate In Vapor Assisted Extraction Of Heavy Oil (Vapex), Vijitha Mohan, Parthasakha Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Heavy oil recovery requires either heat (SAGD) or a solvent (VAPEX) to reduce its high viscosity first and then the less viscous oil can be recovered. We show here that the existing data, on the rate of oil recovered in VAPEX process in sand packs show a square root dependence on the height of pay zone, following expectation. This dependence had remained uncertain and is of importance in oil field operations. We have used dimensional analysis and inverse viscosity-diffusivity dependence to obtain an expression for the rate that agrees well with the available sand pack data. The dimensional analysis overcomes …

Analyzing The Effects Of Attitude Errors When Quantifying The On-Orbit Performance Of A Cubesat Micropropulsion System, Andrew Orion Watson

Masters Theses

"CubeSats and small satellites have become popular methods of performing space research. Accordingly, interest has also grown in designing micropropulsion systems to increase the lifespan of these satellites. This work describes the framework for analyzing the effects of imperfect attitude determination and control when quantifying the on-orbit performance of a micropropulsion system. The Gauss variation of parameters equations were implemented to model the orbital mechanics, with perturbing models for the zonal harmonics, atmospheric drag, and solar radiation pressure included. Two common sources for imperfections in a spacecraft's attitude were considered. The first was to consider the effect of the spacecraft …

Temperature Dependent Thermoelectric Properties Of Cuprous Delafossite Oxides, Yining Feng, Aline Elquist, Yuepeng Zhang, Kaizhong Gao, Ian Ferguson, Athanasios Tzempelikos, Na Lu

Electrical and Computer Engineering Faculty Research & Creative Works

The use of nanostructured delafossite oxides in thermoelectric (TE) applications has attracted a great interest due to their high performance and long-term stability at elevated temperatures. Cuprous delafossites, CuMO₂ (M = Al, Cr, Fe, Ga, Mn), compared to conventional TE materials, such as Bi₂Te₃, PbTe and SiGe, are non-toxic and more earth abundant. In particular, CuAlO₂ compound shows a great potential for high performance thermoelectric materials. In this work, a systematic study of temperature dependent TE properties of cuprous delafossite materials, CuAlO₂, is reported. The optimization of the TE properties has been …

Modeling Land Subsidence Using Insar And Airborne Electromagnetic Data: Dataset, Ryan G. Smith, R. Knight

Research Data

Supporting dataset for article published in Water Resources Research, Volume 55, Issue 4, pages 2801-2819

Epitaxial Growth Of Semiconductors And Chiral Metal Surfaces Using Spin Coating And Electrodeposition, Meagan V. Kelso

Doctoral Dissertations

"The current primary methods for epitaxial growth are energy intensive, requiring high temperature or high vacuum to obtain quality thin films. This dissertation explores the solution process methods of electrodeposition and spin coating for growth of epitaxial thin films. First, a method is developed to directly electrodeposit epitaxial CH₃NH₃PbI₃ perovskite for solar cells on single crystal Au by electrochemically reducing I₂ in organic solution. Perovskite is a newly explored material for solar cells, and its efficiency may be further improved by increasing the crystalline order. Second, a study on epitaxially electrodeposited chiral metal surfaces …

Investigating The Use Of Different Types Of Sealant Materials For Cement Remedial Applications, Murad Mohammedahmed Abdulfarraj

Doctoral Dissertations

"The overall objective is to investigate the ability of several material to mitigate cement failures such as channels, fractures, and micro-annuli in oil and gas wells. The sealant material that can also be used in the wells that are used for geologic storage of carbon dioxide CO₂. Evaluating the sealant material is critical to improve the zonal isolation of the wells, which would lead to safer operations. The approach of this dissertation is to utilize particles gel that has been used successfully in conformance control application, and epoxy resin systems, that have superior seal characteristics compared to conventional …

The Effects Of Fatigue And Weathering On The Failure Behavior Of Commercial Soda-Lime-Silicate Glass, Erica Ann Ronchetto

Doctoral Dissertations

"The principle objective of this research is to advance our understanding of the effects of humid conditions on the strength and susceptibility to fatigue of soda-lime silicate (SLS) glass. The two-point bend method was used to evaluate the fatigue characteristics and the degradation of failure strain of fibers drawn from melts of commercial soda-lime silicate glass and exposed to various environmental conditions. Soda lime silicate glasses from two commercial products but with similar nominal compositions were examined. One glass had pristine failure strains about 10% greater than the other, but both had similar fatigue parameters. The fatigue parameter increased from …

Active-Passive Dynamic Consensus Filters: Theory And Applications, John Daniel Peterson

Doctoral Dissertations

”This dissertation presents a new method for distributively sensing dynamic environments utilizing integral action based system theoretic distributed information fusion methods. Specifically, the main contribution is a new class of dynamic consensus filters, termed active-passive dynamic consensus filters, in which agents are considered to be active, if they are able to sense an exogenous quantity of interest and are considered to be passive, otherwise, where the objective is to drive the states of all agents to the convex hull spanned by the exogenous inputs sensed by active agents. Additionally, we generalize these results to allow agents to locally …

Build Strategy Investigation Of Ti-6al-4v Produced Via A Hybrid Additive Manufacturing Process, Lei Yan

Doctoral Dissertations

“Till now, laser metal deposition (LMD) has been developed with the capability of near-net shape high-performance metal parts fabrication, especially complicated titanium alloys, nickel alloys, and aluminum alloys. However, LMD processed parts usually do not meet end-use requirements without post treatments. In-process part quality inspection and inner features machining are impossible within a single LMD process. Hybrid additive manufacturing (HAM), which integrates additive and subtractive manufacturing in one process, has been proposed to increase the feasibility of complex parts fabrication. This dissertation aims to improve the applications of Ti-6Al-4V parts fabricated via a HAM technique. The first research topic is …

Light Touch Based Virtual Cane For Balance Assistance During Standing, Sindhu Reddy Alluri

Masters Theses

"Can additional information about one's body kinematics provided through hands improve human balance? Light-Touch (LT) through hands helps improve balance in a wide range of populations, both healthy and impaired. The force is too small to provide any meaningful mechanical assistance -- rather, it is suggested that the additional sensory information through hands helps the body improve balance.

To investigate the potential for improving human balance through biofeedback through hands, we developed a Virtual Cane (VC) for balance assistance during standing. The VC mimics the physical cane's function of providing information about one's body in space. Balance experiments on 10 …

Removal Of Antimony And Bismuth From Copper Electrorefining Electrolyte By Two Proprietary Solvent Extraction Extractants, Andrew Artzer

Masters Theses

"Antimony and bismuth are two of the most problematic impurities in copper electrorefining (ER). Because of this, much research has been done investigating the ways to remove them. Processes that are currently being used industrially include anode additions, liberators, ion exchange (IX), and solvent extraction (SX). Of these, liberators and anode additions are the most common while SX is the least, mostly being used for arsenic removal. There are other methods that have been evaluated, but are not in commercial use. These include the use of various electrolyte additives, and adsorbents such as bentonite clay and heavy metal sulfates.

Two …

High-Speed Pcb Trace Design Using A Behavioral Surface Roughness Model And High-Speed Test Coupon Design With Non-Functional Pads, Han Gao

Masters Theses

"In high-speed digital systems as data rates increase to tens of gigabits per second, the loss from the conductor surface roughness cannot be ignored. Djordjeic and Huray roughness model is widely used to count for the conductor roughness loss. However the practical application of the existed models are not straight forward since the frequency-dependent dielectric loss is usually unknown, leading to high discrepancies at high frequencies (above 10 GHz). To solve this problem, a behavioral model was developed by adding a dispersive term to the dielectric. The dispersive term in the model captures dispersion behavior observed in the measurement accurately. …

Diffusion Kinetics In Promising Adsorbents For Gas Capture Processes, Teresa Gelles

Masters Theses

"This reports the results of experimental studies aimed at characterizing the transport properties of promising adsorbents for various gas capture processes by the "zero length column" (ZLC) technique. ZLC was used to measure the intracrystalline diffusivities of single and binary components of ethane and ethylene in powder and pellet samples of paraffin-selective adsorbents Ni(bdc)(ted)_0.5 (Ni-BT) and ZIF-7 for the purpose of olefin/paraffin separation. Results show that binary gaseous systems result in intracrystalline diffusion time constants slightly lower than those in single component gaseous streams due to coadsorption effects. It was also found that ethylene diffusion was affected by surface …

Effects Of Uncertainty Refinement On Satellite Collision Probability, Bruce Thomas Morrison

Masters Theses

"Due to the drastic increase in orbital debris about the Earth, the likelihood for new and current mission satellites to collide with other objects grows. When a mission satellite is placed in a highly populated orbit in the vicinity of other satellites or debris, it is necessary to consider the probability of collision to assess any possible conjunctions. The computation of the collision probability is heavily dependent on the relative position and velocity of the objects during conjunction, as well as the combined covariance. There are two main types of analytic collision probability computations; the first assumes that the objects …

Radiation Immunity In Cable Harnesses And Differential P/N Skew In Pcb, David Nozadze

Masters Theses

"We develop an efficient method to model RF immunity of multiwire cable harnesses and study differential P/N skew effects on channels, channel performance and specifically on the eye diagrams at the SerDes receiver.

External radiation can induce unwanted signals in transmission lines. For example, external radiation from an antenna induces common-mode currents on the outer surface of cable shields. This common-mode signal makes its way through the shied due to its imperfections, inducing the inner common mode. When twisted pairs inside the cable are not balanced, inner common mode is in turn converted to the differential mode, which might compromise …

A Study On End-Anchorage And Bond Behavior Of Steel-Fiber Reinforced Cementitious Matrix Composites Externally Bonded To A Concrete Substrate, Christopher Michael Moore

Masters Theses

"Fiber reinforced cementitious matrix (FRCM) composites are a strengthening material consisting of continuous fibers embedded in an inorganic matrix that have the potential to provide additional flexural and shear strength to concrete and masonry members. When used for external strengthening, however, debonding of the material is often observed due to slippage of the fiber with respect to the matrix, causing loss of composite action and a reduction in load carrying capacity. The composite utilized in this study consisted of continuous steel fibers embedded in an inorganic cementitious matrix bonded to a concrete prism. Additionally, an end-anchorage system was implemented with …

Evaluation Of Naturally Occurring And Anthropogenic Contamination In Missouri Streams, Christina Jane Sehrt

Masters Theses

"The goal of this study is to observe the values and variability of water quality parameters and benthic macroinvertebrates in watersheds with very little anthropogenic impact and to compare these values with those acquired in watersheds with more anthropogenic impact. The following five HUC 12-digit watersheds had very little anthropogenic impact and were considered "pristine": Rogers Creek, Mill Creek, Middle West Fork-Black River, Bee Fork, and Ottery Creek. Five largely urban sub-basins were also considered; these basins are: Grand Glaize Creek, Glaize Creek, Sugar Creek, Hominy Creek, and Grindstone Creek. For each watershed, both water quality parameters and benthic macroinvertebrates …

Program Management For Concurrent University Satellite Programs, Including Propellant Feed System Design Elements, Shannah Withrow-Maser

Masters Theses

"Propulsion options for CubeSats are limited but are necessary for the CubeSat industry to continue future growth. Challenges to CubeSat propulsion include volume/mass constraints, availability of sufficiently small and certified hardware, secondary payload status, and power requirements. A multi-mode (chemical and electric) thruster was developed by at the Missouri University of Science and Technology to enable CubeSat propulsion missions. Two satellite buses, a 3U and 6U, are under development to demonstrate the multi-mode thruster's capabilities. Two key challenges related to these missions are the development of the feed system to support the thruster and management of the two bus programs' …

Computational Fluid Dynamics Modeling Of Proppant Static Settling Velocity In High Viscosity Friction Reducers, Chen Yuan

Masters Theses

"In the current petroleum fracturing industry, it is necessary to understand the downhole migration and settling velocity of the proppant. If we can master this information well, it will be a great help to obtain effective propped fracture conductivity. In order to study the transport of proppants in the well, we used laboratory experiments and computer numerical simulations to compare the results to get a meaningful conclusion. We spent a lot of time building models on a powerful computer and comparing the experimental conclusions. We finally decided to use computational fluid dynamics (CFD) as the simulation platform, discrete phase method …

Modeling Overpressure Development During Shale Rock Compaction Coupling Poroelasticity And Permeability Evolution Above 3km Depth, Wenyu Zhao

Masters Theses

"The evolution of pore pressure including overpressure during sedimentation is an important process to consider when analyzing whether high pore pressure causes rock failure. High pore pressure is caused by under-compaction due to the rapid burial of low-permeability sediments, and as a result, porosity decreases less rapidly with depth than in normally compacted sediments where porosity decreases exponentially with depth. While under-compaction related pore pressure magnitudes have been determined empirically, in most numerical modeling approaches, the pore pressure is either applied as a static magnitude or coupled to a fluid flow simulator. This study simulates the pore pressure evolution during …

Coupling Path Visualization Based On Reciprocity Theorem, Yang Zhong

Masters Theses

"A new method to visualize coupling path is proposed to help solve EMI problems. Based on the reciprocity theorem and the concept of reaction, coupling coefficient (CC) is defined to characterize coupling power density. For two-port networks, surface integral of CC can represent coupled voltage on the open-circuited port or coupled power on the loaded port. For dipole-moment based systems, surface integral of CC can represent coupled field components. The calculated CC should be a complex scalar at each point. By properly adjusting the excitation phases, the imaginary part of surface integral of CC will be zero and thus can …

Using The Ert Method To Differentiate Resistivity Anomalies Attributed To Natural And Man-Made Activities, Ibrahim Faisal Alshareef

Masters Theses

"Karst terrain is considered to be a very complex topography compared with most other geological environments. Many features can be observed such as sinkholes, air-filled cavities, losing streams, and solution widened joints. These karst features can cause subsidence and damage infrastructure such as buildings and roads thus causing economic hardship and disruption of life. The typical geological and hydrological studies are not enough to understand the karst processes.

For this reason, two geophysical methods were involved in investigating the subsurface in the study area. In this research, the electrical resistivity tomography (ERT) and multichannel analysis of surface wave (MASW) data …

Development Of Test Methods For Characterizing Extrudability Of Cement-Based Materials For Use In 3d Printing, Jonathan Thomas Kuchem

Masters Theses

"3D printing is the process of creating three-dimensional objects using an automated additive manufacturing process. The 3D printing process has been used with materials such as metals and polymers, but application with cement based materials for the construction industry has yet to be developed. In this research, two main problems were investigated for printing cement based composite materials: extrudability and tensile reinforcement. Fiber-reinforced concrete (FRC) was studied as an internal reinforcing system to increase tensile/flexural strength. First, FRC was studied to investigate mechanical properties and use of fibers from waste tires as an environmentally friendly option. A reference mixture with …

Temporal Changes Of Nutrients Within The Lower Grand River Watershed And Selected Sites, Weston Scott Duley

Masters Theses

"This report presents the results of a study carried out in collaboration with the U.S. Geological Survey (USGS) and the Missouri Department of Natural Resources (MDNR) to estimate total nitrogen (TN) and total phosphorus (TP) at five USGS monitoring sites within Lower Grand River Watershed (LGRW) and two monitoring sites on the Missouri River. The objective of this study was to quantify temporal changes in TN and TP concentrations and compare those to best management practices (BMPs).

In this study, the approach to the analysis of long-term surface water-quality data by using Weighted Regressions on Time, Discharge and Seasons models …

Characterization Of The Surface Condition In Aa6061 Resulting From Deep Rolling As A Function Of Common Industrial Parameters, Andrew Kenneth Layer

Masters Theses

"Roller burnishing is widely used in industry to improve the surface finish and fatigue life of components. As weight reduction continues to grow in the automotive and transportation industries, deep rolling can help maintain product performance by mitigating the increase in component stresses resulting from lower weight systems. Deep rolling parameters such as tool, applied angle, feed rate, spindle speeds, and relative tool direction all affect cycle time, product performance, and appearance. The effects of common industrial parameters on the resultant surface roughness and residual stress profiles were studied in this investigation. The samples were manufactured on a CNC lathe …

The Effect Of Cell Size And Surface Roughness On The Compressive Properties Of Abs Lattice Structures Fabricated By Fused Deposition Modeling, Leah Hope Mason

Masters Theses

"Postprocessing is an important step in many manufacturing methods, but it is especially important for additive manufacturing. Researchers looking to improve the surface roughness of acrylonitrile butadiene styrene (ABS) parts fabricated by fused deposition modeling (FDM) have determined that acetone smoothing not only achieves improved surface roughness but increases compressive strength as well. This could be very beneficial to lattice structures, which are known for already having an excellent strength to weight ratio. If the compressive strength of ABS lattice structures could be improved even further using acetone smoothing, it could expand the applications for plastic lattice structures and improve …

Small Satellite Earth-To-Moon Direct Transfer Trajectories Using The Cr3bp, Garrett Levi Mcmillan

Masters Theses

"The CubeSat/small satellite field is one of the fastest growing means of space exploration, with applications continuing to expand for component development, communication, and scientific research. This thesis study focuses on establishing suitable small satellite Earth-to-Moon direct-transfer trajectories, providing a baseline understanding of their propulsive demands, determining currently available off-the-shelf propulsive technology capable of meeting these demands, as well as demonstrating the effectiveness of the Circular Restricted Three Body Problem (CR3BP) for preliminary mission design. Using the CR3BP and derived requirements from NASA's Cube Quest Challenge, five different trajectory scenarios were analyzed for their propulsive requirements. Results indicate that the …

Near-Field Scanning Based Shielding Effectiveness Extraction For Board Level Shielding Cans, Harsh Shrivastav

Masters Theses

"The conventional definition of shielding effectiveness is well suited for calculating electromagnetic shielding in the far-field. However, in the near field, shielding effectiveness calculation is not so straight forward. In radio frequency interference problems, most of the field coupling occurs in near field. Having a well-defined method to calculate near-field shielding effectiveness is important for estimating the suppression of radio frequency interference using the shield cans. In this research, a method to extract the shielding effectiveness of board level shielding cans using near field scanning is developed. Shielding effectiveness is defined by modelling the shielded noise source as equivalent dipole …