Chemical Engineering electronic theses and dissertations (MU)
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The items in this collection are the theses and dissertations written by students of the Department of Chemical Engineering. Some items may be viewed only by members of the University of Missouri System and/or University of Missouri-Columbia. Click on one of the browse buttons above for a complete listing of the works.
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Item Detoxification process for a ferric chloride etching waste(University of Missouri--Columbia, 1984) Oberkrom, Stephen Louis; Marrero, Thomas R.The purpose of this study was to determine an economically feasible method for treating a ferric chloride etching solution contaminated with nickel and chromium. The major factors in determining the optimum method of treatment for the etching waste were effectiveness in the conversion of the liquid waste to a solid form and in the conversion of the hazardous waste to a nonhazardous form. Ferric chloride etching waste is a listed hazardous waste according to state of Missouri regulations; however, federal regulations do not list etching solutions as hazardous wastes. A number of treatment methods were tested to determine the most effective method of neutralizing the waste. Drying tests were conducted to study the possibility of removing the water from the waste and thereby producing a solid. Aeration tests were also performed in an effort to learn if the metals could be precipitated as crystalline oxides or hydroxides. Neutralization (hydroxide precipitation) tests were also conducted using three bases, sodium hydroxide, calcium hydroxide, and water treatment plant sludge. The most effective and economic method of treating the ferric chloride etching waste is with hydrated lime. Approximately 0.7 kilogram of calcium hydroxide per liter of waste is necessary to convert the liquid waste stream to a hydroxide sludge. This sludge was evaluated by the standard extraction procedure (EP) toxicity test for hazardous levels of chromium and nickel. The Cr and Ni leachate concentrations are at part per billion levels, thus the sludge qualifies for delistment as a hazardous waste. For this purpose, a practical treatment process has been designed and developed.Item Peptide amphiphile micelles as a universal influenza vaccine delivery vehicle(University of Missouri--Columbia, 2024) Schulte, Megan; Ulery, Bret D.[EMBARGOED UNTIL 12/01/2025] Despite a plethora of influenza vaccines and treatment options, there are millions of cases of influenza each year in the United States alone. Although increasing vaccination rates could potentially alleviate some of this public health burden, a significant problem with existing influenza vaccines is the fact that, because vaccine production must begin well before an increase in cases is observed in a given region, there is a significant reliance on predictions of what will be the prevalent influenza viruses for a given season. Unfortunately, if predictions are inaccurate, vaccine efficacy suffers.1 Avoiding this dependence on inconsistent forecasts is the driving force for research into a universal influenza vaccine. The premise of the concept of a universal vaccine is that epitopes are selected based on their conservation across a wide range of influenza strains. Because the epitopes are conserved, they should offer more broad-spectrum protection and reduce the need for effective predictions. Epitopes in a vaccine can be chosen based on a number of factors including degree of conservation as well as the magnitude and form of immunogenicity. An influenza virus expresses three proteins on its capsid surface, predominantly hemagglutinin (HA) and neuraminidase (NA) with lesser quantity of matrix protein 2 (M2). Traditionally, HA and NA have been the proteins of focus because they contain the most immunogenic epitopes of the influenza virus. However, epitopes in these proteins are under significant evolutionary pressure, so their amino acid sequences are constantly changing. In fact, there are 18 known subtypes of HA and 11 of NA (with additional variants within these subtypes).2 Nonetheless, there are many epitopes that are reasonably well conserved within the three surface proteins of the influenza virus that could prove to be viable candidates for a universal influenza vaccine. For example, the HA stalk, which is less exposed and slightly less immunogenic than the HA head, tends to be more conserved. Another such region is the N-terminal ectodomain of M2 (M2e), which is known to be highly conserved.3 Subunit vaccines, which contain only select parts of the target pathogen, are a promising avenue for taking advantage of conserved epitopes. Because subunit vaccines deliver only the foreign material required to elicit a desired immune response, it can be possible to deliver a higher dose while avoiding side effects caused by unproductive viral components. However, the delivery of disassembled viral components can pose problems because antigens (especially conserved epitopes) can be poorly immunogenic and relatively unstable on their own.4 Nanoparticles offer a way to address this issue and are currently being heavily researched for many drug and vaccine applications.5-7 The use of nanoparticles for immunization involves anchoring the antigenic components to the particle surface or entrapping them within the particle structure. This approach offers several advantages over delivering neat antigen including increasing local antigen concentration and protecting the antigenic components from degradation. There are a wide variety of nanoparticles currently being studied for vaccine development, each with their own advantages and limitations, which will be discussed more in depth in the first chapter.6, 8-11 One particularly promising nanoparticle vaccine delivery technology is micelles, specifically those composed of peptides or lipidated peptides, termed peptide amphiphiles (PAs). Peptide amphiphile micelles (PAMs) can have several advantages in addition to those already mentioned for nanoparticle vaccines -- namely the enhancement of antigen-cell interactions, trafficking, and immunogenicity.11- 13 Additionally, PAMs form spontaneously in aqueous conditions, making their preparation simple and relatively inexpensive. In this work, PAMs were developed using antigens from the well- conserved ectodomain of M2 (M22-16 and M21-24) and their potential as a universal influenza vaccine was evaluated. In the second chapter, I discuss work I completed with M22-16 peptides and PAMs, including the discovery that the M22-16 antigen without any lipidation or modification also self-assembles into nanoparticles. This allowed us to investigate the impact lipidation has on micelle physical properties and immunogenicity decoupled from the effect of self-assembly. This was a unique opportunity because in other studies done by our research group and others, peptide antigens alone have not self-assembled. Excitingly, there were distinct differences in physical properties between the PAMs and the unmodified M22-16 peptides that formed peptidyl micelles (PMs). The differences in the murine immune response against PAMs versus PMs was less pronounced, as the IgG titers and BMDC activation were quite similar between both micelle types. However, the IgM and initial IgG responses were significantly stronger in PAM-vaccinated mice. In the third chapter, I further explored a phenomenon discovered in the second chapter, namely that PAMs elicited a lower-than-expected IgG antibody titer compared to unmodified M2 antigen. The M21-24 antigen was used in this research chapter to see if the same effect was observed when the antigen was expanded from the previously used M22-16 antigen. Indeed, the trends between vaccine groups were quite similar whether the M22-16 or M21-24 antigen was used. Interestingly, we found that PAMs elicited off-target antibody production against the non-native parts of the PA, thus demonstrating the importance of careful consideration when chemically modifying peptide antigens. Despite this, antibodies generated in response to PAMs were still able to recognize the M2 protein just as well as the antibodies generated in PM-vaccinated mice. In the fourth chapter, I discuss approaches that were taken to mitigate off-target antibody production, namely the use of different linkers between the non-native flanking regions and the antigen. While some of the linkers induced changes in micelle shape and peptide secondary structure, all of the linker-containing formulations still induced the production of off-target antibodies. However, one of the formulations (Pam2CS-M22-16-PEG2-(KE)4), which was lipidated with a Pam2CS- moiety on the N-terminus in an attempt to mimic the adjuvanting effects of Pam2CSK4, did elicit antibody titers similar to mice vaccinated with a combination of PAMs and Pam2CSK4. This, along with BMDC activation results, confirmed that the Pam2CS- moiety retained its ability to act as an adjuvant, as well as stimulate antibody production against the M22-16 antigen, which could have applications in situations where co-delivery of an adjuvant and antigen is required. In the fifth chapter, I delineate the remaining work needing to be completed to publish my three manuscripts and future directions for this project. Developing a non-micellized M22-16 peptide control will be essential for differentiating between the effects of micellization and lipidation on immunogenicity. Another important additional work to increase the legitimacy of this platform should include evaluating the type and magnitude of the immune response to intranasal vaccination as this would likely generate a more favorable response in line with the natural immune response to influenza -- i.e., IgA and IgG2a production. Finally, it would be valuable to evaluate the functionality and protectivity of the immune response by antibody functionality assays, survival after influenza challenge, and other similar approaches.Item Dynamic matrix control of multivariable system with multiple deadtimes(University of Missouri--Columbia, 1983) Wang, Min-Chung; Luecke, Richard H.; Retzloff, David G.; Barton, John"The Dynamic Matrix Control (DMC) algorithm is a control technique 1973. As that has been used by Shell Oil Company since its name may imply, DMC algorithm is the technique of representing process dynamics with a set of numerical coefficients arranged in matrices. The numerical approach makes it possible to solve complex control problems using digital computer control which can not solved with traditional PID control concepts. By incorporation of both feedforward and feedback designs, the DMC algorithm can deal successfully with unusual dynamic behaviors and constrainted problems. An introduction of DMC with a simple example is given in this paper. Further, the capability of DMC is demonstrated in the control of a multivariable multidelay system. Systems are difficult to control when dead times exist especially with long dead time. Many chemical engineering processes exhibit apparent dead time and can be adequately represented by multivariable transfer functions with dead times. For multivariable system having only one time delay, useful feedback control designs are available. But when multiple dead times exist in multivariable system the alternates of control algorithm are limited. For example, the optimal feedback control and inverse Nyquist technique have been shown to work well but need rather extensive computation efforts in the presence of dead times. For simpler designed control, a multidelay compensator was developed by Ogunnaike and Ray (1979). The compensator had been shown to work well. The performance of DMC in the control of multivariable multidelay system are compared with the results of the deadtimes compensator for the same system reported by Ogunnaike and Ray (1979). The computer simulations show that the DMC controller works very well. Even for the system with mutiple deadtimes, DMC can work as well or better than the deadtimes compensator."--Introduction.Item Analysis of an oscillating engine for power generation based on the "Drinking Bird Toy"(University of Missouri--Columbia, 1969) Shergill, Sant Singh"The investigation presented here is of an oscillating engine of which the "Drinking Bird Toy" is a prime example. A model is set up to represent the way the toy works and an attempt is made to calculate the power output for a hypothetical large scale engine working on the same principle. This study was stimulated by the paper "A Simple Heat Engine of Possible Utility in Primitive Environments" by R. B. Murrow, published by The Rand Corporation in August, 1966 (11). The investigation carried out was purely theoretical and the solution was obtained based on a mathematical model describing the processes of heat and mass transfer in the engine. The analysis was an extension of the work performed by Fraser (1) and differs primarily in the treatment of heat transfer in the head. The mathematical model resulted in seven linear algebraic equations to be solved simultaneously. The iterative nature of the calculations necessitated the use of the University of Missouri at Columbia IBM36O digital computer. The calculations were performed for Freon-11 as internal working fluid. This was because the fluid must condense and evaporate between dry and wet bulb temperatures at near atmospheric pressures to complete the working cycle of the engine. The normal boiling point of Freon-11 is 75[degrees]F., about 5[degrees]F. below the assumed ambient air temperature. Dry and wet bulb temperatures at 80[degrees]F. and 65[degrees]F. respectively and wind velocity at 5 MPH were chosen as representative (19) of the day time conditions under which the engine* is expected to work. "Sun Incremental temperature"** of 20[degrees]F. was considered available in the day time. The mathematical model assumes steady state temperatures in both body and head chambers for the pumping period of the working cycle. This assumption simplifies otherwise complicated mathematics to linear algebraic equations. Power output was computed for wind velocities up to 10 MPH and sun incremental temperatures up to 30[degrees]F. The calculated power output is compared with Murrow's (15) measured power output. Finally, changing the working liquid density and latent heat of vaporization is also considered."--Introduction.Item Microcomputer process control(University of Missouri--Columbia, 1983) Lewis, John Charles; Luecke, Richard; Bajpai, Rakesh; McFarland, William"The objective of this work is to extend the functions of a MOSTEK micro-computer allowing it to function as data logging and as a digital control unit. It will be capable of accepting multiple inputs from analog sensors; of computing multiple control functions with FORTRAN programming; of using parameters that may be entered via a keyboard; of comparing the control functions with set points that may be entered via the the keyboard; and of outputting multiple control signals that may be used to activate a control device. In the work described here, the output signal would be an on-off control only. Programming will be in FORTRAN, except in very unusualcircumstances. Digital-to-Analog conversion boards are part off the MOSTEK microcomputer system so that extension to analog outputs will be possible fairly easily. The MOSTEK microcomputer is a complex piece of equiptment that is fascinating in its own respect. It is a further objective of this work to make the power of the computer available to those who do not find it fascinating. Typical chemical engineers who need data logging or control capabilites but do not want (or need) to learn anything about the microcomputer itself, should be able to satsify their needs using this paper and an assumed understanding of the FORTRAN language. Any or all of the values of the variables -- input or output -- or any function of the variables as may be computed in a FORTRAN program, may be stored on a diskette or may be printed out. To demonstrate the control system, two primitive processes were controlled: 1. Pressure control of a vacuum vessel by controlling the air bleed-in rate; 2. Temperature control of a stirred bucket of water by proportioning an inlet flow of hot water."--Introduction.