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Title: FACTORS AFFECTING THE SANITIZER EFFICACY IN PREVENTING SALMONELLA TRANSFER DURING POSTHARVESTWASHING OF CUT LETTUCE
Creator: Zang, Mingxia
Date: 2014, 2014-07
Description: This study investigated the spread of Salmonella during postharvest washing of contaminated lettuce and determined the factors that affect the...
Show moreThis study investigated the spread of Salmonella during postharvest washing of contaminated lettuce and determined the factors that affect the efficacy of chlorine in preventing Salmonella cross-contamination. A bench-scale washing system was assembled. It consisted of a 15 gal tank equipped with a submersible pump and various probes to measure wash water properties including pl-l, temperature, chlorine level. oxidation reduction potential (ORP), turbidity, and total organic carbon (TOC) level. Eight grams of cut romaine lettuce inoculated with approximately 7 log CFU/g of Salmonella typhimurium expressing green fluorescent protein were added to 40 L of sterile tap water or spent wash water collected from a commercial produce processing facility together with 800 g of uninoculated lettuce and washed for 2 min. Washing trials were performed at 3°C under different levels of chlorine treatment (0. 5, 10, 20 and 30 ppm of sodium hypochlorite). Small-scale (100 mL) experiments were performed to determine the effects of organic matter (lettuce homogenate) and solids (play sand) on the efficacy of chlorine in wash water. Without chlorine treatment, the spread of Salmonella occurred during lettuce washing in both sterile tap water and in spent industry water. With 5 ppm ofchlorine. although no Salmonella was detected in the wash water, the pathogen was found in the uninoculated lettuce after culture enrichments. When the chlorine level increased to either 10 or 20 ppm of chlorine, no Salmonella was detected in the wash water or the uninoculated lettuce. Similar experiments were performed using the spent industry water. Salmonella transfer occurred at chlorine of 10 or 20 ppm. Transfer was prevented when the chlorine level was raised to 30 ppm. IX Data from the small-scale experiments indicated that the increase in organic contents resulted in a lower level of free chlorine and a greater survival of Salmonella. At 5 ppm of chlorine, the level of Salmonella increased from not detectable « 1 log CFU/ml) to completely unaffected (4.3 ± 0.4 log CFU/ml) when the TOC level increased from 10.6 ± 10.4 to 164.0 ± 21.2 mg/L. Also, the increase in solid contents led to a greater survival of Salmonella even though the free chlorine level remained unchanged. At 0.5 ppm of chlorine, the level ofSalmonella increased from not detectable « 1 log CFU/ml) to completely unaffected (4.2 ± 0.1 log CFU/ml) when the turbidity level increased from 0.7 ± 0.5 to 378.2 ± 53.5 NTU. In summary, the use of sufficient chlorine could prevent Salmonella cross-contamination but the effective chlorine level was affected by the organic load and solid content present in the wash water. Since the chlorine efficacy was the key to preventing cross-contamination and organic load was an important factor affecting the chlorine efficacy, measurements of the organic load was needed to determine the level ofchlorination needed in the wash water. However, current methods for measuring TOC took a few hours to perform. Turbidity measurements which could be done in a minute had been frequently used in the produce industry to determ ine wash water quality. In this study. it was found that a linear correlation could be established between turbidity and TOC suggesting that turbidity could be a good predictor of the organic load in produce wash water.
M.S. in Food Safety and Technology, July 2014
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Title: Laboratory Notebook 119
Creator: Zhang, Zhe, Burton-freeman, Britt
Date: 2010-03-09T21:21:56Z
Description: This laboratory notebook relates to the " Thermal Inactivation of Ricin in phosphate buffer system and orange juice" project with Britt Burton...
Show moreThis laboratory notebook relates to the " Thermal Inactivation of Ricin in phosphate buffer system and orange juice" project with Britt Burton-Freeman as the Principle Investigator.
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Title: NANOPORE STOCHASTIC SENSING OF BIOMARKERS IN HUMAN DISEASE
Creator: Zhou, Shuo
Date: 2016, 2016-07
Description: By measuring the ionic current modulation generated by analytes’ electro-osmotic flow through a nanoscale sized pore, nanopore stochastic...
Show moreBy measuring the ionic current modulation generated by analytes’ electro-osmotic flow through a nanoscale sized pore, nanopore stochastic sensing was invented about 20 years ago. Since then, it has been developed as a powerful and versatile tool for the detection of a wide variety of substances, including metal ions, organic molecules, DNA, RNA, peptides, proteins, etc. Compared with other traditional techniques such as immunochemical detection, colorimetric detection, HPLC, and GC/MS, nanopore detection has many advantages. First and foremost, nanopore stochastic sensing does not need to use sophisticated instruments which are convenient for people who do not have professional training in operating a special device. Furthermore, unlike fluorescent methods which rely on fluorophores labeling, nanopore stochastic sensing is a label-free detection method, which is based on the natural characteristics of analytes of interest. Moreover, nanopore sensing does not need complicated pretreatment of samples and can achieve a very low detection limit rapidly. Most importantly, nanopore detection uses only a small amount of sample with a low assay cost. In this dissertation, I summarize my work on nanopore stochastic sensing of proteases and copper ion, i.e., the detection of the HIV-1 protease (HIV-1 PR), trypsin, and copper ion. It is well-known that the HIV-1 protease is a significant biomarker for AIDS, while trypsin for the pancreatic disease. Considerable effort has been devoted to developing highly sensitive and selective sensors for these two important proteases. By taking advantage of nanopore stochastic sensing, two biosensors are constructed where picomolar concentrations of the HIV-1 protease and trypsin can be detected. On the other hand, copper, an essential trace element, is vital to the health of our human being in many ways. For example, the accumulation of cupric ions in human body may explain the origin of Wilson disease; further, the elevated concentration of copper is also pertinent to some symptoms of Alzheimer disease. Hence, the capability to the sensitive and accurate detection of copper ions is crucial to our health and well-being. For this purpose, a real-time and label-free nanopore biosensor is developed for its detection. The successful research efforts in these projects demonstrate the useful application of nanopore stochastic sensing in medical diagnosis, especially in terms of early disease detection. In addition to the high sensitivity and accuracy as well as low assay cost, other advantages of nanopore sensors include instrumental simplicity, ease of use, and extremely rapid data acquisition rates. Such a field-deployable nanopore sensor is useful as a point-of-care device for early disease detection and diagnosis. Just imagine how convenient your medical diagnosis would become with the pocket size nanopore sensor. We can monitor our own health anytime and anywhere: at home, at workplace, or even outside in remote and isolated places.
Ph.D. in Chemistry, July 2016
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Title: Integration of Process Improvement (sequence unknown), IPRO 304 - Deliverables: IPRO 304 Midterm Presentation F09
Creator: Bauer, Jessie, Bergeron, Tony, Campen, Matt, Gruchalski, Erik, Choi, Tae Ki, Marx, Ryan, Murti, Chaitanya, Robbins, Brian, Sohal, Atinder Pal, Stenson, Amanda, Taboada, Alejandro, Zhang, Bingjian
Date: 2009-12
Description: A. Finkl and Sons require an effective way of detecting carbide inserts on the steel milling machine. These inserts break off due to stress...
Show moreA. Finkl and Sons require an effective way of detecting carbide inserts on the steel milling machine. These inserts break off due to stress and shape of metal and need to be replaced immediately to avoid further damage to the machine and the steel to be milled.
Sponsorship: A. Finkl and Sona
Deliverables for IPRO 304: Integration of Process Improvements for the fall 2009 semester.
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Title: NEOVASCULARIZAnON WITHIN POROUS PEG HYDROGELS
Creator: Chiu, Yu-chieh
Date: 2011-11, 2011-12
Description: Development of engineered tissues of clinically relevant size requires the ability to control vascularization within biomaterial scaffolds....
Show moreDevelopment of engineered tissues of clinically relevant size requires the ability to control vascularization within biomaterial scaffolds. Poly(ethylene glycol) (PEG) hydrogels have been extensively investigated for use as synthetic scaffolds to support engineered tissue formation. The goal of this work described was to develop techniques that can be used to enhance vascularized tissue formation in PEG-based hydrogels. In the first part of the study a technique was developed to generate porous PEG hydrogels using a salt leaching technique. This technique was then used to examine the role of pore size on vascularization and tissue remodeling in porous PEG hydrogel in vitro and in vitro. Both in vitro and in vivo studies showed that vessel invasion was pore size dependent. In addition, a thin layer of inflammatory tissue was observed between PEG hydrogel and blood vessels that formed within the gels. This layer suggested that inflammatory cells, not vascular cells, interacted with the surface of the material. This suggests that peptides covalently incorporated within PEG may not directly interact with endothelial cells (ECs) following implantation. The porous PEG hydrogels were very stable in vitro and in vivo and did not exhibit any signs of degradation. Hydrogels used in tissue engineering need to exhibit controlled degradation. In order to address the stability of PEG hydrogels, porous hydrogels were rendered using degradable PEG-co-(L-Lactic acid) diacrylate PEG-PLLA-DA. This polymer is degraded via hydrolysis of the PLLA chains. The porous PEG-PLLA-DA hydrogels were generated by solvent casting, photopolymerization, and particulate leaching. The influence of polymer conditions on the architecture, degradation, and mechanical properties of the hydrogels were investigated in vitro. The hydrogels were found to exhibit autofluorescence that allowed for the unique ability to nondestructively image hydrogel structure under fully swelled conditions using confocal microscopy. Initial pore size was a function of particulate size and independent of polymer concentration. Interestingly, pore size remained stable though out the study, and was not a function of degradation. In addition, degradation time of porous PEG-LLA-DA hydrogels was influenced by polymer concentration. Compressive modulus was a function of polymer concentration and pore size and decreased during hydrogel degradation. The incorporation of cell adhesion sequences into the hydrogel showed that they can support cell adhesion with morphology varying with pore size. This technique could be used to tailor porous biodegradable scaffolds for tissue engineering applications. In the final portion of this thesis a poly-lysine (PLL) molecule was synthesized in order to allow clustering of adhesion sequences in PEG hydrogels. Clusters of peptide sequences have been shown to enhance cell interactions with substrate surfaces. The sequence was synthesized and purified by high performance liquid chromatography (HPLC) and characterized by mass spectrometry. The side chains of the PLL molecule was used to attach peptide sequences. Cysteine contained within the PLL allowed incorporation into the PEG hydrogel by mixed mode polymerization. Cells were observed to adhere to hydrogels containing the RGD clusters and not to the control gels. The results presented here describe various techniques that can be used to optimize the design of polymer scaffolds for tissue engineering. In addition, the data provide insight into the process of vascularization in porous hydrogels and the influence of synthesis conditions and degradation on properties of porous hydrogels. Future studies should investigate the optimization of these material techniques for control of neovascularization within PEG hydrogels for tissue engineering applications.
Ph.D. in Biomedical Engineering, December 2011
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Title: A Mixed Use High Rise in Mumbai: Mixed Used High Rise_Irshad_Saleji
Creator: Saleji, Irshad
Date: 2011-05, 2011-05
Description: C-ward is the neighborhood (in Mumbai) that was designed and developed around 1940 and thereafter there has been no or very little improvement...
Show moreC-ward is the neighborhood (in Mumbai) that was designed and developed around 1940 and thereafter there has been no or very little improvement in infrastructure, which has led to narrow street, unsafe pedestrian and limited open space. C-ward in one of the most prime real-estate location considering it right next to financial district , close to major train station and close to Shoreline. ROMF (Remaking of Mumbai Federation) has taken the initiative to develop the C-ward and the project site part of ROMF development area. City centers have always been source of density because of scarcity of land. The sensible and effective use of such land would be to build vertical (high-rise) and also to have the possibility of expansion for the future development. A mixed use high rise development diversifies the use of space within a single building structure. Combination of living, entertainment, shopping and lodging in single urban structure, helps to utilize the full potential of an urban site.
Sponsorship: Durbrow, John
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Title: Diagnosis of process disturbances by statistical distance and angle measures
Creator: Raich, A., Cinar, A.
Date: 1997
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Description: Disturbance and fault diagnosis techniques that rely on statistical methods traditionally utilize distance based discrimination functions....
Show moreDisturbance and fault diagnosis techniques that rely on statistical methods traditionally utilize distance based discrimination functions. Complementary information is contained in the angular relations between data clusters representing process operations under various disturbances. A novel disturbance diagnosis approach is presented based on angle discriminants. The diagnosis method is successful in cases where distance based discrimination is not very accurate. The methodology is illustrated by diagnosing various disturbances in the Tennessee Eastman process and compared with the diagnosis utilizing distance based algorithms.
Endnote format citation
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Title: Developing a Tool Crib Management System & Feed Mechanism for Semi-Automated Welding Process (sequence unknown), IPRO 347 - Project Plan
Creator: Chiu, Daniel, Cicero, Joseph, Hill, Ross, Lee, Woong-kyo, Perry, Jonathan, Powers, John, Sanborn, Peter, Sarratt, Meagan, Williams, Robert, Xu, Ran
Date: 2009-12
Description: Smith & Richardson, Inc. manufactures hundreds of different metal parts using a variety of stamping and welding equipment. There are two...
Show moreSmith & Richardson, Inc. manufactures hundreds of different metal parts using a variety of stamping and welding equipment. There are two projects that are to be undertaken by the IPRO team: first to identify methods and programs that can be used to create a cohesive and easy to navigate database for machine shop tool storage and to implement that system so that it meshes with an existing computer system; second to identify methods, materials, and systems that can be used to automate a manual sorting and placement process and to achieve a working prototype of the mechanism.
Sponsorship: Smith & Richardson, Inc. (Geneva, Illinois)
Project Plan for IPRO 347: Developing a Tool Crib Management System & Feed Mechanism for Semi-Automated Welding Process for the fall 2009 semester.
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Title: Shock-induced Flow Resonance in Supersonic Jets of Complex Geometry
Creator: Raman, G.
Date: 1999-03
Publisher: American Inst Physics
Description: Jets with complex shock-cell structures exist in numerous technological applications. This paper describes a fundamental study of shock...
Show moreJets with complex shock-cell structures exist in numerous technological applications. This paper describes a fundamental study of shock-induced flow resonance (commonly referred to as "jet screech") in supersonic jets with spanwise nonuniform shock-cell structures. Experiments that involve flow visualization and detailed mapping of the near field reveal unsteady aspects of shock-induced flow resonances, mode transitions, and directivity of the radiated noise. The following important results about the role of spanwise nonuniform shock-cells emerged: (1) It is possible to have two coexisting, independent feedback loops at nonharmonically related frequencies and different spanwise modes. (2) The same type of spanwise asymmetric mode was produced by two entirely different source configurations. (3) Nozzle geometry significantly altered the intensity and directivity of screech and broadband shock noise. The results presented here provide considerable insight into the fluid dynamics and acoustics of jets with spanwise oblique shock-cell structures and provide grounds for believing that shock-induced noise can be controlled by tailoring nozzle geometry. (C) 1999 American Institute of Physics. [S1070-6631(99)00103-8].
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Title: STUDY ON EX POST PRICING
Creator: Zhao, Zhechong
Date: 2011-05-02, 2011-05
Description: The main objective of this thesis is to study the ex post pricing in electricity market by implementing two new methods (quantity based method...
Show moreThe main objective of this thesis is to study the ex post pricing in electricity market by implementing two new methods (quantity based method and price based method). The quantity based method measures the difference between the actual performance of an individual resource and its bid-based profit-maximizing response to the ex post prices. The price based method measures the different between the ex post price and the supporting price which supports the actual outputs. These two methods are based on a co-optimization market for energy and ancillary service. They are very flexible and can solve the ex post price efficiently and simultaneously.
M.S. in Electrical Engineering, May 2011
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Title: COMPARATIVE GENOMICS OF STREPTOCOCCUS SALIVARIUS ATCC 27945 AND 25975; FROM HELPFUL TO HARMFUL?
Creator: Soomer-james, Jahna T. A.
Date: 2015, 2015-07
Description: Streptococcus salivarius is a commensal bacterium that normally inhabits the oral mucosa. However, preliminary data indicated that the strain...
Show moreStreptococcus salivarius is a commensal bacterium that normally inhabits the oral mucosa. However, preliminary data indicated that the strain ATCC 25975 has acquired parasitic genes from Streptococcus pneumoniae. To investigate the nature of this genetic exchange, the genome of Streptococcus salivarius ATCC 27945 was first sequenced and served as a comparative model to provide insight into the possibility of development of pathogenicity within the salivarius group. Illumina and PacBio sequencing data were used complementarily to generate reliable genomes of the Streptococcus salivarius ATCC 27945 and ATCC 25975 strains. The reads were trimmed, filtered, assembled and annotated using custom Perl scripts and various software. The completed genomes of S. salivarius ATCC 27945 and ATCC 25975 are 2.11 Mbp and 2.20 Mbp long, respectively, with ATCC 25975 featuring an additional plasmid. Comparative genomics with other sequenced salivarius genomes revealed that strain ATCC 27945 was most closely related to strains JIM8777 and NCTC8618, while strain ATCC 25975 was more closely related to strains 57I and CCHSS3. The proteins that were common across the investigated salivarius genomes included housekeeping proteins involved in pathways such as DNA replication, metabolism and DNA repair but the unique protein types and their relative location to each other within the ATCC main chromosomes did not provide conclusive evidence to the identification of the parasitic cassette. However, the plasmid contained in S. salivarius ATCC 25975 showed promising signs of containing these genes of interest. Several genes typically found in S. pneumoniae such as capsular polysaccharide genes and two copies of integrative and conjugative genes were identified in close proximity. The phylogenetic analysis of the two S. salivarius ATCC strains suggested that the proposed genes acquired from S. pneumoniae might have been gained via horizontal gene transfer rather than through sporadic mutations. The plasmid had a 5.1% smaller GC content compared to the other salivarius chromosomes, further suggesting that it was acquired from a distinct organism. Overall, while these results provided useful insights into the nature and location of the parasitic cassette, further investigations will be required to assess the full extent of the genetic shuffling that occurred by horizontal gene transfer in these Streptococcus species.
M.S. in Biology, July 2015
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Title: Delta Shelter (sequence unknown), IPRO 311 - Deliverables: IPRO 311 Midterm Presentation F09
Creator: Schug, Timothy, Bradley, Joshua, Cahan, Noah, Dobbin, Dan, Hallenbeck, Jeff, Jordan, Davyd, Strandquist, Brad, Dohm, Jacob, Hoffman, Kent, Lee, Woong-kyo, Waisath, Nathan
Date: 2009-12
Description: The Delta Tau Delta fraternity wants to make their current house as energy efficient and green as possible. The team will look at all aspects...
Show moreThe Delta Tau Delta fraternity wants to make their current house as energy efficient and green as possible. The team will look at all aspects of the DTD house and their operations to create a more energy efficient fraternity. During the term, the team will consider possible alternatives to many issues including but not limited to: mechanical heating system, building envelope, thermal properties of buildings perimeter, roofing materials, air infiltration, ventilation, and occupancy trends.
Deliverables for IPRO 311: Delta Shelter for the fall 2009
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Title: Resonant interaction of a linear array of supersonic rectangular jets: An experimental study
Creator: Raman, G, Taghavi, R
Date: 1996-11-10
Publisher: CAMBRIDGE UNIV PRESS

Title: ORGANIZATIONAL FLEXIBILITY IN CONSTRUCTION COMPANIES
Creator: Taghizadeh Khamesi, Hossein
Date: 2016, 2016-05
Description: Flexibility is a key factor for an organization survival in a changing environment. Considering the cyclical nature of construction demand,...
Show moreFlexibility is a key factor for an organization survival in a changing environment. Considering the cyclical nature of construction demand, organizational flexibility is of special importance in construction company management. Most previous studies tried to categorize the response strategies of construction contractors to business and environmental changes. However, there is gap in the literature about the dynamic effect of organizational flexibility on the growth and competitiveness in construction companies. The objective of this study is to investigate the organizational flexibility of top construction contractors in the U.S. Engineering News-Records (ENR) top 400 contractors lists were used to collect data for the 52-year period 1963-2015. Using the collected data, several analyses were performed to find the relationship between organizational flexibility and competitive success. This attempt did not indicate a distinct relationship between organizational flexibility and competitiveness. It was found however that organizational flexibility is affected by change in the economy and that it was linked to company expansion/contraction. It is concluded that organizational flexibility is an essential advantage for construction contractors. Those contractors that are consistently ranked in the top 400 contractors list respond well to economic changes by expanding and contracting. On the other hand, different size contractors respond to changes in the economy differently, based on their resources and the nature of their work. In addition, this study concluded that those contractors that seek high growth rates face more fluctuations in their growth path and need more flexibility in response to them.
M.S. in Civil Engineering, May 2016
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Title: Buffalo Food Path
Creator: Huttel, Anna
Date: 2010-07-29

Title: INITIAL TURBULENCE EFFECT ON JET EVOLUTION WITH AND WITHOUT TONAL EXCITATION
Creator: Raman, G, Zaman, Kbmq, Rice, Ej
Date: 1989-07
Publisher: AMER INST PHYSICS

Title: UNDERSTANDING UNCERTAINTIES IN RESOLVED PHOTON STRUCTURE
Creator: Zhan, Hengrui
Date: 2017, 2017-07
Description: The construction of a photon collider has been urged, in order to study the properties of the Higgs boson and electroweak symmetry breaking....
Show moreThe construction of a photon collider has been urged, in order to study the properties of the Higgs boson and electroweak symmetry breaking. It would also provide unique possibilities for measurement of fusion to probe the hadronic structure of the photon. One scheme of design for the photon collider is a linear collider. A study shows that resolved photons contribute about 15% of the cross section to Higgs production with a mass of 120 GeV, but estimates of the resolved photon structure have so far varied greatly. Therefore, resolved photon structure is important to measure. This thesis focuses on the determination of the uncertainties of the cross section of bb production for better understanding of resolved photon structure. The principles of a photon collider are reviewed. In this thesis, the simulation tools for the simulation of the cross section of ! bb collision are developed. After that, the method for determination of the uncertainties of cross section is described. A new set of PDFs to explore these uncertainties is produced. The result of the simulation of the cross section and the calculation for the uncertainties of the cross section is presented and discussed in detailed.
M.S. in Physics, July 2017
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Title: PRICING AND APPLICATION OF ELECTRIC STORAGE
Creator: Zhao, Jialin
Date: 2017, 2017-05
Description: Electric storage provides a vehicle to store power for future use. It contributes to the grids in multiple aspects. For instance, electric...
Show moreElectric storage provides a vehicle to store power for future use. It contributes to the grids in multiple aspects. For instance, electric storage is a more effective approach to provide electricity ancillary services than conventional methods. Additionally, electric storage, especially fast-responding units, allows owners to implement high-frequency power transactions in settings such as the 5-min real-time trading market. Such high-frequency power trades were limited in the past. However, as technology advances, the power markets have evolved. For instance, the California Independent System Operator now supports the 5-min real-time trading and the hourly day-ahead ancillary services bidding. Existing valuation models of electric storage were not designed to accommodate these recent market developments. To fill this gap, I focus on the fast-responding grid-level electric storage that provides both the real-time trading and the day-ahead ancillary services bidding. To evaluate such an asset, I propose a Monte Carlo Simulation-based valuation model. The foundation of my model is simulations of power prices. This study develops a new simulation model of electric prices. It is worth noting that, unlike existing models, my proposed simulation model captures the dependency of the real-time markets on the day-ahead markets. Upon such simulations, this study investigates the pricing and the application of electric storage at a 5-min granularity. Essentially, my model is a Dynamic Programming system with both endogenous variables (i.e., the State-of-Charge of electric storage) and exogenous variables (i.e., power prices). My first numerical example is the valuation of a fictitious 4MWh battery. Similarly, my second example evaluates the application of two units of 2MWh batteries. By comparing these two experiments, I investigate the issues related to battery configurations, such as the impacts of splitting storage capability on the valuation of electric storage.
Ph.D. in Management Science, May 2017
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Title: COMPUTATIONAL FLUID DYNAMICS AND POPULATION BALANCE MODEL FOR SIMULATION OF DRY SORBENT BASED CO2 CAPTURE PROCESS
Creator: Abbasi, Emadoddin
Date: 2013, 2013-12
Description: Carbon capture and sequestration (CCS) is one of the key technologies needed to mitigate carbon dioxide emission from industrial sources and...
Show moreCarbon capture and sequestration (CCS) is one of the key technologies needed to mitigate carbon dioxide emission from industrial sources and power plants. Development of CFD-based design tool for prediction of the extent of CO2 capture in a regenerable dry sorbent-based technology, in an efficient power plant design (i.e., modern IGCC power plants) was the driving force behind this project. In this study, we established a systematic methodology, starting from investigating the properties of the sorbent and its reaction mechanism, to developing a model for design and scale-up of the reactors that is needed to deploy this technology at larger scales. This dissertation provides a coupled CFD-PBE model based on the novel FCMOM approach with broad application in reaction engineering and reactor design where the polydisperse nature of the phases has strong effect on the hydrodynamics of the system. Detailed investigations of the MgO-based sorbent and its performance toward capturing CO2 from a coal gas stream were performed that result in development of the two-zone variable diffusivity shrinking core reaction model. Furthermore, a baseline design for a circulating fluidized bed (CFB) reactor, using numerical modeling and threedimensional simulations of a full-loop circulating fluidized bed reactor was provided based on the coupled CFD-PBE, which in combination with the reaction model can perform as a base for parametric studies and optimization of the process.
PH.D in Chemical Engineering, December 2013
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Title: AN INTRINSICALLY CONDUCTING POLYMER-BASED COATING SYSTEM FOR CORROSION PROTECTION OF STEELS
Creator: Yu, Qifeng
Date: 2016, 2016-12
Description: Among the various corrosion protection strategies for structural steels, coating techniques provide the most cost-effective protection and...
Show moreAmong the various corrosion protection strategies for structural steels, coating techniques provide the most cost-effective protection and have been used as the primary mode for corrosion protection. Existing coating techniques have been used mainly for their barrier capability and all have a limited service life. In this research work, a waterborne two-strand polyaniline: poly (acrylic acid) complex was synthesized and utilized to fabricate the primer layer of a two-layer coating system. The techniques of Scanning Kelvin Probe Force Microscopy (SKPFM) and Electrochemical Impedance Spectroscopy (EIS) were used to evaluate the anti-corrosion capability of the polymeric complex when mixed in an epoxy matrix and coated on steel samples as the primer layer. The evaluation results show that coating systems including a PANi-based primer has measurable anticorrosion capability and the anti-corrosion capability of PANi-based primer depends on the usage of PANi and the type of matrix material of the primer layer. In the laboratory condition, a prototype two-layer coating system including the PANi-based primer and a polyurethane topcoat was manufactured. The ASTM Salt-Spray Test and EIS were used to prove the anti-corrosion performance of the prototype using a two-layer, polyurethane-over-epoxy system (no PANi) as the control system. After the proof of concept, a non-waterborne epoxy was used to fabricate a different PANi-based primer. The two types of primers and two other commercial primers (a zinc-rich primer and an epoxy-only primer) were used to make a total of eight two-layer coating systems using two widely used topcoats. Salt-Spray Test, Cyclic Salt Fog/UV Exposure Test, Pull- Off Adhesion Test, and the techniques of EIS, SKPFM, and Scanning Electron Microscope (SEM) were used to evaluate the long-term performance of the eight systems. Based on the laboratory-based recommendations, six groups of two-layer coating systems were then subjected to the outdoor-exposure test to evaluate their anti-corrosion durability at two testing sites. The field durability of the coating systems was evaluated in terms of their surface gloss reduction, color change, adhesion change and surface deteriorations. The matrix material in which the PANi is mixed plays an important role in the longterm anti-corrosion performance of coatings. The waterborne epoxy is effective in dispersing PANi nano-particles and has zero VOC; however, it does not bond to the steel surface as strongly as the regular non-waterborne epoxy. The topcoat material also plays an important role in the long-term anti-corrosion performance of coatings; polyurethane has higher durability than epoxy as a topcoat material. The PANi-based systems possess long-term corrosion protection comparable to the performance of the conventional zincrich three-layer system based on the one-year field evaluation.
Ph.D. in Civil Engineering, December 2016
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