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Title: ENHANCED DEGRADATION AND PEPTIDE SPECIFICITY OF MMP-SENSITIVE SCAFFOLDS FOR NEOVASCULARIZATION OF ENGINEERED TISSUES
Creator: Sokic, Sonja
Date: 2013, 2013-07
Description: Biomaterial strategies for engineering tissues of clinically relevant size require the formation of rapid and stable neovascularization. The...
Show moreBiomaterial strategies for engineering tissues of clinically relevant size require the formation of rapid and stable neovascularization. The ability of an engineered scaffold to induce vascularization is highly dependent on its rate of degradation. During the process of material degradation, the scaffold should degrade in a manner allowing for cellular infiltration, lumen formation, and extracellular matrix (ECM) synthesis. Matrix metalloproteinases (MMPs) play a key role in mediating cell-induced proteolytic matrix degradation, remodeling, and controlled neovascularization. Poly (ethylene glycol) PEG hydrogels have been extensively investigated as scaffolds for tissue engineering applications due to their ease of chemical modification allowing for the recapitulation of key aspects of the neovascularization process. The goal of the work described in this thesis was to develop strategies to enhance and control the degradation of MMP-sensitive PEG diacrylate (PEGDA) hydrogels without inducing changes to the bulk physical and mechanical properties of the material and to further study the effect of the cleavage site concentration and MMP-sensitive peptide substrate specificity on the rate of neovascularization and tissue remodeling in vitro and in vivo. In the first part of this study, a detailed investigation was completed to investigate the effects of the mechanical and physical properties of the scaffolds as well as the role of proteolytically mediated hydrogel degradation on 3D fibroblast invasion within MMPsensitive PEGDA hydrogels. Initial studies focused on the use of a modified version of a previously published multistep conjugation method to generate degradable PEGDA macromer conjugates containing variations in the number of MMP-sensitive domains. Theoretical and experimental characterization of this multistep conjugation demonstrated xi that this method leads to the formation of multiple species that directly affect the compressive modulus and degradation rate of the scaffold making it difficult to control degradation independent of alterations in the bulk physical and mechanical hydrogel properties. After manipulation of multiple polymerization conditions, hydrogels with similar compressive moduli but different hydrogel degradation rates were synthesized. These initial studies showed that an increase in the incorporation of proteolytically sensitive domains in PEGDA hydrogels of similar modulus lead to enhanced degradation and 3D fibroblast invasion. In this study, the role of soluble FGF-1 on fibroblast invasion within these scaffolds was investigated and it was demonstrated that the inclusion of FGF-1 in the scaffolds results in further enhancement of fibroblast invasion in a dosedependent fashion. Further studies were necessary to develop a more controllable and robust approach in tuning scaffold degradation independent of alterations in the bulk physical and mechanical properties. In order to address this, a novel approach was developed to engineer protease-sensitive peptides with multiple proteolytic cleavage sites that could be covalently crosslinked into hydrogels without compromising the physical and mechanical biomaterial properties. This approach avoided the need for utilizing a multistep conjugation process as peptides could be incorporated into the backbone of PEG using a single step conjugation. Using this approach, hydrogels formed with the engineered peptides led to significantly enhanced degradation and neovascularization in vitro as compared to scaffolds with a single protease sensitive peptide between crosslinks. In addition, hydrogels with enhanced susceptibility to degradation promoted vascularization over a wider range of matrix properties. This approach allowed for controlled xii concentration of the proteolytic cleavage sites within the matrix and thus tuning of hydrogel degradation for tissue engineering applications. In the final study, MMP-sensitive peptide substrates specific to degradation by MMPs known to be expressed during neovascularization were screened for degradation and their role in neovascularization. MMP-sensitive PEGDA hydrogels (SSite and TriSite) were synthesized with peptide substrates sensitive to cleavage by MMP-2, MMP- 9, MMP-14, a mixed sequence of MMP-2, 9 and 14, and compared to the peptide substrate used in the previous studies, which is degraded by collagenase enzymes. The hydrogels were evaluated for their sensitivity and specificity to degradation by MMPs, in terms of cleavage site concentration, and for their role in neovascularization and tissue remodeling in vitro and in vivo. The presented approach allows for the incorporation of varying cleavage site concentration and MMP-sensitive peptide substrates into PEG hydrogels without alterations in the mechanical and physical properties of the hydrogels. Results showed that without the incorporation of growth factors in this scaffold, vascularization and tissue invasion was supported in all MMP-sensitive hydrogel groups regardless of the MMP-sensitive peptide substrate embedded in the matrix. In addition, the cleavage site concentration had a profound impact in enhancing vascularization in vitro and tissue invasion in vivo. These techniques can be used to tune the properties of polymer scaffolds for neovascularization and tissue remodeling. In addition, these studies provide insight into the effect of the physical, mechanical, and degradative properties of these systems and on the role of cleavage site concentration, and MMP substrate specificity on xiii neovascularization and tissue invasion within proteolytically degradable PEG hydrogel constructs.
PH.D in Biomedical Engineering, July 2013
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Title: AN ENERGY EFFICIENT ROUTING PROTOCOL FOR WIRELESS SENSOR NETWORKS
Creator: Lara, Aurobinda
Date: 2012-04-27, 2012-05
Description: Wireless distributed microsensor systems will enable the reliable monitoring of a variety of environments for both civil and military...
Show moreWireless distributed microsensor systems will enable the reliable monitoring of a variety of environments for both civil and military applications. A wireless sensor network consists of nodes that can communicate with each other via wireless links. One way to support efficient communication between sensors is to organize the network into several groups, called clusters, with each cluster electing one node as the head of cluster. Energy efficiency is of great importance for the wireless sensor network (WSN). A popular way to save energy is to construct clusters for data aggregation and forwarding. In this thesis a distributed cluster algorithm is studied to improve the energy consumption efficiency. It was observed that the cluster head has to lie within the transmission range of the base station (sink node) and the distance between cluster head and base station is critical for the energy consumption performance, we proposed a pseudo-cluster and virtual hierarchical clustering scheme (PC-LEACH), which considers the power level of the non-cluster head nodes and the residual energy level during the cluster head selection stage. Consequently we could better balance the chance of being cluster head for all nodes. Simulation results show that the scheme is able to result in longer network lifetime than the well-known protocol LEACH.
M.S. in Electrical Engineering, May 2012
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Title: Test of a 40 hp Halladay chasis
Creator: Fors, A. F., Kuehn, H. R., Semerak, A. W.
Date: 2009, 1913
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/testof40hphallad00fors
Thesis (B.S.)--Armour Institute of Technology

Title: ENHANCEMENT OF BIODESULFURIZATION IN RHODOCOCCUS SPECIES (IGTS8) BY THE EXPRESSION OF VITREOSCILLA HEMOGLOBIN
Creator: Shivdas, Vrushali D.
Date: 2013, 2013-07
Description: The bacterium Rhodococcus sp. IGTS8 contains the dsz operon, which encodes a three enzyme pathway (the “4S pathway”) that is able to...
Show moreThe bacterium Rhodococcus sp. IGTS8 contains the dsz operon, which encodes a three enzyme pathway (the “4S pathway”) that is able to mineralize the sulfur contained in dibenzothiophene (DBT), an organic sulfur containing molecule found in petroleum. The gene vgb, which encodes Vitreoscilla hemoglobin (VHb), has shown wide usefulness in enhancing productivity and other useful properties when expressed in heterologous hosts. We engineered strain IGTS8 to express VHb and measured the effects on growth and desulfurization of DBT, using minimal medium containing DBT as the sole source of sulfur. VHb was clearly detected in the engineered strain using the standard COdifference spectral analysis, but its level (0.38-0.63 nmoles/gm wet weight of cells) was about 10-fold lower than commonly seen for expression of VHb in other heterologous bacterial hosts. The VHb-expressing strain was tested for growth at both low and high aeration in minimal medium containing DBT as sole sulfur source; growth was about 50% lower at low aeration compared with high aeration. Despite this, metabolism of DBT (as detected by accumulation of the end product of the 4S pathway, 2-Hydroxy biphenyl (2-HBP), in the growth medium) was about 30 % higher in the low aeration compared to the high aeration culture. A possible explanation for these results is direct enhancement of the first two (monooxygenase) steps in conversion of DBT to 2-HBP. It was thus concluded from the studies that the expression of vgb in Rhodococcus sp. IGTS8 enhances the process of biodesulfurization under conditions of low aeration
M.S. in Biology, July 2013
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Title: HIGH PERFORMANCE, HIGH STABILITY AND LOW POWER SRAM DESIGN BY USING CARBON NANOTUBE FIELD EFFECT TRANSISTORS
Creator: Wang, Wei
Date: 2012-07-07, 2012-07
Description: As the feature size of silicon semiconductor devices scales down to nanometer range, planar bulk CMOS design and fabrication encounter...
Show moreAs the feature size of silicon semiconductor devices scales down to nanometer range, planar bulk CMOS design and fabrication encounter significant challenges. This situation is exacerbated when it comes to SRAM, as SRAM takes a large part of power consumption and area overhead in modern VLSI processor designs. To achieve higher performance, stability and lower power consumption, carbon nanotube (CNT) has been introduced to SRAM design as an alternative material. The semiconducting single-walled CNTs are promising candidates for the channel material of CMOS devices because of two advantages over the other semiconductor materials: high ON current, leading to high speed and low OFF current, leading to less leakage power. In this research work, characterizing work of technology parameters for 6T carbon nanotube field effect transistor (CNFET) SRAM cell is performed for basic understanding of the relationship between SRAM delay/power and CNFET technology parameters. Stability issue is studied by investigating the diameter and transistor ratio impacts on the SRAM static noise margin (SNM). A stability-optimized 6T CNFET SRAM cell achieves 38.88% reading delay reduction, 21.61% writing delay reduction, 85.65% reading power reduction, 5.88% writing power reduction, 97.80% leakage power reduction, 41.41% SNM increment, 91.23% reading power-delay product (PDP) reduction and 26.23% writing PDP reduction, compared with conventional silicon MOSFET SRAM cell. To mitigate major CNT imperfection impacts on CNFET circuits, a misalignment immune SRAM design method is proposed to eliminate CNT misalignment problem by using etching region defined in circuit layout; and a diameter variation sensing and compensating system is designed to mitigate the negative impacts of CNT diameter variation on SRAM delay and power consumption. A hybrid silicon/CNT 4T SRAM cell design is proposed for low-power high-density cache application, which is better than conventionally used 6T SRAM in terms of power consumption and circuit area. Finally, a design flow of high performance, high stability and low power SRAM is summarized.
Ph.D. in Electrical Engineering, July 2012
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Title: Test of a new type of storage cell
Creator: Allyn, A. J., Torrance, R. S.
Date: 2009, 1906
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/testofnewtypeofs00ally
Thesis (B.S.)--Armour Institute of Technology

Title: DYNAMICS OF A THREE-DIMENSIONAL FOUR-BAR LINKAGE SUBJECT TO RANDOM EXTERNAL FORCING
Creator: Lytell, Mark R.
Date: 2011-11-15, 2011-12
Description: This thesis explores the dynamics of a three-dimensional four-bar mechanical linkage subject to random external forcing. The Lagrangian...
Show moreThis thesis explores the dynamics of a three-dimensional four-bar mechanical linkage subject to random external forcing. The Lagrangian formulation of the equations of motion are index-3 stochastic di erential-algebraic equations (SDAE) that describe the time evolution of the sample paths of the generalized coordinates, velocities, and Lagrange multipliers as stochastic processes. We solve the SDAEs using two di erent approaches: inverse dynamics, Case Study 1, via independent, successive solution of the nonlinear equations for each kinematic variable, where the time evolution of one generalized coordinate is prescribed; and direct dynamics, Case Study 2, via direct solution of the SDAEs in the index-1 formulation, using fourth-order stochastic backward di erentiation formula (BDF) with modi ed Newton iteration and position and velocity stabilization (Ascher and Petzold [2]), where the (deterministic) input driving torque is prescribed. For the particular application of a three-dimensional swing gate security system, we conduct numerical experiments for both approaches. In Case Study 1, we simulate the random external forcing as a Gaussian wind speed process that applies stochastic wind drag onto the gate. The kinematic variables are deterministic, while the required input driving torque is a stochastic process. In Case Study 2, we apply the external forcing as a resistive torque with additive Gaussian noise modeling the wind drag; the kinematic variables are stochastic processes. For both cases, we apply four mean wind speeds: 0 mph (deterministic only), 10 mph, 20 mph, and 30 mph, from which we compute the deterministic solution and three stochastic sample paths for each stochastic process. The overall conclusions are that direct solution is possible for inverse dynamics, that the solution of index-1 SDAEs in multibody dynamics is tractable since the mass matrix is symmetric and positive de nite, and that the deterministic solution is the expectation of the sample paths.
M.S. in Applied Mathematics, December 2011
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Title: GENOME ANNOTATION AND PHYLOGENETIC ANALYSIS OF 27 SALMONELLA STRAINS BASED ON BIOINFORMATIC ANALYSIS OF RESPECTIVE GENOMES AND THREE GENES
Creator: Li, Xinyue
Date: 2013-04-15, 2013-05
Description: Salmonella is the most common food-borne bacterial infectious pathogen worldwide. Different serovars of Salmonella are capable of infecting...
Show moreSalmonella is the most common food-borne bacterial infectious pathogen worldwide. Different serovars of Salmonella are capable of infecting different kinds of hosts, such as humans, mice, pigs, chickens, and can also lead to different syndromes, such as enterica fever, enterocolitis and diarrhea, bacteremia and chronic asymptomatic carriage. Although Salmonella strains are quite diverse, strains within the same serovar usually infect the same host and cause similar symptoms. Thus, it is important, especially in food-borne disease outbreaks, to know which type of Salmonella is present. The current method of typing Salmonella is based on the Kaufmann-White scheme and MLEE, which are laborious and expensive. Although the reliability of this method has not been previously verified, the evolutionary relationship reflected by phylogenetic trees can be a possible alternative to the way of typing the Salmonella strains; this method would be less labor intensive and more economical. MLST is considered as a “gold standard” of typing for many species includes Salmonella. And genome sequence, which certainly reflects the evolutionary relationship of strains, is the most ideal data to construct a more reliable phylogenetic tree; however, genome sequencing is also a laborious and expensive process. Thus, conserved and ubiquitous gene data, which can be accessed with little effort, are generally used to minimize cost. Using16s rRNA is the most widely used method. In this study, 27 Salmonella genome sequences are annotated with RAST, and phylogenetic trees are constructed using three software, (phylip3.69, MEGA5.1, and CVTree). And MLST is also used to construct phylogenetic tree in this study, and the result is used to be compared with genome phylogenetic tree to find a more reliable reference tree. Although Neighbor-Joining method is the only algorithms x available in CVTree, phylip3.69 and MEGA5.1 are capable to use three separate algorithms(Maximum Parsimony, Maximum Likelihood, and Neighbor-Joining, respectively). Finally, these trees are compared in an effort to find a good alternative to replace the reference phylogenetic tree. In this study, it was determined that the groEL gene would be the best replacement.
M.S. Biological and Chemical Sciences, May 2013
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Title: A test of an evaporative condenser to determine the coefficient of heat transmission
Creator: Evans, Robert T.
Date: 2009, 1909
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/testofevaporativ00evan
Thesis (B.S.)--Armour Institute of Technology

Title: A study of motor cycle engine characteristics
Creator: Ott, C. L., Pimstein, S.
Date: 2009, 1916
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/studyofmotorcycl00ottc
Thesis (B.S.)--Armour Institute of Technology

Title: SEARCHING ENCRYPTED CLOUD DATA
Creator: Urs, Karthik Mahendra Raje
Date: 2011-05-04, 2011-05
Description: The major setback of the cloud is its inability to induce strong trust in its users. For us, the users of the cloud, to be sure of the...
Show moreThe major setback of the cloud is its inability to induce strong trust in its users. For us, the users of the cloud, to be sure of the security of the data from other users, we have to trust cloud. In most of the cases, say if the data were to be hosted on Microsoft’s servers, we can trust Microsoft in its policies to prevent unauthorized access to it from other users (via hacking). But, the issue that is haunting the cloud is this - ”How can we be sure that our data is safe from Cloud service providers themselves?” The most intuitive solution for the cloud service provider to gain trust is to insist we encrypt our data. That is an irrefutable act of honesty from the cloud. But this has some obvious setbacks, few of which would negate the very advantages of cloud. One such issue that dictates the scope of this thesis is this - Typical cryptographic algorithms are not amenable to search. Now, if we were to implement a search engine on cloud (which has the data encrypted), the native search techniques have to be extended on to the cryptographic domain so that the cloud can perform the tasks of a search engine. This thesis explores the solutions to the above mentioned problem of searching over encrypted data, specifically using a secure pre-processed index approach. Though significant ideas have been proposed in the area, there is no concrete implementation to analyze if it can be used in the industrial setting. The main goal of the thesis is to implement a system which supports a variety of searching techniques. We make use of Amazon EC2 and test out the designed systems to evaluate how feasible they are for immediate consumption by the industry.
M.S. in Computer Engineering, May 2011
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Title: CONTROLLER DESIGN AND DISTRIBUTED CONTROL WITHIN MULTI-AGENT SYSTEMS
Creator: Shao, Quan Min
Date: 2013, 2013-12
Description: None
PH.D in Chemical and Biological Engineering, December 2013

Title: VALIDATION OF BAKING TO INACTIVATE SALMONELLA IN HIGH-PROTEIN AND HIGH-FAT MODEL FOODS
Creator: Wang, Wenqian
Date: 2017, 2017-07
Description: Baked food products, such as dry pet foods, undergo changes of temperature and water activity (aw) during forced hot air processes. As one of...
Show moreBaked food products, such as dry pet foods, undergo changes of temperature and water activity (aw) during forced hot air processes. As one of the most thermal resistant microorganisms in low-moisture/intermediate moisture foods, Salmonella’s thermal inactivation kinetics during these processes is not well understood and difficult to predict. The objective of this study was to evaluate thermal inactivation kinetics of Salmonella enterica serovar Agona 447967 in model high-protein (HP) and high-fat (HF) multiple-component foods baked in a laboratory-scale oven, as influenced by oven temperature and relative humidity (RH). Model high-protein and high-fat foods, formulated with wheat flour, soy protein and soy oil, were inoculated with Salmonella Agona to a level of ~9 log CFU/g, and mixed to form a homogenous dough. Dough samples (57 mm diameter x 6 mm thick) were baked (3 samples per dwell time, 6 dwell times per condition) in a lab-scale oven at 120°C (10% RH) and 85°C (20%, 35% RH, 50% RH), respectively. Temperature and aw were measured at the surface and geometric center of the product during baking. Processed samples were collected in sterile bags and immediately cooled in an ice-water bath. Salmonella was enumerated on trypticase soy agar supplemented with yeast extract and incubated at 37°C for 24 h. Similar reductions (p>0.05) of 5.12-, 5.11-, 4.55-, and 4.78-log CFU/g were achieved after 40 min at 120°C/10% RH, 90 min at 85°C/20% RH, 50 min at 85°C/35% RH, 8 min at 85°C/50% RH, respectively, in the high-protein model food. Similar results were achieved in the high-fat matrix. The aw at the geometric center of the product (initially at aw =0.98) did not change appreciably during baking, while the aw at the product surface, the location of least lethality, decreased significantly (p<0.05) during baking; the decreases were more pronounced at lower oven RH. The results indicate that thermal inactivation of Salmonella Agona was driven by temperature and relative humidity in the oven. Higher temperature and higher relative humidity level led to greater Salmonella inactivation.
M.S. in Food Process Engineering, July 2017
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Title: NUMERICAL SIMULATION OF AIR FLOW OVER A THIN OIL FILM
Creator: Dziedzic, William M.
Date: 2014, 2014-12
Description: Turbulent boundary layer flow research uses oil film and oil drop interferometry to measure wall shear stress of air flows. Oil film...
Show moreTurbulent boundary layer flow research uses oil film and oil drop interferometry to measure wall shear stress of air flows. Oil film interferometry determines the rate oil decreases on a surface as the function of the shear stress magnitude. Current traditional methods have proven to be accurate but the solution is obtained by assuming a linear height distribution [3]. This assumes a constant shear stress along the oil drop and assures that there is no effect of the oil drop on the incoming boundary layer [3]. This effect maintains the continuity of shear stress at the air/oil interface, but the stream-wise velocity at the interface is discontinuous. It is thought that these approximations contain small errors but this has not been verified for zero pressure gradient turbulent boundary layer [3]. A computational fluid dynamics numerical study was performed to simulate the two-dimensional (2D) and three-dimensional (3D) effects of air flow over an oil drop and the drop’s movement across the channel surface.
M.S. in Mechanical and Aerospace Engineering, December 2014
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Title: EARTH ORIENTATION PARAMETER FAULT MONITOR FOR HIGH INTEGRITY GNSS AVIATION APPLICATIONS
Creator: James Meno, Joel Patrick
Date: 2013-05-01, 2013-05
Description: This paper develops threat models and mitigation techniques for mutually consistent satellite faults that are not detectable using Advanced...
Show moreThis paper develops threat models and mitigation techniques for mutually consistent satellite faults that are not detectable using Advanced Receiver Autonomous Integrity Monitoring (ARAIM) methods but are potentially hazardous to aviation users. Faults in the generation of Earth Orientation Parameters (EOPs), EOP Predictions (EOPPs) and their subsequent processing by the GPS Operational Control Segment (OCS) are of particular interest. In principle, if such faults are not detected by OCS, GPS satellite ephemerides could be corrupted constellation-wide in a consistent way, rendering existing ARAIM algorithms ineffective. The initial credibility of the EOP threat is established by the fact that it is explicitly listed as a potential integrity failure mode in the current GPS Standard Positioning Service Performance Standard (GPS SPS). Additionally, an observed EOP fault occurred on June 17, 2012. The dynamics of EOP faults can be reliably modeled as an initial bias with additive linear time variations. An initial broadcast ephemeris (A) is assumed to be EOP fault free and is verified as such via a ground monitor. If the second ephemeris (B) contains an EOP fault, then all satellite positions computed using ephemeris (B) would be rotated with respect to satellite positions obtained from ephemeris (A). Using the difference between the two computed satellite positions as the monitor 'measurement' in conjunction with the dynamic fault model, the parameters defining the EOP fault can be estimated using weighted least squares estimation. The two monitor components (airborne and ground) are bridged together by an Integrity Support Message (ISM). The ISM is needed to provide airborne users with essential information to bound nominal error distributions and fault prior probabilities. xiii The ISM also provides a means to inform airborne users of which ephemerides have passed civil ground monitor validation. The frequency of ISM updates needed to protect airborne GNSS users from the EOP threat is specified. Finally, global availability analysis show that the inclusion of the EOP fault detection algorithms does not cause any availability loss for LPV-200 aircraft precision approach applications.
M.S. in Mechanical and Aerospace Engineering, May 2013
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Title: Some experiments on heat transmission
Creator: Ruef, J. E.
Date: 2009, 1912
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/someexperimentso00ruef
Thesis (B.S.)--Armour Institute of Technology

Title: The synchronous motor
Creator: Sleezer, Frank W., Williams, Wallace, Kelkenney, Artemas A.
Date: 2009, 1907
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/synchronousmotor00slee
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaves 35-37

Title: POLYMER ELECTROLYTE MEMBRANES FOR ELECTROCHEMICAL ENERGY CONVERSION AND STORAGE SYSTEMS: FUEL CELLS AND REDOX FLOW BATTERIES
Creator: Yun, Sukhwan
Date: 2014, 2014-12
Description: Direct methanol fuel cells (DMFCs) and redox flow batteries (RFBs) are well-known electrochemical energy conversion/storage systems that...
Show moreDirect methanol fuel cells (DMFCs) and redox flow batteries (RFBs) are well-known electrochemical energy conversion/storage systems that utilize redox reactions to convert or store electricity. Ion exchange membranes (IEMs) are used in DMFCs and RFBs as electrolyte separators. The critical requirements for IEMs in these applications are high ionic conductivity, low electrolyte permeability, high stability, and low cost. Silsesquioxane (SQO)-based sulfonated poly(etheretherketone) composite membranes were synthesized. Morphological changes in the composite membranes resulting from the introduction of SQO were studied using small-angle x-ray scattering. A sharp decrease in proton conductivity with SQO loading (> 20 wt%) was attributed to morphological changes in the membrane, including agglomeration and inhomogeneous dispersion of SQO particles within the ionic domains. Anion exchange membranes (AEMs) based on quaternized cardo-poly(etherketone) (QPEK-C) were prepared and evaluated for all-vanadium RFB (VRFB) applications. The QPEK-C AEMs with different degrees of functionalization (0.9–1.6) exhibited sulfate ion conductivities ranging between 5.6 and 15.2 mS cm-1 at 30 oC. The AEM had a lower VO2+ permeability (2.8×10-8 cm2 s-), compared to that of Nafion® 212 (2.9±0.2 ×10-7 cm2 s-1), which was attributed to the Donnan exclusion effect. The mechanical strength of QPEK-C AEM degraded by 35% after exposure to a 1.5 M VO2+ solution for 1500 hours due to the oxidation of aromatic rings. A single-cell VRFB employing the AEM separator yielded current and energy efficiencies (at 30 mA cm-2) of 97-99% and 80-82 %, respectively. Enhanced sulfate ion conductivity (8.4 ± 0.2 mS cm-1) and decreased VO2+ permeability (0.53×10-9 cm2 s-1) were achieved by incorporating 20 wt% of n-(trimethoxysilylpropyl)-n,n,n-trimethylammonium additives into QPEK-C, (the pristine QPEK-C AEM yielded corresponding values of 4.5 ± 0.5 mS cm-1 and 1.09×10-9 cm2 s-1). About 99% coulombic efficiency was achieved with the VRFBs employing the composite AEM. However, a rapid reduction of the ionic conductivity down to the value of the pristine membrane was observed when the composite AEM was immersed in 1.5 M VO2+ solution for 3 days. Vanadium-cerium RFBs (V-Ce RFBs) evaluated with QPEK-C AEM separators yielded identical energy efficiency (84%) to corresponding RFBs evaluated with Nafion® 212. However, after over 20 charge-discharge cycles, the V-Ce RFB with the AEM separator yielded unchanged efficiency and capacity, while a 50% loss of capacity was observed with the Nafion® separator. This suggested that QPEK-C AEMs are promising candidates for RFB separators when different cations are used in the two electrolyte solutions, in that they act as efficient barriers that preclude the intermixing of the cations due to the Donnan exclusion effect.
Ph.D. in Chemical Engineering, December 2014
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Title: Test and report of a modern ice plant
Creator: Heim, Karl, Fitch, Joseph E, Jones, Charles H, Hirschfeld, George
Date: 2009, 1909
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/testreportofmode00heim
Thesis (B.S.)--Armour Institute of Technology

Title: THERMAL STABILITY OF FOOD ALLERGENS AND NONALLERGENIC PROTEINS: A COMPARATIVE STUDY
Creator: Wu, Yan
Date: 2015, 2015-07
Description: Thermal stability has been proposed as a criterion to assess the allergenic potential of genetically modified foods, but there is a lack of...
Show moreThermal stability has been proposed as a criterion to assess the allergenic potential of genetically modified foods, but there is a lack of information on the relative thermal stability of food allergens vs. nonallergenic proteins. This study compared the thermal stability of several paired food allergens and nonallergenic proteins by measuring the changes in their solubility, antigenicity and thermodynamic properties after thermal treatment using BCA total protein assay, inhibition ELISA assay, Differential Scanning Calorimetry and Far-UV Circular Dichroism Spectroscopy. The selected protein pairs included bovine α-lactalbumin (allergen) vs. human α-lactalbumin (nonallergen), peanut lectin (allergen) vs. concanavalin A (nonallergen), soybean trypsin inhibitor (allergen) vs. lima bean trypsin inhibitor (nonallergen). With respect to protein solubility, a greater thermal stability was observed for: (1) bovine α-lactalbumin (bovine ALA) when it was autoclaved in water compared with human α-lactalbumin (human ALA) (2) peanut lectin when it was boiled or autoclaved in water compared with concanavalin A (ConA) and (3) soybean trypsin inhibitor (STI) when it was boiled in water or PBS, or autoclaved in water compared with lima bean trypsin inhibitor (LTI). Regarding TM values determined by DSC: (1) bovine ALA was more thermally stable than human ALA under both dry-heat treatment and moist-heat treatment (2) ConA was more thermally stable than peanut lectin during moist-heat treatment, while a greater thermal stability was observed for peanut lectin when the protein was under dry-heat treatment (3) LTI was more thermally stable than STI during heating in water or under dry-heat treatment, while a greater thermal stability was observed for STI when the protein was heated in PBS. Based on CD analyses, (1) bovine ALA was more thermally stable than human ALA (2) peanut lectin was more thermally stable than ConA (3) STI and LTI showed similar thermal stability. With respect to antigenicity, a greater thermal stability was observed for: (1) human ALA when it was autoclaved in water compared with bovine ALA (2) ConA when it was boiled or autoclaved in water, or under dry-heat treatment at 176℃ compared with peanut lectin (3) STI when it was autoclaved in PBS compared with LTI. In summary, allergens tended to be more thermally stable than nonallergenic proteins with respect to solubility, but there was no consistent trend in the relative thermal stability of these protein pairs regarding the antigenicity or the TM values. No correlation between thermal stability of the proteins and their allergenic potential was observed.ConA (3) STI and LTI showed similar thermal stability. With respect to antigenicity, a greater thermal stability was observed for: (1) human ALA when it was autoclaved in water compared with bovine ALA (2) ConA when it was boiled or autoclaved in water, or under dry-heat treatment at 176℃ compared with peanut lectin (3) STI when it was autoclaved in PBS compared with LTI. In summary, allergens tended to be more thermally stable than nonallergenic proteins with respect to solubility, but there was no consistent trend in the relative thermal stability of these protein pairs regarding the antigenicity or the TM values. No correlation between thermal stability of the proteins and their allergenic potential was observed.
M.S. in Food Safety and Technology, July 2015
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