Search results

Title: Developing Web Applications for the Northern Illinois Hockey League (sequence unknown), IPRO 308 - Deliverables: IPRO 308 Midterm Presentation F09
Creator: Lucchesi, Kristin, Barksdale, Dustin, Hays, Julian, Bartus, Kryzystof, Perkins, William, Savage, Christopher, Scheer, Colin, Semenov, Vladimir, Vidutis, Mantas
Date: 2009-12
Description: The NIHL is the largest hockey league in Illinois. It is also the largest youth all star hockey league in the US, serving over 300 youth teams...
Show moreThe NIHL is the largest hockey league in Illinois. It is also the largest youth all star hockey league in the US, serving over 300 youth teams and over 4,000 players. The team's purpose is to make the NIHL a web-based scheduling and scoring applications that can support their annual operations.
Sponsorship: Northern Illinois Hockey League(NIHL)
Deliverables for IPRO 308: Developing Web Applications for the Northern Illinois Hockey League for the fall 2009 semester
Show less

Title: BOUNDING ESTIMATION INTEGRITY RISK FOR LINEAR SYSTEMS WITH STRUCTURED STOCHASTIC MODELING UNCERTAINTY
Creator: Langel, Steven Edward
Date: 2014, 2014-05
Description: Safety critical estimation applications require quantification of integrity risk, which is the probability of the state estimate error...
Show moreSafety critical estimation applications require quantification of integrity risk, which is the probability of the state estimate error exceeding predefined bounds of acceptability. Integrity risk can only be evaluated when the state estimate error probability density function is precisely known, necessitating stochastic models that exactly describe measurement noise and disturbance inputs. Uncertainty in these models directly results in inaccurate assessments of integrity risk. This dissertation develops the first implementable methods to upper bound integrity risk when the autocorrelation functions of stochastic inputs reside between upper and lower bounding functions. The first part of this work considers real-valued estimation applications that use the Kalman filter or batch weighted least squares estimator. Explicit relations are developed between the estimate error variance and autocorrelation functions using a new generalized covariance matrix derived in this dissertation. From these expressions, two methods are provided to upper bound integrity risk. The first method enables fast computation of a conservative bound, and the second method produces the minimum upper bound via semi-definite optimization. Mixed real/integer estimation applications utilizing integer bootstrapping are the focus of the second part of this work. The integrity risk bound is formally defined as the global solution to a non-convex optimization problem over a polytope. Determination of the polytopic region is difficult, and two bounding approaches are initially developed for a circumscribing hyper-rectangular feasible region. Using an innovative method to define the polytope together with linear programming, a third method is derived to upper bound integrity risk over the true polytopic feasible region.
PH.D in Mechanical and Aerospace Engineering, May 2014
Show less

Title: PA 508 Student Computer Usage Survey: PA508 Student Survey 2010 Results
Creator: Ahrens, Aric G.
Date: 2010-01-19, 2010-01-19
Description: Included are a survey, and the results in graphic form. The survey was designed to find out how and where the Chinese contingent of Master of...
Show moreIncluded are a survey, and the results in graphic form. The survey was designed to find out how and where the Chinese contingent of Master of Public Administration students used computers. The focus was to determine whether they preferred to use computers on the Downtown Campus, where classes were taught, or on Main Campus, where most of the students lived.
Show less

Title: Teacher Knowledge Share (Semester Unknown) IPRO 320: Teacher Knowledge Share IPRO 320 MidTerm Presentation F08
Creator: Bern, David, Bochantin, Marike, Hartline, Julian, Mccall, Ian, Mick, Emily, Peake, Andrew, Pierce, Alison, Pindrik, Dmitriy, Quinn, Michael, Stanford, Carly, Tilatti, Michael
Date: 2008, 2008-12
Description: The goal of IPRO 320 is to create an online professional network for school teachers at the kindergarten through twelfth grade level to allow...
Show moreThe goal of IPRO 320 is to create an online professional network for school teachers at the kindergarten through twelfth grade level to allow for the sharing of ideas, lesson plans and other professionally relevant information. This is a continuing project which saw limited success in the previous semester in that a functioning web site was constructed based on surveys of public school teachers but it saw very little use. This semester, the planned approach is to build on the research generated last semester by performing additional market research with teachers. Following that, IPRO 320 will rework much of the previous web site by refining some of the features, adding additional ones as the research indicates and improving the website in general, both functionally and aesthetically.
Deliverables
Show less

Title: Impacts of Sulfur Capture Technology in Coal Power Plants (sequence unknown), IPRO 302 - Deliverables: IPRO_302_Project_Plan_final
Creator: Contreras, Abraham, Dickman, Justin, Enadeghe, Gregory, Garcia Rodriguez, Hector, Haddad, Michael, Kyle, Ryan, Mongillo, Michael, Murphy, Ryan, Shonubi, Oluwaseun, Swillum, Bryce, Wolber, Brian, Worthon, Terrika
Date: 2009-12
Description: The IPRO team was investigating the net impact of sulfur capture technologies used in current and next generation power plants in the United...
Show moreThe IPRO team was investigating the net impact of sulfur capture technologies used in current and next generation power plants in the United States. It planned to use this knowledge to determine which sulfur capture technologies produce the greatest benefit for industry and society and to find the marketability of the sulfur byproducts created in these power plants.
Sponsorship: Sargent & Lundy, LLC
These are the deliverables for IPRO 302: Impacts of Sulfur Capture Technology in Coal Power Plants from the Fall 2009 semester.
Show less

Title: EBSD CHARACTERIZATION OF LOW TEMPERATURE DEFORMATION MECHANISMS IN MODERN ALLOYS
Creator: Kozmel, Thomas S Ii
Date: 2015, 2015-05
Description: For structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and...
Show moreFor structural applications, grain re nement has been shown to enhance mechanical properties such as strength, fatigue resistance, and fracture toughness. Through control of the thermo-mechanical processing parameters, dynamic recrystallization mechanisms were used to produce microstructures consisting of sub-micron grains in 9310 steel, 4140 steel, and Ti-6Al-4V. In both 9310 and 4140 steel, the distribution of carbides throughout the microstructure a ected the ability of the material to dynamically recrystallize and determined the size of the dynamically recrystallized grains. Processing the materials at lower temperatures and higher strain rates resulted in ner dynamically recrystallized grains. Microstructural process models that can be used to estimate the resulting microstructure based on the processing parameters were developed for both 9310 and 4140 steel. Heat treatment studies performed on 9310 steel showed that the sub-micron grain size obtained during deformation could not be retained due to the low equilibrium volume fraction of carbides. Commercially available aluminum alloys were investigated to explain their high strain rate deformation behavior. Alloys such as 2139, 2519, 5083, and 7039 exhibit strain softening after an ultimate strength is reached, followed by a rapid degradation of mechanical properties after a critical strain level has been reached. Microstructural analysis showed that the formation of shear bands typically preceded this rapid degradation in properties. Shear band boundary misorientations increased as a function of equivalent strain in all cases. Precipitation behavior was found to greatly in uence the microstructural response of the alloys. Additionally, precipitation strengthened alloys were found to exhibit similar ow stress behavior, whereas solid solution strengthened alloys exhibited lower ow stresses but higher ductility during dynamic loading. Schmid factor maps demonstrated that shear band formation behavior was in uenced by texturing in these alloys.
Ph.D. in Materials Science and Engineering, May 2015
Show less

Title: THERMODYNAMIC PROPERTIES AND PHASE EQUILIBRIA OF SELECTED HEUSLER COMPOUNDS
Creator: Yin, Ming
Date: 2015, 2015-12
Description: Heusler compounds are ternary intermetallics with many promising properties such as spin polarization and magnetic shape memory effect. A...
Show moreHeusler compounds are ternary intermetallics with many promising properties such as spin polarization and magnetic shape memory effect. A better understanding of their thermodynamic properties facilitates future design and development. Therefore, standard enthalpies of formation and heat capacities from room temperature to 1500 K of selected Heusler compounds X2YZ (X = Co, Fe, Ni, Pd, Rh, Ru; Y = Co, Cu, Fe, Hf, Mn, Ni, Ti, V, Zr; Z = Al, Ga, In, Si, Ge, Sn) and half-Heusler compounds XYSn (X = Au, Co, Fe, Ir, Ni, Pd, Pt, Rh; Y = Hf, Mn, Ti, Zr) were measured using high temperature direct reaction calorimetry. The measured standard enthalpies of formation were compared with those predicted from ab initio calculations and the extended semiempirical Miedema's model. Trends in standard enthalpy of formation with respect to the periodic classification of elements were discussed. The effect of a fourth element (Co, Cu, Fe, Pd; Ti, V; Al, Ga, In, Si, Ge) on the standard enthalpy of formation of Ni2MnSn was also investigated. Lattice parameters of the compounds with an L21 structure were determined using X-ray powder diffraction analysis. Differential scanning calorimetry was used to determine melting points and phase transformation temperatures. Phase relationships were investigated using scanning electron microscopy with an energy dispersive spectrometer. The isothermal section of the Fe-Sn-Ti ternary system at 873 K was established using equilibrated alloys. Three ternary compounds including the Heusler compound Fe2SnTi were observed. A new ternary compound Fe5Sn9Ti6 was reported and the crystal structure of FeSnTi2 was determined for the first time.
Ph.D. in Mechanical, Materials and Aerospace Engineering
Show less

Title: DEVELOPMENT OF A HIGH ANGULAR RESOLUTION DIFFUSION IMAGING TEMPLATE AND PROBABILISTIC CONNECTIVITY-BASED ATLAS OF THE HUMAN BRAIN
Creator: Varentsova, Anna
Date: 2016, 2016-05
Description: Digital human brain atlases consisting of MRI-based templates and semantic labels delineating different brain regions serve a critical role in...
Show moreDigital human brain atlases consisting of MRI-based templates and semantic labels delineating different brain regions serve a critical role in neuroimaging, mainly facilitating spatial normalization and automated segmentation for the purposes of voxel-wise, region-of-interest, and network analyses. Diffusion MRI templates contain rich information about the microstructure of the brain, however the accuracy of templates constructed based on the diffusion tensor imaging (DTI) model is limited in regions with complex neuronal microarchitecture. High angular resolution diffusion imaging (HARDI) overcomes limitations of the DTI model and is capable of resolving intravoxel heterogeneity. In this work a method to develop artifact-free HARDI template of the human brain from low angular resolution data is presented. Existing white matter (WM) atlases have been generated either based on anatomical landmarks, thus mixing tracts with substantially different roles, or using DTI tractography, which fails in regions with crossing fibers. Connectivity-based atlases developed using HARDI templates and probabilistic tractography have potential to identify functionally distinct subregions of the brain. This work presents connectivity-based atlas of human brain WM created using HARDI template in ICBM-152 space and a set of FreeSurfer grey matter labels.
Ph.D. in Physics, May 2016
Show less

Title: Screech Tones of Supersonic Jets from Bevelled Rectangular Nozzles
Creator: Tam, Ckw, Shen, H., Raman, G.
Date: 1997-07
Publisher: American Inst Aeronaut Astronaut
Description: It is known experimentally that an imperfectly expanded rectangular jet from a thin-lip convergent nozzle emits only a single dominant screech...
Show moreIt is known experimentally that an imperfectly expanded rectangular jet from a thin-lip convergent nozzle emits only a single dominant screech tone. The frequency of the screech tone decreases continuously with an increase in jet Mach number. However, for a supersonic jet issued from a bevelled nozzle or a convergent-divergent nozzle with straight side walls, the shock cell structure and the screech frequency pattern are fairly complicated and have not been predicted before. It is shown that the shock cell structures of these jets can be decomposed into waveguide modes of the jet flow. The screech frequencies are related to the higher-order waveguide modes following the weakest link screech tone theory. The measured screech frequencies are found to compare web with the predicted screech frequency curves.
Show less

Title: Fab Lab: Creating Design-to-Prototype Learning Modules at the Museum of Science and Industry (sequence unknown), IPRO 333 - Deliverables: IPRO 333 Midterm Presentation F09
Creator: Bonesz, Andrew, Clark, Howard, Douglas, Carlie, Gajdorus, Michael, Gottschall, Keenan, Hendricks, Rachel, Kimball, Clayton, Linares, Jared, Marks, Paul, Mellom, James, Oblenida, Cindy, Pop, Sabina, Stelcel, Carl, Young, Jeremy, Zhou, Raymond
Date: 2009-12
Description: The primary objective of IPRO 333 is to partner the knowledge and ideas of young engineers, architects, and scientists at IIT with the...
Show moreThe primary objective of IPRO 333 is to partner the knowledge and ideas of young engineers, architects, and scientists at IIT with the resources of the Museum of Science and Industry (MSI) in Chicago. This partnership endeavors to help the museum's Fabrication Laboratory (Fab Lab) maximize its potential as a resource for museum guests, young and old, as well as for IIT students, staff, and faculty.
Sponsorship: Museum of Science and Industry. Steven Willis- Director, Fabrication Lab
Deliverables for IPRO 333: Fab Lab: Creating Design-to-Prototype Learning Modules at the Museum of Science and Industry for the fall 2009 semester
Show less

Title: Gerry-meandering: An Assessment of the Congressional District Model of Depository Allocation (preprint): AhrensGriffinedrev2
Creator: Ahrens, Aric G., Griffin, Luke A.
Date: 2003-06
Description: The preprint of a published article dealing with the effect of allocating Federal Depositories by Congressional district. Conclusions drawn...
Show moreThe preprint of a published article dealing with the effect of allocating Federal Depositories by Congressional district. Conclusions drawn include the fact that due to redistricting that occurs after each decennial census, over time some districts may have within their boundaries a greater number than the two depositories that Congressional district allocation was intended to produce. Likewise, over time shifting boundaries of districts have created districts that have no depositories whatsoever.
Show less

Title: EXPERIMENTAL STUDY, TIME-RESOLVED OBSERVATION, AND ANALYSIS OF NANOSECOND LASER ABLATION AND LASER-INDUCED PLASMA
Creator: Zhou, Yun
Date: 2013, 2013-05
Description: For lasers, there exist many current and potential competitive applications in the areas of manufacturing, materials processing, and so on....
Show moreFor lasers, there exist many current and potential competitive applications in the areas of manufacturing, materials processing, and so on. Nanosecond (ns)-pulsed lasers are often seen in these applications. This dissertation presents the experimental study, time-resolved observation and analysis of nanosecond laser ablation and laser-induced plasma due to ablation, and the analysis is based on physics-based numerical models. Specifically, the following topics have been studied: (1). Plasma induced by ablation using long-duration nanosecond laser pulse Plasma is often produced in laser-material interactions, and may play an important role in many laser-based or laser-assisted technologies, such as laser shock peening (LSP), laser micromachining (through the laser ablation process), laser-induced breakdown spectroscopy (LIBS), and laser propulsion, etc. However, despite the previous work in the literature, the study is still limited for the plasma induced by the ablation process using long nanosecond laser pulses (with durations on the order of ~100 ns). In this dissertation, investigations have been performed on this kind of plasma through fast photography (imaging) and emission spectroscopy techniques, and the experimental results have been analyzed using physics-based computational models. Based on the investigations, the following major interesting findings have been obtained under the investigated conditions: (i) Two high radiation intensity regions are observed in the plasma, and one of them disappears soon after laser pulse ends. The research work shows that this phenomenon is related to the vaporization process from the target surface and the confinement effect of the ambient air. (ii) Laser-induced plasma xvii backward growth phenomenon occurs for target ablation using 100-ns laser pulses, but not for that using 200-ns pulses. The investigation shows that the underlying mechanism is the backward growth of the boundary of the high temperature region without actual backward motion of vapor material. (iii) Under the studied conditions, the core region of the plasma (~100 μm above the laser-ablated target) has relatively low temperatures as compared to some other regions of the plasma, which contradicts the common intuition. (2). Semiconductor ablation utilizing infrared (IR) nanosecond laser pulses Semiconductor micromachining through laser ablation may have the advantages of high spatial resolution, high processing efficiency, good flexibility, and no tool wear. However, most of the prior investigations in the literature on ns laser ablation of semiconductors often employ lasers at the ultraviolet (UV) or visible wavelength. The work using IR ns lasers is limited, but IR ns lasers may often have lower cost and require less external energy consumption to produce the same average laser power output. In this dissertation, the ablation of semiconductors using IR ns lasers has been studied through time-resolved observations (fast photography) and the results have been analyzed utilizing physics-based numerical models. The research work shows that the ablation mechanism under the studied conditions is the surface vaporization process during the early stage followed by the subsequent liquid ejection process that occurs at a later time. The research work and analysis shows that the underlying mechanism for the observed liquid ejection should be due to the spatial gradient of the pressure exerted on the target surface, instead of phase explosion. (3). Laser-induced backside ablation (LIBA) of sapphire with IR ns laser pulses xviii LIBA may potentially provide a good solution for high-quality and highefficiency micromachining of wide-band-gap dielectrics (WBGD). However, the prior work on LIBA of sapphire (which is a very important WBGD material) using low-cost IR ns lasers has been rarely reported. This kind of work has been carried out in this dissertation, and the investigation shows that under the studied conditions LIBA can produce very high material removal efficiency and reasonably good quality of machining without obvious chemical contamination coming from the employed backing layer. The ablation rate and damage threshold are measured under different laser parameters, and the research work may provide useful information for the applications of LIBA in practical areas using IR ns lasers that may often have relatively lower cost than UV or visible ns lasers.
PH.D in Mechanical and Aerospace Engineering, May 2013
Show less

Title: FIELD AND PHOTO-EMISSION IN A SHORT-PULSE, HIGH-CHARGE CESIUM TELLURIDE RF PHOTOINJECTOR
Creator: Wisniewski, Eric E.
Date: 2014, 2014-05
Description: A new high-charge RF gun is now operating at the Argonne Wakefield Accelerator (AWA) facility at Argonne National Laboratory (ANL). The 1.5...
Show moreA new high-charge RF gun is now operating at the Argonne Wakefield Accelerator (AWA) facility at Argonne National Laboratory (ANL). The 1.5 cell 1.3 GHz gun uses a Cesium telluride photocathode driven with a 248 nm laser to provide short-pulse, high charge electron beams for the new 75 MeV drive beamline. The high-gradient RF gun (peak field on the cathode > 80MV/m) is a key piece of the facility upgrade. The large Cs2Te photocathode (diameter > 30 mm) was fabricated in-house. The photo-injector will be used to generate high-charge, short pulse, single bunches (Q > 100 nC) and bunch-trains (Q>1000 nC) for wakefield experiments, typically involving dielectric-loaded accelerating structures. Details of the photocathode fabrication process and the results of associated diagnostic measurements are presented, including QE measurements and work function measurements performed with a Kelvin probe. Field-emitted dark current from the Cs2Te cathode was measured during RF conditioning and characterized. Fowler-Nordheim plots of the data are presented and compared to similar measurements made using a copper cathode in the initial phase of conditioning. The results for cesium telluride exhibited non-linear regions within the Fowler-Nordheim plots similar to previous experimental results for other p-type semiconductors. Results of quantum efficiency (QE) studies are presented with the cathode operating in both single and bunch-train modes. QE uniformity and lifetime studies are presented. During commissioning, the cesium telluride photocathode produced bunch-charge of 100 nC, breaking the previous record. No evidence of bunch-train position-dependence of QE was found when generating four-bunch trains with total charge up to 200 nC.
PH.D in Physics, May 2014
Show less

Title: BIOLOGICAL STRATEGIES FOR ENHANCEMENT OF LIQUID FUELS: SULFUR REMOVAL FROM PETROLEUM AND BIOETHANOL PRODUCTION
Creator: Wang, Jia
Date: 2013, 2013-12
Description: Rhodococcus baikonurensis CW25 was transformed with the Rhodococcus erythropolis strain IGTS8 desulfurization operon (dszABC, which encodes...
Show moreRhodococcus baikonurensis CW25 was transformed with the Rhodococcus erythropolis strain IGTS8 desulfurization operon (dszABC, which encodes the enzymes of the “4S” desulfurization pathway) or this operon modified to contain a synthetic cysteine-methionine rich “sulpeptide” gene (S1) (dszAS1BC). The two CW25 derivatives were subjected to directed evolution to select faster growing cells using the key 4S pathway substrate dibenzothiophene (DBT) as the sole source of sulfur. Data of cell doubling times verified the success of selection of cultures with increasingly rapid growth. The desulfurization activities of resting cells of early passages demonstrated improvements, and the highest activity of the dszAS1BC-bearing CW25 derivative was 115% higher than that of the CW25 derivative without S1. In addition, a trend of initial high activity was followed by a decrease in subsequent passages. Rates of DBT metabolism of growing cells demonstrated a different trend, probably because the activity of growing cells concurrently reflects the activity of DszABC enzymes and the growth rates of the recombinants. Dry cell weights fluctuated during the evolution process, probably because of variations in the efficiency of the conversion of the sulfur in DBT into sulfite, then into sulfate or biomass, or, for the S1-bearing cells, because the secretion of the S1 peptide from cells might have variable efficiency. A mixed culture of two Paenibacillus species (“W” and “Y”) was isolated that can metabolize DBT at temperatures up to 54 ºC. Strain Y is the only one of the two with desulfurization activity, while strain W enhances the desulfurization ability of Y. The W-Y culture may be a useful starting point for selection of desulfurization cultures with even greater thermal stability. xiii Ethanologenic Escherichia coli strain FBR5 was compared with Vitreoscilla hemoglobin (VHb)-expressing FBR5 (TS3) regarding the concentrations of ATP, NAD+, NADH, NAD+/NADH ratio; and growth and ethanol production at various points during growth. The significant finding was that the NAD+/NADH ratio for TS3 was lower in early growth, but higher in later growth compared to that for FBR5. This is probably because more NADH was required by TS3 for its enhanced ethanol production and VHb-related increased respiration under microaeration conditions.
PH.D in Biology, December 2013
Show less

Title: Gerry-meandering: An Assessment of the Congressional District Model of Depository Allocation (preprint)
Creator: Ahrens, Aric G., Griffin, Luke A.
Date: 2003-06
Description: The preprint of a published article dealing with the effect of allocating Federal Depositories by Congressional district. Conclusions drawn...
Show moreThe preprint of a published article dealing with the effect of allocating Federal Depositories by Congressional district. Conclusions drawn include the fact that due to redistricting that occurs after each decennial census, over time some districts may have within their boundaries a greater number than the two depositories that Congressional district allocation was intended to produce. Likewise, over time shifting boundaries of districts have created districts that have no depositories whatsoever.
Show less

Title: Financial Incubators, India: presentation 26 april
Creator: Shah, Shruti
Date: 2010-05-01, 2010-05

Title: Planning for Human Implantation of a Cortical Visual Prosthesis (sequence unknown), IPRO 334 - Deliverables: IPRO 334 IPRO Day Presentation F09
Creator: Bern, David, Chen, Shanyl, Deroo, Mary, Gorski, David, Kelly, Thomas, Leasenby, Alex, Li, Zhi, Pyrkh, Hanna, Subhani, Maham, Taneja, Aanchal
Date: 2009-12
Description: The Intracortical Visual Prosthesis is based upon that concept that by implanting a large number of subminiature electrodes within the human...
Show moreThe Intracortical Visual Prosthesis is based upon that concept that by implanting a large number of subminiature electrodes within the human visual cortex, coordinated temporal-spatial image information can be artificially communicated to the human visual cortex in the form of electrical currents, acting as a sensory substitute for normal vision.
Sponsorship: IIT Laboratory of Neural Prosthetic Research
Deliverables for IPRO 334: Planning for Human Implantation of a Cortical Visual Prosthesis for the fall 2009 semester
Show less

Title: MATHEMATICAL MODELING OF POLY(ETHYLENE GLYCOL) DIACRYLATE HYDROGEL SYNTHESIS VIA VISIBLE LIGHT FREE-RADICAL PHOTOPOLYMERIZATION FOR TISSUE ENGINEERING APPLICATIONS
Creator: Lee, Chu-yi
Date: 2013, 2013-05
Description: Crosslinked hydrogels of poly(ethylene glycol) diacrylate (PEGDA) have been extensively used as scaffolds for applications in tissue...
Show moreCrosslinked hydrogels of poly(ethylene glycol) diacrylate (PEGDA) have been extensively used as scaffolds for applications in tissue engineering. In this thesis, PEGDA hydrogels are synthesized using visible light free-radical photopolymeriza- tion (λ = 514 nm) in the presence of the visible light photosensitive dye, EosinY, the co-initiator, triethanolamine (TEA), a comonomer, N-vinyl pyrrolidone (NVP), a crosslinking agent, PEGDA, and an optional PEG monoacrylate monomer that contains the cell adhesive ligand YRGDS. The incorporation level of the YRGDS lig- and as well as the physical and mechanical properties of these hydrogels dictate cell behavior and tissue regeneration. These hydrogel properties may be tuned through variations in polymerization conditions. The goal of this thesis was to develop a math- ematical model for PEGDA hydrogel formation which predicts the incorporation level of YRGDS and the crosslink density of hydrogel as a variety of polymerization con- ditions. This model provides insight into the process of hydrogel crosslinking and in effectively guiding the experimental design of these scaffolds for tissue engineering applications. To accomplish this task two major components comprised the studies of this thesis. The first component involved an investigation of the visible light photo- initiation mechanism of EosinY and TEA, and the second component involved the develop of a hydrogel synthesis model and its validation. Experiments and modeling were used to determine an expression for the rate of initiation of the EosinY/TEA initiation system and to propose a photoinitiation mechanism. In Chapter 2, exper- imental data and parameter fitting were utilized to obtain an empirical expression for the rate of initiation. However, this empirical expression did not consider the ef- fect of inhomogeneous light distribution which is present in this experimental system. The dynamics of light absorption during polymerization were measured under differ- xiv ent conditions in order to gain insight into the kinetic photoinitiation mechanism as well as the rate of initiation. In Chapter 3, a mechanism for this photo-initiation was proposed. Using this mechanism the light absorption dynamics accounting for inhomogeneous light distribution were simulated which were found to be in an agree- ment with the light absorption measurements shown in Chapter 2. Further validation of this proposed mechanism was achieved from polyNVP conversion measurements. This photo-initiation mechanism was implemented in the hydrogel model. In Chapter 4, the hydrogel synthesis model was developed based on the kinetic approach of the method of moments combined with the Numerical Fractionation technique. The model was used to predict the dynamics of hydrogel properties such as gel fraction, crosslink density, and RGD incorporation under various polymerization conditions. Model predictions were compared with experimental data. Three sets of experiments were conducted. In the first set of experiments where hydrogels were formed in the absence of Acryl-PEG-RGD, the total double bond concentration was kept constant while varying the compositions of NVP and PEGDA. The model and the experiments showed a maximum crosslink density for an acrylate to double bond ratio of 0.5 to 0.6. This is related to the synergistic cross-propagation between NVP and PEGDA, which results in an increase in the rate of polymerization leading to higher crosslink density. In the second set of experiments, hydrogels were formed in the presence of Acryl-PEG-RGD to investigate its incorporation as well as the hydrogel crosslink density. The model showed reasonable agreement with the experimental data and in some cases the predicted RGD deviated from the experimental measurements due to changes in volume upon swelling. The effect of swelling was not considered by the model. The calculated crosslink densities were compared with the inverse swelling ratios from the experiments. The reduction of free volume due to the space occupied xv by the unreacted pendant double bonds was not considered by the model. This reduc- tion of free volume affected the apparent swelling ratio obtained from experiments thus resulting in the observed mismatch between the experimental trends and the predicted crosslink density by the model. In the third set of experiments, additional crosslink density measurements were conducted using a PEGDA macromer of lower molecular weight (MW = 575 Da.). The experiments were performed in the absence of Acryl-PEG-RGD. Few cases were not accurately predicted since the model did not consider the reduction in the concentration of available pendant double bonds when gelation occurs. Among the three set of experiments, the hydrogel synthesis model offers reasonable predictions for most of the experimental cases. This model can be used as a guide for experimen- tally designing PEGDA hydrogels with the desired properties for tissue engineering applications.
PH.D in Chemical and Biological Engineering, May 2013
Show less

Title: High Performance Green Homes (sequence unknown), IPRO 317 - Deliverables: IPRO 317 Brochure F09
Creator: Bhat, Adnan, Campbell, Brittanie, Cink, Jefferey, Gutstein, Yehuda, Hadi, Shuaib, Hafdi, Kamal, Hasan, Hasan, Kenig, Elezar, Lipski, Brian, Lollino, Luca, Margolis, Jordan, Nigamatzyanov, Tagir, Patel, Hiren, Patel, Neal, Shehada, Hazem, Toops, Melissa, Trauner, Crystal, Zgourdah, Mourad
Date: 2009-12
Description: The purpose of this project is to show how a team committed to helping people help save the world can leapfrog today's best designs. As...
Show moreThe purpose of this project is to show how a team committed to helping people help save the world can leapfrog today's best designs. As opposed to the tradition of minimum design standards that just meeting the building code, highest practical design standards are the focus. True sustainability is the goal of this project, including; Zero Carbon Emissions, Net Zero Energy, 100% Solar Power, 10 times the traditional design life, 1/10th the maintenance, rot proof, termite proof, fire proof, hurricane and earthquake resistant. The project team, using cutting edge technology, will develop all aspects of a start-up design and build company to promote High Performance Green Homes. This project will provide a great opportunity for IIT students to experience a challenging and interesting project and to significantly contribute to a better world.
Sponsorship: Jimmy Eng
Show less

Title: Our Energy Future: Lessons in Sustainability AND IPRO Teams for K-12: The Education Outreach Service Learning Cluster (sequence unknown), IPRO 332 - Deliverables: IPRO 332 Midterm Presentation F09
Creator: Chavez, Jorge, Johnson, Ross, Chin, Jason, Grande, Gina, Lay, Livia, Mccloat, Declain, Nguyen, Nam, Olechno, Patrick, Randle, Jennifer, Tyler Ii, Micheal, Vega, Mayra, Weiner, Andrew, Zajac, Gregory
Date: 2009-12
Description: The mission of the IPRO is to educate the community, focusing mainly on elementary and high school students, on the issues of sustainability...
Show moreThe mission of the IPRO is to educate the community, focusing mainly on elementary and high school students, on the issues of sustainability and energy conservation. The group looks to expand on the work that has been completed in previous semesters, by adding multi-media presentations to enhance the current teaching modules. Previous modules have presented to classrooms simply with information, and the team looks to add upon this by adding interactive and entertaining materials to intrigue the audience.
Deliverables for IPRO 332: IOur Energy Future: Lessons in Sustainability AND IPRO Teams for K-12: The Education Outreach Service Learning Cluster for the fall 2009 semester
Show less

repository.iit

Search the repository

Pages

Pages

Enabled Filters

Refine Results

Type

Date

Academic status of creator

Department

Subject

Creator

Part of