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Title: DETECTION OF SUPEROXIDE ANION RADICALS IN ANION EXCHANGE MEMBRANE FUEL CELLS USING IN-SITU FLUORESCENCE SPECTROSCOPY
Creator: Zhang, Yunzhu
Date: 2016, 2016-07
Description: Anion exchange membrane (AEM) stability is a long-standing challenge that has limited the widespread development and adoption of AEM fuel...
Show moreAnion exchange membrane (AEM) stability is a long-standing challenge that has limited the widespread development and adoption of AEM fuel cells. It is essential to understand the mechanism of AEM degradation during fuel cell operation. There are multiple modes of AEM degradation, broadly classified as chemical, mechanical and thermal degradation. Chemical degradation is among the most destructive modes, and can be further sub-divided into nucleophilic degradation (induced by the hydroxide ion), and oxidative degradation (induced by reactive oxygen species). While the former has been extensively studied, there is minimal work on oxidative AEM degradation. The reactive oxygen chemical species produced during the operation of an AEM fuel cell have hitherto not been detected during operation. Given the high pH, it is postulated that superoxide anion radicals (𝑂2∙−), as opposed to hydroxyl radicals, are primarily involved in the degradation progress. The objective of this study was to confirm the 𝑂2∙− formation during AEM fuel cell operation and to monitor in real-time the rate of 𝑂2∙− generation in an operating fuel cell using in-situ fluorescence spectroscopy. 1,3-diphenlisobenzofuran (DPBF) was chosen as the fluorescence probe, the sensitivity of which towards 𝑂2∙− was evaluated by performing ex-situ experiments in a semi-batch reactor. We demonstrate that the fluorescence intensity of this dye selectively decreased upon exposing 𝑂2∙−. DPBF was then incorporated into an AEM (membrane was solution cast after mixing the dye with the casting solution), which was assembled into a fuel cell. 𝑂2∙− generation in an operating AEM fuel cell was then monitored via in-situ fluorescence spectroscopy using a bifurcated optical probe, when the cell was operated in H2/O2 mode. To confirm the impact of 𝑂2∙− on AEM degradation, independent experiments (without dye) were performed under identical conditions, under both H2/O2 and N2/N2 modes, and the ionic conductivity and ion exchange capacity were monitored to estimate degradation extent. From our in-situ fluorescence studies, we were able to estimate the rate constants and activation energy for oxidative AEM degradation in an operating AEM fuel cell.
M.S. in Chemical Engineering, July 2016
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Title: EFFECT OF HIGH PRESSURE PROCESSING ON MIGRATION CHARACTERISTICS IN POLYETHYLENE TEREPHTHALATE FILM
Creator: Zhou, Yue
Date: 2015, 2015-12
Description: High pressure processing (HPP) is gaining prominence worldwide as an alternative method of food preservation due to its benefits of improved...
Show moreHigh pressure processing (HPP) is gaining prominence worldwide as an alternative method of food preservation due to its benefits of improved quality, freshness and nutrient retention. The use of polymer-based flexible packaging materials has allowed application of HPP to prepackaged food products, without significant loss of physical and mechanical properties. However, there is limited data existing on migration properties in the materials before and/or after HPP. Therefore, it is necessary to evaluate potential migration issues in pre-packed foods during HPP (Song 2014). This research was conducted to determine the migration properties in polyethylene terephthalate (PET) films during and after HPP (121°C and 700MPa) and a comparable thermal processing (TP, 121°C and 0.1MPa), using gas chromatography (GC) coupled with mass spectrometer (MS) technique to quantify four model surrogates in FDA-suggested food simulants (Miglyol). This research will help the U.S Food and Drug Administration (FDA) and food industries to identify whether any safety issue related to chemical migration should be addressed concerning the use of HPP in production of pre-packaged foods.
M.S. in Food Safety and Technology, December 2015
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Title: OPTIMIZATION AND MARKET CLEARING IN THE POWER SYSTEMS WITH HIGH-LEVEL RENEWABLES
Creator: Ye, Hongxing
Date: 2016, 2016-05
Description: The increasing penetration of renewable energy source (RES), such as wind and solar power generation, in recent years to meet various...
Show moreThe increasing penetration of renewable energy source (RES), such as wind and solar power generation, in recent years to meet various renewable portfolio standards (RPS) has led to more uncertainties in power systems. The RES penetration level is expected to further increase in order to reduce emission and fight climate change. The growing uncertainties caused by RES pose new challenges in power and energy systems. Advanced models and technologies are urgent to provide secure, affordable and clean energy to customers. Security-Constrained Unit Commitment (SCUC) problem is one of the most important tools in the modern power system. It determines the optimal short-term generating planning. The electricity is priced and settled based on its solution. In order to manage the uncertainties caused by renewables, it is urgent to develop new SCUC models and solution approaches. SCUCs considering the uncertainties have become a focus of research in recent years. The proposed optimistic robust SCUC combines the idea of robust optimization and reserve concept in the electricity. The merit of the robust optimization is that its solution can be immunized against any uncertainties. It exactly meets the first priority, reliability, in power system operation. The robust optimization is attractive in theory. However, a solution is robust if and only if the system can survive in the worst case scenario. Hence, the key task is to identify the worst case scenario. Unfortunately, finding the worst case scenario in general is a non-deterministic polynomial-time hard (NP-hard) problem. This will create issue in satisfying the timeliness requirement that the optimal scheduling must be obtained quickly (e.g., within several hours) in the day-ahead electricity markets. This dissertation proposes a fast solution approach to finding the worst case scenario by exploring the special structure in the SCUC problem. This dissertation proposes a new market mechanism for managing uncertain ties caused by high-level RES based on the robust optimization. A new concept, Uncertainty Marginal Price (UMP), is proposed to charge uncertainty sources and to credit flexible sources. For the first time, explicit price signals are provided and utilized to manage any level uncertainties within a robust optimization framework. The proposed mechanism manages uncertainties from both the source side (uncertainty reduction) and resource side (uncertainty accommodation). In short term, it provides incentives for RES operators to improve forecasting accuracy (i.e. to reduce uncertainties) and existing flexible resources (e.g. storage) to participate the uncertainty accommodation. In long term, the proposed mechanism provides price signals for siting new flexible resources (e.g. energy storage) to accommodate uncertainties from increasing RES penetration.
Ph.D. in Electrical Engineering, May 2016
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Title: Relationship of Executive Fuction Patterns and Academic Achievement Across DSM-IV Subtypes of Attention-Deficit/Hyperactivity Disorder
Creator: Young, Crystal
Date: 2012-07-18, 2012-07
Description: The aim of this study was to expand our understanding of the impact of executive function skills on academic achievement in children with ADHD...
Show moreThe aim of this study was to expand our understanding of the impact of executive function skills on academic achievement in children with ADHD, as well as investigate trends in executive functioning and academic achievement between ADHD subtypes in an adolescent sample. Each participant completed neuropsychological assessments including a measure of intelligence and academic functioning as well as several measures of executive functioning. Results suggested that children with ADHD – Combined Type do not significantly differ from children with ADHD – Inattentive Type on tasks of academic or executive functioning. Issues regarding outcomes associated with ADHD as well as diagnostic procedures are discussed.
Ph.D. in Psychology, July 2012
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Title: SUPERSONIC JET MIXING ENHANCEMENT USING IMPINGEMENT TONES FROM OBSTACLES OF VARIOUS GEOMETRIES
Creator: Raman, G, Rice, Ej
Date: 1995-03
Publisher: AMER INST AERONAUT ASTRONAUT
Description: This paper reports the results of an experiment that investigated the effect of impingement tones, generated by obstacles of various...
Show moreThis paper reports the results of an experiment that investigated the effect of impingement tones, generated by obstacles of various geometries, on the spreading of a supersonic jet flow. A rectangular supersonic jet was produced using a convergent-divergent nozzle that was operated near its design point (with shocks minimized). Immersing obstacles in the flow produced an intense impingement tone that then propagated upstream (as feedback) to the jet lip and excited the antisymmetric hydrodynamic mode in the jet, thus setting up a resonant self-sustaining loop. The violent flapping motion of the jet due to excitation of the antisymmetric mode, combined with the unsteady wakes of the obstacles, produced large changes in jet mixing. The experiment controlled the frequency and amplitude of the impingement tone excitation by varying the nozzle-to-obstacle distance and the obstacle immersion. Proper shaping of the obstacles made it possible to reduce the thrust penalty significantly.
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Title: FoodLab - A revitalization strategy for the Pari yard, Sao Paulo - Brazil: MariaGarese_MastersProject_FinalBoard_FoodLab
Creator: Lussich Garese, Maria Fernanda
Date: 5/4/2011, 2011-05
Description: This project aims to develop a new design strategy to redevelop the Pari yard and reclaim the adjacent Tamanduatei river by turning it into an...
Show moreThis project aims to develop a new design strategy to redevelop the Pari yard and reclaim the adjacent Tamanduatei river by turning it into an operative landscape. A holistic system to harverst, clean and reuse the abundant summer rainfall was created in order to enable a highly sustainable urban redevelopment.
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Title: Sustainable Theme Park and Museum: Final Board
Creator: Fujishima, Kenta
Date: 5/4/2011, 2011-05
Description: An indoor facility consisting of both theme park and museum components with the integration of green and sustainable elements.

Title: SPATIO-TEMPORAL RECONSTRUCTION FOR GATED CARDIAC SPECT
Creator: Niu, Xiaofeng
Date: 2011-07, 2011-07
Description: In myocardial perfusion imaging using single photon emission computed tomography (SPECT), gated acquisition is often used in order to deal...
Show moreIn myocardial perfusion imaging using single photon emission computed tomography (SPECT), gated acquisition is often used in order to deal with blur caused by cardiac motion in the resulting images. While this can provide useful information about the myocardial function, it also inevitably leads to reduced signal-to-noise ratio in the acquired data due to gating. In this work, we aim to investigate and evaluate image reconstruction methods for improving the quality of the reconstructed images in cardiac gated SPECT imaging. First, we propose a spatio-temporal (aka 4D) reconstruction procedure for gated images based on use of discrete Fourier transform (DFT) basis functions, wherein the image activity at each spatial location is regulated by a Fourier representation along the gate dimension. The gated images are then reconstructed through determination of the coefficients of the Fourier representation. We explore two different reconstruction algorithms, one is a penalized least-square approach and the other is a maximum a posteriori approach. Our simulation results demonstrate that use of DFT-basis functions in gated imaging can improve the accuracy of the reconstruction. While in gated imaging the tracer distribution is traditionally treated as constant, a recent development is gated dynamic imaging where the goal is to obtain an image sequence from a single acquisition which shows simultaneously both cardiac motion and tracer distribution change over the course of imaging. In this work, we further develop and demonstrate a fully 5D (3D space plus time plus gate) reconstruction procedure for cardiac gated, dynamic SPECT imaging, where the challenge is even greater without the use of multiple fast camera rotations. We develop and compare two iterative reconstruction algorithms: one is based on the modified block sequential regularized EM (BSREM-II) algorithm, and the other is based on the Bsplines algorithm. Our simulation results demonstrate that the 5D reconstruction xiii procedure can yield gated dynamic images which show quantitative information for both perfusion defect detection and cardiac motion. Based upon the success of 5D reconstruction, we also study the saliency of 5D images for detection of perfusion defects. We explore efficient ways for characterization and visualization of information pertinent to perfusion defects in a 5D image sequence. We apply various metrics to quantify the degree to which perfusion deficits can be detected. We show that these metrics can be used to produce new types of visualizations, showing wall motion and perfusion information, that may potentially be useful for clinical evaluation. Finally, with the ultimate goal of effective detection of lesion defect for clinical use, we also investigate a direct reconstruction approach to determine a sequence of gated, kinetic parameter images from a single acquisition, which can provide information simultaneously for both tracer kinetics and wall motion. To combat the greatly under-determined nature of the problem, we apply smoothness constraints to exploit the similarity both among the different gates and among the local spatial neighborhood. The parameter images of the different gates are then determined jointly using maximum a posteriori estimation from all the available image data.
Ph.D. in Electrical Engineering, July 2011
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Title: INVOLVEMENT OF MIR-182 IN THE ACTION OF ATORVASTATIN IN PROSTATE CANCER CELLS
Creator: Li, Wenping
Date: 2013-04-10, 2013-05
Description: Atorvastatin (ATO), a widely used statin for lowering cholesterol was examined for its chemopreventive/therapeutic activities in prostate...
Show moreAtorvastatin (ATO), a widely used statin for lowering cholesterol was examined for its chemopreventive/therapeutic activities in prostate cancer cells. We found that ATO inhibited cell proliferation and induced autophagy in PC3 prostate cancer cells, as marked by significant induction of an autophagy marker LC3-II. Using Taqman RT-PCR technique, we also found that ATO treatment for 24h and 48h consistently up-regulated miR-182 in PC3 cells. However, adding geranylgeraniol (GGOH) to the culture media reversed the effect of ATO in regulating miR-182, suggesting that ATO up-regulates miR-182 through inhibition of geranylgeranyl biosynthesis. Overexpression of miR-182 in PC3 cells significantly decreased cell proliferation by about 36% (MTT assay), while knock-down of miR-182 stimulated cell proliferation by about 43% (MTT assay). In screening for miR-182 target genes, we found that Bcl2 and p21 are potential miR-182 target genes; Bcl2 was significantly down-regulated by ATO at both mRNA and protein levels and miR-182 knock-down up-regulated Bcl2 protein; p21 protein expression was positively correlated with alteration of miR-182 expression levels in PC3 cells. Through screening database of miR-182 target genes from TargetScanHuman 6.2 and PicTar, we found that p21 is not the direct target gene of miR-182, so it could be regulated by miR-182 indirectly. It has recently been established that miR-182 regulation is p53-dependent, since PC3 cells are p53 negative, it is clear that ATO regulates miR-182 in a p53-independent manner. These data demonstrate that miR-182 up-regulation and Bcl2 down-regulation by ATO could be two independent events and both could be involved in ATO mediated cell proliferation and autophagy.
M.S. in Biology, May 2013
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Title: Study of automatic electric fire pumps
Creator: Ross, L. R., Ballard, L. E., Swearingen, R.e.
Date: 2009, 1906
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/studyofautomatic00ross
Thesis (B.S.)--Armour Institute of Technology

Title: Museum of Architecture and Design
Creator: Chalermrak, Tearana
Date: 2010-05-01, 2010-05-01
Description: This project is about creating a recreation and education center dedicated to the architectural attributes of Chicago. Redevelopment of the...
Show moreThis project is about creating a recreation and education center dedicated to the architectural attributes of Chicago. Redevelopment of the Chicago Architecture Foundation is explored through the integration of local museums in order to enhance the knowledge of architecture and design for residents and visitors.
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Title: Physics implications of correlation data from the RHIC and LHC heavy-ion programs, Proceedings of the XLIII International Symposium on Multiparticle Dynamics
Creator: Ray, R. L.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Two-dimensional angular correlation data from the STAR experiment at RHIC and from the LHC experiments provide critical information about...
Show moreTwo-dimensional angular correlation data from the STAR experiment at RHIC and from the LHC experiments provide critical information about dynamical processes in relativistic heavy-ion collisions. The principal correlation structures of interest are a broad jet-related peak at small relative azimuth (φ) extending to large relative pseudorapidity (η), the dijet ridge at large relative azimuth, and an independent double ridge on φ represented by a quadrupole function. The broad peak at small relative azimuth has been attributed, in large part, to initial-state fluctuations and hydrodynamic flow which produce higher-order harmonics on φ. That conjecture is challenged in this paper. It is shown that the net effect of additional higher harmonic model elements is to describe small, non-Gaussian (NG) shapes in the broad jet-related peak. The quadrupole correlation, which is also conventionally attributed to hydrodynamic flow, is considered within the Balitsky - Fadin - Kuraev - Lipatov (BFKL) Pomeron framework. Preliminary results using this model for the quadrupole correlation for particle production from 200 GeV p + p collisions are shown to be consistent with recent data from STAR.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Title: EFFECT OF TEMPERATURE, MOISTURE CONTENT AND SOIL SURFACE AREA ON THE BIOLOGICAL DEGRADATION OF BIOSOLIDS ADDED TO SOIL
Creator: Wen, Dongqi
Date: 2016, 2016-05
Description: The objective is to develop and apply an organic matter degradation model (OMDM) that predicts changes in the biological degradation of...
Show moreThe objective is to develop and apply an organic matter degradation model (OMDM) that predicts changes in the biological degradation of organic matter added to soils as a function of soil temperature, moisture content and mineral surface area using data from field and laboratory measurements. A one year long laboratory study was conducted to determine biosolids microbial degradation rates (21 ˚C and 20% moisture content) for soils from eight different fields Biosolids microbial degradation rates were also determined for the eight soils under field condition (10 ˚C and 10% moisture content) by applying a degradation rate model (DRM). The total mineral surface areas for 27 soil samples were also determined. Regression analysis revealed that the degradation rate was positively associated with mineral soil surface area (R2=0.85) and that the biosolids application rate is not significantly associated with the biosolids degradation rate (p value =0.35>0.01). The OMDM determines a decomposition rate of 1.04 yr-1 at 30 ˚C, 20% moisture content, and 10 m2/g soil and provides correction factors for changes in soil temperature, moisture, and mineral surface area. The model predicted in changes of the biological degradation rate of biosolids added to soils with mineral surface areas that vary from 1 to 10 m2/g soil under laboratory and field conditions. A comparison of the measured and simulated degradation rates for eight different soils produced R2 = 0.87 for field data. The model was also able to predict the degradation rate of biosolids for 19 additional soils under field conditions (R2=0.89). The model was also applied to agricultural plant litter. The estimated degradation rates are 0.45 yr-1 corn stover, 0.35 yr-1 oats, 0.26 yr-1 wheat, and 0.13 yr-1 millet at 30 ˚C, 20% moisture content and 10 m2/g. This study demonstrates that the effects of environmental conditions and soil mineral surface area have a significant impact on degradation rates of organic matter and must be considered when assessing degradation rates for organic matter added to soil. Higher temperatures and moisture content and finer soils are related to larger degradation rates.
Ph.D. in Environmental Engineering, May 2016
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Title: A test of a commutating rectifier
Creator: Watt, William T., Stryker, Clinton E.
Date: 2009, 1917
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/testofcommutatin00watt
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 75

Title: Room For Growth: Room for Growth_Final Presentation
Creator: Mckenzie, Jennifer
Date: 2011, 2011-05
Description: The project is a resource center for formally incarcerated people returning to civil society. Many transitional facilities are overrun with...
Show moreThe project is a resource center for formally incarcerated people returning to civil society. Many transitional facilities are overrun with the great flux of people reentering society every year. Room for Growth project proposes to stabalize this group of people by offering another option of counseling centers, housing and work training facilities in the Washington Park neighborhood of Chicago.
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Title: AN ASSESSMENT OF HEAT PUMP APPLICATION AT WATER TREATMENT FACILITIES-THAT USE SURFACE WATER
Creator: Yan, Wenpeng
Date: 2012-07-17, 2012-07
Description: Energy-efficient heat pumps have been applied in the United States and other regions of the world for decades. Geothermal heat pumps have been...
Show moreEnergy-efficient heat pumps have been applied in the United States and other regions of the world for decades. Geothermal heat pumps have been used, but their application is not wide spread due to the high cost of drilling and installing a ground loop. An alternative choice for space conditioning at municipal water utilities is a surface water source heat pump. Because treated surface water is readily available and it exists in a relatively narrow temperature range it could be useful heat transfer fluid. In this project the economic benefits and greenhouse gas emissions of a heat pump system for a building in NE Illinois are analyzed. Heating and cooling requirements for a hypothetical a 1000 m2 space at a drinking water treatment plant are considered. The analysis includes initial, operating and maintenance costs as well as greenhouse gas emissions, between a heat pump system and a conventional natural gas furnace and air-conditioner. The cost savings in this project for the heat pump system were from $39900 to $41511 over the life cycle of the system depending on the different efficiency level of the heat pump system. Surprisingly the initial cost of the standard efficiency heat pump system is lower than the conventional NGAC system. There is no need to take time to make up the additional initial cost. Surface water heat pumps operating at different efficiency level produce less greenhouse gas than the conventional NGAC system. The CO2 emission reduction could be as high as 73%.
M.S. in Environmental Engineering, July 2012
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Title: Using Mitsimlab to Generate Dynamic Traffic for NS2 Simulation of Vanet
Creator: Diao, Zhaoshi
Date: 2011-04-25, 2011-05
Description: The vehicular ad hoc network (VANET) has attracted a lot of attentions due to their interesting and promising functionalities including...
Show moreThe vehicular ad hoc network (VANET) has attracted a lot of attentions due to their interesting and promising functionalities including vehicular safety, traffic congestion avoidance, and location based services. However, using a real VANET to do these researches costs too much. Simulation of VANET is useful and could solve this problem well. Nevertheless, many simulations of VANET base on simple road networks and relatively simple mobility models. Based on this road networks and mobility models, consequently, the results of simulation of VANET would be impractical and inaccurate. Therefore, MITSIMLAB which is a simulation of transportation system developed by Massachusetts Institution of Technology Intelligent Transportation System Program is introduced. In MITSIMLAB, a real world road network could be generated. Moreover, the mobility models in MITSIMLAB are more practical. However, MITSIMLAB is a simulation of transportation system. It cannot be used to simulate the VANET directly, while NS2 could simulate VANET properly. NS2 is an open sourced and free software, and it is widely used and successfully simulates plenty of situations in the wireless environment. It could well simulate the communication protocols and applications of VANET. But it cannot generate road network and mobility models to simulate a practical traffic by itself. As a result, it is important to incorporate MITSIMLAB by using its practical road network and mobility models with NS2. In the thesis, a method about how to translate the output file of MITSIMLAB into the format of NS2 would be proposed. In addition, a road network based on IIT main campus is generated by using MITSIMLAB. After translating it into the format usable by NS2, a VANET based on the map of IIT main campus and practical mobility models could be simulated.
M.S. in Electrical Engineering, May 2011
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Title: IMPROVED DYNAMIC CONTRAST ENHANCED MR IMAGING WITH AN APPLICATION TO PROSTATE CANCER LOCALIZATION
Creator: Afshar, Niloufar Totonchi
Date: 2011-07, 2011-07
Description: Prostate cancer is one of the most frequently detected cancers and a leading cause of death for men in the United States. Fortunately, chances...
Show moreProstate cancer is one of the most frequently detected cancers and a leading cause of death for men in the United States. Fortunately, chances of successful treatment significantly improve when prostate cancer is diagnosed at an early stage. An accurate and reliable imaging technique that can localize tumors is very valuable for example in guiding needle biopsy, therapy, as well as surgery. Current imaging techniques such as ultrasound provide unsatisfactory result for tumor localization. Therefore, Multispectral Magnetic Resonance Imaging (MRI) emerged as an alternative method of imaging for prostate cancer. An important part of multispectral MRI is Dynamic contrast enhanced MRI (DCE-MRI). Traditionally, a compartmental model is used with DCE-MRI to estimate parametric images. However these images are usually very noisy. Therefore, we propose to use directly the series of DCE-MRI for tumor localization instead of the pharmacokinetic parameters which are derived from DCE MR images through a compartmental model. As a second contribution, we have developed new features in addition to traditional parameters based on different characteristic of tumor and normal pixels. These new features are standard deviation and the energy of the first half of the spectrum divided by the energy of the second half of the spectrum based on an analysis of TACs for tumor and normal pixels. We use quantitative and qualitative evaluation methods to demonstrate that employing DCE-MRI directly as features and our proposed features result in an improvement in terms of tumor localization performance.
M.S. in Electrical Engineering, July 2011
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Title: INSTANTANEOUS DETECTION OF SPATIAL GRADIENT ERRORS IN DIFFERENTIAL GNSS
Creator: Jing, Jing
Date: 2014, 2014-12
Description: Differential GNSS (Global Navigation Satellite System) is currently being ex- tended using a high integrity Ground Based Augmentation System ...
Show moreDifferential GNSS (Global Navigation Satellite System) is currently being ex- tended using a high integrity Ground Based Augmentation System (GBAS) to enable civil aircraft precision approach and landing. Differential GPS carrier phase measure- ments between ground-based GBAS reference antennas can provide the means to de- tect and isolate certain signal-in-space (SIS) failures and anomalies that are hazardous to aircraft, most notably ionospheric anomalies and ephemeris failures, which can be characterized as spatial range error gradients. In this research, we develop a monitor capable of instantaneously detecting multi-dimensional spatial gradient faults. The existence of large gradients, while rare, has prompted the development of numerous ground monitors for their detection. One drawback of previously proposed monitors is that their performance for a given ground antenna con guration is de- pendent on how antennas are paired to form measurement differences. In contrast, in this work a new monitor approach is developed to provide consistent detection performance, regardless of how the antennas are paired, by combining measurements from multiple, spatially separated ground antennas through a null space transforma- tion. It is shown that the `null space' monitor signi cantly improves the detection performance over existing fault detection algorithms and enables GBAS to support Category III precision approach and landing. The instantaneous carrier phase monitor cannot detect all gradients due to the presence of integer cycle ambiguities. These ambiguities cannot be resolved because the gradient magnitude is unknown a priori. Furthermore, it has been shown that the performance of such monitors is highly dependent on the reference antenna topol- ogy. The range of detectable gradients for all carrier phase monitors depends on two factors: the number of antennas and their con guration. One can always expand the detection range by using many antennas, but only at greatly increased operational cost. Optimizing antenna con guration has been overlooked as a means to improve performance; simple, heuristic arguments typically prevail in the associated siting decisions. For example, when given four antennas it is generally assumed that they should be sited in a square arrangement to balance performance in all directions. However, such heuristics do not provide the maximum detectable range of gradients, and exploiting the freedom to choose the antenna topology can dramatically expand the detectable range. Due to the presence of carrier phase cycle ambiguities, the re- sulting optimization problem is a constrained, mixed integer nonlinear programming problem. By solving the nonlinear program, the optimal GBAS antenna topology that maximizes the range of detectable gradients can be found for any number of antennas. For ionospheric fronts, the magnitude of the resulting gradient is bounded. However, orbit ephemeris faults can be arbitrarily large. The monitor must be able to detect all large gradients. To detect gradients beyond the capability of the car- rier phase monitor, code phase measurements are integrated into the monitor. Al- though we show this allows for the detection of all gradients, the number and spacing of ground antennas may not be suitable for all ground stations. Therefore, dual frequency carrier phase measurements are also considered to reduce the number of antennas required to achieve the desired detection performance. Finally, a search algorithm is developed to nd the antenna topology that enables the null space mon- itor to detect all hazardous gradients using code and dual frequency carrier phase measurements.
Ph.D. in Mechanical and Aerospace Engineering, December 2014
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Title: CHANGES OF BACTERIAL SPECIES AND HEME PROTEIN OCCURRENCE IN ACTIVATED SLUDGE COMMUNITIES CULTURED IN THE LABORATORY
Creator: Wang, Xiaomeng
Date: 2016, 2016-05
Description: An activated sludge sample that had originally been collected from an aeration tank of the Stickney wastewater treatment plant in Chicago, and...
Show moreAn activated sludge sample that had originally been collected from an aeration tank of the Stickney wastewater treatment plant in Chicago, and had previously been cultured at low dissolved oxygen (DO) for 48 weekly passages was used as starting material for continuation of the low DO acclimation. The culture was continued at low dissolved oxygen in synthetic wastewater for 25 additional weekly passages to study what would happen to the activated sludge if the low DO continued. In order to do that, some important data were measured during the culture, including the specific oxygen uptake rates (SOUR) which could reflect the ability of oxygen utilization, 16S rDNA information which could tell the community diversity of sludge, and the dominant species genome data which suggested what really happened to the sludge and some reasons. The results showed that SOUR decreased modestly during the course of low DO adaptation, which was contrary to the results of the previous study. There were significant changes in community structure with respect to bacterial species during the first fifteen additional passages. Species known to produce both flavohemoglobins (FHbs) and truncated hemoglobins (trHbs) were common at all passages tested, although the dominant species were totally different from passage to passage. Specifically, during the course of the experiment, the frequency of cells encoding an FHb decreased substantially, from 84% to 50%, while the percentage of cells encoding a trHb decreased slightly from 84% to 78%. The overall content in the culture of heme b (the heme type found in bacterial hemoglobins) decreased, however, during continuation of the low DO conditions. So it is indicated that the oxygen utilization ability of the activated sludge does not increase all the time.
M.S. in Biology, May 2016
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