Search results

Title: AUTOMATION OF ULTRASONIC FLAW DETECTION APPLICATIONS USING DEEP LEARNING ALGORITHMS
Creator: Virupakshappa, Kushal
Date: 2021
Description: The Industrial Revolution-4.0 promises to integrate multiple technologies including but not limited to automation, cloud computing, robotics,...
Show moreThe Industrial Revolution-4.0 promises to integrate multiple technologies including but not limited to automation, cloud computing, robotics, and Artificial Intelligence. The non-Destructive Testing (NDT) industry has been shifting towards automation as well. For ultrasound-based NDT, these technological advancements facilitate smart systems hosting complex signal processing algorithms. Therefore, this thesis introduces the effective use of AI algorithms in challenging NDT scenarios. The first objective is to investigate and evaluate the performance of both supervised and unsupervised machine learning algorithms and optimize them for ultrasonic flaw detection utilizing Amplitude-scan (A-scan) data. Several inferences and optimization algorithms have been evaluated. It has been observed that proper choice of features for specific inference algorithms leads to accurate flaw detection. The second objective of this study is the hardware realization of the ultrasonic flaw detection algorithms on embedded systems. Support Vector Machine algorithm has been implemented on a Tegra K1 GPU platform and Supervised Machine Learning algorithms have been implemented on a Zynq FPGA for a comparative study. The third main objective is to introduce new deep learning architectures for more complex flaw detection applications including classification of flaw types and robust detection of multiple flaws in B-scan data. The proposed Deep Learning pipeline combines a novel grid-based localization architecture with meta-learning. This provides a generalized flaw detection solution wherein additional flaw types can be used for inference without retraining or changing the deep learning architecture. Results show that the proposed algorithm performs well in more complex scenarios with high clutter noise and the results are comparable with traditional CNN and achieve the goal of generality and robustness.
Show less

Title: EXPERIMENTAL AND STRUCTURAL STUDIES OF FDA APPROVED EXON SKIPPING TREATMENT DRUGS
Creator: Zhang, Jingwen
Date: 2021
Description: DMD is an X-chromosome related genetic disease caused by loss of dystrophin protein expression, and which impacts 1 in 5000 boys born in the...
Show moreDMD is an X-chromosome related genetic disease caused by loss of dystrophin protein expression, and which impacts 1 in 5000 boys born in the world. The usual cause of this at the genetic level is a frame shift due to internal deletions of one or more exons that results in a change of the reading frame. This results in loss of expression of the protein encoded by this gene, dystrophin, which in turn leads to the disease phenotype. Exon skipping is a therapy for DMD which restores dystrophin pre-mRNA reading frame to produce a modified dystrophin. This is done by antisense oligonucleotides, AONs, which disturb the process of exon splicing and exclude targeted exons near the patient’s defect which restore the correct reading frame in the pre-mRNA transcript. In 2016, the first AON was approved for clinical use targeting exon 51, called eteplirsen. This provided the first disease modifying therapy for DMD, but it was only relevant to ~6% of patients who had defects that were correctable by skipping this specific exon. In 2020 two more AONs targeting exon 53 were developed, viltolarsen and golodirsen, providing benefit to an additional 5% of patients, and in 2021 casimersen targeting exon 45 was approved.However, this raises an interesting issue, in that for some patients, with an exon 52 deletion, skipping exon 51 or skipping exon 53 could both restore the reading frame. Which approved exon skipping treatment is better and the differences between them are still unknown. This is the aim of this study: to help patients figure out which AON can have a consequence of less long-term health problems like cardiomyopathy and longer life and get more precise treatment. We selected three exon skipped edits – two that represent exon 53 skipping repair of an underlying Δe52 defect and one targeting exon 51 skipping repair of a Δe52 defect. We then used a panel of biophysical and biochemical including dynamic light scattering, circular dichroism Spectroscopy, thermal denaturation, and protease K challenge to investigate the biophysical characteristics of these different exon skipped edits. From our results we found that Δe51-52 has the more structure (i.e., is less perturbed), compared to e52-53, as assessed by CD or by proteinase K challenge, but it also has lower thermal stability, with a low Tm=48C transition that begins to unfold at the physiological relevant temperature of 37C. On the other hand, e52-53 has less helical structure, but what structure did form had unfolding transitions in the normal range for wild type STRs, Tm> 60C; but this edit also had more non-helical structure. So, the total experimental results of these three edits are very complex, which may be due to the fact that these edits span the normally unfolded H3 region.
Show less

Title: ENERGY INNOVATIONS IN BUILDINGS AND URBAN FABRICS
Creator: Hirematt, Chandrasekharaiah Ashish
Date: 2021
Description: In his keynote speech on the "Infrastructures of Integration" at the 5th International LafargeHolcim Forum for Sustainable Construction, Ricky...
Show moreIn his keynote speech on the "Infrastructures of Integration" at the 5th International LafargeHolcim Forum for Sustainable Construction, Ricky Burdett, Professor of Urban Studies at the London School of Economics & Political Science (LSE), said “…you can actually invest in better infrastructure to do things better.” However, the population grows at the rate of almost one billion per decade. With about four fifths of it happening in urban areas, the challenge for sustainability is huge and the key for the future.Urban fabrics are expanding both vertically as well as horizontally to accommodate the population growth. With the scale of expansion happening, challenges such deforestation, resource depletion, habitat destruction, energy production and consumption are some of the major challenges that need to be focused on ecologically. It is also important to note that ecological solutions are very highly dependent on social and economic progress of the society. Energy efficient design is one which does zero or minimal damage to the environment while meeting the energy needs of the society. This thesis will discuss the concept of developing energy efficient designs as well as net zero designs in urban settings. With the help of three projects, this thesis aims to discover the challenges along with the obvious advantages of such designs. The first experiment is to look at the reduction of energy consumption in the city of Chicago with multiple neighborhoods set up in an iron grid. It was observed that taller buildings are much more energy efficient due to the reduction of surface area exposed to the external environment. This observation was used to develop a climate specific energy efficient urban fabric design in the city of Shenzhen. The design of the off-shore tower involves tackling larger issues such as the pandemic while having energy production as a bi-product of the same. Thus, the thesis argues that investment in infrastructure to build a better infrastructure should be done to solve social and economic challenges which will, in turn make it easier to produce energy efficient designs.
Show less

Title: IMPLEMENTING ASYNCHRONOUS DISCUSSION AS AN INSTRUCTIONAL STRATEGY IN THE DEVELOPMENTAL MATHEMATICS COURSES TO SUPPORT STUDENT LEARNING
Creator: Zenati, Lynda
Date: 2020
Description: Remedial known as developmental coursework are designed to get under-prepared students ready for college. Ninety one percent of colleges offer...
Show moreRemedial known as developmental coursework are designed to get under-prepared students ready for college. Ninety one percent of colleges offer remedial courses in mathematics and English (Seo, 2014). Evidence suggests that traditional teaching methods do not enable all students to engage with the types of academic literacy constitutive to higher education (Lea and Street, 2006). The popularity of online discussion has been made possible through their availability in most LMS which are widely used in higher education (Dahlstrom, Brooks, & Bichsel, 2014). This study aimed at examining the use of asynchronous discussion (AD) as an instructional strategy to help alleviate some of the difficulties developmental math students make in different topics. Participants were 15 students enrolled in Summer, 2019 semester at a Community College. Results showed that students’ performance increased from pretest to posttest for students’ who participated in AD. Comparison was made with two other sections of the same course at the same college taught by two different instructors. Controlling for prior academic ability, results showed a statistically significant difference between students’ performance in the posttest in the section that utilized the AD but not the other two sections. Content analysis of students' posts showed the use of AD at least temporarily corrected students’ misconceptions when they were active and Consistent. Results were mixed for the lurker and the passive students. Moreover, correlation analysis showed no relationship for the frequency of interaction; however, a significant relationship was found for the quality of participation and students’ performance as measured by the final exam. Furthermore; no relationship between the CoI presences and students’ performance. Students’ reflections indicated that students valued the online experience. Benefits were related to students’ engagement and collaborative learning. Obstacles included students’ behavior, timing and the structure of the AD. This may imply that using structured AD may help in building a community of learners. Also, instructor presence and facilitation were necessary to promote deep learning. Future research can build on this finding by replicating the study using a bigger sample size and a longer period to allow students to reflect and discuss any conflict with their peers.
Show less

Title: ELECTROCHEMICAL BEHAVIOR OF ADDITIVELY MANUFACTURED NON-SPHERICAL TI-6AL-4V POWDER IN 3.5 WT. % NACL SOLUTION
Creator: Bagi, Sourabh Dilip
Date: 2021
Description: In laser powder bed fusion (LPBF), also known as selective laser melting (SLM), the feedstock powder and processing parameters affect the...
Show moreIn laser powder bed fusion (LPBF), also known as selective laser melting (SLM), the feedstock powder and processing parameters affect the properties of additively manufactured parts. Limited research has been conducted on non-spherical Ti6Al4V feedstock powder prepared by Hydride-Dehydride process. Significant progress in metal powder additive manufacturing (AM) requires the inter-linking of multiple variables, which includes starting materials, process settings, and post-treatment to achieve desired resultant properties. Owing to the rapid emergence of metal 3D-printing, process-property relationships, and appropriate post-treatment conditions have not been as extensively characterized as for conventional materials, thus requiring significant attention. Over the years, spherical powders were used in powder bed AM machines and there have been various concerns related to powder as well as processing parameters leading to defects formation, poor part quality, and unsatisfactory performance. It is critical to keep the cost of manufacturing low for large-scale production which results in significant interest in low-cost powder, making it vital to understand the effect of microstructural defects on corrosion behavior. Recently, economical powder attracted attention in AM, thus, making it is necessary to understand the role of possible microstructural defects on corrosion behavior. In powder bed additive manufacturing, feedstock and processing affect final microstructure and properties of the 3D printed parts. While numerous studies have evaluated 3D-printing of spherical powder, very limited research has examined the processing of the non-spherical feedstock. In this research, parts are manufactured by SLM of hydride-dehydride (HDH) Ti6Al4V powder. heat treatment and hot isostatic pressing are applied on SLM parts. The microstructures, potentiodynamic curves, and electrochemical impedance spectroscopy are characterized for SLM processed, heat treated, and hot isostatically pressed HDH Ti6Al4V specimens. Results indicate although the as-built specimen has anisotropic microstructure (i.e., lamellar α + acicular α’ + β phases), the heat treatment and hot isostatic pressing result in homogenized grain structures and enhanced corrosion behavior. Results indicate that type of constituent phase, grain size, and morphology directly determine corrosion resistance. This research is beneficial for the manufacturing of low-cost titanium alloys. In the current research, we evaluate non-spherical powder processing by hydride-dehydride (HDH) method and selective laser melted in powder bed AM machine followed by heat treatment and hot isostatic pressing to alter microstructure and electrochemical behavior. If successful, the usage of non-spherical morphology in conjunction with the newer powder dispensing method of double smoothing will enable remarkable improvements in the quality and performance of additively manufactured products. This method will also cut down costs associated with a greener powder production method and enhance the fabrication rate. It is a well-established fact that corrosion behavior is drastically affected by heterogeneous microstructure and defects. Thus, it is paramount to conduct a systematic study on the role of processing parameters and post process heat treatment, which can enhance our understanding of possible defect formation in micro and macro scale and their impact on electrochemical behavior.
Show less

Title: OPTIMUM WEIGHT STIFFNESS STRUCTURAL DESIGN
Creator: Barnett, Ralph L.
Date: 2021
Description: My adventures with flexible structures began on the IIT campus with an extracurricular undergraduate project to design an “Open House Exhibit”...
Show moreMy adventures with flexible structures began on the IIT campus with an extracurricular undergraduate project to design an “Open House Exhibit” for the Civil Engineering Department. I chose to display a reinforced concrete diving board together with a prestressed concrete diving board. Visitors enthusiastically pounced on the reinforced concrete structure whose rigid response disappointed one and all. Their indignation was transferred to the prestressed cantilever which thrust them upward from six to ten feet into the air. This unexpected response from a diving board became so dangerous that the Exhibit was unceremoniously closed. I still have the display sign, “More Bounce to the Ounce.”While still an undergraduate, I secured a part-time job at Armour Research Foundation where I responded to a bid request from Rock Island Arsenal to design the 26 foot Honest John Rocket Launcher Rail at minimum weight. This tactical weapon was transported by helicopter. I basked in the fantasy that I was Leonardo da Vinci without his artistic proclivity. Rocket launchers that droop during operation are similar in concept to a circular firing squad. So began my research into minimum weight beams based on deflection rather than strength. I searched for the shoulders of Giants. I found them in the form of mathematicians not structural engineers. I achieved a 26.5% weight savings in the 1126 pound rail by optimizing the geometry. When I developed an optimum prestressed and segmented Kentanium cermet rail, the weight savings became 89%. The right material provides a bigger bang for the buck. When my journey into optimum design began, I was armed only with analysis tools: strength, stability, and stiffness. This thesis begins with an outline of my present toolbox which contains eight design concepts: 1. Establish the Geometry, 2. Select a material from a finite number of candidates, 3. Prestress and Prestrain, 4. Statistical Screening (Proof Testing), 5. Manipulation of Boundary Conditions, 6. Energized Systems, 7. Counterweights, 8. Self-Healing and Self-Reinforcing. Four of these are used through this review which focuses on stiffness. Beginning with beams, deflection control examples are described where prestraining and prestressing techniques are used to produce both a zero-deflection beam and a method for pushing with a chain. The calculus of variations made it possible to establish optimum tapers for the flanges and webs of I-beams that minimize beam weight for a specified deflection or, because of reciprocity, minimize beam deflection for a specified beam weight. An anomaly is encountered that enables one to achieve an upward, downward, or zero deflection with a set of beams of vanishing weight. In addition, special circumstances are defined where a uniform strength design is identical to the minimum weight design based on a specific deflection. Closed form solutions are obtained for a variety of loading scenarios. One problem is presented for self-weight that leads to a nonlinear integral equation. The optimum stiffness-weight design of trusses is undertaken where the area distribution of the truss members is optimized using Lagrange’s method of undetermined multipliers. Once again, we obtain a degenerate case where upward, downward, and zero deflection conditions can be met with an infinite set of trusses of vanishing weight. We photograph a simply supported truss under a downward load that leads to an upward deflection at one of the joints. Special loading conditions are identified that lead to uniform stress designs that are identical to the minimum weight designs based on deflections. This study provides a Segway into the world of minimum weight strength design of trusses. The resulting Maxwell and Michell trusses sometimes display the optimum distribution of bar areas from the point of view of stiffness. Many practitioners are under the mistaken impression that Michell structures, when they exist, provide the optimum truss profile for stiffness. Unfortunately, the optimum array of truss joints based on deflection does not exist. For both trusses and beams the optimum distribution of mass is shown to be necessary and sufficient; the sufficiency is established using well-known inequalities. The role of stiffness in the design of columns is explored in our final chapter. This cringe-worthy history of column analysis begins our study as a warning to practitioners who use analysis as their basis for design and especially optimum design. Conventional elastic and inelastic buckling theories provide little insight into the design of columns. The fundamentals of minimum weight column design are presented to show the power of design theory in contrast to analysis. Both prismatic and tapered columns are studied with one surprise result; the optimum taper gives rise to a uniform bending stress (without axial stresses). It was fun to see that in 1733 Lagrange made a mistake in calculus of variations that led to the incorrect solution for the optimum tapered column. It took 78 years before Clausen obtained the correct solution. The problem has been revisited by William Prager and again by the author who used dynamic programming. Of course, we all got the same result which is a dreadful solid circular tapered column that is heavier than any ordinary waterpipe. The best of a class is not necessarily the best possible design. Under the heading, “Intuition is a good servant but a bad master,” we introduce the notions of tension members that buckle, columns constructed from spherical beads, optimum rigging of crane booms, and deflection reversal of beam-columns. In several places we observe that the weight of optimum columns is proportional to P^α where P is the axial load and α is less than unity. We fail to tell the reader that this implies that minimum weight columns require putting all your eggs in one basket; one column under load P is lighter than two columns each under load P/2. On the other hand, we expose the solid circular column as the least efficient shape among all regular polygons, the equilateral triangle is the best. Indeed, there is a family of rectangles that are superior to the circular cross-section. Finally, the author’s prestressed tubular column is introduced that is pressurized to eliminate local buckling. Euler’s buckling can always be eliminated with a thin-wall section of sufficient width without a weight penalty. The weight of the balloon-like member is proportional to (PL) which implies that at last we have a compressive member that meets the requirement of a Michell structure. Bundling of pressurized gas columns are possible without a weight penalty. Further, the column is insensitive to most imperfections. It is the lightest known column for small structural indices (P/L^2 ). When coupled with circulating cryogenic liquid as a prestressing system, a limiting column has a vanishing weight.
Show less

Title: HIGH SURFACE AREA CARBONS FOR ENERGY STORAGE TECHNOLOGIES
Creator: Lee, Youngjin
Date: 2021
Description: Energy storage systems play a pivotal role in harvesting energy from various sources and converting it to the energy forms required for...
Show moreEnergy storage systems play a pivotal role in harvesting energy from various sources and converting it to the energy forms required for applications in several sectors, such as utility, industry, building and transportation. The outstanding growth of portable electronic devices and electric vehicle/hybrid electric vehicles (EVs/HEVs) has promoted the urgent and increasing demand for high‐power energy resources. The most common electrical energy‐storage device is the battery due to the large amount of energy stored in a relatively small volume and weight while providing suitable levels of power for many applications and requirements of everyday life. These days, lithium-sulfur batteries (LSBs) have been drawing attention with their potential to provide 3-5 times more energy than that of current lithium-ion batteries (LIBs) at lower cost. Thus, realization of a practical Li-S technology can move the U.S. rapidly toward a more sustainable transportation future. The electrochemical double-layer capacitor (EDLC) is also an emerging technology, which really plays a key part in fulfilling the demands of electronic devices and systems, for present and future. The EDLC technology strongly depends on the properties of electrode materials. Activated carbons play an important role in developing new electrodes for both LSB and supercapacitor technologies. For example, carbon electrode-based supercapacitors require very high specific surface area and superior pore size distribution for easy accessibility of ions. Thus, the primary objective of this study is to develop a new high surface area carbon material and assess its applicability for both LSB and supercapacitor technologies. In this thesis work, we have designed and synthesized several active carbon materials. One of them displayed very high surface area (1,832 m2/g) and excellent pore diameter (3.6 nm). We investigated the applicability of this carbon material for supercapacitor electrodes. We have also modified this carbon material with a nickel-rich phosphide in order to make it suitable for LSB cathode applications.
Show less

Title: HUMAN TRAFFICKING AND THE INTERNET: EDUCATING OUR COMMUNITY OF THE GROWING PANDEMIC
Creator: Ali, Md
Date: 2020
Description: Human trafficking is a growing pandemic with many traffickers utilizing both the surface web and dark web to recruit and sell victims of human...
Show moreHuman trafficking is a growing pandemic with many traffickers utilizing both the surface web and dark web to recruit and sell victims of human trafficking. We will explore different cases regarding human trafficking as well as how traffickers are uti- lizing technology to conduct their criminal activities. We will be going over different research studies that went over new social engineering methods that technology has introduced into the world of human trafficking and coming to a statistical analysis on preventive measures to be aware of. With increasing advancements in encryption methods and communication the ease of this crime has been committed from one’s own bedroom. This thesis will be answering the question on how to minimize or remedy this atrocious criminal activity from society by analyzing all the recommendations from each study and finding possible solutions to avoid being a victim of human trafficking.
Show less

Title: EVALUATION IF COMPLETENESS, COMPREHENSION AND CREDIBILITY ON AN E-HEALTH WEB SITE
Date: 2007-05,

Title: Public Event Identification Traffic Data Using Machine Learning Approach
Creator: Yang, Hanyi
Date: 2020
Description: This study developed a shock waved diagram based deep learning model (SW-DLM) to predict the occurrence of public events in real-time...
Show moreThis study developed a shock waved diagram based deep learning model (SW-DLM) to predict the occurrence of public events in real-time according to their impacts on nearby highway traffic. Specifically, using point traffic volume data as a boundary condition, shock wave analysis is first conducted to understand the impacts and features of a public event on a nearby highway-ramp intersection. Next, this analysis develops the SWG algorithm to efficiently generate and expand shock wave diagrams in real-time according to the data collection rate. Built upon that, this study contributes a novel approach, which encodes a shock wave diagram with an optimal grid of pixels balancing resolution and computation load. Using the features extracted from encoded time-series shock wave diagrams as inputs, a deep learning approach, Long-short term memory (LSTM) model, is applied to predict the occurring of a public event. The numerical experiments based on the field data demonstrate that using encoded shock wave diagrams rather than point traffic data can significantly improve the accuracy of the deep learning for predicting the occurring of a public event. The SW-DLM presents satisfied prediction performance on the average as well as on an individual day with or without traffic accident interference, happening nearby the venue of a public event. The implementation of this approach to real-time traffic provision tools such as GPS will alert travelers en route on-going events in a transportation network and help travelers to make a smart trip plan and avoid traffic congestion. Moreover, it promotes smart city development by providing a strong capability to monitor the transportation system and conduct real-time traffic management intelligently.
Show less

Title: Parameterization of vertical dispersion coefficient (σz) near roadway: vehicle wake, density and types
Creator: Yu, Yu-Ting
Date: 2020
Description: Pollutants emitted by motor vehicles is one of the major public concern in modern society since pollutants (e.g. ultrafine particles and CO2)...
Show morePollutants emitted by motor vehicles is one of the major public concern in modern society since pollutants (e.g. ultrafine particles and CO2) have been related to adverse health effect and climate change. Currently, air quality dispersion models (e.g. CALINE4 and AERMOD) are widely used to predict concentration near roadway. However, both air quality dispersion models are not account for the vehicle variability (vehicle types), causing the inaccuracy in predicting pollutant concentration near roadway. To better understand the dynamic of dispersive process, it is important to evaluate the variation of vertical dispersion coefficient (σz) for different vehicle types (e.g. LDV and HDV). A “wake area model” is developed based on “effective wake area” and vehicle density to reveal the dynamic of dispersion process that related to vehicles. Results from this thesis demonstrate that the near roadway σz that calculated from field measurements increases as vehicle density increases and HDV can generate higher value of σz compare to LDV. σz increase from 1.7 m to 4 m with LDV density increase from 0.005 m-1 to 0.18 m-1; while σz starts at 2 m and reach up to 6 m with HDV density increase from 0.001 m-1 to 0.01 m-1. The significant differences of σz are due to vehicle density and vehicle types. The effective wake area contributed by one HDV (397 m2) is much larger than effective wake area contributed by one LDV (13 m2), which indicates that one HDV contributes 31 times higher than one LDV in terms of near roadway σz. The significant differences of “effective wake area” are due to vehicle wake structure and vehicle dimension.Compared to the air quality dispersion models results, both CALINE4 and AERMOD failed to respond the variation of σz as vehicle density increases for LDVs and HDVs. CALINE4 shows the value of σz is near 2.8 m and 2.4 m for LDV and for vehicle fleet (mixture of LDV and HDV), respectively. AERMOD shows the value of σz is near 1.2 m and 1.3 m for LDV and for vehicle fleet, respectively. Because both air quality dispersion models did not correctly predict σz near roadway, a new equation that parameterize σz near roadway need to be developed to better predict the σz in real world condition. For a given road segment, the parameterization of σz is a result from dimension of “effective wake area” for different vehicle types and number of “effective wake area” for a vehicle fleet. Comparison of measured and parameterized σz near roadway dispersion coefficients show good agreement (slope=0.99, R2=0.85) with a range between 1 and 4 m for LDVs and 2 to 6 m for HDVs. Also, Comparison of measured and simulated CO2 show good agreement (slope=1, R2=0.90) with a range between 0.01 g m-3 to 0.12 g m-3 for simulated value and 0.01 g m-3 to 0.14 g m-3 for measured value. For UFPs, the results also show good agreement (slope=1.14, R2=0.71) with a range between 600 pt cm-3 to 11,000 pt cm-3 for simulated value and 600 pt cm-3 to 17,000 pt cm-3 for measured value.The “wake area model” provides a new perspective for σz that related to vehicles and bridges vehicle wake to σz. The results from this study will be critical for improving predictions of pollutant concentration from air quality dispersion near roadway.
Show less

Title: Ultraviolet photo-chemical degradation of polyethylene terephthalate for use as an alternative recycling method
Creator: Smith, Andrew Thomas
Date: 2020
Description: Consumer plastics are a deeply integrated part of the modern world. Their inherent properties which make them cheap, durable, moldable, and...
Show moreConsumer plastics are a deeply integrated part of the modern world. Their inherent properties which make them cheap, durable, moldable, and versatile have caused plastics to be used in many consumer products available for market. However, these same properties have made them a detriment to local and global environments. plastic has begun accumulating in the world’s waterways and oceans, leading to severe ecological consequences. Polyethylene terephthalate (PET) is one of the most pervasive consumer plastic, and a large contributor to the amount of waste. Because of its prevalence in the market, PET has been the focus of research into its recycling and reuse. However, all methods face issues of profitability due to operation and equipment costs, preventing widespread recycling of plastic waste. This leaves the door open to explore other processes of plastic recycling.In this study, ultraviolet photo-chemical degradation of PET was explored as an alternate route to plastic recycling. Ultraviolet irradiation has long been known to depolymerize PET plastic products, but has not been studied in order to enhance these effects. This method has the potential to reduce operation and equipment costs associated with traditional chemical recycling methods by carrying out depolymerization in the solid state. By harnessing this process, PET could be used to degrade material down to a state usable in in other, higher value products. An irradiation chamber was built as a preliminary prototype. This chamber used light of a specific ultraviolet wavelength determined from the absorbance spectrum of PET samples. This allowed the irradiation to be safer, while still maintaining absorption.Ultraviolet degradation of PET was first examined using infrared, contact angle, and fluorescence analysis, and birefringence observation to analyze the chemical and surface effects of irradiation. The results were used to understand the complex mechanisms behind the photo-chemical degradation process. Results were then discussed alongside similar experiments performed in the literature for a deeper understanding of the underlying mechanism.The molecular weight of exposed bottle samples was evaluated using both viscosity and dynamic light scattering methods. This information is key, as it is the main metric that determines the success of the process. In addition, the ultraviolet absorbance of the sample was analyzed along with the principles of Beer’s law. This yielded quantitative analysis on the effect of thickness of the sample, the degradation rate, and the quantum yield of the process.Finally, building upon the information gathered in the study, two key process modifications are made. Thinner samples are first produced, and receive irradiation on both surfaces. The degradation of the modified process was compared to that of previous results on the basis of molecular weight reduction, reaction rate and quantum yield. Using these results, conclusions were drawn about using ultraviolet photo-chemical degradation as a recycling process.
Show less

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
Show less

Title: THE STRUCTURAL AND MAGNETIC STABILITY OF SELECT FERROUS HEUSLER SYSTEMS
Creator: Hasier, John J.
Date: 2017, 2017-05
Description: Heusler based functional or smart materials are a deep well of solutions to future energy, heat transport and mechanization problems. The half...
Show moreHeusler based functional or smart materials are a deep well of solutions to future energy, heat transport and mechanization problems. The half-metallic ferromagnetic nature of these crystalline intermetallic compounds is the source of their extraordinary properties. The loss of this magnetic ordering places limits on the range of application temperatures making knowledge of the Curie point of these novel materials essential for understanding of their limitations. High throughput continuous wavelet transform spectrum analysis of magnetic balance data generated on a custom modified Setaram Setsys Evolution 16/18 Differential Scanning Calorimeter- Differential Thermal Analyzer with simultaneous Thermogravimetric Analyzer was performed on select Fe, Co and Mn based Heusler compounds. The phase stability of Co-Fe-Si compounds is explored in relation to the high-Curie Temperature Co2FeSi and Fe2CoSi compounds via generation of equilibrium ternary isothermal phase diagrams at 1160 C and 800 C to enable greater control of the microstructure for future thermomechanically processed bulk smart device fabrication.
Ph.D. in Materials Science and Engineering
Show less

Title: ANALYSIS OF MECHANICAL NOISE GENERATION IN WIND TURBINE DRIVE TRAIN
Creator: Patel, Hirenkumar J.
Date: 2012-05-01, 2012-05
Description: The research work presented here is a part of a project, funded by U.S. Department of Energy to study mechanical noise generated by a wind...
Show moreThe research work presented here is a part of a project, funded by U.S. Department of Energy to study mechanical noise generated by a wind turbine drive train. In our study a Viryd 8 kW wind turbine drive train test bed located at the Illinois Institute of Technology was used. Various wind speeds and turbulence levels could be simulated using a computer program that is used to control the test bed. Acoustic measurements were carried out using a single microphone and a microphone array. The microphone array was used to localize noise sources on the drive train. Various beamforming algorithms such as FDBF, DAMAS2, CLSC, DAS and TIDY were used to study the noise sources. Quali cation experiments using synthetic sources showed that \Clean based on spatial coherence" beamforming algorithm localizes noise sources very accurately for narrowband frequency analysis and TIDY was found to work best for broadband analysis. The resolution of the beamform maps improved for higher frequencies of interest (>700 Hz). The continuous variable planetary (CVP) gearbox, which is a proprietary gearbox by Viryd was used in the drive train to optimize the generator rotational speed. An interesting trend was observed in active power generated for the wind speeds greater than 10 m/s, where the power does not increase signi cantly as it is regulated at 6000 Watts. CVP speed ratio, ratio of input rotational speed to output rotational speed of CVP, was also found to be having similar e ect after wind speed reaches a value of 10 m/s. Vibrations of the drive train test bed were studied using accelerometers. It was observed that the test bed was vibrating at a fundamental frequency of 120 Hz, with harmonics of decreasing amplitude at 240 and 360 Hz. Vibrations in all degrees of motion were found to be occurring at similar frequencies. Acoustic beamforming using a microphone array showed that the test bed was a dominant noise source at the same frequencies. Initially the entire test bed was covered by a Plexi-glass casing for safety reasons. It was found that the glass casing a ected the microphone array measurements as the noise produced by the components had no direct path to the array. Almost all the measured noise was refracted through the gaps between the glass casing and the stretcher holding it, that led to spurious microphone array results. As a result of this, the experiments were conducted without the glass casing. It was discovered after the experiments that the glass casing not only a ects the path of sound but the amplitude is also a ected. The components of the drive train namely gearbox, brake, CVP and generator, were found to be emitting sound at various discrete frequencies ranging from 165 to 3885 Hz. They were also found to be emitting broadband noise, where gearbox and generator were found to be most dominant noise sources. We were able to separate each noise source on a complex wind turbine drive train that contributed to the mechanical noise generation from a wind turbine.
M.S. in Mechanical and Aerospace Engineering, May 2012
Show less

Title: FROM FIREPLACE TO STEAM: DOMESTIC HEATING TECHNOLOGY IN NORTHEASTERN UNITED STATES, 1840-1890
Creator: Morais, Caroline
Date: 2012-12-07, 2012-12
Description: Why study nineteenth-century domestic heating technology? Besides its pop- ular appeal and utilitarian value, domestic heating technology is...
Show moreWhy study nineteenth-century domestic heating technology? Besides its pop- ular appeal and utilitarian value, domestic heating technology is one of the most signi cant yet least explored subjects in American history. American processes of industrialization, manufacturing, and transportation are well known, however, the impact of technological changes on the home is less familiar. Understanding past everyday lives is crucial to recognize the processes of adjusting to new technologies, particularly those technologies essential to today's American lives that have been overlooked. This dissertation examines the shift in domestic heating modes in North- eastern United States between the decades of 1840 and 1890. After carefully reviewing the literature on the subject of nineteenth-century heating technology, I asked myself why the domestic setting has received little schol- arly or historical attention in comparison to those of industrial and commercial set- tings. The answer lies on the fact that, traditionally, historians have been more interested in public events than in those within the private environment. The signi - cance of domestic heating technology has also been reduced duo to divisions between scholarly elds and disciplines. Also, the interpretation of artifacts has been more the eld of anthropologists than that of historians. Thus, few studies have narrowed their focus to a speci c topic of technology and the di erences in form, function, and cultural settings of its development. Investigating a historically obsolete technology and understanding the way people used it can be challenging. Domestic heating technology has advanced, and attitudes towards it have changed over time. It has been di cult to nd physical evidence of early examples in the form in which people originally used it daily. Addi- tionally, few people took the time to record their everyday-life interactions with the equipment and actual models of the old technology are hard to nd. Mid-nineteenth iv century American household heating apparatuses are a clear example of that. The ine ciency of systems previous to central heating challenged inventors and manufac- tures to search for and invest in more convenient and economical options to improve the quality of life. With the development of household heating technology, people gradually abandoned replaces and stoves and adopted furnaces and central heating as their primary source of heating. My goal was to explore the evolving meaning of domestic heating systems as a technological symbol. By analyzing the changing responses from one technological development to the other, I was able to identify some main points that made appro- priate domestic heating and ventilation a necessity for both comfort and health of Americans who lived in the focused period. I chose the ve decades between 1840 and 1890 because most of the modern conveniences were introduced into American homes for the rst time during those years and for their signi cance to the country's technological history. The Northeastern region was chosen as the geographical focus because the dispersion of knowledge began there, especially knowledge in heating and ventila- tion technology and apparatus manufacturing. The sources for the study included domestic advice manuals, architectural pattern books, engineering and architectural periodicals, patent records, manufacturers' and dealers' sales catalogs, and census schedules. The technological development of heating and ventilation systems culmi- nated with the advent of central heating, which currently represents the technology of domestic heating methods. In the design of American homes, central heating systems have superseded previous apparatuses such as replaces and stoves. They have become an option rather than a necessity of a comfortable and convenient domestic life. This disserta- tion is a brief study of that moment of transition. My intention was to expand on v basic assumptions about the technological development of the American home, not to challenge them. There has already been a considerable amount of attention given to the study of the American home and home life. Therefore, I see my research as an addition to the growing knowledge of the history of American domestic technology and the people and innovations that enabled its development.
PH.D in Philosophy in Architecture, December 2012
Show less

Title: BOND STRENGTH COMPARISONS OF DIFFERENT SUBSTRATE PREPARATIONS AND VARIOUS BONDING AGENTS USED IN CONCRETE OVERLAYS AND ENLARGEMENTS
Creator: Eberhardt, Keith
Date: 2017, 2017-05
Description: The bond interface line of concrete overlays and enlargements has been the focus of engineers, contractors, and manufacturers for many years....
Show moreThe bond interface line of concrete overlays and enlargements has been the focus of engineers, contractors, and manufacturers for many years. Many products and procedures have been developed to help the contractor and engineering community achieve the highest bond strength of the repair material to the host material, or substrate, to provide a quality, long-lasting repair. It is well known that the difference between a successful overlay or enlargement and one that fails can be directly linked to the preparation of the bonding surface. The objective of this study is to compare what concrete removal techniques, or surface preparations, in conjunction with bonding conditions and agents have on achieving the best direct tensile and guillotine test results. A unique step of this research is to use an overlay material with the same mix design as the base slab. Most overlay materials are stronger and do not use the same coarse aggregate and cement. By having the substrate and the overlay concrete the same material, a true test of the bond can be accomplished as the core samples should fail in both the substrate and overlay. This study consisted of four concrete slabs that were poured and allowed to naturally cure for a full year. Afterwards, each slab used a different method to remove up to two and one-half inches of the substrate concrete to prepare for the overlay. Removal methods used were hydrodemolition, pneumatic impact hammers, abrasive blasting and a control slab that consisted of a light broom finish. Each panel was then divided into four sections and a different surface condition or bonding agent was applied to the substrate just prior to the placement of the overlay. The surface conditions and agents used were dry, surface-saturated dry (SSD), sand/cement slurry and an epoxy and cementitious material. After the overlay was placed, the overlaid test panels were allowed to remain in place and naturally cure for an additional year before test samples were taken. Results supported that any impact blow force to the surface yielded the worst results by almost 50% for both direct tensile and guillotine tests. Even a change in bonding agents could not overcome the damage to the surface of the base slab. These results support years of similar test reporting. There was no increase in test results using a bonding agent on any of the prepared slabs. The results were similar, and in some cases, less than a surface that was dry or SSD. The highest and most consistent results came from the slab that was either dry or SSD. Results indicate that a dry surface that is prepared with either abrasive blasting or hydrodemolition may yield the most consistent results as all other bonding conditions and agents are subject to difficulty in measuring the application accurately and can be highly susceptible to evaporation rates and variations in multiple mixing operations. A well prepared, clean, dry surface will yield the greatest and most consistent failure results and is the easiest to monitor and duplicate in field conditions.
M.S. in Civil Engineering, May 2017
Show less

Title: THEORETICAL ANALYSIS OF REAL-TIME SCHEDULING ON RESOURCES WITH PERFORMANCE DEGRADATION AND PERIODIC REJUVENATION
Creator: Hua, Xiayu
Date: 2017, 2017-07
Description: In 1973, Liu and Layland [81] published their seminal paper on schedulability analysis of real-time system for both EDF and RM schedulers. In...
Show moreIn 1973, Liu and Layland [81] published their seminal paper on schedulability analysis of real-time system for both EDF and RM schedulers. In this work, they provide schedulability conditions and schedulability utilization bounds for both EDF and RM scheduling algorithms, respectively. In the following four decades, scheduling algorithms, utilization bounds and schedulability analyses for real-time tasks have been studied intensively. Amongst those studies, most of the research rely on a strong assumption that the performance of a computing resource does not change during its lifetime. Unfortunately, for many long standing real-time systems, such as data acquisition systems (DAQ) [74, 99], deep-space exploration programs [120, 119] and SCADA systems for power, water and other national infrastructures [121, 26], the performance of computational resources suffer notably performance degradations after a long and continuous execution period [61]. To overcome the performance degradation in long standing systems, countermeasures, which are also called system rejuvenation approaches in the literature [123, 61, 126], were introduced and studied in depth in the last two decades. Rejuvenation approaches recover system performance when being invoked and hence benefit most long standing applications [30, 102, 11, 12, 39]. However, for applications with real-time requirements, the system downtime caused by rejuvenation process, along with the decreasing performance during the system’s available time, makes the existing real-time scheduling theories difficult to be applied directly. To address this problem, this thesis studies the schedulability issues of a realtime task set running on long standing computing systems that suffers performance degradation and uses rejuvenation mechanism to recover. Our first study in the thesis focus on a simpler resource model, i.e. the periodic resource model, which only considers periodic rejuvenations. We introduce a method, i.e., Periodic Resource Integration, to combine multiple periodic resources into a single equivalent periodic resource and provide the schedulability analysis based on the combined periodic resource for real-time tasks. By integrating multiple periodic resources into one, existing real-time scheduling researches on single periodic resource can be directly applied on multiple periodic resources. In our second study, we extend the periodic resource mode to a new resource model, the P2-resource model, in our second work to characterize resources with both the performance degradation and the periodic rejuvenation. We formally define the P2-resource and analyze the schedulability of real-time task sets on a P2-resource. In particular, we first analyze the resource supply status of a given P2-resource and provide its supply bound and linear supply bound functions. We then developed the schedulability conditions for a task set running on a P2-resource with EDF or RM scheduling algorithms, respectively. We further derive utilization bounds of both EDF and RM scheduling algorithms, respectively, for schedulability test purposes. With the P2-resource model and the schedulability analysis on a single P2- resource, we further extend our work to multiple P2-resources. In this research, we 1) analyze the schedulability of a real-time task set on multiple P2-resources under fixedpriority scheduling algorithm, 2) introduce the GP-RM-P2 algorithm and 3) provide the utilization bound for this algorithm. Simulation results show that in most cases, the sufficient bounds we provide are tight. As the rejuvenation technology keeps advancing, many systems are now able to perform rejuvenations in different system layers. To accommodate this new advances, we study the schedulability conditions of a real-time task set on a single P2-resource with both cold or warm rejuvenations. We introduce a new resource model, the P2-resource with duel-level rejuvenation, i.e., P2D-resource, to accommodate this new feature. We first study the supply bound and the linear supply bound of a given P2D-resource. We then study the sufficient utilization bounds for both RM and EDF scheduling algorithms, respectively.
Ph.D. in Computer Science, July 2017
Show less

Title: THE PERSPECTIVE GRID: MUSEUM AND PARK FOR THE SOUTH LOOP
Creator: Idrovo Orellana, Santiago Javier
Date: 2015, 2015-12
Description: The diverse and infinity of forces that are shaping the cities are luckily unknown. The bigness of the forces may not have a beginning nor an...
Show moreThe diverse and infinity of forces that are shaping the cities are luckily unknown. The bigness of the forces may not have a beginning nor an end. The questions and the answers are always late. Cities are always running behind, trying to code and survive through the economic condition. The speed of the fluids are always mutating, transforming and taking different shapes. We are constantly proposing and putting in practice perception in between the endless spiral of the present. Our human behavior and perceptions are being built by others and by different matters. History in the end is the only parameter from which we can rely. Our mastery of the knowledge technics keep holding the population and transforming the way we live by processing and turning resources into elements of survival. The 21st century characterizes by the transformation of matter and energy into technological tools that we unconsciously rely on while they are also being misused and manipulated, giving non-consistent answers. The thesis travels through different subjects in an attempt to construct a general perspective that will define the decisions on the urban programmatic plans and direct them into educational and cultural performances. Due to economical forces and a projected demographic growth, the near south region of Chicago is looking for a transformation and a direction to travel. Through the general perspective the proposal for the region firstly study to connect cultural collective open spaces injected on a particular area of the South Loop. The area is mainly influenced by industrial infrastructure that can be replaced or reprogrammed according to a considered value. The study will explore the cultural connection from the neighborhood to the Museum Campus as catalyzers for the future interventions of the zone. Secondly, the near south region of Chicago is looking for a transformation and a direction to travel. Through the general perspective the proposal for the region firstly study to connect cultural collective open spaces injected on a particular area of the South Loop. The area is mainly influenced by industrial infrastructure that can be replaced or reprogrammed according to a considered value. The study will explore the cultural connection from the neighborhood to the Museum Campus as catalyzers for the future interventions of the zone. Secondly, the near south region of Chicago is looking for a transformation and a direction to travel. Through the general perspective the proposal for the region firstly study to connect cultural collective open spaces injected on a particular area of the South Loop. The area is mainly influenced by industrial infrastructure that can be replaced or reprogrammed according to a considered value. The study will explore the cultural connection from the neighborhood to the Museum Campus as catalyzers for the future interventions of the zone. Secondly,, the near south region of Chicago is looking for a transformation and a direction to travel. Through the general perspective the proposal for the region firstly study to connect cultural collective open spaces injected on a particular area of the South Loop. The area is mainly influenced by industrial infrastructure that can be replaced or reprogrammed according to a considered value. The study will explore the cultural connection from the neighborhood to the Museum Campus as catalyzers for the future interventions of the zone. Secondly,the general perspective will go more specific into the museum campus and the appropriation of the abandoned McCormick Lake Site Center. An infrastructure located in a zone where the ecological systems and the cultural concern are the roots of its creation. The proposal will face the parameters to reorient the building into a filtered cultural source and as a natural connection infrastructure.
M.S. in Architecture, December 2015
Show less

Title: NEW DIRECTIONS IN POST-EARTHQUAKE FIRE HAZARD ANALYSIS WITH APPLICATIONS TO MIDWESTERN UNITED STATES
Creator: Farshadmanesh, Pegah
Date: 2017, 2017-05
Description: Post-earthquake fire ignition (PEFI) can lead to severe structural damage following an earthquake. Estimating the risk of such ignitions in...
Show morePost-earthquake fire ignition (PEFI) can lead to severe structural damage following an earthquake. Estimating the risk of such ignitions in buildings and identifying methods to abate it are essential steps in an overall effort to mitigate the impact of post-earthquake fires in urban areas. While several models have been developed for areas with available historical PEFI data, such as the Western United States, no such models have been developed for areas with little or no data specific for post-earthquake fires. Examples of such areas are seismic regions in the Midwestern United States. The lack of PEFI data for these areas is due to the fact that at the time of several significant earthquakes in the early nineteenth century, most earthquake-stricken communities where rural. With the growth of urban areas in the region, a need exists for a methodology that can be effectively used in estimating PEFI risks when no or little historical data is available. In this research, it was found that models for PEFI risk estimation may indeed be developed using available data on ignitions for normal conditions as a basis and then using some type of a modification factor to account for the significance of future earthquakes. This modification factor depends on the characteristics of the region in terms of seismic activities and the type and distribution of buildings and their potential in promoting ignitions. The term “normal condition ignition” (NCI) refers to an ignition that occurs due to everyday activities and routine operations in a building. In a residential building, such activities include, for example, operating heating units and burners, cooking, and mechanical malfunction of appliances. In this research, it was found that four factors specifically affect PEFI risk and can be used to develop models for risk estimation. These are (1) spatial characteristics such as geographic concentration of particular building types; (2) ignitability characteristics, such as the sources of ignitions in a particular building type, (3) earthquake characteristics (such as the peak ground acceleration); and (4) temporal characteristics, such as the time of the earthquake and seasonality. Accordingly, models for estimating the risk of post-earthquake fire ignition occurrence are developed. These models are tested, and the model parameters calibrated, using information in areas for which both the NCI and PEFI data are available (such as in the Western United States). To illustrate the applicability of the models developed and proposed in this study, St. Louis City is considered. This constitutes a major urban area vulnerable to potential future seismic activities because of proximity to the New Madrid Fault Zone. Using the NCI data for this area, PEFI risk values are estimated based on probable future seismic activities in the region. The results are presented in terms of estimated annual risk of post-earthquake fires for the area specifically for residential buildings (such as single or multifamily dwellings). The study further discusses the significance of PEFI models, their limitations and also provides suggestions for the future continuation of the research.
Ph.D. in Civil Engineering, May 2017
Show less

repository.iit

Search the repository

Pages

Pages