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- Title
- COMMUNICATION AND COMPUTATION ARCHITECTURES FOR DISTRIBUTED WIRELESS SENSOR NETWORKS AND INTERNET OF THINGS
- Creator
- Yi, Won-jae
- Date
- 2017, 2017-07
- Description
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Real-time data communication has been viral since the era of the smartphone rose to prominence in this decade. All communications from human...
Show moreReal-time data communication has been viral since the era of the smartphone rose to prominence in this decade. All communications from human to human, from device to human, and from device to device are handled over the Internet connection either through a mobile Internet service provider or Wi-Fi, which enables information exchange including weather service, road traffic conditions, news alerts, package tracking notifications. By looking at different perspectives of the role of a smartphone, it reveals itself as an ideal device to mobilize critical user data to construct a real-time monitoring application such as in remote healthcare and home automation systems. Not only can the smartphone handle real-time data transmissions, but it can also handle real-time computations on the device itself by utilizing its embedded CPU. This dissertation is a comprehensive study of the investigation, exploration and experimentation on a real-time health monitoring system where quality of life can be improved when the conventional system may affect and hamper regular daily activities. The design flow of this system is based on the Internet connection where any device that is communicatively associated with the smartphone can be connected to the Internet. By utilizing the Android smartphone, not only does the system gain real-time data transmission capability, but it also obtains flexibility to communicate with different types of sensors and platforms through multiple wireless protocols. This system is highly adaptable to the currently trending Internet of Things (IoT) standards, where significantly increasing anticipation over its social impact, where it can assist populations in rural and distant areas for healthcare, day-to-day activity monitoring, and prevention against hazardous conditions for workers. The system architecture introduced in this research is focused on reconfigurability and compatibility of wireless sensors where they are independent from a certain platform in which sensors are not limited to medical devices but also detect movement, location, climate condition and any other sensor for analyzing the environment. Four major components are introduced in this research including wireless sensor nodes, a central sensor data processing and communication node, an Android application, and a central database server. They are discussed and explored to seek for solutions to improve and enhance features in the fundamental system design. Communication and computation processing capabilities are evaluated for all major components for practical usage of the system for different case studies. Also as a quantitative case study, a posture and fall detection system is presented which determines the patient's activities, medical conditions and the cause of an emergency event through the integration of all system architecture components. Adapting the IoT system is also explored in this dissertation by introducing a protocol standard to improve data transmission efficiency and to enable cross-platform compatibility of wireless devices. In addition to improving system efficiency, a study on data security issues and assessment on sensor data has been explored by implementing a proposed security scheme to each major component within the real-time mobile monitoring system. Also, a concept of Quality-of-Service (QoS) for mobile monitoring system using a wireless sensor network has been investigated to provide a solution to prioritize sensor data transmissions based on the results obtained from the sensor data assessment application. The proposed solutions can be either implemented on or under the application layer.
Ph.D. in Computer Engineering, July 2017
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- Title
- THE EUML-ARC PROGRAMMING MODEL
- Creator
- Marth, Kevin
- Date
- 2014, 2014-07
- Description
-
The EUML-ARC programming model shows that the increasing parallelism available on multi-core processors requires evolutionary (not...
Show moreThe EUML-ARC programming model shows that the increasing parallelism available on multi-core processors requires evolutionary (not revolutionary) changes in software design. The EUML-ARC programming model combines and extends software technology available even before the introduction of multi-core processors to provide software engineers with the ability to specify software systems that expose abstract platform-independent parallelism. The EUML-ARC programming model is a synthesis of Executable UML, the Actor model, role-based modeling, split objects, and aspect-based coordination. Computation in the EUML-ARC programming model is structured in terms of semantic entities composed of actor-based agents whose behaviors are expressed in hierarchical state machines. An entity is composed of a base intrinsic agent and multiple extrinsic role agents, all with dedicated conceptual threads of control. Entities interact through their role agents in the context of featureoriented collaborations orchestrated by coordinator agents. The conceptual threads of control associated with the agents in a software system expose both intra-entity and inter-entity parallelism that is mapped by the EUML-ARC model compiler to the hardware threads available on the target multi-core processor. The hardware and software e ciency achieved with representative benchmark systems show that the EUML-ARC programming model and its compiler can exploit multi-core parallelism while providing a productive model-driven approach to software development.
Ph.D. in Computer Science, July 2014
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- Title
- Optimal Behavior Modeling and Analysis of Electricity Market Participants
- Creator
- Li, Jie
- Date
- 2012-04-27, 2012-05
- Description
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n restructured electricity power markets, competition among market participants is a key issue of concern for both the ISO (Independent System...
Show moren restructured electricity power markets, competition among market participants is a key issue of concern for both the ISO (Independent System Operator) and the market participants themselves. This dissertation analyzes the market behavior of both the generation side and demand side participants, and provides solution guidelines for devising effective competition strategies for market players’ profit maximization objectives. Generation side is the most competitive part in the electricity market with the unbundling of generation, transmission and distribution. Acting as self-interested entities, GENCOs (Generation Companies) are seeking effective and computationally efficient methodology for generation resource scheduling, while keeping its financial risks at acceptable levels when constituting bidding strategies. To help GENCOs achieve such goal, this dissertation propose a game theory based supply function like bidding model to construct the optimal bidding strategies for GENCOs in both energy and ancillary service markets. On the demand side, demand participation in the electricity market has already been advocated for a long time for its benefit to the entire market and the society as a whole. This dissertation focuses on a specific large electricity consumer type – Internet Data Center (IDC). By analyzing the unique energy consumption pattern for different IDC applications, this dissertation devises effective electric demand management solution for IDCs to conserve electricity energy consumption and cut electric bill, and quantifies the demand response effect of IDC on the electricity market.
Ph.D. in Electrical Engineering, May 2012
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- Title
- Development and Application of an Occupational Odor Hazard Index
- Creator
- Wang, Tingting
- Date
- 2011-04-24, 2011-05
- Description
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Odors emitted from wastewater treatment and sludge processing facilities may lead to employee complaints regarding discomfort, stress or...
Show moreOdors emitted from wastewater treatment and sludge processing facilities may lead to employee complaints regarding discomfort, stress or disease, and affect productivity and worker turnover in Water Reclamation Plants (WRPs). This study reports and assesses a comprehensive method that estimates the odor perception and associated hazards from exposures to odors in a post-digestion dewatering building in a WRP and its vicinity areas. An Odor Reference Concentration (ORfC) is developed as an index of acceptable odor level. This index is applied to ensure that the majority of building occupants (80 percent or more) do not perceive the odor. This index is developed to fill the lack of a uniform standard and method to assess hazard of exposed individuals to odors in occupational environments and to regulate odor exposures.A comprehensive odor and odorant concentration database was formulated by a monitoring study in the occupational environment of a post-digestion dewatering building. The presence of odorants in the building are at concentrations below occupational exposure limits but higher than odor detection threshold values. This finding indicates that reducing odorant concentrations below exposure limits does not assure an odor-free environment. A model is formulated and validated for this dewatering building associating odor perception with concentrations of total sulfur compounds and relative humidity and is used for prediction of indoor odor concentrations under various conditions. Odor and odorant emission rates as the strength of sources are input variables of the indoor air quality model. In this study, odor and odorant emission rates from freshly dewatered biosolids in a dewatering building were measured using two widely used dynamic methods: the USEPA flux chamber and wind tunnel, and results from the two methods are not significantly different. Comparison of the two methods indicates that both methods can be used to estimate odor and odorant emission rates but the most effective and efficient method depends on prevailing environmental conditions. The ORfC established based on the comprehensive odor and odorant concentration database for this dewatering building is 13D/T (dilution to threshold). This index is used to evaluate seven control strategies recommended to reduce odor levels. If indoor odor concentrations in the occupational environment exceed the ORfC, then the hazard of odor exposures is unacceptable. Deterministic results of this study indicate that if appropriate control strategy is applied, odor concentration in the dewatering building would reach to below levels that cause unnecessary stress and other effects. The control strategy focus of this work is reduction of the indoor odor perception. But indoor control strategies must not cause outdoor odor problems to surrounding residential areas. Therefore, the potential impact of the control strategy recommended is also investigated in this thesis using the US EPA recommended air dispersion modeling AERMOD. Predictions of hydrogen sulfide concentrations at surrounding areas of the plant indicate that only one strategy, which proposes to add a new exhaust system in the dewatering building, would cause the ambient hydrogen sulfide concentration to be 7% higher than the odor detection threshold; other six strategies would not induce odor annoyance to surrounding areas. Acute and long-term ambient hydrogen sulfide exposure limits based on human health and irritation effects would not be violated under any of the seven control strategies.
Ph.D. in Environmental Engineering, May 2011
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- Title
- INVESTIGATION OF ANION EXCHANGE MEMBRANES FOR ELECTROCHEMICAL ENERGY CONVERSION AND STORAGE SYSTEMS
- Creator
- Wang, Lihui
- Date
- 2017, 2017-05
- Description
-
The alkaline stability of poly (arylene ether) backbones in anion exchange membranes (AEMs) derivatized with quaternary benzyl N, N-...
Show moreThe alkaline stability of poly (arylene ether) backbones in anion exchange membranes (AEMs) derivatized with quaternary benzyl N, N- dimethylhexylammmonium (DMH+) and trimethylammonium (TMA+) cation groups were investigated in poly (2,6- dimethyl 1,4-phenylene) oxide (PPO) and Udel® polysulfone (PSF) polymers. Previous studies have demonstrated that quaternary ammonium and phosphonium groups trigger backbone degradation in commercially available poly (arylene ether)-based AEMs, despite the base polymers’ resilience to alkaline solutions. Herein, I demonstrate that the electron withdrawing or donating character in the poly (arylene ether) backbone ultimately dictates whether the prepared AEMs will become brittle in alkaline media due to cation-triggered backbone degradation (Arges, Parrondo, Johnson, Nadhan, & Ramani, 2012a; Christopher G. Arges, Lihui Wang, Javier Parrondo, & Vijay Ramani, 2013). Mitigation of cation-triggered backbone degradation was only achieved when electron withdrawing substituents (not including the cation), such as sulfone or bromine, were eliminated from the polymer backbone (or, alternately, when electron donating groups were present). Hence, PPO AEMs prepared through chloromethylation, rather than free radical bromination, were resistant to backbone hydrolysis in alkaline media because each cation-functionalized repeat unit had two electron-donating methyl groups rather than a single methyl group. This study presents some design rules for preparing mechanically stable poly (arylene ether) AEMs from low cost, commercially available polymers for alkaline electrochemical devices.
Ph.D. in Chemical Engineering, May 2017
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- Title
- THE EFFECT OF FLOW ON MICROPARTICLE TRANSPORT AND THE ROLE OF MICROPARTICLES IN THROMBOSIS
- Creator
- Lee, Ying-hui
- Date
- 2012-11-27, 2012-12
- Description
-
Elevated monocyte/macrophage-derived microparticles (MPs) have been found to correlate with thrombotic complications. These MPs carry tissue...
Show moreElevated monocyte/macrophage-derived microparticles (MPs) have been found to correlate with thrombotic complications. These MPs carry tissue factor (TF), the principal coagulation pathway initiator, as their parental cells and expose anionic phospholipid phosphatidylserine (PS), which can promote thrombin generation and fibrin formation. During thrombus development, MPs may be delivered to the injured/dysfunctional vascular endothelium or biomaterial surfaces and influence the process of thrombosis. MPs are submicron membrane vesicles that may have increased transport and/or binding capabilities compared to platelets or other cell types due to their decreased size and their higher Brownian diffusion. MPs and their surface molecules can be delivered to surfaces, either biological or prosthetic, and alter the local environment. Little is known of the mechanisms by which MPs are transported to and impart their biological activity on surfaces, especially in blood. Such a transfer of activity will depend on the ability of MPs to be transported to the surface, the strength of adhesion of the MPs on the surface and the nature of the activity/host interaction. In the present study, physical and biological properties of MPs generated from macrophage-like cell lines by endotoxin stimulation were characterized, the transport of MPs to surface by flow was investigated, and the import biological activity on surfaces was elucidated. We observed that the deposition of MPs suspended in buffer on glass surfaces was strongly shear-dependent using a well-defined parallel plate flow chamber. The diffusivity coefficients of MPs at shear rate ranges ranging from 100 to 3200 s-1 were determined from the classical mass transport equation proposed by Leveque and the values were found to be of the same order of magnitude as predicted by Brownian xi diffusion. MPs non-specific attachment to glass was dominated by electrostatic interactions; this was verified by changing the surrounding ionic strength of the suspending solution. In addition to shear rate, red blood cells (RBCs) also influenced MP adhesion due to the complex movement of RBCs. Such movement has been shown to enhance the adhesion of platelets (1-2 micron size cells) to surfaces in flowing blood. MP lateral transport was enhanced at low concentrations of RBCs and reduced at higher concentration of RBCs. The reduction of MP deposition was due to the competition for surface binding sites between the two populations of MPs. The two types of MPs studied here, those produced by macrophages after endotoxin stimulation and those produced by RBCs during experimental preparation (repeated centrifugal washing) have the capability of nonspecific binding to artificial surfaces in a competitive manner. Finally, we demonstrated that the amount of adherent MPs on surfaces influenced fibrin formation via both a TF-dependent and a negatively charged phospholipid pathway. These findings suggest that procoagulant MPs may modulate thrombotic events under certain conditions, especially in MP-associated diseases. The knowledge of the effects of flow on MP transport and the influence of increased MPs on thrombosis may provide novel insights for the transfer of biological activity to relatively passive surfaces.
PH.D in in Biomedical Engineering, December 2012
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- Title
- ULTRASONIC RANGING AND INFRARED DEPTH PROFILING FOR 3D IMAGE RECOl'STRUCTION AND SCENE ANALYSIS
- Creator
- Jia, Weldi
- Date
- 2013, 2013-07
- Description
-
This doctoral work cannot be done without the help, support and dedication of numerous people. First of all, I will give my great thanks to my...
Show moreThis doctoral work cannot be done without the help, support and dedication of numerous people. First of all, I will give my great thanks to my advisor Dr. Jafar Saniie, who is patient, fundamental and knowledgeable in providing advices, suggestions and guidance to all my six years' study. I would like to express my sincere thanks for his encouragement and nancial support during my study. I will never forget the days and nights he spent with me doing research work in the ECASP research lab. His spirit of carefully searching, friendly talking and knowledgeably thinking stays in my mind forever. My gratitude extends to my committee members, Dr. Anjali, Dr. Moderes and Dr. Oruklu. Also, I would like to give my thanks to my colleagues and friends, especially the people in ECASP research lab, Won-Jae, Sufeng, Thomas, Spenser and Pramod. Their kindness and powerful knowledge in di erent elds help me enhance my work so much. I will never forget the days debugging programs with them and the days we cheered for our success. I would like to dedicate this thesis to my family, especially to my grandfather who just passed away but gave me nancial support and advices from childhood till now, my father who is not able to speak after an accident during my study, my mother who is taking care of my father herself during the past six years, and my wife Wenhui Liu, who encouraged and helped me living in the United States. I promise that I will use what I learned from here to change the world and their constant support of my academic ventures from the beginning to the present would be valuable. Thank you Grandpa, rest in peace in heaven.
PH.D in Electrical Engineering, July 2013
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- Title
- EFFICIENT AND FAIR RESOURCE ALLOCATION FOR OFDMA NETWORKS
- Creator
- Alavi, Seyed Mohamad
- Date
- 2012-11-26, 2012-12
- Description
-
In Orthogonal Frequency Division Multiple Access (OFDMA) systems, resources, including subcarriers, bits and power, need to be adaptively...
Show moreIn Orthogonal Frequency Division Multiple Access (OFDMA) systems, resources, including subcarriers, bits and power, need to be adaptively allocated to users in order to improve spectral efficiency, increase capacity, and reduce power consumption, while satisfying the Quality of Service (QoS) requirements for users. Most of the previous works concentrate on satisfying rate and power requirements, however providing delay requirement is also necessary, especially with increasing demand on delay-sensitive applications. We first model the resource allocation problem as a cross-layer optimization problem considering the constraints on bit error rate (BER), data rate, total power, as well as delay. We first develop a nonlinear optimization model, which generally requires high computation complexity. To consider a more realistic scenario, we take into account imperfect Channel State Information (CSI) due to estimation errors or channel feedback delay, and incorporate the imperfect CSI into the optimization problem formulation. We then derive the solution through a dual decomposition method. Due to the duality gap between the original and dual optimizations, we convert the non-linear optimization to an equivalent linear formulation so that an exact solution can be obtained. To further reduce the complexity, we develop a heuristic algorithm to provide a solution close to the optimum. Then, we study the notion of fairness in the context of resource allocation. In particular, cooperative game theory can be applied to OFDMA networks for fair resource allocation. We apply two cooperative games, Non-Transferable Utility (NTU) game and Transferable Utility (TU) game, to provide fairness in OFDMA networks. In NTU game, fairness is achieved by defining appropriate objective function, while in TU game, fairness is provided by forming the appropriate network structure. For NTU game, we analyze the Nash Bargaining Solution (NBS) as a solution of NTU game taking into account CSI and Queue State Information (QSI). In a TU game, we show that coalition among subcarriers to jointly provide rate requirements leads to better performance in terms of power consumpviii tion. We show that although NTU and TU games are modeled as rate adaptive and margin adaptive problems, respectively, but both solutions provide a fair distribution of resources with minimum fairness index of 0.8. Although NBS can provide fairness, the fairness is not from user perspective. In competitive fairness, which is based on auction theory, each user is responsible for his/her own action. A distributed allocation of resources in OFDMA networks is studied through auction theory. A combinatorial auction is formulated in which the users’ utility enforce the truthful resource demands. Since the original problem is NP hard, a method based on simulated annealing applied to find near-optimum results. Then, we turn our attention toward a more complicated scenario of multicell OFDMA networks. A combinatorial auction, which takes into account the interference from adjacent cells is presented. Auction objective is to minimize the interference, while power of users is limited. Due to the complexity of original problem, we apply a heuristic approach, in which the bids are ordered based on the linear programming approximation of combinatorial auction, and then local improvements are made in the order of bids. Our iterative approach along with the proposed load control scheme provides fair distribution of resources to the users, regardless of their position in the cell. Finally, we propose a comprehensive auction in OFDMA network. We present an auction framework for allocation of subcarriers, in which winner pays monitoring and entry fees, in addition to the price which he is paying for the allocated subcarrier. We prove that in our framework users will avoid bidding for the subcarriers where they have a relatively low chance of winning. We obtain optimal bidding strategy based on Bayesian Nash Equilibrium (BNE) in which users are maximizing their net profit. In a Fractional Frequency Reuse (FFR) implementation of frequency planning, we will find a focal distance which classifies the users into cell-center and cell-edge users. It is shown that the focal distance increases as the interference decreases.
PH.D in Electrical Engineering, December 2012
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- Title
- STRUCTURE AND FUNCTION OF NATIVE AND EDITED DYSTROPHIN RODS
- Creator
- Sahni, Neha
- Date
- 2011-05-10, 2011-05
- Description
-
The purpose of this study is to examine the biophysical properties of the rod region of the dystrophin protein. This is important due to the...
Show moreThe purpose of this study is to examine the biophysical properties of the rod region of the dystrophin protein. This is important due to the severity of the disease Duchenne Muscular Dystrophy, (DMD), which is associated with the malfunction of this protein. DMD is one of the most serious single gene genetic defects of man. This rod region consists of a number of repeat motifs called spectrin type repeats or STRs. The thermodynamical and biochemical stability analysis shows, which single motifs are unstable on their own and which ones become more stable when linked to their appropriate tandem neighbors. This knowledge will impact strategies to produce modified mini dystrophins for gene therapy. Exon skipping therapy is an emerging approach to treat such genetic diseases. This is done by the administration of modified antisense oligonucleotides, AONs, which can interfere with exon splicing process and eliminate certain exons from the mature transcript. Furthermore, the rod region has a number of ancillary functions, such as providing secondary binding sites for actin, neuronal NO synthetase and phospholipids, which may be adversely perturbed by the edits.
Ph.D. in Biological, Chemical, and Physical Sciences, May 2011
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- Title
- NEW TOOLS FOR JET ANALYSIS IN HIGH ENERGY COLLISIONS
- Creator
- Duffty, Daniel
- Date
- 2015, 2015-05
- Description
-
Our understanding of the fundamental interactions of particles has come far in the last century, and is still pushing forward. As we build...
Show moreOur understanding of the fundamental interactions of particles has come far in the last century, and is still pushing forward. As we build ever more powerful machines to probe higher and higher energies, we will need to develop new tools to not only understand the new physics objects we are trying to detect, but even to understand the environment that we are searching in. We examine methods of identifying both boosted objects and low energy jets which will be shrouded in a sea of noise from other pasts of the detector. We display the power of boosted-b tagging in a simulated W' search. We also examine the effetc of pile up on low energy jet reconstructions. For this purpose we develop a new priority-based jet algorithm, "p-jets", to cluster the energy that belongs together, but ignore the rest.
Ph.D in Physics, May 2015
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- Title
- PIEZO-BARKHAUSEN PULSE SIGNAL ANALYSES (BPSA) AND DETERMINATION OF THE FATIGUE LIFE OF AISI-1018 STEEL NEAR THE ENDURANCE LIMIT
- Creator
- Nunez-moreno, Federico Alejandro
- Date
- 2014, 2014-05
- Description
-
A series of fatigue tests were performed on two different types of steels named Steel A (annealed and decarbed AISI-1018 steel), and Steel B ...
Show moreA series of fatigue tests were performed on two different types of steels named Steel A (annealed and decarbed AISI-1018 steel), and Steel B (annealed and polished AISI-1018 steel), carried out to separation or to a maximum of 10,000,000 cycles (which was taken to be equivalent to infinite life). Strain levels ranging from 0.0014 in/in (0.0014mm/mm) down to 0.0008in/in (0.0008mm/mm) were used to execute all experimental load tests at a stress ratio R=-1 (complete reversal). An MTS machine was used for these trials. At the same time, magnetic fields and piezo-Barkhausen pulses were recorded by means of a flux gate magnetometer and a copper coil connected to a series of signal filters and amplifiers. Results were used to construct the classical S-N Whöler curve for both steels, as well as in exhibiting the behavior of the magnetic parameters (magnetic excursions, dominant frequencies of the magnetic signals) coupled to the fatigue lives of the samples tested. To describe such couplings, a set of correlations were introduced among the monitored variables as functions of testing time and applied strain. Also, a fractography analysis of the crack patterns using a scanning electron microscope was performed to represent statistically the geometry of “dimples” and fatigue striations from the inception of the crack, until the formation of a shear lip at the final stages of the crack. It was found that the magnitude of the mean amplitude of the piezo-Barkhausen pulses at early stages of the test is correlated to a mid-level energy of cracking, and thus explains the geometry of fatigue striations near the initiation of the crack at higher strain levels, compared to the geometry of the fatigue striations at lower strain levels. x xvi A joint analysis of the amplitudes of the magnetic excursions recorded in time, and the dominant frequencies of the magnetic signals were found to be discriminators of the elastic and plastic behavior of both types of steel. Furthermore the observed magnetic parameter variations determined in a clear way the endurance limit for each type of steel; these values also are in agreement with the strain level for which fatigue lives were greater than 10,000,000 cycles. Based on these results a “bell analogy” for interpreting the fatigue behavior is introduced. Bridge engineering applications and further research is also discussed.
PH.D in Civil Engineering, May 2014
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- Title
- CYBER-PHYSICAL SYSTEM FOR A WATER RECLAMATION PLANT: BALANCING AERATION, ENERGY, AND WATER QUALITY TO MAINTAIN PROCESS RESILIENCE
- Creator
- Zhu, Junjie
- Date
- 2015, 2015-07
- Description
-
Aeration accounts for a large fraction of energy consumption in conventional water reclamation plants (WRPs). Although process operations at...
Show moreAeration accounts for a large fraction of energy consumption in conventional water reclamation plants (WRPs). Although process operations at older WRPs can satisfy effluent permit requirements, they typically operate with excess aeration. More effective process controls at older WRPs can be challenging as operators work to balance higher energy costs and more stringent effluent limitations while managing fluctuating loads. Therefore, understandings of process resilience or ability to quickly return to original operation conditions at a WRP are important. A state-of-art WRP should maintain process resilience to deal with different kinds of perturbations even after optimization of energy demands. This work was to evaluate the applicability and feasibility of cyber-physical system (CPS) for improving operation at Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) Calumet WRP. In this work, a process model was developed and used to better understand the conditions of current Calumet WRP, with additional valuable information from two dissolved oxygen field measurements. Meanwhile, a classification system was developed to reveal the pattern of historical influent scenario based on cluster analysis and cross-tabulation analysis. Based on the results from the classification, typical process control options were investigated. To ensure the feasibility of information acquisition, the reliability and flexibility of soft sensors were assessed to typical influent conditions. Finally, the process resilience was investigated to better balance influent perturbations, energy demands, and effluent quality for long-term operations. These investigations and evaluations show that although the energy demands change as the influent conditions and process controls, in general, aeration savings could be up to 50% from the level of current consumption; with a more xix complex process controls, the saving could be up to 70% in relatively steady-state conditions and at least 40% in relatively challenging transient conditions. The soft sensors can provide reliable and flexible performance on target predictions. The plant can still maintain at a similar level of process resilience after 50% aeration saving, even during long-term perturbations. Overall, this work shows that it is well feasible to provide more cost-effective operations at the Calumet WRP, and meanwhile influent perturbations, effluent quality, and process resilience are well in balance. Keywords: Energy, aeration, effluent quality, perturbation, resilience, water reclamation plant.
Ph.D. in Environmental Engineering, July 2015
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- Title
- NANOPORE STOCHASTIC SENSING OF BIOMARKERS IN HUMAN DISEASE
- Creator
- Zhou, Shuo
- Date
- 2016, 2016-07
- Description
-
By measuring the ionic current modulation generated by analytes’ electro-osmotic flow through a nanoscale sized pore, nanopore stochastic...
Show moreBy measuring the ionic current modulation generated by analytes’ electro-osmotic flow through a nanoscale sized pore, nanopore stochastic sensing was invented about 20 years ago. Since then, it has been developed as a powerful and versatile tool for the detection of a wide variety of substances, including metal ions, organic molecules, DNA, RNA, peptides, proteins, etc. Compared with other traditional techniques such as immunochemical detection, colorimetric detection, HPLC, and GC/MS, nanopore detection has many advantages. First and foremost, nanopore stochastic sensing does not need to use sophisticated instruments which are convenient for people who do not have professional training in operating a special device. Furthermore, unlike fluorescent methods which rely on fluorophores labeling, nanopore stochastic sensing is a label-free detection method, which is based on the natural characteristics of analytes of interest. Moreover, nanopore sensing does not need complicated pretreatment of samples and can achieve a very low detection limit rapidly. Most importantly, nanopore detection uses only a small amount of sample with a low assay cost. In this dissertation, I summarize my work on nanopore stochastic sensing of proteases and copper ion, i.e., the detection of the HIV-1 protease (HIV-1 PR), trypsin, and copper ion. It is well-known that the HIV-1 protease is a significant biomarker for AIDS, while trypsin for the pancreatic disease. Considerable effort has been devoted to developing highly sensitive and selective sensors for these two important proteases. By taking advantage of nanopore stochastic sensing, two biosensors are constructed where picomolar concentrations of the HIV-1 protease and trypsin can be detected. On the other hand, copper, an essential trace element, is vital to the health of our human being in many ways. For example, the accumulation of cupric ions in human body may explain the origin of Wilson disease; further, the elevated concentration of copper is also pertinent to some symptoms of Alzheimer disease. Hence, the capability to the sensitive and accurate detection of copper ions is crucial to our health and well-being. For this purpose, a real-time and label-free nanopore biosensor is developed for its detection. The successful research efforts in these projects demonstrate the useful application of nanopore stochastic sensing in medical diagnosis, especially in terms of early disease detection. In addition to the high sensitivity and accuracy as well as low assay cost, other advantages of nanopore sensors include instrumental simplicity, ease of use, and extremely rapid data acquisition rates. Such a field-deployable nanopore sensor is useful as a point-of-care device for early disease detection and diagnosis. Just imagine how convenient your medical diagnosis would become with the pocket size nanopore sensor. We can monitor our own health anytime and anywhere: at home, at workplace, or even outside in remote and isolated places.
Ph.D. in Chemistry, July 2016
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- Title
- NEOVASCULARIZAnON WITHIN POROUS PEG HYDROGELS
- Creator
- Chiu, Yu-chieh
- Date
- 2011-11, 2011-12
- Description
-
Development of engineered tissues of clinically relevant size requires the ability to control vascularization within biomaterial scaffolds....
Show moreDevelopment of engineered tissues of clinically relevant size requires the ability to control vascularization within biomaterial scaffolds. Poly(ethylene glycol) (PEG) hydrogels have been extensively investigated for use as synthetic scaffolds to support engineered tissue formation. The goal of this work described was to develop techniques that can be used to enhance vascularized tissue formation in PEG-based hydrogels. In the first part of the study a technique was developed to generate porous PEG hydrogels using a salt leaching technique. This technique was then used to examine the role of pore size on vascularization and tissue remodeling in porous PEG hydrogel in vitro and in vitro. Both in vitro and in vivo studies showed that vessel invasion was pore size dependent. In addition, a thin layer of inflammatory tissue was observed between PEG hydrogel and blood vessels that formed within the gels. This layer suggested that inflammatory cells, not vascular cells, interacted with the surface of the material. This suggests that peptides covalently incorporated within PEG may not directly interact with endothelial cells (ECs) following implantation. The porous PEG hydrogels were very stable in vitro and in vivo and did not exhibit any signs of degradation. Hydrogels used in tissue engineering need to exhibit controlled degradation. In order to address the stability of PEG hydrogels, porous hydrogels were rendered using degradable PEG-co-(L-Lactic acid) diacrylate PEG-PLLA-DA. This polymer is degraded via hydrolysis of the PLLA chains. The porous PEG-PLLA-DA hydrogels were generated by solvent casting, photopolymerization, and particulate leaching. The influence of polymer conditions on the architecture, degradation, and mechanical properties of the hydrogels were investigated in vitro. The hydrogels were found to exhibit autofluorescence that allowed for the unique ability to nondestructively image hydrogel structure under fully swelled conditions using confocal microscopy. Initial pore size was a function of particulate size and independent of polymer concentration. Interestingly, pore size remained stable though out the study, and was not a function of degradation. In addition, degradation time of porous PEG-LLA-DA hydrogels was influenced by polymer concentration. Compressive modulus was a function of polymer concentration and pore size and decreased during hydrogel degradation. The incorporation of cell adhesion sequences into the hydrogel showed that they can support cell adhesion with morphology varying with pore size. This technique could be used to tailor porous biodegradable scaffolds for tissue engineering applications. In the final portion of this thesis a poly-lysine (PLL) molecule was synthesized in order to allow clustering of adhesion sequences in PEG hydrogels. Clusters of peptide sequences have been shown to enhance cell interactions with substrate surfaces. The sequence was synthesized and purified by high performance liquid chromatography (HPLC) and characterized by mass spectrometry. The side chains of the PLL molecule was used to attach peptide sequences. Cysteine contained within the PLL allowed incorporation into the PEG hydrogel by mixed mode polymerization. Cells were observed to adhere to hydrogels containing the RGD clusters and not to the control gels. The results presented here describe various techniques that can be used to optimize the design of polymer scaffolds for tissue engineering. In addition, the data provide insight into the process of vascularization in porous hydrogels and the influence of synthesis conditions and degradation on properties of porous hydrogels. Future studies should investigate the optimization of these material techniques for control of neovascularization within PEG hydrogels for tissue engineering applications.
Ph.D. in Biomedical Engineering, December 2011
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- Title
- PRICING AND APPLICATION OF ELECTRIC STORAGE
- Creator
- Zhao, Jialin
- Date
- 2017, 2017-05
- Description
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Electric storage provides a vehicle to store power for future use. It contributes to the grids in multiple aspects. For instance, electric...
Show moreElectric storage provides a vehicle to store power for future use. It contributes to the grids in multiple aspects. For instance, electric storage is a more effective approach to provide electricity ancillary services than conventional methods. Additionally, electric storage, especially fast-responding units, allows owners to implement high-frequency power transactions in settings such as the 5-min real-time trading market. Such high-frequency power trades were limited in the past. However, as technology advances, the power markets have evolved. For instance, the California Independent System Operator now supports the 5-min real-time trading and the hourly day-ahead ancillary services bidding. Existing valuation models of electric storage were not designed to accommodate these recent market developments. To fill this gap, I focus on the fast-responding grid-level electric storage that provides both the real-time trading and the day-ahead ancillary services bidding. To evaluate such an asset, I propose a Monte Carlo Simulation-based valuation model. The foundation of my model is simulations of power prices. This study develops a new simulation model of electric prices. It is worth noting that, unlike existing models, my proposed simulation model captures the dependency of the real-time markets on the day-ahead markets. Upon such simulations, this study investigates the pricing and the application of electric storage at a 5-min granularity. Essentially, my model is a Dynamic Programming system with both endogenous variables (i.e., the State-of-Charge of electric storage) and exogenous variables (i.e., power prices). My first numerical example is the valuation of a fictitious 4MWh battery. Similarly, my second example evaluates the application of two units of 2MWh batteries. By comparing these two experiments, I investigate the issues related to battery configurations, such as the impacts of splitting storage capability on the valuation of electric storage.
Ph.D. in Management Science, May 2017
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- Title
- COMPUTATIONAL FLUID DYNAMICS AND POPULATION BALANCE MODEL FOR SIMULATION OF DRY SORBENT BASED CO2 CAPTURE PROCESS
- Creator
- Abbasi, Emadoddin
- Date
- 2013, 2013-12
- Description
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Carbon capture and sequestration (CCS) is one of the key technologies needed to mitigate carbon dioxide emission from industrial sources and...
Show moreCarbon capture and sequestration (CCS) is one of the key technologies needed to mitigate carbon dioxide emission from industrial sources and power plants. Development of CFD-based design tool for prediction of the extent of CO2 capture in a regenerable dry sorbent-based technology, in an efficient power plant design (i.e., modern IGCC power plants) was the driving force behind this project. In this study, we established a systematic methodology, starting from investigating the properties of the sorbent and its reaction mechanism, to developing a model for design and scale-up of the reactors that is needed to deploy this technology at larger scales. This dissertation provides a coupled CFD-PBE model based on the novel FCMOM approach with broad application in reaction engineering and reactor design where the polydisperse nature of the phases has strong effect on the hydrodynamics of the system. Detailed investigations of the MgO-based sorbent and its performance toward capturing CO2 from a coal gas stream were performed that result in development of the two-zone variable diffusivity shrinking core reaction model. Furthermore, a baseline design for a circulating fluidized bed (CFB) reactor, using numerical modeling and threedimensional simulations of a full-loop circulating fluidized bed reactor was provided based on the coupled CFD-PBE, which in combination with the reaction model can perform as a base for parametric studies and optimization of the process.
PH.D in Chemical Engineering, December 2013
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- Title
- AN INTRINSICALLY CONDUCTING POLYMER-BASED COATING SYSTEM FOR CORROSION PROTECTION OF STEELS
- Creator
- Yu, Qifeng
- Date
- 2016, 2016-12
- Description
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Among the various corrosion protection strategies for structural steels, coating techniques provide the most cost-effective protection and...
Show moreAmong the various corrosion protection strategies for structural steels, coating techniques provide the most cost-effective protection and have been used as the primary mode for corrosion protection. Existing coating techniques have been used mainly for their barrier capability and all have a limited service life. In this research work, a waterborne two-strand polyaniline: poly (acrylic acid) complex was synthesized and utilized to fabricate the primer layer of a two-layer coating system. The techniques of Scanning Kelvin Probe Force Microscopy (SKPFM) and Electrochemical Impedance Spectroscopy (EIS) were used to evaluate the anti-corrosion capability of the polymeric complex when mixed in an epoxy matrix and coated on steel samples as the primer layer. The evaluation results show that coating systems including a PANi-based primer has measurable anticorrosion capability and the anti-corrosion capability of PANi-based primer depends on the usage of PANi and the type of matrix material of the primer layer. In the laboratory condition, a prototype two-layer coating system including the PANi-based primer and a polyurethane topcoat was manufactured. The ASTM Salt-Spray Test and EIS were used to prove the anti-corrosion performance of the prototype using a two-layer, polyurethane-over-epoxy system (no PANi) as the control system. After the proof of concept, a non-waterborne epoxy was used to fabricate a different PANi-based primer. The two types of primers and two other commercial primers (a zinc-rich primer and an epoxy-only primer) were used to make a total of eight two-layer coating systems using two widely used topcoats. Salt-Spray Test, Cyclic Salt Fog/UV Exposure Test, Pull- Off Adhesion Test, and the techniques of EIS, SKPFM, and Scanning Electron Microscope (SEM) were used to evaluate the long-term performance of the eight systems. Based on the laboratory-based recommendations, six groups of two-layer coating systems were then subjected to the outdoor-exposure test to evaluate their anti-corrosion durability at two testing sites. The field durability of the coating systems was evaluated in terms of their surface gloss reduction, color change, adhesion change and surface deteriorations. The matrix material in which the PANi is mixed plays an important role in the longterm anti-corrosion performance of coatings. The waterborne epoxy is effective in dispersing PANi nano-particles and has zero VOC; however, it does not bond to the steel surface as strongly as the regular non-waterborne epoxy. The topcoat material also plays an important role in the long-term anti-corrosion performance of coatings; polyurethane has higher durability than epoxy as a topcoat material. The PANi-based systems possess long-term corrosion protection comparable to the performance of the conventional zincrich three-layer system based on the one-year field evaluation.
Ph.D. in Civil Engineering, December 2016
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- Title
- QUANTITATIVE ANALYSIS OF THE EFFECTS OF BIOFUNCTIONAL AND PHYSICAL GRADIENTS ON CELL BEHAVIOR IN POLY (ETHYLENE GLYCOL) DIACRYLATE HYDROGELS
- Creator
- Turturro, Michael
- Date
- 2012-10-29, 2012-12
- Description
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The continued enhancement of tissue engineered scaffolds relies on their ability to stimulate the formation of a stable microvascular network...
Show moreThe continued enhancement of tissue engineered scaffolds relies on their ability to stimulate the formation of a stable microvascular network within the biomaterial. In vivo, the spatial presentation of immobilized extracellular matrix cues and matrix mechanical properties play an important role in directed and guided cell behavior and neovascularization. The overall goals of this thesis are to develop a technique for the generation of gradients of physical properties and incorporated biofunctionality within poly(ethylene glycol) diacrylate (PEGDA) scaffolds and to investigate the effects of these gradients on 3D cell invasion and neovascularization. To this end, a novel photopolymerization technique for generating spatial variations in matrix properties and incorporated biofunctionality within synthetic PEGDA hydrogels, perfusion-based frontal polymerization (PBFP), was developed. This technique relies on the controlled perfusion of a photoinitiator to a reaction chamber containing a precursor solution and results in the propagation of a polymer reaction front that travels through the monomer solution creating a gradient in hydrogel crosslinking. Manipulation of the magnitude of the gradient can be achieved through alterations in the polymerization conditions. Scaffolds with embedded gradients were designed and optimized based on a range of properties shown to support 2D cell adhesion, proliferation, and 3D vascular cell invasion in bulk photopolymerized hydrogels with homogeneous properties. An in vitro model of neovascularization was used to evaluate the effect of these gradients on vascular sprout formation. Sprout invasion in gradient hydrogels occurred bi-directionally with sprout alignment observed in the direction parallel to the gradient while control hydrogels with homogeneous properties resulted in uniform invasion. In PBFP gradient hydrogels, sprout xvi length was found to be twice as long in the direction parallel to the gradient as compared to the perpendicular direction after three weeks in culture. This directionality was found to be more prominent in gradient regions of increased stiffness, crosslinked matrix metalloproteinase (MMP)-sensitive peptide presentation, and immobilized YRGDS concentration. In vivo tissue invasion was shown to be directly related to gradient properties and orientation. Alterations in the magnitude of the gradient in elastic modulus enhanced the directionality of invading vascular sprouts while restricting in vivo tissue invasion.
PH.D in Biomedical Engineering, December 2012
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- Title
- PSYCHOMETRIC PROPERTIES OF THE CENTER FOR EPIDEMILOGICAL STUDIES DEPRESSION SCALE (CES-D) USED AMONG NATIVE CHINESE INDIVIDUALS WITH SPINAL CORD INJURY
- Creator
- Xiong, Ying
- Date
- 2014, 2014-07
- Description
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Depressive symptoms are highly prevalent among people with Spinal Cord Injury (SCI) and yet there is a lack of consensus over psychometrically...
Show moreDepressive symptoms are highly prevalent among people with Spinal Cord Injury (SCI) and yet there is a lack of consensus over psychometrically sound diagnostic criteria or screening tools for depression. This is particularly true with the SCI population in China. Currently, there is limited information regarding the prevalence of depression, severity, and depressive symptomatology among individuals with SCI in China. CES-D lOis a simple and quick tool to use, and it avoids over-estimating depression due to frequent somatic complaints associated with SCI. To our best knowledge, the CES-D 10 had not been used among the native Chinese population with SCI. The current study used the CES-D 10 to measure depressive symptoms among individuals with SCI in China. The purpose ofthis study was to examine factorial validity, internal consistency, construct validity, and concurrent validity ofCES-D 10 among 260 Chinese individuals with SCI. Results showed an alarmingly high prevalence of depressive symptoms among the sample. Consistent with existing literature and hypotheses, a two-factor structure of CES-D 10 was replicated based on a confirmatory factor analysis. Hierarchical regression analyses showed several important psychosocial constructs such as acceptance of disability, social support, and functional disability were predictors of overall depressive symptoms. Surprisingly, depressive symptoms were not predictive of employment status. The scale showed low internal consistency, and a cultural response bias in which participants are less likely to endorse positively-stated CES-D items among the current sample. Such finding is consistent with past studies among the East Asian population. Limitations and implications ofthe study were discussed.
Ph.D. in Psychology, July 2014
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- Title
- CAPACITY BOUNDS FOR LARGE SCALE WIRELESS SENSOR NETWORKS
- Creator
- Tang, Shaojie
- Date
- 2012-11-20, 2012-12
- Description
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We study the network capacity of large scale wireless sensor networks under both Gaussian Channel model and Protocol Interference Model. To...
Show moreWe study the network capacity of large scale wireless sensor networks under both Gaussian Channel model and Protocol Interference Model. To study network capacity under gaussian channel model, we assume n wireless nodes {v1, v2, · · · , vn} are randomly or arbitrarily distributed in a square region Ba with side-length a. We randomly choose ns multicast sessions. For each source node vi, we randomly select k points pi,j (1 ≤ j ≤ k) in Ba and the node which is closest to pi,j will serve as a destination node of vi. The per-flow unicast(multicast) capacity is defined as the minimum data rate of all unicast(multicast) sessions in this network. We derive the achievable upper bounds on unicast capacity and a upper bound(partial achievable) on multicast capacity of the wireless networks under and Gaussian Channel model. We found that the unicast(multicast) capacity for wireless networks under both two models has three regimes. Under protocol interference model, we assume that n wireless nodes are randomly deployed in a square region with side-length a and all nodes have the uniform transmission range r and uniform interference range R > r. We further assume that each wireless node can transmit/receive at W bits/second over a common wireless channel. For each node vi, we randomly pick k − 1 nodes from the other n − 1 nodes as the receivers of the multicast session rooted at node vi. The aggregated multicast capacity is defined as the total data rate of all multicast sessions in the network. In this work we derive matching asymptotic upper bounds and lower bounds on multicast capacity of large scale random wireless networks under protocol interference model.
PH.D in Computer Science, December 2012
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