Engineering Commons^™

Systems Metabolic Engineering Of Microbial Cell Factories For The Synthesis Of Value-Added Chemicals, Arul Mozhy Varman

All Theses and Dissertations (ETDs)

Microbial cell factories offer us an excellent opportunity for the conversion of many different cheaply available raw materials into valuable chemicals. Systems metabolic engineering aims at developing rational strategies for the engineering of microbial hosts by providing global level information of a cell. This dissertation focuses on metabolic engineering, bioprocess modeling and pathway analysis, to develop robust microbial cell factories for the synthesis of value-added chemicals. The following research tasks were completed in this regard.

First, statistical models were developed for the prediction of product yields in engineered microbial cell factories - Saccharomyces cerevisiae and Escherichia coli: Chapter 2). A …

Intraurban Variability Of Ambient Particulate Matter, Varun Yadav

All Theses and Dissertations (ETDs)

An understanding of spatial and temporal variability in ambient particulate matter: PM) is important for effective air quality management and for assessing potential exposure misclassification in epidemiological and exposure studies used to support health-based standards. Spatiotemporal variability of PM in urban areas can be influenced by many factors, such as local sources of primary PM; source locations and their emission profiles; topographic barriers; meteorological patterns; behavior of semi-volatile components; and measurement errors. Intraurban variability is often gauged by conducting measurements at a network of monitoring stations across the region of interest. While certain statistical metrics are commonly used and interpreted …

Emg-Emg Coherence Analysis Of Elbow And Shoulder Muscles, Manu Stephen

All Theses and Dissertations (ETDs)

Motor coordination can be described by the activation of a few intermuscular coordination patterns, or muscle synergies. Muscle synergy can be defined as a relatively fixed pattern of activation across a set of muscles. The neural mechanisms underlying muscle synergies remain to be fairly unknown. Through a muscle synergy study [13], co-activation in muscle pairs was discovered through a non-negative matrix factorization: NMF) analysis. In order to evaluate the same muscles under the frequency domain, coherence analysis: a correlational method) was used. Additionally, a comparison can be made to determine if the resulting muscle pairs overlap with the muscle pairs …

Oxy-Combustion Of High Water Content Fuels, Fei Yi

All Theses and Dissertations (ETDs)

As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low …

Ecog Correlates Of Visuomotor Transformation, Neural Plasticity, And Application To A Force-Based Brain Computer Interface, Jordan John Williams

All Theses and Dissertations (ETDs)

Electrocorticography: ECoG) has gained increased notoriety over the past decade as a possible recording modality for Brain-Computer Interface: BCI) applications that offers a balance of minimal invasiveness to the patient in addition to robust spectral information over time. More recently, the scale of ECoG devices has begun to shrink to the order of micrometer diameter contacts and millimeter spacings with the intent of extracting more independent signals for BCI control within less cortical real-estate. However, most control signals to date, whether within the field of ECoG or any of the more seasoned recording techniques, have translated their control signals to …

Multiple-Target Tracking In Complex Scenarios, Srinivas Phani Kumar Chavali

All Theses and Dissertations (ETDs)

In this dissertation, we develop computationally efficient algorithms for multiple-target tracking: MTT) in complex scenarios. For each of these scenarios, we develop measurement and state-space models, and then exploit the structure in these models to propose efficient tracking algorithms. In addition, we address design issues such as sensor selection and resource allocation.

First, we consider MTT when the targets themselves are moving in a

time-varying multipath environment. We develop a sparse-measurement model that allows us to exploit the inherent joint delay-Doppler diversity offered by the environment. We then reformulate the problem of MTT as a

block-support recovery problem using the …

Coupling Of The Biogeochemical Cycles Of Uranium And Manganese: Implications For The Fate And Transport Of Uranium In Subsurface Environments, Zimeng Wang

All Theses and Dissertations (ETDs)

Organic electron donor stimulated microbial reduction of U(VI) to U(IV) has been proposed as a strategy for the in situ immobilization of uranium contamination in the subsurface. The success of the bioremediation of uranium relies on the stability of the reduced U(IV) species: e.g., UO2) with respect to reoxidation and/or remobilization under groundwater conditions. Manganese is present at appreciable concentrations at several uranium-contaminated sites, and the redox cycling of manganese may significantly impact uranium's fate and transport. The biogeochemical coupling of uranium and manganese involves multiple interaction pathways that occur in the aqueous phase as well as at solid-water interfaces. …

High-Resolution Low-Noise Polarization Imaging Sensor For Astronomical Applications, Radoslav Marinov

All Theses and Dissertations (ETDs)

Polarization imaging is useful to the field of astronomy because the polarization state caused by reflections, scattering events, and magnetic fields can be used to infer properties such as shape and index of refraction about celestial bodies. This work presents a low-noise high-resolution polarization imaging sensor consisting of a CCD imager overlaid with a nanowire linear polarizer filter array of four different orientations: 0°, 45°, 90°, and 135°) matched to the pixel pitch. Fabrication details and experimental setup for characterization are discussed. The performance of the sensor is assessed over a range of polarization states, light intensities, wavelengths, and incident …

Numerical Simulation Of Separated And Secondary Flows In Diffusing S-Ducts For Air Breathing Propulsion, Colin James Fiola

All Theses and Dissertations (ETDs)

No abstract provided.

End-To-End Delay Analysis For Wireless Control Networks Under Edf Scheduling, Chengjie Wu

All Theses and Dissertations (ETDs)

No abstract provided.

Difficulties And Opportunities In Building Resilient Clinical Monitoring Systems With Wireless Sensor Networks, Rahav Dor

All Theses and Dissertations (ETDs)

No abstract provided.

Ideal Optimum Performance Of Propellers, Lifting Rotors And Wind Turbines, Ramin Modarres

All Theses and Dissertations (ETDs)

No abstract provided.

Wireless Cyber-Physical Simulator And Case Studies On Structural Control, Bo Li

All Theses and Dissertations (ETDs)

No abstract provided.

Delivering Consistent Network Performance In Multi-Tenant Data Centers, Mart Albert Haitjema

All Theses and Dissertations (ETDs)

Data centers are growing rapidly in size and have recently begun acquiring a new role as cloud hosting platforms, allowing outside developers to deploy their own applications on large scales. As a result, today's data centers are multi-tenant environments that host an increasingly diverse set of applications, many of which have very demanding networking requirements. This has prompted research into new data center architectures that offer increased capacity by using topologies that introduce multiple paths between servers. To achieve consistent network performance in these networks, traffic must be effectively load balanced among the available paths. In addition, some form of …

Numerical Simulation And Optimization Of Co2 Sequestration In Saline Aquifers, Zheming Zhang

All Theses and Dissertations (ETDs)

With heightened concerns on CO2 emissions from pulverized-coal power plants, there has been major emphasis in recent years on the development of safe and economical Geological Carbon Sequestration: GCS) technology. Although among one of the most promising technologies to address the problem of anthropogenic global-warming due to CO2 emissions, the detailed mechanisms of GCS are not well-understood. As a result, there remain many uncertainties in determining the sequestration capacity of the formation/reservoir and the safety of sequestered CO2 due to leakage. These uncertainties arise due to lack of information about the detailed interior geometry of the formation and the heterogeneity …

Optimization Of Induced-Power From Dynamic Inflow Theory With Realistic Constraints, Chad File

All Theses and Dissertations (ETDs)

Finite-state induced-inflow theory is used to develop an analytic formulation for general performance of the lifting rotor with arbitrary loading. The theory incorporates conventional blade-element theory for blade lift and provides the integrated loads and the induced-power of the rotor in terms of an arbitrary number of rotor controls such as conventional collective and cyclic pitch as well as higher harmonic radial and azimuthal pitch. The theory provides the basis for a classical quadratic optimization with realistic constraints that is applied to determine minimum induced-power for a variety of available control combinations, rotor trim constraints, and operating conditions. The findings …

Capacity Fade Analysis And Model Based Optimization Of Lithium-Ion Batteries, Venkatasailanathan Ramadesigan

All Theses and Dissertations (ETDs)

Electrochemical power sources have had significant improvements in design, economy, and operating range and are expected to play a vital role in the future in a wide range of applications. The lithium-ion battery is an ideal candidate for a wide variety of applications due to its high energy/power density and operating voltage. Some limitations of existing lithium-ion battery technology include underutilization, stress-induced material damage, capacity fade, and the potential for thermal runaway. This dissertation contributes to the efforts in the modeling, simulation and optimization of lithium-ion batteries and their use in the design of better batteries for the future. While …

Development Of Optimization Models For The Set Behavior And Compressive Strength Of Sodium Activated Geopolymer Pastes, Brian Albert Fillenwarth

All Theses and Dissertations (ETDs)

As large countries such as China begin to industrialize and concerns about global warming continue to grow, there is an increasing need for more environmentally friendly building materials. One promising material known as a geopolymer can be used as a portland cement replacement and in this capacity emits around 67% less carbon dioxide. In addition to potentially reducing carbon emissions, geopolymers can be synthesized with many industrial waste products such as fly ash.

Although the benefits of geopolymers are substantial, there are a few difficulties with designing geopolymer mixes which have hindered widespread commercialization of the material. One such difficulty …

A Rigorous Solution For Finite-State Inflow Throughout The Flowfield, Zhongyang Fei

All Theses and Dissertations (ETDs)

In this research, the Hseih/Duffy model is extended to all three velocity components of inflow across the rotor disk in a mathematically rigorous way so that it can be used to calculate the inflow below the rotor disk plane. This establishes a complete dynamic inflow model for the entire flow field with finite state method. The derivation is for the case of general skewed angle. The cost of the new method is that one needs to compute the co-states of the inflow equations in the upper hemisphere along with the normal states. Numerical comparisons with exact solutions for the z-component …

Chemoprevention Of Lung Carcinogenesis: Aerosol Administration And Deposition In The Mouse Lung, Jingjie Zhang

All Theses and Dissertations (ETDs)

INTRODUCTION Chemoprevention is the use of natural or synthetic agents to inhibit either the initial development or the further progression of early lesions. Chemoprevention of lung cancer aims to decrease lung cancer morbidity and mortality, especially for former smokers. Many synthetic and natural compounds have been investigated for their potential chemopreventive efficacy. Conventional administration of these compounds: especially oral administration) is convenient, but may potentially result in adverse side effects. Aerosol delivery, on the other hand, offers many advantages over conventional routes of administration for diseases of the respiratory tract and the lungs. These advantages include the extensive pulmonary surface …

Optimal Control Of Weakly Forced Nonlinear Oscillators, Isuru Sammana Dasanayake

All Theses and Dissertations (ETDs)

Optimal control of nonlinear oscillatory systems poses numerous theoretical and computational challenges. Motivated by applications in neuroscience, we develop tools and methods to synthesize optimal controls for nonlinear oscillators described by reduced order dynamical systems. Control of neural oscillations by external stimuli has a broad range of applications, ranging from oscillatory neurocomputers to deep brain stimulation for Parkinson's disease. In this dissertation, we investigate fundamental limits on how neuron spiking behavior can be altered by the use of an external stimulus: control). Pontryagin's maximum principle is employed to derive optimal controls that lead to desired spiking times of a neuron …