Engineering Commons^™

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 …

Labview Based Whispering Gallery Mode Microtoroid Coupling Pid Controller, Peiyao Li

All Theses and Dissertations (ETDs)

The aim of this thesis is to test the implementation of PID control algorithm for stabilization of coupling. Efficient and robust coupling is prerequisite in microcavity related applications. But surrounding environments, like temperature and airflow, could easily influence coupling condition. PID algorithm has been used for stabilization and control in industry for several decades. For this reason, the author decided to test further application, with the goal of proving the suitability for Whispering Gallery Mode coupling. The thesis first discusses the Whispering Gallery Mode microtoroid, especially its relative coupling regime. In a second stage, the LabVIEW and Arduino based real …

Development & Testing Of Novel Atmospheric Chemistry Technologies, Peter Johnson Mellott

All Theses and Dissertations (ETDs)

Atmospheric aerosols play an important role in global atmospheric chemistry and climate and have a detrimental impact on human health. Advancements in measurement technologies allow for better monitoring of atmospheric composition and dynamics, creating better predictive models and understanding of atmospheric chemistry and physics. Gas and particle atmospheric oxidation is poorly understood. In order to create a better understanding of atmospheric oxidation, the following equipment was developed: 1) a Potential Aerosol Mass: PAM) flow reaction chamber was developed to create reproducible steady-state oxidation of organic species in a controlled laboratory setting, 2) a custom combustion chamber for introduction of realistic …

Calcium Cycling Disturbances And Arrhythmogenesis, Namit Gaur

McKelvey School of Engineering Theses & Dissertations

In this work, a detailed multiscale computational model of Ca cycling and action potential in a ventricular myocyte is developed and used to study mechanisms of arrhythmias associated with mutations in the ryanodine receptor (RyR). The multiscale ventricular myocyte model reproduces experimentally observed Ca dynamics both at the local dyadic scale and at the global whole-cell scale, while also simulating the action potential (AP) shaped by membrane ionic currents. The model represents stochastic activation of L-type Ca channels (LCCs) and RyRs in the dyads and simulates random generation of Ca sparks both during excitation-contraction coupling (ECC) and during diastole. The …

Economic Prospects For Advanced Combustion Technologies Suited For Climate Change Mitigation, Craig Bryan Jacobson

All Theses and Dissertations (ETDs)

Coal is projected to remain a significant portion of the global energy portfolio in the coming century. Concerns over accelerating climate change have spurred development of technologies aimed at reducing CO2 emissions from coal-fired power plants through carbon capture and sequestration: CCS). Utilities considering expansion of baseload generation capacity face a myriad of uncertainties regarding the timing and scale of future carbon legislation. This study reports on an economic evaluation of various technologies for carbon capture, sequestration, and utilization.

An Algorithm And Methodology For Static Response Based Damage Detection In Structural Systems, Augusto Terlaje

All Theses and Dissertations (ETDs)

A damage detection algorithm and procedure is presented in this dissertation that utilizes static response data and Optimality Criterion optimization. Static displacement measurements are used as constraints in the damage detection algorithm that identifies potential areas of damage in structural systems. The research aims to improve upon the master's level research performed by the author. First, the robustness of the algorithm is improved by use of a least squares approximation for determining the Lagrange multipliers that are necessary for optimization. Second, an active parameter selection subroutine is used to improve the accuracy of damage detection in the presence of experimental …

Atomic Transfer For Distributed Systems, Haraldur Darri Thorvaldsson

McKelvey School of Engineering Theses & Dissertations

Building applications and information systems increasingly means dealing with concurrency and faults stemming from distribution of system components. Atomic transactions are a well-known method for transferring the responsibility for handling concurrency and faults from developers to the software's execution environment, but incur considerable execution overhead. This dissertation investigates methods that shift some of the burden of concurrency control into the network layer, to reduce response times and increase throughput. It anticipates future programmable network devices, enabling customized high-performance network protocols.

We propose Atomic Transfer (AT), a distributed algorithm to prevent race conditions due to messages crossing on a path of …