Engineering Commons^™

Leak Detector System For Positive Airway Pressure Machines, Aishwarya Gopalakrishnan

Electrical Engineering Theses - Archive

The project aims to develop a system to indicate leaks occurring in a Positive Airway Pressure (PAP) machine which sends a passage of air to the patients suffering from sleep apnea, through a hose and a nose mask. The system uses programming software to record and analyse the data obtained from the sensors and provides an interface for the user to select a method for notifying the time instant and location of leak occurrences.The system used an approach of using sensors for leak detection. Two pressure sensors and two audio sensors were selected out of which, one pressure sensor and …

Smartphone-Based Crowd Sourcing Of Bicycle And Pedestrian Conflict Data For Transportation Safety Assessment, Rahul Ankushrao Kawadgave

Electrical Engineering Theses - Archive

This thesis presents the idea of mobile application development that aims at data collection for transportation safety assessment using cloud-based database. At present, transportation safety assessment relies only on data available from crash, accident reports. In combination with this crash data, it is possible that conflict data can become a very influential performance measure for transportation safety assessment. A transportation conflict happens when two parties cross a path and one party must take an action to avoid a collision or a crash. Such conflicts can occur between different transportation elements or parties like vehicle drivers, bicyclists, pedestrians. This project helps …

Active Flyback Based Battery Management System With Proportional Balancing For Use In An Electric Race Car, Matthew Martin

Electrical Engineering Theses - Archive

Battery management systems are responsible for many tasks, most important of which is maintaining balance amongst the cells in a series string to prevent excess aging and unsafe operating conditions \cite{WhyBMS1}\cite{WhyBMS2}. In lithium-ion battery packs, traditionally, and almost exclusively in the world at large today, balancing is achieved by switching a resistor in parallel with high cells to bleed energy out of them and dissipate it as heat. This tactic is not only 100 percent inefficient, but it is slow due to power dissipation restrictions typically thermally imposed within a system, and it is only effective at preventing over-voltage conditions. …

Adaptive Torque Control Of A Robotic Manipulator, Drew F. Waller

Electrical Engineering Theses - Archive

In this thesis, I present the theory and application of enabling intuitive control and physical interaction between a human operator and a mobile manipulator. To do so, the model of the manipulator was estimated for its kinematic and inertial properties. Specifically selected in this project was the Kuka youBot for its ease of use and wide academic availability. With thorough modeling of this device that included the arm as well as the base, and advanced control and guidance techniques, an adaptive controller was used to guide the manipulator towards a goal trajectory with great accuracy. The goal trajectory was built …

Effective And Economical Content Delivery And Storage Strategies For Cloud Systems, Yuhua Lin

All Dissertations

Cloud computing has proved to be an effective infrastructure to host various applications and provide reliable and stable services. Content delivery and storage are two main services provided by the cloud. A high-performance cloud can reduce the cost of both cloud providers and customers, while providing high application performance to cloud clients. Thus, the performance of such cloud-based services is closely related to three issues. First, when delivering contents from the cloud to users or transferring contents between cloud datacenters, it is important to reduce the payment costs and transmission time. Second, when transferring contents between cloud datacenters, it is …

Designs And Reliability Evaluations Of A Scattered Light Measurement System, Kang-Min Lee

Graduate Theses - Physics and Optical Engineering

The purpose of my work was to develop an in-plane stray light measurement system having the advantage of being easily applicable in both motion control and optical configurations. First of all, mechanical designs were conducted based on both 3D modeling and structural analysis through a finite element method (FEM). Optical configurations for both the incident source and the detector were designed to achieve minimum observed source convergence angle of the system. The control panel and micro stepping system were programmed for automated measurement. Finally, the designed system was calibrated and aligned. In order to evaluate the system reliability for scatter …

Seismic Response Of An Older Bridge In Nevada Under Maximum Considered Earthquake, Ryan Thomas Isaac

UNLV Theses, Dissertations, Professional Papers, and Capstones

Given the aging infrastructure in the United States, a study was conducted on an older bridge in Nevada to determine its performance under the maximum considered earthquake. A suite of eight synthetic site-specific ground motions, including a spectrum-matched “RSP” record, were applied along both the longitudinal and transverse axes of Bridge G-953 in Las Vegas, Nevada. The supplementary materials contain the original drawings of Bridge G-953 for reference, including changes to the expansion joints and the addition of cable restrainers at the in-span hinges. A detailed model, including the effects of column nonlinearity, material degradation such as shear keys, abutment …

Supervisory Control Optimization For A Series Hybrid Electric Vehicle With Consideration Of Battery Thermal Management And Aging, Xueyu Zhang

All Dissertations

This dissertation integrates battery thermal management and aging into the supervisory control optimization for a heavy-duty series hybrid electric vehicle (HEV). The framework for multi-objective optimization relies on novel implementation of the Dynamic Programing algorithm, and predictive models of critical phenomena. Electrochemistry based battery aging model is integrated into the framework to assesses the battery aging rate by considering instantaneous lithium ion (Li+) surface concentration rather than average concentration. This creates a large state-action space. Therefore, the computational effort required to solve a Deterministic or Stochastic Dynamic Programming becomes prohibitively intense, and a neuro-dynamic programming approach is proposed to remove …

Towards An Efficient Cloud Computing System: Data Management, Resource Allocation And Job Scheduling, Jinwei Liu

All Dissertations

Cloud computing is an emerging technology in distributed computing, and it has proved to be an effective infrastructure to provide services to users. Cloud is developing day by day and faces many challenges. One of challenges is to build cost-effective data management system that can ensure high data availability while maintaining consistency. Another challenge in cloud is efficient resource allocation which ensures high resource utilization and high SLO availability. Scheduling, referring to a set of policies to control the order of the work to be performed by a computer system, for high throughput is another challenge. In this dissertation, we …

Development Of A New Multimodal Membrane Adsorber And Its Application In Chromatographic Bioseparations, Juan Wang

All Dissertations

This dissertation presents work on the design and synthesis of a new membrane chromatography material, the description of its protein binding behavior using a thermodynamic adsorption isotherm model, and the application of the new membrane material in biologics downstream recovery and purification processes. As protein titers continue to increase dramatically in upstream biomanufacturing, innovations in downstream purification are not keeping pace, resulting in manufacturing capacity constraints and high production costs. Chromatography is the key unit operation used in several steps of the downstream purification platform. Traditional resin bead chromatography, while effective and reliable for isolation and purification of proteins, limits …

Optimization Techniques For Modern Power Systems Planning, Operation And Control, Karthikeyan Balasubramaniam

All Dissertations

Recent developments in computing, communication and improvements in optimization techniques have piqued interest in improving the current operational practices and in addressing the challenges of future power grids. This dissertation leverages these new developments for improved quasi-static analysis of power systems for applications in power system planning, operation and control.

The premise of much of the work presented in this dissertation centers around development of better mathematical modeling for optimization problems which are then used to solve current and future challenges of power grid. To this end, the models developed in this research work contributes to the area of renewable …

Chiral Light Intrinsically Couples To Extrinsic/Pseudo-Chiral Metasurfaces Made Of Tilted Gold Nanowires, Alessandro Belardini, Marco Centini, Grigore Leahu, David C. Hooper, Roberto Li Voti, Eugenio Fazio, Joseph W. Haus, Andrew Sarangan, Ventsislav K. Valev, Concita Sibilia

Electro-Optics and Photonics Faculty Publications

Extrinsic or pseudo-chiral (meta)surfaces have an achiral structure, yet they can give rise to circular dichroism when the experiment itself becomes chiral. Although these surfaces are known to yield differences in reflected and transmitted circularly polarized light, the exact mechanism of the interaction has never been directly demonstrated. Here we present a comprehensive linear and nonlinear optical investigation of a metasurface composed of tilted gold nanowires. In the linear regime, we directly demonstrate the selective absorption of circularly polarised light depending on the orientation of the metasurface. In the nonlinear regime, we demonstrate for the first time how second harmonic …

Risk-Based Approach To Assessment Of Advanced Technologies For Conceptual Design, Adipratnia Asmady

Master's Theses

The conceptual design phase of an aerospace system development program is typically characterized by short duration and relatively limited resources, yet design decisions are made that have critical implications on program risk. To address the more aggressive requirements, one of these decisions is the selection of advanced technologies. System developers need to assess advanced technologies early on, but are faced with uncertainties surrounding the potential net benefits. The concept introduced in this study is uncertainty characterization as a way to better understand the associated risk. A framework was developed to guide the interaction between the technology developer and the system …

Cellno Trap: Novel Device For Quantitative, Real-Time, Direct Measurement Of Nitric Oxide From Cultured Raw 267.4 Macrophages, Weilue He, Megan C. Frost

Michigan Tech Publications, Part 1

Nitric oxide (NO), is arguably one of the most important small signaling molecules in biological systems. It regulates various biological responses in both physiological and pathological conditions, often time producing seemingly contradictory results. The details of the effects of NO are highly dependent on the level of NO that cells experience and the temporal aspect of when and how long cells are exposed to NO. Herein, we present a novel measurement system (CellNO trap) that allows real-time NO measurement via chemiluminescence detection from general adhesive cultured cells using standard cell culture media and reagents that does not perturb the cells …

Mechanical And Thermal Evaluation Of Different Types Of Pcm-Concrete Composite Panels, Dervilla Niall, Oliver Kinnane, Roger West, Sarah Mccormack

Conference papers

ABSTRACT: Thermal mass indicates the ability of a material to store and release heat and is a function of the heat storage capacity of a material. The thermal mass of construction materials can be used to reduce the energy required for heating and cooling buildings. The heat storage capacity of concrete can be increased by incorporating phase change materials (PCMs) into the concrete and hence providing additional latent heat storage capacity. Research was carried out to compare the thermal behaviour of two different types of PCM/concrete composite panels. The first type of panel was formed by adding microencapsulated paraffin to …

Control-Oriented Modeling, Validation, And Analysis Of A Natural Gas Engine Architecture, Chaitanya Panuganti

Open Access Theses

In order to improve performance and meet increasingly tight emissions regulations, engine manufacturers must improve algorithms used to control the engine. One possible strategy is to utilize centralized control algorithms that take into account the coupled interactions between inputs and outputs. Implementing a centralized control strategy often requires some kind of dynamic model of the system, which is a primary motivation for modeling efforts in this thesis. In a methodical fashion, this thesis derives a control model for a natural gas engine architecture and validates this control model against reference data in simulation. Additionally, this thesis performs control-oriented analysis on …

Analysis Of Feedback Control Applied With Command Shaping To Minimize Residual Vibration, Nicholas L. Jacobs

Open Access Theses

Joint flexibility is a physical trait that affects all robotic systems to some degree. This characteristic has been shown to be very detrimental to the performance of these robotic systems when implementing fast point-to-point motion. During such motion, the robot will induce vibrations in its structure that will extend past the completion of the move. Many techniques have been applied over the years in order to minimize these residual vibrations. One such method is known as command shaping, which will construct the input profile so as to avoid exciting the natural frequencies of the system. This work seeks to extend …

Enzymatic Liquefaction Of Untreated Corn Stover, Neal N. Hengge

Open Access Theses

There is an ever increasing need for renewable alternatives to fossil fuels derived from petroleum. This makes feedstocks in the form of lignocellulosic biomass attractive substrates for the production of ethanol and value added chemicals. However, the economics of converting lignocellulosic materials involve high processing costs attributed with pretreatment of the biomass and the use of enzymes for saccharification. Corn stover was obtained for the examination of an upstream processing step to transform the material into a pumpable slurry for subsequent pretreatment and saccharification. Biomass liquefaction was carried out using the enzyme Depol 692L (Biocatalysts, Wales, UK) at 50°C with …

Simulation Of Flow And Water Quality From Tile Drains At The Watershed And Field Scale, Colleen Moloney

Open Access Theses

Simulation models such as the Soil and Water Assessment Tool (SWAT) have become widely used in determining the water quality impacts of various management practices. Ensuring that the algorithms accurately represent the processes simulated has become an important goal. Tile drainage is a standard practice in the Midwest, US in order to reduce risk of yield loss due to excess water. Multiple tile drainage and water table algorithms have been available in the SWAT model between the initial SWAT release and revision 638 used in this study. Testing of those algorithms is often limited. Furthermore, algorithms in the current version …

Phase Field Damage Simulations Of Debonding Between Matrix And Spherical Inclusions, Johanna B. Palsdottir

Open Access Theses

Polymer-bonded explosives (PBX) are complicated composites, and it is important for practical applications to know how they deform and fracture. PBX consists of large volume fraction of energetic particles and experiments show that the interface is a critical region for structural stability since particles are often weakly bonded to the polymer and cracks initiate there and the composite fractures. This study focuses on the interface between a particle and a binder and how the particle inclusion starts to debond from the polymer binder in compressive and tensile loading.

A phase field damage model is used to model the response of …

Development Of A Novel Polymer-Garnet Solid State Composite Electrolyte Incorporating Li-La-Zr-Bi-O And Polyethylene Oxide, Muhammed Ramazan Oduncu

Open Access Theses

Current lithium ion batteries are comprised of organic liquid electrolytes - a mixture of lithium salts and binary solvents such as ethylene carbonate (EC) and dimethyl carbonate (DMC). The main drawbacks of this liquid mixture related to safety are flammability of the organic solvents and chemical instability with the electrode materials. To date, various ceramic and polymer materials have been considered which overcome safety issues. However, a common problem of these solid state materials is that they are not able to provide high ionic conductivity at ambient temperatures. Garnet-type cubic Li7La 3Zr2O12 ceramic material has attracted much interest because of …

Cyclic Tensile Response Of A Polyurethane Material, Yizhou Nie

Open Access Theses

Polyurethane is one of the most widely used polymer materials in the world. With the increasing demand of polyurethane, its mechanical behaviors are particularly of interest. In particular, the response of the material under a quasi-static loading being subject to an impact load. To delineate the effect of rate change on the mechanical response of polyurethane, a tensile experiment was designed where the specimen is initially subjected to quasi-static tensile loading and then to high-rate cyclic tension within the same experiment. Constant strain-rate experiments at both quasi-static and high strain rates are also conducted. The analysis of the results leads …

Advanced Hydraulic Systems For Next Generation Of Skid Steer Loaders, Mrudula Uday Orpe

Open Access Theses

Fluid power systems have been extensively used in off highway applications like skid steer loaders, wheel loaders, excavators since many years. Work has been done by both industry and academia to improve efficiency, reduce noise and leakages in these systems. With increasing competition in the market, importance is now also given to operator comfort and machine productivity in off highway applications.

Mobile, off – highway vehicles like Skid-steer loaders are widely used in labour saving applications like loading earth into a truck, dig and move material on construction sites to, clean roads, clear snow from roads etc. To carry out …

Analyzing The Opinion Of Industry Professionals On Model-Based Definition Datasets To Determine The Most Efficient Method, Shawn P. Ruemler

Open Access Theses

Model-based definition (MBD) has the engineering and manufacturing industries moving towards a model-based enterprise (MBE) where traditional two-dimensional (2D) drawings may one day no longer be needed. With MBD, the product data will be contained in the three-dimensional (3D) computer aided design (CAD) model itself. MBD provides a wealth of benefits to users, including reduced time-to-market, product quality, and task efficiency. Even with all the benefits of MBD, there is still no best practice when it comes to implementing MBD. Different strategies of MBD datasets exist, however none have been compared to see which method is more efficient. This project …

Exploratory Study Of Students' Representational Fluency And Competence Of Electric Circuits, William Fernando Sandchez Cossio

Open Access Theses

Electric circuits are extensively used in today’s devices as computers, phones, cameras and others. This makes them a crucial topic in engineering because almost every engineering branch could be related of used them at different levels. Even though their importance, students often struggle during the learning process of circuit analysis topics. Additionally, other very important abilities for engineering students are the capacities to create, use, express and think about models and representations of technical concepts; and the capacities to translate and map from one representation to another. These abilities are known as representational competence and representational fluency respectively.

The purpose …

Solution Based Processing Of Garnet Type Oxides For Optimized Lithium-Ion Transport, Derek K. W. Schwanz

Open Access Theses

Current lithium based portable electrochemical storage devices are limited by the inherent instability and volatility of conventional electrolytes materials. Ceramic materials show much promise for use in advanced lithium based battery systems due to their inhibition of dendritic growth and high thermal and chemical stability. The main drawback of solid materials is their low ionic conductivity, relying on lattice hopping to transport ions between electrodes during cycling. Garnet type oxides, specifically of the base compositions Li7La3Zr2O12 and Li5L a3Bi2O12 have been synthesized through Pechini method solution based processing by the dissolution of reagent salts into nitric acid and creation of …

Polymerizable Lipids For Controlled Functionalization Of Layered Materials, Kortney Kaye Rupp

Open Access Theses

Self-assembled monolayers (SAM’s) offer a straightforward approach to tailoring the interfacial properties of metals, metal oxides and semiconductors. Noncovalent functionalization of single-layer graphene offers the possibility to finely tune surface chemistry for future applications in electronics. Polymerization of photochemically reactive molecules in a lying-down phase has been used to increase the strength of intermolecular interactions between long alkanes and HOPG substrates. Long-chain fatty acid derivatives with internal diyne groups yield a conjugated ene-yne polymer upon UV irradiation. Diyne lipids with phosphocholine (diyne PC) and phosphoethanolamine (diyne PE) groups offer a charged form of the head group that is robust towards …

Applications Of The Homotopy Analysis Method To Optimal Control Problems, Shubham Singh

Open Access Theses

Traditionally, trajectory optimization for aerospace applications has been performed using either direct or indirect methods. Indirect methods produce highly accurate solutions but suer from a small convergence region, requiring initial guesses close to the optimal solution. In past two decades, a new series of analytical approximation methods have been used for solving systems of dierential equations and boundary value problems.

The Homotopy Analysis Method (HAM) is one such method which has been used to solve typical boundary value problems in nance, science, and engineering. In this investigation, a methodology is created to solve indirect trajectory optimization problems using the Homotopy …

High-Throughput Mechanical Characterization Methods For Composite Electrodes And In-Situ Analysis Of Li-Ion Batteries, Luize Scalco De Vasconcelos

Open Access Theses

Electrodes in commercial rechargeable batteries are microscopically heterogeneous materials. The constituents often have large variation in their mechanical properties, making the characterization process a challenging task. In addition, the mechanical properties and mechanical behaviors of electrodes are closely coupled with the electrochemical processes of lithium insertion and extraction. There is an urgent need to develop an experimental platform to characterize the chemomechanical response of electrodes under the in-situ conditions of charge and discharge.

In the first part of this thesis, instrumented grid indentation is employed to determine the elastic modulus and hardness of the constituent phases of a composite cathode. …

Numerical Methods For Low-Thrust Trajectory Optimization, Robert E. Pritchett

Open Access Theses

The spacecraft trajectory design process frequently includes the optimization of a quantity of importance such as propellant consumption or time of flight. A variety of methods for trajectory optimization are available, however the efficiency of an approach is dependent on the problem scenario it is applied to. Indirect and direct trajectory optimization methods are examined in this investigation with the goal of assessing the characteristics of each approach, and thereby determining the problem scenarios each is best suited for. Insight is gained from application of each optimization method to three sample problems; a circular-to-circular orbit transfer as well as two …