Engineering Commons^™

An Integrated Framework For Cardiac Sounds Diagnosis, Zichun Tong

Masters Theses

The Phonocardiogram (PCG) signal contains valuable information about the cardiac condition and is a useful tool in recognizing dysfunction and heart failure. By analyzing the PCG, early detection and diagnosis of heart diseases can be accomplished since many pathological conditions of the cardiovascular system cause murmurs or abnormal heart sounds. This thesis presents an algorithm to classify normal and abnormal heart sound signals using PCG. The proposed analysis is based on a framework composed of several statistical signal analysis techniques such as wavelet based de-noising, energy-based segmentation, Hilbert-Huang transform based feature extraction, and Support Vector Machine based classification. The MATLAB …

Design And Control Of A Bidirectional Dual Active Bridge Dc-Dc Converter To Interface Solar, Battery Storage, And Grid-Tied Inverters, Kenny George

Electrical Engineering Undergraduate Honors Theses

In order to further reduce the size of today’s power converters, wide bandgap semiconductor technologies are being explored. These devices, such as silicon carbide (SiC), have been shown to outperform their silicon counterparts when used in high frequency switching, high temperature, and high voltage applications. These properties make them highly desirable in the bidirectional dual active bridge power converter. Being an isolated converter topology, the dual active bridge employs a transformer to provide step-up/step-down functionality and galvanic isolation for the converter. Transformers, as well as other passive components such as inductors and capacitors may be reduced in size when higher …

Modeling The Feasibility Of Corn Stover Combustion As A Heat Source At Corn Ethanol Plants, Sulekha Tamvada

Theses and Dissertations

Alternative energy sources are of prime interest for most of the nations across the world. Rising fuel prices and depleting petroleum reserves are of serious national and global concern. Bio-fuels if proved feasible for larger scale implementation could become the ideal breakthrough in easing the extensive dependence on fossil fuels and retaining the current engine technology of fossil fuels. Current methods of producing bio-fuels rely heavily on the consumption of non-renewable energy in the production process. Therefore, it is desirable to find renewable alternatives to these non-renewable energy sources.

Although bio-mass based fuels have been tested and proven to be …

Experimental Evaluation Of Beneficial Use Of Lake Michigan Dredged Materials In Flyash Based Geopolymer Concrete, Sara Dashti

Theses and Dissertations

Dredging harbors and rivers are necessary to maintain the appropriate water depth for navigation. However the disposal facilities for storing dredged materials around the U.S. Great Lakes are at or near their capacities and finding beneficial uses for these materials is a major concern. On the other hand, carbon emission and global warming have become the greatest environmental issues during the last decade. Cement manufacturing is a major contributor to CO2 release into the atmosphere. The objective of this study was to develop a low-cost, environment-friendly geopolymer concrete paste with dredged materials as a substantial mix ingredient. Geopolymer concrete does …

When 1 + 1 > 2: Nanostructured Composites For Hard Tissue Engineering Applications, Vuk Uskoković

Pharmacy Faculty Articles and Research

Multicomponent, synergistic and multifunctional nanostructures have taken over the spotlight in the realm of biomedical nanotechnologies. The most prospective materials for bone regeneration today are almost exclusively composites comprising two or more components that compensate for the shortcomings of each one of them alone. This is quite natural in view of the fact that all hard tissues in the human body, except perhaps the tooth enamel, are composite nanostructures. This review article highlights some of the most prospective breakthroughs made in this research direction, with the hard tissues in main focus being those comprising bone, tooth cementum, dentin and enamel. …

College Football Rankings: Maximum Flow Model, Jaymin Patel

Industrial Engineering Undergraduate Honors Theses

College football is a very popular sport in the United States. There is much debate over the college football rankings every week. A maximum flow network is implemented into the CMS+ rankings to observe the effects it has on the college football rankings.

Evaluation Of Conservation Practices Through Simulation Modeling And Tool Development, Gurdeep Singh

Graduate Theses and Dissertations

For the first objective, predicted impacts of selected Mississippi River Basin Initiative (MRBI) conservation practices (CPs) on sediment and nutrient loss were assessed. The study area was L’Anguille River Watershed (LRW), a priority focus watershed of the MRBI program and the simulated CPs were filter strip, critical area planting, grade stabilization structure, irrigation land leveling, irrigation pipeline, irrigation water management, and nutrient management. The Soil and Water Assessment Tool (SWAT) model was calibrated (1998 – 2005) and validated (2006 – 2012) for flow, sediment, total phosphorus (TP), and nitrate-nitrogen (NO3-N) at the Colt site (503 sq. km. drainage area) and …

Field And Laboratory Study Of The Flàajökull Glacier, Iceland, William Russell Jacobson, Jr.

Theses and Dissertations

The increased surface melting of the outlet glaciers of the Vatnajökull Ice Cap has a profound affect on the dynamics of the ice-bed couple and landform genesis. Soft-bedded glaciers are largely inaccessible, which creates a problem. One challenge is to understand the complex interactions of the glacier bed and its resultant depositional and deformational landform systems. This study investigates an outlet glacier from the Vatnajökull Ice Cap, described herein as the Fláajökull glacier system. To circumvent some of these problems, three separate projects were conducted in this dissertation: (1) magnetic fabric study of effective pressure (difference between the ice-overburden pressure …

A Platform For Fast Detection Of Let-7 Micro Rna Using Polyaniline Fluorescence And Image Analysis Techniques, Partha P. Sengupta

Master's Theses

The project describes a new strategy for transducing hybridization events through modulating intrinsic properties of the electroconductive polymer polyaniline (PANI). When DNA based probes electrostatically interact with PANI, its fluorescence properties are increased, a phenomenon that can be enhanced by UV irradiation. Hybridization of target nucleic acids results in dissociation of probes causing PANI fluorescence to return to basal levels. By monitoring restoration of base PANI fluorescence as little as 10^-11 M (10 pM) of target oligonucleotides could be detected within 15 minutes of hybridization. Detection of complementary oligos was specific, with introduction of a single mismatch failing to …

Development Of A Semicircular Bend (Scb) Test Method For Performance Testing Of Nebraska Asphalt Mixtures, Gabriel Nsengiyumva, Yong-Rak Kim, Taesun You

Nebraska Department of Transportation: Research Reports

No abstract provided.

Mitigating Pavement Edge Drop Off, Wayne Jensen, Niles Uerling

Nebraska Department of Transportation: Research Reports

The objective of this research was to investigate and document practices currently being used by the Nebraska Department of Roads (NDOR) districts and other State DOTs to mitigate pavement edge drop off. The NDOR has developed (or borrowed) and is currently incorporating into its standard practices several procedures that significantly decrease the incidence and magnitude of pavement edge-drop off. As these practices become more fully integrated into highway reconstruction projects, pavement edge drop off is expected to decrease dramatically. Localized areas of pavement edge drop off along paved lanes with bare or vegetated shoulders were noted as posing particular problems …

Feasibility Of Using Raman-Based Techniques For Breast Cancer Detection, Sara Mollamohammada

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Breast cancer is one of the common types of cancer among women all over the world. Early diagnosis is an effective way that improve the treatment process and gives the patients a better chance of survival. Many of the patients infected by breast cancer choose breast conservation surgery (BCS). However, some of those will be subjected to mastectomy, and many will have tumor recurrence as there is no precise technique to show the tumor margins. Raman-based methods are powerful techniques with potential to rapidly differentiate normal from tumor tissues and provides a solution to detect tumor margin. This is because …

Solar Powered Picnic Table For Charging Cellphones And Other Small Devices, Casey B. Potts

Electronic Theses and Dissertations

Solar panels are used in many different applications for generating sustainable energy. Many countries use solar power as a power generation method. It is also, an excellent option for getting power to difficult areas. There are three main systems used when generating solar power: grid-tied, battery banked, and direct driven systems. Most systems use a combination of grid-tied and battery banked so any unused power can be fed back into the main grid for compensation. The solar power application suggested in this thesis will provide USB power to a picnic table enabling students to charge cellphones and other small devices …

Using Basic Quality Tools To Improve Production Yields And Product Quality In Manufacturing, Steve E. Black

Electronic Theses and Dissertations

As the U.S. and world economies emerge from years of recession, the hardwood flooring market is currently enjoying strong growth. With this growth come new challenges for hardwood flooring manufacturers. Strong competition from foreign markets and rising log prices are reducing product margins and forcing companies to think lean, while improving product quality.

QEP Wood Flooring division, who struggled through the worst of the U.S. economic down turn is now regaining ground as a strong competitor in the hardwood flooring market. This turnaround is due to internal changes to decrease waste and increase product quality. This is accomplished by using …

Construction Of An Initiated Chemical Vapor Deposition (Icvd) Reactor And Deposition Of Polytetrafluoroethylene (Ptfe) Thin Films Using Perfluoro-1-Octanesulfonyl Fluoride As The Initiator, Edgar Kiprop Kosgey

MSU Graduate Theses

Initiated Chemical Vapor Deposition (iCVD) is a surface polymerization technique that is different from other traditional chemical vapor deposition (CVD) techniques. iCVD is carried under a vacuum without the use of solvents, therefore eliminating contaminations. An initiator and a monomer are metered into a vacuum reactor chamber. Inside the reaction chamber is an array of resistively heated filaments and a cooled substrate stage. Monomer species adsorb on to the cooled substrate surface underneath the filament array. The thermal energy from the resistively heated filaments breaks the bonds in the initiator molecule, generating free radicals. These generated free radicals chemisorb to …

Low-Velocity Impact Analysis Of Composite Repair Patches Of Different Shapes, Sarvesh Baliga

Doctoral Dissertations and Master's Theses

The area under crack for various structures can be effectively repaired by the use of composite materials. Low velocity impact can cause barely visible damage to the interior structure of laminated composite. These impacts can cause delamination in composite materials. In this study, a Finite Element Analysis was conducted using Abaqus/Explicit and the results of the analysis were compared to the experimental data from literature. E-glass/epoxy composite laminate was subjected to a low velocity impact test. To study the effect of patch repair, a composite patch was applied on a cracked laminate and a low velocity impact was then conducted …

Lagrangian Points And Jacobi Constants For A Class Of Asteroids, Tasneem Rashid

Doctoral Dissertations and Master's Theses

Asteroid Gravitational Potentials are difficult to model owing to their irregularity in shape. This thesis focuses on two approaches to model asteroid gravity fields, namely, multiple-body and spherical harmonics modeling. Computation of gravity potential serves as a first step to determine equilibrium points called Lagrangian points for a spacecraft orbiting as an asteroid. Further, Jacobi analysis is carried out to determine zero-velocity regions, i.e., inaccessible regions corresponding to the unstable Lagrangian points. Multiple sphere modeling was studied through analysis of so called Asteroid Restricted Three and Four Body Problems, providing insight into the method of modeling an asteroid as a …

Aerodynamic Trade Study Of Compound Helicopter Concepts, Julian Roche

Doctoral Dissertations and Master's Theses

The relative performance attributes of compound helicopter concepts have been examined, including their potential for meeting the requirements of several challenging mission profiles. For each concept, which included lift and/or propulsive compounding, a suite of aerodynamic performance models was developed using energy methods. In the case of a lift-compounded concept, an aerodynamic model representing the force interaction effects of the main rotor wake with the wing was also developed. Models of a conventional helicopter and of a tiltrotor were implemented as well, and the results used as a datum for comparison. In each case, the predictive capabilities of the model …

Computation Of Hypersonic Flows With Lateral Jets Using K-Ω Turbulence Model, Spatika Dasharati Iyengar

Doctoral Dissertations and Master's Theses

Thermal Protection systems (TPS) are used as shields in space vehicles which encounter high heat and temperatures at the reentry altitudes. Among them, the cooling techniques and the ablative coatings are most popular. However, they have their own weight limitations. In the recent decade, another classification of TPS called the Non-Ablative Thermal Protection systems (NaTPS) have gained significance. The spike-lateral jet method is an NaTPS concept proposed for drag and heat flux reduction in hypersonic nose cones. Numerical simulations are conducted to analyze the effectiveness of spike-lateral jet concept at re-entry altitudes. The spike attached to the hemispherical nose has …

The Three-Dimensional Turbulent Boundary Layer On A Rotating Disk, Daniel Digre

Doctoral Dissertations and Master's Theses

Three-dimensional turbulent boundary layers (3DTBL) are seen quite commonly in nature as well as in the engineering applications. Despite this, very few high Reynolds number studies have been carried out on these boundary layers, particularly focusing on eddy structure, eddy scales and their interactions. The current study focused on developing, characterizing and evaluating an experimental framework to study high Reynolds number #3DTBL on a rotating disk with the long-term goal of carrying out high-fidelity measurements. The rotating disk flow is characterized by weak centrifugal pumping which sets up the cross flow that leads to turbulence. The tangential and radial velocities …

Design And Development Of A Wearable Wireless Health Monitoring System: A Smart Watch Approach, Keerthi Paranikumar

Graduate Theses and Dissertations

According to Statistics, every year, about 610,000 people die because of heart disease in United States of America. (i.e. 1 in every 4 deaths.*) Heart disease is common for both men and women. Annually, about 370,000 people die because of coronary heart disease, which is the most common type of heart disease [1]. About 735,000 Americans have heart attack every year. In this, 210,000 people gets heart attack who already has heart problems and 525,000 people get heart attack for the first time [2]. Not many people know that they have heart problems. Around 47% of the people in United …

Epitaxial Growth Of Si-Ge-Sn Alloys For Optoelectronic Device Application, Aboozar Mosleh

Graduate Theses and Dissertations

Microelectronics industry has experienced a tremendous change over the last few decades and has shown that Moore’s law has been followed by doubling the number of transistors on the chip every 18 months. However, continuous scaling down of the transistors size is reaching the physical limits and data transfer through metal interconnects will not be able to catch up with the increasing data processing speed in the future. Therefore, optical data transfer between chips and on-chip has been widely investigated. Silicon based optoelectronics has received phenomenal attention since Si has been the core material on which microelectronic industry has been …

Faster Maximium Priority Matchings In Bipartite Graphs, Jonathan Turner

All Computer Science and Engineering Research

A maximum priority matching is a matching in an undirected graph that maximizes a priority score defined with respect to given vertex priorities. An earlier paper showed how to find maximum priority matchings in unweighted graphs. This paper describes an algorithm for bipartite graphs that is faster when the number of distinct priority classes is limited. For graphs with k distinct priority classes it runs in O(kmn1/2) time, where n is the number of vertices in the graph and m is the number of edges.

Microstructure Alone Induced Wetting Transition From Hydrophilic To Hydrophobic On Silicon And Graphene, Henry L. Ems

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

In the present work, transition from hydrophilic to hydrophobic wetting states for an intrinsically hydrophilic surface (contact angle less than 45 degrees) using only surface microstructuring is presented. The surface microstructures are re-entrant microcavities (inverted trapezoidal microstructures) which promote air entrapment below the water droplet causing a Cassie wetting state as opposed to a Wenzel state where the surface is completely wetted. The microstructures were fabricated on a Silicon-On-Insulator (SOI) wafer through steps of deposition, photolithography, etching, and bonding. Contact angle measurements demonstrated the ability of the microfabricated surfaces to sustain large contact angles above 100°, in comparison to a …

Experimental Investigation And Thermal Modeling On Electro Discharge Drilling Of Pcd, Farnaz Nourbakhsh

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This study presents an experimental investigation and finite element simulation of Electro Discharge Drilling (ED-Drilling) of Polycrystalline Diamond (PCD). PCD has many outstanding properties including uniformly high hardness, high wear resistance and strong corrosion which are the main causes of widely using PCD. While PCD has many advantages and an important role in industrial applications, its high level of hardness and wear resistance cause this material to be difficult to form and machine by using traditional machining methods. EDM as a nontraditional machining process is an effective method among other non-traditional methods for PCDs due to its low cost and …

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Reverberation time (RT) is a metric commonly used to describe room acoustic conditions, but different rooms which have the same reverberation time can have different reflection densities. Much less is known about how humans perceive different reflection densities and how sensitive humans are to changes in reflection density. Previous investigations in the existing literature have studied the upper limit of distinguishable reflection density using artificial impulse responses, but not with more realistic impulse responses simulated in room acoustic software or measured from real rooms. The aim of this dissertation is to investigate methods for quantifying reflection density from measured impulse …

Methodology For Selecting The Column Configuration With Lowest Media Replacement Cost For Small Adsorption Systems, Artem Bausk

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The relative performance of three column configurations often used for adsorption systems serving small communities was evaluated in terms of which results in the lowest overall replacement cost. Replacement cost is the cost of fresh media and the transportation, labor, and material costs to replace the media. Both the adsorption capacity and the media replacement costs were modeled. The pore and surface diffusion model was utilized to simulate the fixed-bed adsorption and obtain the breakthrough curves, which were then normalized using the target effluent to influent concentration ratio (C/C_o) and the mass transfer zone fraction (%MTZ_BT). …

Viscoelastic, Fatigue Damage, And Permanent Deformation Characterization Of High Rap Bituminous Mixtures Using Fine Aggregate Matrix (Fam), Hesamaddin Nabizadeh

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Performance characteristics of bituminous mixtures play the most influential role in designing flexible pavement. These asphaltic mixtures can be considered as heterogeneous mixtures which composed of two primary components: fine aggregate matrix (FAM) phase and aggregate phase. The FAM phase acts as a critical phase in evaluating the performance characteristics including viscoelastic, fatigue damage, and permanent deformation characteristics of entire asphalt mixtures. This study evaluates the viscoelastic, fatigue damage and permanent deformation characteristics of bituminous mixtures containing 65% reclaimed asphalt pavement (RAP) by performing oscillatory torsional shear tests of cylindrical bars of FAM using a dynamic mechanical analyzer. Moreover, this …

Phase I Evaluation Of Selected Concrete Material Models In Ls-Dyna, Bradley J. Winkelbauer

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Numerous roadside safety systems are configured with reinforced concrete materials, such as bridge railings, median barriers, and roadside parapets. These protective barrier systems are intended to safely contain and redirect errant vehicles as well as prevent impacts into hazardous fixed objects or other geometric features. The analysis and design of these structures may involve impact simulation with finite element software, like LS-DYNA, which includes multiple concrete material models. For such investigations, limited guidance is available for selecting preferred concrete material models and determining appropriate values for specific parameters. This Phase I study investigated the viability and performance of existing concrete …

Transforming C Openmp Programs For Verification In Civl, Michael Rogers

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

There are numerous way to express parallelism which can make it challenging for developers to verify these programs. Many tools only target a single dialect but the Concurrency Intermediate Verification Language (CIVL) targets MPI, Pthreads, and CUDA. CIVL provides a general concurrency model that can represent pro- grams in a variety of concurrency dialects. CIVL includes a front-end that support all of the dialects mentioned above. The back-end is a verifier that uses model checking and symbolic execution to check standard properties.

In this thesis, we have designed and implemented a transformer that will take C OpenMP programs and transform …