Engineering Commons^™

Stress Shielding Minimized In Femoral Hip Implants A Finite Element Model Optimized By Virtual Compatibility, Christian E. Feldt

Electronic Theses and Dissertations

Bone mechanics and traditional implant materials produce a recurring problem for patients of total hip arthroplasty (THA): the bone is “shielded” from the loading it has become accustomed to over many years of development. Bone adheres to what is called “Wolff’s Law”, meaning it is an adaptive structure which adjusts its geometry based on the loads experienced over its life (Pearson; Goldstein). As the new femoral hip implant transmits reduced stresses to the remaining bone, bone tissue atrophies at the interface, permitting loosening of the implant, pain, and thereby obliging additional surgery to correct the issue (Meade). In the present …

A Multiscale Model Of The Neonatal Circulatory System Following Hybrid Norwood Palliation, Andres Ceballos

Electronic Theses and Dissertations

Hypoplastic left heat syndrome (HLHS) is a complex cardiac malformation in neonates suffering from congenital heart disease and occurs in nearly 1 per 5000 births. HLHS is uniformly fatal within the first hours or days after birth as the severly malformed anatomies of the left ventricle, mitral, and aortic valves, and ascending aorta are not compatable with life. The regularly implemented treatment, the Norwood operation, is a complex open heart procedure that attempts to establish univenticular circulation by removing the atrial septum ( communicating the right and left ventricle), reconstructing the malformed aortic arch, and connecting the main pulmonary artery …

The Power Of Quantum Walk Insights, Implementation, And Applications, Chen Fu Chiang

Electronic Theses and Dissertations

In this thesis, I investigate quantum walks in quantum computing from three aspects: the insights, the implementation, and the applications. Quantum walks are the quantum analogue of classical random walks. For the insights of quantum walks, I list and explain the required components for quantizing a classical random walk into a quantum walk. The components are, for instance, Markov chains, quantum phase estimation, and quantum spectrum theorem. I then demonstrate how the product of two reflections in the walk operator provides a quadratic speed-up, in comparison to the classical counterpart. For the implementation of quantum walks, I show the construction …

Evolution Of Microstructure And Residual Stress In Disc-Shape Eb-Pvd Thermal Barrier Coatings And Temperature Profile Of High Pressure Turbine Blade, Sriparna Mukherjee

Electronic Theses and Dissertations

A detailed understanding of failure mechanisms in thermal barrier coatings (TBCs) can help develop reliable and durable TBCs for advanced gas turbine engines. One of the characteristics of failure in electron beam physical vapor deposited (EB-PVD) TBCs is the development of instability, named rumpling, at the interface between (Ni, Pt)Al bond coat and thermally grown oxide (TGO). In this study, thermal cycling at 1100°C with 1 hr dwell time was carried out on 25.4mm disc specimens of TBCs that consisted of EB-PVD coated ZrO2-7wt. %Y2O3, (Pt,Ni)Al bond coat, and CMSX-4 Ni-based superalloy. At specific fraction of lifetime, TBCs were examined …

Multi-Touch For General-Purpose Computing An Examination Of Text Entry, Paul David Varcholik

Electronic Theses and Dissertations

In recent years, multi-touch has been heralded as a revolution in humancomputer interaction. Multi-touch provides features such as gestural interaction, tangible interfaces, pen-based computing, and interface customization – features embraced by an increasingly tech-savvy public. However, multi-touch platforms have not been adopted as "everyday" computer interaction devices; that is, multi-touch has not been applied to general-purpose computing. The questions this thesis seeks to address are: Will the general public adopt these systems as their chief interaction paradigm? Can multi-touch provide such a compelling platform that it displaces the desktop mouse and keyboard? Is multi-touch truly the next revolution in human-computer …

Effect Of Neutron Radiation On The Mechanical Properties Of B4c, Zichao Xia

Electronic Theses and Dissertations

B4C is an important engineering ceramic used in a number of different applications. One of the promising applications of B4C is in the nuclear industry. B4C has a high neutron absorption cross-section (600 barns) and that is why it can absorb neutrons without forming long lived radio nuclides. As a result, B4C is extensively used as control rods, shielding material and as neutron detectors in nuclear reactors. During the reactor’s operation, the B4C undergoes severe neutron radiation and defects, such as vacancies and helium bubbles, are generated in the structure. These defects are responsible for the degradation of mechanical performance …

Mass Conservation Analysis For The Lower St. Johns River Using Continuous And Discontinuous Galerkin Finite Element Methods, Lillie E. Thomas

Electronic Theses and Dissertations

This thesis provides a mass conservation analysis of the Lower St. Johns River for the purpose of providing basis for future salinity transport modeling. The analysis provides an assessment of the continuous (CG) and discontinuous (DG) Galerkin finite element methods with respect to their mass conservation properties. The following thesis also presents a rigorous literature review pertaining to salinity transport in the Lower St. Johns River, from which this effort generates the data used to initialize and validate numerical simulations. Two research questions are posed and studied in this thesis: can a DG-based modeling approach produce mass conservative numerical solutions; …

Electimize A New Evolutionary Algorithm For Optimization With Applications In Construction Engineering, Raheem, Mohamed Abdel

Electronic Theses and Dissertations

Optimization is considered an essential step in reinforcing the efficiency of performance and economic feasibility of construction projects. In the past few decades, evolutionary algorithms (EAs) have been widely utilized to solve various types of construction-related optimization problems due to their efficiency in finding good solutions in relatively short time periods. However, in many cases, these existing evolutionary algorithms failed to identify the optimal solution to several optimization problems. As such, it is deemed necessary to develop new approaches in order to help identify better-quality solutions. This doctoral research presents the development of a new evolutionary algorithm, named “Electimize,” that …

Development Of A Weigh-In-Motion System Using Acoustic Emission Sensors, Jeanne M. Bowie

Electronic Theses and Dissertations

This dissertation proposes a system for weighing commercial vehicles in motion using acoustic emission sensors attached to a metal bar placed across the roadway. The signal from the sensors is analyzed by a computer and the vehicle weight is determined by a statistical model which correlates the acoustic emission parameters to the vehicle weight. Such a system would be portable and low-cost, allowing for the measurement of vehicle weights in much the same way commercial tube and radar counters routinely collect vehicle speed and count. The system could be used to collect vehicle speed and count data as well as …

Global Secure Sets Of Trees And Grid-Like Graphs, Yiu Yu Ho

Electronic Theses and Dissertations

Let G = (V, E) be a graph and let S ⊆ V be a subset of vertices. The set S is a defensive alliance if for all x ∈ S, |N[x] ∩ S| ≥ |N[x] − S|. The concept of defensive alliances was introduced in [KHH04], primarily for the modeling of nations in times of war, where allied nations are in mutual agreement to join forces if any one of them is attacked. For a vertex x in a defensive alliance, the number of neighbors of x inside the alliance, plus the vertex x, is at least the number …

Vision Based Trajectory Tracking Of Space Debris In Close Proximity Via Integrated Estimation And Control, Ni Li

Electronic Theses and Dissertations

Since the launch of the first rocket by the scientists during the World War II , mankind continues their exploration of space. Those space explorations bring the benefits to human, such as high technology products like GPS, cell phone, etc. and in-depth insight of outside of the earth. However, they produce millions of debris with a total estimated mass of more than 3,000,000 kg in the space around the earth, which has and will continue to threat the safety of manned or unmanned space exploration. According to the research, at least tens of spacecraft were considered been damaged or destroyed …

Ultra-High Performance Fiber Reinforced Concrete In Bridge Deck Applications, Jun Xia

Electronic Theses and Dissertations

The research presented in this dissertation focuses on the material characterization of ultrahigh performance fiber reinforced concrete (UHP-FRC) at both the microscopic and macroscopic scales. The macroscopic mechanical properties of this material are highly related to the orientation of the steel fibers distributed within the matrix. However, the fiber orientation distribution has been confirmed to be anisotropic based on the flow-casting process. The orientation factor and probability density function (PDF) of the crossing fiber (fibers crossing a cutting plane) orientation was obtained based on theoretical derivations and numerical simulations with respect to different levels of anisotropy and cut planes oriented …

Process-Dependent Microstructure And Severe Plastic Deformation In Sicp?? Reinforced Aluminum Metal Matrix Composites, Catalina Uribe-Restrepo

Electronic Theses and Dissertations

Discontinuously reinforced MMCs with optimized microstructure are sought after for exceptional high strain rate behavior. The microstructure evolution of a stir-cast A359 aluminum composite reinforced with 30 vol.% SiCp after isothermal anneal, successive hot-rolling, and high strain rate deformation has been investigated. Quantitative microstructural analysis was carried out for the as-cast, annealed (470°C, 538°C and 570°C) and successively hot rolled specimens (64, 75, 88, and 96% rolling reductions). Selected composites were also examined after high strain rate deformation. X-ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy were employed for microstructural characterization. The strength and ductility of the …

Thermomechanical Behavior Of High-Temperature Shape Memory Alloy Ni-Ti-Pd-Pt Actuators, Douglas E. Nicholson

Electronic Theses and Dissertations

To date the commercial use of shape memory alloys (SMAs) has been mostly limited to binary NiTi alloys with transformation temperatures approximately in the -100 to 100 ºC range. In an ongoing effort to develop high-temperature shape memory alloys (HTSMAs), ternary and quaternary additions are being made to binary NiTi to form NiTi-X (e.g., X: Pd, Pt, Au and Hf) alloys. Stability and repeatability can be further increased at these higher temperatures by limiting the stress, but the tradeoff is reduced work output and stroke. However, HTSMAs operating at decreased stresses can still be used effectively in actuator applications that …

Advancing The Use Of Bim Through A Government Funded Construction Industry Competency Centre In Ireland, Alan V. Hore, Ken Thomas

Conference papers

The main aim of this paper is to develop the early case for a new Competence Centre dedicated to industry led research in the Irish construction industry. It incorporates the results of a survey carried out by the Construction IT Aliance (CITA) and also identifies similiar centres carrying out industry led research around the world. Results from the survey show a clear support for the establishment of such a centre in Ireland and, in particular, a strong interest in Building Information Modelling (BIM) as a immediate priority research area. BIM is having a profound effect worldwide on the construction industry. …

What Difference Does It Make?- The Current Role And Potential Impact Social Enterprise Can Play In The Regeneration Of Disadvantaged Communities, Gerard Doyle

Articles

At European level there is no universally accepted definition of what constitutes a social enterprise (GHK, 2006). However, the number of definitions of what constitutes a social enterprise reflects the diverse understanding of what a social enterprise actually is. The Department of Trade and Industry (DTI) (2002) definition is widely used: A social enterprise is a business with primarily social objectives whose surpluses are principally reinvested for that purpose in the business or in the community, rather than being driven by the need to maximise profit for shareholders and owners. Social enterprises share a number of common characteristics: they are …

Morphological Analysis From Images Of Hyphal Growth Using A Fractional Dynamic Model, Jonathan Blackledge, Dan Barry

Books/Book chapters

The development of methods capable of accurately characterising the morphology of filamentous microbes represents a significant challenge to biotechnologists. This is because the productivity of many industrial fermentation processes is heavily dependent on the morphological form adopted by an organism. It is therefore of significant value if a quantitative model and associated metric(s) for morphological forms determined by complex phenotypes can be determined non-invasively, e.g. through image analysis. Specific interest is in the quantification of the branching behaviour of an organism. This is due to the link between branching frequency, biomass and metabolite production. In this paper we present a …

Single Mode Optical Fiber Based Refractive Index Sensor Using Etched Cladding, Ajay Kumar, Geeta Gupta, Arun Mallik, Anuj Bhatnagar

Articles

The use of optical fiber for sensor applications is a topic of current interest. We report the fabrication of etched single mode optical fiber based refractive index sensor. Experiments are performed to determine the etch rate of fiber in buffered hydrofluoric acid, which can be high or low depending upon the temperature at which etching is carried out. Controlled wet etching of fiber cladding is performed using these measurements and etched fiber region is tested for refractive index sensing application. We report significant optical power change in fiber sensor at 1550 nm wavelength, in the presence of IPAsolution and also …

Successful Engineering And Technology Student Mobility: Key Student Perspectives And Quality Determinants Before, During And After Student Exchange Under The Atlantis Programme, Mike Murphy, Donal Mchale, Michael Dyrenfurth, James Barnes

Articles

The EU-US Agreement through the Atlantis Programmes supports consortia of higher education and training institutions working together at undergraduate or graduate level to improve their educational services, to compare and modernise curricula and to develop joint study programmes with full recognition of credits and qualifications. The EU-US Atlantis Programme funds innovative projects across three strands: mobility projects, double or joint “transatlantic degrees” for students in the EU and US and policy-oriented measures. The main focus of activities must be on transatlantic rather than intra-European or intra-American interactions. Funded activities, such as the development of curricula, joint study programmes, exchanges and …

Critical Issues And Lessons Learned In Establishing Concurrent International Ms Degree Programs In Engineering Technology, Mike Murphy, Michael Dyrenfurth, Gary Bertoline, Robert Herrick, Kathryne Newton, Sancho Maria-Ribera, Nuria Castell, James Barnes, Matthias Kuder, Gareth O'Donnell

Articles

Globalization, competitiveness, and innovation are frequently employed themes as governments, business and industry and universities attempt to respond to the challenges facing them. Clearly business as usual is not likely to be successful in the future. One strategic response for universities has been a significant impetus – in many parts of the world – towards dual, joint or concurrent degree programs involving international partners. It is perhaps not surprising that engineering is among the disciplines that make most use of international collaboration but it seems that engineering technology programs do not yet participate as extensively in this aspect of international …

Engineering Graduates: Preparation And Progression: Institutes Of Technology Honours Bachelor Degree Engineering Graduate Study, June, 2011, James Shivnan, Austin Hanley, Mike Murphy

Reports

The national strategy for higher level education underlines the importance of innovation and enterprise; and well qualified engineers are central to furthering that strategy. This honours bachelor degree engineering graduate study represents an intense dialogue between engineering faculties across the Institutes of Technology to gain insight into the quality of our engineering education. The study provides a fresh insight into how NFQ Level 81honours bachelor degree engineering graduates from the Institutes are perceived by employers, how well the graduates themselves feel they are prepared to perform as engineers, and how both employers and graduates judge the strengths and weaknesses of …

Limited Scope Permitting For Time-Sensitive Project Delivery Systems, Wayne Jensen, Bruce Fischer, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Delivery of construction projects in the United States has traditionally been based upon the design-bid-build system. TIlis system has been used to create numerous impressive structures, but it often proves expensive and usually requires considerable time, because design, permitting and construction are accomplished in sequential order and do not overlap. Several alternatives to the traditional system have been developed, many of which fall under the classification of time-sensitive project delivery systems. The most commonly used time-sensitive project delivery systems are phased and fast-track construction (FaZio, Moselhi, Theberge & Revay 1988a). Figure 1 illustrates some of the major differences between traditional …

Durability Performance Of Frp Strenghtened Concrete Beams And Columns Exposed To Hygrothermal Environment, Abulgasem Mohamed Elarbi

Wayne State University Dissertations

ABSTRACT

DURABILITY PERFORMANCE OF FRP STRENGHTENED CONCRETE BEAMS AND COLUMNS EXPOSED TO HYGROTHERMAL ENVIRONMENT

by

ABULGASEM M. ELARBI

August 2011

Advisor: Dr. Hwai-Chaung Wu

Major: Civil and Environmental Engineering (Structural Engineering)

Degree: Doctor of Philosophy

Concrete structures deteriorate over time due to exposure to various environments, including hot and humid weather. High temperature, wind, and air humidity in many hot climates can all have a negative impact on the performance of concrete structures. The most important factors are temperature and humidity - often times these effects are not immediately evident and develop years later - making determination of responsibility difficult …

Dynamic Routing On Stochastic Time-Dependent Networks Using Real-Time Information, Ali R. Guner

Wayne State University Dissertations

In just-in-time (JIT) manufacturing environments, on-time delivery is one of the key performance measures for dispatching and routing of freight vehicles. Both the travel time delay and its variability impact the efficiency of JIT logistics operations, that are becoming more and more common in many industries, and in particular, the automotive industry. In this dissertation, we first propose a framework for dynamic routing of a single vehicle on a stochastic time dependent transportation network using real-time information from Intelligent Transportation Systems (ITS). Then, we consider milk-run deliveries with several pickup and delivery destinations subject to time windows under same network …

Development Of A Biomechanical Surrogate For The Evaluation Of Commotio Cordis Protection, Nathan Dau

Wayne State University Dissertations

Commotio Cordis (CC) has proven to be life threatening for young athletes as it is the second leading cause of mortality in youth sports. In the past 15 years, researchers have been working to understand the pathophysiology of this event. It has been proven that impacts directly over the cardiac silhouette during a vulnerable period of the cardiac cycle can cause CC. In order to reduce the occurrence of CC in sports, chest protectors need to be tested for efficacy. Currently there is no biofidelic surrogate to serve this purpose. In order to test equipment to a given standard of …

Exploring The Potential Of Inkjet Printing For The Fabrication Of Tissue Test Systems, Vidya Seshadri

All Theses

Animal models and two-dimensional assays involved in drug testing, vaccine development and basic scientific discovery are not an accurate representation of the human body; hence there is a need to develop new bench top methodologies which are better suited to yield information about in vivo behavior. There is a paucity of reliable in vitro-derived information regarding the reasons for the cause and progression of diseases. These concerns have lead to the development of three-dimensional systems which can facilitate improved understanding of disease etiology and also can bridge the path to the clinic.
The long term goal, beyond the scope of …

Ethanol Yields And Cell Wall Properties In Divergently Bred Switchgrass Genotypes, Gautam Sarath, Bruce S. Dien, Aaron J. Saathoff, Kenneth P. Vogel, Robert B. Mitchell, Han Chen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Genetic modification of herbaceous plant cell walls to increase biofuels yields is a primary bioenergy research goal. Using two switchgrass populations developed by divergent breeding for ruminant digestibility, the contributions of several wall-related factors to ethanol yields was evaluated. Field grown low lignin plants significantly out yielded high lignin plants for conversion to ethanol by 39.1% and extraction of xylans by 12%. However, across all plants analyzed, greater than 50% of the variation in ethanol yields was attributable to changes in tissue and cell wall architecture, and responses of stem biomass to diluteacid pretreatment. Although lignin levels were lower in …

Investigation Into The Potential Use Of Windbreaks To Improve Solar Collector Performance, Michael Watts

All Graduate Theses, Dissertations, and Other Capstone Projects

The global demand for energy is ever increasing; however, the world has a limited number of fossil fuels available. Therefore, alternative renewable energy sources must be utilized. For this reason, solar thermal collectors have become an increasingly popular method for providing hot water or space heating. However, solar thermal collectors are most commonly used in areas that experience warm climates throughout the year. In areas that experience seasonal climates, the cold temperatures and harsh climate conditions significantly reduce the performance of solar thermal collectors during the winter months. This thesis examined the potential that the implementation of a windbreak could …

Low Noise, Narrow Optical Linewidth Semiconductor-Based Optical Comb Source And Low Noise Rf Signal Generation, Ibrahim Tuna Ozdur

Electronic Theses and Dissertations

Recently optical frequency combs and low noise RF tones are drawing increased attention due to applications in spectroscopy, metrology, arbitrary waveform generation, optical signal processing etc. This thesis focuses on the generation of low noise RF tones and stabilized optical frequency combs. The optical frequency combs are generated by a semiconductor based external cavity mode-locked laser with a high finesse intracavity etalon. In order to get the lowest noise and broadest bandwidth from the mode-locked laser, it is critical to know the free spectral range (FSR) of the etalon precisely. First the etalon FSR is measured by using the modified …

On The Applications Of Deterministic Chaos For Encrypting Data On The Cloud, Jonathan Blackledge, Nikolai Ptitsyn

Conference papers

Cloud computing is expected to grow considerably in the future because it has so many advantages with regard to sale and cost, change management, next generation architectures, choice and agility. However, one of the principal concerns for users of the Cloud is lack of control and above all, data security. This paper considers an approach to encrypting information before it is ‘placed’ on the Cloud where each user has access to their own encryption algorithm, an algorithm that is based on a set of iterated function systems that outputs a chaotic number stream, designed to produce a cryptographically secure cipher. …