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Articles 1 - 21 of 21
Full-Text Articles in Engineering
3-D Numerical Simulation Of Dam-Break Flows Over Movable Beds, Reza Marsooli
3-D Numerical Simulation Of Dam-Break Flows Over Movable Beds, Reza Marsooli
Electronic Theses and Dissertations
Irvin Cooper was a prominent music educator in boys’ adolescent voice change research. Dr. Cooper developed the Cambiata concept as a method for teaching boys to sing throughout the voice change. This method was starkly different from the traditional model that encouraged the changing voice to be rested during the voice change. While working as the music supervisor for the Montreal protestant school system, Cooper developed his method of having boys sing during the voice change, which included arrangements and compositions specifically for changing voices. Cooper taught many prominent researchers of adolescent voice change, including Don Collins and John Cooksey. …
Geotechnical Technique To Strengthen Traditional I-Walls Through The Use Of Composite Material, Jimmy Irby Jackson
Geotechnical Technique To Strengthen Traditional I-Walls Through The Use Of Composite Material, Jimmy Irby Jackson
Electronic Theses and Dissertations
On Monday, August 29, 2005, Hurricane Katrina struck the southern gulf coast of the United States. Hurricane Katrina produced record high amounts of surge water along the coastal regions, that over topped and eroded levees and flood walls, inevitably flooding the entire city of New Orleans. After Hurricane Katrina, the Department of Homeland Security approved a research grant to The University of Mississippi to develop effective but economic technique of strengthening existing I-walls. Using composite materials, a new retrofitting technique was developed to increase the stability of existing I-walls by implementing composite caps. For economical and practical testing, scale models …
Nanoenhanced Polyurea As A Blast Resistant Coating For Concrete Masonry Walls, Heather Kathryn Daniell Rivera
Nanoenhanced Polyurea As A Blast Resistant Coating For Concrete Masonry Walls, Heather Kathryn Daniell Rivera
Electronic Theses and Dissertations
Blast impact is a major concern in the world today. The leading cause of death due to blast impacts is rapidly moving debris. To prevent this many researchers are looking for methods of improved blast resistance for concrete masonry walls. However, many available protective coatings are not flame retardant. This thesis focuses on nanoenhanced polyurea for applications in improving blast resistance, while possessing improved flame retardancy, of concrete masonry walls. The polyurea that is being researched is enhanced with nanoadditives in an effort improve both blast and fire resistance. These materials are dynamically tested and those showing marked improvement are …
The Manufacturing And Ballistic Testing Of Tri-Axial Quasi Three Dimensional Woven Composites Layered In Polyurea, Brandon Saint
The Manufacturing And Ballistic Testing Of Tri-Axial Quasi Three Dimensional Woven Composites Layered In Polyurea, Brandon Saint
Electronic Theses and Dissertations
The protection of important infrastructure and vital resources of the United States is essential to the Nation's security. Attacks using the Nation's infrastructure as weapons of mass destruction could have a disturbing physical and psychological consequences. Work needs to be done to enhance the protection of the Nation's infrastructure to prevent, deter, or mitigate the effects of deliberate attacks by terrorist. Toxic inhalation hazard (TIH) chemicals such as chlorine gas and anhydrous ammonia are very dangerous hazardous materials. Rail transportation of TIH creates risk that exposes highly populated areas across the country to this threat. This study investigates the ballistic …
Sustainability Of Water And Wastewater Infrastructure: Using A Public-Private Partnership Model For Project Financial Assessment, Rebecca Werner Trotter
Sustainability Of Water And Wastewater Infrastructure: Using A Public-Private Partnership Model For Project Financial Assessment, Rebecca Werner Trotter
Electronic Theses and Dissertations
To supplement current and future budget shortfalls for improvements to water and wastewater infrastructure, Public-Private Partnerships (PPPs or P3) are being advocated by the American Society of Civil Engineers (ASCE) and others as a practical mechanism to ensure financial sustainability. A PPP involves a partnership between a government entity and a concessionaire--consisting of one or more private companies acting as a single, private incorporation--who make an agreement on funding, building, and operating a usually government-provided service, such as drinking water and wastewater infrastructure. This is different from a traditional contract between a government entity and a contractor because the concessionaire …
Design Of Fountain Codes With Error Control, Amrit Kharel
Design Of Fountain Codes With Error Control, Amrit Kharel
Electronic Theses and Dissertations
This thesis is focused on providing unequal error protection (uep) to two disjoint sources which are communicating to a comdestination via a comrelay by using distributed lt codes over a binary erasure channel (bec), and designing fountain codes with error control property by integrating lt codes with turbo codes over a binary input additive white gaussian noise (bi-awgn) channel. A simple yet efficient technique for decomposing the rsd into two entirely different degree distributions is developed and presented in this thesis. These two distributions are used to encode data symbols at the sources and the encoded symbols from the sources …
Enhanced Pvdf Film For Multi Energy Harvesting, Ranmunige Nadeeka Karunarathna
Enhanced Pvdf Film For Multi Energy Harvesting, Ranmunige Nadeeka Karunarathna
Electronic Theses and Dissertations
No abstract provided.
Mechanical Properties Of Portland Cement And Its Constituents At The Nano-Level, Brent French
Mechanical Properties Of Portland Cement And Its Constituents At The Nano-Level, Brent French
Electronic Theses and Dissertations
The following is a summary of research for a portion of the project titled Nano to Continuum Multi-Scale Modeling Techniques and Analysis For Cementitious Materials Under Dynamic Loading in association with North Carolina Agricultural & Technical State University and the US Army. This research investigates several attempts at creating a better Portland cement model at the atomistic level through molecular dynamics simulations. These models are modified to simulate damage to the basic cement structure, and are simulated using several combinations of forcefields and molecular dynamics tools. Experimental techniques such as nanoindentation, atomic force microscopy, and x-ray diffraction are applied to …
Representation Of Dam-Breach Geometry Using Quadtree Local Mesh Refinement, Marcus Zachariah Mcgrath
Representation Of Dam-Breach Geometry Using Quadtree Local Mesh Refinement, Marcus Zachariah Mcgrath
Electronic Theses and Dissertations
Advances in two-dimensional numerical modeling have allodam break floods to be simulated with larger domains than ever before. These types of simulations are important to meet the needs of inundation mapping, consequence analysis, and emergency planning for the large number of significant and high-hazard dams in the United States. Globally refining the mesh to the small cell sizes necessary to resolve small features such as dam breach geometry result in significant computational burden for these types of simulations. This manuscript details the research done to facilitate the implementation of quadtree local mesh refinement to represent dam breach geometry in an …
Subsurface Discontinuity Analysis & Modeling For The Federal Waste Disposal Facility And Compact Waste Disposal Facility Landfills, Shuang Cao
Electronic Theses and Dissertations
This research considers discontinuities mapped by Waste Control Specialists LLC to support the site conditions and performance analysis of the Compact Waste Disposal Facility and the Federal Waste Disposal Facility excavations constructed near Andrews, Texas. Discontinuities observed in excavation walls contain a limited number of discontinuities shoevidence of previous fluid movement. While no networks of such discontinuities were observed in the field, the potential for such networks may exist. This research is significant in understanding the performance of these waste facilities by modeling multiple realizations of possible fracture configurations in three-dimensional spatial models of the type of discontinuities observed in …
Physical, Mechanical And Chemical Aging Of Polyurea Nanocomposites, Ghanshyam Pal
Physical, Mechanical And Chemical Aging Of Polyurea Nanocomposites, Ghanshyam Pal
Electronic Theses and Dissertations
Two component polyurea systems, on one hand, are gaining popularity as corrosion and abrasion resistant coatings and linings while on the other hand there are a few polyurea compositions being used as barrier against blast and ballistic threats to protect nation's critical infrastructure. Physical properties of polymer composites can be tailored with appropriate choice of type, size and amount of reinforcement. In general, nano-sized reinforcements provide better reinforcing over conventional reinforcements due to higher surface to volume ratio. In this dissertation, the first aim is to study effect of nanoreinforcement addition on the overall character (mechanical, chemical and microstructural) of …
Graphics Processing Unit Acceleration Of Computational Electromagnetic Methods, Matthew Joseph Inman
Graphics Processing Unit Acceleration Of Computational Electromagnetic Methods, Matthew Joseph Inman
Electronic Theses and Dissertations
The use of Graphical Processing Units (GPU's) for scientific applications has been evolving and expanding for the decade. GPU's provide an alternative to the CPU in the creation and execution of the numerical codes that are often relied upon in to perform simulations in computational electromagnetics. While originally designed purely to display graphics on the users monitor, GPU's today are essentially powerful floating point co-processors that can be programmed not only to render complex graphics, but also perform the complex mathematical calculations often encountered in scientific computing. Currently the GPU's being produced often contain hundreds of separate cores able to …
Fiber Reinforcement Compaction In Resin Injection Pultrusion Process, Neerad Shakya
Fiber Reinforcement Compaction In Resin Injection Pultrusion Process, Neerad Shakya
Electronic Theses and Dissertations
Resin injection pultrusion is a cost-effective continuous manufacturing process to produce composites of constant cross-section. In this process, fiber reinforcements are continuously pulled through the injection chamber where liquid resin is injected to cause complete wetout of the fibers before exit. The fiber-resin combination obtained from the injection chamber is then cured to obtain the desired pultruded composite. There are various processing and geometric parameters affecting the wetout process. The main objective of this study is to present a numerical model to simulate the resin flow through the fiber reinforcement when compaction of the fibers is also taken into account. …
Fe Modeling In Support Of Vibration Based Damage Detection In Bridges, James Kyle Bethay
Fe Modeling In Support Of Vibration Based Damage Detection In Bridges, James Kyle Bethay
Electronic Theses and Dissertations
Vibration based damage detection in bridges is examined with the objective of defining a relationship between substructure stiffness degradation and frequency and mode shape modulation induced by damage. The relationship is explored through finite element modeling of primarily an experimental representation of a three-span concrete bridge structure located at the entrance to the main campus of The University of Mississippi in Oxford. Equivalent beam and 3D finite element models are created of an experimental setup incorporating levels of damage simulated using deck slab bearing pads of varying stiffness. Eigenvalue analysis is performed to examine the change of frequencies for characteristic …
Impact Mechanics Of A Lap Joint: A Theoretical-Based Parametric Study, Seyed Amir Mansoor Rahmani
Impact Mechanics Of A Lap Joint: A Theoretical-Based Parametric Study, Seyed Amir Mansoor Rahmani
Electronic Theses and Dissertations
The failure of a single connection can cause overload on other structural members, which may consequently fail. Thus, the behavior of damaged or worn joints is of particular concern. In order to represent a loose lap joint, a beam impacting four springs with gaps is modeled. A basis analysis reveals impulse frequency responses with unique dynamic phenomena. Using steady state response, six influential parameters are studied: damping ratio, contact stiffness, position of intermediate springs, gaps, excitation amplitude and beam height. For all parameters, the system response was highly controlled by modes with two contacting springs. Regarding damping, increasing damping ratio …
Sediment Control In Alluvial Rivers Using Simulation-Based Optimization, Moustafa Abdelkader Elgohry
Sediment Control In Alluvial Rivers Using Simulation-Based Optimization, Moustafa Abdelkader Elgohry
Electronic Theses and Dissertations
During storm events in rivers and watersheds, the peak runoff may creates excess erosion and deposition in channels or river reaches and cause changes in flow characteristics and fluvial geomorphology. Severe sediment erosion such as in-stream sever bed and bank erosion or gullying can threaten the stability of in-stream hydraulic structures, river banks, levees, and underground utilities. On the other hand, large amounts of sediment deposition can significantly reduce the flow capacity of channel or reservoir and increases further possibility of flooding. Therefore, sediment control is generally required for rivers and watersheds conservation purposes to maintain stable flow systems in …
Modeling Software Product Lines Using Feature Diagrams, Hazim Husain Shatnawi
Modeling Software Product Lines Using Feature Diagrams, Hazim Husain Shatnawi
Electronic Theses and Dissertations
The leading strategies for systematic software reuse focus on reuse of domain knowledge. One such strategy is software product line engineering. This strategy selects a set of reusable software components that form the core around which software products in a domain are built. Feature modeling is a process that enables engineers to identify these core assets, in particular the com(e.g., shared) and variable features of products. The focus of this thesis is to give an overview of the feature modeling process by introducing feature diagrams. Feature diagrams capture and represent comand variable properties (features) of the software products in a …
An Implicit Finite-Volume Depth-Integrated Model For Coastal Hydrodynamics And Multiple-Sized Sediment Transport, Alejandro Sanchez
An Implicit Finite-Volume Depth-Integrated Model For Coastal Hydrodynamics And Multiple-Sized Sediment Transport, Alejandro Sanchez
Electronic Theses and Dissertations
A two-dimensional depth-integrated model is developed for simulating wave-averaged hydrodynamics and nonuniform sediment transport and morphology change in coastal waters. The hydrodynamic model includes advection, wave-enhanced turbulent mixing and bottom friction; wave-induced volume flux; wind, atmospheric pressure, wave, river, and tidal forcing; and Coriolis-Stokes force. The sediment transport model simulates nonequilibrium total-load transport, and includes flow and sediment transport lags, hiding and exposure, bed material sorting, bed slope effects, nonerodible beds, and avalanching. The flow model is coupled with an existing spectral wave model and a newly developed surface roller model. The hydrodynamic and sediment transport models use finite-volume methods …
Adaptive Encryption Techniques In Wireless Communication Channels With Tradeoffs Between Communication Reliability And Security, Walid Al Zibideh
Adaptive Encryption Techniques In Wireless Communication Channels With Tradeoffs Between Communication Reliability And Security, Walid Al Zibideh
Electronic Theses and Dissertations
Encryption is a vital process to ensure the confidentiality of the information transmitted over an insecure wireless channel. However, the nature of the wireless channel tends to deteriorate because of noise, interference and fading. Therefore, a symmetrically encrypted transmitted signal will be received with some amount of error. Consequently, due to the strict avalanche criterion (sac), this error propagates during the decryption process, resulting in half the bits (on average) after decryption to be in error. In order to alleviate this amount of error, smart coding techniques and/or new encryption algorithms that take into account the nature of wireless channels …
A Gis-Based Watershed Impact Management Model, Chioma Nneamaka Udeze
A Gis-Based Watershed Impact Management Model, Chioma Nneamaka Udeze
Electronic Theses and Dissertations
Assessment of land use changes on hydrological processes is essential for the planning and development of sustainable land management practices and water resources. Understanding how land management practices influence hydrological components is essential for the prediction of hydrological consequences of changes in land use. Given the plethora of hydrological models, digital data sources, and the limited availability of observed data, it is difficult to quantify the impacts of land use changes on hydrology. In this study, a Watershed Impact Management (WIM) model framework was conceptualized. A case study of the Yocona River basin, Mississippi, was implemented with the soil and …
Micro-Mechanics Based Representative Volume Element Modeling Of Heterogeneous Cementitious Materials, Mohammadmehdi Shahzamanian Sichani
Micro-Mechanics Based Representative Volume Element Modeling Of Heterogeneous Cementitious Materials, Mohammadmehdi Shahzamanian Sichani
Electronic Theses and Dissertations
The current work focuses on evaluation of the effective elastic properties of cementitious materials through a voxel based FEA approach. Voxels are generated for a heterogeneous cementitious material (Type-I cement) consisting of typical volume fractions of various constituent phases from digital microstructures. The microstructure is modeled as a micro-scale representative volume element (RVE) in ABAQUS to generate cubes several tens of microns in dimension and subjected to various prescribed deformation modes to generate the effective elastic tensor of the material. The RVE-calculated elastic properties such as moduli and Poisson's ratio are validated through an asymptotic expansion homogenization (AEH) and compared …