Engineering Commons^™

Neutron Multiplicity Measurements Of Target/Blanket Materials, Denis Beller

Transmutation Sciences Physics (TRP)

To optimize the performance of accelerator-driven transmutation subcritical systems (ADS), engineers will need to design the system to operate with a neutron multiplication factor just below that of a critical, or self-sustaining, system. This design criterion requires particle transport codes that instill the highest level of confidence with minimal uncertainty, because larger uncertainties in the codes require larger safety margins in the design and result in a lower efficiency of the ADS transmuter. For current design efforts in the U.S., a Monte Carlo particle transport code MCNPX is used to model neutron production and transport for spallation neutron systems.

While …

Studies In Cardiac Defribrillation, Eamonn Mckenna

Masters

Cardiac disease resulting in cardiac arrest is one of the most common fatal diseases in the developed world. Defibrillation is the medical procedure used to correct the irregular cardiac rhythm (ventricular fibrillation (VF)) which is very often detected in patients suffering cardiac arrest. In the work reported in this thesis, two aspects of the defibrillation of patients in VF were examined. The first area of investigation concentrated on the use of multiple defibrillation electrodes to be used during closed chest (transthoracic) defibrillation. This study was carried out in a saline bath and centred on “focusing” electric fields from perimeter electrodes …

Address Assignment In Ad-Hoc Networks, John Paul O'Grady

Theses

A wireless ad-hoc network is a collection of autonomous nodes or terminals that communicate with each other by forming a multi-hop radio network and maintaining connectivity in a decentralised manner. In an ad hoc network routing is used to find and maintain a path through the network. Routing requires each node to have a unique identifier, to ensure that packets sent to a particular node reach their intended destination. Most ad-hoc routing protocols assume that a node already has an address prior to its entry into a network and so the issue of address assignment is largely ignored. This however …

Forecasting The Onset Of Cloud-Ground Lightning Using S-Pol And Nldn Data, Kartik Ramakrishnan

Electronic Theses and Dissertations

The maximum number of thunderstorms in the United States occur in Central Florida. The cloud-ground lightning from these storms is responsible for extensive damage to life and property. The lightning from these storms is also responsible for delays and cancellations of space shuttle launch attempts at the Kennedy Space Center (KSC) and the 45th Space Wing unmanned launches at Cape Canaveral launch facilities. For these and other reasons accurate forecasting of cloud-ground lightning is of crucial importance. The second phase of NASA's Tropical Rainfall Measuring Mission Texas and Florida Underflights project (TEFLUN-B) was conducted between 1st August and 30th September, …

Measuring The Effect Of Erratic Demandon Simulated Multi-Channel Manuf, Nancy Kohan

Electronic Theses and Dissertations

To handle uncertainties and variabilities in production demands, many manufacturing companies have adopted different strategies, such as varying quoted lead time, rejecting orders, increasing stock or inventory levels, and implementing volume flexibility. Make-to-stock (MTS) systems are designed to offer zero lead time by providing an inventory buffer for the organizations, but they are costly and involve risks such as obsolescence and wasted expenditures. The main concern of make-to-order (MTO) systems is eliminating inventories and reducing the non-value-added processes and wastes; however, these systems are based on the assumption that the manufacturing environments and customers' demand are deterministic. Research shows that …

Evaluation Of The Photo-Induced Structural Mechanisms In Chalcogenide, Cedric Lopez

Electronic Theses and Dissertations

Chalcogenide glasses and their use in a wide range of optical, electronic and memory applications, has created a need for a more thorough understanding of material property variation as a function of composition and in geometries representative of actual devices. This study evaluates compositional dependencies and photo-induced structural mechanisms in As-S-Se chalcogenide glasses. An effective fabrication method for the reproducible processing of bulk chalcogenide materials has been demonstrated and an array of tools developed, for the systematic characterization of the resulting material's physical and optical properties. The influence of compositional variation on the physical properties of 13 glasses within the …

The Spectral Conforming Model And Its Applications, Jaeho Shim

LSU Doctoral Dissertations

It has been observed that finite element or finite difference model of order can approximate with fair accuracy less than one-third of the eigenvalues of the underlying continuous system corresponding to the low spectrum. The new discrete model, namely the spectral conforming model, is developed to predict the eigenvalues of continuous systems in both the low and high spectra. The spectral conforming models are developed using an inverse vibration method. The classical vibration problem is the direct method. In the direct approach, the characteristic behaviors of the system, i.e. frequency response, natural frequency, and steady state response are analyzed and …

Development Of Dynamic Travel Demand Models For Hurricane Evacuation, Haoqiang Fu

LSU Doctoral Dissertations

Little attention has been given to estimating dynamic travel demand in transportation planning in the past. However, when factors influencing travel are changing significantly over time – such as with an approaching hurricane - dynamic demand and the resulting variation in traffic flow on the network become important. In this study, dynamic travel demand models for hurricane evacuation were developed with two methodologies: survival analysis and sequential choice model. Using survival analysis, the time before evacuation from a pending hurricane is modeled with those that do not evacuate considered as censored observations. A Cox proportional hazards regression model with time-dependent …

Electrodeposition Of Feconicu Quaternary System, Qiang Huang

LSU Doctoral Dissertations

Electrodeposition is a cost-effective method to produce thin film materials, which have been used widely in the microelectronic industry, and is advantageous to fabricate metal deposits into recessed and curved areas. In this dissertation, FeCoNiCu quaternary alloy system was investigated, both experimentally and theoretically, for fabrication of multilayers, grating structures, and nanowires. Multilayer structures are composed of alternating ferromagnetic and nonmagnetic nanometric layers, and are of interest due to the giant magnetoresistance (GMR) property it possesses, a change in electric resistance in the presence of an external magnetic field. In addition, the compositional modulation, or the composition contrast, in multilayer …

Modeling The Effects Of Rainfall Intensity And Deep Chiseling On Infiltration And Runoff Within Drainmod For Alluvial Soils, Daniel Nyabiba Moriasi

LSU Doctoral Dissertations

Accurate hydrologic models are needed to aid engineers and researchers design, install and evaluate efficient and cost-effective agricultural water management systems to reduce risks associated with food production, and to reduce soil erosion and water pollution. One model used for the alluvial soils of Louisiana is DRAINMOD. This model does not accurately predict infiltration and runoff for the crusting-prone alluvial soils of Louisiana. The main goal of this study was to modify the current DRAINMOD model to incorporate the effects of rainfall intensity and deep chiseling to improve its estimation of infiltration and surface runoff. The second goal was to …

Advances And Applications Of Dezert-Smarandache Theory (Dsmt), Vol. 1, Florentin Smarandache, Jean Dezert

Branch Mathematics and Statistics Faculty and Staff Publications

The Dezert-Smarandache Theory (DSmT) of plausible and paradoxical reasoning is a natural extension of the classical Dempster-Shafer Theory (DST) but includes fundamental differences with the DST. DSmT allows to formally combine any types of independent sources of information represented in term of belief functions, but is mainly focused on the fusion of uncertain, highly conflicting and imprecise quantitative or qualitative sources of evidence. DSmT is able to solve complex, static or dynamic fusion problems beyond the limits of the DST framework, especially when conflicts between sources become large and when the refinement of the frame of the problem under consideration …

Development Of An Expert Judgement Elicitation And Calibration Methodology For Risk Analysis In Conceptual Vehicle Design, Resit Unal, Charles Keating, Bruce Conway, Trina Chytka

Engineering Management & Systems Engineering Faculty Publications

A comprehensive expert-judgment elicitation methodology to quantify input parameter uncertainty and analysis tool uncertainty in a conceptual launch vehicle design analysis has been developed. The ten-phase methodology seeks to obtain expert judgment opinion for quantifying uncertainties as a probability distribution so that multidisciplinary risk analysis studies can be performed. The calibration and aggregation techniques presented as part of the methodology are aimed at improving individual expert estimates, and provide an approach to aggregate multiple expert judgments into a single probability distribution. The purpose of this report is to document the methodology development and its validation through application to a reference …

An Understanding Of The Application Of Research Methods In Engineering Management, Andres Sousa-Poza, Rafael Landaeta, Leonardo Bedoya, Ipek Bozkurt, Yaneth Correa

Engineering Management & Systems Engineering Faculty Publications

In this article, the use of research methods in the field of Engineering Management is analyzed. For this study, a database was formed by using articles from three journals in the Engineering Management field: the Engineering Management Journal (EMJ), the IEEE Transactions on Engineering Management and the Journal of Engineering and Technology Management (JETM). Articles written between 1999 and 2003 were analyzed and an Engineering Management research position map was developed to describe holistically the research methods being used in Engineering Management. No judgment on the Engineering Management field per se was undertaken as a result of this study. Instead, …

Damage Modeling Method For Turbine Compressor Blade Tuning, Gennadiy Afanasiev

Electronic Theses and Dissertations

The thesis presents a method of evaluation for blade damage in Combustion Turbine Compressor Section. This method involves use of multiple domains within a single Finite Element Model to predict the effect of damage on the blade properties. This approach offers significant time and effort savings when compared to traditional evaluation methods of similar problems. It is demonstrated via examples that the multi-domain modeling approach yields acceptable accuracy results. The economical implications of described method are readily applicable to both the industrial and the aerospace Combustion Turbine fields. It is economically impractical to replace the blade at each damage occurrence. …

Reduced Kinetic Mechanisms For Premixedhydrogen-Air-Cf3br Flames, Yi Zhang

Electronic Theses and Dissertations

Halon 1301 (CF3Br), or bromotrifluoromethane, had been widely used as fire-extinguishing agent for many years before its production and consumption were severely regulated by the Montreal Protocol due to its hazardous depletion effect to the stratospheric ozone layer. It is therefore imperative to find an effective replacement fire-fighting agent before the mandated deadline of the complete phase out of CF3Br. Currently there are intensive efforts in searching for an environmentally acceptable fire suppression replacement. This, however, is hampered by a lack of fundamental understanding of how CF3Br suppresses the chemical reactions in a flame environment so effectively. Recent experimental evidence …

Sub-Optimal Ultra-Wide Band Receivers, Nilesh Bhuvanendran

Electronic Theses and Dissertations

Ultra-wide Band (UWB) has sparked a lot of interest lately from the industry and academia. The growing capacity of the wireless industry is requires a new communication system that satisfies the high data rate which does not interfere with existing RF systems. UWB promises to be this new technology. UWB also promises low power, low cost and flexibility. The UWB Channel opens up a huge new wireless channel with Giga Hertz Capacities as well as the highest spatial capacities measured in bits per hertz per square meter. When properly implemented UWB channel can share spectrum with traditional radio systems without …

Application Of Espi-Method For Strain Analysis In Thin Wall Cylinders, David Kennedy, Zdravko Schauperl, Seamus Greene, Emilia Mihaylova

Articles

The Centre for Industrial and Engineering Optics, DIT, Ireland, have recently developed and applied new optical techniques for the measurement of mechanical strain, one of which was based on electronic speckle pattern interferometry (ESPI). The accuracy of this optical technique when used on flat surfaces is well established. In this research the technique is tested on curved surfaces, and results are compared with the theoretical hoop strain as predicted by the bi-axial strain equation modified for the thin cylinder, and by those obtained by electrical resistance strain gauge (ERSG) undoubtedly the principal method of measuring mechanical strain. For testing procedures, …

Mechancial Characterization Of Unplasticised Polyvinylchloride Thick Pipes Using Electronic Speckle Pattern Interferometry, Emilia Mihaylova, Benjamin Potelon, Guntaka Tulasi Sridhar Reddy, Vincent Toal, Ciaran Smith

Articles

In this work a number of techniques (electronic speckle pattern interferometry, holographic interferometry, strain gauge and finite element method) are brought to bear in order to establish consistency in the results of strain measurement. This is necessary if optical nondestructive testing methods, such as those used here, are to gain acceptance for routine industrial use. The FE model provides a useful check. Furthermore, ESPI fringe data facilitates the extension of FE models, an approach that is of growing importance in component testing. The use of in-plane and out-of-plane sensitive electronic speckle pattern interferometry (ESPI) for non-destructive material characterization of thick …

Control Loop Performance Assessment: A Classification Of Methods, Niall O'Connor, Aidan O'Dwyer

Conference papers

This paper presents an overview of a number of controller performance assessment techniques. The techniques discussed are divided into five categories, namely, time domain assessment, frequency domain assessment, minimum variance control (MVC) as a benchmark, statistical analysis, and other more ‘problem specific’ assessment techniques. Recent work, by various authors, in each of the five categories is outlined.

Tuning Rules For Pi And Pid Control Of Time Delayed Processes: Some Recent Developments, Aidan O'Dwyer

Conference papers

The ability of PI and PID controllers to compensate many practical processes has led to their wide acceptance in industrial applications. The requirement to choose two or three controller parameters is most easily done using tuning rules. Starting with a general discussion of industrial practice, the paper will discuss, in particular, recent work in tuning rule development for processes with time delay.

Comparison Between Theoretical And Practical Phase Computation, Pauline Sourdille, Aidan O'Dwyer

Conference papers

Transfer functions which are a composite of delay terms cause problems for computer packages, such as MATLAB, in calculating the frequency response open loop transfer function, as the form of the open loop transfer function is irrational. So, the delay terms have to be approximated. There are several ways to evaluate a delay term. A calculator such as MATHEMATICA uses the exact representation of the delay called the Euler form. A computer package such as MATLAB uses a rational approximation for the delay. Using the MATLAB built-in function pade(n,tau), the open loop transfer function of a system with delay can …

System Identification Using The Delta Operator, Aidan O'Dwyer

Conference papers

The aim of this contribution is to communicate, to a wide audience in signal processing and telecommunications, work that has been carried out, primarily in control engineering, on the use of alternative discrete time operators to the z-domain operator. The advantages of the delta domain operator will be communicated using examples, primarily with the aid of plotted results, to give a creative and easily understood impact. Some original work carried out by the author on identification issues will also be communicated.

Using Structured P2p Overlay Networks To Build Content Sensitive Communities, Paul Stacey, Damon Berry, Eugene Coyle

Conference papers

This paper details a proposed peer-to-peer system, which allows a user to join communities of other like-minded users in order to exchange files. Utilising the routing capabilities of Pastry, the proposed system includes an indexing service, which facilitates the creation of virtual rendezvous points for users with similar interests (manifested by shared keywords). Users are described by the content they store. By using vector space modelling techniques users can be grouped together to form content sensitive communities. The system is built to serve as the basis for a distributed archive of research papers. The system is designed to improve the …

Application Of Wavelet Transform To Power Quality (Pq) Disturbance Analysis, Malabika Basu, Biswajit Basu

Conference papers

This paper presents a wavelet analysis based time-frequency technique to identify power system transients and disturbances. A mother wavelet basis function (Littlewood- Paley (L-P)) with dyadic non-overlapping frequency hands has been used. The advantage of the proposed approach is in identification of the occurrence and duration of the disturbances. A few power signals with power quality disturbances have been analysed to show the effectiveness of the proposed technique.

Combining Capacitor/Inductor And Idling Asynchronous Motor In Design Of A System For Balance Of A Large Two-Phase Industrial Load Over Three Phases, Eugene Coyle, M Farrell, W. J. Campbell

Conference papers

This paper describes the design and implementation of a new solution to power quality problems associated with large unbalanced nonlinear loads at fine glass furnace production utilities. Such furnaces use two-phase electricity for reasons of enhanced temperature control and in order to maintain consistency of glass viscosity. A significant risk of power failure is introduced due to this requirement. The furnace load is also nonlinear in nature, due to temperature control by electronic power switching. This gives rise to risks associated with high harmonic distortion. A new method in design of filters to alleviate problems associated with this type of …

Project-Based Freshmen Engineering Courses In Civil Engineering Technology, Vernon W. Lewis Jr., Carol L. Considine

Engineering Technology Faculty Publications

Old Dominion University (ODU) has developed two fundamental courses for freshmen engineering students. The first course introduces the fundamentals of the practice of engineering including innovation, creativity, design and manufacturing, commercialization, teaming skills, environmental impact, and ethics. The second course is an exploration of engineering and engineering technology disciplines with an emphasis on projects. The purpose of these courses is to engage the students in the application of engineering early in their course of study with the hope that their interest will be reinforced and the likelihood of their being retained as students will increase. The courses are divided into …

Photonic Band Gap Analysis Using Finite-Difference Frequency-Domain Method, Shangping Guo, Feng Wu, Sacharia Albin

Electrical & Computer Engineering Faculty Publications

A finite-difference frequency-domain (FDFD) method is applied for photonic band gap calculations. The Maxwell’s equations under generalized coordinates are solved for both orthogonal and non-orthogonal lattice geometries. Complete and accurate band gap information is obtained by using this FDFD approach. Numerical results for 2D TE/TM modes in square and triangular lattices are in excellent agreements with results from plane wave method (PWM). The accuracy, convergence and computation time of this method are also discussed.

Synthysis Of Polymer/Nano-Droplet Composites From Reverse Microemulsion Polymerization, Liehui Ge

Master's Theses and Doctoral Dissertations

L₁ and L₂ domains of the water/AOT/MMA ternary system were investigated at 22±1°C. Free radical polymerizations were conducted in L₂ domain. Only opaque polymer rods were obtained. Acrylamide, a water soluble monomer, plays a role of co-surfactant which greatly expands the L₂ domain. However, polymerizations only yielded opaque material. SEM showed images of phase separation.

MDOS (2-Methacryloyloxy)ethyl trimethylammonium bis(2-ethylhexyl) sulfosuccinate, was synthesized by ion exchange method. L₁ and L₂ domains of the water/MDOS/MMA ternary system were also investigated at 22±1°C. Free radical polymerizations were conducted in L₂ domain. Transparent polymer was produced. The …

Promoting Faculty Development With Asee/Nasa Fellowship Programs- Parametric Study Of Laser Beam Cutting (Lbc) Processes- A Case Study, Alok K. Verma, Gary R. Crossman, Carl J. Voglewede, Thomas J. Burns

Engineering Technology Faculty Publications

American Society for Engineering Education (ASEE) and National Aeronautics and Space Administration (NASA) offer a joint program for faculty and research development. This program known as ASEE/NASA Faculty Fellowship program offers opportunities for professional development for Engineering Technology faculty. This paper discusses one such experience involving applied research at NASA Langley Research Center, which resulted in professional development of the faculty member while enhancing the undergraduate curriculum in Engineering Technology.

Enhancing Met Curriculum With Applied Research Experience For Faculty Parametric Study Of Water Jet Cutting Processes- A Case Study, Alok K. Verma, Cheng Y. Lin, Carl J. Voglewede, Mike E. Tall

Engineering Technology Faculty Publications

In today's global competitive environment, the engineering technology curriculum must adopt and reflect the changing needs of industry. This can happen only if the faculty are aware of the current trends in industry and are actively involved with industry and research projects. ASEE/NASA Faculty Fellowship program offers opportunities for professional development for Engineering Technology faculty. A parametric study of water jet cutting (WJC) process was done under the ASEE / NASA faculty fellowship program at NASA Langley Research Center. This research experience has been used to enhance undergraduate curriculum in Mechanical Engineering Technology at Old Dominion University (ODU).