Digital Commons Network^™

Design And Implementation Of An Asynchronous Null Convention Logic (Ncl) Fpga, Indira Priyadarshini Dugganapally

Masters Theses

"This Master’s thesis outlines the design of a completely asynchronous Field Programmable Gate Array (FPGA) for implementing NULL Convention Logic (NCL) digital circuits. The proposed design uses four Configurable Logic Blocks (CLB), each of which in turn is designed using four Logic Elements (LE) to implement NCL logic function. Each LE can be configured to function as any one of the 27 fundamental NCL gates. A Logic Element is designed by concatenating a Look-Up-Table (LUT) with a pull-up pull-down transistor chain and a hysteresis loop. The interconnections and the switch box are designed using pass transistors and SRAM. In this …

Environmental Geochemistry Of Metal Contaminated Sediments From The Big River System Of Southeastern Missouri, Helen Carrie Bender

Masters Theses

"Geochemical analysis of stream sediments from the Big River Watershed of southeastern Missouri indicates that they contain elevated concentrations of contaminant metals such as Pb. Zn, Cu. Co, Ni and Cd. The elevated concentrations are derived from natural exposures of metal enriched strata and the numerous mine tailings piles and water seeps created as a result of about 300 years of lead-zinc mining in the “Old Lead Belt”. Galena (PbS), sphalerite (ZnS), and pyrite (FeS₂) are the primary sulfides found in the tailings piles and Scanning Electron Microscopy analysis of individual metallic sediment particles collected at intervals downstream …

Nano-Structure Formation Driven By Local Protonation Of Polymer Thin Films, Carsten Maedler, Harald Graaf, Mingdi Yan, Andres H. La Rosa

Physics Faculty Publications and Presentations

We report the creation of nano-structures via Dip Pen Nanolithography by locally exploiting the mechanical response of polymer thin films to an acidic environment. Protonation of cross linked poly(4-vinylpyridine) (P4VP) leads to a swelling of the polymer. We studied this process by using an AFM tip coated with a pH 4 buffer. Protons migrate through a water meniscus between tip and sample into the polymer matrix and interact with the nitrogen of the pyridyl group forming a pyridinium cation. The increase in film thickness, which is due to Coulomb repulsion between the charged centers, was investigated using Atomic Force Microscopy. …

Crystallography Open Database – An Open-Access Collection Of Crystal Structures, Saulius Grazulis, Daniel Chateigner, Robert T. Downs, A. F. T. Yokochi, Miguel Quirós, Luca Lutterotti, Elena Manakova, Justas Butkus, Peter Moeck, Armel Le Bail

Physics Faculty Publications and Presentations

The Crystallography Open Database (COD), which is a project that aims to gather all available inorganic, metal–organic and small organic molecule structural data in one database, is described. The database adopts an openaccess model. The COD currently contains 80,000 entries in crystallographic information file format, with nearly full coverage of the International Union of Crystallography publications, and is growing in size and quality.

Electron Microscopy And Optical Characterization Of Cadmium Sulphide Nanocrystals Deposited On The Patterned Surface Of Diatom Biosilica, Timothy Gutu, Debra K. Gale, Clayton Jeffryes, Wei Wang, Chih-Hung Chang, Gregory L. Rorrer, Jun Jiao

Physics Faculty Publications and Presentations

Intricately patterned biosilica obtained from the shell of unicellular algae called diatoms serve as novel templates for fabrication of optoelectronic nanostructures. In this study, the surface of diatom frustules that possessed hierarchical architecture ordered at the micro and nanoscale was coated with a nanostructured polycrystalline cadmium sulphide (CdS) thin film using a chemical bath deposition technique. The CdS thin film was composed of spherical nanoparticles with a diameter of about 75 nm. The CdS nanoparticle thin film imparted new photoluminescent properties to the intricately patterned diatom nanostructure. The imparted photoluminescent properties were dependent on the CdS coverage onto the frustules …

Surgical Smoke Evacuation Guidelines: Compliance Among Perioperative Nurses, Kay A. Ball

Theses and Dissertations

Smoke (plume) is produced when tissue is cut or coagulated with lasers or electrosurgery devices during surgery. Research has documented that surgical smoke creates a serious workplace hazard for over 500,000 healthcare workers. Toxic gases create an offensive odor, small particulate matter causes respiratory complications, and pathogens may be transmitted within the surgical smoke to the surgical team. Previous research notes that smoke evacuation recommendations are not being consistently followed by perioperative nurses.

The purpose of this study is to determine key indicators that are associated with compliance with smoke evacuation recommendations by perioperative nurses. The Diffusion of Innovation theory …

Applications Of Swarm, Evolutionary And Quantum Algorithms In System Identification And Digital Filter Design, Bipul Luitel

Masters Theses

"The thesis focuses on the application of computational intelligence (CI) techniques for two problems - system identification and digital filter design. In system identification, different case studies have been carried out with equal or reduced number of orders as the original system and also in identifying a blackbox model. Lowpass, Highpass, Bandpass and Bandstop FIR and Lowpass IIR filters have been designed using three algorithms using two different fitness functions. Particle Swarm Optimization (PSO), Differential Evolution based PSO (DEPSO) and PSO with Quantum Infusion (PSO-QI) algorithms have been applied in this work"--Abstract, page iii.

Hydrogen Applications For Lambert - St. Louis International Airport, Mathew Thomas

Masters Theses

"Today, major airports are facing challenges related to pollution, energy efficiency, and safety and security. Hydrogen and fuel cell technologies, regarded as one of the key energy solutions of the 21st century are more energy efficient and reliable than conventional systems and have the potential to diminish these challenges. These technologies can also play a significant role in reducing the noise, air, and water pollution and enhancing energy security. This paper presents the design of a set of hydrogen technologies and systems that are commercially available and are ready for practical, real-world use. The hydrogen applications selected for Lambert-St. Louis …

Functional Testing Of Faults In Asynchronous Crossbar Architecture, Sriram Venkateswaran

Masters Theses

"The challenge of extending Moore's Law past the physical limits of the present semiconductor technology calls for novel innovations. Several novel nanotechnologies are being proposed as an alternative to their CMOS counterparts, with nanowire crossbar being one of the most promising paradigms. Quite recently, a new promising clock-free architecture, called the Asynchronous Crossbar Architecture has been proposed to enhance the manufacturability and to improve the robustness of digital circuits by removing various timing related failure modes. Even though the proposed clock-free architecture offers several merits, it is not free from the high defect rates induced due to nondeterministic nanoscale assembly. …

Classification Of Fine Particles Using A Taylor-Couette Device, Navina Durgaiah Tungapindi

Masters Theses

"The study of fine particle classification is common, especially since a well defined particle size distribution is important in most processes and products. Many methods have been developed to classify micron-size particles, and although each has its own advantage, most cannot classify particles to an extremely narrow range. This is partly due to the cohesive nature of fine particles, which can be due to electrostatic attraction, moisture, or van der Waals forces. In order to overcome this problem, a wet method of classification has been chosen here. Taylor vortices, discovered in 1923, develop in the fluid contained in the annulus …

Automatic Vessel And Telangiectases Analysis In Dermoscopy Skin Lesion Images, Beibei Cheng

Masters Theses

"The blood vessels are part of the circulatory system and function to transport blood throughout the body. Vessels have their own features such as distinctive color compared to surrounding skin as well as distinctive curved and/or linear shape. Telangiectases are small dilated blood vessels near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. In this research, image analysis techniques are investigated to detect vessels in dermoscopy skin lesion images. Machine vision and neural network methods are explored to discriminate skin lesions containing telangiectases from those containing normal vessels. A vessels Detection technique …

Information Flow Properties For Cyber-Physical Systems, Rav Akella

Masters Theses

"In cyber-physical systems, which are the integrations of computational and physical processes, security properties are difficult to enforce. Fundamentally, physically observable behavior leads to violations of confidentiality. This work analyzes certain noninterference based security properties to ensure that interactions between the cyber and physical processes preserve confidentiality. A considerable barrier to this analysis is the representation of physical system interactions at the cyber-level. This thesis presents encoding of these physical system properties into a discrete event system and represents the cyber-physical system using Security Process Algebra (SPA). The model checker, Checker of Persistent Security (CoPS) shows Bisimulation based NonDeducibility on …

Communication Models For Monitoring And Mobility Verification In Mission Critical Wireless Networks, Maheswaran Thiagarajan

Masters Theses

"Recent technological advances have seen wireless sensor networks emerge as an interesting research topic because of its ability to realize mission critical applications like in military or wildfire detection. The first part of the thesis focuses on the development of a novel communication scheme referred here as a distributed wireless critical information-aware maintenance network (DWCIMN), which is presented for preventive maintenance of network-centric dynamic systems. The proposed communication scheme addresses quality of service (QoS) issues by using a combination of a head-of-the-line queuing scheme, efficient bandwidth allocation, weight-based backoff mechanism, and a distributed power control scheme. A thorough analysis of …

Decision-Based Design Under Uncertainty With Intervals, Sashank Vasireddy

Masters Theses

"Design requires a series of decisions, and one of the major challenges engineering designers face is making decisions under uncertainty. The engineering designer must choose the best design among various alternatives. This work evaluates the use of utility functions to make decisions under uncertainty with both random and interval variables. Uncertainty cannot be eliminated completely, but it can be reduced. Most current methods treat only aleatory uncertainty. Here, however, both aleatory and epistemic uncertainties are addressed in the context of engineering design. Methods such as moment matching method and worst case analysis are used to incorporate uncertainty into design problems"--Abstract, …

Continuous Control Of Lunar Orbits Via Electric Propulsion, Sunil Aggarwal

Masters Theses

"To find definite answers for the presence of water on the poles of Moon, to facilitate selection of future lunar landing sites and aid in construction of architectural bases, to assist proper lunar resource utilization and to improve lunar gravity models there is a great interest and need for highly accurate, reliable and efficient lunar surface mapping and communication. This thesis is intended to aid in proper selection of orbits for future lunar missions by demonstrating the impact of using electric propulsion on the search space of feasible and useful lunar orbits. The requirements for future lunar mapping and communication …

Verifying Module Heuristics For Large Scale Products, Rachel Marie Day

Masters Theses

"Decreasing time and costs is a major objective in many businesses today. Including modularity in the early design phases can effectively decrease time spent on and costs associated with a project. The task of identifying modules within a product early in the design process (when decisions are less expensive) is made less daunting by using the techniques of functional modeling and module heuristics. The two papers that form this thesis discuss the results of the efforts to verify the module heuristics on large products. Observations on needed modifications to the functional modeling technique and original module heuristics are reported along …

Development Of A One Dimensional Subsurface Contaminant Transport Model With Stochastic Applications, Benjamin Waldon Johnson

Masters Theses

"Contaminant source release history is a necessary element of contaminant mass transport simulation in the saturated zone. The source release history is unknown at many sites, and many inverse models have been developed to define finite release histories. To define a likely domain of three source history parameters, a mass balancebased one dimensional approach is developed and tested by discretizing the spatial domain into bands. By incorporating the approach in a spreadsheet model, observed data is represented by both variable length and constant length bands of analysis. Each representation of observed data was tested to determine the most appropriate band …

On-Line Depth Measurement Of Micro-Scale Laser Drilled Holes, Rock Allen Powell

Masters Theses

"A micron-precision micro-hole depth detection scheme has been developed which utilizes a confocal structure and a photomultiplier tube as a photodetector. This scheme is experimentally confirmed to posses an accuracy of greater than 95% for micro-holes on the order of one-hundred microns in diameter and tens of microns in depth and could be easily be integrated for the control of industrial and research oriented laser micro-machining process"--Abstract, page iii.

Exploring The Use Of A Commercial Game Engine For The Development Of Educational Software, Hussain Alafaireet

Masters Theses

"Three-dimensional visualization and simulation environments are becoming increasingly important in both industrial and educational environments. However, developing these simulations can be a difficult and expensive task. Herein we explore the use of a commercial game engine to develop a 3-D, interactive computer game designed to teach players about the anatomy of a frog. The goal of this project is threefold: 1) to develop high-fidelity virtual reality educational software with a limited budget and limited personnel, 2) to define a software development process by which similar simulations can be developed, and 3) to explore the benefits that these simulations provide to …

On The Effects Of Small-Scale Fading And Mobility In Mobile Wireless Communication Network, Bandana Paudel

Masters Theses

"In this study, a comprehensive analysis of the impact of mobility on end-to-end performance measures of Mobile Ad Hoc Network is performed by using small-scale fading models. Network simulation is performed in order to study a wide range of phenomena occurring during MANET communication. The effectiveness of three reactive routing protocols against different level of mobility is observed under varying network parameter like the network size, number of nodes and network connectivity. The study reveals that the network sparseness or density favors one or the other routing mechanism under varying mobility. Outcome of the simulation also provides a great deal …

Localization Of Nodes In Wired And Wireless Networks, Hindu Kothapalli

Masters Theses

"This thesis focuses on the implementation of algorithms for localization of nodes in wired and wireless networks. The thesis is organized into two papers. The first paper presents the localization algorithms based on time of arrival (TOA) and time difference of arrival (TDOA) techniques for computer networks such as the Internet by using round-trip-time (RTT) measurements obtained from known positions of the gateway nodes. The RTT values provide an approximate measure of distance between the gateway nodes and an unknown node. The least squares technique is then used to obtain an estimated position of the unknown node. The second paper …

Development And Evaluation Of An Effective Process For The Recovery Of Oil And Detoxification Of Meal From Jatropha Curcas, Sarthak Gaur

Masters Theses

"There has been significant research on biofuels to ensure national security and economic stability of the US. Jatropha curcas, a hardy plant, holds tremendous potential as a biodiesel source and cattle feed-stock largely due to its high triglyceride and crude protein content. However, its viable economic utilization is limited due to the presence of important toxic compounds, phorbol esters. A novel and efficient process has been developed that obtains high yields of jatropha oil and detoxifies the defatted (oil free) jatropha meal. Principles of solid-liquid extraction were utilized to detoxify the meal and then liquid chromatography was employed to analyze …

Modeling Of Vias And Via Arrays In High Speed Printed Circuit Boards, Arun Reddy Chada

Masters Theses

"This thesis presents modeling approaches for fast calculation of signals in dense via arrays in high speed printed circuit boards (PCBs) and model to hardware correlation study of solid and perforated disk resonators. A 2D finite difference (FD) method to extract the via capacitance which includes the via pad capacitance obtained by solving the laplace equation in the via domain in multi-layer geometries is presented and validated with analytical formulation for via capacitance. Next, closed-form expression for the impedance of an infinitely large parallel plane pair is derived and validated by comparing with cavity model for several numerical examples. The …

Preventing Chemical Product Failure, Kenneth Ombete

Masters Theses

"The purpose of this thesis is to demonstrate a research methodology to prevent chemical product failures. This methodology extends the risk in early design (RED) method for prevention of failure in electromechanical products to include products with chemical subsystems. Inclusion of this domain is demanded by the ever-growing semiconductor and energy industries. The RED method was extended by first identifying principal chemical failure modes and adding them to the failure mode taxonomy. The RED database was then augmented with historical failures of products that included chemical subsystems. Finally, the extension was validated with a case study of a fuel cell"--Abstract, …

Stressed-Eye Analysis And Jitter Separation For High-Speed Serial Links, Nitin Radhakrishnan

Masters Theses

"As the computer and electronics industry moves towards higher data rates, the most important concern in the field of signal integrity is jitter. A data communication link path often consists of a transmitter, a channel, and a receiver. Many mechanisms can contribute to jitter, a timing uncertainty in the received signal. For example, transmitters have intrinsic noise sources that contribute to random jitter and to certain types of deterministic jitter. In addition, external coupling may cause periodic jitter. The bandwidth limitation of the channel also contributes to a fourth type of jitter, inter-symbol interference. This thesis studies the various components …

Numerical Modeling And Analysis Of Complex Electromagnetic Structures, Including Those Containing Ferrites, Andrea Orlando

Masters Theses

"Application of fast switching amplifiers in power converters, and especially in power inverters, causes unwanted radiated emission, which is a consequence of common mode (CM) currents arising in feed wire bundles. Ferrite chokes are commonly used to suppress those CM currents by increasing the CM impedance of circuits without affecting the differential mode currents, which is important for undisturbed operation of the converters or inverters. Their effective impedance is the main design concern, and it is determined by the material intrinsic properties (permeability, permittivity) and geometry. The goal of this work is to analytically correlate the geometrical and material properties …

Reliability-Based Design With System Reliability And Design Improvement, Gagandeep Singh Saini

Masters Theses

"This thesis focuses on developing a methodology for accurately estimating series system probability of failure. Existing methods for series system based design optimization are not that accurate because they assign reliability to each failure mode; as a result complete system reliability goes down. According to method proposed in this work, the user will assign required system reliability at the start and then optimizer will apportion reliability to every failure mode in order to meet required system reliability level. Detlevson second order upper bounds are used to estimate system probability of failure. Several examples have been shown to verify the results …

Screw Connections Subject To Tension Pull-Out And Shear Forces, Ryan M. Francka

Masters Theses

"Currently, the behavior of screw connections subject to combined tension pull-out and shear forces is not well understood. An experimental study was conducted at Missouri University of Science and Technology to better understand the relationship or interaction between these forces. The test program evaluated four parameters that may influence the behavior of pure tension and pure shear in screw connections: the thickness of the sheet not in contact with the screw head, the ultimate strength of the steel, the ductility of the steel, and the screw diameter. This investigation extends the application of the pure pull-out and pure shear equations …

Fault Detection And Prediction With Application To Rotating Machinery, Gary R. Halligan

Masters Theses

"In this thesis, the detection and prediction of faults in rotating machinery is undertaken and presented in two papers. In the first paper, Principal Component Analysis (PCA), a well known data-driven dimension reduction technique, is applied to data for normal operation and four fault conditions from a one-half horsepower centrifugal water pump. Fault isolation in this scheme is done by observing the location of the data points in the Principal Component domain, and the time to failure (TTF) is calculated by applying statistical regression on the resulting PC scores. The application of the proposed scheme demonstrated that PCA was able …

Formation Of Iron-Rimmed Sandstone Nodules On Earth; Terrestrial Analogue For The Formation Of Martian Blueberries?, Katherine Charlotte Muller

Masters Theses

"NASA's twin Mars Exploration Rovers, MER, Spirit and Opportunity, have identified numerous geologic features that hint at a watery past on Mars noted in Malik, 2004. Prominent among these features are the "Martian Blueberries" that occur as spherical hematite (Fe₂O₃) nodules. Hematite formation is facilitated by the presence of water, although there are presently no known sources of free liquid water on Mars. Chan et al., 2004 states that these "blueberries" are also similar to nodules found in the Jurassic aged Navajo Sandstone in Utah. An understanding of the processes controlling the formation of the Utah nodules may thus be …