Engineering Commons^™

An Experimental Study Of Low Speed Open Cavity Flows, Abraham J. Meganathan

Masters Theses

The experimental work is part of an ongoing study aimed at understanding and controlling of cavity instabilities by passive or active steady or unsteady fluid injection. An experimental setup has been designed to quantitatively visualize the flow-field inside the cavity for varying relative dimensions (L/D ratios of 2.0, 2.67, 3.5 and 4.5, W/D of 3.33) at low subsonic speeds ranging from 55 ft/sec to 214 ft/sec using Particle Image Velocimetry (PIV).

The results showed that PIV could provide instantaneous velocity and other flow field data inside and above the cavity. The quality of data is good and may be used …

Prediction Of Airfoil Stall In Icing Conditions Using Wing Surface Pressures, Erik Pederson

Masters Theses

This thesis presents work on a Normalized Lift Coefficient instrumentation system that predicts airfoil stall in icing conditions. The system uses four surface pressures, measured aft of the ice formation, from which the aircraft's normalized lift coefficient is determined. The pressure port locations were selected such that the calibration algorithm remains nearly constant as the leading edge ice shape and thickness change. Data collected in the Western Michigan University Wind Tunnel is presented for three ice formations varying in both shape and thickness. The ice and no ice conditions were compared and a set of four ports was found that …

Texture And Young’S Modulus Of Nickel/Gamma-Alumina Composites, Abdulaziz Alamr

Masters Theses

To improve Young's modulus of 2024-T3 rolled aluminum specimens, it was electroplated with nickel reinforced with nano-particles of γAl₂O₃. Taguchi method was used to investigate the effect of coating variables, which were current density, coating time, and mixing rate, on the coating thickness. The coatings were tested for crystallographic texture, using pole figures of (200) and (111) for nickel and (400) for γAl₂O₃. Surface topography was measured using WYKO Vertical Interference Microscope. The crystallographic texture of nickel in the coating depended on the coating conditions. A universal testing machine was- used to …

Residual Stress And Wear Resistance Of Composite Coatings Of Nickel/Gamma-Alumina, Khaled Abdulrahman Al-Ogab

Masters Theses

Nickel reinforced with nanoparticles of γ−Al₂O₃ have been successfully codeposited on 2024-T3 cold rolled aluminum alloy by electrodeposition with direct current. The effects of current density, particle concentration in the nickel sulfamate bath, air agitation, and coating time on Ni/γ−Al₂O₃ composite have been investigated. The residual stresses and wear resistance of the Ni/γ−Al₂O₃ composite have been measured using X-ray diffractometer and pin-on-disk techniques respectively. The residual stress and wear resistance behavior of the composite were compared with those of nickel-only deposits. An annealed ground nickel, which was mechanically removed from the …

Small Below-Endurance-Limit Cycle Damage Contributions In Variable Sequence Loading For 2024-T351 Aluminum Alloy, Christopher M. Ngiau

Masters Theses

It is a common practice in industry today to totally discard the presence of small below-endurance/fatigue limit cycles while calculating damage accumulation using the Palmgren-Miner rule. However, it was experimentally found in a number of studies that small cycles with stress amplitudes below the fatigue/endurance limit do in fact contribute significantly to the damage accumulation in all types of materials. There was a need to investigate cases where small cycles would only be present for a certain percentage of the material's life. An experimental study was done on 2024- T351 aluminum alloy. Loading was done in low and high cyclic …

An Evaluation Of Relationships Among Streamflow And Selected Water Quality Parameters In A Forested High-Altitude Watershed, Molly Sarah Mccann

Masters Theses

A long-term water quality program has been established at the Noland Divide Watershed (NDW) in the Great Smoky Mountains National Park. The Noland Divide Watershed is a spruce-fir forested catchment which has been shown in previous research to receive some of the largest fluxes of atmospherically-deposited nitrogen and sulfur compounds in the world. Streamwater chemistry data from November 1991 through August 1998 for two streams, the "northeast" (NE) and "southwest" (SW) stream, were examined to note results of this deposition on water quality. Automatic monitoring equipment on both streams measure and record pH, conductivity, and temperature readings every 15 minutes, …

A Methodology And Sampling System For Monitoring Nonpoint Source Pollution From Land Uses, Bryan Fleet Staley

Masters Theses

Limited research has been done in developing a nonpoint source methodology and monitoring system that enables the quantitative evaluation of land use impacts on water quality in a single watershed. The development of a methodology and sampling system that specifically targets the runoff component of streamflow is important in determining which types of land uses contribute most to water quality degradation. In addition, an established monitoring strategy and sampling system will provide for the collection of water quality data when the pollution potential is greatest.

Both a monitoring methodology and a computer controlled sampling system have been developed that utilize …

Cfmms – Computerized Facilities Maintenance Management System, Prawit Rotsawatsuk

Masters Theses

Computerized facilities maintenance management systems, previously available only to very large facilities, are now accessible to small and medium-sized maintenance organizations. Advertisements for such products promise reductions in maintenance costs. Where a manual system of maintenance management is currently employed, moderate reductions in maintenance costs and facility downtime are fully possible. Where no formal maintenance management procedures are present, the structure and case of a computerized maintenance system can result in dramatic cost reductions and improvements in facility availability. There are, however, practical limits to the applicability of computerized maintenance systems. The objective of any maintenance program is to minimize …

The Development Of A Fmea Process For Design And Maintenance, Tearesa Lynn Wegscheid

Masters Theses

Failure Modes and Effects Analysis (FMEA) is a systematic way to identify and evaluate potential product and process related failure modes, the associated causes of failures, and the necessary actions to eliminate or reduce the chance of the failure. There are a number of published manuals and books on FMEA. The materials provide a definition of the FMEA form and examples of the Design and Process FMEA. However, there are many inconsistencies throughout the literature. As a result, FMEA is not always value-added.

The thesis is twofold. First, it documents a case study that uses Design FMEA extensively. The case …

Internal Forces In A Reinforced Concrete Box Culvert, Scott Mitchell Wood

Masters Theses

In 1996, a reinforced concrete box culvert with approximately 19 meters of embankment fill was instrumented with strain gages and pressure cells to determine the internal forces applied to the culvert. Strain and pressure readings were taken for a period of 3 years during and after the construction of the embankment. From a knowledge of the culvert's dimensions and material properties, the strain readings were converted to forces and bending moments. These forces were then compared to the allowable criteria from the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Highway Bridges. A computer model of …

Layer Properties Of Oriented Strandboard, Caryn Steidl

Masters Theses

It is well known that the density varies through the thickness of oriented strandboard, with the face being much denser than the core. Hence, the modulus of elasticity and the strength should vary through the thickness. To determine the variation in these properties through the thickness of the panel, a commercial oriented strandboard panel was sliced into fifteen layers to obtain specimens for tension and compression testing. Using multiple saw blades and spacers mounted on an arbor in a milling machine, thin specimens were obtained both perpendicular and parallel to panel length. The specimens were tested in tension using straight-sided …

Learning Reinforced Concreyte Design Principles Using A Java-Vrml Based Design Studio, Amarneethi Vamadevan

Masters Theses

Dynamics involving reinforced concrete design are the first real engineering course encountered by the undergraduate construction engineering students. Quite often its associated rigorous theories makes it an uninteresting academic hurdle for many below mediocre students. However when the theory is exemplified with multimedia, interaction and visualization techniques, the conceptual understanding is enhanced. The teaching methodology presented in this thesis is based on presenting students with an individualized, interactive and guided learning environment. The main elements of this approach are: a means of assimilating the student's interactive learning knowledge and behavior (user model), representation of the instructor's guidance and assessment knowledge …

A Cmos Chaotic Oscillator, Boonsin Chansilp

Masters Theses

A chaotic oscillator may be used as the basic component of an associative memory (AM). An AM is capable of pattern separation and noise reduction. Chua's circuit is a widely used chaotic oscillator. This circuit consists of a nonlinear resistor, two capacitors, an inductor and a resistor. A discrete implementation of Chua's circuit may be built using operational amplifiers, resistors, diodes, or discrete bipolar transistors. CMOS integrated circuit technology provides the opportunity for a compact implementation which enables construction of systems requiring a large number of oscillators. This thesis develops an integrated circuit design based on previous work performed by …

Investigation Of Pattern Classification And Feature Selection Of Gaussian Processes, Vivek Ramaprasad

Masters Theses

"This thesis focuses on the application of statistical techniques for pattern classification where the patterns are power spectra of the recorded acoustic signals of occluded objects. Different approaches used to classify are : The Bayes linear and piece-wise linear classifiers, the correlation classifier, classification using error spectra and the clustering algorithm. Classifiers were designed and experiments were conducted to investigate the performance. The performance is evaluated in terms of the percentage efficiency by counting the number of vectors identified correctly and the number of vectors which were misclassified. The feature vectors from primitive measurement space is then reduced to lesser …

A Neural Network Methodology For Path Planning And Coordination Of Car-Like Robots, Prasanna Venkatesan Sadagopan

Masters Theses

"A car-like indoor mobile robot is a kinematically constrained robot that can be modeled as a 2D object translating and rotating in the horizontal plane among well- defined obstacles. The kinematic constraints impose that the linear velocity of the robot is along its main axis (no sideways motion is possible) and restrict the range of admissible values for the steering angle. The goal of this study is to combine neural network techniques and motion planning algorithms to create a new methodology for coordinating the motion of multiple car-like robots avoiding collision with polygonal obstacles in a work environment. An incremental …

Reconstitution And Characterization Of Membrane Proteins, Sarah Mia Pates

Masters Theses

“A membrane protein, cytochrome c reductase, was crystallized and examined using transmission electron microscopy. Two-dimensional crystals were prepared by two methods. In Method 1, the protein was solubilized in 50 mM Tris-Acetate (pH 6.0)/0.5 mM EDTA70.05% (w/v) Triton X-100 and reconstituted into a mixture of phosphatidylcholine and phosphatidylserine (4:1), dissolved in the same buffer. The Triton X-100 was removed from the mixture by dialysis in the presence of Bio-beads (SM-2) at approximately 25-30 °C. Method 2 was the same as Method 1, except that the vesicles were fractionated before reconstitution, and the pH and temperature for crystallization were 7.0 and …

Cellular Automata Study Of The Feasibility Of A Parallel Optical Computer, Jason Robert Lane

Masters Theses

"The speed of modern electronic computers has inherent design limitations which will soon be reached. A possible substitute is the optical computer. In this project, the feasibility of the optical computer is explored by designing and building a parallel optical system. This system is used to test the basic principles that would govern a parallel optical computer. The system is based on the principle of cellular automata, which is a simulation technique used to study interactions of objects in a system. The following goals were set. The system would be based on cellular automata. A one-dimensional array with nine cells, …

Effect Of Antioxidants On Ultra High Molecular Weight Polyethylene (Uhmwpe), Clifford Schrader

Masters Theses

This thesis presents a study on the effects of antioxidants on the oxidative induction time (OIT), thermal behavior, and hardness property of ultra high molecular weight polyethylene (UHMWPE). The antioxidants were dissolved into methanol alcohol before the solution was mixed with UHMWPE powder. The mixture was degassed under vacuum, and then compression-molded into disks 1.25 in. in diameter.

Different antioxidants were evaluated at concentrations up to 0.6 percent. A 0.6 percent concentration was used to screen the effectiveness of various antioxidants. Effect of antioxidant concentration was investigated in the range between 0 and 0.6 percent. OIT was evaluated on UHMWPE …