Engineering Commons^™

An Investigation Of Signs For Median Crossovers, Gillian M. Worsey

Doctoral Dissertations

“This paper describes a study of advance warning signs for median crossovers on divided highways. Candidate crossover signs were identified from a literature review, survey of current State practices and discussions with FHWA personnel. Seven of these signs were selected for further testing in a laboratory study for legibility, understanding and driver preference. Sixty subjects representing a cross-section of drivers took part in the study, thirty at the Turner-Fairbanks Highway Research Center in McLean, Virginia and thirty at the University of Missouri--Rolla in Rolla, Missouri.

Two of the seven signs were word messages and five were symbolic signs. The results …

A New Automated Pulse Testing Analysis Method Applying Inflection Point Theory, Jose Maria Donoso

Masters Theses

"This paper describes a new technique for pulse test analysis that combines the simplicity of the tangent method with the result repeatability of the iterative methods. Inflection points are used instead of time lag with the added advantage that they are calculated by a simple algorithm and are not subject to graphical misinterpretation. Charts are made for the calculation of transmissibility and storage for unequal pulse and shut-in periods from 0.1 to 0.9 relating inflection time to pulse response amplitude and dimensionless inflection time.

The graphs presented for this technique have the same dimensionless cycle period ranges (from 0.44 to …

A New Basin Characteristic For Use In Estimating Impervious Area And Flood Discharges In Urban Missouri Basins, Rodney E. Southard

Masters Theses

"A previous regression analysis of flood peaks on urban basins in St. Louis County, Missouri, indicated that the percentage of impervious area and drainage area were the only basin characteristics of statistical significance in estimating the 2-, 5-, 10-, 25-, 50-, and 100-year peak-flow discharges at ungaged urban basins. In this statewide regression analysis of urban basins, a new basin characteristic called the percentage of developed area was computed and used in a simple regression analysis. The regression analysis included percentage of developed area as the independent variable and impervious area as the dependent variable, resulting in a simplified procedure …

Fuel Loading For A Low-Leakage Core In A Pressurized Water Reactor, Omar Ivan Aguilar

Masters Theses

"A study of low-leakage core fuel loading as a means to reduce fast neutron flux incident upon the pressure vessel is presented. The specific case under study is Cycle 5 of Arkansas Nuclear One - Unit Two (ANO-2), a Combustion Engineering Pressurized Water Reactor. Neutron transport calculations were performed using the DOT two-dimensional transport code. The results from DOT provide the angular distribution of the fast neutron flux at the surface of the pressure vessel.

Seven different fuel loading schemes were studied and compared to the Reference Case. The angular distribution of the fast neutron flux for all cases studied …

Experimental Investigation Of The Effect Of Geological Discontinuity Conditions Of Rock Splitting By Blasting, Shijie Qu

Masters Theses

"A series of modal scale, two borehole splitting test blasts was geometrically designed both with concrete and with Plexiglas. The discontinuities were all symetrically located midway between split holes and were oriented perpendicular to the desired split plane. Sand and clay filled discontinuities of 1/16, 1/8 and 1/4 inch width, and closed discontinuities were used. Both discontinuity frequency and width generally reduced the maximum successful split-hole spacing. The regularity and integrity of the split profile became poorer as the discontinuities were closer to the boreholes and the discontinuity width became greater, due to the cratering effect which occurred from the …

An Experimental Investigation Of Electrochemical Memory Cells, Timothy Jules Martin

Masters Theses

"An experimental electrochemical memory cell was constructed using a Pt cathode, Cu anode, and CuS0₄ electrolyte. The mechanism of operation of this cell consisted of plating and stripping of Cu from the Pt cathode. A cathode surface area of l.33 X 10^-4 cm² required approximately 700 μs to store 5 monolayers of Cu, writing time. The access time would be the time required to measure the Pt/Cu potential and was undetermined. Fifteen seconds were projected to oxidize the plated copper, producing loss of information, resulting in poor volatility characteristics of the cell. However, this electrochemical memory cell …

The Effect Of Oxygen Partial Pressure On Oxygen And Carbon Incorporation In Czochralski Grown Single Crystal Silicon, Paul Shane Carter

Masters Theses

"The study herein detailed was made to determine the effect of varying the oxygen partial pressure of a Czochralski type crystal pulling furnace using conventional hardware and remelt silicon on the level of incorporated oxygen and carbon in the single crystal. The oxygen partial pressure was measured by a zirconia type oxygen sensor and controlled by additions of hydrogen or carbon dioxide to the argon purge gas. The oxygen and carbon incorporation measurements were made by the Fourier Transform Infrared (FTIR) method, using the American Standard for Testing Materials (ASTM) standard calibration.

During the study boules which were zero dislocation …

Utilization Of A Carbon-Dioxide Laser To Form An Amorphous Metallic Layer On Gray Cast Iron With Various Amount Of Boron, Majid Torkzadeh Tabrizi

Dissertations and Theses @ UNI

The study of the amorphous metals in important because of their technological usefulness. One class of these materials, iron-based metallic glass, has shown great promise in application because of the superior chemical, mechanical, electrical, and magnetic properties of these materials.

This study was conducted to examine the capability of a medium-powered carbon-dioxide laser to form an amorphous metallic layer on the surface of a ferritic gray cast iron in order to improve the wear and corrosion resistance of engineered components. Boron was used as an alloying element for the retardation of nucleation and for the formation of the amorphous metallic …

Investigation Of Vscous/Inviscid Interaction In Transonic Flow Over Airfoils With Suction, Chadra S. Vemuru

Mechanical & Aerospace Engineering Theses & Dissertations

The viscous/inviscid interaction over transonic airfoils with and without suction is studied. The streamline angle at the edge of the boundary layer is used to couple the viscous and inviscid flows. The potential flow equations are solved for the inviscid flow field. In the shock region the Euler equations are solved using the method of integral relations. For this the potential flow solution is used as the initial and boundary conditions. An integral method is used to solve the laminar boundary-layer equations. Since both methods are integral methods, a continuous interaction is allowed between the outer inviscid flow region and …

Quadtree-Based Processing Of Digital Images, Ramin Naderi

Dissertations and Theses

Image representation plays an important role in image processing applications, which usually. contain a huge amount of data. An image is a two-dimensional array of points, and each point contains information (eg: color). A 1024 by 1024 pixel image occupies 1 mega byte of space in the main memory. In actual circumstances 2 to 3 mega bytes of space are needed to facilitate the various image processing tasks. Large amounts of secondary memory are also required to hold various data sets.

In this thesis, two different operations on the quadtree are presented.

There are, in general, two types of data …

Post-Buckled Performance Of Partially Restrained And Intermediately Supported Steel Angles, Perumal Radhakrishnan

Dissertations and Theses

The post-buckled performance of cross-braced single angles was experimentally determined. The results of this study will be used by the Bonneville Power Administration for the analysis of member performance in transmission towers.

Development And Testing Of A Heuristic Line Balancing Program For A Microcomputer, Dean B. Creech

Retrospective Theses and Dissertations

Development, operation, and testing of a heuristic line balancing program for a microcomputer are discussed. Tasks are grouped into work stations along an assembly line such that the number of work stations required is minimized.

The model is built primarily using the Hoffman (1963) procedure with modifications described by Gehrlein and Patterson (1975). For purposes of comparison the Rank Positional Weight technique (Helgeson and Birnie, 1961) is also included in the model.

Testing included thirty-seven different balances using problems from the literature. For each balance, both Rank Positional Weight and Hoffmann solutions were obtained in the forward and reverse directions. …

Separation Plane Priority In Computer Image Generation, Keith A. Stump

Retrospective Theses and Dissertations

Flight simulators are devices in which air crews can be trained without the use of actual aircraft. Potentially dangerous maneuvers, such as air-to-air refueling, and destructive exercises, such as evasive action from weaponry or aerial dogfights, can be practiced repeatedly with no risk to pilot or crew. Flight simulators are cost effective since the fuel costs associated with training pilots in actual aircraft can be excessive. Flight simulators offer an alternate training method with reduced cost. The task of a visual flight simulator is to present the trainee with scenes representative of those that would be seen if the actual …

Numerical Simulation Of Air-Conditioning Heat Recovery Water Heating Systems, Amir H. Gorji

Retrospective Theses and Dissertations

A computer simulation program called TRNSYS (Transient System Simulation) was used to model two air-conditioning waste heat recovery water heating configurations. The first model is a heat recovery unit (HRU) that utilizes an 80-gallon storage tank in conjunction with a conventional home air-conditioning system. The second model is similar to the first, except that there is an additional 80-gallon preheat storage tank. An attempt was made to compare simulation results with experimental field data. However, due to problems encountered during the field tests, such as equipment and/or instrumentation failure, there were not enough experimental data to make a rigorous comparison. …

A Performance Comparison Of Solar Radiation Predictive Models For Both Fixed And Tracking Surfaces, William F. Marion

Retrospective Theses and Dissertations

Accurate performance prediction for a system utilizing solar energy requires accurate estimates of the solar radiation received by the collector surface. This thesis compares the performance of five different diffuse solar radiation models in estimating the diffuse radiation received by a tilted surface in the warm, humid climate of Central Florida.

The following models were studied: Isotropic Model, Temps and Coulson Model, Klucher Model, Hay Model, and Perez Model. The models were evaluated for both a fixed south facing surface and for three different tracking schemes suitable for photovoltaic applications. Model estimates were then compared to the solar radiation data …

A Zero Extraction And Separation Technique For Surface Acoustic Wave And Digital Signal Processing Fir Filter Implementation, Keith V. Lindsay

Retrospective Theses and Dissertations

Presented is a new method of separating the zeros of a Finite Impulse Response (FIR) filter producing optimal digital filter of surface acoustic wave (SAW) design implementation. Overviews of zero extraction algorithms and of FIR filter design using the Remez Exchange algorithm are presented (McClellen et al. 1973).

The computer aided design (CAD) procedure presented allows the designer to specify the general filter characteristic which the Remez algorithm translates to FIR time domain coefficients. These coefficients are readily translated to the frequency (z) domain, producing an Nth order polynomial in z. The characteristic polynomial is factored to determine all roots …

The Design And Implementation Of Surface Acoustic Wave Devices For Linear Fm And Nonlinear Fm Pulse Compression Technique For Radar Applications, James C. Walker

Retrospective Theses and Dissertations

The purpose of this work is to design, fabricate, and compare dispersive SAW devices using both linear FM and a new non-linear FM scheme. This new non-linear FM scheme uses the Blackman function as the modulating signal of the FM waveform. Up-chirped and V-chirped devices for both linear and the new non-linear FM scheme and their corresponding matched filters are compared.

Design considerations are discussed in detail. An efficient sampling algorithm (which can also be applied to other non-linearly modulated FM waveforms) developed to facilitate the design of the SAW devices is presented.

Switched-Capacitor Programmable Sallen And Key Lowpass Filters, Karl P. Eriksson

Retrospective Theses and Dissertations

This thesis deals with a different approach to switched-capacitor filters than previously seen by the use of a Sallen and Key topology. It is shown that a Sallen and Key second-order topology approach to a switched-capacitor filter gives reasonable filter performance results, contrary to what the literature leads one to expect. It is also shown that the Sallen and Key second-order topology with modification to a third-order section with buffers results in a high performance switched-capacitor filter with fewer components than previous switched-capacitor filters. This results in fewer monolithic chip size requirements, reduced power requirements, and less cost. Higher order …

Direct Digital Control Of A Liquid Level/Temperature Control Unit, Pedro J. Claudio

Retrospective Theses and Dissertations

A direct digital control algorithm was implemented on a liquid level and temperature control unit. Two control schemes were implemented on the system and the results were compared against a fourth order Runge-Kutta solution.

Both control schemes involved proportional feedback with dynamic adjustment of the operating point. It was found that the control scheme that contained a feedforward component which dealt with the inlet water temperature had a superior dynamic response to setpoint changes. Steady state offsets in both control schemes were attributable to model parameter estimation errors. Differences between the actual and predicted system dynamic response were also attributable …

Cost Effective Design Of The Activated Sludge Wastewater Treatment System, Robert P. Huguenard

Retrospective Theses and Dissertations

In current design practice the components of the complete mix activated sludge system are designed as individual units with little or no appreciation for the process interactions which occur between system components. To achieve acceptable process efficiency and to realize cost effectiveness a unified design approach is necessary. This research effort was initiated to define the characteristics of the economic optimum complete mix activated sludge configuration while considering system interactions.

A computer program was developed for the completion of the process design and the economic analysis of the aeration basins, the settling basins, and the return sludge pumping facilities for …

A Peripheral Subsystem Optimized For Computer Image Generation Applications, John J. Bloomer

Retrospective Theses and Dissertations

Requirements for ever increasing realism in real time computer image generation for military mission and commercial training, have generated the need for a higher performance, more cost effective front-end processor. Current computer image generators front-end general purpose computers are reaching their performance limits in current architectures.

The tasks of this processor include: realtime computations, magnetic disk control, data transfer and direct memory access to and from the balance of the image generator. A new front-end processor system is under development. This multiple-bus, multiprocessor architecture in and of itself does not address disk and external data transfer. A peripheral subsystem is …

Transient Critical Heat Flux, Kemal O. Pasamehmetoglu

Retrospective Theses and Dissertations

The term Critical Heat Flux (CHF) is used in boiling heat transfer to describe the local value of the heat flux at which a characteristic reduction in heat transfer coefficient first occurs. In today’s technology, the CHF is a phenomenon related to the design and safety of various important devices.

A major limitation on the thermal design of a light-water reactor (LWR) is the necessity to maintain an adequate safety margin between the CHF and the local heat flux. Extended operations at local power levels in excess of the CHF can lead to high temperature oxidation and embrittlement or melting …

High Speed Latchup-Free Cmos Using Tisi2, N-Well, Technology, Faheem Mohamedi

Retrospective Theses and Dissertations

This report discusses high speed latchup-free 0.5 µ m-channel CMOS using self-aligned TiSi₂ and deep-trench isolation n-well technology. This technology of deep-trench isolation combined with the epitaxial layer eliminates many problems such as poor device to device isolation, latchup susceptibility and relatively high sheet resistance of n+ and p+ diffusion layers. Thus CMOS devices operate at a propagation delay time of 140 p with a power dissipation of 1.5mW per inverter and attain a maximum clock frequency of 700 MHZ without suffering from latchup even at a latchup trigger current of 100 mA.

A Task Manager For A Multiprocessor Computer System, Peter J. Ingraham

Retrospective Theses and Dissertations

The advent of the 32-bit microprocessor has sparked the manufacture of a number of 32-bit single-board computers (SBCs). These SBCs rival [performance of minicomputers for a fraction of the cost, and a number of them conform to standard 32-bit bus structures. A 32-bit multiprocessor computer system can be created by connecting two or more SBCs on a 32-bit bus. This computer system has the potential of providing many times the power as a single-processor computer system as well as a significant reduction in cost.

The Multiprocessor Task Manager is designed to efficiently distribute software tasks, schedule their execution, and manage …

Design Considerations In The Development Of An Automated Cartographic System, Robert L. Holden

Retrospective Theses and Dissertations

Cartography, the art of producing maps, is an extremely tedious job which is prone to human error and requires many hours for the completion of maps and their digital data bases. Cartography is a classic example of a job that needs to be automated. Through the new advances in image processing and pattern recognition, the automation of this task is made possible with the cartographer acting as a supervisor. This paper reviews current cartographic techniques, and examines design considerations for a fully automated cartographic system. The benefits of such a system would be improvements in speed, flexibility, and accuracy. The …

Design Of A Two-Layer, Capacitively Coupled, Microstrip Patch Antenna Element For Broadband Applications, Robert T. Cock

Retrospective Theses and Dissertations

A broadband, contiguous stacked, two-layer, square microstrip patch antenna element design is described which can be used for a linear or circular polarization. Single layer microstrip patch theory for the rectangular patch radiator is presented and used as a basis for understanding the two-layer patch configuration. The theory is modified to predict radiation patters and resonant frequencies of the two-layer microstrip patch antenna element. Experimental results include the radiation patterns, dominant resonant frequencies (TM₁₀ mode), return loss (S₁₁), and bandwidth for X band elements as a function of dielectric constants, dielectric thicknesses, and patch sizes.

Computer Aided Supplement For Calculus Review, Gholam A. Shaykhian

Retrospective Theses and Dissertations

Several years ago an experimental re-entry program for women was initiated at the University of Central Florida. Women with B.S. degrees in Math or Science dating back 10 and 20 years ago were given a review course in Mathematics, primarily calculus, preparatory to subsequent courses in their M.S. programs of study. The complete course is available on tape and many students have viewed it since the course’s inception.

This project involved generation of software for testing the manipulative skills presented in the Calculus review. A skeleton format is presented which demonstrates all the features of the different programming modules being …

Data Structure Implementation And Investigation For A Prolog Language Interpreter, Hector Iurcovich

Retrospective Theses and Dissertations

A developmental Prolog language interpreter is constructed in the C programming language. The data type format is a subset of that of the Project Aquarius Prolog Engine proposed and under development at the University of California, Berkley. The design of the Prolog interpreter is part of an investigation at UCF in design of expert system architecture for real time applications. The interpreter facilities of data structure definition and manipulation are developed and applied. The list data structure is used as an example data structure. The scheme for representing structured data is based on the Lisp cons cell. Run-time generated lists …

Ground Penetrating Radar In The Detection Of Subsurface Cavities Related To Sinkhole Activity In Florida, Marianne Sweeney

Retrospective Theses and Dissertations

The Florida peninsula is underlain by limestone undergoing continuous solution process resulting in subsurface cavity formation. Increased land development has led to costly structural damage and water supply contamination due to surface subsidence and collapse in areas overlying such cavities. Conventional drilling methods cannot guarantee detection of isolated cavities. A geophysical technique known as ground penetrating radar (GPR) is a non-destructive method in geotechnical investigation capable of surveying large areas quickly and efficiently. GPR works as an echo sounder with a continuous similar graphic display. Cavities are identified by hyperbolic patterns caused by reflections from variations in electrical properties of …

Automated Q-Factor Measurement Via A Network Analyzer, Fadi E. Ayoub

Retrospective Theses and Dissertations

An algorithm is developed for the HP automated network analyzer that can determine the three basic parameters of microwave cavity resonators: the unloaded resonant frequency fo, the unloaded Q-factor Q_o, and the coupling coefficient β. The input reflection coefficient of the resonator is measured via the network analyzer, which is driven by an HP desk computer. The graphical techniques (Smith Chart) are replaced by the much faster calculations on the computer using numerical techniques. Stirling and Bessel’s formulas, in conjunction with the central difference interpolation method, are used to interpolate between sampled points to enhance the accuracy …