Engineering Commons^™

Non-Destructive Evaluation Of Space Shuttle Thermal Protection System Tile Bond Integrity, George David Mulligan

Retrospective Theses and Dissertations

Experimental modal analysis (EMA) is used as a non-destructive technique for the evaluation of Space Shuttle thermal protection system (TPS) tile bond integrity. Finite element (FE) models for tile systems were developed and were used to generate their vibration characteristics (i.e. natural frequencies and mode shapes). Various TPS tile assembly configurations as well as different bond conditions were analyzed. Results of finite element analyses demonstrated a drop in natural frequencies and a change in mode shapes which correlate with both size and location of disband. Results of experimental testing of tile panels correlated with FE results and demonstrated the feasibility …

Microchannel Fluid Flow In A Silicon Chip, Ronald R. Ulseth

Retrospective Theses and Dissertations

The objective of this study was to analyze theoretically and experimentally the fluid characteristics of forced flow in microchannels. An apparatus was designed and constructed to allow microflow through a 450 μm wide by 17. 5 μm deep microchannel in a silicon chip. The flow through the chip was laminar with Reynolds numbers not exceeding 100. Tuckerman and Pease (1981) theorized that microscopic heat exchangers etched in the back of silicon chips could provide for efficient heat removal from the chips at rates much higher than the conventional methods could attain. The best technologies available provided for heat removal rates …

Emissions Of Hexavalent Chromium From Hard Chromium Plating Operations, Mitchell Scott Hall

Retrospective Theses and Dissertations

This research addresses emissions of hexavalent chromium mist from hard chromium electroplating operations. Most of these emissions are typically captured by a ventilation stack and directed to a pollution control device; those which escape capture are called fugitive emissions. Releases of toxic materials such as hexavalent chromium must be reported annually to the Environmental Protection Agency (EPA) under provisions of the Superfund Amendments and Reauthorization Act (SARA) Title III of 1986 via the Toxic Release Inventory (TRI), Form R. The objectives were: (1) to provide estimates of fugitive hexavalent chromium emissions for the completion of Form R; and (2) to …

Energy Use In Attached And Detached Residential Developments: Survey Results, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

The relationship between land use, density, dwelling types and energy use in Florida has never been comprehensively examined. Few people consider both energy used in housing and energy used for local transportation. Florida state officials and some land planners have called for compact urban growth to reduce traffic congestion and travel distances. However, energy is rarely mentioned in these arguments. Local governments are trying to respond to the state's concern for compact growth. Developers, on the other hand, are concerned with meeting the local regulations. Unfortunately, energy use is seldom considered and there is little data available to guide decision …

Investigation Of Air Distribution System Leakage And Its Impacts In Central Florida Homes, Florida Solar Energy Center, James B. Cummings

FSEC Energy Research Center®

Testing for air leakage in air distribution systems was done in 160 central Florida homes. Tracer gas tests found that infiltration rates were three times greater when the air handler was operating that when it was off, indicating that there are large leaks in the air distribution system. Infiltration averaged 0.91 air changes per hour (ach) with the air handler (AH) operating continuously and 0.28 ach with the AH off. Return leaks were measured by tracer gas and found to average 10.7% of AH total flow. House airtightness, in 99 of these homes, determined by blower door testing, averaged 12.7 …

Measuring Thermostat And Air Conditioner Performance In Florida Homes, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This report summarizes the experimental results from 30 field tests in 23 Central Florida homes during the Summer of 1990. Detailed thermostat measurements were made at each site for a one to three day period. The purpose of this study was to determine how thermostats operate in actual buildings. This knowledge is necessary to understand the part load performance of air conditioners (ACs).

Monitored Energy Use Characteristics Of A Florida Residence: Demonstration Of A Research Monitoring Protocol, Data Acquisition System And Associated Analysis Methods, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

This report summarizes the first four months of data collection on the author's home in Cocoa Beach, Florida. This project was designed to develop and test a residential monitoring protocol for a cooling dominated climate. The project has demonstrated that useful research results can be obtained from the detailed monitoring of a single occupied residential home.

Impacts Of Duct Leakage On Infiltration Rates, Space Conditioning Energy Use, And Peak Electrical Demand In Florida Homes, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Testing for duct leakage was done in 91 homes. Tracer gas tests found that infiltration rates were four times greater when the air handler was operating than when it was off. Return leaks were found to average 10.0% of air handler total flow. House airtightness, in 63 of these homes, determined by blower door testing, averaged 12.38 air changes per hour at 50 Pascals (ACH50). When the duct registers were sealed, ACH50 decreased to 10.93, indicating that 11.7% of the house leaks were in the duct system.

Duct repairs were made on 25 homes. Blower door tests found 12.30 air …

A Stratified Air Model For Simulation Of Attic Thermal Performance, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An improved computer simulation model for attics has been developed. The model accounts for detailed radiation, buoyancy and wind driven air flows and thermal stratification within the attic airspace. Through comparison with measured data, the paper examines the relative importance of the various modeling parameters and assumptions upon simulation accuracy. Stratification of the attic air was found to be a critical modeling characteristic which is typically ignored in building energy simulations. Both model and measurement results shows that air stratification increases significantly when low-emittance surfaces are included.

Combined Photolasticity And Elastostatic Boundary Element Method In Solid Mechanics Applications, Troy Duane Jensen

Retrospective Theses and Dissertations

Considerable efforts have recently been made on combining experimental and numerical techniques in a so called "hybrid" method for stress analysis. One of these techniques is combining photoelastic "experimental" data with the boundary element "numerical" method. Most of this work has centered on using the boundary element method to solve the potential problem (i.e., Laplace's equation) where external boundary conditions must be specified. The results are combined with the photoelastic isochromatic information to separate the principal stresses at any desired interior location. This thesis, however, concentrates on combining the photoelastic data with the elastostatic boundary element method. This is advantageou~ …

Transportation Synthetic Modeling For New Villages In Northeast Florida Using Fsutms, Yazan Kamal Haddad

Retrospective Theses and Dissertations

The Villages of Seminole Forest is a fifty-eight-thousand acre developnent located between Clay arrl Putnam Counties in Northeast Florida and is proposed to have a build-out year in 2043. As required by the Florida Deparbnent of Conmunity Affairs (OCA) , a Developnent of Regional Irn:Pact {DRI) was prepared to study the impact that this developnent might exert on nunerous elements, such as wetlands, wildlife, water, soils, flood-plains, air, and transportation. The Florida Standard Urban Transportation M::>del Structure {FSU'IMS) was utilized in preparing the transportation elanent of the DRI. A roadway network for the project was developed, and FSU'IMS was …

The Enhancemnt Of N-Heptane Vapor Incineration Using Ozone And Hydrogen Peroxide, Michael William Hewett

Retrospective Theses and Dissertations

Using a narrow bore quartz tube reactor set inside a three zone Lindburg furnace, a measured air stream with a known concentration of n-heptane was heated to temperatures between 637°C and 687°C. A separate measured air stream with known concentrations of ozone was injected just prior to the thermal zone of the reactor. The differences in heptane concentration entering and exiting the reactor under varying time, temperature, and ozone conditions were monitored with a gas chromatograph in an effort to generate kinetic data. The reactor was modeled as a first order plug flow reactor. The constants in the Arrhenius equation …

Precipitation, Inter-Event Dry Periods, And Reuse Design Curves For Selected Areas Of Florida, Martin Wanielista

BMP Trains Research and Publications

No abstract provided.

Error Control Coding For Meteor Burst Communications, Thomas J. Frederick

Retrospective Theses and Dissertations

The phenomenon of meteor burst communications is described and its mathematical model is presented. Protocols for meteors burst systems are outlined and examples are given of current use. Recent research in the area of coding performance in meteor burst systems is pointed out. The performance of several error control coding schemes for a meteor burst channel, including two new adaptive algorithms, are evaluated via analysis and simulation. These coding strategies are compared using the probability of successful transmission of a fixed size packet through a single burst as a performance measure. The coding methods are compared via simulation for several …

Itasq : An Ada-Based Interactive Tool For Assessing Software Quality, Ruby Marie Heintze

Retrospective Theses and Dissertations

The goal of producing high quality computer programs brings with it the need for a set of quantitative measures that software engineers can use to measure various aspects of software quality. These quantitative measures, known as software metrics, can measure different aspects of program quality. For example, McCabe's Complexity Metric measures the decision structure of a computer program; Halstead's Software Science measures program "impurities II such as unfactored expressions and unnecessary replacements; and Vitro•s Module Coupling Metric measures data transfer characteristics between modules. Using only one of these metrics would not provide a well rounded measure of overall software quality. …

Surface Acoustic Wave Resonator Parameter Extraction And Oscillator Design, Mark Stephen Cavin

Retrospective Theses and Dissertations

Surface Acoustic Wave (SAW) resonators are frequently used in UHF oscillator designs. SAW resonators are available in the 100 MHz - 1 GHz frequency range which eliminates the need for frequency multiplication necessary with Bulk Acoustic Wave (BAW) devices. As operating frequencies increase, circuit parasitics play a larger role in device performance. One important source of parasitics is the device package and associated interconnects. To model a SAW resonator effectively, these parasitics need to be taken into account Resonator device models and their associated S-parameters can then be used in the design of oscillators. This thesis will discuss the design …

An Evaluation Of A Prototype Osi-Based Communications Architecture For The Distributed Interactive Simulation Application Utilizing The Isode, Margaret Lucas Loper

Retrospective Theses and Dissertations

The advent of computer networking has spawned a wide variety of applications and technologies. Among the most exiciting and pro1nising of these is Distributed Interactive Sin1ulation (DIS). This technology involves the interconnecting of simulated (virtual) environ men ts which allow participants in one simulation to interact, in real time, with those in another simulation, and observe their interactions by means of out-thewindow views of the individual simulators. The key to the evolution and worldwide acceptance of this DIS technology will be the adoption and integration of standard computer networking methodologies (i.e., Open Systems Interconnection (OSI)) into the overall DIS system …

Precipitation And Inter-Event Dry Periods For Selected Areas Of Florida, Teresa Rae Lineback

Retrospective Theses and Dissertations

The increase in the pollution of existing water bodies due to poor management of storwater runoff has demanded continuous re-evaluation of present design methods for stormwater management facilities. Current criteria used in determining water quality (treatment) volumes in pond design neglect antecedent conditions resulting from preceding rainfall. The inter-event dry period refers to that time period (hours) which occurs between rainfall events. The

minimum inter-event dry period used for pollution control design should be consistent with the time required for infiltration, chemical precipitation, sediment removal, and biological assimilation; as well as the period of time required to minimize the cumulative …

Surface Mapping And Automatic Tool Path Generation, Labiche Ferreira

Retrospective Theses and Dissertations

With the use of machine vision systems in the manufacturing cycle of a product, the lead time for producing the final product has been substantially reduced. Efforts in the past have aimed at automating the tasks right from the drawing board stage to final production of the product. Such technologies include CAD, CAM, and CAPP. However the task of tool path (NC code) generation has not yet been fully automated. In the current techniques, the user plays a crucial role in the NC code generation process. There is an increasing trend for using machine vision systems in the fabrication of …

Photorefractive Materials For Optical Signal Processing, William B. Lawler

Retrospective Theses and Dissertations

The optical response of the photorefractive crystals KNbO₃:Ta, KNbO₃:Fe, LiNbO₃:Fe, and nominally pure BaTiO₃ is investigated. In the experiment, a holographic grating is built in the crystal under investigation via a two-wave mixing scheme that utilizes the signal-processing capacities of two acousto-optic Bragg cells. The dynamic interaction of the Bragg cells with the photorefractive grating causes a heterodyned RF signal to appear on the output laser beam, enabling the real-time, direct measurement of the amplitude and phase of the space-charge fields in the crystal. Experimental results are presented for the amplitude and phase …

Application Of A Six-State Passive Track Filter Within A Weapon-Delivery System For A Lock-On-After-Launch Missile, Lynda Jeanne Ciaponi

Retrospective Theses and Dissertations

Knowing the benefits that a passive air target tracking system gives the host aircraft attempting to conceal its own presence on the battlefield, it is desired to determine whether the aircraft can also deliver one of its own lock-on-after-launch air-to-air missiles to the target via use of the same passive system. The objective of this thesis is to demonstrate that a passive six-state track filter can be successfully used within such a weapon delivery system. The role of the filter within the system is to track the enemy target in cartesian space utilizing only line-of-sight measurements and to track the …

Texture Segmentation And Classification Using Fractal And Energy Measures, Qing Chen

Retrospective Theses and Dissertations

This thesis introduces a multi-feature based texture segmentation and classifi­ cation algorithm. We first present general background on segmentation approaches which can be categorized into three groups : characteristic thresholding and clus­ tering, edge detection, and region merging. According to our texture segmentation objective, we choose characteristic thresholding and clustering along with region merging as our segmentation method which is accomplished by a popular K-mean algorithm applied in the feature space. Fractal geometry is receiving increasing attention as a model for natural phe­ nomena. We present an efficient method for estimating the fractal dimension of image surfaces and show that …

Design Curves For The Reuse Of Stormwater, Gregory Miller Harper

Retrospective Theses and Dissertations

The reuse of stormwater runoff is becoming an increasingly popular addition to stormwater management systems. The advantages include a reduction in pollution and volume discharges to surface waters, the return of runoff to the ground, and savings in the cost of using potable water. This research, by developing a relationship between the reuse volume (temporary storage volume), the rate at which stormwater is reused, and the percentage of annual surface runoff that is reused, provides a procedure in which to design stormwater reuse systems. The traditional design of pond temporary storage volume has been based on the consideration of water …

Rs170 Image Processing Interface, Charlotte Christou

Retrospective Theses and Dissertations

This thesis deals with the hardware design and implementation of an image processing board that digitizes RS-170 video, passes it thru a sobel filter and sends the results to a high-resolution color printer. Most sobels deal with black and white images, but this thesis uses a static color image. The hardware design will allow direct printing from a RGB separate channel RSl 70 video source to a Tektronix 4693DX Color Printer through a Centronics port. It will also allow the red, blue and green video channels to pass through a sobel filter, with the resulting image being sent out to …

An Analysis Of The Parameters Affecting The Stabilization Rate Of Yard Waste Compost, Patricia G. Fleming

Retrospective Theses and Dissertations

In recent times, municipalities have turned to yard waste composting in an effort to comply with mandated recycling and reduction laws aimed at extending existing landfill capacity. Composting is a biological process whereby decomposition of organic matter occurs under aerobic conditions, producing a stabilized humified material. The objective of the research was to analyze data gathered during pilot yard waste composting operations utilizing the windrow method. The following tasks were accomplished: temperature and oxygen profiles from daily monitoring data were examined and the effect these parameters had on stabilization was determined; stabilization time of varying yard waste matrices was compared …

The Planet Janitor: A Symbol Of Global Concerns, Florida Solar Energy Center, Public Information Office

FSEC Energy Research Center®

Meet the Planet Janitor. A kindly, yet determined gentleman. He works at the Florida Solar Energy Center where he is a spokesman for energy-related issues. He illustrates the need to sweep up all environmental messes we've made. He reminds us to maintain our home - Planet Earth. He dramatizes our role as custodians of our children's inheritance. He knows and he shows how the individual can make a difference.

Renewable Energy Activities For Middle Grades, Florida Solar Energy Center, David Lahart

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) is a research and education arm of the State University System hosted by the University of Central Florida. The Florida legislature established FSEC in 1974 to conduct research in alternative energy technologies, to ensure the quality of solar energy equipment sold in Florida, and to educate people about renewable energy technology.

One method of disseminating research results has been through teacher education programs and the development of instructional materials. FSEC-developed materials are designed to teach science and social studies research methods and/or process skills. The units have been field-tested and correlated with student performance …

Radon Pressure Differential Project; Phase Ii Infiltration, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Testing has been done on 50 central Florida homes to assess and characterize house infiltration rates in new (age five years or less) Florida homes. These 50 were drawn randomly from a sample of 70 homes which had been previously tested to determine house airtightness, air distribution system leakage, and pressure differentials. The 50 homes had an average airtightness of 7.31 air changes per hour at 50 Pascals (ACH50). Significant leaks were found in the ductwork in a majority of homes tested, both on the supply and return sides of the air handler. When the air distribution system was sealed …

Radon Pressure Differential Project, Phase I, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Testing has been done on 70 central Florida homes to assess and characterize pressure differentials in new (age five years or less) Florida homes. Blower door testing was done to determine house airtightness and air distribution system leakage. The 70 homes had an average airtightness of 7.23 air changes per hour at 50 Pascals (ACH50). Significant leaks were found in the ductwork in a majority of homes tested, both on the supply and return sides of the air handler. When the air distribution system was sealed off, house ACH50 decreased to 6.42, indicating that 11.2% of the house leak area …

Electrical Use, Efficiency, And Peak Demand Of Electric Resistance, Heat Pump, Desuperheater, And Solar Hot Water Systems, Florida Solar Energy Center, Timothy Merrigan

FSEC Energy Research Center®

Eighty single family residences in Florida were monitored for two years in order to collect data on water heating electrical energy consumption, efficiency, and time-of-day demand. The homes were divided into equally sized samples of four different water heating systems: conventional electric resistance, heat pump, desuperheater and solar hot water systems. Electrical consumption for electric resistance water heaters averaged 8.3 kWh per day in Florida with an average water heating system efficiency of 82%. Desuperheaters used an annual average of 7.4 kWh per day at an annual system efficiency of 110% and heat pump water heaters used 6.1 kWh per …