Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (5735)
- Physical Sciences and Mathematics (2950)
- Aerospace Engineering (1674)
- Electrical and Computer Engineering (1344)
- Operations Research, Systems Engineering and Industrial Engineering (1247)
-
- Computer Sciences (1236)
- Business (994)
- Physics (919)
- Operational Research (610)
- Signal Processing (459)
- Civil and Environmental Engineering (422)
- Computer Engineering (414)
- Aviation (353)
- Electrical and Electronics (351)
- Social and Behavioral Sciences (349)
- Operations and Supply Chain Management (346)
- Materials Science and Engineering (335)
- Optics (330)
- Oceanography and Atmospheric Sciences and Meteorology (279)
- Navigation, Guidance, Control and Dynamics (252)
- Other Operations Research, Systems Engineering and Industrial Engineering (233)
- Human Resources Management (232)
- Systems Engineering (229)
- Atomic, Molecular and Optical Physics (198)
- Electromagnetics and Photonics (195)
- Aerodynamics and Fluid Mechanics (188)
- Environmental Sciences (188)
- Environmental Engineering (185)
- Nuclear Engineering (180)
- Applied Mathematics (178)
- Keyword
-
- #antcenter (380)
- #csra (134)
- Machine learning (93)
- Decision making (89)
- Algorithms (75)
-
- Global Positioning System (75)
- Image processing (73)
- Kalman filtering (65)
- Optimization (64)
- #afcec (62)
- Computer networks--Security measures (62)
- Drone aircraft (59)
- Computer security (57)
- Target acquisition (57)
- Neural networks (Computer science) (54)
- Software engineering (54)
- Additive manufacturing (52)
- Remote sensing (49)
- Flight control (48)
- Microelectromechanical systems (45)
- Computer vision (44)
- Artificial satellites (43)
- Decision support systems (43)
- #ctisr (42)
- Adaptive optics (42)
- Composite materials (42)
- Neural networks (41)
- Simulation (41)
- Wireless communication systems (41)
- Scheduling (40)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 7291 - 7320 of 8791
Full-Text Articles in Entire DC Network
Electrical Characterization Of 4h-Silicon Carbide P-N Junction Diodes, Michael E. Dunn
Electrical Characterization Of 4h-Silicon Carbide P-N Junction Diodes, Michael E. Dunn
Theses and Dissertations
The current conduction mechanisms of 4H-SiC p+n mesa diodes were studied using current-voltage-temperature (I-V-T), capacitance-voltage-temperature (C-V-T), deep level transient spectroscopy (DLTS), optical observations, and reverse breakdown measurements. Temperature and voltage dependencies of diffusion, recombination, and tunneling current processes are shown to be consistent with Sah-Noyce-Shockley theory. Recombination currents having an ideality factor of A=1.85-2.1 yielded an activation energy of EA=1.56 eV, whereas for ideal recombination, A=2 and EA=1.6 eV. Forward I-V curves of poor diodes dominated by tunneling and recombination processes, showing low reverse breakdown voltages of approx. 100 V, can be correlated to DLTS results …
A Portable Compton Gamma-Ray Camera Design, Brian L. Evans
A Portable Compton Gamma-Ray Camera Design, Brian L. Evans
Theses and Dissertations
The purpose of this research is to investigate the angular resolution, efficiency, and energy resolution possible from a portable Compton camera gamma ray imaging system for possible use in the field of nuclear nonproliferation. The proposed device uses room temperature semiconductor and position sensitive scintillation detectors. The position and energy resolution (and their energy dependence) of a room temperature lithium drifted silicon (Si(Li)) detector and a position sensitive thallium -doped sodium iodide (NaI(Tl)) scintillation detector are investigated. The position and energy resolution of the position sensitive scintillation detector is also modeled computationally, and the results compared to measured data. An …
The Role Of Frame Selection And Bispectrum Phase Reconstruction For Speckle Imaging Through Atmospheric Turbulence, Elizabeth A. Harpold
The Role Of Frame Selection And Bispectrum Phase Reconstruction For Speckle Imaging Through Atmospheric Turbulence, Elizabeth A. Harpold
Theses and Dissertations
Frame selection using quality sharpness metrics have been shown in previous AFIT theses, to be effective in improving the final product of images obtained using adaptive optics. This thesis extends this idea to noncompensated speckle image data. Speckle image reconstruction is simulated with and without frame selection. Speckle images require the processing of hundreds of data frames. Frame selection is a method of reducing the amount of data required to reconstruct the image. A collection of short exposure image data frames of a single object are sorted based on sharpness metrics. Only the highest quality frames are retained and processed …
A Point Model Of Aquifer Cleanup With A Distribution Of First-Order Rate Parameters, Jon E. Hodge
A Point Model Of Aquifer Cleanup With A Distribution Of First-Order Rate Parameters, Jon E. Hodge
Theses and Dissertations
Many try modeling groundwater contaminant transport to predict it. Is this possible with rate-limited processes, and under what conditions? On occasion, cleanups go slower than predicted (tailing) and hazardous concentrations reappear after cleanup is thought complete (rebound). Rate-limited transport is blamed by many. When immobile water is present, diffusion from varied sizes and shapes of immobile regions can cause varied rate limitations (due to varied diffusion path lengths). Although known, most modelers represent these varied rate-limiting processes with a single 'representative' rate-parameter. This can yield poor predictions for long-term experiments, and the parameter is generally time and pump-rate dependent. This …
Photoluminescence And Electroluminescence Of Erbium And Neodymium Implanted Semiconductors, James R. Hunter
Photoluminescence And Electroluminescence Of Erbium And Neodymium Implanted Semiconductors, James R. Hunter
Theses and Dissertations
Low temperature photoluminescence (PL) and electroluminescence (EL) measurements were used to study the excitation of erbium- and neodymium-implanted GaAs and AlxGa1-xAs (x=0. 1, 0.3) pn-junctions. The rare-earth (RE) emissions were investigated as a function of ion dose, aluminum mole fraction, laser excitation power, and applied forward bias voltage for the implanted samples. Low temperature PL was also measured from Er doped silicon grown by the metalorganic chemical vapor-phase deposition (MOCVD) method using various growth parameters.. The MOCVD-grown Si samples were studied as a function of metalorganic source temperature, silane (SiH4) flow, growth time, and …
A Comparison Of Methods For Estimating Rms Error: A `Brute Force" Approach Versus A Mathematically-Elegant Approach, As Applied To The Calculation Of A Specific Retrieval Error For A Limb-Scanning Microwave Radiometer-Spectrometer, Larry L. Johnson
Theses and Dissertations
The Millimeter-wave Atmospheric Sounder (MAS) is a high resolution limb- scanning microwave radiometer-spectrometer which has been flown aboard the Space Shuttle. The instrument was designed to sense the microwave emission from several upper atmospheric constituents, including water vapor and ozone. The resonant frequencies of water vapor and ozone are extremely close (183 and 184 GHz, respectively), so that the high-frequency wing of the water vapor spectrum overlaps the low frequency wing of the ozone spectrum. Consequently, the measured ozone spectrum incorporates a slight water vapor contribution; therefore, the retrieved ozone profile is dependent on the true water vapor profile. The …
Analysis And Interpretation Of Ion Data Associated With Neutral Gas Releases In The Earth's Ionosphere, Timothy M. Shadid
Analysis And Interpretation Of Ion Data Associated With Neutral Gas Releases In The Earth's Ionosphere, Timothy M. Shadid
Theses and Dissertations
Barium and strontium release experiments were conducted throughout 1991 from the Combined Release and Radiation Effects Satellite (CRRES) to study both natural and man-made disturbances in the earth's ionosphere. A mass spectrometer on the spacecraft counted the Ba and Sr ions as the cloud expanded. In this study, data from the G-1 (in sunlight) and G-11b (in darkness) releases were modeled to understand the source of the ion signals. The model reproduced the Ba+ sun data well assuming photoionization (τ = 28 s) was the primary ionization mechanism. However, it was not able to account for the remaining ion …
Identification Of Molecular Laser Transitions Using The Finite Element Method, Matthew C. Smitham
Identification Of Molecular Laser Transitions Using The Finite Element Method, Matthew C. Smitham
Theses and Dissertations
This thesis is a continuation of a previous effort which developed a finite element solution of Schrodinger's Equation. The purpose of this research is to extend this previous work, and develop a chemical laser engineering tool for the identification of transition lines. Identification of laser transitions for a new chemical gain medium requires knowledge of Einstein's Coefficients. These transitions rates can be obtained by solving Schrodinger's Equation for diatomic molecules using the method of finite elements. Experimental vibrational eigenvalues for a given electronic state are used to determine the molecular potential surface which yields the closest numerical result. A non-linear …
Electrical Characterization Of 4h-And 6h-Silicon Carbide Schottky Diodes, Jeffrey C. Wiemeri
Electrical Characterization Of 4h-And 6h-Silicon Carbide Schottky Diodes, Jeffrey C. Wiemeri
Theses and Dissertations
The electrical properties of silicon carbide (SiC) make it an excellent candidate for use in high temperature/high power devices due to its wide bandgap, high breakdown field, high electron mobility, etc. In this work two Schottky diodes of platinum (Pt) on n-type carbon faced 4H-SiC and three Schottky diodes of nickel (Ni) on n-type silicon faced 6H-SiC were electrically characterized. The diodes exhibited good performance up to 698 K for both the forward and reverse (up to -100v) bias voltages. The barrier heights measured by I-V-T tests were found to be 0.32 and 0.61 eV for the Pt/4H-SiC samples, but …
Micromirror Array Control Of A Phase-Locked Laser Diode Array, Carl J. Christensen
Micromirror Array Control Of A Phase-Locked Laser Diode Array, Carl J. Christensen
Theses and Dissertations
A ten element micromirror array has been designed, fabricated, and employed to control the far field irradiance pattern of a phase locked laser diode array. The laser array used in this experiment was a ten element, gain guided array lasing at a nominal wavelength of 828 nm and operating in the it out of phase supermode. The laser's near field irradiance was imaged onto a micromirror array, where the it phase differences between adjacent laser elements were corrected. This was accomplished by moving the micromirrors with individually applied voltages. The result was the desirable single lobed far field pattern, placing …
Objectism 3.0: A Software Architecture For The Development Of Portable Visual Simulation Applications, Shawn M. Hannan
Objectism 3.0: A Software Architecture For The Development Of Portable Visual Simulation Applications, Shawn M. Hannan
Theses and Dissertations
A visual simulation software architecture is a reusable design for visual simulation applications. This thesis effort was the third stage in an ongoing refinement of such an architecture, named ObjectSim. The primary goals of this stage were to improve the architecture by eliminating its dependence on two platform-specific graphics libraries (named GL and Performer, from Silicon Graphics, Inc.), and to examine the potential for expanding the architecture to accommodate distributed simulations. The effort resulted in a new version of the architecture which allows the development of visual simulation applications which take full advantage of the aforementioned libraries without calling those …
The Automated Wingman: An Airborne Companion For Users Of Dis Compatible Flight Simulators, Mark M. Edwards
The Automated Wingman: An Airborne Companion For Users Of Dis Compatible Flight Simulators, Mark M. Edwards
Theses and Dissertations
A major problem encountered by users of distributed virtual environments is the lack of simulators available to populate these environments. This problem is usually remedied by using computer generated entities. Unfortunately, these entities often lack adequate human behavior and are readily identified as non-human. This violates the realism premise of distributed virtual reality and is a major problem, especially in training situations. This thesis addresses the problem by presenting a computer generated entity called the Automated Wingman. The Automated Wingman is a semi-automated computer generated aircraft simulator that operates under the control of a designated lead simulator and integrates distributed …
An Architecture For Dynamic Meta-Level Process Control For Model-Based Troubleshooting, John E. Friskie
An Architecture For Dynamic Meta-Level Process Control For Model-Based Troubleshooting, John E. Friskie
Theses and Dissertations
There are numerous methods used for troubleshooting devices. Each method has certain domains, knowledge requirements, and assumptions required for it to perform well. However, oftentimes no one method by itself is sufficient to completely solve a troubleshooting problem. Therefore, an architecture is required to control the combined use of many problem solving methods. The combination of multiple problem solving methods makes the troubleshooting process more robust in terms of device domains that can be dealt with and quality of diagnoses produced. Troubleshooting has two tasks: diagnosis and problem resolution. This research provides an architecture that allows dynamic method selection during …
Transforming Algebraically-Based Object Models Into A Canonical Form For Design Refinement, Charles G. Beem
Transforming Algebraically-Based Object Models Into A Canonical Form For Design Refinement, Charles G. Beem
Theses and Dissertations
The understandability of object-oriented design techniques and the rigor of formal methods have improved the state of software development; however, both ideas have limitations. Object-oriented techniques, which are semi-formal, can still result in incorrect designs, while formal methods are complex and require an extensive mathematical background. The two approaches can be coupled, however, to produce designs that are both understandable and verifiable, and to produce executable code. This research proposes an approach where object-oriented models are first represented algebraically in a formal specification language such as LARCH and then transformed into a canonical form suitable for design refinement. In the …
The Application Of Hybridized Genetic Algorithms To The Protein Folding Problem, Robert L. Gaulke
The Application Of Hybridized Genetic Algorithms To The Protein Folding Problem, Robert L. Gaulke
Theses and Dissertations
The protein folding problem consists of attempting to determine the native conformation of a protein given its primary structure. This study examines various methods of hybridizing a genetic algorithm implementation in order to minimize an energy function and predict the conformation (structure) of Met-enkephalin. Genetic Algorithms are semi-optimal algorithms designed to explore and exploit a search space. The genetic algorithm uses selection, recombination, and mutation operators on populations of strings which represent possible solutions to the given problem. One step in solving the protein folding problem is the design of efficient energy minimization techniques. A conjugate gradient minimization technique is …
Probabilistic Knowledge Base Validation, Howard T. Gleason
Probabilistic Knowledge Base Validation, Howard T. Gleason
Theses and Dissertations
Our work develops a new methodology and tool for the validation of probabilistic knowledge bases throughout their lifecycle. The methodology minimizes user interaction by automatically modifying incorrect knowledge; only the occurrence of incomplete knowledge involves interaction. These gains are realized by combining and modifying techniques borrowed from rule-based and artificial neural network validation strategies. The presented methodology is demonstrated through BVAL, which is designed for a new knowledge representation, the Bayesian Knowledge Base. This knowledge representation accommodates incomplete knowledge while remaining firmly grounded in probability theory.
An Object-Oriented, Formal Methods Approach To Organizational Process Modeling, Vincent S. Hibdon
An Object-Oriented, Formal Methods Approach To Organizational Process Modeling, Vincent S. Hibdon
Theses and Dissertations
This document presents a methodology for developing an organizational process model which is based on the principles of object oriented design and formal software engineering methods. The methodology begins with the development of an object oriented Rumbaugh model (27). The Rumbaugh model is then formally specified in Z (Zed) schemas. Finally, the Z specifications are translated into an executable model in the Software Refinery Environment(TM). This model is described based on the AF wing domain and developed in this domain. The proposed methodology is then shown to produce a very general model which is extendable across almost any domain. The …
Semantic Interpretation Of An Artificial Neural Network, Stanley D. Kinderknecht
Semantic Interpretation Of An Artificial Neural Network, Stanley D. Kinderknecht
Theses and Dissertations
Recent advances in machine learning theory have opened the door for applications to many difficult problem domains. One area that has achieved great success for stock market analysis/prediction is artificial neural networks. However, knowledge embedded in the neural network is not easily translated into symbolic form. Recent research, exploring the viability of merging artificial neural networks with traditional rule-based expert systems, has achieved limited success. In particular, extracting production (IF.. THEN) rules from a trained neural net based on connection weights provides a valid set of rules only when neuron outputs are close to 0 or 1 (e.g. the output …
Deriving Optimal Solutions From Incomplete Knowledge Bases, Shawn A. Northrop
Deriving Optimal Solutions From Incomplete Knowledge Bases, Shawn A. Northrop
Theses and Dissertations
Many real world domains cannot be represented using Bayesian Networks due to the need for complete probability tables and acyclic knowledge. However, Bayesian Knowledge Bases (BKBs) are a viable method for representing these incomplete domains, but very little research has been performed on inferencing with them. This paper presents three inference engines for extracting optimal solutions from three distinct BKB subclasses: singly- connected, multiply-connected with mutually exclusive cycles, and cyclic. The singly-connected inference engine has a worst case polynomial run time. Performance improvement techniques for increasing inference engine speed are discussed, in addition to a new tool for measuring incompleteness …
An Assessment Of The Impact Of Fuel Jettisoning Events Using Simulation And Impact Models, Jeffrey M. Todd
An Assessment Of The Impact Of Fuel Jettisoning Events Using Simulation And Impact Models, Jeffrey M. Todd
Theses and Dissertations
Work has been accomplished to determine the impact of jettisoned fuel when it reaches the surface. While previous work indicates that jettisoning JP-4 jet fuel results in a negligible ground fall impact, the impact of jettisoning lower volatile JP-8 jet fuel has not been thoroughly characterized. Several efforts have been made to mathematically model the evaporation, advection, and dispersion of the plume of fuel as it travels to the surface. The AFIT Fuel Jettisoning Model, the Fuel Jettisoning Simulation Model, and Fuel-Dumping Impact Assessment Model were evaluated and compared to assess the impact of jettisoned JP-8 jet fuel. Additionally, the …
Design, Fabrication, Processing, And Testing Of Micro-Electro-Mechanical Chemical Sensors, Brian S. Freeman
Design, Fabrication, Processing, And Testing Of Micro-Electro-Mechanical Chemical Sensors, Brian S. Freeman
Theses and Dissertations
Chemical microsensors are a new field integrating chemical thin film technology with solid-state fabrication techniques to make devices capable of detecting chemicals in the environment. This thesis evaluated commercially available fabrication processes and numerous sensor designs for working chemical sensors. The commercial processes used were MUMPS for surface micromachined devices and MOSIS for bulk micromachined devices. Overall, eight fabrication runs and 29 different designs were made. Of these designs, two were shown to work effectively. Other designs failed due to fabrication problems and design errors that caused release problems. One design that worked was a surface micromachined chemoresistor with interdigitated …
Neural Network Analysis Of Chemical Compounds In Nonrebreathing Fisher-344 Rat Breath, Robert E. Sackett Jr.
Neural Network Analysis Of Chemical Compounds In Nonrebreathing Fisher-344 Rat Breath, Robert E. Sackett Jr.
Theses and Dissertations
This research applies statistical and artificial neural network analysis to data obtained from measurement of organic compounds in the breath of a Fisher-344 rat. The Research Triangle Institute (RTI) developed a breath collection system for use with rats in order to collect and determine volatile organic compounds (VOCs) exhaled. The RTI study tested the hypothesis that VOCs, including endogenous compounds, in breath can serve as markers to exposure to various chemical compounds such as drugs, pesticides, or carcinogens normally foreign to living organisms. From a comparative analysis of chromatograms, it was concluded that the administration of carbon tetrachloride dramatically altered …
Geostatistical Analysis Of Hydraulic Conductivity In Heterogeneous Aquifers, Craig S. Biondo
Geostatistical Analysis Of Hydraulic Conductivity In Heterogeneous Aquifers, Craig S. Biondo
Theses and Dissertations
Observations of the spatial variability of hydraulic conductivity of the heterogeneous alluvial aquifer at Columbus Air Force Base in Mississippi are analyzed using parametric geostatistical approaches. Field studies have revealed that the heterogeneity of the aquifer hydraulic conductivity field controls the movement and dispersion of groundwater solutes. Therefore, a means of quantifying spatial variability is essential for the application of flow and solute transport models to practical problems. Application of these models requires a large number of hydraulic conductivity measurements. Geostatistical analysis and kriging estimation procedures assist in providing these large numbers of values when sampling designs have provided sparse …
Evaluating The Feasibility Of Sequential Indicator Simulation In Reproducing Spatial Connectivity In A Heterogeneous Transmissivity Field, D. Duane Kenyon
Evaluating The Feasibility Of Sequential Indicator Simulation In Reproducing Spatial Connectivity In A Heterogeneous Transmissivity Field, D. Duane Kenyon
Theses and Dissertations
A Non-Parametric estimation technique was used to simulate realizations of a heterogeneous transmissivity field based upon sampled values from three different sampling scenarios. These realizations were compared to output from a parametric estimation technique with respect to truth as defined by an exhaustive data set of 6,000 transmissivity values. Estimated transmissivity fields were then used as input into a flow model from which fields of heads and specific discharges were obtained and compared. Given the financial limitations imposed upon the number and quality of samples reasonably available, Sequential Indicator Simulation, a non-parametric technique, was shown to be of considerable value …
Determining The Effects Of Waste Coal Ash On Landfill Radon Levels, Richard S. Krysiak Jr.
Determining The Effects Of Waste Coal Ash On Landfill Radon Levels, Richard S. Krysiak Jr.
Theses and Dissertations
Coal contains trace amounts of the primary radionuclides 40K, and elements of the 4n (232Th), 4n+2 (238U), and 4n+3 (235U) series including 220Rn and 222Rn. Combustion of coal by electric power and heat plants result in concentration of noncombustible mineral matter, including most of the radionuclides, in the coal ash. The increased radiation due to the concentration of radionuclides is known as technologically enhanced natural radiation. The purpose of this research was to determine the effects of landfilled coal ash on one specific aspect of technologically enhanced natural radiation, radon levels. …
The Effects Of Vegetative Canopies On Atmospheric Dispersion, John R. Lindell
The Effects Of Vegetative Canopies On Atmospheric Dispersion, John R. Lindell
Theses and Dissertations
This research was conducted to improve our understanding of the effects of vegetative canopy-induced turbulence on the dispersion of air pollution. The computer model most often used to calculate atmospheric dispersion is the Gaussian plume model, which requires some method to compute the downwind dispersions coefficients. These coefficients are a parameterization of the atmospheric stability or the level of turbulence in the atmosphere. The Environmental Protection Agency's recommended parameterization scheme is the Pasquill-Gifford method. By comparing the Pasquill-Gifford method to the Modified Mitchell method using sigma theta, the standard deviation of the horizontal wind fluctuations, the relative precision of each …
Study Of The Long-Term Desorption Of Trichloroethylene From Clay Soils Using Infrared Spectroscopy, Mary P. Stager
Study Of The Long-Term Desorption Of Trichloroethylene From Clay Soils Using Infrared Spectroscopy, Mary P. Stager
Theses and Dissertations
Slow desorption of contaminants from soil presents one of the greatest challenges to modeling contaminant fate and transport and implementing effective remediation technologies. The kinetics of long-term desorption of trichloroethylene (TCE) from powdered clay soils were studied to determine the desorption rates and mechanism. Infrared absorption spectroscopy was used to monitor the concentration of TCE desorbed from contaminated flint clay for 71 hours. Observed gas phase TCE concentrations as a function of time were compared to that predicted by a one-site Langmuir desorption mechanism. The Langmuir model, with a single type of bonding site, did not account for the release …
Validation Of Operational Multiscale Environment Model With Grid Adaptivity (Omega), Gordon R. Taylor
Validation Of Operational Multiscale Environment Model With Grid Adaptivity (Omega), Gordon R. Taylor
Theses and Dissertations
The Defense Nuclear Agency (DNA) is improving the military's capability to forecast dosage and hazard levels due to release of chemical, biological, and nuclear agents. During Operation DESERT STORM the military realized the need for models to predict risk levels for military personnel assigned proximate to missile attacks. One project associated with this is the continuing development of the Operational Multiscale Environmental Model with Grid Adaptivity (OMEGA). DNA has sponsored AFIT to validate OMEGA with focus on incorporating weather data obtained from Air Force Combat Climatology Center for the period of the Chernobyl Nuclear Accident. The physics of the model …
The Effect Of Meteorological Data Averaging Times On Plume Concentrations From Explosive Ordnance Disposal Open Burning Operations, Ida L. Widmann
The Effect Of Meteorological Data Averaging Times On Plume Concentrations From Explosive Ordnance Disposal Open Burning Operations, Ida L. Widmann
Theses and Dissertations
Explosive Ordnance Disposal (EOD) Open Burning (OB) operations are performed to treat and dispose of unserviceable munitions in the Department of Defense (DOD) inventory. Air pollution modeling of OB operations is an Environmental Protection Agency requirement for permit issuance at OB sites. Specific OB regulation is still in its infancy; therefore, establishment of OB modeling techniques is still in the early stages. This thesis effort sought to develop a computer model, based upon the Gaussian Puff Equation. The model varies from standard plume modeling practices by not making the assumption that the wind direction, wind speed and turbulence are uniform …
Model Of Chlorocarbon (Cfc-12) Chemisorption On Solid Rocket Motor Alumina Exhaust Particles, Gary E. Lund
Model Of Chlorocarbon (Cfc-12) Chemisorption On Solid Rocket Motor Alumina Exhaust Particles, Gary E. Lund
Theses and Dissertations
Solid Rocket (SRMs) that power Titan IV rockets and Space Shuttles, exhaust large quantities of potentially ozone damaging pollutants directly into the stratosphere, while in powered flight. In the past, studies on potential stratospheric impact of the exhaust products from aluminum/ammonium perchlorate based SRMs have focused on the effect of gaseous HCl from SRMs on the stratosphere. Until recently, the impact of heterogeneous chemistry on stratospheric ozone was believed to be relatively insignificant. This research investigates the potential heterogeneous process of CFC-12 dissociative chemisorption on alumina surfaces and the release of reactive halogen species known to destroy ozone. Through a …