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Title: Survey of Instrumentation for Air Quality Surveillance.
Creator: Bowling, John, Erickson, Ernest E., Engineering
Abstract / Description: Florida Technological University College of Engineering Thesis
Date Issued: 1972
Identifier: CFR0012149, ucf:53128
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0012149

Title: DESIGN AND INVESTIGATION OF VITIATED-AIR HEATER FOR OBLIQUE DETONATION-WAVE ENGINE.
Creator: Hoban, Matthew M, Ahmed, Kareem, University of Central Florida
Abstract / Description: A facility was designed to provide high-enthalpy, hypersonic flow to a detonation chamber. Preliminary investigation identified 1300 K and Mach 5 as the total temperature and Mach number require to stabilize an oblique detonation wave inside the detonation chamber. Vitiated-air heating was the preheating method chosen to meet these capabilities. The vitiator facility heats compressed air while still retaining about 50% of the original oxygen content. Schlieren flow visualization and...
Show moreA facility was designed to provide high-enthalpy, hypersonic flow to a detonation chamber. Preliminary investigation identified 1300 K and Mach 5 as the total temperature and Mach number require to stabilize an oblique detonation wave inside the detonation chamber. Vitiated-air heating was the preheating method chosen to meet these capabilities. The vitiator facility heats compressed air while still retaining about 50% of the original oxygen content. Schlieren flow visualization and conventional photography was performed at the exit plane of a choke plate, which simulated the throat of a converging-diverging nozzle. A shock diamond formation was observed within the jet exhausting out of the choke hole. This is a clear indication that the facility is capable of producing hypersonic flow. A stoichiometric propane-air mixture was burned inside the combustion chamber. A thermocouple survey measured an average temperature of 1099 K at the exit plane of the mixing chamber; however, the actual temperature is likely higher than this, because cool, ambient air could be seen mixing with the hot, vitiated air near the exit plane. Because the adiabatic flame temperature of propane-air is lower than that of hydrogen-air, if hydrogen is used to vitiate the air, the facility is capable of meeting the 1300-K objective.
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Date Issued: 2016
Identifier: CFH0000236, ucf:44676
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0000236

Title: INNOVATION ON A BUDGET:THE DEVELOPMENT OF MILITARY TECHNOLOGY DURING THE INTERWAR PERIOD,1919-1939.
Creator: Deupree, William, Foster, Amy, University of Central Florida
Abstract / Description: This thesis investigates the progress of technological development during the interwar period of 1919 to 1939. The interwar period was a time of slashed military budgets and isolationist policies. However, despite political, financial, and organizational handicaps, each branch of the military made significant progress in the development of military technology, and the air corps and navy achieved significantly better results. The reason these two branches were able succeed was through a...
Show moreThis thesis investigates the progress of technological development during the interwar period of 1919 to 1939. The interwar period was a time of slashed military budgets and isolationist policies. However, despite political, financial, and organizational handicaps, each branch of the military made significant progress in the development of military technology, and the air corps and navy achieved significantly better results. The reason these two branches were able succeed was through a combination of organizational policy and the development of an overarching goal for their respective branch. Within this thesis, I investigated each of the major military branches during the interwar period, specifically the United States Army, Army Air Corps, and Navy. The air corps is considered a separate branch despite being a segment of the army due to its different strategic goal and its growing independence during the interwar period. In my research I found that the army made by far the least technological progress, but did make significant strides in terms of the development of individual components for larger projects. For example, the army developed the M1 rifle and state-of-the-art shock absorbers for tanks. The air corps succeeded in transforming from a small army auxiliary made up of wood-and-fabric biplanes into a largely independent branch of the military made up of all-metal monoplane bombers. The navy developed the aircraft carrier and aircraft to accompany the new ships, in addition to making substantial upgrades to existing ships. These upgrades included strengthening ships against torpedo attacks, making engines more efficient, and adding anti-aircraft guns to the ships' arsenals.
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Date Issued: 2011
Identifier: CFE0004036, ucf:49174
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004036

Title: PREDICTING AIR QUALITY NEAR ROADWAY INTERSECTIONS THROUGH THE APPLICATION OF A GAUSSIAN PUFF MODEL TO MOVING SOURCES.
Creator: Kim, Brian, Wayson, Roger, University of Central Florida
Abstract / Description: With substantial health and economic impacts attached to many highway-related projects, it has become imperative that the models used to assess air quality be as accurate as possible. The United States (US) Environmental Protection Agency (EPA) currently promulgates the use of CAL3QHC to model concentrations of carbon monoxide (CO) near roadway intersections. This model uses steady-state and macroscopic methods to model the physical phenomena (e.g., emission rates, atmospheric dispersion, etc...
Show moreWith substantial health and economic impacts attached to many highway-related projects, it has become imperative that the models used to assess air quality be as accurate as possible. The United States (US) Environmental Protection Agency (EPA) currently promulgates the use of CAL3QHC to model concentrations of carbon monoxide (CO) near roadway intersections. This model uses steady-state and macroscopic methods to model the physical phenomena (e.g., emission rates, atmospheric dispersion, etc.) occurring at intersections. These methods are not straightforward and unintuitive for the users. Therefore, this project investigated the possibility of developing a model that is theoretically more realistic and flexible than CAL3QHC. The new model entitled, Traffic Air Quality Simulation Model (TRAQSIM), uses a microscopic approach by modeling vehicle movements and dispersion in a simulation environment. Instead of steady-state plume equations used in the CAL3QHC model, TRAQSIM uses a discrete puff methodology that can be used to model time-based dispersion of pollutants. Most of the components incorporated into TRAQSIM have been drawn from existing methodologies and therefore, are not new. However, the combination of these different methods into a single integrated model is new and presents a novel approach to such a model. Initial verification and sensitivity/trend studies of the model indicate that TRAQSIM uses reasonable/realistic traffic parameters and behaves intuitively correct. A validation study showed that TRAQSIM produces good results when compared to actual measured data with an overall R2 value of 0.605 for 11 scenarios comprising 264 data points. Although most statistical parameters showed CAL3QHC agrees better overall with measured data (R2 value of 0.721), the comparisons were mixed on a scenario-by-scenario basis; that is, CAL3QHC showed better results for 6 scenarios and TRAQSIM showed better results for 5 scenarios. Additional tests with larger datasets, which were beyond the scope of this work, could be conducted to obtain more definitive conclusions and allow further development of TRAQSIM. While CAL3QHC is a mature model that has been developed over many years, TRAQSIM is new and has much more potential for improvement. The physical parameters used in TRAQSIM allow it to be more directly (more logically) improved than the approximations used in CAL3QHC. In addition, although the fundamental-level modeling in TRAQSIM make it a more complex model internally, it is much more intuitive for the user to understand and use.
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Date Issued: 2004
Identifier: CFE0000316, ucf:46306
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000316

Title: Near-road Dispersion Modeling of Mobile Source Air Toxics (MSATs) in Florida.
Creator: Westerlund, Kurt, Cooper, Charles, Radwan, Ahmed, Randall, Andrew, Hall, Steven, University of Central Florida
Abstract / Description: There is a growing public concern that emissions of mobile source air toxics (MSATs) from motor vehicles may pose a threat to human health. At present, no state or federal agencies require dispersion modeling of these compounds, but many agencies are concerned about potential future requirements. Current air pollution professionals are familiar with Federal Highway Administration (FHWA) and U.S. Environmental Protection Agency (EPA) requirements for dispersion modeling to produce predicted...
Show moreThere is a growing public concern that emissions of mobile source air toxics (MSATs) from motor vehicles may pose a threat to human health. At present, no state or federal agencies require dispersion modeling of these compounds, but many agencies are concerned about potential future requirements. Current air pollution professionals are familiar with Federal Highway Administration (FHWA) and U.S. Environmental Protection Agency (EPA) requirements for dispersion modeling to produce predicted concentrations for comparison with appropriate standards. This research examined a method in which the potential near-road concentrations of MSATs were calculated. It was believed that by assessing MSATs in much the same way that are used for other pollutants, the model and methods developed in this research could become a standard for those quantifying MSAT concentrations near-roadways.This dissertation reports on the results from short-term (1-hour) and long-term (annual average) MSATs dispersion modeling that has been conducted on seven intersections and seven freeway segments in the state of Florida. To accomplish the modeling, the CAL3QHC model was modified to handle individual MSAT emissions input data and to predict the concentrations of several MSATs around these roadway facilities. Additionally, since the CAL3MSAT model is DOS based and not user-friendly, time was invested to develop a Windows(&)#174; graphical user interface (GUI). Real-world data (traffic volumes and site geometry) were gathered, worst-case meteorology was selected, mobile source emission factors (EFs) were obtained from MOVES2010a, and worst-case modeling was conducted. Based on a literature search, maximum acceptable concentrations (MACs) were proposed for comparison with the modeled results, for both a short-term (1-hour) averaging time and a long-term (1-year) averaging time.Results from this CAL3MSAT modeling study indicate that for all of the intersections and freeway segments, the worst-case 1-hour modeled concentrations of the MSATs were several orders of magnitude below the proposed short-term MACs. The worst-case 1-year modeled concentrations were of the same order of magnitude as the proposed long-term MACs.The 1-year concentrations were first developed by applying a persistence factor to the worst-case 1-hour concentrations. In the interest of comparing the predicted concentrations from the CAL3MSAT persistence factor approach to other dispersion models, two EPA regulatory models (CAL3QHCR and AERMOD) with the ability to account for yearly meteorology, traffic, and signal timing were used. Both hourly and annual MSAT concentrations were predicted at one large urban intersection and compared for the three different dispersion models. The short-term 1-hour results from CAL3MSAT were higher than those predicted by the two other models due to the worst-case assumptions. Similarly, results indicate that the CAL3MSAT persistence factor approach predicted a worst-case annual average concentration on the same order of magnitude as the two other more refined models. This indicated that the CAL3MSAT model might be useful as a worst-case screening approach.
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Date Issued: 2013
Identifier: CFE0004772, ucf:49804
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004772

Title: Guide to Orlando Air Force Base, Florida, 1959.
Creator: PALMM (Project)
Abstract / Description: Directory of base facilities and surrounding civic, religious, and recreational opportunities for Air Force personnel. Includes many photographs depicting the Orlando area in 1959, as well as a classified advertisement section.
Date Issued: 1959
Identifier: AAB9022QF00007/26/200511/14/200622398SfasKa D0QF, FIPS12095, FHP C UCF 2005-08-03, FCLA url 20060328xOCLC, 75969518, CF00001721, 2584531, ucf:22413
Format: E-book
PURL: http://purl.flvc.org/fcla/tc/fhp/CF00001721.jpg

Title: VERIFICATION OF FAA'S EMISSIONS AND DISPERSION MODELING SYSTEM (EDMS).
Creator: Martin, Anjoli, Wayson, Roger, University of Central Florida
Abstract / Description: Air quality has been a major environmental concern for many years. Recently the issue of airport emissions has presented growing concerns and is being studied in much more depth. Airport emissions come from a variety of point, line and area sources, making emissions modeling for airports very complex and more involved. Accurate air quality models, specific to airport needs, are required to properly analyze this complex array of air pollution sources created by airports. Accurate air quality...
Show moreAir quality has been a major environmental concern for many years. Recently the issue of airport emissions has presented growing concerns and is being studied in much more depth. Airport emissions come from a variety of point, line and area sources, making emissions modeling for airports very complex and more involved. Accurate air quality models, specific to airport needs, are required to properly analyze this complex array of air pollution sources created by airports. Accurate air quality models are needed to plan for increased growth of current airports and address concerns over proposed new ones. The Federal Aviation Administration's (FAA) Emissions and Dispersion Modeling System (EDMS) is a program that is the required model for assessing emissions from airport sources. This research used EDMS Version 4.21, which incorporates the EPA dispersion model AERMOD, to model detailed airport data and compare the model's predicted values to the actual measured carbon monoxide concentrations at 25 locations at a major U.S. airport. Statistics relating the model characteristics as well as trends are presented. In this way, a thorough investigation of the accuracy of the EDMS modeled values of carbon monoxide was possible. EDMS modeling included two scenarios, the first scenario referred to as practice detail included general airport information that a modeler could find from the airport being studied and the second scenario referred to as research detail utilized very detailed information from observer logs during a three day observation period. Each of the modeling scenarios was compared to the field measured data and to each other. These comparisons are important to insure the model is adequately describing emissions sources at airports. Data analysis of this study was disappointing since measured levels of CO were generally higher than modeled values. Since EDMS is continually changing and improving perhaps these results can help enhance future models.
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Date Issued: 2006
Identifier: CFE0001282, ucf:46903
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001282

Title: Evaluation of Postoperative Air Leak and Chest Tube Drainage Systems after Pulmonary Resection.
Creator: Jacobsen, Kristina, Talbert, Steven, Sole, Mary Lou, Guido-Sanz, Francisco, Bittner, Hartmuth, University of Central Florida
Abstract / Description: Postoperative air leaks are the most common complication after a pulmonary resection. There is no data in the literature comparing the traditional and digital chest drainage system after a robotic-assisted pulmonary lobectomy. In 182 eligible patients, this retrospective study evaluated the association between digital and traditional drainage systems with postoperative chest tube days, hospital length of stay, chest tube reinsertion during hospitalization, and 30-day readmission for...
Show morePostoperative air leaks are the most common complication after a pulmonary resection. There is no data in the literature comparing the traditional and digital chest drainage system after a robotic-assisted pulmonary lobectomy. In 182 eligible patients, this retrospective study evaluated the association between digital and traditional drainage systems with postoperative chest tube days, hospital length of stay, chest tube reinsertion during hospitalization, and 30-day readmission for pneumothorax following a robotic-assisted lobectomy. The groups did not differ significantly in terms of age, gender, BMI, smoking, adhesions or neoadjuvant therapy. Patients with the digital drainage system had a mean chest tube duration of 2.07 days compared with 2.73 days for the traditional drainage system (p = 0.003). Hospital length of stay was also significantly reduced with the digital drainage system. Patients using the digital drainage system had a mean hospital length of stay of 4.02 days compared with 5.06 days with the traditional drainage system (p = 0.010). Although chest tube reinsertion occurred four times more frequently with traditional drainage system, the difference did not achieve the level of statistical significance (p = 0.059). The frequency of readmission due to pneumothorax was very low (1 patient per group), which prevented comparative statistical analysis. In the digital drainage system there are shorter chest tube days and hospital length of stay after a robotic-assisted lobectomy. The decision to remove chest tubes in the traditional drainage system is burdened with uncertainty. The digital drainage system reduces intraobserver variability allowing for improved decision making in chest tube removal.
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Date Issued: 2019
Identifier: CFE0007893, ucf:52771
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007893

Title: The safe removal of frozen air from the annulus of a liquid hydrogen storage tank.
Creator: Krenn, Angela, Bhattacharya, Aniket, Youngquist, Robert, Vasu Sumathi, Subith, University of Central Florida
Abstract / Description: Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system...
Show moreLarge Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boiloff is often the first indicator of an air leak. Severe damage can then result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. Two potential methods for air removal are evaluated here. The first method discussed is the connection of a vacuum pump to the annulus which provides pumping in parallel with drainage of LH2. The goal is to keep the annular pressure below the triple point so that the air continues to sublimate, thus eliminating the threat that liquefaction poses. The second method discussed is the application of heat to the bottom of the outer tank during tank drain. Though liquefaction in the annular space will occur, the goal of the heater design is to keep the outer shell above the embrittlement temperature, so that cracking will not occur.In order to evaluate these methods, it is first necessary to characterize some the physical properties and changes that take place in the system. A thermal model of the storage tank was created in SINDA/FLUINT (C(&)R Technologies, 2014) to identify locations where air can freeze. This model shows the volume that is capable of freezing air under varying conditions. It is also necessary to characterize the changes in thermal conductivity of perlite which has nitrogen frozen into its interstitial spaces. The details and results of an experiment designed for that purpose is outlined. All data, including operational data from existing LH2 tanks, is compiled and a physics-based evaluation of the two proposed air removal techniques is performed.Due to small pumping capacities at low pressure and the large quantity of air inside the annulus, the pumping option is not deemed feasible. It would take many years to remove a significant amount of air by pumping while maintaining the annular pressure below the necessary triple point. Application of heating devices is a feasible option. For a specific case, it is shown that approximately 105 kilowatts of power would be required to vaporize the air in the annulus and keep the temperature of the outer tank wall above the freezing point of water. Several engineering solutions to accomplish this are also discussed. There are many unknowns and complexities in addressing the problem of safely removing frozen air from the annulus of an LH2 storage sphere. The work that follows utilized: research, modeling, experimentation, analysis, and data from existing tanks to arrive at possible solutions to the problem. Heating solutions may be implemented immediately and could result in significant savings to the user.
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Date Issued: 2015
Identifier: CFE0005969, ucf:50766
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005969

Title: DEVELOPMENT OF A GRAPHICAL USER INTERFACE FOR CAL3QHC CALLED CALQCAD.
Creator: Gawalpanchi, Sheetal, Cooper, Charles, University of Central Florida
Abstract / Description: One of the major sources of air pollution in the United States metropolitan areas is due to automobiles. With the huge growth of motor vehicles and, greater dependence on them, air pollution problems have been aggravated. According to the EPA, nearly 95% of carbon monoxide (CO ) (EPA 1999) in urban areas comes from mobile sources, of which 51% is contributed by on road vehicles. It is well known fact that, carbon monoxide is one of the major mobile source pollutants and CO has detrimental...
Show moreOne of the major sources of air pollution in the United States metropolitan areas is due to automobiles. With the huge growth of motor vehicles and, greater dependence on them, air pollution problems have been aggravated. According to the EPA, nearly 95% of carbon monoxide (CO ) (EPA 1999) in urban areas comes from mobile sources, of which 51% is contributed by on road vehicles. It is well known fact that, carbon monoxide is one of the major mobile source pollutants and CO has detrimental effects on the human health. Carbon monoxide is the result of mainly incomplete combustion of gasoline in motor vehicles (FDOT 1996). The National Environmental Policy Act (NEPA) gives important considerations to the actions to be taken. Transportation conformity . The Clean Air Act Amendments (CAAA, 1970) was an important step in meeting the National Ambient Air Quality Standards In order to evaluate the effects of CO and Particulate Matter (PM) impacts based on the criteria for NAAQS standards, it is necessary to conduct dispersion modeling of emissions for mobile source emissions. Design of transportation engineering systems (roadway design) should take care of both the flow of the traffic as well as the air pollution aspects involved. Roadway projects need to conform to the State Implementation Plan (SIP) and meet the NAAQS. EPA guidelines for air quality modeling on such roadway intersections recommend the use of CAL3QHC. The model has embedded in it CALINE 3.0 (Benson 1979) – a line source dispersion model based on the Gaussian equation. The model requires parameters with respect to the roadway geometry, fleet volume, averaging time, surface roughness, emission factors, etc. The CAL3QHC model is a DOS based model which requires the modeling parameters to be fed into an input file. The creation of input the file is a tedious job. Previous work at UCF, resulted in the development of CALQVIEW, which expedites this process of creating input files, but the task of extracting the coordinates still has to be done manually. The main aim of the thesis is to reduce the analysis time for modeling emissions from roadway intersections, by expediting the process of extracting the coordinates required for the CAL3QHC model. Normally, transportation engineers design and model intersections for the traffic flow utilizing tools such as AutoCAD, Microstation etc. This thesis was to develop advanced software allowing graphical editing and coordinates capturing from an AutoCAD file. This software was named as CALQCAD. This advanced version will enable the air quality analyst to capture the coordinates from an AutoCAD 2004 file. This should expedite the process of modeling intersections and decrease analyst time from a few days to few hours. The model helps to assure the air quality analyst to retain accuracy during the modeling process. The idea to create the standalone interface was to give the AutoCAD user full functionality of AutoCAD tools in case editing is required to the main drawing. It also provides the modeler with a separate graphical user interface (GUI).
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Date Issued: 2005
Identifier: CFE0000483, ucf:46364
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000483

Title: A STUDY OF CENTRAL FLORIDA NONROAD VOC AND NOX EMISSIONS AND POTENTIAL ACTIONS TO REDUCE EMISSIONS.
Creator: Radford, Michael, Cooper, C. David, University of Central Florida
Abstract / Description: Ground-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this...
Show moreGround-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this study was to compile an emissions inventory of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from nonroad equipment in Osceola, Seminole, and Orange Counties (OSO) in Central Florida, and to develop possible action steps to reduce those emissions. This is important because VOC and NOx emissions are precursors to ground-level ozone. Thus, compiling emissions inventories is important to identify high VOC and NOx emitters. Mobile and point sources have long been the highest emitters of VOC and NOx and have therefore been targeted and monitored since the Clean Air Act of 1970, but the nonroad sources (such as construction and lawn equipment) have only been regulated since the 1990s. Using the NONROAD and NMIM modeling programs, the highest nonroad emitters of VOC for Central Florida were found to be lawn/garden equipment, and boating equipment, emitting a combined percentage of 77% of the total nonroad mobile source VOC. Construction equipment contributed 67% of the total nonroad mobile source emissions of NOx in Central Florida. The components of these categories were also analyzed to find the largest individual sources of VOC and NOx. Of the individual sources, lawn mowers and outboard boat engines were found to be the largest sources of VOCs. Of the NOx sources, all the construction equipment components had a relatively similar level of NOx emissions. Next, action steps were developed to reduce emissions, focusing on the high emitters, along with an estimated cost and feasibility for each measure. Of these steps, implementing a ban on leafblowers, and reducing use of lawn mowers, edgers, trimmers, etc. seemed to be the most effective for reducing VOCs. Although these are effective measures, the cost and feasibility of both pose challenges. The best action step for reducing NOx emissions in construction equipment seemed to be by simply reducing idling of equipment on job sites. This also poses challenges in feasibility and enforcement by management. Further, constant on/off cycles could result in decreasing the useful life of the older construction equipment. Finally, a survey was conducted with various construction managers and companies to find out the typical equipment and quantity needed for land clearing/grubbing, as well as the typical use, idling time, and total project time for each piece of equipment on a 10-acre site, under various conditions. The purpose of the study was to develop a rough estimate for the average amount of VOC and NOx emissions that will be produced per acre of land clearing activities, and to estimate the emissions reductions and cost savings if idling of the equipment was reduced.
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Date Issued: 2009
Identifier: CFE0002850, ucf:48064
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002850

Title: COALITION FORMATION IN MULTI-AGENT UAV SYSTEMS.
Creator: DeJong, Paul, Boloni, Ladislau, University of Central Florida
Abstract / Description: Coalitions are collections of agents that join together to solve a common problem that either cannot be solved individually or can be solved more efficiently as a group. Each individual agent has capabilities that can benefit the group when working together as a coalition. Typically, individual capabilities are joined together in an additive way when forming a coalition. This work will introduce a new operator that is used when combining capabilities, and suggest that the behavior of the...
Show moreCoalitions are collections of agents that join together to solve a common problem that either cannot be solved individually or can be solved more efficiently as a group. Each individual agent has capabilities that can benefit the group when working together as a coalition. Typically, individual capabilities are joined together in an additive way when forming a coalition. This work will introduce a new operator that is used when combining capabilities, and suggest that the behavior of the operator is contextual, depending on the nature of the capability itself. This work considers six different capabilities of Unmanned Air Vehicles (UAV) and determines the nature of the new operator in the context of each capability as coalitions (squadrons) of UAVs are formed. Coalitions are formed using three different search algorithms, both with and without heuristics: Depth-First, Depth-First Iterative Deepening, and Genetic Algorithm (GA). The effectiveness of each algorithm is evaluated. Multi agent-based UAV simulation software was developed and used to test the ideas presented. In addition to coalition formation, the software aims to address additional multi-agent issues such as agent identity, mutability, and communication as applied to UAV systems, in a realistic simulated environment. Social potential fields provide a means of modeling a clustering attractive force at the same time as a collision-avoiding repulsive force, and are used by the simulation to maintain aircraft position relative to other UAVs.
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Date Issued: 2005
Identifier: CFE0000394, ucf:46332
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000394

Title: DETERMINING FLORIDA LANDFILL ODOR BUFFER DISTANCES USING AERMOD.
Creator: Figueroa, Veronica, Cooper, C. David, University of Central Florida
Abstract / Description: As U.S. landfills continue to grow in size, concerns about odorous gas emissions from landfills are increasing. For states that are expanding in population, such as Florida, odors from landfills are a major concern because new housing developments, needed to accommodate the rapid population growth, are creeping closer and closer to the existing landfills. As homes get closer to landfills, odor complaints are likely to become more frequent, causing landfill managers increased problems with...
Show moreAs U.S. landfills continue to grow in size, concerns about odorous gas emissions from landfills are increasing. For states that are expanding in population, such as Florida, odors from landfills are a major concern because new housing developments, needed to accommodate the rapid population growth, are creeping closer and closer to the existing landfills. As homes get closer to landfills, odor complaints are likely to become more frequent, causing landfill managers increased problems with public interactions. Odor buffer zones around landfills need to be established to give municipalities tools to help prevent the building of future homes too close to landfills. Using the latest air dispersion model, AERMOD, research predicted downwind odor concentrations from a Central Florida landfill. Accurate estimates of methane emissions throughout a Central Florida landfill were determined using a new technique developed as part of this research that uses hundreds of ambient air VOC measurements taken within a landfill, as receptors. Hundreds of point sources were placed on the landfill, and the standard Gaussian dispersion equations were solved by matrix inversion methods. The methane emission rates were then used as surrogates for odor emissions to predict downwind odor concentrations via AERMOD. By determining a critical zone around a landfill with regards to odor, stakeholders will be able to meet regulatory issues and assist their communities. Other beneficial uses from this research include: determination of existing gas collection system efficiencies, calculation of fugitive greenhouse gas emissions from municipal solid waste (MSW) landfills, and improved landfill gas management.
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Date Issued: 2008
Identifier: CFE0002200, ucf:47910
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002200

Title: Fatigue Lifetime Approximation based on Quantitative Microstructural Analysis for Air Plasma Sprayed Thermal Barrier Coatings.
Creator: Bargraser, Carmen, Sohn, Yongho, An, Linan, Heinrich, Helge, University of Central Florida
Abstract / Description: The durability of thermal barrier coatings (TBCs) affects the life of the hot section engine components on which they are applied. Fatigue is the general failure mechanism for such components and is responsible for most unexpected failures; therefore it is desirable to develop lifetime approximation models to ensure reliability and durability.In this study, we first examined the microstructural degradation of air plasma sprayed ZrO2-8wt.%Y2O3 TBCs with a low-pressure plasma sprayed CoNiCrAlY...
Show moreThe durability of thermal barrier coatings (TBCs) affects the life of the hot section engine components on which they are applied. Fatigue is the general failure mechanism for such components and is responsible for most unexpected failures; therefore it is desirable to develop lifetime approximation models to ensure reliability and durability.In this study, we first examined the microstructural degradation of air plasma sprayed ZrO2-8wt.%Y2O3 TBCs with a low-pressure plasma sprayed CoNiCrAlY bond coat on an IN 738LC superalloy substrate. The durability of TBCs were assessed through furnace thermal cyclic tests carried out in air at 1100(&)deg;C with a 1-, 10-, and 50-hour dwell period, preceded by a 10-minute heat-up and followed by a 10-minute forced-air-quench. Failure mechanisms of the TBCs were thoroughly investigated through materials characterization techniques including: X-Ray Diffraction, Scanning Electron Microscopy, and Energy Dispersive X-Ray Spectroscopy.Quantitative microstructural analyses were then carried out to document the growth of the thermally grown oxide (TGO) scale, the depletion of the Al-rich ?-NiAl phase in the bond coat, and the population and growth of micro-cracks near the YSZ/bond coat interface. Trends in the TGO growth and the ?-phase depletion in the bond coat followed those of diffusion-controlled processes(-)parabolic growth of the TGO and exponential depletion of the ?-phase. Formation and propagation of cracks within the YSZ resulted in complete spallation of the YSZ topcoat from the bond-coated superalloy substrate.Evolution in these microstructural features was correlated to the lifetime of TBCs, which showed cracking within the YSZ to be the cause of failure; thus a lifetime approximation model was developed, via modification of Paris Law, based on the experimental data. The model predicted the TBC lifetime within 10% of the experimental lifetime.
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Date Issued: 2011
Identifier: CFE0004087, ucf:49145
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004087

Title: Florida macrolichens as potential bioindicators of environmental quality : a baseline study.
Creator: Neal, Harry V., Wanielista, Martin P., Arts and Sciences
Abstract / Description: University of Central Florida College of Arts and Sciences Thesis; Lichens have been used extensively and with considerable success as bioindicators of atmospheric pollution in North America and Europe for more than thirty years. Little research has followed in tropical and subtropical regions where population growth is rapid and environmental pressures unprecedented. However, taxa used as bioindicators in other studies and/or taxa having this potential, occur naturally in Central Florida. A...
Show moreUniversity of Central Florida College of Arts and Sciences Thesis; Lichens have been used extensively and with considerable success as bioindicators of atmospheric pollution in North America and Europe for more than thirty years. Little research has followed in tropical and subtropical regions where population growth is rapid and environmental pressures unprecedented. However, taxa used as bioindicators in other studies and/or taxa having this potential, occur naturally in Central Florida. A new potential major source of pollution, the coal-fired Curtis H. Stanton Energy Canter, is about to begin operation providing the opportunity to determine the extent of impact. Therefore, lichen monitoring sites have been established and the collection of baseline data reflecting species diversity, frequency, overall cover and vitality has been accomplished. Theme locations will be preserved for future monitoring activities. Voucher specimens and photographic documentation of sample populations have been deposited in the herbarium of the University of Central Florida.
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Date Issued: 1986
Identifier: CFR0004338, ucf:52996
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0004338

Title: Simultaneous Imaging of the Diatomic Carbon and Methylidyne Species Radicals for the Quantification of the Fuel to Air Ratio from Low to High Pressure Combustion.
Creator: Reyes, Jonathan, Ahmed, Kareem, Kassab, Alain, Kapat, Jayanta, University of Central Florida
Abstract / Description: The radical intensity ratio of the diatomic carbon to methylidyne was characterized at initialpressures up to 10 bar using certified gasoline of 93% octane. This gasoline was selected due toits availability as a common fuel. The characterization of the radical intensity ratio of gasoline atelevated pressures enabled the creation of a calibration map of the equivalence ratio at enginerelevant conditions.The proposed calibration map acts as a feedback loop for a combustor. It allows for...
Show moreThe radical intensity ratio of the diatomic carbon to methylidyne was characterized at initialpressures up to 10 bar using certified gasoline of 93% octane. This gasoline was selected due toits availability as a common fuel. The characterization of the radical intensity ratio of gasoline atelevated pressures enabled the creation of a calibration map of the equivalence ratio at enginerelevant conditions.The proposed calibration map acts as a feedback loop for a combustor. It allows for thelocation of local rich and lean zones. The local information acquired can be used as an optimizationparameter for injection and ignition timings, and future combustor designs. The calibration map isapplicable at low and high engine loads to characterize a combustors behavior at all points in itsoperation map.Very little emphasis has been placed on the radical intensity ratio of unsteady flames,flames at high pressure, and liquid fuels. The current work performed the measurement on anunsteady flame ignited at different initial pressures employing a constant volume combustionchamber and liquid gasoline as the fuel source. The chamber can sustain a pressure rise of 200 barand allows for homogenous fuel to air mixtures.The results produced a viable calibration map from 1 to 10 bar. The intensity ratio at initialpressures above 5 bar behaved adversely in comparison to the lower pressure tests. The acquiredratios at the higher initial pressures are viable as individual calibration curves, but created anunexpected calibration map. The data shows promise in creating a calibration map that is usefulfor practical combustors.
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Date Issued: 2017
Identifier: CFE0006910, ucf:51692
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006910

Title: Development of a chemical kinetic model for the combustion of a synthesis gas from a fluidized-bed sewage sludge gasifier in a thermal oxidizer.
Creator: Martinez, Luis, Cooper, David, Randall, Andrew, Vasu Sumathi, Subith, University of Central Florida
Abstract / Description: The need for sustainability has been on the rise. Municipalities are finding ways of reducing waste, but also finding ways to reduce energy costs. Waste-to-energy is a sustainable method that may reduce bio-solids volume while also producing energy. In this research study bio-solids enters a bubbling bed gasifier and within the gasifier a synthesis gas is produced. This synthesis gas exits through the top of the gasifier and enters a thermal oxidizer for combustion. The thermal oxidizer has...
Show moreThe need for sustainability has been on the rise. Municipalities are finding ways of reducing waste, but also finding ways to reduce energy costs. Waste-to-energy is a sustainable method that may reduce bio-solids volume while also producing energy. In this research study bio-solids enters a bubbling bed gasifier and within the gasifier a synthesis gas is produced. This synthesis gas exits through the top of the gasifier and enters a thermal oxidizer for combustion. The thermal oxidizer has an innovative method of oxidizing the synthesis gas. The thermal oxidizer has two air injection sites and the possibility for aqueous ammonia injection for further NOx reduction. Most thermal oxidizers already include an oxidizer such as air in the fuel before it enters the thermal oxidizer; thus making this research and operation different from many other thermal oxidizers and waste-to-energy plants.The reduction in waste means less volume loads to a landfill. This process significantly reduces the amount of bio-solids to a landfill. The energy produced from the synthesis is beneficial for any municipality, as it may be used to run the waste-to-energy facility. The purpose of this study is to determine methods in which operators may configure future plants to reduce NOx emissions. NOx mixed with volatile organic compounds (VOC) and sunlight, produce ozone (O3) a deadly gas at high concentrations.This study developed a model to determine the best methods to reduce NOx emissions. Results indicate that a fuel-rich then fuel-lean injection scheme results in lower NOx emissions. This is because at fuel-rich conditions not all of the ammonia in the first air ring is converted to NOx, but rather a partial of the ammonia is converted to NOx and N2 and then the second air ring operates at fuel-lean which further oxidizes the remaining ammonia which converts to NOx, but also a fraction to N2. If NOx standards reach more stringency then aqueous ammonia injection is a recommended method for NOx reduction; this method is also known as selective non-catalytic reduction (SNCR).The findings in this study will allow operators to make better judgment in the way that they operate a two air injection scheme thermal oxidizer. The goal of the operator and the organization is to meet air quality standards and this study aims at finding ways to reduce emissions, specifically NOx.
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Date Issued: 2014
Identifier: CFE0005528, ucf:50301
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005528

Title: bio-inspired attitude control of micro air vehicles using rich information from airflow sensors.
Creator: Shen, He, Xu, Yunjun, Lin, Kuo-Chi, Kauffman, Jeffrey, An, Linan, University of Central Florida
Abstract / Description: Biological phenomena found in nature can be learned and customized to obtain innovative engineering solutions. In recent years, biologists found that birds and bats use their mechanoreceptors to sense the airflow information and use this information directly to achieve their agile flight performance. Inspired by this phenomenon, an attitude control system for micro air vehicles using rich amount of airflow sensor information is proposed, designed and tested. The dissertation discusses our...
Show moreBiological phenomena found in nature can be learned and customized to obtain innovative engineering solutions. In recent years, biologists found that birds and bats use their mechanoreceptors to sense the airflow information and use this information directly to achieve their agile flight performance. Inspired by this phenomenon, an attitude control system for micro air vehicles using rich amount of airflow sensor information is proposed, designed and tested. The dissertation discusses our research findings on this topic. First, we quantified the errors between the calculated and measured lift and moment profiles using a limited number of micro pressure sensors over a straight wing. Then, we designed a robust pitching controller using 20 micro pressure sensors and tested the closed-loop performance in a simulated environment. Additionally, a straight wing was designed for the pressure sensor based pitching control with twelve pressure sensors, which was then tested in our low-speed wind tunnel. The closed-loop pitching control system can track the commanded angle of attack with a rising time around two seconds and an overshoot around 10%. Third, we extended the idea to the three-axis attitude control scenarios, where both of the pressure and shear stress information are considered in the simulation. Finally, a fault tolerant controller with a guaranteed asymptotically stability is proposed to deal with sensor failures and calculation errors. The results show that the proposed fault tolerant controller is robust, adaptive, and can guarantee an asymptotically stable performance even in case that 50% of the airflow sensors fail in flight.
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Date Issued: 2014
Identifier: CFE0005711, ucf:50150
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005711

Title: MEASUREMENTS IN AIR-WATER BUBBLY FLOW THROUGH A VERTICAL NARROW HIGH-ASPECT RATIO CHANNEL.
Creator: Patrick, Benjamin, Kumar, Ranganathan, University of Central Florida
Abstract / Description: Two-Phase bubbly flows are encountered in a wide range of industrial applications, particularly where phase changes occur as seen in high performance heat exchangers and boiling reactors for power generation. These flows have been extensively studied in channels with circular geometries using air-water flows, though little data exists for flows through narrow rectangular channels. Measurements in thin geometries are particularly challenging since large bubbles bridge the gap, and it is...
Show moreTwo-Phase bubbly flows are encountered in a wide range of industrial applications, particularly where phase changes occur as seen in high performance heat exchangers and boiling reactors for power generation. These flows have been extensively studied in channels with circular geometries using air-water flows, though little data exists for flows through narrow rectangular channels. Measurements in thin geometries are particularly challenging since large bubbles bridge the gap, and it is difficult to compare point measurements with photographic techniques. The objective of this study is to explore the abilities of hot-film anemometry and high speed photography for taking measurements in a narrow vertical rectangular channel for a range of volume fractions, with particular attention on the narrow dimension. Hot-film anemometry (HFA) is a measurement technique originally developed for the measurement of fluid velocities, but has since been found to have applications for broader measurements in multiphase flow. With the sensor operating on the principle of heat loss, the method takes advantage of the differing abilities of the phases to transport heat, with each phase leaving its own signature in the signal response. The linchpin of this method lies in the ability to accurately distinguish between the two phases within the signal, and to execute this operation, various algorithms and techniques have been developed and used with some success for a wide range of flow conditions. This thesis is a study of the various methods of analysis such as amplitude threshold for triggering, and small slope threshold for finely tuning the edges of the bubble interactions, and demonstrates the capabilities of the hot-film sensor in a narrow rectangular vertical duct with a high aspect ratio. A vertical acrylic test section was fabricated for the purposes of this study, inset with a rectangular channel 38.1mm in width and 3.125mm in depth. Experiments were conducted for volume fractions ranging from 2% to 35%, which remained within the limits of the bubbly flow regime, but ranged from small uniform bubbles to larger bubbles coalescing into a transition regime. The hot-film signal was analyzed for void fraction, bubble speed, and bubble size. An in- depth study of the various methods of phase discrimination was performed and the effect of threshold selection was examined. High-speed video footage was taken in conjunction with the anemometer data for a detailed comparison between methods. The bubble speed was found to be in close agreement between the HFA and high-speed video, staying within 10% for volume fractions above 10%, but still remaining under a 30% difference for even as low as the 2% volume fraction, where measurements have been found to be historically difficult. The trends with volume fraction between the HFA and high-speed results were very similar. A correlation for narrow rectangular channels employing a simple drift flux model was found to compare with the void fraction data where appropriate. Good agreement was found between the methods using a hybrid phase discrimination technique for the HFA data for the void fraction and bubble speed results, with the high-speed video results showing a slight over-estimation in regards to the bubble size.
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Date Issued: 2011
Identifier: CFE0004006, ucf:49185
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004006

Title: SPRAY COOLING FOR LAND, SEA, AIR AND SPACE BASED APPLICATIONS,A FLUID MANAGEMENT SYSTEM FOR MULTIPLE NOZZLE SPRAY COOLING AND A GUIDE TO HIGH HEAT FLUX HEATER DESIGN.
Creator: Glassman, Brian, Chow, Louis, University of Central Florida
Abstract / Description: This thesis is divided into four distinct chapters all linked by the topic of spray cooling. Chapter one gives a detailed categorization of future and current spray cooling applications, and reviews the major advantages and disadvantages that spray cooling has over other high heat flux cooling techniques. Chapter two outlines the developmental goals of spray cooling, which are to increase the output of a current system and to enable new technologies to be technically feasible. Furthermore,...
Show moreThis thesis is divided into four distinct chapters all linked by the topic of spray cooling. Chapter one gives a detailed categorization of future and current spray cooling applications, and reviews the major advantages and disadvantages that spray cooling has over other high heat flux cooling techniques. Chapter two outlines the developmental goals of spray cooling, which are to increase the output of a current system and to enable new technologies to be technically feasible. Furthermore, this chapter outlines in detail the impact that land, air, sea, and space environments have on the cooling system and what technologies could be enabled in each environment with the aid of spray cooling. In particular, the heat exchanger, condenser and radiator are analyzed in their corresponding environments. Chapter three presents an experimental investigation of a fluid management system for a large area multiple nozzle spray cooler. A fluid management or suction system was used to control the liquid film layer thickness needed for effective heat transfer. An array of sixteen pressure atomized spray nozzles along with an imbedded fluid suction system was constructed. Two surfaces were spray tested one being a clear grooved Plexiglas plate used for visualization and the other being a bottom heated grooved 4.5 x 4.5 cm2 copper plate used to determine the heat flux. The suction system utilized an array of thin copper tubes to extract excess liquid from the cooled surface. Pure water was ejected from two spray nozzle configurations at flow rates of 0.7 L/min to 1 L/min per nozzle. It was found that the fluid management system provided fluid removal efficiencies of 98% with a 4-nozzle array, and 90% with the full 16-nozzle array for the downward spraying orientation. The corresponding heat fluxes for the 16 nozzle configuration were found with and without the aid of the fluid management system. It was found that the fluid management system increased heat fluxes on the average of 30 W/cm2 at similar values of superheat. Unfortunately, the effectiveness of this array at removing heat at full levels of suction is approximately 50% & 40% of a single nozzle at respective 10„aC & 15„aC values of superheat. The heat transfer data more closely resembled convective pooling boiling. Thus, it was concluded that the poor heat transfer was due to flooding occurring which made the heat transfer mechanism mainly forced convective boiling and not spray cooling. Finally, Chapter four gives a detailed guide for the design and construction of a high heat flux heater for experimental uses where accurate measurements of surface temperatures and heat fluxes are extremely important. The heater designs presented allow for different testing applications; however, an emphasis is placed on heaters designed for use with spray cooling.
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Date Issued: 2005
Identifier: CFE0000473, ucf:46351
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000473

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