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Title: TRANSMISSION LINES FOR IR SIGNAL ROUTING.
Creator: Mandviwala, Tasneem, Boreman, Glenn, University of Central Florida
Abstract / Description: In this dissertation, the design, fabrication, and characterization of coplanar striplines, vias, and microstrip lines is investigated, from the point of view of developing interconnections for antenna-coupled infrared detectors operating in the 8- to 12-micron wavelength range. To our knowledge, no previous efforts have been made to study the performance of metallic-wire transmission lines at infrared frequencies. Both the design and fabrication of these structures present unique challenges....
Show moreIn this dissertation, the design, fabrication, and characterization of coplanar striplines, vias, and microstrip lines is investigated, from the point of view of developing interconnections for antenna-coupled infrared detectors operating in the 8- to 12-micron wavelength range. To our knowledge, no previous efforts have been made to study the performance of metallic-wire transmission lines at infrared frequencies. Both the design and fabrication of these structures present unique challenges. Because of attenuation and dispersion issues, the analytical formulas for transmission-line parameters that are valid below a few hundred GHz are not applicable in the infrared. Therefore, numerical modeling was performed to characterize the coplanar striplines and microstrip structures in terms of transmission-line parameters: characteristic impedance, attenuation constant and effective index of refraction. These parameters were extracted by fitting the computed impedance as a function of transmission-line length to the usual impedance transformation equation. The material properties used in the model are realistic, having been measured at the frequencies of interest by infrared ellipsometric techniques. The transmission-line parameters cannot be measured directly in the infrared, so experimental validation was carried out by measuring the response of a bolometer, which was connected to a dipole antenna by different lengths of both the coplanar and microstrip transmission lines. The modeled and measured responses for both types of transmission lines was in good agreement. A third type of signal-routing structure was also investigated, that of the vertical via, essentially a low-frequency connection that facilitates location of the bondpads away from the plane of the antenna. In the configuration studied, the vias pass vertically down through the SiO2 isolation layer and a groundplane, which provides electromagnetic isolation between the antenna and the structures that allow for signal-extraction from the bolometer. This type of interconnection will be useful for future detailed studies relating the angular antenna pattern to the spatial response of the antenna-coupled sensor.
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Date Issued: 2006
Identifier: CFE0001304, ucf:47025
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001304

Title: A Solid State VHF Single Sideband Transmitter.
Creator: Roos, Ermi, McCarter, Ed R., Engineering
Abstract / Description: Florida Technological University College of Engineering Thesis; This research report investigates a unique method of generating single sideband power, which is particularly useful in transistorized transmitters operating at VHF frequencies. Radio frequency power id developed by class C amplifiers, rather than conventional class A or B amplifiers. Currently, VHF power transistors are not well adapted for use as linear amplifiers, and will function far better in the class C mode. A prototype...
Show moreFlorida Technological University College of Engineering Thesis; This research report investigates a unique method of generating single sideband power, which is particularly useful in transistorized transmitters operating at VHF frequencies. Radio frequency power id developed by class C amplifiers, rather than conventional class A or B amplifiers. Currently, VHF power transistors are not well adapted for use as linear amplifiers, and will function far better in the class C mode. A prototype VHF transmitter which develops single sideband power with nonlinear amplifiers was designed and constructed. The transmitter characteristics were measured and analyzed to establish the feasibility of the new design.
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Date Issued: 1973
Identifier: CFR0004779, ucf:52958
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0004779

Title: THE ROLE OF BREASTFEEDING IN MOTHER-TO-CHILD TRANSMISSION OF HIV/AIDS: A COMPARATIVE CASE STUDY OF THREE COUNTRIES.
Creator: Cherukuri, Anjali, Borgon, Robert, University of Central Florida
Abstract / Description: The HIV pandemic has affected millions of people around the world both medically and socially, since there is a stigma associated with this disease. Common methods of transmission include sexual intercourse and sharing needles, but there are other lesser known methods through which people can contract this disease. One such way is mother-to-child transmission (MTCT), in which a mother could transmit the virus to her child either during pregnancy, childbirth, or through breastfeeding. This...
Show moreThe HIV pandemic has affected millions of people around the world both medically and socially, since there is a stigma associated with this disease. Common methods of transmission include sexual intercourse and sharing needles, but there are other lesser known methods through which people can contract this disease. One such way is mother-to-child transmission (MTCT), in which a mother could transmit the virus to her child either during pregnancy, childbirth, or through breastfeeding. This paper focuses on the role of breastfeeding in the transmission of HIV from mother to child. Many studies have investigated how breastfeeding results in the transmission of the virus, and effective common treatment methods have been established. However, the issue of MTCT of HIV still exists even though it can easily be eradicated with the proper techniques. This suggests that there are still factors that contribute to HIV transmission from mother to child that have yet to be eliminated. Thus, this paper reviews the breastfeeding rates and breastfeeding practices of three different countries: South Africa, India, and the United Kingdom. This paper analyzes epidemiological data, studies from medical journals, and studies from anthropology journals to determine what social influences surround breastfeeding practices in each of these countries to see how these may contribute to MTCT of HIV via breastfeeding. While there were no apparent trends between child HIV prevalence rates and breastfeeding rates in these countries, there were some social and cultural factors that were similar across all three nations. This information may be useful in creating more effective treatment plans that are conducive to the social environments in these countries.
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Date Issued: 2017
Identifier: CFH2000204, ucf:46034
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000204

Title: FAR-INFRARED/MILLIMETER WAVE SOURCE AND COMPONENT DEVELOPMENT FOR IMAGING AND SPECTROSCOPY.
Creator: Du Bosq, Todd, Boreman, Glenn, University of Central Florida
Abstract / Description: The far-infrared and millimeter wave (FIR/mmW) (wavelength 75 micrometer to 10 mm) portion of the electromagnetic spectrum is fairly underdeveloped technologically, owing to the large amount of atmospheric attenuation in that range. At present, the FIR/mmW region is lacking in compact, high-brightness radiation sources and practical imaging systems. This dissertation focuses on development of two complementary technologies in this area – an active mmW imaging system and high-reflectivity...
Show moreThe far-infrared and millimeter wave (FIR/mmW) (wavelength 75 micrometer to 10 mm) portion of the electromagnetic spectrum is fairly underdeveloped technologically, owing to the large amount of atmospheric attenuation in that range. At present, the FIR/mmW region is lacking in compact, high-brightness radiation sources and practical imaging systems. This dissertation focuses on development of two complementary technologies in this area – an active mmW imaging system and high-reflectivity Bragg mirrors for the FIR p-Ge laser. The imaging system uses a vector network analyzer in the frequency range of 90-140 GHz as the radiation source and receiver. Raster scanning is used to map a two-dimensional field of view, demonstrating the detection and imaging of buried plastic landmines. Principal components analysis is used for hyperspectral signal processing, where a series of images is taken at discrete frequencies. Results are obtained as a function of depth and disturbance of the soil surface. In support of this study, various types of soils were characterized for scattering loss across the mmW/FIR region, with measured results compared to theory. This mmW imaging system was also used to demonstrate imaging through walls and other obscuring materials, as well as for imaging of rocks beneath volcanic sand, simulating the conditions encountered by an imaging system on a Mars rover vehicle. Furthermore, a high-reflectivity Si-etalon FIR mirror design was developed and demonstrated as a cavity mirror for the p-Ge laser. These components stand to have a number of systems-level impacts on FIR imagers. In the context of an active illuminator, they may allow narrowband selection from the broad emission spectrum of the p-Ge laser source. These mirrors can also be used in a Fabry-Perot FIR scanning spectrometer, where the resulting high finesse would give discrimination advantages in chemical sensing and astrophysical spectroscopy applications.
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Date Issued: 2007
Identifier: CFE0001665, ucf:47222
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001665

Title: TRANSMISSION ELECTRON MICROSCOPY STUDIES IN SHAPE MEMORY ALLOYS.
Creator: TIYYAGURA, MADHAVI, VAIDYANATHAN, RAJ, University of Central Florida
Abstract / Description: In NiTi, a reversible thermoelastic martensitic transformation can be induced by temperature or stress between a cubic (B2) austenite phase and a monoclinic (B19') martensite phase. Ni-rich binary compositions are cubic at room temperature (requiring stress or cooling to transform to the monoclinic phase), while Ti-rich binary compositions are monoclinic at room temperature (requiring heating to transform to the cubic phase). The stress induced transformation results in the superelastic...
Show moreIn NiTi, a reversible thermoelastic martensitic transformation can be induced by temperature or stress between a cubic (B2) austenite phase and a monoclinic (B19') martensite phase. Ni-rich binary compositions are cubic at room temperature (requiring stress or cooling to transform to the monoclinic phase), while Ti-rich binary compositions are monoclinic at room temperature (requiring heating to transform to the cubic phase). The stress induced transformation results in the superelastic effect, while the thermally induced transformation is associated with strain recovery that results in the shape memory effect. Ternary elemental additions such as Fe can additionally introduce an intermediate rhombohedral (R) phase between the cubic and monoclinic phase transformation. This work was initiated with the broad objective of connecting the macroscopic behavior in shape memory alloys with microstructural observations from transmission electron microscopy (TEM). Specifically, the goals were to examine (i) the effect of mechanical cycling and plastic deformation in superelastic NiTi; (ii) the effect of thermal cycling during loading in shape memory NiTi; (iii) the distribution of twins in martensitic NiTi-TiC composites; and (iv) the R-phase in NiTiFe. Both in situ and ex situ lift out focused ion beam (FIB) and electropolishing techniques were employed to fabricate shape memory alloy samples for TEM characterization. The Ni rich NiTi samples were fully austenitic in the undeformed state. The introduction of plastic deformation (8% and 14% in the samples investigated) resulted in the stabilization of martensite in the unloaded state. An interlaying morphology of the austenite and martensite was observed and the martensite needles tended to orient themselves in preferred orientations. The aforementioned observations were more noticeable in mechanically cycled samples. The observed dislocations in mechanically cycled samples appear to be shielded from the external applied stress via mismatch accommodation since they are not associated with unrecoverable strain after a load-unload cycle. On application of stress, the austenite transforms to martensite and is expected to accommodate the stress and strain mismatch through preferential transformation, variant selection, reorientation and coalescence. The stabilized martensite (i.e., martensite that exists in the unloaded state) is expected to accommodate the mismatch through variant reorientation and coalescence. On thermally cycling a martensitic NiTi sample under load through the phase transformation, significant variant coalescence, variant reorientation and preferred variant selection was observed. This was attributed to the internal stresses generated as a result of the thermal cycling. A martensitic NiTi-TiC composite was also characterized and the interface between the matrix and the inclusion was free of twins while significant twins were observed at a distance away from the matrix-inclusion interface. Incorporating a cold stage, diffraction patterns from NiTiFe samples were obtained at temperatures as low as -160ºC. Overall, this work provided insight in to deformation phenomena in shape memory materials that have implications for engineering applications (e.g., cyclic performance of actuators, engineering life of superelastic components, stiffer shape memory composites and low-hysteresis R-phase based actuators). This work was supported in part by an NSF CAREER award (DMR 0239512).
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Date Issued: 2005
Identifier: CFE0000500, ucf:46462
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000500

Title: A Mathematical Model for Determining the Thermal Distribution Resulting from Discharge of a Heated Effluent.
Creator: Epstein, Alan H., Nimmo, Bruce, Engineering
Abstract / Description: Florida Technological University College of Engineering Thesis; A mathematical model is presented for the problem of determining the two-dimensional temperature distribution resulting from the discharge of a heated effluent into a shallow, quiescent receptacle. The physical model ofr the problem is the two-dimensional jet augmented by an imposed condition of viscous drag due to bottom friction effects. By virtue of the assumption that the physical properties of the effluent are independent of...
Show moreFlorida Technological University College of Engineering Thesis; A mathematical model is presented for the problem of determining the two-dimensional temperature distribution resulting from the discharge of a heated effluent into a shallow, quiescent receptacle. The physical model ofr the problem is the two-dimensional jet augmented by an imposed condition of viscous drag due to bottom friction effects. By virtue of the assumption that the physical properties of the effluent are independent of temperature over the operational temperature range of the plume, the analysis separates the total problem into a flow problem and a temperature problem. Solution of the temperature distribution is accomplished both analytically and numerically. Analytically, the temperature distribution is found through sequential integral solution of the equations defining the mathematical model, under the physical assumptions of a Gaussian flow distribution and the following relationship between the velocity and temperature distributions: [formula] where the subscript (max) denotes conditions along the jet centerline. Numerically, the equations defining the mathematical model are solved by a finite differencing technique implemented with the aid of an I.B.M. 360 digital computer. Comparison of the predictions of the model with the classical two-dimensional momentum jet indicate that the model is a reasonable approximation of the real physical problem. In addition, there is seen to be a critical dependence of the flow in the plume on the depth of the receptacle.
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Date Issued: 1972
Identifier: CFR0012146, ucf:53131
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0012146

Title: Study of Surface Passivation Behavior of Crystalline Silicon Solar Cells.
Creator: Ali, Haider, Schoenfeld, Winston, Coffey, Kevin, Gaume, Romain, Thomas, Jayan, Chanda, Debashis, University of Central Florida
Abstract / Description: To achieve efficiencies approaching the theoretical limit of 29.4% for industrially manufactured solar cells based on crystalline silicon, it is essential to have very low surface recombination velocities at both the front and rear surfaces of the silicon substrate. Typically, the substrate surfaces feature contacted and uncontacted regions, and recombination should be limited for both to maximize the energy conversion efficiency.Uncontacted silicon surfaces are often passivated by the...
Show moreTo achieve efficiencies approaching the theoretical limit of 29.4% for industrially manufactured solar cells based on crystalline silicon, it is essential to have very low surface recombination velocities at both the front and rear surfaces of the silicon substrate. Typically, the substrate surfaces feature contacted and uncontacted regions, and recombination should be limited for both to maximize the energy conversion efficiency.Uncontacted silicon surfaces are often passivated by the deposition of silicon nitride (SiNx) or an aluminum oxide film with SiNx as capping layer (Al2O3/SiNx stack). Further, proper surface preparation and cleaning of Si wafers prior to deposition also plays an important role in minimizing surface recombination. In the present work, the effect of various cleans based on different combinations of HCl, HF, HNO3, and ozonated deionized water (DIO3) on surface passivation quality of boron-diffused and undiffused {100} n-type Cz Si wafers was studied. It was observed that for SiNx passivated Si, carrier lifetime was strongly influenced by cleaning variations and that a DIO3-last treatment resulted in higher lifetimes. Moreover, DIO3+HF+HCl?HF?DIO3 and HNO3?HF?HNO3 cleans emerged as potential low-cost alternatives to HCl/HF clean in the photovoltaics industry.Transmission electron microscopy (TEM) studies were carried out to get insight into the origin of variation in carrier lifetimes for different cleans. Changes in the surface cleans used were not found to have a significant impact on Al2O3/SiNx passivation stacks.ivHowever, an oxide-last cleaning step prior to deposition of SiNx passivation layers was found to create a 1-2 nm SiOx tunnel layer resulting in excellent carrier lifetimes.For contacted regions, low surface recombination can be achieved using passivated carrier selective contacts, which not only passivate the silicon surface and improve the open circuit voltage, but are also carrier selective. This means they only allow the majority carrier to be transported to the metal contacts, limiting recombination by reducing the number of minority carriers. Typically, carrier selectivity is achieved using a thin metal oxide layer, such as titanium oxide (TiO2) for electron-selective contacts and molybdenum oxide (MoOx) for hole-selective contacts. This is normally coupled with a very thin passivation layer (e.g., a-Si:H, SiOx) between the silicon wafer and the contact.In the present work, TiO2-based electron-selective passivated rear contacts were investigated for n-type c-Si solar cells. A low efficiency of 9.8% was obtained for cells featuring a-Si:H/TiO2 rear contact, which can be attributed to rapid degradation of surface passivation of a-Si:H upon FGA at 350(&)deg;C due to hydrogen evolution leading to generation of defect states which increases recombination and hence a much lower Voc of 365 mV is obtained. On the other hand, 21.6% efficiency for cells featuring SiO2/TiO2 rear contact is due to excellent passivation of SiO2/TiO2 stack upon FGA anneal, which can be attributed to the presence of 1-2 nm SiO2 layer whose passivation performance improves upon FGA at 350(&)deg;C whereas presence of large number of oxygen vacancies in TiO2-x reduces rear contact resistivity.vLikewise, MoOx-based contacts were investigated as hole-selective front contacts for an n-type cell with a boron-doped emitter. It has been previously reported that cell efficiencies up to 22.5% have been achieved with silicon heterojunction solar cells featuring a front contact wherein MoOx is inserted between a-Si:H(i) and hydrogenated indium oxide (IO:H). However, device performance and FF degrades upon annealing beyond 130(&)deg;C. In this work, contact resistivity measurements by TLM technique in combination with TEM studies revealed that degradation of device performance is due to oxygen diffusion into MoOx upon annealing in air which reduces concentration of oxygen vacancies in MoOx and increases contact resistivity. The increase in contact resistivity reduces FF resulting in deterioration of device performance.
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Date Issued: 2017
Identifier: CFE0006554, ucf:51351
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006554

Title: HURRICANE EVACUATION: ORIGIN, ROUTE AND DESTINATION.
Creator: Dixit, Vinayak, Radwan, Essam, University of Central Florida
Abstract / Description: Recent natural disasters have highlighted the need to evacuate people as quickly as possible. During hurricane Rita in 2005, people were stuck in queue buildups and large scale congestions, due to improper use of capacity, planning and inadequate response to vehicle breakdown, flooding and accidents. Every minute is precious in situation of such disaster scenarios. Understanding evacuation demand loading is an essential part of any evacuation planning. One of the factors often understood to...
Show moreRecent natural disasters have highlighted the need to evacuate people as quickly as possible. During hurricane Rita in 2005, people were stuck in queue buildups and large scale congestions, due to improper use of capacity, planning and inadequate response to vehicle breakdown, flooding and accidents. Every minute is precious in situation of such disaster scenarios. Understanding evacuation demand loading is an essential part of any evacuation planning. One of the factors often understood to effect evacuation, but not modeled has been the effect of a previous hurricane. This has also been termed as the 'Katrina Effect', where, due to the devastation caused by hurricane Katrina, large number of people decided to evacuate during Hurricane Rita, which hit Texas three weeks after Katrina hit Louisiana. An important aspect influencing the rate of evacuation loading is Evacuation Preparation Time also referred to as 'Mobilization time' in literature. A methodology to model the effect of a recent past hurricane on the mobilization times for evacuees in an evacuation has been presented utilizing simultaneous estimation techniques. The errors for the two simultaneously estimated models were significantly correlated, confirming the idea that a previous hurricane does significantly affect evacuation during a subsequent hurricane. The results show that the home ownership, number of individuals in the household, income levels, and level/risk of surge were significant in the model explaining the mobilization times for the households. Pet ownership and number of kids in the households, known to increase the mobilization times during isolated hurricanes, were not found to be significant in the model. Evacuation operations are marred by unexpected blockages, breakdown of vehicles and sudden flooding of transportation infrastructure. A fast and accurate simulation model to incorporate flexibility into the evacuation planning procedure is required to react to such situations. Presently evacuation guidelines are prepared by the local emergency management, by testing various scenarios utilizing micro-simulation, which is extremely time consuming and do not provide flexibility to evacuation plans. To gain computational speed there is a need to move away from the level of detail of a micro-simulation to more aggregated simulation models. The Cell Transmission Model which is a mesoscopic simulation model is considered, and compared with VISSIM a microscopic simulation model. It was observed that the Cell Transmission Model was significantly faster compared to VISSIM, and was found to be accurate. The Cell Transmission model has a nice linear structure, which is utilized to construct Linear Programming Problems to determine optimal strategies. Optimization models were developed to determine strategies for optimal scheduling of evacuation orders and optimal crossover locations for contraflow operations on freeways. A new strategy termed as 'Dynamic Crossovers Strategy' is proposed to alleviate congestion due to lane blockages (due to vehicle breakdowns, incidents etc.). This research finds that the strategy of implementing dynamic crossovers in the event of lane blockages does improve evacuation operations. The optimization model provides a framework within which optimal strategies are determined quickly, without the need to test multiple scenarios using simulation. Destination networks are the cause of the main bottlenecks for evacuation routes, such aspects of transportation networks are rarely studied as part of evacuation operations. This research studies destination networks from a macroscopic perspective. Various relationships between network level macroscopic variables (Average Flow, Average Density and Average speed) over the network were studied. Utilizing these relationships, a "Network Breathing Strategy" was proposed to improve dissipation of evacuating traffic into the destination networks. The network breathing strategy is a cyclic process of allowing vehicles to enter the network till the network reaches congestion, which is followed by closure of their entry into the network until the network reaches an acceptable state. After which entrance into the network is allowed again. The intuitive motivation behind this methodology is to ensure that the network does not remain in congested conditions. The term 'Network Breathing' was coined due to the analogy seen between this strategy to the process of breathing, where vehicles are inhaled by the network (vehicles allowed in) and dissipated by the network (vehicles are not allowed in). It is shown that the network breathing improves the dissipation of vehicle into the destination network. Evacuation operations can be divided into three main levels: at the origin (region at risk), routes and destination. This research encompasses all the three aspects and proposes a framework to assess the whole system in its entirety. At the Origin the demand dictates when to schedule evacuation orders, it also dictates the capacity required on different routes. These breakthroughs will provide a framework for a real time Decision Support System which will help emergency management official make decisions faster and on the fly.
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Date Issued: 2008
Identifier: CFE0002051, ucf:47589
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002051

Title: CHARACTERIZATION OF MICROSTRUCTURAL AND CHEMICAL FEATURES IN CU-IN-GA-SE-S-BASED THIN-FILM SOLAR CELLS.
Creator: Halbe, Ankush, Heinrich, Helge, University of Central Florida
Abstract / Description: Thin-film solar cells are potentially low-cost devices to convert sunlight into electricity. Improvements in the conversion efficiencies of these cells reduce material utilization cost and make it commercially viable. Solar cells from the Thin-Film Physics Group, ETH Zurich, Switzerland and the Florida Solar Energy Center (FSEC), UCF were characterized for defects and other microstructural features within the thin-film structure and at the interfaces using transmission electron microscopy ...
Show moreThin-film solar cells are potentially low-cost devices to convert sunlight into electricity. Improvements in the conversion efficiencies of these cells reduce material utilization cost and make it commercially viable. Solar cells from the Thin-Film Physics Group, ETH Zurich, Switzerland and the Florida Solar Energy Center (FSEC), UCF were characterized for defects and other microstructural features within the thin-film structure and at the interfaces using transmission electron microscopy (TEM). The present thesis aims to provide a feedback to these groups on their deposition processes to understand the correlations between processing, resulting microstructures, and the conversion efficiencies of these devices. Also, an optical equipment measuring photocurrents from a solar cell was developed for the identification of defect-prone regions of a thin-film solar cell. The focused ion beam (FIB) technique was used to prepare TEM samples. Bright-field TEM along with scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDS) including elemental distribution line scans and maps were extensively used for characterizing the absorber layer and interfaces both above and below the absorber layer. Energy-filtered transmission electron microscopy (EFTEM) was applied in cases where EDS results were inconclusive due to the overlap of X-ray energies of certain elements, especially molybdenum and sulfur. Samples from ETH Zurich were characterized for changes in the CIGS (Cu(In,Ga)Se2) microstructure due to sodium incorporation from soda-lime glass or from a post-deposition treatment with NaF as a function of CIGS deposition temperature. The CIGS-CdS interface becomes smoother and the small columnar CIGS grains close to the Mo back contact disappear with increasing CIGS deposition temperature. At 773 K the two sodium incorporation routes result in large differences in the microstructures with a significantly larger grain size for the samples after post-deposition Na incorporation. Porosity was observed in the absorber layer close to the back contact in the samples from FSEC. The reason for porosity could be materials evaporation in the gallium beam of the FIB or a processing effect. The porosity certainly indicates heterogeneities of the composition of the absorber layer near the back contact. A Mo-Se rich layer (possibly MoSe2) was formed at the interface between CIGS/CIGSS and Mo improving the quality of the junction. Other chemical heterogeneities include un-sulfurized Cu-Ga deposits, residual Se from the selenization/ sulfurization chamber in CIGS2 and the formation of Cu-rich regions which are attributed to decomposition effects in the Ga beam of the FIB. Wavy absorber surfaces were observed for some of the cells with occasional discontinuities in the metal grids. The 50 nm thick CdS layer, however, remained continuous in all the samples under investigation. For a sample with a transparent back contact, a 10 nm Mo layer was deposited on ITO (indium tin oxide) before deposition of the CIGS2 (Cu(In,Ga)S2) layer. EFTEM maps indicate that a MoS2 layer does not form for such a Mo/MoS2-ITO back contact. Instead, absorber layer material diffuses through the thin Mo layer onto the ITO forming two layers of CIGS2 on either side of Mo with different compositions. Furthermore, an optical beam induced current (OBIC) system with micron level resolution was successfully developed and preliminary photocurrent maps were acquired to microscopically identify regions within a thin-film solar cell with undesirable microstructural features. Such a system, when fully operational, will provide the means for the identification of special regions from where samples for TEM analysis can be obtained using the FIB technique to study specifically the defects responsible for local variations in solar cell properties.
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Date Issued: 2006
Identifier: CFE0001022, ucf:46807
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001022

Title: AN EXPLORATION OF TEACHER PERSPECTIVES OF MATHEMATICS ANXIETY AND GENDER STEREOTYPING.
Creator: Browning, Jessica, Gresham, Regina, University of Central Florida
Abstract / Description: The purpose of this study was to identify the current perspective of grades three through twelve in-service teachers regarding mathematics anxiety, its causes, and its relation to gender stereotyping. A short online survey was conducted to gain insight into their classrooms and perspectives of the subject. The results showed that mathematics anxiety did exist in the classroom, and in-service teachers did report seeing a gender gap between the anxiety experienced by females and males. I...
Show moreThe purpose of this study was to identify the current perspective of grades three through twelve in-service teachers regarding mathematics anxiety, its causes, and its relation to gender stereotyping. A short online survey was conducted to gain insight into their classrooms and perspectives of the subject. The results showed that mathematics anxiety did exist in the classroom, and in-service teachers did report seeing a gender gap between the anxiety experienced by females and males. I believe that from these findings it is important to conduct further research on in-service teachers to see in depth what they think. This is important because their beliefs about the subject can have a lasting impact on their students and their feelings towards mathematics.
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Date Issued: 2015
Identifier: CFH0004756, ucf:45347
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0004756

Title: MICRO-SPECTROSCOPY OF BIO-ASSEMBLIES AT THE SINGLE CELL LEVEL.
Creator: Kera, Jeslin, Chakrabarti, Debopam, Schulte, Alfons, University of Central Florida
Abstract / Description: In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 ?m in the lateral and 3.6 ?m in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation...
Show moreIn this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 ?m in the lateral and 3.6 ?m in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single live cells and bio-molecules with less than 10^9 molecules in the probe volume. Employing a multichannel detection system, the absorption spectrum of hemoglobin in a single red blood cell is measured on the timescale of seconds. We also extend the spectral range from the visible range to the experimentally more challenging ultra-violet region where characteristic absorption bands of bio-molecules are observed. Exploiting the ultra-violet range, amino acids, nucleic acids solutions, and plant cells are investigated. We measure the spatially resolved absorption spectra at the nucleus of an onion cell and cytoplasm to probe DNA base-pair absorption. Small variations in our micro-absorption data are seen around 260 nm, possibly due to the abundance of DNA in the nucleus. This thesis contributes to the goal of spectroscopic identification of spatial heterogeneities at the single cell level and the label-free detection of proteins and nucleic acids.
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Date Issued: 2017
Identifier: CFH2000356, ucf:45905
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000356

Title: On the design and performance of cognitive packets over wired networks and mobile ad hoc networks.
Creator: Lent, Marino Ricardo, Gelenbe, Erol, Engineering and Computer Science
Abstract / Description: University of Central Florida College of Engineering Thesis; This dissertation studied cognitive packet networks (CPN) which build networked learning systems that support adaptive, quality of service-driven routing of packets in wired networks and in wireless, mobile ad hoc networks.
Date Issued: 2003
Identifier: CFR0001374, ucf:52931
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0001374

Title: Cryogenic performance projections for ultra-small oxide-free vertical-cavity surface-emitting lasers.
Creator: Bayat, Mina, Deppe, Dennis, Li, Guifang, Schoenfeld, Winston, Lyakh, Arkadiy, University of Central Florida
Abstract / Description: Small-sized vertical-cavity surface-emitting laser (VCSEL) may offer very low power consumption along with high reliability for cryogenic data transfer. Cryogenic data transfer has application in supercomputers and superconducting for efficient computing and also focal plane array cameras operating at 77 K, and at the lower temperature of 4 K for data extraction from superconducting circuits. A theoretical analysis is presented for 77 K and 4 K operation based on small cavity, oxide-free...
Show moreSmall-sized vertical-cavity surface-emitting laser (VCSEL) may offer very low power consumption along with high reliability for cryogenic data transfer. Cryogenic data transfer has application in supercomputers and superconducting for efficient computing and also focal plane array cameras operating at 77 K, and at the lower temperature of 4 K for data extraction from superconducting circuits. A theoretical analysis is presented for 77 K and 4 K operation based on small cavity, oxide-free VCSEL sizes of 2 to 6 (&)#181;m, that have been shown to operate efficiently at room temperature. Temperature dependent operation for optimally-designed VCSELs are studied by calculating the response of the laser at 77 K and 4 K to estimate their bias conditions needed to reach modulation speed for cryogenic optical links. The temperature influence is to decrease threshold for reducing temperature, and to increase differential gain for reducing temperature. The two effects predict very low bias currents for small cavity VCSELs to reach needed data speed for cryogenic optical data links. Projections are made for different cavity structures (half-wave cavity and full-wave cavity) shown that half-wave cavity structure has better performance. Changing the number of top-mirror pairs has also been studied to determine how cavity design impacts speed and bit energy. Our design and performance predictions paves the way for realizing highly efficient, ultra-small VCSEL arrays with applications in optical interconnects.
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Date Issued: 2019
Identifier: CFE0007782, ucf:52330
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007782

Title: THE TYLER PERRY EFFECT: EXAMINING THE INFLUENCE OF BLACK MEDIA IMAGES ON THE BLACK IDENTITY.
Creator: Jackson, Nicole, Musambira, George, University of Central Florida
Abstract / Description: This study investigated the influence of Tyler Perry's House of Payne and Meet the Browns on black viewers' racial identity, based on a survey of 145 members of four predominantly African American churches in the Central Florida area. Mirroring Allen, Dawson, and Brown's (1989) model of an African American racial belief system, this study proposed that both shows would positively influence three dimensions of the black identity including closeness to blacks, black separatism, and the belief...
Show moreThis study investigated the influence of Tyler Perry's House of Payne and Meet the Browns on black viewers' racial identity, based on a survey of 145 members of four predominantly African American churches in the Central Florida area. Mirroring Allen, Dawson, and Brown's (1989) model of an African American racial belief system, this study proposed that both shows would positively influence three dimensions of the black identity including closeness to blacks, black separatism, and the belief in positive stereotypes about blacks, while negatively influencing the dimension that emphasizes negative stereotypes about blacks. Socioeconomic status and religiosity were also hypothesized to predict exposure to both shows. The results show that while House of Payne positively influenced two dimensions of the black identity including closeness to blacks and the belief in positive stereotypes about blacks, Meet the Browns did not have a statistically significant relationship with any of the dimensions of the black identity. Additionally, results showed mixed support for the relationship between socioeconomic status, religiosity, and show exposure. While education had a negative relationship with exposure to both House of Payne and Meet the Browns, the income variable revealed no significant results with either show. Lastly, religiosity was shown to be a significant predictor of exposure to House of Payne, but not Meet the Browns. The findings suggest that Perry's shows may be considered by viewers as more beneficial than harmful to viewers to their racial identity and experience, which contradicts the critiques of his images as reverberating with negative stereotypical images of the past. Findings also suggest the importance of education and religion to black socialization patterns.
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Date Issued: 2011
Identifier: CFE0003957, ucf:48708
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003957

Title: Design and Simulation of Device Failure Models for Electrostatic Discharge (ESD) Event.
Creator: Miao, Meng, Sundaram, Kalpathy, Yuan, Jiann-Shiun, Gong, Xun, Jin, Yier, Salcedo, Javier, University of Central Florida
Abstract / Description: In this dissertation, the research mainly focused on discussing ESD failure event simulation and ESD modeling, seeking solutions for ESD issues by simulating ESD event and predict possible ESD reliability problem in IC design. The research involves failure phenomenon caused by ESD/ EOS stress, mainly on the thermal failure due to inevitable self-heating during an ESD stress. Standard Complementary Metal-Oxide-Semiconductor (CMOS) process and high voltage Doublediffusion Metal-Oxide...
Show moreIn this dissertation, the research mainly focused on discussing ESD failure event simulation and ESD modeling, seeking solutions for ESD issues by simulating ESD event and predict possible ESD reliability problem in IC design. The research involves failure phenomenon caused by ESD/ EOS stress, mainly on the thermal failure due to inevitable self-heating during an ESD stress. Standard Complementary Metal-Oxide-Semiconductor (CMOS) process and high voltage Doublediffusion Metal-Oxide-Semiconductor (DMOS) process are used for design of experiment. A multi-function test platform High Power Pulse Instrument (HPPI) is used for ESD event evaluation and device characterization. SPICE-like software ADICE is for back-end simulation.Electrostatic Discharges (ESD) is one of the hazard that may affect IC circuit function and cause serious damage to the chip. The importance of ESD protection has been raised since the CMOS technology advanced and the dimension of transistors scales down. On the other hand, the variety of applications of chips is also making corresponding ESD protection difficult to meet different design requirement. Aside from typical requirements such as core circuit operation voltage, maximum accepted leakage current, breakdown conditions for the process and overall device sizes, special applications like radio frequency and power electronic requires ESD to be low parasitic capacitance and can sustain high level energy. In that case, a proper ESD protection design demands not only a robust ESD protection scheme, but co-design with the inner circuit. For that purpose, it is necessary to simulate the results of ESD impact on IC and find out possible weak point of the circuit and improve it. The first step of the simulation is to have corresponding models available. Unfortunately, ESD models, especially there are lack of circuit-level ESD models that provide quick and accurate prediction of ESD event.In this dissertation paper, ESD models, especially ESD failure models for device thermal failure are introduced, with modeling methodology accordingly. First, an introduction for ESD event and typical ESD protection schemes are introduced. Its purpose is to give basic concept of ESD. For ESD failure models, two typical types can be categorized depends on the physical mechanisms that cause the ESD damage. One is the gate oxide breakdown, which is electric field related. The other is the thermal-related failure, which stems from the self-heating effect associated with the large current passing through the ESD protection structure. The first one has become increasingly challenging with the aggressive scaling of the gate dielectric in advanced processes and ESD protection for that need to be carefully designed. The second one, thermal failure widely exists in semiconductor devices as long as there is ESD current flow through the device and accumulate heat at junctions. Considering the universality of thermal failure in ESD device, it is imperative to establish a model to simulate ESD caused thermal failure.Several works related to ESD model can be done. One crucial part for a failure model is to define the failure criterion. As common solution for ESD simulation and failure prediction. The maximum current level or breakdown voltage is used to judge whether a device fails under ESD stresses. Such failure criteria based on measurable voltage or current values are straightforward and can be easy to implemented in simulation tools. However, the shortcoming of these failure criteria is each failure criterion is specifically designed for certain ESD stress condition. For example, the failure voltage level for Human Body Model and Charged Device Model are quite different, and it is hard to judge a device's ESD capability under standard test conditions based on its transmission line pulse test result. So it is necessary to look deeper into the physical mechanism of device failure under ESD and find a more universal failure criterion for various stress conditions.As one of the major failure mechanisms, thermal failure evaluated by temperature is a more universal failure criterion for device failure under ESD stress. Whatever the stress model is, the device will fail if a critical temperature is reached at certain part inside the device and cause structural damage. Then finding out that critical temperature is crucial to define the failure point for device thermal failure. One chapter of this dissertation will focus on discussing this issue and propose a simple method to give close estimation of the real failure temperature for typical ESD devices.Combined these related works, a comprehensive diode model for ESD simulation is proposed. Using existing ESD models, diode I-V characteristic from low current turn-on to high current saturation can be simulated. By using temperature as the failure criterion, the last point of diode operation, or the second breakdown point, can be accurately predicted. Additional investigation of ESD capability of devices for special case like vertical GaN diode is discussed in Chapter IV. Due to the distinct material property of GaN, the vertical GaN diode exhibits unique and interesting quasi-static I-V curves quite different from conventional silicon semiconductor devices. And that I-V curve varies with different pulse width, indicating strong conductivity modulation of diode neutral region that will delay the complete turn-on of the vertical GaN diode.
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Date Issued: 2017
Identifier: CFE0006626, ucf:51291
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006626

Title: DESIGN AND FABRICATION OF SPACE VARIANT MICRO OPTICAL ELEMENTS.
Creator: Srinivasan, Pradeep, LiKamWa, Patrick, University of Central Florida
Abstract / Description: A wide range of applications currently utilize conventional optical elements to individually transform the phase, polarization, and spectral transmission/reflection of the incident radiation to realize the desired system level function. The material properties and the feasibility of fabrication primarily impact the device and system functionality that can be realized. With the advancement in micro/nano patterning, growth, deposition and etching technology, devices with novel and multiplexed...
Show moreA wide range of applications currently utilize conventional optical elements to individually transform the phase, polarization, and spectral transmission/reflection of the incident radiation to realize the desired system level function. The material properties and the feasibility of fabrication primarily impact the device and system functionality that can be realized. With the advancement in micro/nano patterning, growth, deposition and etching technology, devices with novel and multiplexed optical functionalities have become feasible. As a result, it has become possible to engineer the device response in the near and far field by controlling the phase, polarization or spectral response at the micro scale. One of the methods that have been explored to realize unique optical functionalities is by varying the structural properties of the device as a function of spatial location at the sub-micron scale across the device aperture. Spatially varying the structural parameters of these devices is analogous to local modifications of the material properties. In this dissertation, the optical response of interference transmission filters, guided mode resonance reflection filters, and diffraction gratings operated in Littrow condition with strategically introduced spatial variation have been investigated. Spatial variations in optical interference filters were used to demonstrate wavelength tunable spatial filters. The effect was realized by integrating diffractive and continuous phase functions on the defect layer of a one-dimensional photonic crystal structure. Guided mode resonance filters are free space optical filters that provide narrow spectral reflection by combining grating and waveguide dispersion effects. Frequency dependent spatial reflection profiles were achieved by spatially varying the grating fill fraction in designed contours. Diffraction gratings with space variant fill fractions operating in Littrow condition were used to provide graded feedback profiles to improve the beam quality and spatial brightness of broad area diode lasers. The fabrication of space variant structures is challenging and has been accomplished primarily by techniques such as ruling, electron beam writing or complex deposition methods. In order to vary the desired structural parameter in a designed manner, a novel technique for the fabrication of space variant structures using projection lithography with a fidelity that rivals any of the current technologies was also developed as a part of this work. The devices exhibit wavelength dependent beam shaping properties in addition to spatial and spectral filtering and have potential applications in advanced imaging systems, graded reflectivity laser mirrors, and engineered illumination. The design, modeling, microfabrication and experimental characterization of space variant micro optical elements with novel optical functionalities are presented.
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Date Issued: 2009
Identifier: CFE0002843, ucf:48066
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002843

Title: Risk Factors Associated with the Arrest for Adolescent to Parent Abuse.
Creator: Cicale, Coleen, Yegidis, Bonnie, Burg, Mary Ann, Gryglewicz, Kimberley, Fisher, Kristina Childs, University of Central Florida
Abstract / Description: This study explored risk factors associated with the arrest for adolescent to parent abuse (ATPA) when compared to arrest for a similar violent misdemeanor against a non-parent. The phenomenon of ATPA is widely under-researched and there is little in terms of prevention policy or treatment. Using 18,548 risk assessment screens performed with adolescents (12-17) arrested in Florida for a violent misdemeanor, and guided by previous literature and social ecological and social bond theories, this...
Show moreThis study explored risk factors associated with the arrest for adolescent to parent abuse (ATPA) when compared to arrest for a similar violent misdemeanor against a non-parent. The phenomenon of ATPA is widely under-researched and there is little in terms of prevention policy or treatment. Using 18,548 risk assessment screens performed with adolescents (12-17) arrested in Florida for a violent misdemeanor, and guided by previous literature and social ecological and social bond theories, this analysis explored the relationship between risk factors (categorized as individual characteristics, beliefs, behavior, commitment and involvement and attachment) and arrest for ATPA versus arrest for a violent misdemeanor against a non-parent. Of the 17 hypothesized risk factors, 9 risk factors were found to be significant risk factors associated with the arrest for ATPA versus the arrest for a violent misdemeanor against a non-parent. Age and ethnicity/race were both found to be associated with ATPA arrests. Risk factors found to increase the likelihood of being arrested for ATPA included a history of mental health problems, the adolescent witnessing domestic violence, the adolescent being a victim of abuse, and adolescents' normative beliefs in resolving conflict. The findings of this study add to the current body of literature and can be used to inform the creation of new policies and interventions in the realm of ATPA and family violence.
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Date Issued: 2018
Identifier: CFE0007165, ucf:52285
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007165

Title: Digital Citizenship Tools for Cause-Based Campaigns: A Broadened Spectrum of Social Media Engagement and Participation-Scale Methodology.
Creator: Miller, Jennifer, Vie, Stephanie, Scott, Blake, Flammia, Madelyn, St. Amant, Kirk, University of Central Florida
Abstract / Description: Digital Citizenship Tools for Cause-Based Campaigns: A Broadened Spectrum of Social Media Engagement and Participation-Scale Methodology develops and applies two new tools for understanding, measuring, and recursively adjusting small to medium-size social media-based philanthropic campaigns to better foster participation and engagement(-)in other words, democratic digital citizenship. First, a theoretical model is offered broadening current binary conceptions of success and failure or impact...
Show moreDigital Citizenship Tools for Cause-Based Campaigns: A Broadened Spectrum of Social Media Engagement and Participation-Scale Methodology develops and applies two new tools for understanding, measuring, and recursively adjusting small to medium-size social media-based philanthropic campaigns to better foster participation and engagement(-)in other words, democratic digital citizenship. First, a theoretical model is offered broadening current binary conceptions of success and failure or impact of campaigns, situating specific participant actions in social media on a spectrum. Then, from that model, a new methodology is provided to measure participation and engagement generated by campaign posts. Recommendations are also offered for recursively adjusting campaign posts to better foster democratic digital citizenship. These tools were developed from data generated by #TheFaceOffChallenge, a research project representative of a typical small to medium-size cause-based campaign. #TheFaceOffChallenge also serves as a sample for analysis illustrating how to use these tools. While explicating these tools, this dissertation explores a broad range of topics related to better understanding democratic digital citizenship: online philanthropy, awareness, and digital activism; viral and memetic transmission; tensions between consumption and creation of ideas, content, and knowledge; public(s), counterpublics, and counter-efforts; literacies and access for engagement and participation in algorithmic environments; and visual communication and semiotics.
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Date Issued: 2018
Identifier: CFE0007227, ucf:52214
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007227

Title: RESPONSE-CALIBRATION TECHNIQUES FOR ANTENNA-COUPLED INFRARED SENSORS.
Creator: Krenz, Peter, Boreman, Glenn, University of Central Florida
Abstract / Description: Infrared antennas are employed in sensing applications requiring specific spectral, polarization, and directional properties. Because of their inherently small dimensions, there is significant interaction, both thermal and electromagnetic, between the antenna, the antenna-coupled sensor, and the low-frequency readout structures necessary for signal extraction at the baseband modulation frequency. Validation of design models against measurements requires separation of these effects so that the...
Show moreInfrared antennas are employed in sensing applications requiring specific spectral, polarization, and directional properties. Because of their inherently small dimensions, there is significant interaction, both thermal and electromagnetic, between the antenna, the antenna-coupled sensor, and the low-frequency readout structures necessary for signal extraction at the baseband modulation frequency. Validation of design models against measurements requires separation of these effects so that the response of the antenna-coupled sensor alone can be measured in a calibrated manner. Such validations will allow confident extension of design techniques to more complex infrared-antenna configurations. Two general techniques are explored to accomplish this goal. The extraneous signal contributions can be measured separately with calibration structures closely co-located near the devices to be characterized. This approach is demonstrated in two specific embodiments, for removal of cross-polarization effects arising from lead lines in an antenna-coupled infrared dipole, and for removal of distributed thermal effects in an infrared phased-array antenna. The second calibration technique uses scanning near-field microscopy to experimentally determine the spatial dependence of the electric-field distributions on the signal-extraction structures, and to include these measured fields in the computational electromagnetic model of the overall device. This approach is demonstrated for infrared dipole antennas which are connected to coplanar strip lines. Specific situations with open-circuit and short-circuit impedances at the termination of the lines are investigated.
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Date Issued: 2010
Identifier: CFE0003177, ucf:48606
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003177

Title: Electromagnetic Environment in Payload Fairing Cavities.
Creator: Trout, Dawn, Wahid, Parveen, Wu, Xinzhang, Gong, Xun, Tang, Philip, University of Central Florida
Abstract / Description: An accurate determination of a spacecraft's radio frequency electromagnetic field environment during launch and flight is critical for mission success. Typical fairing structures consist of a parabolic nose and a cylindrical core with diameters of 1 to 5 meters resulting in electrically large dimensions for typical operational sources at S, C and X band where the free space wavelength varies from 0.15 m to 0.03 m. These electrically large size and complex structures at present have internal...
Show moreAn accurate determination of a spacecraft's radio frequency electromagnetic field environment during launch and flight is critical for mission success. Typical fairing structures consist of a parabolic nose and a cylindrical core with diameters of 1 to 5 meters resulting in electrically large dimensions for typical operational sources at S, C and X band where the free space wavelength varies from 0.15 m to 0.03 m. These electrically large size and complex structures at present have internal fairing electromagnetic field evaluation that is limited to general approximation methods and some test data. Though many of today's computational electromagnetic tools can model increasingly complex and large structures, they still have many limitations when used for field determination in electrically large cavities. In this dissertation, a series of test anchored, full wave computational electromagnetic models along with a novel application of the equivalent material property technique are presented to address the electrical, geometrical, and boundary constraints for electromagnetic field determination in composite fairing cavity structures and fairings with acoustic blanketing layers. Both external and internal excitations for these fairing configurations are examined for continuous wave and transient sources. A novel modification of the Nicholson Ross Weir technique is successfully applied to both blanketed aluminum and composite fairing structures and a significant improvement in computational efficiency over the multilayered model approach is obtained. The advantages and disadvantages of using commercially available tools by incorporating Multilevel Fast Multipole Method (MLFMM) and higher order method of moments (HO MoM) to extend their application of MoM to electrically large objects is examined for each continuous wave transmission case. The results obtained with these models are compared with those obtained using approximation techniques based on the Q factor, commonly utilized in the industry, and a significant improvement is seen in a prediction of the fields in these large cavity structures. A statistical distribution of data points within the fairing cavity is examined to study the nature of the fairing cavity field distribution and the effect of the presence of a spacecraft load on these fields is also discussed. In addition, a model with external application of Green's function is examined to address the shielding effectiveness of honeycomb panels in a fairing cavity. Accurate data for lightning induced effects within a fairing structure is not available and hence in this dissertation, a transmission line matrix method model is used to examine induced lightning effects inside a graphite composite fairing structure. The simulated results are compared with test data and show good agreement.
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Date Issued: 2012
Identifier: CFE0004275, ucf:49505
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004275

Transmission (3)	+ -
transmission electron microscopy (TEM) (2)	+ -
304 stainless steel (1)	+ -
802.11 (1)	+ -
802.11e (1)	+ -

Absorption and Transmission (1)	+ -
Academic (1)	+ -
Admission Control (1)	+ -
Amino Acids (1)	+ -
Anxiety (1)	+ -
Breastfeeding (1)	+ -
Causes (1)	+ -
Cell Transmission Model (1)	+ -
Computer networks (1)	+ -
Confocal Microscope (1)	+ -
Continuous metal film (1)	+ -
Contraflow (1)	+ -
Coupling mode (1)	+ -
Cryogenics. (1)	+ -
Discrete Dipole Approximation (1)	+ -
ESD simulation (1)	+ -
Education (1)	+ -
Electrostatic discharge (1)	+ -
End to End Delay (1)	+ -
Engineering -- Dissertations (1)	+ -
Enhanced electric fields. (1)	+ -
Evacuation Scheduling (1)	+ -
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Gender Stereotype (1)	+ -

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Honors Collection (3)	+ -

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