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- Title
- ZrB2-SiC BASED ULTRA HIGH TEMPERATURE CERAMIC COMPOSITES: MECHANICAL PERFORMANCE AND MEASUREMENT AND DESIGN OF THERMAL RESIDUAL STRESSES FOR HYPERSONIC VEHICLE APPLICATIONS.
- Creator
-
Stadelmann, Richard, Orlovskaya, Nina, Kumar, Ranganathan, Raghavan, Seetha, University of Central Florida
- Abstract / Description
-
Ultra-high temperature ceramics (UHTCs), such as ZrB2-based ceramic composites, have been identified as next generation candidate materials for leading edges and nose cones in hypersonic air breathing vehicles. Mechanical performance of ceramic composites play an important role in the ultra-high temperature applications, therefore SiC is added to ZrB2 as a strengthening phase to enhance its mechanical performance. The high melting temperatures of both ZrB2 and SiC, as well as the ability of...
Show moreUltra-high temperature ceramics (UHTCs), such as ZrB2-based ceramic composites, have been identified as next generation candidate materials for leading edges and nose cones in hypersonic air breathing vehicles. Mechanical performance of ceramic composites play an important role in the ultra-high temperature applications, therefore SiC is added to ZrB2 as a strengthening phase to enhance its mechanical performance. The high melting temperatures of both ZrB2 and SiC, as well as the ability of SiC to form SiO2 refractory oxide layers upon oxidation make ZrB2-SiC ceramics very suitable for aerospace applications. Thermal residual stresses appearing during processing are unavoidable in sintered ZrB2-SiC ceramic composites. Residual microstresses appear at the microstructural level (intergranular microstresses) or at the crystal structure level (intragranular microstresses). These microstresses are of enormous importance for the failure mechanisms in ZrB2-SiC ceramics, such as ratio of the trans- and intergranular fracture; crack branching or bridging, microcracking, subcritical crack growth and others, as they govern crack propagation(-)induced energy dissipation and affect the toughness and strength of the ceramic material. Therefore, understanding the evolution of residual stress state in processed ZrB2-SiC ceramic composites and accurate measurements of these stresses are of high priority. In the present research the ZrB2-17vol%SiC, ZrB2-32vol%SiC, and ZrB2-45vol%SiC ultra-high temperature particulate ceramic composites were sintered using both Hot Pressing (HP) and Spark Plasma Sintering (SPS) techniques. The mechanical performance of the ZrB2-SiC composites was investigated using 3- and 4-point bending techniques for measurements of instantaneous fracture strength and fracture toughness. Resonant Ultrasound Spectroscopy was used for measurement of Young's, shear, and bulk moduli as well as Poisson's ratio of the composites. The distribution of thermal residual stresses and the effect of the applied external load on their re-distribution was studied using micro-Raman spectroscopy. Piezospectroscopic coefficients were determined for all compositions of ZrB2-SiC ceramic under study and their experimentally obtained values were compared with the piezospectroscopic coefficients both published in the literature and calculated using theoretical approach. Finally, the novel ZrB2-IrB2-SiC ceramic composites were also produced using Spark Plasma Sintering (SPS), where IrB2 powder was synthesized using mechanochemical route. It is expected that the IrB2 additive phase might contribute to the improved overall oxidation resistance of ZrB2 based ultra-high temperature ceramic composites.
Show less - Date Issued
- 2015
- Identifier
- CFE0006008, ucf:51004
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006008
- Title
- Zora.
- Creator
-
Tyrrell, Genevieve, Roney, Lisa, Rushin, Patrick, Scott, John, University of Central Florida
- Abstract / Description
-
This mixed-media memoir uses a variety of forms from short epigrammatic essays to straightforward stories and graphic narratives to explore the author's coming-of-age experiences augmented by chronic illness. Trying to succeed in the film industry, romance, and family situations, the young female narrator navigates the often unexpected or disappointing consequences of having an autonomic nervous system disorder. Relationships between conflicting identities emerge(-)between healthy versus sick...
Show moreThis mixed-media memoir uses a variety of forms from short epigrammatic essays to straightforward stories and graphic narratives to explore the author's coming-of-age experiences augmented by chronic illness. Trying to succeed in the film industry, romance, and family situations, the young female narrator navigates the often unexpected or disappointing consequences of having an autonomic nervous system disorder. Relationships between conflicting identities emerge(-)between healthy versus sick self, projected/envisioned versus actual self, and tough versus vulnerable self(-)as the narrator journeys toward a more complete and accepting self-understanding.
Show less - Date Issued
- 2013
- Identifier
- CFE0004763, ucf:49777
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004763
- Title
- Zooplankton abudance and diversity in central Florida grass carp ponds.
- Creator
-
Fry, Douglas Lee, Osborne, John A., Natural Sciences
- Abstract / Description
-
Florida Technological University College of Natural Sciences Thesis; The effect of the Asian grass carp (Ctenopharyngodon idella Val.) and aquatic vegetation upon the zooplankton in four adjacent experimental ponds (0.139 ha each) was studied for one year. Zooplankton were collected with a newly designed shallow-water sampler. Pond 1 contained no aquatic vegetation. Ponds 2, 3, and 4 contained nine species of rooted aquatic plants. Grass carp were stocked into Pond 2 (65 per ha) and Pond 3 ...
Show moreFlorida Technological University College of Natural Sciences Thesis; The effect of the Asian grass carp (Ctenopharyngodon idella Val.) and aquatic vegetation upon the zooplankton in four adjacent experimental ponds (0.139 ha each) was studied for one year. Zooplankton were collected with a newly designed shallow-water sampler. Pond 1 contained no aquatic vegetation. Ponds 2, 3, and 4 contained nine species of rooted aquatic plants. Grass carp were stocked into Pond 2 (65 per ha) and Pond 3 (611 per ha). Physicochemical parameters were similar among the ponds. Eighty-eight zooplankton species were enumerated. The abundance of zooplankton groups (Rotifera, Cladoceza, and Copepoda) was not significantly different among the ponds containing grass carp. No significant differences existed between Pond 3 (high grass carp stocking rate) and Pond 4 (no carp) for species diversity (d) and species dominance. The number of species and species diversity (d) was found to be significantly different in Pond 2 (low grass carp stocking rate) when compared to Ponds 3 and 4; those differences probably were not due to the grass carp. Grass carp did not appear to affect the water quality of the ponds. In general, it was concluded that grass carp had little, if any, direct or indirect affect upon the zooplankton. Species commonness was greatest among ponds containing vegetation. Rotifers were the dominant zooplankton group in those ponds. Zooplankton ware moat abundant in the pond without vegetation and were dominated by copepods (notably Tropocyclops prasinus). That pond contained the lowest number of species and had the largest species diversity (d) of the ponds. The annual mean for the Simpson Index (species dominance) was highest in Pond 1. The lack of vegetation may have influenced the abundance and diversity of the zooplankton in Pond 1 compared to the other ponds. Those differences also may have been due to selective predation by mosquitofish (Gambusia affinis); that fish was significantly less abundant in Pond 1.
Show less - Date Issued
- 1978
- Identifier
- CFR0004339, ucf:52999
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0004339
- Title
- Zooming In On The Money Shot: An Exploratory Quantitative Analysis of Pornographic Film Actors.
- Creator
-
O'Neal, Erin, Huff-Corzine, Lin, Corzine, Harold, Pritchard, Adam, Potter, Roberto, University of Central Florida
- Abstract / Description
-
Sex work is one of the rare elements of our society that is both accepted and stigmatized. Ironically enough, it is stigmatized without being studied in depth. The truth is we know very little about sex work and even less about pornography(-)the most legal of genres. While researchers have spent a great deal of time determining the effects that pornography has on viewers, particularly juvenile viewers, little research has been done on the men and women who make pornography. A 43 question...
Show moreSex work is one of the rare elements of our society that is both accepted and stigmatized. Ironically enough, it is stigmatized without being studied in depth. The truth is we know very little about sex work and even less about pornography(-)the most legal of genres. While researchers have spent a great deal of time determining the effects that pornography has on viewers, particularly juvenile viewers, little research has been done on the men and women who make pornography. A 43 question survey was created and disseminated to those in the pornographic film industry, both amateur and professional, resulting in 210 respondents from all walks of life. The results of the inquiry show that social scientists know relatively little about working in pornography, having a profound impact on the current discussion and future research. Additionally, this investigation presents a new and creative method for surveying hard to reach, hidden, or sensitive subject populations that will aid in aspects of future research on sex work and other stigmatized behaviors.
Show less - Date Issued
- 2016
- Identifier
- CFE0006365, ucf:51532
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006365
- Title
- ZINC-FINGER PROTEIN MCPIP IN CELL DEATH AND DIFFERENTIATION.
- Creator
-
Younce, Craig, Kolattukudy, Pappachan, University of Central Florida
- Abstract / Description
-
Monocyte chemotactic protein-1 (MCP-1) plays a critical role in the development of cardiovascular diseases. How MCP-1 contributes to the development of heart disease is not understood. We present evidence that MCP-1 causes death in cardiac myoblasts, H9c2 by inducing oxidative stress, ER stress and autophagy via a novel Zn-finger protein, MCP-1 induced protein (MCPIP). MCPIP expression caused cell death and knockdown of MCPIP, attenuated MCP-1 induced cell death. Expression of MCPIP resulted...
Show moreMonocyte chemotactic protein-1 (MCP-1) plays a critical role in the development of cardiovascular diseases. How MCP-1 contributes to the development of heart disease is not understood. We present evidence that MCP-1 causes death in cardiac myoblasts, H9c2 by inducing oxidative stress, ER stress and autophagy via a novel Zn-finger protein, MCP-1 induced protein (MCPIP). MCPIP expression caused cell death and knockdown of MCPIP, attenuated MCP-1 induced cell death. Expression of MCPIP resulted in induction of iNOS and production of reactive oxygen (ROS). It caused induction of NADPH oxidase subunit phox47 and its translocation to the cytoplasmic membrane. Oxidative stress led to the induction of ER stress markers HSP40, PDI, GRP78 and IRE1α. ER stress lead to autophagy as indicated by beclin-1 induction, cleavage of LC3 to LCII and autophagolysosome formation. Here, MCPIP-induced processes lead to apoptosis as indicated by caspase 3 activation and TUNEL assay. This cell death involved caspase 2 and caspase 12 as specific inhibitors of these caspases prevented MCPIP-induced cell death. Inhibitors of oxidative stress inhibited ER stress, and cell death. Specific inhibitors of ER stress inhibited autophagy and cell death. Inhibition of autophagy inhibited cell death. Microarray analysis showed that MCPIP expression caused induction of a variety of genes known to be involved in cell death. MCPIP caused activation of JNK and p38 and induction of p53 and PUMA. These results collectively suggest that MCPIP induces ROS/RNS production that causes ER stress which leads to autophagy and apoptosis through caspase 2/12 and IRE1α JNK/p38-p53-PUMA pathway. These results provide the first molecular insights into the mechanism by which elevated MCP-1 levels associated with chronic inflammation may contribute to the development of heart failure. A role for inflammation and MCP-1 in obesity and diabetes has been implicated. Adipogenesis is a key process involved in obesity and associated diseases such as type 2 diabetes. This process involves temporally regulated genes controlled by a set of transcription factors, C/EBPβ, C/EBPδ, C/EBPα, and PPARγ. Currently PPARγ is considered the master regulator of adipogenesis as no known factor can induce adipogenesis without PPARγ. We present evidence that a novel Zn-finger protein, MCPIP, can induce adipogenesis without PPARγ. Classical adipogenesis-inducing medium induces MCP-1 production and MCPIP expression in 3T3-L1 cells before the induction of the C/EBP family of transcription factors and PPARγ. Knockdown of MCPIP prevents their expression and adipogenesis. Treatment of 3T3-L1 cells with MCP-1 or forced expression of MCPIP induces expression of C/EBPβ, C/EBPδ, C/EBPα, PPARγ and adipogenesis without any other inducer. Forced expression of MCPIP induces adipogenesis in PPARγ-/- fibroblasts. Thus, MCPIP is a newly identified master controller that can induce adipogenesis without PPARγ. Heart failure is a major cause of death in diabetic patients. Hyperglycemia is a major factor associated with diabetes that causes cardiomyocyte apoptosis that leads to diabetic cardiomyopathy. Cardiomyoycte apoptosis is a key event involved in the pathophysiological progression of diabetic cardiomyopathy. We have recently found that in ischemic hearts, MCP-1 can induce the zinc-finger protein, MCP-1 induced protein (MCPIP) that causes cardiomyocyte apoptosis. Although there is evidence that inflammation may play a role in diabetic cardiomyopathy, the underlying mechanisms are poorly understood. In this study, we show that treatment of H9c2 cardiomyoblasts and Neonatal Rat Ventricular Myocytes (NRVM) with 28mmol/L glucose concentration results in the induction of both transcript and protein levels of MCP-1 and MCPIP. Inhibition of MCP-1 interaction with CCR2 via specific antibody or with the G-coupled receptor inhibitors propagermanium and pertussis toxin attenuated glucose-induced cell death. Knockdown of MCPIP with specific siRNA yielded similar results. Treatment of cells with 28mmol/L glucose resulted in increased ROS production and phox47 activation. Knockdown of MCPIP attenuated these effects. The increased ROS production observed in H9c2 cardiomyoblasts and NRVM's resulted in increased ER stress proteins GRP78 and PDI. Knockdown of MCPIP attenuated expression of both GRP78 and PDI. Inhibition of ER stress with TUDC and 4'PBA prevented high glucose-induced cell death death. Treatment of cells with 28mmol/l glucose resulted in autophagy as determined by an increase in expression of beclin-1 and through increased cleavage of LC3I to LC3II. Knockdown of MCPIP attenuated expression of beclin-1 and prevented cleavage of LC3. Addition of the autophagy inhibitors 3'methyladenine and LY294002 attenuated high glucose-induced H9c2 cardiomyoblast death. We conclude that high glucose-induced H9c2 cardiomyoblast death is mediated via MCP-1 induction of MCPIP that results in ROS that leads to ER stress that causes autophagy and eventual apoptosis.
Show less - Date Issued
- 2009
- Identifier
- CFE0002888, ucf:48027
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002888
- Title
- Zinc Sulfide:manganese doped Quantum rods for detection of metal ions and a business model for future sales.
- Creator
-
Teblum, Andrew, Santra, Swadeshmukul, Gesquiere, Andre, Soskin, Mark, University of Central Florida
- Abstract / Description
-
Hexavalent chromium is an extremely carcinogenic chemical that has been widely produced in the United States. This has led to major waste contamination and pollution throughout the country. According to the Environmental Working Group Hexavalent chromium has been found in 89% of city tap water. Most people believe they are safe using regular home filter systems however that is not true. A more expensive ion exchange water treatment unit is required. Therefore to protect yourselves from this...
Show moreHexavalent chromium is an extremely carcinogenic chemical that has been widely produced in the United States. This has led to major waste contamination and pollution throughout the country. According to the Environmental Working Group Hexavalent chromium has been found in 89% of city tap water. Most people believe they are safe using regular home filter systems however that is not true. A more expensive ion exchange water treatment unit is required. Therefore to protect yourselves from this carcinogenic metal a reliable test is required. In this study we have developed a Zinc Sulfide Manganese doped Quantum Rod technology to detect for presence of chromate and other harmful transitional metals in drinking water. Quantum Rods were synthesized using a hydrothermal reaction method. They were fully characterized using UV-visible absorption spectroscopy, fluorescence emission spectroscopy, X-ray Photoelectric Spectroscopy (XPS) and High Resolution Transmission Electron Microscopy (HRTEM). Quantum Rod metal detection studies were done with 28 different ions in a 96-well fluorescent plate reader. Results show that highest sensitivity to 8 ions including the toxic ions of chromate and mercury allowing us to create a sensor to detect these items.
Show less - Date Issued
- 2014
- Identifier
- CFE0005268, ucf:50569
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005268
- Title
- ZINC CADMIUM SULPHIDE AND ZINC SULPHIDE AS ALTERNATIVE HETEROJUNCTION PARTNERS FOR CIGS2 SOLAR CELLS.
- Creator
-
Kumar, Bhaskar, Dhere, Neelkanth G, University of Central Florida
- Abstract / Description
-
Devices with ZnCdS/ZnS heterojunction partner layer have shown better blue photon response due to higher band gap of these compounds as compared to devices with CdS heterojunction partner layer. CdS heterojunction partner layer has shown high photovoltaic conversion efficiencies with CIGS absorber layer while efficiencies are lower with CuIn1-xGaxS2 (CIGS2). A negative conduction band offset has been observed for CdS/CIGS2 as compared to near flat conduction band alignment in case of CdS/CIGS...
Show moreDevices with ZnCdS/ZnS heterojunction partner layer have shown better blue photon response due to higher band gap of these compounds as compared to devices with CdS heterojunction partner layer. CdS heterojunction partner layer has shown high photovoltaic conversion efficiencies with CIGS absorber layer while efficiencies are lower with CuIn1-xGaxS2 (CIGS2). A negative conduction band offset has been observed for CdS/CIGS2 as compared to near flat conduction band alignment in case of CdS/CIGS devices, which results in higher interface dominated recombination. Moreover, it has been predicted that optimum band offsets for higher efficiency solar cells may be achieved for cells with alternative heterojunction partner such as ZnS. With varying ratio of Zn/ (Zn+Cd) in ZnxCd1-xS a range of bandgap energies can be obtained and thus an optimum band offset can be engineered. For reducing interface dominated recombination better lattice match between absorber and heterojunction partners is desirable. Although CdS has better lattice match with CuIn1-xGaxS2 absorber layer, same is not true for CuIn1-xGaxS2 absorber layers. Utilizing ZnxCd1-xS as heterojunction partner provides a range of lattice constant (between aZnS= ~5.4 Ǻ and aCdS= ~5.7 Ǻ) depending on Zn/(Zn+Cd). Therefore better lattice match can be obtained between heterojunction partner and absorber layer. Better lattice match will lead to lower interface dominated recombination, hence higher open circuit voltages. In the present study chemical bath deposition parameters are near optimized for high efficiency CIGS2 Solar cells. Effect of various chemical bath deposition parameters on device performance was studied and attempts were made to optimize the deposition parameters in order to improve the device performance.In/(In+Ga) ratio in absorber layer is varied to obtain good lattice match and optimum band alignment. Solar cells with conversion efficiencies comparable to conventional CdS/CIGS2 has been obtained with ZnxCd1-xS /CIGS2. High short current as well as higher open circuit voltages were obtained with ZnxCd1-xS as alternative heterojunction partner for CIGS2 solar cells as compared to SLG/Mo/CIGS2/ CdS / i-ZnO/ZnO:Al.
Show less - Date Issued
- 2007
- Identifier
- CFE0001936, ucf:47469
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001936
- Title
- Zika virus-induced lysis of cervical cancer cells.
- Creator
-
Krishnapura, Harini, Alexander, Kenneth, Parks, Griffith, Jewett, Mollie, University of Central Florida
- Abstract / Description
-
Cervical cancer is the fourth most frequent cancer in women with an estimated 570,000 new cases globally in 2018. Treatment of advanced cervical cancer is often unsuccessful leading to high cancer-related mortality rates, especially in under-resourced countries. Recently, a possible role for the cell surface glycoprotein CD24 in host cell specificity of Zika virus was reported. As an extension of this work, Zika viruses have been proposed as oncolytic therapy for the treatment of...
Show moreCervical cancer is the fourth most frequent cancer in women with an estimated 570,000 new cases globally in 2018. Treatment of advanced cervical cancer is often unsuccessful leading to high cancer-related mortality rates, especially in under-resourced countries. Recently, a possible role for the cell surface glycoprotein CD24 in host cell specificity of Zika virus was reported. As an extension of this work, Zika viruses have been proposed as oncolytic therapy for the treatment of neuroblastoma and other CD24 positive tumors. To determine the permissiveness of cervical cancer cells to Zika virus infection and its association with CD24, we assessed cytopathic effect (CPE) induced by Zika virus in cervical cancer cell lines (HeLa, SiHa and CaSki) by light microscopy and by cytotoxicity assay. Cervical cancer cells were susceptible to Zika virus-induced apoptosis. Upon infection, the morphology of cervical cancer cells changed, exhibiting Zika virus-induced CPE. Cervical cancer cell expression of viral non-structural protein 1 (NS1) after infection demonstrated viral protein translation. Quantitative plaque assays demonstrated the production of competent virions. Because CD24 expression was found to be important for Zika virus infection in neuroblastoma cells, CD24 expression was assessed in cervical cancer cells. Cervical cancer cells expressed low but measurable levels of CD24 mRNA and protein. siRNA-mediated knockdown of CD24 resulted in reduced NS1 expression and reduced levels of virus-induced apoptosis. Taken together our data suggest a possible role for CD24 in Zika virus-induced apoptosis in cervical cancer cells. Zika virus-induced apoptosis of cultured cervical cancer cells presents the possibility for the use of Zika virus as a potential oncolytic therapy for cervical cancer.
Show less - Date Issued
- 2019
- Identifier
- CFE0007480, ucf:52682
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007480
- Title
- ZERO TOLERANCE FOR SOME:THE ROLE OF RACE IN ZERO TOLERANCE EXCLUSIONARY DISCIPLINE.
- Creator
-
Bejarano, Meghan, Ford, Jason, University of Central Florida
- Abstract / Description
-
Within the last few decades, zero tolerance policies and exclusionary discipline have become the standard way in which schools manage student behavior. These policies, namely suspension and expulsion have been shown to have negative impacts on the lives of students who are punished with them. Educationally, the removal of students from the classroom hurts their chances of achieving academic success. Furthermore, these policies have been linked with an increase in the presence of law...
Show moreWithin the last few decades, zero tolerance policies and exclusionary discipline have become the standard way in which schools manage student behavior. These policies, namely suspension and expulsion have been shown to have negative impacts on the lives of students who are punished with them. Educationally, the removal of students from the classroom hurts their chances of achieving academic success. Furthermore, these policies have been linked with an increase in the presence of law enforcement on school campuses, which results in the arrest of students, burdening them with expensive and serious legal battles. This research examines whether nonwhite students are more likely to be sanctioned by this form of discipline. A nationally representative sample of middle and high school students is used to estimate four logistic regression models, with exclusionary discipline as the dependent variable and race as the primary independent variable. The analysis shows that nonwhite students are more likely to suspended or expelled than white students - even when student behavior is the same. This research adds to the existing body of research on exclusionary discipline and provides a nationally generalizable study to support the claim the nonwhite students are at an increased risk to be sanctioned by zero tolerance policies.
Show less - Date Issued
- 2014
- Identifier
- CFH0004643, ucf:45276
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004643
- Title
- Ytterbium-doped fiber-seeded thin-disk master oscillator power amplifier laser system.
- Creator
-
Willis-Ott, Christina, Richardson, Martin, Schulzgen, Axel, Delfyett, Peter, Chow, Louis, University of Central Florida
- Abstract / Description
-
Lasers which operate at both high average power and energy are in demand for a wide range of applications such as materials processing, directed energy and EUV generation. Presented in this dissertation is a high-power 1 ?m ytterbium-based hybrid laser system with temporally tailored pulse shaping capability and up to 62 mJ pulses, with the expectation the system can scale to higher pulse energies. This hybrid system consists of a low power fiber seed and pre-amplifier, and a solid state thin...
Show moreLasers which operate at both high average power and energy are in demand for a wide range of applications such as materials processing, directed energy and EUV generation. Presented in this dissertation is a high-power 1 ?m ytterbium-based hybrid laser system with temporally tailored pulse shaping capability and up to 62 mJ pulses, with the expectation the system can scale to higher pulse energies. This hybrid system consists of a low power fiber seed and pre-amplifier, and a solid state thin-disk regenerative amplifier. This system has been designed to generate high power temporally tailored pulses on the nanosecond time scale. Temporal tailoring and spectral control are performed in the low power fiber portion of the system with the high pulse energy being generated in the regenerative amplifier. The seed system consists of a 1030 nm fiber-coupled diode, which is transmitted through a Mach-Zehnder-type modulator in order to temporally vary the pulse shape. Typical pulses are 20-30 ns in duration and have energies of ~0.2 nJ from the modulator. These are amplified in a fiber pre-amplifier stage to ~100 nJ before being used to seed the free-space Yb:YAG thin-disk regenerative amplifier. Output pulses have maximum demonstrated pulse energies of 62 mJ with 20 ns pulse after ~250 passes in the cavity. The effects of thermal distortion in laser and passive optical materials are also. Generally the development of high power and high energy lasers is limited by thermal management strategies, as thermally-induced distortions can degrade laser performance and potentially cause catastrophic damage. Novel materials, such as optical ceramics, can be used to mitigate thermal distortions; however, thorough analysis is required to optimize their fabrication and minimize thermal distortions. Using a Shack-Hartmann wavefront sensor (SHWFS), it is possible to analyze the distortion induced in passive and doped optical elements by high power lasers. For example, the thin-disk used in the regenerative amplifier is examined in-situ during CW operation (up to 2 kW CW pump power). Additionally, passive oxide-based optical materials and Yb:YAG optical ceramics are also examined by pumping at 2 and 1 ?m respectively to induce thermal distortions which are analyzed with the SHWFS. This method has been developed as a diagnostic for the relative assessment of material quality, and to grade differences in ceramic laser materials associated with differences in manufacturing processes and/or the presence of impurities. In summation, this dissertation presents a high energy 1 ?m laser system which is novel in its combination of energy level and temporal tailoring, and an analysis of thermal distortions relevant to the development of high power laser systems.
Show less - Date Issued
- 2013
- Identifier
- CFE0004961, ucf:49588
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004961
- Title
- Youth Labor Market Conditions and the NEET Population in the EU: Do Poor Labor Market Opportunities Discourage Youth?.
- Creator
-
Hudson, Jennifer, Hamann, Kerstin, Kinsey, Barbara, Powell, Jonathan, University of Central Florida
- Abstract / Description
-
This study examines how poor labor market opportunities discourage youth between the ages of 15 and 24 and 15 to 29 from participating in the labor market in the European Union between 2005 and 2013. A critical portion of inactive NEETs (youth not in employment, education, or training) reports to be discouraged due to a recognized (")lack of opportunities in the labor market.(") Despite indications from descriptive analyses that the conditions that drive the distinct subsets of the NEET...
Show moreThis study examines how poor labor market opportunities discourage youth between the ages of 15 and 24 and 15 to 29 from participating in the labor market in the European Union between 2005 and 2013. A critical portion of inactive NEETs (youth not in employment, education, or training) reports to be discouraged due to a recognized (")lack of opportunities in the labor market.(") Despite indications from descriptive analyses that the conditions that drive the distinct subsets of the NEET population vary, empirical examinations of the effects of these conditions on the rates of different NEET groups across countries and over time are lacking. The policies prescribed for the NEET group as a whole tend to ignore the special needs of discouraged, inactive NEETs. Beyond the fundamental problem of engaging these individuals in the labor market, neglecting this group has a variety of implications, ranging from social exclusion, to poverty, and even radicalism. A central goal of this project is to determine what a recognized (")lack of opportunities(") means. What is known concretely is that fellow youth are increasingly vulnerable to a range of labor market outcomes and conditions beyond unemployment, including difficulty transitioning into the labor market (school-to-work transitions), in-work poverty risk, non-standard employment opportunities (involuntary and voluntary), limited ability to transition into secure employment (i.e. upward mobility), lower wage levels, atypical employment, limited job security and support, and long-term unemployment. Utilizing aggregated survey data from the EU Labor Force Survey and EU Survey on Income and Living Conditions, I examine how a range of labor market outcomes and conditions for youth, representative of the poor labor market opportunities, affect the frequency of discouraged NEETs across 24 EU countries between 2005 and 2013. Findings suggest that the incidence of involuntary non-standard work, in-work poverty risk, and atypical employment among fellow youth and the incidence of decreased work security among the adult working age population are associated with an increase in discouraged, inactive NEETs. This suggests that engaging this hard to reach subgroup of the NEET population requires a greater emphasis on creating improved labor market opportunities.
Show less - Date Issued
- 2017
- Identifier
- CFE0006605, ucf:51292
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006605
- Title
- Young Thinkers.
- Creator
-
Elgeness, Jaclyn, Neal, Mary, Bartkevicius, Jocelyn, Rushin, Patrick, University of Central Florida
- Abstract / Description
-
Young Thinkers is a collection of short fiction dealing with what it means to earn wisdom in the twenty-first century. When our phones can remember everything for us, and we're plagued by a sense that everything has already been said and digitally cataloged, insight becomes even more important, particularly to the thoughtful characters explored throughout the collection. The prolonged American adolescence facilitated by the economic crisis, as well as the societal acceptance of marrying and...
Show moreYoung Thinkers is a collection of short fiction dealing with what it means to earn wisdom in the twenty-first century. When our phones can remember everything for us, and we're plagued by a sense that everything has already been said and digitally cataloged, insight becomes even more important, particularly to the thoughtful characters explored throughout the collection. The prolonged American adolescence facilitated by the economic crisis, as well as the societal acceptance of marrying and having children much later in life, creates an atmosphere of intense self-doubt. A young man working at a gas station after college witnesses a high school boy die in a hit and run, and he longs to comfort others at the vigil. Another young man decides he would rather rob houses than return to community college while wondering at ways to extend his lifespan. Young women struggle to feel important and independent, but find themselves assuaging their fears with cigarettes and alcohol. These characters yearn for the insight and experience that would make them decidedly and authoritatively adult.
Show less - Date Issued
- 2011
- Identifier
- CFE0004106, ucf:49097
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004106
- Title
- YOUNG ONSET DEMENTIA: THE CHILD'S EXPERIENCE WITH COPING.
- Creator
-
Zeher, Jamie, Loerzel, Victoria, University of Central Florida
- Abstract / Description
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Young onset dementia (YOD) affects not only the person diagnosed, but the family unit as a whole. It is estimated that as many as 500,000 people in the United States have YOD and around 250,000 children are involved in caring for these people. A child of a parent with YOD can begin to experience negative effects when the child begins to take part in caregiving for the person with young onset dementia (PWYOD). Feelings of stress, anger, fear of the future, depression, social isolation, and...
Show moreYoung onset dementia (YOD) affects not only the person diagnosed, but the family unit as a whole. It is estimated that as many as 500,000 people in the United States have YOD and around 250,000 children are involved in caring for these people. A child of a parent with YOD can begin to experience negative effects when the child begins to take part in caregiving for the person with young onset dementia (PWYOD). Feelings of stress, anger, fear of the future, depression, social isolation, and increasing responsibility of caring for the PWYOD can be felt by children as caregivers. Research shows that children of people with YOD have reported an extreme lack of support and decreased communication within the family. The purpose of this thesis was to examine current interventions designed to improve coping for children of parents with YOD. A review of literature using CINAHL, Medline, and PsychINFO was conducted to gather peer-reviewed articles and journals relating to interventions to help children of parents with YOD cope. However, no studies have discussed interventions specifically for the child. Therefore, information was pulled from 5 studies regarding what children of people with YOD feel has helped them, in their respective experiences, to deal with the stresses of a parent with YOD. Research suggests that individualized care should be provided for these children based on: age, developmental stage, and experience. Children have reported that they cope by spending time away from the home, participating in extracurricular activities, and spending time with friends. Clear communication by all members of the family is also reported to be vital in easing the stresses of caring for a parent with YOD. While children have developed these coping mechanisms, interventions need to be formally designed and their effect on improving coping examined. Analyzing the experiences of the children with parents with YOD is necessary for clinicians to gain insight into what interventions worked for this population, and what interventions need to be created for further and more individualized support.
Show less - Date Issued
- 2013
- Identifier
- CFH0004405, ucf:45147
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004405
- Title
- Young Children's Fine Motor iPad Gestures When Performed Alone and in Dyads.
- Creator
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Nguyen, Lap, Culp, Anne, Szente, Judit, Hughes-Brand, Nicola Shea, University of Central Florida
- Abstract / Description
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Since the release of the first iPad in 2010, over 200 million have been sold worldwide. In the short time since the iPad's release, the devices have become popular in classrooms. The purpose of this study was twofold: 1) to document the fine motor iPad gestures of 2 , 3-, and 4-year-old children who used iPads by themselves and in dyads and 2) to conduct international comparisons regarding such observed fine motor iPad gestures. In this study, I examined seven iPad gestures: (a) tap, (b) drag...
Show moreSince the release of the first iPad in 2010, over 200 million have been sold worldwide. In the short time since the iPad's release, the devices have become popular in classrooms. The purpose of this study was twofold: 1) to document the fine motor iPad gestures of 2 , 3-, and 4-year-old children who used iPads by themselves and in dyads and 2) to conduct international comparisons regarding such observed fine motor iPad gestures. In this study, I examined seven iPad gestures: (a) tap, (b) drag/slide, (c) free rotate, (d) drag and drop, (e) pinch, (f) spread, and (g) flick. This study had five components. The first component involved observations of the iPad gestures of a sample of Orlando, Florida, children operating iPads by themselves. The first component was a partial replication of the 2013 and 2014 studies conducted by Aziz et al. The second component of this study involved observations of the iPad gestures of the Orlando children operating iPads in dyads. In the third component of this study, I compared the iPad gestures of the Orlando children with the gestures of a sample of 2-, 3-, and 4-year-old children from London. In the fourth component of this study, I compared the iPad gestures of the Orlando children with the gestures of a sample of 2-, 3-, and 4-year-old children from Malaysia. In the fifth component, I compared the iPad gestures of the Orlando sample when the children were paired with classmates and asked to play with the iPads in dyads, rather than operating iPads by themselves. Biographical information was collected, including (a) child's age, (b) household income, (c) child's gender, (d) child's ethnic origin, (e) types of mobile devices in the household, (f) daily usage of mobile devices, (g) people with whom the child used mobile devices, (h) earliest age of device usage, and (i) the primary language spoken at home.
Show less - Date Issued
- 2016
- Identifier
- CFE0006541, ucf:51352
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006541
- Title
- YOUNG ADULTS' ATTITUDES TOWARD SAME-SEX MARRIAGE AND POLYGAMYAS A FUNCTION OF DEMOGRAPHIC, GENDER, AND PERSONALITY VARIABLES.
- Creator
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Pearte, Catherine, Negy, Charles, University of Central Florida
- Abstract / Description
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Based on a sample of 814 university students, pro- and anti-same-sex marriage and polygamous marriage groups were established based on students scoring >1 SD above (n = 145; n = 132, respectively) and
Show moreBased on a sample of 814 university students, pro- and anti-same-sex marriage and polygamous marriage groups were established based on students scoring >1 SD above (n = 145; n = 132, respectively) and < 1 SD below the group mean (n = 127; n = 126) on the Attitudes Toward Same-Sex Marriage Scale (ATSSM: Pearl & Paz-Galupo, 2007) and Attitudes Toward Polygamy Scale, which was generated by modifying the ATSSM (ATPM). Compared to pro-same-sex marriage students, anti-same-sex marriage students were significantly more prejudiced against gays and lesbians, authoritarian, religious, and politically conservative. Anti-same-sex marriage students also had less contact with and appreciation for diverse cultural groups, more desire to dominate out-groups, were less autonomous in their thinking, and were more likely to be men. Anti-polygamous students were more strongly opposed same-sex marriage, idealized the traditional family, authoritarian, religious, less autonomous in their thinking, desire to dominate minority groups, and were more likely to be female compared to those who were propolygamous marriage. Results further indicated that, polygamy and same-sex marriage are predicted by different variables, with same-sex marriage being more strongly tied to prejudice against gays and lesbians and polygamous marriage being more strongly tied to beliefs about the inherent morality of conventions surrounding the traditional family. A regression analysis using data from all 814 students yielded almost identical results with regards to identifying variables most predictive of ATSSM. Followup analyses revealed that prejudice against gays and lesbians was the single best predictor of opposition to same-sex marriage and even accounted for the associations between opposition to same-sex marriage and religiosity, political conservatism, and support of traditional marriage and family. With respect to polygamy, data from regression analyses revealed that ATSSM was the best predictor of ATPM. Despite the cultural focus on this variable, however, controlling for ATSSM did not reduce the predictive power of critical variables to a non-significant level. Recommendations for challenging opposition to marriage equality are discussed.
Show less - Date Issued
- 2010
- Identifier
- CFE0003378, ucf:48457
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003378
- Title
- Young Adult Development and Caregiving: Disposition and Involvement in Care.
- Creator
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James, Nicholas, Paulson, Daniel, Dvorak, Robert, Wharton, Tracy, University of Central Florida
- Abstract / Description
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Caregivers are a diverse group of individuals with a variety of backgrounds and roles; however, research has widely overlooked young adults in this population. This study investigated young adult caregiver circumstance, burden, and use of support services with the purpose of improving future caregiving research and interventions. Study 1 compared burden and circumstance among young, middle aged, and older adult caregivers (N = 285) in addition to developmental indicators among young adults...
Show moreCaregivers are a diverse group of individuals with a variety of backgrounds and roles; however, research has widely overlooked young adults in this population. This study investigated young adult caregiver circumstance, burden, and use of support services with the purpose of improving future caregiving research and interventions. Study 1 compared burden and circumstance among young, middle aged, and older adult caregivers (N = 285) in addition to developmental indicators among young adults caregiver and demographically matched non-caregiver peers (n = 225). Study 2 surveyed caregivers from each age group (N = 151) on barriers to care, treatment preferences, and interest in services. Results from study 1 indicated that young adult caregivers adopted similar caregiving roles and factors linked to burden; however, they reported additional stressors such as higher rates of childcare and commuting to provide care. Compared to demographically matched-peers, young adult caregivers were more likely to work part-time and earn a substantially lower yearly income. Study 2 replicated original findings and revealed that young adult caregivers endorsed elevated attitudinal barriers to care and are the least likely age group to speak to physicians about caregiving. Overall, findings reveal the similarity in caregiving role that young adults take on, as well as several unique burden factors. Caregivers across age groups disclosed moderate treatment expectancy for support services, and all reported greater interest in online-based treatment. Young adult caregivers were more likely to take on responsibilities such as childrearing and employment, thus impacting their available time and financial support. However, these findings do not explain the overwhelming lack of young adult caregivers in research. Future studies should re-evaluate sampling methods and inclusion criteria, or explore more accessible means of intervention, such as web-based services.
Show less - Date Issued
- 2018
- Identifier
- CFE0007018, ucf:52027
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007018
- Title
- YOU'VE GOT MAIL: THE STUDY OF THE ATTORNEY-CLIENT PRIVILEGE AND THE USE OF ELECTRONIC MAIL.
- Creator
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McConnell, Justin, Cook, Kathy, University of Central Florida
- Abstract / Description
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The prolific use of the internet and electronic mail within the legal profession presents novel challenges to the application of the attorney-client privilege; especially, in regards to protecting intended confidential communications relayed through e-mail. This thesis addresses the question of whether an attorney in Florida, through electronic mail use, can waive his client's right to the protections of the attorney-client privilege. After a review of current case law, law review articles,...
Show moreThe prolific use of the internet and electronic mail within the legal profession presents novel challenges to the application of the attorney-client privilege; especially, in regards to protecting intended confidential communications relayed through e-mail. This thesis addresses the question of whether an attorney in Florida, through electronic mail use, can waive his client's right to the protections of the attorney-client privilege. After a review of current case law, law review articles, statutes, and texts, this thesis concluded that an attorney's communication through e-mail warrants a reasonable expectation of privacy, permitting the attorney to speak in reasonable confidence to clients through the web. However, attorneys, ethically, should consider the strong repercussions for using such a potentially transparent medium for communication. By examining the relationship between current law, the application of the attorney-client privilege, and a reasonable expectation of privacy, this study provides a comprehensive analysis for attorneys concerned with electronic mail usage. Lastly, this thesis provides attorneys with best practices for their electronic mail communications.
Show less - Date Issued
- 2011
- Identifier
- CFH0003832, ucf:44756
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0003832
- Title
- YOU SCRATCH MY BACK AND I'LL SCRATCH YOURS: MENTOR-PERCEIVED COSTS AND BENEFITS AND THE FUNCTIONS THEY PROVIDE THEIR PROTéGéS.
- Creator
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Fullick, Julia, Smith-Jentsch, Kimberly, University of Central Florida
- Abstract / Description
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Mentoring relationships can have both costs and benefits for mentors and their protégés. The present research examined the degree to which mentors' perceived costs and benefits affect the functional and dysfunctional mentoring they provide to their protégés. Additionally, I investigated whether mentor-perceived costs and benefits were associated with the mentors' own goal orientation and the goal orientation of their protégés. Data were...
Show moreMentoring relationships can have both costs and benefits for mentors and their protégés. The present research examined the degree to which mentors' perceived costs and benefits affect the functional and dysfunctional mentoring they provide to their protégés. Additionally, I investigated whether mentor-perceived costs and benefits were associated with the mentors' own goal orientation and the goal orientation of their protégés. Data were collected from 86 protégés and their current supervisory mentors. Consistent with expectations, when mentors reported greater costs of embarrassment associated with their relationship, the protégé reported receiving greater dysfunctional mentoring. Protégés who reported receiving greater functional mentoring tended to have mentors who perceived greater benefits of mentoring them. Both protégé and mentor goal orientations demonstrated significant correlations with mentor-perceived costs and benefits of their relationships. Implications for training and reinforcing functional mentoring will be discussed.
Show less - Date Issued
- 2008
- Identifier
- CFE0002404, ucf:47766
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002404
- Title
- YOU CAN'T STOP THE BEAT: BRINGING MUSICAL THEATRE TO UNDERPRIVILEGED YOUTH.
- Creator
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Tsurumaki, Megan, Boyd, Belinda, University of Central Florida
- Abstract / Description
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In an age of standardized testing and quality-controlled classrooms, teachers have lost the freedom to integrate imagination and creativity in their lessons, ultimately cheating todayÃÂ's youth. In the classroom, students no longer have the outlets that transport them from the harsh realities of life. This thesis is an attempt to provide a venue for the Orange County Public School System that will engage the imaginations of under-represented or underprivileged students....
Show moreIn an age of standardized testing and quality-controlled classrooms, teachers have lost the freedom to integrate imagination and creativity in their lessons, ultimately cheating todayÃÂ's youth. In the classroom, students no longer have the outlets that transport them from the harsh realities of life. This thesis is an attempt to provide a venue for the Orange County Public School System that will engage the imaginations of under-represented or underprivileged students. The thesis will chronicle the development of a script with the intent of producing it in Title I elementary schools located in lower socio-economic areas of Orlando, Florida. The script will be based on Hans Christian AndersonÃÂ's fairy tale ÃÂ"The Ugly Duckling.ÃÂ" The final product will be a musical theatre piece to take into the school system to be performed by the students. The body of the thesis will contain my prior experiences of bringing musical theatre to underprivileged youth. The document will also include chapters detailing the process of creating the script and composing the music. Research will determine the socio-economic challenges prevalent in the under-represented cultures in the urban schools of Orlando. Finally, the thesis will contain a section of the actual script and will conclude with a chapter summarizing the reactions to the first reading of the play
Show less - Date Issued
- 2010
- Identifier
- CFE0003408, ucf:48397
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003408
- Title
- YOGIC DIFFUSION: THE EFFECTS OF YOGIC PRACTICE AND PHILOSOPHY ON BELIEFS ABOUT COMPLEMENTARY AND ALTERNATIVE MEDICINE.
- Creator
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Siven, Jacqueline, Mishtal, Joanna, University of Central Florida
- Abstract / Description
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This research is a qualitative study that aimed to anthropologically explore the effects of consistent long-term yogic practice on the acceptance and practice of complementary and alternative medicine (CAM) among yoga practitioners at a South Florida yoga center. I wished to determine, through in-depth interviews, whether or not yogic practice affects acceptance of CAM. The main objective was to interview individuals from a single yoga center that have practiced yoga at least once per week...
Show moreThis research is a qualitative study that aimed to anthropologically explore the effects of consistent long-term yogic practice on the acceptance and practice of complementary and alternative medicine (CAM) among yoga practitioners at a South Florida yoga center. I wished to determine, through in-depth interviews, whether or not yogic practice affects acceptance of CAM. The main objective was to interview individuals from a single yoga center that have practiced yoga at least once per week for at least one year concerning their beliefs about CAM, yoga, and health. This project will begin to fill the gap in social science, in general, and specifically, the anthropological literature. Scholars of various backgrounds have discussed elements of yogic practice and philosophy that were integral to my understanding of the data. The health benefits of yoga as CAM, the associations between yoga and beliefs about health, and the association between yoga and Indian philosophy and medicine have each been explored. However, anthropological scholarship discussing the effects of consistent, long-term yogic practice on the acceptance of other CAM's or Western biomedicine has not been examined.
Show less - Date Issued
- 2011
- Identifier
- CFE0003692, ucf:48807
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003692