952 resultados para electronic theses and dissertations


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Siloxanes are widely used in personal care and industrial products due to their low surface tension, thermal stability, antimicrobial and hydrophobic properties, among other characteristics. Volatile methyl siloxanes (VMS) have been detected both in landfill gas and biogas from anaerobic digesters at wastewater treatment plants. As a result, they are released to gas phase during waste decomposition and wastewater treatment. During transformation processes of digester or landfill gas to energy, siloxanes are converted to silicon oxides, leaving abrasive deposits on engine components. These deposits cause increased maintenance costs and in some cases complete engine overhauls become necessary. The objectives of this study were to compare the VMS types and levels present in biogas generated in the anaerobic digesters and landfills and evaluate the energetics of siloxane transformations under anaerobic conditions. Siloxane emissions, resulting from disposal of silicone-based materials, are expected to increase by 29% within the next 10 years. Estimated concentrations and the risk factors of exposure to siloxanes were evaluated based on the initial concentrations, partitioning characteristics and persistence. It was determined that D4 has the highest risk factor associated to bioaccumulation in liquid and solid phase, whereas D5 was highest in gas phase. Additionally, as siloxanes are combusted, the particle size range causes them to be potentially hazardous to human health. When inhaled, they may affix onto the alveoli of the lungs and may lead to development of silicosis. Siloxane-based COD-loading was evaluated and determined to be an insignificant factor concerning COD limits in wastewater. Removal of siloxane compounds is recommended prior to land application of biosolids or combustion of biogas. A comparison of estimated costs was made between maintenance practices for removal of siloxane deposits and installation/operation of fixed-bed carbon absorption systems. In the majority of cases, the installation of fixed-bed adsorption systems would not be a feasible option for the sole purpose of siloxane removal. However they may be utilized to remove additional compounds simultaneously.

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Biological detectors, such as canines, are valuable tools used for the rapid identification of illicit materials. However, recent increased scrutiny over the reliability, field accuracy, and the capabilities of each detection canine is currently being evaluated in the legal system. For example, the Supreme Court case, State of Florida v. Harris, discussed the need for continuous monitoring of canine abilities, thresholds, and search capabilities. As a result, the fallibility of canines for detection was brought to light, as well as a need for further research and understanding of canine detection. This study is two-fold, as it looks to not only create new training aids for canines that can be manipulated for dissipation control, but also investigates canine field accuracy to objects with similar odors to illicit materials. It was the goal of this research to improve upon current canine training aid mimics. Sol-gel polymer training aids, imprinted with the active odor of cocaine, were developed. This novel training aid improved upon the longevity of currently existing training aids, while also provided a way to manipulate the polymer network to alter the dissipation rate of the imprinted active odors. The manipulation of the polymer network could allow handlers to control the abundance of odors presented to their canines, familiarizing themselves to their canine’s capabilities and thresholds, thereby increasing the canines’ strength in court. The field accuracy of detection canines was recently called into question during the Supreme Court case, State of Florida v. Jardines, where it was argued that if cocaine’s active odor, methyl benzoate, was found to be produced by the popular landscaping flower, snapdragons, canines will false alert to said flowers. Therefore, snapdragon flowers were grown and tested both in the laboratory and in the field to determine the odors produced by snapdragon flowers; the persistence of these odors once flowers have been cut; and whether detection canines will alert to both growing and cut flowers during a blind search scenario. Results revealed that although methyl benzoate is produced by snapdragon flowers, certified narcotics detection canines can distinguish cocaine’s odor profile from that of snapdragon flowers and will not alert.

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Angadenia berteroi is a tropical perennial subshrub of the pine rocklands with large yellow flowers that set very few fruits. My dissertation seeks to elucidate the factors that affect the reproductive fitness of Angadenia berteroi a native species of the south Florida pine rocklands. I provide novel information on the pollination biology of this native species. I also assess the effects of herbivory on growth and the reproductive success of A. berteroi. Finally, I elucidate how habitat fragmentation and quality are correlated with reproductive fitness of this native perennial plant. Using a novel experimental approach, I determined the most effective pollinator group. I used nylon fishing line of widths corresponding to proboscis diameter of the major groups of visitors to examine pollen removal and deposition. In the field, I estimated visitation frequency and efficacy of each pollinator type. Using potted plants, I exposed flowers to single visit from different types of pollinators to measure fruit set. I performed artificial defoliation with scissors on plants growing in the greenhouse to assess the effects of defoliation before flowering as well as during flowering. Additionally, I used structural equation modelling (SEM) to elucidate how A. berteroi reproductive fitness was affected by habitat fragmentation and quality. My experiments provide evidence that Angadenia berteroi is specialized for bee pollination; though butterflies, skippers and others also visit its flowers, A. berteroi is exclusively pollinated by two native bees of the South Florida pine rocklands . This research also demonstrated that herbivory by the oleander moth may have direct and indirect effects on Angadenia berteroi growth and reproductive success. The SEM results suggested that habitat quality (litter depth and subcanopy cover) may favor reproduction in native species of the South Florida pine rocklands that are properly maintained by periodic fires and exotic control. Insights from this threatened and charismatic species may provide impetus to properly manage remaining pine rocklands in South Florida for this and other endemic understory species.

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The purpose of this thesis was to explore selected works from William Shakespeare, Edmund Spenser, and John Keats, in order to expose textual instances of feminist thought. This analysis was aided with feminist theorists falling under the main strains of queer theory, materialism, and gender performance. Specifically, this thesis focused on the ways in which women, particularly virgin daughters, were viewed as property by their male kin. It also looked at how these women engaged in various symbolic masquerades and/or actual cross-dressing as a response to the aforementioned phenomenon. Finally, the thesis exposed how these masquerades can be construed as a queering of identity—manifested through reversals of power and rejection of patriarchal institutions like marriage.

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This dissertation presents a thick ethnography that engages in the micro-analysis of the situationality of black middle-class collective identification processes through an examination of performances by members of the nine historically black sororities and fraternities at Atlanta Greek Picnic, an annual festival that occurs at the beginning of June in Atlanta, Georgia. It mainly attracts undergraduate and graduate members of these university-based organizations, as they exist all over the United States. This exploration of black Greek-letter organization (BGLO) performances uncovers processes through which young black middle-class individuals attempt to combine two universes that are at first glance in complete opposition to each other: the domain of the traditional black middle-class values with representations and fashions stemming from black popular culture. These constructions also attempt to incorporate—in a contradiction of sorts— black popular cultural elements in the objective to deconstruct the social conservatism that characterizes middle-class values, particularly in relation to sexuality and its representation in social behaviors and performances. This negotiation between prescribed v middle-class values of respectability and black popular culture provides a space wherein black individuals challenge and/or perpetuate those dominant tropes through identity performances that feed into the formation of black sexual politics, which I examine through a variety of BGLO staged and non-staged performances.

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This thesis compares two perspectives on the production of Holocaust memory: a novel that leads up to The Holocaust in Britain and one that reflects the hindsight perspective of a liberator in the Soviet Union. The novels are Virginia Woolf’s BETWEEN THE ACTS and Vasily Grossman’s LIFE AND FATE. The analysis offers a locus of analysis for the diasporic literary energy created by the catastrophe in the 20th and 21st centuries. The project offers a theorized standpoint on the role of literature on official historical archives. Proposing a method through which contemporary readers can engage the diasporic event of The Holocaust, the project adopts both the extended metaphor and literal expression of soundscapes. Soundscapes encompass the immaterial processes of memorialization and the literal sonic textures developed in Holocaust novels. The critical perspective incorporates contemporary notions of narratology, archival practices, and cultural manifestations of language into the notion of literary ethnomusicology.

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Invasive plant species are major threats to the biodiversity and ecosystem stability. The purpose of this study is to understand the impacts of invasive plants on soil nutrient cycling and ecological functions. Soil samples were collected from rhizosphere and non-rhizosphere of both native and exotic plants from three genera, Lantana, Ficus and Schinus, at Tree Tops Park in South Florida, USA. Experimental results showed that the cultivable bacterial population in the soil under Brazilian pepper (invasive Schinus) was approximately ten times greater than all other plants. Also, Brazilian pepper lived under conditions of significantly lower available phosphorus but higher phosphatase activities than other sampled sites. Moreover, the respiration rates and soil macronutrients in rhizosphere soils of exotic plants were significantly higher than those of the natives (Phosphorus, p=0.034; Total Nitrogen, p=0.0067; Total Carbon, p=0.0243). Overall, the soil biogeochemical status under invasive plants was different from those of the natives.

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As a result of increased terrorist activity around the world, the development of a canine training aid suitable for daily military operations is necessary to provide effective canine explosive detection. Since the use of sniffer dogs has proven to be a reliable resource for the rapid detection of explosive volatiles organic compounds, the present study evaluated the ability of the Human Scent Collection System (HSCS) device for the creation of training aids for plasticized / tagged explosives, nitroglycerin and TNT containing explosives, and smokeless powders for canine training purposes. Through canine field testing, it was demonstrated that volatiles dynamically collected from real explosive material provided a positive canine response showing the effectiveness of the HSCS in creating canine training aids that can be used immediately or up to several weeks (3) after collection under proper storage conditions. These reliable non-hazardous training aids allow its use in areas where real explosive material aids are not practical and/or available.

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Understanding pathways of neurological disorders requires extensive research on both functional and structural characteristics of the brain. This dissertation introduced two interrelated research endeavors, describing (1) a novel integrated approach for constructing functional connectivity networks (FCNs) of brain using non-invasive scalp EEG recordings; and (2) a decision aid for estimating intracranial volume (ICV). The approach in (1) was developed to study the alterations of networks in patients with pediatric epilepsy. Results demonstrated the existence of statistically significant (p

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The purpose of this project is to ascertain the ways in which Orange is the New Black uses its platform to either complicate or reify narratives about the prison system, prisoners and their relationship to the state. This research uses the works of Giorgio Agamben, Colin Dayan, Michelle Alexander and Lisa Guenther to situate the ways the state uses the prison and social narratives about the prison to extend its control on certain populations beyond prison walls through police presence, parole, the war on drugs and prison fees. From that basis, this work argues that while Orange does challenge some narratives about race and sexuality, because of its reliance on “bad choices” as a humanizing trope and its reliance on certain racialized stereotypes for entertainment, the show ultimately does more to reify existing narratives that support state interests.

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Prior to 2000, there were less than 1.6 million students enrolled in at least one online course. By fall 2010, student enrollment in online distance education showed a phenomenal 283% increase to 6.1 million. Two years later, this number had grown to 7.1 million. In light of this significant growth and skepticism about quality, there have been calls for greater oversight of this format of educational delivery. Accrediting bodies tasked with this oversight have developed guidelines and standards for online education. There is a lack of empirical studies that examine the relationship between accrediting standards and student success. The purpose of this study was to examine the relationship between the presence of Southern Association of Colleges and Schools Commission on College (SACSCOC) standards for online education in online courses, (a) student support services and (b) curriculum and instruction, and student success. An original 24-item survey with an overall reliability coefficient of .94 was administered to students (N=464) at Florida International University, enrolled in 24 university-wide undergraduate online courses during fall 2014, who rated the presence of these standards in their online courses. The general linear model was utilized to analyze the data. The results of the study indicated that the two standards, student support services and curriculum and instruction were both significantly and positively correlated with student success but with small R2 and strengths of association less than .35 and .20 respectively. Mixed results were produced from Chi-square tests for differences in student success between higher and lower rated online courses when controlling for various covariates such as discipline, gender, race/ethnicity, GPA, age, and number of online courses previously taken. A multiple linear regression analysis revealed that the curriculum and instruction standard was the only variable that accounted for a significant amount of unique variance in student success. Another regression test revealed that no significant interaction effect exists between the two SACSCOC standards and GPA in predicting student success. The results of this study are useful for administrators, faculty, and researchers who are interested in accreditation standards for online education and how these standards relate to student success.

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The purpose of this thesis is to discover any existing correlation between gender and student perceptions of reflective writing in the composition classroom. Seventy-five students at Florida International University participated in a survey that explored their approaches to and understanding of reflective writing. In order to connect the specific results of this study to the larger context of composition theory, this thesis includes an examination of the theoretical background of gender and reflective writing. The results of the survey indicate that the only identifiable difference between male and female student responses resulted from their definitions of reflective writing. Beyond this difference, however, there were no significant variances in student perceptions of reflective writing. The response of these students at FIU indicates a shift in expected gender norms and suggests a reconsideration of what it means to be a gendered writer in the composition classroom.

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Attachment and interpersonal theory suggest a sequential pattern of relationships beginning in the earliest stage of development and progressing to social and eventually romantic relationships. Theoretically, cross-sex experiences have an important role in the progression of interpersonal relationships. Despite the prevalence of these theories about the nature of romantic relationship development, the linkage of cross-sex experience (CSE) to romantic relationships has not been established. Indeed, it is an intuitive assumption, especially within Western society and these theories do not consider socio-cultural factors that may influence CSE and relationship satisfaction. This study addresses the varying contextual factors that may contribute to relationship satisfaction and adjustment, aside from CSE, and is divided into two parts. Study 1, addresses CSE, relationship satisfaction, and adjustment in a unique population, ultra-Orthodox Jews. Among this population, social or romantic CSE is limited and sexes are effectively segregated. Study 2, expanded the study to a larger sample of U.S. college students, to assess the linkage of CSE to romantic relationship satisfaction in a more typical Western population. It included social norm and support variables to address the contextual nature of relationship development and satisfaction. Results demonstrated clear differences in the relation between CSE and relationship satisfaction in the two samples. In the first sample CSE was unrelated to relationship satisfaction; nevertheless, relationship satisfaction was associated with adjustment as it is for more typical populations with greater CSE. These results suggested the importance of specifying how social norms and social support relate to CSE, relationship satisfaction and adjustment. The results from the second sample were consistent with the theoretical framework upon which the social/romantic literature is based. CSE was directly connected to relationship satisfaction. As anticipated, CSE, relationship satisfaction, and adjustment also varied as a function of social norms and support. These findings further validate the influence of socio-cultural factors on relationship satisfaction and adjustment. This study contributes to the romantic relationship literature and broadens our understanding of the complex nature of interpersonal and romantic relationships.

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In this thesis, we proposed the use of device-to-device (D2D) communications for extending the coverage area of active base stations, for public safety communications with partial coverage. A 3GPP standard compliant D2D system level simulator is developed for HetNets and public safety scenarios and used to evaluate the performance of D2D discovery and communications underlying cellular networks. For D2D discovery, the benefits of time-domain inter-cell interference coordi- nation (ICIC) approaches by using almost blank subframes were evaluated. Also, the use of multi-hop is proposed to improve, even further, the performance of the D2D discovery process. Finally, the possibility of using multi-hop D2D communications for extending the coverage area of active base stations was evaluated. Improvements in energy and spectral efficiency, when compared with the case of direct UE-eNB communi- cations, were demonstrated. Moreover, UE power control techniques were applied to reduce the effects of interference from neighboring D2D links.

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The present study comparatively examined the socio-political and economic transformation of the indigenous Sámi in Sweden and the Indian American in the United States of America occurring first as a consequence of colonization and later as a product of interaction with the modern territorial and industrial state, from approximately 1500 to 1900. The first colonial encounters of the Europeans with these autochthonous populations ultimately created an imagery of the exotic Other and of the noble savage. Despite these disparaging representations, the cross-cultural settings in which these interactions took place also produced the hybrid communities and syncretic life that allowed levels of cultural accommodation, autonomous space, and indigenous agency to emerge. By the nineteenth century, however, the modern territorial and industrial state rearranges the dynamics and reaches of power across a redefined territorial sovereign space, consequently, remapping belongingness and identity. In this context, the status of indigenous peoples, as in the case of Sámi and of Indian Americans, began to change at par with industrialization and with modernity. At this point in time, indigenous populations became a hindrance to be dealt with the legal re-codification of Indigenousness into a vacuumed limbo of disenfranchisement. It is, thus, the modern territorial and industrial state that re-creates the exotic into an indigenous Other. The present research showed how the initial interaction between indigenous and Europeans changed with the emergence of the modern state, demonstrating that the nineteenth century, with its fundamental impulses of industrialism and modernity, not only excluded and marginalized indigenous populations because they were considered unfit to join modern society, it also re-conceptualized indigenous identity into a constructed authenticity.