http://hdl.handle.net/1957/89 Search the Channel search http://ir.library.oregonstate.edu/dspace/simple-search http://hdl.handle.net/1957/9153 Title: Confessing our sims : the construction of gender and sexuality among women ages 18-22 on MySpace. <br/> <br/>Abstract: MySpace is a social network phenomenon with over 100 million profiles and a strong presence in over 24 countries. As digital media become more commonplace, social networks are becoming sites where women create and manage relationships and identities. This thesis is a study of how women ages 18-22 are constructing their gender and sexuality on the social network site MySpace. By using a rhetorical analysis of 58 MySpace profiles, this study identifies several themes, including the strong presence of horizontal hostility. Rather than functioning as a forum for women to challenge conventional gender roles, MySpace gives women an opportunity to perform femininity. These women are reinforcing the values associated with traditional femininity by competing for both social and romantic attentions in their autobiographical writings and profile photographs. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/9151 Title: Catalytic chemical vapor deposition synthesis of carbon nanotubes from methane on SiO supported Fe and Fe−Ni catalysts <br/> <br/>Abstract: Influences of operating conditions on the production of carbon nanotubes (CNTs) were studied using Fe and Fe-Ni bimetallic catalysts supported on silicon monoxide (SiO). The catalysts were prepared in three steps: (1) impregnation of SiO powders with ferric nitride or combinations of ferric and nickel nitrides, (2) oxidation of nitrides in an air stream, and (3) grinding the powders obtained. CNTs were successfully synthesized by catalytic CVD using NH₃/CH₄ mixtures in a horizontal tubular flow reactor. The following process parameters were varied to investigate their effects on the growth rates of CNTs. The morphologies of catalysts and product CNTs were observed by scanning electron microscope (SEM). • The particle size of SiO, • metal composition, • metal loading, • temperature for catalyst oxidation, • extent of grinding of catalysts, • NH₃ pretreatment time, • reaction temperature for CNT growth, • reaction time, and • NH₃/CH₄ feed ratio. Two different average sizes of SiO particles, 8 μm and 44 μm, were compared based on the growth of CNTs in 5 min. Catalysts supported on 44 μm average sized SiO particles demonstrated higher yields when they were not pretreated in an NH₃ stream. When 1 wt% Fe was loaded, aligned CNTs were formed, and a highest growth rate per unit mass of catalyst was observed. The range of oxidation temperature to achieve highest catalyst activities depended on metals and metal contents: 600 - 750°C for 1 wt% Fe, 450 - 600°C for 3 wt% Fe, and 750 - 900°C for Fe-Ni. Grinding catalysts for at least 3 minutes increased the growth rate of CNTs by approximately 40 percent. The growth of CNTs was enhanced when no NH₃ pretreatment of catalysts was carried out, regardless of metals and metal contents. However, CNTs did not grow appreciably from methane without ammonia. An NH₃/CH₄ feed ratio of 0.15 - 0.25 was observed to yield highest growth rates. The reaction temperature to achieve highest CNT growth rates was found to be in the range between 990 and 1000 °C. The growth of CNTs was not linear but decreased with reaction time. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/9149 Title: Predicting the stability, equilibrium response, and nonequilibrium dynamics of ecological systems <br/> <br/>Abstract: In this dissertation, new theory and its applications are developed to predict three properties of complex ecological communities: stability, equilibrium response, and non-equilibrium dynamics. First, a graph-theoretic analysis identifies the interconnections in a complex ecosystem that promote or diminish stability (Chapter 2). The hierarchy of interactions that influences stability and feedback processes can guide resource allocation for environmental monitoring, investigate alternative management strategies, and help formulate novel research hypotheses. Second, a combined graph-theoretic and probabilistic approach evaluates the potential for long-term changes in equilibrium (Chapter 3). Conditional probabilities of long-term increase and decrease in variables are transferred from the graph-theoretic models into a Bayesian network. The Bayesian network allows researchers both to predict how an ecosystem might change given a perturbation and to diagnose which model structure best matches empirical observations. Third, a threshold index predicts whether or not largemagnitude short-term transitory changes in disease prevalence can occur (Chapter 4). The concept of reactivity is used to derive a threshold index for epidemicity, E0, which gives the maximum number of new infections produced by an infective individual at a disease free equilibrium. This index provides a threshold that determines whether or not major epidemics are possible. The relative importance of parameters differs between control strategies that seek to reduce endemicity and those that seek to reduce epidemicity. The index E0 therefore is an important measure of epidemic potential that may assist efforts to control epidemics. Together these approaches provide new theory that help bridge the gap between our need to understand complex ecological systems and the empirical data available for their characterization. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/9147 Title: Graduate teaching assistant (GTA) development in the college classroom <br/> <br/>Abstract: The graduate student population has been traditionally overlooked within higher education. However, within recent decades, much research has been devoted to addressing the multiple facets of the graduate student experience, including that of the graduate teaching assistant (GTA) position. This thesis seeks to explore in depth the experiences of GTAs in the classroom. A summary and critique of the literature that exists surrounding GTAs is provided, including literature related to national graduate student demographics, the history of GTA/GRA positions, salient issues surrounding the GTA position, and models of GTA development. The goal of this thesis is to share results from a quantitative study that analyzes how graduate students self-identify into a three-stage model of GTA development proposed by Nyquist and Sprague (1998). Within this particular study, an online survey questionnaire was developed to support a quantitative research design. An independent chi-square analysis was conducted on the data derived from this questionnaire. The results from this study will be discussed, and further implications of this research for both researchers and practitioners will be explored. <br/> <br/>Description: Graduation date: 2008; Presentation date: 2008-04-24