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The Stretch Model: Including L2 Student Voices
Snyder, Sarah Elizabeth ProQuest Dissertations & Theses Arizona State Univ 2018 해외박사(DDOD)
The Stretch Model is a model of first year composition (FYC) that "stretches" the first semester's class over two semesters in order to help writing students who arrive at university with low test scores to succeed in their composition courses. Originally piloted in 1994 at Arizona State University (ASU), the Stretch Model of composition has been found to be effective in terms of retention and persistence of first language (L1) writers (e.g., Glau, 1996; 2007). It has become known at ASU and abroad as the Stretch Program. Since 1997, a separate track of the Stretch Program has been solely for second language (L2) writers, and L2 writing students are now roughly 17% of the program's population. Until fairly recently, there was no attempt to collect L2 data to support the Stretch Program's claims for effectiveness for the L2 population. As many universities across the nation have garnered inspiration for their own programs ("Stretch Award" 2016), and L2 writers have the potential to be in any composition class (Matsuda, Saenkhum, & Accardi, 2013), it is imperative to include the voices of L2 writers in the analysis of the Stretch Program. This study addresses the need for L2 writers' voices to be included in the analysis of the Stretch Program at Arizona State University. From the quantitative analysis of 64,085 students' institutional data records, and qualitative analysis of 210 student surveys, findings include L2 writers have the highest rates of passing, but the lowest rates of persistence in the three-semester first year composition requirement when compared to Stretch L1 students and the traditional FYC population. Survey data also lends L2 student perceptions to complicate the main features of the Stretch Program including perceived writing improvement, having the same teacher and classmates for two semesters, and having more time to work on their writing. The quantitative findings are consistent with Snyder's (2017a) analysis of the 2012 fall Stretch Program L1 and L2 cohorts.
Shape and Structure of Neutron-Rich Nuclei from 252 Cf Fission Fragments
Snyder, Jason Benjamin Washington University in St. Louis 2014 해외박사(DDOD)
The transition quadrupole moments, Qt, of rotational bands in the neutron-rich, even-mass 102-108Mo and 108-112 Ru nuclei were measured with the Doppler-shift attenuation method. The nuclei were populated as fission fragments from 252Cf fission. The detector setup consisted of the Gammasphere spectrometer and the Hercules fast-plastic array. This allowed the measurement of asymmetric DSAM lineshapes at different Gammasphere detector angles with respect to the fission axis. The measurements typically covered the 6 to 16h spin range of the ground-state band and at least a strong transition in the gamma band. At moderate spin, the Qt moments are found to be reduced with respect to the values near the ground states, the latter being reported in the literature. An attempt has been made (by Afanasjev) to describe the data in the framework of cranked relativistic Hartree-Bogolyubov theory, and the results are reported in the present work as well as in a Physics Letters paper by Snyder et al. For 104Mo reliable predictions can be made. Here an oblate shape and a low-spin triaxial shape (deformation parameter gamma∼-44°), predicted to be favored in other theoretical calculations, are ruled out by the data. There is some indication for a gradual change, at higher spin, from an initially prolate shape to a triaxial shape in 104Mo. The Qt data for 106Mo and 110,112Ru support this picture. The challenge of theory to describe the Qt data is addressed, which has to do with the very gamma-soft potential-energy surfaces. As a byproduct of the Qt analysis (which requires the determination of the intensities of the feeding transitions), the transition intensities of many weak high-spin or non-yrast states have been determined. These previously unknown intensity data are also reported. In the appendix, the results of an attenuation-coefficient analysis for gamma-ray angular distributions (due to recoil-in-vacuum) in heavy Ba isotopes are reported. These results are from a separate project, though from the same data set.
Processing and properties of prismatic composites that exhibit a threshold strength
Snyder, Mark Richard University of California, Santa Barbara 2004 해외박사(DDOD)
Incorporating thin compressive layers into ceramic composites allows for the arrest of cracks and produces a stress below which failure cannot occur, or threshold strength. This concept has been proven in laminar structures for cracks propagating in one direction. Here, a method for producing a threshold strength in multiple directions is addressed. This was accomplished by using composites consisting of alumina prismatic rods separated by a matrix of thin mullite/alumina layers that develop residual compressive stresses upon cooling from the sintering temperature. A colloidal processing method of producing these architectures was developed. This method consisted of making alumina fibers by extruding a plastically deformable consolidated, alumina body, coating the fibers with a mixture of mullite and alumina and consolidating the coated fibers into void free composites. This method was characterized to isolate the conditions necessary for producing composites. Consolidation of the fibers was accomplished by lowering the flow stress of the fibers and by eliminating the trapped pockets of air between them. Composites with varying residual stresses were produced by varying the thickness and mullite content of the compressive layers. Assessment of the residual stress state was performed by piezospectroscopy and indentation studies. The residual stress measurements were found to coincide with the behavior predicted by theoretical modeling and finite element analysis. Prismatic composites were shown to exhibit both crack arrest and flaw insensitive mechanical behavior. An equation for the propagation of a crack through a semi-circular compressive layer was developed. This model accurately described the average strength when the crack was observed to propagate straight through the compressive layers. In cases where the crack deflected or bifurcated, the model underestimated the average measured strengths. It was shown that increasing the volume fraction of mullite in the compressive layers led to an increase in average strength up to 0.50 volume fraction. Further increases in the mullite content led to a reduction in strength due to the interaction of multiple cracks. In all specimens, a significant variability in strength was measured due to the non-periodic nature of the architecture as well as variations due to the processing method.
Mining and mineral industries in post-apartheid South Africa
Snyder, Kossouth The University of Texas at Austin 2004 해외박사(DDOD)
This dissertation focuses on post-apartheid political factors in South Africa's mining and mineral industries, especially strategic minerals. The government is very important in South Africa's mining and government policies which influence the supply of minerals. After 1990, the government renounced apartheid, and the 1990's were a transition time for the government. During the transition, there was an interim constitution, The Constitution of the Republic of South Africa Act 200 of 1993, and the Act had geopolitical ramifications. The Act divided South Africa's original four provinces into nine provinces with new names. This information is to connect pre-1994 references to post-1994 South African conclusions. This dissertation discusses the government's relationships with the Chamber of Mines of South Africa (Chamber), the Department of Mineral and Energy (DME), and the government's land policies and reforms. The Department of Mineral and Energy is the component of the government that establishes and implements the government's mineral and energy policies. The Department's Mineral Development Branch effects strategic mineral supply. The Mineral Economics Directorate was formerly known as the Minerals Bureau. The MED-Minerals Bureau analyzes mineral data, both inside and outside of South Africa, and has the task to appraise mineral intelligence, international and world development in mineral economics. The government is trying to enhance strategic mineral exports with research and development (R&D) by the government's parastatal organizations such as the Council for Mineral Technology (Mintek). This dissertation discusses the origins of post-1994 land policies and post-1994 mining policies which culminated with the Mineral and Petroleum Resources Development Act (Act 28 of 2002) and the October 2002 Mining Charter. This Act will implement either socialist ideals or regulated industries with capitalist ideals. There are conclusions and recommendations for investors in South Africa's mining industry. Conclusions focus on factions, socialists and centrists, in the government on South Africa's futures mineral industries. Finally, there are recommendations for strategic mineral providers/investors; comply with the Act and the October 2002 Mining Charter, help centrists in elections, and work with the government's Mineral Economic Directorate-Minerals Bureau.