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No description available.

An ultra-high burnup metallic inert matrix nuclear fuel concept is being characterized and evaluated by Lawrence Livermore National Laboratory based on a metal matrix fuel concept originally developed at the Bochvar Institute in Russia. The concept comprises a dispersion of uranium metal microspheres in a Zr-based alloy matrix that provides thermal bonding between the fuel particles and the cladding material. The objective of this study was to experimentally evaluate both the microstructural and thermophysical properties of Zr-Fe-Cu alloys. The experiments and analyses described were divided into three main parts, nominally based on the analysis methods used to examine the alloys. An Electron Probe Microanalyzer (EPMA) was used to characterize the metallurgical properties of the proposed matrix alloys. The groups of alloys were cast using a high temperature inert atmosphere furnace. The cast alloys showed the expected combination of phases with the exception of the ZrFe2 Laves phase which was predicted for the Zr-12Fe-15Cu1 alloy but was not detected. The Zr-12Fe-5Cu alloy consisted of a Zr solution phase dispersed in a matrix of two different intermetallic phases. The second alloy, Zr-12Fe-10Cu, did not produce a homogenous mixture and consisted of two distinct phase morphologies. The top half of the sample was Zr rich and contained Zr precipitates dispersed in a matrix of intermetallic compounds while the bottom half consisted solely of intermetallic compounds. The third alloy, Zr-12Fe-15Cu, was comprised of four different intermetallic phases three of which had the same apparent Zr_(2)(Fe,Cu) structure but had distinct phase morphologies based on the Backscatter Electron (BSE) images. Upon determining the phase morphologies of each of the fabricated alloys Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA) were used to measure phase transformation and melting temperatures. Little difference was observed between the as-cast and annealed samples. The transitions shifted slightly to higher temperatures and the annealed Zr-12Fe-15Cu alloy only had two transitions compared to three seen in the as-cast samples. Slight changes were observed in the melting temperatures between the as-cast and annealed alloys. Zr-12Fe-5Cu had the largest melting temperature (886.3°C) while Zr-12Fe-10Cu had the smallest melting temperature (870°C). The third alloy, Zr-12Fe-15Cu, had a melting point just below that of Zr-12Fe-5Cu at 882.7°C. Light Flash Analysis (LFA) was implemented to determine the low temperature (20-260°C) thermal diffusivity values of each alloy. The as-cast measurements were more precise than the annealed samples, most likely the result of non-ideal sample integrity prior to loading. Each of the three alloys showed a linear increase in thermal diffusivity over the temperature range. Values for Zr-12Fe-5Cu ranged from 3.54 ± 0.06 mm2/s to 4.42 ± 0.10 mm^(2)/s. The Zr-12Fe-10Cu alloy had maximum and minimum values of 4.19 ± 0.22 mm^(2)/s and 3.17 ± 0.16 mm^(2)/s, respectively. Lastly, Zr-12Fe-15Cu had the largest thermal diffusivity ranging from 3.52 ± 0.15 mm^(2)/s at 20°C to 4.64 ± 0.16 mm_(2)/s at 260°C. Overall, the data from the LFA measurements showed that the Zr-Fe-Cu alloy system had similar diffusivity values compared to other common reactor materials.

A methodology for the catalytic asymmetric hydroboration of vinylarenes with pinacolborane has been developed. Use of pinacolborane in hydroboration, especially catalytic asymmetric hydroboration grants direct access to chiral boronate esters, without the cryogenic temperatures required for catalytic hydroboration with catecholborane and the subsequent transesterification with excess pinacol. These chiral boronate esters were then subjected to a homologation/oxidation sequence previously refined in our labs to prepare Naproxen™ in 66% yield and 88% enantiopurity from its corresponding vinyl arene precursor. A survey of metal catalysts, solvents and ligands revealed remarkable changes in regioselectivity with changes in metal. Rhodium catalysts in combination with pinacolborane were able to provide regioselectivity for the secondary branched isomer equivalent to those obtained with catecholborane. Iridium catalysts showed a near perfect regioselectivity for the primary linear isomer. With respect to the choice of chiral ligand, complete reversal in the enantiomer obtained was observed with the choice of hydroborating reagent from catecholborane to pinacolborane. In order to understand the regioselectivity observed under iridium catalysis, deuterium labeling studies were undertaken. A synthesis of the deuterated hydroboration reagent pinacolborane was first completed. From the results of these studies, in combination with published thermodynamic data, a mechanism for the iridium catalyzed hydroboration of alkenes was proposed. / Thesis (Ph.D, Chemistry) -- Queen's University, 2007-08-29 09:30:38.571

For students with emotional and behavioural issues the bridge from middle years to senior years can be particularly challenging. This transition is especially problematic if the students are moving from self-contained or specialized programming supports in middle years to inclusive senior years environments. This qualitative research study examined the perspectives and experiences of four principals and three student services personnel regarding the transition of students from specialized middle years placements to inclusive senior years schools. Each participant was asked their opinions on what strategies, structures, policies and supports assisted with the transition process as well as those that detracted from successful transitioning. Qualitative analysis of the data suggested that students need to connect with a positive adult upon transitioning to senior years, and they need to perceive that their senior years school is a safe and positive place for them to attend.

In this study, I develop a transition follow-up system (TFS) — a data-collection system that tracks information about persons with disabilities from high school to adulthood — that is socially valid in Manitoba. I investigate the current data-collection practices regarding persons with disabilities in Manitoba and analyze stakeholders’ needs for a transition follow-up system using document review, surveys, focus groups, and individual interviews. There is currently no formal data-collection system documenting the transition from school to adulthood of persons with disabilities in the province. Stakeholders have acknowledged the need for such a data-collection system in order to improve current support systems. The key suggestions that stakeholders have made with regard to implementing a transition follow-up system are (a) ensuring impartial, reliable data management, (b) minimizing any additional work required for schools and adult services programs/agencies, (c) utilizing existing data collection practices, (d) applying various data collection methods, (e) carrying out longitudinal data collection regarding individuals with disabilities, (f) including persons with various disabilities, from mild to severe, (g) involving various government departments in the transition process, (h) protecting privacy and confidentiality, and i) ensuring user-friendly data collection and reporting. The most significant concern that stakeholders express relates to securing the financial and human capacity to develop and maintain a transition follow-up system. Based on these suggestions and the current Manitoba context, I propose a transition follow-up system model, recommending operative aspects such as scope, purpose, administrators, target youth, information to collect, data collectors, data-collection methods, data sources, timeline of data collection, reporting, confidentiality and privacy, and methods of ensuring the reliability and validity of data. Although the model proposed is relevant to the Manitoba context, it also offers a useful set of general guidelines on critical issues that need to be considered in developing and implementing a transition follow-up system.

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This study uses Transition Analysis on the Mimbres skeletal remains of the NAN Ranch Ruin to provide a more complete picture of its demography. Previous attempts to reconstruct the demographic structure of prehistoric populations have been hindered by aging methods that provide biased age distribution. Early methods had a tendency to produce age distribution similar to that of the reference sample that was used to create them. In addition, they often overlooked sexual dimorphism and left out the senescent portion of the population which in turns produced inaccurate population structures. Transition Analysis is a multifactorial approach to estimate the age-at-death of adult skeletons that focuses on the cranium, the pubic symphysis and the auricular surface of the ilium. The method relies heavily on the Bayesian probability that a given trait or a given combination of traits is displayed at a given age, it recognizes sexual dimorphism, performs well on fragmentary skeletons and allows for the age estimation of older individuals. The NAN Ranch Ruin sample consists of over 240 individuals, including 185 from the Classic Period. A previous study focused on the 81 individuals from the Classic period that were collected during the first five years of excavations. Following age estimation of adult skeleton I constructed composite abridged life tables. For the Classic Period, I found a high infant mortality rate (47%) and low life expectancy at birth (21.14 years) as expected. However, this analysis produced different mortality patterns than older demographic studies, where mid adult mortality increases only slightly, decreases in late adulthood (40-55 years old) and increases again in senescence (55-80 years old), instead of increasing steadily in adulthood to culminate at age 50. This difference is a consequence of the aging methods that have been used to analyze other southwestern prehistoric samples. Finally, while I was not able to confirm different mortality patterns between males and females, I found that people from the east roomblock enjoyed greater longevity than those from the south roomblock, though the difference is not statistically significant.