No description available.

Bone-to-implant contact of orthodontic mini-screws has been determined via Micro-CT to be a strong predictor of primary stability. Various insertion angulations, including both 900 and 500, have been reported as ideal for providing optimum primary stability. The aim of this investigation was to determine if a statistically significant difference exists in the bone-to-implant contact of mini-screws placed with an insertion angulation of 900 compared to those placed at 500 as determined via Micro-CT. Ten self-drilling, self-tapping orthodontic mini-screws (Aarhus,1.5mmx6mm) (n=5) were inserted into the posterior ramus of an adult pig mandible, an analog to an adult human mandible. A custom stent with ten holes, five at 900 and five at 500, was fitted to the bone surface to control insertion angulation. The bone was cut to 1.5x1.5x1cm segments and scanned using SkyScan 1127 with ideal specifications (8mm pixel size, medium camera, 80Kv, 100mA, 10W, 1800 rotation, and 0.5Al+0.25Cu filter). The raw scans were reconstructed using NReconV1.6.10 and these datasets were then reoriented using DataviewerV1.5.2 along the Z-axis to standardize the peri-implant bone for analysis. A custom task-list was used with CT-AnalyzerV1.14.41 to determine the percent of bone-to-implant contact per mini-screw. A Mann-Whitney U test indicated that the bone-to-implant contact was not statistically significantly different for the mini-screws placed at 900 (Mdn= 72.34) compared to the mini-screws placed at 500 (Mdn= 53.25), U=5, p=.1443. Therefore, the results do not significantly differ at p<.05. There is no statistically significant difference in the bone-to-implant contact between the Aarhus 1.5mmx6mm orthodontic mini-screws placed at 900 compared to those placed at 500 as measured by Micro-CT. This may lead to the conclusion that there is no significant difference in the primary stability of Aarhus mini-screws placed at 900 and 500. / Oral Biology

Metal building roof systems with C- or Z-section purlins require restraint to resist lateral forces developed within the roof system under gravity loads. The currently available procedures for predicting these forces have been shown to be inaccurate for sloped roofs and difficult to apply to roof configurations with multiple points of anchorage. A new method has been developed that builds on the previous research and accurately addresses roof slope as well as the use of multiple anchorage devices of finite stiffness. The development of this method relied on a stiffness model, similar to that used by previous researchers, which was updated and calibrated to the results of recently completed tests. The calculation procedure explicitly addresses the location and stiffness of anchorage devices as well as the inherent stiffness of the purlin system to accurately distribute the anchorage forces. / Master of Science

Literature on the evolution of the American higher education system includes a historical and consistent debate over the definition of the higher education mission in the country. Recent debate focuses on mission differentiation between the university and the community college. Acknowledging systemic changes in higher education historically occurred within regions of the country and even individual states, Alaska higher education development serves as an interesting and relatively unstudied example and the focus of this study. This research addressed this debate in higher education—mission definition—through a historical analysis of the University of Alaska Anchorage (UAA) over the 25-year period between 1984 and 2009. As the largest of the three major administrative units (MAUs) in the University of Alaska system based on credit hours and number of students, UAA became the logical focus of the study. In addition, higher education in Anchorage was greatly influenced by the 1987 state higher education merger as three of the five MAUs in the university system were located there. The purpose of this study was to historically describe the development of and changes in higher education missions—university and community college—at UAA during this period. This historical analysis was designed to answer two primary questions: - How have traditional university missions developed and changed at the University of Alaska Anchorage between 1984 and 2009? - How have traditional community college missions developed and changed at the University of Alaska Anchorage between 1984 and 2009? Data from predominantly primary sources were collected, evaluated, analyzed, and interpreted in four major areas: (a) the 1970s higher education background in Alaska, (b) the University of Alaska leadership (board of regents and presidents), (c) professional external reviews and reports of the university system, and (d) growth and development trends in university and community college trends at UAA. There were six main findings from this study. First, public higher education in southcentral Alaska, in particular Anchorage, was in a tremendous amount of turmoil during the 1970s. This turmoil included debate and conflict primarily over missions, institutional identity, and organizational structure. Secondly, the 1987 merger eliminated the visible and separate identity of community college operations in Anchorage. The community campuses—Kenai Peninsula College (KPC), Kodiak College (KOC), Matanuska-Susitna College (MSC), and Prince William Sound Community College (PWSCC)—were somewhat spared this total identity elimination due to geographical separation from the main UAA campus in Anchorage and the retention of college names associated with these dispersed campus locations. A third finding was the similarity of recommendations from several external reviews concerning the comprehensive—university and community college—missions within the University of Alaska system following the merger. The common theme within all these reviews was a need to better differentiate the missions of the university from the missions of the community college. Fourth, the type of student attending UAA has changed. In the years following the merger, the typical UAA student was older, less diverse, part-time, and non-degree seeking. By 2009, the characteristics were somewhat different; the typical UAA student was now younger, and more diverse, full-time, and degree seeking. A fifth finding was the consistency of growth and development in university missions at UAA. Baccalaureate and graduate degree programming and university-sponsored research prospered under the new university system structure at UAA. The growth in both baccalaureate and graduate degree programs exceeded the averages at UAA and far surpassed similar rates in certificate and associate degree programs. Finally, at UAA, many community college missions remained robust in operation, but often obscured in visibility and identity. These robust community college missions included academic programming focused on transfer education and technical or vocational education. At the same time, other community college missions faltered within the comprehensive university structure, particularly developmental education and continuing education and workforce development. / Graduation date: 2012

Concern about college and career readiness has been expressed in both the business and education arenas. Employers are calling for entry-level employees with basic academic skills and educators are being held accountable for student achievement in academic areas similar to those required by employers. In this environment, WorkKeys has emerged as a set of assessments that could respond to the needs of both employers and educators and serve as an indicator to test takers of their readiness for further education or a career. In Alaska, state policymakers selected WorkKeys for use with high school juniors in an effort to measure both college and career readiness, and statewide testing was implemented in the fall of 2010. While past studies involving WorkKeys have focused on assessment results related to workforce development, academic indicators, or demographic variables, the purpose of this study was to describe the college and career readiness perceptions of high school juniors related to the WorkKeys Reading for Information, Locating Information, and Applied Mathematics assessments. A survey administered to 178 urban high school juniors at the time they received their WorkKeys results gathered student perceptions of the WorkKeys assessments in general as well as perceptions of college and career readiness. The key findings of this study were that student perceptions of college and career readiness were much higher than the results of the assessments indicated, and students found value in using WorkKeys results for college and career planning. This suggested the assessment results would be useful in career development interventions with students. This was the first year of mandatory WorkKeys assessments in the state and further study is recommended to gather rural student perceptions, further explore factors that students believe make the assessments useful, and determine the influence of the assessments and related interventions on academic self-efficacy. / Graduation date: 2012

Many lives and much property are lost in disasters when individuals and communities choose to ignore information which could mitigate the potential disaster. This case study examines community and individual decision processes and rationale which led to construction of a high-occupancy high-rise courthouse on land designated as high risk after the 1964 Alaska earthquake. The study reviews policy and decision making, psychology, and risk management literature to explore the psychological mechanisms and processes of hazard mitigation decisions. It questions why individuals and communities choose not to mitigate when they have the information which makes risk mitigation possible. The hypothesis theorizes risk-based cultural dissociation and submits that individuals and society process risk-related information in a manner that allows for interpretation and acknowledgement of information so that it is compatible with individual and social agendas and constructs. Society and individuals can and do completely deny or dissociate from risk-related information. This exploratory research uses macro, meso, and micro levels of analysis to examine the environmental setting, land ownership and power, and professional and public seismic information. This examination is placed in the context of Anchorage's post-earthquake reconstruction momentum. Indepth interviews with elected officials, a bank president, insurance executives, investors, builders, appointed officials, private and public professionals, court representatives, a judge, a juror, and citizens provide insight into risk perception and individual and community agendas. The interviews revealed each level of analysis had different perceptions of risk and different agendas. Professional warnings not to reconstruct on high-risk land were ignored. Downtown economic interests and powerful individuals significantly impacted the community decision process. One charismatic leader played a major role in the community reconstruction and courthouse decisions. Research findings support the hypothesis. Individuals consistently chose to deny earthquake potential in their daily lives. Selective interpretation of information allowed individuals to support their own agendas. Community decision processes allowed deletion of important information and a transference of responsibility, resulting in no decision body or individual feeling responsible for the decision. Risk-based cultural dissociation is defined and presented in this research as a direction for future study.

Vita. / Digitized by Kansas Correctional Industries

There has been a growing concern of water scarcity in recent years as global water shortages are increasing. The concrete industry consumes about 2 billion tons of potable water annually. For this reason, seawater has drawn attention as a potential substitute for mixing and curing water for concrete if certain challenges can be addressed. One of the main problems associated with the use of seawater in concrete is the risk of corrosion of internal steel reinforcement. Fibre-reinforced polymer (FRP) bars have been shown to be a viable reinforcement alternative in aggressive environments due to their corrosion-resistant properties. Glass FRP (GFRP) bars, due to their acceptable mechanical properties and reasonable price, are currently the most widely used in industry. GFRP bars are manufactured with a variety of surface configurations having different bond performance in concrete, which influences structural behaviour in concrete flexural elements. Therefore, the viability of GFRP bars with sand coated and spiral deformations in seawater concrete is an important topic for research. In this study the bond behaviour is investigated using two different test methods: 1) pullout specimens, and 2) beam anchorage specimens. The results suggest that there is no significant difference between the short-term bond strength of GFRP bars in seawater concrete compared to normal concrete. Additional research is recommended to explore possible long-term issues.

No description available.

Helical anchors are a type of deep foundation element that can be installed quickly in almost any location and can accept the immediate application of operational loads. The use of helical anchors has expanded in recent decades from its established application in the power transmission industry to more traditional civil engineering applications such as residential construction, communication tower installations, and static and seismic structural retrofitting and reconstruction. Despite the wide range of helical anchor applications, few advances have been made in improving the understanding of their behavior. For example, existing helical anchor design methods, for cases where the anchors are loaded in uplift in cohesive soils, are based on the assumption that the soil above the helical plate is mobilized in a manner analogous to that beneath a deep foundation in bearing. An appropriate design method would acknowledge the effect of load directionality on the assumed failure mechanism. This thesis evaluates the existing cylindrical shear and individual plate bearing design methods for helical anchor capacity in uplift. Additionally, new capacity models are proposed to improve prediction accuracy and reduce prediction variability. A load test database of helical anchors loaded in tension is established from tests reported in the literature. The existing and proposed capacity models are compared to the capacities observed during loading tests using the statistical bias and its distribution. Load and Resistance Factor Design (LRFD) resistance factors are derived from closed-form solutions using First Order Second Moment (FOSM) reliability procedures. Finally, load-displacement models are developed through the evaluation of observed individual anchor plate breakout behavior and back-calculation of side shear capacity from load tests on multi-plate anchors. The new displacement models are compared to the load-displacement tests in the database. In general the comparisons indicate that the displacement-based models developed in this thesis provide a reasonable estimate of load-displacement behavior of helical anchors for service-level displacements. These findings provide engineers with new tools for design of helical anchor foundations. / Graduation date: 2012