Cassini spacecraft images of Enceladus' surface have revealed diverse terrains---some heavily cratered, others almost devoid of craters, and even some with ridges and fractures. We have documented crater morphologies in regions for which high-resolution data are available (140 to 360 W and 90 S to 60 N). The south polar region shows a dearth of craters, in sharp contrast to the heavily cratered northern latitudes. Tectonized regions such as Sarandib and Diyar Planitiae also have low crater densities. Viscously relaxed craters are found in the apparently young regions of the anti-Saturnian and trailing hemispheres, as well as in the older, upper northern latitudes. By modeling the viscoelastic relaxation of craters on Enceladus using TEKTON, a finite-element code, we predict large geographical variation in heat flow and a complicated thermal history on Enceladus. Our results are consistent with the planitiae being older examples of the South Polar Terrain, supporting a satellite-reorientation hypothesis.

Analysis of impact craters and their ejecta addresses someunanswered questions about the lunar surface. First I estimatethe regolith depth on the south farside of the Moon to be about40 m, which is significantly deeper than the nearside regolith,estimated to be 3-16 m. This result is obtained by studyinghundred meter diameter flat floored craters, using the method ofQuaide and Oberbeck (J. Geophys. Res., 1968, 73, 5247-5270). This measurement has implications for the formation of the lunarregolith, and for interpretation of samples returned in thefuture by astronauts or automated sample return missions.Next, I report the discovery of a method that distinguishesbetween primary and distant secondary craters in high resolutionplanetary images. For a given crater size, the largest bouldersof secondary craters are significantly larger than those ofprimary craters. The ability to identify distant secondarycraters will help constrain primary production rates of smallcraters and improve surface age determination of small areasbased on small crater counts.Third, I characterize the distributions of boulders ejected from18 lunar impact craters. I find that in large craters, thelargest boulders are preferentially ejected at low velocities(closer to the crater), whereas the largest boulders from smallcraters are ejected over a wider range of ejection velocities. Also, for a given crater size, deeper regolith reduces themaximum ejection velocity attained by a boulder ejected from acrater. I show that this is a logical result of the streamlinesof excavation in an impact when there are no coherent boulders inthe regolith. Cumulative plots of the boulders have slopessteeper than -2, as do secondary craters. This result isexpected because ejecta fragments produce secondary craters.Finally, I describe the morphology of some lunar crater walllandslides that strongly resemble martian gullies, despite thelack of geologically active water on the Moon today or in thepast. The lunar features indicate that alcove-channel-apronmorphology, attributed on Mars to seepage of liquid water, canalso form via a dry landslide mechanism. Therefore alcove-channel-apron morphology is not diagnostic of water carvedgullies.

The main focus of this report is to establish a comparative study of traditional and biodegradable vest-plastic bag production through the utilization of a life cycle assessment (LCA) approach. The measurements were made for the Ukrainian limited liability company “Polymer”, as a representative manufacturer, in order to calculate the environmental impact of plastic bag manufacturing, and identify the more environmental friendly item. This research is based on a literature review of the special characteristics of life cycle assessment and its methods and methodologies, a field study, which included two semi-structure interviews, and measurements and comparison of the harmfulness of traditional and biodegradable bag production. The software SimaPro 7.3.2 and IMACT 2002+ method were chosen in order to accomplish the research purpose. The results of the study show that traditional vest-bags produced by the researched enterprise are less environmentally friendly. Their production process has a bigger impact on environment and human health than that of the biodegradable bags. Moreover, a list of recommendations for possible improvements was developed based on the results of the research. It was sent to the directors of LLC “Polymer” as a suggestion for creating a “green strategy” of further development.

Efforts to alleviate poverty and conserve biodiversity require reliable methods to monitor and assess changes in conservation and development status. Projects intended to achieve biodiversity conservation and poverty alleviation objectives often fall short of their goal. Considering the investments made to support these efforts, this is a real concern to society. Evaluating the effectiveness of these efforts is crucial to receive ongoing support and to learn what’s working, what’s not and how it can be improved. This research examines current M&E and impact assessment practices and systems at conservation and development organizations garnered through a survey and interviews and documents opinions, experiences and lessons learned from key informants. Organizations are facing common barriers but share opportunities to improving M&E. Embracing a culture of learning, synthesizing a common vocabulary and implementing organizational change are important steps in improving M&E practice to provide information and data for better M&E and impact assessment.

Background. Access to health care in northern and rural communities has been an ongoing challenge. Training undergraduate medical students in regional sites is one strategy to enhance physician recruitment and retention in rural regions. With this goal in mind, in 2004, the Northern Medical Program was created to bring undergraduate medical education to Prince George. The NMP is also hypothesized to have wider impacts on the community. This study aimed to describe perceptions of the broader impacts of the NMP. Methods. In this qualitative study, semi-structured interviews were conducted with community leaders in various sectors of Prince George. The interviewer probed about perceived current and anticipated future impacts of the program, both positive and negative. A descriptive content analysis was performed. A conceptual framework of hypothesized impacts was created based on the literature and a model of neighbourhood social capital by Carpiano (2006). Findings. Comments were overwhelmingly positive. Impacts were described on education, health services, economy, politics, and media. Some reported negative impacts included tension between the NMP and other departments at UNBC, and a strain on health system resource capacity. Participants also reported that the NMP has impacted social capital in the region. Social capital, defined as the resources belonging to a network of individuals, was a pervasive theme. Impacts on social cohesion, various forms of social capital, access to social capital and outcomes of social capital are described. Conclusions. The full impact of the NMP will likely not be felt for at least a decade, as the program is still relatively new to Prince George. Findings suggest that an undergraduate medical education program can have pervasive impacts in an underserved community. Evaluation of the impact of such programs should be broad in scope. Findings also suggest that impacts of the program on other community sectors and on social capital may in fact lead to greater human capital gains than originally anticipated. A comprehensive communication strategy should be developed and maintained to ensure continued stakeholder support for the program. Next steps include identifying key quantifiable indicators of community impact to track changes in the community over time.

Climate change will affect Arctic plant communities directly, by altering growth and recruitment, and indirectly, by increasing the frequency of natural disturbance. Since the structure of northern vegetation influences global climate, understanding both temperature and disturbance effects on vegetation is critical. Here, I investigate the influence of temperature and disturbance on Low Arctic vegetation at several spatio-temporal scales in the Mackenzie Delta Region, N.W.T. To disentangle the relative impact of temperature and disturbance on forest-tundra and tundra ecosystems, I sampled microenvironmental variability, plant community composition, and green alder abundance, growth, and reproduction on disturbed (burns and thaw slumps) and undisturbed sites across a regional temperature gradient. Disturbed areas showed increases in alder productivity, catkin production, and seed viability, as well as differences in plant community composition and microenvironment. The magnitude of plot-level responses to disturbance compared to variation across the temperature gradient suggests that in the short-term, increasing the frequency of disturbance may exert a stronger influence on tundra ecosystems than changes in temperature. At the plot level, increases in alder seed viability and recruitment at warmer sites point to the fine-scale mechanisms by which shrub abundance will change. To examine the relative influence of temperature and biophysical variables on landscape-level patterns of shrub dominance, I mapped Low Arctic vegetation using aerial photos. At this broader scale, correlations between temperature and the areal extent of shrub tundra suggest that warming will increase the dominance of shrub tundra. To assess the magnitude of changes in temperature and thaw slump activity, I analyzed climate records and mapped retrogressive thaw slumps using aerial photographs. An increase in thaw slump activity in recent decades, coincident with higher temperatures, suggests that continued warming will change the area affected by thermokarst disturbances like slumps. Taken together, my research indicates that the effects climate change will be magnified by shifts in the frequency of disturbance, initiating changes to Arctic vegetation with significant implications for global climate. My work also shows that to fully understand the influence of patch-landscape feedbacks on Arctic vegetation dynamics, the effects of disturbance must be examined across longer temporal and broader spatial scales.

The analysis of reinforced concrete structures under blast and impact loads is an area of research that has become increasingly relevant in recent years. Complex hydrocodes are typically used for impact analyses, although single-degree-of-freedom methods have also been developed. There are a number of disadvantages associated with both methods, and the Canadian Nuclear Safety Commission (CNSC) is looking for a tool that can be used in conjunction with hydrocodes to analyze hard and soft missile impacts, with target damage ranging from flexural cracking to perforation. The VecTor programs, a suite of nonlinear finite element programs developed at the University of Toronto for the analysis of reinforced concrete structures, can potentially be developed into such tools. The analytical work done in this study serves to investigate the current impact and impulse loading analysis capabilities in VecTor2 and VecTor3, and to identify areas where work should be focused in the future.

The analysis of reinforced concrete structures under blast and impact loads is an area of research that has become increasingly relevant in recent years. Complex hydrocodes are typically used for impact analyses, although single-degree-of-freedom methods have also been developed. There are a number of disadvantages associated with both methods, and the Canadian Nuclear Safety Commission (CNSC) is looking for a tool that can be used in conjunction with hydrocodes to analyze hard and soft missile impacts, with target damage ranging from flexural cracking to perforation. The VecTor programs, a suite of nonlinear finite element programs developed at the University of Toronto for the analysis of reinforced concrete structures, can potentially be developed into such tools. The analytical work done in this study serves to investigate the current impact and impulse loading analysis capabilities in VecTor2 and VecTor3, and to identify areas where work should be focused in the future.

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