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Assessing mechanical loss in typical polyolefins via mechanical reprocessing
No full textHow recyclable is a yogurt cup? A report recently stated that polypropylene (PP) the material for which yogurt cups are made, was not recyclable. The reason for this statement was strictly based on the difficulty of separating PP from the similarly ubiquitous material, polyethylene. Polypropylene and polyethylene are not miscible materials, meaning that when blended, the subsequent blended product is not usable due to the two-phase nature of the blend. (9) Processors that use recycled material would prefer not to deal with the contamination and thus discourage the introduction of PP to their material stream. Simply stating that polypropylene is not recyclable is not true. Anyone familiar with polymer processing knows that you can simply reduce the particle size of the yogurt cup, feed it back into the melt process of your choice, and remake the yogurt cup. But that does come at some cost, but at what cost? How many times can that cup be reprocessed, and it still preform as intended? This study seeks to shed some light on that question
Sensible thermal energy storage in concrete media
No full textUnder the threat of fossil-fuel depletion and global warming, thermal energy storage (TES) has become an effective technology to compensate for the intermittent nature of renewable energy such as solar and wind and improve load efficiency of fossil-fuel power plants. In this dissertation, an innovative sensible TES system is developed using conventional concrete as storage media and thermosiphons as heat exchanger. Concrete constituents are chosen to develop concrete mixes with enhanced thermal and mechanical properties specifically in TES operating conditions. Three TES prototypes with storage capacity varying from 2kWhth, 10kWhth to 150kWhth are designed, fabricated, and tested under operational temperatures ranging from 200ºC to 400ºC. Rapid charging/discharging performance and repeatable cyclic system operation are achieved during experiments. A simplified numerical approach is developed to investigate thermal and mechanical performance of the TES system with focus on heat transfer mechanism of heat exchanger and storage media and stress development within the concrete media. The numerical model is validated against experimental data and is used for performance assessment of the developed system with different scales under different operating conditions. Furthermore, integration of concrete TES with building applications is investigated in an innovative concrete energy column system. Thermal evaluation is conducted both numerically and experimentally demonstrating that the energy column can perform as a buffer to improve building thermal comfort. The energy column is also investigated by conducting destructive structural experiments. The expected ultimate capacity computed by standard concrete design approaches is achieved by the energy column
Context Matters: Examining the Impact of Context on Youth\u27s Mental Health and School Functioning Within an Incarcerated Population
No full textYouth who are detained in detention centers have poor educational and occupational attainment, and experience high rates of behavioral health needs. With such a wide array of needs there are numerous areas for prevention and intervention within this population; however, research and practice have not been able to comprehensively meet the needs of this population. The present study examined the relationships of neighborhood risk, parenting practices, and peers with incarcerated youth\u27s mental health functioning and school functioning. More specifically, it was hypothesized that youth neighborhood risk, protective parenting practices, and antisocial peers are associated with incarcerated youth\u27s mental health and positive school experiences. Neighborhood risk was positively and significantly predicted positive school experiences but did not significantly predict mental health risk, suggesting that as neighborhood risk increased, youth\u27s self-report of positive school experiences increased. Additionally, protective parenting practices significantly predicted both mental health and positive school experiences, such that as protective parenting practices increased, mental health risk decreased. Additionally, as protective parenting practices increased, positive school experiences increased. Lastly, antisocial peers significantly predicted mental health functioning, but did not predict positive school experiences such that as the presence of antisocial peers increased, self-report of mental health risk increased. Overall, the findings suggest that context does matter in regard to understanding incarcerated youth\u27s mental health and school functioning. Practical implications are discussed specifically for potentially efficacious treatments and methods of interventions for juvenile justice involved youth
Improving Reentry Prediction Capability of Naturally Decaying Space Objects
No full textThis paper investigates the utility of GPS transponders in providing an increased predictive capability to reentry times of naturally decaying space objects. It compares the predictions of traditional propagators, such as SGP4 and HPOP models, to that of simulated GPS data for reconstructed orbits of several decayed objects. By screening the public catalog of two line element sets (TLEs) for upcoming reentry dates over a long period of time, several objects are selected to undergo analyses to determine the accuracy of traditional methodologies in natural decay reentry predictions. Since the true trajectory of an object is impossible to obtain, a proxy for truth data is created using the time history of TLEs for each object to reconstruct a best-fit trajectory for the final days prior to reentry. From these trajectories, GPS points are simulated in a real-time flow of data at a regular cadence, which are used as another data source for reentry predictions of each satellite. All data sources are measured against the final Tracking and Impact Prediction (TIP) messages of the respective satellites, which are published by the United States Space Command and used as a proxy for truth data. It is of interest to determine the effectiveness of the time-consistent and low-uncertainty tracking measurements offered by GPS transponders
Et in Macedonia Ego: The Global Arms Trade and Violence as Catalysts for Independence Movements and Nation Building in Ottoman Macedonia, 1878-1913
No full textThe international arms trade at the end of the 19th Century benefited from several technological advances that fomented an arms race among the Great Powers. A surge in the effectiveness of insurgencies and nationalist movements across the globe, due to increased access to contemporary small arms and ammunition, saw agitation for autonomy and national recognition become real concerns for peoples subjected to imperial rule. Ottoman Macedonia stood at the epicenter of some of the most devastating historic, religious, ethnic, political, and national contests that were both raised and came to their bloody conclusions during the final tumultuous decades of the Ottoman presence in Europe. The most effective catalyst for change proved to be the deployment of armed insurgent fighters that delegitimized Ottoman rule, established parallel state structures, and encouraged the people living in Ottoman Macedonia to not only participate in the toppling of Ottoman power in Europe, but to identify themselves with a particular religious or national group in a way that they had never before. As such, the international arms race and military surplus market created the conditions under which the slow-moving tools of nation building in Ottoman Macedonia, such as churches and schools, were subsumed and accelerated by the accessibility of small arms and the use of violence as a tool for winning freedom and sovereignty in the process of national creation
Respect the Locals: Integrating Sociocultural Dynamics for Effective Marine Conservation in Coastal Indonesia
No full textPower dynamics between sovereign entities and local communities are a determinant component of conservation policy in terms of meeting ecological protection goals and ensuring the well-being of local people. There is high pressure for marine conservation programs to generate successful ecological outcomes in the face of our current environmental crisis. However, natural science should not be the only information guiding conservation policy; it is equally - if not more - crucial to consider the social aspect of conservation initiatives to develop effective long-term solutions. Indonesia is a global cornerstone of marine conservation due to its high levels of biodiversity and rich natural resources, which are currently threatened by overfishing, habitat destruction, and climate change. There are many conservation programs throughout the Indonesian archipelago, all of which have achieved varying degrees of ecological and social success. The goal of this thesis is to identify common attributes of successful Indonesian conservation programs and make general recommendations based on those characteristics for environmental policies worldwide. Through a review of current literature on Indonesian conservation, I have found that successful programs apply (1) a biocultural perspective, (2) co-management strategies with an emphasis on the devolution of power, (3) local wisdom/indigenous knowledge system (IKS) consideration and the inclusion of indigenous minority input, and (4) improved and diverse alternative livelihood options. Ultimately, local agency and the inclusion of regional context in policy design are paramount in the development of impactful conservation programs around the world
Systematic Review of AI Ethics Education for K-12 and Higher Education - Project Summary
No full textSystematic review of AI ethics education in K-12 and higher education to uncover themes, challenges, and teaching practices.This project focuses on conducting a systematic review of AI ethics education for K-12 and higher education, addressing the critical gap in understanding the current state of teaching AI ethics. With the rapid integration of AI into daily life, there is an increasing need to ensure that students not only grasp fundamental AI concepts but also develop the ethical awareness necessary to responsibly use and create AI technologies. This project how and what AI ethics topics have been introduced in educational contexts.
Currently, I am in the data extraction stage of the project. This involves systematically reviewing and coding data from selected peer-reviewed articles using a comprehensive coding scheme. This coding scheme has been iteratively refined to capture education motivation, key topics, instructional strategies, program types, and challenges associated with AI ethics education.
The outcomes of this systematic review will provide valuable insights into existing AI ethics curricula and their implementation across diverse educational settings. These findings will serve as a foundation for designing improved AI ethics education frameworks, informing educators, policymakers, and researchers on how to foster ethical awareness among students