Simulation and Analysis of Vacancies in Carbon Nanostructures

The discovery of the Buckminsterfullerenes in 1985 marked the beginning of the research field in carbon nanostructures. Since then, several more carbon allotropes existing in the nanoscale have been discovered, most notably the carbon nanotube and graphene. Due to the small scale of these materials, research is difficult, and production requires state of the art equipment to create even small samples. However, study has only increased with the accumulation of desirable properties these materials hold, boasting thermal and electrical conductivity, as well as immense strength. As the properties of carbon nanostructures continue to emerge, numerous research groups in academia have begun studying the synthesis and applications of these versatile materials. This thesis aims to provide a supplementary insight to how the behavior of a vacancy in carbon nanostructures changes when energy is added to the system. While research of this kind is often done in a laboratory, this analysis is conducted in a digital environment, examining the relevance of simulations in comparison to ideal results. The two primary software packages used for the simulations are Atomic Simulation Environment (ASE) and Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). ASE provides tools to build, visualize, and export atomistic structures. These tools were used to generate and prepare the carbon nanotube and graphene nanoribbon for the forth-coming simulations. LAMMPS imports the exported ASE structures and executes the molecular dynamics simulations using the Tersoff potential for interatomic interactions. Digital experiments regarding phenomena in natural science is enhancing how modern re-search is conducted. They provide both valuable insights to experiments and can model hypothetical scenarios that are difficult to physically execute. Simulations do have limitations such as system size and complexity of the model. The molecular dynamics simulations con-ducted in this project can be ran on a personal computer; however, some systems require considerable computation, needing the computing power a supercomputer. While there will always be need for the laboratory, simulations can be an economical and effective means for augmenting research

Novel Material Behavior in Carbon Nanotube/Elastomer Composites

Composites are multiphasic materials with individual constituent parts that work cooperatively to produce some desired result. For the common case of structural composites, the use of nanoscale additives does not always yield a predictable outcome due to the complex interactions that occur in the interfacial region where a reinforcing filler meets the supporting matrix. It stands to reason, however, that the thoughtful and deliberate exploitation of unusual effects in this region could lead to the development of nanocomposite materials with extraordinary properties. In this thesis work, I will introduce two such responses in a compliant nanocomposite consisting of highly-aligned carbon nanotubes (CNTs) encased within a poly(dimethylsiloxane) (PDMS) matrix. It is first demonstrated that the material exhibits extremely anisotropic dynamic mechanical behavior. The composite will behave in a way that is evocative of the neat polymer when deformed orthogonal to the CNT alignment direction, yet will exhibit strain softening when cyclically compressed along their axis due to the collective buckling of the nanotube struts. Next, it is shown that this nanocomposite material has the ability to respond and adapt to applied loads. Independent, yet complimentary tests reveal that the structure of the polymer in the presence of nanoscale interstitials will evolve during dynamic stressing, an effect that was predicted nearly 50 years ago. With support from both recent and established literature, an updated mechanism is proposed. Collectively, these results provide insight into the complicated mechanics between polymer matrices and embedded nanoparticles, and assist in the design of advanced synthetic materials with unique physical properties

Wireless Infrastructure Design for Industrial Data Acquisition

With the trend of digitalization in industry, many companies are improving their processes with digital solutions, making them more efficient, cost effective and sustainable. Metso Outotec aims to improve the pressure filtration process by monitoring the parts of the filter susceptible to failure. By analyzing these parts' state of wear, the Smart Parts system can provide predictive maintenance. However, there must be an infrastructure deployed to the filter that acquires the parts data for analysis. This thesis work designs an IoT system for the acquisition of filtration parts data. The design consists of two device types: the hub device and spoke device. The system architecture is similar to the star topology, where each of the filter's susceptible parts are equip with a spoke device that wirelessly communicates sensor data to the hub device. Furthermore this thesis implements a prototype of the designed system and evaluates the validity of the solution. Evaluation of the prototype showed that the system design proposed in this thesis was an acceptable solution to the Smart Parts data acquisition infrastructure. Through a series of experiments and qualitative observations, the evaluation proved all system requirements were satisfied

Tailoring vertically-aligned carbon nanotube growth for poly(dimethylsiloxane)-infiltrated nanocomposites

This thesis discusses the viability of the polymer infiltration nanocomposite preparation technique for aligned carbon nanotubes (A-CNTs) as produced by two methods: pre-deposited catalyst chemical vapor deposition (CVD), and vapor-phase CVD. Both types of growth furnaces were constructed, and the resultant A-CNT "forests" were impregnated with poly(dimethylsiloxane), a highly-compliant silicone elastomer. The survivability of the CNT alignment subsequent to the polymer infiltration was studied for the respective nanocomposites, and it was observed that the thin-walled CNTs produced by the pre-deposited catalyst CVD method were not robust enough to maintain alignment during the infiltration, in contrast to the thicker-walled vapor-phase-grown CNTs. The dynamic mechanical properties of the successfully-impregnated composites were then studied, and their strain- and frequency-dependent behavior was probed both transverse and longitudinal to the alignment direction of the CNTs, revealing distinct responses due to their anisotropy

Developing a dashboard to meet Competence Committee needs: a design-based research project

Background: Competency-based programs are being adopted in medical education around the world. Competence Committees must visualize learner assessment data effectively to support their decision-making. Dashboards play an integral role in decision support systems in other fields. Design-based research allows the simultaneous development and study of educational environments. Methods: We utilized a design-based research process within the emergency medicine residency program at the University of Saskatchewan to identify the data, analytics, and visualizations needed by its Competence Committee, and developed a dashboard incorporating these elements. Narrative data were collected from two focus groups, five interviews, and the observation of two Competence Committee meetings. Data were qualitatively analyzed to develop a thematic framework outlining the needs of the Competence Committee and to inform the development of the dashboard. Results: The qualitative analysis identified four Competence Committee needs (Explore Workplace-Based Assessment Data, Explore Other Assessment Data, Understand the Data in Context, and Ensure the Security of the Data). These needs were described with narratives and represented through visualizations of the dashboard elements. Conclusions: This work addresses the practical challenges of supporting data-driven decision making by Competence Committees and will inform the development of dashboards for programs, institutions, and learner management systems

Créer un tableau de bord permettant de répondre aux besoins des résidents d’un programme de formation fondé sur les compétences : projet de recherche basé sur la conception

Background: Canadian specialty programs are implementing Competence By Design, a competency-based medical education (CBME) program which requires frequent assessments of entrustable professional activities. To be used for learning, the large amount of assessment data needs to be interpreted by residents, but little work has been done to determine how visualizing and interacting with this data can be supported. Within the University of Saskatchewan emergency medicine residency program, we sought to determine how our residents’ CBME assessment data should be presented to support their learning and to develop a dashboard that meets our residents’ needs. Methods: We utilized a design-based research process to identify and address resident needs surrounding the presentation of their assessment data. Data was collected within the emergency medicine residency program at the University of Saskatchewan via four resident focus groups held over 10 months. Focus group discussions were analyzed using a grounded theory approach to identify resident needs. This guided the development of a dashboard which contained elements (data, analytics, and visualizations) that support their interpretation of the data. The identified needs are described using quotes from the focus groups as well as visualizations of the dashboard elements. Results: Resident needs were classified under three themes: (1) Provide guidance through the assessment program, (2) Present workplace-based assessment data, and (3) Present other assessment data. Seventeen dashboard elements were designed to address these needs. Conclusions: Our design-based research process identified resident needs and developed dashboard elements to meet them. This work will inform the creation and evolution of CBME assessment dashboards designed to support resident learning.Contexte : Les programmes canadiens de spécialité sont à implanter la compétence par conception (CPC), un programme d’éducation médicale par compétences qui nécessite des évaluations fréquentes des activités professionnelles confiables. Pour servir aux fins d’apprentissage, la grande quantité de données d’évaluation doit être interprétée par les résidents, mais peu de travaux ont été réalisés pour déterminer comment la visualisation et l’interaction avec ces données peuvent être soutenues. Dans le cadre du programme de résidence en médecine d’urgence de l’Université de Saskatchewan, nous avons cherché à déterminer comment les données d’évaluation de la CPC de nos résidents devraient être présentées pour soutenir leur apprentissage et pour développer un tableau de bord qui réponde aux besoins de nos résidents. Méthodologie : Nous avons utilisé un processus de recherche orientée par la conception pour cerner les besoins des résidents en lien avec la présentation de leurs données d’évaluation. Les données ont été recueillies au cours du programme de résidence en médecine d’urgence de l’Université de Saskatchewan grâce à quatre groupes de discussion de résidents qui se sont tenus sur une période de 10 mois. Les groupes de discussion ont été analysés en utilisant l’approche de la théorisation ancrée (Grounded Theory) pour cerner les besoins des résidents, pour guider le développement d’un tableau de bord contenant des éléments (données, analyses et visualisations) qui soutiennent leur interprétation de leurs propres données. Les besoins identifiés sont décrits à l’aide de citations des groupes de discussion ainsi que de visualisations des éléments du tableau de bord. Résultats : Les besoins des résidents ont été classés sous trois thèmes : 1. être guidés quant au programme d'évaluation, 2. présenter des données d’évaluation en milieu de travail, et 3. présenter d’autres données d’évaluation. Dix-sept éléments du tableau de bord ont été conçus pour répondre à ces besoins. Conclusions : Notre méthode de recherche orientée par conception a permis de cerner les besoins des résidents et d’élaborer les éléments d’un tableau de bord pour y répondre. Ce travail servira de base à la création et à l’évolution des tableaux de bord d’évaluation en CPC conçus pour soutenir l’apprentissage des résidents

Élaboration d’un tableau de bord pour la formation professorale dans les programmes de formation axés sur les compétences : projet de recherche orientée par la conception

Background: Canadian specialist residency training programs are implementing a form of competency-based medical education (CBME) that requires frequent assessments of entrustable professional activities (EPAs). Faculty struggle to provide helpful feedback and assign appropriate entrustment scores. CBME faculty development initiatives rarely incorporate teaching metrics. Dashboards could be used to visualize faculty assessment data to support faculty development. Methods: Using a design-based research process, we identified faculty development needs related to CBME assessments and designed a dashboard containing elements (data, analytics, and visualizations) meeting these needs. Data was collected within the emergency medicine residency program at the University of Saskatchewan through interviews with program leaders, faculty development experts, and faculty participating in development sessions. Two investigators thematically analyzed interview transcripts to identify faculty needs that were audited by a third investigator. The needs were described using representative quotes and the dashboard elements designed to address them. Results: Between July 1, 2019 and December 11, 2020 we conducted 15 interviews with nine participants (two program leaders, three faculty development experts, and four faculty members). Three needs emerged as themes from the analysis: analysis of assessments, contextualization of assessments, and accessible reporting. We addressed these needs by designing an accessible dashboard to present contextualized quantitative and narrative assessment data for each faculty member. Conclusions: We identified faculty development needs related to EPA assessments and designed dashboard elements to meet them. The resulting dashboard was used for faculty development sessions. This work will inform the development of CBME assessment dashboards for faculty.Contexte : Les programmes de résidence de spécialité au Canada mettent en œuvre une forme d’éducation axée sur les compétences (EASC) qui exige des évaluations formatives fréquentes des activités professionnelles confiables (APC). Les enseignants ont du mal à fournir une rétroaction utile et à attribuer des notes appropriées au niveau de confiance. Les initiatives de formation professorale des enseignants qui interviennent dans la EASC intègrent rarement leurs données psychométriques. Des tableaux de bord pourraient être utilisés pour visualiser les données d’évaluation du corps professoral afin de soutenir leur perfectionnement. Méthodes : En utilisant un processus de recherche orientée par la conception, nous avons déterminé les besoins de formation professorale liés aux évaluations dans la EASC et nous avons conçu un tableau de bord contenant des éléments (données, analyses et éléments visuels) pour répondre à ces besoins. Les données ont été recueillies dans le cadre du programme de résidence en médecine d’urgence de l’Université de Saskatchewan par le biais d’entretiens avec les responsables du programme, des experts en formation professorale et les enseignants participant aux séances de formation. Deux chercheurs ont procédé à une analyse thématique des transcriptions d’entrevues afin d’identifier les besoins des enseignants, et un troisième chercheur les a vérifiées. Les besoins ont été décrits à l’aide de citations représentatives et des éléments du tableau de bord conçus pour y répondre. Résultats : Entre le 1er juillet 2019 et le 11 décembre 2020, nous avons mené 15 entretiens avec neuf participants (deux responsables de programme, trois experts en formation professorale et quatre membres du corps professoral). Trois besoins sont ressortis comme thèmes de l’analyse : l’analyse des évaluations formatives, la contextualisation des évaluations formatives et l’accessibilité des rapports. Pour répondre à ces besoins, nous avons conçu un tableau de bord accessible présentant des données d’évaluation quantitatives et narratives contextualisées pour chaque membre du corps professoral. Conclusions : Nous avons identifié les besoins de formation professorale liés aux évaluations des APC et conçu les éléments d’un tableau de bord permettant d’y répondre. Le tableau de bord a été utilisé dans des séances de formation professorale. Ce travail orientera la réalisation de tableaux de bord afin de faciliter l’évaluation pour les enseignants dans le cadre de la EASC

Multi-wavelength diagnostic properties of Galactic Planetary Nebulae detected by GLIMPSE-I

We uniformly analyze 136 optically detected PNe and candidates from the GLIMPSE-I survey in order to to develop robust, multi-wavelength, classification criteria to augment existing diagnostics and provide pure PN samples. PNe represent powerful astrophysical probes. They are important dynamical tracers, key sources of ISM chemical enrichment, windows into late stellar evolution, and potent cosmological yardsticks. But their utility depends on separating them unequivocally from the many nebular mimics which can strongly resemble bona fide PNe in traditional optical images and spectra. We merge new PNe from the carefully evaluated, homogeneous MASH-I and MASH-II surveys, which offer a wider evolutionary range of PNe than hitherto available, with previously known PNe classified by SIMBAD. Mid-infrared (MIR) measurements vitally complement optical data because they reveal other physical processes and morphologies via fine-structure lines, molecular bands and dust. MIR colour-colour planes, optical emission line ratios and radio fluxes show the unambiguous classification of PNe to be complex, requiring all available evidence. Statistical trends provide predictive value and we offer quantitative MIR criteria to determine whether an emission nebula is most likely to be a PN or one of the frequent contaminants such as compact HII regions or symbiotic systems. Prerequisites have been optical images and spectra but MIR morphology, colours, environment and a candidate's MIR/radio flux ratio provide a more rigorous classification. Our ultimate goal is to recognize PNe using only MIR and radio characteristics, enabling us to trawl for PNe effectively even in heavily obscured regions of the Galaxy.Comment: 32 pages, 18 figures, 10 table

Desert Research and Technology Studies (DRATS) 2010 Science Operations: Operational Approaches and Lessons Learned for Managing Science during Human Planetary Surface Missions

Desert Research and Technology Studies (Desert RATS) is a multi-year series of hardware and operations tests carried out annually in the high desert of Arizona on the San Francisco Volcanic Field. These activities are designed to exercise planetary surface hardware and operations in conditions where long-distance, multi-day roving is achievable, and they allow NASA to evaluate different mission concepts and approaches in an environment less costly and more forgiving than space.The results from the RATS tests allows election of potential operational approaches to planetary surface exploration prior to making commitments to specific flight and mission hardware development. In previous RATS operations, the Science Support Room has operated largely in an advisory role, an approach that was driven by the need to provide a loose science mission framework that would underpin the engineering tests. However, the extensive nature of the traverse operations for 2010 expanded the role of the science operations and tested specific operational approaches. Science mission operations approaches from the Apollo and Mars-Phoenix missions were merged to become the baseline for this test. Six days of traverse operations were conducted during each week of the 2-week test, with three traverse days each week conducted with voice and data communications continuously available, and three traverse days conducted with only two 1-hour communications periods per day. Within this framework, the team evaluated integrated science operations management using real-time, tactical science operations to oversee daily crew activities, and strategic level evaluations of science data and daily traverse results during a post-traverse planning shift. During continuous communications, both tactical and strategic teams were employed. On days when communications were reduced to only two communications periods per day, only a strategic team was employed. The Science Operations Team found that, if communications are good and down-linking of science data is ensured, high quality science returns is possible regardless of communications. What is absent from reduced communications is the scientific interaction between the crew on the planet and the scientists on the ground. These scientific interactions were a critical part of the science process and significantly improved mission science return over reduced communications conditions. The test also showed that the quality of science return is not measurable by simple numerical quantities but is, in fact, based on strongly non-quantifiable factors, such as the interactions between the crew and the Science Operations Teams. Although the metric evaluation data suggested some trends, there was not sufficient granularity in the data or specificity in the metrics to allow those trends to be understood on numerical data alone

The Coexistence of Natural and Supernatural Explanations Across Cultures and Development

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91141/1/j.1467-8624.2012.01743.x.pd