Violence Against Black People in America: A ClioVis Timeline

Histor

The Three-Dimensional Structure of Interior Ejecta in Cassiopeia A at High Spectral Resolution

We used the Spitzer Space Telescope's Infrared Spectrograph to create a high resolution spectral map of the central region of the Cassiopeia A supernova remnant, allowing us to make a Doppler reconstruction of its 3D structure. The ejecta responsible for this emission have not yet encountered the remnant's reverse shock or the circumstellar medium, making it an ideal laboratory for exploring the dynamics of the supernova explosion itself. We observe that the O, Si, and S ejecta can form both sheet-like structures as well as filaments. Si and O, which come from different nucleosynthetic layers of the star, are observed to be coincident in velocity space in some regions, and separated by 500 km/s or more in others. Ejecta traveling toward us are, on average, ~900 km/s slower than the material traveling away from us. We compare our observations to recent supernova explosion models and find that no single model can simultaneously reproduce all the observed features. However, models of different supernova explosions can collectively produce the observed geometries and structures of the interior emission. We use the results from the models to address the conditions during the supernova explosion, concentrating on asymmetries in the shock structure. We also predict that the back surface of Cassiopeia A will begin brightening in ~30 years, and the front surface in ~100 years.Comment: 35 pages, 16 figures, accepted to Ap

A Mindfulness-Based Intervention for University Students: A Feasibility Study

Background: Koru is a 4-week group mindfulness-based intervention that previously demonstrated psychological benefits in university students through its offering via a counseling center (Greeson, Juberg, Mayatan, James, & Rogers, 2014). Aim: This study examined the feasibility of Koru offered universally to students via collaborative outreach (i.e., student interest, attendance, adverse events, participant acceptability, and participant willingness to complete assessments). Method: Across five semesters, Koru was advertised via flyers, emails to student organizations and faculty and staff, and counseling center referrals at a southeastern public university with 29,000-students. Interested students were randomly assigned to Koru or a waitlist. In-person Koru groups took place in classrooms on campus. Assessments included practice logs, program evaluations, and pre- and post-intervention surveys measuring mindfulness and psychological symptoms. Results: Interest was sufficient to offer 2-3 groups per semester (171 students). Of those assigned to Koru, 44.4% completed 3-4 sessions and 34.9% did not attend any sessions. The adverse event rate was 2.9%. Evaluations were positive and all participants attending the last session completed them. The response rate was 29.0% for log completion and 17.9% for survey completion. Conclusion: Results support student interest in, and acceptability of Koru offered to all students on campus outside of a counseling center. Data collection was challenging

A high-sensitivity resonant sensor realised through the exploitation of nonlinear dynamic behaviour

Measurements of viscosity and density allow for the monitoring of fluid quality and processes involving a fluid environment. There are various fields in which such measurements may be required, including oil exploration and production, environmental monitoring, process control, medicine, and the automotive industry. Existing MEMS viscometers and density meters typically measure vibrational characteristics such as resonant frequency, bandwidth and quality factor. This thesis reports on the development of a high-sensitivity resonant sensor. In order to significantly improve sensitivity to changes in viscosity and/or density the proposed sensor will exploit nonlinear dynamic behaviour and measure the frequency separation between singular jump points in the frequency response function. By using a one-mode approximation when excited near resonance, the dynamics of a clamped-clamped slender beam immersed in fluid is that of a standard Duffing oscillator. With harmonic forcing of sufficient magnitude, a bistable region, bounded by amplitude jump points, is seen to occur. The width of this bistable region, δF , is dependent on the damping ratio of the system, which is shown to be a function of the dynamic viscosity and density. Experiments with clamped-clamped silicon beams in a range of Newtonian gases demonstrate that the measurand δF can uniquely identify a fluid, and may be amplified to magnitudes greatly exceeding bandwidth measurements for the same device. In addition, the sensitivity of the proposed nonlinear sensor to changes in fluid properties at low viscosity can be at least an order of magnitude better than that of conventional devices. Forcing magnitude and control is identified as being critical to the measured width of the bistable region. Beam dimensions can be chosen to optimise measurements for the desired application.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Documentation for the CETACEA database of marine mammal literature references

This documentation for the CETACEA database of marine mammal literature references updates and expands the original work by Watkins, Bird, Moore, and Tyack 1988 (Reference Database Marine Mammal Literature, Technical Report WHOI-88-2). The CETACEA database is a comprehensive index of literature references used to file, store, search, retrieve, and format the data on marine animals. Organization of the references is complementary to features developed by William E. Schevill for his library of older cetacea literature, having direct association of species with over 300 indexed subjects, and with observation dates, locations, etc. This documentation describes the operation of the database (360 records), including indexing, sorting, and retrieval information developed though continued use of these systems. SPECIES and SUBJECT HEADING lists with their codes have been updated. Other databases have also developed around these indexing and sorting strategies to complement the CETACEA database, including databases of animal sounds for both the recordng data and the acoustic spectral information stored in libraries of digital sound cuts.Funding was provided by the Office of Naval Research through Contract Number N00014-88-K-0273