Denison University

About: Denison University is a education organization based out in Granville, Ohio, United States. It is known for research contribution in the topics: Population & Politics. The organization has 921 authors who have published 1828 publications receiving 41060 citations. The organization is also known as: Denison & DU.

Physical Properties of Jets in AGN

Abstract: I review constraints on the physical properties of AGN jets revealed through Very Long Baseline Interferometry (VLBI) studies of the structure and time-evolution of parsec-scale jets, including recent results from the MOJAVE program. In particular I focus on constraints available from very long time baseline studies which probe a wide range of jet behavior over many outbursts. Kinematic studies of propagating jet features find an apparent speed distribution that peaks around 10c for blazars, with speeds up to 50c observed. These observed speeds require Lorentz factors at least as large, implying that parsec-scale Lorentz factors up to 10-20 are common for blazars with a tail up to ~ 50. Jet flows are still becoming organized on these scales as evidenced by the high incidence of non-radial motions and/or accelerations of jet features (including increases and decreases in apparent speed and direction). Changes in Lorentz factors of propagating jet features appear to play a significant role in the observed accelerations, and while the connection between acceleration of jet features and the underlying flow is not clear, the pattern of observed accelerations suggest the flow may increase in speed near the base of the jet and decrease further out. In some jets, ejections of new features span a range of ejection angles over many epochs, tracing out wider opening angles on parsec-scales than are apparent in single epoch observations.

Predicting quasibound states of negative ions: La− as a test case

Abstract: We demonstrated the accurate prediction of a quasibound spectrum of a negative ion using a high-precision theoretical approach. We used ${\mathrm{La}}^{\ensuremath{-}}$ as a test case due to a recent experiment that measured energies of 11 resonances in its photodetachment spectrum attributed to transitions to quasibound states [Phys. Rev. A 102, 042812 (2020)]. We identified all of the observed resonances and predicted one more peak just outside the range of the prior experiment. Following the theoretical prediction, the peak was observed at the predicted wavelength, validating the identification. The same approach is applicable to a wide range of negative ions.

Teaching an Undergraduate Lecture/Research Course in Health Psychology

Abstract: I describe an upper level undergraduate course in health psychology. The course consists of two separate but related segments lecture and laboratory/research. Components, assignments, activities, and resource materials for the lecture segment are described. For the research segment, I describe five preparatory instructional laboratories and the main activity of the course-planning and conducting a class-designed research project. Students' evaluations of the course are summarized.