Preston Alan Harris in a Senior Baritone Recital

This is the program for the senior baritone recital of Preston Alan Harris. Mr. Harris was accompanied by Lowella Cherry on the piano. This recital took place on February 5, 1999, in the McBeth Recital Hall in the Mabee Fine Arts Center

Freezing Point Mobile Munitions Assessment Sytem: Thermal Chamber Redesign

The Army is actively investigating non-intrusive methods to identify six chemical weapons agents. The chemical munitions in question are often found scattered across military bases and other facilities. These non-stockpile munitions are specifically targeted for identification using the mobile munitions assessment system. This program is being administered by the Idaho National Engineering Laboratory

Polarization of circumstellar debris disk light echoes

Light echoes of debris disks around active stars can reveal disk structure and composition even when disks are not spatially resolved. Unfortunately, distinguishing reflected light from quiescent starlight and unexpected post-peak flare structure is challenging, especially for edge-on geometries where the time delay between observed flare photons and light scattered from the near side of the disk is short. Here, we take advantage of the fact that scattered light from a dusty disk is polarized, depending on the location of the scattering site and the orientation of the disk relative to a distant observer. Filtering reflected light into its polarized components allows echoes to stand out in predictable ways. We test this idea with a simple model for a disk around an active M dwarf. Our results demonstrate that the use of polarimetric data of flaring stars can significantly enhance echo signals relative to starlight and yield more robust and accurate fits to disk parameters compared to analyses based on the total intensity alone.Comment: 14 pages, 9 figures, 1 table, AJ accepte

Bolometric technique for high-resolution broadband microwave spectroscopy of ultra-low-loss samples

A novel low temperature bolometric method has been devised and implemented for high-precision measurements of the microwave surface resistance of small single-crystal platelet samples having very low absorption, as a continuous function of frequency. The key to the success of this non-resonant method is the in-situ use of a normal metal reference sample that calibrates the absolute rf field strength. The sample temperature can be controlled independently of the 1.2 K liquid helium bath, allowing for measurements of the temperature evolution of the absorption. However, the instrument's sensitivity decreases at higher temperatures, placing a limit on the useful temperature range. Using this method, the minimum detectable power at 1.3 K is 1.5 pW, corresponding to a surface resistance sensitivity of $\approx$1 $\mu\Omega$ for a typical 1 mm$\times$1 mm platelet sample.Comment: 13 pages, 12 figures, submitted to Review of Scientific Instrument

The Mass of the Milky Way: Limits from a Newly Assembled Set of Halo Objects

We set new limits on the mass of the Milky Way, making use of the latest kinematic information for Galactic satellites and halo objects. In order to bind these sample objects to the Galaxy, their rest-frame velocities must be lower than their escape velocities at their estimated distances. This constraint enables us to show that the mass estimate of the Galaxy is largely affected by several high-velocity objects (Leo I, Pal 3, Draco, and a few FHB stars), not by a single object alone (such as Leo I), as has often been the case in past analyses. We also find that a gravitational potential that gives rise to a declining rotation curve is insufficient to bind many of our sample objects to the Galaxy; a possible lower limit on the mass of the Galaxy is about 2.2 x 10^12 Msolar. To be more quantitative, we adopt a Bayesian likelihood approach to reproduce the observed distribution of the current positions and motions of the sample, in a prescribed Galactic potential that yields a flat rotation curve. This method enables a search for the most likely total mass of the Galaxy, without undue influence in the final result arising from the presence or absence of Leo I, provided that both radial velocities and proper motions are used. The most likely total mass derived from this method is 2.5^+0.5_-1.0 x 10^12 Msolar (including Leo I), and 1.8^+0.4_-0.7 x 10^12 Msolar (excluding Leo I).Comment: 14 pages, including 9 figures and 3 tables, accepted for publication in Astronomy and Astrophysic

Ephemeral detection of Bonamia exitiosa (Haplosporida) in adult and larval European flat oysters Ostrea edulis in the Solent, United Kingdo

The haplosporidian parasite Bonamia exitiosa was detected using PCR in four adult and six larval brood samples of the European flat oyster Ostrea edulis from the Solent, UK. This represents the second reported detection of this parasite along the south coast of England. Adult oysters were collected and preserved from seabed populations or restoration broodstock cages between 2015 and 2018. The larvae within brooding adults sampled during 2017 and 2018 were also preserved. Molecular analysis of all samples was performed in 2019. The DNA of B. exitiosa was confirmed to be present within the gill tissue of one oyster within the Portsmouth wild fishery seabed population (n = 48), sampled in November 2015; the congeneric parasite Bonamia ostreae was not detected in this individual. This is the earliest record of B. exitiosa in the Solent. Concurrent presence of both B. ostreae and B. exitiosa, determined by DNA presence, was confirmed in the gill and heart tissue of three mature individuals from broodstock cages sampled in October 2017 (n = 99), two from a location on the River Hamble and one from the Camber Dock in Portsmouth Harbour. B. exitiosa was not detected in the November 2018 broodstock populations. A total of six larval broods were positive for B. exitiosa, with five also positive for B. ostreae. None of the brooding adults were positive for B. exitiosa suggesting that horizontal transmission from the surrounding environment to the brooding larvae is occurring. Further sampling of broodstock populations conducted by the Fish Health Inspectorate at the Centre for Environment, Fisheries and Aquaculture Science in June 2019 did not detect infection of O. edulis by B. exitiosa. These findings together suggest that the pathogen has not currently established in the area