Rotational Characterization of TESS Stars with Deep Learning

Ph.D

Kudzu, Pueraria Montana (Lour.) Merr. Abundance and Distribution in Oklahoma

Invasive species are a growing problem in the United States, and kudzu (Pueraria montana) (Lour.) Merr. is one of the most well documented invaders of southeastern states. Documenting the invasion of kudzu in Oklahoma, however, has not been a targeted focus in previous studies; thus, maps of its occurrence differ among sources. Our primary objective was to locate and confirm the presence of kudzu throughout Oklahoma. Specifically, we attempted to confirm previously recorded populations of kudzu and estimate the extent of the invasion at those sites. In addition, we wanted to locate stands of kudzu within Oklahoma that had not been recorded and to assess the extent of invasion. A survey was sent to state and county officials to acquire information on locations and general knowledge of kudzu. Points of occurrence and estimated extent of invasion in hectares were then placed in ArcMap programming to create a consolidated map of kudzu. Samples were collected, pressed, and placed in the University of Oklahoma’s Bebb Herbarium (OKL). We determined the majority of kudzu locations are in the southeastern portion of the state and total a minimum of 32.4 hectares. Results of the survey indicated half of the respondents polled were unaware of kudzu’s presence in the state

Get the Most From Your Cotton Stamps.

12 p

Genomic Sequence of a Ranavirus Isolated from Pike-Perch Sander lucioperca

The pike-perch iridovirus (PPIV) was isolated in Finland from apparently healthy pike-perch fingerlings during routine disease surveillance. Our phylogenomic analysis revealed that PPIV is the first fish member of a clade of ranaviruses previously described from European and Chinese amphibians

Acoustic wave studies during fast ion beam interactions with solds

Ion beam material modification is currently being used for several important technological applications such as semiconductor doping [1], surface modification of metals [2], cold etching [1], micro machining [1] and material analysis [3]. Ion beam processing has many advantages [4]. The speed, homogeneity and reproducibility of the doping process are easily controlled. Tight control of the number of doping atoms is possible. Low purity dopants can be used. The target can be kept at low temperatures allowing for low melting temperature materials to be modified. Simple masking methods can be employed and doping can be performed through passive films. Low penetration depths can be achieved and multiple implantations can produce varied doping profiles. Devices with small dimensions can be manufactured due to the small size of the ion beam. Since ion implantation is not an equilibrium process, equilibrium solubility limits of the ion species in the target material can be exceeded. There are some disadvantages of this type of doping process. Damage is caused to the crystal structure creating defects. Implantation is limited to near-surface regions and theoretical profiles can be difficult to obtain due to effects of channeling and diffusion [5]

Some Performance Characteristics of Subsurface Gravel Wetlands for Stormwater Management

Subsurface gravel wetlands were originally purposed for wastewater treatment and more recently have been used for stormwater treatment as a green infrastructure technology. Systems are sized to hold the water quality volume above, and drain within 24–48 hours. Design guidance follows static sizing principles with very little hydraulic calculations, which has left a gap in hydraulic performance data. Data from 12 years of field monitoring of various systems constructed in the northeast United States is presented. These systems include fully-sized as well as undersized (hold less that the water quality volume). Hydraulics are controlled by a restrictive outlet. At the same time, this outlet also creates the wetland characteristics of the system. Pollutant removal efficiencies for common stormwater pollutants are some of the highest for green infrastructure systems, with a significant component being microbially-mediated in the low dissolved oxygen gravel layers. This is a book chapter published by the American Society of Civil Engineers in World Environmental and Water Resources Congress 2020: Emerging and Innovative Technologies and International Perspectives in 2020, available online: https://doi.org/10.1061/978078448294

Rotation Distributions around the Kraft Break with TESS and Kepler: The Influences of Age, Metallicity, and Binarity

Stellar rotation is a complex function of mass, metallicity, and age and can be altered by binarity. To understand the importance of these parameters in main sequence stars, we have assembled a sample of observations that spans a range of these parameters using a combination of observations from The Transiting Exoplanet Survey Satellite (TESS) and the Kepler Space Telescope. We find that while we can measure rotation periods and identify other classes of stellar variability (e.g., pulsations) from TESS lightcurves, instrument systematics prevent the detection of rotation signals longer than the TESS orbital period of 13.7 days. Due to this detection limit, we also utilize rotation periods constrained using rotational velocities measured by the APOGEE spectroscopic survey and radii estimated using the Gaia mission for both TESS and Kepler stars. From these rotation periods, we 1) find we can track rotational evolution along discrete mass tracks as a function of stellar age, 2) find we are unable to recover trends between rotation and metallicity that were observed by previous studies, and 3) note that our sample reveals that wide binary companions do not affect rotation, while close binary companions cause stars to exhibit more rapid rotation than single stars.Comment: 19 pages, 13 figures, Accepted for publication in the Astrophysical Journa

The Asymptotic distribution of circles in the orbits of Kleinian groups

Let P be a locally finite circle packing in the plane invariant under a non-elementary Kleinian group Gamma and with finitely many Gamma-orbits. When Gamma is geometrically finite, we construct an explicit Borel measure on the plane which describes the asymptotic distribution of small circles in P, assuming that either the critical exponent of Gamma is strictly bigger than 1 or P does not contain an infinite bouquet of tangent circles glued at a parabolic fixed point of Gamma. Our construction also works for P invariant under a geometrically infinite group Gamma, provided Gamma admits a finite Bowen-Margulis-Sullivan measure and the Gamma-skinning size of P is finite. Some concrete circle packings to which our result applies include Apollonian circle packings, Sierpinski curves, Schottky dances, etc.Comment: 31 pages, 8 figures. Final version. To appear in Inventiones Mat