The spectroscopic indistinguishability of red giant branch and red clump stars

Stellar spectroscopy provides useful information on the physical properties of stars such as effective temperature, metallicity and surface gravity (log g). However, those photospheric characteristics are often hampered by systematic uncertainties. The joint spectro-seismo project (APOKASC) of field red giants has revealed a puzzling offset between the log g determined spectroscopically and those determined using asteroseismology, which is largely dependent on the stellar evolutionary status. Therefore, in this letter, we aim to shed light on the spectroscopic source of the offset using the APOKASC sample. We analyse the log g discrepancy as a function of stellar mass and evolutionary status and discuss the impact of He and carbon isotopic ratio. We first show that for stars at the bottom of the red giant branch, the discrepancy between spectroscopic and asteroseismic log g depends on stellar mass. This indicates that the discrepancy is related to CN cycling. We demonstrate that the C isotopic ratio ($\rm ^{12}C/^{13}C$) has the largest impact on the stellar spectrum. We find that this log g discrepancy shows a similar trend in mass as the $\rm ^{12}C/^{13}C$ ratios expected by stellar evolution theory. Although we do not detect a direct signature of $\rm ^{13}C$, the data suggests that the discrepancy is tightly correlated to the production of $\rm ^{13}C$. Moreover, by running a data-driven algorithm (the Cannon) on a synthetic grid trained on the APOGEE data, we quantitatively evaluate the impact of various $\rm ^{12}C/^{13}C$ ratios. While we have demonstrated that $\rm ^{13}C$ impacts all parameters, the size of the impact is smaller than the observed offset in log g. If further tests confirm that $\rm ^{13}C$ is not the main element responsible of the log g problem, the number of spectroscopic effects remaining to be investigated is now relatively limited. [Abridged]Comment: 4 Pages, 6 Figures. Accepted for publication in A&

The Creation of the Theory of Group Characters

Paper by Thomas Hawkin

Data broadcast scheduling: Models, algorithms, and analysis

Inherent in the field of data broadcasting is a communication problem in which a server is to transmit a subset of data items in response to requests received from clients. The intent of the server is to optimize metrics quantifying the quality of service the system provides. This method of data dissemination has proved to be an efficient means of delivering information in asymmetric environments demanding massive scalability. of critical importance in such a system is the algorithm used by the server to construct a schedule of item broadcasts.;Due to the real-time nature of this problem, performances of heuristics designed to construct such schedules are heavily dependent on request instances. Thus it is challenging to establish the quality of one algorithm over another. Though several scheduling methods have been developed, these algorithms have been studied with a reliance on probabilistic assumptions and little emphasis on analytical results.;In contrast, we provide a formal treatment of the data broadcast scheduling problem in which analytical methods are applied, complemented by simulation experiments. Utilizing a worst-case technique known as competitive analysis, we establish bounds on the performance of various algorithms in the context of several different broadcast models. We describe results in three different settings.;Minimizing the total wait time of all requests with a single channel and multiple database items we establish the competitive ratios for two well-known algorithms, First Come First Served (FCFS) and Most Requests First (MRF) to be equal, and provide a general lower bound for all algorithms in this context. We describe simulation results that indicate the superior performance of MRF over FCFS on average. Minimizing two conflicting metrics, the total wait time and total broadcast cost, with a single channel and single database item we develop two on-line algorithms, establish their competitive ratios, and provide an optimal off-line algorithm used to simulate the impact of various parameters on the performance of both on-line heuristics. Finally, we extend the previous model by including multiple database items and establish a lower bound to a greedy algorithm for this context

An Exploration of Public Misconceptions of Municipal Water Fluoridation Relating to Oral and Public Health

Municipal water fluoridation began in 1945, and in the past 70 years, it appears to have decreased the rate of dental caries nationwide. Despite being deemed one of the top ten innovations of the 20th century, there continues to be misconceptions with this controversial practice. The intent of this thesis is to address some of the misconceptions with water fluoridation, and what possible solutions could be provided to alleviate the concerns. This was accomplished through a literature review of current research articles. Two main topics were explored: the public health and oral health concerns and how they contribute to the controversy. Results from the literature show that there was an increasing campaign from anti-fluoridators that use misleading information to advocate for ceasing water fluoridation. There was also a common concern about fluoridated water causing dental fluorosis. Furthermore, there was a trend with the lack of education and knowledge about water fluoridation, predominately in rural and low-income communities. Overall, it was reasoned that the best way to reduce the misconceptions of water fluoridation is to increase educational opportunities through medical professionals creating inter-department relationships and redirecting various government programs to target different populations

A History of the Pickles Gap Baptist Church

The purpose of this thesis was to gather and to get in readable form information on the origin, life, personalities, and developments of the Pickles Gap Baptist Church in Faulkner County, Arkansas. The procedure took four lines: (1) a summary history from around 1878 to the present by families, (2) a review of the organizational and functional development, (3) a listing of family contributions to the work of the church, and (4) a resume of contributions by pastors. The church began in 1878 as the Sulphur Springs Baptist Church. In 1921 the name was changed to Pickles Gap Baptist Church because there were at that time two churches by the old name in the Greenbrier Baptist Association. In the early years, the church was a quarter-time pastorate. It became a full-time pastorate in 1952. Three houses of worship have been built by the church, the present one being built in 1945. The unified budget plan of finance was developed under the Reverend T.W. Hayes\u27 leadership. The organizational development was slow and gradual. The church in 1964 has the four conventional church organizations: Sunday School, Training Union, Women\u27s Missionary Union, and Brotherhood. Such a study of the Pickles Gap Baptist Church is particularly significant this year because it comes during the Baptist Jubilee Advance devoted to Baptist Heritage

The Materials Science and Engineering of Advanced YB-Doped Glasses and Fibers for High-Power Lasers

This research studies and yields new understandings into the materials science and engineering of advanced multicomponent glass systems, which is critical for next generation fiber lasers operating at high output powers. This begins with the study and development of Yb-doped glasses in the Al2O3-P2O5-SiO2 (APS) ternary system, fabricated using modified chemical vapor deposition (MCVD), that, despite being highly doped, possess an average refractive index matched to that of silica (SiO2). The highly doped active core material was subsequently processed through a multiple stack-and-draw process to realize a single fiber with high doping, compositionally-tailored index, and scalability for fiber lasers. Based on the knowledge gained in this first focal area, further strategic compositional tailoring to influence the glass’ photoelastic and thermo-optic coefficient, was performed in order to understand and realize significant decreases in Brillouin and thermal-Rayleigh scattering, which instigate parasitic stimulated Brillouin scattering (SBS) and transverse mode instabilities (TMI) in high power fiber lasers. In addition to understanding the composition / structure / properties of these glasses, a double-clad fiber laser will be fabricated, scaled to over 1 kW of output laser power, and studied in order to relate the materials science and engineering of multiple glass systems and fibers designs to laser performance and properties