Some influences of the 1950 Evaluative Criteria in six Northern New England secondary schools

Thesis (Ed. M.)--Boston University, 195

Absolute dimensions of detached eclipsing binaries. I. The metallic-lined system WW Aurigae

WW Aurigae is a detached eclipsing binary composed of two metallic-lined A-type stars orbiting each other every 2.5 days. We have determined the masses and radii of both components to accuracies of 0.4 and 0.6 percent, respectively. From a cross-correlation analysis of high-resolution spectra we find masses of 1.964 +/- 0.007 Msun for the primary star and 1.814 +/- 0.007 Msun for the secondary star. From an analysis of photoelectric uvby and UBV light curves we find the radii of the stars to be 1.927 +/- 0.011 Rsun and 1.841 +/- 0.011 Rsun, where the uncertainties have been calculated using a Monte Carlo algorithm. Fundamental effective temperatures of the two stars have been derived, using the Hipparcos parallax of WW Aur and published ultraviolet, optical and infrared fluxes, and are 7960 +/- 420 and 7670 +/- 410 K. The masses, radii and effective temperatures of WW Aur are only matched by theoretical evolutionary models for a fractional initial metal abundance, Z, of approximately 0.06 and an age of roughly 90 Myr. This seems to be the highest metal abundance inferred for a well-studied detached eclipsing binary, but we find no evidence that it is related to the metallic-lined nature of the stars. The circular orbit of WW Aur is in conflict with the circularization timescales of both the Tassoul and the Zahn tidal theories and we suggest that this is due to pre-main-sequence evolution or the presence of a circular orbit when the stars were formed.Comment: Accepted for publication in MNRAS (14 pages, 8 figures). Photometric data will be made available at the CDS once the final version appear

Stress Resources and Responses of Student-Athlete Counseling Services Clients, Non-Student-Athlete Clients and Non-Athlete Clients

It is widely believed that because of the unique demands of their lifestyles, college student-athletes often experience greater levels of life-stress than do non-athlete students. For the purpose of this study stress was considered a complex process characterized by the presence of various stress sources, perceptions of threat or danger to self, and cognitive, affective and/or behavioral, and physical reactions to these phenomena (Spielberger, 1989). Accordingly, stress response may be manifested cognitively (e.g., worry), behaviorally (e.g., avoidance behaviors), emotionally (e.g., depression), or somatically (e.g., muscle aches). Limited research on this topic has provided inconsistent support for this notion. Quick Stress Questionnaire (QSQ) responses of student-athlete counseling service clients, non-athlete student counseling service clients, and a non-client sample were compared to examine differences in the frequency and severity of life-stress and life-stress responses. Quick Stress Questionnaire (QSQ) (Otani, 1985) of student clients were obtained from the counseling service closed files at a medium sized, land grant institution. The QSQ is a problem checklist completed by clients, as a routine part of all intake assessments and becomes a part a each student's permanent, confidential file. Clients did not provide consent to access their QSQs. The QSQs of 91 athlete clients (i.e., those student-athletes who had sought counseling) were examined, although a random sample of 207 QSQs was obtained from the non-athlete client population over a three-year period. These two sets of QSQ data were compared with non-athlete, non-client QSQ student norms (N=218) developed from the general student population over the same period of time. All groups reported moderate to moderately high stress levels, but student-athletes reported fewer sources of distress and fewer serve stress-related symptoms than non-athlete clients or non-clients. Interestingly, student athlete clients reported lower financial related distress than non athlete clients and non clients. Findings were discussed in the context of the student-athlete lifestyle and recommendations for further study were provided

Career Counseling and Student-Athletes: A Needs Assessment

The self-reported personal/social needs of a random sample of 170 college student-athletes and a general student sample (n=300) at a Division I institution were compared. The authors used a needs assessment survey with 54 Likert items modified from an instrument by Talley (1985) and 14 additional items about athletic competition and counseling services. Usable surveys returned were 201 total from both groups. Survey data revelated that both groups shared many needs. Respondents indicated that career-related concerns and various sources of stress associated with participation in athletics were of primary concern. Findings provide suggestions for the planning and delivery of helping services to student-athletes and non-athletes

MEASURING THE MASS OF 4UO900-40 DYNAMICALLY

Accurate measurements of neutron star masses are needed to constrain the equation of state of neutron star matter - of importance to both particle physics and the astrophysics of neutron stars - and to identify the evolutionary track of the progenitor stars that form neutron stars. The best measured values of the mass of 4UO900-40 (= Vela XR-l), 1.86 +/- 0.16 Msun (Barziv et al. 2001) and 1.93 +/- 0.20 Msun (Abubekerov et al. 2004), make it a leading candidate for the most massive neutron star known. The direct relationship between the maximum mass of neutron stars and the equation of state of ultra-dense matter makes 4UO900-40 an important neutron star mass to determine accurately. The confidence interval on previous mass estimates, obtained from observations that include parameters determined by non-dynamical methods, are not small enough to significantly restrict possible equations of state. We describe here a purely dynamical method for determining the mass of 4UO900-40, an X-ray pulsar, using the reprocessed UV pulses emitted by its BO.5Ib companion. One can derive the instantaneous radial velocity of each component by simultaneous X-ray and UV observations at the two quadratures of the system. The Doppler shift caused by the primary's rotational velocity and the illumination pattern of the X-rays on the primary, two of the three principal contributors to the uncertainty on the derived mass of the neutron star, almost exactly cancel by symmetry in this method. A heuristic measurement of the mass of 4UO900-40 using observations obtained previously with the High Speed Photometer on HST is given in Appendix A

Accurate fundamental parameters of eclipsing binary stars

The study of detached eclipsing binaries is one of the most powerful ways to investigate the properties of individual stars and stellar systems. We present preliminary masses, radii and effective temperatures for the eclipsing binary WW Aurigae, which is composed of two metallic-lined A-type stars. We also reanalyse the data on HD 23642, an A-type eclipsing binary member of the Pleiades open cluster with a metallic-lined component, and determine its distance to be 139 +/- 4 pc. This is in agreement with the traditional Pleiades distance, but in disagreement with distance to the Pleiades, and to HD 23642 itself, derived from Hipparcos trigonometrical parallaxes.Comment: 15 pages, 11 figures, Poster presented at IAU Symposium 224 "The A Star Puzzle", 7-13 July 2004, Poprad, Slovaki

Student-Athletes’ Experiences with Racial Microaggressions in Sport: A Foucauldian Discourse Analysis

Despite growing research on racial microaggressions as a subtle but prevalent form of racial discrimination, research on microaggressions in sport and their effects on the psychosocial wellbeing of athletes is scarce. Moreover, some researchers question the legitimacy of microaggressions due to their subtle nature and inconsistency in how they are experienced (Lilienfeld, 2017). The purpose of this study was to examine U.S. collegiate student-athletes-of-color experiences with racial microaggressions in sport through a new theoretical lens, Foucauldian poststructuralist theory. We theorized microaggressions as an example of the daily panoptic gaze that leads to self-surveillance and the production of normalized individuals (Foucault, 1995). Eight student-athletes-of-color participated in two interviews: a two-person focus group interview followed by an individual interview. The interviews were analyzed deductively using Sue’s (2010) microaggression typology followed by a Foucauldian discourse analysis (Willig, 2013). The results illustrated how student-athletes-of-color experiences and subjectivities were racialized. Within sport, the sport as transcending race discourse was widely circulated and legitimized through various sporting practices, which limited athletes’ ability to perceive and acknowledge race and microaggressions. This study sheds light on how racial microaggressions manifest in the lives of student-athletes and how the discourses and practices we take for granted constitute racial subjectivities

Absolute properties of BG Ind - a bright F3 system just leaving the Main Sequence

We present photometric and spectroscopic analysis of the bright detached eclipsing binary BG Ind. The masses of the components are found to be 1.428 +- 0.008 and 1.293 +- 0.008 Msun and the radii to be 2.290+-0.017 and 1.680+-0.038 Rsun for primary and secondary stars, respectively. Spectra- and isochrone-fitting coupled with color indices calibration yield [Fe/H]=-0.2+-0.1. At an age of 2.65+-0.20 Gyr BG Ind is well advanced in the main-sequence evolutionary phase - in fact, its primary is at TAMS or just beyond it. Together with three similar systems (BK Peg, BW Aqr and GX Gem) it offers an interesting opportunity to test the theoretical description of overshooting in the critical mass range 1.2-1.5 Msun.Comment: 8 pages, 5 figures, corrected bugs in author lis

Tanque hidráulico experimental para cálculo de perda de carga em tubulações

O artigo descreve a construção de um tanque hidráulico para o cálculo da perda de carga em dutos cilíndricos retos e a execução dos ensaios. O tanque possui estrutura simples, baixo custo, robustez e versatilidade necessárias para a realização de ensaios de fácil execução, baseados no registro dos tempos associados à variação da altura da coluna de água num tubo vertical. A utilização deste equipamento em aulas experimentais mostrou-se muito eficaz, possibilitando a comprovação de resultados teóricos a partir da utilização de modelos reais. Os resultados obtidos são apresentados em planilhas eletrônicas, cuja elaboração baseou-se na aplicação dos princípios de conservação de massa e energia no escoamento de fluidos viscosos, e nas equações de perda de carga distribuída e localizada. O experimento proposto constitui uma ferramenta pedagógica interessante, tendo em vista que sua execução requer a participação ativa dos alunos na realização dos ensaios e na execução de cálculos. A rotina de cálculos, visando comparar valores experimentais perda de carga obtidos experimentalmente com valores teóricos, abrange uma série de conceitos e equações da Mecânica dos Fluidos, propiciando que a aprendizagem desse conteúdo seja feita a partir de um problema real.

Absolute properties of the low-mass eclipsing binary CM Draconis

Spectroscopic and eclipsing binary systems offer the best means for determining accurate physical properties of stars, including their masses and radii. The data available for low-mass stars have yielded firm evidence that stellar structure models predict smaller radii and higher effective temperatures than observed, but the number of systems with detailed analyses is still small. In this paper we present a complete reanalysis of one of such eclipsing systems, CM Dra, composed of two dM4.5 stars. New and existing light curves as well as a radial velocity curve are modeled to measure the physical properties of both components. The masses and radii determined for the components of CM Dra are M1=0.2310+/-0.0009 Msun, M2=0.2141+/-0.0010 Msun, R1=0.2534+/-0.0019 Rsun, and R2=0.2396+/-0.0015 Rsun. With relative uncertainties well below the 1% level, these values constitute the most accurate properties to date for fully convective stars. This makes CM Dra a valuable benchmark for testing theoretical models. In comparing our measurements with theory, we confirm the discrepancies reported previously for other low-mass eclipsing binaries. These discrepancies seem likely to be due to the effects of magnetic activity. We find that the orbit of this system is slightly eccentric, and we have made use of eclipse timings spanning three decades to infer the apsidal motion and other related properties.Comment: 19 pages, 9 figures. Accepted for publication in Ap