Low power arcjet thruster pulse ignition

An investigation of the pulse ignition characteristics of a 1 kW class arcjet using an inductive energy storage pulse generator with a pulse width modulated power converter identified several thruster and pulse generator parameters that influence breakdown voltage including pulse generator rate of voltage rise. This work was conducted with an arcjet tested on hydrogen-nitrogen gas mixtures to simulate fully decomposed hydrazine. Over all ranges of thruster and pulser parameters investigated, the mean breakdown voltages varied from 1.4 to 2.7 kV. Ignition tests at elevated thruster temperatures under certain conditions revealed occasional breakdowns to thruster voltages higher than the power converter output voltage. These post breakdown discharges sometimes failed to transition to the lower voltage arc discharge mode and the thruster would not ignite. Under the same conditions, a transition to the arc mode would occur for a subsequent pulse and the thruster would ignite. An automated 11 600 cycle starting and transition to steady state test demonstrated ignition on the first pulse and required application of a second pulse only two times to initiate breakdown

Senior Recital, Alexis Gruber, soprano

The presentation of this senior recital will fulfill in part the requirements for the Bachelor of Music degree in Performance. Alexis Gruber studies voice with Michelle Harmon-Gulick and receives vocal coaching from James Smith-Parham

Suggested Improvements in the Law of Evidence

The Washington Committee on Judicial Administration assigned a section of its membership to study the law of evidence in the state of Washington in the light of the Reports of the Section of Judicial Administration of the American Bar Association, published in July, 1938. The observations and recommendations of the Washington Section on the Law of Evidence appear in the following report

The Fermi GBM Gamma-Ray Burst Spectral Catalog: Four Years Of Data

In this catalog we present the updated set of spectral analyses of GRBs detected by the Fermi Gamma-Ray Burst Monitor (GBM) during its first four years of operation. It contains two types of spectra, time-integrated spectral fits and spectral fits at the brightest time bin, from 943 triggered GRBs. Four different spectral models were fitted to the data, resulting in a compendium of more than 7500 spectra. The analysis was performed similarly, but not identically to Goldstein et al. 2012. All 487 GRBs from the first two years have been re-fitted using the same methodology as that of the 456 GRBs in years three and four. We describe, in detail, our procedure and criteria for the analysis, and present the results in the form of parameter distributions both for the observer-frame and rest-frame quantities. The data files containing the complete results are available from the High-Energy Astrophysics Science Archive Research Center (HEASARC).Comment: Accepted for publication in ApJ

Statement on the Effects of Law Enforcement in School Settings

School-based law enforcement (SBLE) have become increasingly common in U.S. schools over recent decades despite the controversy surrounding their presence and lack of consensus around their associated benefits and harms. Drawing on the history and evidence base regarding SBLE, we advocate for an end to SBLE programs. Grounding our argument in principles of Community Psychology and positive youth development, we outline how the presence and actions of SBLE negatively affect individual students as well as school systems, with particularly harmful outcomes for students with minoritized and marginalized identities. Research on SBLE and school crime does not provide consistent evidence of positive impacts, and many studies find null effects for the relationship between SBLE and school crime or increases in crime and violence in schools. Though funding for SBLE is often prompted by high-profile acts of gun violence in schools, evidence suggests that SBLE neither prevents these incidents, nor lessens the severity when they do occur. Thus, we advocate for removing law enforcement from school settings and redirecting resources into inclusive, evidence-informed responses that are generally safer and more effective than SBLE. We close by outlining the policy landscape governing SBLE programs and ways communities can lobby for change

The Strayed Reveller, No. 1

The Strayed Reveller is a literary magazine of stories, songs, poems, essays, reviews and artwork by students at Stephen F. Austin State University. It is published monthly andsponsered by the School of Liberal Arts and Department of English.https://scholarworks.sfasu.edu/reveller/1000/thumbnail.jp

Do Public Hospitals Respond to Changes in DRG Price Regulation? The Case of Birth Deliveries in the Italian NHS

We study how changes in Diagnosis-Related Group price regulation affect hospital behaviour in quasi-markets with exclusive provision by public hospitals. Exploiting a quasi-natural experiment, we use a difference-in-differences approach to test whether public hospitals respond to an exogenous change in Diagnosis-Related Group tariffs by increasing C-section rates and/or by upcoding. Controlling for a detailed set of mother characteristics, we find that price changes did not affect the probability of a C-section. We do however find evidence of upcoding: Conditional on the birth delivery method (either a C-section or a vaginal delivery), public hospitals experiencing the largest price change exhibit a higher probability of treating patients coded as complicated. This finding suggests that even public hospitals may be sensitive to market incentives

Prediction of Face-Lift Outcomes Using the Preoperative Supine Test

Patients considering a facelift (facial rhytidectomy) need some means of predicting their surgical outcomes. This will help them decide whether to proceed with the operation. A total of 50 consecutive patients were asked to examine themselves with a hand-held mirror while lying supine on an examining table to give them a reasonable approximation of their postoperative result. The tissues of the face redrape in a very aesthetic manner when lying completely supine. The appearance that the patient sees of himself or herself during the “supine test” correlated very well with the actual postop result after rhytidectomy consisting of subcutaneous undermining, SMAS plication, and platysmaplasty. This supine test may be useful in helping patients preoperatively predict their facelift outcomes and may serve as a good adjunct to imaging