Recent developments in rotary-balance testing of fighter aircraft configurations at NASA Ames Research Center

Two rotary balance apparatuses were developed for testing airplane models in a coning motion. A large scale apparatus, developed for use in the 12-Foot Pressure Wind tunnel primarily to permit testing at high Reynolds numbers, was recently used to investigate the aerodynamics of 0.05-scale model of the F-15 fighter aircraft. Effects of Reynolds number, spin rate parameter, model attitude, presence of a nose boom, and model/sting mounting angle were investigated. A smaller apparatus, which investigates the aerodynamics of bodies of revolution in a coning motion, was used in the 6-by-6 foot Supersonic Wind Tunnel to investigate the aerodynamic behavior of a simple representation of a modern fighter, the Standard Dynamic Model (SDM). Effects of spin rate parameter and model attitude were investigated. A description of the two rigs and a discussion of some of the results obtained in the respective test are presented

First Freedom: The Baptist Perspective on Religious Liberty

First Freedom is an important gathering of messages from a recent conference on religious liberty held at Southwestern Baptist Theological Seminary. Editor Jason B. Duesing explains: The purpose of this collection is, first, to provide an introductory look into the biblical and historical foundations of religious liberty combined with several instances of contemporary expression and defense for the purpose of instruction, edification, and encouragement to all who take the time to read this volume. Second, however, we wish to remind Baptists in the twenty-first century of the price that was paid by their forefathers for the establishment and defense of religious liberty. To be sure, there were people of various religious and denominational preferences that providence used to implement the religious freedoms now enjoyed by all, but for Baptists to overlook the contribution of their own would be a travesty.https://digitalcommons.cedarville.edu/faculty_books/1147/thumbnail.jp

Restoring Integrity in Baptist Churches

A compilation of articles seeking to answer the question, How does the local church - which is often influenced by a consumer-driven, numbers-oriented society - restore integrity and establish purpose? The articles written by Dr. White are the introduction, What Makes Baptism Valid? , and A Baptist\u27s Theology of the Lord\u27s Supper .https://digitalcommons.cedarville.edu/faculty_books/1149/thumbnail.jp

Upon This Rock: A Baptist Understanding of the Church

This book arose from the fourth consecutive Baptist Distinctives Conference held at Southwestern Baptist Theological Seminary in Fort Worth, Texas, during September 2008. Dr. White contributed two chapters: The Universal and Local Church and The Offices and Women: Can Women Be Pastors? Or Deacons? (co-written with his wife, Joy).https://digitalcommons.cedarville.edu/faculty_books/1151/thumbnail.jp

Narrow Linewidth 780 nm Distributed Feedback Lasers for Cold Atom Quantum Technology

Cold atom quantum technology systems have a wide range of potential applications which includes atomic clocks, rotational sensors, inertial sensors, quantum navigators, magnetometers and gravimeters. The UK Quantum Technology Hub in Sensors and Metrology has the aim of developing miniature cold atom systems using an approach similar to that pioneered by the chip scale atomic clock where microfabricated vacuum chambers have atomic transitions excited and probed by lasers. Whilst narrow linewidth Ti:Sa and external cavity diode lasers have been required for cooling and control, such lasers are too large, power hungry and expensive for future miniature cold atom systems. Here we demonstrate 1 mm long 780.24 nm GaAs/AlGaAs distributed feedback (DFB) lasers aimed at 87Rb cold atom systems operating at 20 ˚C with over 50 mW of power and side-mode suppression ratios of 46 dB using sidewall gratings and no regrowth. Rb spectroscopy is used to demonstrate linewidths below the required 6.07 MHz natural linewidth of the 87Rb D2 optical transition used for cooling. Initial packaged fibre-coupled devices demonstrate lifetimes greater than 200 hours. We also investigate the use of integrated semiconductor amplifiers (SOAs) and longer devices to further reduce the linewidths well below 1 MHz. A range of options to control the populations of electrons in the hyperfine split energy levels spaced by 3.417 GHz are examined. Two integrated lasers, integrated electro-absorption modulators (EAMs) and the direct modulation of a single DFB laser approaches are investigated and we will discuss which is best suited to integrated cold atom systems

The BTC40 Survey for Quasars at 4.8 < z < 6

The BTC40 Survey for high-redshift quasars is a multicolor search using images obtained with the Big Throughput Camera (BTC) on the CTIO 4-m telescope in V, I, and z filters to search for quasars at redshifts of 4.8 < z < 6. The survey covers 40 sq. deg. in B, V, & I and 36 sq. deg. in z. Limiting magnitudes (3 sigma) reach to V = 24.6, I = 22.9 and z = 22.9. We used the (V-I) vs. (I-z) two-color diagram to select high-redshift quasar candidates from the objects classified as point sources in the imaging data. Follow-up spectroscopy with the AAT and CTIO 4-m telescopes of candidates having I < 21.5 has yielded two quasars with redshifts of z = 4.6 and z = 4.8 as well as four emission line galaxies with z = 0.6. Fainter candidates have been identified down to I = 22 for future spectroscopy on 8-m class telescopes.Comment: 27 pages, 8 figures; Accepted for publication in the Astronomical Journa