Cryogenic wind tunnels for high Reynolds number testing

A compilation of lectures presented at various Universities over a span of several years is discussed. A central theme of these lectures has been to present the research facility in terms of the service it provides to, and its potential effect on, the entire community, rather than just the research community. This theme is preserved in this paper which deals with the cryogenic transonic wind tunnels at Langley Research Center. Transonic aerodynamics is a focus both because of its crucial role in determining the success of aeronautical systems and because cryogenic wind tunnels are especially applicable to the transonics problem. The paper also provides historical perspective and technical background for cryogenic tunnels, culminating in a brief review of cryogenic wind tunnel projects around the world. An appendix is included to provide up to date information on testing techniques that have been developed for the cryogenic tunnels at Langley Research Center. In order to be as inclusive and as current as possible, the appendix is less formal than the main body of the paper. It is anticipated that this paper will be of particular value to the technical layman who is inquisitive as to the value of, and need for, cryogneic tunnels

Higgs + 2 jets via gluon fusion

Real emission corrections to gg -> H, which lead to H+2 jet events, are calculated at order alpha_s^4. Contributions include top-quark triangles, boxes and pentagon diagrams and are evaluated analytically for arbitrary top mass m_t. This new source of H+2 jet events is compared to the weak-boson fusion cross section for a range of Higgs boson masses. The heavy top-mass approximation appears to work well for intermediate Higgs-boson masses, provided that the transverse momenta of the final-state partons are smaller than the top-quark mass.Comment: 8 pages, 3 figure

Exploring College Student Experiences in a Kinesiology Course Using a Gamified Grading System

Past findings indicate mixed results on the effectiveness of gamification in college courses. The use of a gamified version of specifications-based grading (e.g., gamified grading) is not yet well understood. The purpose of this two-part study was to understand students’ perceptions of intrinsic motivation and engagement in a kinesiology course using gamified grading, facilitated by a gamified grading platform called GradeCraft©. We used qualitative inquiry to capture a robust description of the student experience across a semester, identifying themes describing the course management (e.g., comparison with traditional course, individual approach), and the psychological experience (e.g., autonomy, stress). The following semester, we surveyed students, finding an increase in competence and choice and decrease in pressure from the beginning of the term to the end. Findings suggest that students perceived GradeCraft to promote intrinsic motivation, but only to a small degree and not without some initial stress due to the novelty associated with the gamified grading system

Ralph Lamar Webb - Scrapbook Resolutions from Fergus Lodge pg. 2

Scrapbook page created by Fay Webb Gardner documenting the death of her brother, Ralph Lamar Webb. Page includes a news clipping of the Resolution passed by the Fergus Lodge (Masonic) of Loganville, GA in honor of Ralph\u27s passing. Page includes a contemporary photograph of Ralph Lamar Webb. Page also includes a document in the upper right corner which has degraded over time and is illegible.https://digitalcommons.gardner-webb.edu/fay-webb-gardner-ralph-lamar-webb/1002/thumbnail.jp

Effects of Single versus Multiple Warnings on Driver Performance

Objective: To explore how a single master alarm system affects drivers’ responses when compared to multiple, distinct warnings. Background: Advanced driver warning systems are intended to improve safety, yet inappropriate integration may increase the complexity of driving, especially in high workload situations. This study investigated the effects of auditory alarm scheme, reliability, and collision event-type on driver performance. Method: A 2x2x4 mixed factorial design investigated the impact of two alarm schemes (master vs. individual) and two levels of alarm reliability (high and low) on distracted drivers’ performance across four collision event-types (frontal collision warnings, left and right lane departure warnings, and follow vehicle fast approach). Results: Participants’ reaction times and accuracy rates were significantly affected by the type of collision event and alarm reliability. The use of individual alarms, rather than a single master alarm, did not significantly affect driving performance in terms of reaction time or response accuracy. Conclusion: Even though a master alarm is a relatively uninformative warning, it produced statistically no different reaction times or accuracy results when compared to information-rich auditory icons, some of which were spatially located. In addition, unreliable alarms negatively impacted driver performance, regardless of event type or alarm scheme. Application: These results have important implications for the development and implementation of multiple driver warning systems.This project was sponsored by the Ford Motor Company

Testing Ecological Theory with Lianas

Lianas constitute a diverse polyphyletic plant group that is advancing our understanding of ecological theory. Specifically, lianas are providing new insights into the mechanisms that control plant distribution and diversity maintenance. For example, there is now evidence that a single, scalable mechanism may explain local, regional, and pan‐tropical distribution of lianas, as well as the maintenance of liana species diversity. The ability to outcompete trees under dry, stressful conditions in seasonal forests provides lianas a growth advantage that, over time, results in relatively high abundance in seasonal forests and low abundance in aseasonal forests. Lianas may also gain a similar growth advantage following disturbance, thus explaining why liana density and diversity peak following disturbance at the local, forest scale. The study of ecology, however, is more than the effect of the environment on organisms; it also includes the effects of organisms on the environment. Considerable empirical evidence now indicates that lianas substantially alter their environment by consuming resources, suppressing tree performance, and influencing emergent properties of forests, such as ecosystem functioning, plant and animal diversity, and community composition. These recent studies using lianas are transcending classical tropical ecology research and are now providing novel insights into fundamental ecological theory