Space Launch System Aeroacoustic Wind Tunnel Test Results

Characterization of accurate launch vehicle unsteady aerodynamics is critical for component and secondary structure vibroacoustic design. For the National Aeronautics and Space Administration (NASA) Space Launch System (SLS), aeroacoustic environments have been derived primarily through sub-scale wind tunnel testing. Both optical techniques and high frequency pressure measurements have been utilized across multiple testing facilities and numerous vehicle configurations to develop a range of preliminary and detailed environments. As the vehicle has matured and evolved, the data collected from each subsequent configuration has allowed for comparison studies which isolate the effects of certain outer mold line (OML) features on measured fluctuating pressure levels. This paper presents observations on some of those effects for features which include abort system protuberances, various fairings geometries, interstage flanges, and multibody interactions between a central core and fall away boosters. These features, and the flow conditions produced by them, are broadly applicable to many launch vehicle configurations

Overview of the Space Launch System Ascent Aeroacoustic Environment Test Program

Characterization of accurate flight vehicle unsteady aerodynamics is critical for component and secondary structure vibroacoustic design. The Aerosciences Branch at the National Aeronautics and Space Administration (NASA) Marshall Space Flight Center has conducted a test at the NASA Ames Research Center (ARC) Unitary Plan Wind Tunnels (UPWT) to determine such ascent aeroacoustic environments for the Space Launch System (SLS). Surface static pressure measurements were also collected to aid in determination of local environments for venting, CFD substantiation, and calibration of the flush air data system located on the launch abort system. Additionally, this test supported a NASA Engineering and Safety Center study of alternate booster nose caps. Testing occurred during two test campaigns: August - September 2013 and December 2013 - January 2014. Four primary model configurations were tested for ascent aeroacoustic environment definition. The SLS Block 1 vehicle was represented by a 2.5% full stack model and a 4% truncated model. Preliminary Block 1B payload and manned configurations were also tested, using 2.5% full stack and 4% truncated models respectively. This test utilized the 11 x 11 foot transonic and 9 x 7 foot supersonic tunnel sections at the ARC UPWT to collect data from Mach 0.7 through 2.5 at various total angles of attack. SLS Block 1 design environments were developed primarily using these data. SLS Block 1B preliminary environments have also been prepared using these data. This paper discusses the test and analysis methodology utilized, with a focus on the unsteady data collection and processing

The Demonstrable Value of Honors Education: New Research Evidence

“We all know—instinctively, experientially—that what we as honors teachers and administrators do for our students adds value to their college education and general college experience. Providing hard, demonstrable evidence for that which we know in our bodies as it were . . . turns out not to be so easy, a fact anyone who has had to make the case for additional, or even simply continued, honors funding to a new dean or college president has likely encountered. The results presented in this volume provide, in a diversity of ways via a diversity of research approaches, the sorts of evidence honors teachers and administrators have long needed. Will that evidence be enough to convince every dean or college president of the need for continued honors sustenance? The answer may have to depend on the particular dean or president in question. I believe the essays in this monograph provide the strongest case for the added value of honors that has been made to date.” —Dr. Rusty Rushton, University of Alabama at Birmingham Contents Acknowledgments Introduction: The Demonstrable Value of Honors Education • Andrew J. Cognard-Black Honors Value Added: Where We Came From, and What We Need to Know Next • Hallie E. Savage History and Current Practices of Assessment to Demonstrate Value Added • Patricia J. Smith Proving the Value of Honors Education: The Right Data and the Right Messaging • Bette L. Bottoms and Stacie L. McCloud Honors Education Has a Positive Effect on College Student Success • Dulce Diaz, Susan P. Farruggia, Meredith E. Wellman, and Bette L. Bottoms High-Impact Honors Practices: Success Outcomes among Honors and Comparable High-Achieving Non-Honors Students at Eastern Kentucky University • Katie Patton, David Coleman, and Lisa W. Kay GPA as a Product, Not a Measure, of Success in Honors • Lorelle A. Meadows, Maura Hollister, Mary Raber, and Laura Kasson Fiss Adding Value through Honors at the University of Iowa: Effects of a Pre-Semester Honors Class and Honors Residence on First-Year Students • Art L. Spisak, Robert F. Kirby, and Emily M. Johnson The Value Added of Honors Programs in Recruitment, Retention, and Student Success: Impacts of the Honors College at the University of Mississippi • Robert D. Brown, Jonathan Winburn, and Douglass Sullivan-Gonzalez Community College Honors Benefits: A Propensity Score Analysis • Jane B. Honeycutt Contributions of Small Honors Programs: The Case of a Public Liberal Arts College • George Smeaton and Margaret Walsh Demonstrating the Value of Honors: What Next? • Jerry Herron and D. Carl Freeman Appendix: Original Call for Proposals About the Authors About the NCHC Monograph Serie

Reducing the Effect of Transducer Mount Induced Noise on Aeroacoustic Wind Tunnel Testing Data with a New Transducer Mount Design

Flight vehicle aeroacoustic environments induced during transonic and supersonic flight are usually predicted by subscale wind tunnel testing utilizing high frequency miniature pressure transducers. In order to minimize noise induced by the measurement itself, transducer flush mounting with the model surface is very important. The National Aeronautics and Space Administration (NASA) has accomplished flushness in recent testing campaigns via use of a transducer holder that can be machined and sanded. A single hole in the holder allows the flow medium to interact with the transducer diaphragm. Noise is induced by the resulting cavity however, and is a challenge to remove in post-processing. A new holder design has been developed that minimizes the effects of this transducer mount induced noise (XMIN) by reducing the resonance amplitude or increasing its resonance frequency beyond the range of interest. This paper describes a test conducted at the NASA/George C. Marshall Space Flight Center Trisonic Wind Tunnel intended to verify the effectiveness of this design. The results from this test show that this new transducer holder design does significantly reduce the influence of XMIN on measured fluctuating pressure levels without degrading a transducer's ability to accurately measure the noise external to the model

Quantitative Image Analysis Techniques with High-Speed Schlieren Photography

Optical flow visualization techniques such as schlieren and shadowgraph photography are essential to understanding fluid flow when interpreting acquired wind tunnel test data. Output of the standard implementations of these visualization techniques in test facilities are often limited only to qualitative interpretation of the resulting images. Although various quantitative optical techniques have been developed, these techniques often require special equipment or are focused on obtaining very precise and accurate data about the visualized flow. These systems are not practical in small, production wind tunnel test facilities. However, high-speed photography capability has become a common upgrade to many test facilities in order to better capture images of unsteady flow phenomena such as oscillating shocks and flow separation. This paper describes novel techniques utilized by the authors to analyze captured high-speed schlieren and shadowgraph imagery from wind tunnel testing for quantification of observed unsteady flow frequency content. Such techniques have applications in parametric geometry studies and in small facilities where more specialized equipment may not be available

Overview of the Space Launch System Ascent Aeroacoustic Environment Test Program

No abstract availabl

Reducing the Effect of Transducer Mount Induced Noise (XMIN) on Aeroacoustic Wind Tunnel Testing Data with a New Transducer Mount Design

Characterization of flight vehicle unsteady aerodynamics is often studied via large scale wind tunnel testing. Boundary layer noise is measured by miniature pressure transducers installed in a model. Noise levels (2-5 dB ref. 20 Pa) can be induced when transducer is mounted out of flush with model outer surface. This effect must be minimized to accurately determine aerodynamically induced acoustic environments

Demonstrating commercial hollow fibre membrane contactor performance at industrial scale for biogas upgrading at a sewage treatment works

Hollow fibre membrane contactor (HFMC) technology has been developed for CO2 absorption primarily using synthetic gas, which neglects the critical impact that trace contaminants might have on separation efficiency and robustness in industrial gases. This study, therefore, commissioned a demonstration-scale HFMC for CO2 separation at a full-scale anaerobic digester facility to evaluate membrane integrity over six months of operation on real biogas. The CO2 capture efficiency identified using real biogas was benchmarked at comparable conditions on synthetic gas of an equivalent partial pressure, and an equivalent performance identified. Two HFMC were subsequently compared, one with and one without a pre-treatment stage that targeted particulates, volatile organic compounds (VOCs) and humidity. Similar CO2 separation efficiency was again demonstrated, indicating limited impact within the timescale evaluated. However, gas phase pre-treatment is advised in order to ensure robustness in the long term. Over longer-term operation, a decline in CO2 separation efficiency was observed. Membrane autopsy identified shell-side deposition, where the structural morphology and confirmation of amide I and II groups, indicated biofouling. Separation efficiency was reinstated via chemical cleaning, which demonstrated that proactive maintenance could minimise process risk

Amyloid-β nanotubes are associated with prion protein-dependent synaptotoxicity

Growing evidence suggests water-soluble, non-fibrillar forms of amyloid-β protein (Aβ) have important roles in Alzheimer’s disease with toxicities mimicked by synthetic Aβ1–42. However, no defined toxic structures acting via specific receptors have been identified and roles of proposed receptors, such as prion protein (PrP), remain controversial. Here we quantify binding to PrP of Aβ1–42 after different durations of aggregation. We show PrP-binding and PrP-dependent inhibition of long-term potentiation (LTP) correlate with the presence of protofibrils. Globular oligomers bind less avidly to PrP and do not inhibit LTP, whereas fibrils inhibit LTP in a PrP-independent manner. That only certain transient Aβ assemblies cause PrP-dependent toxicity explains conflicting reports regarding the involvement of PrP in Aβ-induced impairments. We show that these protofibrils contain a defined nanotubular structure with a previously unidentified triple helical conformation. Blocking the formation of Aβ nanotubes or their interaction with PrP might have a role in treatment of Alzheimer’s disease

Attitudes Toward the Ethics of Research Using Social Media: A Systematic Review.

BACKGROUND: Although primarily used for social networking and often used for social support and dissemination, data on social media platforms are increasingly being used to facilitate research. However, the ethical challenges in conducting social media research remain of great concern. Although much debated in the literature, it is the views of the public that are most pertinent to inform future practice. OBJECTIVE: The aim of our study was to ascertain attitudes on the ethical considerations of using social media as a data source for research as expressed by social media users and researchers. METHODS: A systematic review was conducted, wherein 16 databases and 2 Internet search engines were searched in addition to handsearching, reference checking, citation searching, and contacting authors and experts. Studies that conducted any qualitative methods to collect data on attitudes on the ethical implications of research using social media were included. Quality assessment was conducted using the quality of reporting tool (QuaRT) and findings analyzed using inductive thematic synthesis. RESULTS: In total, 17 studies met the inclusion criteria. Attitudes varied from overly positive with people expressing the views about the essential nature of such research for the public good, to very concerned with views that social media research should not happen. Underlying reasons for this variation related to issues such as the purpose and quality of the research, the researcher affiliation, and the potential harms. The methods used to conduct the research were also important. Many respondents were positive about social media research while adding caveats such as the need for informed consent or use restricted to public platforms only. CONCLUSIONS: Many conflicting issues contribute to the complexity of good ethical practice in social media research. However, this should not deter researchers from conducting social media research. Each Internet research project requires an individual assessment of its own ethical issues. Guidelines on ethical conduct should be based on current evidence and standardized to avoid discrepancies between, and duplication across, different institutions, taking into consideration different jurisdictions