Advancing Development of Environmental Barrier Coatings Resistant to Attack by Molten Calcium-Magnesium-Aluminosilicate (CMAS)

Ceramic matrix composites (CMCs) are a leading material system to replace metal-based parts in the hot-section of air-breathing turbine engines to improve fuel efficiency in aircraft engines. CMCs have higher temperature capabilities and lower density compared with traditional metallic structural materials. However, silicon-based CMCs are susceptible to oxidation in the harsh combustion environment encountered in turbine engines. Consequently, environmental barrier coatings (EBCs) are being developed to protect CMC components to improve durability and extend service life of CMCs. Sand, volcanic ash and other particulate debris, which are generally comprised of calcium-magnesium-aluminosilicate (CMAS) and other trace oxides, are routinely ingested by aircraft engines. At temperatures above 1200C, CMAS particulates melt. Near target operating temperatures (~1500C) of future CMC-based aircraft engines, molten CMAS behaves like a viscous melt that can infiltrate and chemically interact with protective coatings. These interactions can cause premature failure of the EBC system and ultimately the overall CMC engine component. Degradation of candidate EBC materials by molten CMAS will be presented with a focus on recent work, as well as methods of evaluating the complex high-temperature materials interactions, underway at NASA Glenn Research Center

Human and mouse essentiality screens as a resource for disease gene discovery.

The identification of causal variants in sequencing studies remains a considerable challenge that can be partially addressed by new gene-specific knowledge. Here, we integrate measures of how essential a gene is to supporting life, as inferred from viability and phenotyping screens performed on knockout mice by the International Mouse Phenotyping Consortium and essentiality screens carried out on human cell lines. We propose a cross-species gene classification across the Full Spectrum of Intolerance to Loss-of-function (FUSIL) and demonstrate that genes in five mutually exclusive FUSIL categories have differing biological properties. Most notably, Mendelian disease genes, particularly those associated with developmental disorders, are highly overrepresented among genes non-essential for cell survival but required for organism development. After screening developmental disorder cases from three independent disease sequencing consortia, we identify potentially pathogenic variants in genes not previously associated with rare diseases. We therefore propose FUSIL as an efficient approach for disease gene discovery

Thermophotovoltaic energy conversion in space nuclear reactor power systems

Thermophotovoltaic energy conversion offers a means of efficiently converting heat into electrical power. This has potential benefits for space nuclear reactor power systems currently in development. The primary obstacle to space operation of thermophotovoltaic devices appears to be the low heat rejection temperatures which necessitate large radiator areas. A study of the tradespace between efficiency and radiator size indicates that feasible multi-junction TPV efficiencies result in substantial overall system mass reduction with manageable radiator area. The appendices introduce the endothermodynamic model of a TPV cell and briefly assess the utility of advanced carbon-carbon heat pipe radiator concepts.http://archive.org/details/thermophotovolta109451196Lieutenant, United States NavyApproved for public release; distribution is unlimited

PRE-SLEEP FEEDING IN NCAA DIVISION I FEMALE ATHLETES

Casey Greenwalt1, Lilliana Rentería1, Katherine Schiltz1, Elisa Angeles1, Abbie Smith-Ryan, FACSM2, Chris Bach3, Matthew Vukovich, FACSM4, Stacy Sims5, Tucker Zeleny3, Kristen Holmes6, David Presby7, Michael Ormsbee, FACSM1. 1Florida State University, Tallahassee, FL. 2University of North Carolina, Chapel Hill, NC. 3University of Nebraska, Lincoln, NE. 4South Dakota State University, Brookings, SD. 5Auckland University of Technology, Auckland. 6WHOOP, Inc., Boston, MA. 7WHOOP, Inc, Boston, MA. BACKGROUND: Due to the high metabolic demand of sport, it is essential that athletes meet their caloric need to support training, recovery, and muscle growth. Consuming protein (30-40g) before sleep may have positive effects on muscle protein synthesis, overnight recovery, and performance. Currently no data exists to assess pre-sleep nutrition habits in elite female athletes. PURPOSE: To examine the frequency and content of pre-sleep nutrition in elite female athletes. METHODS: 483 Division I female athletes (mean ± SD: age: 21.4 ± 2.5 yrs, weight 67.1 ± 10.2 kg, height 171.2 ± 8.9 cm) from four universities wore a WHOOP, Inc. band 24h a day for the entire 2020-2021 competitive season to measure activity, sleep, and recovery. Surveys were administered through the WHOOP app every 3 days over the season to collect data on pre-sleep feeding habits. Descriptive results were completed using R studio. RESULTS: 3741 pre-sleep feeding survey responses were recorded. Of that, 23.9% (n = 895) of the data was unusable as caloric content could not be determined due to insufficient data reported. The remaining 76.1% (n = 2846) of the survey responses were made up of 276 athletes, of which, 21% (n = 58) ate before bed more than once. The average pre-sleep food intake for n=58 consisted of total kcals (mean ± SD: 283.4 ± 68.8 kcals), protein (8.3 ± 3.2g; 11.5% of total kcals), carbohydrate (35.8 ± 13.0 g; 50.4% of total kcals), and fat (12.1 ± 3.8 g; 38.1% of total kcals). Percentage of each sport that ate before sleep was 24.1% soccer, 13.8% swimming, 12.2% cross country, 8.6% volleyball, 6.9% softball, 5.3% beach volleyball, 3.4% golf, lacrosse, and tennis, 1.7% basketball, and 17.2% the sport was not specified. CONCLUSIONS: This is the first study to investigate the self-reported frequency of pre-sleep feeding in a wide range of female sports at the NCAA Division I level. Of 483 female athletes in the study, only 58 users recorded that they ate before bed on more than one occurrence. Meals prior to bed primarily consisted of carbohydrate (50.4%) and fat (38.1%), with only 11.5% of pre-sleep kcals coming from protein. The impact of pre-sleep feeding on next-day performance and recovery is warranted. This study was supported by WHOOP, Inc

Measures of effect size

Two different approaches have been used to derive measures of effect size. One approach is based on the comparison of treatment means. The standardized mean difference is an appropriate measure of effect size when one is merely comparing two treatments, but there is no satisfactory analogue for comparing more than two treatments. The second approach is based on the proportion of variance in the dependent variable that is explained by the independent variable. Estimates have been proposed for both fixed-factor and random-factor designs, but their sampling properties are not well understood. Nevertheless, measures of effect size can allow quantitative comparisons to be made across different studies, and they can be a useful adjunct to more traditional outcome measures such as test statistics and significance levels