6,256 research outputs found
Additional support for the TDK/MABL computer program
An advanced version of the Two-Dimensional Kinetics (TDK) computer program was developed under contract and released to the propulsion community in early 1989. Exposure of the code to this community indicated a need for improvements in certain areas. In particular, the TDK code needed to be adapted to the special requirements imposed by the Space Transportation Main Engine (STME) development program. This engine utilizes injection of the gas generator exhaust into the primary nozzle by means of a set of slots. The subsequent mixing of this secondary stream with the primary stream with finite rate chemical reaction can have a major impact on the engine performance and the thermal protection of the nozzle wall. In attempting to calculate this reacting boundary layer problem, the Mass Addition Boundary Layer (MABL) module of TDK was found to be deficient in several respects. For example, when finite rate chemistry was used to determine gas properties, (MABL-K option) the program run times became excessive because extremely small step sizes were required to maintain numerical stability. A robust solution algorithm was required so that the MABL-K option could be viable as a rocket propulsion industry design tool. Solving this problem was a primary goal of the phase 1 work effort
A Process Plan for Consensus Building in the Evaluation of NSGC & EPSCoR Native American Outreach Program
The NASA Nebraska Space Grant (NSGC) & EPSCoR Programs at the University of Nebraska at Omaha have embarked on a unique educational journey known as the Nebraska Native American Outreach program (NNAOP). The NNAOPâs main objective is to encourage and motivate Native American students to be more competitive in mathematics and science. This program has allowed for a variety of educational and public outreach activities to take place. However, in order to continually provide effective support to Nebraskaâs Native American community, NSGC & EPSCoR sought an evaluation technique for the NNAOP. To execute such an evaluation, NSGC organized the first Nebraska Aeronautics Education Summit (NAES) Meeting. This diverse group of educators, researchers, and practitioners provided a unique opportunity to gather the evaluative information. The utilization of the summit participantsâ recommendations and innovative future plans will ensure continued shared success between NSGC & EPSCoR and the Nebraska Native American community
Kiloparsec-scale Simulations of Star Formation in Disk Galaxies. IV. Regulation of Galactic Star Formation Rates by Stellar Feedback
Star formation from the interstellar medium of galactic disks is a basic process controlling the evolution of galaxies. Understanding the star formation rate in a local patch of a disk with a given gas mass is thus an important challenge for theoretical models. Here we simulate a kiloparsec region of a disk, following the evolution of self-gravitating molecular clouds down to subparsec scales, as they form stars that then inject feedback energy by dissociating and ionizing UV photons and supernova explosions. We assess the relative importance of each feedback mechanism. We find that H2-dissociating feedback results in the largest absolute reduction in star formation compared to the run with no feedback. Subsequently adding photoionization feedback produces a more modest reduction. Our fiducial models that combine all three feedback mechanisms yield, without fine-tuning, star formation rates that are in excellent agreement with observations, with H2-dissociating photons playing a crucial role. Models that only include supernova feedbackâa common method in galaxy evolution simulationsâsettle to similar star formation rates, but with very different temperature and chemical states of the gas, and with very different spatial distributions of young stars
Correspondence from E.B. Lovejoy, August 11, 1862
Correspondence from E.B. Lovejoy regarding absent soldiers from Androscoggin Countyhttps://digitalmaine.com/absent_soldiers/1008/thumbnail.jp
Histone acetylation increases in response to ferulic, gallic, and sinapic acids acting synergistically in vitro to inhibit \u3ci\u3eCandida albicans\u3c/i\u3e yeastâtoâhyphae transition
Novel treatments are needed to prevent candidiasis/candidemia infection due to the emergence of Candida species resistant to current antifungals. Considering the yeast-toâhyphae switch is a critical factor to Candida albicans virulence, phenols common in plant sources have been reported to demonstrating their ability to prevent dimorphism. Therefore, phenols present in many agricultural waste stress (ferulic (FA) and gallic (GA) acid) were initially screened in isolation for their yeastâtoâhyphae inhibitory properties at times 3, 6, and 24 hr. Both FA and GA inhibited 50% of hyphae formation inhibitory concentration (IC50) but at a concentration of 8.0 ± 0.09 and 90.6 ± 1.05 mM, respectively, at 24 hr. However, the inhibitory effect of FA increased by 1.9â2.6 fold when combined with different GA concentrations. GA and FA values decreased even lower when sinapic acid (SA) was added as a third component. As evidenced by concave isobolograms and combination indexes less than 1, both GA:F A and GA:FA:SA combinations acted synergistically to inhibit 50% hyphae formation at 24 hr. Lastly, acetylation of histone H3 lysine 56 acetylation (H3K56) was higher in response to the triple phenolic cocktail (using the IC50 24 hr inhibitory concentration level) comparable with the nontreated samples, indicating that the phenols inhibited hyphal growth in part by targeting H3K56 acetylation
A CAT with caveats: is the Consensual Assessment Technique a reliable measure of graphic design creativity?
The Consensual Assessment Technique (CAT) is considered one of the gold standards for creativity assessment, and graphic design, arguably, is the most ubiquitous domain within the creative industries. For the first time, this study tests two tasks to measure graphic design creativity, and by extension, the reliability of the CAT as a measure of graphic design creativity. Initial research suggested the level of consensus amongst judges (often referred to as inter-rater reliability) was too low to be reliable, and may be unduly influenced by a judgeâs preference for technical execution. In this study, 16 professional graphic designers were randomly assigned instructions to discount technical execution from creativity ratings, or given instruction that gave no stipulation, for 60 artworks. Inter-rater reliability scores were acceptable for each task and experimental condition, but were higher for judges that received instructions to discount technical execution. These and other results are discussed, and the argument presented that, for future CAT studies in this domain, specific instructions to discount technical execution offers a more reliable measure of graphic design creativity
Parent and teacher ratings of peer interactive play and social-emotional development of preschool children at risk
ABSTRACT Estimates of agreement and consistency between parent and teacher ratings of peer-interactive play and social emotional development were examined in a sample of preschool children at risk for academic difficulties. Eighty-three pairs of parents and teachers of 4-year-old children completed the Penn Interactive Peer Play Scale (PIPPS) and 69 of these pairs also were interviewed with the Vineland Social-Emotional Early Childhood Scales (SEEC). Significant mean differences were found between parent and teacher scores on the PIPPS, but not on the SEEC. No noteworthy correlations were found between raters on the PIPPS, though low to moderate correlations were revealed between parent and teacher responses on the SEEC. Multivariate techniques revealed statistically significant and noteworthy correlations between parent and teacher responses on the SEEC but not on the PIPPS. Results are discussed within the context of conducting multifaceted, ecological assessments with preschool children. Implications for early childhood educators and interventionists are noted regarding the importance of gathering and interpreting multiple sources of information that contribute to an understanding of young children's behavior
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