907 research outputs found

    Nonflammable organic-base paint for oxygen-rich atmospheres

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    New paint formulations, which combine aqueous latex paints with inorganic pigments and additives, produce coatings that are self-extinguishing in pure oxygen at pressures up to twice the partial pressure of atmospheric oxygen. A paint formulation in percent by weight is given and the properties of resultant coatings are discussed

    Exploring the New South Agenda in the Records of Southern Colleges and Universities

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    On 21 December 1886, Southern editor Henry W. Grady gave a speech at New York\u27s Delmonico\u27s Restaurant in which he called for the South to lift itself out of its slump of poverty, backwardness, and defeatism, and make itself over into a New South. In this speech, soon to be known as the New South speech, Grady stated: The Old South rested everything on slavery and agriculture, unconscious that these could neither give nor maintain healthy growth. The new South presents a perfect democracy, the oligarchs leading in the popular movement-a social system compact and closely knitted, less splendid on the surface, but stronger at the core-a hundred farms for every plantation, fifty homes for every palace-and a diversified industry that meets the complex needs of this complex age. The two main goals of the New South agenda, industrialization and agricultural diversification, were thus set forth in this ringing manner

    Long-distance dispersal potential in a marine macrophyte

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    Plant populations have long been noted to migrate faster than predicted based on their life history and seed dispersal characteristics (i.e., Reid\u27s paradox of rapid plant migration). Although precise mechanisms to account for such phenomena are not fully known for all plant species, a combination of theoretical and empirically driven mechanisms often resolves this paradox. Here, we couple a series of direct and indirect field and laboratory exercises on one marine macrophyte, Zostera marina L. (eelgrass), to measured distances between new patches and established beds in order to elucidate the longdistance dispersal and colonization potential of this marine seagrass. Detached, floating reproductive shoots with mature seeds were found to remain positively buoyant for up to 2 wk and retain mature seeds for up to 3 wk before release under laboratory conditions. Analysis of the, detritus wrack along a remote shoreline found reproductive fragments with viable seeds up to 34 km from established, natural beds. Analysis of different regions of the Chesapeake Bay and coastal bays of the Delmarva Peninsula that once supported eelgrass populations, revealed natural patches at 13 sites ranging from 1 to 108 km from established populations. A combination of tidal currents and wind influences has the potential to move a passive particle at the surface (e.g., a floating reproductive fragment) up to 23 km in a 6-h tidal window suggesting that most unvegetated areas in this region that can support eelgrass are within the colonization potential envelope. We suggest that, when combined with earlier work on seed dispersal ecology of this species, eelgrass has strong qualities for high colonization potential of new habitat. The finding of natural patches at such great distances from established beds when studied in the context of the dispersal mechanism (currents and wind) make the dispersal distances of this species one of the highest for angiosperms, comparable in scale to mangroves and coconuts. This new understanding of the dispersal dynamics of eelgrass is critical in the context of seagrass restoration in areas distant from established beds, maintenance of existing populations threatened by anthropogenic inputs of sediments arid nutrients, and examining metapopulation concepts in seagrass ecology

    Development of an Instrument to Assess Attitudes Toward Science, Technology, Engineering, and Mathematics (STEM)

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    There is a need for more students to be interested in science, technology, engineering, and mathematics (STEM) careers to advance U.S. competitiveness and economic growth. A consensus exits that improving STEM education is necessary for motivating more students to pursue STEM careers. In this study, a survey to measure student (grades 4-6) attitudes toward STEM and STEM careers was developed and administered to 662 students from two STEM-focused and three comprehensive (non-STEM focused) schools. Cronbach’s alphas for the whole survey and subscales indicated a high internal consistency. Statistically significant difference in means between students attending the STEM-focused and comprehensive schools on the two subscales of the survey and the overall survey were found. However, the explained variance for these results was approximately 1%. The survey is a useful tool to assess efficacy of STEM education programs on student attitudes toward STEM and STEM careers

    Navigating by the Stars: Library Leadership Lessons

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    In this unique and interactive Lively Lunch, participants will engage with four librarians with backgrounds in technical services and collections who transitioned to leadership roles. While some were thrust unexpectedly into the role, others followed a directed career trajectory. Yet, they all share the commonality of facing unforeseen challenges while seeking to emerge from the depths of inexperience. They will briefly share their experiences in leadership, as well as strategies for preparation, challenges they continue to face, and lessons they are still learning. Participants will learn about developing a personal leadership practice, as well as networking, mentoring, and professional development to prepare for senior leadership positions. They will also gain practical advice on managing the interview process and surviving the early days of the job. The panel will provide participants with a leadership “toolkit” that includes suggested readings, professional organizations, and educational opportunities, adding recommendations from participants throughout the Lively Lunch session

    The Development of a Human Well-Being Index for the United States

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    The US Environmental Protection Agency (EPA) has developed a human well-being index (HWBI) that assesses the over-all well-being of its population at the county level. The HWBI contains eight domains representing social, economic and environmental well-being. These domains include 25 indicators comprised of 80 metrics and 22 social, economic and environmental services. The application of the HWBI has been made for the nation as a whole at the county level and two alternative applications have been made to represent key populations within the overall US population—Native Americans and children. A number of advances have been made to estimate the values of metrics for counties where no data is available and one such estimator—MERLIN—is discussed. Finally, efforts to make the index into an interactive web site are described

    The Effects of Foam Rolling and Static Stretching on Flexibility and Acute Muscle Soreness

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    Please view abstract in the attached PDF file

    A review of issues in seagrass seed dormancy and germination: implications for conservation and restoration

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    Seagrasses have received considerable attention over the past 2 decades because of the multiple ecological roles they play in estuarine and coastal ecosystems and concerns over worldwide losses of seagrass habitat due to direct and indirect human impacts. Restoration and conservation efforts are underway in some areas of the world, but progress may be limited by the paucity of information on the role of seeds in bed dynamics. Although flowering occurs in most of the 58 seagrass species, seed germination data exist for only 19 of the 42 species that have some period of dormancy, with only 93 published references to field and/or laboratory studies. This review addresses critical issues in conservation and restoration of seagrasses involving seed dormancy (e.g. environmental vs physiological), existence and type of seed bank (transient or persistent), and factors influencing seed germination (e.g, salinity, temperature, light). Results of many earlier published studies relating seed germination to various environmental factors may need re-examination given more recent published data which show a confounding influence of oxygen level on the germination process. We highlight the importance of conducting ecologically meaningful germination studies, including germination experiments conducted in sediments. We also identify questions for future research that may figure prominently in landscape level questions regarding protected marine or estuarine reserves, habitat fragmentation, and restoration

    Hybrid propulsion for launch vehicle boosters: A program status update

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    Results obtained in studying the origin and suppression of large-amplitude pressure oscillations in a 24 in. diameter hybrid motor using a liquid oxygen/hydroxylterminated polybutadiene/polycyclopentadiene propellant system are discussed. Tests conducted with liquid oxygen flow rates varying from 10 to 40 lbm/sec were designed to gauge the effectiveness of various vaporization chamber flow fields, injector designs, and levels of heat addition in suppressing high-frequency longitudinal mode oscillations. Longitudinal acoustic modes did not arise in any tests. However, initial testing revealed the presence of high-amplitude, sinusoidal, nonacoustic oscillations persisting throughout the burn durations. Analysis showed this to be analogous to chug mode instability in liquid rocket engines brought about by a coupling of motor combustion processes and the liquid oxygen feed system. Analytical models were developed and verified by test data to predict the amplitude and frequency of feed-system-coupled combustion pressure oscillations. Subsequent testing showed that increasing the feed system impedance eliminated the bulk mode instability. This paper documents the work completed to date in performance of the Hybrid Propulsion Technology for Launch Vehicle Boosters Program (NAS8-39942) sponsored by NASA's George C. Marshall Space Flight Center
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