22,967 research outputs found

    Analysis of nuclear waste disposal in space, phase 3. Volume 2: Technical report

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    The options, reference definitions and/or requirements currently envisioned for the total nuclear waste disposal in space mission are summarized. The waste form evaluation and selection process is documented along with the physical characteristics of the iron nickel-base cermet matrix chosen for disposal of commercial and defense wastes. Safety aspects of radioisotope thermal generators, the general purpose heat source, and the Lewis Research Center concept for space disposal are assessed as well as the on-pad catastrophic accident environments for the uprated space shuttle and the heavy lift launch vehicle. The radionuclides that contribute most to long-term risk of terrestrial disposal were determined and the effects of resuspension of fallout particles from an accidental release of waste material were studied. Health effects are considered. Payload breakup and rescue technology are discussed as well as expected requirements for licensing, supporting research and technology, and safety testing

    Analysis of nuclear waste disposal in space, phase 3. Volume 1: Executive summary of technical report

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    The objectives, approach, assumptions, and limitations of a study of nuclear waste disposal in space are discussed with emphasis on the following: (1) payload characterization; (2) safety assessment; (3) health effects assessment; (4) long-term risk assessment; and (5) program planning support to NASA and DOE. Conclusions are presented for each task

    Investigation of infrared phonon modes in multiferroic single-crystal FeTe2_{2}O5_{5}Br

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    Reflection and transmission as a function of temperature (5--300 K) have been measured on single crystals of the multiferroic compound FeTe2_{2}O5_{5}Br utilizing light spanning the far infrared to the visible portions of the electromagnetic spectrum. The complex dielectric function and optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have lead to the observation of all 52 IR-active modes predicted in the acac plane and 43 or the 53 modes predicted along the b axis of the monoclinic cell. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.Comment: 9 pages, 7 figure

    Geoacoustic Inversion of Ship Radiated Noise in Shallow Water Using Data From a Single Hydrophone

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    The Centre for Maritime Research and Experimentation conducted a geoacoustic inverse experiment in the Mediterranean Sea in the summer of 2012. Among the objectives was to employ an autono- mous underwater vehicle to collect acoustic data to invert for properties of the seafloor. Inversion results for the compression wave speed in the bottom and the source spectrum of the R/V Alliance during a close approach to the bottom moored vehicle are presented. The estimated wave speed was 1529 m/s (r ¼ 10). The source spectrum of the Alliance was estimated across more than six octaves of frequency

    Leading from the Center Out: The Joint Library Services Leadership Team at James Madison University

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    In a system with multiple service points, how can leadership work together to keep the library as a whole relevant and central to students? James Madison University Libraries created the Joint Library Services Leadership Team, which works outside traditional departmental silos to provide coherent, consistent, and collaborative services regardless of location. Three major service points of James Madison University Libraries, the two main library circulation/reference departments and the media resources center, have historically been both physically and philosophically separate from each other. Although the departments shared common goals of providing excellent student learning-focused services, they did not systematically work together to do so. Library hierarchical structures placed each department parallel to the others, with limited connections across leadership levels. As a result, each created unique services and outreach and competed in planning and budgeting processes. When collaboration across the departments happened, it was often project based, convenient, personality driven, and an extra duty on top of regular job expectations. Some excellent service programs came out of these ad hoc collaborations, including the development of core competencies for circulation services, joint training events, and the development of and training on procedures for emergency response. This competitive model did not help the libraries fulfill the goal of providing student learning-focused services that are consistent, cohesive, and collaborative across locations and departments. After much debate, and some changes in personnel, the leadership of the three departments reworked the parallel department model to place collaboration in service planning and deployment at the center, with departmental hierarchies radiating out in rings. This allows for collaboration to be thoughtful, deliberate, intentional, position driven, and included in job expectations at all levels. While the departments are still physically separated, the philosophical differences melt away, allowing for joint services and outreach, and shared planning and budgeting. It is the experience – and the continuing hope – of the JLSL Team that this model allows the three departments to lead from the center out ensures that we put our services and outreach for our students, and their academic, civic, and cultural lives, at the center of our concerns

    Nutritional Quality of Leaves and Unripe Fruit Consumed as Famine Foods by the Flying Foxes of Samoa

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    Many tropical herbivores alter their diets throughout the year in response to different levels of food availability. Fruit bats, including Pteropus samoensis Peale and Pteropus tonganus Quoy & Gaimard, are phytophagous species that may increase their consumption of foods such as unripe fruit and leaves in periods of low fruit diversity and volume. These periods include the tropical dry season or following the frequent hurricanes that batter the Samoan Archipelago. We examined the nutritional composition of leaves and immature fruits and compared the levels of organic and mineral nutrients with those of ripe fruit. We used principal components analysis (PCA) to examine patterns of variation in nutrient components of leaves, unripe fruit, and ripe fruit, as well as to compare the mean levels of nutrients. Overall, unripe fruit provided levels of nutrients comparable with those of ripe fruit of the same species for many organic and mineral components. Unripe fruit were only half as rich in iron as ripe fruit, but unripe fruit had high levels of calcium compared with ripe fruit of the same species. Leaves are often cited as a rich source of protein for fruit bats, and our results were consistent with this suggestion. Leaves were also found to be rich in zinc, manganese, and calcium. Therefore, flying foxes and other herbivores probably do not avoid unripe fruits and leaves because of their low nutrient levels. It may be that these famine foods are not normally consumed because of the presence of secondary compounds, low concentrations of palatable sugars, or a distasteful and hard pericarp on unripe fruits
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