114 research outputs found

    Liquid metal extraction of Nd from NdFeB magnet scrap

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    This research involves using molten magnesium (Mg) to remove neodymium (Nd) from NdFeB magnet scrap by diffusion. Mg was melted over pieces of NdFeB scrap and held at temperatures in the range 675–705 °C for 2–8 h. The Mg was allowed to solidify, and the castings were then sectioned and characterized using scanning electron microscopy, x-ray diffraction, and chemical analysis. Nd was found to have diffused out of the solid scrap into the molten Mg. The thickness of the diffusion layer was measured, the diffusion of Nd through the NdFeB scrap into liquid Mg was described, and the diffusion coefficient of Nd in liquid Mg was estimated

    Synthesis and Processing of MgB2MgB_2 powders and wires

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    Sintered powders and wires of superconducting MgB2MgB_2 have been fabricated under a variety of conditions in order to determine details of the diffusion of the MgMg into BB and to study the types of defects that arise during growth. For samples prepared by exposure of boron to MgMg vapor at 950∘C950^{\circ}C, the conversion of particles of less than 100μm100\mu m size particles to MgB2MgB_2 is complete in about 2h2 h. The lattice parameters of the MgB2MgB_2 phase determined from X-ray are independent of the starting stoichiometry and the time of reaction. Wire segments of MgB2MgB_2 with very little porosity have been produced by reacting 141μm141 \mu m diameter boron fibers in an atmosphere of excess MgMg vapor at 950∘C950^{\circ}C. Defects in the reacted fibers are predominantly the voids left as the boron is converted to MgB2MgB_2

    The Economic Resource Receipt of New Mothers

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    U.S. federal policies do not provide a universal social safety net of economic support for women during pregnancy or the immediate postpartum period but assume that employment and/or marriage will protect families from poverty. Yet even mothers with considerable human and marital capital may experience disruptions in employment, earnings, and family socioeconomic status postbirth. We use the National Survey of Families and Households to examine the economic resources that mothers with children ages 2 and younger receive postbirth, including employment, spouses, extended family and social network support, and public assistance. Results show that many new mothers receive resources postbirth. Marriage or postbirth employment does not protect new mothers and their families from poverty, but education, race, and the receipt of economic supports from social networks do

    A Tunable Narrowband Source in the Sub-THz and THz Range at DELTA

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    At DELTA, a 1.5-GeV electron storage ring operated as a synchrotron light source by the TU Dortmund University, an interaction of ultrashort laser pulses with electron bunches is used to generate broadband as well as tunable narrowband radiation in the frequency range between 75 GHz and 5.6 THz. The performance of the source was studied using two different Fourier-transform spectrometers. It was demonstrated that the source can be used for the characterization and comparison of Schottky-diode based detectors, e.g., an on-chip spectrometer enabling single-shot applications

    IT controls in the public cloud : success factors for allocation of roles and responsibilities

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    The rapid adoption of cloud computing by organizations has resulted in the transformation of the roles and responsibilities of staff in managing the information technology (IT) resources (via IT governance controls) that have migrated to the cloud. Hence, the objective of this research is to provide a set of success factors that can assist IT managers to allocate the roles and responsibilities of IT controls appropriately to staff to manage the migrated IT resources. Accordingly, we generated a set of success factors from behavioral and information systems (IS) literature. These success factors were verified using in-depth interviews of executives from the United Arab Emirates (UAE). The empirical intervention suggests that the role allocation is driven predominantly by people’s skills, competencies, organizational strategy, structures, and policies. In addition, the research made clear that the most significant competency and skill for a person allocated to IT controls is to be able to evaluate and manage a cloud service provider, especially in terms of risks, compliance, and security issues related to public cloud technology. The findings of this study not only offer new insights for scholars and practitioners involved in assigning responsibilities but also provide extensions for IT governance framework authorities to align their guidelines to the emerging cloud technology
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