6,846 research outputs found

    Interplanetary Coronal Mass Ejections observed by MESSENGER and Venus Express

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    Interplanetary coronal mass ejections (ICMEs) observed by the MESSENGER (MES) and Venus Express (VEX) spacecraft have been catalogued and analysed. The ICMEs were identified by a relatively smooth rotation of the magnetic field direction consistent with a flux rope structure, coinciding with a relatively enhanced magnetic field strength. A total of 35 ICMEs were found in the surveyed MES data (primarily from March 2007 to April 2012), and 84 ICMEs in the surveyed VEX data (from May 2006 to December 2013). The ICME flux rope configurations have been determined. Ropes with northward leading edges were about four times more common than ropes with southward leading edges, in agreement with a previously established solar cycle dependence. Ropes with low inclinations to the solar equatorial plane were about four times more common than ropes with high inclinations, possibly an observational effect. Left and right-handed ropes were observed in almost equal numbers. In addition, data from MES, VEX, STEREO-A, STEREO-B and ACE were examined for multipoint signatures of the catalogued ICMEs. For spacecraft separations below 15{\deg} in heliocentric longitude, the second spacecraft observed the ICME flux rope in 82% of cases; this percentage dropped to 49% for separations between 15 and 30{\deg}, to 18% for separations between 30 and 45{\deg}, and to 12% for separations between 45 and 60{\deg}. As spacecraft separation increased, it became increasingly likely that only the sheath and not the flux rope of the ICME was observed, in agreement with the notion that ICME flux ropes are smaller in longitudinal extent than the shocks or discontinuities that they often drive. Furthermore, this study has identified 23 ICMEs observed by pairs of spacecraft close to radial alignment. A detailed analysis of these events could lead to a better understanding of how ICMEs evolve during propagation.Comment: 28 pages, 7 figure

    On the metrizability of spaces with a sharp base

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    A base B\mathcal{B} for a space XX is said to be sharp if, whenever x∈Xx\in X and (Bn)n∈ω(B_n)_{n\in\omega} is a sequence of pairwise distinct elements of B\mathcal{B} each containing xx, the collection {⋂j≤nBj:n∈ω}\{\bigcap_{j\le n}B_j:n\in\omega\} is a local base at xx. We answer questions raised by Alleche et al. and Arhangel′'ski\u{\i} et al. by showing that a pseudocompact Tychonoff space with a sharp base need not be metrizable and that the product of a space with a sharp base and [0,1][0,1] need not have a sharp base. We prove various metrization theorems and provide a characterization along the lines of Ponomarev's for point countable bases.Comment: 10 pages. Reprinted from Topology and its Applications, in press, Chris Good, Robin W. Knight and Abdul M. Mohamad, On the metrizability of spaces with a sharp bas

    Simulating Ability: Representing Skills in Games

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    Throughout the history of games, representing the abilities of the various agents acting on behalf of the players has been a central concern. With increasingly sophisticated games emerging, these simulations have become more realistic, but the underlying mechanisms are still, to a large extent, of an ad hoc nature. This paper proposes using a logistic model from psychometrics as a unified mechanism for task resolution in simulation-oriented games

    Low dimensional magnetic solids and single crystal elpasolites: Need for improved crystal growing techniques

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    The need for extensive crystal growing experiments to develop techniques for preparing crystals suitable for magnetic anisotropy measurements and detailed X-ray and neutron diffraction studies is rationalized on the basis of the unique magnetic properties of the materials and their hydrogen bonded structures which have many features in common with metalloenzyme and metalloprotein active sites. Single crystals of the single and mixed lanthanide species are prepared by the Bridgeman technique of gradient solidification of molten samples. The effects of crystal imperfections on the optical properties of these materials are an important part of the projected research. A series of a-amido acid complexes of first row transition metals were prepared which crystallize as infinite linear chains and exhibit low dimensional magnetic ordering (one or two) at temperature below 40 K

    Leadership Implications for College and University Administrators as the Present Morphs into the Future

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    Colleges and universities are unique organizations and, as such, require a different type of approach to leadership than might be effective in other types of organizations. It is argued participative leadership is more desirable and effective than other approaches and such this leadership style will be even more important in the future. The effectiveness of participative leadership on structural units within institutions of higher education is discussed with the focus upon making decisions with the greatest benefit to students, now and in the future, as a top priority. The issue is examined within the context of available data concerning trends of issues including changing student demographics, cultural shifts, and budgetary matters

    Reflections on the Present and Future of Leadership in Higher Education

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    Colleges and universities are unique organizations and, as such, require a different type of approach to leadership than might we effective in other types of organizations. A participative style of leadership is advocated. It is argued participative leadership is more desirable and effective than other approaches. The effectiveness of participative leadership on structural units within institutions of higher education is discussed with the focus upon making decisions with the greatest benefit to students, now and in the future, as a top priority

    Expendable as a Battleship: UAW Local 50, Demobilization, and the Post war Future of the Willow Run Bomber Plant, 1940-1945

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    The Willow Run Bomber Plant was leased to the Ford Motor Company during World War II and specialized in the mass production of Consolidated B-24 bombers. While Willow Run’s war service and production record is often highlighted, the plant’s demobilization experience is often ignored along with the United Auto Workers Local 50 that represented the plant’s 21,000 workers. Allied victory in Europe was accompanied with layoffs that threatened Willow Run’s continued operation. This study investigates the advocacy and goals of Local 50 leaders as they underwent a unique campaign through the spring and summer of 1945 that advocated for the plant’s continued use in the post-war economy. While Local 50’s leadership was only marginally influential in shaping Willow Run’s post-war future, the study concludes that the local union was active through their advocacy efforts to preserve worker jobs in the economic readjustment from war to peace

    College Experiences of the Eastern Band of Cherokee Indians

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    A survey was distributed to all enrolled members of the Eastern Band of Cherokee Indian (EBCI) college students to compare the experiences of those attending Tribal and non-tribal colleges. The results of the survey provided data for a nonexperimental quantitative study that addressed 18 research questions in an effort to determine whether there is a significant difference between the educational experiences of EBCI college students who attend non-tribal institutions and those who attend Tribal colleges. In particular, there was a focus on three domains: student viewpoints on separation and alienation from their tribal community; tribal community connections; and individual perceptions of success. A comparison of the experiences by gender between students attending Tribal versus non-tribal colleges was made. The researcher used the Native American Collective Orientation and Pursuits in Education Scale (NACOPE) survey results as determinants of the college students’ experiences. The findings of this study indicated there were no significant differences between the experiences of EBCI students who attended either Tribal or nontribal colleges. In addition, there were no significant differences when gender and type of college were considered. However, there were significant differences in those attending Tribal and nontribal colleges regarding some dimensions. Students in both groups had significantly higher survey scores than the median test value on the NACOPE in three areas. These higher scores were observed in their overall experiences being reported as positive; feelings of community connectedness to their home tribe; and less feelings of separation and alienation on their college campuses
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