9,761 research outputs found

    Ground and flight test experience with a triple redundant digital fly by wire control system

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    A triplex digital fly by wire flight control system was developed and installed in an F-8C aircraft to provide fail operative, full authority control. Hardware and software redundancy management techniques were designed to detect and identify failures in the system. Control functions typical of those projected for future actively controlled vehicles were implemented

    A note on monopole moduli spaces

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    We discuss the structure of the framed moduli space of Bogomolny monopoles for arbitrary symmetry breaking and extend the definition of its stratification to the case of arbitrary compact Lie groups. We show that each stratum is a union of submanifolds for which we conjecture that the natural L2L^2 metric is hyperKahler. The dimensions of the strata and of these submanifolds are calculated, and it is found that for the latter, the dimension is always a multiple of four.Comment: 17 pages, LaTe

    The 6C** Sample and the Highest Redshift Radio Galaxies

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    We present a new radio sample, 6C** designed to find radio galaxies at z > 4 and discuss some of its near-infrared imaging follow-up results.Comment: 2 pages, 2 figures, to appear in proceedings of 'Multi-wavelength AGN surveys', Cozumel, 200

    Women In Pk-12 Educational Leadership: Identity And Insight

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    Because the number of female educational leaders is disproportionate to the number of males, I conducted a qualitative study about the experiences of female educational leaders. After inquiring about these experiences and analyzing the data, I made recommendations about how to recruit and interest more women to go in to those roles. The study involved participating in face-to-face interviews with fifteen women. With participant consent, I recorded the interviews and transcribed them so that further analysis could take place. I asked approximately five questions and the interviews lasted approximately sixty minutes apiece. The women conveyed many different responses and helped in the attempt to explore female educational leaders’ experiences. The data remained confidential and was coded and analyzed by me as part of the qualitative study. The study helped in gaining useful knowledge about the nature of female educational leaders’ experiences. Chapters IV, V, and VI cover the results of this study. The findings yielded a greater understanding of why and how women become educational leaders, including examining how they identify themselves as leaders and led to recommendations for encouraging more women to seek out and obtain those positions. All stakeholders involved in education will benefit from the findings, including school board members, women, teachers, administrators, families, students, and legislators. KEYWORDS: women in educational leadership; gender identity theory; female educational leader

    A Selected Ion Flow Tube Study of the Reactions of Several Cations with the Group 6B Hexafluorides SF6, SeF6, and TeF6

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    The first investigation of the ion chemistry of SeF6_6 and TeF6_6 is presented. Using a selected ion flow tube, the thermal rate coefficients and ion product distributions have been determined at 300 K for the reactions of fourteen atomic and molecular cations, namely H3_3O+^+, CF3+_3^+, CF+^+, CF2+_2^+, H2_2O+^+, N2_2O+^+, O+^+, CO2+_2^+, CO+^+, N+^+, N2+_2^+, Ar+^+, F+^+ and Ne+^+ (in order of increasing recombination energy), with SeF6_6 and TeF6_6. The results are compared with those from the reactions of these ions with SF6_6, for which the reactions with CF+^+, CF2+_2^+, N2_2O+^+ and F+^+ are reported for the first time. Several distinct processes are observed amongst the large number of reactions studied, including dissociative charge transfer, and F−^-, F, F2−_2^- and F2_2 abstraction from the neutral reactant molecule to the reagent ion. The dissociative charge transfer channels are discussed in relation to vacuum ultraviolet photoelectron and threshold photoelectron-photoion coincidence spectra of XF6_6 (X = S, Se, and Te). For reagent ions whose recombination energies lie between the first dissociative ionisation limit, XF6_6 →\rightarrow XF5+_5^+ + F + e−^-, and the onset of ionisation of the XF6_6 molecule, the results suggest that if dissociative charge transfer occurs, it proceeds via an intimate encounter. For those reagent ions whose recombination energies are greater than the onset of ionisation, long-range electron transfer may occur depending on whether certain physical factors apply, for example non-zero Franck-Condon overlap. From the reaction kinetics, limits for the heats of formation of SeF4_4, SeF5_5, TeF4_4 and TeF5_5 at 298 K have been obtained; Δf\Delta_fHo^o(SeF4_4) < -369 kJ mol−1^{-1}, Δf\Delta_fHo^o(SeF5_5) < -621 kJ mol−1^{-1}, Δf\Delta_fHo^o(TeF4_4) > -570 kJ mol−1^{-1}, and Δf\Delta_fHo^o(TeF5_5) < -822 kJ mol−1^{-1}
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