High current lightning test of space shuttle external tank lightning protection system

During lift-off, the shuttle launch vehicle (external tank, solid rocket booster and orbiter) may be subjected to a lightning strike. Tests of a proposed lightning protection method for the external tank and development materials which were subjected to simulated lightning strikes are described. Results show that certain of the high resistant paint strips performed remarkably well in diverting the 50 kA lightning strikes

Regular Incidence Complexes, Polytopes, and C-Groups

Regular incidence complexes are combinatorial incidence structures generalizing regular convex polytopes, regular complex polytopes, various types of incidence geometries, and many other highly symmetric objects. The special case of abstract regular polytopes has been well-studied. The paper describes the combinatorial structure of a regular incidence complex in terms of a system of distinguished generating subgroups of its automorphism group or a flag-transitive subgroup. Then the groups admitting a flag-transitive action on an incidence complex are characterized as generalized string C-groups. Further, extensions of regular incidence complexes are studied, and certain incidence complexes particularly close to abstract polytopes, called abstract polytope complexes, are investigated.Comment: 24 pages; to appear in "Discrete Geometry and Symmetry", M. Conder, A. Deza, and A. Ivic Weiss (eds), Springe

Polarimetric Evidence of Non-Spherical Winds

Polarization observations yield otherwise unobtainable information about the geometrical structure of unresolved objects. In this talk we review the evidences for non-spherically symmetric structures around Luminous Hot Stars from polarimetry and what we can learn with this technique. Polarimetry has added a new dimension to the study of the envelopes of Luminous Blue Variables, Wolf-Rayet stars and B[e] stars, all of which are discussed in some detail.Comment: 8 pages, 2 encapsulated Postscript figures, uses lamuphys.sty. Invited review to appear in IAU Coll. 169, Variable and Non-Spherical Stellar Winds in Luminous Hot Stars, eds. B. Wolf, A.Fullerton and O. Stahl (Springer

Breeding of resistant strawberry cultivars for organic fruit production – Diallel crossing strategies and resistance tests for Botrytis cinerea and Xanthomonas fragariae

Organic strawberry production suffers from high yield losses caused by numerous fungal and bacterial diseases. Two of the most important diseases are the grey mould disease caused by Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana), and the bacterial angular leaf spot disease caused by Xanthomonas fragariae (Kennedy & King). Beside cultivation methods and organic plant protection measures, the development of resistant cultivars seems to be the most promising strategy in order to improve the productivity in organic strawberry cultivation. Therefore, we established resistance tests to determine resistant and susceptible strawberry cultivars and breeding selections. In a first run, 40 different cultivars and selections were tested for their susceptibility towards B. cinerea by artificial inoculation of fruits and leaves and evaluation of the disease symptoms. Plants of 40 cultivars were tested for susceptibility to X. fragariae by artificial inoculation in the greenhouse. In a diallel crossing approach, 12 commonly cultivated strawberry cultivars have been crossed reciprocally and propagated in a field trial. Important characteristics of the progeny such as ripening time, yield, morphological traits and occurrence of diseases have been evaluated for a period of two consecutive years and lead to the determination of general (GCA) and specific (SCA) combining abilities. Together with the results of the resistance tests we identified a set of genotypes that show resistant characteristics towards B. cinerea and might be suitable for use in organic cultivation systems. Furthermore, they can be used for targeted breeding experiments in the future

Optimal Control for Generating Quantum Gates in Open Dissipative Systems

Optimal control methods for implementing quantum modules with least amount of relaxative loss are devised to give best approximations to unitary gates under relaxation. The potential gain by optimal control using relaxation parameters against time-optimal control is explored and exemplified in numerical and in algebraic terms: it is the method of choice to govern quantum systems within subspaces of weak relaxation whenever the drift Hamiltonian would otherwise drive the system through fast decaying modes. In a standard model system generalising decoherence-free subspaces to more realistic scenarios, openGRAPE-derived controls realise a CNOT with fidelities beyond 95% instead of at most 15% for a standard Trotter expansion. As additional benefit it requires control fields orders of magnitude lower than the bang-bang decouplings in the latter.Comment: largely expanded version, superseedes v1: 10 pages, 5 figure

Testing the Higgs Mechanism in the Lepton Sector with multi-TeV e+e- Collisions

Multi-TeV e+e- collisions provide with a large enough sample of Higgs bosons to enable measurements of its suppressed decays. Results of a detailed study of the determination of the muon Yukawa coupling at 3 TeV, based on full detector simulation and event reconstruction, are presented. The muon Yukawa coupling can be determined with a relative accuracy of 0.04 to 0.08 for Higgs bosons masses from 120 GeV to 150 GeV, with an integrated luminosity of 5 inverse-ab. The result is not affected by overlapping two-photon background.Comment: 6 pages, 2 figures, submitted to J Phys G.: Nucl. Phy

The Development and Validation of the Diversity Dispositions Index

The population of the U.S. is becoming increasingly more diverse. Yet, administrators and teachers in the U.S. are predominantly European Americans from middle-class backgrounds who speak only English. Many of their students are racial and ethnic minorities, live in poverty, and speak a first language other than English (Banks et aI., 2005, p. 237). The No Child Left Behind Act signed into law in2002 requires school districts to hire highly qualified teachers who possess the necessary dispositions to ensure that all children learn (Center on Education Policy, 2002). School administrators and teachers must understand students\u27 backgrounds and experiences, and they must possess the necessary dispositions to work with students from diverse backgrounds (Villegas & Lucas, 2007)