1,807 research outputs found

    Paramagnon dispersion in β\beta-FeSe observed by Fe LL-edge resonant inelastic x-ray scattering

    Full text link
    We report an Fe LL-edge resonant inelastic x-ray scattering (RIXS) study of the unusual superconductor β\beta-FeSe. The high energy resolution of this RIXS experiment (\approx\,55\,meV FWHM) made it possible to resolve low-energy excitations of the Fe 3d3d manifold. These include a broad peak which shows dispersive trends between 100-200\,meV along the (π,0)(\pi,0) and (π,π)(\pi,\pi) directions of the one-Fe square reciprocal lattice, and which can be attributed to paramagnon excitations. The multi-band valence state of FeSe is among the most metallic in which such excitations have been discerned by soft x-ray RIXS

    Cohomology of Line Bundles: A Computational Algorithm

    Full text link
    We present an algorithm for computing line bundle valued cohomology classes over toric varieties. This is the basic starting point for computing massless modes in both heterotic and Type IIB/F-theory compactifications, where the manifolds of interest are complete intersections of hypersurfaces in toric varieties supporting additional vector bundles.Comment: 11 pages, 1 figure, 2 tables; v2: typos and references corrected; v3: proof-related statements updated, cohomCalg implementation available at http://wwwth.mppmu.mpg.de/members/blumenha/cohomcalg

    The Emperor’s New Clothes: How the Judicial System and the Housing-Mortgage Market Have Turned a Blind Eye to the Destruction of the Negotiability of Mortgage Promissory Notes

    Full text link
    This Article examines the common notions of negotiable instruments as they relate to the modern day promissory note in the context of residential mortgage lending. The Article further addresses the destruction of the negotiability of such promissory notes through various undertakings added for the benefit of the banking industry, often to the detriment of a borrower. The use of negotiable instruments commenced in the 1800s in England as a way of ensuring a fluid market between trades as there was no fiat currency system in place. The fundamental purpose behind the concept of negotiability was subsequently abrogated by the modernization of the financial industry, and the creation of a global marketplace for the purchase and sale of promissory notes. Furthermore, the Article discusses how the holder in due course doctrine, which limits a borrower’s defenses when a promissory note has been transferred from one note holder to another, has created significant abuse to consumers by the financial industry. The abuse of consumers through the holder in due course doctrine remains a problem unchecked by many courts that continue to apply negotiability law to modern day promissory notes in real estate mortgage transactions despite the fact that modern day promissory notes lack any of the tenets of “negotiability” under article 3 of the Uniform Commercial Code. The Article then calls on the judiciary, as theoretically the least political and most impartial branch of government, to find that such promissory notes are no longer negotiable instruments, and therefore must be transferred via assignment pursuant to article 9 of the Uniform Commercial Code. Such a new construct or approach would provide the transparency necessary to protect consumers and preserve defenses to predatory lending by the financial industry

    Systematic design of single-mode coupled-resonator optical waveguides in photonic crystals

    Get PDF
    By establishing a direct relation between the dispersion and the field profile of a coupled-resonator optical waveguide (CROW) and those of its constituent cavities, we present a systematic method for the design of a single-mode CROW and for control of its dispersion. The procedure includes the design of a single-mode cavity and control of its frequency by engineering its structure. Then, by chaining these cavities in the proper direction and at an appropriate distance, we achieve the desired dispersion for the CROW

    Seed production of barnyardgrass (Echinochloa crus-galli) in response to time of emergence in cotton and rice

    Get PDF
    The spread of herbicide resistance in barnyardgrass (Echinochloa crus-galli (L.) Beauv.) poses a serious threat to crop production in the southern United States. A thorough knowledge of the biology of barnyardgrass is fundamental for designing effective resistance-management programmes. In the present study, seed production of barnyardgrass in response to time of emergence was investigated in cotton and rice, respectively, in Fayetteville and Rohwer, Arkansas, over a 2-year period (2008–09). Barnyardgrass seed production was greater when seedlings emerged with the crop, but some seed production was observed even if seedlings emerged several weeks after crop emergence. Moreover, barnyardgrass seed production was highly variable across environments. When emerging with the crop (0 weeks after crop emergence (WAE)), barnyardgrass produced c. 35 500 and 16 500 seeds/plant in cotton, and c. 39 000 and 2900 seeds/plant in rice, in 2008 and 2009, respectively. Seed production was observed when seedlings emerged up to 5 WAE (2008) or 7 WAE (2009) in cotton and up to 5 WAE (2008, 2009) in rice; corresponding seed production was c. 2500 and 1500 seeds/plant in cotton, and c. 14 700 and 110 seeds/plant in rice, in 2008 and 2009, respectively. The results suggest that cultural approaches that delay the emergence of barnyardgrass or approaches that make the associated crop more competitive will be useful in integrated management programmes. In the context of herbicide resistance management, it may be valuable to prevent seed return to the seedbank, irrespective of cohorts. The findings are vital for parameterizing herbicide resistance simulation models for barnyardgrass

    Educational Interpreter Services for Hearing-Impaired Students: Provider and Consumer Disagreements

    Get PDF
    Thirteen supervisors of educational programs for hearing-impaired students completed an assessment designed to determine the need for educational interpreters in a midwestern state and how well it was being met. The results suggested that the trend toward the integration of hearing-impaired students in to regular programs continues and that, with the higher incidence of integration, there is an associated unmet need for educational interpreters. Nine supervisors, 24 teachers, 27 interpreters and 18 hearing-impaired college students rated the characteristics and skills of interpreters which they perceived to be most important. Significant differences existed between and within groups in the characteristics and skills perceived important to educational interpreting (p\u3c .05). Major differences existed between the skills and characteristics cited as most important by hearing-impaired persons and those cited by teachers and interpreters
    corecore