1,071 research outputs found

    Transition probabilities in OH A 2 sigma + - X 2 pi i: Bands with v prime = 0 and 1, v double prime = 0 to 4

    Get PDF
    Experimental results for relative vibrational band transition probabilities for v prime = 0 and 1, and v double prime = 0 to 4 in the A-X electronic system of OH are presented. The measurements, part of a larger set involving v prime = 0 to 4 and v double prime = 0 to 6, were made using spectrally dispersed laser-induced fluorescence (LIF) in the burnt gases of a flame. These Einstein coefficients will be useful in dynamics experiments for quantitative LIF determinations of OH radical concentrations in high v double prime

    Supporting New School Leaders Through Mentoring

    Get PDF
    Mentoring may best be defined as “a process where one person provides individual support and challenge to another professional (Bush, 2009, p.379). The importance of mentoring new teachers and administrators has long been recognized. For example, since 2000 more than half of the states have passed laws requiring mentoring of new principals (Daresh, 2004; Spiro, Mattis, & Mitgang 2007). Most of these laws have required mentoring in the first two years of practice. Grissom & Harrington (2010) found under the mentorship model, a more experienced principal mentor provides the support, guidance, advice and sounding board as the new principal becomes acclimated to the position

    Cosmological perturbation spectra from SL(4,R)-invariant effective actions

    Get PDF
    We investigate four-dimensional cosmological vacuum solutions derived from an effective action invariant under global SL(n,R) transformations. We find the general solutions for linear axion field perturbations about homogeneous dilaton-moduli-vacuum solutions for an SL(4,R)-invariant action and find the spectrum of super-horizon perturbations resulting from vacuum fluctuations in a pre big bang scenario. We show that for SL(n,R)-invariant actions with n>3 there exists a regime of parameter space of non-zero measure where all the axion field spectra have positive spectral tilt, as required if light axion fields are to provide a seed for anisotropies in the microwave background and large-scale structure in the universe.Comment: 8 pages, 3 figures, revtex plus epsf, minor typos corrected, version to appear in Physical Review

    Fanny Copeland and the geographical imagination

    Get PDF
    Raised in Scotland, married and divorced in the English south, an adopted Slovene, Fanny Copeland (1872 – 1970) occupied the intersection of a number of complex spatial and temporal conjunctures. A Slavophile, she played a part in the formation of what subsequently became the Kingdom of Yugoslavia that emerged from the First World War. Living in Ljubljana, she facilitated the first ‘foreign visit’ (in 1932) of the newly formed Le Play Society (a precursor of the Institute of British Geographers) and guided its studies of Solčava (a then ‘remote’ Alpine valley system) which, led by Dudley Stamp and commended by Halford Mackinder, were subsequently hailed as a model for regional studies elsewhere. Arrested by the Gestapo and interned in Italy during the Second World War, she eventually returned to a socialist Yugoslavia, a celebrated figure. An accomplished musician, linguist, and mountaineer, she became an authority on (and populist for) the Julian Alps and was instrumental in the establishment of the Triglav National Park. Copeland’s role as participant observer (and protagonist) enriches our understanding of the particularities of her time and place and illuminates some inter-war relationships within G/geography, inside and outside the academy, suggesting their relative autonomy in the production of geographical knowledge

    Bullying in Public Schools in Missouri

    Get PDF
    The research conducted sought to find evidence and data to support or lack of support to the following questions: Do school administrators perceive a problem with bullying in their schools in Missouri? Is there a relationship between the victim of bullying and the learning process? Do female adolescents engage in cyber bullying more than male adolescents? Do public schools in Missouri have policies in place that address bullying? The researcher used the Olweus Bullying Prevention Program survey on bullying. The study examined the perceptions and beliefs of the superintendents in the State of Missouri concerning bullying and student responses from students in the Western Missouri Conference Schools. Significant findings included more experienced Ssuperintendents stating that there is little or no problem with bullying in their schools or in the schools throughout Missouri, while less experienced superintendents believe that there is a tremendous problem with bullying in schools. One hundred percent of the superintendent responses revealed that all believe that there is a need for more anti-bullying programs in their schools. Out of the students surveyed, more than 50 percent reported that they had never been a victim of a bully, however, other studies make valid points to stress that younger students have a tendency to be bullied, or at least report the bullying behavior, than the older adolescents or adults. Eighty-three percent of the student responses showed that they had bullied another student in some way other than a physical confrontation. With 100% of the superintendents reporting the need for more anti-bullying programs in schools and 83% of students responding that they have bullied other students in some way, more studies and research on this topic would appear to the researcher to be of great value in the ongoing attempt to keep all children safe

    Running-mass models of inflation, and their observational constraints

    Get PDF
    If the inflaton sector is described by softly broken supersymmetry, and the inflaton has unsuppressed couplings, the inflaton mass will run strongly with scale. Four types of model are possible. The prediction for the spectral index involves two parameters, while the COBE normalization involves a third, all of them calculable functions of the relevant masses and couplings. A crude estimate is made of the region of parameter space allowed by present observation.Comment: Latex file, 20 pages, 11 figures, uses epsf.sty. Comment on the observation of the spectral index scale dependence added; Fig. 3-6 improve

    Duality Invariance of Cosmological Perturbation Spectra

    Get PDF
    I show that cosmological perturbation spectra produced from quantum fluctuations in massless or self-interacting scalar fields during an inflationary era remain invariant under a two parameter family of transformations of the homogeneous background fields. This relates slow-roll inflation models to solutions which may be far from the usual slow-roll limit. For example, a scale-invariant spectrum of perturbations in a minimally coupled, massless field can be produced by an exponential expansion with aeHta\propto e^{Ht}, or by a collapsing universe with a(t)2/3a\propto (-t)^{2/3}.Comment: 5 pages, Latex with Revtex. Hamiltonian formulation added and discussion expanded. Version to appear in Phys Rev

    Cosmic Strings from Supersymmetric Flat Directions

    Get PDF
    Flat directions are a generic feature of the scalar potential in supersymmetric gauge field theories. They can arise, for example, from D-terms associated with an extra abelian gauge symmetry. Even when supersymmetry is broken softly, there often remain directions in the scalar field space along which the potential is almost flat. Upon breaking a gauge symmetry along one of these almost flat directions, cosmic strings may form. Relative to the standard cosmic string picture based on the abelian Higgs model, these flat-direction cosmic strings have the extreme Type-I properties of a thin gauge core surrounded by a much wider scalar field profile. We perform a comprehensive study of the microscopic, macroscopic, and observational characteristics of this class of strings. We find many differences from the standard string scenario, including stable higher winding mode strings, the dynamical formation of higher mode strings from lower ones, and a resultant multi-tension scaling string network in the early universe. These strings are only moderately constrained by current observations, and their gravitational wave signatures may be detectable at future gravity wave detectors. Furthermore, there is the interesting but speculative prospect that the decays of cosmic string loops in the early universe could be a source of ultra-high energy cosmic rays or non-thermal dark matter. We also compare the observational signatures of flat-direction cosmic strings with those of ordinary cosmic strings as well as (p,q) cosmic strings motivated by superstring theory.Comment: 58 pages, 16 figures, v2. accepted to PRD, added comments about baryogenesis and boosted decay products from cusp annihilatio
    corecore