33,764 research outputs found

    Analysis of watersheds and river systems: short course

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    Short course: Analysis of Watersheds and River Systems, Session I and II, held on May 28-June 1, 1979 and June 4-June 8, 1979 at Colorado State University, Fort Collins, Colorado.Speakers: Dr. E. V. Richardson, Dr. David Duttweiller, Mr. Lee Mulkey, Dr. Stanley A. Schumm, Dr. Daryl B. Simons, Dr. Ross Carder.Includes bibliographical references.This short course is designed for individuals dealing with the analysis of watersheds and rivers. Practical applications concerning physical processes will be emphasized.Chapter 1. General introduction / Daryl B. Simons and Ruh-Ming Li -- Chapter 2. Introduction to watershed and river analysis / Daryl B. Simons and Ruh-Ming Li -- Chapter 3. Physical processes governing response of watersheds and rivers / Daryl B. Simons, Timothy J. Ward and Ruh-Ming Li -- Chapter 4. Sediment transport / H. W. Shen -- Chapter 5. Alluvial bed roughness / H. W. Shen -- Chapter 6. Overview of flood routing methods / Ruh-Ming Li and V. Miguel Ponce -- Chapter 7. Water routing and yield from watersheds, Part I and II / Ruh-Ming Li, Daryl B. Simons, and Kenneth G. Eggert -- Chapter 8. Water routing in rivers / Yung-Hai Chen -- Chapter 9. Stage discharge relations / Robert K. Simons, Ruh-Ming Li, and Daryl B. Simons -- Chapter 10. Watershed sediment yield / Ruh-Ming Li, Daryl B. Simons, and Timothy J. Ward -- Chapter 11. Unsteady sediment routing models in rivers / Yung-Hai Chen and Daryl B. Simons -- Chapter 12. Known discharge sediment routing / Glenn O. Brown and Ruh-Ming Li -- Chapter 13. Landslide potential delineation / Timothy J. Ward, Ruh-Ming Li, and Daryl B. Simons -- Chapter 14. Application of Kalman filtering in watershed and river analysis / Nguyen Duong -- Chapter 15. Handheld calculator programs for analysis / Kenneth G. Eggert, Ruh-Ming Li, and Daryl B. Simons -- Chapter 16. Overview of case studies and data management / Daryl B. Simons, Ruh-Ming Li, and Nguyen Duong -- Chapter 17. Canal and channel design and river response analysis / Daryl B. Simons, Ruh-Ming Li, and Yung-Hai Chen -- Chapter 18. Degradation and aggradation analysis / Ruh-Ming Li and Daryl B. Simons -- Chapter 19. Watershed best management analysis / Ruh-Ming Li, Timothy J. Ward, and Daryl B. Simons -- Chapter 20. Large river basin analysis: Yazoo River Sedimentation Study / Daryl B. Simons and Ruh-Ming Li

    Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′

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    First evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)

    P. Levy, J. d'Oliveira e Souza, D. Simons, A.-P. Frognier, V. Werner, J. Freund, Une paix pour notre temps. Réflexion sur un texte du cardinal Roy. 1975

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    Guelluy Robert. P. Levy, J. d'Oliveira e Souza, D. Simons, A.-P. Frognier, V. Werner, J. Freund, Une paix pour notre temps. Réflexion sur un texte du cardinal Roy. 1975. In: Revue théologique de Louvain, 7ᵉ année, fasc. 2, 1976. p. 244

    Letter from Carl Hayden to J. V. Lloyd

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    Letter from Carl Hayden to J. V. Lloyd, Assistant Superintendent of Grand Canyon National Park, thanking him for his support in maintaining Civilian Conservation Corp companies at full strength. Handwritten note in red pencil, "Jack - For my attention in January. Hayden"

    Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV

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    The prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region

    Scattering Amplitudes of Massive N=2 Gauge Theories in Three Dimensions

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    We study the scattering amplitudes of mass-deformed Chern-Simons theories and Yang-Mills-Chern-Simons theories with N=2 supersymmetry in three dimensions. In particular, we derive the on-shell supersymmetry algebras which underlie the scattering matrices of these theories. We then compute various 3 and 4-point on-shell tree-level amplitudes in these theories. For the mass-deformed Chern-Simons theory, odd-point amplitudes vanish and we find that all of the 4-point amplitudes can be encoded elegantly in superamplitudes. For the Yang-Mills-Chern-Simons theory, we obtain all of the 4-point tree-level amplitudes using a combination of perturbative techniques and algebraic constraints and we comment on difficulties related to computing amplitudes with external gauge fields using Feynman diagrams. Finally, we propose a BCFW recursion relation for mass-deformed theories in three dimensions and discuss the applicability of this proposal to mass-deformed N=2 theories

    A K-theoretic approach to Chern-Cheeger-Simons invariants

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    summary:The aim of this paper is to construct a natural mapping \check C\sb k, k=1,2,3,k=1,2,3,\dots, from the multiplicative KK-theory K(X)K(X) of a differential manifold XX, associated to the trivial filtration of the de Rham complex, as defined by {\it M. Karoubi} in [C. R. Acad. Sci., Paris, S\'er. I 302, 321-324 (1986; Zbl 0593.55004)] to the odd cohomology H\sb s\sp{2k-1} (X;C\sp*). By using this mapping, the author associates to any flat complex vector bundle EE on XX characteristic classes \check C\sb k(E) \in H\sb{dR}\sp{2k-1} (X;C\sp*) analogous to the classes studied by {\it S. Chern}, {\it J. Cheeger} and {\it J. Simons} in [Differential characters and geometric invariants, in `Geometry and topology', Lect. Notes Math. 1167, 50-80 (1985; Zbl 0621.57010), Characteristic forms and geometric invariants, Ann. Math., II. Ser. 99, 48-69 (1974; Zbl 0283.53036)]

    Solitons in low-dimensional sigma models

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    The aim of this thesis is to study topological soliton solutions in classical field theories, called sigma models, on a three-dimensional space. In chapter 1 we review the general field-theoretical framework of classical soliton solutions and exemplify it on the main features of the 0(3) σ-model and the Abehan Higgs model in (2+1) dimensions. In chapter 2 a U(l)-gauged 0(3) σ-model is discussed, where the behaviour of the gauge field is determined by a Chern-Simons term in the action. We find numerical solutions for radially symmetric fields and discuss those of degree one and two. They carry a non-vanishing angular momentum and can be interpreted as classical anyons. A similar model is studied in chapter 3. Here the potential is of Higgs-type and chosen to produce a Bogomol'nyi model where the energy is bounded from below by a linear combination of the topological degree of the matter fields and the local U(l)-charge. Depending on internal parameters, the solutions are solitons or vortices. We study them numerically and prove for a certain range of the matter field's vacuum value that there cannot be a 1-soliton.In chapter 4 we discuss a modified 0(3) σ-model in (3+0) dimensions. The topological stability of the solitons is here imphed by the degree of the map S(^3) → S(^2), which provides a lower boundon the potential energy of the configuration. Numerical solutions are obtained for configurations of azimuthal symmetry and the spectrum of slowly rotating solitons is approximated. Chapter 5 deals with a theory where the fields are maps IR(^2+1) → CP(^2). The Lagrangian includes a potential and a fourth-order term in the field-gradient. We find a family of static analytic solutions of degree one and study the 2-soIiton configuration numerically by using a gradient-flow equation on the moduli space of solutions. We conclude this thesis with a brief summary and give an outlook to open questions

    First VLBA observations of 28SiO J=1-0, v=3 maser emission from AGB stars

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    The v=1 &amp; v=2 J=1-0 (43 GHz), and v=1 J=2-1 (86 GHz) SiO masers are intense in AGB stars. They have been mapped using VLBI displaying spots ring-like distributions. The rings of the v=1, v=2 J=1-0 masers are similar, but the spots are rarely coincident, while the v=1 J=2-1 maser arises from a well separated region farther out. The v=3 J=1-0 line is not directly affected by any line overlap and its spot structure and position, relative to the other lines, is a good test to the standard pumping models. We present simultaneous single dish and VLBI observations of the v=1, v=2, and v=3 J=1-0 maser transitions of 28SiO in several AGB stars and compare them to model predictions. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
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