45,114 research outputs found
Miscellaneous -- 1956 -- Correspondence, Toxoplasmosis -- letter, 1956-10-30?
No full textLetter from Sanders, Dorothea F. to Sabin, Albert B. dated 1956-10-30?.Sabin Collection Fair Use Policy</a
Haruki Murakami’s Deconstructive Reading of the Myth of Johnnie Walker and Colonel Sanders in Kafka on the Shore
No full textThis study aims to analyze how Haruki Murakami reads the real icons of Johnnie Walker and Colonel Sanders in Kafka on
the Shore deconstructively. First, we will focus on the signification process of the icon, which are to a great extent molded by advertisements, and then on the deconstruction of their signifieds. For the purpose, we will apply Barthes‟ idea of myth. We are also interested in revealing how Murakami constructs Johnnie Walker and Colonel Sanders to be characters in the novel. The analysis shows that the construction of the icons through advertisements leads to the creation of their mtyhs, and then Murakami reads them deconstructively to be opposite signifieds
Sulfur geochemistry of the Salitre Formation phosphorites
No full textComma-delimited version of table containing measured δ34S of CAS, PAS, CRS, and pyrite in phosphatic and non-phosphatic microfacies of the Salitre Formation.Sample ID includes abbreviation for stratigraphic column and locality, as well as numbers indicating stratigraphic height and lateral distance in a measured section (both in meters) from a datum for the given column, or depth in a drill core (in cm) from the top of the core. Powders collected from the same hand samples (within centimeters of each other) are indicated with lowercase letters a-c. Note: Aris = Aristeia, Min = Minotaur, Cer = Cerberus, FuroV = CBPM Core 5, and FuroX = CBPM Core 10. Locality/Section names, stratigraphic columns, and geographic location are provided in Sanders and Grotzinger (2021), Sanders et al. (2023), and Sanders et al. (submitted).Microfacies A = carbonate-cemented grainstone, B = carbonate-cemented grainstone adjacent to phospatic digitate stromatolite buildup, C = carbonate-cemented grainy inter-stromatolite fill, D = carbonate-cemented laminated mudstone, E = carbonate-cemented stromatolite laminae, and F = CFA-cemented stromatolite laminae. CAS = trace structural sulfate in the lattice of the indicated carbonate mineral(s), collected via protocols for trace sulfate extraction and purification, and measured via ICP-MS. PAS = trace structural sulfate in the lattice of the indicated phosphate mineral, collected via protocols for bulk phosphate-associated sulfate extraction, and measured via EA-IRMS. CRS = chromium-reducible sulfur, extracted and fixed as Ag2S from acid-insoluble residues, representative of sulfur in the lattice of pyrite measured via EA-IRMS. “Pyrite” and “pyrite/marcasite/pyrrhotite” refer to SIMS measurement of structural sulfur in individual crystals or aggregates of crystals. ‰ is expressed with respect to Vienna Canyon Diablo Troilite (VCDT). Works Cited: 1. Sanders C. B., Eiler J. C. and Grotzinger J. P. (2023) Paragenesis of an Ediacaran carbonate-platform phosphorite: Constraints from optical petrography and texture-specific clumped isotope paleothermometry. Sediment. Geol. 444, 106316. Available at: https://doi.org/10.1016/j.sedgeo.2022.106316.2. Sanders C. and Grotzinger J. (2021) Sedimentological and stratigraphic constraints on depositional environment for Ediacaran carbonate rocks of the São Francisco Craton: Implications for phosphogenesis and paleoecology. Precambrian Res. 363, 106328. Available at: https://doi.org/10.1016/j.precamres.2021.106328.3. Sanders C., Present T., Marroquin S. and Grotzinger J. (submitted) Sulfur geochemistry of the Salitre Formation phosphorites: Implications for the role of microbial ecology, sulfur cycling in phosphogenesis on an Ediacaran carbonate platform. Geochim. et Cosmochim. Acta
Unstructured Grid Finite-Volume Algorithm for Shallow-Water Flow and Scalar Transport with Wetting and Drying
No full textA high-resolution, unstructured grid, finite-volume algorithm is developed for unsteady, two-dimensional, shallow-water flow and scalar transport over arbitrary topography with wetting and drying. The algorithm uses a grid of triangular cells to facilitate grid generation and localized refinement when modeling natural waterways. The algorithm uses Roe’s approximate Riemann solver to compute fluxes, a multidimensional limiter for second-order spatial accuracy, and predictor-corrector time stepping for second-order temporal accuracy. The novel aspect of the algorithm is a robust and efficient procedure to consistently track fluid volume and the free surface elevation in partially submerged cells. This leads to perfect conservation of both fluid and dissolved mass, preservation of stationarity, and near elimination of artificial concentration and dilution of scalars at stationary or moving wet/dry interfaces. Multi-dimensional slope limiters, variable reconstruction, and flux evaluation schemes are optimized in the algorithm on the basis of accuracy per computational effort
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst 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)
Wetting and Drying of Triangular Computational Cells
No full textA robust and novel procedure is introduced into a fixed-grid finite volume shallow-water model to consistently track fluid volume and the free surface elevation in partially submerged triangular cells, which leads to excellent flow and scalar transport predictions in the presence of a stationary or moving wet/dry interface. Using this procedure, a Roe-type finite volume scheme is found to perfectly conserve both fluid and dissolved mass, preserve stationarity, and nearly eliminate artificial concentration and dilution of scalars at wet/dry interfaces
Simulation of the St Francis dam-break flood
No full textNumerical simulation of the 1928 St. Francis Dam failure in southern California was accomplished using a 2D Godunov-type finite-volume shallow-water algorithm run on an unstructured grid of triangular cells. The model was found to be accurate based on historical accounts, including flood maps and arrival time data, and sensitivity analysis was performed to determine factors that control the predictability of flooded area and flood arrival times. Results show that predictions of flood arrival times are sensitive to both mesh resolution and Manning coefficient (used to scale flow resistance), while predictions of flooded area were found to be relatively insensitive to the Manning coefficient. These results suggest that bed resistance controlled the speed of the St. Francis flood while flooded area was controlled by topography and the volume of released water. The study also revealed two types of previously unreported oscillatory surging in the dam-break flood. The first is due to a standing wave that develops in a tortuous reach of channel downstream of the dam. The wave is excited by reflections off canyon walls and accounts for a 30% fluctuation in discharge. The second is due to a mode-two standing wave in the reservoir. This wave is caused by the reflection of dam-break rarefaction waves off reservoir walls, and accounts for only 2-3% fluctuation in discharge. Both oscillations are therefore shown to be physically based and should not beinterpreted as spurious oscillations common to many numerical wave models
Conservative Wetting and Drying Methodology for Quadrilateral Grid Finite Volume Models
No full textAlgebraic equations relating fluid volume and the free surface elevation in partially wetted quadrilateral computational cells are derived and incorporated into a Godunov-type, finite-volume, shallow-water model. These equations make it straightforward to reconstruct the free surface elevation based on the volume of fluid in a computational cell, the dependent variable tracked by finite volume models for conservation purposes, regardless of whether the cell is fully or partially wetted. Improvements to the variable reconstruction process streamline the computation of mass and momentum fluxes with approximate Riemann solvers, yielding a model that simulates sub-, super-, and transcritical flows over irregular topography with wetting and drying fronts. Furthermore, the model is free from fluid and scalar mass conservation errors and it eliminates nonphysical distributions of scalars by avoiding artificial concentration and/or dilution at wet/dry interfaces. Use of this wetting and drying methodology adds roughly 10% to the execution time of flow simulations
Helen F. Sanders Taking Notes at Sun Dance
No full textA stereoscope card showing Helen F. Sanders taking notes in the middle of a circle of people at a Sun Dance
A balanced treatment of secondary currents, turbulence and dispersion in a depth-integrated hydrodynamic and bed deformation model for channel bends
No full textThis work deals with the formulation and numerical implementation of a two-dimensional mathematical and numerical model describing open channel hydrodynamics, sediment and/or scalar transport and riverbed evolution in curved channels. It is shown that a well balanced 2D model can predict flow features, sediment and scalar concentration, and bed elevation with an accuracy that is suitable for practical river engineering. The term “balanced” implies that important physical processes are modeled with a similar degree of complexity and exhaustiveness. The starting point of the model formulation is the assumption of self-similarity of vertical velocity profiles (horizontal velocities in the longitudinal and transverse directions), that are scaled by shear velocity and streamline curvature, both resolved by the model. The former is scaled by a bed-resistance coefficient that must be estimated or calibrated – as usual – on a application-specific basis, and the latter is computed by a new, grid-based but grid orientation independent, scheme that acts on the discrete solution. All processes, including bottom shear, momentum dispersion, scalar dispersion, turbulent diffusion, bed load, and suspended load, are modeled using physically based, averaged values of empirical or semi-empirical constants, and consistently with the assumed velocity profiles (and bed-generated turbulence). Bed deformation modeling can be implemented with either an equilibrium or non-equilibrium formulation of the Exner equation, depending on the adaptation length scale, which must be taken under consideration if significantly larger than the length scale of the spatial discretization. The governing equations are solved by high-resolution, unstructured-grid Godunov method, which is elsewhere tested and shown to be reliable and second-order accurate. Application of the model to laboratory test cases, using standard parameter values and previously reported bed-resistance coefficients, gives results comparable to many 2D and 3D models previously applied to the same cases, most part of which benefit from case-specific parameter tuning. There are obviously intrinsic limits to the descriptive ability of 2D models in river modeling, but the results of this study point to the utility and cost-effectiveness of a well-designed 2D model
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