61,478 research outputs found
William Tecumseh Sherman on horseback carte de visite
No full textIn this carte de visite, Lieutenant General William T. Sherman (1820-1891) appears mounted on his horse Duke in Atlanta, Georgia during the Civil War. This 2.5 by 4-inch (6.35 by 10.16 cm) carte de visite dates from 1864. William Tecumseh Sherman was born in Lancaster, Ohio. Orphaned at age nine, he was raised by Thomas Ewing, a U. S. senator who also served as secretary of the treasury and secretary of the interior. He graduated sixth in his class from the United States Military Academy at West Point and served in positions in the South, where he gained great knowledge of the Southern people and the geography of the region. Sherman served in the Mexican War, but left the army in 1853. At the outbreak of the Civil War, he accepted a position as a colonel in the regular army. Sherman became well known for his tactics of property damage and psychological warfare against the southern people, best illustrated by his march through Georgia. His goal was to convince the Southern people to stop the war, and prevent more battlefield deaths. Sherman's military career continued after the Civil War. In 1869, President Ulysses S. Grant promoted Sherman to full general and commander of the United States army
Surface complexation of U(VI) on goethite (-FeOOH)
No full textIt has previously been established that U(VI), as the uranyl cation UO2+2, sorbs to Fe oxide hydroxide phases by forming an inner-sphere complex with the surface hydroxyls. Here, we argue that on goethite (a-FeOOH) there are two inner-sphere surface complexes of UO2+2: the E2 complex resulting from bidentate edge-sharing with free FeO6 polyhedra on the {210} and {010} surfaces (space group setting Pnma) and a C2 complex resulting from bidentate corner-sharing with two adjacent FeO6 polyhedra on (predominantly) the {101} surface. Ab initio (density functional theory) predictions of the surface-complex geometries and stabilities suggest that the C2 complex is 0.12 eV (12 kJ/mol) less stable than the E2 complex. However, since the {101} sites are ~10(2) more abundant than the {210} and {010} sites, sorption on the {101} sites via the C2 complexes is favoured by configurational entropy. We argue that the C2 complex is dominant at high surface loadings and only this complex can account for the sorption capacity of goethite for U. We show that EXAFS spectra are consistent with this hypothesis. Inclusion of multiple scattering paths in the UO2(OH)+ and UO2CO3 surface complexes can account for nearly all of the signal previously attributed to the edge-sharing (E2) complex. We develop a new surface complexation model for UO2+2 on goethite using the 1pK model for surface protonation and the Basic Stern model for surface electrostatics. The model is able to account for sorption and desorption of UO2+2 in both ambient and reduced CO2 environments at surface loadings of 0.02-2.0 wt. % U
Sherman House photograph
No full textThis photograph depicts the Sherman House, birthplace of the brothers General William Tecumseh Sherman and statesman John Sherman. The home is a Registered National Landmark and is listed on the National Register of Historic Places. William Tecumseh Sherman (1820-1891) was born in Lancaster, Ohio. Orphaned at age nine, he was raised by Thomas Ewing, a U. S. senator who also served as secretary of the treasury and secretary of the interior. He graduated sixth in his class from the United States Military Academy at West Point and served in positions in the South, where he gained great knowledge of the Southern people and the geography of the region. Sherman served in the Mexican War, but left the army in 1853. At the outbreak of the Civil War, Sherman accepted a position as a colonel in the regular army. He became well known for his tactics of property damage and psychological warfare against the southern people, best illustrated by his march through Georgia. His goal was to convince the southern people to stop the war, and prevent more battle field deaths. Sherman is credited with the saying "War is hell." John Sherman (1823-1900) grew up in Lancaster, Ohio, one of eleven children of Ohio Supreme Court Justice Charles Sherman. In 1840, Sherman moved to Mansfield to live with his oldest brother, Charles Jr. He served in the U.S. House of Representatives and Senate, as secretary of the treasury, and secretary of state. He authored numerous pieces of legislation, though he is best remembered for the Sherman Anti-Trust Act. Sherman was considered for the Republican presidential ticket three times, but never gained his party's nomination. Critics claimed that he was a cool and distant man and that these personality traits cost him the presidency
A Dynamic Subfilter-scale Stress Model for Large Eddy Simulations Based on Physical Flow Scales
No full textWe propose a new definition of the length scale in an eddy-viscosity model for large-eddy simulations (LES). This formulation extends and generalizes a previous proposal [Piomelli, Rouhi and Geurts, Proc. ETMM10, 2014], in which the LES length scale was expressed in terms of the integral length-scale of turbulence determined by the flow characteristics and explicitly decoupled from the simulation grid; this approach was named Integral Length-Scale Approximation (ILSA). As in the original ILSA, the model coefficient was determined by the user, and required to maintain a desired contribution of the unresolved, subfilter scales (SFS) to the global transport. We propose a local formulation (local ILSA) in which the model coefficient is local in space, allowing a precise control over SFS activity as a function of location. This new formulation preserves the properties of the global model; application to channel flow and backward-facing step verifies its features and accuracy
Large-eddy simulation of a separated flow with a sub-filter scale model based on the integral length-scale
No full textA new sub-filter scale model for large-eddy simulations, which uses a length-scale proportional to the integral scale of the turbulence instead of the grid resolution to parametrize the modelled stresses, will be assessed in the prediction of the flow of a boundary-layer over a rough surface, which includes separation and reattachment
Gen. U. S. T. Sherman and staff
No full textTitle from unverified information on negative sleeve.Annotation from negative, scratched on emulsion: Sherman & Generals.Forms part of Civil War glass negative collection (Library of Congress)
Near Wall PIV-Measurements on the Windward Slope of a Hill
No full textThe turbulent flow over periodic hills was measured near to the wall, using planar Particle-Image-Velocimetry (PIV) at high spatial resolution. Our focus is on the near wall turbulence structure on the windward slope of the hill. For large-eddy simulation (LES) we suspect that, if this was not predicted accurately, it affects the prediction of the velocity profiles over the hill crest which in turn will affect the recirculation length downstream of the hill. Regarding the time averaged velocities, we were able to resolve the linear viscous region of the boundary layer. The velocity distribution and also the Reynolds stress does not comply with the law of the wall as it is valid for a turbulent boundary layer at equilibrium
Energy dissipation and flux laws for unsteady turbulence
No full textDirect Numerical Simulations of spatially periodic unsteady turbulence show that the high Reynolds number scalings of the instantaneous energy dissipation rate and interscale energy flux at intermediate wavenumbers are qualitatively different from the well-known cornerstone scalings of equilibrium turbulence where and are time-dependent rms velocity and integral length-scales. Instead, they both scale as where and are length and velocity scales characterizing initial/overall unsteady turbulence conditions
Direct numerical simulation of turbulent Couette-Poiseuille flow with zero skin friction
No full textThe near-wall scaling of mean velocity U(y) is addressed for the case of zero skin friction on one wall of a fully turbulent channel flow. The present DNS results can be added to the evidence in support of the conjecture that U is proportional to √yw in the region just above the wall at which the mean shear dU/dy = 0
Real-space Manifestations of Bottlenecks in Turbulence Spectra
No full textAn energy-spectrum bottleneck, a bump in the turbulence spectrum between the inertial and dissipation ranges, is shown to occur in the non-turbulent, one-dimensional, hyperviscous Burgers equation and found to be the Fourier-space signature of oscillations in the real-space velocity, which are explained by boundary-layer-expansion techniques. Pseudospectral simulations are used to show that such oscillations occur in velocity correlation functions in one- and three-dimensional hyperviscous hydrodynamical equations that display genuine turbulence
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