3,247 research outputs found
sweet money: cultural and economic value in Trollope's Autobiography
Trollope wrote his Autobiography at a time when the value of his literary stock was at a low point. Not surprisingly, the question of value\u2014the tension between literary value and economic value\u2014is a recurrent concern in this text. In the mid 1870s he was also a member of the Royal Commission on International Copyright. The debate on international copyright pivoted on the issue of control. English authors feared that, in an open, global marketplace, they had little power to control the dissemination of their works. It is with reference to this controversial scenario that I reconsider the model of control Trollope meticulously elaborates (and even promotes) in An Autobiography. As I argue in this essay, Trollope\u2019s appeal to the language of trade serves the ideological function of repositioning the author who writes for the market as a free agent who is not subservient to the market. The figure of the literary tradesman depicted in this text is not one-sided, nor is this tradesman always perfectly at ease in the marketplace. His sense of comfort is constructed retrospectively by mobilizing the entrepreneurial rhetoric and, more conspicuously, by flaunting grand totals. These sums, however, are not simple, unproblematic quantifications. The narrator of the Autobiography constantly worries about the tension between aesthetic and economic value, between cultural and market price. To describe himself as a good negotiator and an efficient price maker is not enough. The price he demands has to be justified as a fair one in the dual market he supplies: the market where commodities are bought and sold and the market where creative ideas circulate. Trollope\u2019s theory of realism, I contend, functions as an ad hoc construction that allows Trollope to justify his profits and his addictive productivity by invoking a different regime of value in which the author as creator, rather than the author as producer, becomes prominent
Comparison of reductive dehalogenation by microbial populations on adsorptive versus non-adsorptive bioreactor support materials
The overall performance of two bioreactors was studied. The reactor with a wood-based activated carbon as a biosupport completely dehalogenated a higher feed concentration of trichlorophenol than that with Manville beads. The carbon reactor was further characterized by the development of adsorption isotherms for most of the class of chlorophenols. Competitive adsorption wag investigated using an anaerobic medium, and a lignite-based carbon was studied for comparison. The order of adsorption strength on both carbons is trichloropenols\u3e dichlorophenols\u3e monochlorophenols, with the wood-based carbon having higher overall adsorption than the lignite-based carbon. The presence of the anaerobic medium decreased the extent of chlorophenol adsorption at lower liquid concentrations.
The investigation of the effect of a biofilm on the adsorption characteristics of the activated carbon showed that the biofilm decreased the rate at which adsorption equilibrium of 4-CP was obtained. However, the equilibrium itself was not effected. It was also determined that the organisms serve as adsorptive material
Surface detonation in type Ia supernova explosions?
We explore the evolution of thermonuclear supernova explosions when the
progenitor white dwarf star ignites asymmetrically off-center. Several
numerical simulations are carried out in two and three dimensions to test the
consequences of different initial flame configurations such as spherical
bubbles displaced from the center, more complex deformed configurations, and
teardrop-shaped ignitions. The burning bubbles float towards the surface while
releasing energy due to the nuclear reactions. If the energy release is too
small to gravitationally unbind the star, the ash sweeps around it, once the
burning bubble approaches the surface. Collisions in the fuel on the opposite
side increase its temperature and density and may -- in some cases -- initiate
a detonation wave which will then propagate inward burning the core of the star
and leading to a strong explosion. However, for initial setups in two
dimensions that seem realistic from pre-ignition evolution, as well as for all
three-dimensional simulations the collimation of the surface material is found
to be too weak to trigger a detonation.Comment: 5 pages, 3 figures, in: Proceedings of the SciDAC 2006 Meeting,
Denver June 25-26 2006, also available at
http://herald.iop.org/jpcs46/m51/gbr//link/40
A Space-time Smooth Artificial Viscosity Method For Nonlinear Conservation Laws
We introduce a new methodology for adding localized, space-time smooth,
artificial viscosity to nonlinear systems of conservation laws which propagate
shock waves, rarefactions, and contact discontinuities, which we call the
-method. We shall focus our attention on the compressible Euler equations in
one space dimension. The novel feature of our approach involves the coupling of
a linear scalar reaction-diffusion equation to our system of conservation laws,
whose solution is the coefficient to an additional (and artificial)
term added to the flux, which determines the location, localization, and
strength of the artificial viscosity. Near shock discontinuities, is
large and localized, and transitions smoothly in space-time to zero away from
discontinuities. Our approach is a provably convergent, spacetime-regularized
variant of the original idea of Richtmeyer and Von Neumann, and is provided at
the level of the PDE, thus allowing a host of numerical discretization schemes
to be employed. We demonstrate the effectiveness of the -method with three
different numerical implementations and apply these to a collection of
classical problems: the Sod shock-tube, the Osher-Shu shock-tube, the
Woodward-Colella blast wave and the Leblanc shock-tube. First, we use a
classical continuous finite-element implementation using second-order
discretization in both space and time, FEM-C. Second, we use a simplified WENO
scheme within our -method framework, WENO-C. Third, we use WENO with the
Lax-Friedrichs flux together with the -equation, and call this WENO-LF-C.
All three schemes yield higher-order discretization strategies, which provide
sharp shock resolution with minimal overshoot and noise, and compare well with
higher-order WENO schemes that employ approximate Riemann solvers,
outperforming them for the difficult Leblanc shock tube experiment.Comment: 34 pages, 27 figure
Multidimensional HLLE Riemann solver; Application to Euler and Magnetohydrodynamic Flows
In this work we present a general strategy for constructing multidimensional
Riemann solvers with a single intermediate state, with particular attention
paid to detailing the two-dimensional Riemann solver. This is accomplished by
introducing a constant resolved state between the states being considered,
which introduces sufficient dissipation for systems of conservation laws.
Closed form expressions for the resolved fluxes are also provided to facilitate
numerical implementation. The Riemann solver is proved to be positively
conservative for the density variable; the positivity of the pressure variable
has been demonstrated for Euler flows when the divergence in the fluid
velocities is suitably restricted so as to prevent the formation of cavitation
in the flow.
We also focus on the construction of multidimensionally upwinded electric
fields for divergence-free magnetohydrodynamical flows. A robust and efficient
second order accurate numerical scheme for two and three dimensional Euler and
magnetohydrodynamic flows is presented. The scheme is built on the current
multidimensional Riemann solver. The number of zones updated per second by this
scheme on a modern processor is shown to be cost competitive with schemes that
are based on a one-dimensional Riemann solver. However, the present scheme
permits larger timesteps
A Two-dimensional HLLC Riemann Solver for Conservation Laws : Application to Euler and MHD Flows
In this paper we present a genuinely two-dimensional HLLC Riemann solver. On
logically rectangular meshes, it accepts four input states that come together
at an edge and outputs the multi-dimensionally upwinded fluxes in both
directions. This work builds on, and improves, our prior work on
two-dimensional HLL Riemann solvers. The HLL Riemann solver presented here
achieves its stabilization by introducing a constant state in the region of
strong interaction, where four one-dimensional Riemann problems interact
vigorously with one another. A robust version of the HLL Riemann solver is
presented here along with a strategy for introducing sub-structure in the
strongly-interacting state. Introducing sub-structure turns the two-dimensional
HLL Riemann solver into a two-dimensional HLLC Riemann solver. The
sub-structure that we introduce represents a contact discontinuity which can be
oriented in any direction relative to the mesh.
The Riemann solver presented here is general and can work with any system of
conservation laws. We also present a second order accurate Godunov scheme that
works in three dimensions and is entirely based on the present multidimensional
HLLC Riemann solver technology. The methods presented are cost-competitive with
traditional higher order Godunov schemes
Predictive methods of electricity price: An application to the Italian electricity market
Price forecasting is a crucial element for the members of the electricity markets and business decision making to maximize their profits. The electricity prices have an impact on the behavior of market participants, and thus, predicting prices for generation companies, and consumers is essential for both the short-term profits in the Day-Ahead, Intra-Day and Ancillary markets, and the long-term benefits in the future planning, investment, and risk management. Therefore, participants in the electricity market need to accurately and effectively predict the price signal to manage market risk. In this paper, different forecasting models have been compared, and the most promising ones have been employed to forecast the short term Italian electricity market clearing price for achieving forecasting accuracy. In particular, simulations are performed for four principal regression methods, including Support Vector Machine, Gaussian Processes Regression, Regression Trees, and Multi-Layer Perceptron. The performance of predicted models is compared through several performance metrics, including MAE, RMSE, R, and the total number of percentage error anomalies. The results indicate the SVM is the best choice for forecasting the electricity market price on the Italian case study
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