5,868 research outputs found

    Spatial distribution of Chlorpyrifos and Endosulfan in USA coastal waters and the Great Lakes

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    Between 1994 and 1997, 258 tissue and 178 sediment samples were analyzed for chlorpyrifos throughout the coastal United States and the Great Lakes. Subsequently, 95 of the 1997 tissue samples were reanalyzed for endosulfan. Tissue chlorpyrifos concentrations, which exceeded the 90th percentile, were found in coastal regions known to have high agricultural use rates but also strongly correlated with sites near high population. The highest concentrations of endosulfans in contrast, were generally limited to agricultural regions of the country. Detections of chlorpyrifos at several Alaskan sites suggest an atmospheric transport mechanism. Many Great Lakes sites had chlorpyrifos tissue concentrations above the 90th percentile which decreased with increasing distance from the Corn Belt region (Iowa, Indiana, Illinois, and Wisconsin) where most agriculturally applied chlorpyrifos is used. Correlation analysis suggests that fluvial discharge is the primary transport pathway on the Atlantic and Gulf of Mexico coasts for chlorpyrifos but not necessarily for endosulfans. (PDF contains 28 pages

    Dimensional Crossover in the Large N Limit

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    We consider dimensional crossover for an O(N)O(N) Landau-Ginzburg-Wilson model on a dd-dimensional film geometry of thickness LL in the large NN-limit. We calculate the full universal crossover scaling forms for the free energy and the equation of state. We compare the results obtained using ``environmentally friendly'' renormalization with those found using a direct, non-renormalization group approach. A set of effective critical exponents are calculated and scaling laws for these exponents are shown to hold exactly, thereby yielding non-trivial relations between the various thermodynamic scaling functions.Comment: 25 pages of PlainTe

    Opportunities for disruptive advances through engineering for next generation energy storage

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    Throughout human history, major economic disruption has been due to technological breakthroughs. Since 1990 the energy density of lithium-ion cells has increased by a factor of four and the cost has dropped by a factor of 10. This has caused disruption to the energy industry, but advances are slowing. The manufacturing and supply chain complexity means that the next big technology will take 15 years to dominate. The academic literature charts this process of development and can be used to show what is in the pipeline. Three candidates that have had a large increase in publication count are: lithium sulphur, solid-state, and sodium-ion technology. From the level of investments in start-ups and academic publication counts, solid‑state cells are closest to maturity. To identify disruption potential, look at uncertainty in performance. Cell lifetime in lithium-ion cells indicates room for improvement. Define a new disruption metric: . Look for areas of industry that lower this metric. Thermal management is a lucrative area for improvement. Cooling the cell tabs of a 5Ah cell reduces the lifetime cost by 66%, compared to 8%/pa for 13 years relying on cost reduction. Second life applications lower the lifetime cost by using the remaining 75% of energy throughput available in a cell after use in an electric vehicle. Drop-in changes to standard manufacturing processes enable huge disruption. Electrolyte additives can increase cell life by 10 times, lowering lifetime cost by 90% in a simple manufacturing intervention

    The Specific Heat of a Ferromagnetic Film.

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    We analyze the specific heat for the O(N)O(N) vector model on a dd-dimensional film geometry of thickness LL using ``environmentally friendly'' renormalization. We consider periodic, Dirichlet and antiperiodic boundary conditions, deriving expressions for the specific heat and an effective specific heat exponent, \alpha\ef. In the case of d=3d=3, for N=1N=1, by matching to the exact exponent of the two dimensional Ising model we capture the crossover for \xi_L\ra\infty between power law behaviour in the limit {L\over\xi_L}\ra\infty and logarithmic behaviour in the limit {L\over\xi_L}\ra0 for fixed LL, where ξL\xi_L is the correlation length in the transverse dimensions.Comment: 21 pages of Plain TeX. Postscript figures available upon request from [email protected]

    Dallas with balls: televized sport, soap opera and male and female pleasures

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    Two of the most popular of television genres, soap opera and sports coverage have been very much differentiated along gender lines in terms of their audiences. Soap opera has been regarded very much as a 'gynocentric' genre with a large female viewing audience while the audiences for television sport have been predominantly male. Gender differentiation between the genres has had implications for the popular image of each. Soap opera has been perceived as inferior; as mere fantasy and escapism for women while television sports has been perceived as a legitimate, even edifying experience for men. In this article the authors challenge the view that soap opera and television sport are radically different and argue that they are, in fact, very similar in a number of significant ways. They suggest that both genres invoke similar structures of feeling and sensibility in their respective audiences and that television sport is a 'male soap opera'. They consider the ways in which the viewing context of each genre is related to domestic life and leisure, the ways in which the textual structure and conventions of each genre invoke emotional identification, and finally, the ways in which both genres re-affirm gender identities

    Heat conduction in the disordered harmonic chain revisited

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    A general formulation is developed to study heat conduction in disordered harmonic chains with arbitrary heat baths that satisfy the fluctuation-dissipation theorem. A simple formal expression for the heat current J is obtained, from which its asymptotic system-size (N) dependence is extracted. It is shown that the ``thermal conductivity'' depends not just on the system itself but also on the spectral properties of the fluctuation and noise used to model the heat baths. As special cases of our heat baths we recover earlier results which reported that for fixed boundaries J1/N3/2J \sim 1/N^{3/2}, while for free boundaries J1/N1/2J \sim 1/N^{1/2}. For other choices we find that one can get other power laws including the ``Fourier behaviour'' J1/NJ \sim 1/N.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev. Let

    Simulational Study on Dimensionality-Dependence of Heat Conduction

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    Heat conduction phenomena are studied theoretically using computer simulation. The systems are crystal with nonlinear interaction, and fluid of hard-core particles. Quasi-one-dimensional system of the size of Lx×Ly×Lz(LzLx,Ly)L_x\times L_y\times L_z(L_z\gg L_x,L_y) is simulated. Heat baths are put in both end: one has higher temperature than the other. In the crystal case, the interaction potential VV has fourth-order non-linear term in addition to the harmonic term, and Nose-Hoover method is used for the heat baths. In the fluid case, stochastic boundary condition is charged, which works as the heat baths. Fourier-type heat conduction is reproduced both in crystal and fluid models in three-dimensional system, but it is not observed in lower dimensional system. Autocorrelation function of heat flux is also observed and long-time tails of the form of td/2\sim t^{-d/2}, where dd denotes the dimensionality of the system, are confirmed.Comment: 4 pages including 3 figure

    Distribution, localization, and phylogeny of abundant populations of Crenarchaeota in anaerobic granular sludge

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    Eight anaerobic granular sludges were surveyed for Crenarchaeota using rRNA gene cloning. Microbial arrangement and substrate uptake patterns were elucidated by fluorescent in situ hybridization and beta imaging. Group 1.3 Crenarchaeota represented up to 50% of Archaea and 25% of the total microbiota in five sludges. Crenarchaeota were localized in close association with methanogenic Archaea
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