93 research outputs found

    Formation of runoff at the hillslope scale during intense precipitation

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    On 60 m<sup>2</sup> hillslope plots, at 18 mainly grassland locations in Switzerland rain was applied at rates of 50&ndash;100 mm/h for between 3 and 6 h. The generated flows were measured, including overland flow, near surface and subsurface flow 0.5&ndash;1.3 m below the surface. At some locations less than 2% of the rain flowed down the slope either on or below the surface, whereas at some others more than 90% of the rain ran off. At the majority of sites most runoff was overland flow, though at a few sites subsurface flow, usually via macropores was dominant. Data collected during each of 48 high intensity sprinkling experiments were used to distinguish, which processes were dominant in each experiment. Which dominant and subsidiary processes occurred depended on interactions between infiltration rate, change in soil water storage and drainage of the soil water. These attributes were often not directly linked to parameters usually considered important like vegetation, slope, soil clay content and antecedent soil moisture. Considering the structure of the soil in combination with these attributes, process determination was in many cases fairly straightforward, indicating the possibility of reliably predicting runoff processes at a site. However, at some sites, effects occurred that were not easily recognizable and led to surprising results

    Domain Growth in a 1-D Driven Diffusive System

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    The low-temperature coarsening dynamics of a one-dimensional Ising model, with conserved magnetisation and subject to a small external driving force, is studied analytically in the limit where the volume fraction \mu of the minority phase is small, and numerically for general \mu. The mean domain size L(t) grows as t^{1/2} in all cases, and the domain-size distribution for domains of one sign is very well described by the form P_l(l) \propto (l/L^3)\exp[-\lambda(\mu)(l^2/L^2)], which is exact for small \mu (and possibly for all \mu). The persistence exponent for the minority phase has the value 3/2 for \mu \to 0.Comment: 8 pages, REVTeX, 7 Postscript figures, uses multicol.sty and epsf.sty. Submitted to Phys. Rev.

    The future of public sector accounting research. A polyphonic debate

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    PurposeThe purpose of this polyphonic paper is to report on interdisciplinary discussions on the state-of-the-art and future of public sector accounting research (PSAR). The authors hope to enliven the debates of the past and future developments in terms of context, themes, theories, methods and impacts in the field of PSAR by the exchanges they include here. Design/methodology/approachThis polyphonic paper adopts an interdisciplinary approach. It brings into conversation ideas, views and approaches of several scholars on the actual and future developments of PSAR in various contexts, and explores potential implications. FindingsThis paper has brought together scholars from a plurality of disciplines, research methods and geographical areas, showing at the same time several points of convergence on important future themes (such as accounting as a mean for public, accounting, hybridity and value pluralism) and enabling conditions (accounting capabilities, profession and digitalisation) for PSA scholarship and practice, and the richness of looking at them from a plurality of perspectives. Research limitations/implicationsExploring these past and future developments opens up the potential for interesting theoretical insights. A much greater theoretical and practical reconsideration of PSAR will be fostered by the exchanges included here. Originality/valueIn setting out a future research agenda, this paper fosters theoretical and methodological pluralism in the interdisciplinary research community interested in PSAR in various contexts. The discussion perspectives presented in this paper constitute not only a basis for further research in this relevant accounting area on the role, status and developments of PSAR but also creative potential for practitioners to be more reflective on their practices and also intended and united outcomes of such practices

    Transverse-field Ising spin chain with inhomogeneous disorder

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    We consider the critical and off-critical properties at the boundary of the random transverse-field Ising spin chain when the distribution of the couplings and/or transverse fields, at a distance ll from the surface, deviates from its uniform bulk value by terms of order lκl^{-\kappa} with an amplitude AA. Exact results are obtained using a correspondence between the surface magnetization of the model and the surviving probability of a random walk with time-dependent absorbing boundary conditions. For slow enough decay, κ<1/2\kappa<1/2, the inhomogeneity is relevant: Either the surface stays ordered at the bulk critical point or the average surface magnetization displays an essential singularity, depending on the sign of AA. In the marginal situation, κ=1/2\kappa=1/2, the average surface magnetization decays as a power law with a continuously varying, AA-dependent, critical exponent which is obtained analytically. The behavior of the critical and off-critical autocorrelation functions as well as the scaling form of the probability distributions for the surface magnetization and the first gaps are determined through a phenomenological scaling theory. In the Griffiths phase, the properties of the Griffiths-McCoy singularities are not affected by the inhomogeneity. The various results are checked using numerical methods based on a mapping to free fermions.Comment: 11 pages (Revtex), 11 figure

    New Dynamic Monte Carlo Renormalization Group Method

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    The dynamical critical exponent of the two-dimensional spin-flip Ising model is evaluated by a Monte Carlo renormalization group method involving a transformation in time. The results agree very well with a finite-size scaling analysis performed on the same data. The value of z=2.13±0.01z = 2.13 \pm 0.01 is obtained, which is consistent with most recent estimates

    Heat Resistance Mediated by a New Plasmid Encoded Clp ATPase, ClpK, as a Possible Novel Mechanism for Nosocomial Persistence of Klebsiella pneumoniae

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    Klebsiella pneumoniae is an important opportunistic pathogen and a frequent cause of nosocomial infections. We have characterized a K. pneumoniae strain responsible for a series of critical infections in an intensive care unit over a two-year period. The strain was found to be remarkably thermotolerant providing a conceivable explanation of its persistence in the hospital environment. This marked phenotype is mediated by a novel type of Clp ATPase, designated ClpK. The clpK gene is encoded by a conjugative plasmid and we find that the clpK gene alone renders an otherwise sensitive E. coli strain resistant to lethal heat shock. Furthermore, one third of a collection of nosocomial K. pneumoniae isolates carry clpK and exhibit a heat resistant phenotype. The discovery of ClpK as a plasmid encoded factor and its profound impact on thermal stress survival sheds new light on the biological relevance of Clp ATPases in acquired environmental fitness and highlights the challenges of mobile genetic elements in fighting nosocomial infections
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