Characteristic Angles in the Wetting of an Angular Region: Surface Shape

The shape of a liquid surface bounded by an acute or obtuse planar angular sector is considered by using classical analysis methods. For acute angular sectors the two principal curvatures are of the order of the (fixed) mean curvature. But for obtuse sectors, the principal curvatures both diverge as the vertex is approached. The power-law divergence becomes stronger with increasing opening angle. Possible implications of this contrasting behavior are suggested.Comment: 19 pages, 9 figures, LaTeX; submitted to The European Physics Journal E; v2: Introduction was revised (a number of references added), minor changes to the main part (mostly typos), former Implications subsection was almost entirely rewritten and is now called Experimental Realizations (experimental results and two figures added); v3: Introduction was slightly modified, four references added; v4: Title was modified, section Calculation was significantly modified (subsections Bounary Problem and Horizontal Solution almost entirely rewritten, minor changes to the other subsections), subsection Curvature in section Discussion was revised, one reference adde

Did NEPA Drown New Orleans? The Levees, the Blame Game, and the Hazards of Hindsight

This Article highlights the. hazards of hindsight analysis of the causes of catastrophic events, focusing on theories of why the New Orleans levees failed during Hurricane Katrina in 2005 and particularly on the theory that the levee failures were caused by a 1977 National Environmental Policy Act (NEPA) lawsuit that resulted in a temporary injunction against the Army Corps of Engineers\u27 hurricane protection project for New Orleans. The Article provides a detailed historical reconstruction of the decision process that eventuated in the New Orleans storm surge protection system, focusing both on the political and legal factors involved and on the standard project hurricane risk assessment model that lay at the heart of the Army Corps of Engineers\u27 decisionmaking process. The Article then offers a detailed analysis. of how and why Hurricane Katrina overcame the New Orleans levee system. As this analysis demonstrates, the argument that the NEPA lawsuit played a meaningful causal role in the Katrina disaster is not persuasive. Parallel lessons are then drawn for forward-looking disaster policy. The same problems of uncertainty and complexity that confound the attempt through hindsight to attribute causal responsibility for a disaster also confound the attempt to predict using foresight the variety of outcomes, including potentially disastrous ones, that may flow from policy choices. Focusing narrowly on any single parameter of complex natural and human systems is likely to dramatically distort environmental, health, and safety decisionmaking, whether the parameter is a standard project hurricane when planning a hurricane protection plan, or the equally mythical lawsuit that sunk New Orleans when attempting to allocate responsibility for the plan\u27s failure some forty years later

Did NEPA Drown New Orleans? The Levees, the Blame Game, and the Hazards of Hindsight

This Article highlights the. hazards of hindsight analysis of the causes of catastrophic events, focusing on theories of why the New Orleans levees failed during Hurricane Katrina in 2005 and particularly on the theory that the levee failures were caused by a 1977 National Environmental Policy Act (NEPA) lawsuit that resulted in a temporary injunction against the Army Corps of Engineers\u27 hurricane protection project for New Orleans. The Article provides a detailed historical reconstruction of the decision process that eventuated in the New Orleans storm surge protection system, focusing both on the political and legal factors involved and on the standard project hurricane risk assessment model that lay at the heart of the Army Corps of Engineers\u27 decisionmaking process. The Article then offers a detailed analysis. of how and why Hurricane Katrina overcame the New Orleans levee system. As this analysis demonstrates, the argument that the NEPA lawsuit played a meaningful causal role in the Katrina disaster is not persuasive. Parallel lessons are then drawn for forward-looking disaster policy. The same problems of uncertainty and complexity that confound the attempt through hindsight to attribute causal responsibility for a disaster also confound the attempt to predict using foresight the variety of outcomes, including potentially disastrous ones, that may flow from policy choices. Focusing narrowly on any single parameter of complex natural and human systems is likely to dramatically distort environmental, health, and safety decisionmaking, whether the parameter is a standard project hurricane when planning a hurricane protection plan, or the equally mythical lawsuit that sunk New Orleans when attempting to allocate responsibility for the plan\u27s failure some forty years later

Strings And Dyonic Plasmas

Recently Olesen has shown the existence of dual string solutions to the equations of ideal Magnetohydrodynamics that describe the long wavelength properties of electrically charged plasmas. Here, we extend these solutions to include the case of plasmas consisting of point like dyons, which carry both electric and magnetic charge. Such strings are dyonic in that they consist of both magnetic and electric flux. We contrast some physical features of dyonic plasmas with those of the purely electric or magnetic type, particularly in relation to the validity of the ideal approximation.Comment: 11 pages, LaTeX, no figure

QCD Factorization in BB Decays into ρπ\rho \pi

Based on the QCD factorization approach we analyse the branching ratios for the channel $B \to \rho \pi$. From the comparisons with experimental data provided by CLEO, BELLE and BABAR we constrain the form factor $F^{B \to \pi}(m_{\rho}^{2})$ and propose boundaries for this form factor depending on the CKM matrix element parameters $\rho$ and $\eta$.Comment: 11 pages, 9 figures. Talk presented at Fourth Tropical Workshop, Cairns, Australia, 9--13 June 2003. Proceedings to be published by AI