2,448 research outputs found

    The synthesis of some acylglycines and related oxazolones

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    A Model of Adaptive Behavior in the New England Fishing Industry, Report to the National Science Foundation, Volume III

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    This volume is the third in a three volume series of reports submitted to the National Science Foundation for a project entitled University of Rhode Island, University of Maine Study of Social and Cultural Aspects of Fisheries Management Under Extended Jurisdiction (N.S.F. Grant Number AER77-060l8). This project was funded through the RANN Directorate of N.S.F. (Research Applied to National Needs), and was designed to provide data on social, cultural, and economic aspects of the New England fishinq scene which would be of value to those in industry and government concerned with managing the marine fisheries of the northeastern part of the United States, particularly those concerned with management under PL 94-265, the Fisheries Conservation and Management Act of 1976

    Evolution of the Maine Lobster Co-management Law

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    In fisheries management circles, there is growing realization that traditional ways of managing marine resources are not working and that new approaches to management need to be tried. One of the most promising of these new approaches is co-management, where authority for managing fish stocks is shared between the industry and government agencies. This paper discusses the implementation of the new co-management system, which was initiated in the Maine lobster industry in 1995. The law has clearly been successful; it has been framed in a way to allow lobster fishermen to be able to generate rules to constrain their own exploitative effort. At the same time, a number of problems have come to the fore, not least of which was the fact that passage of one regulatory measure caused problems for certain groups of fishermen who demanded remedial legislation. Thus, the co-management effort in Maine has moved ahead by solving a sequence of problems. But the fact that these problems are being solved places Maine in the forefront of jurisdictions experimenting with new ways to manage fisheries

    Liquid drop splashing on smooth, rough and textured surfaces

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    Splashing occurs when a liquid drop hits a dry solid surface at high velocity. This paper reports experimental studies of how the splash depends on the roughness and the texture of the surfaces as well as the viscosity of the liquid. For smooth surfaces, there is a "corona" splash caused by the presence of air surrounding the drop. There are several regimes that occur as the velocity and liquid viscosity are varied. There is also a "prompt" splash that depends on the roughness and texture of the surfaces. A measurement of the size distribution of the ejected droplets is sensitive to the surface roughness. For a textured surface in which pillars are arranged in a square lattice, experiment shows that the splashing has a four-fold symmetry. The splash occurs predominantly along the diagonal directions. In this geometry, two factors affect splashing the most: the pillar height and spacing between pillars.Comment: 9 pages, 11 figure

    Water entry of a flat elastic plate at high horizontal speed

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    The two-dimensional problem of an elastic-plate impact onto an undisturbed surface of water of infinite depth is analysed. The plate is forced to move with a constant horizontal velocity component which is much larger than the vertical velocity component of penetration. The small angle of attack of the plate and its vertical velocity vary in time, and are determined as part of the solution, together with the elastic deflection of the plate and the hydrodynamic loads within the potential flow theory. The boundary conditions on the free surface and on the wetted part of the plate are linearized and imposed on the initial equilibrium position of the liquid surface. The wetted part of the plate depends on the plate motion and its elastic deflection. To determine the length of the wetted part we assume that the spray jet in front of the advancing plate is negligible. A smooth separation of the free-surface flow from the trailing edge is imposed. The wake behind the moving body is included in the model. The plate deflection is governed by Euler’s beam equation, subject to free–free boundary conditions. Four different regimes of plate motion are distinguished depending on the impact conditions: (a) the plate becomes fully wetted; (b) the leading edge of the plate touches the water surface and traps an air cavity; (c) the free surface at the forward contact point starts to separate from the plate; (d) the plate exits the water. We could not detect any impact conditions which lead to steady planing of the free plate after the impact. It is shown that a large part of the total energy in the fluid–plate interaction leaves the main bulk of the liquid with the spray jet. It is demonstrated that the flexibility of the plate may increase the hydrodynamic loads acting on it. The impact loads can cause large bending stresses, which may exceed the yield stress of the plate material. The elastic vibrations of the plate are shown to have a significant effect on the fluid flow in the wake

    Stochastic Perturbations in Vortex Tube Dynamics

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    A dual lattice vortex formulation of homogeneous turbulence is developed, within the Martin-Siggia-Rose field theoretical approach. It consists of a generalization of the usual dipole version of the Navier-Stokes equations, known to hold in the limit of vanishing external forcing. We investigate, as a straightforward application of our formalism, the dynamics of closed vortex tubes, randomly stirred at large length scales by gaussian stochastic forces. We find that besides the usual self-induced propagation, the vortex tube evolution may be effectively modeled through the introduction of an additional white-noise correlated velocity field background. The resulting phenomenological picture is closely related to observations previously reported from a wavelet decomposition analysis of turbulent flow configurations.Comment: 16 pages + 2 eps figures, REVTeX

    Incentivizing Faculty-led Study Abroad and Intercultural Learning Outcomes: A Grant Program Model

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    Short Abstract: It is imperative that faculty focus on intercultural learning outcomes when they lead a study abroad program. We use Study Abroad Intercultural Learning (SAIL) Grants and Intercultural Pedagogy Grants (IPG) to address this issue. We will share the perspectives of a dean, an associate director of intercultural pedagogy and learning, and an associate dean of one of our colleges. Full Abstract: Incentivizing faculty to lead study abroad programs is important, but insufficient. We have learned that it is imperative to ensure that faculty focus on intercultural learning outcomes and the assessment of such outcomes, in addition to their specific discipline. At Purdue, Study Abroad Intercultural Learning (SAIL) Grants and Intercultural Pedagogy Grants (IPG) have been created to address this issue. SAIL grants provide subsidies to reduce program costs for students while IPG grants incentive faculty to learn how to select and facilitate intercultural learning outcomes into their study abroad program, and also how to assess them. In this session we will share how our process works from the perspectives of a dean, an associate director of intercultural pedagogy and teaching, and an associate dean of one of our colleges

    A Simple Model for Solar Isorotational Contours

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    The solar convective zone, or SCZ, is nearly adiabatic and marginally convectively unstable. But the SCZ is also in a state of differential rotation, and its dynamical stability properties are those of a weakly magnetized gas. This renders it far more prone to rapidly growing rotational baroclinic instabilities than a hydrodynamical system would be. These instabilities should be treated on the same footing as convective instabilites. If isentropic and isorotational surfaces coincide in the SCZ, the gas is marginally (un)stable to {\em both} convective and rotational disturbances. This is a plausible resolution for the instabilities associated with these more general rotating convective systems. This motivates an analysis of the thermal wind equation in which isentropes and isorotational surfaces are identical. The characteristics of this partial differential equation correspond to isorotation contours, and their form may be deduced even without precise knowledge of how the entropy and rotation are functionally related. Although the exact solution of the global SCZ problem in principle requires this knowledge, even the simplest models produce striking results in broad agreement with helioseismology data. This includes horizontal (i.e. quasi-spherical) isorotational contours at the poles, axial contours at the equator, and approximately radial contours at midlatitudes. The theory does not apply directly to the tachocline, where a simple thermal wind balance is not expected to be valid. The work presented here is subject to tests of self-consistency, among them the prediction that there should be good agreement between isentropes and isorotational contours in sufficiently well-resolved large scale numerical MHD simulations.Comment: Final version: 21 pages, 4 figures, to appear in MNRAS; thorough revision, typos and minor errors corrected, expanded development and reordering of the material. Conclusions unchanged from origina
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