A Bioeconomic Analysis of the Greenland Shrimp Fishery in the Davis Strait

This paper presents a bioeconomic analysis determining the resource rent and optimum effort of the shrimp (Pandalus borealis) fishery in the Davis Strait, taking into account the discard behaviour of the fleet. It is demonstrated that, from an economic point of view, the shrimp stock in the Davis Strait is substantially overfished. In order to obtain the maximum economic yield, the effort must be reduced by at least 40% compared to the effort level of 1991. The gain in resource rent by reducing effort is estimated to be at least 20% compared to the resource rent of 1991.Bioeconomics, rent, discard, shrimp, Greenland, Environmental Economics and Policy, Production Economics,

The effect of a coastal shelf on long waves in a rotating hemispherical basin

Using finite difference methods, the effect on long waves of a coastal shelf in a rotating hemispherical basin, symmetric about the equator, is studied. Of the four modes investigated, with a shelf added to a constant-depth basin, two modes respond weakly: one is a planetary mode antisymmetric in the sea surface about the equator; the other is a gravity mode symmetric in the sea surface...

On free modes of oscillation of a hemispherical basin centered on the equator

Five barotropic modes of oscillation are computed for a hemispherical basin centered on the equator of a rotating earth. The method of Longuet-Higgins and Pond (1970), which takes full account of horizontal divergence and the sphericity of the earth, is used. Two of the modes are planetary modes and three are gravity modes. Periods of oscillation for the five modes range from one day to over four days...

Torsional Newton-Cartan Geometry and Lifshitz Holography

We obtain the Lifshitz UV completion in a specific model for z=2 Lifshitz geometries. We use a vielbein formalism which enables identification of all the sources as leading components of well-chosen bulk fields. We show that the geometry induced from the bulk onto the boundary is a novel extension of Newton-Cartan geometry with a specific torsion tensor. We explicitly compute all the vevs including the boundary stress-energy tensor and their Ward identities. After using local symmetries/Ward identities the system exhibits 6+6 sources and vevs. The FG expansion exhibits, however, an additional free function which is related to an irrelevant operator whose source has been turned off. We show that this is related to a second UV completion.Comment: v2: 5 pages, matches version published in PR

Frequency Dependent Specific Heat from Thermal Effusion in Spherical Geometry

We present a novel method of measuring the frequency dependent specific heat at the glass transition applied to 5-polyphenyl-4-ether. The method employs thermal waves effusing radially out from the surface of a spherical thermistor that acts as both a heat generator and thermometer. It is a merit of the method compared to planar effusion methods that the influence of the mechanical boundary conditions are analytically known. This implies that it is the longitudinal rather than the isobaric specific heat that is measured. As another merit the thermal conductivity and specific heat can be found independently. The method has highest sensitivity at a frequency where the thermal diffusion length is comparable to the radius of the heat generator. This limits in practise the frequency range to 2-3 decades. An account of the 3omega-technique used including higher order terms in the temperature dependency of the thermistor and in the power generated is furthermore given.Comment: 17 pages, 15 figures, Substantially revised versio

Coloured Petri Nets Extended with Channels for Synchronous Communication

This paper shows how Coloured Petri Nets (CP-nets) can be extended to support synchronous communication. We introduce typed communication channels through which transitions are allowed to communicate. Small examples show how channel commnunication is convenient for creating compact and comprehensive models. The concepts introduced in this paper originate from the practical use of Petri nets for modelling, and they are formally defined in such a way that they preserve the basic properties of CP-nets. We show how a CP-net with channels can be transformed into a behaviourally equivalent CP-net. This allows us to deduce properties of CP-nets with channels from well-known properties of CP-nets.As an example,we extend the concept of place invariants to cope with CP-nets with channels and show how place invariants can be found. This is done without transforming the CP-nets with channels into their equivalent CP-nets. CP-nets with channels can be used as a basis for new hierarchy constructs, and we outline an alternative to invocation transitions, based on CP-nets with channels. The reader is assumed to be familiar with the notion of CP-nets

Assessing the European potential for geological storage of CO2: the GESTCO project

GESTCO is an acronym for European potential for the Geological Storage of CO2 from fossil fuel combustion. The project formed part of the ENERGIE Programme of the European Union 5th Framework and was concluded in 2003. The Geological Survey of Denmark and Greenland (GEUS) led the project, with the national geological surveys of Belgium, France, Germany, Greece, the Netherlands, Norway and UK as research partners (Fig. 1). The primary goal of the GESTCO project was to determine whether the geological storage of carbon dioxide captured at large industrial plants is a viable method of reducing greenhouse gas emissions in Europe (Christensen 2000; Gale et al. 2001; Christensen & Holloway 2003). This was evaluated by a series of case studies that assessed the CO2 storage potential of saline aquifers, geothermal reservoirs, coal seams and oil and gas reservoirs. The case study approach was used so that currently available, largely theoretical, generic information could be applied to real geological situations. In addition aspects of safety and environment, conflicts of using underground space and public and stakeholder perception were evaluated. Secondary goals of the GESTCOproject were to establish an inventory of major CO2 point sources in Europe and a Decision Support System (DSS) to serve as an economic analysis tool for CO2 storage in Europe