509 research outputs found

    Market Power and Structural Adjustment: The Case of West African Cocoa Market Liberalization

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    Liberalization of the cocoa market in West Africa, due to structural adjustment reforms, has resulted in the elimination of para-statal marketing boards and initiated the creation of new institutions to replace the marketing services of those agencies. Concerns have been raised as to the effects of these reforms on prices of cocoa received by farmers, welfare measures and competitiveness of marketing channels. Of particular importance is backward integration of multinational processing firms, who take over exporting activities and may collect rents previously captured as export taxes. This paper uses a conjectural variations approach to estimate the degree of market power present in the post-liberalized cocoa bean markets of Ivory Coast and Nigeria. Evidence of market power is found in the Ivory Coast markets between the farmgate and U.S./EU15 imports. The market power, exercised by multinational exporter/processors, must be considered in concert with the Ivorian government who is still collecting export taxes. In contrast, no evidence of market power is found in the Nigerian markets or domestic (farmer to trader) markets of Ivory Coast.Marketing,

    Ethanol Plant Location Determinants and County Comparative Advantage

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    The location of ethanol plants is determined by infrastructure, product and input markets, fiscal attributes of local communities, and state and federal incentives. This empirical analysis uses probit regression along with spatial clustering methods to analyze investment activity of ethanol plants at the county level for the lower U.S. 48 states from 2000 to 2007. The availability of feedstock dominates the site selection decision. Other factors, such as access to navigable rivers or railroads, product markets, producer credit and excise tax exemptions, and methyl tertiary-butyl ether bans provided some counties with a comparative advantage in attracting ethanol plants.cluster analysis, comparative advantage, ethanol production, location model, Community/Rural/Urban Development, Environmental Economics and Policy, Political Economy, R1, R3,

    A probabilistic approach for the optimisation of ultrasonic array inspection techniques

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    AbstractUltrasonic arrays are now used routinely for the inspection of engineering structures in order to maintain their integrity and assess their performance. Such inspections are usually optimised manually using empirical measurements and parametric studies which are laborious, time-consuming, and may not result in an optimal approach. In this paper, a general framework for the optimisation of ultrasonic array inspection techniques in NDE is presented. Defect detection rate is set as the main inspection objective and used to assess the performance of the optimisation framework. Statistical modelling of the inspection is used to form the optimisation problem and incorporate inspection uncertainty such as crack type and location, material properties and geometry, etc. A genetic algorithm is used to solve the global optimisation problem. As a demonstration, the optimisation framework is used with two objective functions based on array signal amplitude and signal-to-noise ratio (SNR). The optimal use of plane B-scan and total focusing method imaging algorithms is also investigated. The performance of the optimisation scheme is explored in simulation and then validated experimentally. It has been found that, for the inspection scenarios considered, TFM provides better detectability in a statistical sense than plane B-scan imaging in scenarios where uncertainty in the inspection is expected

    Mixing of scalar glueballs and flavour-singlet scalar mesons

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    We discuss in detail the extraction of hadronic mixing strengths from lattice studies. We apply this to the mixing of a scalar glueball and a scalar meson in the quenched approximation. We also measure correlations appropriate for flavour-singlet scalar mesons using dynamical quark configurations from UKQCD. This enables us to compare the results from the quenched study of the mixing with the direct determination of the mixed spectrum. Improved methods of evaluating the disconnected quark diagrams are also presented.Comment: 23 pages, 5 postscript figure

    Failure Analysis of Heavy-Ion-Irradiated Schottky Diodes

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    In this work, we use high- and low-magnitude optical microscope images, infrared camera images, and scanning electron microscope images to identify and describe the failure locations in heavy-ion-irradiated Schottky diodes

    Bowen Ratio Energy Balance Measurement of Carbon Dioxide (CO2) Fluxes of No-Till and Conventional Tillage Agriculture in Lesotho

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    Global food demand requires that soils be used intensively for agriculture, but how these soils are managed greatly impacts soil fluxes of carbon dioxide (CO2). Soil management practices can cause carbon to be either sequestered or emitted, with corresponding uncertain influence on atmospheric CO2 concentrations. The situation is further complicated by the lack of CO2 flux measurements for African subsistence farms. For widespread application in remote areas, a simple experimental methodology is desired. As a first step, the present study investigated the use of Bowen Ratio Energy Balance (BREB) instrumentation to measure the energy balance and CO2 fluxes of two contrasting crop management systems, till and no-till, in the lowlands within the mountains of Lesotho. Two BREB micrometeorological systems were established on 100-m by 100-m sites, both planted with maize (Zea mays) but under either conventional (plow, disk-disk) or no-till soil mangement systems. The results demonstrate that with careful maintenance of the instruments by appropriately trained local personnel, the BREB approach offers substantial benefits in measuring real time changes in agroecosystem CO2 flux. The periods where the two treatments could be compared indicated greater CO2 sequestration over the no-till treatments during both the growing and non-growing seasons
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