New conformal mapping for adaptive resolving of the complex singularities of Stokes wave

A new highly efficient method is developed for computation of traveling periodic waves (Stokes waves) on the free surface of deep water. A convergence of numerical approximation is determined by the complex singularites above the free surface for the analytical continuation of the travelling wave into the complex plane. An auxiliary conformal mapping is introduced which moves singularities away from the free surface thus dramatically speeding up numerical convergence by adapting the numerical grid for resolving singularities while being consistent with the fluid dynamics. The efficiency of that conformal mapping is demonstrated for Stokes wave approaching the limiting Stokes wave (the wave of the greatest height) which significantly expands the family of numerically accessible solutions. It allows to provide a detailed study of the oscillatory approach of these solutions to the limiting wave. Generalizations of the conformal mapping to resolve multiple singularities are also introduced

Acquired Elliptocytosis as a Manifestation of Myelodysplastic Syndrome with Ring Sideroblasts and Multilineage Dysplasia.

Acquired elliptocytosis is a known but rarely described abnormality in the myelodysplastic syndromes (MDS). Here we report the case of an elderly male who was admitted to the hospital with chest pain, dyspnea, and fatigue and was found to be anemic with an elliptocytosis that had only recently been noted on peripheral smears of his blood. After bone marrow biopsy he was diagnosed with MDS with ring sideroblasts and multilineage dysplasia and acquired elliptocytosis. Here we report a rare case of acquired elliptocytosis cooccurring with MDS with ring sideroblasts and multilineage dysplasia

The Oblate Schwarzschild Approximation for Light Curves of Rapidly Rotating Neutron Stars

We present a simple method for including the oblateness of a rapidly rotating neutron star when fitting X-ray light curves. In previous work we showed that the oblateness induced by rotation at frequencies above 300 Hz produces a geometric effect which needs to be accounted for when modelling light curves to extract constraints on the neutron star's mass and radius. In our model X-rays are emitted from the surface of an oblate neutron star and propagate to the observer along geodesics of the Schwarzschild metric for a spherical neutron star. Doppler effects due to rotation are added in the same manner as in the case of a spherical neutron star. We show that this model captures the most important effects due to the neutron star's rotation. We also explain how the geometric oblateness effect can rival the Doppler effect for some emission geometries.Comment: 8 pages, 4 figures. v2: minor changes. Accepted by the Astrophysical Journa

Crop Contracts versus Spot Markets under the Marketing Assistance Loan Program: The Case of Peanuts

We analyze two types of crop marketing contracts between agricultural producers and processors, delivery-at-harvest and an "option-to-purchase" that emerged in US peanut market after the 2002 Farm Act. This contract structure is interpreted as a marketing strategy trying to fill the gap left by the former quota system.Marketing,

Can Rank-Order Tournaments Improve Efficiency of Quality Differentiated Crop Markets Under Marketing Loan Program Operation? The Case of U.S. Peanuts.

In the paper, alternative contractual arrangements between crop producers and processors are evaluated with a view of addressing the major issues present in peanut markets in the U.S., the major EU supplier of high quality peanuts. The issues are the thinness of the spot markets and the absence of quality premiums, both of which impair market efficiency. Results indicate that introducing contracts with a system of quality differentials creates incentives for producer self-selection to participate in the post harvest cash market. Moreover, in the presence of sufficiently high common production risk, tournament contracts are more efficient and preferred by the producers than the standard fixed premium schedules.contracts, tournaments, efficiency, spot markets, peanuts, Marketing,

Contract Marketing after the 2002 Farm Act: The Case of Peanuts

The elimination of the marketing quota system that regulated the peanut market since the 1930s has been accompanied by the emergence of marketing contracts between farmers and peanut buyers (mainly peanut shellers). Two types of contracts have been observed, forward contracts for delivery at harvest or at a later date and "option to purchase" contracts. We analyze the clauses of contracts used by major shellers in order to infer the motivation behind these contracts (i.e., risk sharing, reduction of transaction costs, improve coordination, exercise of market power, etc.). The analysis points out that the main role of the contracts is to replace the marketing structure existing prior the 2002 Farm Act, where peanut marketing was quite regulated. In this sense, the reduction of transaction costs associated to the need for coordinating a continuous supply of homogeneous quality seems to be the most plausible explanation.Marketing,

Strategic Behavior and Trade in Agricultural Commodities - Competition in World Peanut Markets

In this paper, we make an attempt to rationalize the strategic behavior of major peanut exporting and importing countries in the framework of imperfectly competitive markets with the focus on the global and inter-American peanut trade. This study is motivated by the fact that liberalizing imperfectly competitive and often distorted markets can have unorthodox effects, in particular increase the incentives to overuse certain trade policies. The results suggest that the South American peanut producers stand to benefit from the reductions in the U.S. peanut production supports but, paradoxically, preservation of a tariff may still be mutually welfare enhancing. In the broader context of global peanut trade, multi-lateral tariff reduction increases the low-cost exporters' incentives to subsidize export production, which benefits the consumers but hurts the higher-cost producers.trade, peanuts, strategic behavior, tariffs, TRQs, subsidies, Crop Production/Industries, International Relations/Trade, F12, F13, Q17,

Fatigue delamination behaviour of unidirectional carbon fibre/epoxy laminates reinforced by Z-Fiber® pinnin

-Pin reinforced carbon-fibre epoxy laminates were tested under Mode I and Mode II conditions, both quasi-statically and in fatigue. Test procedures were adapted from existing standard or pre-standard tests. Samples containing 2% and 4% areal densities of carbon-fibre Z-pins (0.28mm diameter) were compared with unpinned laminates. Quasi-static tests under displacement control yielded a dramatic increase of the apparent delamination resistance. Specimens with 2% pin density failed in Mode I at loads 170N, equivalent to an apparent GIC of 2kJ/m2. Fatigue testing under load control showed that the presence of the through- thickness reinforcement slowed down fatigue delamination propagation