13,679 research outputs found

    Experimental aerodynamic heating to simulated shuttle tiles

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    The heat transfer to simulated shuttle thermal protection system tiles was investigated experimentally using a highly instrumented metallic thin wall tile arranged with other metal tiles in a staggered tile array. Cold-wall heating rate data for laminar and turbulent flow were obtained in the Langley 8-foot high temperature tunnel at a nominal Mach number of 7, a nominal total temperature of 3300 R, free-stream unit Reynolds number from 3.4 x 10 to the 5th power to 2.2 x 10 to the 6th power per foot, and free-stream dynamic pressure of 1.8 psia to 9.1 psia. Experimental data are presented to illustrate the effects of flow angularity and gap width on both local peak heating and overall heating loads

    Food Safety Incidents, Collateral Damage and Trade Policy Responses: China-Canada Agri-Food Trade

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    As markets become globalized, food safety policy and international trade policy are increasingly intertwined. Globalization also means that food safety incidents are widely reported internationally. One result is that food safety incidents can negatively impact products where no food safety issue exists as consumers lose trust in both foreign and domestic food safety institutions. While the policy framework for dealing with directly effected imported foods is well understood, how to deal with the market failure associated with indirectly affected products within the existing trade policy rules has not been explored. Using the example of China’s 2007 problems with a spate of products safety incidents, a theoretical framework is developed and the response of both the Chinese and Canadian governments analyzed. A cooperative approach to the issues appears to have a number of advantages and does not contravene trade policy commitments.Canada, China, cooperation, food safety, market failure, trade policy, Agricultural and Food Policy, International Development, International Relations/Trade,

    International Product Differentiation Through a Country Brand: An Economic Analysis of National Branding as a Marketing Strategy for Agricultural Products

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    branding, marketing, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,

    International Product Differentiation through a Country Brand: An Economic Analysis of National Branding as a Marketing Strategy for Agricultural Products

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    Trade policy initiatives of developed country governments are in flux. Governments’ need for new trade policy measures has arisen partly because of constraints imposed on the use of export subsidies by the Agreement on Agriculture reached as part of the Uruguay Round of General Agreement on Tariffs and Trade in 1994. Further disciplines on export subsidies and other policy measures may be agreed on in the Doha Round of World Trade Organization (WTO) negotiations, accentuating the need for new policy measures. While the Doha Round may not successfully reach an agreement, the current modalities show provisional agreement on the elimination of multiple forms of export subsidies. There is provisional agreement on more stringent restrictions on the use of export credit programs. Controls on exporting state trading agencies’ ability to subsidize exports are tentatively agreed (Furtan, 2005). Food aid, which can also be used to circumvent disciplines on export subsidies, is also likely to be subject to WTO disciplines.International Relations/Trade,

    Development of biaxial test fixture includes cryogenic application

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    Test fixture has the capability of producing biaxial stress fields in test specimens to the point of failure. It determines biaxial stress by dividing the applied load by the net cross section. With modification it can evaluate materials, design concepts, and production hardware at cryogenic temperatures

    The New Food Safety Regime in the US: How Will it Affect Canadian Competitiveness

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    The FSMA appears to be a major undertaking with a very large responsibility placed on the FDA. It would seem that bottlenecks to exporting are bound to appear which will be very frustrating for Canadian firms. It is important for Canadian firms and Canadian policy makers to work hard to ensure that temporary bottlenecks do not become permanent inhibitors of trade. The Canadian government needs to understand industry concerns and use any mechanisms – including those in the NAFTA – to initiate consultations with the US. Given the likely lags in implementation, North American food markets are likely to exhibit considerable disequilibrium over the near term. Trade flows will be affected. As the implementation programs of the FSMA become more transparent, more sophisticated analysis into its effect on Canadian competitiveness in the US market can be undertaken.food, safety, competitiveness, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,

    The New Food Safety Regime in the US: How Will it Affect Canadian Competitiveness

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    The Food Safety Modernization Act (FSMA) which was signed into law in January, 2011 represents a major initiative to improve food safety in the US. The legislation mandates the US Food and Drug Administration with developing a regulatory system to implement the Act. As yet, the full effect of the Act cannot be evaluated because the regulatory requirements are yet to be developed. There is little doubt, however, that those firms, both domestic and foreign, that wish to supply US consumers with food will face a considerable increase in regulatory costs. This paper outlines the major requirements of the FSMA and suggests how the regulatory burden may fall on foreign versus US domestic suppliers. Areas where Canadian firms may be disadvantaged relative to US firms are outlined. Opportunities that may arise from the FSMA for Canadian agri-food firms are discussed, as are the areas where the FSMA may not conform with the international trade commitments of the United States.competitiveness, food safety, regulatory burden, SPS, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, International Relations/Trade,

    A Dynamical Systems Approach to Schwarzschild Null Geodesics

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    The null geodesics of a Schwarzschild black hole are studied from a dynamical systems perspective. Written in terms of Kerr-Schild coordinates, the null geodesic equation takes on the simple form of a particle moving under the influence of a Newtonian central force with an inverse-cubic potential. We apply a McGehee transformation to these equations, which clearly elucidates the full phase space of solutions. All the null geodesics belong to one of four families of invariant manifolds and their limiting cases, further characterized by the angular momentum L of the orbit: for |L|>|L_c|, (1) the set that flow outward from the white hole, turn around, then fall into the black hole, (2) the set that fall inward from past null infinity, turn around outside the black hole to continue to future null infinity, and for |L|<|L_c|, (3) the set that flow outward from the white hole and continue to future null infinity, (4) the set that flow inward from past null infinity and into the black hole. The critical angular momentum Lc corresponds to the unstable circular orbit at r=3M, and the homoclinic orbits associated with it. There are two additional critical points of the flow at the singularity at r=0. Though the solutions of geodesic motion and Hamiltonian flow we describe here are well known, what we believe is a novel aspect of this work is the mapping between the two equivalent descriptions, and the different insights each approach can give to the problem. For example, the McGehee picture points to a particularly interesting limiting case of the class (1) that move from the white to black hole: in the limit as L goes to infinity, as described in Schwarzschild coordinates, these geodesics begin at r=0, flow along t=constant lines, turn around at r=2M, then continue to r=0. During this motion they circle in azimuth exactly once, and complete the journey in zero affine time.Comment: 14 pages, 3 Figure

    On-Farm Food Safety and Environmental Farm Plans: A Conceptual Framework for Identifying and Classifying Benefits and Costs

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    This series of six reports entitled: "On-Farm Food Safety and Environmental Farm Plans: Identifying and Classifying Benefits and Costs" was initiated soon after the launch of the Agricultural Policy Framework (APF) in 2002. The APF recognized the importance of food safety and environmental concerns for the future growth of the agriculture and Agri-food sector. For this reason, Agriculture and Agri-Food Canada (AAFC) commissioned this series of reports to develop a conceptual framework to strengthen our understanding of the potential benefit and cost implications of On-farm Food Safety (OFFS) and Environmental Farm Plans (EFP) that were key components of the APF. The reports were prepared by a group of academics with extensive knowledge of the agriculture and Agri-food sector and issues related to food safety, traceability and the environment. The first report presents a summary of the findings in the five main reports in the series. The second report presents the conceptual framework that was developed to help identify qualitatively the potential benefits and costs that the various players in the agriculture and agri-food supply chain would face in implementing OFFS and EFP programs. The third report applies this framework to pork, the fourth, to beef, the fifth, to grains and the sixth, to dairy. In general, benefits and costs are divided into both demand and supply side effects. In addition, both public and private costs and benefits are considered, especially since they help indicate where a role for government might be required and where markets are not working as well as they might. Based on these preliminary qualitative assessments, the beef and pork sector have more to gain from HACCP-based OFFS and EFP initiatives, due to their ability to gain market share from marketing their products internationally, while the grains sector already benefits internationally from its high quality reputation and the dairy sector is restricted to produce only for the domestic market. However, more work is required in these areas to validate and quantify costs and benefits.Agribusiness, Agricultural and Food Policy, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Production Economics, Resource /Energy Economics and Policy,
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