Environmental qualification testing of the prototype pool boiling experiment

The prototype Pool Boiling Experiment (PBE) flew on the STS-47 mission in September 1992. This report describes the purpose of the experiment and the environmental qualification testing program that was used to prove the integrity of the prototype hardware. Component and box level vibration and thermal cycling tests were performed to give an early level of confidence in the hardware designs. At the system level, vibration, thermal extreme soaks, and thermal vacuum cycling tests were performed to qualify the complete design for the expected shuttle environment. The system level vibration testing included three axis sine sweeps and random inputs. The system level hot and cold soak tests demonstrated the hardware's capability to operate over a wide range of temperatures and gave the project team a wider latitude in determining which shuttle thermal altitudes were compatible with the experiment. The system level thermal vacuum cycling tests demonstrated the hardware's capability to operate in a convection free environment. A unique environmental chamber was designed and fabricated by the PBE team and allowed most of the environmental testing to be performed within the project's laboratory. The completion of the test program gave the project team high confidence in the hardware's ability to function as designed during flight

Grocery Retailers' Dominant Role in Evolving World Food Markets

market consolidation, food retailers, food quality, vertical coordination, supermarket, market power, farmer welfare, Agribusiness, International Relations/Trade, Q13, L13,

Thick section aluminum weldments for SRB structures

The Space Shuttle Solid Rocket Booster (SRB) forward and aft skirts were designed with fracture control considerations used in the design data. Fracture control is based on reliance upon nondestructive evaluation (NDE) techniques to detect potentially critical flaws. In the aerospace industry, welds on aluminum in the thicknesses (0.500 to 1.375 in.) such as those encountered on the SRB skirts are normally welded from both sides to minimize distortion. This presents a problem with the potential presence of undefined areas of incomplete fusion and the inability to detect these potential flaws by NDE techniques. To eliminate the possibility of an undetectable defect, weld joint design was revised to eliminate blind root penetrations. Weld parameters and mechanical property data were developed to verify the adequacy of the new joint design

Effects of Market Power on the Size and Distribution of Subsidy Benefits: The Case of Ethanol Promotion

The subject of market power is discussed frequently in debates about subsidies for ethanol production, and structural conditions in the industry create a prima-facie case for concerns about market power. This paper develops a prototype model for determining the production and price impacts and distribution of benefits from the U.S. ethanol subsidy when upstream sellers in the seed sector and downstream buyers in the processing sector may exercise market power. The impact of the subsidy is analyzed within a simulation framework for alternative levels of market power. Results demonstrate that the impacts on prices and output are limited for modest departures from competition. Distributional impacts are much greater. Seed producers and corn processors with market power are able to capture relatively large shares of the benefits from the subsidy. A perhaps surprising result is that upstream oligopoly power exercised by seed producers is prospectively as important in influencing the positive and distributional impacts of the subsidy as the much more frequently discussed and debated prospect that downstream corn processors may exercise buyer power.Resource /Energy Economics and Policy,

What Do We Know About the Economic Efficiency of Cooperatives: An Evaluative Survey

A debate has arisen concerning the economic efficiency of cooperatives relative to other organizational forms. This paper discusses the efficiency concepts and economic theory relevant to the debate and then proceeds to study the empirical evidence. No credible evidence exists to support the proposition that cooperatives are inefficient relative to investor-owned businesses.Agribusiness,

Retailer Pricing Strategies for Differentiated Products: The Case of Bagged Salads and Lettuce

Demand and Price Analysis,

Retail Pricing Behavior for Perishable Produce Products in the US with Implications for Farmer Welfare

The typical model of retail pricing for produce products assumes retailers set price equal to the farm price plus a certain markup. However, observations from scanner data indicate a large degree of price dispersion in the grocery retailing market. In addition to markup pricing behavior, we document three alternative leading pricing patterns: fixed (constant) pricing, periodic sale, and high-low pricing. Retail price variations under these alternative pricing regimes in general have little correlation with the farm price. How do retailers’ alternative pricing behaviors affect farmers’ welfare? Using markup pricing as the baseline case, we parameterize the model to reflect a prototypical fresh produce market and carry out a series of simulations under different pricing regimes. Our study shows that if harvest cost is sufficiently low, retail prices adjusting only partially, or not at all, to supply shocks tends to diminish farm income and exacerbate farm price volatility relative to the baseline case. However, we also find that if harvest cost is sufficiently large and the harvest-cost constraint places a lower bound on the farm price, increased farm price volatility induced by retailers’ alternative pricing strategies may result in higher farm income, compared to markup pricing. Our study is the first to evaluate the welfare implications for producers of the diversified pricing strategies that retailers utilize in practice and the resulting attenuation of the relationship between prices at retail and at the farm gate.Agribusiness, Demand and Price Analysis,