The effect of friction in the hold down post spherical bearings on hold down post loads

The effect of friction at the connection of the Solid Rocket Booster (SRB) aft skirt and the mobile launch platform (MLP) hold down posts was analyzed. A simplified model of the shuttle response during the Space Shuttle Main Engine (SSME) buildup was constructed. The model included the effect of stick-slip friction for the rotation of the skirt about the spherical bearing. Current finite element models assume the joint is completely frictionless in rotation and therefore no moment is transferred between the skirt and the hold down posts. The model was partially verified against test data and preliminary parameter studies were performed. The parameter studies indicated that the coefficient of friction strongly influenced the moment on the hold down posts. The coefficient of friction had little effect on hold down post vertical loads, however. Further calibration of the model is necessary before the effect of friction on the hold down post horizontal loads can be analyzed

RESEARCH IN AGRICULTURAL ECONOMICS--IS ANYONE LISTENING? DISCUSSION

Research and Development/Tech Change/Emerging Technologies,

FARM PROGRAMS, PESTICIDE USE, AND SOCIAL COSTS

Environmental Economics and Policy,

THE 2002 FARM BILL: WHAT DOES IT MEAN FOR WESTERN AGRICULTURE?

Agricultural and Food Policy,

Using probabilistic analysis to assess the reliability of predicted SRB aft-skirt stresses

Probabilistic failure analysis is a tool to predict the reliability of a part or system. Probabalistic techniques were used to predict critical stresses which occur in the solid rocket booster aft-skirt during main engine buildup, immediately prior to lift-off. More than any other hold down post (HDP) load component, the Z loads are sensitive to variations in strains and calibration constants. Also, predicted aft-skirt stresses are strongly affected by HDP load variations. Therefore, the instrumented HDP are not effective load transducers for Z loads, and, when used with aft skirt stress indicator equations, yield estimates with large uncertainty. Monte Carlo simulation proved to be a straight forward way of studying the overlapping effects of multiple parameters on predicted equipment performance. An advantage of probabilistic analysis is the degree of uncertainty of each parameter as stated explicitly by its probability distribution. It was noted, however, that the choice of parameter distribution had a large effect on the simulation results. Many times these distributions must be assumed. The engineer who is designing the part should be responsible for the choice of parameter distribution

IMPACTS OF ALTERNATIVE FARM POLICIES ON RURAL COMMUNITIES

The purpose of this study was to describe an LP/IO model for evaluating the economic impacts of alternative farm policies on rural communities and demonstrate its capabilities by analyzing the impacts of three farm policies on a rural community in Texas. Results indicate that in the noncrop sector, two groups of industries are most affected by farm policy. The first group relates to production directly (agricultural services, banking and credit, and nondurable manufacturing) and the second group relates to households (retail trade and services). Farm policies which reduce production but increase net returns cause losses for the first group while benefitting the second group. Both groups are made worse off by farm policies which reduce agricultural production and the value of output.Agricultural and Food Policy, Community/Rural/Urban Development,

Does "skin in the game" reduce risk taking? Leverage, liability and the long-run consequences of new deal financial reforms

We examine how the Banking Acts of the 1933 and 1935 and related New Deal legislation influenced risk taking in the financial sector of the U.S. economy. Our analysis focuses on contingent liability of bank owners for losses incurred by their firms and how the elimination of this liability influenced leverage and lending by commercial banks. Using a new panel data set that compares balance sheets of state and national banks, we find contingent liability reduced risk taking, particularly when coupled with rules requiring banks to join the Federal Deposit Insurance Corporation. Leverage ratios are higher in states with limited liability for bank owners. Banks in states with contingent liability converted each dollar of capital into fewer loans, and thus could sustain larger loan losses (as a fraction of their portfolio) than banks in limited liability states. The New Deal replaced a regime of contingent liability with stricter balance sheet regulation and increased capital requirements, shifting the onus of risk management from banks to state and federal regulators. By separating investment banks from commercial banks, the Glass-Steagall Act left investment banks to manage their own leverage, a feature of financial regulation that, in part, depended on their partnership structur

Private experiments in global governance : primary commodity roundtables and the politics of deliberation

Emerging scholarship on global governance offers ever-more detailed analyses of private regulatory regimes. These regimes aim to regulate some area of social activity without a mandate from, or participation of, states or international organizations. While there are numerous empirical studies of these regimes, the normative theoretical literature has arguably struggled to keep pace with such developments. This is unfortunate, as the proliferation of private regulatory regimes raises important issues about legitimacy in global governance. The aim of this paper is to address some of these issues by elaborating a theoretical framework that can orientate normative investigation of these schemes. It does this through turning to the idea of experimentalist governance. It is argued that experimentalism can provide an important and provocative set of insights about the processes and logics of emerging governance schemes. The critical purchase of this theory is illustrated through an application to the case of primary commodities roundtables, part of ongoing attempts by NGOs, producers, and buyers to set sustainability criteria for commodity production across a range of sectors. The idea of experimentalist governance, we argue, can lend much needed theoretical structure to debates about the normative legitimacy of private regulatory regimes

Measuring Producer Level Beef Cattle Alliance Financial Performance

There has been a movement toward developing production and marketing alliances in the beef cattle sector in the United States to improve communications and ultimately provide higher priced branded products consistent with consumer demand. Beef cattle producers do not employ a consistent methodology to measure the financial performance of alliance participation. Nor do they have the information to negotiate financially sustainable agreements. The concentrated packer and retail sector do not share cost and returns information beyond total business data required by public traded corporations. A methodology using cost accounting and economic analysis is described to measure return on producer's assets for an alliance agreement. This information can be used to inform the margin sectors, feedyards, packers and retailers on what share of increased revenue from branded product sales to pass to the cow-calf segment to make participation competitive and the alliance financially sustainable. The cow-calf segment must absorb the added costs and cyclical financial loss to participate in alliances. Increased revenue is required to make branded products a more profitable marketing option than producing commodity beef.Agricultural Finance, Livestock Production/Industries,