29 research outputs found

    Creep Burst Testing of a Woven Inflatable Module

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    A woven Vectran inflatable module 88 inches in diameter and 10 feet long was tested at the NASA Johnson Space Center until failure from creep. The module was pressurized pneumatically to an internal pressure of 145 psig, and was held at pressure until burst. The external environment remained at standard atmospheric temperature and pressure. The module burst occurred after 49 minutes at the target pressure. The test article pressure and temperature were monitored, and video footage of the burst was captured at 60 FPS. Photogrammetry was used to obtain strain measurements of some of the webbing. Accelerometers on the test article measured the dynamic response. This paper discusses the test article, test setup, predictions, observations, photogrammetry technique and strain results, structural dynamics methods and quick-look results, and a comparison of the module level creep behavior to the strap level creep behavior

    Between Convergence and Exceptionalism: Americans and the British Model of Labor Relations, c. 1867–1920

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    Drivers of conflict and resilience in shifting transboundary fisheries

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    Climate change is causing fish stocks to shift, upending the social-ecological systems that rely on the historic distributions of these stocks and creating or exacerbating fisheries conflicts. The movements of internationally shared stocks between Exclusive Economic Zones (EEZs) or between EEZs and the high seas are especially concerning because they bring into play a variety of geopolitical factors and equity issues surrounding missing or conflicting regulations of jurisdictional boundary zones. Though many studies have explored the responses to and repercussions of shifting stocks on fisheries management, there is a dearth of interdisciplinary case studies that provide insight into the complexity of conflict formation in shifting transboundary fisheries, and that highlight the initial response stages where inclusion of proactive and cooperative measures can greatly improve a system's resilience to conflict. Our study helps to fill this gap by drawing on the knowledge of a diverse group of experts to analyze four case studies where transboundary stock shifts, geopolitical or governance tensions, and uncertainty regarding the future of the marine environment collide. Through synthesis of case study findings, we create a causal model of fishery conflict, within which we highlight factors that may heighten or mitigate the risk of conflict over shifting resources such as complex histories of power imbalance, unequal access to resources, or a lack of consistent and transparent data collection. Cooperation and equitable decision-making processes are recognized as vital components of internationally shared stock management which can promote lasting, effective, and conflict-resilient fisheries

    Labor unions, alternative forms of representation, and the exercise of authority relations in U.S. workplaces

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    The authors draw on a telephone survey of 1,000 U.S. workers to explore whether alternative, nonunion forms of representation are filling the gap left by union decline; whether this matters to authority relations at work; and whether these first two points help to explain union decline. The authors find that nonunion associations do not appear to be filling the gap, but that management-established, nonunion representation systems are one-and-a-half times as widespread as is union representation and are evaluated somewhat more favorably by workers. Both unions and management-established systems bear positive associations with authority relations at work before controlling for management practices, but these are substantially weakened once management practices - especially "bureaucratic" practices - are entered. The authors argue that, in the case of unions, this is likely because unions cause employers to adopt these practices. This is not likely to be the case in management-established systems, however, which are more likely to be set up in conjunction with these practices. Finally, results suggest that management-established systems are often in violation of the Wagner Act, but they bear no association with the propensity to vote for a union. Instead, bureaucratic practices matter, independently of these systems
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