5 research outputs found

    Effects of Head Formation and Heat Treatment on the Mechanical Properties of Connecting Rod Bolts

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    Oliver Racing Parts (ORP; Charlevoix, Michigan) is looking to optimize their manufacturing process for high-strength connecting rod bolts. A high yield strength is desired for the bolts because deformation would result in catastrophic engine failure. The bolts were made of H11, a chromium hot-work tool steel; and MLX17, a precipitation hardenable stainless steel. Tensile testing was performed to determine the tensile and yield strengths of the bolts. Fracture surfaces were imaged via scanning electron microscopy to characterize the failure modes. To observe the effects of bolt heading on microstructure and bolt strength, two batches of MLX17 were prepared; one batch being headed then aged (Group A); the other batch being headed, solution annealed, and then aged (Group B). These bolts were compared to H11 bolts to determine their viability for use, with the results being in the order of highest to lowest yield strength: H11 (272 ksi), MLX17 Treatment B (250 ksi), and MLX17 Treatment A (235 ksi). In the order of highest to lowest tensile strength: H11 (300 ksi), MLX17 Group B (255 ksi), MLX17 Group A (238 ksi). It is suggested that the bolt heading process is causing some overaging in the MLX17 samples, shown by the increase in strength when strain and aging from the heading process are undone through heat treatment. H11 bolts were the strongest tested. Recommendations are to not replace H11 bolts with MLX17 due to a decrease in strength

    Creative destruction in science

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    Drawing on the concept of a gale of creative destruction in a capitalistic economy, we argue that initiatives to assess the robustness of findings in the organizational literature should aim to simultaneously test competing ideas operating in the same theoretical space. In other words, replication efforts should seek not just to support or question the original findings, but also to replace them with revised, stronger theories with greater explanatory power. Achieving this will typically require adding new measures, conditions, and subject populations to research designs, in order to carry out conceptual tests of multiple theories in addition to directly replicating the original findings. To illustrate the value of the creative destruction approach for theory pruning in organizational scholarship, we describe recent replication initiatives re-examining culture and work morality, working parents\u2019 reasoning about day care options, and gender discrimination in hiring decisions. Significance statement It is becoming increasingly clear that many, if not most, published research findings across scientific fields are not readily replicable when the same method is repeated. Although extremely valuable, failed replications risk leaving a theoretical void\u2014 reducing confidence the original theoretical prediction is true, but not replacing it with positive evidence in favor of an alternative theory. We introduce the creative destruction approach to replication, which combines theory pruning methods from the field of management with emerging best practices from the open science movement, with the aim of making replications as generative as possible. In effect, we advocate for a Replication 2.0 movement in which the goal shifts from checking on the reliability of past findings to actively engaging in competitive theory testing and theory building. Scientific transparency statement The materials, code, and data for this article are posted publicly on the Open Science Framework, with links provided in the article

    A randomized, double-blind, placebo-controlled study of latrepirdine in patients with mild to moderate huntington disease: HORIZON investigators of the huntington study group and european huntington's disease network

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    On Aging—Where Are the Advocates? An Annotated Bibliography

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