289 research outputs found

    The Ultrasonic Measurement of Stress on Ferrous Plate using Pulsed Electromagnet Magnetostrictive Emat Probes

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    Last year we finished the design and assembly of a semi-automatic system for the measurement of stress in textured ferritic steel[2], Magneto- strictive EMATs, which have no contributions generated by Lorentz force, were used on ferrous alloys since the absence of the Lorentz force mechanism precludes any velocity errors that might be produced by interference of Lorentz force and magnetostrictively generated signals. Phase shifts due to lift-off were solved by driving the transmitter EMAT’s in series. To make reliable wave-speed measurements in an industrial environment with an economical sampling period of 100 nanoseconds, a Fourier Transform-Phase-Slope technique was implemented which not only solves the zero-crossing problem[1,2], but achieves accuracy approaching the Cramer-Rao bound[3], Initial data are improved over the previous year’s work, however, further refinements are required to archive the expected error bound of ± 2 ksi. These refinements take the form of reducing the effects of temperature induced velocity changes during the measurement process

    Long and Intermediate Wavelength Flaw Reconstruction

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    An automated multiviewing ultrasonic transducer and a first generation signal processing program have been developed for the purpose of detecting and characterizing flaws in materials. The multiviewing transducer has been designed and developed to exploit advances in theoretical inverse elastic wave scattering in the long and intermediate wavelength regime made in recent years. The signal processing algorithm has been assembled as a first step in the development of a decision-tree algorithm for flaw characterization. First results that have been obtained in a completely automatic mode are given in this paper. It is concluded that this new long and intermediate wavelength, model-based reconstruction is feasible and potentially very useful in quantitative NDE applications on real systems.</p

    Rim Pathway-Mediated Alterations in the Fungal Cell Wall Influence Immune Recognition and Inflammation

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    ACKNOWLEDGMENTS We acknowledge Jennifer Lodge, Woei Lam, and Rajendra Upadhya for developing and sharing the chitin and chitosan MTBH assay. We thank Todd Brennan of Duke University for providing MyD88-deficient mice. We acknowledge Neil Gow for providing access to the Dionex HPAEC-PAD instrumentation. We also acknowledge Connie Nichols for critical reading of the manuscript. These experiments were supported by an NIH grant to J.A.A. and F.L.W., Jr. (R01 AI074677). C.M.L.W. was supported by a fellowship provided through the Army Research Office of the Department of Defense (no. W911NF-11-1-0136 f) (F.L.W., Jr.). J.W., L.W., and C.M. were supported by the Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377) and the MRC, Centre for Medical Mycology (MR/N006364/1). FUNDING INFORMATION MRC Centre for Medical MycologyMR/N006364/1 Carol A. Munro HHS | NIH | National Institute of Allergy and Infectious Diseases (NIAID) https://doi.org/10.13039/100000060R01 AI074677J. Andrew Alspaugh Wellcome https://doi.org/10.13039/100010269097377 Carol A. Munro DOD | United States Army | RDECOM | Army Research Office (ARO) https://doi.org/10.13039/100000183W911NF-11-1-0136 f Chrissy M. Leopold WagerPeer reviewedPublisher PD

    Long and Intermediate Wavelength Flaw Reconstruction

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    Higher Order Acoustoelastic Lamb Wave Propagation in Stressed Plates

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    Residual stresses can be generated during fabrication processes, such as, welding, forging, rolling etc[1-3] . They have obvious influence on the performance of the material, like cracking and corrosion. To better control residual stresses, the initial distribution of them in materials must be clear. Ultrasonic methods can be used as a good tool for residual stress detection, and this approach is non-destructive and costs are modest. Methods which utilize longitudinal critically refracted (LCR) waves are receiving increased attention and it can be used on thick material. However, there have only been a limited number of studies which consider the acoustoelastic effect for thin plate materials which generate Lamb waves[4] . This paper reports a study in which a numerical model[5-6] is used to investigate the Lamb wave dispersion curves under loading that induce stresses. The effects of stress on various Lamb modes are discussed and those which appear to be most sensitive are identified. It is found that when the stress’s direction is the same with wave propagation direction in a 1 mm thick aluminum plate the A0 mode is the most sensitive to the applied stress

    The Ultrasonic Measurement of Stress on Ferrous Plate

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    It has recently been shown that one can measure stress, in the presence of texture, or other metallurgical variables, by comparing the velocities of horizontally polarized (SH) ultrasonic waves propagating in orthogonal directions [1,2].</p

    Defects in intracellular trafficking of fungal cell wall synthases lead to aberrant host immune recognition

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    Acknowledgments We acknowledge Jeanette Wagener and Louise Walker for performing the HPAEC-PAD analysis and Neil Gow for providing access to the Dionex HPAEC-PAD instrumentation. We thank Mike Cook and the Duke University Cancer Center Flow Cytometry Shared Resource for assistance with the flow cytometry. We also acknowledge Michelle Plue and the Duke University Shared Materials Institute Facility for performing the transmission electron microscopy. We thank Marcel Wušthrich for providing the MyD88-/-and TLR2/4-/- mice, and Mari Shinohara and Elizabeth Deerhake for providing the Dectin-1-/- mice. Funding: These experiments were supported by a National Institutes of Health grant awarded to JAA and FLW, Jr. (R01 AI074677, https://grants.nih.gov/grants/oer.html). CM and colleagues Jeanette Wagener, Louise Walker, Neil Gow were supported by the Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377, https://wellcome.ac.uk), Wellcome Trust Senior Investigator Award (101873) and the MRC Centre for Medical Mycology (MR/N006364/1, https://www.abdn.ac.uk/cmm/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Higher order acoustoelastic Lamb wave propagation in stressed plates

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    On the Accuracy, Media Representation, and Public Perception of Psychological Scientists’ Judgments of Societal Change

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    At the onset of the COVID-19 pandemic, psychological scientists frequently made on-the-record predictions in public media about how individuals and society would change. Such predictions were often made outside these scientists’ areas of expertise, with justifications based on intuition, heuristics, and analogical reasoning (Study 1; N = 719 statements). How accurate are these kinds of judgments regarding societal change? In Study 2, we obtained predictions from scientists (N = 717) and lay Americans (N = 394) in the spring of 2020 regarding the direction of change for a range of social and psychological phenomena. We compared them to objective data obtained at six months and one year. To further probe how experience impacts such judgments, six months later (Study 3), we obtained retrospective judgments of societal change for the same domains (Nscientists = 270; NlayPeople = 411). Bayesian analysis suggested greater credibility of the null hypothesis that scientists’ judgments were at chance on average for both prospective and retrospective judgments. Moreover, neither domain-general expertise (i.e., judgmental accuracy of scientists compared to laypeople) nor self-identified domain-specific expertise improved accuracy. In a follow-up study on meta-accuracy (Study 4), we show that the public nevertheless expects psychological scientists to make more accurate predictions about individual and societal change compared to most other scientific disciplines, politicians, and non-scientists, and they prefer to follow their recommendations. These findings raise questions about the role psychological scientists could and should play in helping the public and policymakers plan for future events

    Fundamental social motives measured across forty-two cultures in two waves

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    How does psychology vary across human societies? The fundamental social motives framework adopts an evolutionary approach to capture the broad range of human social goals within a taxonomy of ancestrally recurring threats and opportunities. These motives—self-protection, disease avoidance, affiliation, status, mate acquisition, mate retention, and kin care—are high in fitness relevance and everyday salience, yet understudied cross-culturally. Here, we gathered data on these motives in 41 countries (N=15,885) in two cross-sectional waves, including 19 countries (N=11,095) for which data were gathered in both waves. Wave 1 was collected from 2016 through mid-2019 (32 countries, N=9353; 3537 male, 5574 female; Mage=24.58, SD=8.07). Wave 2 was collected from May through October 2020, during the COVID-19 pandemic (N=6532; 2194 male, 4165 female; Mage=28.82, SD=11.49). These data can be used to assess differences and similarities in people’s fundamental social motives both across and within cultures, at different time points, and in relation to other commonly studied cultural indicators and outcomes
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