4,505 research outputs found

    Thermal fatigue and oxidation data on TAZ-8A, MAR-M 200, and Udimet 700 superalloys

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    The fluidized bed technique was used to determine the relative thermal fatigue and oxidation resistance of three superalloys: TAZ-8A, Mar-M 200, and Udimet 700. The alloys TAZ-8A and MAR-M 200 were also tested in the directionally-solidified form. For the 13 combinations of composition, solidification method, surface protection, and specimen geometry, the cycles to cracking varied from 1250 to 15,000. The alloy/coating having the best resistance to thermal fatigue cracking was coated directionally-solidified NASA TAZ-8A. This combination also had excellent oxidation resistance

    Loudness (annoyance), prediction procedure for steady sounds

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    Method has been devised to predict loudness level of any steady sound solely from its measured power spectrum level. Method is based on assumption that, with respect to loudness sensation, the human auditory system acts as open-loop transmission system with transmittance function determined from measured tone curves

    Analytical model for determining spacecraft impact velocity and orientation relative to an impact surface

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    Development of analytical model for determining spacecraft impact velocity and orientation relative to impact surface for variable dynamic condition

    Polarized Neutron Matter: A Lowest Order Constrained Variational Approach

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    In this paper, we calculate some of the polarized neutron matter properties, using the lowest order constrained variational method with the AV18AV_{18} potential and employing a microscopic point of view. A comparison is also made between our results and those of other many-body techniques.Comment: 23 pages, 8 figure

    Picasso on Staff: Employee Classification, Copyrights, and the Creative Process

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    An amplification-free ultra-sensitive electrochemical CRISPR/Cas biosensor for drug-resistant bacteria detection.

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    Continued development of high-performance and cost-effective diagnostic tools is vital for improving infectious disease treatment and transmission control. For nucleic acid diagnostics, moving beyond enzyme-mediated amplification assays will be critical in reducing the time and complexity of diagnostic technologies. Further, an emerging area of threat, in which diagnostics will play an increasingly important role, is antimicrobial resistance (AMR) in bacterial infections. Herein, we present an amplification-free electrochemical CRISPR/Cas biosensor utilizing silver metallization (termed E-Si-CRISPR) to detect methicillin-resistant (MRSA). Using a custom-designed guide RNA (gRNA) targeting the gene of MRSA, the Cas12a enzyme allows highly sensitive and specific detection when employed with silver metallization and square wave voltammetry (SWV). Our biosensor exhibits excellent analytical performance, with detection and quantitation limits of 3.5 and 10 fM, respectively, and linearity over five orders of magnitude (from 10 fM to 0.1 nM). Importantly, we observe no degradation in performance when moving from buffer to human serum samples, and achieve excellent selectivity for MRSA in human serum in the presence of other common bacteria. The E-Si-CRISPR method shows significant promise as an ultrasensitive field-deployable device for nucleic acid-based diagnostics, without requiring nucleic acid amplification. Finally, adjustment to a different disease target can be achieved by simple modification of the gRNA protospacer. [Abstract copyright: This journal is © The Royal Society of Chemistry.

    Concepts and procedures used to determine certain sea wave characteristics

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    A technique and its application are presented by which wave parameters, critical to spacecraft water impact load analysis, may be determined
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