A CrN/MoS2(Ti) coating was developed in order to improve the tribological characteristics of single CrN coatings as a possible alternative for high wear low friction applications. The MoS2(Ti) ...coating was produced by PVD closed-field unbalanced magnetron sputtering on CrN coated stainless steel substrates. The tribological performance of both, the single CrN coating and the CrN/MoS2(Ti) coating was evaluated and compared. Characterization of the coatings included: scratch testing, wear testing, nanoindentation, X-ray diffraction, optical and scanning electron microscopy. The CrN coating exhibited excellent adhesion, hardness and stiffness. However, adding the MoS2(Ti) layer led to a significant improvement in the tribological properties, while maintaining the good adhesion characteristics of the underlying CrN layer. A maximum wear volume and coefficient of friction reduction of 95% was observed. Surface roughness of the coatings did not play a major role on the tribological properties. The results of this work provide with enough evidence to consider the CrN/MoS2(Ti) coating as a promising alternative for high wear low friction applications. Materials used as substrates: 440C steel.
This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely 235U-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High ...Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. Further, the reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5–7 MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.0 and 3.7 standard deviations the hypotheses that antineutrinos from 235U are solely responsible and noncontributors to the excess observed at commercial reactors, respectively.
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The PROSPECT and STEREO collaborations present a combined measurement of the pure 235U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral ...measurements of the two highest precision experiments at research reactors are found to be compatible with χ2/ndf = 24.1/21, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This $\bar{ν}_e$ energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model χ2 value is improved, corresponding to a 2.4σ significance.
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