6,420 research outputs found

    Advanced thermoplastic resins, phase 2

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    High temperature structural resins are required for use on advanced aerospace vehicles as adhesives and composite matrices. NASA-Langley developed polyimide resins were evaluated as high temperature structural adhesives for metal to metal bonding and as composite matrices. Adhesive tapes were prepared on glass scrim fabric from solutions of polyamide acids of the semicrystalline polyimide LARC-CPI, developed at the NASA-Langley Research Center. Using 6Al-4V titanium adherends, high lap shear bond strengths were obtained at ambient temperature (45.2 MPa, 6550 psi) and acceptable strengths were obtained at elevated temperature (14.0 MPa, 2030 psi) using the Pasa-Jell 107 conversion coating on the titanium and a bonding pressure of 1.38 MPa (200 psi). Average zero degree composite tensile and compressive strengths of 1290 MPa (187 ksi) and 883 MPa (128 ksi) respectively were obtained at ambient temperature with unsized AS-4 carbon fiber reinforcement

    Efficient and Generalized Decentralized Monitoring of Regular Languages

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    Part 2: Monitoring and TestingInternational audienceThis paper proposes an efficient and generalized decentralized monitoring algorithm allowing to detect satisfaction or violation of any regular specification by local monitors alone in a system without central observation point. Our algorithm does not assume any form of synchronization between system events and communication of monitors, uses state machines as underlying mechanism for efficiency, and tries to keep the number and size of messages exchanged between monitors to a minimum. We provide a full implementation of the algorithm with an open-source benchmark to evaluate its efficiency in terms of number, size of exchanged messages, and delay induced by communication between monitors. Experimental results demonstrate the effectiveness of our algorithm which outperforms the previous most general one along several (new) monitoring metrics

    2021 Graduate Program Rankings for UNLV & UNR

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    This Fact Sheet presents the 2021 U.S. News and World Report graduate program rankings for the University of Nevada, Las Vegas (UNLV) and the University of Nevada, Reno (UNR). The rankings for 2021 are important when taking into consideration that both UNLV and UNR achieved Carnegie R1 status in 2018. This status marks their place in the top 130 research universities in the country

    Leptogenesis and Low-energy Observables

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    We relate leptogenesis in a class of theories to low-energy experimental observables: quark and lepton masses and mixings. With reasonable assumptions motivated by grand unification, one can show that the CP-asymmetry parameter takes a universal form. Furthermore the dilution mass is related to the light neutrino masses. Overall, these models offer a natural explanation for a lepton asymmetry in the early universe.Comment: 10 pages, revised discussion on light neutrino masse

    The role of Industry 4.0 enabling technologies for safety management: A systematic literature review

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    Innovations introduced during the Industry 4.0 era consist in the integration of the so called "nine pillars of technologies" in manufacturing, transforming the conventional factory in a smart factory. The aim of this study is to investigate enabling technologies of Industry 4.0, focusing on technologies that have a greater impact on safety management. Main characteristics of such technologies will be identified and described according to their use in an industrial environment. In order to do this, we chose a systematic literature review (SLR) to answer the research question in a comprehensively way. Results show that articles can be grouped according to different criteria. Moreover, we found that Industry 4.0 can increase safety levels in warehouse and logistic, as well as several solutions are available for building sector

    Environmental Control Systems for Exploration Missions One and Two

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    In preparing for Exploration Missions One and Two (EM-1 & EM-2), the Ground Systems Development and Operations Program has significant updates to be made to nearly all facilities. This is all being done to accommodate the Space Launch System, which will be the worlds largest rocket in history upon fruition. Facilitating the launch of such a rocket requires an updated Vehicle Assembly Building, an upgraded Launchpad, Payload Processing Facility, and more. In this project, Environmental Control Systems across several facilities were involved, though there is a focus around the Mobile Launcher and Launchpad. Parts were ordered, analysis models were updated, design drawings were updated, and more
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