792 research outputs found

    Constructive Logic with Strong Negation is a Substructural Logic. II

    Get PDF
    The goal of this two-part series of papers is to show that constructive logic with strong negation N is definitionally equivalent to a certain axiomatic extension NFL ew of the substructural logic FL ew . The main result of Part I of this series [41] shows that the equivalent variety semantics of N (namely, the variety of Nelson algebras) and the equivalent variety semantics of NFL ew (namely, a certain variety of FL ew -algebras) are term equivalent. In this paper, the term equivalence result of Part I [41] is lifted to the setting of deductive systems to establish the definitional equivalence of the logics N and NFL ew . It follows from the definitional equivalence of these systems that constructive logic with strong negation is a substructural logi

    A Real-Time Ultrasonic Imaging System (ARIS) for Manual Inspection of Aircraft Composite Structures

    Get PDF
    Inspection of aircraft composite structures at field site facilities (air bases) is routinely performed using manual ultrasonic testing (UT) techniques. Using these techniques, the examiner detects and sizes defects such as disbonds and delaminations by monitoring and interpreting A-scan waveform signals on a UT instrument display screen. Manual probe manipula- tion permits maximum scanning flexibility and optimization of the ultrasonic signal response by the examiner using manual motions not possible with mechanized scanners. However, the examiner also must be responsible for instrument calibration, signal interpretation, documentation of inspection results, and completeness of coverage. The data reviewer must be able to validate instrument calibration and completeness of coverage, confirm signal interpretation, and compare current UT results to those obtained during previous inspections

    Hydrogels containing the ferri/ferrocyanide redox couple and ionic liquids for thermocells

    Full text link
    Thermoelectrochemical cells are a promising new technology for harvesting low-grade waste heat. The operation of these cells relies on a redox couple within an electrolyte, which is most commonly water-based, and improvement of these materials is a key aspect of the advancement of this technology. Here, we report the gelation of aqueous electrolytes containing the K3Fe(CN)6/K4Fe(CN)6 redox couple using a range of different polymers, including polyvinyl alcohol (PVA), sodium carboxymethyl cellulose (Cmc), polyacrylamide (PAAm), and two commercial polyurethane-based polymers: HydroMed D640 and HydroSlip C. These polymers produce quasi-solid-state electrolytes with sufficient mechanical properties to prevent leakage, and allow improved device flexibility and safety. Furthermore, the incorporation of various ionic liquids within the optimized hydrogel network is investigated as a route to enhance the electrochemical and mechanical properties and thermal energy harvesting performance of the hydrogels

    Reducing the SPS Machine Impedance

    Get PDF
    The SPS as LHC Injector project has been working for some time to prepare the SPS for its role as final injector for the LHC. This included major work related to injection, acceleration, extraction and beam instrumentation for the LHC beams [1]. Measurements carried out with the high brightness LHC beam showed that a major improvement of the machine impedance would also be necessary [2]. In addition to removing all lepton related components (once LEP operation ended in 2000), the decision was made to shield the vacuum system pumping port cavities. These accidental cavities had been identified as having characteristic frequencies in the 1-1.5GHz range. Since the SPS vacuum system contains roughly 1000 of these cavities, they constitute a major fraction of the machine impedance. As removal of the ports and associated bellows is not possible, transition shields (PPS) had to be designed to insert within the pumping port cavities

    Barriers and facilitators for the use of NURSING bedside handovers : implications for evidence‐based practice

    No full text
    BACKGROUND: Previous studies on bedside handovers have identified nurse-related barriers and facilitators for implementing bedside handovers, but have neglected the existing ward's nursing care system as an important influencing factor. AIMS: To determine the association between the existing nursing care system (i.e., decentralized, two-tier, or centralized) on a ward and the barriers and facilitators of the bedside handover. METHODS: Structured individual interviews (N = 106) on 14 nursing wards in eight hospitals were performed before implementation of bedside handovers. The structured interview guide was based on a narrative review. Direct content analysis was used to determine the nursing care system of a ward and the degree to which barriers and facilitators were present. Pearson's Chi-square analysis was used to determine whether there were associations between the nursing care systems concerning the presence of barriers and facilitators for implementing bedside handovers. RESULTS: Twelve barriers and facilitators were identified, of which three are new to literature: the possible loss of opportunities for socializing, collegiality, and overview; head nurse's role; and role of colleagues. The extent to which barriers and facilitators were present differed across nursing care systems, with the exception of breach of confidentiality (barrier), and an existing structured handover (facilitator). Overall, nurses working in decentralized nursing care systems report fewer barriers against and more facilitators in favor of using bedside handovers than nurses in two-tier or centralized systems. LINKING EVIDENCE TO ACTION: Before implementing bedside handovers, the context of the nursing care system may be considered to determine the most effective process to implement change. Based on these study findings, implementing bedside handovers could be more challenging on wards with a two-tier or centralized care system

    The Bionic Bra: Using electromaterials to sense and modify breast support to enhance active living

    Get PDF
    Background: Although the most supportive sports bras can control breast motion and associated breast pain, they are frequently deemed uncomfortable to wear and, as a result, many women report exercise bra discomfort. Given that exercise bra discomfort is associated with decreased levels of physical activity, there is a pertinent need to develop innovative solutions to address this problem. Objectives: This research aimed to evaluate the use of electromaterial sensors and artificial muscle technology to create a bra that was capable of detecting increases in breast motion and then responding with increased breast support to enhance active living. Methods: The research involved two phases: (i) evaluating sensors suitable for monitoring and providing feedback on changes in the amplitude and frequency of breast motion, and (ii) evaluating an actuator capable of changing breast support provided by a bra during activity. Results: When assessed in isolation, the developed technologies were capable of sensing breast motion and actuating to provide some additional breast support. Conclusions: The challenge now lies in integrating both technologies into a functional sports bra prototype, and assessing this prototype in a controlled biomechanical analysis to provide a breast support solution that will enable women to enjoy active living in comfort

    Proton acceleration by irradiation of isolated spheres with an intense laser pulse

    Get PDF
    We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3 x 10(20) W cm(-2). With a laser focal spot size of 10 mu m full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 mu m. Maximum proton energies of similar to 25 MeV are achieved for targets matching the focal spot size of 10 mu m in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.DFG via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) Transregio SFB TR18NNSA DE-NA0002008Super-MUC pr48meIvo CermakCGC Instruments in design and realization of the Paul trap systemIMPRS-APSLMUexcellent Junior Research FundDAAD|ToIFEEuropean Union's Horizon research and innovation programme 633053Physic
    corecore