3,427 research outputs found

    Method and system for respiration analysis Patent

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    Respiration analyzing method and apparatus for determining subjects oxygen consumption in aerospace environment

    Light transport and general aviation aircraft icing research requirements

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    A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer management file and an industry/Government agency survey. Assessment of the current facilities and icing technology was accomplished by presenting summaries of ice sensitive components and protection methods; and assessments of penalty evaluation, the experimental data base, ice accretion prediction methods, research facilities, new protection methods, ice protection requirements, and icing instrumentation. The intent of the research plan was to determine what icing research NASA LeRC must do or sponsor to ultimately provide for increased utilization and safety of light transport and general aviation aircraft

    Electron paramagnetic resonance and photochromism of N3V0\mathrm{N}_{3}\mathrm{V}^{0} in diamond

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    The defect in diamond formed by a vacancy surrounded by three nearest-neighbor nitrogen atoms and one carbon atom, N3V\mathrm{N}_{3}\mathrm{V}, is found in ā‰ˆ98%\approx98\% of natural diamonds. Despite N3V0\mathrm{N}_{3}\mathrm{V}^{0} being the earliest electron paramagnetic resonance spectrum observed in diamond, to date no satisfactory simulation of the spectrum for an arbitrary magnetic field direction has been produced due to its complexity. In this work, N3V0\mathrm{N}_{3}\mathrm{V}^{0} is identified in 15N^{15}\mathrm{N}-doped synthetic diamond following irradiation and annealing. The 15N3V0\mathrm{^{15}N}_{3}\mathrm{V}^{0} spin Hamiltonian parameters are revised and used to refine the parameters for 14N3V0\mathrm{^{14}N}_{3}\mathrm{V}^{0}, enabling the latter to be accurately simulated and fitted for an arbitrary magnetic field direction. Study of 15N3V0\mathrm{^{15}N}_{3}\mathrm{V}^{0} under excitation with green light indicates charge transfer between N3V\mathrm{N}_{3}\mathrm{V} and Ns\mathrm{N_s}. It is argued that this charge transfer is facilitated by direct ionization of N3Vāˆ’\mathrm{N}_{3}\mathrm{V}^{-}, an as-yet unobserved charge state of N3V\mathrm{N}_{3}\mathrm{V}

    Socio-economic inequalities in physical functioning: a comparative study of English and Greek elderly men

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    The associations between socio-economic position (SEP) and physical functioning have frequently been investigated but little is known about which measures of SEP are the best to use for older people. This study examined how different SEP indicators related to the physical functioning of men aged 50 or more years in England and Greece. The data derived from Wave 1 of the English Longitudinal Study of Ageing (ELSA) and from the Survey of Health, Ageing and Retirement in Europe (SHARE). Self-reported physical functioning limitations and mobility difficulties were combined and categorised into ā€˜no disabilityā€™, ā€˜mild disabilityā€™ and ā€˜severe disabilityā€™. The SEP indicators studied were: wealth, educational level and occupational class. The findings indicate that respondents with less wealth, fewer educational qualifications and lower occupational class were more likely to experience mild or severe physical disability than those of high SEP. When all three measures of SEP were adjusted for each other, in both samples wealth maintained a strong association with mild and severe disability, while education was associated with severe disability but only among English men. Occupational class was not strongly associated with physical disability in either case. Hence, among English and Greek older men, wealth was a more important predictor of physical functioning difficulties than either occupational class or education

    Socioeconomic inequalities in physical functioning: A comparative study of English and Greek elderly males

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    The associations between socio-economic position (SEP) and physical functioning have frequently been investigated but little is known about which measures of SEP are the best to use for older people. This study examined how different SEP indicators related to the physical functioning of men aged 50 or more years in England and Greece. The data derived from Wave 1 of the English Longitudinal Study of Ageing (ELSA) and from the Survey of Health, Ageing and Retirement in Europe (SHARE). Self-reported physical functioning limitations and mobility difficulties were combined and categorised into ā€˜no disabilityā€™, ā€˜mild disabilityā€™ and ā€˜severe disabilityā€™. The SEP indicators studied were: wealth, educational level and occupational class. The findings indicate that respondents with less wealth, fewer educational qualifications and lower occupational class were more likely to experience mild or severe physical disability than those of high SEP. When all three measures of SEP were adjusted for each other, in both samples wealth maintained a strong association with mild and severe disability, while education was associated with severe disability but only among English men. Occupational class was not strongly associated with physical disability in either case. Hence, among English and Greek older men, wealth was a more important predictor of physical functioning difficulties than either occupational class or education

    Gelatine backing affects the performance of single-layer ballistic-resistant materials against blast fragments

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    Penetrating trauma by energized fragments is the most common injury from explosive devices, the main threat in the contemporary battlefield. Such devices produce projectiles dependent upon their design, including preformed fragments, casings, glass, or stones; these are subsequently energized to high velocities and cause serious injuries to the body. Current body armor focuses on the essential coverage, which is mainly the thoracic and abdominal area, and can be heavy and cumbersome. In addition, there may be coverage gaps that can benefit from the additional protection provided by one or more layers of lightweight ballistic fabrics. This study assessed the performance of single layers of commercially available ballistic protective fabrics such as KevlarĀ®, TwaronĀ®, and DyneemaĀ®, in both woven and knitted configurations. Experiments were carried out using a custom-built gas-gun system, with a 0.78-g cylindrical steel fragment simulating projectile (FSP) as the impactor, and ballistic gelatine as the backing material. FSP velocity at 50% risk of material perforation, gelatine penetration, and high-risk wounding to soft tissue, as well as the depth of penetration (DoP) against impact velocity and the normalized energy absorption were used as metrics to rank the performance of the materials tested. Additional tests were performed to investigate the effect of not including a soft-tissue simulant backing material on the performance of the fabrics. The results show that a thin layer of ballistic material may offer meaningful protection against the penetration of this FSP. Additionally, it is essential to ensure a biofidelic boundary condition as the protective efficacy of fabrics was markedly altered by a gelatine backing

    All-optical hyperpolarization of electron and nuclear spins in diamond

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    Low thermal polarization of nuclear spins is a primary sensitivity limitation for nuclear magnetic resonance. Here we demonstrate optically pumped (microwave-free) nuclear spin polarization of 13C^{13}\mathrm{C} and 15N^{15}\mathrm{N} in 15N^{15}\mathrm{N}-doped diamond. 15N^{15}\mathrm{N} polarization enhancements up to āˆ’2000-2000 above thermal equilibrium are observed in the paramagnetic system Ns0\mathrm{N_s}^{0}. Nuclear spin polarization is shown to diffuse to bulk 13C^{13}\mathrm{C} with NMR enhancements of āˆ’200-200 at room temperature and āˆ’500-500 at 240Ā K\mathrm{240~K}, enabling a route to microwave-free high-sensitivity NMR study of biological samples in ambient conditions.Comment: 5 pages, 5 figure
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