1,571 research outputs found

    Soul Work

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    Soul work is the process of bringing the essential self - the soul - out of hiding

    Cost effective use of liquid nitrogen in cryogenic wind tunnels

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    A method of reliquefying from 12 to 19% of the nitrogen exhaust gas from a cryogenic wind tunnel has been developed. Technical feasibility and cost effectiveness of the system depends on performance of an innovative positive displacement expander which requires scale model testing to confirm design studies. The existing cryogenic system at the 0.3-m transonic cryogenic tunnel has been surveyed and extensive upgrades proposed. Upgrades are generally cost effective and may be implemented immediately since they are based on established technology

    Molecular orientational dynamics of the endohedral fullerene Sc3_{3}N@C80_{80} as probed by 13^{13}C and 45^{45}Sc NMR

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    We measure 13C and 45Sc NMR lineshapes and spin-lattice relaxation times (T1) to probe the orientational dynamics of the endohedral metallofullerene Sc3N@C80. The measurements show an activated behavior for molecular reorientations over the full temperature range with a similar behavior for the temperature dependence of the 13C and 45Sc data. Combined with spectral data from Magic Angle Spinning (MAS) NMR, the measurements can be interpreted to mean the motion of the encapsulated Sc3N molecule is independent of that of the C80 cage, although this requires the similar temperature dependence of the 13C and 45Sc spin-lattice relaxation times to be coincidental. For the Sc3N to be fixed to the C80 cage, one must overcome the symmetry breaking effect this has on the Sc3N@C80 system since this would result in more than the observed two 13C lines.Comment: 6 pages, 5 figure

    Magnetic field independence of the spin gap in YBa_2Cu_3O_{7-delta}

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    We report, for magnetic fields of 0, 8.8, and 14.8 Tesla, measurements of the temperature dependent ^{63}Cu NMR spin lattice relaxation rate for near optimally doped YBa_2Cu_3O_{7-delta}, near and above T_c. In sharp contrast with previous work we find no magnetic field dependence. We discuss experimental issues arising in measurements of this required precision, and implications of the experiment regarding issues including the spin or pseudo gap.Comment: 4 pages, 3 figures, as accepted for publication in Physical Review Letter

    Capabilities of a lobster eye telescope in the outer solar system

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    Current lobster eye telescopes demonstrate that it’s possible to produce light-weight, large field of view instruments for observing X-rays for both planetary science and astronomy. Jupiter is the most powerful particle accelerator in the solar system and the other outer planets have intricate and complicated magnetospheres which their moons often orbit within. Particle bombardment of the surfaces of their moons induces the emission of characteristic X-rays which enables their composition to be studied. An orbiting X-ray instrument would transform our understanding of the moons’ composition, as well as the aurorae, atmosphere, plasma tori of outer planet systems and could also enable direct imaging of the entire radiation belt. Lobster eye telescopes are perfect for this application due to their light weight and wide field of view. This paper begins to identify a lobster eye telescope design to fulfil these science goals

    A-STAR: The All-Sky Transient Astrophysics Reporter

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    The small mission A-STAR (All-Sky Transient Astrophysics Reporter) aims to locate the X-ray counterparts to ALIGO and other gravitational wave detector sources, to study the poorly-understood low luminosity gamma-ray bursts, and to find a wide variety of transient high-energy source types, A-STAR will survey the entire available sky twice per 24 hours. The payload consists of a coded mask instrument, Owl, operating in the novel low energy band 4-150 keV, and a sensitive wide-field focussing soft X-ray instrument, Lobster, working over 0.15-5 keV. A-STAR will trigger on ~100 GRBs/yr, rapidly distributing their locations.Comment: Accepted for the European Astronomical Society Publications Series: Proceedings of the Fall 2012 Gamma-Ray Burst Symposium held in Marbella, Spain, 8-12 Oct 201

    Approach to Acute Heart Failure in the Emergency Department

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    Acute heart failure (AHF) patients rarely present complaining of ‘acute heart failure.’ Rather, they initially present to the emergency department (ED) with a myriad of chief complaints, symptoms, and physical exam findings. Such heterogeneity prompts an initially broad differential diagnosis; securing the correct diagnosis can be challenging. Although AHF may be the ultimate diagnosis, the precipitant of decompensation must also be sought and addressed. For those AHF patients who present in respiratory or circulatory failure requiring immediate stabilization, treatment begins even while the diagnosis is uncertain. The initial diagnostic workup consists of a thorough history and exam (with a particular focus on the cause of decompensation), an EKG, chest X-ray, laboratory testing, and point-of-care ultrasonography performed by a qualified clinician or technologist. We recommend initial treatment be guided by presenting phenotype. Hypertensive patients, particularly those in severe distress and markedly elevated blood pressure, should be treated aggressively with vasodilators, most commonly nitroglycerin. Normotensive patients generally require significant diuresis with intravenous loop diuretics. A small minority of patients present with hypotension or circulatory collapse. These patients are the most difficult to manage and require careful assessment of intra- and extra-vascular volume status. After stabilization, diagnosis, and management, most ED patients with AHF in the United States (US) are admitted. While this is understandable, it may be unnecessary. Ongoing research to improve diagnosis, initial treatment, risk stratification, and disposition may help ease the tremendous public health burden of AHF

    Parental separation in childhood and adult smoking in the 1958 British birth cohort

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    BACKGROUND: Parental separation or divorce is a known risk factor for poorer adult health. One mechanism may operate through the uptake of risky health behaviours, such as smoking. This study investigated the association between parental separation and adult smoking in a large British birth cohort and also examined potential socioeconomic, relational and psychosocial mediators. Differences by gender and timing of parental separation were also assessed. METHODS: Multiply imputed data on 11 375 participants of the National Child Development Study (the 1958 British birth cohort) were used. A series of multinomial logistic regression models were estimated to investigate the association between parental separation (0–16 years) and adult smoking status (age 42), and the role of potential socioeconomic, relational and psychosocial mediators. RESULTS: Parental separation in childhood was associated with an increased risk of being a current (RRR = 2.14, 95% CI: 1.77, 2.60) or ex-smoker (RRR = 1.50, 95% CI: 1.22, 1.85) at age 42. This association remained after consideration of potential socioeconomic, psychosocial and relational mediators. Relational (parent–child relationship quality, parental involvement and adult partnership status) and socioeconomic factors (overcrowding, financial hardship, housing tenure, household amenities, free school meal receipt and educational attainment) appeared to be the most important of the groups of mediators investigated. No differences by gender or the timing of parental separation were observed. CONCLUSION: Parental separation experienced in childhood was associated with increased risk of smoking. Families undergoing separation should be further supported in order to prevent the uptake of smoking and to prevent later health problems

    The Value of Participating in British Exploring Society Expeditions: A Three Year Multi Cohort Study

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    A primary aim of many expeditions is to facilitate personal development of young people and 15 while there is much anecdotal evidence to support this aim, there is limited empirical work of 16 varied quality that explores the specific nature of such benefits. This research examined nine 17 summer BES expeditions (Norway, Namibia & Amazon in 2012; Finnmark, Ladakh and 18 Namibia in 2013 and 2014) involving 58 young people (aged between 15 and 22) who completed 19 three on-line questionnaires to collect qualitative (open ended questions) and quantitative (likert 20 scale) data. Measurement of four psychological attributes associated with effective character 21 development were used: mental toughness, coping skills, GRIT and leadership skills. Surveys 22 were completed at three stages; 1) pre expedition, 2) immediately post expedition and 3) three 23 months post expedition. Results indicated that the expeditions impacted positively on the 24 psychological attributes of young people, with short term effects (three months). 25 For the 58 participants, there were statistically significant improvements and small positive 26 effect sizes in mental toughness (P=.006; ηp 2 .167), leadership skills (P=.004; ηp 2 .18), and 27 GRIT (P=.001; ηp 2 .218). There was no significant difference (P>0.05) or effect size for the 28 application of coping strategies. Qualitative data provided insights into how the learning took 29 place and individual perspectives on the overall value of the expedition in relation to narrative 30 understandin

    Incommensurate Charge and Spin Fluctuations in d-wave Superconductors

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    We show analytic results for the irreducible charge and spin susceptibilities, χ0(ω,Q)\chi_0 (\omega, {\bf Q}), where Q{\bf Q} is the momentum transfer between the nodes in d-wave superconductors. Using the BCS theory and a circular Fermi surface, we find that the singular behavior of the irreducible charge susceptibility leads to the dynamic incommensurate charge collective modes. The peaks in the charge structure factor occur at a set of wave vectors which form an ellipse around Qπ=(π,π){\bf Q}_{\pi}=(\pi,\pi) and Q0=(0,0){\bf Q}_0=(0,0) in momentum space with momentum dependent spectral weight. It is also found that, due to the non-singular irreducible spin susceptibility, an extremely strong interaction via random phase approximation is required to support the magnetic peaks near Qπ{\bf Q}_{\pi}. Under certain conditions, the peaks in the magnetic structure factor occur near Q=(π,π(1±δ)){\bf Q}=(\pi,\pi (1 \pm \delta)) and (π(1±δ),π)(\pi (1 \pm \delta),\pi).Comment: 5 pages, 3 figure
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