8,614 research outputs found

    High-performance fiber/epoxy composite pressure vessels

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    Activities described include: (1) determining the applicability of an ultrahigh-strength graphite fiber to composite pressure vessels; (2) defining the fatigue performance of thin-titanium-lined, high-strength graphite/epoxy pressure vessel; (3) selecting epoxy resin systems suitable for filament winding; (4) studying the fatigue life potential of Kevlar 49/epoxy pressure vessels; and (5) developing polymer liners for composite pressure vessels. Kevlar 49/epoxy and graphite fiber/epoxy pressure vessels, 10.2 cm in diameter, some with aluminum liners and some with alternation layers of rubber and polymer were fabricated. To determine liner performance, vessels were subjected to gas permeation tests, fatigue cycling, and burst tests, measuring composite performance, fatigue life, and leak rates. Both the metal and the rubber/polymer liner performed well. Proportionately larger pressure vessels (20.3 and 38 cm in diameter) were made and subjected to the same tests. In these larger vessels, line leakage problems with both liners developed the causes of the leaks were identified and some solutions to such liner problems are recommended

    The contested and contingent outcomes of Thatcherism in the UK

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    The death of Margaret Thatcher in April 2013 sparked a range of discussions and debates about the significance of her period in office and the political project to which she gave her name: Thatcherism. This article argues that Thatcherism is best understood as a symbolically important part of the emergence of first-phase neoliberalism. It engages with contemporary debates about Thatcherism among Marxist commentators and suggests that several apparently divergent positions can help us now reach a more useful analysis of Thatcherism’s short- and long-term outcomes for British political economy. The outcomes identified include: an initial crisis in the neoliberal project in the UK; the transformation of the party political system to be reflective of the politics of neoliberalism, rather than its contestation; long-term attempts at the inculcation of the neoliberal individual; de-industrialisation and financial sector dependence; and a fractured and partially unconscious working class. In all long-term outcomes, the contribution of Thatcherism is best understood as partial and largely negative, in that it cleared the way for a longer-term and more constructive attempt to embed neoliberal political economy. The paper concludes by suggesting that this analysis can inform current debates on the left of British politics about how to oppose and challenge the imposition of neoliberal discipline today

    Pre- and postsurgical cognitive trajectories and quantitative MRI changes in Rasmussen syndrome

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    OBJECTIVE: To quantify the longitudinal cognitive trajectory, before and after surgery, of Rasmussen syndrome (RS), a rare disease characterized by focal epilepsy and progressive atrophy of one cerebral hemisphere. METHOD: Thirty-two patients (mean age = 6.7 years; 17 male, 16 left hemispheres affected) were identified from hospital records. The changes in intelligence scores during 2 important phases in the patients' journey to treatment were investigated: (1) during the preoperative period (n = 28, mean follow-up 3.4 years) and (2) from before to after surgery (n = 21 patients, mean time to follow-up 1.5 years). A volumetric magnetic resonance imaging (MRI) analysis of longitudinal changes in gray matter volume was conducted in a subsample of 18 patients. RESULTS: (1) IQ during the preoperative period: At baseline assessment (on average 2.4 years after seizure onset), the left RS group had lower verbal than nonverbal intellectual abilities, whereas the right group exhibited more difficulties in nonverbal than verbal intellect. Verbal and nonverbal scores declined during the follow-up in both groups, irrespective of the affected side. Hemispheric gray matter volumes declined over time in both groups in affected as well as unaffected hemispheres. (2) Postoperative IQ change: The left surgery group declined further in verbal and nonverbal intellect. The right group's nonverbal intellect declined after surgery, whereas verbal abilities did not. Patients with higher abilities preoperatively experienced large declines, whereas those with poorer abilities showed little change. Postoperative seizures negatively impacted on cognitive abilities. SIGNIFICANCE: During the chronic phase of the disease, parallel decline of verbal and nonverbal abilities suggest progressive bilateral hemispheric involvement, supported by evidence from MRI morphometry. Postsurgical cognitive losses are predicted by greater presurgical ability and continuing seizures. A shorter duration from seizure onset to surgery could reduce the postoperative cognitive burden by minimizing the decline in functions supported by the unaffected hemisphere

    Use of the Dexamethasone-Corticotrophin Releasing Hormone Test to Assess Hypothalamic-Pituitary-Adrenal Axis Function in Rheumatoid Arthritis

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    Objectives. Hypothalamic-Pituitary-Adrenal axis function may be abnormal in rheumatoid arthritis (RA). A pilot study in 7 patients suggested impaired glucocorticoid feedback in some patients after the dexamethasone-corticotrophin releasing hormone (CRH) test. This study aimed to investigate the dexamethasone-corticotrophin releasing factor test in a larger group of patients and relate the results to characteristics of the disease. Methods. Outpatients with active RA (≥3 swollen and tender joints and C-reactive protein > 10 mg/L) took dexamethasone (1.5 mg) at 23:00 hour in the evening. Next day, baseline saliva and plasma samples were collected, CRH was infused at 11:00 hour, and 4 serial blood and saliva samples were collected. Plasma samples were stored at −80°C and a radioimmunoassay performed for saliva and plasma cortisol. Results. All 20 participants showed normal dexamethasone suppression and mounted no response to the CRH challenge. In samples with measurable cortisol, there was a strong correlation between saliva and plasma values (r = 0.876, n = 26, P < .01). Conclusion. No abnormalities were found in the Dexamethasone-CRH test in RA patients in contrast to a previous pilot study. Salivary cortisol measurement may offer an alternative noninvasive technique to plasma cortisol in RA patients in future studies

    The Political Economy of Myanmar's Transition

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    This is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in the JOURNAL OF CONTEMPORARY ASIA, 07 Feb 2013, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/00472336.2013.764143.Since holding elections in 2010, Myanmar has transitioned from a direct military dictatorship to a formally democratic system and has embarked on a period of rapid economic reform. After two decades of military rule, the pace of change has startled almost everyone and led to a great deal of cautious optimism. To make sense of the transition and assess the case for optimism, this article explores the political economy of Myanmar's dual transition from state socialism to capitalism and from dictatorship to democracy. It analyses changes within Myanmar society from a critical political economy perspective in order to both situate these developments within broader regional trends and to evaluate the country's current trajectory. In particular, the emergence of state-mediated capitalism and politico-business complexes in Myanmar's borderlands are emphasised. These dynamics, which have empowered a narrow oligarchy, are less likely to be undone by the reform process than to fundamentally shape the contours of reform. Consequently, Myanmar's future may not be unlike those of other Southeast Asian states that have experienced similar developmental trajectories

    Nonresonant Contributions in B->rho pi Decay

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    We consider nonresonant contributions in the Dalitz plot analysis of B->rho pi->pi^+ pi^- pi^0 decay and their potential impact on the extraction of the CKM parameter alpha. In particular, we examine the role of the heavy mesons B^* and B_0, via the process B->pi (B^*, B_0)->pi^+ pi^- pi^0, and their interference with resonant contributions in the rho-mass region. We discuss the inherent uncertainties and suggest that the effects may be substantially smaller than previously indicated.Comment: 15 pages, 3 figures; minor changes, version to appear in Phys. Rev.

    The Big Society and the Conjunction of Crises: Justifying Welfare Reform and Undermining Social Housing

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    The idea of the “Big Society” can be seen as culmination of a long-standing debate about the regulation of welfare. Situating the concept within governance theory, the article considers how the UK coalition government has justified a radical restructuring of welfare provision, and considers its implications for housing provision. Although drawing on earlier modernization processes, the article contends that the genesis for welfare reform was based on an analysis that the government was forced to respond to a unique conjunction of crises: in morality, the state, ideology and economics. The government has therefore embarked upon a programme, which has served to undermine the legitimacy of the social housing sector (most notably in England), with detrimental consequences for residents and raising significant dilemmas for those working in the housing sector

    Upper and Lower Limits on Neutralino WIMP Mass and Spin--Independent Scattering Cross Section, and Impact of New (g-2)_{mu} Measurement

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    We derive the allowed ranges of the spin--independent interaction cross section \sigsip for the elastic scattering of neutralinos on proton for wide ranges of parameters of the general Minimal Supersymmetric Standard Model. We investigate the effects of the lower limits on Higgs and superpartner masses from colliders, as well as the impact of constraints from \bsgamma and the new measurement of \gmtwo on the upper and lower limits on \sigsip. We further explore the impact of the neutralino relic density, including coannihilation, and of theoretical assumptions about the largest allowed values of the supersymmetric parameters. For μ>0\mu>0, requiring the latter to lie below 1\tev leads to \sigsip\gsim 10^{-11}\pb at \mchi\sim100\gev and \sigsip\gsim 10^{-8}\pb at \mchi\sim1\tev. When the supersymmetric parameters are allowed above 1\tev, for 440\gev \lsim \mchi\lsim 1020 \gev we derive a {\em parameter--independent lower limit} of \sigsip \gsim 2\times 10^{-12}\pb. (No similar lower limits can be set for μ<0\mu<0 nor for 1020\gev\lsim\mchi\lsim2.6\tev.) Requiring \abundchi<0.3 implies a {\em parameter--independent upper limit} \mchi\lsim2.6\tev. The new \epem--based measurement of (g2)μ(g-2)_{\mu} restricts \mchi\lsim 350\gev at 1σ1 \sigma CL and \mchi\lsim515\gev at 2σ2 \sigma CL, and implies μ>0\mu>0. The largest allowed values of \sigsip have already become accessible to recent experimental searches.Comment: LaTeX, 17 pages, 9 eps figures. Version to appear in JHE

    Charmless two-body B decays: A global analysis with QCD factorization

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    In this paper, we perform a global analysis of BPPB \to PP and PVPV decays with the QCD factorization approach. It is encouraging to observe that the predictions of QCD factorization are in good agreement with experiment. The best fit γ\gamma is around 7979^\circ. The penguin-to-tree ratio Pππ/Tππ|P_{\pi \pi}/T_{\pi \pi}| of π+π\pi^+ \pi^- decays is preferred to be larger than 0.3. We also show the confidence levels for some interesting channels: B0π0π0B^0 \to \pi^0 \pi^0, K+KK^+ K^- and B+ωπ+B^+ \to \omega \pi^+, ωK+\omega K^+. For BπKB \to \pi K^\ast decays, they are expected to have smaller branching ratios with more precise measurements.Comment: 20 pages, 4 figures, version to appear in Phys. Rev.
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