10,661 research outputs found
Advanced technology for minimum weight pressure vessel system
Bosses were made of fiber/resin composite materials to evaluate their potential in lightweight pressure vessels. An approximate 25% weight savings over the standard aluminum boss was achieved without boss failures during burst tests. Polymer liners and metal liners are used in fiber composite pressure vessels for containment of gases. The internal support of these liners required during the filament winding process has previously been provided by dissolvable salt mandrels. An internal pressurization technique has been developed which allows overwinding the liner without other means of support and without collapse. Study was made of several additional concepts including styrene/Saran, styrene/flexible epoxy
High-performance fiber/epoxy composite pressure vessels
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
On the Motion of Fluidized Granular Currents: Motion Along Horizontal Surfaces
The motion of fuidised granular currents over horizontal surfaces is investigated experi- mentally and by mathematical modelling of solid and fluid phases. Analytical solutions for the bulk motion were tested by experiments involving material being introduced at a constant volume flux, and a reasonable agreement found between theoretical predictions and laboratory measurements
The contested and contingent outcomes of Thatcherism in the UK
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
Cabibbo-suppressed non-leptonic B- and D-decays involving tensor mesons
The Cabibbo-suppressed non-leptonic decays of B (and D) mesons to final
states involving tensor mesons are computed using the non-relativistic quark
model of Isgur-Scora-Grinstein-Wise with the factorization hypothesis. We find
that some of these B decay modes, as B --> (K^*, D^*)D^*_2, can have branching
ratios as large as 6 x 10^{-5} which seems to be at the reach of future B
factories.Comment: Latex, 11 pages, to appear in Phys. Rev.
The influence of individual differences and family relations on HPA axis activity in pre-school children attending daycare
Psychological and stress hormone correlates in chronic illness and early development:Potential indicators of HPA axis normalisation?
Exploring the anthelmintic properties of Australian native shrubs with respect to their potential role in livestock grazing systems
We measured in vitro anthelmintic activity in extracts from 85 species of Australian native shrub, with a view to identifying species able to provide a degree of worm control in grazing systems. Approximately 40% of the species showed significant activity in inhibiting development of Haemonchus contortus larvae. The most active extracts showed IC50 values of 60–300 mg/ml. Pre-incubation with polyvinylpolypyrrolidine removed the activity from some extracts, implicating tannins as the bioactive agent, while in other cases the pre-incubation had no effect, indicating the presence of other anthelmintic compounds. Plant reproductive maturity (onset of flowering or fruiting) was associated with increasing anthelmintic activity in some species. Variability was observed between plants of the same species growing in different environments, while variation between individual plants of the same species within a single field suggests the existence of distinct chemotypes. Significant activity against adult H. contortus worms in vitro was also demonstrated in a limited number of extracts tested against this life stage. Our study indicates that there is potential for Australian native shrubs to play an anthelmintic role in grazing systems, and highlights some plant biology factors which will need to be considered in order to maximize any anthelmintic effects.A. C. Kotze, J. O’Grady, J. Emms, A. F. Toovey, S. Hughes, P. Jessop, M. Bennell P. E. Vercoe and D. K. Revel
Incidences of road kills and injuries of Komodo dragons along the north coast of Flores Island, Indonesia
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