3,258 research outputs found
Experimental and theoretical study of the gasâwater two phase flow through a conductance multiphase Venturi meter in vertical annular (wet gas) flow
Annular gasâliquid two phase flow widely occurs in nuclear industry. Various combinations of techniques have been employed in annular gasâliquid two phase flows to measure the flow parameters (e.g. liquid film thickness, gas volume fraction and the phase flow rates). One of the most useful techniques which has proven attractive for many multiphase flow applications is the electrical conductance technique. This paper presents an advanced conductance multiphase Venturi meter (CMVM) which is capable of measuring the gas volume fractions at the inlet and the throat of the Venturi. A new model was investigated to measure the gas flow rate. This model is based on the measurement of the gas volume fractions at the inlet and the throat of the Venturi meter using a conductance technique rather than relying on prior knowledge of the mass flow quality x. We measure conductance using two ring electrodes flush with the inner surface of the Venturi throat and two ring electrodes flush with the inner surface of the Venturi inlet. The basic operation of the electrical conductance technique in a multiphase flow is that the conductance of the mixture depends on the gas volume fraction in the water. An electronic circuit was built and calibrated to give a dc voltage output which is proportional to the conductance of the mixture which can then be related to the water film thickness in annular flow (and hence to the gas volume fraction). It was inferred from the experimental results that the minimum average percentage error of the predicted gas mass flow rates (i.e. â0.0428%) can be achieved at the optimum gas discharge coefficient of 0.932
On the 3D steady flow of a second grade fluid past an obstacle
We study steady flow of a second grade fluid past an obstacle in three space
dimensions. We prove existence of solution in weighted Lebesgue spaces with
anisotropic weights and thus existence of the wake region behind the obstacle.
We use properties of the fundamental Oseen tensor together with results
achieved in \cite{Koch} and properties of solutions to steady transport
equation to get up to arbitrarily small \ep the same decay as the Oseen
fundamental solution
First results from the VIMOS-IFU survey of gravitationally lensing clusters at z~0.2
We present the on-going observational program of a VIMOS Integral Field Unit
survey of the central regions of massive, gravitational lensing galaxy clusters
at redshift z~0.2. We have observed six clusters using the low-resolution blue
grism (R about 200), and the spectroscopic survey is complemented by a wealth
of photometric data, including Hubble Space Telescope optical data and near
infrared VLT data. The principal scientific aims of this project are: the study
of the high-z lensed galaxies, the transformation and evolution of galaxies in
cluster cores and the use of multiple images to constrain cosmography. We
briefly report here on the first results from this project on the clusters
Abell 2667 and Abell 68.Comment: 5 pages, 5 figures. To appear in "Sciences Perspectives for 3D
Spectroscopy. ESO Astrophysics Symposia". Ed by M.Kissler-Patig, M.M. Roth
and J.R. Wals
Edges of Diplomacy: Literary Representations of the (Honorary) Consul and the Public-Private Divide in Diplomatic Studies
History and International Relation
Liminal liberalism? Ivan Kats, the Congress for Cultural Freedom, and the Obor Foundation in Cold War Indonesia
The story of the Obor Foundation is important for several reasons. Firstly, it covers the contribution of an up-till-now largely overlooked Western philanthropic enterprise to promote a cohesive national cultural identity for Indonesia in the wake of the fall of Sukarno. Secondly, Obor was an attempt to move beyond previous Cold War efforts to spread liberal ideas globally, most notably by the Congress for Cultural Freedom. To overcome critiques of top-down Westernization and neocolonialism, Obor sought to establish local control over the publishing process in a reciprocal arrangement of shared responsibility. Thirdly, it was symbolic of the move of the Ford Foundation, which had invested a great deal in the modernisation (i.e. Westernization) of Indonesian education, towards introducing a greater level of autonomy in their operations from the late 1960s onwards, expressing a general confidence in (and sufficient monitoring of) Western-trained and/or -oriented local leadership.History and International Relation
Le transatlantisme: un paradigme sur le déclin ?
History and International Relation
Bill and Edâs big adventure: William Fulbright, cold warriors, and right-wing propaganda in the US military, 1961-62
This article analyses a notorious episode of the early 1960s when Senator J. William Fulbright, then Chair of the Senate Foreign Relations Committee, investigated the anti-communist propaganda activities of right-wing 'ultras' in the US military. The episode is used to investigate the phenomenon of âcold warriorsâ, those figures who associated their entire political identity with the 'fighting' of the Cold War. One particular figure soon stood out as epitomizing the anti-communist paranoia that so worried Fulbright: Major General Edwin Walker. The contest between Fulbright and Walker (and their supporters in Congress) was not a political side-show, since it soon involved President Kennedy and saw Defense Secretary Robert McNamara testifying before a Senate investigative committee. It also marked a contest between an orthodox anti-Soviet position and the new, uncertain but more flexible world-view to be known as DĂ©tente. The Walker case encapsulated the debate and the widening divide in US politics and society between those who saw the Cold War as a do-or-die struggle to the bitter end, and those who were willing to accept the existence of the Soviet Union for the sake of a stable DĂ©tente. By drawing on the work of Anders Stephanson, this article explores the broader political ramifications of the Fulbright-Walker contest in the context of the changing dynamics of the Cold War. History and International Relation
Analytic Estimates of the QCD Corrections to Neutrino-Nucleus Scattering
We study the QCD corrections to neutrino deep-inelastic scattering on a
nucleus, and analytically estimate their size. For an isoscalar target, we show
that the dominant QCD corrections to the ratio of the neutral- to
charged-current events are suppressed by sin^4 theta_W, where theta_W is the
weak mixing angle. We then discuss the implications for the NuTeV determination
of sin^2 theta_W.Comment: 16 pages, Late
Measurement of CH2O in low and atmospheric pressure flames by Laser Induced Fluorescence and Cavity RingDown absorption
We have investigated the spatial structure of formaldehyde usinglaser-induced fluorescence (LIF), LIF imaging, and cavity ringdownspectroscopy (CRDS) in two flames. The first is an atmospheric pressureBunsen flame, into which are inserted various metal to simulatedifferent types of heat removal inserts in appliance flames. Here LIFimaging is used. The second is a low pressure flat flame that can bemodeled with a one-dimensional code. All three techniques are used. Theresults in both cases show that CH2O appears prior to CH, inlower pressure regions of the flame
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