13,513 research outputs found

    Implementation experiences of NASTRAN on CDC CYBER 74 SCOPE 3.4 operating system

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    The implementation of the NASTRAN system on the CDC CYBER 74 SCOPE 3.4 Operating System is described. The flexibility of the NASTRAN system made it possible to accomplish the change with no major problems. Various sizes of benchmark and test problems, ranging from two hours to less than one minute CP time were run on the CDC CYBER SCOPE 3.3, Univac EXEC-8, and CDC CYBER SCOPE 3.4. The NASTRAN installation deck is provided

    Structure functions near the chiral limit

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    We compute hadron masses and the lowest moments of unpolarized and polarized nucleon structure functions down to pion masses of 300 MeV, in an effort to make unambiguous predictions at the physical light quark mass.Comment: 3 pages, 3 figures, Lattice2002(matrixel

    Modelling and simulation framework for reactive transport of organic contaminants in bed-sediments using a pure java object - oriented paradigm

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    Numerical modelling and simulation of organic contaminant reactive transport in the environment is being increasingly relied upon for a wide range of tasks associated with risk-based decision-making, such as prediction of contaminant profiles, optimisation of remediation methods, and monitoring of changes resulting from an implemented remediation scheme. The lack of integration of multiple mechanistic models to a single modelling framework, however, has prevented the field of reactive transport modelling in bed-sediments from developing a cohesive understanding of contaminant fate and behaviour in the aquatic sediment environment. This paper will investigate the problems involved in the model integration process, discuss modelling and software development approaches, and present preliminary results from use of CORETRANS, a predictive modelling framework that simulates 1-dimensional organic contaminant reaction and transport in bed-sediments

    Determining the venting efficiency of simple chimneys for buoyant plumes

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    We present preliminary results from an examination of the capture and venting of a buoyant plume by a chimney. The aim is to enable improved management of indoor pollutant sources – for instance, the plume rising from a cooking pan in a kitchen or a cooking fire in a hut. Using the principle of dynamic similarity, we precise ly and controllably model the behaviour of indoor plumes by using saline solutions ejected into an enclosure containing freshwater. These well - established laboratory analogue techniques enable the location and concentration of tracer in the plume to be eas ily tracked, reflecting the evolution of pollutants carried in the plume. Focusing on a plume within a room containing a quiescent ambient environment, we identify two physical mechanisms potentially responsible for driving the removal of pollutants. The f irst, we describe as the capture of the plume, a process driven by the direct interaction between the plume and the evacuation opening; the second, we describe as the draining flow driven by a buoyant layer of fluid which may accumulate at the ceiling and is then evacuated through the effects of buoyancy. We first demonstrate that the addition of a simple cylindrical chimney that hangs downwards from an opening in the (analogue) ceiling increases the venting efficiency of these potentially polluting plumes. We go on to examine how the capture efficiency of these simple chimneys varies as the relative size of the plume and the chimney are altered, and demonstrate that simple model can provide predictions of the observed variation in capture efficiency

    Optimal entanglement manipulation via coherent-state transmission

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    We derive an optimal bound for arbitrary entanglement manipulation based on the transmission of a pulse in coherent states over a lossy channel followed by local operations and unlimited classical communication (LOCC). This stands on a theorem to reduce LOCC via a local unital qubit channel to local filtering. We also present an optimal protocol based on beam splitters and a quantum nondemolition (QND) measurement on photons. Even if we replace the QND measurement with photon detectors, the protocol outperforms known entanglement generation schemes.Comment: 5 pages, 1 figur

    Discovery of K-Shell Emission Lines of Neutral Atoms in the Galactic Center Region

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    The K-shell emission line of neutral irons from the Galactic center (GC) region is one of the key for the structure and activity of the GC. The origin is still open question, but possibly due either to X-ray radiation or to electron bombarding to neutral atoms. To address this issue, we analyzed the Suzaku X-ray spectrum from the GC region of intense neutral iron line emission, and report on the discovery of Kalpha lines of neutral argon, calcium, chrome, and manganese atoms. The equivalent widths of these Kalpha lines indicate that the metal abundances in the GC region should be ~1.6 and ~4 of solar value, depending on the X-ray and the electron origins, respectively. On the other hand, the metal abundances in the hot plasma in the GC region are found to be ~1-2 solar. These results favor that the origin of the neutral Kalpha lines are due to X-ray irradiation.Comment: 7 pages, 5 figures, accepted for publication in PASJ (Vol.62, No.2, pp.423--429

    Bell's inequality tests: from photons to B-mesons

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    We analyse the recent claim that a violation of a Bell's inequality has been observed in the BB--meson system [A. Go, {\em Journal of Modern Optics} {\bf 51} (2004) 991]. The results of this experiment are a convincing proof of quantum entanglement in BB--meson pairs similar to that shown by polarization entangled photon pairs. However, we conclude that the tested inequality is not a genuine Bell's inequality and thus cannot discriminate between quantum mechanics and local realistic approaches.Comment: 5 page

    Phosphorus fractionation and crop performance on an alfisol amended with phosphate rock combined with or without plant residues

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    The effects of Sokoto phosphate rock (PR) and plant residues on soil phosphorus (P) fractions and crop performance was studied in the field on an alfisol in the derived savanna of southwestern Nigeria.The plant residues studied were leaves of Dactyladenia barteri, Flemingia macrophylla, Gliricidia sepium, Leucaena leucocephala, maize (Zea mays) stover and rice (Oryza sativa) straw. They were applied alone or in combination with phosphate rock. The PR was applied at a rate of 60 kg P ha-1 and the plant residues at 5 ton dry matter ha-1 during the onset of the major rainy season. Plots without PR and plant residues application were included as control. After four weeks incubation period of PR and plant residues, Crotalaria ochroleuca (shrub legume) was planted in 1999 and maize (Zea mays) was planted in 2001 as test crops. When PR was not combined with plant residues, incubation of Dactyladenia residues increased resin P from 0.13 to 0.79 mg P kg-1 at 4 weeks after incubation (WAI). Other plant residues did not cause appreciable changes in resin P. Application of Leucaena residues increased NaOHextractable inorganic P (Pi) from 14.36 to 20.47 mg P kg-1 at 4 WAI. Total extractable P increased underall the plant residues at 4 WAI but decreased at 8 WAI. When PR was combined with plant residues, there were increases in almost all the P fractions under the plant residues at 4 WAI followed by decreases at 8 WAI. Averaged across P levels, addition of Leucaena residues resulted in higher resin P, NaOH-Pi, residual P and total extractable P compared with the other plant residue treatments. Averaged across residue treatments, resin P increased from 0.12 mg P kg-1 to 0.75 mg P kg-1 at 4 WAI and decreased to 0.08 mg P kg-1 at 8 WAI. All other P pools showed similar trends but with less pronounced decreases at 8 WAI. When PR was not applied with plant residues, Crotalaria dry matter correlate positively with NaHCO3-Pi (R2 = 0.59), NaOH-Pi (R2 = 0.53) and total extractable P (R2 = 0.50), while Crotalaria P uptake correlate positively with NaHCO3-Pi (R2 = 0.50) at 4 WAI. Maize grain yield and P uptake did not correlate with any of the P fractions. However, when PR was applied with plant residues, maize P uptake was positively correlated with resin P (R2 = 0.53) while Crotalaria dry matter (R2 = 0.60) and P uptake (R2 = 0.49) correlate positively with NaOH-Po at 4 WAI. Application of PR alone did not affect yields and P uptakes of Crotalaria and maize crops. Compared with the control without residues, Crotalaria dry matter production and P uptake increased significantly when residues were applied. Interaction effects between PR and Leucaena and rice straw residues on Crotalaria dry matter production and P uptake was significant. Interaction effects between PR and plant residues on maize yield and P uptake were not significant. Ourresults suggest that combined application of PR with selected plant residues may enhance P dissolution from PR and improve crop performance in some cases

    Multichannel Distribution Meter: A Veritable Solution in Power Distribution and Theft Prevention in Congested Environments

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    Power theft in partitioned commercial apartments, especially in the form of unpaid bills due to disputes, is a major challenge to revenue recovery in the power sector. This paper presents a multi-channel power distribution metering solution that serves to resolve disputes among users in partitioned apartments, and between the power distribution company and the end users of electricity. Partitioned apartments in commercial buildings particularly in congested environments shares energy supply meters among several users. This often leads to disputes and results to power theft in the form of unpaid bills and meter tampering. This paper described how power from a single supply meter can be adequately shared among a number of users with dispute arbitration. Each user’s channel is fed, monitored and controlled from a central unit which calculate and display energy usage, per unit cost and amount in cash consumed per channel. Compliant/non-compliant channel are connected/disconnected through a remote wireless access. It is envisaged that the use of this method for electricity distribution in commercial apartments, will greatly reduce power theft and increase revenue generation for the power industry. It will also eliminate disputes and possible litigations for the power industry and among users.http://dx.doi.org/10.4314/njt.v34i4.2
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