898 research outputs found

    Short-term impacts of the filling transition across elevations in intermittent water supply systems

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    Intermittent Water Supply (IWS) is characterised as drinking water distribution systems that are supplied with water for less than 24 hours/day on average. The filling transition from non-supply to pressurised supply is a period of hydraulic instability that negatively impacts water quality, deteriorates infrastructure integrity and intensifies social inequalities. Understanding the factors contributing to the severity of impact from filling is vital to develop effective management strategies. This paper investigates the hydraulic phenomena induced during the short-term IWS filling period and how this behaviour can be exacerbated by elevation and other hydraulic system factors, such as velocity and pressure. Controlled laboratory experiments conducted in the UK and field studies performed in operational networks across South Africa are presented. Results demonstrate the crucial role elevation plays in the network response during the filling transition, emphasising the need for greater consideration of elevation in IWS and well-maintained air relief valves in strategic locations

    First Direct Measurement of Jets in sNN=200\sqrt{s_{NN}}=200 GeV Heavy Ion Collisions by STAR

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    We present the first measurement of reconstructed jets in ultra-relativistic heavy ion collisions. Utilizing the large coverage of the STAR Time Projection Chamber and Electromagnetic Calorimeter, we apply several modern jet reconstruction algorithms and background subtraction techniques and explore their systematic uncertainties in heavy ion events. The differential spectrum for inclusive jet production in central Au+Au collisions at sNN=200\sqrt {s_{NN}}= 200 GeV is presented. In order to assess the jet reconstruction biases, this spectrum is compared with the jet cross section measured in s=200\sqrt{s}=200 GeV p+p collisions scaled by the number of binary N-N collisions to account for nuclear geometric effects.Comment: Proceedings of the 3rd International Conference on Hard and Electro- Magnetic Probes of High-Energy Nuclear Collisions 8-14 June 2008, Illa da Toxa (Galicia-Spain

    Demonstration of Feed-Forward Control for Linear Optics Quantum Computation

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    One of the main requirements in linear optics quantum computing is the ability to perform single-qubit operations that are controlled by classical information fed forward from the output of single photon detectors. These operations correspond to pre-determined combinations of phase corrections and bit-flips that are applied to the post-selected output modes of non-deterministic quantum logic devices. Corrections of this kind are required in order to obtain the correct logical output for certain detection events, and their use can increase the overall success probability of the devices. In this paper, we report on the experimental demonstration of the use of this type of feed-forward system to increase the probability of success of a simple non-deterministic quantum logic operation from approximately 1/4 to 1/2. This logic operation involves the use of one target qubit and one ancilla qubit which, in this experiment, are derived from a parametric down-conversion photon pair. Classical information describing the detection of the ancilla photon is fed-forward in real-time and used to alter the quantum state of the output photon. A fiber optic delay line is used to store the output photon until a polarization-dependent phase shift can be applied using a high speed Pockels cell

    Quête de la justice pour les déplacés internes à Bukavu

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    Effective Protection of Fundamental Rights in a pluralist worl

    A Short Review on Jet Identification

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    Jets can be used to probe the physical properties of the high energy density matter created in collisions at the Relativistic Heavy Ion Collider (RHIC). Measurements of strong suppression of inclusive hadron distributions and di-hadron correlations at high pTp_{T} have already provided evidence for partonic energy loss. However, these measurements suffer from well-known geometric biases due to the competition of energy loss and fragmentation. These biases can be avoided if the jets are reconstructed independently of their fragmentation details - quenched or unquenched. In this paper, we discuss modern jet reconstruction algorithms (cone and sequential recombination) and their corresponding background subtraction techniques required by the high multiplicities of heavy ion collisions. We review recent results from the STAR experiment at RHIC on direct jet reconstruction in central Au+Au collisions at sNN=200\sqrt {s_{NN}}= 200 GeV.Comment: Proceedings for the invited talk of Hot Quarks 2008, Estes Park, CO 18-23 August 200

    Organizational and Leadership Implications for Transformational Development

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    Transformational development is a concept of change that originated in the Christian context but has now become generally used in the work of both secular and faith-based organizations. The growing use of the concept by organizations that are fundamentally different has naturally led to some confusion about what the concept means and what it takes to effectively implement it. In this article, we describe the key features of the concept and how they are important in determining the organizational requirements for its effective implementation. Drawing on a few cases, the paper highlights the centrality of faith in transformational development work

    Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

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    We present the first measurement of directed flow (v1v_1) at RHIC. v1v_1 is found to be consistent with zero at pseudorapidities η\eta from -1.2 to 1.2, then rises to the level of a couple of percent over the range 2.4<η<42.4 < |\eta| < 4. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure

    Azimuthal anisotropy: the higher harmonics

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    We report the first observations of the fourth harmonic (v_4) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding
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