225 research outputs found

    Future in Marine Fire-Fighting: High Pressure Water Mist Extinguisher with Abrasive Water Jet Cutting

    Get PDF
    This paper is dealing with the problem of extinguishing fire on ships and off-shore equipment characterized by high degree of danger caused by presence of explosive or life threatening substances. Special device Cold Cut System Cobra combining cutting possibility and production of water mist is presented. Its advantages and application possibilities are discussed. This fire extinguisher has been widely used for more than one decade but based on a literature search we suppose that its potential is not fully exploited in marine applications. In cooperation with fire-fighting rescue station in Silesian Ostrava laboratory measurement of reaction forces of Cobra slurry jet was realized at the Technical University of Ostrava. It was discovered that measured force was about 120 – 150 N therefore it represented approximately one third of the theoretical maximum value. The measured force appeared to change not only with the type of material but also with the thickness of the layer being cut, but the change was not significant from the point of view of handling the lance during intervention. Our research may deepen firefighter’s knowledge of the tool they are working with and therefore improve safety of their work

    VANETs Signal Quality-based Route Selection in Smart Cities

    Get PDF
    In road networks, the most common metrics to determine the optimal route relaying two points are either the path length or the travel time. However, as autonomous smart cars are expected to emerge in future smart cities and lead to an unprecedented growth of mobile applications spectrum for both drivers and passengers, we argue that other metrics can be also considered for route selection. Therefore, the best route for a driver will be also determined by specific in-vehicle users' requirements such as, ensuring sufficient quality for wireless connection with minimum cost, and selecting preferred access networks, etc. To this end, we propose an original algorithm that enables route selection based on maximum expected signal quality with respect to the drivers' maximum tolerated prolongation of journey. Our ultimate objective is to select the route that ensures sufficient signal quality for users on board by maximizing the usage of VANETs resources, through RSUs, while minimizing the usage of the costly LTE-A resources. The obtained simulation results, under several scenarios, have proven the high efficiency of the proposed algorithm

    Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    Get PDF
    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q2>1 (GeV/c)2Q^2>1~({\rm GeV}/c)^2. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/cc polarised muon beam impinging on a polarised 6^6LiD target. By analysing the full range in hadron transverse momentum pTp_{\rm T}, the different pTp_{\rm T}-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g\Delta g/g is evaluated at leading order in pQCD at a hard scale of μ2=Q2=3(GeV/c)2\mu^2= \langle Q^2 \rangle = 3 ({\rm GeV}/c)^2. It is determined in three intervals of the nucleon momentum fraction carried by gluons, xgx_{\rm g}, covering the range 0.04 ⁣< ⁣xg ⁣< ⁣0.280.04 \!<\! x_{ \rm g}\! <\! 0.28~ and does not exhibit a significant dependence on xgx_{\rm g}. The average over the three intervals, Δg/g=0.113±0.038(stat.)±0.036(syst.)\langle \Delta g/g \rangle = 0.113 \pm 0.038_{\rm (stat.)}\pm 0.036_{\rm (syst.)} at xg0.10\langle x_{\rm g} \rangle \approx 0.10, suggests that the gluon polarisation is positive in the measured xgx_{\rm g} range.Comment: 14 pages, 6 figure

    Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target

    Get PDF
    Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable xx, the relative virtual-photon energy yy and the relative hadron energy zz. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and an isoscalar target (6^6LiD). They cover the kinematic domain in the photon virtuality Q2Q^2 > 1(GeV/c)2)^2, 0.004<x<0.40.004 < x < 0.4, 0.2<z<0.850.2 < z < 0.85 and 0.1<y<0.70.1 < y < 0.7. In addition, a leading-order pQCD analysis was performed using the pion multiplicity results to extract quark fragmentation functions

    Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons

    Get PDF
    Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS longitudinally polarised muon beam at 160 GeV/c and a (LiD)-Li-6 target. The amplitudes of the three azimuthal modulations cos phi(h), cos 2 phi(h) and sin phi(h) were obtained binning the data separately in each of the relevant kinematic variables x, z or p(T)(h), and binning in a three-dimensional grid of these three variables. The amplitudes of the cos phi(h) and cos 2 phi(h) modulations show strong kinematic dependencies both for positive and negative hadrons

    Optimal deployment of components of cloud-hosted application for guaranteeing multitenancy isolation

    Get PDF
    One of the challenges of deploying multitenant cloud-hosted services that are designed to use (or be integrated with) several components is how to implement the required degree of isolation between the components when there is a change in the workload. Achieving the highest degree of isolation implies deploying a component exclusively for one tenant; which leads to high resource consumption and running cost per component. A low degree of isolation allows sharing of resources which could possibly reduce cost, but with known limitations of performance and security interference. This paper presents a model-based algorithm together with four variants of a metaheuristic that can be used with it, to provide near-optimal solutions for deploying components of a cloud-hosted application in a way that guarantees multitenancy isolation. When the workload changes, the model based algorithm solves an open multiclass QN model to determine the average number of requests that can access the components and then uses a metaheuristic to provide near-optimal solutions for deploying the components. Performance evaluation showed that the obtained solutions had low variability and percent deviation when compared to the reference/optimal solution. We also provide recommendations and best practice guidelines for deploying components in a way that guarantees the required degree of isolation
    corecore