External explosion in an industrial site Sochet, I.; Sauvan, P.E.; Boulanger, R. ...
Journal of loss prevention in the process industries,
05/2014, Letnik:
29
Journal Article
Recenzirano
The scenario of an intentional explosion in an industrial site is studied here with the objective of understanding the propagation and interaction of shock waves in a complex environment standing for ...a gas storage warehouse. We conducted a small-scale experimental study supported by numerical simulations in order to lead a discussion. We are interested in the effects of an explosive charge located at the entrance of the gas storage infrastructure. The walls of the gas storage infrastructure and bottles of gas are assumed to be undeformable in this study. The propagation and reflection of the shock waves with overpressure effects are assessed in this study.
•Multiple reflections of shock waves with the bottle crates located in gas storage infrastructure.•Low-pressure due to circumvention of the walls.•Good correlation between small-scale experiments and simulation.
Excited fermions at H1 Sauvan, E
Journal of physics. Conference series,
05/2008, Letnik:
110, Številka:
7
Journal Article
Recenzirano
Odprti dostop
We present a search for excited neutrinos and electrons using all data collected by the HI experiment at HERA at a center-of-mass energy of 320 GeV with an integrated luminosity of up to 435 pb-1. No ...evidence for excited neutrino or electron production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the compositeness scale, f/Λ. These limits greatly extend the excluded region to higher masses than has been possible in previous searches.
This study analyzes the propagation and reflections of regular Mach and shock waves through small-scale experiments and numerical modeling of an explosion in a gas storage plan. The gas storage area ...is a “U-shape” and contains two racks of 9 horizontal bottles (3 × 3) each. An explosive charge is located in a corner at the closed end of the system. The analyses of the shock waves and the effects of overpressure are conducted both inside and outside the plant.
•Accidental detonation scenario in a gas storage warehouse.•Multiple reflections of shock waves with the bottle crates located in gas storage infrastructure.•Propagation of a Mach stem along the interior walls of the warehouse clearly showed.•Good correlation between small scale experiments and simulation.
To understand the blast effects of confined explosions, it is necessary to study the characteristic parameters of the blast wave in terms of overpressure, impulse and arrival time. In a previous ...study, experiments were performed using two different scales of a pyrotechnic workshop. The main purpose of these experiments was to compare the TNT equivalent for solid and gaseous explosives in terms of mass to define a TNT equivalent in a reflection field and to validate the similitude between real and small scales. To study the interactions and propagations of the reflected shock waves, the present study was conducted by progressively building a confined volume around the charge. In this way, the influence of each wall and the origins of the reflected shock waves can be determined. The purpose of this paper is to report the blast wave interactions that resulted from the detonation of a stoichiometric propane-oxygen mixture in a confined room.
A first measurement is presented of exclusive photoproduction of $\rho^0$ mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years $2006$ and $2007$ at a ...centre-of-mass energy of $\sqrt{s}=319$ GeV and correspond to an integrated luminosity of $1.16$ pb$^{-1}$. The $\rho^0$ mesons with transverse momenta $p_T<1$ GeV are reconstructed from their decays to charged pions, while leading neutrons carrying a large fraction of the incoming proton momentum, $x_L>0.35$, are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality $Q^2 < 2$ GeV$^2$, the total energy of the photon-proton system $20 < W_{\gamma p} < 100$ GeV and the polar angle of the leading neutron $\theta_n < 0.75$ mrad. The cross section of the reaction $\gamma p \to \rho^0 n \pi^+$ is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a $\rho^0$ meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, $\sigma^{\rm el}(\gamma\pi^+ \to \rho^0\pi^+)$, is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction $\gamma p\to\rho^0 n \pi^+$.
A systematic study of high energy, one-neutron removal reactions on 23 neutron-rich, psd-shell nuclei (
Z=5–9,
A=12–25) has been carried out. The longitudinal momentum distributions of the core ...fragments and corresponding single-neutron removal cross sections are reported for reactions on a carbon target. Extended Glauber model calculations, weighted by the spectroscopic factors obtained from shell model calculations, are compared to the experimental results. Conclusions are drawn regarding the use of such reactions as a spectroscopic tool and spin-parity assignments are proposed for
15B,
17C,
19–21N,
21,23O,
23–25F. The nature of the weakly bound systems
14B and
15,17C is discussed.
Inclusive ep double differential cross sections for neutral current deep inelastic scattering are measured with the H1 detector at HERA. The data were taken with a lepton beam energy of 27.6 GeV and ...two proton beam energies of Ep = 460 and 575 GeV corresponding to centre-of-mass energies of 225 and 252 GeV, respectively. The measurements cover the region of 6.5 *10^{-4}<=x<= 0.65 for 35<=Q^2<=800 GeV^2 up to y = 0.85. The measurements are used together with previously published H1 data at Ep = 920 GeV and lower Q2 data at Ep = 460, 575 and 920 GeV to extract the longitudinal proton structure function FL in the region 1.5<=Q^2 <=800 GeV^2.
PDF
