27,940 research outputs found
Large water-hammer pressure for column separation in pipelines
Water-hammer pressures in a pipeline due to the collapse of a vapor cavity adjacent to a valve are investigated. A water-hammer event is initiated by the closure of a valve in a simple reservoir-pipeline-valve system. The sequence of events following an instantaneous valve closure leading to the formation and collapse of a vapor cavity and the resultant occurrence of a short-duration pressure pulse are described. Short-duration pressure pulses result from the superposition of the valve-closure water-hammer wave and the wave generated by the collapse of the vapor cavity. The resulting maximum pressure may exceed the Joukowsky pressure generated from the initial valve closure. A series of numerical model analyses exhibiting short-duration pressure pulses are presented. In addition, experimental results supporting the findings of the numerical studies are also presented. Experimental plots of hydraulic grade line versus time exhibit short-duration pressure pulses of different shape and characteristics.Angus R. Simpson and E. Benjamin Wyli
Cooper pair correlations and energetic knock-out reactions
Two-nucleon removal (or knock-out) reactions at intermediate energies are a
developing tool for both nuclear spectroscopy and for the study of certain
nucleon correlations in very exotic and some stable nuclei. We present an
overview of these reactions with specific emphasis on the nature of the
two-nucleon correlations that can be probed. We outline future possibilities
and tests needed to fully establish these sensitivities.Comment: 12 pages, 3 figures: Contribution to the Volume 50 years of Nuclear
BCS edited by World Scientifi
A cometary ion mass spectrometer
The development of flight suitable analyzer units for that part of the GIOTTO Ion Mass Spectrometer (IMS) experiment designated the High Energy Range Spectrometer (HERS) is discussed. Topics covered include: design of the total ion-optical system for the HERS analyzer; the preparation of the design of analyzing magnet; the evaluation of microchannel plate detectors and associated two-dimensional anode arrays; and the fabrication and evaluation of two flight-suitable units of the complete ion-optical analyzer system including two-dimensional imaging detectors and associated image encoding electronics
Absorption spectrum of iron in the vacuum ultraviolet 2950 - 1588 angstrom
Absorption spectrum of iron in vacuum ultraviole
Physics case of the very high energy electron--proton collider, VHEeP
The possibility of a very high energy electron-proton (VHEeP) collider with a
centre-of-mass energy of 9 TeV has been presented at previous workshops. These
proceedings briefly summarise the VHEeP concept, which was recently published,
and developments since then, as well as future directions. At the VHEeP
collider, with a centre-of-mass energy 30 times greater than HERA, parton
momentum fractions, , down to about are accessible for photon
virtualities, , of 1 GeV. This extension in the kinematic range to low
complements proposals for other electron-proton or electron-ion colliders.Comment: 6 pages, 2 figures, for proceedings of DIS 2017 worksho
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