Search results for "Collision"
showing 10 items of 908 documents
Collision efficiencies empirically determined from laboratory investigations of collisional growth of small raindrops in a laminar flow field
2007
In laboratory experiments at the vertical wind tunnel of the University of Mainz the collisional growth of drops with radii between 70 and 170 μm in radius were observed while the collector drop freely floated in a cloud of droplets with radii ranging from 1 to 7 μm. Previously existing tables with collision efficiency values were interpolated and completed in such a way that drop growth rates calculated with these collision efficiencies match with observed growth rates. These new tables provide collision efficiency values for a wide range of drop sizes and radius ratios p including those ranges where efficiency values missed so far. This is of high importance for small p-ratios where the c…
Collision of Akhmediev Breathers in Nonlinear Fiber Optics
2013
We report here a novel fiber-based test bed using tailored spectral shaping of an optical-frequency comb to excite the formation of two Akhmediev breathers that collide during propagation. We have found specific initial conditions by controlling the phase and velocity differences between breathers that lead, with certainty, to their efficient collision and the appearance of a giant-amplitude wave. Temporal and spectral characteristics of the collision dynamics are in agreement with the corresponding analytical solution. We anticipate that experimental evidence of breather-collision dynamics is of fundamental importance in the understanding of extreme ocean waves and in other disciplines dri…
Comparison of electromagnetic and nuclear dissociation of Ne-17
2018
8 pags., 10 figs., 3 tabs.
INTERFERENCE REMOVAL IN ICP-MS USING HE COLLISION CELL WITH TANDEM MS
2021
A wind tunnel study of the effects of collision processes on the shape and oscillation for moderate-size raindrops
2014
Abstract Drop–drop collision experiments were carried out at the Mainz vertical wind tunnel. Water drops of 2.5 mm diameter were freely floated at their terminal velocities in a vertical air stream and collided with 0.5 mm diameter droplets. The collisions were recorded with a high speed digital video camera at a frame rate of 1000 per second. Altogether 116 collision events were observed, 75 of which ended with coalescence, and the rest with filament type breakup. The coalescence efficiency and its dependence on the Weber number and on the eccentricity of the colliding drops showed good agreement with earlier numerical studies. Thirty-six recorded collisions were further analyzed in order …
The Mainz Cluster Trap
1999
When cluster ions are stored by electromagnetic forces they are available in the gas phase for extended preparations and investigations. Over the last decade a Penning trap (Ion Cyclotron Resonance) apparatus has been constructed and further developed with respect to metal cluster research at the Institute of Physics at Mainz. It allows to capture and accumulate ion bunches injected from an external cluster source and to manipulate the ions’ motion, i.e. select and center the clusters of interest. The interactions that have been investigated include those with inert and chemically reactive gases, photons and electrons. Multiple mass spectrometric steps such as fragment ion selection can be …
Observation of electronic and geometric shell structures of small silver clusters
1999
Singly charged silver clusters Open image in new window in the size range n = 17 to n = 78 have been captured and stored in a Penning trap, size selected and subjected to an electron beam which leads to further ionization as well as dissociation. The resulting abundance spectra of doubly and triply charged clusters show several features: (1) A critical size for the production of doubly charged clusters which can be understood in terms of the decay pathways as previously investigated by collision induced dissociation, (2) an odd-even alternation in the abundance of singly and doubly charged clusters which inverses sign with change of charge state, (3) prominent signals for particular doubly …
Experimental dissociation energies of metal cluster dications and their interpretation in a liquid-drop model with empirical corrections
1999
The dissociation energies of doubly charged silver cluster ions in the size range $9l~nl~25$ are measured by multiple collision induced dissociation. They are compared to the dissociation energies of singly charged clusters. To this end, the latter are used to calculate shell corrections in a macroscopic-microscopic model. Good agreement between the resulting predictions of the dissociation energies of the doubly charged systems and the experimental values is found, which indicates the strong influence of electronic effects on the stability of small silver clusters.
Gauge-invariant condensation in the nonequilibrium quark-gluon plasma
2020
The large density of gluons, which is present shortly after a nuclear collision at very high energies, can lead to the formation of a condensate. We identify a gauge-invariant order parameter for condensation based on elementary non-perturbative excitations of the plasma, which are described by spatial Wilson loops. Using real-time lattice simulations, we demonstrate that a self-similar transport process towards low momenta builds up a macroscopic zero mode. Our findings reveal intriguing similarities to recent discoveries of condensation phenomena out of equilibrium in table-top experiments with ultracold Bose gases.