$\Xi ^{-}$ production by $\Sigma ^{-}$ , $\pi^{-}$ and neutrons in the hyperon beam experiment at CERN

1997 ◽  
Vol 76 (1) ◽  
pp. 35-44 ◽  
Author(s):  
M.I. Adamovich et al.
Author(s):  
W. Brückner ◽  
E. Chudakov ◽  
R. Edelhoff ◽  
S. Gerassimov ◽  
Th. Kallakowsky ◽  
...  

Author(s):  
Mark Wendel ◽  
David Felde ◽  
Thomas Karnowski ◽  
Bernard Riemer ◽  
Arthur Ruggles

One option that shows promise for protecting solid surfaces from cavitation damage in liquid metal spallation targets involves introducing an interstitial gas layer between the liquid metal and the containment vessel wall. Several approaches toward establishing such a protective gas layer are being investigated at the Oak Ridge National Laboratory including large bubble injection and methods that involve stabilization of the layer by surface modifications to enhance gas hold-up on the wall or by inserting a porous media. It has previously been reported that using a gas layer configuration in a test target showed an order-of-magnitude decrease in damage for an in-beam experiment. Video images that were taken of the successful gas/mercury flow configuration have been analyzed and correlated. The results show that the success was obtained under conditions where only 60% of the solid wall was covered with gas. Such a result implies that this mitigation scheme may have much more potential. Additional experiments with gas injection into water are underway. Multi-component flow simulations are also being used to provide direction for these new experiments. These simulations have been used to size the gas layer and position multiple inlet nozzles.


2019 ◽  
Vol 21 (16) ◽  
pp. 8221-8227 ◽  
Author(s):  
Kateryna Grygoryeva ◽  
Milan Ončák ◽  
Andriy Pysanenko ◽  
Michal Fárník

We investigate ion chemistry in pyruvic acid (PA) clusters in a molecular beam experiment.


2020 ◽  
Author(s):  
Gloria Ma ◽  
Siben Dasgupta ◽  
Anthony Duva

2019 ◽  
Vol 9 (4) ◽  
pp. 712
Author(s):  
Dashan Zhang ◽  
Liangfei Fang ◽  
Ye Wei ◽  
Jie Guo ◽  
Bo Tian

The development of high-speed camera systems and image processing techniques has promoted the use of vision-based methods as a practical alternative for the analysis of non-contact structural dynamic responses. In this study, a deviation extraction method is introduced to obtain deviation signals from structural idealized edge profiles. Given that the deviation temporal variations can reflect the structural vibration characteristics, a method based on singular-value decomposition (SVD) is proposed to extract valuable vibration signals from the matrix composed of deviations from all video frames. However, this method exhibits limitations when handling low-level motions that reflect high-frequency vibration components. Hence, a video acceleration magnification algorithm is employed to enhance low-level deviation variations before the extraction. The enhancement of low-level deviation variations is validated by a light-weight cantilever beam experiment and a noise barrier field test. From the extracted waveforms and their spectrums from the original and magnified videos, subtle deviations of the selected straight-line edge profiles are magnified in the reconstructed videos, and low-level high-frequency vibration signals are successfully enhanced in the final extraction results. Vibration characteristics of the test beam and the noise barrier are then analyzed using signals obtained by the proposed method.


1997 ◽  
Vol 119 (4) ◽  
pp. 809-814 ◽  
Author(s):  
S. M. Yang ◽  
J. A. Jeng ◽  
Y. C. Liu

The vibration control of a slewing flexible structure by collocated and noncollocated feedback is presented in this paper. A stability criterion derived from the root locus method in frequency domain is applied to predict the closed-loop system stability of the distributed parameter model whose analytical transfer functions are formulated. It is shown that the control law design requires neither distributed state sensing/estimation nor functional feedback gain; moreover, the spillover problem associated with discrete parameter model can be prevented. Implementation of the noncollocated feedback in a slewing beam experiment validates that the control law is effective in pointing accuracy while suppressing the tip vibration.


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