Simulation on sand grain/bed collision mechanism: Cascade collision and ejection (1)

Geomorphology ◽  
2007 ◽  
Vol 89 (3-4) ◽  
pp. 348-357 ◽  
Author(s):  
Wanquan Ta ◽  
Zhibao Dong
Keyword(s):  
Collision Mechanism ◽  
Cascade Collision

scholarly journals The role of a mid-air collision in drifting snow

2018 ◽  
Author(s):  
Shuming Jia ◽  
Zhengshi Wang ◽  
Shumin Li
Keyword(s):  
Friction Velocity ◽  
Global Climate ◽  
Three Dimensional ◽  
Particle Collision ◽  
High Concentration ◽  
Three Dimensional Model ◽  
Two Phase ◽  
Drifting Snow ◽  
Collision Mechanism

Abstract. Drifting snow, a common two-phase flow movement in high and cold areas, contributes greatly to the mass and energy balance of glacier and ice sheets and further affects the global climate system. Mid-air collisions occur frequently in high-concentration snow flows; however, this mechanism is rarely considered in current models of drifting snow. In this work, a three-dimensional model of drifting snow with consideration of inter-particle collisions is established; this model enables the investigation of the role of a mid-air collision mechanism in openly drifting snow. It is found that the particle collision frequency increases with the particle concentration and friction velocity, and the blown snow with a mid-air collision effect produces more realistic transport fluxes since inter-particle collision can enhance the particle activity under the same condition. However, the snow saltation mass flux basically shows a cubic dependency with friction velocity, which distinguishes it from the quadratic dependence of blown sand movement. Moreover, the snow saltation flux is found to be largely sensitive to the particle size distribution since the suspension snow may restrain the saltation movement. This research could improve our understanding of the role of the mid-air collision mechanism in natural drifting snow.

Mass spectrometric studies of chemical reactions in shock waves: the thermal decomposition of nitrous oxide

1969 ◽  
Vol 47 (4) ◽  
pp. 521-538 ◽  
Author(s):  
S. C. Barton ◽  
J. E. Dove
Keyword(s):  
Thermal Decomposition ◽  
Shock Waves ◽  
Rate Coefficient ◽  
Mass Spectrometric Study ◽  
Mass Spectrometric ◽  
Unimolecular Decomposition ◽  
Reflected Shock ◽  
Secondary Reactions ◽  
Gas Reactions ◽  
Collision Mechanism

Apparatus for the mass spectrometric study of rapid gas reactions in reflected shock waves is described. This apparatus has been applied to the thermal decomposition of 2% N2O in Kr at total gas concentrations of about 1.6 × 10−6 mole cm−3, in the temperature range 1800 to 2800 °K. The principal products of the reaction were found to be N2, O2, NO, and O. The rate coefficient for the unimolecular decomposition of N2O was calculated from the experimental data, and the rates of the secondary reactions between O and N2O were estimated. The possibility of the occurrence of a "weak collision" mechanism in the unimolecular reaction of N2O is discussed.

scholarly journals The Formation of Disks by Inelastic Collisions of Gravitating Particles. Applications to the Dynamics of the Saturn's Ring and to the Formation of the Solar System

1974 ◽  
Vol 62 ◽  
pp. 83-93
Author(s):  
A. Brahic
Keyword(s):  
Solar System ◽  
Three Dimensional ◽  
Inelastic Collisions ◽  
Dimensional System ◽  
Central Mass ◽  
System Of Particles ◽  
Final Equilibrium State ◽  
First Results ◽  
Three Dimensional System ◽  
Collision Mechanism

We integrate numerically the evolution of a three-dimensional system of particles with finite dimensions, which bounce inelastically upon each other. The particles are subjected to the attraction of a central mass; their mutual attraction is neglected. This model is used to study the evolution of Saturn's ring. The first results are presented: such a collision mechanism can flatten very quickly the Saturn's ring and the system tends towards a final equilibrium state.

The reactive collision mechanism evinced: stereodynamical control of the elementary Br + H2 → H + HBr reaction

2013 ◽  
Vol 15 (32) ◽  
pp. 13513 ◽  
Author(s):  
D. Herráez-Aguilar ◽  
P. G. Jambrina ◽  
J. Aldegunde ◽  
Vicente Sáez-Rábanos ◽  
M. P. de Miranda ◽  
...  
Keyword(s):  
Reactive Collision ◽  
Collision Mechanism

scholarly journals The Deceleration of Radio/Light Transmission; A Collision Mechanism Dependent Radio Signal Emission, Transmission, and Reception

2021 ◽  
Author(s):  
Jing Zhang
Keyword(s):  
Light Transmission ◽  
Radio Signal ◽  
Slow Fading ◽  
Fast Fading ◽  
Before And After ◽  
Radio Signals ◽  
Electron Photon ◽  
The Relationship ◽  
Group Pattern ◽  
Collision Mechanism

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either in consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.

scholarly journals The Deceleration of Radio/Light Transmission; A Collision Mechanism Dependent Radio Signal Emission, Transmission, and Reception

2021 ◽  
Author(s):  
Jing Zhang
Keyword(s):  
Light Transmission ◽  
Radio Signal ◽  
Slow Fading ◽  
Fast Fading ◽  
Before And After ◽  
Radio Signals ◽  
Electron Photon ◽  
The Relationship ◽  
Group Pattern ◽  
Collision Mechanism

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either in consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.

scholarly journals The Deceleration of Radio/Light Transmission; A Collision Mechanism Dependent Radio Signal Emission, Transmission, and Reception

2021 ◽  
Author(s):  
Jing Zhang
Keyword(s):  
Light Transmission ◽  
Radio Signal ◽  
Slow Fading ◽  
Fast Fading ◽  
Before And After ◽  
Radio Signals ◽  
Electron Photon ◽  
The Relationship ◽  
Group Pattern ◽  
Collision Mechanism

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either in consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.

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