Molecular Dynamics Simulation of Cracking Process of Bisphenol F Epoxy Resin under High-Energy Particle Impact

The current lead insulation of high-temperature superconductivity equipment is under the combined action of large temperature gradient field and strong electric field. Compared with a uniform temperature field, its electric field distortion is more serious, and it is easy to induce surface discharge to generate high-energy particles, destroy the insulation surface structure and accelerate insulation degradation. In this paper, the degradation reaction process of bisphenol F epoxy resin under the impact of high-energy particles, such as O3−, HO–, H3O+ and NO+, is calculated based on ReaxFF simulation. According to the different types of high-energy particles under different voltage polarities, the micro-degradation mechanism, pyrolysis degree and pyrolysis products of epoxy resin are analyzed. The results show that in addition to the chemical reaction of high-energy particles with epoxy resin, their kinetic energy will also destroy the molecular structure of the material, causing the cross-linked epoxy resin to pyrolyze, and the impact of positive particles has a more obvious impact on the pyrolysis of epoxy resin.

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The Impact of the Electric Field on Surface Condensation of Water Vapor: Insight from Molecular Dynamics Simulation

Nanomaterials ◽

10.3390/nano9010064 ◽

2019 ◽

Vol 9 (1) ◽

pp. 64 ◽

Cited By ~ 7

Author(s):

Qin Wang ◽

Hui Xie ◽

Zhiming Hu ◽

Chao Liu

Keyword(s):

Molecular Dynamics ◽

Water Vapor ◽

Electric Field ◽

Intermolecular Forces ◽

Dynamics Simulation ◽

Water Molecules ◽

Attraction Force ◽

Condensation Rate ◽

Shape Transformation ◽

The Impact

In this study, molecular dynamics simulations were carried out to study the coupling effect of electric field strength and surface wettability on the condensation process of water vapor. Our results show that an electric field can rotate water molecules upward and restrict condensation. Formed clusters are stretched to become columns above the threshold strength of the field, causing the condensation rate to drop quickly. The enhancement of surface attraction force boosts the rearrangement of water molecules adjacent to the surface and exaggerates the threshold value for shape transformation. In addition, the contact area between clusters and the surface increases with increasing amounts of surface attraction force, which raises the condensation efficiency. Thus, the condensation rate of water vapor on a surface under an electric field is determined by competition between intermolecular forces from the electric field and the surface.

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Interactions of Beams with Surroundings

Particle Physics Reference Library ◽

10.1007/978-3-030-34245-6_5 ◽

2020 ◽

pp. 183-203

Author(s):

M. Brugger ◽

H. Burkhardt ◽

B. Goddard ◽

F. Cerutti ◽

R. G. Alia

Keyword(s):

High Energy Physics ◽

High Energy ◽

Fixed Target ◽

Fixed Target Experiments ◽

Secondary Particles ◽

Radiation Sources ◽

Residual Gas ◽

The Impact ◽

High Energy Particles ◽

Energy Physics

AbstractWith the exceptions of Synchrotron Radiation sources, beams of accelerated particles are generally designed to interact either with one another (in the case of colliders) or with a specific target (for the operation of Fixed Target experiments, the production of secondary beams and for medical applications). However, in addition to the desired interactions there are unwanted interactions of the high energy particles which can produce undesirable side effects. These interactions can arise from the unavoidable presence of residual gas in the accelerator vacuum chamber, or from the impact of particles lost from the beam on aperture limits around the accelerator, as well as the final beam dump. The wanted collisions of the beams in a collider to produce potentially interesting High Energy Physics events also reduces the density of the circulating beam and can produce high fluxes of secondary particles.

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High Temperature Thermoelectric Properties of Nano-Bulk Silicon and Silicon Germanium

MRS Proceedings ◽

10.1557/proc-1166-n02-04 ◽

2009 ◽

Vol 1166 ◽

Cited By ~ 7

Author(s):

Sabah Bux ◽

Jean-Pierre Fleurial ◽

Richard G. Blair ◽

Pawan K. Gogna ◽

Thierry Caillat ◽

...

Keyword(s):

Electron Microscopy ◽

Thermal Conductivity ◽

Silicon Germanium ◽

Carrier Mobility ◽

Nanoparticle Synthesis ◽

High Energy ◽

Large Temperature ◽

Lattice Contribution ◽

Low Dimensional ◽

The Impact

AbstractPoint defect scattering via the formation of solid solutions to reduce the lattice thermal conductivity has been an effective method for increasing ZT in state-of-the-art thermoelectric materials such as Si-Ge, Bi2Te3-Sb2Te3 and PbTe-SnTe. However, increases in ZT are limited by a concurrent decrease in charge carrier mobility values. The search for effective methods for decoupling electronic and thermal transport led to the study of low dimensional thin film and wire structures, in particular because scattering rates for phonons and electrons can be better independently controlled. While promising results have been achieved on several material systems, integration of low dimensional structures into practical power generation devices that need to operate across large temperature differential is extremely challenging. We present achieving similar effects on the bulk scale via high pressure sintering of doped and undoped Si and Si-Ge nanoparticles. The nanoparticles are prepared via techniques that include high energy ball milling of the pure elements. The nanostructure of the materials is confirmed by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Thermal conductivity measurements on the densified pellets show a drastic 90% reduction in the lattice contribution at room temperature when compared to doped single crystal Si. Additionally, Hall effect measurements show a much more limited degradation in the carrier mobility. The combination of low thermal conductivity and high power factor in heavily doped n-type nanostructured bulk Si leads to an unprecedented increase in ZT at 1275 K by a factor of 3.5 over that of single crystalline samples. Experimental results on both n-type and p-type Si are discussed in terms of the impact of the size distribution of the nanoparticles, doping impurities and nanoparticle synthesis processes.

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Molecular dynamics simulation on the impact of electric field on the yield behavior of insulation paper

Proceedings of 2014 International Symposium on Electrical Insulating Materials ◽

10.1109/iseim.2014.6870817 ◽

2014 ◽

Author(s):

Peng Fan ◽

Youyuan Wang ◽

Miao Tian ◽

Junfeng Wu

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Electric Field ◽

Dynamics Simulation ◽

Yield Behavior ◽

The Impact

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Shielding of Cosmic Radiation by Fibrous Materials

Fibers ◽

10.3390/fib9100060 ◽

2021 ◽

Vol 9 (10) ◽

pp. 60

Author(s):

Tomasz Blachowicz ◽

Andrea Ehrmann

Keyword(s):

Cosmic Radiation ◽

High Energy ◽

Space Travel ◽

Fibrous Materials ◽

Inanimate Matter ◽

Unmanned Spacecraft ◽

Potential Impact ◽

The Impact ◽

High Energy Particles

Cosmic radiation belongs to the challenges engineers have to deal with when further developing space travel. Besides the severe risks for humans due to high-energy particles or waves, the impact of cosmic radiation on electronics and diverse materials cannot be neglected, even in microsatellites or other unmanned spacecraft. Here, we explain the different particles or waves found in cosmic radiation and their potential impact on biological and inanimate matter. We give an overview of fiber-based shielding materials, mostly applied in the form of composites, and explain why these materials can help shielding spaceships or satellites from cosmic radiation.

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Ion acceleration at dipolarization fronts associated with interchange instability in the magnetotail

10.5194/npg-2018-43 ◽

2018 ◽

Author(s):

Chao Sun ◽

Yasong Ge ◽

Haoyu Lu

Keyword(s):

Electric Field ◽

Physical Phenomenon ◽

Leading Edge ◽

High Energy ◽

Particle Simulation ◽

Ion Acceleration ◽

Interchange Instability ◽

Almost All ◽

High Energy Particles ◽

Hall Mhd

Abstract. It has been confirmed that dipolarization fronts (DFs) can be a result from the existence of interchange instability in the magnetotail. In this paper, we used a Hall MHD model to simulate the evolution of the interchange instability, which produces DFs on the leading edge. A test particle simulation was performed to study the physical phenomenon of ion acceleration on DF. Numerical simulation indicates that almost all particles move towards the earthward and dawnward and then drift to the tail. The DF-reflected ion population on the duskside appears earlier as a consequence of the asymmetric Hall electric field. Ions, with dawn-dusk asymmetric semicircle behind the DF, may tend to be accelerated to a higher energy (> 13.5 keV). These high-energy particles are eventually concentrated in the dawnside. Ions experience effective acceleration by the dawnward electric field Ey while they drift through the dawn flank of the front towards the tail.

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