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Microparticle and Nanoparticle Manipulation
Published in Sushanta K. Mitra, Suman Chakraborty, Fabrication, Implementation, and Applications, 2016
Under uniform electric field conditions, charged particles, such as the negatively charged DNA, will move toward the electrode with the opposite charge. This is the basis for DNA gel separation. Strong and weakly charged DNA strands will move at different speeds toward the positively charged electrode. A pool of different DNA strands could be separated and then analyzed. Neutral particles, however, behave in a different way. Under a constant electric field, induced charges gather and distribute themselves at the surface of the neutral particle. By definition, a neutral particle has the same number of positive and negative charges. As we can see in Figure 12.1, the neutral particle will remain stationary because the forces induced toward the positive and negative electrodes are identical. Nevertheless, when the electric field is nonuniform, the neutral particle will move toward the region of high electric field density if the particle is more permeable than the medium, and the neutral particle will move toward the region of low electric field density if it is less permeable than the medium.
Diffusion Synthetic Acceleration for Heterogeneous Domains, Compatible with Voids
Published in Nuclear Science and Engineering, 2021
B. S. Southworth, Milan Holec, T. S. Haut
Here, are the spatially dependent scattering and total cross sections, respectively, and we assume isotropic scattering for simplicity. This equation is fundamental to models of neutral particle transport such as neutron or photon transport and is also a prerequisite for solving more complicated physical models such as thermal radiative transfer. The left side of Eq. (1) is a three-dimensional advection-reaction equation in direction and the right side is an integral-operator coupling over direction. More complex physical models introduce a nonlinearity in temperature on the right side, while including time and energy leads to seven dimensions, overall requiring massively parallel simulations.
Energy distribution in cool electrode of electrical discharge machining based on wave-particle dualism
Published in Machining Science and Technology, 2019
Qiu Mingbo, Han Yunxiao, Zhang Chao, Chen Haoran, Hui Zhiguang
The matter wavelength of positive ion λp is considerably less than , which cannot perform volatility characteristics and occur diffraction like electron. The positive ion can only perform particle characteristics that hit forward and radiate energy when it changes into photon. Its movement distance is restricted within the smaller mean free path. The vast majority of positive ions cannot reach the surface of the cathode. However, positive charge can reach the cathode in the form of neutral particle transmission (Figure 3). Positive ion P under the effect of the electric field force moves to the cathode. Given the limitation of free path , crash on the particle Q and all the energy losses, and the charge transfer to Q, the P particle changes into neutral particle, and the Q particle that carries the electric charge continues to move to the cathode under the action of the electric field force.
A study of neutral collisions and viscous force on the formation of astronomical objects including with QMHD fluid model
Published in Radiation Effects and Defects in Solids, 2022
D. L. Sutar, S. Sharma, A. Saxena, T. A. Pathan, R. K. Pensia
Magnetic field, viscosity, quantum corrections, radiative effects, thermal conductivity and neutral particle effects are all part of the dispersion relation (19). For finitely and infinitely conducting media, the condition of instability comes from the constant terms of the simplified equations from (19)