Particle In Uniform Magnetic Field Research Articles

Experimental investigation on the agglomeration performance of pre-charged micro-nano particles in uniform magnetic field

Agglomeration of fine particles is an essential procedure to improve separation efficiency of dust-removal devices. This paper focuses on the treatment of biomass Micro-Nano particles using cascade electrostatic and magnetic fields. A carefully designed wind tunnel is built to investigate the agglomeration performance of pre-charged Micron-Nano particles (0.016–9.84 µm) in uniform magnetic field. The influence of supply voltage (10–30 kV) in the electrostatic unit and the bulk flow velocity (1–5 m/s) across the device upon agglomeration is studied. The results indicated noticeable agglomeration behavior because of reduced submicron particles and increased larger particles. Strengthening Supply voltage input has a positive yet minimum effect on the overall agglomeration efficiency. Effect of bulk flow velocity on agglomeration is remarkable due to magnetic field. Therefore, agglomeration of pre-charged particles in uniform magnetic field is dominated by Lorentz effect and stream-wise spacing of the device. This work provides a reference for further computational attempt in the future.

Development of an Empirical Model of the Force between Paramagnetic Particles in Uniform Magnetic Field on M-type Asteroids

M-type asteroids may have remanent magnetic fields. Regolith particles on M-type asteroids are likely to have metallic components, causing them to be paramagnetic and respond to an external magnetic field. Paramagnetic particles placed in an external magnetic field are influenced by induced magnetic moments of neighboring particles. Therefore, the magnetic force between regolith particles on an M-type asteroid can change the net cohesion of the regolith. Previous works have shown the influence of cohesive forces in the evolution of rubble-pile asteroids. This work characterizes the magnetic force between regolith particles on M-type asteroids. We implement existing models of the magnetic force between paramagnetic particles placed in an external magnetic field and then present an empirical model of this force for two magnetic field orientations as an essential step toward a general semiempirical model that the wider planetary science community can more easily use to investigate the significance of this force.

On the classical dynamics of charged particle in special class of spatially non-uniform magnetic field

Motion of a charged particle in uniform magnetic field has been studied in detail, classically as well as quantum mechanically. However, classical dynamics of a charged particle in non-uniform magnetic field is solvable only for some specific cases. We present in this paper, a general integral equation for some specific class of non-uniform magnetic field and its solutions for some of them. We also examine the supersymmetry of Hamiltonians in exponentially decaying magnetic field with radial dependence and conclude that this kind of non-uniformity breaks supersymmetry.

Exact Parent Hamiltonian for the Quantum Hall States in a Lattice

We study lattice models of charged particles in uniform magnetic fields. We show how longer range hopping can be engineered to produce a massively degenerate manifold of single-particle ground states with wave functions identical to those making up the lowest Landau level of continuum electrons in a magnetic field. We find that in the presence of local interactions, and at the appropriate filling factors, Laughlin's fractional quantum Hall wave function is an exact many-body ground state of our lattice model. The hopping matrix elements in our model fall off as a Gaussian, and when the flux per plaquette is small compared to the fundamental flux quantum one only needs to include nearest and next-nearest neighbor hoppings. We suggest how to realize this model using atoms in optical lattices, and describe observable consequences of the resulting fractional quantum Hall physics.

Two-dimensional Monte Carlo simulations of structures of a suspension comprised of magnetic and nonmagnetic particles in uniform magnetic fields

The structures of suspensions comprised of magnetic and nonmagnetic particles in magnetic fields are studied using two-dimensional Monte Carlo simulations. The magnetic interaction among magnetic particles, magnetic field strength, and concentrations of both magnetic and nonmagnetic particles are considered as key influencing factors in the present work. The results show that chain-like clusters of magnetic particles are formed along the field direction. The size of the clusters increases with increasing magnetic interaction between magnetic particles, while it keeps nearly unchanged as the field strength increases. As the concentration of magnetic particles increases, both the number and size of the clusters increase. Moreover, nonmagnetic particles are found to hinder the migration of magnetic ones. As the concentration of nonmagnetic particles increases, the hindrance on migration of magnetic particles is enhanced.

Aggregation mechanism of fine fly ash particles in uniform magnetic field

Aggregation of fly ash particles with size range of 0.023-9.314 μm in a uniform magnetic field was investigated for removing them. A binary collision-aggregation model evaluating particle aggregation coefficient was developed. Based on the model, particle removal efficiency was calculated by solving the General Dynamic Equation. The comparison was done between the calculated and experimental data. The modeling aggregation coefficient shows that the aggregation coefficient increases with particle size, and the bigger the size difference between two particles is, the more strongly the gravity difference promotes aggregation. For the mid-sized particles, their removal efficiencies are higher than those of the smaller and bigger ones. The effect of the magnetic flux density on total particle removal efficiency is similar to that on aggregation coefficient. Before particles are saturatedly magnetized, their total removal efficiency increases with an increase in the magnetic flux density. Higher removal efficiency can also be caused by prolonging the particle residence time in the magnetic field or increasing their mass concentration. The particle number median diameter decreases with an increase in the total removal efficiency. Calculation results are found to coincide essentially with the experimental data.

Aggregation experiments on fine fly ash particles in uniform magnetic field

Aggregation experiments on three fly ash samples in the size range of 0.023–9.314 μm were conducted in a uniform magnetic field. The fly ash particles were produced from combustion of three different bituminous coals. The coals were originated Dongshen, Datong and Xuzhou of China, respectively. A fluidized bed aerosol generator was used to disperse the fly ash particles to generate a constant aerosol. The aerosol particles aggregated when passing through the magnetic field. The variation of particle number concentration caused by particle aggregation was measured in real time by an Electrical Low Pressure Impactor (ELPI). The effects of several parameters, such as particle size, magnetic flux density, particle residence time in the magnetic field, total particle mass concentration and average gas velocity, on particle aggregation were examined. Experimental results indicated that removal efficiencies are the highest for particles with sizes in the middle of the size ranges tested. Increasing magnetic flux density, total particle mass concentration, particle residence time in the magnetic field or by reducing average gas velocity can increase removal efficiencies of single-sized and total fly ash particles. When fly ash particle magnetization reached saturation state, further increase of the magnetic flux density will have no effect on particle aggregation. The single-sized and total particle removal efficiencies of the three fly ashes are different under the same operating conditions. The removal efficiency is the highest for fly ash generated from Dongshen coal, followed by fly ash from Datong coal, and then fly ash from Xuzhou coal. Particle number median diameters decreases with the increase in the total particle removal efficiencies. The model prediction of particle aggregation under high total particle mass concentrations conditions indicated that the single-sized and total particle removal efficiencies will increase greatly with the increase in total particle mass concentration. The model predicted total removal efficiencies of the three fly ash particles are 53%, 43% and 14%, for Dongshen, Datong and Xuzhou coals respectively when total particle mass concentration is 40 g/m 3.

Gravitational sedimentation of aggregates of ferromagnetic particles of magnetic fluid in uniform magnetic fields

A mathematical model describing the gravitational sedimentation of aggregates of magnetic fluid particles in uniform magnetic fields is proposed to compare the sedimentation rates in vertical and horizontal magnetic fields of the same intensity. Conducted for intensities that are substantially less or substantially greater than some characteristic value, the comparison is consistent with experimental data.

LANDAU LEVEL SPECTRUM FOR CHARGED PARTICLE IN A CLASS OF NON-UNIFORM MAGNETIC FIELDS

The spectrum of a charged particle in uniform magnetic field consists of equally spaced Landau levels which are infinitely degenerate. We consider isospectral deformations of this problem and show that the spectrum is again equispaced but nondegenerate for a wide class of non-uniform magnetic fields.

The dispersion patterns of acicular particles in viscous medium

A lattice model of ferrofluid with time dependent viscosity has been developed to simulate the dispersion patterns of interacting fine ferromagnetic particles during the manufacturing process of magnetic recording medium. Closure and chaining of the magnetic particles in uniform magnetic field have been obtained. The length of the chain is dependent on the packing factor. For magnetic particles possessing electric charge, the agglomeration of particles will reduce. The hysteresis corresponding to different patterns are calculated using quasi-dynamic vectorial model.