Effect Of Dust Size Distribution Research Articles

Effects of dust size distribution and non-Maxwellian electrons on shock waves in a dusty plasma

We present a study of dust acoustic shock waves in a non-Maxwellian plasma with dust charge fluctuations, which are seen to cause a dissipation term in fluid model, and consequently shocks are generated. In particular, we focus on dust acoustic waves as affected by various dust size distributions. Two distinct dust size distributions—the polynomial and the power law distributions—have been used. For analytical investigation of nonlinear wave propagation in complex plasmas, a reductive perturbation approach is used to obtain the Burgers equation. A dusty plasma system with non-Maxwellian Kappa distribution is considered and it is shown that the amplitude of a shock wave, for the dust size distribution is larger than that for the mono-sized counterpart, while the shock width manifests an opposite trend. Furthermore, the shock wave speed is also affected by the dust size distributions as well as by the nature of velocity distribution function. To benchmark our findings, we apply the proper limit on the spectral index, i.e., κ→∞, and retrieve the Maxwellian results. The current findings are crucial for comprehending respective shock distributions for a plasma system exhibiting non-thermal characteristics and having dust size distributions.

Effect of dust size distribution and nonadiabatic charge variation on dispersion relation for linear waves in inhomogeneous complex plasmas

This paper explores linear waves’ instability in nonuniform complex plasmas with dust size distribution and non-adiabatic dust charge fluctuation. For this purpose, the dispersion relation is obtained with the aid of linearizing the hydrodynamic equations governing the properties of linear waves. The contribution of physical parameters such as inhomogeneity, nonadiabatic dust charge fluctuation, and dust size distribution to the features of dust acoustic waves is examined at great length. The numerical results show that the present research results are very important in the phenomenon of space astrophysical and experimental plasmas.

Kinetic effects of dust size distribution on Alfvén waves in magnetized space plasmas

ABSTRACT Dust populations in space plasmas are often described by a size distribution function, generally a power law distribution. In view of that, we include this feature in the kinetic description of a homogeneous magnetized dusty plasma with electrically charged immobile dust grains, in order to study its effects in the propagation and damping of Alfvén waves. The dispersion relation is numerically solved using parameters typically found in the dust-driven stellar winds of carbon-rich stars and in Earth’s auroral acceleration region, two space systems with unalike plasma parameters and in which Alfvén waves are known to play important roles in the plasma acceleration and heating processes. We show that the characteristics of the normal modes, namely the ion cyclotron and whistler modes, will change when one considers a power law distribution of dust sizes in the theory, as compared to a mono-sized dust population; and that these differences will depend on the exponent p of the power law, which alters the plasma charge imbalance between electrons and ions. We also notice that power-law distribution functions will modify the waves’ damping rate values. In particular, we show that in a stellar wind environment the ion cyclotron mode at very small wavenumber decreases with the reduction of p, while for higher wavenumber the damping of this mode increases with the reduction of p. For the Earth’s magnetosphere, the results obtained show that the wave damping increases with the decrease of p for all wavenumbers, for the parameters considered in the analysis.

Effect of dust size distribution on dust acoustic solitary waves in a six component cometary plasma

Effect of dust size distribution on dust acoustic solitary waves in a six component cometary plasma

The effect of dust size distribution on shock wave in quantum dusty plasma

The effect of dust size distribution on shock wave in quantum dusty plasma

Growth of magnetorotational instability in circumstellar discs around class 0 protostars

ABSTRACT We investigate the possibility of the growth of magnetorotational instability (MRI) in discs around Class 0 protostars. We construct a disc model and calculate the chemical reactions of neutral and charged atoms, molecules, and dust grains to derive the abundance of each species and the ionization degree of the disc. Then, we estimate the diffusion coefficients of non-ideal magnetohydrodynamics effects such as ohmic dissipation, ambipolar diffusion, and the Hall effect. Finally, we evaluate the linear growth rate of MRI in each area of the disc. We investigate the effect of changes in the strength and direction of the magnetic field in our disc model and we adopt four different dust models to investigate the effect of dust size distribution on the diffusion coefficients. Our results indicate that an MRI-active region possibly exists with a weak magnetic field in a region far from the protostar where the Hall effect plays a role in the growth of MRI. On the other hand, in all models, the disc is stable against MRI in the region within <20 au from the protostar on the equatorial plane. Since the size of the discs in the early stage of star formation is limited to ≲10–20 au, it is difficult to develop MRI-driven turbulence in such discs.

Effects of dust size distribution on nonlinear magnetosonic wave in a dusty plasma

Both the linear and the nonlinear magnetosonic wave in a multi-component dusty plasma are studied in the present paper. The dependence of the dispersion relation of the linear waves on the dust size distribution are given. It seems that the larger the difference between the maximum and the minimum radius of the dust grains, the lower the wave frequency for all cases of the dust size distribution. Furthermore, it is noted that the width, the amplitude and the propagation velocity of the KdV solitary wave depend on the dust size distribution, especially it depend on whether the number density of the larger sized dust grain is larger or smaller than that of the smaller sized dust grain. For the power law dust size distribution, the width and the propagation velocity of the KdV solitary wave between the maximum and the minimum radius of the dust grains is larger than that of mono-sized dusty plasma.

The Effect of Dust Size Distribution on the Propagation of Electromagnetic Waves in a Weakly Ionized Dusty Plasma

The propagation characteristics of electromagnetic (EM) waves in dusty plasma of rocket exhaust are studied. Usually, the dust sizes are different in a general dusty plasma. However, most previous studies have focused on the mono-sized dusty plasma. The influence of dust size distribution on the EM wave attenuation of dusty plasmas has been investigated. The dependence of the EM wave attenuation on the electron density of dusty plasmas, the neutral gas density and the EM wave frequency are obtained and discussed. The results illustrate that the EM wave attenuation constant has a maximum value when the electron-neutral particles collision frequency is close to the EM wave frequency. The EM wave attenuation constant increase with the increase of electron density and dust particles density. Moreover, the EM wave attenuation constant decreases as the dust size decrease for mono-sized dust particles. It indicates that the attenuation of the EM wave is mainly determined by the largest dust particles. Finally, we conclude that the larger the dust particle, the stronger the attenuation to the EM wave.

Incrustation of wet dirt on glass surfaces through convective drying

The macroscopic and microscopic structural patterns formed during the convective drying of aqueous suspensions of dirt (mixture of dust, salt and water) on glass surfaces are investigated. The effects of dust size distribution, convective airflow temperature and velocity on the morphology of the deposited dust aggregates and salt crystals are studied. The critical removal forces necessary to leave behind a clean surface is experimentally determined. Drying at high temperature would cause a strong evaporation rate gradient leading to formation of salt rings and “cauliflower growths”, while drying at low temperature results in large individual crystals. The critical removal forces also correlate to these deposition patterns with the more raised structures requiring the lowest removal force. The strongest adhesive contacts are observed for samples with smoother morphology. The latter usually forms at high level of salt supersaturation (fast drying) in the presence of dust particles.

Effect of dust size distribution on ion-acoustic solitons in dusty plasmas with different dust grains

Theoretical studies are carried out for ion acoustic solitons in multicomponent nonuniform plasma considering the dust size distribution. The Korteweg−de Vries equation for ion acoustic solitons is given by using the reductive perturbation technique. Two special dust size distributions are considered. The dependences of the width and amplitude of solitons on dust size parameters are shown. It is found that the properties of a solitary wave depend on the shape of the size distribution function of dust grains.

Head-on collision of dust acoustic solitons in a nonextensive plasma with variable size dust grains of arbitrary charge.

The head-on collision of two dust acoustic solitons (DASs) in a nonextensive plasma with positive or negative dust grains fluid including the effect of dust size distribution (DSD) is studied. The phase shifts for the two solitons due to the collision are derived by applying the extended Poincaré-Lighthill-Kuo (PLK) method. The influences of the power law DSD and the nonextensivity of plasma particles on the characteristic properties of the head-on collision of DASs are analyzed. It is found that the phase shifts can vanish, only for the case of positive dust grains, for certain values and ranges of the dust grain radius and the entropic index of ions (q_{i}). Also, they undergo a cutoff in the range of q_{i}>1 for the subextensive distribution. A brief discussion of possible applications in laboratory and space plasmas is included.

Effect of dust size distribution and dust charge fluctuation on dust ion-acoustic shock waves in a multi-ion dusty plasma

The effects of dust size distribution and dust charge fluctuation of dust grains on the small but finite amplitude nonlinear dust ion-acoustic shock waves, in an unmagnetized multi-ion dusty plasma which contains negative ions, positive ions and electrons, are studied in this paper. A Burgers equation and its stationary solutions are obtained by using the reductive perturbation method. The analytical and numerical results show that the height with polynomial dust size distribution is larger than that of the monosized dusty plasmas with the same dust grains, but the thickness in the case of different dust grains is smaller than that of the monosized dusty plasmas. Furthermore, the moving speed of the shock waves also depend on different dust size distributions.

Effects dust size distribution on transportation of dust grains in a weakly ionized plasma

Transportation of charges, mass and heat of dust particles in a weakly ionized plasma is studied in the present paper. The dependence of electric conductivity, diffusion coefficient and heat conduction coefficient of dust particles on total number density and temperature of dust particles, number density and mass of neutrals, as well as collision cross section area between dust particles and neutrals are given. Effects of dust size distribution on electric conductivity, diffusion coefficient and heat conduction coefficient of dust particles have also been investigated. It is noted that they increase as the mean value of radius of dust particles increases. They increase as difference between maximum and minimum values of dust particles increases when density of the small grains is smaller than that of large grains. However, they decrease as difference between maximum and minimum values of dust particles increases when density of the small grains is larger than that of large grains.

Effects of dust size distribution on dust negative ion acoustic solitary waves in a magnetized dusty plasma

Dust negative ion acoustic solitary waves in a magnetized multi-ion dusty plasma containing hot isothermal electron, ions (light positive ions and heavy negative ions) and extremely massive charge fluctuating dust grains are investigated by employing the reductive perturbation method. How the dust size distribution affect the height and the thickness of the nonlinear solitary wave are given. It is noted that the characteristic of the solitary waves are different with the different dust size distribution. The magnitude of the external magnetic field also affects the solitary wave form.

The effect of dust size distribution on the damping of the solitary waves in a dusty plasma

The effect of the dust size distribution on the damping rate of the solitary wave in a dusty plasma is investigated in the present paper. It is found that the damping rate increases as either the mean radius of dust grains increases or as the total number density of the dust grains increases. The damping rate is less for usual dusty plasma (about which the number density of the smaller dust grains is larger than that of the larger dust grains) than that of the unusual dusty plasma (about which the number density of the larger dust grains is larger than that of the smaller dust grains).

Influence of charging process and size distribution of dust grain on the electric conductivity of dusty plasma

The effects of dust size distribution and charging process of dust grains on the complex electric conductivity of dusty plasmas have been investigated in the present paper. Comparisons are made between real dusty plasma in which there are many different dust grain species and the mono-sized dusty plasma (MDP) in which there is only one kind of dust grain whose size is the average dust size. In some cases the complex electric conductivity of real dusty plasma is larger than that of MDP, while in other cases it is smaller than that of MDP, it depends on the dust size distribution function.

The effect of dust size distribution and dust charge fluctuation on dust acoustic solitary waves in a magnetized dusty plasma

Dust acoustic solitary waves in a magnetized dusty plasma are studied taking into account the effect of dust size and dust charge variations. Using the analytical and numerical results the influence of different plasma parameters on dust acoustic solitary waves are examined. It is observed that the dust size distribution and dust charge variation have significant contributions on the characteristics of dust acoustic solitary waves.

Effects of dust size distribution in ultracold quantum dusty plasmas

The effect of dust size distribution in ultracold quantum dusty plasmas are investigated in this paper. How the dispersion relation and the propagation velocity for the quantum dusty plasma vary with the system parameters and the different dust distribution are studied. It is found that as the Fermi temperature of the dust grains increases the frequency of the wave increases for large wave number dust acoustic wave. The quantum parameter of Hd also increases the frequency of the large wave number dust acoustic wave. It is also found that the frequency ω0 and the propagation velocity ν0 of quantum dust acoustic waves all increase as the total number density increases. They are greater for unusual dusty plasmas than those of the usual dusty plasma.

Effects of dust size distribution on instability of obliquely propagating waves in a magnetized dusty plasma

In the present paper, the obliquely propagating solitary waves are investigated in a magnetized dusty plasma considering vortexlike ion distribution and dust size distribution. A plane solitary traveling-wave solution propagating at an arbitrary angle to the magnetic field is considered. The growth rate caused by small perturbations of any direction to a solitary traveling waves is studied. The effects of the dust size distribution and perturbations on the growth rate are discussed in detail.

The effect of dust size distribution on quantum dust acoustic wave

Based on the quantum hydrodynamics theory, a proposed model for quantum dust acoustic waves (QDAWs) is presented including the dust size distribution (DSD) effect. A quantum version of Zakharov–Kuznetsov equation is derived adequate for describing QDAWs. Two different DSD functions are applied. The relevance of the wave velocity, amplitude, and width to the DSD is investigated numerically. The quantum effect changes only the soliton width. A brief conclusion is presented to the current findings and their relevance to astrophysics data is also discussed.