Dust-Acoustic Rogue Waves in an Electron-Positron-Ion-Dust Plasma Medium

In this work, the modulational instability of dust-acoustic (DA) waves (DAWs) is theoretically studied in a four-component plasma medium with electrons, positrons, ions, and negative dust grains. The nonlinear and dispersive coefficients of the nonlinear Schrödinger equation (NLSE) are used to recognize the stable and unstable parametric regimes of the DAWs. It can be seen from the numerical analysis that the amplitude of the DA rogue waves decreases with increasing populations of positrons and ions. It is also observed that the direction of the variation of the critical wave number is independent (dependent) of the sign (magnitude) of q. The applications of the outcomes from the present investigation are briefly addressed.

Scientific Co-operative Rover with Artificial Intelligence for Futuristic Scientific Experiments on Moon

<p>With recent scientific experiments carried out and results have shown an immense studies in<br />operation in the complex lunar environment and exploiting the moon base as a scientific platform<br />for both research and major challenges in exploration. Notion Robotics Lab proposes a highly<br />advanced lunar lander to prepare future missions on moon. The scientific areas for investigation<br />on the lunar lander include the radiation environmental and its effect, dust, plasma, the most<br />important being the properties of moon dust and its effect on human intervention. Notion<br />Robotics Lab will propose a payload which interfaces the information and the boundary<br />conditions. This paper discusses the scientific objectives for the futuristic mission which<br />emphasizes human robot exploration and builds a prototype scientific payload to be part of the<br />mission and also design of scientific instruments.<br />Notion Robotics Lab has developed the sophisticated autonomous co-operative rovers with<br />multiple intelligence systems to study life on lunar base and capable of handling multiple<br />decisions without human interference. This rover will be built as per the map of the terrains in<br />the lunar base thus operating different tasks. With advancement of different payloads and<br />scientific instruments the rover may able to map the large tracts of the surface thus do complex<br />tasks and experiments. Notion Robotics Lab plans to execute with the partnership with<br />Universities and Space Agencies thus proposing broader experiments in futuristic lunar mission.<br />Keywords:- Autonomous Co-operative Rover, Artificial Intelligence, Scientific Instruments,<br />Understanding Life, Lunar Lander</p>

Simulating diverse instabilities of dust in magnetized gas

ABSTRACT Recently, Squire & Hopkins showed that charged dust grains moving through magnetized gas under the influence of a uniform external force (such as radiation pressure or gravity) are subject to a spectrum of instabilities. Qualitatively distinct instability families are associated with different Alfvén or magnetosonic waves and drift or gyro motion. We present a suite of simulations exploring these instabilities, for grains in a homogeneous medium subject to an external acceleration. We vary parameters such as the ratio of Lorentz-to-drag forces on dust, plasma β, size scale, and acceleration. All regimes studied drive turbulent motions and dust-to-gas fluctuations in the saturated state, rapidly amplify magnetic fields into equipartition with velocity fluctuations, and produce instabilities that persist indefinitely (despite random grain motions). Different parameters produce diverse morphologies and qualitatively different features in dust, but the saturated gas state can be broadly characterized as anisotropic magnetosonic or Alfvénic turbulence. Quasi-linear theory can qualitatively predict the gas turbulent properties. Turbulence grows from small to large scales, and larger scale modes usually drive more vigorous gas turbulence, but dust velocity and density fluctuations are more complicated. In many regimes, dust forms structures (clumps, filaments, sheets) that reach extreme overdensities (up to ≫109 times mean), and exhibit substantial substructure even in nearly incompressible gas. These can be even more prominent at lower dust-to-gas ratios. In other regimes, dust self-excites scattering via magnetic fluctuations that isotropize and amplify dust velocities, producing fast, diffusive dust motions.

Effect of the pressure of the dust grains in strongly coupled dusty plasma on the head-on collision between two nonlinear waves

The head-on collision between two dust-acoustic solitary waves in a non-magnetized, collisionless and strongly coupled dust plasma has been studied. The application scope of the analytical solution of the head-on collision is given in the present paper by using the particle-in-cell simulation method. It is noted that the analytical results are valid if the amplitudes of both of the solitary waves are small enough. The effects of the coupling parameters on both the head-on collision and the waveform are also studied in the present paper.

An Application of (3+1)-Dimensional Time-Space Fractional ZK Model to Analyze the Complex Dust Acoustic Waves

Dust plasma is a new field of physics which has developed rapidly in recent decades. The study of dust plasma has received much attention due to its importance in the environment of space and the Earth. Dust acoustic waves are generated because of the inertia of dust mass while the restoring force is provided by the thermal pressure of electrons and ions. Since dust acoustic waves were first reported theoretically in unmagnetized dust plasma by Rao et al., they have become a research hot spot. In this paper, the excitation of dust acoustic waves by a gravity field in a dust plasma is analyzed. According to the control equations of dust plasma motion and employing multiscale analysis and perturbation method, we have obtained a (3+1)-dimensional ZK model. Because of the space property of dust plasma, (3+1)-dimensional ZK equation is more suitable than KdV equation and (2+1)-dimensional ZK equation to describe the real dust acoustic waves. Then, the (3+1)-dimensional time-space fractional ZK (TSF-ZK) equation describing the fractal process of nonlinear dust acoustic waves is given for the first time. To further explore how dust acoustic waves change energy as they travel, we discuss the conservation laws of the new model. Moreover, we study the exact solution of (3+1)-dimensional TSF-ZK equation by using extended Kudryashov method. Finally, based on the exact solution, we further investigate the effect of the parameter k, the charge properties of dust particle Zd0, the fractional order values α, β, γ, and θ, the temperature Td, the gravity g, and the collision frequency β0 and β1 on the properties of dust acoustic waves by a gravity field in dust plasma.