Response of a dusty plasma system to external charge perturbations

The excitation of nonlinear wave structures in a dusty plasma caused by a moving external charge perturbation is examined in this work, which uses a 1-D flux corrected transport simulation. The plasma responds uniquely to different nature of the moving charge, depending on which, for small amplitude perturbations, pinned envelope solitons are generated and electrostatic dispersive ion-acoustic shock waves are formed for a large amplitude perturbation. The presence of dust particles is found to suppress the formation of dispersive shocks at low velocity of the external charge debris. The results are also investigated theoretically as a solution to the generalized Gross-Piteavskii equation, which broadly supports the simulation results.Comment: 19 pages, 11 figure

The possibility of hypersonic electrostatic solitons in a plasma with turbulence heating

Here, we show that electrostatic solitons in a plasma with turbulent heating of the electrons through an accelerating electric field, can form with very high velocities, reaching up to several order of magnitudes larger than the ion-sound speed. We call these solitons hypersonic solitons. The possible parameter regime, where this work may be relevant, can be found the so-called ``dead zones'' of a protoplanetary disk. These zones are stable to magnetorotational instability but the resultant turbulence can in effect heat the electrons make them follow a highly non-Maxwellian velocity distribution. We show that these hypersonic solitons can also reach very high velocities. With electron velocity distribution described by Davydov distribution function, we argue that these solitons can be an effective mechanism for energy equilibration in such a situation through soliton decay and radiation.Comment: 12 pages, 5 figure

Effect of TBHQ on the Combustion Characteristics of Pomelo oil Biodiesel in a Compression Ignition Engine

81-83Biodiesel is a biomass-based fuel. Biodiesel faces the difficult issue of storage stability. The storage stability of a biodiesel can be enhanced by adding an antioxidant to the fuel, which represses oxidation reactions that take place upon exposure to sunlight, heat, moisture, humidity, and metal. In the present study, biodiesel is synthesized from pomelo oil (Citrus maxima) and treated with a synthetic antioxidant called TBHQ (Tertiary butyl hydroquinone). The engine and emission performance of the biodiesel with TBHQ in various concentrations have been determined in a single cylinder four stroke diesel engine. It is observed that brake specific fuel consumption increases with the increasing concentration of TBHQ. Brake power stays unaltered for the biodiesel with or without TBHQ. Considerable reduction in carbon monoxide and carbon dioxide has been observed for biodiesel irrespective of antioxidant treatment

Effect of TBHQ on the Combustion Characteristics of Pomelo oil Biodiesel in a Compression Ignition Engine

Biodiesel is a biomass-based fuel. Biodiesel faces the difficult issue of storage stability. The storage stability of a biodiesel can be enhanced by adding an antioxidant to the fuel, which represses oxidation reactions that take place upon exposure to sunlight, heat, moisture, humidity, and metal. In the present study, biodiesel is synthesized from pomelo oil (Citrus maxima) and treated with a synthetic antioxidant called TBHQ (Tertiary butyl hydroquinone). The engine and emission performance of the biodiesel with TBHQ in various concentrations have been determined in a single cylinder four stroke diesel engine. It is observed that brake specific fuel consumption increases with the increasing concentration of TBHQ. Brake power stays unaltered for the biodiesel with or without TBHQ. Considerable reduction in carbon monoxide and carbon dioxide has been observed for biodiesel irrespective of antioxidant treatment

Thermal instability of an expanding dusty plasma with equilibrium cooling

We present an analysis of radiation induced instabilities in an expanding plasma with considerable presence of dust particles and equilibrium cooling. We have shown that the equilibrium expansion and cooling destabilize the radiation condensation modes and the presence of dust particles enhances this effect. We have examined our results in the context of ionized, dusty-plasma environments such as those found in planetary nebulae (PNe). We show that due to the non-static equilibrium and finite equilibrium cooling, small-scale localized structures formed out of thermal instability, become transient, which agrees with the observational results. The dust-charge fluctuation is found to heavily suppress these instabilities, though in view of non-availability of convincing experimental data, a definitive conclusion could not be made.Comment: 23 pages, 14 figure

Plasma Dynamics

Contains table of contents for Section 2 and reports on two research projects.Princeton University/National Spherical Torus Experiment Grant S04020G PPPLU.S. Department of Energy Grant DE-FGO2-91-ER-54109National Science Foundation Grant ECS 94-24282Los Alamos National Laboratory Grant No. E29060017