R. K. Tyagi

Analysis of electrostatic ion-cyclotron instability driven by parallel flow velocity shear

Analysis and study of parallel flow velocity shear and electrostatic ion cyclotron (EIC) instability performed in plasma containing massive positive ions and electron by using the method of characteristics solution and kinetic theory in the presence of homogeneous direct-current (DC) electric field perpendicular to ambient magnetic field. The calculation of growth rate and real frequency has been done by using the computational technique. The effect of many parameters like shear scale length, homogenous d.c.electric field, magnetic field, electron ion temperature ratio, angle between wave number k⊥ and k|, on growth rate and also the effect of homogenous d.c.electric field, magnetic field on real frequency has been discussed by using the experimental data. Applications to possible laboratory plasmas and industries are also analyzed.

Mechanical Characterization of Banana/Sisal Fibre Reinforced PLA Hybrid Composites for Structural Application

Advanced technology emergence in the field of petrochemical-based polymers has brought many benefits to mankind. It is validating that the ecosystem is considerably disturbed and damaged as a result of the nondegradable plastic materials used for disposable items. This paper relates the use of hybrid bio-composites, which is eco-friendly and easily degradable. Previous literature related to hybrid bio-composites proves its eco-friendly and excellent degradable properties. In this paper, banana and sisal fibers were selected to execute the hybrid bio-composite preparation with poly lactic as its matrix. Specimens were made with and without fibre treatment and their mechanical properties like tensile, flexural and impact were evaluated as per the standard test procedures. The test results obtained evident that the treated fibers having the best mechanical properties than pure PLA and untreated fibre bio-composites. The chemical treatment also improved fiber matrix interaction by removal of lignin and hemicellulose, which led to the better incorporation of fiber with the matrix. The SEM micrographs of untreated banana/sisal fibre reinforced PLA bio-composites and treated banana/sisal fibre reinforced PLA bio-composites clearly indicated the extent of the fiber-matrix interface adhesion.

Effect of heating the catalytic converter on emission characteristic of gasoline automotive vehicles

Gasoline engines have been widely used as engineering machinery, automobile and shipping power equipment due to their excellent drivability and economy. At the same time, gasoline engines are major contributors to various types of air pollutants such as carbon monoxide (CO), oxides of nitrogen (NOx), and other harmful compounds. With the increasing concern of environment and more stringent government regulation on exhaust emissions, the reduction in engine emissions such as particulate matter and NOx is a major research objective in engine development. In this article the effect of heating the catalytic converter on emission characteristic of automotive vehicles in its starting phase of combustion has been studied. In this work, the emission characteristic of hydrocarbons has been improved from 800 to 15 ppm, CO from 4 to 0.07 (V/V%) and NOx from 1200 to 115 ppm.

Non-traditional machining processes by means of velocity shear instability in plasma

The material removal within different machining process can be performed in distinct modalities. One of the modality is based on the effect of impact phenomenon. In this paper theoretical model of non-traditional machining process based on impact phenomenon is discussed. The material is removed from the surface due to the impact of ions. The velocity of ions is equal to the velocity at which the electrostatic ion-cyclotron instability driven by parallel flow velocity shear generated by massive ions takes place. The main ways for the material removal as consequence of the impact phenomenon are the microcracking, microcutting, melting and vaporizing of small quantities from the work-piece surface layer.

Effect of hydrogen and gasoline fuel blend on the performance of SI engine

This paper presents the effects of introducing hydrogen with gasoline on the engine performance like power, torque and efficiency of spark ignition (SI) engine. Hydrogen is found to be one of the important energy substitutes of the future era. Hydrogen as a renewable energy source provides the potential for a sustainable development, particularly in the automotive and energy storing sector. Hydrogen driven vehicles reduce both local as well as global emissions. By changing the amount of hydrogen percentage with gasoline, the data has been recorded and analyzed to achieve the economical blend percentage of hydrogen and gasoline to obtain the best performance of the SI engine. Key words: Hydrogen gasoline blend, engine performance, ignition timing, efficiency.

Theoretical analysis of silicon surface roughness induced by plasma etching

A theoretical study of single-crystal silicon surface roughness induced by SF6 plasma has been carried out by means of atomic force microscopy. Plasma which contains the velocity shear instability has been used to study the relation between the plasma parameters and subsequent surface roughness. The surface roughness has been examined in the dependence on experimental parameters. The results obtained by theoretical calculations are identical to the experimental ones. The present paper has quantified the influence of a DC electric field values on plasma parameters such as the ratio of ion flux to the neutral reactant flux (J+/JF), exposure time, DC electric field, magnetic field and inhomogeneity. Theoretical investigation shows that the roughness of silicon surface increases with the increase of the values of J+/JF, exposure time, of magnetic field, of inhomogeneity in a DC electric field and decreases through increasing the value of a DC electric field.

Conversion efficiency of catalytic converter

Around 50 million vehicles are manufactured every year and over 700 million vehicles are used worldwide. Vehicle population is predictable to grow close to 1300 million by the year 2030. Automobile produced 10,037,168 short tons of nitrogen oxides and 59,383,083 short tons of carbon dioxide in 2008 alone. In the present scenario, air pollution generation from the mobile sources is a big problem in the world. The maximum quantity of air pollution is due to the emissions from Internal Combustion Engines. Combustion of pollutants released from the vehicular exhaust is one of the best approaches to decrease their attentiveness before their release to the atmosphere. The main attention of the work is the research of catalytic converter working effectiveness in used passenger cars. In this work the fuel which is used is commercial gasoline with blends and the testing is done in the passenger car. The testing is done in three ways: (1) with a new CatCoN [1000 km], (2) with an old CatCoN [55,000 km] and (3) without a CatCoN. After comparing the test results, it is concluded that the conversion efficiency of the catalytic converter decreases when the vehicle runs above 45,000 km. The best result of the exhaust gases is shown with a new catalytic converter.

Performance studies on flat plate solar air heater subjected to various flow patterns

The performance of flat plate solar air heater subjected to various flow patterns (over flow, under flow and double pass) were experimentally investigated. An aluminium flat plate of 1.2. × 0.7 m2 size was employed as absorber plate. Two glass plates of similar size were used as protection for heat loss from absorber plate to atmosphere. Performance of the solar air heater at various mass flow rates (0.014, 0.0279 and 0.042 kg/s) was also reported. Thermal efficiency is recorded higher during double pass experimental conditions. Heat gained by air is found higher at experimental conditions having double pass when compared with over flow and under flow.

Surface coating by means of velocity shear instability in plasma

In this paper the effect of different parameters like magnetic field, homogenous direct-current electric field, shear scale length, temperature anisotropy, inhomogeneity in direct-current electric field and density gradient on ions velocity is discussed. A mathematical model for ions/micron size particles velocity is discussed and its values are calculated by taking experimental parameters and by applying computer technique. A model of plasma spray machine is also suggested, which contains plasma production with velocity shear instability in laboratory, powder injection and mass and momentum transfers between particles. The coating process by means of velocity shear instability in plasma has possibility to spray hard and arduous material (alloy) with minimum defects and maximum technical and economic efficiency.

Heat flux and plasma parameters in plasma welding by means of velocity shear instability

Industrial applications of plasma welding technology are in spot light in many industries. The flexibility of coupling electric field, magnetic field and parameters in plasma heat flux has been demonstrated in selected pilot scale and plasma welding for metallurgical and parametallurgical purpose. This paper present effect of different parameters: magnetic field, homogenous Direct Current electric field (DC), shear scale length, temperature anisotropy, inhomogeneoity in DC electric field, density gradient on heat flux. Theoretical results from mathematical model shows that plasma parameters affect the heat flux in plasma welding by velocity shear instability.