KCG College of Technology

About: KCG College of Technology is a based out in . It is known for research contribution in the topics: Adsorption & Diesel fuel. The organization has 427 authors who have published 381 publications receiving 2193 citations.

Effect of Tool Pin Profile on Microstructure and Hardness of Magnesium Alloy Zk60/SiCp Surface Composites Fabricated by Friction Stir Processing

Abstract: The combination of stiffness, good castability, high specific strength, and low density makes magnesium alloys ideal materials, particularly in lightweight structural applications. The two major drawbacks of magnesium alloys are poor friction and wear resistance, because they restrict the structural applications. Therefore, it is necessary to enhance the tribological properties of magnesium alloys without creating many adverse effects on the properties of the base metal by using surface engineering. In order to achieve a sound fabrication of surface metal matrix composites on the magnesium plate, friction stir processing (FSP) often serves as a good candidate. However, the process parameters should be suitably selected to fabricate a sound FSP zone. Tool pin profile is a major significant process parameter, particularly in FSP, as it plays major part in the formation of a processed region with a uniform distribution of reinforcement particles. In this study, an attempt was made to understand the major effects of tool pin profiles, namely, cylindrical thread, plain cylindrical, plain tapered cylindrical (PTC), and square on the microstructure characteristics and particle distribution of FSP ZK60/Silicon Carbide particle (SiCp) surface composites. Of the four pin profiles, surface composites fabricated by means of PTC pin profile resulted in a defect-free and higher hardness processed zone. This was attributed to the higher shear force offered by the PTC pin profile, which aids proper material flow with evenly distributed particles.

Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet

Abstract: Laser action in methyl methacrylate (MMA) co-doped with sulforhodamine B and crystal violet dyes was investigated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd:YAG laser. Distributed feedback dye laser (DFDL) action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor—donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor—donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

Reduction of Wingtip Vortex from Suction at Wingtip

Abstract: Wingtip vortices are strongly associated with induced drag for a three-dimensional wing. So it is important to study the characteristics of wingtip vortices in order to reduce the induced drag. In this paper, numerical simulations of the tip vortices for an unswept and untwisted rectangular wing (NACA 0012) are carried out at a geometric angle of attack 10° using the commercial Computational Fluid Dynamics code (Fluent), and numerical results are compared with the low speed wind tunnel experimental measurements carried out at NASA. The numerical results that were obtained by using CFD code show a good agreement with the experimental results. This has been done for the purpose of validation so that the code can be applied with confidence for modified configuration. Few different configurations have been evaluated computationally to explore their potential to reduce the wing tip vortex. It is shown by numerical calculation that the strength of the vorticity is significantly reduced when suction is applied on the wing tip and along a slot on the bottom surface near to trailing edge.