National Institute of Technology, Karnataka

About: National Institute of Technology, Karnataka is a education organization based out in Mangalore, Karnataka, India. It is known for research contribution in the topics: Computer science & Corrosion. The organization has 5017 authors who have published 7057 publications receiving 70367 citations.

Mechanical, Dynamic Mechanical and Vibration Behavior of Nanoclay Dispersed Natural Fiber Hybrid Intra-ply Woven Fabric Composite

Abstract: Influence of nanoclay dispersion on mechanical, dynamic mechanical and free vibration characteristics of basket type intra-ply woven banana/jute (banana yarn-weft direction, jute yarn-warp direction) hybrid polyester composite has been investigated. Results revealed that loading of nanoclay enhances the mechanical properties of the composite significantly as it improves the adhesion between fiber and matrix. Dynamic mechanical analysis result reveals that nanoclay addition significantly increases the storage modulus and glass transition temperature of the intra-ply hybrid composite. From free vibration studies, carried out on laminated beam like structures, it is found that the natural frequency of the composite laminate increases till 2 wt% of nanoclay while the modal damping increases when the wt% of nanoclay is more than 2. However, due to the agglomeration effect of nanoclay the properties are not improved for nanoclay loading beyond 2 wt%.

Optimisation of monotube magnetorheological damper under shear mode

Abstract: Magnetorheological dampers (MR) are one of the semi active devices, which has the capability of providing variable damping force for the variable input current. Induced force is directly dependent on the amount of magnetic flux density developed in effective fluid flow gap of the MR damper. In the present work, influence of material properties on the magnetic flux is investigated by considering magnetic and nonmagnetic material for the outer cylinder of shear mode type MR damper. Magnetostatic analysis is carried out to obtain magnetic flux density for the initial configuration of the MR damper. From the analysis, it is found that usage of magnetic material cylinder which is insulated with nonmagnetic material provided higher value of magnetic flux and damping force. The geometric optimisation of MR damper is carried out to obtain the maximum flux density in the fluid flow gap. The objective function of the optimisation includes the maximum magnetic flux density and minimising fluid flow gap. Design variables considered are fluid flow gap, number of turns in the electromagnetic coil, length of the flange and DC current input. The optimisation is performed through response surface method using finite element analysis software (ANSYS). The best optimal design parameters are obtained by choosing the appropriate value of objective function. The best configuration of the design parameters, which induce the maximum magnetic flux density, is identified. The force induced in the MR damper is estimated analytically and a comparative study of the optimised and non-optimised results was carried out.

Ru–TiO2 semiconducting nanoparticles for the photo-catalytic degradation of bromothymol blue

Abstract: Photo-catalytic degradation of bromothymol blue (BTB) in an aqueous medium by Ru–TiO2 using UVC (254 nm) irradiation was investigated for a pH range of 4.0–8.0. The liquid impregnation method was used to synthesize 0.2, 0.4 and 0.8 % ruthenium doped TiO2 (Ru–TiO2) nanoparticles. The characterizations of resulting nanoparticles were done using X-ray diffraction, scanning electron microscopy, fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy analysis. The crystallite sizes of doped and undoped nanoparticles were determined from X-ray diffraction spectra using Scherrer equation. The average crystallite size of undoped TiO2 was found to be 17.00 nm, whereas the crystallite sizes of 0.2, 0.4 and 0.8 % Ru–TiO2 were 16.67, 15.70 and 14.40 nm respectively. The TEM images confirm the particle sizes to be 10–40 nm. Pseudo-first order rate constants (kobs) determined were found to decrease with increase in pH. The effect of BTB Concentration, catalyst dosage, a percentage of doping of photo catalyst, pH and UV light intensity of BTB on the degradation rate were also examined.