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: Corrosion & Cloud computing. The organization has 5017 authors who have published 7057 publications receiving 70367 citations.

Enhanced Permeation Performance of Cellulose Acetate Ultrafiltration Membranes by Incorporation of Sulfonated Poly(1,4-phenylene ether ether sulfone) and Poly(styrene-co-maleic anhydride)

Abstract: A cellulose acetate (CA)-based ultrafiltration membrane was prepared by incorporation of mechanically strong, sulfonated poly(1,4-phenylene ether ether sulfone) (SPEES) to which hydrolyzed poly(styrene-co-maleic anhydride) (PSMA) was added as a novel additive. The preparation of SPEES was investigated in detail. SPEES having a degree of sulfonation of 21%, was more suitable for the blend. The chemical constitutions of SPEES, PSMA, and the blend membranes were confirmed by attenuated total reflectance fourier transform infrared spectroscopy. The scanning electron microscopy images revealed finger-like projections in the membrane structure. The performance of the membranes was analyzed on the basis of water content, porosity, flux, and antifouling studies. A membrane comprising 30% SPEES and 2% additive showed superior performance with flux and flux recovery ratio of 228 L/(m2 h) and 91%, respectively. It was concluded that the prepared membranes showed better performance in comparison with neat CA membranes.

Fabrication of polyetherimide nanocomposite membrane with amine functionalised halloysite nanotubes for effective removal of cationic dye effluents

Abstract: Naturally, occurring, low cost and eco-friendly halloysite nanotubes were chemically modified and uniformly immobilised into the polyetherimide membrane matrix with the aim of enhancing the properties and possible cationic dye rejection efficacy. The properties of fabricated nanocomposite membranes were examined by means of porosity, hydrophilicity, zeta potential and permeability. Permeation experiments revealed the enhanced water flux up to 195 L/m2h with 4 wt% additive dosage. The dye rejection efficacy of the prepared membranes was determined by using rhodamine B (Rh.B) and methylene blue (MB). The dye rejection studies were executed in terms of pH, contact time and initial dye concentration. The membrane with 4 wt% of nanomaterial dosage, showed rejection of 97% at pH 8 and 94% at pH 7 for MB and Rh.B dyes, respectively. Langmuir adsorption isotherm is the best model to explain interaction between dye molecules and membrane surface, with quantity of dye adsorbed (qmax) was observed to be 20.4 mg/g and 19.6 mg/g for MB and Rh.B, respectively. This approach showed modified membrane has good cationic dye rejection efficacy and can be efficiently employed to remove the dyes from aqueous streams.

Buckling and vibration behaviour of syntactic foam core sandwich beam with natural fiber composite facings under axial compressive loads

Abstract: An experimental study of buckling and dynamic response of cenosphere reinforced epoxy composite (syntactic foam) core sandwich beam with sisal fabric/epoxy composite facings under compressive load is presented. Influence of cenosphere loading and surface modification on critical buckling load and natural frequencies of the sandwich beam under compressive load is presented. The critical buckling load is obtained from the experimental load-deflection data while natural frequencies are obtained by performing experimental modal analysis. Results reveal that natural frequencies and critical buckling load increase significantly with fly ash cenosphere content. It is also observed that surface modified cenospheres enhance natural frequencies and critical buckling load of the sandwich beam under compressive load. Vibration frequencies reduce with increase in compressive load. Fundamental frequency increases exponentially in post-buckling regime. Experimentally obtained load-deflection curve and natural frequencies are compared with finite element analysis wherein results are found to be in good agreement.

High temperature erosion behavior of plasma sprayed NiCrAlY/WC-Co/cenosphere coating

Abstract: High temperature erosive behavior of plasma sprayed NiCrAlY-25WC-Co/cenosphere coating deposited on MDN 321 steel is investigated in the present work. Coating is characterized using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). Microhardness, porosity, adhesion strength, fracture toughness and ductility of the coating are quantified. Solid particle erosion test is conducted at 200, 400 and 600 °C with 30 and 90° impact angles using alumina erodent. Optical profilometer is used to evaluate erosion volume loss. Erosion resistance of the coating is observed to be higher than the substrate for the test temperatures chosen and noted to be more prominent at lower impact angle and higher temperature. High temperature stability of mullite, alumina and oxide layer assists in increasing erosion resistance of coating. The eroded coating surface morphology reveals the brittle mode of material removal.