NOPR Community:

Bubble size measurement and error analysis in a gas liquid ejector

2016-07-20T04:52:56Z

Title: Bubble size measurement and error analysis in a gas liquid ejector Authors: Suneetha, T B; Raghuram, P T Abstract: Bubble size in a gas liquid ejector has been measured using the image technique and analysed for estimation of Sauter mean diameter. The individual bubble diameter is estimated by considering the two dimensional contour of the ellipse, for the actual three dimensional ellipsoid in the system by equating the volume of the ellipsoid to that of the sphere. It is observed that the bubbles are of oblate and prolate shaped ellipsoid in this air water system. The bubble diameter is calculated based on this concept and the Sauter mean diameter is estimated. The error between these considerations is reported. The bubble size at different locations from the nozzle of the ejector is presented along with their percentage error which is around 18%. Page(s): 442-446

Development and characterization of electrically conductive polyaniline coated fabrics

2016-07-20T04:49:45Z

Title: Development and characterization of electrically conductive polyaniline coated fabrics Authors: Muthukumar, N; Thilagavathi, G Abstract: Electrically conductive cotton, polyester and nylon fabrics have been prepared from conductive polyaniline (PANI) polymer by in situ chemical oxidative polymerization of aniline using ammonium persulphate as the oxidant by a process of diffusion polymerization in a mixed bath. These fabrics are then characterized by ATR-FTIR, WAXD, SEM and DSC. The tensile strength, stiffness and electrical and electromagnetic measurements of the fabric samples are also studied. The structural studies show that the crystalline region of cotton, polyester and nylon is not affected by the polyaniline and the interaction of polyaniline with the fabrics. The SEM studies reveal a very uniform deposition of polyaniline on the fabrics. The thermal studies show that the PANI-treated fabrics have better thermal stability. The intact textile characteristics of the polyester and nylon fabrics coated with PANI are found to be protected, whereas the characteristics of the cotton fabric coated with PANI become inferior. The conductivity studies show that the treated fabrics have good electrical conductivity. The electromagnetic shielding tests show that the cotton, polyester and nylon fabrics have the electromagnetic interference values of -1.62, -2.78 and -1.5 dB respectively in the frequency range 8-12 GHz. Page(s): 434-441

Experimental and modeling studies on extraction of amyrins from latex of mandar (Calotropis gigantea)

2016-07-20T04:47:48Z

Title: Experimental and modeling studies on extraction of amyrins from latex of mandar (Calotropis gigantea) Authors: Wagh, S J; Gujar, J G; Gaikar, V G Abstract: The effect of various process parameters, such as solvent, temperature, speed of agitation, and solid loading, on the percentage extraction of -amyrin and -amyrin from the latex of Calotropis gigantea has been studied. Extraction of -amyrin and -amyrin is performed with different solvents such as methanol, ethanol, propanol, and chloroform. Methanol is found to be the best solvent for both -amyrin and -amyrin. As the temperature of the extraction increases, easy release of amyrin takes place, because of destruction of cellular structure of the matrix. The percentage extraction increases with the increase in speed of agitation. Assuming the flat geometry of the particles, the process has been modeled and the results are compared with experimental data at different experimental conditions. The values of energy of activation are obtained as 40.64 kJ/mol for alpha amyrin and 26.96 kJ/mol for beta amyrin. Page(s): 427-433

A novel binder-free and energy-efficient process for making ceramic tiles using red mud and sericitic pyrophyllite

2016-07-20T04:51:10Z

Title: A novel binder-free and energy-efficient process for making ceramic tiles using red mud and sericitic pyrophyllite Authors: Khan, Jeeshan; Amritphale, S S; Chandra, Navin; Patel, M Abstract: A new process for utilizing the waste from alumina refinery plant such as red mud in production of ceramic tiles has been developed. Pyrophyllite mineral has been added to the red mud to improve the strength properties. The tiles are produced at comparatively lower temperature (950-1000°C) then the conventional process of making ceramic tiles and without addition of phosphatic binders. Impact strength of the optimized composition of 40-60% (w/w) sericitic pyrophyllite in red mud system meets the acceptable limit of impact strength (19.6 J/m) and other properties for ceramic. The achieved impact strength has been attributed to the densification in the matrix of ceramic tiles due to the formation of new phases like calcium aluminum silicate, iron silicate, potassium titanium oxide and magnetite by thermal reaction and transformation of various mineral phases present in the sericitic pyrophyllite and red mud. The structural features of the red mud have been studied using scanning electron micrographs, exhibiting rhombohedral shaped crystals of calcium aluminum silicate and elongated crystal formation of metals silicates, which provides reinforcement to the ceramic tiles matrix. Page(s): 420-426