Effect of Drying Conditions on Microwave Conductivity of Polyaniline

ABSTRACT: Polyaniline was synthesized by using ammonium persulfate initiator in the presence of 1M HC1. It was dried under different drying conditions like room temperature drying (for 48 h), oven drying (at 50-60°C for 8 h under a vacuum), and vacuum drying (at room temperature for 16 h). The conductivities of these samples were measured at microwave frequencies. These samples were also pelletized and the measurements were repeated. The cavity perturbation technique was used for the study.

Studies on the use of drying oils as ingredient in the vulcanization of elastomers

Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology

Dielectric Studies of Corn Syrup for Applications in Microwave Breast Imaging

Permittivity and conductivity studies of corn syrup in various concentrations are performed using coaxial cavity perturbation technique over a frequency range of 250 MHz–3000 MHz. The results are utilized to estimate relaxation time and dipole moments of the samples. The stability of the material over the variations of time is studied. The measured specific absorption rate of the material complies with the microwave power absorption rate of biological tissues. This suggests the feasibility of using corn syrup as a suitable, cost effective coupling medium for microwave breast imaging. The material can also be used as an efficient breast phantom in microwave breast imaging studies.

Development of solar air heaters & thermal energy storage system for drying applications in food processing industries

In the present work, the author has designed and developed all types of solar air heaters called porous and nonporous collectors. The developed solar air heaters were subjected to different air mass flow rates in order to standardize the flow per unit area of the collector. Much attention was given to investigate the performance of the solar air heaters fitted with baffles. The output obtained from the experiments on pilot models, helped the installation of solar air heating system for industrial drying applications also. Apart from these, various types of solar dryers, for small and medium scale drying applications, were also built up. The feasibility of ‘latent heat thermal energy storage system’ based on Phase Change Material was also undertaken. The application of solar greenhouse for drying industrial effluent was analyzed in the present study and a solar greenhouse was developed. The effectiveness of Computational Fluid Dynamics (CFD) in the field of solar air heaters was also analyzed. The thesis is divided into eight chapters.