17 resultados para Solution dispersion


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Kochi, the commercial capital of Kerala, South India and second most important city next to Mumbai on the Western coast is a land having a wide variety of residential environments. Due to rapid population growth, changing lifestyles, food habits and living standards, institutional weaknesses, improper choice of technology and public apathy, the present pattern of the city can be classified as that of haphazard growth with typical problems characteristics of unplanned urban development especially in the case of solid waste management. To have a better living condition for us and our future generations, we must know where we are now and how far we need to go. We, each individual must calculate how much nature we use and compare it to how much nature we have available. This can be achieved by applying the concept of ecological footprint. Ecological footprint analysis (EFA) is a quantitative tool that represents the ecological load imposed on earth by humans in spatial terms. The aim of applying EFA to Kochi city is to quantify the consumption and waste generation of a population and to compare it with the existing biocapacity. By quantifying the ecological footprint we can formulate strategies to reduce the footprint and there by having a sustainable living. The paper discusses the various footprint components of Kochi city and in detail analyses the waste footprint of the residential areas using waste footprint analyzer. An attempt is also made to suggest some waste foot print reduction strategies thereby making the city sustainable as far as solid waste management is concerned.

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The present work emphasises on the synthesis and characterization of electro-active polymer-ceramic nanocomposites which can be used for pyroelectric thermal/infrared detection applications. Two sets of samples belong to polymer-microcrystalline composites have also been investigated in the work. The polymers used in the work have been commercially available ones, but the nanoceramics have been synthesized following simple chemical routes and aqueous organic gel routes. After characterizing the nanoceramics for their structure by powder XRD, they have been dispersed in liquid polymer and sonicated for uniform dispersion. The viscous mixture so formed was cast in the form of films for experimentation. Samples with volume fraction of the ceramic phase varied from 0 to 0.25 have been prepared. Solution growth was followed to prepare microcrystalline samples for the polymer-microcrystalline composites. The physical properties that determine the pyroelectric sensitivity of a material are dielectric constant, dielectric loss, pyroelectric coefficient, thermal conductivity and specific heat capacity. These parameters have been determined for all the samples and compositions reported in this work.The pyroelectric figures of merit for all the samples were determined. The pyroelectric figures of merit that determine the pyroelectric sensitivity of a material are current sensitivity, voltage responsivity and detectivity. All these have been determined for each set of samples and reported in the thesis. In order to assess the flexibility and mouldability of the composites we have measured the Shore hardness of each of the composites by indentation technique and compared with the pyroelectric figures of merit. Some important factors considered during the material fabrication stages were maximum flexibility and maximum figures of merit for pyroelectric thermal/IR detection applications. In order to achieve these goals, all the samples are synthesized as composites of polymers and nano/microcrystalline particles and are prepared in the form of freestanding films. The selected polymer matrices and particle inclusions possess good pyroelectric coefficients, low thermal and dielectric properties, so that good pyroelectric figures of merit could be achieved. The salient features of the work include the particle size of the selected ceramic materials. Since they are in nanometer size it was possible to achieve high flexibility and moldability with high figures of merit for even low volume fractions of inclusions of the prepared nanocrystalline composites. In the case of microcrystalline TGS and DTGS, their composites in PU matrix protect them from fragility and humidity susceptibility and made them for environmental friendly applications.