Cochin University of Science and Technology

About: Cochin University of Science and Technology is a education organization based out in Kochi, Kerala, India. It is known for research contribution in the topics: Thin film & Natural rubber. The organization has 5382 authors who have published 7690 publications receiving 103827 citations. The organization is also known as: CUSAT & Cochin University.

A Compact Triband Quad-Element MIMO Antenna Using SRR Ring for High Isolation

Abstract: A compact multiband four port diversity-based antenna with high isolation between elements is proposed for multiple-input-multiple-output applications. The antenna resonates at following three bands: 1.95-2.5 GHz (covering UMTS, LTE 2300, and 2.4-GHz ISM bands), 3.15-3.85 GHz (covering WiMAX band), and 4.95-6.6 GHz (covering 5.2/5.8-GHz ISM bands). The stub-loaded meander-line antenna is loaded with split-ring resonators arranged in the form of a ring to enhance isolation by 17 dB at 2.4 GHz. All four elements radiate with equal efficiency with measured peak gains of 2.5, 3.7, and 4.4 dBi, respectively, in three bands and have a very low envelope correlation coefficient between elements. The overall size of the compact multiport antenna system is 0.26λ × 0.26λ × 0.01λ with a minimum isolation of 22 dB between its elements. The antenna elements and the isolation enhancement structure are fully planar for an easier integration.

Toxic Metals Enrichment in the Surficial Sediments of a Eutrophic Tropical Estuary (Cochin Backwaters, Southwest Coast of India)

Abstract: Concentrations and distributions of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in surficial sediments of the Cochin backwaters were studied during both monsoon and pre-monsoon periods. Spatial variations were in accordance with textural charaterstics and organic matter content. A principal component analysis distinguished three zones with different metal accumulation capacity: (i) highest levels in north estuary, (ii) moderate levels in central zone, and (iii) lowest levels in southern part. Trace metal enrichments are mainly due to anthropogenic contribution of industrial, domestic, and agricultural effluents, whose effect is enhanced by settling of metals due to organic flocculation and inorganic precipitation associated with salinity changes. Enrichments factors using Fe as a normalizer showed that metal contamination was the product of anthropogenic activities. An assessment of degree of pollution-categorized sediments as moderately polluted with Cu and Pb, moderately-to-heavily polluted with Zn, and heavily-to-extremely polluted with Cd. Concentrations at many sites largely exceed NOAA ERL (e.g., Cu, Cr, and Pb) or ERM (e.g., Cd, Ni, and Zn). This means that adverse effects for benthic organisms are possible or even highly probable.

Preparation, characterization and properties of Sm2Si2O7 loaded polymer composites for microelectronic applications

Abstract: The dielectric and thermo-mechanical properties of Sm2Si2O7 filled polyethylene and polystyrene composites for microwave packaging applications are reported in this paper. The composites were synthesized by melt mixing and hot pressing methods. The effect of different volume fractions of the ceramic (vf = 0–0.5) on the dielectric properties of the composites was investigated at 1 MHz and at 8 GHz. The dielectric properties (relative permittivity and dielectric loss) were found to increase with the ceramic filler content. It was observed that the addition of 0.5 vf of Sm2Si2O7 filler to polyethylene, increased the relative permittivity and the dielectric loss to 5.3 and 0.009 respectively whereas the corresponding values for the polystyrene–Sm2Si2O7 composite are 4.6 and 0.01 respectively at 8 GHz. The variation of relative permittivity with temperature in the range −25 °C to 60 °C was investigated for both the composites. The relative permittivities obtained experimentally were compared with that of the theoretical predictions and Effective Medium Theory was found to agree well for both the composites. The thermal conductivity, thermal expansion coefficient and Vickers microhardness of the composites were also investigated.