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The permittivity of a material is an important parameter to characterize the degree of polarization of a material and identify components and impurities. This paper presents a non-invasive measurement technique to characterize materials in terms of their permittivity based on a modified metamaterial unit-cell sensor. The sensor consists of a complementary split-ring resonator (C-SRR), but its fringe electric field is contained with a conductive shield to intensify the normal component of the electric field. It is shown that by tightly electromagnetically coupling opposite sides of the unit-cell sensor to the input/output microstrip feedlines, two distinct resonant modes are excited. Perturbation of the fundamental mode is exploited here for determining the permittivity of materials. The sensitivity of the modified metamaterial unit-cell sensor is enhanced four-fold by using it to construct a tri-composite split-ring resonator (TC-SRR). The measured results confirm that the proposed technique provides an accurate and inexpensive solution to determine the permittivity of materials.

Based on the concept of Modern Control theory, an optimal robust power system controller for power restoration problem using Disturbance Accommodation theory has been adopted in this paper. This proposed methodology is applied to a TwoArea Two-Unit thermal Reheat Interconnected Power System (TATURIPS) taking into account of Super Conducting Magnetic Energy Storage (SMES) device and Gas Turbine (GT) unit in either area to meet out the system uncertainties due to various disturbances. For Load-Frequency Control (LFC) a decentralized PI controller for each area and a centralized Disturbance Accommodation Controller (DAC) in TATURIPS co-ordinated with SMES and GT units as back-up energy suppliers have been implemented in this proposed methodology. Feasible Restoration Index (FRI) and Complete Restoration Index (CRI) are computed for various disturbances based on settling time of the output response of the system and the control input deviation. The decentralized controller is tuned using the Artificial Bee Colony (ABC) algorithm. With these two Restoration Indices obtained from the Intelligent Controller (IC) as well as DAC, the conditions required to be satisfied in ensuring the restoration of the power system are listed out and with proper implementation will result in high degree of reliability and stability of power supply reducing the frequency deviations to a greater extent and the settling time is also reduced to a minimum time span.