National Institute of Technology, Silchar

About: National Institute of Technology, Silchar is a education organization based out in Silchar, Assam, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1934 authors who have published 4219 publications receiving 41149 citations. The organization is also known as: NIT Silchar.

A dual polarized multiband rectenna for RF energy harvesting

Abstract: The paper presents a multiband dual polarized rectenna for RF energy harvesting in C-band application range. The receiving antenna of the designed rectenna is consisting of a truncated corner square patch loaded with several circular slots, L-slots and U-slot. A proximity coupled feeding arrangement is used for obtaining a wide impedance bandwidth so that the complete C-band from 4 to 8 GHz can be covered. The proposed antenna has the advantage of compact size and dual polarization since circular polarization is realized at three bands (5.42 GHz, 6.9 GHz and 7.61 GHz) in the −10 dB impedance bandwidth range. For efficient RF to DC conversion a two-stage voltage doubler rectifier is used considering that it provides a higher voltage multiplication with a small threshold voltage at its primary stage. For ensuring maximum RF to DC conversion efficiency; a matching network has been designed and is connected in between receiving antenna and the rectifier circuitry in order to match the antenna and load in different frequency bands. It is observed that a maximum conversion efficiency of 84% is achieved at 5.76 GHz. The proposed rectenna has been fabricated and it is found that measured results are in good match with the simulated results.

A novel and green process for the production of tin oxide quantum dots and its application as a photocatalyst for the degradation of dyes from aqueous phase.

Abstract: Green synthesis of SnO2 quantum dots (QDs) was developed by microwave heating method using the amino acids, namely, aspartic and glutamic acid. This method resulted in the formation of spherical SnO2 quantum dots with an average diameter less than the exciton Bohr radius of SnO2. The average diameter of SnO2 quantum dots formed using glutamic acid is ∼1.6 nm and is smaller than that formed using aspartic acid (∼2.6 nm). In the electronic spectra, a clear blue shift in the band gap energy from 4.33 to 4.4 eV is observed with a decrease in particle size (2.6–1.6 nm) due to three dimensional quantum confinement effects. The synthesized SnO2 QDs were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FT-IR). The optical properties were investigated using UV–visible spectroscopy. The synthesized SnO2 QDs act as an efficient photocatalyst in the degradation of Rose Bengal and Eosin Y dye under direct sunlight. For the first time, Rose Bengal dye was degraded using SnO2 QDs as a photocatalyst by solar irradiation.

Stochastic dynamic stability analysis of composite curved panels subjected to non-uniform partial edge loading

Abstract: The stochastic dynamic stability analysis of laminated composite curved panels under non-uniform partial edge loading is studied using finite element analysis. The system input parameters are randomized to ascertain the stochastic first buckling load and zone of resonance. Considering the effects of transverse shear deformation and rotary inertia, first order shear deformation theory is used to model the composite doubly curved shells. The stochasticity is introduced in Love's and Donnell's theory considering dynamic and shear deformable theory according to the Sander's first approximation by tracers for doubly curved laminated shells. The moving least square method is employed as a surrogate of the actual finite element model to reduce the computational cost. The results are compared with those available in the literature. Statistical results are presented to show the effects of radius of curvatures, material properties, fibre parameters, and non-uniform load parameters on the stability boundaries.