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In this paper, the effect of high concentrated Iron (Fe) doping on the structural, electronic and optical properties of Barium Titanate (BaTiO3) based on density functional theory (DFT) are reported. The calculated lattice parameters show that the phase of BaTiO3 transformed into tetragonal from cubic phase after Fe doping. The electronic structure shows that Fe creates some defect states in the energy band which create weak coordinate covalent bond because of metal-metal interaction. The complex dielectric function, absorption, reflectivity, refractive index, optical conductivity and energy-loss spectrum for BaTiO3 and Fe doped BaTiO3 are calculated, and the results show a dramatic behavior near Fermi level after Fe doping.

High-performance plasma polymerized organic thin films have been synthesized by employing a capacitively coupled glow discharge technique and cyclohexane is used as a precursor material. The surface of the plasma polymerized cyclohexane (PPCHex) thin films observed to be smooth, pinhole free and uniform. It is observed from thermal analysis that the rate of loss of mass is very low in air atmosphere below 510 K and the films are thermally stable. Above 510 K weight loss takes place in different stages in air. The current density of the PPCHex thin films is increased when the thicknesses is decreased and that is increased with increasing temperatures. The conduction mechanism of carrier transport operative in these PPCHex thin film is dominated by Schottky type conduction mechanism. The activation energy of the PPCHex thin films for applied voltage 10 V is found 0.14 ± 0.05 eV near room temperature region and that in the higher temperature region is 0.57 ± 0.04 eV. The activation energy in the Schottky region for the applied voltage 50 V is about 0.16 ± 0.06 eV near the room temperature region and that is 0.83 ± 0.05 eV at the higher temperature region.

Density functional theory based First-principles calculations have been performed to investigate the structural, optical and electronic properties of CuO and Zn doped CuO and compared with experimental results. Calculations are demonstrated by Cambridge Serial Total Energy Package. Calculated values of lattice parameters matched 80% with experimental data of CuO and for Zn doped CuO, there was a 55% match. Figures of electronic band structure, TDOS and PDOS have been computed from the electronic structure of CuO and Zn doped CuO. Significant transition occurs in band gap after Zn doping. Optical properties showed that CuO and Zn doped CuO were transparent, having a small energy gap and maximum reflectivity at infrared region. The real part of refractive index was higher at lower energy region and imaginary part of refractive index was zero at 28 eV photon energy. The calculated value of band gap was in good agreement with the experimental value.

Mango (Mangifera indica) is an important, and popular fruit in Bangladesh. However, the post-harvest processing of it is still mostly performed manually, a situation far from satisfactory, in terms of accuracy and throughput. To automate the grading of mangos (geometry and shape), we developed an image acquisition and processing system to extract projected area, perimeter, and roundness features. In this system, images were acquired using a XGA format color camera of 8-bit gray levels using fluorescent lighting. An image processing algorithm based on region based global thresholding color binarization, combined with median filter and morphological analysis was developed to classify mangos into one of three mass grades such as large, medium, and small. This system achieved an accuracy of 97% for projected area and Feret diameter, 79% for perimeter, and 36% for roundness. To achieve a finer grading, two different grading features could be used in sequence. The image grading system is simple and efficient and can be considered a suitable first stage to mechanizing the commercial grading of mangos in Bangladesh. Moreover, the method has the potential to be applied to other crops with suitable adjustments.

This research is carried out to develop a machine vision system which could identify the fluorescence area on injured or defective citrus surfaces. The target objects whose surfaces were injured by needle insertions were acquired by a camera VGA using UV lamps (radiating Blacklight and UV-B wave-lengths) and white LEDs. Because damaged citrus peel includes fluorescent substances, it was easy to discriminate fluorescence parts from healthy parts. The results showed that the blacklighting system is practical and feasible, and that the proposed algorithm of fluorescence area detection is effective for some varieties of citrus.