Ghulam Ishaq Khan Institute of Engineering Sciences and Technology

About: Ghulam Ishaq Khan Institute of Engineering Sciences and Technology is a education organization based out in Topi, Pakistan. It is known for research contribution in the topics: Quantum efficiency & Diode. The organization has 618 authors who have published 940 publications receiving 10674 citations.

A novel core@shell magnetic molecular imprinted nanoparticles for selective determination of folic acid in different food samples

Abstract: In this work, magnetic molecularly imprinted polymers (MMIPs) were synthesized and tested for the determination of folic acid (FA) in different food samples. The MMIPs were polymerized at the surface of Fe3O4@SiO2 magnetic nanoparticles (MNPs) using acrylonitrile (functional monomer), ethylene glycol dimethacrylate (EGDMA) as cross-linking agent and azobiisobutyronitrile (AIBN) as an radical initiator. The morphological, topological and chemical characteristics of the MMIPs were investigated by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared (FTIR) techniques. The physico-chemical characterization, such as adsorption capacities and selectivity of MMIPs was investigated and compared with the respective MNIPs. The adsorption experimental data demonstrate that maximum adsorption capacity of MMIP at equilibrium was 8 mg g− 1 and than the adsorption process of FA over MMIPs follows Freundlich adsorption isotherm model and pseudo-first-order reaction kinetic. For evaluation of this new proposed material, the recovery studies were carried out in spiked samples at different concentration levels and the obtained values were in the range of 95–104% for orange and for spinach the recoveries were between 99.5 and 102.5%. The relative standard deviations (RSD) for the recoveries were < 0.5% for both samples. These results demonstrate that this novel MMIP material can be efficiently used for the selective extraction of folic acid from different food complex matrices.

Multiple watermarking of medical images for content authentication and recovery

Abstract: Medical Image data require strict security, confidentiality and integrity when transmitted from one hospital to another hospital. This can be achieved by adopting the procedures which can guarantee the image quality as well as secrecy of patient data to unauthorized users. To achieve these requirements we have proposed a multiple watermarking method. The scheme embeds robust watermark in region of non interest (RONI) for achieving security and confidentiality. While integrity control is achieved by inserting fragile watermark in region of interest ROI. Since ROI in the medical image is important from diagnosis point of view so it must be preserved. In order to avoid the distortion caused in ROI due to watermark insertion process, original ROI data is first separated and embedded outside the ROI. This will help in recovery of original ROI at the receiving end in contrast to the techniques reported in the literature which do not guarantee the integrity of the ROI after watermarking process. The image visual quality as well as tamper localization has been evaluated. We have used weighted peak signal to noise ratio (WPSNR) for measuring image quality after watermarking.

Electrical characterization of the organic semiconductor Ag/CuPc/Au Schottky diode

Abstract: This paper reports on the fabrication and investigation of a surface-type organic semiconductor copper phthalocyanine (CuPc) based diode. A thin film of CuPc of thickness 100 nm was thermally sublimed onto a glass substrate with preliminary deposited metallic electrodes to form a surface-type Ag/CuPc/Au Schottky diode. The current-voltage characteristics were measured at room temperature under dark conditions. The barrier height was calculated as 1.05 eV The values of mobility and conductivity was found to be 1.74 × 10−9 cm2 (V · s) and 5.5 × 10−6 Ω−1 · cm−1, respectively. At low voltages the device showed ohmic conduction and the space charge limited current conduction mechanisms were dominated at higher voltages.