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.

Diffusion effect on plane harmonic waves through thermoelastic microstretch medium in context of Green–Naghdi theory

Abstract: In this article, wave propagation phenomena are studied in a diffusive microstretch thermoelastic medium. Thermal signals moving in the medium are studied by a generalized thermoelastic theory presented by Green and Naghdi. The effect of two temperatures along with diffusion effect on waves is calculated analytically by considering a time harmonic wave solution. Finally, the analytical results obtained for general medium are presented graphically for a specific material.

Step-by-Step Heating of Dye Solution for Efficient Solar Energy Harvesting in Dye-Sensitized Solar Cells

Abstract: A step-by-step heat treatment was applied to ruthenium-based N719 dye solution for its potential application in dye-sensitized solar cells (DSSCs). The effects were analyzed and compared with standard untreated devices. A significant increase in short circuit current density was observed by employing a step-by-step heating method for dye solution in DSSCs. This increase of Jsc is attributed to the enhancement in dye adsorption by the surface of the semiconductor and the higher number of charge carriers generated. DSSCs fabricated by a heated dye solution have achieved an overall power conversion efficiency of 8.41% which is significantly higher than the efficiency of 7.31% achieved with DSSCs fabricated without heated dye. Electrochemical impedance spectroscopy and capacitance voltage studies were performed to understand the better performance of the device fabricated with heated dye. Furthermore, transient photocurrent and transient photovoltage measurements were also performed to gain an insight into interfacial charge carrier recombinations.

Enhancing Contrast of Compressed Images: Reducing Block Artifacts Adaptively

Abstract: Block artifacts in DCT-based compression are a significant problem. A small reduction in block artifacts could easily improve the quality of the resultant image. For this purpose, in the present work, we propose a novel approach that adaptively enhances the DCT coefficients relying on their band importance. The proposed technique is designed to enhance the contrast in DCT domain and moreover preserves edges and details. Since the image enhancement is performed in DCT domain, therefore, the compressibility of the original image is not affected. Experimental results on standard images validate the concept of adaptively modifying different bands.

The resistive and capacitive Cu2O–PEPC composite-based displacement transducer

Abstract: In this paper, the Ag/Cu2O?PEPC (poly-N-epoxypropylcarbazole)/Al displacement transducer was designed and fabricated by drop-casting the blend Cu2O?PEPC microcomposite thin films consisting of copper oxide (Cu2O) micropowder (3 wt%) and PEPC (2 wt%) in benzol on glass substrates with pre-deposited silver electrodes of thickness 100?nm. The thicknesses of the Cu2O?PEPC films were in the range of 50?60??m. The dc resistance of the transducer decreased 1.56 times as the displacement was changed over the range 0?0.6?mm, and accordingly, the ac capacitance at 120?Hz increased 2.31 times as the displacement was changed over the range 0?1.3?mm. The resistance?displacement and capacitance?displacement relationships were simulated. With respect to initial values, the maximum deviations of simulated resistance?displacement and capacitance?displacement graphs from experimental curves were in the range of 3 and 5%, respectively.