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.

Growth behavior of oxide forming on a sputtered oxygen-enriched type 304 stainless steel

Abstract: Type 304 stainless steel was deposited with and without added oxygen and then oxidized at 900 °C in 0.1 atm oxygen. The oxidation rate of the oxygen-enriched steel was lower than that of the steel without added oxygen, and the oxide adhesion was better. Line scans on cross-sectioned scale on the oxygen-enriched steel showed that inward oxygen diffusion had occurred; however, this was not shown by any of the line scans on the steel without added oxygen. The diffusion rate of cations through chromia scale was reduced by the oxygen enrichment. A secondary ion mass microscopy study showed that sulfur segregation to the oxide scale occurred during oxidation. The extent of this segregation for the oxygen-enriched steel was much lower than that for the steel without added oxygen. The results are explained in terms of the sulfur effect theory by postulating that impurity sulfur segregated to oxide particles in the oxygen-enriched steel, resulting in a reduced sulfur level in the scale and at the oxide/metal interface.

Effect of Bolt Behaviour on the Performance of a Bolted Joint

Abstract: For proper bolted joint's performance, it is known that the higher the pre-load the better the joint will be. In order to achieve proper pre-load and to utilise proper strength of the bolt to increase the joint strength and joint sealing, bolt quality is of prime importance. It is realized that selection of the proper quality bolt is not given enough importance, which results in poor performance of the bolted joints. Due to the improper bolt selection, overloading of the bolts can cause the gasket crushing and flange yielding in a gasketed joint, especially for the large diameter flanges where hammering and flogging applications are adopted. This paper discusses the need of a good quality bolt using detailed experimental study and highlights the effect of surface treatment on bolts; different makes of bolts, use of different number of nuts and washers, use of different nuts, number of tightening on the same bolt, use of lock nuts and use of proper tooling in detail.

Combined uncovered sheet-and-tube pvt-collector system with built-in storage water heater

Abstract: This work describes the design and investigation of a simple combined uncovered sheet-and-tube photo-voltaic-thermal (PVT) collector system. The PVT-collector system consists of a support, standard PV module (1.22x0.305m, area=0.37m2, fill factor=0.75), sheet-and-tube water collector and storage tank-heater. The collector was fixed under PV module. Inclination angle of the PVT-collector to the horizontal plane was 45 degree. The storage tank-heater played double role i.e. for storage of hot water and for water heating. The PVT-collector system could work in the fixed and tracking modes of operation. During investigations of PVT-collector in natural conditions, solar irradiance, voltage and current of PV module, ambient temperature and water temperature in storage tank were measured. Average thermal and electrical powers of the PVT-collector system at the tracking mode of operation observed were 39W and 21W, with efficiencies of 15% and 8% respectively at the input power of 260W. The maximum temperature of the water obtained was 42oC. The system was observed efficient for low-temperature applications. The PVT-collector system may be used as a prototype for design of PVT-collector system for domestic application, teaching aid and for demonstration purposes.

Automated Latin Text Detection in Document Images and Natural Scene Images based on Connected Component Analysis

Abstract: Robust and accurate detection of text in natural scene images and document images is a very challenging and common research problem. Over the past few decades, a variety of algorithms for text detection in images have been developed but there is still need for more robust and accurate text detection methods. In this work, we have proposed an accurate and robust text detection framework in which canny edge detection, maximally stable extremal regions and geometric filtering are employed in combination to efficiently collect and filter letter candidates in an image. Subsequently, individual letter patches are grouped to detect text sequences, which are then fragmented into isolated word patches. Finally, optical character recognition is employed to digitize the word patches. The proposed algorithm is tested on images representing different scenarios ranging from documents to natural scenes. Promising results have been reported which prove the accuracy and robustness of the proposed framework and encourage its practical implementation in real world applications.

Investigating tool performance and wear when simulating bandsawing of nickel-based superalloy under interrupted orthogonal turning condition

Abstract: © 2017, IMechE 2017. The manufacturing industries still face the most challenging job at hand to machine nickel-based superalloy, Inconel 718, efficiently and economically. In contrast to the extensive research efforts in secondary machining processes such as turning, milling and drilling, very little or no attention is paid on bandsawing of Inconel 718. This article presents an experimental investigation of machining Inconel 718 using carbide-tipped bandsaw teeth in a custom-made experimental facility. Cutting forces were measured during the bandsawing operation using a dynamometer, and the wear modes and mechanisms in the bandsaw teeth were investigated in a scanning electron microscope. Three different feeds or depths of cut (10, 20 and 30 μm) were employed with a cutting speed of 30 m/min during the machining tests. At smaller feed or depth of cut (10 μm), abrasive wear, adhesive wear and some degree of plastic deformation were identified as the governing mechanisms of tool wear. The higher depth of cut (30 μm) could cause cracking, chipping or premature failure of the carbide tip in bandsaw tooth. Strong welding of workpiece material to the cutting edge formed a built-up edge, which would impair the bandsawability due to the modification of the cutting edge. The higher depth of cut significantly improved the machining performance due to the reduction in specific cutting energy. However, it was not recommended to apply higher depth of cut as there were obvious possibilities of premature tooth failure. Machining force and specific cutting energy results along with chip characteristics were correlated with the tool performance and tool wear. The results of this investigation would be helpful for bandsaw manufacturers and end users to get a fundamental understanding of the bandsawability of Inconel 718 with the carbide-tipped bandsaw.