Beyond Ritualism: Impact and Implications of Ḥajj on the Society of Pakistan

Ḥajj―an annual Islamic congregation―is a supreme manifestation of Faith (Imān) in which muslims assemble to pronounce explicitly their subservience and loyalty to Almighty Allah alone. Besides freeing themselves from the squalor of Shirk, Muslims satiate their souls with the feelings of ‘Faith’ and ‘Unity.’ This fact is purely accomplished when the Muslims shed off their outer difference by donning the dress of unity (Iḥrām). Ḥajj is a perfect blend between ‘Creator’ and ‘creature’, ‘soul’ and ‘spirit’ on the one hand and an enduring and invaluable expression physically, socially, and materially on the other. From this pragmatic Institution, Pakistan―one of the premier countries of the Islamic world―can derive unprecedented benefits politically, socially, and economically. One of the important objectives of the paper is to describe the significance of Ḥajj to the people of Pakistan. In so doing, the paper examines and explores, objectively and analytically, the institution of Ḥajj and its implications on the Muslim world, particularly Pakistan. The first section of the paper, “Ḥajj―At a Glance”, presents meaning and historical background of Ḥajj. The second section “Revitalizing the Ḥajj”, besides presenting the revitalization of the Institution by the final Messenger (peace be upon him) also gives an overview of some of the very important rituals to be realized (during Ḥajj). The subsequent sections, “Socio-Economic Dimension of Ḥajj” and “Ḥajj―Implications and Impact on the Society of Pakistan”, describe respectively the socio-economic impact and leverage of the Ḥajj on the Muslim world in general and on Pakistan in particular. The study is followed by “Conclusion” wherein it has been argued that the Ḥajj can bring an immense transformation and positivity in a country if its sweetness is sought in all earnestness.

Sliding Mode Framework Based Fault Tolerant Control for Air Path Actuators of a Turbocharged Diesel Engine

Exhaust emission control, especially in case of diesel engines, is a challenging re search problem as the emission regulating authorities place stringent protocols against emissions. The air management system of a diesel engine, that is fit ted with Variable Geometry Turbocharger (VGT) and Exhaust Gas Recirculation (EGR) actuators, is among the sub-systems, whose effective control ensures that emissions are kept to minimum. Both EGR and VGT sub-systems are located in the engine exhaust channel, hence, they are strongly coupled and exposed to high temperatures, un-burnt hydrocarbons and lubricants and thus prone to faults/cho king. One way to increase tolerance against faults is to have redundancy. Diesel engines do not have high number of identical actuators to preserve satisfactory operation, but, still have prospects for enhancing the reliability of these control loops by constructing algorithms, that are capable of performing online detection, diagnosis, estimation and compensation of faults. This research investigates the possible options for development of Fault Tolerant Control (FTC) schemes for coordinated control of air management system actuators of diesel engine. The dynamic nature of a control system and real time environment of Fault Detection and Isolation (FDI) and controller re-configuration requires FTC system to be capable of detecting, identifying and accommodating the faults as swiftly as pos sible. To meet the purpose, unified and systematic design techniques need to be developed to guarantee swift integration of FDI and FTC schemes, such that, the faults are handled in an early design phase by extending the control system with additional modules, i.e., FDI module. The model used in this research is a fully validated industrial scale Mean Value Model of a diesel engine that is equipped with VGT and EGR actuators. It has eight states and three control inputs. Two types of approaches i.e., passive FTC and unified FDI and FTC with further two algorithms of each have been proposed based on the sliding mode framework. The simulation results have shown that the proposed controllers can comfortably meet strict emission regulations even in the event of system faults. Specially fault de tection, estimation and compensation capability of unified approaches give them an edge over passive schemes.