No abstract

The fluctuations in the heating value of an underground coal gasification (UCG) process limit its application in electricity generation, where a desired composition of the combustible gases is required to operate gas turbines efficiently. This shortcoming can be addressed by designing a robust control scheme for the process. In the current research work, a model-based, chattering-free sliding mode control (CFSMC) algorithm is developed to maintain a desired heating value trajectory of the syngas mixture. Besides robustness, CFSMC yields reduced chattering due to continuous control law, and the tracking error also converges in finite time. To estimate the unmeasurable states required for the controller synthesis, a state-dependent Kalman filter (SDKF) based on the quasi-linear decomposition of the nonlinear model is employed. The simulation results demonstrate that despite the external disturbance and measurement noise, the control methodology yields good tracking performance. A comparative analysis is also made between CFSMC, a conventional SMC, and an already designed dynamic integral SMC (DISMC), which shows that CFSMC yields 71.2% and 69.9% improvement in the root mean squared tracking error with respect to SMC and DISMC, respectively. Moreover, CFSMC consumes 97% and 23.2% less control energy as compared to SMC and DISMC, respectively.

No abstract

Insecure borders always provide passage to criminals for their institution. Borders depict the geographical limits of a particular state and determine its power and functioning in a region. Internal security of the country cannot be assured until its boundaries are not regularized. Countries like Afghanistan and Pakistan having numerous social, economic, and security challenges serve as an avenue for traffickers. A disputed border is waning the bilateral relations and promoting the narco-economy in the Af-Pak region. The Afghan opiate is also serving as solid financial support for the Taliban and other terrorist groups. The existence of persistent mistrust and blame game policy is contagiously affecting the lives of ordinary people. The political leadership of Afghanistan and Pakistan should learn a lesson from their past to protect their nationals from economic disasters and smugglers. In addition, the nature of this study is qualitative. Both primary and secondary data prove the main agenda of this study by highlighting the deep and robust linkage of the border dispute in the spread of drug trafficking in both countries. Moreover, there is a dire need for Pak-Afghan border management to provide shelter to the locals and the legal economy. For gaining mutual economic benefits, both states can utilize borders by articulating the mechanism for border regulation.