Certainty equivalence-based robust sliding mode control strategy and its application to uncertain PMSG-WECS.

This work focuses on maximum power extraction via certainty equivalence-based robust sliding mode control protocols for an uncertain Permanent Magnet Synchronous Generator-based Wind Energy Conversion System (PMSG-WECS). The considered system is subjected to both structured and unstructured disturbances, which may occur through the input channel. Initially, the PMSG-WECS system is transformed into a Bronwsky form, i.e., controllable canonical form, which is composed of both internal and visible dynamics. The internal dynamics are proved stable, i.e., the system is in the minimum phase. However, the control of visible dynamics, to track the desired trajectory, is the main concern. To carry out this task, the certainty equivalence-based control strategies, i.e., conventional sliding mode control, terminal sliding mode control and integral sliding mode control are designed. Consequently, a chattering phenomenon is suppressed by the employment of equivalent estimated disturbances, which also enhance the robustness of the proposed control strategies. Eventually, a comprehensive stability analysis of the proposed control techniques is presented. All the theoretical claims are verified via computer simulations, which are performed in MATLAB/Simulink.

Epilepsy associated tuberous sclerosis; a case report from Bangladesh.

Tuberous sclerosis or Bourneville's disease is a rare autosomal dominant disease affecting many organs like the brain, heart, lungs, eyes, kidneys and skin. It is characterized by neurological manifestation like epilepsy, cutaneous changes and the formation of benign lesions in multiple organs. The symptoms are apparent only in late childhood, which limits the early diagnosis in infancy. Here, we report a case of a 15 year old female child with tuberous sclerosis.

Arbitrary-order sliding mode-based robust control algorithm for the developing artificial pancreas mechanism.

In Diabetes Mellitus, the pancreas remains incapable of insulin administration that leads to hyperglycaemia, an escalated glycaemic concentration, which may stimulate many complications. To circumvent this situation, a closed-loop control strategy is much needed for the exogenous insulin infusion in diabetic patients. This closed-loop structure is often termed as an artificial pancreas that is generally established by the employment of different feedback control strategies. In this work, the authors have proposed an arbitrary-order sliding mode control approach for development of the said mechanism. The term, arbitrary, is exercised in the sense of its applicability to any n-order controllable canonical system. The proposed control algorithm affirms the finite-time effective stabilisation of the glucose-insulin regulatory system, at the desired level, with the alleviation of sharp fluctuations. The novelty of this work lies in the sliding manifold that incorporates indirect non-linear terms. In addition, the necessary discontinuous terms are filtered-out once before its employment to the plant, i.e. diabetic patient. The robustness, in the presence of external disturbances, i.e. meal intake is confirmed via rigorous mathematical stability analysis. In addition, the effectiveness of the proposed control strategy is ascertained by comparing the results with the standard literature.

Does pin tract infection after external fixator limits its advantage as a cost-effective solution for open fractures in low-middle income countries, a prospective cohort study.

OBJECTIVE: To determine the frequency of pin tract infection in external fixator tibia and its effects on the definite fracture fixation and bone healing. Methods: The prospective study was conducted at Lady Reading Hospital, Peshawar, Pakistan, from August 2017 to July 2018, and comprised patients regardless of age and gender with open fracture tibia Gustillo-Anderson type II and type IIIA. Pin tract infection was assessed following the application of locally made external fixation of tibia open fractures. Follow-up was done fortnightly till soft tissue healing, removal of external fixator and definite fracture healing. Pin tract infection was classifiedand treated according to the Checketts-Otterburn classification system. SPSS 20 was used for data analysis. Results: Of the 117 patients, 95(81%) were males and 22(19%) were females with an overall mean age of 24.7±9.35 years. Pin tract infection was documented in 28(23.9%) patients. Minor and major pin tract infections were reported in 27(96.4%) and 1(3.5%) patient respectively. Soft tissues healed in 27(96.4%) cases. Conclusion: External fixator for initial stabilisation of open tibial fractures in all patients is recommended..

Trauma management in a tertiary care hospital in Peshawar, Pakistan.

BACKGROUND: With an increasing incidence of road traffic accidents and weapon injuries there is increasing need for improvement in trauma management. Liver being a highly vascular organ and strategically located is difficult to manage. METHODS: Study was conducted in Surgical 'A' Unit, Lady Reading Hospital, Peshawar from August 2003 to September 2005. It was a descriptive study and all patients were operated in emergency department. All relevant data of patients were recorded from the emergency and admission protocols. RESULTS: A total of 364 trauma patients were received and among those 48 patients had liver trauma, 75% of patients had penetrating and 25% had blunt trauma. Most of the patients had grade III liver injuries. There were no grade V and VI injury. Repair with perihepatic packing for liver injuries remains the most frequently performed procedure (41% of patients). CONCLUSION: In a stable patient blunt trauma liver can be managed conservatively by serial examinations and investigations with emergency laparotomy facilities at hand. Perihepatic packing and damage control surgery is the valuable procedure at hand. Increasing grades of liver injuries leads to increasing morbidity and mortality. The same is the case with multiple organ injuries.