Determination of Thermal Barrier Coatings Layers Optimum Thickness via PSO-SA Hybrid Optimization Method concerning Thermal Stress

Turbine entry temperature of turbo-engines has been increased to improve proficiency. Consequently, protecting the hot section elements experiencing aggressive service conditions necessitates the applying of thermal barrier coatings (TBC). Developing TBC systems and improving performance is an ongoing endeavour to prolong the lifetime. Thus, various studies have been conducted to find the optimum properties and dimensions. In this paper, the optimum thickness of intermediate bond coat (BC) and top coat (TC) have been determined via a novel hybrid particle swarm and simulated annealing stochastic optimization method. The optimum thicknesses have been achieved under the constraint of thermal stress induced by thermal fatigue, creep, and oxidation in the TC while minimizing the weight during twenty cycles. The solutions for BC and TC thicknesses are respectively 50 μm and 450 μm. Plane stress condition has been adopted for theoretical and finite element stress analysis, and the results are successfully compared

Evaluation of the efficacy of Mannitol and overhydration in anesthesia for kideny grafting

History and Objectives: Considering the incidence and incremental trend for kidney grafting and the significance of initiation of diuresis and the positive effect of mannitol and overhydration and for evaluation of simultaneous use of them, this study was carried out on referrals of Labafinejad hospital in 2000. Materials and Methods: The quasi-experimental strategy of this study was carried out on 40 patients with indications for kidney grafting with their written consent. Twenty min before anastomosis of renal vein, intravenous injection of mannitol (5 ml/kg) was initiated and its effect on the initiation of diuresis in min was recorded with a confidence interval of 95. Results: This study was performed on 40 patients (25 females and 15 males) with an average age of 33.6 years and average weight of 52.6kg. The results showed that in 80 of patients, diuresis was initiated in less than a minute and in 90 of them, diuresis was initiated in less than 2 min. Conclusion and Recommendations: Simultaneous use of mannitol and overhydration could accelerate the initiation of diuresis and because this is very important in survival of grafted kidney, therefore it recommended to carry out thorough experimental study