in this research, softening and ratcheting behaviors of ck20 alloy steel cylindrical shells were studied under displacement-control and force-control cyclic axial loading and the behavior of hysteresis curves of specimens was also investigated. experimental tests were performed by a servo-hydraulic instron 8802 machine. the mechanical properties of specimens were determined according to astm e8...

Surgical valve replacement in patients with severe calcific aortic valve disease using either bioprosthetic or mechanical heart valves is still limited by structural valve deterioration for the former and thrombosis risk mandating anticoagulant therapy for the latter. Prosthetic polymeric heart valves have the potential to overcome the inherent material and design limitations of these valves, b...

This paper presents an application of evolution programming (EP), which has no limitation on objective function, for transient stability constrained optimal power flow (TSCOPF) problem. Swing equation and limit of rotor angle deviation with respect to centre of inertia (COI) are treated as additional constraints in transient stability concern. The generator fuel cost minimization is selected as...

This paper proposes a superior Mixed Integer based hybrid Genetic Algorithm (MIGA) which inherits the advantages of binary and real coded Genetic Algorithm approach. The proposed algorithm is applied for the conventional generation cost minimization Optimal Power Flow (OPF) problem and for the Security Constrained Optimal Power Flow problem. Here, the main shortcoming with the conventional Gene...

This paper presents an efficient Water Evaporation Optimization algorithm (WEO) is proposed to solve a Dynamic Economic Dispatch problem (DED). The dynamic dispatch problem differs from the static economic dispatch problem by incorporating generator spinning reserve, ramp rate limits, and valve point loading and transmission losses. The proposed water evaporation optimization algorithm is based...

Particle swarm optimization (PSO) is a population-based swarm intelligence algorithm driven by the simulation of a social psychological metaphor instead of the survival of the fittest individual. Based on the chaotic systems theory, this paper proposed a novel chaotic PSO combined with an implicit filtering (IF) local search method to solve economic dispatch problems. Since chaotic mapping enjo...

This paper presents an artificial bee colony algorithm for solving optimal short term hydrothermal scheduling problem. To demonstrate the effectiveness of the proposed algorithm, hydrothermal test system consists of three thermal units and four cascaded hydro power plants has been tested. The valve point loading effect is taken into consideration. In order to show the feasibility and robustness...

BACKGROUND New generation devices for transfemoral aortic valve replacement were optimized on valve positioning and reduction of residual aortic regurgitation. We compared 30-day, 12-month, and 24-month outcomes of the Boston Scientific Lotus valve (Lotus) and the balloon-expandable Edwards Sapien 3 (ES3) valve. Primary end point was all-cause mortality or disabling stroke within 12 months. M...

The left atrium (LA) acts as a booster pump during late diastole, generating the Doppler transmitral A wave and contributing incrementally to left ventricular (LV) filling. However, after volume loading and in certain disease states, LA contraction fills the LV less effectively, and retrograde flow (i.e., the Doppler Ar wave) into the pulmonary veins increases. The purpose of this study was to ...

Patients who receive prosthetic heart valve (PHV) implants require mandatory anticoagulation medication after implantation due to the thrombogenic potential of the valve. Optimization of PHV designs may facilitate reduction of flow-induced thrombogenicity and reduce or eliminate the need for post-implant anticoagulants. We present a methodology entitled Device Thrombogenicty Emulator (DTE) for ...