The comparison of incomplete sensitivities and Genetic algorithms applications in 3D radial turbomachinery blade optimization

In the present work, a centrifugal pump impeller’s blades shape was redesigned to reach a higher efficiency in turbine mode using two different optimization algorithms: one is a local method as incomplete sensitivities–gradient based optimization algorithm coupled by 3D Navier–Stokes flow solver, and another is a global method as Genetic algorithms and artificial neural network coupled by 3D Navier–Stokes flow solver. New impeller was manufactured and tested in the test rig. Comparison of the local optimization method results with the global optimization method results showed that the gradient based method has detected the global optimum point. Experimental results confirmed the numerical efficiency improvement in all measured points. This study illustrated that the developed gradient based optimization method is efficient for 3D radial turbomachinery blade optimization.     

Numerical simulation and optimization of steam-assisted gravity drainage with temperature,rate, and well distance control using an efficient hybrid optimization technique

Steam-assisted gravity drainage (SAGD) is a thermal enhanced oil recovery technique through drilling of two horizontal wells. Effects of steam injection temperature, well rates, and their distance on oil recovery were analyzed and optimized. Steam temperature and well distances remarkably affect SAGD performance. Four metaheuristic algorithms (particle swarm optimization (PSO), imperialist competitive algorithm, cultural algorithm, and Bees algorithm) and pattern search optimization algorithm (PSA) are used for optimization. PSO performs better than other metaheuristics and PSA is the fastest one, while it is probable to be trapped in local optimums. Hybrid PSO-PS is proposed that starts with PSO and proceeds with PSA, and tested in an SAGD project and showed excellence over other techniques.     

Estimating the Aquifer’s Renewable Water to Mitigate the Challenges of Upcoming Megadrought Events

Water Resources Management - In arid and semi-arid regions of the world, the occurrence of prolonged drought events (megadroughts) associated with climate change can seriously affect the balance...     

Novel electro-conductive nanocomposites based on electrospun PLGA/CNT for biomedical applications

Electro-conductive nanocomposites have several applications in biomedical field. Development of a biocompatible electro-conductive polymeric materials is therefore of prime importance. In this study, electro-conductive nanofibrous mats of PLGA/CNT were fabricated through different methods including blend electrospinning, simultaneous PLGA electrospinning and CNT electrospraying and ultrasound-induced adsorption of CNTs on the electrospun PLGA nanofibers. The morphology and diameter of fibers were characterized by SEM and TEM, showing the lowest average diameters of 477?±?136?nm for PLGA/MWCNT blend nanocomposites. MWCNT-sprayed PLGA specimens showed significant lower water contact angle (83°), electrical resistance (3.0?×?10⁴?Ω) and higher mechanical properties (UTS: 5.50?±?0.46?MPa) compared to the untreated PLGA scaffolds. Also, results of PC12 cell study demonstrated highest viability percentage on the MWCNT-sprayed PLGA nanofibers. We propose that the conductive nanocomposites have capability to use as tool for the neural regeneration and biosensors.

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A Molecular Dynamics Study of Description Models for Shear Viscosity in Nanochannels: Mixtures and Effect of Temperature

Equilibrium molecular dynamics simulation was utilized to calculate the shear viscosity of monoatomic molecules liquid flow confined in a nanochannel in the pure state and their binary mixtures. The pure flow viscosity data of argon, krypton, and xenon were used to predict their binary mixture viscosities using prediction methods proposed in the literature. Each method was evaluated by comparison of its results with those obtained by validated molecular dynamics simulation at different temperatures. In addition, correlative methods for mixture viscosity estimation and temperature dependence models were evaluated and corresponding model parameters were obtained. Moreover, the relations representing mixture parameter values as a function of the pure ones were determined and evaluated according to their accuracy.     

Optimal fuzzy controller based on non-monotonic Lyapunov function with a case study on laboratory helicopter

This paper presents a new approach to design an observer-based optimal fuzzy state feedback controller for discrete-time Takagi–Sugeno fuzzy systems via LQR based on the non-monotonic Lyapunov function. Non-monotonic Lyapunov stability theorem proposed less conservative conditions rather than common quadratic method. To compare with optimal fuzzy feedback controller design based on common quadratic Lyapunov function, this paper proceeds reformulation of the observer-based optimal fuzzy state feedback controller based on common quadratic Lyapunov function. Also in both methodologies, the dependence of optimisation problem on initial conditions is omitted. As a practical case study, the controllers are implemented on a laboratory twin-rotor helicopter to compare the controllers' performance.     

Predicting the combined effect of TiO2 nano-particles and welding input parameters on the hardness of melted zone in submerged arc welding by fuzzy logic

Submerged arc welding (SAW) is a high-quality arc welding process used in heavy industries for welding thick plates. In this process, selecting appropriate values for the input parameters is required for high productivity and cost effectiveness. A very important weld quality characteristic affected by welding input parameters is the hardness of melted zone (HMZ). This paper reports the applicability of fuzzy logic (FL) to predict HMZ in the SAW process which is affected by the combined effect of TiO₂ nano-particles and welding input parameters. The arc voltage, welding current, welding speed, contact tip-to-plate distance, and TiO₂ nano-particles were used as input parameters and HMZ as the response to develop FL model. A five-level five-factor central composite rotatable design (CCRD) was used in the experiments to generate experimental data. Experiments were performed, and HMZs were measured. The predicted results from FL were compared with the experimental data. The correlation factor value obtained was 99.99% between the measured and predicted values of HMZ. The results showed that FL is an accurate and reliable technique for predicting HMZ because of its low error rate.     

Plasmonic photothermal therapy of colon cancer cells utilising gold nanoshells: an in vitro study

In this study, gold nanoshell (GNS) were synthesised utilising the Halas method. The obtained nanoparticles (NPs) were characterised by Fourier‐transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy and dynamic light scattering. FTIR spectra demonstrated the successful functionalisation of silica NP with 3‐aminopropyl trimethoxysilane. SEM and TEM images showed the morphology and diameter of the synthesised silica NPs (137 ± 26 nm) and GNS. UV–Vis spectrum illustrated the maximum absorbance of the resultant GNS and their average hydrodynamic diameter was 159 nm. For in vitro study, HCT‐116 cells were exposed to gold nanoshells and intense pulsed light in different experiment groups. The results showed that exposing the cells to nanoshells and 30 s irradiation would efficiently decrease the viability percentage of the cells to about 30% compared with the control. A continued exposure of 4 min decreased the viability of the cancer cells to 20%. The results demonstrated that photothermal therapy would be promising in treatment of colon cancer cells utilising gold nanoshells.Inspec keywords: gold, silicon compounds, nanomedicine, plasmonics, radiation therapy, bio‐optics, cancer, cellular biophysics, nanoparticles, Fourier transform spectra, infrared spectra, scanning electron microscopy, transmission electron microscopy, ultraviolet spectra, visible spectraOther keywords: plasmonic photothermal therapy, colon cancer cells, gold‐silica nanoshells, GNS, Halas method, Fourier transform infrared spectroscopy, FTIR, scanning electron microscopy, SEM, transmission electron microscopy, TEM, UV‐vis spectroscopy, dynamic light scattering, FTIR spectra, 3‐aminopropyl trimethoxysilane, morphology, in vitro study, HCT‐116 cells, cell viability, nanoparticles, time 30 s, time 4 min, Au     

Project governance and stakeholders: a literature review

Despite the importance of stakeholders in project governance, project management literature lacks from an inclusive framework which defines the roles, relationships and positions of internal and external stakeholders inside and outside of the organization's governance structure. This paper has the purpose to report a review on project governance literature to draw attention to the context within which the stakeholders are positioned, to extract their roles and relationships inside and outside of the organization and to develop new avenues for research regarding stakeholders in project governance. The conducted thematic analysis reveals that there are three contexts influencing organization's approaches towards stakeholders: success, megaprojects and ethics. The developed conceptual framework illustrates that organizations are in direct contact with external stakeholders at the organizational level and project level. Strategic decisions made at the organizational level are operationalised at the portfolio level and influence the approach towards external stakeholders at the project level. Considering the lack of theories to support general doctrine of stakeholder theory, this research suggests that future governance researchers adopt a broader view in selection of theoretical lenses in order to include the social and psychological aspects of the management of external stakeholders.