Effect of storage options on price-based scheduling for a hybrid trigeneration system

Trigeneration is efficient to supply cooling, heat, and power demands. Also, hydro (pumped) storage with zero fuel costs can increase profit when price-based scheduling problem is solved. The goal of this study is to investigate the effects of electric boiler, hydro storage, and heat storage tank on price-based scheduling problem for hybrid trigeneration (trigeneration-conventional-gas boiler) system. A heuristic algorithm is applied to a power system where in validation case, total cost reduction of 0.63% to 0.91% is reached as compared with reported in literature. The results show that the utilization of electric boiler, hydro storage, and heat storage tank leads to profit improvement by 4.58%. Also, a critical sensitivity analysis is conducted and the results show the significant effects of several factors on scheduling results.     

Corrosion behavior of porous magnesium coated by plasma electrolytic oxidation in simulated body fluid

Porous magnesium has a great potential to be used as degradable bone scaffolds. In this study, porous magnesium with 35% percolating porosity has been successfully fabricated through powder metallurgy route utilizing space holders. The intrinsic mechanical properties of the porous magnesium were measured by nanoindentation testing and analyzed with the Oliver–Pharr method. Afterward, a ceramic coating on the surface of the porous magnesium was performed by plasma electrolytic oxidation (PEO) treatment in a silicate‐based solution. The morphology and composition results of the PEO coatings indicated that it is possible to apply a homogenous and adhesive ceramic coating layer on all free surface of the porous magnesium through PEO method. The protective performance of the PEO coatings was evaluated using by potentiodynamic polarization and electrochemical impedance spectroscopy tests in simulated body fluid. The results revealed the PEO coating significantly improves biocorrosion resistance of the porous magnesium. Therefore, it can be used as an effective method to control the degradation rate of porous magnesium implants in the human body.     

Application of the Electrodiffusion Method to Measure Wall Shear Stress: Integrating Theory and Practice

The electrodiffusion method has been used in fluid dynamic research for the past 50 years. It allows the measurement of wall shear stress, a crucial parameter, e.g., for the cleaning of membrane modules used in water filtration. Various authors have published articles dealing with the theory behind this technique. But no paper collects all the knowledge assembled over five decades of application. Here, comprehensive summary of the theory of steady flow, unsteady flow, and transient voltage step experiments is given. Factors influencing the accuracy of the measurements are discussed. Furthermore, a new approach to calibrate the system from voltage step experiments is introduced, and practical issues related to its application in flow measurements are discussed for an exemplary signal response to a near‐wall flow.     

Predication of concrete mix design using adaptive neural fuzzy inference systems and fuzzy inference systems

The aim of this study is to design adaptive neural-fuzzy inference system (ANFIS) model and fuzzy expert system for determination of concrete mix designs and finally compare their results. Idea of these systems based on two surveys: first, ACI structures and principles, second a concrete mix designs dataset that collected via Prof. I-Cheng Yeh. Datasets that loaded in to ANFIS has 552 mix designs and based on ACI mix designs. Moreover, in this study, we have designed fuzzy expert system. Input fields of fuzzy expert system are Slump, Maximum Size of Aggregate (D _max), Concrete Compressive Strength (CCS), and Fineness Modulus. Output fields are quantities of water, cement, fine aggregate (F.A.) and coarse aggregate (C.A.). In the ANFIS model, we have four layers (four ANFIS models): the first layer takes values of D _max and Slump and then determines the quantity of Water, the second layer takes values of Water (computed in the past layer) and CCS then measures the value of Cement, the third layer takes values of D _max and Slump to compute C.A. and the fourth layer takes values of Water, Cement, and C.A. (determined in past layers) and then measures the value of F.A. When these systems were designed and tested, comparison between two systems (FIS and ANFIS) results showed that results of ANFIS model are better than fuzzy expert system’s results. In the ANFIS model, for Water output field, training and average testing errors are 0.86 and 0.8. For cement field, training error and average testing error are in the orders of 0.21 and 0.22. Training and average testing error of C.A. are in the orders of 0.0001 and 0.0004 and finally, training and average testing errors of F.A. are in the orders of 0.0049 and 0.0063. Results of fuzzy expert system in comparison to ACI results follow average errors: average error of Water, Cement, C.A., and F.A. are in the orders of 9.5%, 27.6%, 96.5%, and 49%.     

Janus particle amphiphilicity and capillary interactions at a fluid interface

Studying the behavior of anisotropic particles at fluid interfaces is a rapidly expanding field, as understanding how the introduced anisotropy affects the resulting properties is essential in the engineering of interfacial systems. Surface anisotropic particles, also known as Janus particles (JPs), offer new possibilities for novel applications due to their amphiphilicity and stronger binding to fluid interfaces compared to homogeneous particles. Introducing surface anisotropy creates complexity as the orientation of interfacially bound particles affects interparticle interactions, a contributing factor to the microstructure formation. In this work, we have investigated the microstructure of JP monolayers formed at the air–water interface using particles with different degrees of amphiphilicity and examined the response of the networks to applied compressions. Our findings demonstrate that JPs amphiphilicity is a crucial factor governing their orientation at the interface, which in turn dictates the complexity of the capillary interactions present and the mechanical properties of the ensuing networks.     

A facile and efficient method for preparation of chiral supported poly(styrene–divinylbenzene) copolymers

A new and efficient method for preparation of optically active poly(styrene–divinylbenzene) copolymers (PS-DVB) is presented here. This is carried out by Friedel–Crafts acylation reaction of chiral N-phthaloyl -leucine acid chloride with PS-DVB beads in the presence of aluminum chloride as Lewis acid catalyst and 1,2-dichloroethane as the solvent at ambient temperature. Reagents’ amounts and reaction conditions are mentioned and four samples with different amounts of functionality have been prepared. Final products were characterized by FT-IR and elemental analysis. The results obtained confirm that the above modification in preparation of chiral supported PS-DVB has been achieved well and in moderate yield.