Evaluating the effect of using different sets of enrichment for FAs on fuel management optimization using CA

In nuclear reactor core design, achieving the optimized arrangement of fuel assemblies (FAs) is the most important step towards satisfying safety and economic requirements. In most studies, nuclear fuel optimizations have been performed by using a finite number of different types of FAs. However the effect of FA numbers with different enrichments and the difference between their maximum and minimum enrichment values can be important and should be evaluated in the optimization process.     

Evaluating fuzzy earned value indices and estimates by applying alpha cuts

The earned value technique is an essential technique in analyzing and controlling the performance of a project by providing a more accurate measurement of both project performance and project progress. This paper presents an approach to deal with fuzzy earned value indices. This includes developing new indices under fuzzy circumstances and evaluating them using alpha cut method. The model improves the applicability of the earned value techniques under real-life and uncertain conditions. A small example illustrates how the new model can be implemented in reality.     

A compensated PID active queue management controller using an improved queue dynamic model

Beside the major objective of providing congestion control, achieving predictable queuing delay, maximizing link utilization, and robustness are the main objectives of an active queue management (AQM) controller. This paper proposes an improved queue dynamic model while incorporating the packet drop probability as well. By applying the improved model, a new compensated PID AQM controller is developed for Transmission Control Protocol/Internet Protocol (TCP/IP) networks. The non‐minimum phase characteristic caused by Padé approximation of the network delay restricts the direct application of control methods because of the unstable internal dynamics. In this paper, a parameter‐varying dynamic compensator, which operates on tracking error and internal dynamics, is proposed to not only capture the unstable internal dynamics but also reduce the effect of uncertainties by unresponsive flows. The proposed dynamic compensator is then used to design a PID AQM controller whose gains are obtained directly from the state‐space representation of the system with no further gain tuning requirements. The packet‐level simulations using network simulator (ns2) show the outperformance of the developed controller for both queuing delay stability and resource utilization. The improved underlying model leads also to the faster response of the controller. Copyright © 2013 John Wiley & Sons, Ltd.     

Microstructure and mechanical properties of dual phase steels,with different martensite morphology,produced during TLP bonding of a low C-Mn steel

In this research, production of ferrite - martensite dual phase Steels with different martensite morphology was considered during transient liquid phase bonding of a low carbon steel. The steel was bonded using an iron base interlayer with melting point of 1443 K and 40 μm thickness. Bonding process carried out at 1473 K, under pressure of 0.5 MPa, at different holding time of 10, 20, 30 and 40 minutes. Microstructural studies of joint region showed that isothermal solidification completed at the bonding time of 40 minutes. Microstructure of joints made at the bonding time of 10, 20, and 30 minutes consists of two distinct region, athermal and isothermal solidified zones. Microstructure of these zones was studied and chemical composition of these zones was determined by EDS. Joints made with bonding time of 40 minutes were homogenized at 1008 K and then cooled into cold water to produce dual phase ferrite and martensite microstructure with different martensite morphology. According to shear test results, it was found that the shear strength of ferrite - fibrous martensite microstructure is greater than those with ferrite - continuous martensite and ferrite - blocky martensite microstructure.     

Toward an intelligent approach for predicting surface tension of binary mixtures containing ionic liquids

Knowledge of the surface tension of ionic liquids (ILs) and their related mixtures is of central importance and enables engineers to efficiently design new processes dealing with these fluids on an industrial scale. It’s obvious that experimental determination of surface tension of every conceivable IL and its mixture with other compounds would be a herculean task. Besides, experimental measurements are intrinsically laborious and expensive; therefore, accurate prediction of the property using a reliable technique would be overwhelmingly favorable. To do so, a modeling method based on artificial neural network (ANN) trained by Bayesian regulation back propagation training algorithm (trainbr) has been proposed to predict surface tension of the binary ILs mixtures. A total set of 748 data points of binary surface tension of IL systems within temperature range of 283.1-348.15 K was used to train and test the applied network. The obtained results indicated that the predictive values and experimental data are quite matching, representing reliability of the used ANN model for such purpose. Also, compared with other methods, such as SVM, GA-SVM, GA-LSSVM, CSA-LSSVM, GMDH-PNN and ANN trained with trainlm algorithm the proposed model was better in terms of accuracy.     

A multi-objective and integrated model for supply chain scheduling optimization in a multi-site manufacturing system

In a supply chain, scheduling plays a significant role in coordinating and cooperation. This article considers an integration of supplier and vehicle scheduling problems in terms of vehicle routing determination for transporting raw materials from the suppliers to some manufacturing centres. The aim is to minimize the total tardiness of all assigned orders to the suppliers and simultaneously minimize the total travelled distance of the vehicles. Most manufacturing companies, which have to manage their suppliers as an industrial unit, experience this problem. A new metaheuristic algorithm called the multiple league championship algorithm (MLCA), inspired by championship matches, is proposed to solve this problem. To show the efficiency of MLCA, it is compared with two different algorithms used for the problems in the literature that are closest to this problem and a soccer-based algorithm called golden ball. The experimental results prove that the proposed algorithm has better performance than these algorithms.     

Sentic PROMs: Application of sentic computing to the development of a novel unified framework for measuring health-care quality

Barriers to use health related quality of life measuring systems include the time needed to complete the forms and the need for staff to be trained to understand the results. An ideal system of health assessment needs to be clinically useful, timely, sensitive to change, culturally sensitive, low burden, low cost, involving for the patient and built into standard procedures. A new generation of short and easy-to-use tools to monitor patient outcomes on a regular basis has been recently proposed. These tools are quick, effective and easy to understand, as they are very structured and rigid. Such structuredness, however, leaves no space to those patients who would like to say something more. Patients, in fact, are usually willing to express their opinions and feelings in free text, rather than simply filling in a questionnaire, for either speaking out their satisfaction or for cathartic complaining. Sentic PROMs allow patients to evaluate their health status and experience in a semi-structured way and accordingly aggregate input data by means of sentic computing, while tracking patients’ physio-emotional sensitivity.     

Dielectric abnormality and high-permittivity microwave dielectric properties of SrO-TiO2-CeO2 solid solution

The SrO-TiO₂-CeO₂ (Sr_1?1.5×Ce_xTiO₃, SCTO, 0?≤?x?≤?0.2, sintered in N₂) solid solution exhibited the existence of dielectric abnormality/anomaly (for polished samples) and high-permittivity microwave dielectric properties (for unpolished samples). X-ray diffraction (XRD) and Rietveld refinement, along with high-resolution transmission electron microscopy (HRTEM), indicated the evidence of cubic like structure. The SEM-EDX maps demonstrated the formation of a complete solid solution, which further support the XRD results. X-ray photoelectron spectroscopy (XPS) analysis showed mixture of ion valence states upon lattice defects formation. The activation of the TO2/TiO4 polar bands usually described a relaxor-type-dielectric anomaly. The ε′-T curve, together with the polar nature measurements exhibited hysteresis loops, indicating that ceria ions induced weak relaxor behavior. The observed Q×f values were primarily dependent on the lattice defects and Ti³⁺ cations. The temperature coefficient of resonant frequency (${\tau }_f$) shifted gradually from more positive (+1321?ppm/°C) to less positive (+539?ppm/°C) values with a rise of Ce content (x). The unpolished sample with x?=?0.2 exhibited a high permittivity microwave dielectric properties with ε_r =?182, ${\tau }_f$?=?+539?ppm/°C, and Q×f =?668?GHz.     

Prediction of gas hydrate formation in the presence of methanol,ethanol, (ethylene,diethylene and triethylene) glycol thermodynamic inhibitors

Hydrate formation is a serious, fundamental problem in the blocking of process equipment and pipelines in gas transportation pipelines. The objective of the present work is the simulation of the pipelines in the 15th and 16th phases of South Pars and investigation of operating conditions for hydrate formation. The effects of injecting various thermodynamic inhibitors on the hydrate formation conditions have also been studied. According to the simulation results, investigation of the operational reasons and the cost of these compounds, pure methanol and monoethylene glycol were determined as the best inhibitors for gas flow rates of 500 and 1000 mmscfd.     

Hydrogen Production from Co‐Gasification of Coal and Biomass in the Presence of CaO as a Sorbent

Among the options for clean energy production, the gasification process is receiving increasing attention as it offers the best combination of investment and value of produced electricity compared to other methods. An Aspen Plus model of co‐gasification of biomass and coal with in situ CO₂ capture was developed to evaluate its potential for hydrogen production and cracking of organic impurities, i.e., tars. The effects of some critical operational variables on gas composition and yields of hydrogen gas and tar were investigated. The obtained results indicate that the fuel particle size plays a minor role in the process; smaller particles favor the conversion of tar and production of more hydrogen gas.