Thermodynamic performance analysis of three solid oxide fuel cell and gas microturbine hybrid systems for application in auxiliary power units

In this study, three different configurations of a solid oxide fuel cell and gas microturbine hybrid system are evaluated for application in auxiliary power units. The first configuration is a common hybrid system in auxiliary power units, utilizing a fuel cell stack in the structure of the gas turbine cycle. The other configurations use two series and parallel fuel cell stacks in the structure of the gas turbine cycle. The main purpose of this research is thermodynamic analysis, evaluation of the performance of the proposed hybrid systems in similar conditions, and selection of an appropriate system in terms of efficiency, power generation, and entropy generation rate. In this study, the utilized fuel cells were subjected to electrochemical, thermodynamic, and thermal analyses and their working temperatures were calculated under various working conditions. Results indicate that the hybrid system with two series stacks had maximum power generation and efficiency compared with the other two cases. Moreover, the simple hybrid system and the system with two parallel stacks had relatively equal pure power generation and efficiency. According to the investigations, hybrid system with two series fuel cell stacks, which had 3424 and 1712 cells, respectively, can achieve the electrical efficiency of over 48%. A hybrid system with two parallel fuel cell stacks, in which each stack had 2568 cells, had the electrical efficiency of 46.3%. Findings suggested that maximum electrical efficiency occurred between the pressure ratios of 5–6 in the proposed hybrid systems.     

A local view on the Hudetz correction of the Yager entropy of dynamical systems

In this paper, we define a local version of Hudetz correction for the Yager entropy of dynamical systems. It is proved that the introduced function is indeed a local entropy map for the Hudetz correction of the Yager entropy, in the sense that, the Hudetz correction of the Yager entropy of a continuous map on a compact metric space is attained by integrating the introduced local entropy.     

Fault isolation in manufacturing systems based on learning algorithm and fuzzy rule selection

Neural Computing and Applications - This paper addresses the fault detection and isolation problem in manufacturing systems. Some of these systems can be affected by several faults, a first way of...     

XPloreRank: exploring XML data via you may also like queries

World Wide Web - In many cases, users are not familiar with their exact information needs while searching complicated data sources. This lack of understanding may cause the users to feel...     

Methacrylate-functionalized POSS as an efficient adhesion promoter in olefin-based adhesives

This study aims to investigate the effects of methacrylate-functionalized polyhedral oligomeric silsesquioxane (MA-POSS) on polyolefin-based adhesives. The so called adhesive was synthesized by the cooligomerization of 1-decene/9-decene-1-ol monomers using a Ti amine bis-phenolate catalyst, [Ti{2,2′-(OC₆H₂-4,6-^tBu₂)₂NHC₂H₄NH(OⁱPr)₂], which was subsequentlyacrylated via a simple reaction with methacryloyl chloride. Different weight fractions of MA-POSS nanoparticles were solution blended with synthesized adhesive and undergone curing reaction with blue light. Observation of a unique tan δ peak in dynamic mechanical thermal analysis (DMTA) curve was clear evidence that two employed moieties were miscible and only one hybrid polymeric phase was created. Most noticeably, significant increase in mechanical parameters was detected in the lower inclusion compositions, 0.2-1 wt% of MA-POSS, where flexural strength and flexural modulus were increased up to 99 and 110%, respectively. Furthermore, thermal stability of the synthesized nanocomposite enhanced dramatically by increasing MA-POSS weight fraction. Influence of employed nanoparticles on adhesion properties of synthesized nanocomposites was evaluated with tensile shear bond strength and pull off analysis. According to the adhesion results, the MA-POSS causes an adhesion promotion on the fabricated adhesive/POSS nanocomposites.     

Novel Fault Management Framework Using Markov Chain in Wireless Sensor Networks: FMMC

Wireless Personal Communications - Due to using wireless sensor nodes (WSNs) in inaccessible areas and applying limitations in making nodes to reduce costs, these networks are prone to faults. The...     

Development of a Robust Carrier Synchronizer for High Dynamic and Low Signal to Noise Ratio Signals in GPS Receivers

Wireless Personal Communications - In this paper, a robust carrier recovery loop for high dynamic and weak signals in GPS receivers is proposed. To achieve optimal tracking performance at...     

Rotational and axial flow of pseudoplastic fluids

Mechanics of Time-Dependent Materials - Effects of a controllable axial flow on the stability of rotational flow of pseudoplastic fluids in the gap between concentric cylinders are studied. It is...     

On the numerical solution of Fredholm integral equations utilizing the local radial basis function method

The current investigation describes a computational technique to solve one- and two-dimensional Fredholm integral equations of the second kind. The method estimates the solution using the discrete collocation method by combining locally supported radial basis functions (RBFs) constructed on a small set of nodes instead of all points over the analysed domain. In this work, we employ the Gauss–Legendre integration rule on the influence domains of shape functions to approximate the local integrals appearing in the method. In comparison with the globally supported RBFs for solving integral equations, the proposed method is stable and uses much less computer memory. The scheme does not require any cell structures, so it is meshless. We also obtain the error analysis of the proposed method and demonstrate that the convergence rate of the approach is high. Illustrative examples clearly show the reliability and efficiency of the new method.