Adaptive neuro‐fuzzy inference system and artificial neural network modeling of proton exchange membrane fuel cells based on nanocomposite and recast Nafion membranes

In this study, a proton exchange membrane fuel cell (PEMFC) is modeled by multilayer perceptron neural network (MLPNN), RBF neural network (RBFNN), and adaptive neuro‐fuzzy inference system (ANFIS). Experimental data are obtained on the basis of the fabricated membrane‐electrode assembly (MEA) responses using prepared nanocomposite and recast Nafion membranes in the PEMFC. Four parameters including cell temperature, inlet gas temperature, current density, and inorganic additive percent are used as inputs, and the cell voltage is considered as the output. The results show that there is no considerable discrepancy between the RBFNN accuracy (R = 0.99554) and the MLPNN accuracy (R = 0.99609) for the performance prediction. The required time for developing the RBFNN model is significantly lower than the MLPNN model. A variety of ANFIS structure is explored to approximate the behavior of the system. The effect of cell and inlet gas temperatures on the PEMFC performance is investigated by the ANFIS developed model. Predicted polarization and power–current behavior by the ANFIS for the MEA prepared by the recast Nafion and the nanocomposite membranes at the cell temperatures 50 °C to110°C are in high agreement with the experimental data. Predicted data by the ANFIS show that because of the property of Cs_2.5H_0.5PW₁₂O₄₀ additive for retaining water, much higher current density and power density at the same voltage are achieved for the nanocomposite membrane compared with the recast Nafion membrane in the PEMFC. Copyright © 2011 John Wiley & Sons, Ltd.     

Experimental characterization of single and two-phase flow through nickel foams

Experimental tests are performed to determine the hydraulics parameters, which characterize one-phase (air) and two-phase flow (air and water) in thin metallic foams (thickness of the order of 1.5 mm). Three types of nickel foams produced by INCO and RECEMAT are considered. The specific experimental set-up allows the study of low in-situ compression effects on the foam sample. Regarding one-phase flow, intrinsic permeability and inertial coefficient (also named passability) are determined from a semi-analytical solution of the Darcy-Forchheimer-Brinkman equation, whereas concerning two-phase flow only gas phase relative properties are estimated through the generalized Darcy-Forchheimer equation. For the used experimental flow range, the results which are in line with former studies show the importance of the inertial effects. The in-situ foam compression and tightening effects lead to higher permeability and passability values, knowing that permeability coefficient is determined with a better accuracy than the inertial coefficient.     

Fixed mobile internet convergence (FMIC)

Convergence is one of the most frequently used catchwords in the information and communication field. While in general the increasing growing together of telecommunication, information and media technology is understood by this term and much has already been written about it, the term FMIC has existed for only a short time yet in telecommunication, and has not yet appeared much in the literature. FMIC stands for fixed mobile internet convergence and means the growing together of fixed networks, mobile networks and the Internet. In this article it will be demonstrated by means of three top existing current services what one should expect from the so-called FMIC-services.     

Effect of functionalized trititanate nanotubes on the properties of crosslinked cationic polymer nanocomposite

The synthesis and characterization of a crosslinked polymer nanocomposite containing titanium oxide nanotubes as filler are presented. First, the TiO₂ nanotubes were synthesized using a hydrothermal procedure and further functionalized using the organosilane reagent γ‐methacryloxypropyltrimethoxysilane. Subsequently, the modified nanotubes were incorporated into a polymer matrix using in situ polymerization of a mixture of monomer, crosslinker and initiator. Diverse characterization techniques were used at different stages of the synthesis, including transmission (TEM) and scanning electron microscopies, X‐ray diffraction (XRD), solid‐state ²⁹Si NMR and ¹³C NMR spectroscopy and nitrogen adsorption isotherms at 77 K. The as‐synthesized nanotubes correspond to the trititanate phase verified using XRD, and their presence within the nanocomposite was confirmed using TEM analysis. In addition, TiO₂ particles were detected on the surface of the nanocomposite. The nanocomposite exhibited a slight increase of Vickers microhardness while the water absorption decreased with oxide content attributed to trititanate nanotubes acting as multifunctional crosslinker.© 2015 Society of Chemical Industry     

Experimental validation of a CFD model for tubes in a phase change thermal energy storage system

A computational fluid dynamic (CFD) model for tubes in a phase change thermal energy storage system has been developed and validated with experimental results. The heat transfer fluid (HTF) flows in tubes which are configured in a unique arrangement during the charging and discharging processes. Water was used as the phase change material (PCM) which was contained in a cylindrical tank with four tubes coiled inside it. Experiments were conducted for both freezing and melting processes. A three-dimensional CFD model using Ansys code was developed and validated with experimental results. This model endeavoured to describe both the freezing and melting processes of the PCM. The inlet and outlet HTF temperatures as well as nine temperature locations in the PCM were compared with the CFD results. The average effectiveness as well as the duration of the phase change process of each experimental point was also compared with results from the CFD. From this study, it was concluded that the CFD model developed can accurately predict the behaviour of the thermal storage system during charging and discharging. The paper gives details of the CFD model and compares results from the model and experiments.     

永磁直流电机供电H桥的微控制器驱动

驱动一个中、小功率永磁直流电机的传统方式是采用搭成H桥结构的四支MOSFET或双极晶体管.例如在图1中,电机连接在集电极对C1、C2和C3、C4之间.     

Joined in death: highlights of the Sixth International Meeting on Yeast Apoptosis in Leuven,Belgium, 30 April–4 May 2008

While yeast apoptosis was still a controversial issue less than 10 years ago, the efforts of many groups have revealed cell death mechanisms that resemble, in many aspects, those described for mammalian apoptosis. Here, we provide an overview of new insights on yeast apoptosis and the link with lifespan of yeast cells, based on data presented at the 6th International Meeting of Yeast Apoptosis (IMYA). Together, these data demonstrate the power and advantages of the yeast system to uncover novel cellular factors governing life and death, placing yeast at the forefront of apoptosis research. Copyright © 2009 John Wiley & Sons, Ltd.