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Abstract We provide a detailed description of a numerically stable and efficient coupling scheme for steady-state Monte Carlo neutronic calculations with thermal–hydraulic feedback. While we have previously derived and published the stochastic approximation based method for coupling the Monte Carlo criticality and thermal–hydraulic calculations, its possible implementation has not been described in a step-by-step manner. As the simple description of the coupling scheme was repeatedly requested from us, we have decided to make it available via this note.

A water-soluble organic redox couple (TT−/DTT) and new organic dyes (D45 and D51) have been developed for aqueous dye-sensitized solar cells (DSCs). An optimal efficiency of 3.5% was obtained using the D51 dye and an optimized electrolyte composition. The highest IPCE value obtained was 68% at 460 nm.

A numerical study of heat transfer to supercritical water in vertical tubes is carried out using the ANSYS-CFX code and employing the k-omega SST turbulence model. The numerical results on wall tem ...

Numerically stable Monte Carlo burnup calculations of nuclear fuel cycles are now possible with the previously derived Stochastic Implicit Euler method based coupling scheme. In this paper, we show that this scheme can be easily extended to include the thermal–hydraulic feedback during the Monte Carlo burnup simulations, while preserving its unconditional stability property. At each time step, the implicit solution (for the end-of-step neutron flux, fuel nuclide densities and thermal–hydraulic conditions) is calculated iteratively by the stochastic approximation; the fuel nuclide densities and thermal–hydraulic conditions are iterated simultaneously. This coupling scheme is derived as stable in theory; i.e., its stability is not conditioned by the choice of time steps.

Abstract Electrolyte-separator-free fuel cell (EFFC) is a new emerging energy conversion technology. The EFFC consists of a single-component of nanocomposite material which works as a one-layer fuel cell device contrary to the traditional three-layer anode–electrolyte–cathode structure, in which an electrolyte layer plays a critical role. The nanocomposite of a single homogenous layer consists of a mixture of semiconducting and ionic materials that provides the necessary electrochemical reaction sites and charge transport paths for a fuel cell. These can be accomplished through tailoring ionic and electronic (n, p) conductivities and catalyst activities, which enable redox reactions to occur on nano-particles and finally accomplish a fuel cell function.

Most existing industrial control systems (ICSs), such as building energy management systems (EMSs), were installed when potential security threats were only physical. With advances in connectivity, ICSs are now, typically, connected to communications networks and, as a result, can be accessed remotely. This extends the attack surface to include the potential for sophisticated cyber attacks, which can adversely impact ICS operation, resulting in service interruption, equipment damage, safety concerns, and associated financial implications. In this work, a novel cyber–physical security framework for ICSs is proposed, which incorporates an analytics tool for attack detection and executes a reliable estimation-based attack-resilient control policy, whenever an attack is detected. The proposed framework is adaptable to already implemented ICS and the stability and optimal performance of the controlled system under attack has been proved. The performance of the proposed framework is evaluated using a reduced order model of a real EMS site and simulated attacks.

Abstract Electrolyte-free fuel cell (EFFC) which holds the similar function with the traditional solid oxide fuel cell (SOFC) but possesses a completely different structure, has draw much attention during these years. Herein, we report a complex of MZSDC–LNCS (Mg 0.4 Zn 0.6 O/Ce 0.8 Sm 0.2 O 2− δ –Li 0.3 Ni 0.6 Cu 0.07 Sr 0.03 O 2− δ ) for EFFC that demonstrates a high electrochemical power output of about 600 mW cm −2 at 630 °C. The co-doped MZSDC is synthesized by a co-precipitation method. Semiconductor material of LNCS is synthesized by direct solid state reaction. The microstructure and morphology of the composite materials are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray spectrometer (EDS). The performance of the cell with a large size (6 × 6 cm 2 ) is comparable or even better than that of the conventional solid oxide fuel cells with large sizes. The maximum power output of 9.28 W is obtained from the large-size cell at 600 °C. This paper develops a new functional nanocomposite for EFFC which is conducive to its commercial use.

Abstract The single component fuel cell (SCFC) is a novel physical-electrochemical device for energy conversion which is recently discovered. The functional composite materials of Li0.15Ni0.25Cu0.3Zn0.3O2−δ (LNCZO) and Ce0.8Sm0.2O1.9 (SDC)-carbonate are proved as unique materials in SCFC (or one-layer fuel cell). In this work, the microstructure and morphology of two composite materials of LNCZO-SDC-Na2CO3 (LNCZO-NSDC) and LNCZO-SDC-(Li/Na)2CO3 (LNCZO-LNSDC) are investigated by SEM-EDX and HR-TEM. Their catalytic activities for both hydrogen oxidation and oxygen reduction are studied by H2-TPR and O2-TPD, respectively. It is discovered for the first time that binary carbonates as ionic conductor mixing with semiconductor homogenously help to form unique semiconducting-ionic microstructure. The particle arrangement and interface conduction in the microstructure significantly influences on the SCFC performances due to different catalytic activity and polarization resistance. Even this, O2 reduction reaction (ORR) for the single homogeneous layer still predominates in the redox reaction and binary carbonates are in favor of the oxygen conduction and desorption. These fin dings are essential to exactly understand the connections among structure, catalytic activities and performances underlying SCFC.