bluuebunny/crossref_metadata_2025 huggingface dataset:
Refractory depression: mechanisms and evaluation of radically open dialectical behaviour therapy (RO-DBT) [REFRAMED]: protocol for randomised trial
Authors: Lynch T R , Whalley B , Hempel R J , Byford S , Clarke P , Clarke S , Kingdon D , O'Mahen H , Russell I T , Shearer J , Stanton M , Swales M , Watkins A , Remington B
Published: July 2015

Introduction

Only 30–40% of depressed patients treated with medication achieve full remission. Studies that change medication or augment it by psychotherapy achieve only limited benefits, in part because current treatments are not designed for chronic and complex patients. Previous trials have excluded high-risk patients and those with comorbid personality disorder. Radically Open Dialectical Behaviour Therapy (RO-DBT) is a novel, transdiagnostic treatment for disorders of emotional over-control. The REFRAMED trial aims to evaluate the effectiveness and cost-effectiveness of RO-DBT for patients with treatment-resistant depression.

Methods and analysis

REFRAMED is a multicentre randomised controlled trial, comparing 7 months of individual and group RO-DBT treatment with treatment as usual (TAU). Our primary outcome measure is depressive symptoms 12 months after randomisation. We shall estimate the cost-effectiveness of RO-DBT by cost per quality-adjusted life year. Causal analyses will explore the mechanisms by which RO-DBT is effective.

Ethics and dissemination

The National Research Ethics Service (NRES) Committee South Central – Southampton A first granted ethical approval on 20 June 2011, reference number 11/SC/0146.

Trial registration number

ISRCTN85784627.
Usefulness of flat detector CT (FD-CT) with biplane fluoroscopy for complication avoidance during radiofrequency thermal rhizotomy for trigeminal neuralgia
Authors: Easwer Hariharan Venkat Iyer , Chatterjee Nilay , Thomas Ajith , Santhosh Kannath , Raman Kapilamoorthy Tirur , Sridhar Rupa
Published: July 2015

Introduction

Trigeminal neuralgia (TN) is characterized by episodes of shooting pain in the areas innervated by one or more divisions of the trigeminal nerve. The initial treatment of TN is with drugs but the increased frequency and intensity of the neuralgic episodes often force the patient to seek alternative therapies. Microvascular decompression (MVD) and radiofrequency thermal lesioning of trigeminal rootlets (RFTR) offer close to the best results for TN. MVD has the disadvantage of being an open surgical procedure with its attendant risks and longer hospital stay, whereas RFTR is a short, ‘day-care’ procedure. However this latter procedure involves positioning of the RF needle in the area behind the trigeminal ganglion through the foramen ovale, which can pose significant challenges.

Objective

To use the fluoroscopic support of a biplane catheter laboratory to access the foramen, and flat detector CT to confirm the location of the tip of the RF needle in the optimal position.

Methods

Fifty-three patients with TN underwent RFTR under local anesthesia with conscious sedation.

Results

All patients reported pain relief with hypesthesia over the offending trigeminal division. In seven patients the needle tip required repositioning according to the CT images. Two patients each had loss of corneal reflex and abducens nerve palsy after the procedure. No other complications were seen.

Conclusions

The superior view in two planes coupled with the anatomical confirmation of the position of the needle tip in the Meckel's cave during the rhizotomy reduces the need for multiple passages of the needle to access the foramen ovale and achieves accurate needle tip positioning. The technique increases the safety and precision of such treatments and helps to manage potential complications.
Unitary equivalence of normal matrices over topological spaces
Authors: Friedman Greg , Park Efton
Published: July 2015

Let [Formula: see text] and [Formula: see text] be normal matrices with coefficients that are continuous complex-valued functions on a topological space [Formula: see text] that has the homotopy type of a CW complex, and suppose these matrices have the same distinct eigenvalues at each point of [Formula: see text]. We use obstruction theory to establish a necessary and sufficient condition for [Formula: see text] and [Formula: see text] to be unitarily equivalent. We also determine bounds on the number of possible unitary equivalence classes in terms of cohomological invariants of [Formula: see text].
Touching the virtual
Authors: Kugler Logan
Published: July 2015

Feeling the way across new frontiers at the interface of people and machines.
Hickory dickory doc
Authors: Neville-Neil George V.
Published: July 2015

On null encryption and automated documentation.
Hexis and the SOFC System Galileo 1000 N: Experiences from Lab and Field Testing
Authors: Mai Andreas , Schuler J. Andreas , Fleischhauer Felix , Nerlich Volker , Schuler Alexander
Published: July 2015

Hexis is developing and manufacturing SOFC-based micro-CHP systems for single-family or small multi-family houses. The current system Galileo 1000 N has an output of 1 kW electrical power. It furthermore covers the full heat demand of a standard single family house. More than 250 Galileo 1000 N systems have been installed up to now and are operated at customer's sites and in the lab.The newest achievements in the field test and in the lab on durability and cyclability of SOFC stacks and complete micro-CHP systems are reported. Achievements are total system efficiencies of 95% (LHV) and electrical efficiencies of 35% (AC net, LHV). In tests with steam reforming, electrical efficiencies of more than 55 % (DC) have been shown on short-stack level. The longest system test had been running for more than 40 000 h. More recently, power degradation rates of approx. 0.5% per 1 000 h over more than 20 000 hours on short-stack level and over more than 12 000 h on full-system level have been demonstrated which were also confirmed in field tests. Cycling tests have shown a tolerance against 100 complete redox-cycles on short-stack level and 50 on-off cycles on system level. Summarized, stack lifetimes of 7 to 8 years are considered to be realistic. All-in-all, the technical market readiness has been achieved with the Galileo 1000 N. Consequently, an introduction into pilot-markets in Europe was started in autumn 2013.
Development, Manufacturing and Deployment of SOFC-Based Products at SOLIDpower
Authors: Bertoldi Massimo , Bucheli Olivier , Ravagni Alberto
Published: July 2015

SOLIDpower provides efficient energy solutions based on its proprietary planar SOFC technology. The first commercial product of the company is the EnGen™-2500. The company deploys the CE certified 2.5 kW combined heat and power generator within the FCH-JU project ene.field and with selected European partners. The EnGen™-2500 uses natural gas for combined heat and power generation (CHP) at high electrical and total efficiencies. The product targets multi-family houses and commercial applications. More than 60 units are to be installed within 2015 and field test results will be presented. SOLIDpower operates a first “to scale” production cell in Northern Italy with a production capacity of 2MW/yr. Based on an ordering volume of 50 MW, the stack and balance of stack components match target market requirements, allowing selling and operating systems at grid parity prices. Besides the micro-CHP generator deployment, SOFCpower also pursues strategic development activities to demonstrate biogas and waste-to-energy (WTE) applications on larger than 2.5 kW scale. SOLIDpower progressed on the technological level for SO Electrolysis. Improved electrode materials and production technology open the door for lifetime for electrolysers stacks beyond 16’000 hrs. SOLIDpower expects that SOFC stack cost reductions stemming from SOFC volume manufacturing can be transferred to a large extend also to SOE stacks. In this field, SOLIDpower intends to work with integration partners on the systems level. The paper provides an update of the stack and system development, including operational results of SOFC-based micro-CHP.
Application-Oriented Design and Field Trial of the Eneramic® Power Generator
Authors: Reuber Sebastian , Megel Stefan , Jürgens Christian , Pfeifer Thomas , Bednarz Marc , Wunderlich Christian , Michaelis Alexander
Published: July 2015

Off-grid power generation is considered as an attractive market for fuel cells. For this reason, a compact SOFC battery hybrid system is being developed and commercialized by Fraunhofer IKTS. The 100 W hybrid system operates on commercially available LPG fuels. Different prototypes are being tested in the lab and under real-life applications while a first product version is available for industrial customers. For off-grid applications frequent start-stop cycles are expected, which are challenging for the SOFC technology. Following these requirements IKTS has consistently improved robustness of the SOFC up to now 110 start-stop cycles by quality measures and the operating procedure. The reliability of the core technology highlights the power degradation of < 0.6 % per 1,000 h over 16,000 h of Hotbox operation. The results of the automated laboratory and field tests will be discussed in this paper.
Small Scale Power Generation for Road Trucks with Planar SOFC System
Authors: Bossel Ulf
Published: July 2015

There is increasing interest in small SOFC generators for the conversion of commercial butane/propane fuel into DC electricity. However, with minor modification of the pre-reformer such units can also be used for the conversion of methane, natural gas, biogas or LNG. A consortium of six groups form the UK, Spain, Poland and Switzerland is presently engaged in the development of a small SOFC power source for road trucks powered by LNG. The project “SAFARI” is funded by the FCH-JU Programme of the European Union. Two different types of SOFC are simultaneously prepared for comparative evaluation. While the project leader “Adelan Ltd.” is optimizing its tubular SOFC design (see separate conference presentation), ALMUS AG is perfecting its planar approach for road truck applications. Stacks of 60 mm x 60 mm foot print are used. They are composed of metal bipolar plates and anode-supported cells. To match the generator output to the power demand, up to four such stacks can be arranged in line, each delivering up to 80 Watts at 24 VDC and 700°C operating temperature. For low heat losses and maximum conversion efficiency, the stack arrangement is surrounded by a 100 mm thick thermal jacket made of the best available insulation material (Calcium silicate). The arrangement is contained in a metal box for safe handling and mounting on the truck platform. A partial oxidation methane reformer is part of the system. Start-up heat is generated by burning small amounts of fuel.
Degradation of LSCF Cathode Induced by SO2 in Air
Authors: Kishimoto Haruo , Wang Fangfang , Cho Do-Hyung , Lv Peiling , Bagarinao Katherine Develos- , Yamaji Katsuhiko , Horita Teruhisa , Yokokawa Harumi
Published: July 2015

Sulfur dioxide (SO2) is one of the most major impurities in air and it induces a performance degradation of SOFC cathodes. Our group has investigated the enforced degradation behaviors of (LaSr)(CoFe)O3 (LSCF) cathodes by sulfur dioxide (SO2) containing air. It is clearly observed that SO2-induced degradation is affected by cell operation conditions, such as impurity concentration and the operating temperature. We observed two degradation steps; one is a rapid degradation rate occurring at an early stage and the other is a constant degradation with relatively slow rate. During progress of degradation, both ohmic resistance, R
ohm, and oxygen reduction reaction resistance (polarization resistance), R
p, increased. There is a relationship between increasing rates of R
p and R
ohm in each degradation step.
Characterization of Cracks and their Effects on the Effective Transport Pathways in Ni-YSZ Anodes after Reoxidation Using X-Ray Nanotomography
Authors: Nakajo Arata , Kiss Andrew M. , Cocco Alex P. , Harris William M. , DeGostin M. B. , Greco Fabio , Nelson George J. , Peracchio Aldo A. , Cassenti Brice N. , Deriy Alex , Wang Steve , Chen-Wiegart Yuchen , Wang Jun , Van herle Jan , Chiu Wilson K. S.
Published: July 2015

Reduction-oxidation cycling of Ni-based electrodes for solid oxide fuel/electrolysis cells irreversibly alters their microstructure and can cause the fracture of the electrolyte. Non-destructive 3-D imaging enables tracking of microstructural changes that occur during cycling. Despite recent advances, the understanding of how local 3-D geometrical features in the heterogeneous electrode material contribute to the material degradation remains incomplete. Absorption contrast X-ray nanotomography (XNT) of a same Ni(O)-yttria-stabilized zirconia (YSZ) sample was performed at the Ni K-edge white-line peak (8348 eV), before and after exposure to air at 800°C during 45 minutes. A complimentary XNT at 8376 eV confirmed a degree of oxidation higher than 98%. The morphology of the Ni(O) phase was as expected completely different after re-oxidation. The spatial resolution better than 20 nm enabled the detection of cracks in the brittle YSZ phase above this dimension. The detrimental effects of the cracks on the effective 3-D transport pathways in the Ni-YSZ anode under polarization was investigated using a skeleton-based discrete representation of the imaged volume and an analytical electrochemical fin model. Topological properties, effective ionic conductivity and polarization resistance were calculated before and after oxidation. For the latter estimate, the effect of the cracked YSZ network was considered alone so far; that of the spatial re-distribution of triple-phase boundaries induced by re-oxidation will be included in the future. Cracks in the brittle YSZ phase induced an increase in the effective ionic resistivity and in the polarization resistance in the range of 25 ± 9% and 12 ± 5%, respectively.
Gas Composition Analysis on Ni-YSZ Anode in Direct Internal Reforming Solid Oxide Fuel Cell
Authors: Muroyama Hiroki , Ando Daiki , Okanishi Takeou , Matsui Toshiaki , Eguchi Koichi
Published: July 2015

Direct internal reforming SOFCs have attracted a lot of interest due to high energy conversion efficiency and simple system configuration. In this study, the distribution of gas composition over the anode surface along the gas flow direction was directly analyzed by gas chromatograph under the open-circuit and discharge conditions with a supply of methane fuel. Regardless of total flow rate, a remarkable increase in methane conversion was confirmed at the upstream part under a constant fuel composition in open-circuit condition. The extent of conversion enhancement was more significant at slower flow rates. The gas–catalyst contacting time determined the methane conversion. The enhancement of methane conversion with an increase in current density was confirmed. The methane reforming was promoted by the consumption of hydrogen and the formation of steam via the electrochemical reaction.
Permeability of Gases in the Anode of an Anode Supported SOFC
Authors: Geagea Maya , Genov Ivaylo , Stoynov Zdravko , Vladikova Daria , Chesnaud Anthony , Thorel Alain
Published: July 2015

In the high current density regime, the performance of SOFCs is limited by concentration overpotentials when the demand for reactants exceeds the capacity of the porous cermet anode to supply them by gas diffusion mechanisms, and when the rate at which water is produced exceeds the ability of the anode to evacuate water. A compromise should be found between maintaining a high level of activation in the anode, which means a high density of Triple Phase Boundaries (TPB) usually associated with small grains size and small pores, and high gas permeability generally associated with large interconnected pores. The present work aims at determining experimentally the gas permeability of the anode as a function of the percolation, tortuosity and volume fraction of the pores. Anodes with varying porosity ensured by different quantities of pore former were obtained by cold pressing and sintering. SEM image analysis, mercury intrusion porosimetry and permeability measurements for different gases were performed. However, non-linearity as a function of the gases molecular weight is observed.
Evaluating the Behavior of CO/CO2 in Ni/GDC Solid Oxide Fuel Cell Anodes
Authors: Wang Lei , Jackson Gregory S
Published: July 2015

To better understand carbon oxide chemistry in Ni/GDC anode functional layers, we have studied CO oxidation and CO2 dissociation on sputtered thin-film GDC (Ce0.8Gd0.2O1.9) electrodes with open Ni sputtered overlayers. The well-characterized electrode allows optical access to study fundamental CO and CO2 reactions around Ni/GDC interfaces in both dry and wet environments. To isolate the GDC chemistry, Ni/GDC cell results were compared to those from GDC films with less active Au overlayers. Dry CO oxidation and CO2 dissociation are slower than their H2 and H2O analogs on Ni/GDC with fitted exchange current densities for CO/CO2 approximately one order of magnitude lower than H2/H2O from 600 to 700 °C. With optical access to the active Ni and GDC interfaces, ambient pressure XPS was used to obtain local overpotentials across the Ni/GDC for some test conditions and thereby extract fundamental information about the CO and CO2 chemistry in the Ni/GDC cell.
Local Evolution of Three-Dimensional Microstructure Morphology of Planar Anode-Supported SOFC
Authors: Brus Grzegorz Adam , Iwai Hiroshi , Otani Yuki , Sciazko Anna , Saito Motohiro , Yoshida Hideo , Szmyd Janusz S.
Published: July 2015

In this research a cell stack with standard power output 100 W was tested over the period of 3700 hours. After the long-term operation subsequent post-test analysis of anode microstructure has been conducted using combination of focused ion beam and scanning electron microscopy. Obtained data was reconstructed into three-dimensional images, based on which the microstructure parameters were obtained. The microstructure parameters were quantified at three different location in the selected cells; inlet, middle and outlet. The obtained results indicate strong microstructure morphology change after long operation time and revealed a non-homogeneous degradation behavior.
Enhancing the Stability of Infiltrated Ni/YSZ Anodes
Authors: Keyvanfar Parastoo , Hanifi Amir Reza , Sarkar Partha , Etsell Thomas H. , Birss Viola
Published: July 2015

One possible solution to the redox cycling problem in Ni-based anodes is the fabrication of a pre-sintered porous electrolyte matrix, followed by infiltration of 10-20 vol% of a Ni-based catalyst into this scaffold. However, this can lead to instability as a result of sintering of the infiltrated phase at SOFC working temperatures. In this study, various Ni-containing solutions were infiltrated into a symmetrical tubular half-cell, with electrochemical impedance spectroscopy (EIS) and electron microscopy imaging used to determine the long term stability of the cells. It was found that the amount of infiltrated Ni has a significant impact on the long term stability of the Ni/YSZ anodes, explained by the better connectivity between Ni particles when there is more Ni present. It was also demonstrated that high temperature treatment of the infiltrated Ni/YSZ anodes just after the first few infiltrations, followed by several further Ni infiltration steps, has a significant effect not only on the stability of the anode at 800 oC, but also on the anode performance. As the YSZ backbone has the ability to dissolve NiO at higher temperatures, the dissolved NiO can be ex-soluted in the form of at least partially inter-connected nano-sized Ni particles at cell working temperatures under a reducing atmosphere.
Performance Optimization of Cermet SOFC Anodes: An Evaluation of Nanostructured NiO
Authors: Burmistrov Ilya , Agarkov Dmitrii , Tartakovskii Ilya , Kharton Vladislav , Bredikhin Sergey
Published: July 2015

The electrochemical performance of the Ni-containing cermet anodes, widely used for all types of SOFCs, is essentially governed by the triple phase boundary (TPB) formed by metal, solid electrolyte and gaseous phase. Although the TPB length and electrode surface area may be drastically increased using nanostructured components, information on the resultant effects in terms of the cermet properties and SOFC production technology is still scarce. The present work is centered on the appraisal of NiO morphologies and optimization of pre-treatment conditions for the powders used for anode screen-printing, with commercial nanocrystalline nickel (II) oxide as a model starting material. A series of NiO powders were prepared via annealing at various temperatures (300 – 1100oC) followed by chemical, structural and morphological characterization. The results of X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/ TEM), thermogravimentry and Raman spectroscopy reveal core-shell structure of nanosized NiO grains, formed due to surface hydration and oxidation under ambient conditions. Thermally induced desorption, and likely oxidation of organic components of the screen-printing pastes by the hyperstoichiometric oxygen, lead to poor quality of the electrode layers, thus making it necessary to introduce an additional powder pre-annealing step. The optimum pre-treatment temperature enabling to remove the absorbates, simultaneously preserving submicron grain size in the electrodes, corresponds to approximately 700oC.
Numerical Assessment of SOFC Anode Polarization with Microstructure Evolution
Authors: Jiao Zhenjun , Shimura Takaaki , Shikazono Naoki
Published: July 2015

In order to quantitatively investigate the correlation between the solid oxide fuel cell anode microstructure evolution and the resulting electrochemical performance, the evolution of three-phase boundary and nickel specific surface area were calculated. A three dimensional numerical simulation of the anode overpotential is conducted using a Lattice Boltzmann Method (LBM), which solves the species transport equations coupled with the electrochemical reaction at three-phases-boundary. Phase field method is introduced to simulate the microstructural evolution of nickel-yttria stabilized zirconia composite anode. The increase of anode overpotential during long time operation can be simulated based on the LBM and the phase field modeling.
Development of High Performance Anodes for Metal-Supported Fuel Cells
Authors: Rojek Veronika , Roehrens Daniel , Brandner Marco , Menzler Norbert H. , Guillon Olivier , Opitz Alexander Karl , Bram Martin
Published: July 2015

Metal-supported solid oxide fuel cells (MSCs) offer various potentials like cost reduction and abuse tolerance, which make them attractive for mobile applications such as auxiliary power units (APUs). The implementation of the metallic substrate requires specific adaption of SOFC processing technologies since sintering of functional layers at high temperatures under oxidizing atmosphere is restricted by the substrate. Therefore, one of the current challenges is the development of an anode layer, which can be sintered under reducing atmospheres, which improves i.a. the performance, the ageing behavior and the ability of the anode to withstand sulfur contaminations of the fuel gas. In the present work, a new anode concept is presented, which is based on a Ni/GDC cermet replacing the established Ni/YSZ cermet. The sintering study is supported by some preliminary results of characterizing the electrochemical performance of the Ni/GDC anodes by impedance spectroscopy. In addition, a thin GDC layer is currently used as diffusion barrier layer between the anode and the metallic substrate. A systematic study of the stability of this barrier layer under anode sintering conditions is given.
SOFC Anode Based on YSZ Pillars
Authors: Nagato Keisuke , Shinagawa Shunta , Shikazono Naoki , Iwasaki Shiko , Nakao Masayuki
Published: July 2015

From the view point of tortuosity, aligned yttria-stabilized zirconia (YSZ) and Ni particles and triple-phase boundaries (TPBs) are promising structures for the low-resistance transportation of species and their chemical reaction in the anode of solid oxide fuel cells (SOFCs). In this study, we formed prototype patterns of YSZ pillars with infiltrated Ni and investigated the effect of the configuration of pillars, corresponding to the TPB length, on the electric-generation performance of full cell including the anode. The YSZ pillars were fabricated using an excimer laser. The pillar width was set to 5, 10, 20, and 40 μm, and deeper trenches were fabricated in wider pillars. The trenches in the YSZ patterns were infiltrated with Ni particles. Finer pillars resulted in higher electric-generation performance. The surface area density of the YSZ pillars was approximately proportional to the maximum power density. This shows that the TPB length density is more important than the transportation resistance of oxygen ions in YSZ pillars. This phenomena is discussed on the basis of simulation by the lattice-Boltzmann method.
Sulfur Tolerance of Au-Mo-Ni/GDC SOFC Anodes Under Various CH4 Internal Steam Reforming Conditions
Authors: Neofytides Charalampos , Athanasiou Michalis , Neophytides Stylianos G. , Niakolas Dimitrios K.
Published: July 2015

The present work refers to the short communication of a first series of obtained results on how Au and/or Mo addition can affect the stability of modified Ni/GDC anodes for the reaction of internal CH4 steam reforming, in the presence of H2S. Specifically, it is shown that Ni/GDC is stable in the presence of 10 ppm H2S, but only in the case where 100 vol% of H2 is the anode feed. In the case where CH4 and H2O (diluted in Helium carrier gas) comprise the anode feed, then at ratios equal to S/C = 2 or S/C = 0.13 the performance of Ni/GDC shows severe degradation, while the Au-Mo-Ni/GDC anode has the best and most stable electrocatalytic behavior. Finally, the effect of the electrocatalyst`s loading on the sulfur tolerance is also investigated.
Lifetime and Performance Prediction of SOFC Anodes Operated with Trace Amounts of Hydrogen Sulfide
Authors: Riegraf Matthias , Schiller Guenter , Costa Rémi , Friedrich K. Andreas , Latz Arnulf , Yurkiv Vitaliy
Published: July 2015

An elementary kinetic model is developed to predict the influence of sulfur on Ni/YSZ anodes of solid oxide fuel cells (SOFC) performance. A multi-step reaction mechanism describing the formation and oxidation of sulfur on the Ni surface is coupled with gas transport in the channel and porous phase, and charge-transfer processes. A thermodynamic and kinetic data set of sulfur formation and oxidation is derived based upon various literature sources including a coverage-dependent description of the enthalpy of surface-adsorbed sulfur. The validity of the model is demonstrated on two SOFC operation modes, namely H2/H2O/H2S and CH4/H2/H2O/H2S fuel mixtures, at different operating conditions using various electrochemical literature experiments. The first concern is the influence of adsorbed sulfur on charge-transfer processes and the second concern is the effect of adsorbed sulfur on complex methane reforming chemistry. The results reveal that sulfur surface coverage increases with current density demonstrating a low sulfur oxidation rate.
Impedance Study of Anodic Properties of Ni-Fe Impregnated SDC
Authors: Itagaki Yoshiteru , Takemasa Tomohisa , Yamaguchi Syuhei , Yahiro Hidenori
Published: July 2015

Bimetallic Ni1-xFex/SDC powders containing 20wt% Ni-Fe were prepared and their anodic properties for SOFC were evaluated. The impedance spectra of the Ni1-xFex/SDC anodes at 800oC consisted of the ohmic component, R
ohmic, and depressed arcs, R
HF and R
LF. The R
ohmic component was due to the solid electrolyte layer, (ScO1.5)0.18(CeO2)0.01(ZrO2)0.81. The R
HF component was significantly reduced by the Fe addition, but apparent dependence was not observed for the R
LF component. The x=0.5 composition possessed the small R
HF and R
LF values. Accordingly, the single cell performance at 800oC was the maximum at x=0.5, and that was in the order of x=0.5 ~ 0.2 > 0.8 ~ 0 >1.0. The mean crystallite size of Ni-Fe alloy increased approximately in this order. Therefore, we obtained conclusion that the Fe addition to Ni would decrease the particle size of Ni-Fe alloy, resulting in the enhancement of the catalytic activity of Ni1-xFex/SDC anode.
La, Y and Nb Doped SrTiO3 Anodes for Electrolyte Supported SOFC
Authors: Tiwari Pankaj Kr , Basu Suddhasatwa
Published: July 2015

Single and bi-doped materials, viz. La, Y and Nb, present at both A and B sites of SrTiO3 have been synthesized and tested as anode material in electrolyte supported SOFC. The cell performance of bi-doped anode material e.g., L0.4Y0.2Sr0.4TiO3 (LYST) and La0.4Sr0.6Ti0.9Nb0.1O3 (LSTN) found to be higher than single-doped anode e.g., La0.4Sr0.6TiO3 (LST) and SrTi0.9Nb0.1O3 (STN). 20 wt % Ni-YSZ addition to LYST and LSTN increased the cell performance from 23 mW/cm2 to 77 mW/cm2 and 25 mW/cm2 to 38 mW/cm2, respectively. LYST-Ni-YSZ anode gave the maximum power density 70 mW/cm2, which is stable for 60 h of operation. Physical characterizations e.g., SEM, XRD and TEM of anode materials were investigated to correlate performance of different anodes.
Development of Robust SOFC Anode Materials Using La-Doped SrTiO3
Authors: Shen Xuesong , Sasaki Kazunari
Published: July 2015

We utilized stable Sr0.9La0.1TiO3 (SLT) with Ce0.9Gd0.1O2 (GDC) and (Sc2O3)0.1(CeO2)0.01(ZrO2)0.89 (SSZ) to fabricate robust anode for SSZ electrolyte-supported SOFC single cell. The anode consisted of three layers: a layer of 60wt% GDC-SLT or 40wt% SSZ-SLT as a functional layer and two layers of SLT as current conducting layers. Cathode was composed of a layer of 50wt% SSZ-LSM as a functional layer and a layer of LSM as a current conducting layer. Impregnation method has been employed to decorate nano-sized Ni and CeO2 into the ceramic anode. We measured electrochemical properties of single cells in 3%-humidified H2 at 800°C, and investigated long-term redox stability of the nano-sized catalyst impregnated ceramic anodes by fuel interruption method.
Coking-Resistance and Sulfur-Tolerance Study of La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ Anode
Authors: Han Minfang , Xu Na , Yang Zhibin , Zhu Tenglong
Published: July 2015

Coking-resistance and sulfur-tolerance study in Solid Oxide Fuel Cell (SOFC) were conducted using La0.4Sr0.6Co0.2Fe0.7Nb0.1O3-δ (LSCFN) anode with La0.8Sr0.2Ga0.83Mg0.17O3-δ (LSGM) electrolyte. Results show that LSCFN exhibited high catalytic activity in methane combustion reaction, the total conversion temperature of 1% CH4 using LSCFN as catalyst was as low as 650 oC. At 850 oC, the maximum power density of LSCFN||LSGM||Ba0.9Co0.7Fe0.2Nb0.1O3-δ (BCFN) single cell was 693 mW cm-2 and 212 mW cm-2 under H2 and CH4, respectively. Long-term operation of such single cell under methane lasted for 120 hours without degradation. The output power density fueled with H2-50 ppm H2S was stable enough in 120 hours’ operation which indicated a good sulfur-tolerant performance. LSCFN is a promising anode material for SOFC due to its coking-resistant and sulfur-tolerant properties.
Evaluation of a Novel Perovskite-Based Conversion Coating for Corrosion Protection of 13Cr Ferritic Stainless Steels under Relevant SOFC Oxidizing Conditions
Authors: Masi Andrea , Frangini Stefano , Carlini Maurizio , Masci Amedeo , McPhail Stephen J.
Published: July 2015

Low Cr stainless steels could represent a cost-effective alternative to high Cr alloys for use as metallic interconnects at the lower end range of Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs). Main drawback is represented by their insufficient long-term corrosion resistance, requiring suitable corrosion protection methods to avoid both electrical contact and chrome evaporation related issues. In this work, the stability of a perovskite conversion coating applied onto a commercial 13Cr ferritic stainless steel has been evaluated during prolonged exposure at 700°C in static air atmosphere. The passivation layer was produced with a molten carbonate bath treatment that resulted in the formation of a thin-film passive layer prevalently consisting of a LaFeO3 perovskite oxide. Surface morphology and structure of the perovskite-based passive layer remained almost unchanged during 400 hour oxidation exposure showing thus a promising corrosion protection ability in IT-SOFC oxidizing environments.
Interdiffusion and Charge Transport Across Surface-Modified Current Collectors in Planar SOFCs
Authors: Demeneva Nataliya , Matveev Danila , Kharton Vladislav , Bredikhin Sergey
Published: July 2015

Current collectors are a key component of planar SOFCs, separating air and fuel supplied onto the electrodes and connecting the cells in series. One of main challenges in the SOFC technology developments is to suppress degradation processes, often associated with the interconnect materials, and to provide low contact resistivity in oxidizing atmospheres. The present work is focused on the studies of near-surface interdiffusion phenomena in Crofer 22 APU ferritic steel interconnects with Ni-based protective layers. Particular emphasis was centered on the area-specific resistance (ASR) between the current collectors and La0.8Sr0.2MnO3 (LSM) cathodes, which exhibits time dependencies governed by the protective interlayer composition and interface microstructure alterations. The ASR changes, tested during over 30,000 hours at atmospheric oxygen pressure, can be described in terms of a model assuming that the current across the interconnector | LSM interface is essentially controlled by electron transfer via the interfacial Schottky barrier. The experimental observations validate this approach, explaining the junction resistivity and Schottky barrier height variations as a result of metal interdiffusion between the current collector and Ni-based protective coating.
Electrochemical Performance of Plasma Sprayed Metal Supported Planar Solid Oxide Fuel Cells
Authors: Gupta Mohit , Weber André , Markocsan Nicolaie , Gindrat Malko
Published: July 2015

High production cost is one of the major barriers to widespread commercialization of solid oxide fuel cells (SOFCs). Thermal spray techniques are a low cost alternative for the production of SOFCs. The objective of this work was to evaluate the electrochemical performance of half-cells produced by plasma spraying. The anode was deposited on a porous metallic support by atmospheric plasma spraying (APS) whereas the electrolyte was deposited by plasma spray-thin film (PS-TF) technique which can produce thin and dense coatings at high deposition rates. The cathode was deposited by screen-printing. The electrochemical tests were performed at 650-800°C. Current-voltage characteristics and impedance spectra were measured and analyzed. The impact of electrolyte composition and layer thickness on the gas tightness of the electrolyte and the area specific resistance of the cell is discussed. The results show that the applied thermal spraying techniques are a potential alternative for producing SOFCs.
Ni-Mo Porous Alloy Fabricated as Supporting Component for Metal-Supported Solid Oxide Fuel Cell and Cell Performance
Authors: Yang Sheng-Fu , Chuang Shie Zong Yang , Hwang Chang-Sing , Tsai Chun-Huang , Chang Chun-Liang , Huang Te-Jung , Lee Ruey-Yi
Published: July 2015

In this study, a continuous manufacturing process including spray drying, compression molding and sintering steps is developed and constructed to produce molybdenum (Mo)-containing nickel (Ni)-based porous alloy as a supporting component for metal-supported solid oxide fuel cell (SOFC). The porous interconnected networks of Ni-Mo alloy are made of introducing pyrolyzable filler during fabrication processes. The particle size distribution analysis results showed d50 of starting material (E.g., Ni, Mo, pyrolyzable filler and binder) after spray drying is 40.7 um. A compression load of 35 ton is applied to form a specimen with size of 60×60×1.2 mm and then sintered at 1200°C to obtain porous alloy. The anode (Ce0.55La0.45O2-
δ -NiO, LDC-NiO), electrolyte (La0.8Sr0.2Ga0.8Mg0.2O3-δ, LSGM) and cathode (Sm0.5Sr0.5CoO3-
δ, SSC) is coated by using an atmospheric plasma spraying (APS) technique. The active electrode area of the cell is 16cm2
and the open circuit voltage (OCV) is higher than 1.0 V under cell performance testing from 600 to 750 °C, indicating that a fully dense layer of LSGM electrolyte is successfully fabricated via APS coating process. The measured maximum output power densities (@0.6V) of this cell have reached 1196, 1012, 716 and 415 mW/cm2 at 750, 700, 650 and 600 °C respectively, by employing H2 as fuel and air as oxidant.
Development of a Novel Co-fired SOFC at Murata
Authors: Mori Naoya , Sato Yosuke , Nakai Hideaki , Iha Michiaki , Takada Takahiro , Konoike Takehiro
Published: July 2015

Murata Manufacturing Co., Ltd. has been developing planar type solid oxide fuel cells (SOFCs) based on a new design concept. The cell is fabricated by a single-step co-firing process (1). In this study, we report the results of a new type of cell with an improved cooling ability to remove heat of the electrochemical reactions. By arranging the gas manifolds in the central line of the cell, the temperature distribution in the plane of the cell was moderated while keeping a high volume power density. As a result, the stack operated stably and achieved a high power efficiency. A long-term operation has been carried out at 750ºC over 8000 h under galvanostatic conditions. The cell power degradation rate was less than 0.20 %/kh after 2000 h operation. Cr-poisoning in the LSCF cathode after the durability test was not observed, which led to the high durability of the cell.
Development of Electrolyte Supported Cells Based on a Thin 3YSZ Substrate: Through Optimized Contact Layer to High Power Density
Authors: Trofimenko Nikolai , Kusnezoff Mihails , Klemm Denis , Schimanke Danilo
Published: July 2015

Development and progress in manufacturing of high power density electrolyte supported cell based on a thin (50 µm) 3YSZ substrate is presented. The cells with improved cathode based on LSMM’/ScSZ and the multilayer anode based on Ni/GDC cermet show very good electrochemical performance. The maximum power density increases up to 750 mW/cm2 at 0.7V@860 °C for developed cell without additional contact layer and is greater than one of the commercial cells based on partially scandia stabilized zirconia electrolytes as well as 95µm 3YSZ. The changes in polarization resistance of tested cells under different operating conditions as well as during redox-cycling and durability tests were performed and are discussed on basis of analysis of impedance spectra. The developed cells show a good long-term stability (proved for >1300 h) under high current density (500mA/cm²@850°C, N2:H2:H2O=55:40:5, air). The estimated power degradation rate is below 0.5%/1000 h.
A Parametric Study of SOFC Performances with Multi-Stage Electrochemical Oxidation for Enhancement of Electric Efficiency
Authors: Matsuzaki Yoshio , Tachikawa Yuya , Hatae Toru , Matsumoto Hiroshige , Taniguchi Shunsuke , Sasaki Kazunari
Published: July 2015

The solid-state ceramic construction of SOFCs enables high fuel to electricity conversion efficiencies of as high as 50 to 60 percent LHV in high temperature operation, and allows more flexibility in fuel choice. In this study, we have developed a symbolic analysis method to investigate the availability of variable parameters appeared in multi-stage electrochemical oxidation mechanism that is expected to further improve the electric efficiencies of SOFCs. In the flow system of the multi-stage oxidation, the fuel utilization, Uf, at the most downstream stack, Uf
M, is expressed as a function of number of stacks, n, and total fuel utilization, Uf
T. When n = 10 and Uf
T = 85%, Uf
M is calculated to be 36%, which is much smaller than Uf
T. Therefore, if the most downstream stack has high robustness against lean fuel gas, Uf
T could be set to be higher values without serious degradation by using this flow system.
A Simple Pressurized SOFC Test Rig for Measurements of Cell Performance, Impedance, and Various Overvoltages
Authors: Liang Jyun-De , Hong Li-han , Wu P. C. , Shy Shenqyang Steven
Published: July 2015

This paper reports a newly designed high-pressure full button cell test platform for measurements of various effects on pressurized solid oxide fuel cells (PSOFC). The testing platform has several parts, from inside out including a specially thread-designed housing carrier for the full button cell, a serpentine heating pipe system for uniform heating of the supplied fuel and air gases, a temperature-controlled furnace, and a large high-pressure vessel together with measuring devices and their associates. Hence, current-voltage curves and AC impedance spectra of any full/half button cells can be conveniently measured. In this study, we present power-generating characteristics and electrochemical impedance spectra (EIS) data of an anode-supported full button cell over a range of pressure (p = 1~5 atm) at a temperature T = 800 oC. Results show that power densities increase with increasing p at any given current densities. These results are explained by the corresponding EIS data. In addition to the aforesaid power-generating characteristics and EIS results, this study also presents analyses of activation and concentration overvoltages using the Butler-Volmer equation and the related concentration overvoltage equation based on a 1D diffusion model. These overvoltage results will be compared with previous numerical and experimental data to enhance our understanding of the effect of pressurization on the polarization mechanisms in SOFCs.
Durability Assessment of SOFC Stacks with Several Types of Structures for Thermal Cycles during Their Lifetimes on Residential Use
Authors: Hatae Toru , Sato Koki , Somekawa Takaaki , Matsuzaki Yoshio , Amaha Shinji , Yoshikawa Masahiro , Mugikura Yoshihiro , Miyara Kengo , Oshima Toshihiro , Taniguchi Shunsuke , Sasaki Kazunari , Shimazu Megumi , Takahashi Yuya , Kawakami Akira , Mori Naoya , Yokokawa Harumi
Published: July 2015

We have been developing a rapid evaluation method for durability of SOFC stacks for thermal cycles during their lifetimes based on the assumption of residential use. The durability for thermal cycles is expected to be affected by the degradation during their long-term operation. In order to accelerate the evaluation, some treatments to intentionally cause the degradation were investigated. A degradation factor was determined depending on the SOFC stacks with different structures respectively because each degradation mechanism during their long-term operation also depends on them. The SOFC stacks were supplied by four SOFC stack manufactures in Japan. In this work, we investigated the Cr poisoning treatment to tubular SOFC (TOTO) and the S poisoning treatment to single step co-fired planar SOFC (Murata Manufacturing). As results of both cases, 10 years’ worth of degradation was successful to be intentionally caused in short period.
Investigation of 2R-Cell Degradation under Thermal Cycling and RedOx Cycling Conditions by Electrochemical Impedance Spectroscopy
Authors: Diethelm Stefan , Singh Vaibhav , Van herle Jan
Published: July 2015

A 2R-cell with a 10cm2 active area LSCF cathode on a CGO buffer layer, was tested at 780°C under thermal and RedOx cycling conditions: 20 thermal cycles were performed between 780 and 100°C, using 200°C/h heating ramps and natural cooling, followed by 20 RedOx cycles, during which air was fed to the anode for 1 hour at 780°C, causing the cell potential to drop to zero. V-i polarisation curves and electrochemical impedance spectroscopy (EIS) measurements were performed before and after each consecutive cycle in order to monitor the performance losses. The OCV remained stable during the whole test whereas the area specific resistance (ASR) measured at 0.5 A/cm2 increased by +1.3 mΩcm2 per thermal cycle and by +1.8 mΩcm2 per redox cycle. The cell was examined after the test by scanning electron microscopy (SEM).
A review of recent developments and applications of morphometry/stereology in lung research
Authors: Mühlfeld Christian , Hegermann Jan , Wrede Christoph , Ochs Matthias
Published: July 2015

Design-based stereology is the gold standard of morphometry in lung research. Here, we analyze the current use of morphometric and stereological methods in lung research and provide an overview on recent methodological developments and biological observations made by the use of stereology. Based on this analysis we hope to provide useful recommendations for a good stereological practice to further the use of advanced and unbiased stereological methods.
The HO-1/CO system regulates mitochondrial-capillary density relationships in human skeletal muscle
Authors: Pecorella Shelly R. H. , Potter Jennifer V. F. , Cherry Anne D. , Peacher Dionne F. , Welty-Wolf Karen E. , Moon Richard E. , Piantadosi Claude A. , Suliman Hagir B.
Published: July 2015

The heme oxygenase-1 (HO-1)/carbon monoxide (CO) system induces mitochondrial biogenesis, but its biological impact in human skeletal muscle is uncertain. The enzyme system generates CO, which stimulates mitochondrial proliferation in normal muscle. Here we examined whether CO breathing can be used to produce a coordinated metabolic and vascular response in human skeletal muscle. In 19 healthy subjects, we performed vastus lateralis muscle biopsies and tested one-legged maximal O2uptake (V̇o2max) before and after breathing air or CO (200 ppm) for 1 h daily for 5 days. In response to CO, there was robust HO-1 induction along with increased mRNA levels for nuclear-encoded mitochondrial transcription factor A (Tfam), cytochrome c, cytochrome oxidase subunit IV (COX IV), and mitochondrial-encoded COX I and NADH dehydrogenase subunit 1 (NDI). CO breathing did not increase V̇o2max(1.96 ± 0.51 pre-CO, 1.87 ± 0.50 post-CO l/min; P = not significant) but did increase muscle citrate synthase, mitochondrial density (139.0 ± 34.9 pre-CO, 219.0 ± 36.2 post-CO; no. of mitochondrial profiles/field), myoglobin content and glucose transporter (GLUT4) protein level and led to GLUT4 localization to the myocyte membrane, all consistent with expansion of the tissue O2transport system. These responses were attended by increased cluster of differentiation 31 (CD31)-positive muscle capillaries (1.78 ± 0.16 pre-CO, 2.37 ± 0.59 post-CO; capillaries/muscle fiber), implying the enrichment of microvascular O2reserve. The findings support that induction of the HO-1/CO system by CO not only improves muscle mitochondrial density, but regulates myoglobin content, GLUT4 localization, and capillarity in accordance with current concepts of skeletal muscle plasticity.
Indirect Inverse Substructuring Method for Multibody Product Transport System with Rigid and Flexible Coupling
Authors: Wang Jun , Lu Li-xin , Qian Pengjiang , Huang Li-qiang , Hua Yan , Pu Guang-yi
Published: July 2015

The aim of this paper is to develop a new frequency response function- (FRF-) based indirect inverse substructuring method without measuring system-level FRFs in the coupling DOFs for the analysis of the dynamic characteristics of a three-substructure coupled product transport system with rigid and flexible coupling. By enforcing the dynamic equilibrium conditions at the coupling coordinates and the displacement compatibility conditions, a closed-form analytical solution to inverse substructuring analysis of multisubstructure coupled product transport system is derived based on the relationship of easy-to-monitor component-level FRFs and the system-level FRFs at the coupling coordinates. The proposed method is validated by a lumped mass-spring-damper model, and the predicted coupling dynamic stiffness is compared with the direct computation, showing exact agreement. The method developed offers an approach to predict the unknown coupling dynamic stiffness from measured FRFs purely. The suggested method may help to obtain the main controlling factors and contributions from the various structure-borne paths for product transport system.