WorldWideScience

Sample records for solid cell nests

  1. Solid cell nests of the thyroid gland: morphological, immunohistochemical and genetic features.

    Science.gov (United States)

    Manzoni, Marco; Roversi, Gaia; Di Bella, Camillo; Pincelli, Angela I; Cimino, Vincenzo; Perotti, Mario; Garancini, Mattia; Pagni, Fabio

    2016-05-01

    The correct identification of solid cell nests (SCNs) is an important issue in thyroid pathology because of the spectrum of differential diagnoses of this type of lesion. Ten cases of 295 consecutive thyroidectomies showed the presence of SCNs at histological examination. The identification of the exact SCN type required the distinction of the cystic and solid pattern; SCNs were usually composed of a mixture of main cells (MCs) and C-cells (CCs). The immunohistochemical calcitonin stain identified CCs easily, both inside SCNs and dispersed in islets at the periphery. For the characterization of MCs, we added the utility of p40 to p63. The use of thyroid transcription factor-1 (TTF-1) helped in their identification, as MCs did not react with this marker; the combination of TTF-1 and p40 or p63 IHC stains was useful for the characterization of cystic SCNs of both types 3 and 4. The negativity of mouse monoclonal mesothelioma antibody (HMBE-1) and a very low proliferative index (MIB-1) supported the diagnosis. [Correction added on 23 November 2015, after online publication: MIB-1 was incorrectly defined, the expanded form was deleted.] We discourage the use of galectin-3 (Gal-3) and cytokeratin-19 (CK-19), as they have an important overlap with papillary thyroid carcinoma. The complete absence of any B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutations is an additional fundamental finding. We reviewed the most relevant morphological and immunohistochemical features of SCNs and have provided a genetic analysis of the BRAF gene because of its expanding use in thyroid pathology. © 2015 John Wiley & Sons Ltd.

  2. A carcinoma showing thymus-like elements of the thyroid arising in close association with solid cell nests: evidence for a precursor lesion?

    Science.gov (United States)

    Yerly, Stéphane; Lobrinus, Johannes-Alexander; Bongiovanni, Massimo; Becker, Minerva; Zare, Maryam; Granger, Perrine; Pusztaszeri, Marc

    2013-04-01

    Carcinoma showing thymus-like elements (CASTLE) is a rare malignant neoplasm of the thyroid gland, morphologically and immunohistologically similar to a thymic carcinoma, whose histogenesis is still debated. Hypotheses include an origin from ectopic thymic tissue, vestige of the thymopharyngeal duct, or branchial pouch remnants from which solid cell nests (SC-nests) originate. The diagnosis of CASTLE may be treacherous due to its rarity and its propensity to mimic other poorly differentiated tumors such as squamous cell carcinoma. We present a case of CASTLE in a 58-year-old man initially diagnosed as a poorly differentiated squamous cell carcinoma both on fine-needle aspiration cytology (FNAC) and on biopsy, arising in close association with SC-nests. A thorough literature review, with special emphasis on its diagnosis and histogenesis of CASTLE, was also conducted. Magnetic resonance images revealed a 4.0-cm cervical mass on the left side of the trachea, involving the lateral middle/inferior portion of the left lobe of the thyroid gland. FNAC was performed with a diagnosis of "malignant cells, consistent with squamous cell carcinoma." A histological evaluation of the resected specimen revealed a malignant proliferation of cells, focally exhibiting a squamoid appearance, which were immunopositive for CD5 and p63. A diagnosis of CASTLE was made. The tumor was located in direct continuity with SC-Nests, and the cell morphology of both the SC-nests and CASTLE was very similar with merging. Moreover, the immunohistochemical expression profiles of most markers useful in the diagnosis of CASTLE were identical in the SC-nests. The inclusion of CASTLE in the differential diagnosis of poorly differentiated tumors of the thyroid region and the use of ancillary studies are essential to diagnose this rare entity associated with a relatively favorable prognosis. The close association of CASTLE with SC-nests opens the way to a new scenario for studies of its histogenesis.

  3. Solid-phase nested deletion: a new subcloning-less method for generating nested deletions.

    Science.gov (United States)

    Yohda, M; Kato, N; Endo, I

    1995-08-31

    We have developed a new subcloning-less method for generating nested deletions which we have termed Solid-Phase Nested Deletion. The basic procedure for this method is as follows. The target DNA fragment is cloned in the multiple cloning site of a cloning vector, pUC or its derivatives, and amplified by PCR using a set of primers, one of which is 5'-biotinylated. The amplified DNA is partially digested by a restriction enzyme with a 4-base recognition sequence. The digested DNA is ligated with a synthetic adapter DNA. Monodiverse beads coupled with streptavidin (Dynabeads M-280 streptavidin) are added to the mixture and the biotinylated DNA fragments are separated by applying magnetic field. The unidirectionally deleted DNA fragments are recovered by PCR from the magnetic beads, and size-fractionated by agarose gel electrophoresis. The DNA fragments are amplified by PCR and used for sequencing. We demonstrate the potential of this method using a 4878-bp EcoRI fragment of lambda phage DNA.

  4. Thin Solid Oxide Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material, at least one metal and a catalyst...... material, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same. The present invention also relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous...... cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material and a catalyst material, wherein the electrolyte material is doper zirconia, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same...

  5. Solid Oxide Fuel Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The solid oxide fuel cell comprising a metallic support material, an active anode layer consisting of a good hydrocarbon cracking catalyst, an electrolyte layer, an active cathode layer, and a transition layer consisting of preferably a mixture of LSM and a ferrite to the cathode current collector...

  6. Solid Oxide Electrolyser Cell

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard

    Solid oxide fuel cells (SOFCs) produced at Risø National Laboratory was tested as steam electrolysers under various current densities, operating temperatures and steam partial pressures. At 950 °C and a cell voltage of 1.48V the current density was -3.6A/cm2 with app. 30% H2 + 70% H2O in the inlet...... it is possible to achieve a production price of 0.7 US$/kg H2 with an electricity price of 1.3 US¢/kWh. The cell voltage was measured as function of time. In test ofabout two month of duration a long-term degradation was observed. At 850 °C, -0.5 A/cm2 with 50 vol% H2 the degradation rate was app. 20 mV/1000h...

  7. Solid oxide electrolyser cell

    Energy Technology Data Exchange (ETDEWEB)

    Hoejgaard Jensen, S.

    2006-12-15

    Solid oxide fuel cells (SOFCs) produced at Riso National Laboratory was tested as steam electrolysers under various current densities, operating temperatures and steam partial pressures. At 950 deg. C and a cell voltage of 1.48V the current density was -3.6 A/cm{sup 2} with app. 30% H{sub 2} + 70% H{sub 2}O in the inlet gas and a H{sub 2}O utilization of app. 40%. The tested SOECs were also used for CO{sub 2} electrolysis. Economy studies of CO and H2 production show that especially H{sub 2} production can be competitive in areas with cheap electricity. Assuming the above described initial performance and a lifetime of 10 years it is possible to achieve a production price of 0.7 US dollar/kg H{sub 2} with an electricity price of 1.3 US cent/kWh. The cell voltage was measured as function of time. In test of about two month of duration a long-term degradation was observed. At 850 deg. C, -0.5 A/cm{sup 2} with 50 vol% H{sub 2} the degradation rate was app. 20 mV/1000h. It was shown that the degradation happens at Ni/YSZ-electrode. The long term degradation is probably caused by coarsening of the Ni-particles. After onset of electrolysis operation a transient passivation/reactivation phenomena with duration of several days was observed. It was shown that the phenomenon is attributed to the SiO{sub 2} contamination at the Ni/YSZ electrode-electrolyte interface. The SiO{sub 2} arises from the albite glass sealing (NaAlSi{sub 3}O{sub 8}) that surrounds the electrode. Si may enter the Ni/YSZ electrode via the reaction Si(OH){sub 4}(g) {r_reversible} SiO{sub 2}(l)+H{sub 2}O(g). At the active sites of the Ni/YSZ electrode steam is reduced via the reaction H{sub 2}O - 2e {yields} H{sub 2}+O{sup 2-} . This shifts the equilibrium of the first reaction to form SiO{sub 2}(l) at the active sites. After a certain time the sealing crystallizes and the SiO{sub 2}(l) evaporates from the active sites and the cell reactivates. The passivation is shown to relate to a build up of a

  8. Solid Oxide Fuel Cell Experimental Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Solid Oxide Fuel Cell Experimental Laboratory in Morgantown, WV, gives researchers access to models and simulations that predict how solid oxide fuel cells...

  9. High temperature solid state storage cell

    Science.gov (United States)

    Rea, Jesse R.; Kallianidis, Milton; Kelsey, G. Stephen

    1983-01-01

    A completely solid state high temperature storage cell comprised of a solid rechargeable cathode such as TiS.sub.2, a solid electrolyte which remains solid at the high temperature operating conditions of the cell and which exhibits high ionic conductivity at such elevated temperatures such as an electrolyte comprised of lithium iodide, and a solid lithium or other alkali metal alloy anode (such as a lithium-silicon alloy) with 5-50% by weight of said anode being comprised of said solid electrolyte.

  10. Gas transport in solid oxide fuel cells

    CERN Document Server

    He, Weidong; Dickerson, James

    2014-01-01

    This book provides a comprehensive overview of contemporary research and emerging measurement technologies associated with gas transport in solid oxide fuel cells. Within these pages, an introduction to the concept of gas diffusion in solid oxide fuel cells is presented. This book also discusses the history and underlying fundamental mechanisms of gas diffusion in solid oxide fuel cells, general theoretical mathematical models for gas diffusion, and traditional and advanced techniques for gas diffusivity measurement.

  11. Composite Solid Electrolyte For Lithium Cells

    Science.gov (United States)

    Peled, Emmanuel; Nagasubramanian, Ganesan; Halpert, Gerald; Attia, Alan I.

    1994-01-01

    Composite solid electrolyte material consists of very small particles, each coated with thin layer of Lil, bonded together with polymer electrolyte or other organic binder. Material offers significant advantages over other solid electrolytes in lithium cells and batteries. Features include high ionic conductivity and strength. Composite solid electrolyte expected to exhibit flexibility of polymeric electrolytes. Polymer in composite solid electrolyte serves two purposes: used as binder alone, conduction taking place only in AI2O3 particles coated with solid Lil; or used as both binder and polymeric electrolyte, providing ionic conductivity between solid particles that it binds together.

  12. Snail promotes Cyr61 secretion to prime collective cell migration and form invasive tumor nests in squamous cell carcinoma.

    Science.gov (United States)

    Tanaka, Fumi; Rizqiawan, Andra; Higashikawa, Koichiro; Tobiume, Kei; Okui, Gaku; Shigeishi, Hideo; Ono, Shigehiro; Shimasue, Hiroshi; Kamata, Nobuyuki

    2013-02-28

    We previously identified genes associated with Snail-mediated squamous cell carcinoma (SCC) invasiveness, in which we observed significant elevation of Cyr61 expression. In this study, SCC cell lines overexpressing Cyr61 exhibited constitutive activation of Rho A and upregulated invasiveness without the disruption of homophilic cell attachment. Humoral Cyr61 enhanced further production of endogenous Cyr61 by SCC cells, which stimulated collective cell migration and the development of an invasive tumor nest. We propose a Cyr61-dependent model for the development of invasive SCC nest, whereby a subset of tumor cells that highly produce Cyr61 may direct other tumor cells to undergo collective cell migration, resulting in a formation of primary SCC mass. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  13. Solid polymer MEMS-based fuel cells

    Science.gov (United States)

    Jankowski, Alan F [Livermore, CA; Morse, Jeffrey D [Pleasant Hill, CA

    2008-04-22

    A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

  14. Durable and Robust Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Knibbe, Ruth; Hauch, Anne

    The solid oxide fuel cell (SOFC) is an attractive technology for the generation of electricity with high efficiency and low emissions. Risø DTU (now DTU Energy Conversion) works closely together with Topsoe Fuel Cell A/S in their effort to bring competitive SOFC systems to the market. This 2-year...

  15. Ni-Based Solid Oxide Cell Electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Holtappels, Peter

    2013-01-01

    This paper is a critical review of the literature on nickel-based electrodes for application in solid oxide cells at temperature from 500 to 1000 _C. The applications may be fuel cells or electrolyser cells. The reviewed literature is that of experimental results on both model electrodes...... and practical composite cermet electrodes. A substantially longer three-phase boundary (TPB) can be obtained per unit area of cell in such a composite of nickel and electrolyte material, provided that two interwoven solid networks of the two solid and one gaseous phases are obtained to provide a three...... such as milling and sintering. The various electrode properties are deeply related to these parameters, but also much related to the atomic scale structure of the Ni-electrolyte interface, which in turn is affected by segregation of electrolyte components and impurities as well as poisons in the gas phase...

  16. Durability of Solid Oxide Cells

    DEFF Research Database (Denmark)

    Knibbe, Ruth; Hauch, Anne; Hjelm, Johan

    2011-01-01

    that not all degradation mechanisms are fully understood. Traditionally, cell degradation has been attributed to the materials, processing and cell operating conditions. More recently, focus has been placed on the effect of raw material and gas impurities and their long-term effect on cell degradation. Minor...... impurities have been found to play a significant role in degradation and in some cases can overshadow the cell operation condition related degradation phenomenon. In this review, several degradation diagnostic tools are discussed, a benchmark for a desirable degradation rate is proposed and degradation...

  17. Detection of circulating tumor cells by nested RT-PCR targeting ...

    African Journals Online (AJOL)

    Salwa H. Teama

    We used nested RT-PCR-based reverse transcription PCR assay for the detection of circu- lating cancer cells in the peripheral blood. Results: The blood samples from the colon cancer patients showed detection of EGFR in 15/36 patients (41.7%); CEAmRNA in 22/36 patients (61.1%) and CK20mRNA in 24/36 patients.

  18. Solid Acid Based Fuel Cells

    National Research Council Canada - National Science Library

    Haile, Sossina M

    2005-01-01

    ...) without pressurization. In this configuration, the thin-film fuel cell is supported on a porous stainless steel gas diffusion layer and the electrocatalyst and electrolyte layers are spray-deposited...

  19. Modular solid-state detector cell

    International Nuclear Information System (INIS)

    Hoffman, D.M.; Ehlert, R.C.; Loomis, N.W.; Shelley, P.S.

    1983-01-01

    A modular solid-state detector cell is disclosed which intimately associates a scintillator body with a pair of photoresponsive semiconductors so as to present on a single collimator plate all of the elements necessary for transforming incident X-radiation into a measurable electrical signal. The detector is provided with a precision slotted mounting arrangement for receiving the unit cells, and the cells when positioned within the detector assembly have the photoresponsive semiconductors enclosed within the light tight cell. The unit is adaptable to off-line testing of the separate cells for screening before assembly

  20. Solid polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Giorgi, L.; Pozio, A.

    1995-05-01

    The report summarizes the state of art of systems for energy production in electrical vehicles, looking into the general characteristics of electrodes and membranes. The water and thermal balance of the cell in relation to operative conditions, the pressure and temperature influence on the performance are examined. Special emphasis is given to the electrode characteristics-fabrication techniques and assembly of membrane electrodes. The problems related to the oxygen reduction kinetics at the cathode are examined, in relation to the fabrication techniques and to operative conditions of the cells. Finally, the possible alternative catalyzers for anode and cathode are reviewed

  1. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; John Noetzel; Larry Chick

    2003-12-08

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from January 1, 2003 to June 30, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; and Task 9 Stack Testing with Coal-Based Reformate.

  2. Interconnection of bundled solid oxide fuel cells

    Science.gov (United States)

    Brown, Michael; Bessette, II, Norman F; Litka, Anthony F; Schmidt, Douglas S

    2014-01-14

    A system and method for electrically interconnecting a plurality of fuel cells to provide dense packing of the fuel cells. Each one of the plurality of fuel cells has a plurality of discrete electrical connection points along an outer surface. Electrical connections are made directly between the discrete electrical connection points of adjacent fuel cells so that the fuel cells can be packed more densely. Fuel cells have at least one outer electrode and at least one discrete interconnection to an inner electrode, wherein the outer electrode is one of a cathode and and anode and wherein the inner electrode is the other of the cathode and the anode. In tubular solid oxide fuel cells the discrete electrical connection points are spaced along the length of the fuel cell.

  3. Mathematical modeling of solid oxide fuel cells

    Science.gov (United States)

    Lu, Cheng-Yi; Maloney, Thomas M.

    1988-01-01

    Development of predictive techniques, with regard to cell behavior, under various operating conditions is needed to improve cell performance, increase energy density, reduce manufacturing cost, and to broaden utilization of various fuels. Such technology would be especially beneficial for the solid oxide fuel cells (SOFC) at it early demonstration stage. The development of computer models to calculate the temperature, CD, reactant distributions in the tubular and monolithic SOFCs. Results indicate that problems of nonuniform heat generation and fuel gas depletion in the tubular cell module, and of size limitions in the monolithic (MOD 0) design may be encountered during FC operation.

  4. Exceptional Durability of Solid Oxide Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Mogensen, Mogens Bjerg

    2010-01-01

    Extensive efforts to resolve the degradation normally associated with solid oxide electrolysis cells (SOECs) have been conducted during the past decade. To date, the degradation is assumed to be caused by adsorption of impurities in the cathode, although no firm evidence for this degradation...

  5. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; Larry Chick

    2004-05-07

    The objective of this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from July 1, 2003 to December 31, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; Task 9 Stack Testing with Coal-Based Reformate; and Task 10 Technology Transfer from SECA CORE Technology Program. In this reporting period, unless otherwise noted Task 6--System Fabrication and Task 7--System Testing will be reported within Task 1 System Design and Integration. Task 8--Program Management, Task 9--Stack Testing with Coal Based Reformate, and Task 10--Technology Transfer from SECA CORE Technology Program will be reported on in the Executive Summary section of this report.

  6. Intermediate temperature solid oxide fuel cells.

    Science.gov (United States)

    Brett, Daniel J L; Atkinson, Alan; Brandon, Nigel P; Skinner, Stephen J

    2008-08-01

    High temperature solid oxide fuel cells (SOFCs), typified by developers such as Siemens Westinghouse and Rolls-Royce, operate in the temperature region of 850-1000 degrees C. For such systems, very high efficiencies can be achieved from integration with gas turbines for large-scale stationary applications. However, high temperature operation means that the components of the stack need to be predominantly ceramic and high temperature metal alloys are needed for many balance-of-plant components. For smaller scale applications, where integration with a heat engine is not appropriate, there is a trend to move to lower temperatures of operation, into the so-called intermediate temperature (IT) range of 500-750 degrees C. This expands the choice of materials and stack geometries that can be used, offering reduced system cost and, in principle, reducing the corrosion rate of stack and system components. This review introduces the IT-SOFC and explains the advantages of operation in this temperature regime. The main advances made in materials chemistry that have made IT operation possible are described and some of the engineering issues and the new opportunities that reduced temperature operation affords are discussed. This tutorial review examines the advances being made in materials and engineering that are allowing solid oxide fuel cells to operate at lower temperature. The challenges and advantages of operating in the so-called 'intermediate temperature' range of 500-750 degrees C are discussed and the opportunities for applications not traditionally associated with solid oxide fuel cells are highlighted. This article serves as an introduction for scientists and engineers interested in intermediate temperature solid oxide fuel cells and the challenges and opportunities of reduced temperature operation.

  7. Stability of solid oxide fuel cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.R.; Bates, J.L.; Chick, L.A. [Pacific Northwest Lab., Richland, WA (United States)

    1996-04-01

    Interconnection materials in a solid oxide fuel cell are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. The thermal expansion characteristics of substituted lanthanum and yttrium chromite interconnect materials were evaluated by dilatometry as a function of oxygen partial pressures from 1 atm to 10{sup -18} atm, controlled using a carbon dioxide/hydrogen buffer.

  8. Near-ambient solid polymer fuel cell

    Science.gov (United States)

    Holleck, G. L.

    1993-01-01

    Fuel cells are extremely attractive for extraterrestrial and terrestrial applications because of their high energy conversion efficiency without noise or environmental pollution. Among the various fuel cell systems the advanced polymer electrolyte membrane fuel cells based on sulfonated fluoropolymers (e.g., Nafion) are particularly attractive because they are fairly rugged, solid state, quite conductive, of good chemical and thermal stability and show good oxygen reduction kinetics due to the low specific adsorption of the electrolyte on the platinum catalyst. The objective of this program is to develop a solid polymer fuel cell which can efficiently operate at near ambient temperatures without ancillary components for humidification and/or pressurization of the fuel or oxidant gases. During the Phase 1 effort we fabricated novel integral electrode-membrane structures where the dispersed platinum catalyst is precipitated within the Nafion ionomer. This resulted in electrode-membrane units without interfacial barriers permitting unhindered water diffusion from cathode to anode. The integral electrode-membrane structures were tested as fuel cells operating on H2 and O2 or air at 1 to 2 atm and 10 to 50 C without gas humidification. We demonstrated that cells with completely dry membranes could be self started at room temperature and subsequently operated on dry gas for extended time. Typical room temperature low pressure operation with unoptimized electrodes yielded 100 mA/cm(exp 2) at 0.5V and maximum currents over 300 mA/cm(exp 2) with low platinum loadings. Our results clearly demonstrate that operation of proton exchange membrane fuel cells at ambient conditions is feasible. Optimization of the electrode-membrane structure is necessary to assess the full performance potential but we expect significant gains in weight and volume power density for the system. The reduced complexity will make fuel cells also attractive for smaller and portable power supplies and as

  9. Catalysis in solid oxide fuel cells.

    Science.gov (United States)

    Gorte, R J; Vohs, J M

    2011-01-01

    Solid oxide fuel cells (SOFCs) and solid oxide electrolyzers (SOEs) hold much promise as highly efficient devices for the direct interconversion of chemical and electrical energy. Commercial application of these devices, however, requires further improvements in their performance and stability. Because the performance of SOFC and SOE electrodes depends on their microstructures, electronic and ionic conductivities, and chemical reactivities, the needed improvements require the expertise of various disciplines, with catalytic science playing an important role. Highly active and thermally stable catalysts are required to limit the internal losses in the devices, increase the range of fuels they can use, and decrease the temperatures at which they operate. In this article we review some of the most important recent advances in catalysis for SOFC and SOE electrodes and highlight additional improvements that are needed.

  10. Advanced materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.; Stevenson, J.

    1995-12-31

    The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs.

  11. High power density solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Ai Quoc; Glass, Robert S.

    2004-10-12

    A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O (LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

  12. Solid oxide fuel cell with monolithic core

    Science.gov (United States)

    McPheeters, C.C.; Mrazek, F.C.

    1988-08-02

    A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700 C and 1,100 C. 8 figs.

  13. Solid Oxide Fuel Cell Systems PVL Line

    International Nuclear Information System (INIS)

    Shearer, Susan; Rush, Gregory

    2012-01-01

    In July 2010, Stark State College (SSC), received Grant DE-EE0003229 from the U.S. Department of Energy (DOE), Golden Field Office, for the development of the electrical and control systems, and mechanical commissioning of a unique 20kW scale high-pressure, high temperature, natural gas fueled Stack Block Test System (SBTS). SSC worked closely with subcontractor, Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) over a 13 month period to successfully complete the project activities. This system will be utilized by RRFCS for pre-commercial technology development and training of SSC student interns. In the longer term, when RRFCS is producing commercial products, SSC will utilize the equipment for workforce training. In addition to DOE Hydrogen, Fuel Cells, and Infrastructure Technologies program funding, RRFCS internal funds, funds from the state of Ohio, and funding from the DOE Solid State Energy Conversion Alliance (SECA) program have been utilized to design, develop and commission this equipment. Construction of the SBTS (mechanical components) was performed under a Grant from the State of Ohio through Ohio's Third Frontier program (Grant TECH 08-053). This Ohio program supported development of a system that uses natural gas as a fuel. Funding was provided under the Department of Energy (DOE) Solid-state Energy Conversion Alliance (SECA) program for modifications required to test on coal synthesis gas. The subject DOE program provided funding for the electrical build, control system development and mechanical commissioning. Performance testing, which includes electrical commissioning, was subsequently performed under the DOE SECA program. Rolls-Royce Fuel Cell Systems is developing a megawatt-scale solid oxide fuel cell (SOFC) stationary power generation system. This system, based on RRFCS proprietary technology, is fueled with natural gas, and operates at elevated pressure. A critical success factor for development of the full scale system is the capability to

  14. Intermediate Temperature Solid Oxide Fuel Cell Development

    Energy Technology Data Exchange (ETDEWEB)

    S. Elangovan; Scott Barnett; Sossina Haile

    2008-06-30

    Solid oxide fuel cells (SOFCs) are high efficiency energy conversion devices. Present materials set, using yttria stabilized zirconia (YSZ) electrolyte, limit the cell operating temperatures to 800 C or higher. It has become increasingly evident however that lowering the operating temperature would provide a more expeditious route to commercialization. The advantages of intermediate temperature (600 to 800 C) operation are related to both economic and materials issues. Lower operating temperature allows the use of low cost materials for the balance of plant and limits degradation arising from materials interactions. When the SOFC operating temperature is in the range of 600 to 700 C, it is also possible to partially reform hydrocarbon fuels within the stack providing additional system cost savings by reducing the air preheat heat-exchanger and blower size. The promise of Sr and Mg doped lanthanum gallate (LSGM) electrolyte materials, based on their high ionic conductivity and oxygen transference number at the intermediate temperature is well recognized. The focus of the present project was two-fold: (a) Identify a cell fabrication technique to achieve the benefits of lanthanum gallate material, and (b) Investigate alternative cathode materials that demonstrate low cathode polarization losses at the intermediate temperature. A porous matrix supported, thin film cell configuration was fabricated. The electrode material precursor was infiltrated into the porous matrix and the counter electrode was screen printed. Both anode and cathode infiltration produced high performance cells. Comparison of the two approaches showed that an infiltrated cathode cells may have advantages in high fuel utilization operations. Two new cathode materials were evaluated. Northwestern University investigated LSGM-ceria composite cathode while Caltech evaluated Ba-Sr-Co-Fe (BSCF) based pervoskite cathode. Both cathode materials showed lower polarization losses at temperatures as low as 600

  15. Interaction between the solitary bee Chelostoma florisomne and its nest parasite Sapyga clavicornis - empty cells reduce the impact of parasites

    DEFF Research Database (Denmark)

    Münster-Swendsen (deceased), Mikael; Calabuig, Isabel

    2000-01-01

    a cell closure. A cell closure does not prevent the nest parasite from oviposition inside the brood cell, however, and parasite eggs deposited through the cell closure are not detected and removed by the bee. Only an additional cell closure, i.e. the formation of an empty cell, may protect a brood cell...... without an anterior, empty cell; 27.4% of the empty cells contained dead parasite offspring (eggs and larvae). Thus, the empty cells provided significant protection and, combined with additional means of protection of brood cells, led to a low degree of parasitism. More than 77% of the wasp offspring died......Summary 1. Nesting behaviour and interactions between the bee Chelostoma florisomne (L.) (Megachilidae) and its nest parasite Sapyga clavicornis (L.) (Sapygidae) were studied through continual observations of individuals and dissections of bee nests. Protection of bee offspring is based on (1...

  16. Reviews on Solid Oxide Fuel Cell Technology

    Directory of Open Access Journals (Sweden)

    Apinan Soottitantawat

    2009-02-01

    Full Text Available Solid Oxide Fuel Cell (SOFC is one type of high temperature fuel cell that appears to be one of the most promising technology to provide the efficient and clean energy production for wide range of applications (from small units to large scale power plants. This paper reviews the current status and related researches on SOFC technologies. In details, the research trend for the development of SOFC components(i.e. anode, electrolyte, cathode, and interconnect are presented. Later, the current important designs of SOFC (i.e. Seal-less Tubular Design, Segmented Cell in Series Design, Monolithic Design and Flat Plate Design are exampled. In addition, the possible operations of SOFC (i.e. external reforming, indirect internal reforming, and direct internal reforming are discussed. Lastly, the research studies on applications of SOFCs with co-generation (i.e. SOFC with Combined Heat and Power (SOFC-CHP, SOFC with Gas Turbine (SOFC-GT and SOFC with chemical production are given.

  17. Nanostructured Solid Oxide Fuel Cell Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sholklapper, Tal Zvi [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

  18. Engineered glass seals for solid-oxide fuel cells

    Science.gov (United States)

    Surdoval, Wayne; Lara-Curzio, Edgar; Stevenson, Jeffry; Muth, Joseph Thomas; Armstrong, Beth L.; Shyam, Amit; Trejo, Rosa M.; Wang, Yanli; Chou, Yeong Shyung; Shultz, Travis Ray

    2017-02-07

    A seal for a solid oxide fuel cell includes a glass matrix having glass percolation therethrough and having a glass transition temperature below 650.degree. C. A deformable second phase material is dispersed in the glass matrix. The second phase material can be a compliant material. The second phase material can be a crushable material. A solid oxide fuel cell, a precursor for forming a seal for a solid oxide fuel cell, and a method of making a seal for a solid oxide fuel cell are also disclosed.

  19. Solid state sodium cells. Faststof natriumbatterier

    Energy Technology Data Exchange (ETDEWEB)

    Skaarup, S.; West, K. (eds.)

    1989-04-15

    The report describes the results from the project: ''Secondary Sodium Cells with Intercalation Electrodes'' which was financed by the Danish Department of Energy. The work was carried out by the Solid State Electrochemistry Group at the Technical University of Denmark which is formed by collaborators from the Institute of Physical Chemistry and Physics Laboratory III. The use of sodium has several advantages in theory compared to lithium systems: Sodium is much more abundant and lower priced than lithium, it may be easier to find solid electrolytes of sufficiently high conductivity, sodium forms no alloy with aluminium thereby making it possible to use this metal for current collectors instead of the costlier and heavier nickel. The softness of sodium metal may make it easier to achieve and maintain contact to other components in the battery during repeated cycling. This might be of importance for room temperature operation especially. Results from the project have primarily been published in the form of articles in international scientific journals and as contributions to monographs. Copies of these articles form the backbone of the report together with a short commentary to each article. Also included in the report are some general observations, as well as results that are unsuited for publication (e.g. unsuccessful experiments) but which may still contain relevant information for other experimental workers. Lastly, the report includes results on several intercalation compounds that will be published at a later stage as well as some details about the experimental equipment. The report is divided into three main sections, Intercalation Cathode Materials, Polymer Electrolytes and Battery Cycling Equipment. (AB).

  20. A Two Photoelectrode Solid-State Photoelectrochemical Cell,

    Science.gov (United States)

    1984-09-14

    unique approach for the PEC conversion and storage of selected redox species incorporated within the proximity of the semiconductor /solid electrolyte... semiconductor and solid electrolyte materials are present at the junction. As a consequence, PEC cells fabricated to contain such interfaces...consequence of the high resistivity of the SPE material used. PEn had earlier been used in the solid-state PEC cell n-Si/PEO,KI, 2 / SnO 2 glass, whicre the n

  1. Degradation in Solid Oxide Cells During High Temperature Electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Sohal

    2009-05-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells. One goal of that project is to address the technical and degradation issues associated with solid oxide electrolysis cells. This report covers a variety of these degradation issues, which were discussed during a workshop on “Degradation in Solid Oxide Electrolysis Cells and Strategies for its Mitigation,” held in Phoenix, AZ on October 27, 2008. Three major degradation issues related to solid oxide electrolysis cells discussed at the workshop are: • Delamination of O2-electrode and bond layer on steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites (triple-phase boundary) • Loss of electrical/ionic conductivity of electrolyte. This list is not all inclusive, but the workshop summary can be useful in providing a direction for future research related to the degradation of solid oxide electrolysis cells.

  2. Solid oxide electrolysis cells - Performance and durability

    Energy Technology Data Exchange (ETDEWEB)

    Hauch, A.

    2007-10-15

    In this work H2 electrode supported solid oxide cells (SOC) produced at Risoe National Laboratory, DTU, have been used for steam electrolysis. Electrolysis tests have been performed at temperatures from 650AeC to 950AeC, p(H2O)/p(H2) from 0.99/0.01 to 0.30/0.70 and current densities from -0.25 A/cm2 to -2 A/cm2. The solid oxide electrolysis cells (SOEC) have been characterised by iV curves and electrochemical impedance spectroscopy (EIS) at start and end of tests and by EIS under current load during electrolysis testing. The tested SOCs have shown the best initial electrolysis performance reported in literature to date. Area specific resistances of 0.26 Oecm2 at 850AeC and 0.17 Oecm2 at 950AeC were obtained from electrolysis iV curves. The general trend for the SOEC tests was: 1) a short-term passivation in first few hundred hours, 2) then an activation and 3) a subsequent and underlying long-term degradation. The transient phenomenon (passivation/activation) was shown to be a set-up dependent artefact caused by the albite glass sealing with a p(Si(OH)4) of 1.10-7 atm, leading to silica contamination of the triple-phase boundaries (TPBs) of the electrode. The long-term degradation for the SOECs was more pronounced than for fuel cell testing of similar cells. Long-term degradation of 2%/1000 h was obtained at 850AeC, p(H2O)/p(H2) = 0.5/0.5 and -0.5 A/cm2, whereas the degradation rate increased to 6%/1000h at 950AeC, p(H2O)/p(H2) = 0.9/0.1 and -1.0 A/cm2. Both the short-term passivation and the long-term degradation appear mainly to be related to processes in the H2 electrode. Scanning electron microscopy micrographs show that only limited changes occur in the Ni particle size distribution and these are not the main degradation mechanism for the SOECs. Micro and nano analysis using energy dispersive spectroscopy in combination with transmission electron microscopy (TEM) and scanning TEM reveals that glassy phase impurities have accumulated at the TPBs as a result of

  3. Sealing materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, P.H.

    1999-02-01

    A major obstacle in the achievement of high electrical efficiency for planar solid oxide fuel cell stacks (SOFC) is the need for long term stable seals at the operational temperature between 850 and 1000 deg. C. In the present work the formation and properties of sealing materials for SOFC stacks that fulfil the necessary requirements were investigated. The work comprises analysis of sealing material properties independently, in simple systems as well as tests in real SOFC stacks. The analysed sealing materials were based on pure glasses or glass-ceramic composites having B{sub 2}O{sub 3}, P{sub 2}O{sub 5} or siO{sub 2} as glass formers, and the following four glass systems were investigated: MgO/caO/Cr{sub 2}O{sub 3}-Al{sub 2}O{sub 3}B{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}-SiO{sub 2} and BaO/Na{sub 2}O-Al{sub 2}O{sub 3}-SiO{sub 2}. (au) 32 tabs., 106 ills., 107 refs.

  4. Modeling Degradation in Solid Oxide Electrolysis Cells

    Energy Technology Data Exchange (ETDEWEB)

    Manohar S. Sohal; Anil V. Virkar; Sergey N. Rashkeev; Michael V. Glazoff

    2010-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic no equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, , within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, no equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  5. Solid Oxide Fuel Cells Canada (SOFCC)

    International Nuclear Information System (INIS)

    Birss, V.; Borglum, B.

    2006-01-01

    Vision: To enhance co-ordination and to ensure sustainable funding of research, development, and commercialization of solid oxide fuel cells and related technologies in Canada in order to create products that serve the world. Current Research Areas of Investigation: Mission: To provide cleaner air, reduce CO 2 emissions, better utilize fuel resources, increase economic prosperity, and enhance the quality of life in Canada and the world by enabling and accelerating development of the Canadian SOFC industry. To achieve this, we will: 1. Establish national priorities for the research, development, design, demonstration, and the innovation process; commercialization of SOFC and related technologies; 2. Develop a strategy to produce commercial products within 5 years; 3. Co-ordinate activities as one integrated Canada-wide initiative; 4. Facilitate effective access to funding by providing a venue for funders to directly participate in; 5. Provide an integrating and interdisciplinary function to maximize the collective knowledge, expertise, and capacity of the alliance partners; 6. Maintain strategic relevance within an ever changing global context by providing high-quality intelligence. (author)

  6. MANOVA for Nested Designs with Unequal Cell Sizes and Unequal Cell Covariance Matrices

    Directory of Open Access Journals (Sweden)

    Li-Wen Xu

    2014-01-01

    satisfactorily for various cell sizes and parameter configurations and generally outperforms the AHT test in terms of controlling the nominal size. For the heteroscedastic cases, the PB test outperforms the AHT test in terms of power. In addition, the PB test does not lose too much power when the homogeneity assumption is actually valid.

  7. Solid oxide fuel cells fueled with reducible oxides

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Steven S.; Fan, Liang Shih

    2018-01-09

    A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing the solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.

  8. Advanced methods of solid oxide fuel cell modeling

    CERN Document Server

    Milewski, Jaroslaw; Santarelli, Massimo; Leone, Pierluigi

    2011-01-01

    Fuel cells are widely regarded as the future of the power and transportation industries. Intensive research in this area now requires new methods of fuel cell operation modeling and cell design. Typical mathematical models are based on the physical process description of fuel cells and require a detailed knowledge of the microscopic properties that govern both chemical and electrochemical reactions. ""Advanced Methods of Solid Oxide Fuel Cell Modeling"" proposes the alternative methodology of generalized artificial neural networks (ANN) solid oxide fuel cell (SOFC) modeling. ""Advanced Methods

  9. The nested variant of bladder transitional cell carcinoma: Review of 12 cases and review of the literature.

    Science.gov (United States)

    Carrion-Ballardo, C J; Gala-Solana, L; Portillo-Martin, J A; Azueta-Etxebarria, A; Truan-Cacho, D; Campos-Juanatey, F

    2015-01-01

    The nested variant of bladder transitional cell carcinoma is extremely rare and has a different biological behavior to other bladder tumors. The aim of this study is to analize if their behavior is as aggressive as has been described in the literature. Review of 12 diagnosed cases with nested variant of bladder transitional cell carcinoma and analysis of demographic characteristics, clinical presentation, tumor characteristics, treatment options, analysis of recurrence and cancer-specific survival between January 1997 and December 2010 in our hospital. 50% of the cases had a pathologic stage ≥T2, with grade of differentiation G2 (50%) or G3 (50%). After the pathological result of the TUR (transurethral resection) Bladder, 5 cases underwent radical cystoprostatectomy, 3 a second TUR bladder and 4 cases with treatment chemotherapy and/or radiotherapy (RT). Five out of 12 cases (41.7%) died due to bladder cancer and 3 died (25%) of other causes (urinary sepsis, respiratory failure, renal failure). With a median follow up of 40 months, the overall survival was 50% and cancer-specific survival of 65.6%. The nested variant of bladder transitional cell carcinoma is a disease with an advanced-stage presentation, with high recurrence and mortality rates despite the use of different treatments. So far there is not a clinical practice guideline for this variety of urothelial tumor. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. A review of liquid metal anode solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    ALIYA TOLEUOVA

    2013-06-01

    Full Text Available This review discusses recent advances in a solid oxide fuel cell (SOFC variant that uses liquid metal electrodes (anodes with the advantage of greater fuel tolerance and the ability to operate on solid fuel. Key features of the approach are discussed along with the technological and research challenges that need to be overcome for scale-up and commercialisation.

  11. Chimeric antigen receptor T-cell therapy for solid tumors

    Directory of Open Access Journals (Sweden)

    Kheng Newick

    2016-01-01

    Full Text Available Chimeric antigen receptor (CAR T cells are engineered constructs composed of synthetic receptors that direct T cells to surface antigens for subsequent elimination. Many CAR constructs are also manufactured with elements that augment T-cell persistence and activity. To date, CAR T cells have demonstrated tremendous success in eradicating hematological malignancies (e.g., CD19 CARs in leukemias. This success is not yet extrapolated to solid tumors, and the reasons for this are being actively investigated. Here in this mini-review, we discuss some of the key hurdles encountered by CAR T cells in the solid tumor microenvironment.

  12. Detection of circulating tumor cells by nested RT-PCR targeting ...

    African Journals Online (AJOL)

    Background: EGFR is involved in the epidermal growth factors pathway that regulates cellular processes and is associated with the development of many types of cancer including colorectal cancer. Molecular methods with high sensitivity such as nested polymerase chain reaction (PCR) based assays have been used to ...

  13. Cancer Chemotherapy Specific to Acidic Nests.

    Science.gov (United States)

    Kobayashi, Hiroshi

    2017-04-20

    The realization of cancer therapeutics specific to cancer cells with less of an effect on normal tissues is our goal. Many trials have been carried out for this purpose, but this goal is still far from being realized. It was found more than 80 years ago that solid cancer nests are acidified, but in vitro studies under acidic conditions have not been extensively studied. Recently, in vitro experiments under acidic conditions were started and anti-cancer drugs specific to acidic areas have been identified. Many genes have been reported to be expressed at a high level under acidic conditions, and such genes may be potent targets for anti-cancer drugs specific to acidic nests. In this review article, recent in vitro, in vivo, and clinical achievements in anti-cancer drugs with marked efficacy under acidic conditions are summarized, and the clinical use of anti-cancer drugs specific to acidic nests is discussed.

  14. Cutaneous Human Papillomaviruses and Squamous Cell Carcinoma of the Skin: Nested Case-Control Study.

    Science.gov (United States)

    Faust, Helena; Andersson, Kristin; Luostarinen, Tapio; Gislefoss, Randi E; Dillner, Joakim

    2016-04-01

    Cutaneous human papillomavirus (HPV) types have been associated with non-melanoma skin cancer (NMSC), including a previous nested case-control study using HPV serology with bacterially derived fusion proteins with the major HPV capsid protein L1 (GST-L1). However, HPV serology using conformationally intact pseudovirions has been shown to correlate better with natural infection. Prospective studies using a more valid marker of infection are therefore warranted. Cancer registry follow-up of large Nordic biobanks identified prediagnostic serum samples from 633 subjects who later developed SCC, 1,990 subjects who developed basal cell carcinoma (BCC). The samples from cases and matched controls were tested for IgG to pseudovirions to 16 different HPV types (3, 5, 6, 11, 15: , 16, 18, 31, 32, 33, 38: , 45, 52, 58, 68, and 76: ) and two polyomaviruses (MCPyV and JCPyV). Baseline seropositivity was not associated with SCC risk, and there were only weak associations with BCC risk [HPV-5 (OR, 1.1; 95% confidence interval [CI], 1.0-1.3), HPV-15 (OR, 1.2; 95% CI, 1.0-1.4), HPV-38 (OR, 1.2; 95% CI, 1.0-1.3), and MCPyV (OR, 1.1; 95% CI, 1.0-1.3)]. Acquisition of HPV-5 seropositivity during follow-up was associated with SCC risk (OR, 3.2; 95% CI, 1.3-7.6). Persistent seropositivity for HPV-15 was weakly associated with BCC (OR, 1.4; 95% CI, 1.0-1.9) and HPV-6 antibody persistence was weakly associated with SCC (OR, 2.2; 95% CI, 1.0-4.8). Considering the large number of viruses tested, the weak associations found do not support any strong links between studied HPV and NMSC, with the possible exception of HPV-5 seroconversion and SCC. Known alpha and beta papillomaviruses do not appear to be risk factors for NMSC. Cancer Epidemiol Biomarkers Prev; 25(4); 721-4. ©2016 AACR. ©2016 American Association for Cancer Research.

  15. Glass/BNNT Composite for Sealing Solid Oxide Fuel Cells

    Science.gov (United States)

    Bansal, Narottam P.; Hurst, Janet B.; Choi, Sung R.

    2007-01-01

    A material consisting of a barium calcium aluminosilicate glass reinforced with 4 weight percent of boron nitride nanotubes (BNNTs) has shown promise for use as a sealant in planar solid oxide fuel cells (SOFCs).

  16. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...... configurations are compared with each other. Technoeconomy is used when calculating the cost if the plants. It is found that when a solid oxide fuel cell plant is combined with a gas turbine cycle then the plant efficiency will be the highest one while if a biomass gasification plant is integrated...... with these hybrid cycles then integrated biomass gasification with solid oxide fuel cell and steam cycle will have the highest plant efficiency. The cost of solid oxide fuel cell with steam plant is found to be the lowest one with a value of about 1030$/kW....

  17. Symmetrical, bi-electrode supported solid oxide fuel cell

    Science.gov (United States)

    Cable, Thomas L. (Inventor); Sofie, Stephen W. (Inventor)

    2009-01-01

    The present invention is a symmetrical bi-electrode supported solid oxide fuel cell comprising a sintered monolithic framework having graded pore electrode scaffolds that, upon treatment with metal solutions and heat subsequent to sintering, acquire respective anodic and cathodic catalytic activity. The invention is also a method for making such a solid oxide fuel cell. The graded pore structure of the graded pore electrode scaffolds in achieved by a novel freeze casting for YSZ tape.

  18. In utero bisphenol A exposure disrupts germ cell nest breakdown and reduces fertility with age in the mouse

    International Nuclear Information System (INIS)

    Wang, Wei; Hafner, Katlyn S.; Flaws, Jodi A.

    2014-01-01

    Bisphenol A (BPA) is a known reproductive toxicant in rodents. However, the effects of in utero BPA exposure on early ovarian development and the consequences of such exposure on female reproduction in later reproductive life are unclear. Thus, we determined the effects of in utero BPA exposure during a critical developmental window on germ cell nest breakdown, a process required for establishment of the finite primordial follicle pool, and on female reproduction. Pregnant FVB mice (F0) were orally dosed daily with tocopherol-striped corn oil (vehicle), diethylstilbestrol (DES; 0.05 μg/kg, positive control), or BPA (0.5, 20, and 50 μg/kg) from gestational day 11 until birth. Ovarian morphology and gene expression profiles then were examined in F1 female offspring on postnatal day (PND) 4 and estrous cyclicity was examined daily after weaning for 30 days. F1 females were also subjected to breeding studies with untreated males at three to nine months. The results indicate that BPA inhibits germ cell nest breakdown via altering expression of selected apoptotic factors. BPA also significantly advances the age of first estrus, shortens the time that the females remain in estrus, and increases the time that the females remain in metestrus and diestrus compared to controls. Further, F1 females exposed to low doses of BPA exhibit various fertility problems and have a significantly higher percentage of dead pups compared to controls. These results indicate that in utero exposure to low doses of BPA during a critical ovarian developmental window interferes with early ovarian development and reduces fertility with age. - Highlights: • In utero BPA exposure inhibits germ cell nest breakdown in female mouse offspring. • In utero BPA exposure alters expression of apoptosis regulators in the ovaries of mouse offspring. • In utero BPA exposure advances first estrus age and alters cyclicity in mouse offspring. • In utero BPA exposure causes various fertility problems in

  19. Performance and durability of solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Hauch, Anne; Jensen, Søren H; Ramousse, Severine

    2006-01-01

    Solid oxide fuel cells produced at Riso National Laboratory have been tested as electrolysis cells by applying an external voltage. Results on initial performance and durability of such reversible solid oxide cells at temperatures from 750 to 950 degrees C and current densities from -0.25 A/cm(2......) to -0.50 A/cm(2) are reported. The full cells have an initial area specific resistance as low as 0.27 Omega cm(2) for electrolysis operation at 850 degrees C. During galvanostatic long-term electrolysis tests, the cells were observed to passivate mainly during the first similar to 100 h of electrolysis....... Cells that have been passivated during electrolysis tests can be partly activated again by operation in fuel cell mode or even at constant electrolysis conditions after several hundred hours of testing....

  20. Strength of Anode‐Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Faes, A.; Frandsen, Henrik Lund; Kaiser, Andreas

    2011-01-01

    Nickel oxide and yttria doped zirconia composite strength is crucial for anode‐supported solid oxide fuel cells, especially during transient operation, but also for the initial stacking process, where cell curvature after sintering can cause problems. This work first compares tensile and ball...

  1. Performance Evaluation of Solid Oxide Fuel Cell by Computer ...

    African Journals Online (AJOL)

    The search for sustainable energy source that can compete with the existing one led to the discovery and acceptance of fuel cell technologies as a perfect replacement for fossil fuel. The ability of Solid Oxide Fuel Cells (SOFC) to capture the heat generation during the process of energy generation from electrochemical ...

  2. Maryland ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for raptors in Maryland. Vector points in this data set represent bird nesting sites. Species-specific...

  3. Louisiana ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabird and wading bird nesting colonies in coastal Louisiana. Vector points in this data set represent...

  4. Hawaii ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabird nesting colonies in coastal Hawaii. Vector points in this data set represent locations of...

  5. Multidimensional Solid-State NMR Spectroscopy of Plant Cell Walls

    OpenAIRE

    Wang, Tuo; Phyo, Pyae; Hong, Mei

    2016-01-01

    Plant biomass has become an important source of bio-renewable energy in modern society. The molecular structure of plant cell walls is difficult to characterize by most atomic-resolution techniques due to the insoluble and disordered nature of the cell wall. Solid-state NMR (SSNMR) spectroscopy is uniquely suited for studying native hydrated plant cell walls at the molecular level with chemical resolution. Significant progress has been made in the last five years to elucidate the molecular st...

  6. Electrochemical characterisation of solid oxide cell electrodes for hydrogen production

    DEFF Research Database (Denmark)

    Bernuy-Lopez, Carlos; Knibbe, Ruth; He, Zeming

    2011-01-01

    Oxygen electrodes and steam electrodes are designed and tested to develop improved solid oxide electrolysis cells for H2 production with the cell support on the oxygen electrode. The electrode performance is evaluated by impedance spectroscopy testing of symmetric cells at open circuit voltage (OCV...... and impregnated with CGO/Ni, with an Rp of 0.08 Ω cm2 at 850 °C in 3% H2O/H2....

  7. High performance solid acid fuel cells through humidity stabilization

    OpenAIRE

    Boysen, Dane A.; Uda, Tetsuya; Chisholm, Calum R. I.; Haile, Sossina M.

    2004-01-01

    Although they hold the promise of clean energy, state-of-the-art fuel cells based on polymer electrolyte membrane fuel cells are inoperable above 100°C, require cumbersome humidification systems, and suffer from fuel permeation. These difficulties all arise from the hydrated nature of the electrolyte. In contrast, “solid acids” exhibit anhydrous proton transport and high-temperature stability. We demonstrate continuous, stable power generation for both H_2/O_2 and direct methanol fuel cells o...

  8. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible to separate the loss...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

  9. FUEL TRANSFORMER SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Lars Allfather; Anthony Litka

    2005-03-24

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from July of 2004 through January 2004. Work was focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the lay out plans for further progress in next budget period.

  10. Fuel Transformer Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Rhys Foster; Anthony Litka

    2006-07-27

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from January of 2006 through June 2006. Work focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the layout plans for further progress in next budget period.

  11. Lowering the temperature of solid oxide fuel cells.

    Science.gov (United States)

    Wachsman, Eric D; Lee, Kang Taek

    2011-11-18

    Fuel cells are uniquely capable of overcoming combustion efficiency limitations (e.g., the Carnot cycle). However, the linking of fuel cells (an energy conversion device) and hydrogen (an energy carrier) has emphasized investment in proton-exchange membrane fuel cells as part of a larger hydrogen economy and thus relegated fuel cells to a future technology. In contrast, solid oxide fuel cells are capable of operating on conventional fuels (as well as hydrogen) today. The main issue for solid oxide fuel cells is high operating temperature (about 800°C) and the resulting materials and cost limitations and operating complexities (e.g., thermal cycling). Recent solid oxide fuel cells results have demonstrated extremely high power densities of about 2 watts per square centimeter at 650°C along with flexible fueling, thus enabling higher efficiency within the current fuel infrastructure. Newly developed, high-conductivity electrolytes and nanostructured electrode designs provide a path for further performance improvement at much lower temperatures, down to ~350°C, thus providing opportunity to transform the way we convert and store energy.

  12. Nested cellular automata

    International Nuclear Information System (INIS)

    Quasthoff, U.

    1985-07-01

    Cellular automata by definition consist of a finite or infinite number of cells, say of unit length, with each cell having the same transition function. These cells are usually considered as the smallest elements and so the space filled with these cells becomes discrete. Nevertheless, large pictures created by such cellular automata look very fractal. So we try to replace each cell by a couple of smaller cells, which have the same transition functions as the large ones. There are automata where this replacement does not destroy the macroscopic structure. In these cases this nesting process can be iterated. The paper contains large classes of automata with the above properties. In the case of one dimensional automata with two states and next neighbour interaction and a nesting function of the same type a complete classification is given. (author)

  13. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2015-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s......Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance...... bituminous coal (73 mW/cm2). © 2015 ECS - The Electrochemical Society...

  14. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2017-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s......Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon......-carbonate slurry or anode layer. The nature of the coal affects both open circuit voltage and power output. Highest OCV and power densities were observed for bituminous coal and by adding manganese oxide or praseodymium-doped ceria to the carbon/carbonate mixture. Comparing the carbon black fueled performance...... bituminous coal (73 mW/cm2)....

  15. Thermoneutral Operation of Solid Oxide Electrolysis Cells in Potentiostatic Mode

    DEFF Research Database (Denmark)

    Chen, Ming; Sun, Xiufu; Chatzichristodoulou, Christodoulos

    2017-01-01

    High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a promising technology for energy storage and synthetic fuel production. In recent years extensive efforts have been devoted to improving performance and durability of SOEC cells and stacks. Due to historical reasons...... and the convenience of doing constant current tests, (almost) all the reported SOEC tests have been galvanostatic. In this work, we report test results on two types of SOEC cells operated for electrolysis of steam in potentiostatic mode at 1.29 V. Both cells are Ni/YSZ fuel electrode supported type with different...... cause of the degradation. Operation strategies were further proposed for electrolysis operation in potentiostatic mode....

  16. Impedance Modeling of Solid Oxide Fuel Cell Cathodes

    DEFF Research Database (Denmark)

    Mortensen, Jakob Egeberg; Søgaard, Martin; Jacobsen, Torben

    2010-01-01

    A 1-dimensional impedance model for a solid oxide fuel cell cathode is formulated and applied to a cathode consisting of 50/50 wt% strontium doped lanthanum cobaltite and gadolinia doped ceria. A total of 42 impedance spectra were recorded in the temperature range: 555-852°C and in the oxygen...

  17. Concentration Impedance in Testing of Solid Oxide Cells Revisited

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Ebbesen, Sune Dalgaard; Jensen, Søren Højgaard

    2017-01-01

    The concentration impedance originating from diffusion and reactant conversion impedance of the Ni-YSZ supported fuel electrode in solid oxide cell has been treated many times during the latest couple of decades. In spite of this, the separation of the diffusion impedance from the conversion...

  18. Conversion of hydrocarbons in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Kammer Hansen, K.

    2003-01-01

    Recently, a number of papers about direct oxidation of methane and hydrocarbon in solid oxide fuel cells (SOFC) at relatively low temperatures (about 700degreesC) have been published. Even though the conversion of almost dry CH4 at 1000degreesC on ceramic anodes was demonstrated more than 10 years...

  19. Current status of Westinghouse tubular solid oxide fuel cell program

    Energy Technology Data Exchange (ETDEWEB)

    Parker, W.G. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

    1996-04-01

    In the last ten years the solid oxide fuel cell (SOFC) development program at Westinghouse has evolved from a focus on basic material science to the engineering of fully integrated electric power systems. Our endurance for this cell is 5 to 10 years. To date we have successfully operated at power for over six years. For power plants it is our goal to have operated before the end of this decade a MW class power plant. Progress toward these goals is described.

  20. Characterising of solid state electrochemical cells under operation

    DEFF Research Database (Denmark)

    Holtappels, Peter

    2014-01-01

    Compared to significant progress in PEMFC especially regarding the utilization of complex fuels such as methanol significant progress has been made by applying spectroscopic / differential IR and spectrometric techniques to working fuel cells, the processes in solid state high temperature....... This relates to interrelation between NOx/ O2 on cathodes but also to sulfur and carbon exposure at the anode. Past and recent activities on SOFC anodes and cathodes will be presented as well as perspectives and gaps discussed for these systems. Especially interaction between sulfur interactions with solids...

  1. Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

    Science.gov (United States)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2015-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  2. Pressurized Operation of a Planar Solid Oxide Cell Stack

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune Dalgaard

    2016-01-01

    Solid oxide cells (SOCs) can be operated either as fuel cells (SOFC) to convert fuels to electricity or as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane. Pressurized operation of SOCs provide several benefits on both cell and system level. If successfully matured...... (electrode performance) increases for thermodynamic and kinetic reasons, respectively. Further, the summit frequency of the gas concentration impedance arc and the pressure difference across the stack and heat exchangers is seen to decrease with increasing pressure following a power-law expression. Finally...

  3. Neste Corporation - a successful year

    International Nuclear Information System (INIS)

    Ihamuotila, J.

    1991-01-01

    The past year proved a successful one for Neste Corporation. Profitability was good and operations were consistently developed. Neste is committed to giving high priority to productivity and know- how to ensure that this success continues into the future. Important developments affecting the structure of Neste Corporation during 1990 included the amalgamation of Neste's oil-related activities into a single division, the increasing concentration of Neste Chemicals, activities in Central and Southern Europe and a major strengthening of oil exploration and production operations. Neste Oil turned in a good result during 1990. Neste imported a total of 8.9 million tonnes of crude oil during 1990. Imports from the Soviet Union at 5.2 million tonnes, were over 2 million tonnes less than planned. Some 2.5 million tonnes were imported from the North Sea, and 1.2 million tonnes from the Middle East. The year was one of expansion, diversification, and solid profit for Neste Chemicals. Net sales grew by 18 % compared to 1989 and the division recorded a satisfactory performance. Petrochemicals and polyolefins production increased suhstantially as a result of plants completed, acquired, or leased during 1989. The gas division's net sales during 1990 were 46 % higher than during 1989. This growth largely resulted from an increase in the consumption of natural gas and an expansion in the volume of international IPG business. The division's profitability remained satisfactory

  4. LG Solid Oxide Fuel Cell (SOFC) Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Haberman, Ben [LG Fuel Cell Systems Inc., North Canton, OH (United States); Martinez-Baca, Carlos [LG Fuel Cell Systems Inc., North Canton, OH (United States); Rush, Greg [LG Fuel Cell Systems Inc., North Canton, OH (United States)

    2013-05-31

    This report presents a summary of the work performed by LG Fuel Cell Systems Inc. during the project LG Solid Oxide Fuel Cell (SOFC) Model Development (DOE Award Number: DE-FE0000773) which commenced on October 1, 2009 and was completed on March 31, 2013. The aim of this project is for LG Fuel Cell Systems Inc. (formerly known as Rolls-Royce Fuel Cell Systems (US) Inc.) (LGFCS) to develop a multi-physics solid oxide fuel cell (SOFC) computer code (MPC) for performance calculations of the LGFCS fuel cell structure to support fuel cell product design and development. A summary of the initial stages of the project is provided which describes the MPC requirements that were developed and the selection of a candidate code, STAR-CCM+ (CD-adapco). This is followed by a detailed description of the subsequent work program including code enhancement and model verification and validation activities. Details of the code enhancements that were implemented to facilitate MPC SOFC simulations are provided along with a description of the models that were built using the MPC and validated against experimental data. The modeling work described in this report represents a level of calculation detail that has not been previously available within LGFCS.

  5. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  6. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    David Deangelis; Rich Depuy; Debashis Dey; Georgia Karvountzi; Nguyen Minh; Max Peter; Faress Rahman; Pavel Sokolov; Deliang Yang

    2004-09-30

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the April to October 2004 reporting period in Task 2.3 (SOFC Scaleup for Hybrid and Fuel Cell Systems) under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL), entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. This study analyzes the performance and economics of power generation systems for central power generation application based on Solid Oxide Fuel Cell (SOFC) technology and fueled by natural gas. The main objective of this task is to develop credible scale up strategies for large solid oxide fuel cell-gas turbine systems. System concepts that integrate a SOFC with a gas turbine were developed and analyzed for plant sizes in excess of 20 MW. A 25 MW plant configuration was selected with projected system efficiency of over 65% and a factory cost of under $400/kW. The plant design is modular and can be scaled to both higher and lower plant power ratings. Technology gaps and required engineering development efforts were identified and evaluated.

  7. Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh

    2006-07-31

    This report summarizes the work performed for Phase I (October 2001 - August 2006) under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled 'Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program'. The program focuses on the development of a low-cost, high-performance 3-to-10-kW solid oxide fuel cell (SOFC) system suitable for a broad spectrum of power-generation applications. During Phase I of the program significant progress has been made in the area of SOFC technology. A high-efficiency low-cost system was designed and supporting technology developed such as fuel processing, controls, thermal management, and power electronics. Phase I culminated in the successful demonstration of a prototype system that achieved a peak efficiency of 41%, a high-volume cost of $724/kW, a peak power of 5.4 kW, and a degradation rate of 1.8% per 500 hours. . An improved prototype system was designed, assembled, and delivered to DOE/NETL at the end of the program. This prototype achieved an extraordinary peak efficiency of 49.6%.

  8. Development of highly efficient solid oxide electrolyzer cell systems

    DEFF Research Database (Denmark)

    Duhn, Jakob Dragsbæk

    Solid oxide electrolyzer cells (SOEC) are electrochemical devices capable of converting H2O or CO2 to H2 and CO, respectively. In this thesis, the possibility of production of CO with SOECs are investigated, since it is currently of commercial interest, but could also play a major role in the fut......Solid oxide electrolyzer cells (SOEC) are electrochemical devices capable of converting H2O or CO2 to H2 and CO, respectively. In this thesis, the possibility of production of CO with SOECs are investigated, since it is currently of commercial interest, but could also play a major role...... in the future energy system. The overall objective of the thesis was to investigate the limits for the allowed CO concentration during electrolysis of CO2 in SOECs and how the limit could be increased. A high CO concentration is desired because it lowers the strain on the separation unit and amount of recycle...

  9. Turnover rate of hypoxic cells in solid tumors

    International Nuclear Information System (INIS)

    Ljungkvist, A.S.E.; Bussink, J.; Rijken, P.F.J.W.; Van Der Kogel, A.J.

    2003-01-01

    Most solid tumors contain hypoxic cells, and both the amount and duration of tumor hypoxia has been shown to influence the effect of radiation treatment negatively. It is important to understand the dynamic processes within the hypoxic cell population in non-treated tumors, and the effect of different treatment modalities on the kinetics of hypoxic cells to be able to design optimal combined modality treatments. The turnover rate of hypoxic cells was analyzed in three different solid tumor models with a double bio-reductive hypoxic marker assay with sequential injection of the two hypoxic markers. Previously it was shown that this assay could be used to detect both a decrease and an increase of tumor hypoxia in relation to the tumor vasculature with high spatial resolution. In this study the first hypoxic marker, pimonidazole, was administered at variable times relative to tumor harvest, and the second hypoxic marker, CCI-103F, was injected at a fixed time before harvest. The hypoxic cell turnover rate was calculated as the loss of pimonidazole positive cells relative to CCI-103F. The murine C38 line had the fastest hypoxic turnover rate of 60% /24h and the human xenograft line SCCNij3 had the slowest hypoxic turnover rate of 30% /24 h. The hypoxic turnover rate was most heterogeneous in the SCCNij3 line that even contained viable groups of cells that had been hypoxic for at least 5 days. The human xenograft line MEC82 fell in between with a hypoxic turnover rate of 50% /24 h. The hypoxic cell turnover was related to the potential tumor volume doubling time (Tpot) with a Tpot of 26h in C38 and 103h in SCCNij3. The dynamics of hypoxic cells, quantified with a double hypoxic marker method, showed large differences in hypoxic cell turnover rate and were related to Tpot

  10. Solid Oxide Electrolysis Cells: Degradation at High Current Densities

    DEFF Research Database (Denmark)

    Knibbe, Ruth; Traulsen, Marie Lund; Hauch, Anne

    2010-01-01

    The degradation of Ni/yttria-stabilized zirconia (YSZ)-based solid oxide electrolysis cells operated at high current densities was studied. The degradation was examined at 850°C, at current densities of −1.0, −1.5, and −2.0 A/cm2, with a 50:50 (H2O:H2) gas supplied to the Ni/YSZ hydrogen electrode...

  11. Method to fabricate high performance tubular solid oxide fuel cells

    Science.gov (United States)

    Chen, Fanglin; Yang, Chenghao; Jin, Chao

    2013-06-18

    In accordance with the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes forming an asymmetric porous ceramic tube by using a phase inversion process. The method further includes forming an asymmetric porous ceramic layer on a surface of the asymmetric porous ceramic tube by using a phase inversion process. The tube is co-sintered to form a structure having a first porous layer, a second porous layer, and a dense layer positioned therebetween.

  12. Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Turgut Gur

    2010-04-30

    This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

  13. Effect of solid distribution on elastic properties of open-cell cellular solids using numerical and experimental methods.

    Science.gov (United States)

    Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

    2014-09-01

    Effect of solid distribution between edges and vertices of three-dimensional cellular solid with an open-cell structure was investigated both numerically and experimentally. Finite element analysis (FEA) with continuum elements and appropriate periodic boundary condition was employed to calculate the elastic properties of cellular solids using tetrakaidecahedral (Kelvin) unit cell. Relative densities between 0.01 and 0.1 and various values of solid fractions were considered. In order to validate the numerical model, three scaffolds with the relative density of 0.08, but different amounts of solid in vertices, were fabricated via 3-D printing technique. Good agreement was observed between numerical simulation and experimental results. Results of numerical simulation showed that, at low relative densities (numerical simulation and considering the relative density and solid fraction in vertices, empirical relations were derived for Young׳s modulus and Poisson׳s ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Durability of Solid Oxide Electrolysis Cells for Syngas Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2013-01-01

    Performance and durability of Ni-YSZ supported solid oxide electrolysis cells (SOECs) for co-electrolysis of H2O and CO2 at high current density was investigated. The cells consist of a Ni-YSZ support, a Ni-YSZ electrode, a YSZ electrolyte, and an LSM-YSZ electrode. The durability was examined...... at 800°C and electrolysis current densities of −1 or −1.5 A/cm2 with 60% reactant (H2O + CO2) utilization. The cell voltage degradation showed a strong dependence on the electrolysis current density. Electrochemical characterization of the cells showed that the degradation was mainly related to the LSM...

  15. Electrochemical Synthesis of Ammonia in Solid Electrolyte Cells

    Directory of Open Access Journals (Sweden)

    Ioannis eGaragounis

    2014-01-01

    Full Text Available Developed in the early 1900's, the Haber-Bosch synthesis is the dominant NH3 synthesis process. Parallel to catalyst optimization, current research efforts are also focused on the investigation of new methods for ammonia synthesis, including the electrochemical synthesis with the use of solid electrolyte cells. Since the first report on Solid State Ammonia Synthesis (SSAS, more than 30 solid electrolyte materials were tested and at least 15 catalysts were used as working electrodes. Thus far, the highest rate of ammonia formation reported is 1.13×10−8 mol s−1 cm−2, obtained at 80°C with a Nafion solid electrolyte and a mixed oxide, SmFe0.7Cu0.1Ni0.2O3, cathode. At high temperatures (>500oC the maximum rate was 9.5*10-9 mol s−1 cm−2 using Ce0.8Y0.2O2-δ -[Ca3(PO42 -K3PO4] as electrolyte and Ag-Pd as cathode. In this paper, the advantages and the disadvantages of SSAS vs the conventional process and the requirements that must be met in order to promote the electrochemical process into an industrial level, are discussed.

  16. Electrochemical Synthesis of Ammonia in Solid Electrolyte Cells

    International Nuclear Information System (INIS)

    Garagounis, Ioannis; Kyriakou, Vasileios; Skodra, Aglaia; Vasileiou, Eirini; Stoukides, Michael

    2014-01-01

    Developed in the early 1900s, the “Haber–Bosch” synthesis is the dominant NH 3 synthesis process. Parallel to catalyst optimization, current research efforts are also focused on the investigation of new methods for ammonia synthesis, including the electrochemical synthesis with the use of solid electrolyte cells. Since the first report on Solid State Ammonia Synthesis (SSAS), more than 30 solid electrolyte materials were tested and at least 15 catalysts were used as working electrodes. Thus far, the highest rate of ammonia formation reported is 1.13 × 10 -8 mol s -1 cm -2 , obtained at 80°C with a Nafion solid electrolyte and a mixed oxide, SmFe 0.7 Cu 0.1 Ni 0.2 O 3 , cathode. At high temperatures (>500°C), the maximum rate was 9.5 × 10 −9 mol s -1 cm -2 using Ce 0.8 Y 0.2 O 2-δ –[Ca 3 (PO 4 ) 2 –K 3 PO 4 ] as electrolyte and Ag–Pd as cathode. In this paper, the advantages and the disadvantages of SSAS vs. the conventional process and the requirements that must be met in order to promote the electrochemical process into an industrial level are discussed.

  17. Durable solid oxide electrolysis cells for hydrogen production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

    2014-01-01

    Solid oxide cell (SOC) for electrolysis application has attracted great interest in recent years due to its high power-to-gas efficiency and capability of co-electrolysis of H2O and CO2 for syngas (H2 + CO) production. The demonstration of durable solid oxide electrolysis cell operation for fuel...... increased during the durability test. Further analyses of the cell impedance show that both the LSCFCGO electrode and Ni-YSZ electrode degraded and the degradation was dominated by that of the Ni-YSZ electrode. Post-mortem analysis on the Ni-YSZ electrode revealed loss of percolation between Ni-Ni grains...... and changing of porosity inside the active layer. The degree of these microstructural changes becomes less and less severe along the hydrogen-steam flow path. The present test results show that this type of cell can be used for early demonstration electrolysis at 1A/cm2. Future work should be focus on reducing...

  18. Durable solid oxide electrolysis cells for hydrogen production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

    2014-01-01

    Solid oxide cell (SOC) for electrolysis application has attracted great interest in recent years due to its high power-to-gas efficiency and capability of co-electrolysis of H2O and CO2 for syngas (H2 + CO) production. The demonstration of durable solid oxide electrolysis cell operation for fuel...... production is required for promoting commercialization of the SOEC technology. In this work, we report a recent 4400 hours test of a state-of-the-art Ni-YSZ electrode supported SOEC cell. The cell consists of a Ni-YSZ (YSZ: yttria stabilized zirconia) support and active fuel electrode, an YSZ electrolyte...... layer, a CGO (Gd doped ceria) inter-diffusion barrier layer and a LSCF-CGO (LSCF: lanthanum ferrite doped with strontium and cobalt) oxygen electrode layer. The electrolysis test was carried out at 800 °C under 1 A/cm2 with 90 % H2O + 10 % H2 supplied to Ni-YSZ electrode compartment. The results show...

  19. Bevacizumab for non-small-cell lung cancer: A nested case control study of risk factors for hemoptysis.

    Science.gov (United States)

    Goto, Koichi; Endo, Masahiro; Kusumoto, Masahiko; Yamamoto, Nobuyuki; Ohe, Yuichiro; Shimizu, Ayaka; Fukuoka, Masahiro

    2016-12-01

    Potentially life-threatening, serious hemoptysis is an adverse event associated with bevacizumab in non-squamous non-small-cell lung cancer (NSCLC) trials. Suggested risk factors include central tumor location and cavitation; however, the profile of hemoptysis occurrence in clinical practice is still unclear. A nested case-control study was conducted to assess the onset profile and risk factors for hemoptysis in bevacizumab-treated patients in a real-world setting in Japan. After bevacizumab was approved for NSCLC, physicians registered all NSCLC patients scheduled for bevacizumab therapy, from November 2009 to August 2011. Patients developing grade 2 hemoptysis requiring an injectable hemostatic agent or grade ≥3 hemoptysis were selected as case subjects, matched with four control subjects each. Case report forms were collected after an observation period of 24 weeks. Radiologists assessed blinded thoracic images. Risk factors for hemoptysis were assessed by univariate and stepwise multivariate analysis. Of 6774 patients registered, 23 (0.3%) experienced grade ≥2 drug-related hemoptysis. A total of 104 patients (21 cases, 83 controls) were analyzed by central reviewers for risk factors of hemoptysis occurrence. In the univariate analysis seven factors were associated with hemoptysis. In the step-wise multivariate analysis, prior thoracic radiotherapy (P = 0.1844), presence of tumor exposure in the central airway (P = 0.0256) and concomitant radiotherapy (P = 0.1169) were identified as risk factors for hemoptysis. While the incidence of hemoptysis was low in the real-world setting in Japan, the three risk factors identified, prior thoracic radiotherapy, presence of tumor exposure in the central airway and concomitant radiotherapy, should be considered when selecting patients for bevacizumab treatment. Although technically classed as a clinical trial, a nested case-control study was a non-interventional surveillance study analyzing all NSCLC patients receiving

  20. Direct liquid methanol-fueled solid oxide fuel cell

    Science.gov (United States)

    Liu, Mingfei; Peng, Ranran; Dong, Dehua; Gao, Jianfeng; Liu, Xingqin; Meng, Guangyao

    Anode coking problem of solid oxide fuel cell (SOFC) when using hydrocarbon fuels has been the major barrier for the practice and commercialization of well-developed high performance SOFC. In this work, based on fuels consideration, we chose liquid methanol as the candidate fuel for SOFC with the configuration of NiO/SDC-SDC-SSC/SDC. For comparison, traditional fuels, hydrogen and ammonia, were tested. With methanol as fuel, the maximum power densities were 698, 430 and 223 mW cm -2 at 650, 600 and 550 °C, respectively, which were higher than that with ammonia and lower than that of hydrogen. The electrochemical properties of the cells with the three fuels were investigated by AC impedance spectroscopy. The long-term stability of the cell with methanol, methane and ethanol were also studied at a constant output voltage of 0.5 V.

  1. AlliedSignal solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.; Barr, K.; Kelly, P.; Montgomery, K. [AlliedSignal Aerospace Equipment Systems, Torrance, CA (United States)

    1996-12-31

    AlliedSignal has been developing high-performance, lightweight solid oxide fuel cell (SOFC) technology for a broad spectrum of electric power generation applications. This technology is well suited for use in a variety of power systems, ranging from commercial cogeneration to military mobile power sources. The AlliedSignal SOFC is based on stacking high-performance thin-electrolyte cells with lightweight metallic interconnect assemblies to form a compact structure. The fuel cell can be operated at reduced temperatures (600{degrees} to 800{degrees}C). SOFC stacks based on this design has the potential of producing 1 kW/kg and 1 ML. This paper summarizes the technical status of the design, manufacture, and operation of AlliedSignal SOFCs.

  2. Advanced impedance modeling of solid oxide electrochemical cells

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Hjelm, Johan

    2014-01-01

    Impedance spectroscopy is a powerful technique for detailed study of the electrochemical and transport processes that take place in fuel cells and electrolysis cells, including solid oxide cells (SOCs). Meaningful analysis of impedance measurements is nontrivial, however, because a large number...... of modeling parameters are fit to the many processes which often overlap in the same frequency ranges. Also, commonly used equivalent circuit (EC) models only provide zero-dimensional (0-D) approximations of the processes of the two electrodes, electrolyte and gas transport. Employing improved analytical...... electrode and 2-D gas transport models which have fewer unknown parameters for the same number of processes, (ii) use of a new model fitting algorithm, “multi-fitting”, in which multiple impedance spectra are fit simultaneously with parameters linked based on the variation of measurement conditions, (iii...

  3. Advanced impedance modeling of solid oxide electrochemical cells

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Hjelm, Johan

    2014-01-01

    Impedance spectroscopy is a powerful technique for detailed study of the electrochemical and transport processes that take place in fuel cells and electrolysis cells, including solid oxide cells (SOCs). Meaningful analysis of impedance measurements is nontrivial, however, because a large number...... techniques to provide good guesses for the modeling parameters, like transforming the impedance data to the distribution of relaxation times (DRT), together with experimental parameter sensitivity studies, is the state-of-the-art approach to achieve good EC model fits. Here we present new impedance modeling......) constraining the parameter values during fitting to ranges of physically reasonable values. Using these methods, the number of fitting parameters for four impedance spectra measured with isolated changes to the fuel and oxidant gas compositions, has been reduced from 80 to 21-34 depending on the model...

  4. Nondestructive characterization methods for monolithic solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, W.A.

    1993-01-01

    Monolithic solid oxide fuel cells (MSOFCS) represent a potential breakthrough in fuel cell technology, provided that reliable fabrication methods can be developed. Fabrication difficulties arise in several steps of the processing: First is the fabrication of uniform thin (305 {mu}m) single-layer and trilayer green tapes (the trilayer tapes of anode/electrolyte/cathode and anode/interconnect/cathode must have similar coefficients of thermal expansion to sinter uniformly and to have the necessary electrochemical properties); Second is the development of fuel and oxidant channels in which residual stresses are likely to develop in the tapes; Third is the fabrication of a ``complete`` cell for which the bond quality between layers and the quality of the trilayers must be established; and Last, attachment of fuel and oxidant manifolds and verification of seal integrity. Purpose of this report is to assess nondestructive characterization methods that could be developed for application to laboratory, prototype, and full-scale MSOFCs.

  5. Performance characterization of solid oxide cells under high pressure

    DEFF Research Database (Denmark)

    Sun, Xiufu; Bonaccorso, Alfredo Damiano; Graves, Christopher R.

    2014-01-01

    Solid oxide electrolysis cells (SOECs) offer a great potential for large scale conversion of renewable electrical energy into chemical energy via electrolysis of H2O and CO2 to produce syngas (H2 + CO). The produced syngas can be further catalytically converted into various gaseous or liquid...... hydrocarbon fuels, which is normally performed at high pressure to achieve a high yield. Operation of SOECs at elevated pressure will therefore facilitate integration with the downstream fuel synthesis and is furthermore advantageous as it increases the cell performance. In this work, recent pressurised test...... in both fuel cell mode and electrolysis mode. In electrolysis mode at low current density, the performance improvement was counteracted by the increase in open circuit voltage, but it has to be born in mind that the pressurised gas contains higher molar free energy. Operating at high current density...

  6. Color contrast of red blood cells on solid substrate

    Science.gov (United States)

    Paiziev, Adkham A.

    2013-02-01

    In present study we developed the new method of colour visualization of red blood cells without using any chemical staining. The method based on physical phenomena a white light interference on thin transparent films. It is shown that in the case of thin human blood smears colour interference contrast occurs on solid polished substrates. The best contrast shows substrates with maximal refractive index (Mo, W, Si). These materials have been selected as substrate instead of ordinary microscopic slide in reflected light microscopy. It is shown that reflection of incident white light from blood cell surface and boundary cell-substrate generate two coherent lights. The second one (object signal) after passing through red blood cell gathers additional phase and after interference interaction with reference signal (light reflected from outer cell surface) enables cell image in colour. Number of blood smears of healthy persons (control) and patients who were diagnosed with cancer are presented. It is concluded that the offered method may be used as an effective diagnostic tool to detect early stage blood cells lesion by its interference painting in white light. Offered method may be used in research laboratories, hospitals, diagnostic centres, emergency medicine and other as complementary diagnostic tool to present convenient optical and electron microscopy technique.

  7. An association between newly diagnosed cutaneous T cell lymphoma and prior impetigo: a nested case-control study.

    Science.gov (United States)

    Boursi, Ben; Haynes, Kevin; Mamtani, Ronac; Yang, Yu-Xiao

    2016-11-01

    Colonization with staphylococcus aureus (SA) is associated with disease activity and progression in patients with cutaneous T-cell lymphoma (CTCL) secondary to T-cell activation by bacterial superantigens. The aim of the current study was to evaluate the possible role of SA as an etiologic factor affecting CTCL initiation. We conducted a nested case-control study in a large population-representative database from the UK. Cases were defined as all patients with an incident diagnosis of mycosis fungoides (MF) or Sezary syndrome (SS) between 1995 and 2013. For every case, four eligible controls matched on age, sex, practice-site, and duration of follow-up were selected. Exposure of interest was clinical diagnosis of impetigo prior to CTCL diagnosis. Conditional logistic regression was used to calculate odds-ratio (ORs) and 95 % confidence-interval (CI) for CTCL risk. The results were further stratified according to age, sex and time interval between impetigo and CTCL diagnosis. The study population included 310 cases with MF or SS and 1223 matched controls. Among cases with CTCL 4.8 % (n = 15) had impetigo prior to cancer diagnosis compared to 2 % (n = 24) of controls. The adjusted OR for CTCL diagnosis among patients with prior impetigo was 2.33 (95 % CI 1.12-4.83). The risk was elevated among individuals with impetigo 1-5 years before cancer diagnosis (OR 3.33, 95 % CI 1.00-11.10). There was no change in risk among patients with impetigo more than 5 years before cancer diagnosis (OR 1.09, 95 % CI 0.35-3.37). Our results suggest a possible association between SA colonization and CTCL initiation that might serve as an important etiological factor for the disease.

  8. Solid Oxide Fuel Cells Operating on Alternative and Renewable Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoxing; Quan, Wenying; Xiao, Jing; Peduzzi, Emanuela; Fujii, Mamoru; Sun, Funxia; Shalaby, Cigdem; Li, Yan; Xie, Chao; Ma, Xiaoliang; Johnson, David; Lee, Jeong; Fedkin, Mark; LaBarbera, Mark; Das, Debanjan; Thompson, David; Lvov, Serguei; Song, Chunshan

    2014-09-30

    This DOE project at the Pennsylvania State University (Penn State) initially involved Siemens Energy, Inc. to (1) develop new fuel processing approaches for using selected alternative and renewable fuels – anaerobic digester gas (ADG) and commercial diesel fuel (with 15 ppm sulfur) – in solid oxide fuel cell (SOFC) power generation systems; and (2) conduct integrated fuel processor – SOFC system tests to evaluate the performance of the fuel processors and overall systems. Siemens Energy Inc. was to provide SOFC system to Penn State for testing. The Siemens work was carried out at Siemens Energy Inc. in Pittsburgh, PA. The unexpected restructuring in Siemens organization, however, led to the elimination of the Siemens Stationary Fuel Cell Division within the company. Unfortunately, this led to the Siemens subcontract with Penn State ending on September 23rd, 2010. SOFC system was never delivered to Penn State. With the assistance of NETL project manager, the Penn State team has since developed a collaborative research with Delphi as the new subcontractor and this work involved the testing of a stack of planar solid oxide fuel cells from Delphi.

  9. Perovskite enhanced solid state ZnO solar cells

    Science.gov (United States)

    Loh, L.; Briscoe, J.; Dunn, S.

    2013-12-01

    This paper will report on the design, fabrication and testing of a solid-state perovskite enhanced ZnO solar cell. The p-type perovskite material used is bismuth ferrite (BFO) which has an absorption range within the blue range of the visible light spectrum. The solid state solar cell, was sensitized with N719 dye and used a CuSCN hole conductor. A disadvantage of ZnO is its poor chemical stability in acidic and corrosive environments. As chemical solution techniques were used in depositing BFO, a buffer method using an aminosilane ((3-aminopropyltrimethoxysilane or H2N(CH2)3Si(OCH3)3)) coating was used to provide a protective coating on the ZnO nanorods before the BFO film was spin coated onto the ZnO nanorods. The photovoltaic performance of the solar cells were tested using a Keithley 2400 source meter under 100mW/cm2, AM 1.5G simulated sunlight, where improvements in Jsc and efficiency were observed. The BFO was able to harness more electrons and also acted as a buffer from electron recombination.

  10. Strategies for Lowering Solid Oxide Fuel Cells Operating Temperature

    Directory of Open Access Journals (Sweden)

    Albert Tarancón

    2009-11-01

    Full Text Available Lowering the operating temperature of solid oxide fuel cells (SOFCs to the intermediate range (500–700 ºC has become one of the main SOFC research goals. High operating temperatures put numerous requirements on materials selection and on secondary units, limiting the commercial development of SOFCs. The present review first focuses on the main effects of reducing the operating temperature in terms of materials stability, thermo-mechanical mismatch, thermal management and efficiency. After a brief survey of the state-of-the-art materials for SOFCs, attention is focused on emerging oxide-ionic conductors with high conductivity in the intermediate range of temperatures with an introductory section on materials technology for reducing the electrolyte thickness. Finally, recent advances in cathode materials based on layered mixed ionic-electronic conductors are highlighted because the decreasing temperature converts the cathode into the major source of electrical losses for the whole SOFC system. It is concluded that the introduction of alternative materials that would enable solid oxide fuel cells to operate in the intermediate range of temperatures would have a major impact on the commercialization of fuel cell technology.

  11. PREPARATION AND CHARACTERIZATION OF SOLID ELECTROLYTES: FUEL CELL APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rambabu Bobba; Josef Hormes; T. Wang; Jaymes A. Baker; Donald G. Prier; Tommy Rockwood; Dinesha Hawkins; Saleem Hasan; V. Rayanki

    1997-12-31

    The intent of this project with Federal Energy Technology Center (FETC)/Morgantown Energy Technology Center (METC) is to develop research infrastructure conductive to Fuel Cell research at Southern University and A and M College, Baton Route. A state of the art research laboratory (James Hall No.123 and No.114) for energy conversion and storage devices was developed during this project duration. The Solid State Ionics laboratory is now fully equipped with materials research instruments: Arbin Battery Cycling and testing (8 channel) unit, Electrochemical Analyzer (EG and G PAR Model 273 and Solartron AC impedance analyzer), Fuel Cell test station (Globe Tech), Differential Scanning Calorimeter (DSC-10), Thermogravimetric Analyzer (TGA), Scanning Tunneling Microscope (STM), UV-VIS-NIR Absorption Spectrometer, Fluorescence Spectrometer, FT-IR Spectrometer, Extended X-ray Absorption Fine Structure (EXAFS) measurement capability at Center for Advanced Microstructure and Devices (CAMD- a multimillion dollar DOE facility), Glove Box, gas hood chamber, high temperature furnaces, hydraulic press and several high performance computers. IN particular, a high temperature furnace (Thermodyne 6000 furnace) and a high temperature oven were acquired through this project funds. The PI Dr. R Bobba has acquired additional funds from federal agencies include NSF-Academic Research Infrastructure program and other DOE sites. They have extensively used the multimillion dollar DOE facility ''Center'' for Advanced Microstructures and Devices (CAMD) for electrochemical research. The students were heavily involved in the experimental EXAFS measurements and made use of their DCM beamline for EXAFS research. The primary objective was to provide hands on experience to the selected African American undergraduate and graduate students in experimental energy research.The goal was to develop research skills and involve them in the Preparation and Characterization of Solid

  12. Trends for Methane Oxidation at Solid Oxide Fuel Cell Conditions

    DEFF Research Database (Denmark)

    Kleis, Jesper; Jones, Glenn; Abild-Pedersen, Frank

    2009-01-01

    First-principles calculations are used to predict a plausible reaction pathway for the methane oxidation reaction. In turn, this pathway is used to obtain trends in methane oxidation activity at solid oxide fuel cell (SOFC) anode materials. Reaction energetics and barriers for the elementary...... reaction steps on both the close-packed Ni{111} and stepped Ni{211} surfaces are presented. Quantum-mechanical calculations augmented with thermodynamic corrections allow appropriate treatment of the elevated temperatures in SOFCs. Linear scaling relationships are used to extrapolate the results from...

  13. Durability of solid oxide fuel cells using sulfur containing fuels

    DEFF Research Database (Denmark)

    Hagen, Anke; Rasmussen, Jens Foldager Bregnballe; Thydén, Karl Tor Sune

    2011-01-01

    The usability of hydrogen and also carbon containing fuels is one of the important advantages of solid oxide fuel cells (SOFCs), which opens the possibility to use fuels derived from conventional sources such as natural gas and from renewable sources such as biogas. Impurities like sulfur compounds...... are critical in this respect. State-of-the-art Ni/YSZ SOFC anodes suffer from being rather sensitive towards sulfur impurities. In the current study, anode supported SOFCs with Ni/YSZ or Ni/ScYSZ anodes were exposed to H2S in the ppm range both for short periods of 24h and for a few hundred hours. In a fuel...

  14. Materials System for Intermediate Temperature Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Uday B. Pal; Srikanth Gopalan

    2006-01-12

    The objective of this work was to obtain a stable materials system for intermediate temperature solid oxide fuel cell (SOFC) capable of operating between 600-800 C with a power density greater than 0.2 W/cm{sup 2}. The solid electrolyte chosen for this system was La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3}, (LSGM). To select the right electrode materials from a group of possible candidate materials, AC complex impedance spectroscopy studies were conducted between 600-800 C on symmetrical cells that employed the LSGM electrolyte. Based on the results of the investigation, LSGM electrolyte supported SOFCs were fabricated with La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3}-La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3} (LSCF-LSGM) composite cathode and Nickel-Ce{sub 0.6}La{sub 0.4}O{sub 3} (Ni-LDC) composite anode having a barrier layer of Ce{sub 0.6}La{sub 0.4}O{sub 3} (LDC) between the LSGM electrolyte and the Ni-LDC anode. Electrical performance and stability of these cells were determined and the electrode polarization behavior as a function of cell current was modeled between 600-800 C. The electrical performance of the anode-supported SOFC was simulated assuming an electrode polarization behavior identical to the LSGM-electrolyte-supported SOFC. The simulated electrical performance indicated that the selected material system would provide a stable cell capable of operating between 600-800 C with a power density between 0.2 to 1 W/cm{sup 2}.

  15. Five Kilowatt Solid Oxide Fuel Cell/Diesel Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Witmer; Thomas Johnson

    2008-12-31

    Reducing fossil fuel consumption both for energy security and for reduction in global greenhouse emissions has been a major goal of energy research in the US for many years. Fuel cells have been proposed as a technology that can address both these issues--as devices that convert the energy of a fuel directly into electrical energy, they offer low emissions and high efficiencies. These advantages are of particular interest to remote power users, where grid connected power is unavailable, and most electrical power comes from diesel electric generators. Diesel fuel is the fuel of choice because it can be easily transported and stored in quantities large enough to supply energy for small communities for extended periods of time. This projected aimed to demonstrate the operation of a solid oxide fuel cell on diesel fuel, and to measure the resulting efficiency. Results from this project have been somewhat encouraging, with a laboratory breadboard integration of a small scale diesel reformer and a Solid Oxide Fuel Cell demonstrated in the first 18 months of the project. This initial demonstration was conducted at INEEL in the spring of 2005 using a small scale diesel reformer provided by SOFCo and a fuel cell provided by Acumentrics. However, attempts to integrate and automate the available technology have not proved successful as yet. This is due both to the lack of movement on the fuel processing side as well as the rather poor stack lifetimes exhibited by the fuel cells. Commercial product is still unavailable, and precommercial devices are both extremely expensive and require extensive field support.

  16. Planar solid oxide fuel cells: the Australian experience and outlook

    Science.gov (United States)

    Godfrey, Bruce; Föger, Karl; Gillespie, Rohan; Bolden, Roger; Badwal, S. P. S.

    Since 1992, Ceramic Fuel Cells (CFCL) has grown to what is now the largest focussed program globally for development of planar ceramic (solid oxide) fuel cell, SOFC, technology. A significant intellectual property position in know-how and patents has been developed, with over 80 people involved in the venture. Over $A60 million in funding for the activities of the company has been raised from private companies, government-owned corporations and government business-support programs, including from energy — particularly electricity — industry shareholders that can facilitate access to local markets for our products. CFCL has established state-of-the-art facilities for planar SOFC R&D, with their expansion and scaling-up to pilot manufacturing capability underway. We expect to achieve commercial introduction of our market-entry products in 2002, with prototype systems expected to be available from early 2001.

  17. Review on MIEC Cathode Materials for Solid Oxide Fuel Cells

    Science.gov (United States)

    Burnwal, Suman Kumar; Bharadwaj, S.; Kistaiah, P.

    2016-11-01

    The cathode is one of the most important components of solid oxide fuel cells (SOFCs). The reduction of oxygen at the cathode (traditional cathodes like LSM, LSGM, etc.) is the slow step in the cell reaction at intermediate temperature (600-800∘C) which is one of the key obstacles to the development of SOFCs. The mixed ionic and electronic conducting cathode (MIEC) like LSCF, BSCF, etc., has recently been proposed as a promising cathode material for SOFC due to the improvement of the kinetic of the cathode reaction. The MIEC materials provide not only the electrons for the reduction of oxygen, but also the ionic conduction required to ensure the transport of the formed oxygen ions and thereby improves the overall electrochemical performance of SOFC system. The characteristics of MIEC cathode materials and its comparison with other traditional cathode materials is studied and presented in the paper.

  18. Redox Stable Anodes for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Guoliang eXiao

    2014-06-01

    Full Text Available Solid oxide fuel cells (SOFCs can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as the fuel. This review aims to highlight recent progresses on improving redox stability of the conventional Ni-based anode through microstructure optimization and exploration of alternative ceramic-based anode materials.

  19. Isolation of Precursor Cells from Waste Solid Fat Tissue

    Science.gov (United States)

    Byerly, Diane; Sognier, Marguerite A.

    2009-01-01

    A process for isolating tissue-specific progenitor cells exploits solid fat tissue obtained as waste from such elective surgical procedures as abdominoplasties (tummy tucks) and breast reductions. Until now, a painful and risky process of aspiration of bone marrow has been used to obtain a limited number of tissue- specific progenitor cells. The present process yields more tissue-specific progenitor cells and involves much less pain and risk for the patient. This process includes separation of fat from skin, mincing of the fat into small pieces, and forcing a fat saline mixture through a sieve. The mixture is then digested with collagenase type I in an incubator. After centrifugation tissue-specific progenitor cells are recovered and placed in a tissue-culture medium in flasks or Petri dishes. The tissue-specific progenitor cells can be used for such purposes as (1) generating three-dimensional tissue equivalent models for studying bone loss and muscle atrophy (among other deficiencies) and, ultimately, (2) generating replacements for tissues lost by the fat donor because of injury or disease.

  20. Solid oxide fuel cell performance under severe operating conditions

    DEFF Research Database (Denmark)

    Koch, Søren; Hendriksen, P.V.; Mogensen, Mogens Bjerg

    2006-01-01

    The performance and degradation of Solid Oxide Fuel Cells (SOFC) were studied under severe operating conditions. The cells studied were manufactured in a small series by ECN, in the framework of the EU funded CORE-SOFC project. The cells were of the anode-supported type with a double layer LSM...... cathode. They were operated at 750 °C or 850 °C in hydrogen with 5% or 50% water at current densities ranging from 0.25 A cm–2 to 1 A cm–2 for periods of 300 hours or more. The area specific cell resistance, corrected for fuel utilisation, ranged between 0.20 Ω cm2 and 0.34 Ω cm2 at 850 °C and 520 m......V, and between 0.51 Ω cm2 and 0.92 Ω cm2 at 750 °C and 520 mV. The degradation of cell performance was found to be low (ranging from 0 to 8%/1,000 hours) at regular operating conditions. Voltage degradation rates of 20 to 40%/1,000 hours were observed under severe operating conditions, depending on the test...

  1. Carbon monoxide-fueled solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Homel, Michael; Koh, Joon Ho [Materials and Systems Research, Inc., 5395 West 700 South, Salt Lake City, UT 84104 (United States); Guer, Turgut M. [Direct Carbon Technologies, LLC, 525 University Avenue, Suite 1400, Palo Alto, CA 94301 (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 (United States); Virkar, Anil V. [Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

    2010-10-01

    This study explored CO as a primary fuel in anode-supported solid oxide fuel cells (SOFCs) of both tubular and planar geometries. Tubular single cells with active areas of 24 cm{sup 2} generated power up to 16 W. Open circuit voltages for various CO/CO{sub 2} mixture compositions agreed well with the expected values. In flowing dry CO, power densities up to 0.67 W cm{sup -2} were achieved at 1 A cm{sup -2} and 850 C. This performance compared well with 0.74 W cm{sup -2} measured for pure H{sub 2} in the same cell and under the same operating conditions. Performance stability of tubular cells was investigated by long-term testing in flowing CO during which no carbon deposition was observed. At a constant current of 9.96 A (or, 0.414 A cm{sup -2}) power output remained unchanged over 375 h of continuous operation at 850 C. In addition, a 50-cell planar SOFC stack was operated at 800 C on 95% CO (balance CO{sub 2}), which generated 1176 W of total power at a power density of 224 mW cm{sup -2}. The results demonstrate that CO is a viable primary fuel for SOFCs. (author)

  2. A solid oxide fuel cell system for buildings

    International Nuclear Information System (INIS)

    Zink, Florian; Lu, Yixin; Schaefer, Laura

    2007-01-01

    This paper examines an integrated solid oxide fuel cell (SOFC) absorption heating and cooling system used for buildings. The integrated system can provide heating/cooling and/or hot water for buildings while consuming natural gas. The aim of this study is to give an overall description of the system. The possibility of such an integrated system is discussed and the configuration of the system is described. A system model is presented, and a specific case study of the system, which consists of a pre-commercial SOFC system and a commercial LiBr absorption system, is performed. In the case study, the detailed configuration of an integrated system is given, and the heat and mass balance and system performance are obtained through numerical calculation. Based on the case study, some considerations with respect to system component selection, system configuration and design are discussed. Additionally, the economic and environmental issues of this specific system are evaluated briefly. The results show that the combined system demonstrates great advantages in both technical and environmental aspects. With the present development trends in solid oxide fuel cells and the commercial status of absorption heating and cooling systems, it is very likely that such a combined system will become increasingly feasible within the following decade

  3. Thermal stress analysis of sulfur deactivated solid oxide fuel cells

    Science.gov (United States)

    Zeng, Shumao; Parbey, Joseph; Yu, Guangsen; Xu, Min; Li, Tingshuai; Andersson, Martin

    2018-03-01

    Hydrogen sulfide in fuels can deactivate catalyst for solid oxide fuel cells, which has become one of the most critical challenges to stability. The reactions between sulfur and catalyst will cause phase changes, leading to increase in cell polarization and mechanical mismatch. A three-dimensional computational fluid dynamics (CFD) approach based on the finite element method (FEM) is thus used to investigate the polarization, temperature and thermal stress in a sulfur deactivated SOFC by coupling equations for gas-phase species, heat, momentum, ion and electron transport. The results indicate that sulfur in fuels can strongly affect the cell polarization and thermal stresses, which shows a sharp decrease in the vicinity of electrolyte when 10% nickel in the functional layer is poisoned, but they remain almost unchanged even when the poisoned Ni content was increased to 90%. This investigation is helpful to deeply understand the sulfur poisoning effects and also benefit the material design and optimization of electrode structure to enhance cell performance and lifetimes in various hydrocarbon fuels containing impurities.

  4. Surface-modified low-temperature solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Beom; Holme, Timothy P. [Department of Mechanical Engineering, Stanford University, Stanford, CA 94305 (United States); Guer, Turgut M. [Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 (United States); Prinz, Fritz B. [Department of Mechanical Engineering, Stanford University, Stanford, CA 94305 (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 (United States)

    2011-12-20

    This paper reports both experimental and theoretical results of the role of surface modification on the oxygen reduction reaction in low-temperature solid oxide fuel cells (LT-SOFC). Epitaxial ultrathin films of yttria-doped ceria (YDC) cathode interlayers (<10-130 nm) are grown by pulsed laser deposition (PLD) on single-crystalline YSZ(100). Fuel cell current-voltage measurements and electrochemical impedance spectroscopy are performed in the temperature range of 350 C {approx} 450 C. Quantum mechanical simulations of oxygen incorporation energetics support the experimental results and indicate a low activation energy of only 0.07 eV for YDC, while the incorporation reaction on YSZ is activated by a significantly higher energy barrier of 0.38 eV. Due to enhanced oxygen incorporation at the modified Pt/YDC interface, the cathodic interface resistance is reduced by two-fold, while fuel cell performance shows more than a two-fold enhancement with the addition of an ultrathin YDC interlayer at the cathode side of an SOFC element. The results of this study open up opportunities for improving cell performance, particularly of LT-SOFCs by adopting surface modification of YSZ surface with catalytically superior, ultrathin cathodic interlayers. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Development of multilayer imprint process for solid oxide fuel cells

    Science.gov (United States)

    Tokumaru, Kazuki; Tsumori, Fujio; Kudo, Kentaro; Osada, Toshiko; Shinagawa, Kazunari

    2017-06-01

    Solid oxide fuel cells (SOFCs) are fuel cells made of ceramics. To increase the SOFC energy density, we developed an SOFC with a wavy electrolyte layer. As a wavy electrolyte has a larger reaction surface area than a flat electrolyte, a higher energy density could be obtained. Our proposed process is named micro-powder imprint (µPI) with a multilayer imprint process that is useful for fabricating a microscale pattern on a ceramic sheet such as an SOFC electrolyte layer. µPI is based on nanoimprint lithography; therefore, it also exhibits the same advantages of high resolution and mass productivity. The starting material for µPI is a compound sheet containing ceramic powder and binder materials consisting of thermoplastic resin. In this study, two different sheets were stacked into one sheet as a multilayer sheet for the µPI process to form a wavy compound sheet. As the initial state of the stacked sheet, including the mechanical properties of each layer, affects the final wavy shape, we changed the material composition. As a result, the SOFCs unit cell with a wavy electrolyte was fabricated. Note that the anode layer was formed at the same time. After adding the cathode layer, we succeeded in preparing a complete cell for testing power generation.

  6. Solid electrolyte-electrode system for an electrochemical cell

    Science.gov (United States)

    Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.

    1995-01-01

    An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is also provided.

  7. Switching on electrocatalytic activity in solid oxide cells

    Science.gov (United States)

    Myung, Jae-Ha; Neagu, Dragos; Miller, David N.; Irvine, John T. S.

    2016-09-01

    Solid oxide cells (SOCs) can operate with high efficiency in two ways—as fuel cells, oxidizing a fuel to produce electricity, and as electrolysis cells, electrolysing water to produce hydrogen and oxygen gases. Ideally, SOCs should perform well, be durable and be inexpensive, but there are often competitive tensions, meaning that, for example, performance is achieved at the expense of durability. SOCs consist of porous electrodes—the fuel and air electrodes—separated by a dense electrolyte. In terms of the electrodes, the greatest challenge is to deliver high, long-lasting electrocatalytic activity while ensuring cost- and time-efficient manufacture. This has typically been achieved through lengthy and intricate ex situ procedures. These often require dedicated precursors and equipment; moreover, although the degradation of such electrodes associated with their reversible operation can be mitigated, they are susceptible to many other forms of degradation. An alternative is to grow appropriate electrode nanoarchitectures under operationally relevant conditions, for example, via redox exsolution. Here we describe the growth of a finely dispersed array of anchored metal nanoparticles on an oxide electrode through electrochemical poling of a SOC at 2 volts for a few seconds. These electrode structures perform well as both fuel cells and electrolysis cells (for example, at 900 °C they deliver 2 watts per square centimetre of power in humidified hydrogen gas, and a current of 2.75 amps per square centimetre at 1.3 volts in 50% water/nitrogen gas). The nanostructures and corresponding electrochemical activity do not degrade in 150 hours of testing. These results not only prove that in operando methods can yield emergent nanomaterials, which in turn deliver exceptional performance, but also offer proof of concept that electrolysis and fuel cells can be unified in a single, high-performance, versatile and easily manufactured device. This opens up the possibility of

  8. Solid oxide fuel cell generator with removable modular fuel cell stack configurations

    Science.gov (United States)

    Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

    1998-04-21

    A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

  9. Electrode design for low temperature direct-hydrocarbon solid oxide fuel cells

    Science.gov (United States)

    Chen, Fanglin; Zhao, Fei; Liu, Qiang

    2015-10-06

    In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.

  10. Electrode Design for Low Temperature Direct-Hydrocarbon Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Fanglin (Inventor); Zhao, Fei (Inventor); Liu, Qiang (Inventor)

    2015-01-01

    In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.

  11. Resilient Sealing Materials for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Signo T. Reis; Richard K. Brow

    2006-09-30

    This report describes the development of ''invert'' glass compositions designed for hermetic seals in solid oxide fuel cells (SOFC). Upon sealing at temperatures compatible with other SOFC materials (generally {le}900 C), these glasses transform to glass-ceramics with desirable thermo-mechanical properties, including coefficients of thermal expansion (CTE) over 11 x 10{sup -6}/C. The long-term (>four months) stability of CTE under SOFC operational conditions (e.g., 800 C in wet forming gas or in air) has been evaluated, as have weight losses under similar conditions. The dependence of sealant properties on glass composition are described in this report, as are experiments to develop glass-matrix composites by adding second phases, including Ni and YSZ. This information provides design-guidance to produce desirable sealing materials.

  12. Solid Oxide Fuel Cell Seal Glass - BN Nanotubes Composites

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.; Hurst, Janet B.; Garg, Anita

    2005-01-01

    Solid oxide fuel cell seal glass G18 composites reinforced with approx.4 weight percent of BN nanotubes were fabricated via hot pressing. Room temperature strength and fracture toughness of the composite were determined by four-point flexure and single edge V-notch beam methods, respectively. The strength and fracture toughness of the composite were higher by as much as 90% and 35%, respectively, than those of the glass G18. Microscopic examination of the composite fracture surfaces using SEM and TEM showed pullout of the BN nanotubes, similar in feature to fiber-reinforced ceramic matrix composites with weak interfaces. Other mechanical and physical properties of the composite will also be presented.

  13. Anodes for Solid Oxide Fuel Cells Operating at Low Temperatures

    DEFF Research Database (Denmark)

    Abdul Jabbar, Mohammed Hussain

    An important issue that has limited the potential of Solid Oxide Fuel Cells (SOFCs) for portable applications is its high operating temperatures (800-1000 ºC). Lowering the operating temperature of SOFCs to 400-600 ºC enable a wider material selection, reduced degradation and increased lifetime....... On the other hand, low-temperature operation poses serious challenges to the electrode performance. Effective catalysts, redox stable electrodes with improved microstructures are the prime requisite for the development of efficient SOFC anodes. The performance of Nb-doped SrT iO3 (STN) ceramic anodes...... at 400ºC. The potential of using WO3 ceramic as an alternative anode materials has been explored. The relatively high electrode polarization resistance obtained, 11 Ohm cm2 at 600 ºC, proved the inadequate catalytic activity of this system for hydrogen oxidation. At the end of this thesis...

  14. High Performance Nano-Ceria Electrodes for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Martinez Aguilera, Lev; Sudireddy, Bhaskar Reddy

    2016-01-01

    In solid oxide electrochemical cells, the conventional Ni-based fuel-electrodes provide high electrocatalytic activity but they are often a major source of long-term performance degradation due to carbon deposition, poisoning of reaction sites, Ni mobility, etc. Doped-ceria is a promising mixed...... ionic-electronic conducting oxide that could solve these issues if it can be integrated into an appropriate electrode structure. Two new approaches to obtain high-performance nanostructured doped-ceria electrodes are highlighted. The first is an infiltration-based architecture with Ce0.8Pr0.2O2-δ...... forming the active surfaces on a porous backbone with embedded electronic current collector material, yielding one of the highest performances reported for an electrode that operates either on fuel or oxidant. The second is a nano-Ce0.9Gd0.1O2-δ thin film prepared by spin-coating, which provides...

  15. Solid oxide fuel cell having a glass composite seal

    Science.gov (United States)

    De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

    2013-04-16

    A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

  16. Differential effects of antofine N-oxide on solid tumor and leukemia cells.

    Science.gov (United States)

    Bour, Tania; Yang, Xianwen; Li, Weihong; Bernardin, Francois; Kaoma, Tony; Muller, Arnaud; Vallar, Laurent; Steinmetz, André

    2014-01-01

    We have studied the anti-cancer activities of antofine N-oxide isolated and purified from the medicinal plant Cynanchum vincetoxicum. Antofine N-oxide displayed a strong inhibitory effect on several solid tumor cell lines (glioblastoma, breast carcinoma and lung carcinoma) and on a T-cell leukemia cell line. Remarkably, its cytotoxic effect was considerably weaker in non-cancer cells. Antofine N-oxide was found to inhibit proliferation of the solid tumor cells whereas it caused apoptotic cell death in the leukemia cells. A microarray analysis after a short treatment revealed that the number of differentially expressed genes was considerably higher in solid tumor than in leukemia cells. Up-regulated genes in the three solid tumor cell lines include genes related to TNFα signaling, of which TNFα was among the most significantly induced. A functional analysis revealed that TNFR1 signaling was most likely activated in the solid tumor cells. The increased mRNA levels of several genes of this pathway (namely TNFα, TNFAIP3 and BIRC3) were confirmed by real-time quantitative PCR after different treatment durations. Finally a slight inhibition of NFκB-mediated transcription was observed in the same cells. Together our results suggest that inhibition of cell proliferation in solid tumor cells essentially occurs through TNFα signaling whereas this pathway is not activated in leukemia cells. Apoptotic cell death in the latter is induced by a distinct yet unknown pathway.

  17. Desensitization for solid organ and hematopoietic stem cell transplantation

    Science.gov (United States)

    Zachary, Andrea A; Leffell, Mary S

    2014-01-01

    Desensitization protocols are being used worldwide to enable kidney transplantation across immunologic barriers, i.e. antibody to donor HLA or ABO antigens, which were once thought to be absolute contraindications to transplantation. Desensitization protocols are also being applied to permit transplantation of HLA mismatched hematopoietic stem cells to patients with antibody to donor HLA, to enhance the opportunity for transplantation of non-renal organs, and to treat antibody-mediated rejection. Although desensitization for organ transplantation carries an increased risk of antibody-mediated rejection, ultimately these transplants extend and enhance the quality of life for solid organ recipients, and desensitization that permits transplantation of hematopoietic stem cells is life saving for patients with limited donor options. Complex patient factors and variability in treatment protocols have made it difficult to identify, precisely, the mechanisms underlying the downregulation of donor-specific antibodies. The mechanisms underlying desensitization may differ among the various protocols in use, although there are likely to be some common features. However, it is likely that desensitization achieves a sort of immune detente by first reducing the immunologic barrier and then by creating an environment in which an autoregulatory process restricts the immune response to the allograft. PMID:24517434

  18. Integrated Solid Oxide Fuel Cell Power System Characteristics Prediction

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2009-07-01

    Full Text Available The main objective of this paper is to deduce the specific characteristics of the CHP 100kWe Solid Oxide Fuel Cell (SOFC Power System from the steady state experimental data. From the experimental data, the authors have been developed and validated the steady state mathematical model. From the control room the steady state experimental data of the SOFC power conditioning are available and using the developed steady state mathematical model, the authors have been obtained the characteristic curves of the system performed by Siemens-Westinghouse Power Corporation. As a methodology the backward and forward power flow analysis has been employed. The backward power flow makes possible to obtain the SOFC power system operating point at different load levels, resulting as the load characteristic. By knowing the fuel cell output characteristic, the forward power flow analysis is used to predict the power system efficiency in different operating points, to choose the adequate control decision in order to obtain the high efficiency operation of the SOFC power system at different load levels. The CHP 100kWe power system is located at Gas Turbine Technologies Company (a Siemens Subsidiary, TurboCare brand in Turin, Italy. The work was carried out through the Energia da Ossidi Solidi (EOS Project. The SOFC stack delivers constant power permanently in order to supply the electric and thermal power both to the TurboCare Company and to the national grid.

  19. Glass/Ceramic Composites for Sealing Solid Oxide Fuel Cells

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2007-01-01

    A family of glass/ceramic composite materials has been investigated for use as sealants in planar solid oxide fuel cells. These materials are modified versions of a barium calcium aluminosilicate glass developed previously for the same purpose. The composition of the glass in mole percentages is 35BaO + 15CaO + 5Al2O3 + 10B2O3 + 35SiO2. The glass seal was found to be susceptible to cracking during thermal cycling of the fuel cells. The goal in formulating the glass/ ceramic composite materials was to (1) retain the physical and chemical advantages that led to the prior selection of the barium calcium aluminosilicate glass as the sealant while (2) increasing strength and fracture toughness so as to reduce the tendency toward cracking. Each of the composite formulations consists of the glass plus either of two ceramic reinforcements in a proportion between 0 and 30 mole percent. One of the ceramic reinforcements consists of alumina platelets; the other one consists of particles of yttria-stabilized zirconia wherein the yttria content is 3 mole percent (3YSZ). In preparation for experiments, panels of the glass/ceramic composites were hot-pressed and machined into test bars.

  20. Filled glass composites for sealing of solid oxide fuel cells.

    Energy Technology Data Exchange (ETDEWEB)

    Tandon, Rajan; Widgeon, Scarlett Joyce; Garino, Terry J.; Brochu, Mathieu; Gauntt, Bryan D.; Corral, Erica L.; Loehman, Ronald E.

    2009-04-01

    Glasses filled with ceramic or metallic powders have been developed for use as seals for solid oxide fuel cells (SOFC's) as part of the U.S. Department of Energy's Solid State Energy Conversion Alliance (SECA) Program. The composites of glass (alkaline earth-alumina-borate) and powders ({approx}20 vol% of yttria-stabilized zirconia or silver) were shown to form seals with SOFC materials at or below 900 C. The type and amount of powder were adjusted to optimize thermal expansion to match the SOFC materials and viscosity. Wetting studies indicated good wetting was achieved on the micro-scale and reaction studies indicated that the degree of reaction between the filled glasses and SOFC materials, including spinel-coated 441 stainless steel, at 750 C is acceptable. A test rig was developed for measuring strengths of seals cycled between room temperature and typical SOFC operating temperatures. Our measurements showed that many of the 410 SS to 410 SS seals, made using silver-filled glass composites, were hermetic at 0.2 MPa (2 atm.) of pressure and that seals that leaked could be resealed by briefly heating them to 900 C. Seal strength measurements at elevated temperature (up to 950 C), measured using a second apparatus that we developed, indicated that seals maintained 0.02 MPa (0.2 atm.) overpressures for 30 min at 750 C with no leakage. Finally, the volatility of the borate component of sealing glasses under SOFC operational conditions was studied using weight loss measurements and found by extrapolation to be less than 5% for the projected SOFC lifetime.

  1. Solid oxide fuel cells towards real life applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    Solid Oxide Fuel Cells offer a clean and efficient way of producing electricity and heat from a wide selection of fuels. The project addressed three major challenges to be overcome by the technology to make commercialisation possible. (1) At the cell level, increased efficiency combined with production cost reduction has been achieved through an optimization of the manufacturing processes, b) by using alternative raw materials with a lower purchase price and c) by introducing a new generation of fuel cells with reduced loss and higher efficiency. (2) At the stack level, production cost reduction is reduced and manufacturing capacity is increased through an optimization of the stack production. (3) At the system level, development of integrated hotbox concepts for the market segments distributed generation (DG), micro combined heat and power (mCHP), and auxiliary power units (APU) have been developed. In the mCHP segment, two concepts have been developed and validated with regards to market requirements and scalability. In the APU-segment, different types of reformers have been tested and it has been proven that diesel can be reformed through appropriate reformers. Finally, operation experience and feedback has been gained by deployment of stacks in the test facility at the H.C. OErsted Power Plant (HCV). This demonstration has been carried out in collaboration between TOFC and DONG Energy Power A/S (DONG), who has participated as a subcontractor to TOFC. The demonstration has given valuable knowledge and experience with design, start-up and operation of small power units connected to the grid and future development within especially the mCHP segment will benefit from this. In this report, the project results are described for each of the work packages in the project. (Author)

  2. Evaluation of apatite silicates as solid oxide fuel cell electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-Lopez, D. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Martin-Sedeno, M.C.; Aranda, M.A.G. [Dpto. de Quimica Inorganica, Universidad Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C.; Nunez, P. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Ramos-Barrado, J.R. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain)

    2010-05-01

    Apatite-type silicates have been considered as promising electrolytes for Solid Oxide Fuel Cells (SOFC); however studies on the potential use of these materials in SOFC devices have received relatively little attention. The lanthanum silicate with composition La{sub 10}Si{sub 5.5}Al{sub 0.5}O{sub 26.75} has been evaluated as electrolyte with the electrode materials commonly used in SOFC, i.e. manganite, ferrite and cobaltite as cathode materials and NiO-CGO composite, chromium-manganite and Sr{sub 2}MgMoO{sub 6} as anode materials. Chemical compatibility, area-specific resistance and fuel cell studies have been performed. X-ray powder diffraction (XRPD) analysis did not reveal any trace of reaction products between the apatite electrolyte and most of the aforementioned electrode materials. However, the area-specific polarisation resistance (ASR) of these electrodes in contact with apatite electrolyte increased significantly with the sintering temperature, indicating reactivity at the electrolyte/electrode interface. On the other hand, the ASR values are significantly improved using a ceria buffer layer between the electrolyte and electrode materials to prevent reactivity. Maximum power densities of 195 and 65 mWcm{sup -2} were obtained at 850 and 700 C, respectively in H{sub 2} fuel, using an 1 mm-thick electrolyte, a NiO-Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9} composite as anode and La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} as cathode materials. This fuel cell was tested for 100 h in 5%H{sub 2}-Ar atmosphere showing stable performance. (author)

  3. Low Temperature, High Energy Density Micro Thin Film Solid Oxide Fuel Cell Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of solid oxide fuel cell based on thin film technology and ultra-thin electrolyte is being proposed to develop to realize major reductions in fuel cell...

  4. Localized Carbon Deposition in Solid Oxide Electrolysis Cells Studied By Multiphysics Modeling

    DEFF Research Database (Denmark)

    Navasa, Maria; Graves, Christopher R.; Frandsen, Henrik Lund

    2016-01-01

    Modeling for optimizing performance has attracted substantial research efforts in the last twenty years with special focus on solid oxide fuel cells (SOFCs). However, limited amount of the modeling work has been focused on the solid oxide electrolysis cell (SOEC) operation mode and even less...

  5. Compact hydrogen production systems for solid polymer fuel cells

    Science.gov (United States)

    Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

    Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

  6. Constrained Sintering in Fabrication of Solid Oxide Fuel Cells.

    Science.gov (United States)

    Lee, Hae-Weon; Park, Mansoo; Hong, Jongsup; Kim, Hyoungchul; Yoon, Kyung Joong; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook

    2016-08-09

    Solid oxide fuel cells (SOFCs) are inevitably affected by the tensile stress field imposed by the rigid substrate during constrained sintering, which strongly affects microstructural evolution and flaw generation in the fabrication process and subsequent operation. In the case of sintering a composite cathode, one component acts as a continuous matrix phase while the other acts as a dispersed phase depending upon the initial composition and packing structure. The clustering of dispersed particles in the matrix has significant effects on the final microstructure, and strong rigidity of the clusters covering the entire cathode volume is desirable to obtain stable pore structure. The local constraints developed around the dispersed particles and their clusters effectively suppress generation of major process flaws, and microstructural features such as triple phase boundary and porosity could be readily controlled by adjusting the content and size of the dispersed particles. However, in the fabrication of the dense electrolyte layer via the chemical solution deposition route using slow-sintering nanoparticles dispersed in a sol matrix, the rigidity of the cluster should be minimized for the fine matrix to continuously densify, and special care should be taken in selecting the size of the dispersed particles to optimize the thermodynamic stability criteria of the grain size and film thickness. The principles of constrained sintering presented in this paper could be used as basic guidelines for realizing the ideal microstructure of SOFCs.

  7. Low temperature processing solid-state dye sensitized solar cells

    Science.gov (United States)

    Jiang, C. Y.; Koh, W. L.; Leung, M. Y.; Chiam, S. Y.; Wu, J. S.; Zhang, J.

    2012-03-01

    A study on low temperature processed solid state dye sensitized solar cell (LT-SDSC) is reported. The LT-SDSC uses a photoelectrode with a mesoporous TiO2 (mp-TiO2) film fabricated from a binder-free nanoparticle-TiO2 paste at room temperature, and a blocking layer of an amorphous TiO2 thin film deposited by atomic layer deposition (ALD) at 150 °C. A power conversion efficiency of 1.30% is obtained from the LT-SDSC with 0.9 μm mp-TiO2 layer and 20 nm ALD-TiO2 blocking layer, in cooperating with organic indoline dyes and a hole conductor, 2,2',7,7'-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD). The lower electron conductivity of the low-temperature-processed mp-TiO2 film and the amorphous blocking layer is equilibrated by using smaller thicknesses of the films. Ways to further boost the LT-SDSC performance are proposed. These LT-SDSC are potentially compatible with low cost plastic substrates and show promising manufacturing potential for low cost flexible SDSCs.

  8. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Motwani

    2011-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential,, within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, non-equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  9. Electrolysis of carbon dioxide in Solid Oxide Electrolysis Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Mogensen, Mogens Bjerg

    2009-01-01

    Carbon dioxide electrolysis was studied in Ni/YSZ electrode supported Solid Oxide Electrolysis Cells (SOECs) consisting of a Ni-YSZ support, a Ni-YSZ electrode layer, a YSZ electrolyte, and a LSM-YSZ O2 electrode (YSZ = Yttria Stabilized Zirconia). The results of this study show that long term CO2...... electrolysis is possible in SOECs with nickel electrodes.The passivation rate of the SOEC was between 0.22 and 0.44 mV h−1 when operated in mixtures of CO2/CO = 70/30 or CO2/CO = 98/02 (industrial grade) at 850 °C and current densities between −0.25 and −0.50 A cm−2. The passivation rate was independent...... of the current density and irreversible when operated at conditions that would oxidise carbon. This clearly shows that the passivation was not caused by coke formation. On the other hand, the passivation was partly reversible when introducing hydrogen. The passivation may be a consequence of impurities...

  10. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    W.L. Lundberg; G.A. Israelson; R.R. Moritz(Rolls-Royce Allison); S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann (Consultant)

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  11. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  12. Functionally Graded Cathodes for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harry Abernathy; Meilin Liu

    2006-12-31

    One primary suspected cause of long-term performance degradation of solid oxide fuels (SOFCs) is the accumulation of chromium (Cr) species at or near the cathode/electrolyte interface due to reactive Cr molecules originating from Cr-containing components (such as the interconnect) in fuel cell stacks. To date, considerable efforts have been devoted to the characterization of cathodes exposed to Cr sources; however, little progress has been made because a detailed understanding of the chemistry and electrochemistry relevant to the Cr-poisoning processes is still lacking. This project applied multiple characterization methods - including various Raman spectroscopic techniques and various electrochemical performance measurement techniques - to elucidate and quantify the effect of Cr-related electrochemical degradation at the cathode/electrolyte interface. Using Raman microspectroscopy the identity and location of Cr contaminants (SrCrO{sub 4}, (Mn/Cr){sub 3}O{sub 4} spinel) have been observed in situ on an LSM cathode. These Cr contaminants were shown to form chemically (in the absence of current flowing through the cell) at temperatures as low as 625 C. While SrCrO{sub 4} and (Mn/Cr){sub 3}O{sub 4} spinel must preferentially form on LSM, since the LSM supplies the Sr and Mn cations necessary for these compounds, LSM was also shown to be an active site for the deposition of Ag{sub 2}CrO{sub 4} for samples that also contained silver. In contrast, Pt and YSZ do not appear to be active for formation of Cr-containing phases. The work presented here supports the theory that Cr contamination is predominantly chemically-driven and that in order to minimize the effect, cathode materials should be chosen that are free of cations/elements that could preferentially react with chromium, including silver, strontium, and manganese.

  13. Mathematical modeling of oxygen transport in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Ann Mari

    1997-12-31

    This thesis develops mathematical models to describe the electrochemical performance of a solid oxide fuel cell cathode based on electrochemical kinetics and mass transfer. The individual effects of various coupled processes are investigated. A one-dimensional model is developed based on porous electrode theory. Two different mechanisms are investigated for the charge transfer reaction. One of these assumes that intermediately adsorbed oxygen atoms are reduced at the electrode/electrolyte interface, similar to the models proposed for metal electrodes. Simulated polarization curves exhibit limited currents due to depletion of oxygen adsorbates at high cathodic overvoltages. An empirical correlation is confirmed to exist between the limiting current an the oxygen partial pressure, however, a similar correlation often assumed to exist between the measured polarization resistance and the oxygen partial pressure could not be justified. For the other model, oxygen vacancies are assumed to be exchanged directly at the electrode/electrolyte interface. The electrochemical behaviour is improved by reducing the oxygen partial pressure, due to increased vacancy concentration of the electrode material. Simulated polarization curves exhibit Tafel-like slopes in the cathodic direction, which are due to polarization concentration, and not activation polarization in the conventional sense. Anodic limiting currents are predicted due to lack of available free sites for vacancy exchange at the cathode side. The thesis also presents a theoretical treatment of current and potential distributions in simple two-dimensional cell geometries, and a two-dimensional model for a porous electrode-electrolyte system for investigation of the effect of interfacial diffusion of adsorbates along the electrode/electrolyte interface. 172 refs., 60 figs., 11 tabs.

  14. Development of single chamber solid oxide fuel cells (SCFC)

    Energy Technology Data Exchange (ETDEWEB)

    Viricelle, J.-P.; Udroiu, S.; Gadacz, G.; Pijolat, M.; Pijolat, C. [Ecole Nationale Superieure des Mines de Saint-Etienne, Centre SPIN, LPMG-UMR CNRS 5148, 158 cours Fauriel, 42023 Saint-Etienne Cedex 02 (France)

    2010-08-15

    Single Chamber Solid Oxide Fuel Cells (SCFC) have been prepared using an electrolyte as support (Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} named GDC). Anode (Ni-GDC) and different cathodes (Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3} (SSC), Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.2}Fe{sub 0.8}O{sub 3} (BSCF) and La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSM)) were placed on the same side of the electrolyte. All the electrodes were deposited using screen-printing technology. A gold collector was also deposited on the cathode to decrease the over-potential. The different materials and fuel cell devices were tested under propane/air mixture, after a preliminary treatment under hydrogen to reduce the as-deposited nickel oxide anode. The results show that SSC and BSCF cathodes are not stable in these conditions, leading to a very low open circuit voltage (OCV) of 150 mV. Although LSM material is not the more adequate cathode regarding its high catalytic activity towards hydrocarbon conversion, it has a better chemical stability than SSC and BSCF. Ni-GDC-LSM SCFC devices were elaborated and tested; an OCV of nearly 750 mV could be obtained with maximum power densities around 20 mW cm{sup -2} at 620 C, under air-propane mixture with C{sub 3}H{sub 8}/O{sub 2} ratio equal to 0.53. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  15. Hurdles of CAR-T cell-based cancer immunotherapy directed against solid tumors.

    Science.gov (United States)

    Zhang, Bing-Lan; Qin, Di-Yuan; Mo, Ze-Ming; Li, Yi; Wei, Wei; Wang, Yong-Sheng; Wang, Wei; Wei, Yu-Quan

    2016-04-01

    Recent reports on the impressive efficacy of chimeric antigen receptor (CAR)-modified T cells against hematologic malignancies have inspired oncologists to extend these efforts for the treatment of solid tumors. Clinical trials of CAR-T-based cancer immunotherapy for solid tumors showed that the efficacies are not as remarkable as in the case of hematologic malignancies. There are several challenges that researchers must face when treating solid cancers with CAR-T cells, these include choosing an ideal target, promoting efficient trafficking and infiltration, overcoming the immunosuppressive microenvironment, and avoiding associated toxicity. In this review, we discuss the obstacles imposed by solid tumors on CAR-T cell-based immunotherapy and strategies adopted to improve the therapeutic potential of this approach. Continued investigations are necessary to improve therapeutic outcomes and decrease the adverse effects of CAR-T cell therapy in patients with solid malignancies in the future.

  16. Functionally Graded Cathodes for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    YongMan Choi; Meilin Liu

    2006-09-30

    This DOE SECA project focused on both experimental and theoretical understanding of oxygen reduction processes in a porous mixed-conducting cathode in a solid oxide fuel cell (SOFC). Elucidation of the detailed oxygen reduction mechanism, especially the rate-limiting step(s), is critical to the development of low-temperature SOFCs (400 C to 700 C) and to cost reduction since much less expensive materials may be used for cell components. However, cell performance at low temperatures is limited primarily by the interfacial polarization resistances, specifically by those associated with oxygen reduction at the cathode, including transport of oxygen gas through the porous cathode, the adsorption of oxygen onto the cathode surface, the reduction and dissociation of the oxygen molecule (O{sub 2}) into the oxygen ion (O{sup 2-}), and the incorporation of the oxygen ion into the electrolyte. In order to most effectively enhance the performance of the cathode at low temperatures, we must understand the mechanism and kinetics of the elementary processes at the interfaces. Under the support of this DOE SECA project, our accomplishments included: (1) Experimental determination of the rate-limiting step in the oxygen reduction mechanism at the cathode using in situ FTIR and Raman spectroscopy, including surface- and tip-enhanced Raman spectroscopy (SERS and TERS). (2) Fabrication and testing of micro-patterned cathodes to compare the relative activity of the TPB to the rest of the cathode surface. (3) Construction of a mathematical model to predict cathode performance based on different geometries and microstructures and analyze the kinetics of oxygen-reduction reactions occurring at charged mixed ionic-electronic conductors (MIECs) using two-dimensional finite volume models with ab initio calculations. (4) Fabrication of cathodes that are graded in composition and microstructure to generate large amounts of active surface area near the cathode/electrolyte interface using a

  17. Probing and Mapping Electrode Surfaces in Solid Oxide Fuel Cells

    Science.gov (United States)

    Blinn, Kevin S.; Li, Xiaxi; Liu, Mingfei; Bottomley, Lawrence A.; Liu, Meilin

    2012-01-01

    Solid oxide fuel cells (SOFCs) are potentially the most efficient and cost-effective solution to utilization of a wide variety of fuels beyond hydrogen 1-7. The performance of SOFCs and the rates of many chemical and energy transformation processes in energy storage and conversion devices in general are limited primarily by charge and mass transfer along electrode surfaces and across interfaces. Unfortunately, the mechanistic understanding of these processes is still lacking, due largely to the difficulty of characterizing these processes under in situ conditions. This knowledge gap is a chief obstacle to SOFC commercialization. The development of tools for probing and mapping surface chemistries relevant to electrode reactions is vital to unraveling the mechanisms of surface processes and to achieving rational design of new electrode materials for more efficient energy storage and conversion2. Among the relatively few in situ surface analysis methods, Raman spectroscopy can be performed even with high temperatures and harsh atmospheres, making it ideal for characterizing chemical processes relevant to SOFC anode performance and degradation8-12. It can also be used alongside electrochemical measurements, potentially allowing direct correlation of electrochemistry to surface chemistry in an operating cell. Proper in situ Raman mapping measurements would be useful for pin-pointing important anode reaction mechanisms because of its sensitivity to the relevant species, including anode performance degradation through carbon deposition8, 10, 13, 14 ("coking") and sulfur poisoning11, 15 and the manner in which surface modifications stave off this degradation16. The current work demonstrates significant progress towards this capability. In addition, the family of scanning probe microscopy (SPM) techniques provides a special approach to interrogate the electrode surface with nanoscale resolution. Besides the surface topography that is routinely collected by AFM and STM

  18. Pressurized reversible operation of a 30-cell solid oxide cell stack using carbonaceous gases

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Langnickel, Hendrik; Hintzen, N.

    2017-01-01

    Recent theoretical studies show that reversible electrochemical conversion of H2O and CO2 to CH4 inside pressurized solid oxide cells (SOCs) combined with subsurface storage of the produced gases can facilitate seasonal electricity storage with a round-trip efficiency reaching 70-80% and a storag...... in electrolysis mode. The degradation rates in both fuel cell and electrolysis mode were comparable to previously reported SOFCMAN stack degradation rates measured at ambient pressure operation with H2/H2O gas mixtures.......Recent theoretical studies show that reversible electrochemical conversion of H2O and CO2 to CH4 inside pressurized solid oxide cells (SOCs) combined with subsurface storage of the produced gases can facilitate seasonal electricity storage with a round-trip efficiency reaching 70-80% and a storage...... cost below 3 ¢/kWh. Here we show test results with a 30-cell SOFCMAN 301 stack operated with carbonaceous gases at 18.7 bar and 700 ˚C in both electrolysis and fuel cell mode. The CH4 content in the stack outlet gas increased from 0.22% at open circuit voltage (OCV) to 18% at -0.17 A cm-2...

  19. Columbia River ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for bird nesting sites in the Columbia River area. Vector points in this data set represent locations of...

  20. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell/stack as......In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell...

  1. Lanthanum manganate based cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Juhl Joergensen, M.

    2001-07-01

    Composite cathodes for solid oxide fuel cells were investigated using electrochemical impedance spectroscopy and scanning electron microscopy. The aim was to study the oxygen reduction process in the electrode in order to minimise the voltage drop in the cathode. The electrodes contained a composite layer made from lanthanum strontium manganate (LSM) and yttria stabilised zirconia (YSZ) and a layer of pure LSM aimed for current collection. The performance of the composite electrodes was sensitive to microstructure and thickness. Further, the interface between the composite and the current collecting layer proved to affect the performance. In a durability study severe deg-radation of the composite electrodes was found when passing current through the electrode for 2000 hours at 1000 deg. C. This was ascribed to pore formation along the composite interfaces and densification of the composite and current collector microstructure. An evaluation of the measurement approach indicated that impedance spectroscopy is a very sensitive method. This affects the reproducibility, as small undesirable variations in for instance the microstructure from electrode to electrode may change the impedance. At least five processes were found to affect the impedance of LSM/YSZ composite electrodes. Two high frequency processes were ascribed to transport of oxide ions/oxygen intermediates across LSM/YSZ interfaces and through YSZ in the composite. Several competitive elementary reaction steps, which appear as one medium frequency process in the impedance spectra, were observed. A low frequency arc related to gas diffusion limitation in a stagnant gas layer above the composite structure was detected. Finally, an inductive process, assumed to be connected to an activation process involving segregates at the triple phase boundary between electrode, electrolyte and gas phase, was found. (au)

  2. Comparison of tumour age response to radiation for cells derived from tissue culture or solid tumours

    International Nuclear Information System (INIS)

    Keng, P.C.; Siemann, D.W.; Rochester Univ., NY; Rochester Univ., NY; Wheeler, K.T.

    1984-01-01

    Direct comparison of the cell age response of 9L and KHT tumour cells derived either from tissue culture or solid tumours was achieved. Cells from dissociated KHT and 9L tumours (the latter implanted either subcutaneously or intracerebrally) and cells from tissue culture were separated into homogenous sized populations by centrifugal elutriation. In both tumour models these homogeneous sized populations correspond to populations enriched at different stages of the cell cycle. The survival of these elutriated cell populations was measured after a single dose of Cs-137 gamma rays. For cells isolated from 9L solid tumours, there was little variation in radiosensitivity throughout the cell cycle; however, a very small but significant increase in resistance was found in late G 1 cells. This lack of a large variation in radiosensitivity through the cell cycle for 9L cells from solid tumours also was seen in 9L cells growing in monolayer tissue culture. When similar experiments were performed using the KHT sarcoma tumour model, the results showed that KHT cells in vitro exhibited a fairly conventional increase in radioresistance in both mid G 1 and late S. However, the cell age response of KHT cells from solid tumours was different; particularly in the late S and G 2 + M phases. (author)

  3. Modifying ferritic stainless steels for solid oxide fuel cell applications

    Science.gov (United States)

    Laney, Scot Jason

    2007-12-01

    One of the most important problem areas associated with the solid oxide fuel cells is selection of a cost effective material for use as the interconnect component of the cell. Metals are now being considered as materials for this component, with ferritic stainless steels being the leading candidate. This work evaluates methods to combat the problem areas, namely rapid growth rate and vaporization of the oxide scale, that hinder the use of these materials. Oxidation experiments have been performed in dry and wet single atmosphere exposures as well as a dual environment exposure to simulate the conditions in a working SOFC. Measurements of the electrical properties of the oxides that formed were also performed. Commercial alloys, E-Brite and Crofer 22APU, were tested to form a baseline and resultant oxidation and electrical behaviors match those found in the literature. Isothermal oxidation tests for short exposure times have also led to a possible mechanism for the formation of the MnCr2O4 layer on Crofer. All of these tests were then replicated on a series of experimental Fe-22Cr-XTi (X=0-4) alloys. These alloys are shown to form a rutile layer analogous to the MnCr2O4 layer on Crofer. While this layer does prevent some chromia vaporization, the consequences due to the presence of Ti in the chromia include increased growth rate, decreased resistivity, extensive internal oxidation and nitridation of Ti, and a change of the growth direction of the chromia. The alloys containing ˜2--3 wt%Ti appear to offer the best combination of oxidation, electrical, and mechanical properties. Coatings of lanthanum chromites and ferrites were also tested and shown to be very sensitive to exposure condition, resulting in the formation of pores, and to coating thickness, where thicker coatings are subject to cracking. Finally, reactive element oxide doping was attempted to slow the oxide growth rate for E-Brite (CeO2 doping) and for the Fe-Cr-Ti alloys (CeO 2 and La2O3 doping). A

  4. Tumor-infiltrating tryptase+mast cells predict unfavorable clinical outcome in solid tumors.

    Science.gov (United States)

    Hu, Guoming; Wang, Shimin; Cheng, Pu

    2018-02-15

    The prognostic role of tumor-infiltrating tryptase + mast cells in human solid tumors remains controversial. Herein, we conducted a meta-analysis including 28 published studies with 4224 patients identified from PubMed and EBSCO to assess the prognostic impact of tumor-infiltrating tryptase + mast cells in human solid tumors. We found that tryptase + mast cell infiltration significantly decreased overall survival (OS) and disease-free survival (DFS) in all types of solid tumors. In stratified analyses, tryptase + mast cell infiltration was significantly associated with worse OS in non-small cell lung cancer, hepatocellular carcinoma and 5-year survival in colorectal cancer. And these cells were inversely associated with DFS in hepatocellular and colorectal cancer. In addition, high density of intratumoral tryptase + mast cells significantly correlated with lymph node metastasis of solid tumor. In conclusion, Tryptase + mast cell infiltration leads to an unfavorable clinical outcome in solid tumors, implicating that it is a valuable biomarker for prognostic prediction for human solid malignances and targeting it may have a potential for effective treatment. © 2017 UICC.

  5. Nest structure and communal nesting in Euglossa (Glossura annectans Dressler (Hymenoptera, Apidae, Euglossini

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Garófalo

    1998-01-01

    Full Text Available Three nests of Euglossa (Glossura annectans Dressier, 1982 were obtained from trap nests at Serra do Japi, Jundiai, São Paulo State, Brazil. The bees nested in bamboo cane (one nest and in wooden-boxes (two nests. Solitary (two cases and pleometrotic (one case foundations were observed. Two nests were re-used once by two females working in each of them. Re-using females that shared the nests were of the same generation and each built, provisioned and oviposited in her own cells, characterizing a communal association. The brood development period was related to climatic conditions. Natural enemies included Anthrax oedipus oedipus Fabricius, 1805 (Bombyliidae, Coelioxys sp. (Megachilidae and Melittobia sp. (Eulophidae.

  6. Comparative radiosensitivity of clonogenic cells of inoculated Ehrlich ascites and solid tumors

    International Nuclear Information System (INIS)

    Konoplyannikov, A.G.; Kolesnikova, A.I.; Lepekhina, L.A.; Shtejn, L.V.

    1988-01-01

    Survival of clonogenic cells of solid Ehrlich ascited tumor (EAT) exposed to 60 Co-γ-radiation in vitro under the oxygenation conditions was investigated and the clonogenic capacity and radiosensitivity of these cells and cells of the previously studied EAT ascitic form and Lewis solid tumor comparatively studied to elucidate how the efficiency of colony formation (ECF) would affect their radiosensitivity. ECF for solid EAT cells was 2.6±0.3%, which was lower, by about an order of magnitude, than that for ascitic form of this tumor and was nearly the same as that for Luis tumor cells. A median cell lethal dose (D 0 ) was practically the same for all tumors under study. It is suggested that the differences in ECF do not substantially influence the radiosensitivity of clonogenic cells of the studied tumors

  7. Chimeric-antigen receptor T (CAR-T) cell therapy for solid tumors: challenges and opportunities.

    Science.gov (United States)

    Xia, An-Liang; Wang, Xiao-Chen; Lu, Yi-Jun; Lu, Xiao-Jie; Sun, Beicheng

    2017-10-27

    Chimeric antigen receptor (CAR)-engineered T cells (CAR-T cells) have been shown to have unprecedented efficacy in B cell malignancies, most notably in B cell acute lymphoblastic leukemia (B-ALL) with up to a 90% complete remission rate using anti-CD19 CAR-T cells. However, CAR T-cell therapy for solid tumors currently is faced with numerous challenges such as physical barriers, the immunosuppressive tumor microenvironment and the specificity and safety. The clinical results in solid tumors have been much less encouraging, with multiple cases of toxicity and a lack of therapeutic response. In this review, we will discuss the current stats and challenges of CAR-T cell therapy for solid tumors, and propose possibl e solutions and future perspectives.

  8. Free Energies of Formation Measurements on Solid-State Electrochemical Cells

    Science.gov (United States)

    Rollino, J. A.; Aronson, S.

    1972-01-01

    A simple experiment is proposed that can provide the student with some insight into the chemical properties of solids. It also demonstrates the relationship between the Gibbs free energy of formation of an ionic solid and the emf of an electrochemical cell. (DF)

  9. Biomass-powered Solid Oxide Fuel Cells : Experimental and Modeling Studies for System Integrations

    NARCIS (Netherlands)

    Liu, M.

    2013-01-01

    Biomass is a sustainable energy source which, through thermo-chemical processes of biomass gasification, is able to be converted from a solid biomass fuel into a gas mixture, known as syngas or biosyngas. A solid oxide fuel cell (SOFC) is a power generation device that directly converts the chemical

  10. CAR-T cells: the long and winding road to solid tumors.

    Science.gov (United States)

    D'Aloia, Maria Michela; Zizzari, Ilaria Grazia; Sacchetti, Benedetto; Pierelli, Luca; Alimandi, Maurizio

    2018-02-15

    Adoptive cell therapy of solid tumors with reprogrammed T cells can be considered the "next generation" of cancer hallmarks. CAR-T cells fail to be as effective as in liquid tumors for the inability to reach and survive in the microenvironment surrounding the neoplastic foci. The intricate net of cross-interactions occurring between tumor components, stromal and immune cells leads to an ineffective anergic status favoring the evasion from the host's defenses. Our goal is hereby to trace the road imposed by solid tumors to CAR-T cells, highlighting pitfalls and strategies to be developed and refined to possibly overcome these hurdles.

  11. Stem Cells: All that Is Solid Melts into Air

    NARCIS (Netherlands)

    van der Heijden, Maartje; Vermeulen, Louis

    2017-01-01

    The intestinal epithelium displays great resilience, as several cell populations can replenish the stem cell pool upon damage. Two studies in Cell Stem Cell extend this capacity to enteroendocrine cells, addressing the molecular basis underlying cellular plasticity observed in the intestine and the

  12. Municipal Solid Waste Gasification with Solid Oxide Fuel Cells and Stirling Engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Municipal Solid Waste (MSW) can be considered a valid biomass to be used in a power plant. The major advantage is the reduction of pollutants and greenhouse gases emissions not only within large cities but also globally. Another advantage is that by th eir use it is possible to reduce the waste......, waste is subject to chemical treatments through air or/and steam utilization; the result is a synthesis gas, called “Syngas” which is principally composed of hydrogen and carbon monoxide. Traces of hydrogen sulfide could also be present which can easily be separated in a desulfurization reactor...... studied to optimize the plant efficiency in terms of operating conditions. Compared with modern waste incinerators with heat recovery, the gasification process integrated with SOFC and Stirling engine permits an increase in electricity output up of 50%, which means that the solid waste gasification...

  13. Efficient and Scalable Fabrication of Solid Oxide Fuel Cells via 3D-Printing

    Data.gov (United States)

    National Aeronautics and Space Administration — Although solid oxide fuel cells (SOFCs) are a source of both efficient and clean electricity, the brittle ceramic materials which comprise them are difficult to form...

  14. Microstructural evolution of nanograin nickel-zirconia cermet anode materials for solid oxide fuel cell applications

    International Nuclear Information System (INIS)

    Nayak, Bibhuti Bhusan

    2012-01-01

    The aim of the study is to study the structure, microstructure, porosity, thermal expansion, electrical conductivity and electrochemical behavior of the anode material thus synthesized in order to find its suitability for solid oxide fuel cell (SOFC) anode application

  15. Fuel cells with solid polymer electrolyte and their application on vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, V.

    1996-04-01

    In Russia, solid polymer electrolyte MF-4-SK has been developed for fuel cells. This electrolyte is based on perfluorinated polymer with functional sulfogroups. Investigations on electrolyte properties and electrocatalysts have been carried out.

  16. Methane Steam Reforming over an Ni-YSZ Solid Oxide Fuel Cell Anode in Stack Configuration

    DEFF Research Database (Denmark)

    Mogensen, David; Grunwaldt, Jan-Dierk; Hendriksen, Peter Vang

    2014-01-01

    The kinetics of catalytic steam reforming of methane over an Ni-YSZ anode of a solid oxide fuel cell (SOFC) have been investigated with the cell placed in a stack configuration. In order to decrease the degree of conversion, a single cell stack with reduced area was used. Measurements were...

  17. Optimizing solid oxide fuel cell cathode processing route for intermediate temperature operation

    DEFF Research Database (Denmark)

    Ortiz-Vitoriano, N.; Bernuy-Lopez, Carlos; Ruiz de Larramendi, I.

    2013-01-01

    For Solid Oxide Fuel Cells (SOFCs) to become an economically attractive energy conversion technology suitable materials which allow operation at lower temperatures, while retaining cell performance, must be developed. At the same time, the cell components must be inexpensive - requiring both low-...

  18. Ni/YSZ microstructure optimization for long-term stability of solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Hauch, Anne; Brodersen, Karen; Karas, Filip

    2014-01-01

    ; i.e. solid oxide fuel cells (SOFC). However, previous long-term tests have shown that the stability behavior of the Ni/yttria-stabilized-zirconia (Ni/YSZ) fuel electrode may fall out quite differently depending on whether the cell is operated in fuel cell or electrolysis mode at otherwise similar...

  19. Performance and Durability of Solid Oxide Electrolysis Cells for Syngas Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Hjalmarsson, Per

    2012-01-01

    Performance and durability of Ni/YSZ based solid oxide electrolysis cells (SOECs) for co-electrolysis of H2O and CO2 at high current density were investigated. The cells consist of a Ni/YSZ support, a Ni/YSZ fuel electrode, a YSZ electrolyte, and a LSM-YSZ oxygen electrode. The cell durability wa...

  20. Ni/YSZ microstructure optimization for long-term stability of solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Hauch, Anne; Brodersen, Karen; Karas, Filip

    2014-01-01

    In the last decade there has been a renewed and increased interest in electrolysis using solid oxide cells (SOC). So far the vast majority of results reported on long-term durability of solid oxide electrolysis cells (SOEC) have been obtained using SOC produced and optimized for fuel cell operation......; i.e. solid oxide fuel cells (SOFC). However, previous long-term tests have shown that the stability behavior of the Ni/yttria-stabilized-zirconia (Ni/YSZ) fuel electrode may fall out quite differently depending on whether the cell is operated in fuel cell or electrolysis mode at otherwise similar...... test conditions. Initial work has shown significant microstructural changes of the Ni/YSZ electrode close to the electrolyte interface after long-term steam electrolysis test at -1 A/cm2 at 800 C. The results indicate that it will be advantageous to optimize the electrode structure with the aim...

  1. Chimeric Antigen Receptors T Cell Therapy in Solid Tumor: Challenges and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Hamid R. Mirzaei

    2017-12-01

    Full Text Available Adoptive cellular immunotherapy (ACT employing engineered T lymphocytes expressing chimeric antigen receptors (CARs has demonstrated promising antitumor effects in advanced hematologic cancers, such as relapsed or refractory acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma, supporting the translation of ACT to non-hematological malignancies. Although CAR T cell therapy has made remarkable strides in the treatment of patients with certain hematological cancers, in solid tumors success has been limited likely due to heterogeneous antigen expression, immunosuppressive networks in the tumor microenvironment limiting CAR T cell function and persistence, and suboptimal trafficking to solid tumors. Here, we outline specific approaches to overcome barriers to CAR T cell effectiveness in the context of the tumor microenvironment and offer our perspective on how expanding the use of CAR T cells in solid tumors may require modifications in CAR T cell design. We anticipate these modifications will further expand CAR T cell therapy in clinical practice.

  2. Conversion of solid carbonaceous fuels in a fluidized bed fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A.C.; Li, S.; Mitchell, R.E.; Guer, T.M. [Stanford University, Stanford, CA (United States). Dept. of Mechanical Engineering

    2008-07-01

    A fluidized bed direct carbon fuel cell was employed to achieve direct conversion of solid fuels into electricity. Power was generated from pulverized Lower Kittanning (bituminous) coal, synthetic carbon, and biomass in a single process step. Current-voltage characteristics exhibited typical fuel cell behavior. Fluidization in flowing CO{sub 2} overcomes the difficulty of attaining solid fuel-to-anode contact and generates CO in situ via the Boudouard reaction. A mechanistic reaction pathway is proposed for anodic oxidation of the solid fuel. Conversion was verified by gas analysis of oxidation products in the flue stream and by oxygen mass balance.

  3. Integration of a municipal solid waste gasification plant with solid oxide fuel cell and gas turbine

    DEFF Research Database (Denmark)

    Bellomare, Filippo; Rokni, Masoud

    2013-01-01

    An interesting source of producing energy with low pollutants emission and reduced environmental impact are the biomasses; particularly using Municipal Solid Waste (MSW) as fuel, can be a competitive solution not only to produce energy with negligible costs but also to decrease the storage...... it reacts with air and produces electricity. The exhausted gases out of the SOFC enter a burner for further fuel combusting and finally the off-gases are sent to a gas turbine to produce additional electricity. Different plant configurations have been studied and the best one found to be a regenerative gas...

  4. Effects of accelerated degradation on metal supported thin film-based solid oxide fuel cell

    DEFF Research Database (Denmark)

    Reolon, R. P.; Sanna, S.; Xu, Yu

    2018-01-01

    A thin film-based solid oxide fuel cell is deposited on a Ni-based metal porous support by pulsed laser deposition with a multi-scale-graded microstructure design. The fuel cell, around 1 μm in thickness, is composed of a stabilized-zirconia/doped-ceria bi-layered dense electrolyte and nanostruct......A thin film-based solid oxide fuel cell is deposited on a Ni-based metal porous support by pulsed laser deposition with a multi-scale-graded microstructure design. The fuel cell, around 1 μm in thickness, is composed of a stabilized-zirconia/doped-ceria bi-layered dense electrolyte...

  5. Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

    Science.gov (United States)

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-07-30

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

  6. Plasma Membranes Modified by Plasma Treatment or Deposition as Solid Electrolytes for Potential Application in Solid Alkaline Fuel Cells

    Science.gov (United States)

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-01-01

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane. PMID:24958295

  7. Nested Term Graphs

    NARCIS (Netherlands)

    Grabmayer, C.A.; van Oostrom, V.

    2014-01-01

    We report on work in progress on `nested term graphs' for formalizing higher-order terms (e.g. finite or infinite lambda-terms), including those expressing recursion (e.g. terms in the lambda-calculus with letrec). The idea is to represent the nested scope structure of a higher-order term by a

  8. Potential electrode materials for symmetrical Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ruiz Morales, J. C.

    2008-08-01

    Full Text Available Chromites, titanates and Pt-YSZ-CeO2 cermets have been investigated as potential electrode materials for an alternative concept of Solid Oxide Fuel Cell (SOFC, the symmetrical SOFCs (SFC. In this configuration, the same electrode material is used simultaneously as anode and cathode. Interconnector materials, such as chromites, could be considered as potential SFC electrodes, at least under pure hydrogen-fed at relatively high temperatures, as they do not exhibit significant catalytic activity towards hydrocarbon oxidation. This may be overcome by partially substituting Cr in the perovskite B-sites by other transition metal cations such as Mn. La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCM is a good candidate for such SFCs, rendering fuel cell performances in excess of 500 and 300mW/cm2 using pure H2 and CH4 as fuel, at 950 oC. Similarly, typical n-type electronic conductors traditionally regarded as anode materials, such as strontium titanates, may also operate under oxidising conditions as cathodes by substituting some Ti content for Fe to introduce p-type conductivity. Preliminary electrochemical experiments on La4Sr8Ti12-xFexO38-δ-based SFCs show that they perform reasonably well under humidified H2, at high temperatures. A third group of materials is the support material of any typical cermet anode, i.e. YSZ, CeO2 plus a current collector. It has been found that this combination could be optimised to operate as SFC electrodes, rendering performances of 400mW/cm2 under humidified pure H2 at 950oC.

    Cromitas, titanatos y cermets de Pt-YSZ-CeO2 han sido investigados como potenciales materiales de electrodo para un concepto alternativo de Pilas de Combustible de Óxidos Sólidos (SOFC, las pilas SOFC simétricas (SFC. En

  9. Electrode activation and passivation of solid oxide fuel cell electrodes

    DEFF Research Database (Denmark)

    Koch, Søren; Mogensen, Mogens Bjerg; Hendriksen, P.V.

    2006-01-01

    The performance of anode-supported cells with a composite LSM-YSZ cathode and an LSM current collector was investigated. Over the first 48 hours, after the application of a constant current, the cell voltage was observed to increase by up to 20%. When the current was switched off, the cell...... resistance increased significantly over the next four days at open circuit conditions. Apparently, at OCV conditions cell passivation occurs. The cell gradually reactivates, once the current is switched on again. Part of this activation/passivation process is fast enough to influence the resistance...... of the cell during i-V measurements (over less than 1 hour) and a considerable hysteresis is observed in the cell voltage during these measurements. Impedance spectroscopy was used to investigate the activation/passivation process. It was found that the series resistance and the part of the polarisation...

  10. Copper-substituted perovskite compositions for solid oxide fuel cell cathodes and oxygen reduction electrodes in other electrochemical devices

    Science.gov (United States)

    Rieke, Peter C [Pasco, WA; Coffey, Gregory W [Richland, WA; Pederson, Larry R [Kennewick, WA; Marina, Olga A [Richland, WA; Hardy, John S [Richland, WA; Singh, Prabhaker [Richland, WA; Thomsen, Edwin C [Richland, WA

    2010-07-20

    The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells. Also provided are electrochemical devices that include active oxygen reduction electrodes, such as solid oxide fuel cells, sensors, pumps and the like. The compositions comprises a copper-substituted ferrite perovskite material. The invention also provides novel methods for making and using the electrode compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having cathodes comprising the compositions.

  11. Chimeric antigen receptor-modified T cells for the treatment of solid tumors: Defining the challenges and next steps☆

    OpenAIRE

    Beatty, Gregory L.; O’Hara, Mark

    2016-01-01

    Chimeric antigen receptor (CAR) T cell therapy has shown promise in CD19 expressing hematologic malignancies, but how to translate this success to solid malignancies remains elusive. Effective translation of CAR T cells to solid tumors will require an understanding of potential therapeutic barriers, including factors that regulate CAR T cells expansion, persistence, trafficking, and fate within tumors. Herein, we describe the current state of CAR T cells in solid tumors; define key barriers t...

  12. The metabolic cooperation between cells in solid cancer tumors.

    Science.gov (United States)

    Icard, Philippe; Kafara, Perrine; Steyaert, Jean-Marc; Schwartz, Laurent; Lincet, Hubert

    2014-08-01

    Cancer cells cooperate with stromal cells and use their environment to promote tumor growth. Energy production depends on nutrient availability and O₂ concentration. Well-oxygenated cells are highly proliferative and reorient the glucose metabolism towards biosynthesis, whereas glutamine oxidation replenishes the TCA cycle coupled with OXPHOS-ATP production. Glucose, glutamine and alanine transformations sustain nucleotide and fatty acid synthesis. In contrast, hypoxic cells slow down their proliferation, enhance glycolysis to produce ATP and reject lactate which is recycled as fuel by normoxic cells. Thus, glucose is spared for biosynthesis and/or for hypoxic cell function. Environmental cells, such as fibroblasts and adipocytes, serve as food donors for cancer cells, which reject waste products (CO₂ , H⁺, ammoniac, polyamines…) promoting EMT, invasion, angiogenesis and proliferation. This metabolic-coupling can be considered as a form of commensalism whereby non-malignant cells support the growth of cancer cells. Understanding these cellular cooperations within tumors may be a source of inspiration to develop new anti-cancer agents. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Quality Assurance of Solid Oxide Fuel Cell (SOFC) and Electrolyser (SOEC) Stacks

    DEFF Research Database (Denmark)

    Lang, Michael; Auer, Corinna; Couturier, Karine

    2017-01-01

    In the EU-funded project “Solid oxide cell and stack testing and quality assurance” (SOCTESQA) standardized and industry wide test modules and programs for high temperature solid oxide cells and stacks are being developed. These test procedures can be applied for the fuel cell (SOFC......), the electrolysis (SOEC) and in the combined SOFC/SOEC mode. In order to optimize the test modules the project partners have tested identical SOC stacks with the same test programs in several testing campaigns. Altogether 10 pre-normative test modules were developed: Start-up, current-voltage characteristics...

  14. Reversing and Repairing Microstructure Degradation in Solid Oxide Cells During Operation

    DEFF Research Database (Denmark)

    Graves, Christopher R.

    2013-01-01

    The elevated operating temperature of solid oxide electrochemical cells (SOCs) can lead to long-term degradation of cell components due to instability of materials and microstructures. However, this unique possibility for microstructural changes to occur can also be advantageously exploited...

  15. Co-Electrolysis of Steam and Carbon Dioxide in Solid Oxide Cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Knibbe, Ruth; Mogensen, Mogens Bjerg

    2012-01-01

    Reduction of H2O and CO2 as well as oxidation of H2 and CO was studied in a Ni/YSZ electrode supported Solid Oxide Cell (SOC) produced at DTU Energy conversion (former Risø DTU). Even though these Ni/YSZ based SOCs were developed and optimized for fuel cell use, they can work as reversible SOCs...

  16. Operation of real landfill gas fueled solid oxide fuel cell (SOFC) using internal dry reforming

    DEFF Research Database (Denmark)

    Langnickel, Hendrik; Hagen, Anke

    2017-01-01

    Biomass is one renewable energy source, which is independent from solar radiation and wind effect. Solid oxide fuel cells (SOFC’s) are able to convert landfill gas derived from landfill directly into electricity and heat with a high efficiency. In the present work a planar 16cm2 SOFC cell...

  17. Thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell in combined heat and power applications

    Science.gov (United States)

    Abraham, F.; Dincer, I.

    2015-12-01

    This paper presents a comprehensive steady state modelling and thermodynamic analysis of Direct Urea Solid Oxide Fuel Cell integrated with Gas Turbine power cycle (DU-SOFC/GT). The use of urea as direct fuel mitigates public health and safety risks associated with the use of hydrogen and ammonia. The integration scheme in this study covers both oxygen ion-conducting solid oxide fuel cells (SOFC-O) and hydrogen proton-conducting solid oxide fuel cells (SOFC-H). Parametric case studies are carried out to investigate the effects of design and operating parameters on the overall performance of the system. The results reveal that the fuel cell exhibited the highest level of exergy destruction among other system components. Furthermore, the SOFC-O based system offers better overall performance than that with the SOFC-H option mainly due to the detrimental reverse water-gas shift reaction at the SOFC anode as well as the unique configuration of the system.

  18. Characterising of solid state electrochemical cells under operation

    DEFF Research Database (Denmark)

    Holtappels, Peter

    2014-01-01

    electrochemical cells are still a "black box". In order to identify local reaction sites, surface coverage and potential/current introduced materials and surface modifications, in situ techniques are needed to gain a better understanding of the elementary and performance limiting steps for these cells...

  19. Solid Oxide Fuel Cell (SOFC) Development in Denmark

    DEFF Research Database (Denmark)

    Linderoth, Søren; Larsen, Peter Halvor; Mogensen, Mogens Bjerg

    2007-01-01

    on larger anode-supported cells as well as a new generation of SOFCs based on porous metal supports and new electrode and electrolyte materials. The SOFC program comprises development of next generation of cells and multi stack modules for operation at lower temperature with increased durability...

  20. Performance Characterization of Solid Oxide Cells Under High Pressure

    DEFF Research Database (Denmark)

    Sun, Xiufu; Bonaccorso, Alfredo Damiano; Graves, Christopher R.

    2015-01-01

    of the cell at 1 and 3 bar shows a significant and equal performance gain at higher pressure in both fuel cell mode and electrolysis mode. Electrochemical impedance spectroscopy revealed that the serial resistance was not affected by the operation pressure; all the other processes that are dependent...

  1. Therapy of solid cancers using T cells and running shoes

    DEFF Research Database (Denmark)

    Straten, Per Thor

    2017-01-01

    of tumor specific T cells at the tumor site, and underscores the need to define ways as how to increase immune cell infiltration to the tumor site. Regular exercise reduces the risk of cancer and disease recurrence, by largely unknown mechanisms. We recently demonstrated that voluntary wheel running showed...

  2. Semi-solid electrode cell having a porous current collector and methods of manufacture

    Science.gov (United States)

    Chiang, Yet-Ming; Carter, William Craig; Cross, III, James C.; Bazzarella, Ricardo; Ota, Naoki

    2017-11-21

    An electrochemical cell includes an anode, a semi-solid cathode, and a separator disposed therebetween. The semi-solid cathode includes a porous current collector and a suspension of an active material and a conductive material disposed in a non-aqueous liquid electrolyte. The porous current collector is at least partially disposed within the suspension such that the suspension substantially encapsulates the porous current collector.

  3. Directing nanoparticle-drug complexes to solid tumor by hypoxic cell radiosensitizer

    International Nuclear Information System (INIS)

    Sreeja, S.; Krishnan Nair, C.K.

    2016-01-01

    Hypoxic region in solid tumor is one of the major targets in cancer therapy. Specific targeting of cytotoxic drugs to hypoxic region in tumor can prevent hypoxia- associated expression of genes and enhance tumor regression. The hypoxic cell radiosensitizer - Sanazole (SAN), a nitrotriazole compound, has been shown to accumulate in the hypoxic microenvironment of solid tumor. In the present study, we complexed a cytotoxic alkaloid Berberine together with Sanazole to surface modified iron oxide nanoparticles to obtain the complex NP-BBN-SAN. The complexes were characterized by FTIR, XRD and TEM. The animals (Swiss albino) - bearing solid tumor on the hind limbs were administered with NP-BBN-SAN complexes

  4. Fermi Potential across Working Solid Oxide Cells with Zirconia or Ceria Electrolytes

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    A solid electrolyte will always possess a finite electronic conductivity, in particular electrolytes like doped ceria that easily get reduced and become mixed ionic and electronic conductors. This given rise too high leak currents through the solid oxide cell (SOC). Especially, problems have been...... driving the O2-ions is not the Fermi potential, which is the potential of the electrons, but the Galvani potential (or inner potential) (1). The concepts of potentials describing the electrical situation of a solid electrolyte is shown i Fig. 1, and an example of the Fermi potential (π) and Galvani...

  5. Advances in tubular solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, S.C. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

    1996-12-31

    The design, materials and fabrication processes for the earlier technology Westinghouse tubular geometry cell have been described in detail previously. In that design, the active cell components were deposited in the form of thin layers on a ceramic porous support tube (PST). The tubular design of these cells and the materials used therein have been validated by successful electrical testing for over 65,000 h (>7 years). In these early technology PST cells, the support tube, although sufficiently porous, presented an inherent impedance to air flow toward air electrode. In order to reduce such impedance to air flow, the wall thickness of the PST was first decreased from the original 2 mm (the thick-wall PST) to 1.2 mm (the thin-wall PST). The calcia-stabilized zirconia support tube has now been completely eliminated and replaced by a doped lanthanum manganite tube in state-of-the-art SOFCs. This doped lanthanum manganite tube is extruded and sintered to about 30 to 35 percent porosity, and serves as the air electrode onto which the other cell components are fabricated in thin layer form. These latest technology cells are designated as air electrode supported (AES) cells.

  6. Perovskite solid electrolytes: Structure, transport properties and fuel cell applications

    DEFF Research Database (Denmark)

    Bonanos, N.; Knight, K.S.; Ellis, B.

    1995-01-01

    vapour transfer in a cell in which the perovskite is exposed to wet hydrogen on both sides. The evolution of transport properties with temperature is discussed in relation to structure. Neutron diffraction studies of doped and undoped barium cerate are reported, revealing a series of phase transitions......Doped barium cerate perovskites, first investigated by Iwahara and co-workers, have ionic conductivities of the order of 20 mS/cm at 800 degrees C making them attractive as fuel cell electrolytes for this temperature region. They have been used to construct laboratory scale fuel cells, which...

  7. Pressurized solid oxide fuel cell integral air accumular containment

    Science.gov (United States)

    Gillett, James E.; Zafred, Paolo R.; Basel, Richard A.

    2004-02-10

    A fuel cell generator apparatus contains at least one fuel cell subassembly module in a module housing, where the housing is surrounded by a pressure vessel such that there is an air accumulator space, where the apparatus is associated with an air compressor of a turbine/generator/air compressor system, where pressurized air from the compressor passes into the space and occupies the space and then flows to the fuel cells in the subassembly module, where the air accumulation space provides an accumulator to control any unreacted fuel gas that might flow from the module.

  8. High temperature lithium cells with solid polymer electrolytes

    Science.gov (United States)

    Yang, Jin; Eitouni, Hany Basam; Singh, Mohit

    2017-03-07

    Electrochemical cells that use electrolytes made from new polymer compositions based on poly(2,6-dimethyl-1,4-phenylene oxide) and other high-softening-temperature polymers are disclosed. These materials have a microphase domain structure that has an ionically-conductive phase and a phase with good mechanical strength and a high softening temperature. In one arrangement, the structural block has a softening temperature of about 210.degree. C. These materials can be made with either homopolymers or with block copolymers. Such electrochemical cells can operate safely at higher temperatures than have been possible before, especially in lithium cells. The ionic conductivity of the electrolytes increases with increasing temperature.

  9. Understanding the processes governing performance and durability of solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Sun, Xiufu; Mogensen, Mogens Bjerg

    2015-01-01

    Operation of a Ni–YSZ electrode supported Solid Oxide Cell (SOC) was studied in both fuel cell mode (FC-mode) and electrolysis cell mode (EC-mode) in mixtures of H2O/H2, CO2/CO, H2O/H2O/CO2/CO at 750 °C, 800 °C and 850 °C. Although the SOCs are reversible, the polarisation characterisation shows...

  10. Design and performance of tubular flat-plate solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, T.; Ikeda, D.; Kanagawa, H. [NTT Integrated Information & Energy Systems Labs., Tokyo (Japan)] [and others

    1996-12-31

    With the growing interest in conserving the environmental conditions, much attention is being paid to Solid Oxide Fuel Cell (SOFC), which has high energy-conversion efficiency. Many organizations have conducted studies on tubular and flat type SOFCs. Nippon Telegraph and Telephone Corporation (NTT) has studied a combined tubular flat-plate SOFC, and already presented the I-V characteristics of a single cell. Here, we report the construction of a stack of this SOFC cell and successful generation tests results.

  11. Diffusion and conversion impedance in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Hendriksen, Peter Vang; Koch, Søren

    2008-01-01

    In fuel cell electrodes where the thin, active electrode layer is supported by a porous layer the diffusion processes as well as the change in the gas phase composition due to the conversion of reactants will influence the cell impedance. Two models are developed for the description of these proc......In fuel cell electrodes where the thin, active electrode layer is supported by a porous layer the diffusion processes as well as the change in the gas phase composition due to the conversion of reactants will influence the cell impedance. Two models are developed for the description...... to consumption of reactants and accumulation of products. For simplicity this model is restricted to cases dominated by mass transfer and conversion of the gas supply. Qualitatively the predictions by both models are alike. At high frequencies a Warburg diffusion impedance is seen. Depending on the dimensions...

  12. Methane-Oxygen Solid Oxide Fuel Cell System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has a defined need for energy dense and highly efficient energy storage and power delivery systems for future space missions. Compared to other fuel cell...

  13. Solid Oxide Fuel Cell Operating on Hydrocarbon Fuel

    Data.gov (United States)

    National Aeronautics and Space Administration — Objective is to dramatically increase power density of liquid tin oxide SOFC systems by combining liquid tin oxide SOFC with GRC-developed bilayer supported cell...

  14. High Temperature Solid Oxide Fuel Cell Generator Development

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Pierre

    2007-09-30

    This report describes the results of the tubular SOFC development program from August 22, 1997 to September 30, 2007 under the Siemens/U.S. Department of Energy Cooperative Agreement. The technical areas discussed include cell manufacturing development, cell power enhancement, SOFC module and system cost reduction and technology advancement, and our field unit test program. Whereas significant progress has been made toward commercialization, significant effort remains to achieve our cost, performance and reliability targets for successful commercialization.

  15. Cell kinetic parameters of a solid mammary adenocarcinoma

    International Nuclear Information System (INIS)

    Porschen, R.; Feinendegen, L.E.

    1978-01-01

    Several cell kinetic parameters of the mammary adenocarcinoma EO 771 were evaluated by means of tumor volume measurements and of 125 I-UdR. The in-situ measured activity loss rate is disturbed by a slow elimination of labelled necrotic cells and by reutilization of 125 I-UdR. The restrictions of the I-UdR method are mentioned and the measured activity loss rates are compared with calculated volume loss rates. (orig./MG) [de

  16. Kinetic and geometric aspects of solid oxide fuel cell electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Skaarup, Steen

    1996-01-01

    the size of the polarisation resistance greatly and may also change the rate limiting step for oxygen reduction as evidenced by the change in dependence on oxygen partial pressure and in the apparent activation energy. O-16/O-19 isotope exchange measurements have shown that oxygen surface exchange takes...... are is much more dependent on the structure than the low frequency arcs. In the case of LSM-YSZ composite it has been demonstrated that both the ratio of LSM to YSZ and the conductivity of the YSZ is of major importance. The length and the nature of the three-phase-boundary between LSM, YSZ and air influence...... place with significant rates on both electrodes and electrolyte types of materials. Results from pointed electrodes indicate that the electrochemical reaction occurs on both the solid electrolyte and the electrode materials but only in a narrow zone (few mu m) along the three-phase-boundary....

  17. Induction of oncogene addiction shift to NF-κB by camptothecin in solid tumor cells

    International Nuclear Information System (INIS)

    Togano, Tomiteru; Sasaki, Masataka; Watanabe, Mariko; Nakashima, Makoto; Tsuruo, Takashi; Umezawa, Kazuo; Higashihara, Masaaki; Watanabe, Toshiki; Horie, Ryouichi

    2009-01-01

    The biological basis of the resistance of solid tumor cells to chemotherapy is not well understood. While addressing this problem, we found that gastric cancer cell line St-4/CPT, lung cancer cell line A549/CPT, and colon cancer cell line HT-29/CPT, all of which are resistant to camptothecin (CPT), showed strong and constitutive nuclear factor (NF)-κB activity driven by IκB kinase compared with their parental cell lines St-4, A549, and HT-29. A new NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), reduced viability and induced apoptosis in St-4/CPT, A549/CPT, and HT-29/CPT cell lines, while their parental cell lines were resistant to DHMEQ. The results in this study present an example of the shift in signals that support the survival of solid tumor cells to NF-κB during the acquisition of resistance to CPT. The results also indicate that solid tumor cells that become resistant to chemotherapy may be more easily treated by NF-κB inhibitors.

  18. Induction of oncogene addiction shift to NF-{kappa}B by camptothecin in solid tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Togano, Tomiteru; Sasaki, Masataka; Watanabe, Mariko; Nakashima, Makoto [Department of Hematology, School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555 (Japan); Tsuruo, Takashi [Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Umezawa, Kazuo [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-0061 (Japan); Higashihara, Masaaki [Department of Hematology, School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555 (Japan); Watanabe, Toshiki [Laboratory of Tumor Cell Biology, Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Horie, Ryouichi, E-mail: rhorie@med.kitasato-u.ac.jp [Department of Hematology, School of Medicine, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555 (Japan)

    2009-12-04

    The biological basis of the resistance of solid tumor cells to chemotherapy is not well understood. While addressing this problem, we found that gastric cancer cell line St-4/CPT, lung cancer cell line A549/CPT, and colon cancer cell line HT-29/CPT, all of which are resistant to camptothecin (CPT), showed strong and constitutive nuclear factor (NF)-{kappa}B activity driven by I{kappa}B kinase compared with their parental cell lines St-4, A549, and HT-29. A new NF-{kappa}B inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), reduced viability and induced apoptosis in St-4/CPT, A549/CPT, and HT-29/CPT cell lines, while their parental cell lines were resistant to DHMEQ. The results in this study present an example of the shift in signals that support the survival of solid tumor cells to NF-{kappa}B during the acquisition of resistance to CPT. The results also indicate that solid tumor cells that become resistant to chemotherapy may be more easily treated by NF-{kappa}B inhibitors.

  19. TAPE CALENDERING MANUFACTURING PROCESS FOR MULTILAYER THIN-FILM SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh; Kurt Montgomery

    2004-10-01

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC during the Phases I and II under Contract DE-AC26-00NT40705 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Tape Calendering Manufacturing Process For Multilayer Thin-Film Solid Oxide Fuel Cells''. The main objective of this project was to develop the manufacturing process based on tape calendering for multilayer solid oxide fuel cells (SOFC's) using the unitized cell design concept and to demonstrate cell performance under specified operating conditions. Summarized in this report is the development and improvements to multilayer SOFC cells and the unitized cell design. Improvements to the multilayer SOFC cell were made in electrochemical performance, in both the anode and cathode, with cells demonstrating power densities of nearly 0.9 W/cm{sup 2} for 650 C operation and other cell configurations showing greater than 1.0 W/cm{sup 2} at 75% fuel utilization and 800 C. The unitized cell design was matured through design, analysis and development testing to a point that cell operation at greater than 70% fuel utilization was demonstrated at 800 C. The manufacturing process for both the multilayer cell and unitized cell design were assessed and refined, process maps were developed, forming approaches explored, and nondestructive evaluation (NDE) techniques examined.

  20. New Strategies for the Treatment of Solid Tumors with CAR-T Cells.

    Science.gov (United States)

    Zhang, Hao; Ye, Zhen-Long; Yuan, Zhen-Gang; Luo, Zheng-Qiang; Jin, Hua-Jun; Qian, Qi-Jun

    2016-01-01

    Recent years, we have witnessed significant progresses in both basic and clinical studies regarding novel therapeutic strategies with genetically engineered T cells. Modification with chimeric antigen receptors (CARs) endows T cells with tumor specific cytotoxicity and thus induce anti-tumor immunity against malignancies. However, targeting solid tumors is more challenging than targeting B-cell malignancies with CAR-T cells because of the histopathological structure features, specific antigens shortage and strong immunosuppressive environment of solid tumors. Meanwhile, the on-target/off-tumor toxicity caused by relative expression of target on normal tissues is another issue that should be reckoned. Optimization of the design of CAR vectors, exploration of new targets, addition of safe switches and combination with other treatments bring new vitality to the CAR-T cell based immunotherapy against solid tumors. In this review, we focus on the major obstacles limiting the application of CAR-T cell therapy toward solid tumors and summarize the measures to refine this new cancer therapeutic modality.

  1. Solid oxide fuel cell bi-layer anode with gadolinia-doped ceria for utilization of solid carbon fuel

    Science.gov (United States)

    Kellogg, Isaiah D.; Koylu, Umit O.; Dogan, Fatih

    Pyrolytic carbon was used as fuel in a solid oxide fuel cell (SOFC) with a yttria-stabilized zirconia (YSZ) electrolyte and a bi-layer anode composed of nickel oxide gadolinia-doped ceria (NiO-GDC) and NiO-YSZ. The common problems of bulk shrinkage and emergent porosity in the YSZ layer adjacent to the GDC/YSZ interface were avoided by using an interlayer of porous NiO-YSZ as a buffer anode layer between the electrolyte and the NiO-GDC primary anode. Cells were fabricated from commercially available component powders so that unconventional production methods suggested in the literature were avoided, that is, the necessity of glycine-nitrate combustion synthesis, specialty multicomponent oxide powders, sputtering, or chemical vapor deposition. The easily-fabricated cell was successfully utilized with hydrogen and propane fuels as well as carbon deposited on the anode during the cyclic operation with the propane. A cell of similar construction could be used in the exhaust stream of a diesel engine to capture and utilize soot for secondary power generation and decreased particulate pollution without the need for filter regeneration.

  2. Status of solid polymer electrolyte fuel cell technology and potential for transportation applications

    Science.gov (United States)

    McElroy, J. F.; Nuttall, L. J.

    The solid polymer electrolyte (SPE) fuel cell represents the first fuel cell technology known to be used operationally. Current activities are mainly related to the development of a space regenerative fuel cell system for energy storage on board space stations, or other large orbiting vehicles and platforms. During 1981, a study was performed to determine the feasibility of using SPE fuel cells for automotive or other vehicular applications, using methanol as the fuel. The results of this study were very encouraging. Details concerning a conceptual automotive fuel cell power plant study are discussed, taking into account also a layout of major components for compact passenger car installation.

  3. Modelling of Physical, Chemical, and Material Properties of Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jakub Kupecki

    2015-01-01

    Full Text Available This paper provides a review of modelling techniques applicable for system-level studies to account for physical, chemical, and material properties of solid oxide fuel cells. Functionality of 0D to 3D models is discussed and selected examples are given. Author provides information on typical length scales in evaluation of power systems with solid oxide fuel cells. In each section, proper examples of previous studies done in the field of 0D–3D modelling are recalled and discussed.

  4. Solid pseudopapillary tumor of pancreas with sickle cell trait: A rare case report

    Directory of Open Access Journals (Sweden)

    Harish S Permi

    2013-01-01

    Full Text Available Solid pseudopapillary tumor of pancreas is a rare pancreatic neoplasm affecting young women, has low malignant potential and amenable for surgical excision with good long-term survival. Sickle cell trait is benign condition, which involves one normal beta-globin chain and one HbS chain. Although it is a benign condition, individuals are prone to have rare complications that may predispose to death under certain circumstances. We report a rare coexistence of solid pseudopapillary tumor of pancreas with sickle cell trait in an 18-year-old female who underwent distal pancreatectomy with splenectomy. Histopathological examination and haemoglobin electrophoresis confirmed the diagnosis.

  5. Solid-state electrochromic cell with anodic iridium oxide film electrodes

    International Nuclear Information System (INIS)

    Dautremont-Smith, W.C.; Beni, G.; Schiavone, L.M.; Shay, J.L.

    1979-01-01

    A new solid-state electrochromic cell has been fabricated using an anodic iridium oxide film (AIROF) display electrode. The cell has the symmetric sandwich structure AIROFvertical-barNafionvertical-barAIROF, with the Nafion solid electrolyte opacified by an in situ precipitation technique. A symmetric square-wave voltage of 1.5 V amplitude produces clearly perceivable color changes from pale to dark blue-gray in approx. =1 sec when viewed in diffuse reflection. Good open-circuit optical memory is exhibited:

  6. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    OpenAIRE

    Plawski Michal; Bakalarz Alicja

    2016-01-01

    The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equ...

  7. A mathematical model of the solid-polymer-electrolyte fuel cell

    International Nuclear Information System (INIS)

    Bernardi, D.M.; Verbrugge, M.W.

    1992-01-01

    This paper presents a mathematical model of the solid-polymer-electrolyte fuel cell and apply it to (i) investigate factors that limit cell performance and (ii) elucidate the mechanism of species transport in the complex network of gas, liquid, and solid phases of the cell. Calculations of cell polarization behavior compare favorably with existing experimental data. For most practical electrode thicknesses, model results indicate that the volume fraction of the cathode available for gas transport must exceed 20% in order to avoid unacceptably low cell-limiting current densities. It is shown that membrane dehydration can also pose limitations on operating current density; circumvention of this problem by appropriate membrane and electrode design and efficient water-management schemes is discussed. The authors' model results indicate that for a broad range of practical current densities there are no external water requirements because the water produced at the cathode is enough to satisfy the water requirement of the membrane

  8. Modelling of solid polymer and direct methanol fuel cells: Phenomenological equations and analytical solutions

    Science.gov (United States)

    Kauranen, P. S.

    1993-04-01

    In the solid state concept of a direct methanol fuel cell (DMFC), methanol is directly oxidized at the anode of a solid polymer electrolyte fuel cell (SPEFC). Mathematical modelling of the transport and reaction phenomena within the electrodes and the electrolyte membrane is needed in order to get a closer insight into the operation of the fuel cell. In the work, macro-homogenous porous electrode and dilute solution theories are used to derive the phenomenological equations describing the transport and reaction mechanisms in a SPEFC single cell. The equations are first derived for a conventional H2/air SPEFC, and then extended for a DMFC. The basic model is derived in a one dimensional form in which it is assumed that species transport take place only in the direction crossing the cell sandwich. In addition, two dimensional descriptions of the catalyst layer are reviewed.

  9. In situ solid-state NMR spectroscopy of electrochemical cells: batteries, supercapacitors, and fuel cells.

    Science.gov (United States)

    Blanc, Frédéric; Leskes, Michal; Grey, Clare P

    2013-09-17

    Electrochemical cells, in the form of batteries (or supercapacitors) and fuel cells, are efficient devices for energy storage and conversion. These devices show considerable promise for use in portable and static devices to power electronics and various modes of transport and to produce and store electricity both locally and on the grid. For example, high power and energy density lithium-ion batteries are being developed for use in hybrid electric vehicles where they improve the efficiency of fuel use and help to reduce greenhouse gas emissions. To gain insight into the chemical reactions involving the multiple components (electrodes, electrolytes, interfaces) in the electrochemical cells and to determine how cells operate and how they fail, researchers ideally should employ techniques that allow real-time characterization of the behavior of the cells under operating conditions. This Account reviews the recent use of in situ solid-state NMR spectroscopy, a technique that probes local structure and dynamics, to study these devices. In situ NMR studies of lithium-ion batteries are performed on the entire battery, by using a coin cell design, a flat sealed plastic bag, or a cylindrical cell. The battery is placed inside the NMR coil, leads are connected to a potentiostat, and the NMR spectra are recorded as a function of state of charge. (7)Li is used for many of these experiments because of its high sensitivity, straightforward spectral interpretation, and relevance to these devices. For example, (7)Li spectroscopy was used to detect intermediates formed during electrochemical cycling such as LixC and LiySiz species in batteries with carbon and silicon anodes, respectively. It was also used to observe and quantify the formation and growth of metallic lithium microstructures, which can cause short circuits and battery failure. This approach can be utilized to identify conditions that promote dendrite formation and whether different electrolytes and additives can help

  10. Poisoning of Solid Oxide Electrolysis Cells by Impurities

    DEFF Research Database (Denmark)

    Ebbesen, Sune; Graves, Christopher R.; Hauch, Anne

    2010-01-01

    )/YSZ oxygen electrode When applying the gases as received, the cells degraded significantly at the Ni/YSZ electrode, whereas only minor (and initial) degradation was observed for either the Ni/YSZ or LSM/YSZ electrode. Application of clean gases to the Ni/YSZ electrode resulted in operation without any long...

  11. Study of upscaling possibilities for antimony sulfide solid state sensitized solar cells

    Science.gov (United States)

    Nikolakopoulou, Archontoula; Raptis, Dimitrios; Dracopoulos, Vasilios; Sygellou, Lamprini; Andrikopoulos, Konstantinos S.; Lianos, Panagiotis

    2015-03-01

    Solid state solar cells of inverted structure were constructed by successive deposition of nanoparticulate titania, antimony sulfide sensitizer and P3HT on FTO electrodes with PEDOT:PSS:Ag as counter electrode. Sensitized photoanode electrodes were characterized by XRD, Raman, XPS, FESEM and UV-vis. Small laboratory scale cells were first constructed and optimized. Functional cells were obtained by annealing the antimony sulfide film either in air or in inert atmosphere. High short-circuit currents were recorded in both cases with air-annealed sample producing more current but lower voltage. Small unit cells were combined to form cell modules. Connection of unit cells in parallel increased current but not proportionally to that of the unit cell. Connection in series preserved current and generated voltage multiplication. Cells were constructed and studied under ambient conditions, without encapsulation. The results encourage upscaling of antimony sulfide solar cells.

  12. Tailored Core Shell Cathode Powders for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, Scott [NexTech Materials, Ltd.,Lewis Center, OH (United States)

    2015-03-23

    In this Phase I SBIR project, a “core-shell” composite cathode approach was evaluated for improving SOFC performance and reducing degradation of lanthanum strontium cobalt ferrite (LSCF) cathode materials, following previous successful demonstrations of infiltration approaches for achieving the same goals. The intent was to establish core-shell cathode powders that enabled high performance to be obtained with “drop-in” process capability for SOFC manufacturing (i.e., rather than adding an infiltration step to the SOFC manufacturing process). Milling, precipitation and hetero-coagulation methods were evaluated for making core-shell composite cathode powders comprised of coarse LSCF “core” particles and nanoscale “shell” particles of lanthanum strontium manganite (LSM) or praseodymium strontium manganite (PSM). Precipitation and hetero-coagulation methods were successful for obtaining the targeted core-shell morphology, although perfect coverage of the LSCF core particles by the LSM and PSM particles was not obtained. Electrochemical characterization of core-shell cathode powders and conventional (baseline) cathode powders was performed via electrochemical impedance spectroscopy (EIS) half-cell measurements and single-cell SOFC testing. Reliable EIS testing methods were established, which enabled comparative area-specific resistance measurements to be obtained. A single-cell SOFC testing approach also was established that enabled cathode resistance to be separated from overall cell resistance, and for cathode degradation to be separated from overall cell degradation. The results of these EIS and SOFC tests conclusively determined that the core-shell cathode powders resulted in significant lowering of performance, compared to the baseline cathodes. Based on the results of this project, it was concluded that the core-shell cathode approach did not warrant further investigation.

  13. Solid Oxide Fuel Cell Technology Stationary Power Application Project

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Pierre

    2009-03-05

    The objectives of this program were to: (1) Develop a reliable, cost-effective, and production-friendly technique to apply the power-enhancing layer at the interface of the air electrode and electrolyte of the Siemens SOFC; (2) Design, build, install, and operate in the field two 5 kWe SOFC systems fabricated with the state-of-the-art cylindrical, tubular cell and bundle technology and incorporating advanced module design features. Siemens successfully demonstrated, first in a number of single cell tests and subsequently in a 48-cell bundle test, a significant power enhancement by employing a power-enhancing composite interlayer at the interface between the air electrode and electrolyte. While successful from a cell power enhancement perspective, the interlayer application process was not suitable for mass manufacturing. The application process was of inconsistent quality, labor intensive, and did not have an acceptable yield. This program evaluated the technical feasibility of four interlayer application techniques. The candidate techniques were selected based on their potential to achieve the technical requirements of the interlayer, to minimize costs (both labor and material), and suitably for large-scale manufacturing. Preliminary screening, utilizing lessons learned in manufacturing tubular cells, narrowed the candidate processes to two, ink-roller coating (IRC) and dip coating (DC). Prototype fixtures were successfully built and utilized to further evaluate the two candidate processes for applying the interlayer to the high power density Delta8 cell geometry. The electrical performance of interlayer cells manufactured via the candidate processes was validated. Dip coating was eventually selected as the application technique of choice for applying the interlayer to the high power Delta8 cell. The technical readiness of the DC process and product quality was successfully and repeatedly demonstrated, and its throughput and cost are amenable to large scale

  14. Program Area of Interest: Fuel Transformer Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Norman Bessette; Douglas S. Schmidt; Jolyon Rawson; Rhys Foster; Anthony Litka

    2006-02-01

    The following report documents the technical approach and conclusions made by Acumentrics Corporation during latest budget period toward the development of a low cost 10kW tubular SOFC power system. The present program, guided under direction from the National Energy Technology Laboratory of the US DOE, is a nine-year cost shared Cooperative Agreement totaling close to $74M funded both by the US DOE as well as Acumentrics Corporation and its partners. The latest budget period ran from July of 2005 through December 2005. Work focused on cell technology enhancements as well as BOP and power electronics improvements and overall system design. Significant progress was made in increasing cell power enhancements as well as decreasing material cost in a drive to meet the SECA cost targets. The following report documents these accomplishments in detail as well as the layout plans for further progress in next budget period.

  15. Parallel recognition of cancer cells using an addressable array of solid-state micropores.

    Science.gov (United States)

    Ilyas, Azhar; Asghar, Waseem; Kim, Young-tae; Iqbal, Samir M

    2014-12-15

    Early stage detection and precise quantification of circulating tumor cells (CTCs) in the peripheral blood of cancer patients are important for early diagnosis. Early diagnosis improves the effectiveness of the therapy and results in better prognosis. Several techniques have been used for CTC detection but are limited by their need for dye tagging, low throughput and lack of statistical reliability at single cell level. Solid-state micropores can characterize each cell in a sample providing interesting information about cellular populations. We report a multi-channel device which utilized solid-state micropores array assembly for simultaneous measurement of cell translocation. This increased the throughput of measurement and as the cells passed the micropores, tumor cells showed distinctive current blockade pulses, when compared to leukocytes. The ionic current across each micropore channel was continuously monitored and recorded. The measurement system not only increased throughput but also provided on-chip cross-relation. The whole blood was lysed to get rid of red blood cells, so the blood dilution was not needed. The approach facilitated faster processing of blood samples with tumor cell detection efficiency of about 70%. The design provided a simple and inexpensive method for rapid and reliable detection of tumor cells without any cell staining or surface functionalization. The device can also be used for high throughput electrophysiological analysis of other cell types. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A novel design for solid oxide fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qattan, A.M.; Chmielewski, D.J.; Al-Hallaj, S.; Selman, J.R. [Illinois Inst. of Technology, Chicago, IL (United States). Dept. of Chemical and Environmental Engineering

    2004-01-01

    Conventional fuel cell stack designs suffer from severe spatial nonuniformity in both temperature and current density. Such variations are known to create damaging thermal stresses within the stack and thus, impact overall lifespan. In this work, we propose a novel stack design aimed at reducing spatial variations at the source. We propose a mechanism of distributed fuel feed in which the heat generation profile can be influenced directly. Simulation results are presented to illustrate the potential of the proposed scheme. (author)

  17. Size matters: nest colonization patterns for twig-nesting ants.

    Science.gov (United States)

    Jiménez-Soto, Estelí; Philpott, Stacy M

    2015-08-01

    Understanding the drivers of ant diversity and co-occurrence in agroecosystems is fundamental because ants participate in interactions that influence agroecosystem processes. Multiple local and regional factors influence ant community assembly.We examined local factors that influence the structure of a twig-nesting ant community in a coffee system in Mexico using an experimental approach. We investigated whether twig characteristics (nest entrance size and diversity of nest entrance sizes) and nest strata (canopy shade tree or coffee shrub) affected occupation, species richness, and community composition of twig-nesting ants and whether frequency of occupation of ant species varied with particular nest entrance sizes or strata.We conducted our study in a shaded coffee farm in Chiapas, Mexico, between March and June 2012. We studied ant nest colonization by placing artificial nests (bamboo twigs) on coffee shrubs and shade trees either in diverse or uniform treatments. We also examined whether differences in vegetation (no. of trees, canopy cover and coffee density) influenced nest colonization.We found 33 ant species occupying 73% of nests placed. Nest colonization did not differ with nest strata or size. Mean species richness of colonizing ants was significantly higher in the diverse nest size entrance treatment, but did not differ with nest strata. Community composition differed between strata and also between the diverse and uniform size treatments on coffee shrubs, but not on shade trees. Some individual ant species were more frequently found in certain nest strata and in nests with certain entrance sizes.Our results indicate that twig-nesting ants are nest-site limited, quickly occupy artificial nests of many sizes, and that trees or shrubs with twigs of a diversity of entrance sizes likely support higher ant species richness. Further, individual ant species more frequently occupy nests with different sized entrances promoting ant richness on individual coffee

  18. Carbon as a fuel for efficient electricity generation in carbon solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available In this paper, the impact of the physicochemical properties of carbonaceous solid fuels on the performance of a direct carbon solid oxide fuel cell (DC-SOFC was investigated. High-purity synthetic carbon powders such as carbon black N-220 and Carbo Medicinalis FP5 were chosen for analytical and electrochemical investigations in a DC-SOFC. The research focussed on choosing an optimised, cost-effective, high-purity carbon powder which could be applied as a solid reference fuel for all tests performed on a single DC-SOFC cell as well as on DC-SOFC stack constructions. Most of the electrochemical investigations described in this paper were performed using square DCSOFCs with dimensions of 5 × 5 cm. The relationship between structure, physicochemical properties, and electrochemical reactivity in a DC-SOFC was analysed.

  19. CHALLENGES IN GENERATING HYDROGEN BY HIGH TEMPERATURE ELECTROLYSIS USING SOLID OXIDE CELLS

    Energy Technology Data Exchange (ETDEWEB)

    M. S. Sohal; J. E. O' Brien; C. M. Stoots; M. G. McKellar; J. S. Herring; E. A. Harvego

    2008-03-01

    Idaho National Laboratory’s (INL) high temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells is presented in this paper. The research results reported here have been obtained in a laboratory-scale apparatus. These results and common scale-up issues also indicate that for the technology to be successful in a large industrial setting, several technical, economical, and manufacturing issues have to be resolved. Some of the issues related to solid oxide cells are stack design and performance optimization, identification and evaluation of cell performance degradation parameters and processes, integrity and reliability of the solid oxide electrolysis (SOEC) stacks, life-time prediction and extension of the SOEC stack, and cost reduction and economic manufacturing of the SOEC stacks. Besides the solid oxide cells, balance of the hydrogen generating plant also needs significant development. These issues are process and ohmic heat source needed for maintaining the reaction temperature (~830°C), high temperature heat exchangers and recuperators, equal distribution of the reactants into each cell, system analysis of hydrogen and associated energy generating plant, and cost optimization. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.23/kg of hydrogen assuming an internal rate of return of 10%. These issues need interdisciplinary research effort of federal laboratories, solid oxide cell manufacturers, hydrogen consumers, and other such stakeholders. This paper discusses research and development accomplished by INL on such issues and highlights associated challenges that need to

  20. The Effect of radiation on T-cell mitosis and natural killer cell mediated cytotoxicity in solid cancer patients

    International Nuclear Information System (INIS)

    Choi, Il Bong; Bahk, Yong Whee

    1986-01-01

    The present study has been conducted to investigate whether such tests can be used as a guideline in planning radiation therapy and in prognosticating radiation treatment of patients with a solid cancer. The first group consisted of 68 patients with solid tumors who received radiation therapy from May 1984 until July 1985 at the Department of Radiology, Catholic Medical College and these showed the following results of T-cell function change by the phytohemagglutinin (PHA) stimulation test and the response of the NK cell in vivo following radiation by NKMC test. Secondly the NKMC and PHA stimulation tests have been studied in 27 patients with solid tumors who did not receive radiation therapy (cancer control group) and thirdly 30 normal subjects were tested as normal control. (Author)

  1. Hydrogen and synthetic fuel production using pressurized solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune

    2010-01-01

    Wind and solar power is troubled by large fluctuations in delivery due to changing weather. The surplus electricity can be used in a Solid Oxide Electrolyzer Cell (SOEC) to split CO2 + H2O into CO + H2 (+O2). The synthesis gas (CO + H2) can subsequently be catalyzed into various types of synthetic...... fuels using a suitable catalyst. As the catalyst operates at elevated pressure the fuel production system can be simplified by operating the SOEC at elevated pressure. Here we present the results of a cell test with pressures ranging from 0.4 bar to 10 bar. The cell was tested both as an SOEC...... and as a Solid Oxide Fuel Cell (SOFC). In agreement with previous reports, the SOFC performance increases with pressure. The SOEC performance, at 750 °C, was found to be weakly affected by the pressure range in this study, however the internal resistance decreased significantly with increasing pressure....

  2. High performance metal-supported solid oxide fuel cells with Gd-doped ceria barrier layers

    DEFF Research Database (Denmark)

    Klemensø, Trine; Nielsen, Jimmi; Blennow Tullmar, Peter

    2011-01-01

    Metal-supported solid oxide fuel cells are believed to have commercial advantages compared to conventional anode (Ni–YSZ) supported cells, with the metal-supported cells having lower material costs, increased tolerance to mechanical and thermal stresses, and lower operational temperatures...... at 650 °C and 0.6 V, were obtained on cells with barrier layers fabricated by magnetron sputtering. The performance is dependent on the density of the barrier layer, indicating Sr2+ diffusion is occurring at the intermediate SOFC temperatures. The optimized design further demonstrate improved durability...

  3. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    The market penetration of fuel and electrolysis cell energy systems in Europe requires the development of reliable assessment, testing and prediction of performance and durability of solid oxide cells and stacks (SOC). To advance in this field the EU-project “SOCTESQA” was launched in May 2014....... Partners from different countries in Europe and one external party from Singapore are working together to develop uniform and industry wide test procedures and protocols for SOC cell/stack assembly. In this project new application fields which are based on the operation of the SOC cell/stack assembly...

  4. Micromechanical Modeling of Solid Oxide Fuel Cell Anode Supports based on Three-dimensional Reconstructions

    DEFF Research Database (Denmark)

    Kwok, Kawai; Jørgensen, Peter Stanley; Frandsen, Henrik Lund

    2014-01-01

    The efficiency and lifetime of solid oxide fuel cells (SOFCs) is compromised by mechanical failure of cells in the system. Improving the mechanical reliability is a major step in ensuring feasibility of the technology. To quantify the stress in a cell, mechanical properties of the different layers...... need to be accurately known. Since the mechanical properties are heavily dependent on the microstructures of the materials, it is highly advantageous to understand the impact of microstructures and to be able to determine accurate effective mechanical properties for cell or stack scale analyses...

  5. Human natural killer cells: news in the therapy of solid tumors and high-risk leukemias.

    Science.gov (United States)

    Pietra, Gabriella; Vitale, Chiara; Pende, Daniela; Bertaina, Alice; Moretta, Francesca; Falco, Michela; Vacca, Paola; Montaldo, Elisa; Cantoni, Claudia; Mingari, Maria Cristina; Moretta, Alessandro; Locatelli, Franco; Moretta, Lorenzo

    2016-04-01

    It is well established that natural killer (NK) cells play an important role in the immunity against cancer, while the involvement of other recently identified, NK-related innate lymphoid cells is still poorly defined. In the haploidentical hematopoietic stem cell transplantation for the therapy of high-risk leukemias, NK cells have been shown to exert a key role in killing leukemic blasts residual after conditioning. While the clinical results in the cure of leukemias are excellent, the exploitation of NK cells in the therapy of solid tumors is still limited and unsatisfactory. In solid tumors, NK cell function may be inhibited via different mechanisms, occurring primarily at the tumor site. The cellular interactions in the tumor microenvironment involve tumor cells, stromal cells and resident or recruited leukocytes and may favor tumor evasion from the host's defenses. In this context, a number of cytokines, growth factors and enzymes synthesized by tumor cells, stromal cells, suppressive/regulatory myeloid and lymphoid cells may substantially impair the function of different tumor-reactive effector cells, including NK cells. The identification and characterization of such mechanisms may offer clues for the development of new immunotherapeutic strategies to restore effective anti-tumor responses. In order to harness NK cell-based immunotherapies, several approaches have been proposed, including reinforcement of NK cell cytotoxicity by means of specific cytokines, antibodies or drugs. These new tools may improve NK cell function and/or increase tumor susceptibility to NK-mediated killing. Hence, the integration of NK-based immunotherapies with conventional anti-tumor therapies may increase chances of successful cancer treatment.

  6. High Spatial Resolution Imaging of Endogenous Hydrogen Peroxide in Living Cells by Solid-State Fluorescence.

    Science.gov (United States)

    Lindberg, Eric; Winssinger, Nicolas

    2016-09-02

    Herein, we describe selective imaging of hydrogen peroxide using a precipitating dye conjugated to a boronic acid-based immolative linker. We achieved visualization of endogenous hydrogen peroxide in phagosomes by solid-state two-photon fluorescence imaging in living cells with exceptionally high spatial resolution. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Ni modified ceramic anodes for direct-methane solid oxide fuel cells

    Science.gov (United States)

    Xiao, Guoliang; Chen, Fanglin

    2016-01-19

    In accordance with certain embodiments of the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes synthesizing a composition having a perovskite present therein. The method further includes applying the composition on an electrolyte support to form an anode and applying Ni to the composition on the anode.

  8. Optimization of a new flow design for solid oxide cells using computational fluid dynamics modelling

    DEFF Research Database (Denmark)

    Duhn, Jakob Dragsbæk; Jensen, Anker Degn; Wedel, Stig

    2016-01-01

    Design of a gas distributor to distribute gas flow into parallel channels for Solid Oxide Cells (SOC) is optimized, with respect to flow distribution, using Computational Fluid Dynamics (CFD) modelling. The CFD model is based on a 3d geometric model and the optimized structural parameters include...

  9. Novel materials for more robust solid oxide fuel cells in small scale applications

    DEFF Research Database (Denmark)

    Holtappels, Peter

    Solid oxide fuel cells can offer supply of electrical energy with a high efficiency and based on a wide range of fuels. While natural gas and/or bio methane is a commonly used fuel for combined heat and power supply, liquid fuels such as gasoline, Diesel and alcohols are interesting fuels...

  10. Prediction of solid oxide fuel cell cathode activity with first-principles descriptors

    DEFF Research Database (Denmark)

    Lee, Yueh-Lin; Kleis, Jesper; Rossmeisl, Jan

    2011-01-01

    In this work we demonstrate that the experimentally measured area specific resistance and oxygen surface exchange of solid oxide fuel cell cathode perovskites are strongly correlated with the first-principles calculated oxygen p-band center and vacancy formation energy. These quantities...

  11. Strontium Titanate-based Composite Anodes for Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Blennow Tullmar, Peter; Kammer Hansen, Kent; Wallenberg, L.R.

    2008-01-01

    Surfactant-assisted infiltration of Gd-doped ceria (CGO) in Nb-doped SrTiO3 (STN) was investigated as a potential fuel electrode for solid oxide fuel cells (SOFC). An electronically conductive backbone structure of STN was first fabricated at high temperatures and then combined with the mixed con...

  12. Physical Properties of Mixed Conductor Solid Oxide Fuel Cell Anodes of Doped CeO2

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Lindegaard, Thomas; Hansen, Uffe Rud

    1994-01-01

    conductivity vs. oxygen partial pressure. For both typesof conductivity a dependence on dopant valency was observed. The electronic conductivity was independent of dopantradius in contrast to the ionic which was highly dependent. These measured physical properties are compared with the idealrequirements...... for solid oxide fuel cell anodes. Not all requirements are fulfilled. Measures to compensate for this arediscussed....

  13. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    Energy Technology Data Exchange (ETDEWEB)

    Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.

    2016-05-17

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  14. Development Of A Solid Oxide Fuel Cell Stack By Delphi And Battelle

    Energy Technology Data Exchange (ETDEWEB)

    Mukerjee, Subhasish; Shaffer, Steven J.; Zizelman, James; Chick, Lawrence A.; Baskaran, Suresh; Chou, Y. S.; Coyle, Christopher A.; Deibler, John E.; Maupin, Gary D.; Meinhardt, Kerry D.; Paxton, Dean M.; Peters, Timothy J.; Sprenkle, Vince L.; Weil, K. Scott; Williford, Rick E.

    2003-01-20

    Delphi and Battelle are developing a Solid Oxide Fuel Cell (SOFC) stack for transportation and residential applications. This paper describes the status of development of the Generation 2 stack and key progress made in addressing some of the challenges in this technology.

  15. Investigation of Novel Electrocatalysts for Metal Supported Solid Oxide Fuel Cells - Ru:GDC

    DEFF Research Database (Denmark)

    Sudireddy, Bhaskar Reddy; Nielsen, Jimmi; Thydén, Karl Tor Sune

    2015-01-01

    Even though solid oxide fuel cells (SOFCs) have a high potential with respect to efficiency and fuel flexibility they are not yet competitive in terms of cost and durability with conventional chemical energy conversion technologies. The potential cost reduction can be achieved through the develop...

  16. Investigation of Novel Electrocatalysts for Metal Supported Solid Oxide Fuel Cells - Ru:GDC

    DEFF Research Database (Denmark)

    Sudireddy, Bhaskar Reddy; Nielsen, Jimmy; Thydén, Karl Tor Sune

    2015-01-01

    The electrochemical performance and stability of the planar metal supported solid oxide fuel cells (MS-SOFC) with two different electrocatalytically active materials, namely, Ni:GDC and Ru:GDC were investigated. Ru:GDC with an ASR of 0.322 Ωcm2 performed better than Ni:GDC with an ASR of 0.453 Ωc...

  17. Ab initio Defect Energetics in LaBO3 Perovskite Solid Oxide Fuel Cell Materials

    DEFF Research Database (Denmark)

    Lee, Yueh-Lin; Morgan, Dane; Kleis, Jesper

    2009-01-01

    Perovskite materials of the form ABO3 are a promising family of compounds for use in solid oxide fuel cell (SOFC) cathodes. Study of the physics of these compounds under SOFC conditions with ab initio methods is particularly challenging due to high temperatures, exchange of oxygen with O2 gas...

  18. Flexible, low-temperature, solution processed ZnO-based perovskite solid state solar cells.

    Science.gov (United States)

    Kumar, Mulmudi Hemant; Yantara, Natalia; Dharani, Sabba; Graetzel, Michael; Mhaisalkar, Subodh; Boix, Pablo P; Mathews, Nripan

    2013-12-07

    A ZnO compact layer formed by electrodeposition and ZnO nanorods grown by chemical bath deposition (CBD) allow the processing of low-temperature, solution based and flexible solid state perovskite CH3NH3PbI3 solar cells. Conversion efficiencies of 8.90% were achieved on rigid substrates while the flexible ones yielded 2.62%.

  19. Magnetron sputtered gadolinia-doped ceria diffusion barriers for metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Sønderby, Steffen; Klemensø, Trine; Christensen, Bjarke H.

    2014-01-01

    Gadolinia-doped ceria (GDC) thin films are deposited by reactive magnetron sputtering in an industrial-scale setup and implemented as barrier layers between the cathode and electrolyte in metal-based solid oxide fuel cells consisting of a metal support, an electrolyte of ZrO2 co-doped with Sc2O3 ...

  20. A combined SEM and CV Study of Solid Oxide Fuel Cell Interconnect Steels

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent; Ofoegbu, Stanley; Mikkelsen, Lars

    2012-01-01

    Scanning electron microscopy and cyclic voltammetry were used to investigate the high temperature oxidation behavior of two solid oxide fuel cell interconnect steels. One alloy had a low content of manganese; the other alloy had a high content of manganese. Four reduction and four oxidation peaks...

  1. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Gail E. [Delphi Automotive Systems, LLC., Gillingham (United Kingdom)

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  2. Micromachined Dense Palladium Electrodes for Thin-film Solid Acid Fuel Cells

    NARCIS (Netherlands)

    Unnikrishnan, S.

    2009-01-01

    This thesis paves the way towards the microfabrication of a solid acid electrolyte based fuel cell (µSAFC), which has a membrane electrode assembly (MEA) consisting of a thin-film of water soluble electrolyte encapsulated between two dense palladium electrode membranes. This project work

  3. Nested and Hierarchical Archimax copulas

    KAUST Repository

    Hofert, Marius

    2017-07-03

    The class of Archimax copulas is generalized to nested and hierarchical Archimax copulas in several ways. First, nested extreme-value copulas or nested stable tail dependence functions are introduced to construct nested Archimax copulas based on a single frailty variable. Second, a hierarchical construction of d-norm generators is presented to construct hierarchical stable tail dependence functions and thus hierarchical extreme-value copulas. Moreover, one can, by itself or additionally, introduce nested frailties to extend Archimax copulas to nested Archimax copulas in a similar way as nested Archimedean copulas extend Archimedean copulas. Further results include a general formula for the density of Archimax copulas.

  4. Fermi Potential across Working Solid Oxide Cells with Zirconia or Ceria Electrolytes

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Two kinds of electrochemical relevant potentials are important in order to describe several observed phenomena in operating electrochemical cells with solid electrolytes. This paper gives illustrative examples of how the profiles of the two potential types, the Galvani potential, φ, and the elect...... stabilized zirconia (YSZ) electrolytes. The nature of the two potential types and the importance of each of them for the cell operation are explained....

  5. Highly durable anode supported solid oxide fuel cell with an infiltrated cathode

    DEFF Research Database (Denmark)

    Samson, Alfred Junio; Hjalmarsson, Per; Søgaard, Martin

    2012-01-01

    An anode supported solid oxide fuel cell with an La0.6Sr0.4Co1.05O3_δ (LSC) infiltrated-Ce0.9Gd0.1O1.95 (CGO) cathode that shows a stable performance has been developed. The cathode was prepared by screen printing a porous CGO backbone on top of a laminated and co-fired anode supported half cell...

  6. Superposition Enhanced Nested Sampling

    Directory of Open Access Journals (Sweden)

    Stefano Martiniani

    2014-08-01

    Full Text Available The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

  7. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    Directory of Open Access Journals (Sweden)

    Plawski Michal

    2016-01-01

    Full Text Available The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equation, while the remaining components according to the first-order equation. The kinetic rate constants and maximum recovery of the studied components decreased with increasing solids mass in the flotation cell, regardless of the capacity of the cell. The best results were obtained for tests using a 1.0 dm3 cell, while the less favorable kinetics results were observed in the test with the smallest cell of 0.75 dm3 volume. The obtained results can be helpful in choosing the most appropriate methodology of upgrading the sulfide copper ore from Poland in order to obtain the best kinetics results.

  8. Engineered Breast Cancer Cell Spheroids Reproduce Biologic Properties of Solid Tumors.

    Science.gov (United States)

    Ham, Stephanie L; Joshi, Ramila; Luker, Gary D; Tavana, Hossein

    2016-11-01

    Solid tumors develop as 3D tissue constructs. As tumors grow larger, spatial gradients of nutrients and oxygen and inadequate diffusive supply to cells distant from vasculature develops. Hypoxia initiates signaling and transcriptional alterations to promote survival of cancer cells and generation of cancer stem cells (CSCs) that have self-renewal and tumor-initiation capabilities. Both hypoxia and CSCs are associated with resistance to therapies and tumor relapse. This study demonstrates that 3D cancer cell models, known as tumor spheroids, generated with a polymeric aqueous two-phase system (ATPS) technology capture these important biological processes. Similar to solid tumors, spheroids of triple negative breast cancer cells deposit major extracellular matrix proteins. The molecular analysis establishes presence of hypoxic cells in the core region and expression of CSC gene and protein markers including CD24, CD133, and Nanog. Importantly, these spheroids resist treatment with chemotherapy drugs. A combination treatment approach using a hypoxia-activated prodrug, TH-302, and a chemotherapy drug, doxorubicin, successfully targets drug resistant spheroids. This study demonstrates that ATPS spheroids recapitulate important biological and functional properties of solid tumors and provide a unique model for studies in cancer research. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Development of low temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, W.T.; Goldstein, R. [Electric Power Research Institute, Palo Alto, CA (United States)

    1996-12-31

    The historical focus of the electric utility industry has been central station power plants. These plants are usually sited outside urban areas and electricity was delivered via high voltage transmission lines. Several things are beginning to change this historical precedent One is the popular concern with EMF as a health hazard. This has rendered the construction of new lines as well as upgrading old ones very difficult. Installation of power generating equipment near the customer enables the utility to better utilize existing transmission and distribution networks and defer investments. Power quality and lark of disturbances and interruptions is also becoming increasingly more important to many customers. Grid connected, but dedicated small power plants can greatly improve power quality. Finally the development of high efficiency, low emission, modular fuel cells promises near pollution free localized power generation with an efficiency equal to or exceeding that of even the most efficient central power stations.

  10. Colloidal quantum dot solids for solution-processed solar cells

    KAUST Repository

    Yuan, Mingjian

    2016-02-29

    Solution-processed photovoltaic technologies represent a promising way to reduce the cost and increase the efficiency of solar energy harvesting. Among these, colloidal semiconductor quantum dot photovoltaics have the advantage of a spectrally tuneable infrared bandgap, which enables use in multi-junction cells, as well as the benefit of generating and harvesting multiple charge carrier pairs per absorbed photon. Here we review recent progress in colloidal quantum dot photovoltaics, focusing on three fronts. First, we examine strategies to manage the abundant surfaces of quantum dots, strategies that have led to progress in the removal of electronic trap states. Second, we consider new device architectures that have improved device performance to certified efficiencies of 10.6%. Third, we focus on progress in solution-phase chemical processing, such as spray-coating and centrifugal casting, which has led to the demonstration of manufacturing-ready process technologies.

  11. Degradation of solid oxide fuel cells with wood

    International Nuclear Information System (INIS)

    N Frank; M Saule; J Karl

    2006-01-01

    The Technical University of Munich investigates the degradation effects observed on SOFCs when fired with product gases from biomass gasification processes. The TUM has concentrated its research on tubular SOFCs. For this purpose tubular electrolyte-supported SOFCs have been manufactured using commercially available electrolyte tubes, anode foil and cathode paste. The tubular SOFCs were first run with hydrogen and synthetic fuels. Once stable and reproducible results were achieved, tests with product gas from four different biomass gasifiers have started. These gasifiers have been coupled to a gas cleaning device which includes sulphur and particle removal and pre-reforming. Different operation conditions of the gasifiers and the gas cleaning device have been realized and the corresponding fuel cell degradations have been analysed. (authors)

  12. Modeling and Structural Optimization of Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Panagakos, Grigorios

    the problem in the micro-scale. Taking as starting point the homogenization method for getting an upscaled equation for the diffusion of ion vacancies in a fuel cell's cathode, we derive formulas that express the Area Specific Resistance (ASR) of the electrode as a function of geometric parameters......, such as the tortuosity and the porosity of the material, for preselected micro-structures. Furthermore, we apply optimization techniques to lead this ASR to minimization. This work has been the fruit of collaboration with Professor Sossina Haile at the California Institute of Technology (Caltech) and with assistant...... the compound of magnesium hydrides encapsulated in PMMA for a set of experiments aiming at the development of a mass production method through laser ablation for cheap and effective hydrogen storage. This work was done in collaboration with Dr. Athanasios Stubos at the National Center for Scientific Research...

  13. Therapeutic potential and challenges of Natural killer cells in treatment of solid tumors

    Directory of Open Access Journals (Sweden)

    Andrea eGras Navarro

    2015-04-01

    Full Text Available Natural killer (NK cells are innate lymphoid cells that hold tremendous potential for effective immunotherapy for a broad range of cancers. Due to the mode of NK cell killing requiring one–to-one target engagement and site directed release of cytolytic granules, the therapeutic potential of NK cells has been most extensively explored in hematological malignancies. However, their ability to precisely kill antibody coated cells, cancer stem cells (CSCs and genotoxically altered cells, while maintaining tolerance to healthy cells makes them appealing therapeutic effectors for all cancer forms, including metastases. Due to their release of pro-inflammatory cytokines, NK cells may potently reverse the anti-inflammatory tumor microenvironment (TME and augment adaptive immune responses by promoting differentiation, activation and/ or recruitment of accessory immune cells to sites of malignancy. Nevertheless, integrated and coordinated mechanisms of subversion of NK cell activity against the tumor and its microenvironment exist. Although our understanding of the receptor ligand interactions that regulate NK cell functionality has evolved remarkably, the diversity of ligands and receptors is complex, as is their mechanistic foundations in regulating NK cell function. In this article, we review the literature and highlight how the TME manipulates the NK cell phenotypes, genotypes and tropism to evade tumor recognition and elimination. We discuss counter strategies that may be adopted to augment the efficacy of NK cell anti-tumor surveillance, the clinical trials that have been undertaken so far in solid malignancies, critically weighing the challenges and opportunities with this approach.

  14. THE STRUCTURE AND CONCENTRATION OF SOLIDS IN PHOTORECEPTOR CELLS STUDIED BY REFRACTOMETRY AND INTERFERENCE MICROSCOPY

    Science.gov (United States)

    Sidman, Richard L.

    1957-01-01

    Fragments of freshly obtained retinas of several vertebrate species were studied by refractometry, with reference to the structure of the rods and cones. The findings allowed a reassessment of previous descriptions based mainly on fixed material. The refractometric method was used also to measure the refractice indices and to calculate the concentrations of solids and water in the various cell segments. The main quantitative data were confirmed by interference microscopy. When examined by the method of refractometry the outer segments of freshly prepared retinal rods appear homogeneous. Within a few minutes a single eccentric longitudinal fiber appears, and transverse striations may develop. These changes are attributed to imbibition of water and swelling in structures normally too small for detection by light microscopy. The central "core" of outer segments and the chromophobic disc between outer and inner segments appear to be artifacts resulting from shrinkage during dehydration. The fresh outer segments of cones, and the inner segments of rods and cones also are described and illustrated. The volumes, refractive indices, concentrations of solids, and wet and dry weights of various segments of the photoreceptor cells were tabulated. Rod outer segments of the different species vary more than 100-fold in volume and mass but all have concentrations of solids of 40 to 43 per cent. Cone outer segments contain only about 30 per cent solids. The myoids, paraboloids, and ellipsoids of the inner segments likewise have characteristic refractive indices and concentrations of solids. Some of the limitations and particular virtues of refractometry as a method for quantitative analysis of living cells are discussed in comparison with more conventional biochemical techniques. Also the shapes and refractive indices of the various segments of photoreceptor cells are considered in relation to the absorption and transmission of light. The Stiles-Crawford effect can be accounted

  15. Study of catalysis for solid oxide fuel cells and direct methanol fuel cells

    Science.gov (United States)

    Jiang, Xirong

    Fuel cells offer the enticing promise of cleaner electricity with lower environmental impact than traditional energy conversion technologies. Driven by the interest in power sources for portable electronics, and distributed generation and automotive propulsion markets, active development efforts in the technologies of both solid oxide fuel cell (SOFC) and direct methanol fuel cell (DMFC) devices have achieved significant progress. However, current catalysts for fuel cells are either of low catalytic activity or extremely expensive, presenting a key barrier toward the widespread commercialization of fuel cell devices. In this thesis work, atomic layer deposition (ALD), a novel thin film deposition technique, was employed to apply catalytic Pt to SOFC, and investigate both Pt skin catalysts and Pt-Ru catalysts for methanol oxidation, a very important reaction for DMFC, to increase the activity and utilization levels of the catalysts while simultaneously reducing the catalyst loading. For SOFCs, we explored the use of ALD for the fabrication of electrode components, including an ultra-thin Pt film for use as the electrocatalyst, and a Pt mesh structure for a current collector for SOFCs, aiming for precise control over the catalyst loading and catalyst geometry, and enhancement in the current collect efficiency. We choose Pt since it has high chemical stability and excellent catalytic activity for the O2 reduction reaction and the H2 oxidation reaction even at low operating temperatures. Working SOFC fuel cells were fabricated with ALD-deposited Pt thin films as an electrode/catalyst layer. The measured fuel cell performance reveals that comparable peak power densities were achieved for ALD-deposited Pt anodes with only one-fifth of the Pt loading relative to a DC-sputtered counterpart. In addition to the continuous electrocatalyst layer, a micro-patterned Pt structure was developed via the technique of area selective ALD. By coating yttria-stabilized zirconia, a

  16. Enclosed nests may provide greater thermal than nest predation benefits compared with open nests across latitudes

    Science.gov (United States)

    Martin, Thomas E.; Boyce, Andy J.; Fierro-Calderon, Karolina; Mitchell, Adam E.; Armstad, Connor E.; Mouton, James C.; Bin Soudi, Evertius E.

    2017-01-01

    Nest structure is thought to provide benefits that have fitness consequences for several taxa. Traditionally, reduced nest predation has been considered the primary benefit underlying evolution of nest structure, whereas thermal benefits have been considered a secondary or even non-existent factor. Yet, the relative roles of these factors on nest structures remain largely unexplored.Enclosed nests have a constructed or natural roof connected to sides that allow a restricted opening or tube entrance that provides cover in all directions except the entrance, whereas open nests are cups or platforms that are open above. We show that construction of enclosed nests is more common among songbirds (Passeriformes) in tropical and southern hemisphere regions than in north temperate regions. This geographic pattern may reflect selection from predation risk, under long-standing assumptions that nest predation rates are higher in southern regions and that enclosed nests reduce predation risk compared with open cup nests. We therefore compared nest predation rates between enclosed vs. open nests in 114 songbird species that do not nest in tree holes among five communities of coexisting birds, and for 205 non-hole-nesting species from the literature, across northern temperate, tropical, and southern hemisphere regions.Among coexisting species, enclosed nests had lower nest predation rates than open nests in two south temperate sites, but not in either of two tropical sites or a north temperate site. Nest predation did not differ between nest types at any latitude based on literature data. Among 319 species from both our field studies and the literature, enclosed nests did not show consistent benefits of reduced predation and, in fact, predation was not consistently higher in the tropics, contrary to long-standing perspectives.Thermal benefits of enclosed nests were indicated based on three indirect results. First, species that built enclosed nests were smaller than species using

  17. Structure{leftrightarrow}property relationships in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, W.; Reed, D.M.; Anderson, H.U. [Univ. of Missouri, Rolla, MO (United States)

    1996-12-31

    The electrode reactions are a major cause of the energy losses in SOFC`s, and limit their use to higher temperatures, typically 800-1000{degrees}C. The electrode reactions have received much attention aimed at better understanding the electrode kinetics and mechanisms, but are still very primitive in their basic understanding. The electrode microstructure and its corresponding reactivity has commonly been studied by DC and AC impedance techniques. A common method of examining electrode reactions employs surface-mounted reference electrodes, although this technique often limits the experiment to examination of one electrode. In this study a new technique has been developed of utilizing a Pt voltage probe placed internally into the electrolyte to measure the IN and impedance spectra of both electrodes operating under cell conditions. Unlike surface mounted electrodes which need to be concerned with distance and dimensions of reference electrodes with respect to working and counter electrodes the internal Pt voltage probe is centered internally at a known depth within the electrolyte and between corresponding electrodes.

  18. Solid organ transplants following hematopoietic stem cell transplant in children.

    Science.gov (United States)

    Bunin, Nancy; Guzikowski, Virginia; Rand, Elizabeth R; Goldfarb, Samuel; Baluarte, Jorge; Meyers, Kevin; Olthoff, Kim M

    2010-12-01

    SOT may be indicated for a select group of pediatric patients who experience permanent organ failure following HSCT. However, there is limited information available about outcomes. We identified eight children at our center who received an SOT following an HSCT. Patients were six months to 18 yr at HSCT. Diseases for which children underwent HSCT included thalassemia, Wiskott-Aldrich syndrome, Shwachman-Diamond/bone marrow failure, sickle cell disease (SCD), erythropoietic porphyria (EP), ALL, chronic granulomatous disease, and neuroblastoma. Time from HSCT to SOT was 13 days to seven yr (median, 27 months. Lung SOT was performed for two patients with BO, kidney transplants for three patients, and liver transplants for three patients (VOD, chronic GVHD). Seven patients are alive with functioning allografts 6-180 months from SOT. Advances in organ procurement, operative technique, immunosuppressant therapy, and infection control may allow SOT for a select group of patients post-HSCT. However, scarcity of donor organs available in a timely fashion continues to be a limiting factor. Children who have undergone HSCT and develop single organ failure should be considered for an SOT if there is a high likelihood of cure of the primary disease. © 2010 John Wiley & Sons A/S.

  19. Perovskites as electrodes of solid cells in sensitive elements of oxygen ion

    International Nuclear Information System (INIS)

    Gandurska, J.; Sniezynska, I.; Marek, A.; Szwagierczak, D.; Kulawik, J.

    1997-01-01

    The perovskite family comprises many compounds used in electronic applications. In this work perovskite materials based on LaCrO 3 were investigated, destined for electrodes of solid electrolyte oxygen sensors. lanthanum chromite powders modified by calcium, strontium and aluminium were prepared by the coprecipitation-calcination technique. The powders were examined using thermal analysis, x-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. Introductory studies of electromotive force of oxygen cells with yttria stabilized zirconia as solid electrolyte and perovskite-based electrodes proved that it is possible to replace expensive Pt electrodes by much cheaper perovskite ones. (author)

  20. The study of flow and proton exchange interactions in the cylindrical solid oxide fuel cell

    CERN Document Server

    Saievar-Iranizad, E

    2002-01-01

    The solid oxide fuel cell operates at high temperature of about 1000 deg C. In this temperature, some known materials such as Ni, ... which is abundant in the nature, can be used as a catalyst in the electrodes. The electrolytes of such cell solid oxide fuel cell can be made through non-porous solid ceramics such as Zircon's (ZrO sub 2). It can be stabilized using a doped Yttrium oxide. The importance of Yttria-stabilised Zirconia at high temperature belongs to the transport of oxygen ions through the electrolyte. Oxygen using in the hot cathode side causes a considerable reduction in the concentration of oxygen molecules. The oxygen ions exchange through the electrolyte relates to the molecular oxygen concentration gradient between the anode and cathode. Applying fuels such as hydrogen or natural gas in the anode and its chemical reaction with oxygen ions transfer from cathode through the electrolyte, produce electricity, water and heat. To study the ion exchange and its interaction into solid oxide fuel cel...

  1. Long term performance degradation analysis and optimization of anode supported solid oxide fuel cell stacks

    International Nuclear Information System (INIS)

    Parhizkar, Tarannom; Roshandel, Ramin

    2017-01-01

    Highlights: • A degradation based optimization framework is developed. • The cost of electricity based on degradation of solid oxide fuel cells is minimized. • The effects of operating conditions on degradation mechanisms are investigated. • Results show 7.12% lower cost of electricity in comparison with base case. • Degradation based optimization is a beneficial concept for long term analysis. - Abstract: The main objective of this work is minimizing the cost of electricity of solid oxide fuel cell stacks by decelerating degradation mechanisms rate in long term operation for stationary power generation applications. The degradation mechanisms in solid oxide fuel cells are caused by microstructural changes, reactions between lanthanum strontium manganite and electrolyte, poisoning by chromium, carburization on nickel particles, formation of nickel sulfide, nickel coarsening, nickel oxidation, loss of conductivity and crack formation in the electrolyte. The rate of degradation mechanisms depends on the cell operating conditions (cell voltage and fuel utilization). In this study, the degradation based optimization framework is developed which determines optimum operating conditions to achieve a minimum cost of electricity. To show the effectiveness of the developed framework, optimization results are compared with the case that system operates at its design point. Results illustrate optimum operating conditions decrease the cost of electricity by 7.12%. The performed study indicates that degradation based optimization is a beneficial concept for long term performance degradation analysis of energy conversion systems.

  2. Solid Oxide Electrolysis Cells: Microstructure and Degradation of the Ni/Yttria-Stabilized Zirconia Electrode

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard

    2008-01-01

    Solid oxide fuel cells produced at Risø DTU have been tested as solid oxide electrolysis cells for steam electrolysis by applying an external voltage. Varying the sealing on the hydrogen electrode side of the setup verifies that the previously reported passivation over the first few hundred hours...... of electrolysis testing was an effect of the applied glass sealing. Degradation of the cells during long-term galvanostatic electrolysis testing [850°C, −1/2 A/cm2, p(H2O)/p(H2)=0.5/0.5] was analyzed by impedance spectroscopy and the degradation was found mainly to be caused by increasing polarization resistance...

  3. Creep behaviour of porous metal supports for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Boccaccini, Dino; Frandsen, Henrik Lund; Sudireddy, Bhaskar Reddy

    2014-01-01

    The creep behaviour of porous ironechromium alloy used as solid oxide fuel cell support was investigated, and the creep parameters are compared with those of dense strips of similar composition under different testing conditions. The creep parameters were determined using a thermo-mechanical anal......The creep behaviour of porous ironechromium alloy used as solid oxide fuel cell support was investigated, and the creep parameters are compared with those of dense strips of similar composition under different testing conditions. The creep parameters were determined using a thermo......-mechanical analyser with applied stresses in the range from 1 to 15 MPa and temperatures between 650 and 800 _C. The GibsoneAshby and Mueller models developed for uniaxial creep of open-cell foams were used to analyse the results. The influence of scale formation on creep behaviour was assessed by comparing the creep...

  4. Edible bird's nest impact on rats' uterine histomorphology, expressions of genes of growth factors and proliferating cell nuclear antigen, and oxidative stress level

    Directory of Open Access Journals (Sweden)

    Abdulla A. Albishtue

    2018-01-01

    Full Text Available Aim: This study aimed to evaluate the effect of edible bird's nest (EBN supplementation on the uteri of rats based on analyses of the morphological and histomorphometric changes, and expressions of epidermal growth factor (EGF and its receptor (REGF genes, vascular endothelial growth factor (VEGF, proliferating cell nuclear antigen (PCNA, and steroid receptors. Materials and Methods: Twenty-four Sprague Dawley rats were equally distributed into the following four groups: G1 (control, G2, G3, and G4 represented the groups treated with EBN at graded concentrations of 0, 30, 60, and 120 mg/kg body weight (BW per day for 8 weeks, respectively. During the experimental period, the BW of each rat was recorded weekly. At the proestrus stage of estrous cycle, blood samples were collected from the hearts of anesthetized rats that were later sacrificed. The uteri were removed for histological and immunohistochemical analyses. Results: The EBN-treated groups showed an increase in the weights and lengths of uteri as compared to the control. Results showed that relative to G1 and G2, G3 and G4 exhibited proliferation in their uterine luminal and glandular epithelia and uterine glands, and up-regulated expressions of EGF, REGF, VEGF, PCNA, and progesterone receptor, and estrogen receptor in their uteri. The EBN increased the antioxidant (AO and total AO capacities and reduced the oxidative stress (OS levels in non-pregnant rats. Conclusion: Findings of this study revealed that EBN promotes proliferation of the uterine structures as evidenced by the upregulation of the expressions of steroid receptors,EGF, REGF, VEGF, and PCNA in the uterus and increased in the plasma concentrations of AO and reduced levels of OS.

  5. Micro solid oxide fuel cell on the chip. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M.; Hotz, N.; Bieri, N.; Poulikakos, D.

    2006-07-01

    The aim of this project is the numerical and experimental investigation of hydrocarbon-to-syngas reforming in micro reformers for incorporation into an entire micro fuel cell system. Numerical simulations are used to achieve deeper understanding of several determining aspects in such a micro reformer. These insights are used to optimize the reforming performance by proper choice of operational and geometrical parameters of a reformer. These numerical results are continued by comprehensive experimental studies. In the first chapter, the effect of wall conduction of a tubular methane micro reformer is investigated numerically. Methane is used as the representative hydrocarbon because its detailed surface reaction mechanism is known. It is found that the axial wall conduction can strongly influence the performance of the microreactor and should not be neglected without a careful a priori investigation of its impact. In the second chapter, the effect of the catalyst amount and reactor geometry on the reforming process was investigated. It was found that the hydrogen selectivity changes significantly with varying catalyst loading. Thus, the reaction path leading to higher hydrogen production becomes more important by increasing the catalyst surface site density on the active surface. Another unexpected result is the presence of optimum channel geometry and optimum catalyst amount. In the third chapter of this project, the capability of flame-made Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles catalyzing the reforming of butane to H{sub 2}- and CO-rich syngas was investigated experimentally in a packed bed reactor. The main goal of this study was the efficient reforming of butane at temperatures between 500 and 600 {sup o}C for a micro intermediate-temperature SOFC system. Our results showed that Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles proved to be a very promising material for butane-to-syngas reforming with complete butane conversion and a hydrogen yield of 77

  6. Fiber Tracking Cylinder Nesting

    International Nuclear Information System (INIS)

    Stredde, H.

    1999-01-01

    The fiber tracker consists of 8 concentric carbon fiber cylinders of varying diameters, from 399mm to 1032.2mm and two different lengths. 1.66 and 2.52 meters. Each completed cylinder is covered over the entire o.d. with scintillating fiber ribbons with a connector on each ribbon. These ribbons are axial (parallel to the beam line) at one end and stereo (at 3 deg. to the beam line) at the other. The ribbon connectors have dowel pins which are used to match with the connectors on the wave guide ribbons. These dowel pins are also used during the nesting operation, locating and positioning measurements. The nesting operation is the insertion of one cylinder into another, aligning them with one another and fastening them together into a homogeneous assembly. For ease of assembly. the nesting operation is accomplished working from largest diameter to smallest. Although the completed assembly of all 8 cylinders glued and bolted together is very stiff. individual cylinders are relatively flexible. Therefore. during this operation, No.8 must be supported in a manner which maintains its integrity and yet allows the insertion of No.7. This is accomplished by essentially building a set of dummy end plates which replicate a No.9 cylinder. These end plates are mounted on a wheeled cart that becomes the nesting cart. Provisions for a protective cover fastened to these rings has been made and will be incorporated in finished product. These covers can be easily removed for access to No.8 and/or the connection of No.8 to No.9. Another wheeled cart, transfer cart, is used to push a completed cylinder into the cylinder(s) already mounted in the nesting cart.

  7. Microstructure characterisation of solid oxide electrolysis cells operated at high current density

    DEFF Research Database (Denmark)

    Bowen, Jacob R.; Bentzen, Janet Jonna; Chen, Ming

    quantified using the mean linear intercept method as a function of current density and correlated to increases in serial resistance. The above structural changes are then compared in terms of electrode degradation observed during the co-electrolysis of steam and CO2 at current densities up to -1.5 A cm-2......High temperature solid oxide cells can be operated either as fuel cells or electrolysis cells for efficient power generation or production of hydrogen from steam or synthesis gas (H2 + CO) from steam and CO2 respectively. When operated under harsh conditions, they often exhibit microstructural...

  8. Manufacturing and characterization of metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Blennow Tullmar, Peter; Hjelm, Johan; Klemensø, Trine

    2011-01-01

    A metal-supported solid oxide fuel cell design offers competitive advantages, for example reduced material costs and improved robustness. This paper reports the performance and stability of a recently developed metal-supported cell design, based on a novel cermet anode, on a 25cm2 (1cm2/16cm2...... functional layer, oxygen reduction in the mixed ionic-electronic conducting cathode and an additional polarization process with a rather high relaxation frequency, which may be assigned to an insulating corrosion interlayer.The durability of the cells was investigated by means of galvanostatic operation...

  9. Quantitative review of degradation and lifetime of solid oxide cells and stacks

    DEFF Research Database (Denmark)

    Skafte, Theis Løye; Hjelm, Johan; Blennow, Peter

    2016-01-01

    A comprehensive review of degradation and lifetime for solid oxide cells and stacks hasbeen conducted. Based on more than 50 parameters from 150 publications and 1 000 000hours of accumulated testing, this paper presents a quantitative analysis of the currentinternational status of degradation...... updating by thecommunity is encouraged. Furthermore, the commonly reported test parameters anddegradation indicators are discussed. The difficulty in standardizing testing due tovariations in cell and stack design, materials and intended purpose of the system isacknowledged. A standardization of reporting...... of long-term single-cell- and stack-tests isproposed....

  10. Solid oxide cell R&D at Riso National Laboratory-and its transfer to technology

    DEFF Research Database (Denmark)

    Linderoth, Søren

    2009-01-01

    Risø National Laboratory has conducted R&D on solid oxide cells for almost 20 years—all the time together with industries with interest in deploying the technology when mature. Risø National Laboratory (Risø) and Topsoe Fuel Cell A/S (TOFC) have for several years jointly carried out a development...... by the consortium, e.g. a metal-supported cell. TOFC has an extended program to develop the SOFC technology all the way to a marketable product....

  11. The cavity-nest ant Temnothorax crassispinus prefers larger nests.

    Science.gov (United States)

    Mitrus, S

    Colonies of the ant Temnothorax crassispinus inhabit mostly cavities in wood and hollow acorns. Typically in the field, nest sites that can be used by the ant are a limited resource. In a field experiment, it was investigated whether the ants prefer a specific size of nest, when different ones are available. In July 2011, a total of 160 artificial nests were placed in a beech-pine forest. Four artificial nests (pieces of wood with volume cavities, ca 415, 605, 730, and 980 mm 3 , respectively) were located on each square meter of the experimental plot. One year later, shortly before the emergence of new sexuals, the nests were collected. In July 2012, colonies inhabited more frequently bigger nests. Among queenright colonies, the ones which inhabited bigger nests had more workers. However, there was no relationship between volume of nest and number of workers for queenless colonies. Queenright colonies from bigger nests produced more sexual individuals, but there was no correlation between number of workers and sex allocation ratio, or between volume of nest and sex allocation ratio. In a laboratory experiment where ant colonies were kept in 470 and 860 mm 3 nests, larger colonies allocated more energy to produce sexual individuals. The results of this study show the selectivity of T. crassispinus ants regarding the size of nest cavity, and that the nest volume has an impact on life history parameters.

  12. Modelling the impact of creep on the probability of failure of a solid oxidefuel cell stack

    DEFF Research Database (Denmark)

    Greco, Fabio; Frandsen, Henrik Lund; Nakajo, Arata

    2014-01-01

    In solid oxide fuel cell (SOFC) technology a major challenge lies in balancing thermal stresses from an inevitable thermal field. The cells are known to creep, changing over time the stress field. The main objective of this study was to assess the influence of creep on the failure probability...... of an SOFC stack. A finite element analysis on a single repeating unit of the stack was performed, in which the influence of the mechanical interactions,the temperature-dependent mechanical properties and creep of the SOFC materials are considered. Moreover, stresses from the thermo-mechanical simulation...... of sintering of the cells have been obtained and were implemented into the model of the single repeating unit. The significance of the relaxation of the stresses by creep in the cell components and its influence on the probability of cell survival was investigated. Finally, the influence of cell size...

  13. HLA-mismatched hematopoietic stem cell tranplantation for pediatric solid tumors

    Directory of Open Access Journals (Sweden)

    Andrea Pession

    2011-06-01

    Full Text Available Even if the overall survival of children with cancer is significantly improved over these decades, the cure rate of high-risk pediatric solid tumors such as neuroblastoma, Ewing’s sarcoma family tumors or rhabdomiosarcoma remain challenging. Autologous hematopoietic stem cell transplantation (HSCT allows chemotherapy dose intensification beyond marrow tolerance and has become a fundamental tool in the multimodal therapeutical approach of these patients. Anyway this procedure does not allow to these children an eventfree survival approaching more than 50% at 5 years. New concepts of allogeneic HSCT and in particular HLA-mismatched HSCT for high risk solid tumors do not rely on escalation of chemo therapy intensity and tumor load reduction but rather on a graft-versus-tumor effect. We here report an experimental study design of HLA-mismatched HSCT for the treatment of pediatric solid tumors and the inherent preliminary results.

  14. Analysis of sugarcane herbicides in marine turtle nesting areas and assessment of risk using in vitro toxicity assays.

    Science.gov (United States)

    Allan, Hannah L; van de Merwe, Jason P; Finlayson, Kimberly A; O'Brien, Jake W; Mueller, Jochen F; Leusch, Frederic D L

    2017-10-01

    Agricultural processes are associated with many different herbicides that can contaminate surrounding environments. In Queensland, Australia, herbicides applied to agricultural crops may pose a threat to valuable coastal habitats including nesting beaches for threatened loggerhead turtles (Caretta caretta). This study 1) measured concentrations of herbicides in the beach sand of Mon Repos, an important marine turtle nesting beach in Australia that is adjacent to significant sugarcane crops, and 2) investigated the toxicity of these herbicides to marine turtles using a cell-based assay. Samples of sand from turtle nest depth and water from surrounding agricultural drains and wetlands were collected during the wet season when herbicide runoff was expected to be the greatest and turtles were nesting. Samples were extracted using solid phase extraction and extracts were analysed using chemical analysis targeting herbicides, as well as bioanalytical techniques (IPAM-assay and loggerhead turtle skin cell cytotoxicity assay). Twenty herbicides were detected in areas between sugarcane crops and the nesting beach, seven of which were also detected in the sand extracts. Herbicides present in the nearby wetland were also detected in the beach sand, indicating potential contamination of the nesting beach via the river outlet as well as ground water. Although herbicides were detected in nesting sand, bioassays using loggerhead turtle skin cells indicated a low risk of acute toxicity at measured environmental concentrations. Further research should investigate potentially more subtle effects, such as endocrine disruption and mixture effects, to better assess the threat that herbicides pose to this population of marine turtles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Complementary techniques for solid oxide cell characterisation on micro- and nano-scale

    International Nuclear Information System (INIS)

    Wiedenmann, D.; Hauch, A.; Grobety, B.; Mogensen, M.; Vogt, U.

    2009-01-01

    High temperature steam electrolysis by solid oxide electrolysis cells (SOEC) is a way with great potential to transform clean and renewable energy from non-fossil sources to synthetic fuels such as hydrogen, methane or dimethyl ether, which have been identified as promising alternative energy carriers. Also, as SOEC can operate in the reverse mode as solid oxide fuel cells (SOFC), during high peak hours e.g. hydrogen can be used in a very efficient way to reconvert chemically stored energy into electrical energy. As solid oxide cells (SOC) are working at high temperatures (700-900 o C), material degradation and evaporation can occur e.g. from the cell sealing material, leading to poisoning effects and aging mechanisms which are decreasing the cell efficiency and long-term durability. In order to investigate such cell degradation processes, thorough examination on SOC often requires the chemical and structural characterisation on the microscopic and the nanoscopic level. The combination of different microscope techniques like conventional scanning electron microscopy (SEM), electron-probe microanalysis (EPMA) and the focused ion-beam (FIB) preparation technique for transmission electron microscopy (TEM) allows performing post mortem analysis on a multi scale level of cells after testing. These complementary techniques can be used to characterize structural and chemical changes over a large and representative sample area (micro-scale) on the one hand, and also on the nano-scale level for selected sample details on the other hand. This article presents a methodical approach for the structural and chemical characterisation of changes in aged cathode-supported electrolysis cells produced at Riso DTU, Denmark. Also, results from the characterisation of impurities at the electrolyte/hydrogen interface caused by evaporation from sealing material are discussed. (author)

  16. Diffusion and Gas Conversion Analysis of Solid Oxide Fuel Cells at Loads via AC Impedance

    Directory of Open Access Journals (Sweden)

    Robert U. Payne

    2011-01-01

    Full Text Available Impedance measurements were conducted under practical load conditions in solid oxide fuel cells of differing sizes. For a 2 cm2 button cell, impedance spectra data were separately measured for the anode, cathode, and total cell. Improved equivalent circuit models are proposed and applied to simulate each of measured impedance data. Circuit elements related to the chemical and physical processes have been added to the total-cell model to account for an extra relaxation process in the spectra not measured at either electrode. The processes to which elements are attributed have been deduced by varying cell temperature, load current, and hydrogen concentration. Spectra data were also obtained for a planar stack of five 61 cm2 cells and the individual cells therein, which were fitted to a simplified equivalent circuit model of the total button cell. Similar to the button cell, the planar cells and stack exhibit a pronounced low-frequency relaxation process, which has been attributed to concentration losses, that is, the combined effects of diffusion and gas conversion. The simplified total-cell model approximates well the dynamic behavior of the SOFC cells and the whole stack.

  17. Plexin D1 is ubiquitously expressed on tumor vessels and tumor cells in solid malignancies

    International Nuclear Information System (INIS)

    Roodink, Ilse; Verrijp, Kiek; Raats, Jos; Leenders, William PJ

    2009-01-01

    Plexin D1 is expressed on both tumor-associated endothelium and malignant cells in a number of clinical brain tumors. Recently we demonstrated that Plexin D1 expression is correlated with tumor invasion level and metastasis in a human melanoma progression series. The objective of this study was to examine whether Plexin D1 might be clinically useful as a pan-tumor vessel and pan-tumor cell target in solid tumors. We examined Plexin D1 expression in clinical solid tumors (n = 77) of different origin, a selection of pre-malignant lesions (n = 29) and a variety of non-tumor related tissues (n = 52) by immunohistochemistry. Signals were verified in a selection of tissues via mRNA in situ hybridization. Plexin D1 is abundantly expressed on both activated established tumor vasculature and malignant cells in the majority of primary and metastatic clinical tumors, as well as on macrophages and fibroblasts. Importantly, in non-tumor related tissues Plexin D1 expression is restricted to a subset of, presumably activated, fibroblasts and macrophages. We demonstrate that Plexin D1 is in general ubiquitously expressed in tumor but not normal vasculature, as well as in malignant cells in a wide range of human tissues. This expression profile highlights Plexin D1 as a potentially valuable therapeutic target in clinical solid tumors, enabling simultaneous targeting of different tumor compartments

  18. Study of ceria-carbonate nanocomposite electrolytes for low-temperature solid oxide fuel cells.

    Science.gov (United States)

    Fan, L; Wang, C; Di, J; Chen, M; Zheng, J; Zhu, B

    2012-06-01

    Composite and nanocomposite samarium doped ceria-carbonates powders were prepared by solid-state reaction, citric acid-nitrate combustion and modified nanocomposite approaches and used as electrolytes for low temperature solid oxide fuel cells. X-ray Diffraction, Scanning Electron Microscope, low-temperature Nitrogen Adsorption/desorption Experiments, Electrochemical Impedance Spectroscopy and fuel cell performance test were employed in characterization of these materials. All powders are nano-size particles with slight aggregation and carbonates are amorphous in composites. Nanocomposite electrolyte exhibits much lower impedance resistance and higher ionic conductivity than those of the other electrolytes at lower temperature. Fuel cell using the electrolyte prepared by modified nanocomposite approach exhibits the best performance in the whole operation temperature range and achieves a maximum power density of 839 mW cm(-2) at 600 degrees C with H2 as fuel. The excellent physical and electrochemical performances of nanocomposite electrolyte make it a promising candidate for low-temperature solid oxide fuel cells.

  19. Identifying a compound modifying a cellular response, comprises attaching cells having a reporter system onto solid supports, releasing a library member, screening and identifying target cells

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to methods for identifying compounds capable of modulating a cellular response. The methods involve attaching living cells to solid supports comprising a library of test compounds. Test compounds modulating a cellular response, for example via a cell surface molecule...... may be identified by selecting solid supports comprising cells, wherein the cellular response of interest has been modulated. The cellular response may for example be changes in signal transduction pathways modulated by a cell surface molecule....

  20. T cell receptor-engineered T cells to treat solid tumors: T cell processing toward optimal T cell fitness

    NARCIS (Netherlands)

    C.H.J. Lamers (Cor); S. van Steenbergen-Langeveld (Sabine); M. van Brakel (Mandy); C.M. Groot-van Ruijven (Corrien); P.M.M.L. van Elzakker (Pascal); B.A. van Krimpen (Brigitte); S. Sleijfer (Stefan); J.E.M.A. Debets (Reno)

    2014-01-01

    textabstractTherapy with autologous T cells that have been gene-engineered to express chimeric antigen receptors (CAR) or T cell receptors (TCR) provides a feasible and broadly applicable treatment for cancer patients. In a clinical study in advanced renal cell carcinoma (RCC) patients with CAR T

  1. Clear cell carcinoma of the palate.

    Science.gov (United States)

    Grenevicki, L F; Barker, B F; Fiorella, R M; Mosby, E L

    2001-10-01

    A case of minor salivary gland clear cell adenocarcinoma of the palate with metastasis to the lungs in a 53-year-old female is presented. Histologically, the cells were characterized by glycogen rich clear cells arranged in solid nests, trabeculae, surrounded by hyalinized fibrous stroma. We believe this represents an aggressive form of this type of tumor.

  2. Testing and improving the redox stability of Ni-based solid oxide fuel cells

    DEFF Research Database (Denmark)

    Pihlatie, Mikko; Ramos, Tania; Kaiser, Andreas

    2009-01-01

    cells. When the symmetric cells are reduced and redox cycled isothermally at 850 °C, no major change in the serial or polarisation resistance of the cell and electrodes was measured. When the cells are, after the similar initial reduction treatment, redox cycled at 650 °C, the serial resistance remains......Despite active development, solid oxide fuel cells (SOFCs) based on Ni-YSZ anodes still suffer from thermomechanical instability under conditions where the anode side is exposed to oxidising conditions at high temperature. In the first part of the paper, structures and solutions, which could...... improve the redox stability of Ni-YSZ anode supported SOFC's in terms of dimensional and mechanical stability are reported. Porosity is identified as a major microstructural parameter linked to the dimensional and structural stability during redox cycling. The cumulative redox strain (CRS) after three...

  3. Thermodynamic analysis of synthetic hydrocarbon fuel production in pressurized solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Jensen, Søren Højgaard

    2012-01-01

    improved system efficiency, potentially lowering the fuel production cost significantly. In this paper, we present a thermodynamic analysis of synthetic methane and dimethyl ether (DME) production using pressurized SOECs, in order to determine feasible operating conditions for producing the desired......A promising way to store wind and solar electricity is by electrolysis of H2O and CO2 using solid oxide electrolysis cells (SOECs) to produce synthetic hydrocarbon fuels that can be used in existing fuel infrastructure. Pressurized operation decreases the cell internal resistance and enables...... hydrocarbon fuel and avoiding damage to the cells. The main parameters of cell operating temperature, pressure, inlet gas composition and reactant utilization are varied to examine how they influence cell thermoneutral and reversible potentials, in situ formation of methane and carbon at the Ni–YSZ electrode...

  4. Thin film galvanic cell with RbAg4I5 solid electrolyte

    International Nuclear Information System (INIS)

    Bodnaruk, L.I.; Danilov, A.V.; Kulinkovich, V.E.; Aleskovskij, V.B.

    1975-01-01

    In order to decrease the size and weight and to increase the specific capacity and energy of galvanic cells, some solid electrolytes in the form of thin films are proposed. The galvanic cells were prepared by a combined method: the cathodic and anodic materials (Te and Ag) were evaporated under vacuo to cover an electrolyte layer, the latter being obtained by impregnating the porous materials with RbAg 4 I 5 acetonic solution. The most specific charge curves of the galvanic cells at various current densities are given: specific energy of the samples was 0.2 to 0.7 watt-h/kg, their capacity being 0.1 to 0.2 mah. Behaviour of the cells when stored (that of Ag(RbAg 4 I 5 ) interface in particular) was investigated, namely, the effect of the storage time on the capacity and internal resistance of the galvanic cell

  5. Nanoimprint-Transfer-Patterned Solids Enhance Light Absorption in Colloidal Quantum Dot Solar Cells

    KAUST Repository

    Kim, Younghoon

    2017-03-13

    Colloidal quantum dot (CQD) materials are of interest in thin-film solar cells due to their size-tunable bandgap and low-cost solution-processing. However, CQD solar cells suffer from inefficient charge extraction over the film thicknesses required for complete absorption of solar light. Here we show a new strategy to enhance light absorption in CQD solar cells by nanostructuring the CQD film itself at the back interface. We use two-dimensional finite-difference time-domain (FDTD) simulations to study quantitatively the light absorption enhancement in nanostructured back interfaces in CQD solar cells. We implement this experimentally by demonstrating a nanoimprint-transfer-patterning (NTP) process for the fabrication of nanostructured CQD solids with highly ordered patterns. We show that this approach enables a boost in the power conversion efficiency in CQD solar cells primarily due to an increase in short-circuit current density as a result of enhanced absorption through light-trapping.

  6. Characterization of Solid Oxide Fuel Cell Components Using Electromagnetic Model-Based Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Zilberstein, Vladimir; Craven, Chris; Goldfine, Neil

    2004-12-28

    In this Phase I SBIR, the contractor demonstrated a number of capabilities of model-based sensors such as MWM sensors and MWM-Arrays. The key results include (1) porosity/microstructure characterization for anodes, (2) potential for cathode material characterization, (3) stress measurements in nickel and cobalt, and (4) potential for stress measurements in non-magnetic materials with a ferromagnetic layer. In addition, potential applications for manufacturing quality control of nonconductive layers using interdigitated electrode dielectrometers have been identified. The results indicate that JENTEK's MWM technology can be used to significantly reduce solid oxide fuel cell production and operating costs in a number of ways. Preliminary investigations of solid oxide fuel cell health monitoring and scale-up issues to address industry needs have also been performed.

  7. Biomass gasification integrated with a solid oxide fuel cell and Stirling engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    An integrated gasification solid oxide fuel cell (SOFC) and Stirling engine for combined heat and power application is analyzed. The target for electricity production is 120 kW. Woodchips are used as gasification feedstock to produce syngas, which is then used to feed the SOFC stacks for electric......An integrated gasification solid oxide fuel cell (SOFC) and Stirling engine for combined heat and power application is analyzed. The target for electricity production is 120 kW. Woodchips are used as gasification feedstock to produce syngas, which is then used to feed the SOFC stacks......-of-plant is designed and suggested. Thermodynamic analysis shows that a thermal efficiency of 42.4% based on the lower heating value (LHV) can be achieved if all input parameters are selected conservatively. Different parameter studies are performed to analyze the system behavior under different conditions...

  8. Secondary creep of porous metal supports for solid oxide fuel cells by a CDM approach

    DEFF Research Database (Denmark)

    Esposito, L.; Boccaccini, D. N.; Pucillo, G. P.

    2017-01-01

    The creep behaviour of porous iron-chromium alloy used in solid oxide fuel cells (SOFCs) becomes relevant under SOFC operating temperatures. In this paper, the secondary creep stage of infiltrated and non-infiltrated porous metal supports (MS) was investigated and theoretically modelled by a cont......The creep behaviour of porous iron-chromium alloy used in solid oxide fuel cells (SOFCs) becomes relevant under SOFC operating temperatures. In this paper, the secondary creep stage of infiltrated and non-infiltrated porous metal supports (MS) was investigated and theoretically modelled...... as function of temperature, determined by the high temperature impulse excitation technique, was directly used to account for the porosity and the related effective stress acting during the creep tests. The proposed creep rate formulation was used to extend the Crofer® 22 APU Monkman-Grant diagram...

  9. Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fue......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation.......Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel...

  10. Notes on the Nest Architecture of Halictus senilis (Eversmann) in Southeast Kazakhstan (Hymenoptera, Halictidae)

    OpenAIRE

    Miyanaga, Ryoichi; Tadauchi, Osamu; Murao, Ryuki

    2006-01-01

    Four nests of Halictus senilis (Eversmann) were excavated near Chimkent, southeast Kazakhstan. The nest of H. senilis was similar in structure to nests of the other species of Halictus s. s., i.e., each cell directly, not by means of lateral, connected to the main burrow. On the other hand, the deviation from the typical nest structure of Halictus was found. The coexistence of delayed eusocial and solitary nests was suggested in this species.

  11. High pressure operation of tubular solid oxide fuel cells and their intergration with gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, C.; Wepfer, W.J. [Georgia Institute of Technology, Atlanta, GA (United States)

    1996-12-31

    Fossil fuels continue to be used at a rate greater than that of their natural formation, and the current byproducts from their use are believed to have a detrimental effect on the environment (e.g. global warming). There is thus a significant impetus to have cleaner, more efficient fuel consumption alternatives. Recent progress has led to renewed vigor in the development of fuel cell technology, which has been shown to be capable of producing high efficiencies with relatively benign exhaust products. The tubular solid oxide fuel cell developed by Westinghouse Electric Corporation has shown significant promise. Modeling efforts have been and are underway to optimize and better understand this fuel cell technology. Thus far, the bulk of modeling efforts has been for operation at atmospheric pressure. There is now interest in developing high-efficiency integrated gas turbine/solid oxide fuel cell systems. Such operation of fuel cells would obviously occur at higher pressures. The fuel cells have been successfully modeled under high pressure operation and further investigated as integrated components of an open loop gas turbine cycle.

  12. Curvature and Strength of Ni-YSZ Solid Oxide Half-Cells After Redox Treatments

    DEFF Research Database (Denmark)

    Faes, Antonin; Frandsen, Henrik Lund; Pihlatie, Mikko

    2010-01-01

    One of the main drawbacks of anode-supported solid oxide fuel cell technology is the limited capability to withstand reduction and oxidation (“RedOx”) of the Ni phase. This study compares the effect of RedOx cycles on curvature and strength of half-cells, composed of a nickel-yttria-stabilized-zi......One of the main drawbacks of anode-supported solid oxide fuel cell technology is the limited capability to withstand reduction and oxidation (“RedOx”) of the Ni phase. This study compares the effect of RedOx cycles on curvature and strength of half-cells, composed of a nickel...... it is calculated analytically from the force. In this calculation the thermal stresses are estimated from the curvature of the half-cell. For each treatment, more than 30 samples are tested. About 20 ball-on-ring samples are laser cut from one original 12×12 cm2 half-cell. Curvature and porosity are measured...

  13. Generator module architecture for a large solid oxide fuel cell power plant

    Science.gov (United States)

    Gillett, James E.; Zafred, Paolo R.; Riggle, Matthew W.; Litzinger, Kevin P.

    2013-06-11

    A solid oxide fuel cell module contains a plurality of integral bundle assemblies, the module containing a top portion with an inlet fuel plenum and a bottom portion receiving air inlet feed and containing a base support, the base supports dense, ceramic exhaust manifolds which are below and connect to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the fuel cells comprise a fuel cell stack bundle all surrounded within an outer module enclosure having top power leads to provide electrical output from the stack bundle, where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all 100% of the weight of the stack, and each bundle assembly has its own control for vertical and horizontal thermal expansion control.

  14. Selected aspects of the design and diagnostics of solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Lis Bartłomiej

    2016-01-01

    Full Text Available An increased growth in demand for energy accompanied by efforts to limit its negative impact on the environment is forcing society to seek new, more efficient energy sources. Fuel cells are one of the most promising solutions among the widely developed new generation of electrical generators. Fuel cells directly convert chemical fuel into electricity. Water and waste heat are by-products of fuel cell operation. Solid oxide fuel cells (SOFCs have proven to be one of the most interesting solutions among the five types of technologically advanced fuel cells, for their ability to operate at temperatures above 800°C. Furthermore, SOFCs are characterized by other advantages in comparison to PEMFCs, including: (1 no need to use expensive catalysts (e.g. platinum, the price of which is high, and its resources limited, (2 the possibility of direct, internal conversion of hydrocarbon fuels, (3 lower sensitivity to contaminants (in particular, hydrogen fuel containing CO, which is useful for SOFCs instead of the platinum catalyst poisoners, and (4 the possibility of using waste heat in a gas turbine, or for heating or other industrial purposes. The paper discusses selected issues regarding the construction and characteristics of planar solid oxide fuel cells. Selected results of the following electrochemical investigations: Ba0.9Ca0.1Ce0.9Y0.1O3-based proton electrolyte as possible components of SOFCs operating at intermediate temperature range (500-700°C.

  15. Optimal design and operation of solid oxide fuel cell systems for small-scale stationary applications

    Science.gov (United States)

    Braun, Robert Joseph

    The advent of maturing fuel cell technologies presents an opportunity to achieve significant improvements in energy conversion efficiencies at many scales; thereby, simultaneously extending our finite resources and reducing "harmful" energy-related emissions to levels well below that of near-future regulatory standards. However, before realization of the advantages of fuel cells can take place, systems-level design issues regarding their application must be addressed. Using modeling and simulation, the present work offers optimal system design and operation strategies for stationary solid oxide fuel cell systems applied to single-family detached dwellings. A one-dimensional, steady-state finite-difference model of a solid oxide fuel cell (SOFC) is generated and verified against other mathematical SOFC models in the literature. Fuel cell system balance-of-plant components and costs are also modeled and used to provide an estimate of system capital and life cycle costs. The models are used to evaluate optimal cell-stack power output, the impact of cell operating and design parameters, fuel type, thermal energy recovery, system process design, and operating strategy on overall system energetic and economic performance. Optimal cell design voltage, fuel utilization, and operating temperature parameters are found using minimization of the life cycle costs. System design evaluations reveal that hydrogen-fueled SOFC systems demonstrate lower system efficiencies than methane-fueled systems. The use of recycled cell exhaust gases in process design in the stack periphery are found to produce the highest system electric and cogeneration efficiencies while achieving the lowest capital costs. Annual simulations reveal that efficiencies of 45% electric (LHV basis), 85% cogenerative, and simple economic paybacks of 5--8 years are feasible for 1--2 kW SOFC systems in residential-scale applications. Design guidelines that offer additional suggestions related to fuel cell

  16. Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2015-01-01

    Solid oxide electrolysis cells (SOECs) offer a promising technological solution for efficient energy conversion and production of hydrogen or syngas. The commercialization of the SOEC technology can be promoted if SOECs can be operated at high current density with stable performance over ~5 years...... - 3 years (continuous operation, setting 1.5 V as the upper voltage defining “end of life”). The results provide technological input to future design of electrolysis plants for hydrogen production. © 2015 ECS - The Electrochemical Society...

  17. Strategies for carbon and sulfur tolerant solid oxide fuel cell materials, incorporating lessons from heterogeneous catalysis

    OpenAIRE

    Boldrin, P; Ruiz Trejo, E; Mermelstein, J; Bermudez Menendez, J; Ramirez Reina, T; Brandon, N

    2016-01-01

    Solid oxide fuel cells (SOFCs) are a rapidly emerging energy technology for a low carbon world, providing high efficiency, potential to use carbonaceous fuels and compatibility with carbon capture and storage. However, current state-of-the-art materials have low tolerance to sulfur, a common contaminant of many fuels, and are vulnerable to deactivation due to carbon deposition when using carbon-containing compounds. In this review we first study the theoretical basis behind carbon and sulfur ...

  18. A novel electronic current-blocked stable mixed ionic conductor for solid oxide fuel cells

    NARCIS (Netherlands)

    Sun, Wenping; Jiang, Yinzhu; Wang, Yanfei; Fang, S.; Zhu, Zhiwen; Liu, Wei

    2011-01-01

    A novel ionic conductor, BaCe0.8Sm0.2O3¿¿¿Ce0.8Sm0.2O2¿¿ (BCS¿SDC, weight ratio 1:1), is reported as an electrolyte material for solid oxide fuel cells (SOFCs). Homogeneous BCS¿SDC composite powders are synthesized via a one-step gel combustion method. The BCS and SDC crystalline grains play a role

  19. A novel electronic current-blocked stable mixed ionic conductor for solid oxide fuel cells

    NARCIS (Netherlands)

    Sun, Wenping; Jiang, Yinzhu; Wang, Yanfei; Fang, S.; Zhu, Zhiwen; Liu, Wei

    2011-01-01

    A novel ionic conductor, BaCe0.8Sm0.2O3−δ–Ce0.8Sm0.2O2−δ (BCS–SDC, weight ratio 1:1), is reported as an electrolyte material for solid oxide fuel cells (SOFCs). Homogeneous BCS–SDC composite powders are synthesized via a one-step gel combustion method. The BCS and SDC crystalline grains play a role

  20. Advances in medium and high temperature solid oxide fuel cell technology

    CERN Document Server

    Salvatore, Aricò

    2017-01-01

    In this book well-known experts highlight cutting-edge research priorities and discuss the state of the art in the field of solid oxide fuel cells giving an update on specific subjects such as protonic conductors, interconnects, electrocatalytic and catalytic processes and modelling approaches. Fundamentals and advances in this field are illustrated to help young researchers address issues in the characterization of materials and in the analysis of processes, not often tackled in scholarly books.

  1. DEVELOPMENT OF LOW-COST MANUFACTURING PROCESSES FOR PLANAR, MULTILAYER SOLID OXIDE FUEL CELL ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scott Swartz; Matthew Seabaugh; William Dawson; Harlan Anderson; Tim Armstrong; Michael Cobb; Kirby Meacham; James Stephan; Russell Bennett; Bob Remick; Chuck Sishtla; Scott Barnett; John Lannutti

    2004-06-12

    This report summarizes the results of a four-year project, entitled, ''Low-Cost Manufacturing Of Multilayer Ceramic Fuel Cells'', jointly funded by the U.S. Department of Energy, the State of Ohio, and by project participants. The project was led by NexTech Materials, Ltd., with subcontracting support provided by University of Missouri-Rolla, Michael A. Cobb & Co., Advanced Materials Technologies, Inc., Edison Materials Technology Center, Gas Technology Institute, Northwestern University, and The Ohio State University. Oak Ridge National Laboratory, though not formally a subcontractor on the program, supported the effort with separate DOE funding. The objective of the program was to develop advanced manufacturing technologies for making solid oxide fuel cell components that are more economical and reliable for a variety of applications. The program was carried out in three phases. In the Phase I effort, several manufacturing approaches were considered and subjected to detailed assessments of manufacturability and development risk. Estimated manufacturing costs for 5-kW stacks were in the range of $139/kW to $179/kW. The risk assessment identified a number of technical issues that would need to be considered during development. Phase II development work focused on development of planar solid oxide fuel cell elements, using a number of ceramic manufacturing methods, including tape casting, colloidal-spray deposition, screen printing, spin-coating, and sintering. Several processes were successfully established for fabrication of anode-supported, thin-film electrolyte cells, with performance levels at or near the state-of-the-art. The work in Phase III involved scale-up of cell manufacturing methods, development of non-destructive evaluation methods, and comprehensive electrical and electrochemical testing of solid oxide fuel cell materials and components.

  2. Lowering the operational temperature of all-solid-state lithium polymer cell with highly conductive and interfacially robust solid polymer electrolytes

    Science.gov (United States)

    Aldalur, Itziar; Martinez-Ibañez, Maria; Piszcz, Michal; Rodriguez-Martinez, Lide M.; Zhang, Heng; Armand, Michel

    2018-04-01

    Novel solid polymer electrolytes (SPEs), comprising of comb polymer matrix grafted with soft and disordered polyether moieties (Jeffamine®) and lithium bis(fluorosulfonyl)imide (LiFSI) are investigated in all-solid-state lithium metal (Li°) polymer cells. The LiFSI/Jeffamine-based SPEs are fully amorphous at room temperature with glass transitions as low as ca. -55 °C. They show higher ionic conductivities than conventional poly(ethylene oxide) (PEO)-based SPEs at ambient temperature region, and good electrochemical compatibility with Li° electrode. These exceptional properties enable the operational temperature of Li° | LiFePO4 cells to be decreased from an elevated temperature (70 °C) to room temperature. Those results suggest that LiFSI/Jeffamine-based SPEs can be promising electrolyte candidates for developing safe and high performance all-solid-state Li° batteries.

  3. Microstructural Degradation of Ni/YSZ Electrodes in Solid Oxide Electrolysis Cells under High Current

    DEFF Research Database (Denmark)

    Chen, Ming; Liu, Yi-Lin; Bentzen, Janet Jonna

    2013-01-01

    Ni/yttria stabilized zirconia (YSZ) supported solid oxide electrolysis cells (SOECs) were exposed to long-term galvanostatic electrolysis tests, under different testing conditions (temperature, gas composition, current density etc.) with an emphasis on high current density (above −1 A/cm2...... of Ni-YSZ interfacial reactions, taking place under the conditions prevailing under strong polarization. A mechanism for the formation of ZrO2 nano-particles on the Ni surface under the electrolysis cell testing is proposed and the possibility of Ni-YSZ interfacial reactions under such conditions (T, p...

  4. Operation strategy for solid oxide fuel cell systems for small-scale stationary applications

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2009-01-01

    Solid oxide fuel cell micro cogeneration systems have the potential to reduce domestic energy consumption by providing both heat and power on site without transmission losses. The high grade heat produced during the operation of the power causes high thermal transients during startup....../shutdown phases and degrades the fuel cells. To counteract the degradation, the system has not to be stressed with rapid load variation during the operation. The analysis will consider an average profile for heat and power demand of a family house. Finally data analysis and power system limitations will be used...

  5. Fuel electrode containing pre-sintered nickel/zirconia for a solid oxide fuel cell

    Science.gov (United States)

    Ruka, Roswell J.; Vora, Shailesh D.

    2001-01-01

    A fuel cell structure (2) is provided, having a pre-sintered nickel-zirconia fuel electrode (6) and an air electrode (4), with a ceramic electrolyte (5) disposed between the electrodes, where the pre-sintered fuel electrode (6) contains particles selected from the group consisting of nickel oxide, cobalt and cerium dioxide particles and mixtures thereof, and titanium dioxide particles, within a matrix of yttria-stabilized zirconia and spaced-apart filamentary nickel strings having a chain structure, and where the fuel electrode can be sintered to provide an active solid oxide fuel cell.

  6. Study of Seal Glass for Solid Oxide Fuel/Electrolyzer Cells

    OpenAIRE

    Mahapatra, Manoj Kumar

    2009-01-01

    Seal glass is essential and plays a crucial role in solid oxide fuel/electrolyzer cell performance and durability. A seal glass should have a combination of thermal, chemical, mechanical, and electrical properties in order to seal different cell components and stacks and prevent gas leakage. All the desired properties can simultaneously be obtained in a seal glass by suitable compositional design. In this dissertation, SrO-La₂O₃-A₂O₃-B₂O₃3-SiO₂ based seal glasses have been developed and compo...

  7. Bond layer for a solid oxide fuel cell, and related processes and devices

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian; Striker, Todd-Michael; Renou, Stephane; Gaunt, Simon William

    2017-03-21

    An electrically-conductive layer of material having a composition comprising lanthanum and strontium is described. The material is characterized by a microstructure having bimodal porosity. Another concept in this disclosure relates to a solid oxide fuel cell attached to at least one cathode interconnect by a cathode bond layer. The bond layer includes a microstructure having bimodal porosity. A fuel cell stack which incorporates at least one of the cathode bond layers is also described herein, along with related processes for forming the cathode bond layer.

  8. High temperature solid oxide regenerative fuel cell for solar photovoltaic energy storage

    Science.gov (United States)

    Bents, David J.

    1987-01-01

    A hydrogen-oxygen regenerative fuel cell energy storage system based on high temperature solid oxide fuel cell technology is discussed which has application to darkside energy storage for solar photovoltaics. The forward and reverse operating cycles are described, and heat flow, mass, and energy balance data are presented to characterize the system's performance and the variation of performance with changing reactant storage pressure. The present system weighs less than nickel hydrogen battery systems after 0.7 darkside operation, and it maintains a specific weight advantage over radioisotope generators for discharge periods up to 72 hours.

  9. Open-source computational model of a solid oxide fuel cell

    Science.gov (United States)

    Beale, Steven B.; Choi, Hae-Won; Pharoah, Jon G.; Roth, Helmut K.; Jasak, Hrvoje; Jeon, Dong Hyup

    2016-03-01

    The solid oxide fuel cell is an electro-chemical device which converts chemical energy into electricity and heat. To compete in today's market, design improvements, in terms of performance and life cycle, are required. Numerical prototypes can accelerate design and development progress. In this programme of research, a three-dimensional solid oxide fuel cell prototype, openFuelCell, based on open-source computational fluid dynamics software was developed and applied to a single cell. Transport phenomena, combined with the solution to the local Nernst equation for the open-circuit potential, as well as the Kirchhoff-Ohm relationship for the local current density, allow local electro-chemistry, fluid flow, multi-component species transport, and multi-region thermal analysis to be considered. The underlying physicochemical hydrodynamics, including porous-electrode and electro-chemical effects are described in detail. The openFuelCell program is developed in an object-oriented open-source C++ library. The code is available at http://openfuelcell.sourceforge.net/. The paper also describes domain decomposition techniques considered in the context of highly efficient parallel programming.

  10. Versatile in situ powder X-ray diffraction cells for solid-gas investigations

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Torben R.; Nielsen, Thomas K.; Joergensen, Jens-Erik [Aarhus Univ. (Denmark). Center for Energy Materials, Center for Materials Crystallography; Filinchuk, Yaroslav [European Synchrotron Radiation Facility, Grenoble (France). Swiss-Norwegian Beam Lines; Cerenius, Yngve [Lund Univ. (Sweden). MAX-lab; Gray, Evan MacA.; Webb, Colin J. [Griffith Univ., Nathan, Brisbane (Australia). Queensland Micro- and Nanotechnology Centre

    2010-12-15

    This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid-gas reactions in dosing or flow mode, but can also handle samples involved in solid-liquid-gas studies. The sample can be loaded into a single-crystal sapphire (Al{sub 2}O{sub 3}) capillary, or a quartz (SiO{sub 2}) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be {proportional_to}300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to {proportional_to}100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies. (orig.)

  11. Versatile in situ powder X-ray diffraction cells for solid-gas investigations

    International Nuclear Information System (INIS)

    Jensen, Torben R.; Nielsen, Thomas K.; Joergensen, Jens-Erik; Filinchuk, Yaroslav; Cerenius, Yngve; Gray, Evan MacA.; Webb, Colin J.

    2010-01-01

    This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid-gas reactions in dosing or flow mode, but can also handle samples involved in solid-liquid-gas studies. The sample can be loaded into a single-crystal sapphire (Al 2 O 3 ) capillary, or a quartz (SiO 2 ) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be ∝300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to ∝100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies. (orig.)

  12. Intensive chemotherapy as salvage treatment for solid tumors: focus on germ cell cancer

    Energy Technology Data Exchange (ETDEWEB)

    Selle, F.; Gligorov, J. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Pierre & Marie Curie University (UPMC Paris VI), Paris (France); Richard, S.; Khalil, A. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Alexandre, I. [Medical Oncology Department, Hospital Centre of Bligny, Briis-sous-Forges (France); Avenin, D.; Provent, S.; Soares, D.G. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Lotz, J.P. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Pierre & Marie Curie University (UPMC Paris VI), Paris (France)

    2014-11-04

    Germ cell tumors present contrasting biological and molecular features compared to many solid tumors, which may partially explain their unusual sensitivity to chemotherapy. Reduced DNA repair capacity and enhanced induction of apoptosis appear to be key factors in the sensitivity of germ cell tumors to cisplatin. Despite substantial cure rates, some patients relapse and subsequently die of their disease. Intensive doses of chemotherapy are used to counter mechanisms of drug resistance. So far, high-dose chemotherapy with hematopoietic stem cell support for solid tumors is used only in the setting of testicular germ cell tumors. In that indication, high-dose chemotherapy is given as the first or late salvage treatment for patients with either relapsed or progressive tumors after initial conventional salvage chemotherapy. High-dose chemotherapy is usually given as two or three sequential cycles using carboplatin and etoposide with or without ifosfamide. The administration of intensive therapy carries significant side effects and can only be efficiently and safely conducted in specialized referral centers to assure optimum patient care outcomes. In breast and ovarian cancer, most studies have demonstrated improvement in progression-free survival (PFS), but overall survival remained unchanged. Therefore, most of these approaches have been dropped. In germ cell tumors, clinical trials are currently investigating novel therapeutic combinations and active treatments. In particular, the integration of targeted therapies constitutes an important area of research for patients with a poor prognosis.

  13. CFD Model Of A Planar Solid Oxide Electrolysis Cell For Hydrogen Production From Nuclear Energy

    International Nuclear Information System (INIS)

    Grant L. Hawkes; James E. O'Brien; Carl M. Stoots; J. Stephen Herring

    2005-01-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec2, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL

  14. Intensive chemotherapy as salvage treatment for solid tumors: focus on germ cell cancer

    International Nuclear Information System (INIS)

    Selle, F.; Gligorov, J.; Richard, S.; Khalil, A.; Alexandre, I.; Avenin, D.; Provent, S.; Soares, D.G.; Lotz, J.P.

    2014-01-01

    Germ cell tumors present contrasting biological and molecular features compared to many solid tumors, which may partially explain their unusual sensitivity to chemotherapy. Reduced DNA repair capacity and enhanced induction of apoptosis appear to be key factors in the sensitivity of germ cell tumors to cisplatin. Despite substantial cure rates, some patients relapse and subsequently die of their disease. Intensive doses of chemotherapy are used to counter mechanisms of drug resistance. So far, high-dose chemotherapy with hematopoietic stem cell support for solid tumors is used only in the setting of testicular germ cell tumors. In that indication, high-dose chemotherapy is given as the first or late salvage treatment for patients with either relapsed or progressive tumors after initial conventional salvage chemotherapy. High-dose chemotherapy is usually given as two or three sequential cycles using carboplatin and etoposide with or without ifosfamide. The administration of intensive therapy carries significant side effects and can only be efficiently and safely conducted in specialized referral centers to assure optimum patient care outcomes. In breast and ovarian cancer, most studies have demonstrated improvement in progression-free survival (PFS), but overall survival remained unchanged. Therefore, most of these approaches have been dropped. In germ cell tumors, clinical trials are currently investigating novel therapeutic combinations and active treatments. In particular, the integration of targeted therapies constitutes an important area of research for patients with a poor prognosis

  15. Characterization of electrode-electrolyte interface in solid oxide fuel cell

    International Nuclear Information System (INIS)

    Lenka, R.K.; Mahata, T.; Sinha, P.K.; Tyagi, A.K.

    2010-01-01

    Full text: Solid oxide fuel cell (SOFC) is an electrochemical device in which chemical energy of fuel, such as, hydrogen, is directly converted to electrical energy in an efficient and environment-friendly manner.The SOFC is primarily a multi-layer structure in which impervious solid oxide electrolyte is sandwiched between porous electrodes. For good performance the cell resistance should be reasonably low. The internal resistance of a working cell is primarily determined by the resistance of the electrolyte layer and the resistances at the electrode - electrolyte interfaces. The later is dependent on the catalytic activity of the electrode material for the corresponding electrode reaction and the interface microstructure in terms of length of the triple phase boundary (TBP). The ceramic fabrication technique plays an important role in determining the interfacial microstructure and hence, the overall performance of a cell. In the present study, gadolinium cobaltate based cathode material and nickel-gadolinia doped ceria (Ni-GDC) composite anode material have been synthesized and integrated with GDC electrolyte. The interfacial microstructures have been studied by scanning electron microscopy (SEM). The area specific resistance (ASR) at the electrode-electrolyte interfaces have been evaluated by electrochemical impedance spectroscopy (EIS) using symmetrical cell. Using our optimum processing technique ASR values of 0.41 U.cm 2 and 0.03 U.cm 2 have been obtained at Ba-doped GdCoO 3 /GDC interface and Ni-GDC/GDC interface respectively at 900 deg C

  16. Why Wasp Foundresses Change Nests: Relatedness, Dominance, and Nest Quality

    Science.gov (United States)

    Seppä, Perttu; Queller, David C.; Strassmann, Joan E.

    2012-01-01

    The costs and benefits of different social options are best understood when individuals can be followed as they make different choices, something that can be difficult in social insects. In this detailed study, we follow overwintered females of the social wasp Polistes carolina through different nesting strategies in a stratified habitat where nest site quality varies with proximity to a foraging area, and genetic relatedness among females is known. Females may initiate nests, join nests temporarily or permanently, or abandon nests. Females can become helpers or egglayers, effectively workers or queens. What they actually do can be predicted by a combination of ecological and relatedness factors. Advantages through increased lifetime success of individuals and nests drives foundresses of the social wasp Polistes from solitary to social nest founding. We studied reproductive options of spring foundresses of P. carolina by monitoring individually-marked wasps and assessing reproductive success of each foundress by using DNA microsatellites. We examined what behavioral decisions foundresses make after relaxing a strong ecological constraint, shortage of nesting sites. We also look at the reproductive consequences of different behaviors. As in other Polistes, the most successful strategy for a foundress was to initiate a nest as early as possible and then accept others as subordinates. A common feature for many P. carolina foundresses was, however, that they reassessed their reproductive options by actively monitoring other nests at the field site and sometimes moving permanently to new nests should that offer better (inclusive) fitness prospects compared to their original nests. A clear motivation for moving to new nests was high genetic relatedness; by the end of the foundress period all females were on nests with full sisters. PMID:23049791

  17. Method for Making a Fuel Cell from a Solid Oxide Monolithic Framework

    Science.gov (United States)

    Cable, Thomas L. (Inventor); Sofie, Stephen W. (Inventor)

    2014-01-01

    The invention is a novel solid oxide fuel cell (SOFC) stack comprising individual bi-electrode supported fuel cells in which a thin electrolyte is supported between electrodes of essentially equal thickness. Individual cell units are made from graded pore ceramic tape that has been created by the freeze cast method followed by freeze drying. Each piece of graded pore tape later becomes a graded pore electrode scaffold that subsequent to sintering, is made into either an anode or a cathode by means of appropriate solution and thermal treatment means. Each cell unit is assembled by depositing of a thin coating of ion conducting ceramic material upon the side of each of two pieces of tape surface having the smallest pore openings, and then mating the coated surfaces to create an unsintered electrode scaffold pair sandwiching an electrolyte layer. The opposing major outer exposed surfaces of each cell unit is given a thin coating of electrically conductive ceramic, and multiple cell units are stacked, or built up by stacking of individual cell layers, to create an unsintered fuel cell stack. Ceramic or glass edge seals are installed to create flow channels for fuel and air. The cell stack with edge sealants is then sintered into a ceramic monolithic framework. Said solution and thermal treatments means convert the electrode scaffolds into anodes and cathodes. The thin layers of electrically conductive ceramic become the interconnects in the assembled stack.

  18. Oridonin Loaded Solid Lipid Nanoparticles Enhanced Antitumor Activity in MCF-7 Cells

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2014-01-01

    Full Text Available Oridonin (ORI, a famous diterpenoid from Chinese herbal medicine, has drawn rising attention for its remarkable apoptosis and autophagy-inducing activity in human cancer therapy, while clinical application of ORI is limited by its strong hydrophobicity and rapid plasma clearance. The purpose of this study was to evaluate whether the antitumor activity of ORI could be enhanced by loading into solid lipid nanoparticles (SLNs. ORI-loaded SLNs were prepared by hot high pressure homogenization with narrow size distribution and good entrapment efficacy. MTT assay indicated that ORI-loaded SLNs enhanced the inhibition of proliferation against several human cancer cell lines including breast cancer MCF-7 cells, hepatocellular carcinoma HepG 2 cells, and lung carcinoma A549 cells compared with free ORI, while no significant enhancement of toxicity to human mammary epithelial MCF-10A cells was shown. Meanwhile, flow cytometric analysis demonstrated that ORI-SLNs induced more significant cell cycle arrest at S and decreased cell cycle arrest at G1/G0 phase in MCF-7 cells than bulk ORI solution. Hoechst 33342 staining and Annexin V/PI assay indicated that apoptotic rates of cells treated with ORI-loaded SLNs were higher compared with free ORI. In summary, our data indicated that SLNs may be a potential carrier for enhancing the antitumor effect of hydrophobic drug ORI.

  19. Chimeric antigen receptor T cells: a novel therapy for solid tumors

    Directory of Open Access Journals (Sweden)

    Shengnan Yu

    2017-03-01

    Full Text Available Abstract The chimeric antigen receptor T (CAR-T cell therapy is a newly developed adoptive antitumor treatment. Theoretically, CAR-T cells can specifically localize and eliminate tumor cells by interacting with the tumor-associated antigens (TAAs expressing on tumor cell surface. Current studies demonstrated that various TAAs could act as target antigens for CAR-T cells, for instance, the type III variant epidermal growth factor receptor (EGFRvIII was considered as an ideal target for its aberrant expression on the cell surface of several tumor types. CAR-T cell therapy has achieved gratifying breakthrough in hematological malignancies and promising outcome in solid tumor as showed in various clinical trials. The third generation of CAR-T demonstrates increased antitumor cytotoxicity and persistence through modification of CAR structure. In this review, we summarized the preclinical and clinical progress of CAR-T cells targeting EGFR, human epidermal growth factor receptor 2 (HER2, and mesothelin (MSLN, as well as the challenges for CAR-T cell therapy.

  20. Effect of cathode gas humidification on performance and durability of Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Hagen, Anke; Liu, Yi-Lin

    2010-01-01

    The effect of cathode inlet gas humidification was studied on single anode supported Solid Oxide Fuel Cells (SOFC's). The studied cells were Risø 2 G and 2.5 G. The former consists of a LSM:YSZ composite cathode, while the latter consists of a LSCF:CGO composite cathode on a CGO protection layer...... respectively. A clear effect of humidification was observed for 2 G cells with a fast transient upon humidification followed by an ongoing long term passivation/degradation during humidification. Removal of humidification resulted in a partial regain of the cell voltage prior to humidification....... The humidification effect was found to be dependent on both the degree of humidification and the cathode polarization. No significant effect of humidification was found at OCV which rules out the possibility of a traditional poisoning effect with a blocking of active sites. Post-mortem high resolution FEG...

  1. An experimental investigation of pressurized planar solid oxide fuel cells using two different flow distributors

    Science.gov (United States)

    Chang, H. W.; Huang, C. M.; Shy, S. S.

    2014-03-01

    A high-pressure high-temperature dual-chamber facility is established for electrochemical impedance measurements of pressurized solid oxide fuel cells (PSOFC) to explain why and how the cell performance is increased with increasing pressure (p). By comparing two sets of nearly identical single-cell stacks except using different flow distributors with different degrees of flow uniformity at 850 °C over a range of p varying from 0.1 MPa to 0.5 MPa, we found that the better flow uniformity in flow distributors is, the better the cell performance is, and such performance enhancement is increased with increasing p. This finding is explained by impedance spectra and their associated equivalent circuit models, showing the coupling impact of flow uniformity and pressure elevation to the decrease of ohmic and polarization resistances. These results should be useful to the development of PSOFC integrating with micro gas turbines for future stationary power generation.

  2. Precision monitoring of immunotherapies in solid organ and hematopoietic stem cell transplantation.

    Science.gov (United States)

    DiLoreto, Rose; Khush, Kiran; De Vlaminck, Iwijn

    2017-05-15

    Pharmacological immunotherapies are a key component of post-transplant therapy in solid-organ and hematopoietic stem cell transplantation. In current clinical practice, immunotherapies largely follow a one-size fits all approach, leaving a large portion of transplant recipients either over- or under-immunosuppressed, and consequently at risk of infections or immune-mediated complications. Our goal here is to review recent and rapid advances in precision and genomic medicine approaches to monitoring of post-transplant immunotherapies. We will discuss recent advances in precision measurements of pharmacological immunosuppression, measurements of the plasma and gut microbiome, strategies to monitor for allograft injury and post-transplant malignancies via circulating cell-free DNA, and comprehensive measurements of the B and T cell immune cell repertoire. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Degradation of Solid Oxide Electrolysis Cells Operated at High Current Densities

    DEFF Research Database (Denmark)

    Tao, Youkun; Ebbesen, Sune Dalgaard; Mogensen, Mogens Bjerg

    2014-01-01

    In this work the durability of solid oxide cells for co-electrolysis of steam and carbon dioxide (45 % H2O + 45 % CO2 + 10 % H2) at high current densities was investigated. The tested cells are Ni-YSZ electrode supported, with a YSZ electrolyte and either a LSM-YSZ or LSCF-CGO oxygen electrode....... A current density of -1.5 and -2.0 A/cm2 was applied to the cell and the gas conversion was 45 % and 60 %, respectively. The cells were operated for a period of up to 700 hours. The electrochemical analysis revealed significant performance degradation for the ohmic process, oxygen ion interfacial transfer...

  4. Towards High Power Density Metal Supported Solid Oxide Fuel Cell for Mobile Applications

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Persson, Åsa H.; Muhl, Thuy Thanh

    2018-01-01

    For use of metal supported solid oxide fuel cell (MS-SOFC) in mobile applications it is important to reduce the thermal mass to enable fast startup, increase stack power density in terms of weight and volume and reduce costs. In the present study, we report on the effect of reducing the Technical...... loss, two different routes for increasing the porosity of the support layer and thus performance were explored. The first route is the introduction of gas channels by puncturing of the green tape casted support layer. The second route is modification of the co-sintering profile. In summary, the cell...... thickness and thus weight and volume was reduced and the cell power density at 0.7 V at 700°C was increased by 46% to 1.01 Wcm−2 at a fuel utilization of 48%. All modifications were performed on a stack technological relevant cell size of 12 cm × 12 cm....

  5. Preliminary Electrochemical Characterization of Anode Supported Solid Oxide Cell (AS-SOC) Produced in the Institute of Power Engineering Operated in Electrolysis Mode (SOEC)

    Science.gov (United States)

    Kupecki, Jakub; Motyliński, Konrad; Skrzypkiewicz, Marek; Wierzbicki, Michał; Naumovich, Yevgeniy

    2017-12-01

    The article discusses the operation of solid oxide electrochemical cells (SOC) developed in the Institute of Power Engineering as prospective key components of power-to-gas systems. The fundamentals of the solid oxide cells operated as fuel cells (SOFC - solid oxide fuel cells) and electrolysers (SOEC - solid oxide fuel cells) are given. The experimental technique used for electrochemical characterization of cells is presented. The results obtained for planar cell with anodic support are given and discussed. Based on the results, the applicability of the cells in power-to-gas systems (P2G) is evaluated.

  6. Binder Jetting: A Novel Solid Oxide Fuel-Cell Fabrication Process and Evaluation

    Science.gov (United States)

    Manogharan, Guha; Kioko, Meshack; Linkous, Clovis

    2015-03-01

    With an ever-growing concern to find a more efficient and less polluting means of producing electricity, fuel cells have constantly been of great interest. Fuel cells electrochemically convert chemical energy directly into electricity and heat without resorting to combustion/mechanical cycling. This article studies the solid oxide fuel cell (SOFC), which is a high-temperature (100°C to 1000°C) ceramic cell made from all solid-state components and can operate under a wide range of fuel sources such as hydrogen, methanol, gasoline, diesel, and gasified coal. Traditionally, SOFCs are fabricated using processes such as tape casting, calendaring, extrusion, and warm pressing for substrate support, followed by screen printing, slurry coating, spray techniques, vapor deposition, and sputter techniques, which have limited control in substrate microstructure. In this article, the feasibility of engineering the porosity and configuration of an SOFC via an additive manufacturing (AM) method known as binder jet printing was explored. The anode, cathode and oxygen ion-conducting electrolyte layers were fabricated through AM sequentially as a complete fuel cell unit. The cell performance was measured in two modes: (I) as an electrolytic oxygen pump and (II) as a galvanic electricity generator using hydrogen gas as the fuel. An analysis on influence of porosity was performed through SEM studies and permeability testing. An additional study on fuel cell material composition was conducted to verify the effects of binder jetting through SEM-EDS. Electrical discharge of the AM fabricated SOFC and nonlinearity of permeability tests show that, with additional work, the porosity of the cell can be modified for optimal performance at operating flow and temperature conditions.

  7. Effect of binder burnout on the sealing performance of glass ceramics for solid oxide fuel cells

    Science.gov (United States)

    Ertugrul, Tugrul Y.; Celik, Selahattin; Mat, Mahmut D.

    2013-11-01

    The glass ceramics composite sealants are among few materials suitable for the solid oxide fuel cells (SOFC) due to their high operating temperatures (600 °C-850 °C). The glass ceramics chemically bond to both the metallic interconnector and the ceramic electrolyte and provide a gas tight connection. A careful and several stages manufacturing procedure is required to obtain a gas tight sealing. In this study, effects of binder burnout process on the sealing performance are investigated employing commercially available glass ceramic powders. The glass ceramic laminates are produced by mixing glass ceramic powders with the organic binders and employing a tape casting method. The laminates are sandwiched between the metallic interconnectors of an SOFC cell. The burnout and subsequent sealing quality are analyzed by measuring leakage rate and final macrostructure of sealing region. The effects of heating rate, dead weight load, solid loading, carrier gas and their flow rates are investigated. It is found that sealing quality is affected from all investigated parameters. While a slower heating rate is required for a better burnout, the mass flow rate of sweep gas must be adequate for removal of the burned gas. The leakage rate is reduced to 0.1 ml min-1 with 2 °C min-1 + 1 °C min-1 heating rate, 86.25% solid loading, 200 N dead weight load and 500 ml min-1 sweep gas flow rate.

  8. Advanced materials for solid oxide fuel cells: Hafnium-Praseodymium-Indium Oxide System

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.L.; Griffin, C.W.; Weber, W.J.

    1988-06-01

    The HfO/sub 2/-PrO/sub 1.83/-In/sub 2/O/sub 3/ system has been studied at the Pacific Northwest Laboratory to develop alternative, highly electrically conducting oxides as electrode and interconnection materials for solid oxide fuel cells. A coprecipitation process was developed for synthesizing single-phase, mixed oxide powders necessary to fabricate powders and dense oxides. A ternary phase diagram was developed, and the phases and structures were related to electrical transport properties. Two new phases, an orthorhombic PrInO/sub 3/ and a rhombohedral Hf/sub 2/In/sub 2/O/sub 7/ phase, were identified. The highest electronic conductivity is related to the presence of a bcc, In/sub 2/O/sub 3/ solid solution (ss) containing HfO/sub 2/ and PrO/sub 1.83/. Compositions containing more than 35 mol % of the In/sub 2/O/sub 3/ ss have electrical conductivities greater than 10/sup /minus/1/ (ohm-cm)/sup /minus/1/, and the two or three phase structures that contain this phase appear to exhibit mixed electronic-ionic conduction. The high electrical conductivities and structures similar to the Y/sub 2/O/sub 3/-stabilized ZrO/sub 2/(HfO/sub 2/) electrolyte give these oxides potential for use as cathodes in solid oxide fuel cells. 21 refs.

  9. Solid Oxide Fuel Cell/Turbine Hybrid Power System for Advanced Aero-propulsion and Power, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Solid oxide fuel cell (SOFC)/ gas turbine hybrid power systems (HPSs) have been recognized by federal agencies and other entities as having the potential to operate...

  10. Advanced manufacturing of intermediate temperature, direct methane oxidation membrane electrode assemblies for durable solid oxide fuel cell, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ITN proposes to create an innovative anode supported membrane electrode assembly (MEA) for solid oxide fuel cells (SOFCs) that is capable of long-term operation at...

  11. Models for solid oxide fuel cell systems exploitation of models hierarchy for industrial design of control and diagnosis strategies

    CERN Document Server

    Marra, Dario; Polverino, Pierpaolo; Sorrentino, Marco

    2016-01-01

    This book presents methodologies for optimal design of control and diagnosis strategies for Solid Oxide Fuel Cell systems. A key feature of the methodologies presented is the exploitation of modelling tools that balance accuracy and computational burden.

  12. Preparation and Evaluation of Multi-Layer Anodes of Solid Oxide Fuel Cell

    Science.gov (United States)

    Santiago, Diana; Farmer, Serene C.; Setlock, John A.

    2012-01-01

    The development of an energy device with abundant energy generation, ultra-high specific power density, high stability and long life is critical for enabling longer missions and for reducing mission costs. Of all different types of fuel cells, the solid oxide fuel cells (SOFC) is a promising high temperature device that can generate electricity as a byproduct of a chemical reaction in a clean way and produce high quality heat that can be used for other purposes. For aerospace applications, a power-to-weight of (is) greater than 1.0 kW/kg is required. NASA has a patented fuel cell technology under development, capable of achieving the 1.0 kW/kg figure of merit. The first step toward achieving these goals is increasing anode durability. The catalyst plays an important role in the fuel cells for power generation, stability, efficiency and long life. Not only the anode composition, but its preparation and reduction are key to achieving better cell performance. In this research, multi-layer anodes were prepared varying the chemistry of each layer to optimize the performance of the cells. Microstructure analyses were done to the new anodes before and after fuel cell operation. The cells' durability and performance were evaluated in 200 hrs life tests in hydrogen at 850 C. The chemistry of the standard nickel anode was modified successfully reducing the anode degradation from 40% to 8.4% in 1000 hrs and retaining its microstructure.

  13. Mechanistic modelling of a cathode-supported tubular solid oxide fuel cell

    Science.gov (United States)

    Suwanwarangkul, R.; Croiset, E.; Pritzker, M. D.; Fowler, M. W.; Douglas, P. L.; Entchev, E.

    A two-dimensional mechanistic model of a tubular solid oxide fuel cell (SOFC) considering momentum, energy, mass and charge transport is developed. The model geometry of a single cell comprises an air-preheating tube, air channel, fuel channel, anode, cathode and electrolyte layers. The heat radiation between cell and air-preheating tube is also incorporated into the model. This allows the model to predict heat transfer between the cell and air-preheating tube accurately. The model is validated and shows good agreement with literature data. It is anticipated that this model can be used to help develop efficient fuel cell designs and set operating variables under practical conditions. The transport phenomena inside the cell, including gas flow behaviour, temperature, overpotential, current density and species concentration, are analysed and discussed in detail. Fuel and air velocities are found to vary along flow passages depending on the local temperature and species concentrations. This model demonstrates the importance of incorporating heat radiation into a tubular SOFC model. Furthermore, the model shows that the overall cell performance is limited by O 2 diffusion through the thick porous cathode and points to the development of new cathode materials and designs being important avenues to enhance cell performance.

  14. Low temperature electrochemical cells with sodium β″-alumina solid electrolyte (BASE)

    Science.gov (United States)

    Girija, T. C.; Virkar, Anil V.

    Cells of Daniell-type with copper-zinc electrochemical couples and sodium β″-alumina solid electrolyte (BASE) were constructed. The cathode consisted of copper in contact with its ions (Cu/Cu 2+) while zinc in contact with its ions (Zn/Zn 2+) constituted the anode. Dimethyl sulfoxide (DMSO) containing 1 M NaBF 4 was used as the liquid electrolyte. The configuration of the cell constructed can be written as follows: Zn(s)/ZnCl 2(DMSO)(0.1 M), NaBF 4(1 M)/BASE/NaBF 4(1 M), CuCl 2(DMSO)(0.1 M)/Cu(s). The cell was subjected to charge-discharge cycles at 100 °C. The BASE discs were found to be stable even after the cell was subjected to several electrochemical charge-discharge cycles. Cells were also constructed using BASE discs with porous BASE surface layers introduced to lower the interfacial resistance. Cells with surface modified BASE exhibited a lower resistance in comparison to those using unmodified BASE. XRD and SEM analyses indicated that no detectable degradation of BASE discs occurred after cell testing. Preliminary cell tests were also conducted with NaCF 3SO 3 in place of NaBF 4.

  15. Low temperature electrochemical cells with sodium {beta}''-alumina solid electrolyte (BASE)

    Energy Technology Data Exchange (ETDEWEB)

    Girija, T.C.; Virkar, Anil V. [Department of Materials Science and Engineering, 122 S. Central Campus Drive, University of Utah, Salt Lake City, UT 84112 (United States)

    2008-05-15

    Cells of Daniell-type with copper-zinc electrochemical couples and sodium {beta}''-alumina solid electrolyte (BASE) were constructed. The cathode consisted of copper in contact with its ions (Cu/Cu{sup 2+}) while zinc in contact with its ions (Zn/Zn{sup 2+}) constituted the anode. Dimethyl sulfoxide (DMSO) containing 1 M NaBF{sub 4} was used as the liquid electrolyte. The configuration of the cell constructed can be written as follows: Zn(s)/ZnCl{sub 2}(DMSO)(0.1 M), NaBF{sub 4}(1 M)/BASE/NaBF{sub 4}(1 M), CuCl{sub 2}(DMSO)(0.1 M)/Cu(s) The cell was subjected to charge-discharge cycles at 100 C. The BASE discs were found to be stable even after the cell was subjected to several electrochemical charge-discharge cycles. Cells were also constructed using BASE discs with porous BASE surface layers introduced to lower the interfacial resistance. Cells with surface modified BASE exhibited a lower resistance in comparison to those using unmodified BASE. XRD and SEM analyses indicated that no detectable degradation of BASE discs occurred after cell testing. Preliminary cell tests were also conducted with NaCF{sub 3}SO{sub 3} in place of NaBF{sub 4}. (author)

  16. Fabrication of All-Solid-State Lithium-ion Cells using Three-Dimensionally Structured Solid Electrolyte Li7La3Zr2O12 Pellets

    Directory of Open Access Journals (Sweden)

    MAO SHOJI

    2016-08-01

    Full Text Available All-solid-state lithium-ion batteries using Li+-ion conducting ceramic electrolytes have been focused on as attractive future batteries for electric vehicles and renewable energy conversion systems because high safety can be realized due to non-flammability of ceramic electrolytes. In addition, a higher volumetric energy density than that of current lithium-ion batteries is expected since the all-solid-state lithium-ion batteries can be made in bipolar cell configurations. However, the special ideas and techniques based on ceramic processing are required to construct the electrochemical interface for all-solid-state lithium-ion batteries since the battery development has been done so far based on liquid electrolyte system over 100 years. As one of promising approaches to develop practical all-solid-state batteries, we have been focusing on three-dimensionally (3D structured cell configurations such as an interdigitated combination of 3D pillars of cathode and anode, which can be realized by using solid electrolyte membranes with hole-array structures. The application of such kinds of 3D structures effectively increases the interface between solid electrode and solid electrolyte per unit volume, lowering the internal resistance of all-solid-state lithium-ion batteries. In this study, Li6.25Al0.25La3Zr2O12 (LLZAl, which is a Al-doped Li7La3Zr2O12 (LLZ with Li+-ion conductivity of ~10–4 S cm–1 at room temperature and high stability against lithium-metal, was used as a solid electrolyte, and its pellets with 700 um depth holes in 700 x 700 um2 area were fabricated to construct 3D-structured all-solid-state batteries with LiCoO2 / LLZAl / lithium-metal configuration. It is expected that the LiCoO2-LLZAl interface is formed by point to point contact even when the LLZAl pellet with 3D hole-array structure is applied. Therefore, the application of mechanically soft Li3BO3 with a low melting point at around 700 °C was also performed as a supporting

  17. Numerical evaluation of micro-structural parameters of porous supports in metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Reiss, Georg; Frandsen, Henrik Lund; Brandstätter, Wilhelm

    2014-01-01

    Metallic supported Solid Oxide Fuel Cells (SOFCs) are considered as a durable and cost effective alternative to the state-of-the-art ceramic supported cell designs. In order to understand the mass and charge transport in the metal-support of this new type of cell a novel technique involving X...

  18. Enhanced performance with bismuth ferrite perovskite in ZnO nanorod solid state solar cells

    Science.gov (United States)

    Loh, Leonard; Briscoe, Joe; Dunn, Steve

    2014-05-01

    This paper reports for the first time the use of perovskite bismuth ferrite (BiFeO3 or BFO) on ZnO-based solid state solar cells using only chemical solution methods for materials synthesis. As ZnO has poor chemical stability in acidic and corrosive environments, a buffer method using aminosilane ((3-aminopropyltriethoxysilane or H2N(CH2)3Si(OC2H5)3)) coating was used to provide a protective coating on the ZnO nanorods. The aminosilane layer was removed after BFO coating. The solid state solar cells, sensitized by N719, used CuSCN as the hole conductor and were tested under 100 mW cm-2, AM 1.5G simulated sunlight. The photovoltaic performance showed current density improvement from 0.64 mA cm-2 to 1.4 mA cm-2 and efficiencies from 0.1% to 0.38% when comparing between ZnO and ZnO/BFO solar cells. The observed ca. 400% improved performance is shown to result from BFO's role as an electron blocking layer.This paper reports for the first time the use of perovskite bismuth ferrite (BiFeO3 or BFO) on ZnO-based solid state solar cells using only chemical solution methods for materials synthesis. As ZnO has poor chemical stability in acidic and corrosive environments, a buffer method using aminosilane ((3-aminopropyltriethoxysilane or H2N(CH2)3Si(OC2H5)3)) coating was used to provide a protective coating on the ZnO nanorods. The aminosilane layer was removed after BFO coating. The solid state solar cells, sensitized by N719, used CuSCN as the hole conductor and were tested under 100 mW cm-2, AM 1.5G simulated sunlight. The photovoltaic performance showed current density improvement from 0.64 mA cm-2 to 1.4 mA cm-2 and efficiencies from 0.1% to 0.38% when comparing between ZnO and ZnO/BFO solar cells. The observed ca. 400% improved performance is shown to result from BFO's role as an electron blocking layer. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00911h

  19. Reversible solid oxide fuel cells (R-SOFCs) with chemically stable proton-conducting oxides

    KAUST Repository

    Bi, Lei

    2015-07-01

    Proton-conducting oxides offer a promising way of lowering the working temperature of solid oxide cells to the intermediate temperate range (500 to 700. °C) due to their better ionic conductivity. In addition, the application of proton-conducting oxides in both solid oxide fuel cells (SOFCs) and sold oxide electrolysis cells (SOECs) provides unique advantages compared with the use of conventional oxygen-ion conducting conductors, including the formation of water at the air electrode site. Since the discovery of proton conduction in some oxides about 30. years ago, the development of proton-conducting oxides in SOFCs and SOECs (the reverse mode of SOFCs) has gained increased attention. This paper briefly summarizes the development in the recent years of R-SOFCs with proton-conducting electrolytes, focusing on discussing the importance of adopting chemically stable materials in both fuel cell and electrolysis modes. The development of electrode materials for proton-conducting R-SOFCs is also discussed. © 2015 Elsevier B.V.

  20. High performance solid oxide fuel cell operating on dry gasified coal

    Energy Technology Data Exchange (ETDEWEB)

    Guer, Turgut M. [Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305 (United States); Direct Carbon Technologies, LLC, 525 University Avenue, Suite 1400, Palo Alto, CA 94301 (United States); Homel, Michael [Materials and Systems Research, Inc., 5395 West 700 South, Salt lake City, UT 84104 (United States); Virkar, Anil V. [Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112 (United States)

    2010-02-15

    A fluidized coal bed-solid oxide fuel cell (FB-SOFC) arrangement is employed for efficient conversion of dry gasified coal into electricity at 850 C. It consists of an anode-supported tubular solid oxide fuel cell of 24 cm{sup 2} active area coupled to a Boudouard gasifier. A minimally fluidized bed of low sulfur (0.15 wt%) Alaska coal is gasified at 930 C by flowing CO{sub 2} to generate CO. The resulting CO fuel is oxidized at the Ni/YSZ cermet anode. The highest cell power density achieved is 0.45 W cm{sup -2} at 0.64 V with 35.7% electrical conversion efficiency based on CO utilization. This power density is the highest reported in the literature for such systems and corresponds to a total power generation of 10.8 W by this cell. Similarly, 48.4% is the highest conversion efficiency measured at a power density of 0.30 W cm{sup -2} and 0.7 V. The open circuit voltages are in good agreement with values expected based on thermodynamic data. (author)

  1. Final Technical Report, Oct 2004 - Nov. 2006, High Performance Flexible Reversible Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Jie; Minh, Nguyen

    2007-02-21

    This report summarizes the work performed for the program entitled “High Performance Flexible Reversible Solid Oxide Fuel Cell” under Cooperative Agreement DE-FC36-04GO14351 for the U. S. Department of Energy. The overall objective of this project is to demonstrate a single modular stack that generates electricity from a variety of fuels (hydrogen and other fuels such as biomass, distributed natural gas, etc.) and when operated in the reverse mode, produces hydrogen from steam. This project has evaluated and selected baseline cell materials, developed a set of materials for oxygen and hydrogen electrodes, and optimized electrode microstructures for reversible solid oxide fuel cells (RSOFCs); and demonstrated the feasibility and operation of a RSOFC multi-cell stack. A 10-cell reversible SOFC stack was operated over 1000 hours alternating between fuel cell (with hydrogen and methane as fuel) and steam electrolysis modes. The stack ran very successfully with high power density of 480 mW/cm2 at 0.7V and 80% fuel utilization in fuel cell mode and >6 SLPM hydrogen production in steam electrolysis mode using about 1.1 kW electrical power. The hydrogen generation is equivalent to a specific capability of 2.59 Nm3/m2 with electrical energy demand of 3 kWh/Nm3. The performance stability in electrolysis mode was improved vastly during the program with a degradation rate reduction from 8000 to 200 mohm-cm2/1000 hrs. This was accomplished by increasing the activity and improving microstructure of the oxygen electrode. Both cost estimate and technology assessment were conducted. Besides the flexibility running under both fuel cell mode and electrolysis mode, the reversible SOFC system has the potentials for low cost and high efficient hydrogen production through steam electrolysis. The cost for hydrogen production at large scale was estimated at ~$2.7/kg H2, comparing favorably with other electrolysis techology.

  2. Present status of solid state photoelectrochemical solar cells and dye sensitized solar cells using PEO-based polymer electrolytes

    International Nuclear Information System (INIS)

    Singh, Pramod Kumar; Bhattacharya, Bhaskar; Nagarale, R K; Pandey, S P; Rhee, H W

    2011-01-01

    Due to energy crises in the future, much effort is being directed towards alternate sources. Solar energy is accepted as a novel substitute for conventional sources of energy. Out of the long list of various types of solar cells available on the market, solid state photoelectrochemical solar cells (SSPECs) and dye sensitized solar cells (DSSCs) are proposed as an alternative to costly crystalline solar cell. This review provides a common platform for SSPECs and DSSCs using polymer electrolyte, particularly on polyethylene oxide (PEO)-based polymer electrolytes. Due to numerous advantageous properties of PEO, it is frequently used as an electrolyte in both SSPECs as well as DSSCs. In DSSCs, so far high efficiency (more than 11%) has been obtained only by using volatile liquid electrolyte, which suffers many disadvantages, such as corrosion, leakage and evaporation. The PEO-based solid polymer proves its importance and could be used to solve the problems stated above. The recent developments in SSPECs and DSSCs using modified PEO electrolytes by adding nano size inorganic fillers, blending with low molecular weight polymers and ionic liquid (IL) are discussed in detail. The role of ionic liquid in modifying the electrical, structural and photoelectrochemical properties of PEO polymer electrolytes is also described. (review)

  3. A method of producing a multilayer barrier structure for a solid oxide fuel cell

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention provides a method of producing a multilayer barrier structure for a solid oxide cell stack, comprising the steps of: - providing a metal interconnect, wherein the metal interconnect is a ferritic stainless steel layer; - applying a first metal oxide layer on said metal...... oxide; and - reacting the metal oxide in said first metal oxide layer with the metal of said metal interconnect during the SOC-stack initialisation, and a solid oxide stack comprising an anode contact layer and support structure, an anode layer, an electrolyte layer, a cathode layer, a cathode contact...... layer, a metallic interconnect, and a multilayer barrier structure which is obtainable by the above method and through an initialisation step, which is carried out under controlled conditions for atmosphere composition and current load, which depends on the layer composition facilitating the formation...

  4. Intelligent nesting system

    Directory of Open Access Journals (Sweden)

    Đuričić Zoran

    2003-01-01

    Full Text Available The economy of the process for the manufacture of parts from sheet metal plates depends on successful solution of the process of cutting various parts from sheet metal plates. Essentially, the problem is to arrange contours within a defined space so that they take up minimal surface. When taken in this way, the considered problem assumes a more general nature; it refers to the utilization of a flat surface, and it can represent a general principle of arranging 2D contours on a certain surface. The paper presents a conceptual solution and a prototypal intelligent nesting system for optimal cutting. The problem of nesting can generally be divided into two intellectual phases: recognition and classification of shapes, and arrangement of recognized shapes on a given surface. In solving these problems, methods of artificial intelligence are applied. In the paper, trained neural network is used for recognition of shapes; on the basis of raster record of a part's drawing, it recognizes the part's shape and which class it belongs to. By means of the expert system, based on rules defined on the basis of acquisition of knowledge from manufacturing sections, as well as on the basis of certain mathematical algorithms, parts are arranged on the arrangement surface. Both systems can also work independently, having been built on the modular principle. The system uses various product models as elements of integration for the entire system. .

  5. Neste plans three projects

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Neste Chemicals (Helsinki) is discussing three joint ventures with local authorities in China, says Mikko Haapavaara, v.p./Asia. The projects should help the Finnish producer to increase sales in Asia by a considerable amount by 2000, he says. The plan involves production of polyethylene (PE), unsaturated polyester resins and PE compounding-all core operations. Sites have not been selected, but Shanghai is the favored location for the PE operations. The company is also looking at a site in the south, near Hong Kong, and at locations near Beijing. The PE plant would need to be near an ethylene unit, says Haapavaara. The PE resin plant would be designed to produce about 150,000 m.t./year and would cost about No. 150 million. A part of the output would need to be exported to take care of the financing, the company says. A feasibility study now under way with the potential Chinese partners should be completed by the end of March. The plant would use Neste's linear low-density PE process, proved in a world-scale plant at Beringen, Belgium. The compounding units would produce specialty PE material for the wire and cable and pipe industry. The company is a joint venture partner in a propane dehydrogenation/polypropylene (PP) plant and a minority partner in a Qualipoly, the 20,000 m.t./year unsaturated polyester resin producer

  6. A direct carbon solid oxide fuel cell operated on a plant derived biofuel with natural catalyst

    International Nuclear Information System (INIS)

    Cai, Weizi; Zhou, Qian; Xie, Yongmin; Liu, Jiang; Long, Guohui; Cheng, Shuang; Liu, Meilin

    2016-01-01

    Graphical abstract: A plant-derived biochar, with biologically accumulated chemical elements as catalyst for the Boudouard reaction, is a superior fuel to the all-solid-state direct carbon solid oxide fuel cells (DC-SOFCs), and, it enables DC-SOFCs to be a novel technology, of high efficient, low cost and environmental friendliness, for distributed power generation. - Highlights: • Orchid leaf char is a good fuel of all-solid-state DC-SOFCs. • Performance of DC-SOFC with leaf char is better than that with Fe-loaded carbon. • Biologically accumulated Ca in leaf char acts as catalyst for Boudouard reaction. • Leaf char with natural Ca performs better than C with Ca added by mechanical mixing. • Biochar with natural catalyst provides low cost and low pollutant fuel to DC-SOFCs. - Abstract: Biochar derived from orchid tree leaves is utilised as the fuel of a direct carbon solid oxide fuel cell (DC-SOFC), with yttrium stabilized zirconia (YSZ) as electrolyte and cermet of silver and gadolinium doped ceria (Ag-GDC) as the material of both cathode and anode, operating without any liquid medium or feeding gas. The performance of the DC-SOFC operated on the leaf char is higher than that operated on the best reported carbon fuel for DC-SOFCs, Fe-loaded activated carbon. XRD, Raman spectroscopy, SEM and EDX are applied to characterize the leaf char. It turns out that the leaf char is with porous structure and there is much Ca along with some K and Mg uniformly distributing in the leaf char. The effects of the naturally existing alkaline earth metal and alkaline metal and their distribution on the performance of the DC-SOFCs operated on the leaf char are analyzed in detail.

  7. FLAG-tagged CD19-specific CAR-T cells eliminate CD19-bearing solid tumor cells in vitro and in vivo.

    Science.gov (United States)

    Berahovich, Robert; Xu, Shirley; Zhou, Hua; Harto, Hizkia; Xu, Qumiao; Garcia, Andres; Liu, Fenyong; Golubovskaya, Vita M; Wu, Lijun

    2017-06-01

    Autologous T cells expressing chimeric antigen receptors (CARs) specific for CD19 have demonstrated remarkable efficacy as therapeutics for B cell malignancies. In the present study, we generated FLAG-tagged CD19-specific CAR-T cells (CD19-FLAG) and compared them to their non-tagged counterparts for their effects on solid and hematological cancer cells in vitro and in vivo . For solid tumors, we used HeLa cervical carcinoma cells engineered to overexpress CD19 (HeLa-CD19), and for hematological cancer we used Raji Burkitt's lymphoma cells, which endogenously express CD19. Like non-tagged CD19 CAR-T cells, CD19-FLAG CAR-T cells expanded in culture >100-fold and exhibited potent cytolytic activity against both HeLa-CD19 and Raji cells in vitro . CD19-FLAG CAR-T cells also secreted significantly more IFN-gamma and IL-2 than the control T cells. In vivo , CD19-FLAG CAR-T cells significantly blocked the growth of HeLa-CD19 solid tumors, increased tumor cleaved caspase-3 levels, and expanded systemically. CD19-FLAG CAR-T cells also significantly reduced Raji tumor burden and extended mouse survival. These results demonstrate the strong efficacy of FLAG-tagged CD19 CAR-T cells in solid and hematological cancer models.

  8. Assessment of bio-fuel options for solid oxide fuel cell applications

    Science.gov (United States)

    Lin, Jiefeng

    Rising concerns of inadequate petroleum supply, volatile crude oil price, and adverse environmental impacts from using fossil fuels have spurred the United States to promote bio-fuel domestic production and develop advanced energy systems such as fuel cells. The present dissertation analyzed the bio-fuel applications in a solid oxide fuel cell-based auxiliary power unit from environmental, economic, and technological perspectives. Life cycle assessment integrated with thermodynamics was applied to evaluate the environmental impacts (e.g., greenhouse gas emission, fossil energy consumption) of producing bio-fuels from waste biomass. Landfill gas from municipal solid wastes and biodiesel from waste cooking oil are both suggested as the promising bio-fuel options. A nonlinear optimization model was developed with a multi-objective optimization technique to analyze the economic aspect of biodiesel-ethanol-diesel ternary blends used in transportation sectors and capture the dynamic variables affecting bio-fuel productions and applications (e.g., market disturbances, bio-fuel tax credit, policy changes, fuel specification, and technological innovation). A single-tube catalytic reformer with rhodium/ceria-zirconia catalyst was used for autothermal reformation of various heavy hydrocarbon fuels (e.g., diesel, biodiesel, biodiesel-diesel, and biodiesel-ethanol-diesel) to produce a hydrogen-rich stream reformates suitable for use in solid oxide fuel cell systems. A customized mixing chamber was designed and integrated with the reformer to overcome the technical challenges of heavy hydrocarbon reformation. A thermodynamic analysis, based on total Gibbs free energy minimization, was implemented to optimize the operating environment for the reformations of various fuels. This was complimented by experimental investigations of fuel autothermal reformation. 25% biodiesel blended with 10% ethanol and 65% diesel was determined to be viable fuel for use on a truck travelling with

  9. Optimizations of large area quasi-solid-state dye-sensitized solar cells

    DEFF Research Database (Denmark)

    Biancardo, M.; West, K.; Krebs, Frederik C

    2006-01-01

    In this paper, we address optimizations of dye sensitized solar cells (DSSCs) through the combination of important issues like semi-transparency, quasi-solid-state constructions and low-cost realization of serially connected modules. DSSCs with a transparency of 50% in the visible region, moderate...... efficiency similar to 1%, and long lifetime allow solar cells application in building elements like windows, facades and semi-transparent roofs. The use in DSSCs of gel polymer electrolytes prepared by liquid electrolyte incorporation into a polymer matrix such as poly-methyl-methacrylate presents...... encouraging results. A short circuit current (I-sc) of 4.45 mA cm(-2) with an open circuit voltage (V-oc) of 0.5 V were recorded in standard solar cells sensitized by cis-bis(thiocyano) ruthenium(II)-bis-2, 2'-bipyridine-4, 4'-dicarboxylate. Up-scaling tests demonstrate the easy realization of a 625 cm(2...

  10. Numerical simulation of mass and energy transport phenomena in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Arpino, F. [Dipartimento di Meccanica, Strutture, Ambiente e Territorio (DiMSAT), University of Cassino, via Di Biasio 43, Cassino (Italy); Massarotti, N. [Dipertimento per le Tecnologie (DiT), University of Naples ' ' Parthenope' ' , Centro Direzionale, isola C4, 80143 Napoli (Italy)

    2009-12-15

    Solid Oxide Fuel Cells (SOFCs) represent a very promising technology for near future energy conversion thanks to a number of advantages, including the possibility of using different fuels. In this paper, a detailed numerical model, based on a general mathematical description and on a finite element Characteristic based Split (CBS) algorithm code is employed to simulate mass and energy transport phenomena in SOFCs. The model predicts the thermodynamic quantity of interest in the fuel cell. Full details of the numerical solution obtained are presented both in terms of heat and mass transfer in the cell and in terms of electro-chemical reactions that occur in the system considered. The results obtained with the present algorithm is compared with the experimental data available in the literature for validation, showing an excellent agreement. (author)

  11. Reactivating the Ni-YSZ electrode in solid oxide cells and stacks by infiltration

    Science.gov (United States)

    Skafte, Theis Løye; Hjelm, Johan; Blennow, Peter; Graves, Christopher

    2018-02-01

    The solid oxide cell (SOC) could play a vital role in energy storage when the share of intermittent electricity production is high. However, large-scale commercialization of the technology is still hindered by the limited lifetime. Here, we address this issue by examining the potential for repairing various failure and degradation mechanisms occurring in the fuel electrode, thereby extending the potential lifetime of a SOC system. We successfully infiltrated the nickel and yttria-stabilized zirconia cermet electrode in commercial cells with Gd-doped ceria after operation. By this method we fully reactivated the fuel electrode after simulated reactant starvation and after carbon formation. Furthermore, by infiltrating after 900 h of operation, the degradation of the fuel electrode was reduced by a factor of two over the course of 2300 h. Lastly, the scalability of the concept is demonstrated by reactivating an 8-cell stack based on a commercial design.

  12. New methodology of preparation support for solid oxide fuel cells using different pore forming agent

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, Raigenis da P.; Guedes, Bruna C.F.; Silva, Marcos A. da; Carvalho, Luiz F.V. de; Boaventura, Jaime S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Pontes, Luiz A.M. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica

    2008-07-01

    The development of environment-friendly energy sources has been of the most important scientific and technological area. Solid oxide fuel cells (SOFC) are very promising alternative for their ability to handle renewable fuels with low emissions and high efficiency. However, this device requires massive improvement before commercial application. This work studies the pore formation in the cell anode and cathode with NaHCO{sub 3} or citric acid, comparing to graphite. The three agents make pore with similar features, but the use of NaHCO{sub 3} and citric acid considerably improves the adhesion of the electrode-electrolyte interface, critical characteristic for good cell efficiency. The prepared anode-electrolyte-cathode structure was studied by SEM technique. The SOFC prepared using citric acid was tested with gaseous ethanol, natural gas and hydrogen. For all these three fuels the SOFC shows virtually no overpotential, indicating the good ionic conductance of the electrodes-electrolyte interface.. (author)

  13. Methane Steam Reforming over an Ni-YSZ Solid Oxide Fuel Cell Anode in Stack Configuration

    Directory of Open Access Journals (Sweden)

    D. Mogensen

    2014-01-01

    Full Text Available The kinetics of catalytic steam reforming of methane over an Ni-YSZ anode of a solid oxide fuel cell (SOFC have been investigated with the cell placed in a stack configuration. In order to decrease the degree of conversion, a single cell stack with reduced area was used. Measurements were performed in the temperature range 600–800°C and the partial pressures of all reactants and products were varied. The obtained rates could be well fitted with a power law expression (r ∝PCH40.7. A simple model is presented which is capable of predicting the methane conversion in a stack configuration from intrinsic kinetics of the anode support material. The predictions are compared with the stack measurements presented here, and good agreement is observed.

  14. Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, Shayenne Diniz da; Monteiro, Natalia Kondo; Tabuti, Francisco; Fonseca, Fabio Coral, E-mail: shaynnedn@hotmail.com, E-mail: nataliakm@usp.br, E-mail: fntabuti@ipen.br, E-mail: fabiocf@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Florio, Daniel Zanetti de, E-mail: daniel.florio@ufabc.edu.br [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2017-01-15

    Electrodes for electrolyte-supported solid oxide fuel cells (SOFC’s) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs. (author)

  15. Computational Fluid Dynamics calculation of a planar solid oxide fuel cell design running on syngas

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-12-01

    Full Text Available The present study deals with modelling and validation of a planar Solid Oxide Fuel Cell (SOFC design fuelled by gas mixture of partially pre-reformed methane. A 3D model was developed using the ANSYS Fluent Computational Fluid Dynamics (CFD tool that was supported by an additional Fuel Cell Tools module. The governing equations for momentum, heat, gas species, ion and electron transport were implemented and coupled to kinetics describing the electrochemical and reforming reactions. In the model, the Water Gas Shift reaction in a porous anode layer was included. Electrochemical oxidation of hydrogen and carbon monoxide fuels were both considered. The developed model enabled to predict the distributions of temperature, current density and gas flow in the fuel cell.

  16. CONDUCTIVITY STUDIES OF (PEO +KHCO3 SOLID ELECTROLYTE SYSTEM AND ITS APPLICATION AS AN ELECTROCHEMICAL CELL

    Directory of Open Access Journals (Sweden)

    K. VIJAY KUMAR

    2010-06-01

    Full Text Available Solid polymer electrolyte system, polyethylene oxide (PEO complexed with potassium bicarbonate (KHCO3 salt was prepared by solution-cast technique. Several experimental techniques such as infrared radiation (IR, differential scanning calorimeter (DSC, and composition dependence conductivity, temperature dependence conductivity in the temperature range of 308–368 K and transport number measurements were employed to characterize this polymer electrolyte system. The conductivity of the (PEO+KHCO3 electrolyte was found to be about 3 times larger than that of pure PEO at room temperature. The transference data indicated that the charge transport in these polymer electrolyte systems is predominantly due to K+ ions. Using this polymer electrolyte an electrochemical cell with configuration K+/(PEO+KHCO3/(I2+C+electrolyte was fabricated and its discharge characteristics are studied. A number of other cell parameters associated with the cell were evaluated and are reported in this paper.

  17. Carbon and Redox Tolerant Infiltrated Oxide Fuel-Electrodes for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Skafte, Theis Løye; Sudireddy, Bhaskar Reddy; Blennow, P.

    2016-01-01

    by infiltrating nano-sized CGO orNiCGO on top of SFM, while still sustaining the high electronicconductivity. Ohmic resistance of the electrodes was thuspractically eliminated and performance comparable to, or betterthan, state-of-the-art fuel electrodes was achieved. The Nicontaining cells were damaged by carbon......To solve issues of coking and redox instability related to the presence of nickel in typical fuel electrodes in solid oxide cells,Gd-doped CeO2 (CGO) electrodes were studied using symmetriccells. These electrodes showed high electro-catalytic activity, butlow electronic conductivity. When...... deposition in a CO/CO2-atmosphere, while none of the non-nickel cells catalyzed carbon.Stability towards redox cycles was also proven....

  18. Table 2.4. Cell voltages with solid state electrolyte systems

    Science.gov (United States)

    Holze, R.

    This document is part of Volume 9 `Electrochemistry', Subvolume A, of Landolt-Börnstein - Group IV `Physical Chemistry'. The document lists normal voltages of cells with solid state electrolyte systems. The cells are composed of the following materials: silver (Ag), aluminium (Al), barium (Ba), bismuth (Bi), carbon (C), cadmium (Cd), cobalt (Co), chromium (Cr), cesium (Cs), copper (Cu), iron (Fe), germanium (Ge), hafnium (Hf), iridium (Ir), potassium (K), lanthanum (La), lithium (Li), magnesium (Mg), manganese (Mn), molybdenum (Mo), nitrogen (N), natrium (Na), niobium (Nb), neodymium (Nd), nickel (Ni), lead (Pb), palladium (Pd), rhodium (Rh), ruthenium (Ru), antimony (Sb), samarium (Sm), tin (Sn), strontium (Sr), tantalum (Ta), tellurium (Te), thorium (Th), thallium (Tl), uranium (U), yttrium (Y), zinc (Zn), zirconium (Zr). The compositions of the cells are given along with, where available, the temperatures of mesurements of the voltages.

  19. Spray pyrolysis of doped-ceria barrier layers for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Chrzan, Aleksander; Karczewski, Jakub

    2017-01-01

    of elements. The parameters of the fabrication process are linked to the measured area specific resistances of the symmetrical cells and the efficiency of the fuel cells. Results show, that application of 800 nm thick barrier effectively hinder negative reactions, while 400 nm thick layer is sufficient......Gadolinium doped ceria (Ce0.8Gd0.2O2 − x-CGO) layer fabricated by spray pyrolysis is investigated as the diffusion barrier for solid oxide fuel cell. It is deposited between the La0.6Sr0.4FeO3 − δ cathode and the yttria stabilized zirconia electrolyte to mitigate harmful interdiffusion...

  20. Numerical investigation of the effect of operating parameters on a planar solid oxide fuel cell

    International Nuclear Information System (INIS)

    Raj, Abhishek; Sasmito, Agus P.; Shamim, Tariq

    2015-01-01

    Highlights: • Effects of operating parameters on a planar type of SOFC are investigated. • The studies carried out by developing a three dimensional mathematical model. • The cell performance is enhanced at high temperatures and cathode stoichiometry. • Cathode stoichiometry has a high influence on the cell performance. • The effect of anode stoichiometry on the cell performance is low. - Abstract: The three operating parameters – temperature, stoichiometry and the degree of humidification – constitute key factors required to ensure high performance of the solid oxide fuel cell (SOFC). A careful trade-off between performance and parasitic loads is required in order to optimize the output. The present study numerically analyzes the influence of the key operating parameters on the performance of planar type of SOFC and parasitic loads utilizing a validated three dimensional mathematical model which takes into account of the conservation of mass, momentum, species and charge. The numerical results indicate that the cell performance is enhanced at high temperatures and cathode stoichiometry and it declines with increasing cathode relative humidity. Furthermore, cathode stoichiometry is found to have higher influence on the cell performance as compared to the anode stoichiometry. The gain in cell performance however, has to be balanced with the changing parasitic load requirement from pumping, humidification and heating. The results presented herein can assist in the selection of optimum or near-to-optimum operating parameters for high performance planar type SOFC

  1. Coating Solid Lipid Nanoparticles with Hyaluronic Acid Enhances Antitumor Activity against Melanoma Stem-like Cells.

    Science.gov (United States)

    Shen, Hongxin; Shi, Sanjun; Zhang, Zhirong; Gong, Tao; Sun, Xun

    2015-01-01

    Successful anticancer chemotherapy requires targeting tumors efficiently and further potential to eliminate cancer stem cell (CSC) subpopulations. Since CD44 is present on many types of CSCs, and it binds specially to hyaluronic acid (HA), we tested whether coating solid lipid nanoparticles with hyaluronan (HA-SLNs)would allow targeted delivery of paclitaxel (PTX) to CD44-overexpressing B16F10 melanoma cells. First, we developed a model system based on melanoma stem-like cells for experiments in vitro and in mouse xenografts, and we showed that cells expressing high levels of CD44 (CD44(+)) displayed a strong CSC phenotype while cells expressing low levels of CD44 (CD44(-)) did not. This phenotype included sphere and colony formation, higher proportion of side population cells, expression of CSC-related markers (ALDH, CD133, Oct-4) and tumorigenicity in vivo. Next we showed that administering PTX-loaded HA-SLNs led to efficient intracellular delivery of PTX and induced substantial apoptosis in CD44(+) cells in vitro. In the B16F10-CD44(+) lung metastasis model, PTX-loaded HA-SLNs targeted the tumor-bearing lung tissues well and subsequently exhibited significant antitumor effects with a relative low dose of PTX, which provided significant survival benefit without evidence of adverse events. These findings suggest that the HA-SLNs targeting system shows promise for enhancing cancer therapy.

  2. Development of planar solid oxide fuel cells for power generation applications

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.Q. [AlliedSignal Aerospce Equipment Systems, Torrance, CA (United States)

    1996-04-01

    Planar solid oxide fuel cells (SOFCs) are presently being developed for a variety of electric power generation application. The planar design offers simple cell geometry, high power density, and multiple fabrication and gas manifolding options. Planar SOFC technology has received much attention recently, and significant progress has been made in this area. Recent effort at AlliedSignal has focused on the development of high-performance, lightweight planar SOFCs, having thin-electrolyte films, that can be operated efficiently at reduced temperatures (< 1000{degrees}C). The advantages of reduced-temperature operation include wider material choice (including use of metallic interconnects), expected longer cell life, reduced thermal stress, improved reliability, and reduced fuel cell cost. The key aspect in the development of thin-film SIFCs is to incorporate the thin electrolyte layer into the desired structure of cells in a manner that yields the required characteristics. AlliedSignal has developed a simple and cost-effective method based on tape calendering for the fabrication of thin-electrolyte SOFCs. Thin-electrolyte cells made by tape calendering have shown extraordinary performance, e.g., producing more than 500mW/cm{sup 2} at 700{degrees}C and 800mW/cm{sup 2} at 800{degrees}C with hydrogen as fuel and air is oxidant. thin-electrolyte single cells have been incorporated into a compliant metallic stack structure and operated at reduced and operated at reduced-temperature conditions.

  3. Thermodynamic analysis of solid oxide fuel cell gas turbine systems operating with various biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Patel, H.C.; Woudstra, T.; Aravind, P.V. [Process and Energy Laboratory, Delft University of Technology, Section Energy Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands)

    2012-12-15

    Solid oxide fuel cell-gas turbine (SOFC-GT) systems provide a thermodynamically high efficiency alternative for power generation from biofuels. In this study biofuels namely methane, ethanol, methanol, hydrogen, and ammonia are evaluated exergetically with respect to their performance at system level and in system components like heat exchangers, fuel cell, gas turbine, combustor, compressor, and the stack. Further, the fuel cell losses are investigated in detail with respect to their dependence on operating parameters such as fuel utilization, Nernst voltage, etc. as well as fuel specific parameters like heat effects. It is found that the heat effects play a major role in setting up the flows in the system and hence, power levels attained in individual components. The per pass fuel utilization dictates the efficiency of the fuel cell itself, but the system efficiency is not entirely dependent on fuel cell efficiency alone, but depends on the split between the fuel cell and gas turbine powers which in turn depends highly on the nature of the fuel and its chemistry. Counter intuitively it is found that with recycle, the fuel cell efficiency of methane is less than that of hydrogen but the system efficiency of methane is higher. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Synthesis, characterization and electrical properties of solid electrolyte for solid oxide fuel cell; Preparacao, caracterizacao e propriedades eletricas de eletrolito solido para celula a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Marco Antonio Coelho; Garcia, Carlos Mario; Matos, Jeferson Hrenechen [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], Emails: felsky@latec.org.br, garcia@latec.org.br, jeferson.h@latec.org.br

    2010-04-15

    Solid electrolytes of BaCe{sub 08}Gd{sub O29} were prepared by the polymeric precursor method. X-ray diffraction data shows a single phase with orthorhombic crystalline structure. The densification process was followed by scanning electronic microscopy and apparent density measurements. The apparent density was developed for different temperatures of sintering, reaching > 96% for sintered temperature of 1550 {sup 0}C deg . The electrochemical impedance analysis was development in the temperature of 400-700 deg C, in air atmosphere at 700 deg C a value of 30,6 mS.cm{sup -1} was obtained. The results of conductivity have confirmed the gadolinium doped barium cerate has a great potential for use as solid electrolyte for intermediate temperature solid oxide fuel cell, at experimental controlled conditions. (author)

  5. PyNEST: a convenient interface to the NEST simulator

    Directory of Open Access Journals (Sweden)

    Jochen M Eppler

    2009-01-01

    Full Text Available The neural simulation tool NEST (http://www.nest-initiative.org is a simulator for heterogeneous networks of point neurons or neurons with a small number of compartments. It aims at simulations of large neural systems with more than 10^4 neurons and 10^7 to 10^9 synapses. NEST is implemented in C++ and can be used on a large range of architectures from single-core laptops over multi-core desktop computers to super-computers with thousands of processor cores. Python (http://www.python.org is a modern programming language that has recently received considerable attention in Computational Neuroscience. Python is easy to learn and has many extension modules for scientific computing (e.g. http://www.scipy.org. In this contribution we describe PyNEST, the new user interface to NEST. PyNEST combines NEST’s efficient simulation kernel with the simplicity and flexibility of Python. Compared to NEST’s native simulation language SLI, PyNEST makes it easier to set up simulations, generate stimuli, and analyze simulation results. We describe how PyNEST connects NEST and Python and how it is implemented. With a number of examples, we illustrate how it is used.

  6. Composite electrolyte with proton conductivity for low-temperature solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Raza, Rizwan, E-mail: razahussaini786@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Energy Technology, Royal Institute of Technology, KTH, Stockholm 10044 (Sweden); Ahmed, Akhlaq; Akram, Nadeem; Saleem, Muhammad; Niaz Akhtar, Majid; Ajmal Khan, M.; Abbas, Ghazanfar; Alvi, Farah; Yasir Rafique, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Sherazi, Tauqir A. [Department of Chemistry, COMSATS Institute of Information Technology, Abbotabad 22060 (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) center, College of Engineering, King Saud University, PO-BOX 800, Riyadh 11421 (Saudi Arabia); Mohsin, Munazza [Department of Physics, Lahore College for Women University, Lahore, 54000 (Pakistan); Javed, Muhammad Sufyan [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Zhu, Bin, E-mail: binzhu@kth.se, E-mail: zhubin@hubu.edu.cn [Department of Energy Technology, Royal Institute of Technology, KTH, Stockholm 10044 (Sweden); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science/Faculty of Computer and Information, Hubei University, Wuhan, Hubei 430062 (China)

    2015-11-02

    In the present work, cost-effective nanocomposite electrolyte (Ba-SDC) oxide is developed for efficient low-temperature solid oxide fuel cells (LTSOFCs). Analysis has shown that dual phase conduction of O{sup −2} (oxygen ions) and H{sup +} (protons) plays a significant role in the development of advanced LTSOFCs. Comparatively high proton ion conductivity (0.19 s/cm) for LTSOFCs was achieved at low temperature (460 °C). In this article, the ionic conduction behaviour of LTSOFCs is explained by carrying out electrochemical impedance spectroscopy measurements. Further, the phase and structure analysis are investigated by X-ray diffraction and scanning electron microscopy techniques. Finally, we achieved an ionic transport number of the composite electrolyte for LTSOFCs as high as 0.95 and energy and power density of 90% and 550 mW/cm{sup 2}, respectively, after sintering the composite electrolyte at 800 °C for 4 h, which is promising. Our current effort toward the development of an efficient, green, low-temperature solid oxide fuel cell with the incorporation of high proton conductivity composite electrolyte may open frontiers in the fields of energy and fuel cell technology.

  7. Electrochemical investigation of mixed metal oxide nanocomposite electrode for low temperature solid oxide fuel cell

    Science.gov (United States)

    Abbas, Ghazanfar; Raza, Rizwan; Ashfaq Ahmad, M.; Ajmal Khan, M.; Jafar Hussain, M.; Ahmad, Mukhtar; Aziz, Hammad; Ahmad, Imran; Batool, Rida; Altaf, Faizah; Zhu, Bin

    2017-10-01

    Zinc-based nanostructured nickel (Ni) free metal oxide electrode material Zn0.60/Cu0.20Mn0.20 oxide (CMZO) was synthesized by solid state reaction and investigated for low temperature solid oxide fuel cell (LTSOFC) applications. The crystal structure and surface morphology of the synthesized electrode material were examined by XRD and SEM techniques respectively. The particle size of ZnO phase estimated by Scherer’s equation was 31.50 nm. The maximum electrical conductivity was found to be 12.567 S/cm and 5.846 S/cm in hydrogen and air atmosphere, respectively at 600∘C. The activation energy of the CMZO material was also calculated from the DC conductivity data using Arrhenius plots and it was found to be 0.060 and 0.075 eV in hydrogen and air atmosphere, respectively. The CMZO electrode-based fuel cell was tested using carbonated samarium doped ceria composite (NSDC) electrolyte. The three layers 13 mm in diameter and 1 mm thickness of the symmetric fuel cell were fabricated by dry pressing. The maximum power density of 728.86 mW/cm2 was measured at 550∘C.

  8. Composite electrolyte with proton conductivity for low-temperature solid oxide fuel cell

    Science.gov (United States)

    Raza, Rizwan; Ahmed, Akhlaq; Akram, Nadeem; Saleem, Muhammad; Niaz Akhtar, Majid; Sherazi, Tauqir A.; Ajmal Khan, M.; Abbas, Ghazanfar; Shakir, Imran; Mohsin, Munazza; Alvi, Farah; Javed, Muhammad Sufyan; Yasir Rafique, M.; Zhu, Bin

    2015-11-01

    In the present work, cost-effective nanocomposite electrolyte (Ba-SDC) oxide is developed for efficient low-temperature solid oxide fuel cells (LTSOFCs). Analysis has shown that dual phase conduction of O-2 (oxygen ions) and H+ (protons) plays a significant role in the development of advanced LTSOFCs. Comparatively high proton ion conductivity (0.19 s/cm) for LTSOFCs was achieved at low temperature (460 °C). In this article, the ionic conduction behaviour of LTSOFCs is explained by carrying out electrochemical impedance spectroscopy measurements. Further, the phase and structure analysis are investigated by X-ray diffraction and scanning electron microscopy techniques. Finally, we achieved an ionic transport number of the composite electrolyte for LTSOFCs as high as 0.95 and energy and power density of 90% and 550 mW/cm2, respectively, after sintering the composite electrolyte at 800 °C for 4 h, which is promising. Our current effort toward the development of an efficient, green, low-temperature solid oxide fuel cell with the incorporation of high proton conductivity composite electrolyte may open frontiers in the fields of energy and fuel cell technology.

  9. Bipolar stacked quasi-all-solid-state lithium secondary batteries with output cell potentials of over 6 V.

    Science.gov (United States)

    Matsuo, Takahiro; Gambe, Yoshiyuki; Sun, Yan; Honma, Itaru

    2014-08-15

    Designing a lithium ion battery (LIB) with a three-dimensional device structure is crucial for increasing the practical energy storage density by avoiding unnecessary supporting parts of the cell modules. Here, we describe the superior secondary battery performance of the bulk all-solid-state LIB cell and a multilayered stacked bipolar cell with doubled cell potential of 6.5 V, for the first time. The bipolar-type solid LIB cell runs its charge/discharge cycle over 200 times in a range of 0.1-1.0 C with negligible capacity decrease despite their doubled output cell potentials. This extremely high performance of the bipolar cell is a result of the superior battery performance of the single cell; the bulk all-solid-state cell has a charge/discharge cycle capability of over 1500 although metallic lithium and LiFePO₄ are employed as anodes and cathodes, respectively. The use of a quasi-solid electrolyte consisting of ionic liquid and Al₂O₃ nanoparticles is considered to be responsible for the high ionic conductivity and electrochemical stability at the interface between the electrodes and the electrolyte. This paper presents the effective applications of SiO₂, Al₂O₃, and CeO₂ nanoparticles and various Li(+) conducting ionic liquids for the quasi-solid electrolytes and reports the best ever known cycle performances. Moreover, the results of this study show that the bipolar stacked three-dimensional device structure would be a smart choice for future LIBs with higher cell energy density and output potential. In addition, our report presents the advantages of adopting a three-dimensional cell design based on the solid-state electrolytes, which is of particular interest in energy-device engineering for mobile applications.

  10. Bipolar stacked quasi-all-solid-state lithium secondary batteries with output cell potentials of over 6 V

    Science.gov (United States)

    Matsuo, Takahiro; Gambe, Yoshiyuki; Sun, Yan; Honma, Itaru

    2014-01-01

    Designing a lithium ion battery (LIB) with a three-dimensional device structure is crucial for increasing the practical energy storage density by avoiding unnecessary supporting parts of the cell modules. Here, we describe the superior secondary battery performance of the bulk all-solid-state LIB cell and a multilayered stacked bipolar cell with doubled cell potential of 6.5 V, for the first time. The bipolar-type solid LIB cell runs its charge/discharge cycle over 200 times in a range of 0.1–1.0 C with negligible capacity decrease despite their doubled output cell potentials. This extremely high performance of the bipolar cell is a result of the superior battery performance of the single cell; the bulk all-solid-state cell has a charge/discharge cycle capability of over 1500 although metallic lithium and LiFePO4 are employed as anodes and cathodes, respectively. The use of a quasi-solid electrolyte consisting of ionic liquid and Al2O3 nanoparticles is considered to be responsible for the high ionic conductivity and electrochemical stability at the interface between the electrodes and the electrolyte. This paper presents the effective applications of SiO2, Al2O3, and CeO2 nanoparticles and various Li+ conducting ionic liquids for the quasi-solid electrolytes and reports the best ever known cycle performances. Moreover, the results of this study show that the bipolar stacked three-dimensional device structure would be a smart choice for future LIBs with higher cell energy density and output potential. In addition, our report presents the advantages of adopting a three-dimensional cell design based on the solid-state electrolytes, which is of particular interest in energy-device engineering for mobile applications. PMID:25124398

  11. Interconnect-integrated solid oxide fuel cell with high temperature sinter-joining process

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seung-Wook [KAIST Institute (KI) for Eco-Energy, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-Dong, Yuseong-Gu, Daejeon 305-701 (Korea); Jeong, Jihoon; Bae, Joongmyeon [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-Dong, Yuseong-Gu, Daejeon 305-701 (Korea); Kim, Jung Hyun [School of Chemistry, University of St. Andrews, Fife KY16 9ST (United Kingdom); Lee, Changbo [SAMSUNG Electro-Mechanics Co., 314 Maetan-3-Dong, Yeongtong-Gu, Suwon (Korea)

    2010-11-15

    In this study, a recently developed interconnect-integrated solid oxide fuel cell (SOFC) is characterized in terms of cell components, cell area enlargement, potential cathode material and mechanical/electrochemical properties. First, a high temperature sinter-joining process is used to fabricate an interconnect-integrated SOFC. This manuscript describes the interconnect material and the slurry composition design for bonding the interconnect and ceramic cell. The oxidation and thermal expansion characteristics of the starting materials of the interconnect-integrated cell, including the interconnect, metal powder of the bonding layer and metal powder/8YSZ/NiO compositions, are investigated to enhance both cell joining performance and cell stability during operation. Cell area enlargements of 50 mm x 50 mm and 100 mm x 100 mm are successfully realized using the optimized cell processing conditions. The cathode of the interconnect-integrated cell cannot be sintered in an air atmosphere due to the oxidation of the interconnect. Accordingly, a Sm{sub 1.0}Ba{sub 0.5}Sr{sub 0.5}Co{sub 2.0}O{sub 5-d}/Gd{sub 0.1}Ce{sub 0.9}O{sub 1.9} (50:50 wt%) (SBSCO50) composite cathode is selected and used as the potential in situ cathode for the interconnect-integrated SOFC. The in situ sintering properties of a conventional LSM82/8YSZ(6:4) composite cathode is also studied as the reference material. The mechanical and electrochemical performance of the resulting interconnect-integrated cell is tested. The mechanical strengths of the anode-supported cell and the interconnect-integrated cell are compared, and the electrochemical properties of the interconnect-integrated button cell and the large area (50 mm x 50 mm) interconnect-integrated cell are investigated. The button cell of a SBSCO50 composite cathode exhibits a maximum power density of 0.57 W cm{sup -2} at 800 C. The large area single repeat unit with an area of 50 mm x 50 mm with a SBSCO50 in situ cathode exhibits a maximum

  12. Solid oxide fuel cells powered by biomass gasification for high efficiency power generation

    DEFF Research Database (Denmark)

    Gadsbøll, Rasmus Østergaard; Thomsen, Jesper; Bang-Møller, Christian

    2017-01-01

    efficiencies, flexibility and possibly costs of current biomass power generating systems, a power plant concept combining solid oxide fuel cells (SOFC) and gasification is investigated experimentally. The aim of the study is to examine the commercial operation system potential of these two technologies......Increased use of bioenergy is a very cost-effective and flexible measure to limit changes in the climate and the infrastructure. One of the key technologies toward a higher implementation of biomass is thermal gasification, which enables a wide span of downstream applications. In order to improve...

  13. Solid oxide fuel cells having porous cathodes infiltrated with oxygen-reducing catalysts

    Science.gov (United States)

    Liu, Meilin; Liu, Ze; Liu, Mingfei; Nie, Lifang; Mebane, David Spencer; Wilson, Lane Curtis; Surdoval, Wayne

    2014-08-12

    Solid-oxide fuel cells include an electrolyte and an anode electrically coupled to a first surface of the electrolyte. A cathode is provided, which is electrically coupled to a second surface of the electrolyte. The cathode includes a porous backbone having a porosity in a range from about 20% to about 70%. The porous backbone contains a mixed ionic-electronic conductor (MIEC) of a first material infiltrated with an oxygen-reducing catalyst of a second material different from the first material.

  14. Ni-YSZ solid oxide fuel cell anode behavior upon redox cycling based on electrical characterization

    DEFF Research Database (Denmark)

    Klemensø, Trine; Mogensen, Mogens Bjerg

    2006-01-01

    Ni-YSZ cermets are a prevalent material used for solid oxide fuel cells. However, the cermet degrades upon redox cycling. The degradation is related to microstructural changes, but knowledge of the mechanisms has been limited. DC conductivity measurements were performed on cermets and cermets......, where the Ni component was removed, before, during and after redox cycling the cermet. The cermet conductivity degraded over time due to sintering of the nickel phase. Following oxidizing events, the conductivity of the cermets improved, whereas the conductivity of the YSZ phase decreased. A model...

  15. Ni-YSZ solid oxide fuel cell anode behavior upon redox cycling based on electrical characterization

    DEFF Research Database (Denmark)

    Klemensø, Trine; Mogensen, Mogens Bjerg

    2007-01-01

    Nickel (Ni)—yttria-stabilized zirconia (YSZ) cermets are a prevalent material used for solid oxide fuel cells. The cermet degrades upon redox cycling. The degradation is related to microstructural changes, but knowledge of the mechanisms has been limited. Direct current conductivity measurements...... were performed on cermets and cermets where the Ni component was removed. Measurements were carried out before, during, and after redox cycling the cermet. The cermet conductivity degraded over time due to sintering of the nickel phase. Following oxidizing events, the conductivity of the cermets...

  16. Determination of the bonding strength in solid oxide fuel cells' interfaces by Schwickerath crack initiation test

    DEFF Research Database (Denmark)

    Boccaccini, D. N.; Sevecek, O.; Frandsen, Henrik Lund

    2017-01-01

    An adaptation of the Schwickerath crack initiation test (ISO 9693) was used to determine the bonding strength between an anode support and three different cathodes with a solid oxide fuel cell interconnect. Interfacial elemental characterization of the interfaces was carried out by SEM/EDS analysis...... on fracture surfaces to investigate the bonding mechanisms. SEM/EDS of fresh fractures were also performed to determine the cohesion/adhesion mechanism of bonding. Calculations of the residual stresses were determined by finite element simulation using ANSYS, based on thermo-mechanical properties...

  17. Residential Systems Based on Solid Oxide Fuel Cells for Scandinavian Climate

    DEFF Research Database (Denmark)

    Rokni, Masoud; Vialetto, Giulio

    2015-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence and to increase the use of renewable energies. In the last several years, new technologies have been developed, and some...... of them received subsidies to increase installation and reduce cost. This article presents an innovative cogeneration system based on a solid oxide fuel cell (SOFC) system and heat pump for household applications with a focus on primary energy and economic savings using electric equivalent load parameter...

  18. Thermodynamic Analysis of an Integrated Gasification Solid Oxide Fuel Cell Plant with a Kalina Cycle

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud

    2015-01-01

    A hybrid plant that consists of a gasification system, Solid Oxide Fuel Cells (SOFC) and a Simple Kalina Cycle (SKC) is investigated. Woodchips are introduced into a fixed bed gasification plant to produce syngas, which is then fed into an integrated SOFC-SKC plant to produce electricity. The pre......-treated fuel then enters the anode side of the SOFC. Complete fuel oxidation is ensured in a burner by off-gases exiting the SOFC stacks. Off-gases are utilized as heat source for a SKC where a mixture of ammonia and water is expanded in a turbine to produce additional electric power. Thus, a triple novel...

  19. Thermodynamic Investigation of an Integrated Gasification Plant with Solid Oxide Fuel Cell and Steam Cycles

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2012-01-01

    A gasification plant is integrated on the top of a solid oxide fuel cell (SOFC) cycle, while a steam turbine (ST) cycle is used as a bottoming cycle for the SOFC plant. The gasification plant was fueled by woodchips to produce biogas and the SOFC stacks were fired with biogas. The produced gas...... was rather clean for feeding to the SOFC stacks after a simple cleaning step. Because all the fuel cannot be burned in the SOFC stacks, a burner was used to combust the remaining fuel. The off-gases from the burner were then used to produce steam for the bottoming steam cycle in a heat recovery steam...

  20. Thermodynamic analysis of SOFC (solid oxide fuel cell) - Stirling hybrid plants using alternative fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2013-01-01

    A novel hybrid power system (∼10 kW) for an average family home is proposed. The system investigated contains a solid oxide fuel cell (SOFC) on top of a Stirling engine. The off-gases produced in the SOFC cycle are fed to a bottoming Stirling engine, at which additional power is generated...... investigated by comparing the effects of key factors, such as the utilization factor and the operating conditions under which these fuels are used. Moreover, the effect of using a methanator on the plant efficiency is also studied. The combined system improves the overall electrical efficiency relative...

  1. Design of Waste Gasification Energy Systems with Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2017-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence, and to increase the use of renewable energies. In the last several years, new technologies have been developed and some...... of them received subsidies to increase installation and reduce cost. This article presents a new sustainable trigeneration system (power, heat and cool) based on a solid oxide fuel cell (SOFC) system integrated with an absorption chiller for special applications such as hotels, resorts, hospitals, etc...

  2. Thermodynamic Analysis of a Woodchips Gasification Integrated with Solid Oxide Fuel Cell and Stirling Engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2013-01-01

    Integrated gasification Solid Oxide Fuel Cell (SOFC) and Stirling engine for combined heat and power application is analysed. The target for electricity production is 120 kW. Woodchips are used as gasification feedstock to produce syngas which is utilized for feeding the SOFC stacks for electricity...... and suggested. Thermodynamic analysis shows that a thermal efficiency of 42.4% based on LHV (lower heating value) can be achieved. Different parameter studies are performed to analysis system behaviour under different conditions. The analysis show that increasing fuel mass flow from the design point results...

  3. Morphology Control of the Electrode for Solid Oxide Fuel Cells by Using Nanoparticles

    International Nuclear Information System (INIS)

    Fukui, Takehisa; Ohara, Satoshi; Naito, Makio; Nogi, Kiyoshi

    2001-01-01

    LSM(La(Sr)MnO 3 )/YSZ(Y 2 O 3 stabilized ZrO 2 ) composite cathode for Solid Oxide Fuel Cells (SOFCs) was fabricated by using the composite particle consisting of well-dispersed nano-size grains of LSM and YSZ. The composite cathode had a porous structure as well as uniformly dispersed fine LSM and YSZ grains. Such unique morphology of the composite cathode led high electrochemical activity at 800 deg. C. It suggests that the intermediate temperature (less than 800 o C) operation of SOFCs will be achieved by using composite particles

  4. Transient deformational properties of high temperature alloys used in solid oxide fuel cell stacks

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Kwok, Kawai; Frandsen, Henrik Lund

    2017-01-01

    Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through...... the transient behavior of Crofer 22 APU, a typical iron-chromium alloy used in SOFC stacks. The material parameters for the model are determined by measurements involving relaxation and constant strain rate experiments. The constitutive law is implemented into commercial finite element software using a user...

  5. Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

    International Nuclear Information System (INIS)

    James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

    2005-01-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

  6. Study on component interface evolution of a solid oxide fuel cell stack after long term operation

    Science.gov (United States)

    Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

    2018-05-01

    A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

  7. Aggravated test of Intermediate temperature solid oxide fuel cells fed with tar-contaminated syngas

    Science.gov (United States)

    Pumiglia, Davide; Vaccaro, Simone; Masi, Andrea; McPhail, Stephen J.; Falconieri, Mauro; Gagliardi, Serena; Della Seta, Livia; Carlini, Maurizio

    2017-02-01

    In the present work, the effects of a tar-containing simulated syngas on an IT-SOFC (Intermediate Temperature Solid Oxide Fuel Cell) are evaluated. Performance and degradation rate of a planar anode-supported cell, operating under a simulated syngas obtained from steam-enriched air gasification of biomass, have been studied. The simulated syngas was contaminated using toluene as a model tar. Polarization curves and electrochemical impedance spectroscopy have been carried out under different toluene concentrations. A cell was then operated under a constant current density on a long run. EIS measurements were made during the operation to analyze the degradation, and the voltage evolution of the cell was compared to that obtained from another identical cell operated in clean syngas for 1000 h under similar conditions. A deep post-mortem characterization was performed by means of XRD measurements, Raman spectroscopy and SEM/EDS analysis. Results show that the presence of tar dramatically reduces the electrochemical performances of the cell, affecting both activation and mass transport processes. Post-mortem analysis shows the formation of carbon deposits, oxidation of Ni to NiO, segregation of ZrO2 from the YSZ phase, particle coarsening and enhanced fragility of the anode structure, in good agreement with what suggested from the electrochemical results.

  8. Cytotoxicity of municipal solid waste incinerator ash wastes toward mammalian kidney cell lines.

    Science.gov (United States)

    Huang, Wu-Jang; Tsai, Jia-Lin; Liao, Ming-Huei

    2008-05-01

    In this study, three municipal solid waste incinerator (MSWI) ash wastes-bottom ash, scrubber residue, and baghouse ash-were extracted using a toxicity characteristic leaching procedure (TCLP) extractant. These so-called final TCLP extracts were applied to African green monkey kidney cells (Vero), baby hamster kidney cells (BHK-21), and pig kidney cells (PK-15), multi-well absorption reader analysis was performed to test how the cytotoxicity of the incineration ashes would affect the digestive systems of animals. Ion-coupled plasma analyses indicated that the baghouse ash extract possessed the highest pH and heavy metal concentration, its cytotoxicity was also the highest. In contrast, the bottom ash and the scrubber residue exhibited very low cytotoxicities. The cytotoxicities of mixtures of baghouse ash and scrubber residue toward the three tested cell lines increased as the relative ratio of the baghouse ash increased, especially for the Vero cells. The slight cytotoxicity of the scrubber residue arose mainly from the presence of Cr species, whereas the high cytotoxicity of the baghouse ash resulted from its high content of heavy metals and alkali ions. In addition, it appears that the dissolved total organic carbon content of these ash wastes can reduce the cytotoxicity of ash wastes that collect in animal cells.

  9. Reimagining the Cuckoo's Nest.

    Science.gov (United States)

    Rochefort, David A

    2018-03-01

    One Flew Over the Cuckoo's Nest (1962) by Ken Kesey and The Devil in Silver (2012) by Victor LaValle are two novels that focus on mental hospitalization as a medical and social practice. Published fifty years apart, however, the books possess important differences in setting, method, and message reflecting the times that spawned them. The purpose of this paper is to examine the changing documentary and metaphorical uses of the asylum novel by comparing an iconic work in the genre with a respectful, but divergent, successor. What emerges from this comparison is an appreciation of the literary conventions shared by Kesey and LaValle but also the ingredients that separate their work. Whereas Kesey produced an enduring tribute to the virtue of nonconformity, LaValle's social criticism expresses itself as a disturbing portrayal of class-based disparities and administrative dysfunction inside the contemporary American mental health system.

  10. Study on Zinc Oxide-Based Electrolytes in Low-Temperature Solid Oxide Fuel Cells.

    Science.gov (United States)

    Xia, Chen; Qiao, Zheng; Feng, Chu; Kim, Jung-Sik; Wang, Baoyuan; Zhu, Bin

    2017-12-28

    Semiconducting-ionic conductors have been recently described as excellent electrolyte membranes for low-temperature operation solid oxide fuel cells (LT-SOFCs). In the present work, two new functional materials based on zinc oxide (ZnO)-a legacy material in semiconductors but exceptionally novel to solid state ionics-are developed as membranes in SOFCs for the first time. The proposed ZnO and ZnO-LCP (La/Pr doped CeO₂) electrolytes are respectively sandwiched between two Ni 0.8 Co 0.15 Al 0.05 Li-oxide (NCAL) electrodes to construct fuel cell devices. The assembled ZnO fuel cell demonstrates encouraging power outputs of 158-482 mW cm -2 and high open circuit voltages (OCVs) of 1-1.06 V at 450-550 °C, while the ZnO-LCP cell delivers significantly enhanced performance with maximum power density of 864 mW cm -2 and OCV of 1.07 V at 550 °C. The conductive properties of the materials are investigated. As a consequence, the ZnO electrolyte and ZnO-LCP composite exhibit extraordinary ionic conductivities of 0.09 and 0.156 S cm -1 at 550 °C, respectively, and the proton conductive behavior of ZnO is verified. Furthermore, performance enhancement of the ZnO-LCP cell is studied by electrochemical impedance spectroscopy (EIS), which is found to be as a result of the significantly reduced grain boundary and electrode polarization resistances. These findings indicate that ZnO is a highly promising alternative semiconducting-ionic membrane to replace the electrolyte materials for advanced LT-SOFCs, which in turn provides a new strategic pathway for the future development of electrolytes.

  11. Solid Lipid Curcumin Particles Induce More DNA Fragmentation and Cell Death in Cultured Human Glioblastoma Cells than Does Natural Curcumin

    Directory of Open Access Journals (Sweden)

    Panchanan Maiti

    2017-01-01

    Full Text Available Despite recent advancements in cancer therapies, glioblastoma multiforme (GBM remains largely incurable. Curcumin (Cur, a natural polyphenol, has potent anticancer effects against several malignancies, including metastatic brain tumors. However, its limited bioavailability reduces its efficiency for treating GBM. Recently, we have shown that solid lipid Cur particles (SLCPs have greater bioavailability and brain tissue penetration. The present study compares the efficiency of cell death by Cur and/or SLCPs in cultured GBM cells derived from human (U-87MG and mouse (GL261 tissues. Several cell viability and cell death assays and marker proteins (MTT assay, annexin-V staining, TUNEL staining, comet assay, DNA gel electrophoresis, and Western blot were investigated following the treatment of Cur and/or SLCP (25 μM for 24–72 h. Relative to Cur, the use of SLCP increased cell death and DNA fragmentation, produced longer DNA tails, and induced more fragmented nuclear lobes. In addition, cultured GBM cells had increased levels of caspase-3, Bax, and p53, with decreases in Bcl2, c-Myc, and both total Akt, as well as phosphorylated Akt, when SLCP, rather Cur, was used. Our in vitro work suggests that the use of SLCP may be a promising strategy for reversing or preventing GBM growth, as compared to using Cur.

  12. Thermodynamic analyses of municipal solid waste gasification plant integrated with solid oxide fuel cell and Stirling hybrid system

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2015-01-01

    the plant efficiency in terms of operating conditions. Compared with modern waste incinerators with heat recovery, the gasification process integrated with SOFC and Stirling engine permits an increase in electricity output up of 50%, which means that the solid waste gasification process can compete...

  13. Regenerative Performance of the NASA Symmetrical Solid Oxide Fuel Cell Design

    Science.gov (United States)

    Cable, Thomas L.; Setlock, John A.; Farmer, Serene C.; Eckel, Andy J.

    2009-01-01

    The NASA Glenn Research Center is developing both a novel cell design (BSC) and a novel ceramic fabrication technique to produce fuel cells predicted to exceed a specific power density of 1.0 kW/kg. The NASA Glenn cell design has taken a completely different approach among planar designs by removing the metal interconnect and returning to the use of a thin, doped LaCrO3 interconnect. The cell is structurally symmetrical. Both electrodes support the thin electrolyte and contain micro-channels for gas flow-- a geometry referred to as a bi-electrode supported cell or BSC. The cell characteristics have been demonstrated under both SOFC and SOE conditions. Electrolysis tests verify that this cell design operates at very high electrochemical voltage efficiencies (EVE) and high H2O conversion percentages, even at the low flow rates predicted for closed loop systems encountered in unmanned aerial vehicle (UAV) applications. For UAVs the volume, weight and the efficiency are critical as they determine the size of the water tank, the solar panel size, and other system requirements. For UAVs, regenerative solid oxide fuel cell stacks (RSOFC) use solar panels during daylight to generate power for electrolysis and then operate in fuel cell mode during the night to power the UAV and electronics. Recent studies, performed by NASA for a more electric commercial aircraft, evaluated SOFCs for auxiliary power units (APUs). System studies were also conducted for regenerative RSOFC systems. One common requirement for aerospace SOFCs and RSOFCs, determined independently in each application study, was the need for high specific power density and volume density, on the order of 1.0 kW/kg and greater than 1.0 kW/L. Until recently the best reported performance for SOFCs was 0.2 kW/kg or less for stacks. NASA Glenn is working to prototype the light weight, low volume BSC design for such high specific power aerospace applications.

  14. In situ TEM analysis of a symmetric solid oxide cell in oxygen and vacuum–cation diffusion observations

    DEFF Research Database (Denmark)

    Gualandris, Fabrizio; Simonsen, Søren Bredmose; Wagner, Jakob Birkedal

    2017-01-01

    In order to establish the use of solid oxide fuel/electrolysis cells (SOFC/SOEC) in the energy market, a deeper understanding of degradation effects during operation is necessary. This study apply in situ transmission electron microscopy (TEM) of a symmetric model cell composed by two oxygen...... between LSC and STN. Strontium depletion is observed in both electrodes. Finally, a faster grain growth occurs in LSC for the cell exposed to oxygen in comparison with the cell in vacuum....

  15. NiF2/NaF:CaF2/Ca Solid-State High-Temperature Battery Cells

    Science.gov (United States)

    West, William; Whitacre, Jay; DelCastillo, Linda

    2009-01-01

    Experiments and theoretical study have demonstrated the promise of all-solid-state, high-temperature electrochemical battery cells based on NiF2 as the active cathode material, CaF2 doped with NaF as the electrolyte material, and Ca as the active anode material. These and other all-solid-state cells have been investigated in a continuing effort to develop batteries for instruments that must operate in environments much hotter than can be withstood by ordinary commercially available batteries. Batteries of this type are needed for exploration of Venus (where the mean surface temperature is about 450 C), and could be used on Earth for such applications as measuring physical and chemical conditions in geothermal wells and oil wells. All-solid-state high-temperature power cells are sought as alternatives to other high-temperature power cells based, variously, on molten anodes and cathodes or molten eutectic salt electrolytes. Among the all-solid-state predecessors of the present NiF2/NaF:CaF2/Ca cells are those described in "Solid-State High-Temperature Power Cells" (NPO-44396), NASA Tech Briefs, Vol. 32, No. 5 (May 2008), page 40. In those cells, the active cathode material is FeS2, the electrolyte material is a crystalline solid solution of equimolar amounts of Li3PO4 and LiSiO4, and the active anode material is Li contained within an alloy that remains solid in the intended high operational temperature range.

  16. Cooperative TRAIL production mediates IFNα/Smac mimetic-induced cell death in TNFα-resistant solid cancer cells.

    Science.gov (United States)

    Roesler, Stefanie; Eckhardt, Ines; Wolf, Sebastian; Fulda, Simone

    2016-01-26

    Smac mimetics antagonize IAP proteins, which are highly expressed in several cancers. Recent reports indicate that Smac mimetics trigger a broad cytokine response and synergize with immune modulators to induce cell death. Here, we identify a differential requirement of TRAIL or TNFα as mediators of IFNα/Smac mimetic-induced cell death depending on the cellular context. Subtoxic concentrations of Smac mimetics cooperate with IFNα to induce cell death in various solid tumor cell lines in a highly synergistic manner as determined by combination index. Mechanistic studies show that IFNα/BV6 cotreatment promotes the formation of a caspase-8-activating complex together with the adaptor protein FADD and RIP1. Assembly of this RIP1/FADD/caspase-8 complex represents a critical event, since RIP1 silencing inhibits IFNα/BV6-induced cell death. Strikingly, pharmacological inhibition of paracrine/autocrine TNFα signaling by the TNFα scavenger Enbrel rescues HT-29 colon carcinoma cells, but not A172 glioblastoma cells from IFNα/BV6-induced cell death. By comparison, A172 cells are significantly protected against IFNα/BV6 treatment by blockage of TRAIL signaling through genetic silencing of TRAIL or its cognate receptor TRAIL receptor 2 (DR5). Despite this differential requirement of TNFα and TRAIL signaling, mRNA and protein expression is increased by IFNα/BV6 cotreatment in both cell lines. Interestingly, A172 cells turn out to be resistant to exogenously added recombinant TNFα even in the presence of BV6, whereas they display a high sensitivity towards TRAIL/BV6. In contrast, BV6 efficiently sensitizes HT-29 cells to TNFα while TRAIL only had limited efficacy. This demonstrates that a differential sensitivity towards TRAIL or TNFα determines the dependency on either death receptor ligand for IFNα/Smac mimetic-induced cell death. Thus, by concomitant stimulation of both death receptor systems IFNα/Smac mimetic combination treatment is an effective strategy to

  17. Method of Fabrication of High Power Density Solid Oxide Fuel Cells

    Science.gov (United States)

    Pham, Ai Quoc; Glass, Robert S.

    2008-09-09

    A method for producing ultra-high power density solid oxide fuel cells (SOFCs). The method involves the formation of a multilayer structure cells wherein a buffer layer of doped-ceria is deposited intermediate a zirconia electrolyte and a cobalt iron based electrode using a colloidal spray deposition (CSD) technique. For example, a cobalt iron based cathode composed of (La,Sr)(Co,Fe)O(LSCF) may be deposited on a zirconia electrolyte via a buffer layer of doped-ceria deposited by the CSD technique. The thus formed SOFC have a power density of 1400 mW/cm.sup.2 at 600.degree. C. and 900 mW/cm.sup.2 at 700.degree. C. which constitutes a 2-3 times increased in power density over conventionally produced SOFCs.

  18. A Review of RedOx Cycling of Solid Oxide Fuel Cells Anode

    Science.gov (United States)

    Faes, Antonin; Hessler-Wyser, Aïcha; Zryd, Amédée; Van Herle, Jan

    2012-01-01

    Solid oxide fuel cells are able to convert fuels, including hydrocarbons, to electricity with an unbeatable efficiency even for small systems. One of the main limitations for long-term utilization is the reduction-oxidation cycling (RedOx cycles) of the nickel-based anodes. This paper will review the effects and parameters influencing RedOx cycles of the Ni-ceramic anode. Second, solutions for RedOx instability are reviewed in the patent and open scientific literature. The solutions are described from the point of view of the system, stack design, cell design, new materials and microstructure optimization. Finally, a brief synthesis on RedOx cycling of Ni-based anode supports for standard and optimized microstructures is depicted. PMID:24958298

  19. Modelling and control of solid oxide fuel cell generation system in microgrid

    Science.gov (United States)

    Zhou, Niancheng; Li, Chunyan; Sun, Fangqing; Wang, Qianggang

    2017-11-01

    Compared with other kinds of fuel cells, solid oxide fuel cell (SOFC) has been widely used in microgrids because of its higher efficiency and longer operation life. The weakness of SOFC lies in its slow response speed when grid disturbance occurs. This paper presents a control strategy that can promote the response speed and limit the fault current impulse for SOFC systems integrated into microgrids. First, the hysteretic control of the bidirectional DC-DC converter, which joins the SOFC and DC bus together, is explored. In addition, an improved droop control with limited current protection is applied in the DC-AC inverter, and the active synchronization control is applied to ensure a smooth transition of the microgrid between the grid-connected mode and the islanded mode. To validate the effectiveness of this control strategy, the control model was built and simulated in PSCAD/EMTDC.

  20. Recombination barrier layers in solid-state quantum dot-sensitized solar cells

    KAUST Repository

    Roelofs, Katherine E.

    2012-06-01

    By replacing the dye in the dye-sensitized solar cell design with semiconductor quantum dots as the light-absorbing material, solid-state quantum dot-sensitized solar cells (ss-QDSSCs) were fabricated. Cadmium sulfide quantum dots (QDs) were grown in situ by successive ion layer adsorption and reaction (SILAR). Aluminum oxide recombination barrier layers were deposited by atomic layer deposition (ALD) at the TiO2/hole-conductor interface. For low numbers of ALD cycles, the Al2O3 barrier layer increased open circuit voltage, causing an increase in device efficiency. For thicker Al2O3 barrier layers, photocurrent decreased substantially, leading to a decrease in device efficiency. © 2012 IEEE.

  1. Development of a solid oxide fuel cell (SOFC) automotive auxiliary power unit (APU) fueled by gasoline

    International Nuclear Information System (INIS)

    DeMinco, C.; Mukerjee, S.; Grieve, J.; Faville, M.; Noetzel, J.; Perry, M.; Horvath, A.; Prediger, D.; Pastula, M.; Boersma, R.; Ghosh, D.

    2000-01-01

    This paper describes the design and the development progress of a 3 to 5 auxiliary power unit (APU) based on a gasoline fueled solid oxide fuel cell (SOFC). This fuel cell was supplied reformate gas (reactant) by a partial oxidation (POx) catalytic reformer utilizing liquid gasoline and designed by Delphi Automotive Systems. This reformate gas consists mainly of hydrogen, carbon monoxide and nitrogen and was fed directly in to the SOFC stack without any additional fuel reformer processing. The SOFC stack was developed by Global Thermoelectric and operates around 700 o C. This automotive APU produces power to support future 42 volt vehicle electrical architectures and loads. The balance of the APU, designed by Delphi Automotive Systems, employs a packaging and insulation design to facilitate installation and operation on-board automobiles. (author)

  2. Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis.

    Science.gov (United States)

    Boldrin, Paul; Ruiz-Trejo, Enrique; Mermelstein, Joshua; Bermúdez Menéndez, José Miguel; Ramı Rez Reina, Tomás; Brandon, Nigel P

    2016-11-23

    Solid oxide fuel cells (SOFCs) are a rapidly emerging energy technology for a low carbon world, providing high efficiency, potential to use carbonaceous fuels, and compatibility with carbon capture and storage. However, current state-of-the-art materials have low tolerance to sulfur, a common contaminant of many fuels, and are vulnerable to deactivation due to carbon deposition when using carbon-containing compounds. In this review, we first study the theoretical basis behind carbon and sulfur poisoning, before examining the strategies toward carbon and sulfur tolerance used so far in the SOFC literature. We then study the more extensive relevant heterogeneous catalysis literature for strategies and materials which could be incorporated into carbon and sulfur tolerant fuel cells.

  3. Transport phenomena in solid oxide fuel cell electrodes focusing on heat transfer related to chemical reactions

    International Nuclear Information System (INIS)

    Navasa, M; Andersson, M; Yuan, J; Sundén, B

    2012-01-01

    Solid oxide fuel cells (SOFCs) are widely studied for their advantages especially at high temperatures. However, operating at high temperatures represents a high cost due to the strict requirements the materials are expected to fulfill. Thus, the main goal in SOFC research has been to decrease the operating temperature so that the range of available materials is widened and hence, the operating cost can be reduced. In this paper, the different heat sources that contribute to the cell energy balance are presented with strong emphasis on the chemical reactions that take place in SOFCs. The knowledge of which heat sources or sinks taking place and their locations within the SOFC can provide useful information for further design and efficiency improvements.

  4. Addressing fuel recycling in solid oxide fuel cell systems fed by alternative fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2017-01-01

    %. Furthermore, it is founded that for the case with methanol, ethanol and DME then at high utilization factors, low anode recirculation is recommended while at low utilization factors, high anode recirculation is recommended. If the plant is fed by biogas from biomass gasification then for each utilization......An innovative study on anode recirculation in solid oxide fuel cell systems with alternative fuels is carried out and investigated. Alternative fuels under study are ammonia, pure hydrogen, methanol, ethanol, DME and biogas from biomass gasification. It is shown that the amount of anode off......-fuel recirculation depends strongly on type of the fuel used in the system. Anode recycling combined with fuel cell utilization factors have an important impact on plant efficiency, which will be analysed here. The current study may provide an in-depth understanding of reasons for using anode off-fuel recycling...

  5. System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles

    Science.gov (United States)

    Burke, A. Alan; Carreiro, Louis G.

    To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants. A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5 kW for 40 h. Heat sources and sinks have been coupled to show viable means of thermal management. The critical design issues involve proper recycling of exhaust steam from the fuel cell back into the reformer and effective use of the SOFC stack radiant heat for steam reformation of the hydrocarbon fuel.

  6. Performance of a novel type of electrolyte-supported solid oxide fuel cell with honeycomb structure

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Juan Carlos; Savvin, Stanislav N.; Nunez, Pedro [Departmento de Quimica Inorganica, Universidad de La Laguna, 38200 Tenerife (Spain); Marrero-Lopez, David [Departamento de Fisica Aplicada I, Universidad de Malaga, 29071 Malaga (Spain); Pena-Martinez, Juan; Canales-Vazquez, Jesus [Instituto de Energias Renovables-Universidad de Castilla la Mancha, 02006 Albacete (Spain); Roa, Joan Josep; Segarra, Merce [DIOPMA, Departamento de Ciencia de los Materiales e Ing. Metalurgica, 08028 Barcelona (Spain)

    2010-01-15

    A novel design, alternative to the conventional electrolyte-supported solid oxide fuel cell (SOFC) is presented. In this new design, a honeycomb-electrolyte is fabricated from hexagonal cells, providing high mechanical strength to the whole structure and supporting the thin layer used as electrolyte of a SOFC. This new design allows a reduction of {proportional_to}70% of the electrolyte material and it renders modest performances over 320 mW cm{sup -2} but high volumetric power densities, i.e. 1.22 W cm{sup -3} under pure CH{sub 4} at 900 C, with a high OCV of 1.13 V, using the standard Ni-YSZ cermet as anode, Pt as cathode material and air as the oxidant gas. (author)

  7. A Review of RedOx Cycling of Solid Oxide Fuel Cells Anode

    Directory of Open Access Journals (Sweden)

    Jan Van herle

    2012-08-01

    Full Text Available Solid oxide fuel cells are able to convert fuels, including hydrocarbons, to electricity with an unbeatable efficiency even for small systems. One of the main limitations for long-term utilization is the reduction-oxidation cycling (RedOx cycles of the nickel-based anodes. This paper will review the effects and parameters influencing RedOx cycles of the Ni-ceramic anode. Second, solutions for RedOx instability are reviewed in the patent and open scientific literature. The solutions are described from the point of view of the system, stack design, cell design, new materials and microstructure optimization. Finally, a brief synthesis on RedOx cycling of Ni-based anode supports for standard and optimized microstructures is depicted.

  8. A unique nest-protection strategy in a new species of spider wasp.

    Directory of Open Access Journals (Sweden)

    Michael Staab

    Full Text Available Hymenoptera show a great variation in reproductive potential and nesting behavior, from thousands of eggs in sawflies to just a dozen in nest-provisioning wasps. Reduction in reproductive potential in evolutionary derived Hymenoptera is often facilitated by advanced behavioral mechanisms and nesting strategies. Here we describe a surprising nesting behavior that was previously unknown in the entire animal kingdom: the use of a vestibular cell filled with dead ants in a new spider wasp (Hymenoptera: Pompilidae species collected with trap nests in South-East China. We scientifically describe the 'Bone-house Wasp' as Deuteragenia ossarium sp. nov., named after graveyard bone-houses or ossuaries. We show that D. ossarium nests are less vulnerable to natural enemies than nests of other sympatric trap-nesting wasps, suggesting an effective nest protection strategy, most likely by utilizing chemical cues emanating from the dead ants.

  9. Degradation of solid oxide fuel cell metallic interconnects in fuels containing sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Ziomek-Moroz, M.; Hawk, Jeffrey A.

    2005-01-01

    Hydrogen is the main fuel for all types of fuel cells except direct methanol fuel cells. Hydrogen can be generated from all manner of fossil fuels, including coal, natural gas, diesel, gasoline, other hydrocarbons, and oxygenates (e.g., methanol, ethanol, butanol, etc.). Impurities in the fuel can cause significant performance problems and sulfur, in particular, can decrease the cell performance of fuel cells, including solid oxide fuel cells (SOFC). In the SOFC, the high (800-1000°C) operating temperature yields advantages (e.g., internal fuel reforming) and disadvantages (e.g., material selection and degradation problems). Significant progress in reducing the operating temperature of the SOFC from ~1000 ºC to ~750 ºC may allow less expensive metallic materials to be used for interconnects and as balance of plant (BOP) materials. This paper provides insight on the material performance of nickel, ferritic steels, and nickel-based alloys in fuels containing sulfur, primarily in the form of H2S, and seeks to quantify the extent of possible degradation due to sulfur in the gas stream.

  10. Planar solid oxide fuel cell with staged indirect-internal air and fuel preheating and reformation

    Science.gov (United States)

    Geisbrecht, Rodney A; Williams, Mark C

    2003-10-21

    A solid oxide fuel cell arrangement and method of use that provides internal preheating of both fuel and air in order to maintain the optimum operating temperature for the production of energy. The internal preheat passes are created by the addition of two plates, one on either side of the bipolar plate, such that these plates create additional passes through the fuel cell. This internal preheat fuel cell configuration and method reduce the requirements for external heat exchanger units and air compressors. Air or fuel may be added to the fuel cell as required to maintain the optimum operating temperature through a cathode control valve or an anode control valve, respectively. A control loop comprises a temperature sensing means within the preheat air and fuel passes, a means to compare the measured temperature to a set point temperature and a determination based on the comparison as to whether the control valves should allow additional air or fuel into the preheat or bypass manifolds of the fuel cell.

  11. A high-performance cathode for the next generation of solid-oxide fuel cells

    Science.gov (United States)

    Shao, Zongping; Haile, Sossina M.

    2004-09-01

    Fuel cells directly and efficiently convert chemical energy to electrical energy. Of the various fuel cell types, solid-oxide fuel cells (SOFCs) combine the benefits of environmentally benign power generation with fuel flexibility. However, the necessity for high operating temperatures (800-1,000°C) has resulted in high costs and materials compatibility challenges. As a consequence, significant effort has been devoted to the development of intermediate-temperature (500-700°C) SOFCs. A key obstacle to reduced-temperature operation of SOFCs is the poor activity of traditional cathode materials for electrochemical reduction of oxygen in this temperature regime. Here we present Ba0.5Sr0.5Co0.8Fe0.2O3-δ(BSCF) as a new cathode material for reduced-temperature SOFC operation. BSCF, incorporated into a thin-film doped ceria fuel cell, exhibits high power densities (1,010mWcm-2 and 402mWcm-2 at 600°C and 500°C, respectively) when operated with humidified hydrogen as the fuel and air as the cathode gas. We further demonstrate that BSCF is ideally suited to `single-chamber' fuel-cell operation, where anode and cathode reactions take place within the same physical chamber. The high power output of BSCF cathodes results from the high rate of oxygen diffusion through the material. By enabling operation at reduced temperatures, BSCF cathodes may result in widespread practical implementation of SOFCs.

  12. Demonstration of high efficiency intermediate-temperature solid oxide fuel cell based on lanthanum gallate electrolyte

    International Nuclear Information System (INIS)

    Inagaki, Toru; Nishiwaki, Futoshi; Kanou, Jirou; Yamasaki, Satoru; Hosoi, Kei; Miyazawa, Takashi; Yamada, Masaharu; Komada, Norikazu

    2006-01-01

    The Kansai Electric Power Co., Inc. (KEPCO) and Mitsubishi Materials Corporation (MMC) have been jointly developing intermediate-temperature solid oxide fuel cells (SOFCs). The operation temperatures between 600 and 800 o C were set as the target, which enable SOFC to use less expensive metallic separators for cell-stacking and to carry out internal reforming of hydrocarbon fuels. The electrolyte-supported planar-type cells were fabricated using highly conductive lanthanum gallate-based electrolyte, La(Sr)Ga(Mg,Co)O 3-δ , Ni-(CeO 2 ) 1-x (SmO 1.5 ) x cermet anode, and Sm(Sr)CoO 3-δ cathode. The 1 kW-class power generation modules were fabricated using a seal-less stack of the cells and metallic separators. The 1 kW-class prototype power generation system with the module was developed with the high performance cell, which showed the thermally self-sustainability. The system included an SOFC module, a dc-ac inverter, a desulfurizer, and a heat recovery unit. It provided stable ac power output of 1 kW with the electrical efficiency of 45% LHV based on ac output by using city gas as a fuel, which was considered to be excellent for such a small power generation system. And the hot water of 90 o C was obtained using high temperature off-gas from SOFC

  13. Analysis and design of solid oxide fuel cell for railroad applications

    Science.gov (United States)

    Kothapally, Adarsh Srivatsav

    Solid oxide fuel cell (SOFC) is a direct chemical-to-electrical energy conversion system using hydrogen and oxygen as reactants, operating at a higher temperature range (800°--1100° C). With the advantages of low-cost materials for anode, cathode, membrane, and the versatility in the use of various types of fuels as compared to other fuel cell types, the SOFC is one of the most recommendable fuel cells for large power generating system. An additional distinct advantage is of using the hot exhaust by-product gases to generate electricity in an advance combined power generation system along with a gas turbine. The objective of the present work is to analyze a tri-layer SOFC using a two-dimensional simulation model. This work was concerned with the evaluation of different fuel cell losses, heat generation, and determining the performance polarization of the SOFC using in-house computer code. The operation characteristics were evaluated with a wide spectrum of cell parameters and operating conditions. Further, a 1-MW SOFC is designed for a locomotive engine based on the selected operating characteristics and using the state-of-the-art SOFC materials.

  14. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Zueqian [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  15. A complete carbon counter electrode for high performance quasi solid state dye sensitized solar cell

    Science.gov (United States)

    Arbab, Alvira Ayoub; Peerzada, Mazhar Hussain; Sahito, Iftikhar Ali; Jeong, Sung Hoon

    2017-03-01

    The proposed research describes the design and fabrication of a quasi-solid state dye sensitized solar cells (Q-DSSCs) with a complete carbon based counter electrode (CC-CE) and gel infused membrane electrolyte. For CE, the platinized fluorinated tin oxide glass (Pt/FTO) was replaced by the soft cationic functioned multiwall carbon nanotubes (SCF-MWCNT) catalytic layer coated on woven carbon fiber fabric (CFF) prepared on handloom by interlacing of carbon filament tapes. SCF-MWCNT were synthesized by functionalization of cationised lipase from Candida Ragusa. Cationised enzyme solution was prepared at pH ∼3 by using acetic acid. The cationic enzyme functionalization of MWCNT causes the minimum damage to the tubular morphology and assist in fast anchoring of negative iodide ions present in membrane electrolyte. The high electrocatalytic activity and low charge transfer resistance (RCT = 2.12 Ω) of our proposed system of CC-CE shows that the woven CFF coated with cationised lipase treated carbon nanotubes enriched with positive surface ions. The Q-DSSCs fabricated with CC-CE and 5 wt% PEO gel infused PVDF-HFP membrane electrolyte exhibit power conversion efficiency of 8.90% under masking. Our suggested low cost and highly efficient system of CC-CE helps the proposed quasi-solid state DSSCs structure to stand out as sustainable next generation solar cells.

  16. Cell viability of mycorrhiza helper bacteria solid inoculant in different carrier material

    Science.gov (United States)

    Asyiah, Iis Nur; Hindersah, Reginawanti; Harni, Rita

    2018-02-01

    Roots of food crops are colonized by nonpathogenic mycorrhizal fungi which show natural ability to control plant pathogen. Mycorrhizal establishment in plant roots is affected by rhizobacteria, known as mycorrhiza helper bacteria (MHB), which has synergetic effects on mycorrhizal associations. Laboratory experiment has been conducted to assess the best carrier material to develop well-qualified MHB of Pseudomonas diminuta and Bacillus subtilis solid inoculant. Carrier materials were 100 mesh organic matter of agricultural waste. Different spore concentration of both bacterial liquid inoculants were grown on three kinds of 100-mesh organic matter and stored at room temperature up to 90 days. Cell viability of both MHB were counted by serial dilution plate method by using specific medium. The results showed that sugar cane baggase ash was the best carrier material to maintain cell viability for both MHB. However, the population of Pseudomonas diminuta and Bacillus subtilis in sugar cane baggase ash were slightly decreased after 90 days. The use of sugarcane baggase ash for solid MHB inoculant development could be suggested.

  17. Modeling of thermal expansion coefficient of perovskite oxide for solid oxide fuel cell cathode

    Science.gov (United States)

    Heydari, F.; Maghsoudipour, A.; Alizadeh, M.; Khakpour, Z.; Javaheri, M.

    2015-09-01

    Artificial intelligence models have the capacity to eliminate the need for expensive experimental investigation in various areas of manufacturing processes, including the material science. This study investigates the applicability of adaptive neuro-fuzzy inference system (ANFIS) approach for modeling the performance parameters of thermal expansion coefficient (TEC) of perovskite oxide for solid oxide fuel cell cathode. Oxides (Ln = La, Nd, Sm and M = Fe, Ni, Mn) have been prepared and characterized to study the influence of the different cations on TEC. Experimental results have shown TEC decreases favorably with substitution of Nd3+ and Mn3+ ions in the lattice. Structural parameters of compounds have been determined by X-ray diffraction, and field emission scanning electron microscopy has been used for the morphological study. Comparison results indicated that the ANFIS technique could be employed successfully in modeling thermal expansion coefficient of perovskite oxide for solid oxide fuel cell cathode, and considerable savings in terms of cost and time could be obtained by using ANFIS technique.

  18. Reversible solid oxide fuel cell for natural gas/renewable hybrid power generation systems

    Science.gov (United States)

    Luo, Yu; Shi, Yixiang; Zheng, Yi; Cai, Ningsheng

    2017-02-01

    Renewable energy (RE) is expected to be the major part of the future energy. Presently, the intermittence and fluctuation of RE lead to the limitation of its penetration. Reversible solid oxide fuel cell (RSOFC) as the energy storage device can effectively store the renewable energy and build a bidirectional connection with natural gas (NG). In this paper, the energy storage strategy was designed to improve the RE penetration and dynamic operation stability in a distributed system coupling wind generators, internal combustion engine, RSOFC and lithium-ion batteries. By compromising the relative deviation of power supply and demand, RE penetration, system efficiency and capacity requirement, the strategy that no more than 36% of the maximum wind power output is directly supplied to users and the other is stored by the combination of battery and reversible solid oxide fuel cell is optimal for the distributed system. In the case, the RE penetration reached 56.9% and the system efficiency reached 55.2%. The maximum relative deviation of power supply and demand is also lower than 4%, which is significantly superior to that in the wind curtailment case.

  19. Electrospun polymethylacrylate nanofibers membranes for quasi-solid-state dye sensitized solar cells

    Directory of Open Access Journals (Sweden)

    M. Fathy

    2016-06-01

    Full Text Available Polymethylacrylate (PMA nanofibers membranes are fabricated by electrospinning technique and applied to the polymer matrix in quasi-solid-state electrolytes for dye sensitized solar cells (DSSCs. There is no previous studies reporting the production of PMA nanofibers. The electrospinning parameters such as polymer concentration, applied voltage, feed rate, tip to collector distance and solvent were optimized. Electrospun PMA fibrous membrane with average fiber diameter of 350 nm was prepared from a 10 wt% solution of PMA in a mixture of acetone/N,N-dimethylacetamide (6:4 v/v at an applied voltage of 20 kV. It was then activated by immersing it in 0.5 M LiI, 0.05 M I2, and 0.5 M 4-tert-butylpyridine in 3-methoxyproponitrile to obtain the corresponding membrane electrolyte with an ionic conductivity of 2.4 × 10−3 S cm−1 at 25 °C. Dye sensitized solar cells (DSSCs employing the quasi solid-state electrolyte have an open-circuit voltage (Voc of 0.65 V and a short circuit current (Jsc of 6.5 mA cm−2 and photoelectric energy conversion efficiency (η of 1.4% at an incident light intensity of 100 mW cm−2.

  20. The influence of nest-site characteristics on the nesting success of ...

    African Journals Online (AJOL)

    Choice of nest site has important consequences for nest survival. We examined nest-site characteristics relative to nest success in Karoo Prinias breeding in coastal dwarf shrubland, where high nest predation is the main cause of nest failure. Initially, we compared nests that failed during the building, laying, incubation and ...

  1. On the Properties and Long-Term Stability of Infiltrated Lanthanum Cobalt Nickelates (LCN) in Solid Oxide Fuel Cell Cathodes

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Zielke, Philipp; Veltzé, Sune

    2017-01-01

    Infiltration as a fabrication method for solid oxide fuel cells (SOFC) electrodes is offering significant improvements in cell performance at reduced materials and fabrication costs, especially when combined with co-sintering. However, important questions regarding the long-term performance and m...

  2. Recent progress in all-solid-state quantum dot-sensitized TiO{sub 2} nanotube array solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qingyao, E-mail: wangqingyao0532@163.com [Ludong University, School of Chemistry and Materials Science (China); Chen, Chao; Liu, Wei [Tongji University, School of Materials Science and Engineering (China); Gao, Shanmin [Ludong University, School of Chemistry and Materials Science (China); Yang, Xiuchun, E-mail: yangxc@tongji.edu.cn [Tongji University, School of Materials Science and Engineering (China)

    2016-01-15

    All-solid-state quantum dot-sensitized TiO{sub 2} nanotube array solar cells have been drawing great attention to solar energy conversion, which break through restrictions in traditional solar cells, such as the high recombination at interfaces of porous TiO{sub 2} films/sensitizers/hole conductors/counter electrodes, instability of dyes, and leakage of solution electrolyte, and so the novel solar cells exhibit promising applications in the future. In this Minireview article, the assembling of solar cells including the preparation of TiO{sub 2} nanotube array photoanodes, quantum dot preparation and sensitization on photoanodes, filling of hole conductors in TiO{sub 2} nanotubes, and selection of counter electrodes are overviewed, and the development course of all-solid-state quantum dot-sensitized TiO{sub 2} nanotube array solar cells in recent years are summarized in detail. Moreover, the influences of TiO{sub 2} nanotube array photoanodes, quantum dots, solid electrolyte, and counter electrodes on photon-to-current efficiencies of solar cells are summarized. In addition, current problems of solid-state quantum dot-sensitized TiO{sub 2} nanotube array solar cells are analyzed, and the corresponding improvements, such as multisensitizers and passivation layers, are proposed to improve the photoelectric conversion efficiency. Finally, this Minireview provides a perspective for the future development of this novel solar cell.

  3. High-temperature, Knudsen cell-mass spectroscopic studies on lanthanum oxide/uranium dioxide solid solutions

    International Nuclear Information System (INIS)

    Sunder, S.; McEachern, R.; LeBlanc, J.C.

    2001-01-01

    Knudsen cell-mass spectroscopic experiments were carried out with lanthanum oxide/uranium oxide solid solutions (1%, 2% and 5% (metal at.% basis)) to assess the volatilization characteristics of rare earths present in irradiated nuclear fuel. The oxidation state of each sample used was conditioned to the 'uranium dioxide stage' by heating in the Knudsen cell under an atmosphere of 10% C0 2 in CO. The mass spectra were analyzed to obtain the vapour pressures of the lanthanum and uranium species. It was found that the vapour pressure of lanthanum oxide follows Henry's law, i.e., its value is directly proportional to its concentration in the solid phase. Also, the vapour pressure of lanthanum oxide over the solid solution, after correction for its concentration in the solid phase, is similar to that of uranium dioxide. (author)

  4. High-temperature, Knudsen cell-mass spectroscopic studies on lanthanum oxide/uranium dioxide solid solutions

    International Nuclear Information System (INIS)

    Sunder, S.; McEachern, R.; LeBlanc, J.C.

    2001-01-01

    Knudsen cell-mass spectroscopic experiments were carried out with lanthanum oxide/uranium oxide solid solutions (1%, 2% and 5% (metal at.% basis)) to assess the volatilization characteristics of rare earths present in irradiated nuclear fuel. The oxidation state of each sample used was conditioned to the 'uranium dioxide stage' by heating in the Knudsen cell under an atmosphere of 10% CO 2 in CO. The mass spectra were analyzed to obtain the vapour pressures of the lanthanum and uranium species. It was found that the vapour pressure of lanthanum oxide follows Henry's law, i.e., its value is directly proportional to its concentration in the solid phase. Also, the vapour pressure of lanthanum oxide over the solid solution, after correction for its concentration in the solid phase, is similar to that of uranium dioxide. (authors)

  5. Solidification of liquid electrolyte with imidazole polymers for quasi-solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Miao; Lin Yuan; Zhou Xiaowen; Xiao Xurui; Yang Lei; Feng Shujing; Li Xueping

    2008-01-01

    Quasi-solid-state electrolytes were prepared by employing the imidazole polymers to solidify the liquid electrolyte containing lithium iodide, iodine and ethylene carbonate (EC)/propylene carbonate (PC) mixed solvent. The ionic conductivity and diffusion behavior of triiodide in the quasi-solid-state electrolytes were examined in terms of the polymer content. Application of the quasi-solid-state electrolytes to the dye-sensitized solar cells, the maximum energy conversion efficiency of 7.6% (AM 1.5, 100 mW cm -2 ) was achieved. The dependence of the photovoltaic performance on the polymer content and on the different anions of the imidazole polymers was studied by electrochemical impedance spectroscopy and cyclic voltammetry. The results indicate the charge transfer behaviors occurred at nanocrystalline TiO 2 /electrolyte and Pt/electrolyte interface play an important role in influencing the photovoltaic performance of quasi-solid-state dye-sensitized solar cells

  6. Jordan Isomorphisms on Nest Subalgebras

    Directory of Open Access Journals (Sweden)

    Aili Yang

    2015-01-01

    Full Text Available This paper is devoted to the study of Jordan isomorphisms on nest subalgebras of factor von Neumann algebras. It is shown that every Jordan isomorphism ϕ between the two nest subalgebras algMβ and algMγ is either an isomorphism or an anti-isomorphism.

  7. Simulation of tubular solid oxide fuel cell behavior for integration into gas turbine cycles

    Science.gov (United States)

    Haynes, Comas Lamar

    Models have been developed and validated for the characterization of tubular solid oxide fuel cells (TSOFCs) and a corresponding fuel cell/gas turbine (FC/GT) power cycle. This promising area of technology is expected to attain near-term commercialization (most notably the SiemensWestinghouse "SureCell" initiative). There is a need for continued conceptual design research in order for the full potential of these systems to be realized. Parametric studies were performed to delineate the impact of cell stack operating conditions on power generation, cell stack thermal management, independent cell load-following and performance quality. The diverse operating conditions included variations in physical cell design, stack pressure, operating voltage, stoichiometric number and stack fuel utilization. A number of novel findings are reported throughout the thesis. As an example, it has been shown that lowering cell stack fuel utilization has a number of benefits for both the simple TSOFC arrangement and the hybrid TSOFC/ GT scenario. The cell stack produces more power at lower fuel utilizations, because fuel supply to the stack actually increases. Additionally, fuel depletion issues (i.e., Nernst potential decrease and smaller limiting currents) are not as influential. A gas turbine bottoming engine would also increase in power production, at lower stack fuel utilizations, because a greater amount of fuel would then fire it. Note that power generation expense is measured per unit rating (e.g., $/kW). Increasing power capacity may then be a means of lowering cost, which is the key obstacle to commercialization. Another cost reduction may stein from the greater contribution of turbomachinery to system power generation, when stack fuel utilization is lowered. FC/GT system efficiency remains stable across a wide domain of cell stack fuel utilizations. This is a result of both the indirect internally reforming (IIR) fuel processor efficiency and Brayton cycle regeneration

  8. Thermal stress management of a solid oxide fuel cell using neural network predictive control

    International Nuclear Information System (INIS)

    Hajimolana, S.A.; Tonekabonimoghadam, S.M.; Hussain, M.A.; Chakrabarti, M.H.; Jayakumar, N.S.; Hashim, M.A.

    2013-01-01

    In SOFC (solid oxide fuel cell) systems operating at high temperatures, temperature fluctuation induces a thermal stress in the electrodes and electrolyte ceramics; therefore, the cell temperature distribution is recommended to be kept as constant as possible. In the present work, a mathematical model based on first principles is presented to avert such temperature fluctuations. The fuel cell running on ammonia is divided into five subsystems and factors such as mass/energy/momentum transfer, diffusion through porous media, electrochemical reactions, and polarization losses inside the subsystems are presented. Dynamic cell-tube temperature responses of the cell to step changes in conditions of the feed streams is investigated. The results of simulation indicate that the transient response of the SOFC is mainly influenced by the temperature dynamics. It is also shown that the inlet stream temperatures are associated with the highest long term start-up time (467 s) among other parameters in terms of step changes. In contrast the step change in fuel velocity has the lowest influence on the start-up time (about 190 s from initial steady state to the new steady state) among other parameters. A NNPC (neural network predictive controller) is then implemented for thermal stress management by controlling the cell tube temperature to avoid performance degradation by manipulating the temperature of the inlet air stream. The regulatory performance of the NNPC is compared with a PI (proportional–integral) controller. The performance of the control system confirms that NNPC is a non-linear-model-based strategy which can assure less oscillating control responses with shorter settling times in comparison to the PI controller. - Highlights: • Effect of the operating parameters on the fuel cell temperature is analysed. • A neural network predictive controller (NNPC) is implemented. • The performance of NNPC is compared with the PI controller. • A detailed model is used for

  9. The Nest Home

    Energy Technology Data Exchange (ETDEWEB)

    Pickerill, Heath [Missouri Univ. of Science and Technology, Rolla, MO (United States)

    2016-07-11

    The purpose of the project was to build a competitive solar-powered house for the U.S. Department of Energy Solar Decathlon 2015 held in Irvine, California. The house, named the Nest Home, was an innovative design that works with the environment to meet the needs of the occupants, identified as a growing family. Reused materials were instrumental in the design. Three refurbished shipping containers composed the primary structure of the house, creating an open floor plan that defies common architecture for container homes. The exterior siding was made of deconstructed shipping pallets collected locally. Other recycled products included carpet composed of discarded fishing nets, denim batting made of recycled blue jeans that outperform traditional fiberglass insulation in sound proofing and thermal resistance, and kitchen cabinets that were purchased used and refinished. Collectively these elements formed a well-balanced blend of modern design, comfort, and sustainability. The house was Missouri University of Science and Technology’s sixth entry in the DOE Solar Decathlon. Missouri S&T has been invited to compete in six of the seven decathlons held, more than any other university worldwide. The house was brought back to Rolla after the Decathlon in California where it has been placed in its permanent location on the S&T campus.

  10. Computer Simulations of Composite Electrodes in Solid-Oxide Fuel-Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sunde, Svein

    1999-07-01

    Fuel cells are devices for converting the combined chemical (free) energy of fuels and oxygen (air) directly to electrical energy without relying on the dynamic action of steam heated by reacting fuel-oxygen mixtures, like in steam turbines, or of the reacting gas mixtures themselves, like in gas turbines. The basic rationale for fuel cells is their high efficiencies as compared to indirect-conversion methods. Fuel cells are currently being considered for a number of applications, among them de-centralised power supply. Fuel cells come in five basic types and are usually classified according to the type of electrolyte used, which in turn to a significant degree limits the options for anode and cathode materials. The solid-oxide fuel-cell (SOFC) , with which this thesis is concerned, is thus named after its oxide electrolyte, typically the oxide-ion conducting material yttria-stabilised zirconia (YSZ). While the cathode of an SOFC is often uniform in chemical composition (or at least intended to be), various problems of delamination, cracking etc. associated with the use of metallic anode electrocatalysts led to the development of composite SOFC anodes. Porous anodes consisting of Ni and YSZ particles in roughly 50/50 wt-% mixtures are now almost standard with any SOFC-development programme. The designer of composite SOFC electrodes is faced with at least three, interrelated questions: (1) What will be the optimum microstructure and composition of the composite electrode? (2) If the structure changes during operation, as is often observed, what will be the consequences for the internal losses in the cell? (3) How do we interpret electrochemical and conductivity measurements with regard to structure and composition? It is the primary purpose of this thesis to provide a framework for modelling the electrochemical and transport properties of composite electrodes for SOFC, and to arrive at some new insights that cannot be offered by experiment alone. Emphasis is put on

  11. Mesoporous NiO-samaria doped ceria for low-temperature solid oxide fuel cells.

    Science.gov (United States)

    Kim, Jin-Yeop; Kim, Ji Hyeon; Choi, Hyung Wook; Kim, Kyung Hwan; Park, Sang Joon

    2014-08-01

    In order to prepare anode material for low-temperature solid oxide fuel cells (SOFCs), the mesoporous NiO-SDC was synthesized using a cationic surfactant (cetyltrimethyl-ammonium bromide; CTAB) for obtaining wide triple-phase boundary (TPB). In addition, Ni-SDC anode-supported SOFC single cells with YSZ electrolyte and LSM cathode were fabricated and the performance of single cells was evaluated at 600 °C. The microstructure of NiO-SDC was characterized by XRD, EDX, SEM, and BET, and the results showed that the mesoporous NiO-SDC with 10 nm pores could be obtained. It was found that the surface area and the electrical performance were strongly influenced by the Ni content in Ni-SDC cermets. After calcined at 600 °C, the surface area of NiO-SDC was between 90-117 m2/g at 35-45 Ni wt%, which was sufficiently high for providing large TPB in SOFC anode. The optimum Ni content for cell performance was around 45 wt% and the corresponding MPD was 0.36 W/cm2. Indeed, the mesoporous NiO-SDC cermet may be of interest for use as an anode for low-temperature SOFCs.

  12. Reactive co-sputter deposition of nanostructured cermet anodes for solid oxide fuel cells

    Science.gov (United States)

    Ionov, Igor V.; Solovyev, Andrey A.; Shipilova, Anna V.; Lebedynskiy, Alexey M.; Smolyanskiy, Egor A.; Lauk, Alexander L.; Semenov, Vyacheslav A.

    2018-01-01

    The impact of a nanostructured NiO/yttria-stabilized zirconia (NiO/YSZ) and NiO/gadolinia-doped ceria (NiO/GDC) anode functional layers on low- and intermediate-temperature solid oxide fuel cell (SOFC) performance is investigated. NiO/YSZ and NiO/GDC thin films were reactively sputter-deposited by pulsed direct current magnetron sputtering from the Ni, Zr–Y, and Ce–Gd targets onto commercial NiO/YSZ substrates. Anode-supported SOFCs based on magnetron sputtered YSZ and GDC electrolytes (∼4 µm) with and without the nanostructured anode layers are fabricated. A direct comparison of the YSZ- and GDC-based SOFCs in temperature range of 600–800 and 400–600 °C is made. The performance of cells with the nanostructured anode layers significantly increases as compared to that of the cell without it, especially at lower temperatures. Increase of cells performance was achieved by reduction of the total area-specific resistance by 26–30%.

  13. Development of a Novel Ceramic Support Layer for Planar Solid Oxide Cells

    DEFF Research Database (Denmark)

    Klemensø, Trine; Boccaccini, Dino; Brodersen, Karen

    2014-01-01

    properties to the conventional Ni/YSZ support were seen, and sufficient and fairly stable conductivity of LSC infiltrated 3YSZ was observed. The conductivity of 8–15 S cm–1 at 850 °C seen for over 600 h, corresponds to a serial resistance of less than 3.5 m Ω cm2 of a 300 μm thick support layer.......The conventional solid oxide cell is based on a Ni–YSZ support layer, placed on the fuel side of the cell, also known as the anode supported SOFC. An alternative design, based on a support of porous 3YSZ (3 mol.% Y2O3–doped ZrO2), placed on the oxygen electrode side of the cell, is proposed....... Electronic conductivity in the 3YSZ support is obtained post sintering by infiltrating LSC (La0.6Sr0.4Co1.05O3). The potential advantages of the proposed design is a strong cell, due to the base of a strong ceramic material (3YSZ is a partially stabilized zirconia), and that the LSC infiltration...

  14. Energy analysis of a trigeneration plant based on solid oxide fuel cell and organic Rankine cycle

    International Nuclear Information System (INIS)

    Al-Sulaiman, F.A.; Dincer, I.; Hamdullahpur, F.

    2009-01-01

    In this paper, energy analysis of a trigeneration plant based on Solid Oxide Fuel cell (SOFC) and organic Rankine cycle (ORC) is carried out. The physical and thermodynamic elements of the plant include a SOFC, ORC, a heating process and a single-effect absorption chiller. The waste heat from the SOFC is used as an input heat to the ORC. In turn, the waste heat from the ORC is used to heat the inlet water, and to provide the heat needed for the single-effect absorption chiller. The results obtained from this study show that the highest cycle efficiency that can be attained under the proposed scheme is 48% and the highest SOFC efficiency is 43%. Furthermore, it is found that the highest net work rate is 435 kW and the highest SOFC-AC work rate is 337 kW. At a current density higher than 0.87 A/cm 2 , the SOFC and cycle efficiencies drop abruptly because of the sharp increase in the voltage losses of the SOFC. At a current density of 0.75 A/cm 2 , the highest SOFC efficiency of 41% is obtained at the inlet fuel cell temperature of 890 K. The change in the inlet pressure of the turbine has insignificant effect on the efficiencies of the ORC and overall cycle. The study shows the effect of both the current density and the inlet fuel cell temperature on the cell voltage and voltage loss. (author)

  15. Thermodynamic simulation of biomass gas steam reforming for a solid oxide fuel cell (SOFC system

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-12-01

    Full Text Available This paper presents a methodology to simulate a small-scale fuel cell system for power generation using biomass gas as fuel. The methodology encompasses the thermodynamic and electrochemical aspects of a solid oxide fuel cell (SOFC, as well as solves the problem of chemical equilibrium in complex systems. In this case the complex system is the internal reforming of biomass gas to produce hydrogen. The fuel cell input variables are: operational voltage, cell power output, composition of the biomass gas reforming, thermodynamic efficiency, electrochemical efficiency, practical efficiency, the First and Second law efficiencies for the whole system. The chemical compositions, molar flows and temperatures are presented to each point of the system as well as the exergetic efficiency. For a molar water/carbon ratio of 2, the thermodynamic simulation of the biomass gas reforming indicates the maximum hydrogen production at a temperature of 1070 K, which can vary as a function of the biomass gas composition. The comparison with the efficiency of simple gas turbine cycle and regenerative gas turbine cycle shows the superiority of SOFC for the considered electrical power range.

  16. Thermomechanical analysis of porous solid oxide fuel cell by using peridynamics

    Directory of Open Access Journals (Sweden)

    Hanlin Wang

    2017-06-01

    Full Text Available Solid oxide fuel cell (SOFC is widely used in hybrid marine propulsion systems due to its high power output, excellent emission control and wide fuel suitability. However, the operating temperature in SOFC will rise up to 800–1000 ℃ due to redox reaction among hydrogen and oxygen ions. This provides a suitable environment for ions transporting through ceramic materials. Under such operation temperatures, degradation may occur in the electrodes and electrolyte. As a result, unstable voltage, low capacity and cell failure may eventually occur. This study presents thermomechanical analysis of a porous SOFC cell plate which contains electrodes, electrolytes and pores. A microscale specimen in the shape of a plate is considered in order to maintain uniform temperature loading and increase the accuracy of estimation. A new computational technique, peridynamics, is utilized to calculate the deformations and stresses of the cell plate. Moreover, the crack formation and propagation are also obtained by using peridynamics. According to the numerical results, damage evolution depends on the electrolyte/electrode interface strength during the charging process. For weak interface strength case, damage emerges at the electrode/electrolyte interface. On the other hand, for stronger interface cases, damage emerges on pore boundaries especially with sharp corner.

  17. Quantitative analysis of solid oxide fuel cell anode microstructure change during redox cycles

    Science.gov (United States)

    Shimura, Takaaki; Jiao, Zhenjun; Hara, Shotaro; Shikazono, Naoki

    2014-12-01

    In the present study, correlation between solid oxide fuel cell anode microstructure and electrochemical performance during redox cycles was investigated. Electrolyte-support cell with nickel/yttria stabilized zirconia composite anode was prepared and tested under discharge process with redox cycles. Redox treatment was basically conducted every 20 h during discharge process. Polarization resistance decreased just after redox treatment and increased during discharge process. Enhancement of cell performance after every redox cycles and faster degradation in the following discharge process were observed. Polarization resistance gradually increased as redox cycles were repeated. Focused ion beam-scanning electron microscopy (FIB-SEM) observation was conducted for reconstructing the three dimensional microstructures of the tested samples. From the three dimensional microstructure reconstruction, it is found that the shape of nickel particle got thinner and complicated after redox cycles. Triple phase boundary (TPB) length increased after redox treatment and decreased after discharge process. This TPB change was highly associated with Ni connectivity and Ni specific surface area. These microstructure changes are consistent with the change of cell performance enhancement after redox treatment and degradation after discharge process. However, TPB length density kept on increasing as redox cycles are repeated, which is inconsistent with the gradual degradation of anode performance.

  18. Mathematical modeling analysis of regenerative solid oxide fuel cells in switching mode conditions

    Science.gov (United States)

    Jin, Xinfang; Xue, Xingjian

    A 2D transient mathematical model is developed for regenerative solid oxide cells operated in both SOFC mode and SOEC mode. The steady state performance of the model is validated using experimental results of in-house prepared NiO-YSZ/YSZ/LSM cell under different operating temperatures. The model is employed to investigate complicated multi-physics processes during the transient process of mode switching. Simulation results indicate that the trend of internal parameter distributions, including H 2/O 2/H 2O and ionic potentials, flip when the operating cell is switched from one mode to another. However, the electronic potential shows different behaviors. At H 2 electrode, electronic potential keeps at zero voltage level, while at O 2 electrode, it increases from a relatively low level in SOFC mode to a relatively high level in SOEC mode. Transient results also show that an overshooting phenomenon occurs for mass fraction distribution of water vapor at H 2 side when the operating cell switches from SOFC mode to SOEC mode. The mass fractions of O 2 and H 2 as well as charge (electrons and ions) potentials may quickly follow the operating mode changes without over-shootings. The simulation results facilitate the internal mechanism understanding for regenerative SOFCs.

  19. Solid-oxide fuel cell operated on in situ catalytic decomposition products of liquid hydrazine

    Science.gov (United States)

    Gu, Hongxia; Ran, Ran; Zhou, Wei; Shao, Zongping; Jin, Wanqin; Xu, Nanping; Ahn, Jeongmin

    Hydrazine was examined as a fuel for a solid-oxide fuel cell (SOFC) that employed a typical nickel-based anode. An in situ catalytic decomposition of hydrazine at liquid state under room temperature and ambient pressure before introducing to the fuel cell was developed by applying a Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ (BSCF) oxide catalyst. Catalytic testing demonstrated that liquid N 2H 4 can be decomposed to gaseous NH 3 and H 2 at a favorable rate and at a temperature as low as 20 °C and H 2 selectivity reaching values as high as 10% at 60 °C. Comparable fuel cell performance was observed using either the in situ decomposition products of hydrazine or pure hydrogen as fuel. A peak power density of ∼850 mW cm -2 at 900 °C was obtained with a typical fuel cell composed of scandia-stabilized zirconia and La 0.8Sr 0.2MnO 3 cathode. The high energy and power density, easy storage and simplicity in fuel delivery make it highly attractive for portable applications.

  20. Characterization and quantification of uncertainty in solid oxide fuel cell hybrid power plants

    Science.gov (United States)

    Subramanyan, Karthik; Diwekar, Urmila M.

    Distributed power generation is one of the most powerful applications of fuel cell technology. Several types of configurations have been hypothesized and tested for these kinds of applications at the conceptual level, but hybrid power plants are one of the most efficient. These are designs that combine the fuel cell cycle with other thermodynamic cycles to provide higher efficiency. The power plant in focus is the high pressure (HP)-low pressure (LP) solid oxide fuel cells (SOFC)/steam turbine (ST)/gas turbine (GT) configuration which is a part of the vision-21 program, which is a new approach, the U.S. Department of Energy's (DOE's) Office of Fossil Energy has begun, for developing 21st century energy plants that would have virtually no environmental impact. The overall goal is to effectively eliminate—at competitive costs—environmental concerns associated with the use of fossil fuels, for producing electricity and transportation fuels. In this design, coal is gasified in an entrained bed gasifier and the syn-gas produced is cleaned in a transport bed desulfurizer and passed over to cascaded SOFC modules (at two pressure levels). This module is integrated with a reheat GT cycle. The heat of the exhaust from the GT cycle is used to convert water to steam, which is eventually used in a steam bottoming cycle. Since this hybrid technology is new and futuristic, the system level models used for predicting the fuel cells' performance and for other modules like the desulfurizer have significant uncertainties in them. Also, the performance curves of the SOFC would differ depending on the materials used for the anode, cathode and electrolyte. The accurate characterization and quantification of these uncertainties is crucial for the validity of the model predictions and hence is the main focus of this paper. This work performs a two-level uncertainty analysis of the fuel cell module: uncertainty associated with (1) model and (2) material used for anode, cathode and

  1. Methane-free biogas for direct feeding of solid oxide fuel cells

    Science.gov (United States)

    Leone, P.; Lanzini, A.; Santarelli, M.; Calì, M.; Sagnelli, F.; Boulanger, A.; Scaletta, A.; Zitella, P.

    This paper deals with the experimental analysis of the performance and degradation issues of a Ni-based anode-supported solid oxide fuel cell fed by a methane-free biogas from dark-anaerobic digestion of wastes by pastry and fruit shops. The biogas is produced by means of an innovative process where the biomass is fermented with a pre-treated bacteria inoculum (Clostridia) able to completely inhibit the methanization step during the fermentation process and to produce a H 2/CO 2 mixture instead of conventional CH 4/CO 2 anaerobic digested gas (bio-methane). The proposed biogas production route leads to a biogas composition which avoids the need of introducing a reformer agent into or before the SOFC anode in order to reformate it. In order to analyse the complete behaviour of a SOFC with the bio-hydrogen fuel, an experimental session with several H 2/CO 2 synthetic mixtures was performed on an anode-supported solid oxide fuel cell with a Ni-based anode. It was found that side reactions occur with such mixtures in the typical thermodynamic conditions of SOFCs (650-800 °C), which have an effect especially at high currents, due to the shift to a mixture consisting of hydrogen, carbon monoxide, carbon dioxide and water. However, cells operated with acceptable performance and carbon deposits (typical of a traditional hydrocarbon-containing biogas) were avoided after 50 h of cell operation even at 650 °C. Experiments were also performed with traditional bio-methane from anaerobic digestion with 60/40 vol% of composition. It was found that the cell performance dropped after few hours of operation due to the formation of carbon deposits. A short-term test with the real as-produced biogas was also successfully performed. The cell showed an acceptable power output (at 800 °C, 0.35 W cm -2 with biogas, versus 0.55 W cm -2 with H 2) although a huge quantity of sulphur was present in the feeding fuel (hydrogen sulphide at 103 ppm and mercaptans up to 10 ppm). Therefore, it

  2. Detection of Aspergillus flavus and A. fumigatus in Bronchoalveolar Lavage Specimens of Hematopoietic Stem Cell Transplants and Hematological Malignancies Patients by Real-Time Polymerase Chain Reaction, Nested PCR and Mycological Assays

    Science.gov (United States)

    Zarrinfar, Hossein; Mirhendi, Hossein; Fata, Abdolmajid; Khodadadi, Hossein; Kordbacheh, Parivash

    2015-01-01

    Background: Pulmonary aspergillosis (PA) is one of the most serious complications in immunocompromised patients, in particular among hematopoietic stem cell transplants (HSCT) and patients with hematological malignancies. Objectives: The current study aimed to evaluate the incidence of PA and utility of molecular methods in HSCT and patients with hematological malignancies, four methods including direct examination, culture, nested polymerase chain reaction (PCR) and real-time PCR were performed on bronchoalveolar lavage (BAL) specimens in Tehran, Iran. Patients and Methods: During 16 months, 46 BAL specimens were obtained from individuals with allogeneic HSCT (n = 18) and patients with hematological malignancies (n = 28). Direct wet mounts with 20% potassium hydroxide (KOH) and culture on mycological media were performed. The molecular detection of Aspergillus fumigatus and A. flavus was done by amplifying the conserved sequences of internal transcribed spacer 1 (ITS1) ribosomal DNA by nested-PCR and the β-tubulin gene by TaqMan real-time PCR. Results: Seven (15.2%) out of 46 specimens were positive in direct examination and showed branched septate hyphae; 11 (23.9%) had positive culture including eight (72.7%) A. flavus and three (27.3%) A. fumigatus; 22 (47.8%) had positive nested-PCR and eight (17.4%) had positive real-time PCR. The incidence of invasive pulmonary aspergillosis (IPA) in these patients included proven IPA in 1 (2.2%), probable IPA in 10 (21.7%), possible IPA in 19 (41.3%) and not IPA in 16 cases (34.8%). Conclusions: The incidence of IPA in allogeneic HSCT and patients with hematological malignancies was relatively high and A. flavus was the most common cause of PA. As molecular methods had higher sensitivity, it may be useful as screening methods in HSCT and patients with hematological malignancies, or to determine when empirical antifungal therapy can be withheld. PMID:25763133

  3. Structural, morphological, and electrical properties of doped ceria as a solid electrolyte for intermediate-temperature solid oxide fuel cells

    KAUST Repository

    Stojmenović, M.

    2015-03-11

    The solid solutions of CeO2 with one or more rare-earth oxides among Yb2O3, Sm2O3, and Gd2O3 are synthesized by either modified glycine nitrate procedure (MGNP) or self-propagating reaction at room temperature (SPRT). The overall mole fraction of rare-earth oxide dopants was x = 0.2. The characterization was committed by XRPD, TEM, BET, and Raman Spectroscopy methods. According to XRPD and Raman spectroscopy, the obtained products presented the single-phase solid solutions with basic fluorite-type CeO2 structure, regardless on the number and the concentration of dopants. Both XRPD and TEM analysis evidenced the nanometer particle dimensions. The defect model was applied to calculate lattice parameters of single-, co-, and multi-doped solids. The sintering of the sample nanopowders was performed at 1550 °C, in air atmosphere. The sintered samples were characterized by XRPD, SEM, and complex impedance methods. The sintering did not affect the concentration ratios of the constituents. The highest conductivity at 700 °C amounting to 2.14 × 10−2 and 1.92 × 10−2 Ω−1 cm−1 was measured for the sample Ce0.8Sm0.08Gd0.12O2−δ, synthesized by SPRT and MGNP methods, respectively. The corresponding activation energies of conductivity, measured in the temperature range 500–700 °C, amounted to 0.24 and 0.23 eV.

  4. Study and fabrication of solid oxide fuel cells through tape casting and co-sintering

    International Nuclear Information System (INIS)

    Grosjean, A.

    2004-11-01

    This work is dedicated to the devising of a low-cost fabrication process of solid oxide fuel cells (SOFC). Technical requirements impose the shaping method: stripe casting as well as the materials used: Yttria-stabilized zirconia (YSZ), nickel and lanthanum manganite doped with strontium (LSM). In order to comply with environmental requirements the developed process uses an aqueous barbotine solvent. We get electrodes and the electrolyte separately, the use of an absorbent drying process has enabled us to join 3 layers to form an elementary cell with great interfacial homogeneity. The resistance of the cell to sintering has been improved through the symmetrization of the deformations of the cell. In order to interpret the low electrical properties of the cell and its quick damaging, transmission microscopy studies have been performed. These studies have shown 2 facts. First, 2 isolating phases appear at the cathode (at the LSM/YSZ interface) because of a too high sintering temperature and secondly, a quick clustering of nickel grains appears during cell operation that leads to a local loss of the nickel grid percolation. This problem has been solved by increasing the size of nickel oxide grains from 0.5 μm to 3 μm) to stabilize the microstructure. The issue of the reactivity at the LSM/YSZ interfaces was tackled in 2 different ways, we have tried to lower the sintering temperature by using a zirconia nano-powder first and then by replacing zirconia in the electrolyte by gadolinium-doped ceria. The use of zirconia nano-powder has failed to decrease sintering temperature while preserving the electrolyte density and the use of ceria has triggered instabilities that have not yet been solved. Despite all these drawbacks, this process allows the fabrication of an excellent anode/electrolyte interface. (A.C.)

  5. Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

    KAUST Repository

    Jain, Harsh Vardhan

    2012-07-01

    Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O(2)) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O(2)-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O(2) pressure (pO(2)) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO(2) to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases.

  6. Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

    Science.gov (United States)

    Moldovan, Nicanor I.; Byrne, Helen M.

    2012-01-01

    Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O2) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O2-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O2 pressure (pO2) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO2 to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases. PMID:22224628

  7. Phase 1 - Evaluation of a Functional Interconnect System for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    James M. Rakowski

    2006-09-30

    This project is focused on evaluating the suitability of materials and complex multi-materials systems for use as solid oxide fuel cell interconnects. ATI Allegheny Ludlum has generated promising results for interconnect materials which incorporate modified surfaces. Methods for producing these surfaces include cladding, which permits the use of novel materials, and modifications via unique thermomechanical processing, which allows for the modification of materials chemistry. The University of Pittsburgh is assisting in this effort by providing use of their in-place facilities for dual atmosphere testing and ASR measurements, along with substantial work to characterize post-exposure specimens. Carnegie Mellon is testing interconnects for chromia scale spallation resistance using macro-scale and nano-scale indentation tests. Chromia spallation can increase electrical resistance to unacceptable levels and interconnect systems must be developed that will not experience spallation within 40,000 hours at operating temperatures. Spallation is one of three interconnect failure mechanisms, the others being excessive growth of the chromia scale (increasing electrical resistance) and scale evaporation (which can poison the cathode). The goal of indentation fracture testing at Carnegie Mellon is to accelerate the evaluation of new interconnect systems (by inducing spalls at after short exposure times) and to use fracture mechanics to understand mechanisms leading to premature interconnect failure by spallation. Tests include bare alloys from ATI and coated systems from DOE Laboratories and industrial partners, using ATI alloy substrates. West Virginia University is working towards developing a cost-effective material for use as a contact material in the cathode chamber of the SOFC. Currently materials such as platinum are well suited for this purpose, but are cost-prohibitive. For the solid-oxide fuel cell to become a commercial reality it is imperative that lower cost

  8. Thermodynamic analysis of an integrated gasification solid oxide fuel cell plant combined with an organic Rankine cycle

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud; Larsen, Ulrik

    2013-01-01

    A 100 kWe hybrid plant consisting of gasification system, solid oxide fuel cells and organic Rankine cycle is presented. The nominal power is selected based on cultivation area requirement. For the considered output a land of around 0.5 km2 needs to be utilized. Woodchips are introduced...... into a fixed bed gasification plant to produce syngas which fuels the combined solid oxide fuel cells e organic Rankine cycle system to produce electricity. More than a hundred fluids are considered as possible alternative for the organic cycle using non-ideal equations of state (or state-of-the-art equations...... achieved by simple and double stage organic Rankine cycle plants and around the same efficiency of a combined gasification, solid oxide fuel cells and micro gas turbine plant. © 2013 Elsevier Ltd. All rights reserved....

  9. Thermodynamic analysis of SOFC (solid oxide fuel cell)–Stirling hybrid plants using alternative fuels

    International Nuclear Information System (INIS)

    Rokni, Masoud

    2013-01-01

    A novel hybrid power system (∼10 kW) for an average family home is proposed. The system investigated contains a solid oxide fuel cell (SOFC) on top of a Stirling engine. The off-gases produced in the SOFC cycle are fed to a bottoming Stirling engine, at which additional power is generated. Simulations of the proposed system were conducted using different fuels, which should facilitate the use of a variety of fuels depending on availability. Here, the results for natural gas (NG), ammonia, di-methyl ether (DME), methanol and ethanol are presented and analyzed. The system behavior is further investigated by comparing the effects of key factors, such as the utilization factor and the operating conditions under which these fuels are used. Moreover, the effect of using a methanator on the plant efficiency is also studied. The combined system improves the overall electrical efficiency relative to that of a stand-alone Stirling engine or SOFC plant. For the combined SOFC and Stirling configuration, the overall power production was increased by approximately 10% compared to that of a stand-alone SOFC plant. System efficiencies of approximately 60% are achieved, which is remarkable for such small plant sizes. Additionally, heat is also produced to heat the family home when necessary. - Highlights: • Integrating a solid oxide fuel with a Stirling engine • Design of multi-fuel hybrid plants • Plants running on alternative fuels; natural gas, methanol, ethanol, DME and ammonia • Thermodynamic analysis of hybrid SOFC–Stirling engine plants

  10. Simultaneous Removal of Phenol and Dissolved Solids from Wastewater Using Multichambered Microbial Desalination Cell.

    Science.gov (United States)

    Pradhan, Harapriya; Jain, Sumat Chand; Ghangrekar, Makarand M

    2015-12-01

    Microbial desalination cell (MDC) has great potential toward direct electricity generation from wastewater and concurrent desalination through potential difference developed due to microbial activity. Degradation of phenol by isolate Pseudomonas aeruginosa in anodic chamber and simultaneous desalination of water in middle desalination chamber of multichamber MDC is demonstrated in this study. Performance of the MDCs with different anodic inoculum conditions, namely pure culture of P. aeruginosa (MDC-1), 50 % v/v mixture of P. aeruginosa and anaerobic mixed consortia (MDC-2) and anaerobic mixed consortia (MDC-3), was evaluated to compare the phenol degradation in anodic chamber, bioelectricity generation, and simultaneous total dissolved solids (TDS) removal from saline water in desalination chamber. Synergistic effect between P. aeruginosa and mixed anaerobic consortia as inoculum was evident in MDC-2 demonstrating phenol degradation of 90 %, TDS removal of 75 % in 72 h of reaction time along with higher power generation of 27.5 mW/m(2) as compared to MDC-1 (95 %, 64 %, 12.8 mW/m(2), respectively) and MDC-3 (58 %, 52 %, 4.8 mW/m(2), respectively). The results illustrate that the multichamber MDC-2 is effective for simultaneous removal of phenol and dissolved solids contained in industrial wastewaters.

  11. Direct internal steam reforming of ethanol in a solid oxide fuel cell (SOFC) - A thermodynamic analysis

    International Nuclear Information System (INIS)

    Lima da Silva, Aline; De Fraga Malfatti, Celia; Heck, Nestor Cesar; Melo Halmenschlager, Cibele

    2003-01-01

    Among the various types of fuel cells, the solid oxide fuel cell (SOFC) has attracted considerable interest due to the possibility for operation with an internal reformer and higher system efficiency. In SOFC, high operative temperature allows the direct conversion of ethanol into H 2 and CO to take place in the electrochemical cell. Ethanol is considered to be an attractive fuel because it is a renewable energy source and presents some advantages over other green fuels such as safety in storage and handling. Direct internal reforming of ethanol, however, can produce undesirable products that diminish system efficiency and, in the case of carbon deposition over the anode, promote the growth of carbon filaments attached to the anode crystallites which generate massive forces within the electrode structure leading to its rapid breakdown. In this context, a thermodynamic analysis is fundamental to predict the product distribution as well as the conditions favorable for carbon to precipitate inside the cell. Despite of such importance, there are few works in literature dealing with thermodynamic analysis of the direct internal steam reforming of ethanol in fuel cell systems. Hence, the aim of this work is to find appropriate ranges for operating conditions where carbon deposition in SOFC with direct internal reforming operation is not feasible, in temperature range of 500- 1200K. The calculation here is more complicated than that for a reformer because the disappearance of hydrogen and the generation of H 2 O from electrochemical reaction must be taken into account. In the present study, the effects of hydrogen consumption on anode components and on carbon formation are investigated. Equilibrium determinations are performed by the Gibbs energy minimization method, considering the following species: H 2 , H 2 O, CH 4 , CO, CO 2 and C gr . (graphite). The effect of the type of solid electrolyte (oxygen-conducting and hydrogen-conducting) on carbon formation is also

  12. Study of tape casting of Yttria stabilized zirconia for apply in solid oxide fuel cell

    International Nuclear Information System (INIS)

    Santana, Leonardo de Paulo

    2008-01-01

    The hydrogen economy has been risen as new option for supply the growing global demand for energy. A fuel cell is an electrochemical device able to use hydrogen as a energy source. Carbon dioxide (CO 2 ) emission is very low so it is ecologically friendly, once energy is produced by a reaction of hydrogen and oxygen. The production of energy from hydrogen fuelled devices can be done even in small unities and in a distributed way. It can bring energy for isolated communities, where traditional energy distribution systems can not be reached. A fuel cell is composed essentially of 3 components: anode, cathode and the electrolyte. In present days, there are many materials proposed for use as electrolyte in fuel cells. Among then, Yttria stabilized zirconia (YSZ) is the most studied and effectively used in solid oxide fuel cell. Tape casting technology is a cheap, simple and efficient way to cast ceramics slurries in laminates thick enough to be used as components for fuel cells. Considering theses aspects, in this work, ceramic thin film forming was studied using tape casting technology with raw materials prepared from Brazilian zircon ores. It is described in literature that ceramic slurries are generally made from powders with low surface area (often between 0,5 to 10m 2 /g), and the powders used in this study had larger surface area (often between 40 to 80m 2 /g). The use of zeta potential is indicated to study the stability of a suspension of ceramic powders. However, for suspensions with large concentration of solid, it is also necessary to determine the flow curve, because in these conditions, the double electric layer formed during the stabilization of suspensions can be compressed. In the rheological properties study, calcined ceramic powders were classified using a set of ABNT series screens and separated and retained by the de mesh 60 screen. Flow curve of suspension was determined in aqueous suspensions of these powders. For tape casting processing, a binder

  13. STABLE HIGH CONDUCTIVITY BILAYERED ELECTROLYTES FOR LOW TEMPERATURE SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Eric D. Wachsman; Keith L. Duncan

    2001-09-30

    Solid oxide fuel cells (SOFCs) are the future of energy production in America. They offer great promise as a clean and efficient process for directly converting chemical energy to electricity while providing significant environmental benefits (they produce negligible hydrocarbons, CO, or NO{sub x} and, as a result of their high efficiency, produce about one-third less CO{sub 2} per kilowatt hour than internal combustion engines). Unfortunately, the current SOFC technology, based on a stabilized zirconia electrolyte, must operate in the region of 1000 C to avoid unacceptably high ohmic losses. These high temperatures demand (a) specialized (expensive) materials for the fuel cell interconnects and insulation, (b) time to heat up to the operating temperature and (c) energy input to arrive at the operating temperature. Therefore, if fuel cells could be designed to give a reasonable power output at low to intermediate1 temperatures tremendous benefits may be accrued. At low temperatures, in particular, it becomes feasible to use ferritic steel for interconnects instead of expensive and brittle ceramic materials such as those based on LaCrO{sub 3}. In addition, sealing the fuel cell becomes easier and more reliable; rapid start-up is facilitated; thermal stresses (e.g., those caused by thermal expansion mismatches) are reduced; radiative losses ({approx}T{sup 4}) become minimal; electrode sintering becomes negligible and (due to a smaller thermodynamic penalty) the SOFC operating cycle (heating from ambient) would be more efficient. Combined, all these improvements further result in reduced initial and operating costs. The problem is, at lower temperatures the conductivity of the conventional stabilized zirconia electrolyte decreases to the point where it cannot supply electrical current efficiently to an external load. The primary objectives of the proposed research are to develop a stable high conductivity (> 0.05 S cm{sup -1} at {le} 550 C) electrolyte for lower

  14. Bristol Bay, Alaska Subarea ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for nesting seabirds (alcids, pelagic birds), gulls, terns, diving birds, and raptors in the Bristol Bay...

  15. Final Technical Report: Affordable, High-Performance, Intermediate Temperature Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Blackburn, Bryan [Redox Power Systems, LLC; Bishop, Sean [Redox Power Systems, LLC; Gore, Colin [Redox Power Systems, LLC; Wang, Lei [Redox Power Systems, LLC; Correa, Luis [Redox Power Systems, LLC; Langdo, Thomas [Redox Power Systems, LLC; Deaconu, Stelu [Redox Power Systems, LLC; Pan, Keji [Redox Power Systems, LLC

    2018-02-15

    In this project, we improved the power output and voltage efficiency of our intermediate temperature solid oxide fuel cells (IT-SOFCs) with a focus on ~600 °C operation. At these temperatures and with the increased power density (i.e., fewer cells for same power output), the stack cost should be greatly reduced while extending durability. Most SOFC stacks operate at temperatures greater than 800 °C. This can greatly increase the cost of the system (stacks and BOP) as well as maintenance costs since the most common degradation mechanisms are thermally driven. Our approach uses no platinum group metal (PGM) materials and the lower operating temperature allows use of simple stainless steel interconnects and commercial off-the-shelf gaskets in the stack. Furthermore, for combined heating and power (CHP) applications the stack exhaust still provides “high quality” waste heat that can be recovered and used in a chiller or boiler. The anticipated performance, durability, and resulting cost improvements (< $700/kWe) will also move us closer to reaching the full potential of this technology for distributed generation (DG) and residential/commercial CHP. This includes eventual extension to cleaner, more efficient portable generators, auxiliary power units (APUs), and range extenders for transportation. The research added to the understanding of the area investigated by exploring various methods for increasing power density (Watts/square centimeter of active area in each cell) and increasing cell efficiency (increasing the open circuit voltage, or cell voltage with zero external electrical current). The results from this work demonstrated an optimized cell that had greater than 1 W/cm2 at 600 °C and greater than 1.6 W/cm2 at 650 °C. This was demonstrated in large format sizes using both 5 cm by 5 cm and 10 cm by 10 cm cells. Furthermore, this work demonstrated that high stability (no degradation over > 500 hours) can be achieved together with high performance in large

  16. Nanostructured Gd-CeO2 electrolyte for solid oxide fuel cell by aqueous tape casting

    Science.gov (United States)

    Akbari-Fakhrabadi, A.; Mangalaraja, R. V.; Sanhueza, Felipe A.; Avila, Ricardo E.; Ananthakumar, S.; Chan, S. H.

    2012-11-01

    Gadolinia-doped ceria (Ce0.9Gd0.1O1.95, GDC) electrolyte was fabricated by aqueous-based tape casting method for solid oxide fuel cells (SOFCs). The ceramic powder prepared by combustion synthesis was used with poly acrylic acid (PAA), poly vinyl alcohol (PVA), poly ethylene glycol (PEG), Octanol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate and double distilled water as dispersant, binder, plasticizer, defoamer, surfactant and solvent respectively, to prepare stable GDC slurry. The conditions for preparing stable GDC slurries were studied and optimized by sedimentation, zeta potential and viscosity measurements. Green tapes with smooth surface, flexibility, thickness in the range of 0.35-0.4 mm and 45% relative green density were prepared. Conventional and flash sintering techniques were used and compared for densification which demonstrated the possibility of surpassing sintering at high temperatures and retarding related grain growth.

  17. Tracking Solid Oxide Cell Microstructure Evolution by High Resolution 3D Nano-Tomography

    DEFF Research Database (Denmark)

    De Angelis, Salvatore

    Solid oxide cells (SOCs) oer great prospects for the ecient and reversible conversion of chemical to electrical energy. Therefore, they are expected to play a key role in the renewable energy landscape. However, their limited lifetime under operating conditions hinders their widespread usage...... temperature in dry hydrogen. The analyses show the substantial evolution of the nickel and pore networks during the rst 3 hours of treatment. The nickel coarsening leads to loss of nickel connectivity, a decrease in specic interface area and a decrease in total triple phase boundary density. The ex...... tomography is applied. Preliminary results show rapid kinetics for the two reactions. During oxidation, void formation in metallic particles is observed. During reduction, the nickel oxide particles rst evolve to a nano-porous system of nickel crystallites and then coarsen towards dense nickel particles....

  18. Mechanism of chromium poisoning the conventional cathode material for solid oxide fuel cells

    Science.gov (United States)

    Zhang, Xiaoqiang; Yu, Guangsen; Zeng, Shumao; Parbey, Joseph; Xiao, Shuhao; Li, Baihai; Li, Tingshuai; Andersson, Martin

    2018-03-01

    Chromium poisoning the La0.875Sr0.125MnO3 (LSM) cathode for solid oxide fuel cells is a critical issue that can strongly affect the stability. In this study, we evaluate the temperature distribution in a SOFC based on a 3D model and then combine conductivity test and material computation to reveal the effects of chromium in SUS430 stainless steels on LSM conductivities. The starch concentration in LSM pellets and the applied pressure on the contact with interconnect materials show close relationships with the chromium poisoning behavior. The density functional theory (DFT) computing results indicate that chromium atoms preferably adsorb on the MnO2-terminated and La (Sr)-O-terminated (001) surfaces. The resulting conclusions are expected to deeply understand mechanism of chromium deactivating conventional cathodes at some typical operational conditions, and offer crucial information to optimize the structure to avoid the poisoning effect.

  19. Electrochemically active thickness of solid oxide fuel cell electrodes: Effectiveness model prediction

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jin Hyun [School of Mechanical Engineering, Daegu University, Gyungsan (Korea, Republic of)

    2017-04-15

    The three-phase boundaries (TPBs) in the electrodes of solid oxide fuel cells (SOFCs) have different activity because of the distributed nature of the electrochemical reactions. The electrochemically active thickness (EAT) is a good measure to evaluate the extension of the active reaction zone into the electrode and the effective utilization of TPBs. In this study, an electrochemical reaction/charge conduction problem is formulated based on the Butler–Volmer reaction kinetics and then numerically solved to determine the EATs for the active electrode layers of SOFCs with various microstructural, dimensional, and property parameters. Thus, the EAT data and correlations presented in this study are expected to provide useful information for designing efficient electrodes of SOFCs.

  20. Materials and Components for Low Temperature Solid Oxide Fuel Cells – an Overview

    Directory of Open Access Journals (Sweden)

    D. Radhika

    2013-06-01

    Full Text Available This article summarizes the recent advancements made in the area of materials and components for low temperature solid oxide fuel cells (LT-SOFCs. LT-SOFC is a new trend in SOFCtechnology since high temperature SOFC puts very high demands on the materials and too expensive to match marketability. The current status of the electrolyte and electrode materials used in SOFCs, their specific features and the need for utilizing them for LT-SOFC are presented precisely in this review article. The section on electrolytes gives an overview of zirconia, lanthanum gallate and ceria based materials. Also, this review article explains the application of different anode, cathode and interconnect materials used for SOFC systems. SOFC can result in better performance with the application of liquid fuels such methanol and ethanol. As a whole, this review article discusses the novel materials suitable for operation of SOFC systems especially for low temperature operation.

  1. Microstructural densification and electrical performance of yttria stabilized zirconia SOCF (Solid Oxide Fuel Cell) electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, J.G. de M., E-mail: furtado@cepel.b [Centro de Pesquisas de Energia Eletrica (ELETROBRAS/CEPEL), Rio de Janeiro, RJ (Brazil); Silva, C.A. da; Miranda, P.E.V. de [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Metalurgica e de Materiais

    2010-07-01

    The understanding of the mechanisms associated with densification and sintering of Yttria stabilized zirconia (YSZ), a main solid oxide fuel cell electrolyte, enables the improvement of its microstructure. The present work that has the objective to study the sintering and densification processes of polycrystalline nanostructured 8% mol YSZ (8YSZ), correlating the microstructural development with the electrical performance of the material. The sintering behaviors of nanocrystalline 8YSZ powders obtained by two different chemical synthesis techniques (glycine-nitrate combustion process and Pechini method) were studied based on sintering dilatometer method. X-ray diffraction and scanning electron microscopy were used in the microstructural characterization. Full-densified 8YSZ (98.8%) were obtained and it was found that the samples obtained by the Pechini's method showed a higher densification degree in the final stage of sintering and resulted in ceramics with higher final relative density and better electrical behavior. (author)

  2. A New Cogeneration Residential System Based on Solid Oxide Fuel Cells for a Northern European Climate

    DEFF Research Database (Denmark)

    Vialetto, Giulio; Rokni, Masoud

    2015-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence and to increase the use of renewable energies. In the last several years, new technologies have been developed, and some...... of them received subsidies to increase installation and reduce cost. This article presents an innovative cogeneration system based on a solid oxide fuel cell (SOFC) system and heat pump for household applications with a focus on primary energy and economic savings using electric equivalent load parameter...... are performed under different strategies at a resort located in a northern European climate (Denmark) to cover electricity, space heating and domestic hot water (DHW) demands. The results of these simulations are analyzed with thermodynamic and techno-economic benchmarks, considering different economic...

  3. Innovative Household Systems Based on Solid Oxide Fuel Cells for a Northern European climate

    DEFF Research Database (Denmark)

    Rokni, Masoud; Vialetto, Giulio

    2015-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence and to increase the use of renewable energies. In the last several years, new technologies have been developed, and some...... of them received subsidies to increase installation and reduce cost.This article presents an innovative cogeneration system based on a solid oxide fuel cell (SOFC) systemand heat pump for household applications with a focus on primary energy and economic savings using electric equivalent load parameter...... are performed under different strategies at a resort located in a northern European climate (Denmark) to cover electricity, space heating and domestic hot water (DHW) demands.The results of these simulations are analyzed with thermodynamic and techno-economic benchmarks,considering different economic scenarios...

  4. Thermodynamic analysis of an integrated solid oxide fuel cell cycle with a rankine cycle

    International Nuclear Information System (INIS)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of solid oxide fuel cells (SOFC) on the top of a steam turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydro-carbons. The pre-treated fuel enters then into the anode side of the SOFC. The remaining fuels after the SOFC stacks enter a burner for further burning. The off-gases are then used to produce steam for a Rankine cycle in a heat recovery steam generator (HRSG). Different system setups are suggested. Cyclic efficiencies up to 67% are achieved which is considerably higher than the conventional combined cycles (CC). Both adiabatic steam reformer (ASR) and catalytic partial oxidation (CPO) fuel pre-reformer reactors are considered in this investigation.

  5. Gradient Meshed and Toughened SOEC (Solid Oxide Electrolyzer Cell) Composite Seal with Self-Healing Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Kathy Lu; W. T. Reynolds, Jr.

    2010-06-08

    High-temperature electrolysis of water steam is a promising approach for hydrogen production. The potential is even more promising when abundant heat source from nuclear power reactors can be efficiently utilized. Hydrogen production through the above approach also allows for low electric consumption. Overall energy conversion efficiencies for high temperature electrolysis are in the 45-50% range compared to ~30% for the conventional electrolysis. Under such motivation, this research is focused on increasing the operation time and high temperature stability of solid oxide electrolyzer cells (SOEC) for splitting water into hydrogen. Specifically, our focus is to improve the SOEC seal thermal stability and performances by alleviating thermal stress and seal cracking issues.

  6. Complete relaxation of residual stresses during reduction of solid oxide fuel cells

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Chatzichristodoulou, Christodoulos; Hendriksen, Peter Vang

    2015-01-01

    , accelerated creep, taking place during the reduction of the anode. This relaxes stresses at a much higher rate (~×104) than creep during operation. The phenomenon has previously been studied by simultaneous loading and reduction. With the recorded high creep rates, the stresses at the time of reduction should...... reduce significantly over minutes. In this work the stresses are measured in-situ before and after the reduction by use of XRD. The phenomenon of accelerated creep has to be considered both in the production of stacks and in the analysis of the stress field in a stack based on anode supported SOFCs.......To asses the reliability of solid oxide fuel cell (SOFC) stacks during operation, the stress field in the stack must be known. During operation the stress field will depend on time as creep processes relax stresses. This work reports further details on a newly discovered creep phenomenon...

  7. Solid organ transplantation after allogeneic hematopoietic stem cell transplantation: a retrospective, multicenter study of the EBMT

    DEFF Research Database (Denmark)

    Koenecke, C; Hertenstein, B; Schetelig, J

    2010-01-01

    To analyze the outcome of solid organ transplantation (SOT) in patients who had undergone allogeneic hematopoietic stem cell transplantation (HSCT), a questionnaire survey was carried out within 107 European Group of Blood and Marrow Transplantation centers. This study covered HSCT between 1984...... and 2007 in Europe. Forty-five SOT in 40 patients were reported. Fifteen liver, 15 renal, 13 lung, 1 heart and 1 skin transplantations were performed in 28 centers. Overall survival (OS) of patients after SOT was 78% at 5 years (95% confidence interval [CI], 64% to 92%). OS at 5 years was 100% for renal......, 71% (95% CI, 46% to 96%) for liver and 63% (95% CI, 23% to 100%) for lung transplant recipients. The 2-year-incidence of SOT failure was 20% (95% CI, 4% to 36%) in patients with graft-versus-host disease (GvHD) and 7% (95% CI, 0% to 21%) in patients without GvHD before SOT. The relapse incidence...

  8. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2016-09-27

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  9. Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    hydrocarbons in an adiabatic steam reformer (ASR). The pre-treated fuel then entered to the anode side of the SOFC. The remaining fuels after the SOFC stacks entered a catalytic burner for further combusting. The burned gases from the burner were then used to produce steam for the Rankine cycle in a heat......Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier...... and the pre-reformer reactor had no effect on the plant efficiency, which was also true when decreasing the anode temperature. However, increasing the cathode temperature had a significant effect on the plant efficiency. In addition, decreasing the SOFC utilization factor from 0.8 to 0.7, increases the plant...

  10. Corrosive characteristics of surface-modified stainless steel bipolar plate in solid polymer fuel cell

    Science.gov (United States)

    Zhang, Xiaowen; Wang, Lixia; Sun, Juncai

    2015-03-01

    In this paper, corrosion behavior of an AISI 304 stainless steel modified by niobium or niobium nitride (denoted as niobized 304 SS and Nb-N 304 SS, respectively) is investigated in simulated solid polymer fuel cell (SPFC) operating conditions. Potentiodynamic polarizations show that the corrosion potentials of surface modified 304 SS shift to positive direction while the corrosion current densities decrease greatly comparing with the bare 304 SS in simulated anodic SPFC environments. The order of corrosive resistance in corrosive potential, corrosive current density and pitting potential is: Nb-N 304 SS > niobized 304 SS > bare 304 SS. In the methanol-fueled SPFC operating conditions, the results show that the corrosion resistance of bare and niobized 304 SS increases with the methanol concentration increasing in the test solutions.

  11. Experimental study of methane partial oxidation on Ni-YSZ anode of solid oxide fuel cells

    Science.gov (United States)

    Iwai, Hiroshi; Tada, Koshi; Kishimoto, Masashi; Saito, Motohiro; Yoshida, Hideo

    2017-08-01

    The effects of oxygen addition to methane directly supplied to solid oxide fuel cells were investigated. Fundamental experiments were conducted using Ni-YSZ (yttria-stabilized zirconia) cermet as a typical anode material, and Ni-YSZ catalysts having different streamwise lengths were fabricated on YSZ flat plates. A premixed gas of methane, oxygen, nitrogen and steam was supplied to a test catalyst set in a rectangular test channel. The exhaust gas compositions and the surface temperature distributions of the test catalysts were measured. It was found that the oxidation of methane prominently proceeded near the upstream edge of the catalyst followed by steam/dry reforming reactions downstream. This resulted in the formation of a high-temperature region, leading to a large temperature gradient in the streamwise direction.

  12. Design and development of major balance of plant components in solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wen-Tang; Huang, Cheng-Nan; Tan, Hsueh-I; Chao, Yu [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546 (Taiwan, Province of China); Yen, Tzu-Hsiang [Green Technology Research Institute, CPC Corporation, Chia-Yi City 60036 (Taiwan, Province of China)

    2013-07-01

    The balance of plant (BOP) of a Solid Oxide Fuel Cell (SOFC) system with a 2 kW stack and an electric efficiency of 40% is optimized using commercial GCTool software. The simulation results provide a detailed understanding of the optimal operating temperature, pressure and mass flow rate in all of the major BOP components, i.e., the gas distributor, the afterburner, the reformer and the heat exchanger. A series of experimental trials are performed to validate the simulation results. Overall, the results presented in this study not only indicate an appropriate set of operating conditions for the SOFC power system, but also suggest potential design improvements for several of the BOP components.

  13. Nanofiber-based composite cathodes for intermediate temperature solid oxide fuel cells

    Science.gov (United States)

    Ahn, Minwoo; Lee, Jongseo; Lee, Wonyoung

    2017-06-01

    We demonstrate the Sm0.5Sr0.5CoO3-δ (SSC) nanofiber-based composite cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs), showing a cathode area-specific resistance (ASR) value of 0.024 Ωcm2 at 650 °C. The hollow and porous SSC nanofiber layer, fabricated by electrospinning, is sintered at low temperatures to preserve the high specific surface area for facile oxygen surface exchange reactions. The low sintering temperature is enabled by additional SSC powder layer, providing sufficient adhesion between the electrolyte and the nanofiber layer. Our results can provide a design guideline to fully utilize the nanostructured electrodes by engineering the structural properties of the surface and the interface, and hence high-performance IT-SOFCs can be achieved by structural modification with conventional materials.

  14. Novel in situ method (vacuum assisted electroless plating) modified porous cathode for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Su, Ren; Lue, Zhe; Chen, Kongfa; Ai, Na; Li, Shuyan; Wei, Bo [Center for the Condensed Matter Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Su, Wenhui [Center for the Condensed Matter Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Department of Condensed Matter Physics, Jilin University, Changchun 130023 (China); International Centre for Materials Physics, Academia Sinica, Shenyang 110015 (China)

    2008-06-15

    A novel in situ method - vacuum assisted electroless plating (VA-EP) is developed to modify the porous structure of various materials. The advantage of this method is that it can form a metal network based on the already-given structure. We utilize this method to deposit silver (VA-EPA) in porous perovskite cathode Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF) for an intermediate temperature solid oxide fuel cell (IT-SOFC) in the present research. The results of investigation show the performance of the modified cathode (VA-EPA-BSCF) enhances greatly, for example, the polarization resistance of VA-EPA-BSCF decreases by 60% at 600 C compared to BSCF. (author)

  15. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Science.gov (United States)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2015-07-14

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  16. Electrode materials: a challenge for the exploitation of protonic solid oxide fuel cells

    International Nuclear Information System (INIS)

    Fabbri, Emiliana; Pergolesi, Daniele; Traversa, Enrico

    2010-01-01

    High temperature proton conductor (HTPC) oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs) operating at intermediate temperatures (400-700 0 C). The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs. (topical review)

  17. Molybdate Based Ceramic Negative-Electrode Materials for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Reddy Sudireddy, Bhaskar; Mogensen, Mogens Bjerg

    2010-01-01

    Novel molybdate materials with varying Mo valence were synthesized as possible negative-electrode materials for solid oxide cells. The phase, stability, microstructure and electrical conductivity were characterized. The electrochemical activity for H2O and CO2 reduction and H2 and CO oxidation...... was studied using simplified geometry point-contact electrodes. Unique phenomena were observed for some of the materials - they decomposed into multiple phases and formed a nanostructured surface upon exposure to operating conditions (in certain reducing atmospheres). The new phases and surface features...... enhanced the electrocatalytic activity and electronic conductivity. The polarization resistances of the best molybdates were two orders of magnitude lower than that of donor-doped strontium titanates. Many of the molybdate materials were significantly activated by cathodic polarization, and they exhibited...

  18. Controllable Impregnation Via Inkjet Printing for the Fabrication of Solid Oxide Cell Air Electrodes

    KAUST Repository

    Da'as, E. H.

    2013-10-07

    The impregnation method has been considered as one of the most successful techniques for the fabrication of highly efficient electrodes for solid oxide fuel and electrolysis cells (SOCs) at the lab scale. However, because the impregnation is usually performed manually, its irreproducibility remains a major problem that can be solved by using controllable techniques, such as inkjet printing. In this paper, lanthanum strontium manganite (LSM)/yttria stabilized zirconia (YSZ) air electrodes were prepared by infiltrating YSZ porous bodies with LSM precursor solution using inkjet printing, followed by annealing at 800°C for 2 hours. XRD analysis confirmed the formation of the LSM phase, which was in the form of nanoparticles with size in the 50-70 nm range on the YSZ walls, as revealed by FEG-SEM observations. The effect of printing parameters on the distribution of the impregnated phase was investigated and discussed.

  19. Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... steam in a HRSG (heat recovery steam generator). The bottoming steam cycle was modeled with two configurations: (1) a simple single pressure level and (2) a dual pressure level with both a reheat and a pre-heater. The SOFC stacks in the present SOFC-ST hybrid cycles were not pressurized. The dual...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...

  20. Electrode materials: a challenge for the exploitation of protonic solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Emiliana Fabbri, Daniele Pergolesi and Enrico Traversa

    2010-01-01

    Full Text Available High temperature proton conductor (HTPC oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs operating at intermediate temperatures (400–700 °C. The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs.