| 1. |
- Abbas, Ghazanfar, et al.
(författare)
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Study of CuNiZnGdCe-Nanocomposite Anode for Low Temperature SOFC
- 2012
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Ingår i: Nanoscience and Nanotechnology Letters. - : American Scientific Publishers. - 1941-4900 .- 1941-4919. ; 4:4, s. 389-393
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Tidskriftsartikel (refereegranskat)abstract
- Composite electrodes of Cu0.16Ni0.27Zn0.37Ce0.16Gd0.04 (CNZGC) oxides have been successfully synthesized by solid state reaction method as anode material for low temperature solid oxide fuel cell (LTSOFC). These electrodes are characterized by XRD followed by sintering at various time periods and temperatures. Particle size of optimized composition was calculated 40-85 nm and sintered at 800 degrees C for 4 hours. Electrical conductivity of 4.14 S/cm was obtained at a temperature of 550 degrees C by the 4-prob DC method. The activation energy was calculated 4 x 10(-2) eV at 550 degrees C. Hydrogen was used as fuel and air as oxidant at anode and cathode sides respectively. I-V/I-P curves were obtained in the temperature range of 400-550 degrees C. The maximum power density was achieved for 570 mW/cm(2) at 550 degrees C.
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| 2. |
- Jing, Yifu, et al.
(författare)
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Synthesis and electrochemical performances of linicuzn oxides as anode and cathode catalyst for low temperature solid oxide fuel cell
- 2012
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 12:6, s. 5102-5105
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Tidskriftsartikel (refereegranskat)abstract
- Low temperature solid oxide fuel cell (LTSOFC, 300-600 °C) is developed with advantages compared to conventional SOFC (800-1000 °C). The electrodes with good catalytic activity, high electronic and ionic conductivity are required to achieve high power output. In this work, a LiNiCuZn oxides as anode and cathode catalyst is prepared by slurry method. The structure and morphology of the prepared LiNiCuZn oxides are characterized by X-ray diffraction and field emission scanning electron microscopy. The LiNiCuZn oxides prepared by slurry method are nano Li 0.28Ni 0.72O, ZnO and CuO compound. The nano-crystallites are congregated to form ball-shape particles with diameter of 800-1000 nm. The LiNiCuZn oxides electrodes exhibits high ion conductivity and low polarization resistance to hydrogen oxidation reaction and oxygen reduction reaction at low temperature. The LTSOFC using the LiNiCuZn oxides electrodes demonstrates good cell performance of 1000 mW cm -2 when it operates at 470 °C. It is considered that nano-composite would be an effective way to develop catalyst for LTSOFC.
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| 3. |
- Karamyshev, Andrey L., et al.
(författare)
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Inefficient SRP Interaction with a Nascent Chain Triggers a mRNA Quality Control Pathway
- 2014
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Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 156:1-2, s. 146-157
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Tidskriftsartikel (refereegranskat)abstract
- Misfolded proteins are often cytotoxic, unless cellular systems prevent their accumulation. Data presented here uncover a mechanism by which defects in secretory proteins lead to a dramatic reduction in their mRNAs and protein expression. When mutant signal sequences fail to bind to the signal recognition particle (SRP) at the ribosome exit site, the nascent chain instead contacts Argonaute2 (Ago2), and the mutant mRNAs are specifically degraded. Severity of signal sequence mutations correlated with increased proximity of Ago2 to nascent chain and mRNA degradation. Ago2 knockdown inhibited degradation of the mutant mRNA, while overexpression of Ago2 or knockdown of SRP54 promoted degradation of secretory protein mRNA. The results reveal a previously unappreciated general mechanismof translational quality control, in which specific mRNA degradation preemptively regulates aberrant protein production (RAPP).
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| 4. |
- Li, Yingming, et al.
(författare)
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Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling
- 2012
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Ingår i: Atmospheric Environment. - : Elsevier. - 1352-2310 .- 1873-2844. ; 51, s. 140-145
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Tidskriftsartikel (refereegranskat)abstract
- Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of Sigma indicator PCBs and Sigma(14) PBDEs ranged from 1.66 to 6.50 pg m(-3) and from 0.67 to 2.98 pg m(-3), respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m(-3) (average 15.2 pg m(-3)). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.
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| 5. |
- Liu, Qinghua, et al.
(författare)
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Advanced electrolyte-free fuel cells based on functional nanocomposites of a single porous component : analysis, modeling and validation
- 2012
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 2:21, s. 8036-8040
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Tidskriftsartikel (refereegranskat)abstract
- Recently, a fuel cell device constructed with only one layer composited of ceria-based nanocomposites (typically, lithium nickel oxide and gadolinium doped ceria (LiNiO2-GDC) composite materials), called an electrolyte-free fuel cell (EFFC), was realized for energy conversion by Zhu et al. The maxium power density of this single-component fuel cell is 450 mW cm(-2) at 550 degrees C when using hydrogen fuel. In this study, a model was developed to evaluate the performance of an EFFC. The kinetics of anodic and cathodic reactions were modeled based on electrochemical impedance spectroscopy (EIS) measurements. The results show that both of the anodic and cathodic reactions are kinetically fast processes at 500 degrees C. Safety issues of an EFFC using oxidant and fuels at the same time without a gas-tight separator were analyzed under open circuit and normal operation states, respectively. The reaction depth of anodic and cathodic processes dominated the competition between surface electrochemical and gas-phase reactions which were effected by the catalytic activity and porosity of the materials. The voltage and power output of an EFFC were calculated based on the model and compared with the experimental results.
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| 6. |
- Liu, Qinghua, et al.
(författare)
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Theoretical description of superionic conductivities in samaria doped ceria based nanocomposites
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:18, s. 183115-
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Tidskriftsartikel (refereegranskat)abstract
- Superionic conductivity becomes true based on recent developments on ceria-based nanocomposites as electrolytes with application for low temperature (300-600 degrees C) solid oxide fuel cells. We theoretically describe the superionic conductivity phenomena in samaria doped ceria nanocomposites. An improved effective-medium model was used to determine the ionic conductivity of the materials focusing on a core-shell structure of the as-prepared samaria doped ceria based composite particles. This work reveals the enhancement of ionic conductivity by interface proton and oxygen ion transportation in the composites, which agrees well with the experimental results.
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| 7. |
- Qin, Haiying, et al.
(författare)
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Direct biofuel low-temperature solid oxide fuel cells
- 2011
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Ingår i: ENERGY & ENVIRONMENTAL SCIENCE. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 4:4, s. 1273-1276
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Tidskriftsartikel (refereegranskat)abstract
- A low-temperature solid oxide fuel cell system was developed to use bioethanol and glycerol as fuels directly. This system achieved a maximum power density of 215 mW cm(-2) by using glycerol at 580 degrees C and produced a great impact on sustainable energy and the environment.
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| 8. |
- Raza, Rizwan, 1980-, et al.
(författare)
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Advanced Multi-Fuelled Solid Oxide Fuel Cells (ASOFCs) Using Functional Nanocomposites for Polygeneration
- 2011
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Ingår i: Advanced Energy Materials. - Germany : Wiley-VCH Verlagsgesellschaft. - 1614-6832 .- 1614-6840. ; 1:6, s. 1225-1233
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Tidskriftsartikel (refereegranskat)abstract
- An advanced multifuelled solid oxide fuel cell (ASOFC) with a functional nanocomposite was developed and tested for use in a polygeneration system. Several different types of fuel, for example, gaseous (hydrogen and biogas) and liquid fuels (bio-ethanol and bio-methanol), were used in the experiments. Maximum power densities of 1000, 300, 600, 550 mW cm−2 were achieved using hydrogen, bio-gas, bio-methanol, and bio-ethanol, respectively, in the ASOFC. Electrical and total efficiencies of 54% and 80% were achieved using the single cell with hydrogen fuel. These results show that the use of a multi-fuelled system for polygeneration is a promising means of generating sustainable power.
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| 9. |
- Raza, Rizwan, et al.
(författare)
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La 0.3Sr 0.2Mn 0.1Zn 0.4 oxide-Sm 0.2Ce 0.8O 1.9 (LSMZ-SDC) nanocomposite cathode for low temperature SOFCs
- 2012
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Ingår i: Journal of Nanoscience and Nanotechnology. - : American Scientific Publishers. - 1533-4880 .- 1533-4899. ; 12:6, s. 4994-4997
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposite based cathode materials compatible for low temperature solid oxide fuel cells (LTSOFCs) are being developed. In pursuit of compatible cathode, this research aims to synthesis and investigation nanocomposite La 0.3Sr 0.2Mn 0.1Zn 0.4 oxide-Sm 0.2Ce 0.8O1.9 (LSMZ-SDC) based system. The material was synthesized through wet chemical method and investigated for oxideceria composite based electrolyte LTSOFCs. Electrical property was studied by AC electrochemical impedance spectroscopy (EIS). The microstructure, thermal properties, and elemental analysis of the samples were characterized by TGA/DSC, XRD, SEM, respectively. The AC conductivity of cathode was obtained for 2.4 Scm ?1 at 550 °C in air. This cathode is compatible with ceria-based composite electrolytes and has improved the stability of the material in SOFC cathode environment.
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| 10. |
- Raza, Rizwan, et al.
(författare)
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ZnO/NiO nanocomposite electrodes for low-temperature solid oxide fuel cells
- 2011
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Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 13:9, s. 917-920
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Tidskriftsartikel (refereegranskat)abstract
- ZnO/NiO nanocomposite electrodes have successfully been developed using a cost-effective method, and for the first time used in LT-SOFCs at 300-600 degrees C. They exhibit high conductivity and a dual catalytic functionality in both the cathode and the anode for the electrochemical reduction of O(2) and oxidation of H(2), respectively. An excellent fuel cell performance, e.g. a maximum power density of 1107 W cm(-2), has been shown for a symmetrical fuel cell that contained ZnO/NiO nanocomposite electrodes at 500 degrees C. To our knowledge, to date this is by far the highest power density achieved at this temperature.
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