| 2. |
- Zhu, Bin, et al.
(författare)
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Novel hybrid conductors based on doped ceria and BCY20 for ITSOFC applications
- 2004
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Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 6:4, s. 378-383
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Tidskriftsartikel (refereegranskat)abstract
- Ceria-based composites have been previously developed as functional electrolytes for high performance ITSOFC applications. These composites display hybrid proton and oxygen ion conduction. To meet demands for more functional hybrid proton and oxygen ion conductors we developed further composite electrolyte materials containing a proton conductor, BaCe0.8Y0.2O3-delta (BCY20), and an oxygen ion conductor, samarium doped ceria (SDC). The BCY20 and SDC composites were prepared based on composite technology using their starting powders produced via sol-gel and co-precipitation processes, respectively. Using the SDC-BCY20 composites as the electrolytes ITSOFCs were constructed using NiO-based composite anodes, silver-based cathodes. Applying hydrogen as the fuel, compressed air as the oxidant, the fuel cells were tested in the temperature region between 300 and 700 degreesC. The SDC-BCY20 electrolyte ITSOFCs reached a performance of 0.25 W/cm(2) at 550 degreesC. Under a constant discharge water was observed both, on the anode and the cathode side, indicative of hybrid conduction based on proton and oxygen ion transport. Initial experimental results showed that combining a proton with an oxygen ion conductor forming a novel hybrid ion conductor with promising applications for ITSOFCs was successful.
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| 3. |
- Zhu, K, et al.
(författare)
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Quality issues in harvested rainwater in arid and semi-arid Loess Plateau of northern China
- 2004
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Ingår i: Journal of Arid Environments. - 1095-922X. ; 57:4, s. 487-505
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Tidskriftsartikel (refereegranskat)abstract
- Loess soils cover vast areas in the arid and semi-arid regions of northern China. Due to the lack of reliable surface water and ground-water, rainwater harvesting has played a prominent role in farmers' domestic usage and agricultural irrigation. An economical arid valid type of water storage cistern with optimum design of components has been introduced to rural areas in the Loess Plateau. Different collection alternatives showed apparent variations in rainwater quality. By using different catchments, such as mortar roofs and cement-paved courtyards, compacted land or road surfaces, rainwater can be effectively collected for storage in cisterns. This study focused mainly on the quality of rainwater harvested from the different catchment systems and stored for different periods of time. By analysis of the water samples stored in these cisterns, it was evident that rainwater quality could be improved significantly by self-purification during the storage. With emphasis on rainwater quality affected by the different catchment systems, it was found that the measured inorganic compounds in the rainwater harvested from roof-yard catchment systems generally matched the WHO standards for drinking water, while the concentrations of some inorganic compounds in the rainwater collected from land and road surfaces appeared to be higher than the guideline values for drinking water, but generally not beyond the maximum permissible concentrations. However, Fecal Coliform, which is an important bacteriological parameter for the three catchment systems, exceeded the limits of drinking water to a greater extend. Trace amounts of 55 organic pollutants were identified, including aliphatic hydrocarbons, aromatic compounds and phthalate esters, etc. The analytical results indicated that roof-yard catchments that included the "first flush" usually provided safe drinking water with low organic contents, even for rainwater collected immediately after rainfall. In contrast, rainwater harvested from road surfaces had poor quality with respect to the organic constituents, regardless of stored time.
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