| 1. |
- Andersson, Martin, et al.
(författare)
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Analysis of Microscopic Anode Structure Effects on an Anode-Supported SOFC Including Knudsen Diffusion
- 2011
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Ingår i: SOFC12. - : The Electrochemical Society. ; 35, s. 1799-1809
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Konferensbidrag (refereegranskat)abstract
- In this study a two dimensional CFD (COMSOL Multiphysics) is employed to study the effect of anode microscopic structures on the transport phenomena and reactions for an anode-supported solid oxide fuel cell (SOFC). FCs can be considered as energy devices, involving multiple processes, such as (electro-) chemical reactions, heat exchange, gas- and ionic transport. All these complex processes are strongly integrated, needing modeling as an important tool to understand the couplings between mass-, heat-, momentum transport and chemical reactions. For the porous material, the Knudsen diffusion is taken into account in this study. The chemical- and electrochemical reaction rates depend on temperature, material structure, catalytic activity, degradation and partial pressure among others. It is found that the anode thickness and also the anode pore size need to be optimized to achieve high cell efficiency, when the Knudsen diffusion effects are included.
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| 2. |
- Yang, Guogang, et al.
(författare)
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Analysis Of Heat Transfer And Transport Processes In Sofcs Involving Internal Reforming Reactions
- 2009
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Ingår i: International Journal of Green Energy. - : Informa UK Limited. - 1543-5075 .- 1543-5083. ; 6:5, s. 466-478
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Konferensbidrag (refereegranskat)abstract
- The heat transfer rates in solid oxide fuel cells (SOFCs) are controlled by various operating and design parameters and have significant effects on chemical reactions and coupled transport processes. In this article, the considered composite duct consists of a porous anode layer for the internal reforming reactions of methane, the fuel gas flow duct, and the solid plate. A fully three-dimensional calculation code is employed to analyze heat transfer and combined effects of internal reforming/electrochemical reactions on the coupled transport processes, with the purpose to reveal the importance of various parameters. The results show that the internal reforming reactions are mostly confined within 200-300 mu m into the anode porous layer and almost no methane reaches the triple phase boundary (TPB) after the first 10% of the duct length. The operating temperatures have significant effects on the chemical reactions, fuel gas distribution, and overall performance. This study also evaluated the convective heat transfer in the fuel flow duct, in terms of interface thermal boundary/temperature gradients and convective heat transfer coefficients.
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| 3. |
- Zhang, Shunming, et al.
(författare)
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Added sugar intake and its forms and sources in relation to risk of non-alcoholic fatty liver disease : results from the Tianjin Chronic Low-grade Systemic Inflammation and Health cohort study
- 2023
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Ingår i: British Journal of Nutrition. - 1475-2662. ; 129:12, s. 2094-2101
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that added sugar intake is associated with non-alcoholic fatty liver disease (NAFLD). However, previous studies only focused on sugar-sweetened beverages; the evidence for associations with total added sugars and their sources is scarce. This study aimed to examine the associations of total added sugars, their physical forms (liquid vs. solid), and food sources with risk of NAFLD among adults in Tianjin, China. We used data from 15,538 participants, free of NAFLD, other liver diseases, cardiovascular disease, cancer, or diabetes at baseline (2013-2018 years). Added sugar intake was estimated from a validated 100-item food frequency questionnaire. NAFLD was diagnosed by ultrasonography after exclusion of other causes of liver diseases. Multivariable Cox proportional hazards models were fitted to calculate hazards ratios (HRs) and corresponding 95% confidence intervals (CIs) for NAFLD risk with added sugar intake. During a median follow-up of 4.2 years, 3,476 incident NAFLD cases were documented. After adjusting for age, sex, body mass index and its change from baseline to follow-up, lifestyle factors, personal and family medical history, and overall diet quality, the multivariable HRs (95% CIs) of NAFLD risk were 1.18 (1.06, 1.32) for total added sugars, 1.20 (1.08, 1.33) for liquid added sugars, and 0.96 (0.86, 1.07) for solid added sugars when comparing the highest quartiles of intake with the lowest quartiles of intake. In this prospective cohort of Chinese adults, higher intakes of total added sugars and liquid added sugars, but not solid added sugars, were associated with a higher risk of NAFLD.
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