Effect of Ionic Mass Transport on the Performance of a Novel Tubular Direct Carbon Fuel Cell for the Maximal Use of a Carbon-Filled Porous Anode.

Despite a large number of existing studies about direct carbon fuel cells (DCFCs), sufficient power generation has remained a major technical challenge for the commercialization of DCFCs. This study was designed to implement the benefits of a carbon-filled porous anode developed in our recent studies in a unit cell. First, we developed a new tubular cell assembly comprising an anode, a thin matrix, and a tubular cathode with a certain number of holes in its surface. By employing a reference electrode, we measured the resistance and I-V-P characteristics of the anode, a cathode with a single hole, and the entire cell. As a result, we found that the cathode performance was degraded by resistance to ionic mass transfer, while the anode resistance was invariant (∼0.4 Ω cm2). By developing a semi-empirical current-potential model including an ion mass transport effect, we proved that the number of holes in the cathode surface is the key to the maximal utilization of the present anode. This eventually led to notable gains in the maximum power density to 205 mW cm-2 at 700 °C in experiments. Lastly, a durability test was conducted to reconfirm the effect of ionic mass transfer on the power generation over time.

Association between alcohol consumption and osteoarthritis prevalence in Korea as assessed by the alcohol use disorders identification test (AUDIT): a cross-sectional study.

BACKGROUND: Osteoarthritis (OA) holds significance as a highly prevalent disorder in elderly populations. Various studies have been conducted on the association between alcohol consumption and OA, but the results have often been conflicting. The aim of this study was to investigate the relationship between alcohol consumption and OA in a large-scale sample representative of the Korean population. METHODS: Among the 25,534 participants surveyed in the fifth Korean National Health and Nutrition Examination Survey (2010-2012), 7165 individuals aged ≥50 who responded to drinking-related items were analyzed. The Alcohol Use Disorders Identification Test (AUDIT) grade was calculated, and radiologic examination analysis included the Kellgren-Lawrence (KL) grade of the lumbar spine, hip, and knee joints. Logistic regression analysis was performed to evaluate the association between AUDIT grades and OA through estimation of odds ratios (ORs). RESULTS: In crude analyses, OA (KL grade ≥ 2) of the lumbar spine and knee was more prevalent towards Zone I, but following adjustment, knee OA prevalence significantly increased in Zone III and IV compared to Zone I (Zone III: OR 1.464, 95% confidence interval (CI) 1.027-2.088; Zone IV: OR 1.543, 95% CI 1.028-2.317, respectively). Meanwhile, adjusted hip and lumbar OA values showed positive associations towards Zone IV, but did not reach statistical significance. Additional analyses of the association between alcohol consumption and pain severity of knee OA patients were nonsignificant. CONCLUSIONS: These results imply that radiological knee OA, rather than symptomatic knee OA, is associated with alcohol consumption.