Composition of Organic Carbon-Based Compounds in the Stem Wood of Quercus mongolica Seedlings Grown Under Elevated CO2 and/or O3 Concentrations

In this study, we examined the composition of organic constituents of stem woody tissue together with tree growth in Quercus mongolica var. grosseserrata Blume seedlings raised under controlled CO2 and/or O3 concentrations in a Free-Air Concentration Enrichment system. After exposure to ambient air (control), elevated CO2 concentration (550 μmol mol–1 CO2), elevated O3 concentration (double that of the control), and a combination of elevated CO2 and O3 concentrations during a growing season, we measured the diameter and length of stem, and biomass of sampled seedlings and quantified the lignin, extractive, and holocellulose contents of the woody tissue of current-year stems. We confirmed that the growth of seedlings was enhanced under an elevated CO2 concentration condition. In line with this, the extractive content was lower in woody tissue formed under an elevated CO2 concentration than that formed under ambient air, whereas holocellulose content showed an inverse pattern. Elevated O3 concentration itself did not change the organic constituents of the woody tissue, but it reduced the influence of an elevated CO2 concentration. We thus assume that Q. mongolica formed woody tissue with a low extractive content under the high CO2 concentration condition, although this response was possibly mitigated by an elevated O3 concentration. Extractives contains antimicrobial components such as tannins, flavonoids, quinones, and terpenoids. The decrease in extractives within the widely distributed Q. mongolica in East Asia may have a non-negligible impact on C cycling in the future earth with high atmospheric CO2 concentration.

Optimization and Performance Evaluation of Pilot-scale Electrochemical H2O2 Generator according to Spacer Structure Changes and Catholyte Concentration Condition

Objectives:In this study, We developed pilot-scale bipolar-electrochemical generator (or bipolar-electrolyzer) for generating hydrogen peroxide (H2O2). By comparing H2O2 concentration and generation efficiency of H2O2 according to structure and arrangement of anode/cathode spacer, the structure and arrangement of spacer have been optimised for high H₂O₂ concentration and generation efficiency. Methods:The concentration and generation efficiency of H2O2 were evaluated by changing the width of the channel supporter in anode/cathode spacer and we optimised the arrangement of anode/cathode spacer in electrochemical generator. Additionally, we also evaluated the efficiency of H₂O₂ generation with different concentration catholyte (Na₂SO₄).Results and Discussion:The electrochemical H₂O₂ generator applied anode/cathode supporter with narrow channel supporter showed high H₂O₂ concentration of 2023.83 mg/L. Electrochemical H₂O₂ generator with N-C type spacer (anode: no channel supporter, cathode: channel supporter) showed the highest H₂O₂ concentration (2295.95 mg/L) and H₂O₂ generation efficiency (86.87%). also, we observed that the electrolyzer with 20 PSU has higher H₂O₂ concentration (4217.74 mg/L) and generation efficiency (74.80%).Conclusions:As a results, We generated H₂O₂ with high concentration and high generation efficiency by optimising structure and arrangement of spacer in electrochemical H₂O₂ generator. Also, We concluded that the developed bioplar-electrochemical generator in our study could be applied to the real industry.

Serious Games as Potential Therapies: A Validation Study of a Neurofeedback Game

Serious (biofeedback) games offer promising ways to supplement or replace more expensive face-to-face interventions in health care. However, studies on the validity and effectiveness of EEG-based serious games remain scarce. In the current study, we investigated whether the conditions of the neurofeedback game “Daydream” indeed trained the brain activity as mentioned in the game manual. EEG activity was assessed in 14 healthy male volunteers while playing the 2 conditions of the game. The participants completed a training of 5 sessions. EEG frequency analyses were performed to verify the claims of the manual. We found significant differences in α- to β-ratio between the 2 conditions although only in the amplitude data, not in the power data. Within the conditions, mean α-amplitude only differed significantly from the β-amplitude in the concentration condition. Our analyses showed that neither α nor β brain activity differed significantly between game levels (higher level requiring increased brain activity) in either of the two conditions. In conclusion, we found only marginal evidence for the proposed claims stated in the manual of the game. Our research emphasizes that it is crucial to validate the claims that serious games make, especially before implementing them in the clinic or as therapeutic devices.

Discussion About Sodium-Concrete Reaction in Presence of Internal Heater

Sodium-concrete reaction (SCR) is one of the important phenomena during severe accidents in sodium-cooled fast reactors (SFRs) owing to the generation of large sources of hydrogen and aerosols in the containment vessel [1–3]. In this study, SCR experiments were performed to investigate the chemical reaction beneath the internal heater (800 °C), which was used to simulate the obstacle and heating effect for SCR. Furthermore, the effects of the internal heater on the self-termination mechanism were discussed. The internal heater on the concrete seemed to hinder the transport of Na into the concrete. Therefore, Na could react with the concrete at the periphery of the internal heater. The concrete ablation depth at the periphery was larger than under the internal heater. However, the Na concentration around the reaction front was about 30 wt.% despite the position of the internal heater. The Na concentration was similar to that of Na2SiO3, which was almost same as that in our past study [4–5]. It was found that the Na concentration condition was one of the dominant parameters for the self-termination of SCR, even in the presence of the internal heater.