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A single atom photocatalyst co-doped with potassium and gallium for enhancing photocatalytic hydrogen peroxide synthesis
Get PDFPolymer carbon nitride (PCN) is widely used in photocatalysis. However, pristine PCN has disadvantages such as insufficient visible light absorption and low photogenerated carrier separation efficiency that greatly limited the photocatalytic efficiency. As a non-toxic metal, gallium has the potential to solve the defects of PCN. Gallium ions coordinated with nitrogen in carbon nitride to form Ga-N active sites and improved the photocatalytic activity. The doped potassium ions form a transmission channel for charge redistribution and transfer between adjacent layers, which is beneficial for better separation of photoexcited carriers. In this study, a series of PCN co-doped with gallium and potassium (Ga-K-PCN) were prepared. The experimental results indicated photocatalytic generation of hydrogen peroxide proceeds through the 2e- oxygen reduction reaction pathway. Notably, Nyquist plots and photocurrent results further proved that the presence of Ga-N sites and potassium ion doping could significantly improve the separation/transfer of intra-planar and interlayer charge carriers and thus enhance photocatalytic efficiency. The Ga10-K3-PCN photocatalysts promoted yield of H2O2, with reactivity at 28.2 μmol/(g·h) and solar-to-chemical conversion efficiency at 0.64%, surpassed that of a typical photo-catalyst based on PCN (0.18%).journal articl
Recognition of Fish in Aqua Cage by Machine Learning with Image Enhancement
Get PDFWith the gradual decrease in fisheries resources and the increasing demand for fishery production, the production of capture fisheries is saturated. On the other hand, aquaculture production is increasing rapidly and now accounts for almost half of all fishery production. In aquaculture, monitoring aqua cages and collecting basic information, such as the number of fish in the cages and their sizes, is one of the most crucial tasks. However, automation of these basic tasks is insufficient, and there is an expectation for the implementation of ICT (Information and Communication Technology) in the fisheries industry. To move towards smart fishery farms, efficient fisheries resource management is required. This paper introduces a computer vision-based fish counting system that utilizes image enhancement and machine learning algorithms to achieve automated fish counting in aqua cages. Experimental results demonstrate that the proposed method can detect fish and identify the same fish in images captured by underwater cameras set at different depths. The proposed method can contribute to fisheries management and ecological conservation.journal articl
Sol–gel multilayer coatings for spectral control of thermal radiation
Get PDFOptical properties, shrinkage, and crack formation up to 800 °C were studied on TiO2 and SiO2 sol–gel films for application to thermal radiation control. Using precursor sols comprising hydrolyzed alkoxides and polymers, high-transparency films were obtained for TiO2 and SiO2. However, after heating at high temperatures, TiO2 films exhibited a slight degradation in transmittance due to light scattering by rutile grains. For both materials film thickness decreased by nearly half by increasing the heating temperature from 130 to 800 °C, giving rise to a much smaller critical cracking thickness than that obtained at low temperatures. Within the maximum thickness of the crack-free films, we fabricated TiO2/SiO2 alternating stacks as very near-infrared optical filters that allowed the control of the radiation spectra from a plate heater. The emissivity spectra measured on the film/heater system at 750 °C indicated fair agreement with the designed optical transmittance of the stacks, proving the feasibility of applying sol–gel films to thermal radiation control.journal articl
An Investigation of the Effects of Presentation Methods for Visual Elements and Thinking Styles on Text Comprehension
Get PDFResearch has been conducted using diagrammatic elements to support the improvement of reading comprehension of expository texts, particularly in the context of declining reading comprehension skills among Japanese students. It has also been suggested that “thinking style” contributes to understanding individual differences in “thinking preferences”, which affect reading and text comprehension. Therefore, we investigated the impact of an individual’s thinking style and use of diagrammatic elements in texts on reading comprehension. We also explored which of the three most common thinking styles– planning, compliance, and evaluation– is influenced by environmental differences between online and offline settings in the context of reading comprehension. The participants were asked to read a stimulus text presented with diagrams using a specific method. We obtained mean scores and 95% confidence intervals for adapting thinking styles and tasks for each presentation method in both the online and offline environments. The mean scores on the reaffirmation task for each thinking style were checked for normality at the 1% significance level. The planning and compliance styles were analyzed using an aligned rank transform, while the evaluation style was analyzed using a two-way ANOVA. All significance levels were set at 5%. We tested the extent to which participants could comprehend the text. The results suggest that both the presentation of the diagram and thinking style significantly impact text comprehension in offline environments. By contrast, text comprehension in a unique and new online environment is not as easily influenced by factors that might be considered in a traditional face-to-face setting.journal articl
How can People Continue to Cooperate? -An Examination of the Cognitive Foundations of Sociality under Uncertainty-
Get PDFHumans are social animals and live in cooperative relationships with others. The purpose of this study was to elucidate the cognitive mechanisms underlying the maintenance of cooperative behavior, which is important for sociality. Previously, the cognitive basis of sociability was considered to be the ability to infer others' mental states correctly. However, since understanding the mental states of others is in principle uncertain, the basis of sociability is thought to be the recognition of uncertainty in one's understanding of the mental states of others. Therefore, in this study, we constructed a new social interaction task that incorporates uncertainty and continuity of others' mental states into the Prisoner's Dilemma and examined participants' cooperative behavior. 10 game experiments were conducted with 66 undergraduate students in which it was difficult to maintain cooperation. We analyzed the transition patterns of cooperation/ noncooperation, the degree of liking for the partner, and the positive attitude toward cooperation/ noncooperation, all of which were classified into two classes. The results suggest that two factors contribute to the maintenance of cooperative behavior: a positive prediction of cooperation that the partner will choose to cooperate, and the perception of uncertainty that the prediction may not always be true. The results also suggest that the perception of uncertainty about the partner's prediction of cooperative behavior may suppress the occurrence of conflict situations in group work, even when the partner is uncooperative.departmental bulletin pape
Fostered ‘Realism’: The Emergence and Expansion of the Multilayered Human Network in Postwar Japan
Get PDF本論文は「九州地区国立大学教育系・文系研究論文集」Vol.10,No.2に査読を経て受理された。journal articl
In Situ Synthesis and Characterizations of a Strontium-Substituted Dicalcium Phosphate Anhydrous/Hydroxyapatite Biphasic Whisker and Its Properties Evaluation
Get PDFDicalcium phosphate anhydrous (DCPA) presents good biomineralization ability, the strontium element is known for superior bone affinity, and a whisker possesses good mechanical strength; all these are beneficial for improving the drawbacks of hydroxyapatite (HAP) like weaker mechanical properties, poor biomineralization, and slower degradation/absorption. Therefore, a homogeneous precipitation was adopted to synthesize Sr-substituted and DCPA and HAP coexisting whiskers. The composition, structure, and morphology based on urea dosage and substitution content were characterized, and the roles of DCPA, Sr, and whisker shape were investigated. It turned out that Sr-DCPA/HAP biphasic products contained about 19% DCPA and 81% HAP, and both phases occupied the outer and inner parts of the whisker, respectively. Increasing the urea dosage made the morphology transform from a sea urchin shape to fiber clusters and then whiskers, while Sr substitution brought the whisker back to the porous microsphere shape. Only 5% of Sr content and 15 g of urea could maintain the whisker shape. Sr could promote the proliferation of MC3T3-E1 cells even at a higher extract concentration of 10 mg/mL. The cells stayed in a healthy state whether cocultured with the whisker or the microsphere. The unstable DCPA combined with the decreased crystallinity brought by Sr doping contributed to shortening the apatite deposition period to within 7 days. The whisker morphology enhanced the compressive strength of acrylic resin, and the apatite layer helped to reduce the strength loss during soaking. The Sr-DCPA/HAP biphasic whisker with enhanced overall properties possessed more promising potential for biomedical application.journal articl
