For a virtual problem-based learning (PBL) class in Metaverse, an eye blinking system for avatars was introduced. It correlated their eye blinking behavior with an emotional response to various problems that they were asked to discuss on behalf of their users. Three Japanese college students joined the project where they discussed a simple and difficult problem, respectively. Teachers proposed online (mathematical problems) for them. Each session was 10minutes in length. During the classes, the number of eye blinks was recorded for each student by using special software. After completing the PBL classes, the students answered questionnaires. Then the results were analyzed. All of the results suggested that the difficult question would make students’ feelings unstable and increase the number of eye blinks. Using this system, teachers could analyze students’ responses well to achieve a better outcome of virtual PBL

Biofilms have caused many problems, not only in the industrial fields, but also in our daily lives. Therefore, it is important for us to control them by evaluating them properly. There are many instrumental analytical methods available for evaluating formed biofilm qualitatively. These methods include the use of Raman spectroscopy and various microscopes (optical microscopes, confocal laser microscopes, scanning electron microscopes, transmission electron microscopes, atomic force microscopes, etc.). On the other hand, there are some biological methods, such as staining, gene analyses, etc. From the practical viewpoint, staining methods seem to be the best due to various reasons. Therefore, we focused on the staining method that used a crystal violet solution. In the previous study, we devised an evaluation process for biofilms using a color meter to analyze the various staining situations. However, this method was complicated and expensive for practical engineers. For this experiment, we investigated the process of using regular photos that were quantified without any instruments except for digitized cameras. Digitized cameras were used to compare the results. As a result, we confirmed that the absolute values were different for both cases, respectively. However, the tendency of changes was the same. Therefore, we plan to utilize the changes before and after biofilm formation as indicators for the future.

The blend education of e-learning and hands-on activity was carried out, using Metaverse. The topic was picked up, relating to radioactivity, nuclear safety education and STEM education. The students were six 5th and 6th graders in an elementary school. The lecture was given to them through the virtual class in Metaverse (Second Life). And then, the hands-on experiments relating to radioactivity were carried out in real life, lead and guided by the teacher in Second Life synchronistically and supported by the teacher in real life sometimes. The questionnaire given to each of students after the hands-on experiments showed very clearly that the project satisfied with the original goals very well, from both viewpoints of STEM education and nuclear safety education at early stage (pre secondary) levels. We concluded that the blend education worked well for STEM education to much extent

In this study, we examined the relationship between the effect of a zinc coating on protecting carbon steel against biofilm formation in both air and water environments. SS400 carbon steel coupons were covered with a zinc thermal spray coating or copper thermal spray coating. Coated coupons were exposed to either air or water conditions. Following exposure, the surface conditions of each coupon were observed using optical microscopy, and quantitatively analyzed using an x-ray fluorescence analyzer. Debris on the surface of the coupons was used for biofilm analysis including crystal violet staining for quantification, Raman spectroscopic analysis for qualification, and microbiome analysis. The results showed that the zinc thermal spray coating significantly inhibited iron corrosion as well as biofilm formation in both air and water environments. The copper thermal spray coating, however, accelerated iron corrosion in both air and water environments, but accelerated biofilm formation only in a water environment. microbially-influenced-corrosion-related bacteria were barely detected on any coupons, whereas biofilms were detected on all coupons. To summarize these results, electrochemical corrosion is dominant in an air environment and microbially influenced corrosion is strongly involved in water corrosion. Additionally, biofilm formation plays a crucial rule in carbon steel corrosion in both air and water, even though microbially-influenced-corrosion-related bacteria are barely involved in this corrosion.

In marine environments and water systems, it is easy for many structures to form biofilms on their surfaces and to be deteriorated due to the corrosion caused by biofilm formation by bacteria. The authors have investigated the antibacterial effects of metallic elements in practical steels so far to solve food-related problems, using Escherichia coli and Staphylococcus aureus. However, from the viewpoint of material deterioration caused by bacteria and their antifouling measures, we should consider the biofilm behavior as aggregate rather than individual bacterium. Therefore, we picked up Pseudomonas aeruginosa and Pseudoalteromonas carageenovara in this study, since they easily form biofilms in estuarine and marine environments. We investigated what kind of metallic elements could inhibit the biofilm formation at first and then discussed how the thin films of those inhibitory elements on steels could affect biofilm formation. The information would lead to the establishment of effective antifouling measures against corrosion in estuarine and marine environments.