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The Briggs Rauscher reaction (BR reaction) is one of the famous oscillating reactions; the aqueous mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch exhibit color change between yellow and blue-purple repeatedly. The blue-purple color formation is due to the iodine test reaction caused by inclusions of polyiodides such as I3- and I5- in the helical structure of starch. Therefore, starch has been regarded as only an indicator in the BR reaction. But our seniors have found that the oscillation did not last without starch. They hypothesized that starch’s linear helical framework is necessary to elongate the lifetime of the oscillating reaction. If this hypothesis is correct, similar BR-type oscillations must be observed when other polymers with helical structures are used instead of starch. We found the literature which reports that polyvinyl alcohol (PVA) forms a helical structure and indicates the iodine test reaction. In our research, we studied the BR reactions using PVA, with different saponification degrees and viscosities. First, we studied the correlation between the structural features of PVA and the iodine color reaction by spectroscopic approach, exhibiting that PVA with low saponification form helical structures and show the iodine color reactions, which gives red color solutions. Second, we found that additions of the helical-structured PVA to the reaction solution instead of starch induces the BR-type oscillating reactions, while PVA without helical structure induces only a few numbers of oscillations. This is the world-first example of the oscillating reaction using PVA. The oscillation that lasted for 6 minutes with 23 oscillations was almost the same as that of the general BR reaction using starch. We concluded that the polymers with helical structures are intrinsic to elongate the lifetime of the BR reaction. Furthermore, we found that the addition of K3[Fe(CN)6], which has a high redox activity, in the reaction solution with PVA drastically elongated the lifetime (50 min) and increased the numbers of the oscillations (nearly 100 times). This result suggests that the oxidation-reduction reactions by the ferricyanide ion promotes the redox process of iodine and iodide ions.

The Briggs Rauscher reaction (BR reaction) is one of the famous oscillating reactions; the aqueous mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch exhibit color change between yellow and blue-purple repeatedly. The blue-purple color formation is due to the iodine test reaction caused by inclusions of polyiodides such as I3- and I5- in the helical structure of starch. Therefore, starch has been regarded as only an indicator in the BR reaction. But our seniors have found that the oscillation did not last without starch. They hypothesized that starch’s linear helical framework is necessary to elongate the lifetime of the oscillating reaction. If this hypothesis is correct, similar BR-type oscillations must be observed when other polymers with helical structures are used instead of starch. We found the literature which reports that polyvinyl alcohol (PVA) forms a helical structure and indicates the iodine test reaction. In our research, we studied the BR reactions using PVA, with different saponification degrees and viscosities. First, we studied the correlation between the structural features of PVA and the iodine color reaction by spectroscopic approach, exhibiting that PVA with low saponification form helical structures and show the iodine color reactions, which gives red color solutions. Second, we found that additions of the helical-structured PVA to the reaction solution instead of starch induces the BR-type oscillating reactions, while PVA without helical structure induces only a few numbers of oscillations. This is the world-first example of the oscillating reaction using PVA. The oscillation that lasted for 6 minutes with 23 oscillations was almost the same as that of the general BR reaction using starch. We concluded that the polymers with helical structures are intrinsic to elongate the lifetime of the BR reaction. Furthermore, we found that the addition of K3[Fe(CN)6], which has a high redox activity, in the reaction solution with PVA drastically elongated the lifetime (50 min) and increased the numbers of the oscillations (nearly 100 times). This result suggests that the oxidation-reduction reactions by the ferricyanide ion promotes the redox process of iodine and iodide ions.

Inhibitory effects of the secondary metabolite of actinomycete were examined on cell cycle of the yeasts of S. pombe and S. cerevisiae. The secondary metabolite was obtained from cultivation of the actinomycete isolated from the soil of Owakudani in Hakone, Japan. The fifth fraction of the secondary metabolite by ODS column separation (HK-T5), which was soluble to pure methanol, was used in the present experiments. The HK-T5 brought about the delay of forming colonies of S. pombe for about 11 days compared to that cultivated without the HK-T5. The delay of the colony formation was longer for the S. pombe cultivated with more amount of the HK-T5. The cultivation with HK-T5 also brought about the extension of the lifespan of the S. pombe for more than 10 weeks in a liquidus medium. The cell life recovered the ordinary manner by removal of the HK-T5, meaning that the activities of the HK-T5 is reversible. These facts confirm the suppression of cell cycle, and the delay of cell growth by the HK-T5. These phenomena were similarly observed for S. cerevisiae. Comparison of the action of HK-T5 with hydroxyurea, which is an anticancer drug inhibiting the cell cycle at S phase, clarified that the inhibitory action of HK-T5 worked at the phase earlier than S phase. The combined effects of HK-T5 on the cell cycle were evaluated with triamcinolone acetonide (TA), or aspirin, the former of which is a drug synchronizing cancer cells in S phase, and the latter keeping human cells in G1/G0 phases. The combined use of HK-T5 with TA synchronized the cells at the phase slightly proceeding from G1 to S phase without toxicity. On the other hand, the combined use with aspirin made the inhibitory effect of HK-T5 inactive. Hence, the HK-T5 is attractive as a drug for the extension of cell lifespan, and anticancer therapy.

Inhibitory effects of the secondary metabolite of actinomycete were examined on cell cycle of the yeasts of S. pombe and S. cerevisiae. The secondary metabolite was obtained from cultivation of the actinomycete isolated from the soil of Owakudani in Hakone, Japan. The fifth fraction of the secondary metabolite by ODS column separation (HK-T5), which was soluble to pure methanol, was used in the present experiments. The HK-T5 brought about the delay of forming colonies of S. pombe for about 11 days compared to that cultivated without the HK-T5. The delay of the colony formation was longer for the S. pombe cultivated with more amount of the HK-T5. The cultivation with HK-T5 also brought about the extension of the lifespan of the S. pombe for more than 10 weeks in a liquidus medium. The cell life recovered the ordinary manner by removal of the HK-T5, meaning that the activities of the HK-T5 is reversible. These facts confirm the suppression of cell cycle, and the delay of cell growth by the HK-T5. These phenomena were similarly observed for S. cerevisiae. Comparison of the action of HK-T5 with hydroxyurea, which is an anticancer drug inhibiting the cell cycle at S phase, clarified that the inhibitory action of HK-T5 worked at the phase earlier than S phase. The combined effects of HK-T5 on the cell cycle were evaluated with triamcinolone acetonide (TA), or aspirin, the former of which is a drug synchronizing cancer cells in S phase, and the latter keeping human cells in G1/G0 phases. The combined use of HK-T5 with TA synchronized the cells at the phase slightly proceeding from G1 to S phase without toxicity. On the other hand, the combined use with aspirin made the inhibitory effect of HK-T5 inactive. Hence, the HK-T5 is attractive as a drug for the extension of cell lifespan, and anticancer therapy.

In order to recycle disposable diapers, we investigated the conditions where sodium sesquicarbonate (Chemical formula Na2CO3・ NaHCO3・ 2H2O hereinafter called sesqui) precipitates selectively from sodium carbonate and the conditions for high yield. For the selective precipitation of sesqui, we defined the time required for the reaction solution to pass through the sesqui precipitation area in the Na2CO3-NaHCO3-H2O phase diagram (45°C) as Δ t. As a result, we revealed that Δt is involved in the selective precipitation of sesqui, and that we can synthesize sesqui without the expensive addition of L-Arginine as used in a previous research. Also, we proposed the “Stay method”, in which the supply of CO2 is stopped for 30 minutes to the lengthen the Δ t, and found that we could synthesize sesqui selectively even under conditions in which sodium bicarbonate is likely to be precipitated as well. Regarding the high yield of sesqui, the yield was greatly improved by the common ion effect of Na by adding NaOH to the reaction solution, sesqui synthesis by repeated reactions with CO2, and sesqui recovery by adding the anti-solvent ethanol, reaching a sesqui conversion rate of 95%. This means 109 g of sesqui can be synthesized from 100 g of Na2CO3. Moreover, we confirmed that these synthesized samples have almost the same detergency as commercial sesqui. We did a test calculation to reveal the usefulness of this research. First, if diaper recycling technology is put into practical use and all used diaper waste in Saijo City can be recycled, a reduction of 534 t/year of used diaper waste can be expected. This corresponds to a 2.3% reduction in Saijo City's waste output. From the ash that would ultimately remain after being recycled, we expect up to 35.3 t/year of synthesized sesqui using our experimental method. In addition, a CO2 reduction of 8.2 t/year is possible in the process, which is about equivalent to the volume of one gymnasium.

We elucidated the cause of the phenomenon, in which silver deposits on a bamboo charcoal when the bamboo charcoal is soaked in an AgNO3 water solution. From the experimental results, we considered that the hydrogen which is generated while the bamboo wood is carbonized is chemisorbed as C-H bonds on the surface edge of charcoal (the end of the carbon), and that these hydrogen atoms become hydrogen ions,which then reduce the silver ions and deposit silver. In addition, we created a graph of the mass of deposited silver versus the mass of charcoal, and the graph showed that the mass of deposited silver was strongly correlated with the surface area calculated from the mass of the charcoal. Besides, we showed that charcoal can be used in applications for the treatment of inorganic liquid waste, depositing metals from inorganic liquid waste by bamboo charcoals. Also, the charcoal is used for interior decoration because of its deodorizing effect and beauty. In our study, we create a work of art used silverdeposited charcoal with a motif of Karesansui (Traditional Japanese rock garden).

We invented the Midori which means green Bioreactor (MBR), beads of euglena and other microalgae fixed in calcium alginate that absorbs carbon dioxide (CO2). We examined the effect of 19 different solutions and two different organisms on MBR cultivation. Surprisingly, when the MBR was supplied with carbon dioxide or cultured with yeast, they became drastically darker green. Chromatography revealed this green color to be that of microalgae such as green algae or Euglena because chlorophyll a and chlorophyll b were detected. Under sunlight, MBR absorbed CO2 and the absorption rate was 1.5 L CO2/day/1L of MBR. Furthermore, when we put MBR in the water tank, they increased the amount of dissolved oxygen without polluting the environment. These results indicate that MBR can absorb CO2 by photosynthesizing without leaking out the inside microalgae.

When doing an experiment to produce colloidal ferric hydroxide, the bottom of the beaker used was colored in yellow-brown with thin film interference. This phenomenon is well-known, but the cause has not been clearly studied. As a result of the research, the coloration on the bottom of the beaker is caused by β-FeOOH forming a thin film which is chemically bonded with Si-OH on the glass surface. Also, the amount of β-FeOOH depends on the number of experiments, the area of the bottom of the beaker, and the concentration of FeCl3 aq. We found that it can be possible to determine the amount of β-FeOOH from the formula m=knsc and the adhesion constant was found to be 6.8✕10-3 (L/m2). In addition, from machine learning we predicted that the thin film thickness becomes thicker as it moves away from the center.

There are many active volcanoes in Kagoshima Prefecture, including Sakurajima Volcano. So, the volcanic disaster prevention is an urgent issue. Also, Hirabayashi of Tokyo Institute of Technology reported that the molar ratio of HCl/SO2 is large during periods of high HCl/SO2 and conversely small during periods of low HCl/SO2 , and that explosions increase one month after the molar ratio of HCl/SO2 increases during periods of no explosions. We decided to determine the composition ratio of volcanic gases (sulfur dioxide, hydrogen chloride, and hydrogen fluoride) emitted from Sakurajima crater in order to understand and predict volcanic activities. Th us, we established a simple collection method for volcanic gases using alkaline filter paper and a quantitative method using a self m ade absorbance photometer so that even high school students could perform the measurement at many points, and we discussed the data from various perspectives. Furthermore, since last year, we have found a correlation between the variation of Cl-/SO2 ratio and the number of eruptions at Sakurajima volcano. Also, a model for the behavior of volcanic gases was developed based on a comparison of the amount of volcanic ash and the number of eruptions.

The study aimed to resolve global phosphate scarcity by developing a cost-effective method for phosphorus recovery from industrial wastewater. In existing wastewater treatment, oxidizing phosphite ions (PHO32-) posed a significant challenge. However, our research aimed to develop an effective method for this oxidation process, crucial for phosphorus recovery in industrial wastewater treatment. By utilizing low-cost iron compounds and innovative catalysts, such as iodine obtained from seawater and copper, we achieved remarkable success. Our method demonstrated the ability to oxidize over 80% of PHO32- into phosphate ions (PO43-) within 120 minutes, overcoming the limitations of existing costly methods involving palladium catalysts or high-voltage conditioned ozone (O3). Moreover, the process exhibited profitability, with a gross profit of $1.84 per kilogram of phosphorus, presenting a drastic reduction in cost compared to conventional methods using palladium catalysts. This breakthrough not only offers sustainable wastewater purification but also promises a pathway for resource recovery. Additionally, our future prospects involve refining this method into a device capable of purifying industrial wastewater and recovering phosphorus, emphasizing sustainability and reduced power consumption through innovative techniques like using iron and carbon plates forming a battery. This novel technology represents a sustainable solution utilizing abundant resources such as iodine from seawater, iron, and calcium, paving the way for sustainable phosphorus resource recovery.