• Analytical Science and Technology
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• v.11 no.1
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• pp.20-28
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• 1998

Fluorimetric and absorption spectroscopic studies were performed to elucidate the photocurrent decay with time in the conversion process of solar energy into electrical energy using a photoelectrochemical cell containing rose bengal as a sensitizer, and allylthiourea as a supersensitizer. Spectra of dye solution before and after irradiation revealed a new photocatalytic dimerization reaction between sensitizer and supersensitizer. It was also found that the geometrical arrangement of the transition dipoles is oblique in the dimer of dye molecules.

• Analytical Science and Technology
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• v.11 no.1
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• pp.13-19
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• 1998

In the dye sensitization for the solar energy conversion with a photoelectrochemical cell containing allylthiourea, the time profile of the sensitized photocurrent showed a rise and fall with the irradiation time. The dye solution before and after irradiation was analyzed by means of spectroscopic methods. A new precipitation reaction between sensitizer and supersensitizer and photobleaching of the dye appeared to be involved in the decreased photocurrent.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.719-723
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• 2013

Nitrification in wastewater treatment emits a significant amount of nitrous oxide ($N_2O$), which is one of the major greenhouse gases. However, the actual mechanism or metabolic pathway is still largely unknown. Selective nitrification inhibitors were used to determine the nitrification steps responsible for $N_2O$ emission with activated sludge and enriched nitrifiers. Allylthiourea (86 ${\mu}M$) completely inhibited ammonia oxidation and $N_2O$ emission both in activated sludge and enriched nitrifiers. Sodium azide (24 ${\mu}M$) selectively inhibited nitrite oxidation and it led to more $N_2O$ emission than the control experiment both in activated sludge and enriched nitrifiers. The inhibition tests showed that $N_2O$ emission was mainly related to the activity of ammonia oxidizers in aerobic condition, and the inhibition of ammonia monooxygenase completely blocked $N_2O$ emission. On the other hand, $N_2O$ emission increased significantly as the nitrogen flux from nitrite to nitrate was blocked by the selective inhibition of nitrite oxidation.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.75-80
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• 1992

The electrochemical spectral sensitization of a $SnO_2$ electrode with eosin B, a Xanthene dye, has been studied in acetonitrile. Measurements of the photocurrent have been carried out in the presence of supersensitizers such as thiourea, 1-allyl-2-thiourea, NaSCN, and NaI. The magnitude of the supersensitized photocurrent was greater than that of the sensitized photocurrent for all of the supersensitizers studied. However, the long time span of irradiation causes a significant decrease of the supersensitized photocurrent as well as the absorbance. These results, together with infrared spectra and fluorescence spectra, are taken into account to elucidate the mechanism of photoreaction between eosin B and supersensitizers in acetonitrile.