Sustainable Biological Ammonia Production towards a Carbon-Free Society

脱炭素・次世代エネルギーとしてのアンモニアの食品加工廃棄物からのバイオ生産プラットフォーム --脱炭素社会構築へのバイオテクノロジーによる貢献をめざして--. 京都大学プレスリリース. 2021-09-06.A sustainable society was proposed more than 50 years ago. However, it is yet to be realised. For example, the production of ammonia, an important chemical widely used in the agriculture, steel, chemical, textile, and pharmaceutical industries, still depends on fossil fuels. Recently, biological approaches to achieve sustainable ammonia production have been gaining attention. Moreover, unlike chemical methods, biological approaches have a lesser environmental impact because ammonia can be produced under mild conditions of normal temperature and pressure. Therefore, in previous studies, nitrogen fixation by nitrogenase, including enzymatic ammonia production using food waste, has been attempted. Additionally, the production of crops using nitrogen-fixing bacteria has been implemented in the industry as one of the most promising approaches to achieving a sustainable ammonia economy. Thus, in this review, we described previous studies on biological ammonia production and showed the prospects for realising a sustainable society

Are the Epiphytic Animal Communities in the Sargassum Forests off the Pacific Coast of Miyagi Recovering from the Alteration Caused by the 2011 Tsunami?

Oral Presentation

Possible Use of Blue Light in Undaria Pinnatifida Aquaculture

Symposium mini revie

Monoaxial Dzyaloshinskii-Moriya interaction-induced topological Hall effect in a new chiral-lattice magnet GdPt2_2B

We investigate the topological Hall effect (THE) in the monoaxial chiral crystal GdPt$_2$B, a recently discovered compound that exhibits putative helimagnetism below 87 K. The distinct THE was observed in GdPt2B in the magnetically ordered state. The scaling relations for anomalous and topological Hall conductivities differed from those of conventional models based on the scattering process. We further demonstrate the clear scaling behavior of the THE in a wide temperature range, which we attribute to the monoaxial Dzyaloshinskii-Moriya (DM) interaction under external magnetic fields perpendicular to the screw axis. The THE induced by the monoaxial DM interaction as well as the THE in a monoaxial chiral crystal of f-electron system are demonstrated in this study.Comment: 6 pages, 4 figures. To be published in Phys. Rev.

Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO1−x_{1-x}Fx_x}

For a newly discovered iron-based high $T_c$ superconductor LaFeAsO$_{1-x}$F$_x$, we have constructed a minimal model, where inclusion of all the five Fe $d$ bands is found to be necessary. Random-phase approximation is applied to the model to investigate the origin of superconductivity. We conclude that the multiple spin fluctuation modes arising from the nesting across the disconnected Fermi surfaces realize an extended s-wave pairing, while d-wave pairing can also be another candidate.Comment: 5 pages, 2 figures, to be published in Phys. Rev. Let