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Seismic performance evaluation of a century‐old RC columns for railway's structural concrete
Get PDFSince the Great Kanto Earthquake of 1923 in Japan, reinforced concrete (RC) has been adopted for railway bridge piers, and some of these structures, now over 100 years old, continue to support transportation in the capital city of Tokyo. Evaluating the seismic performance of these few remaining RC structures has become an urgent issue. Because these structures predate the industrialization of deformed bars, all reinforcing bars used were plain round bars, and the anchorage details differ significantly from current design specifications, which are based on deformed bars. Therefore, current seismic performance evaluation methods cannot be directly applied to them. This study experimentally verifies the seismic performance of century-old RC columns through a series of component experiments and, as a part of this effort, develops a nonlinear response analysis method for RC columns using round bars with inferior bond characteristics. As a result, it was shown that many RC bridge piers designed and constructed 100 years ago still provide sufficient deformation capacity, owing to large rotational capacities induced by pull-out of longitudinal reinforcement from the footing. This also reduces damage to structural concrete in the column body, indicating that a number of these structures still may satisfy current seismic performance requirements, an assessment scheme of which is proposed practically as well
Selection of microbes and seaweeds suitable for fermentation of biomass fuels and study on fermentation methods
Get PDF横浜国立大学博士（工学）Doctor of Engineerin
<Articles>Rethinking Adult Support and Protection in Japan: Towards a Rights-Based and Culturally Responsive Framework (Part 1)
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Dissociation and Diffusion of Glyme-Sodium Bis(trifluoromethanesulfonyl)amide Complexes in Hydrofluoroether-Based Electrolytes for Sodium Batteries
Get PDFGlymes (Gn, CH3−O−(CH2−CH2−O)n−CH3) form complexes in certain molar ratios with metal ions such as Li+, Na+, K+, Mg2+, and Al3+ owing to the electron-pair donating ability of ether oxygen atoms.1−13 Ether oxygen atoms have lone pairs, and the electrostatic and induction interactions between the oxygen atoms and the metal ion result in complex formation.14 The crystal structures and physicochemical properties of [M(glyme)x]Xy (M: metal ion, X: counter anion) complexes have been previously established.1-13 The metal ion interacts with the ligand (glyme) as well as with the anion in the [M(glyme)x]Xy complex with the ligand and anion conferring significant effects on the physicochemical properties of the complex.15−19 Previously, we reported the electrochemical properties and battery applications of such complexes.20−29 In the case of the [Li(glyme)][TFSA] (TFSA: bis(trifluoromethanesulfonyl)amide) complex, the Li+ forms a 1:1 complex with the glyme molecule when the glyme chain length (n) is 3 or 4. [Li(G3 or G4)][TFSA] complexes are low melting and remain in the liquid state at room temperature.30,31 Pappenfus et al. pointed out that the [Li(G4)][TFSA] can be regarded as an ionic liquid and shows ionic conductivity at ambient temperature.30 Our recent studies demonstrated that the molten [Li(glyme)][TFSA] complexes are solvate ionic liquids consisting of [Li(glyme)]+ and [TFSA]−.16,17 The molten [Li(glyme)][TFSA] partially dissociates into complex cation and anion, has ionic conductivity, and can be used as electrolytes for Li batteries.22−27 In this study, we investigated the [Na(glyme)][TFSA] complexes as electrolytes for Na batteries. Na batteries are attracting attention because Na is earth-abundant compared to Li. In the case of the [Na(glyme)][TFSA] complex, Na+ forms a 1:1 complex with a glyme molecule when the chain length, n, is 4 or 5.9,10 The melting points of [Na(G4)][TFSA] and [Na(G5)][TFSA] are 72 and 32 °C, respectively. [Na(G5)][TFSA] remains in the liquid state as a supercooled liquid at room temperature while [Na(G4)][TFSA] remains in the solid state. Molten [Na(G5)][TFSA] shows a low ionic conductivity of 0.6 mS cm−1 at 30 °C.29 Using a molten complex as an electrolyte for Na batteries at room temperature is challenging because the low ionic conductivity causes high internal resistance in the cells. To utilize [Na(glyme)][TFSA] complexes in Na batteries at room temperature, the addition of another solvent is a facile and effective way to lower viscosity and enhance ionic conductivity. The complexes of [M(glyme)][TFSA] can dissolve into various solvents.32 Interestingly, low polar solvents such as toluene are also miscible with [M(glyme)][TFSA] and can be used as electrolyte solutions. In this work, a hydrofluoroether (HFE), 1,1,2,2–tetrafluoroethyl 2,2,3,3–tetrafluoropropyl ether (CF2H−CF2−O−CH2−CF2−CF2H), was used as the solvent for electrolyte solutions of [Na(G4 or G5)][TFSA]. The HFE is a low polar solvent, and is chemically stable and non-flammable.25,33 Previously, we prepared electrolyte solutions of [Li(glyme)][TFSA]/HFE and used these as electrolytes for Li-S batteries.25 The addition of HFE increased ionic conductivity and was effective in improving battery performance. In this work, we elucidated the solvation structures of Na+ and ion-pair formations in the [Na(G4 or G5)][TFSA]/HFE solutions using Raman spectroscopy. In addition, the self-diffusion coefficients of ions in [Na(G4 or G5)][TFSA]/HFE were measured using pulsed field gradient (PFG) NMR, and the dissociativity, so called “ionicity”,34 of [Na(G4 or G5)][TFSA] was evaluated in solution. Ionicity is correlated with Na+ solvation structures and ion-pair formation. Finally, the [Na(G4 or G5)][TFSA]/HFE solutions were used as electrolytes in Na batteries. The relationships between electrolyte properties and battery performance are discussed
Oxygen Reduction Reaction in Highly Concentrated Electrolyte Solutions of Lithium Bis(trifluoromethanesulfonyl)amide/Dimethyl Sulfoxide
Get PDFThe performance of current Li-air batteries is greatly limited by critical obstacles such as electrolyte decomposition, high charging overpotentials, and limited cycle life. Thus, much effort is devoted to fundamental studies in order to understand the mechanisms of discharge/charge processes and overcome the above mentioned obstacles. In particular, the search for new stable electrolytes is vital for long lasting and highly cyclable batteries. The highly reactive lithium superoxide intermediate (LiO2) produced during discharge process can react with the electrolyte and produce a variety of byproducts that will shorten battery life span. To study this degradation mechanism we investigated oxygen reduction reaction (ORR) in highly concentrated electrolyte solutions of lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA])/dimethyl sulfoxide (DMSO). Based on rotating ring disk electrode measurements we showed that LiO2 dissolution can be limited by increasing lithium salt concentration over 2.3 mol dm−3. Our Raman results suggested that this phenomenon can be related to lack of free DMSO molecules and increasing DMSO-Li+ interactions with higher Li+ concentration. X-ray diffraction measurements for the products of ORR suggested that the side reaction of DMSO with Li2O2 and/or LiO2 could be suppressed by decreasing the solubility of LiO2 in highly concentrated electrolytes
Sustainability of Public Interest Foundations in Managing the Assets of Older Adults: Strategies for Collaboration with Corporations and Local Governments, and Human Resource Development
Get PDF現状の課題
日本は急速な高齢社会に突入しており、特に認知症高齢者の増加にともない、財産管理支援の社会的需要が飛躍的に高まっている。これまで主流であった家族や親しい第三者による非公式な支援は、単身高齢者の増加、核家族化、地域とのつながりの希薄化により限界を迎えている。一方、米国、シンガポール、オーストラリア・ビクトリア州などの先進国では、法制度を活用し、弁護士、金融事業者、公的財産管理機関、行政が連携し、多層的かつ持続可能な支援体制の構築が進んでいる。日本でも、成年後見制度利用促進法や「持続可能な権利擁護推進事業」などの法的・政策的枠組みにより、地域連携型の支援体制整備が推進されているが、地域間格差、専門人材や財源の不足といった構造的課題が依然として存在する。このような状況下で、公益法人が高齢者財産管理支援の新たな担い手として期待されており、とくに地域に根ざした有力企業の参画と専門性の高い人材の確保が、公益法人の持続的運営の鍵となる。
研究目的と手法
本稿は、国内外の先進事例と現行制度を参照しつつ、公益法人が高齢者の財産管理支援において中核的役割を担うための人的・組織的戦略を提示することを目的とする。具体的には、企業の社会的責任や地域貢献の観点からの持続的スポンサーシップのあり方、専門人材の確保と育成、地方自治体との協働体制の構築など、多角的な視点から検討を行った。政府の政策動向を踏まえ、法学、政策学を中心とした学際的な文献調査研究を実施している。
結論
本稿の考察から、高齢社会における財産管理支援を担う公益法人が信頼性のある支援主体となるためには、実務能力と倫理性を兼ね備えた専門人材の育成と組織機能の強化が不可欠であることが明らかとなった。くわえて、企業からの持続的なスポンサーシップと、地域ニーズに即した地方自治体との協働体制を制度化することが求められる。これらの要素を統合することで、公益法人は高齢化社会の財産管理支援における中核的な役割を果たすことができる。今後は、本提案の実現に向けた中長期的なロードマップを策定し、政府、企業、学術機関がそれぞれの役割と責任を明確にした上で、具体的な取り組みを速やかに開始することを提言する。Abstract by author: Japan’s rapidly aging population and increasing prevalence of dementia necessitate a more robust institutional framework for elder financial management, particularly as traditional family-based support structures become less reliable. This paper argues that Public Interest Corporations (PICs) can serve as key institutional providers in this field and focuses on strengthening their professional human resources and organizational capacity. Drawing on comparative legal analysis and interdisciplinary scholarship, it proposes strategies for PICs to enhance professional expertise, improve organizational governance, and elevate ethical standards. The study also highlights the importance of establishing sustainable corporate sponsorship and structured collaboration with local governments. Furthermore, it presents a medium- to long-term roadmap for consolidating the role of PICs as reliable actors in elder financial management through coordinated efforts among government, industry, and academia.マーサージャパン人と仕事の未来研究所第2回懸賞論文特別賞受
