A5063445271- Concrete Corrosion and Durability
- Non-Destructive Testing Techniques
- Corrosion Behavior and Inhibition
- Ultrasonics and Acoustic Wave Propagation
- Photoreceptor and optogenetics research
- Infrastructure Maintenance and Monitoring
- Rock Mechanics and Modeling
- Structural Response to Dynamic Loads
- Structural Health Monitoring Techniques
- Geophysical Methods and Applications
- Concrete and Cement Materials Research
- Neuroscience and Neuropharmacology Research
- Hydrogen embrittlement and corrosion behaviors in metals
- Innovations in Concrete and Construction Materials
- Geotechnical Engineering and Underground Structures
- Earthquake and Tsunami Effects
- Material Properties and Processing
- Materials Engineering and Processing
- Structural Behavior of Reinforced Concrete
- Evacuation and Crowd Dynamics
- Engineering Applied Research
- Retinal Development and Disorders
- Smart Materials for Construction
- Mechanical Failure Analysis and Simulation
- Molecular Communication and Nanonetworks
The University of Tokyo
2021-2024
Ritsumeikan University
2015-2024
Institute for Solid State Physics and Optics
2023
Ibaraki National College of Technology
2022
Hitachi (Japan)
2022
Hiroshima City University
2021
Kumamoto University
2010-2016
Abstract Microbial rhodopsins are a family of photoreceptive membrane proteins with wide distribution across the Tree Life. Within candidate phyla radiation (CPR), diverse group putatively episymbiotic bacteria, genetic potential to produce appears be confined small clade organisms from sunlit environments. Here, we characterize metabolic context and biophysical features Saccharibacteria Type-1 rhodopsin sequences derived metagenomic surveys show that these function as outward proton pumps....
Abstract: Concrete structures could suffer from the corrosion of reinforcing steel bars (rebars) because penetration chloride ions. For crack detection and damage evaluation in concrete, acoustic emission (AE) techniques have been extensively applied to concrete structures. In process reinforced it is demonstrated that continuous AE monitoring available identify onset nucleation cracking expansion products. At latter stage, products generates corrosion‐induced cracks concrete. The generating...
Schizorhodopsins (SzR), a sub-family of microbial rhodopsin, are light-driven inward proton pumps using retinal chromophore. Here, we studied new SzRs, MtSzR and MsSzR, from methanogenic archaea (genus Methanoculleus) reported as mesophilic sampled at hot spring, respectively. While MsSzR exhibited transport, they were more stable against high temperature compared with SzR (SzR1) non-high-temperature environment. The Arrhenius plots heat-denaturation rates amino acid sequences suggested...
Heliorhodopsins (HeRs) are a new category of rhodopsins. They exist as dimer and exhibit characteristic inverted topology. HeRs bind all-trans-retinal chromophore in the dark, its isomerization to 13-cis form by light illumination leads photocyclic reaction involving several photo-intermediates: K, L, M, O. In this study, kinetics conformational changes HeR from Thermoplasmatales archaeon SG8-52-1 (TaHeR) were studied transient grating (TG) circular dichroism (CD) methods. The TG method...
Corrosion of reinforcing steel bar is a critical issue in concrete structures. In response, variety techniques have been developed for early detection corrosion phenomena, including nondestructive evaluation (NDE) techniques. Recently, we reported that continuous acoustic emission (AE) monitoring applicable to identify the onset and nucleation corrosion-induced cracks due expansion products. order clarify kinematics these AE activities concrete, cyclic wet dry tests on reinforced beams were...
2011年東日本大震災では,数多くの橋が津波によって流された.橋の流出を防ぐためには,支承や落橋防止構造の耐力を上げる構造力学的対策と,桁断面形状を変えることによる流体力学的対策とが考えられる.本研究では,整流板を桁に取り付けることによる流体力学的対策について実験的に検討した.桁の側面に直線状や半円状の整流板を取り付け,桁に作用する流体力を計測するとともに,桁周辺の流況を観察した.その結果,四角形の整流板を取り付けることにより揚力を軽減することができたが,水平力は変わらなかった.一方,三角形の整流板や半円形の整流板では水平力も鉛直力も軽減することができた.また,津波が橋に到達する際には,水だけではなく漂流物の衝突も問題となる.氷を流した実験より,特に揚力に影響があることがわかった.
Conference paper written by Yuma Kawasaki, Naoto Teramura, Katsuyoshi Nozaka and Kazuyuki Izuno presented at IABSE Workshop: Safety, Robustness Condition Assessment of Structures, Helsinki, Finland, 11-12 February 2015.
In this work, the acoustic emission (AE) technique is used to evaluate fracture process of corroded and healthy reinforced concrete (RC) beams subjected a monotonic bending test. fact, many researchers have conducted laboratory experiments considering different conditions perform rebar corrosion monitoring in RC structures using AE method. However, previous studies not investigated evolution performance at degrees, interaction single with concrete. study, electrically are evaluated, levels....
我が国の橋梁には，1995年に発生した兵庫県南部地震以降，積層ゴム支承が積極的に導入された．近年，経年劣化や地震などにより，積層ゴム支承の損傷が報告されている．しかし，ゴム支承内部を含めた損傷度評価が困難であり検査手法もないのが現状である．本研究では，非破壊検査法の一つであるアコースティック・エミッション（AE）法を用いた損傷評価について検討した． 事前にせん断試験を受けた供試体を使用して，繰返し圧縮載荷による試験を行った．その結果，もっとも大きな負荷履歴を有する供試体において特徴的なAEパラメータ挙動が確認され，マイクロスコープによる観察においても内部の損傷が確認された．さらに，現地計測においても同様の結果が得られ，交通荷重による加振のみでAE法によるゴム支承の損傷評価ができることを示した．
1995年の兵庫県南部地震以降,ゴム支承の採用事例が増えた.しかし,それから20年以上経過した近年,ゴム支承の経年劣化の顕在化や大地震によるゴム支承の破断が報告されている.しかし,現在までにゴム支承の損傷度を評価できる手法は明確にされていない.著者らは,非破壊試験法の一つであるAcoustic Emission(AE)法を用いて,損傷したゴム支承の損傷評価に取り組んできた.その既往の研究成果から,せん断載荷を受けたゴム支承に対してAE計測を行い,特徴的なAE現象が確認された.しかし,せん断試験前にAE計測を実施しておらず,それらのAE現象がせん断載荷に伴う損傷によるものか確認していなかった.本稿では,せん断試験前後で繰返し圧縮載荷試験を行いAEモニタリングを実施した.その結果,せん断試験前と後で異なるAE特性が確認された.