Nippon Koei (Japan)

This study proposes a framework to assess the seismic risk by integrating city‐scale numerical simulations with sensor data prediction. The study begins with advanced numerical simulations using two primary methods: the integrated earthquake simulator (IES) and the stochastic Green's function method. The stochastic Green function method is used to generate the motion from the fault model to the outcropped engineering bedrock. The IES is used to simulate the ground motion on the surface, considering different scenarios, and the sumulation results are seperated into training and validation datasets. In this study, all scenarios are generated from a single fault model, and variability is introduced by changing the rupture initiation point, representing a limited dataset but practically relevant setting. Proper orthogonal decomposition (POD) is then applied to the training datasets to extract spatial modes, and those modes are used for identifying the most suitable distributions for sensors. In this study, the sensors are strategically placed to maximize data collection efficiency while minimizing the overall number of sensors used. Optimizing sensor distribution is crucial owing to the challenges associated with deploying numerous sensors in actual situations. The distribution of sensors obtained by this method is validated using a test set generated from IES simualation. The case study focusing on Sendai city (Japan), for scenarios associated with the Nagamachi–Rifu fault, finds an optimal solution for the distribution of sensors and allows for an overall prediction of the expected accuracy. The results show that seismic risk prediction and assessment on a city scale can be achieved by this method while maintaining accuracy and the number of sensors. The present work therefore demonstrates the feasibility of the proposed rapid prediction framework under limited dataset conditions for a specific, high impact seismic source, while the extension to multiple faults and magnitudes is left for future work.

Abstract Water scarcity arises not only from chronic water shortage but also from seasonal and interannual variability. Water infrastructure fills the gaps in water requirements and sustainably available water. However, its role in mitigating water deficits and the differences across regions have been insufficiently explored. Here, we quantify the contribution of reservoirs and desalination plants (RDs) in reducing water deficits using a global hydrological model and indicators that capture spatiotemporal dynamics. We find that RDs substantially reduce global water deficits and that their functions vary regionally: seasonal reallocation dominates in Asian monsoon regions, whereas interannual buffering is more prominent in regions of the Southern Hemisphere. Globally, RDs alleviate water deficits equivalent to more than 5% of the global human water requirements on average and over 13% during drought periods. These findings provide a quantitative assessment of how water infrastructure contributes to water security across regions with differing hydroclimatic and socioeconomic conditions.

Fast frequency response (FFR) of the Battery Energy Storage System (BESS) is an effective way to mitigate the grid frequency deviations induced by the fluctuation of power generation from the variable renewable energy resources and the reduced system inertia caused by decreased number of synchronous generators. According to the above trends, several grid operators have launched the scheme of the procurement of FFR resources from the market, by specifying the technical requirements of FFR such as response speed, the deadband, and droop coefficient. Although there are many studies investigating the effect of the FFR characteristics on the grid frequency stabilization, most of them have been performed using either offline time-domain simulation or hardware-in-the-loop simulation. This paper exhibits the operational waveform of the 49.5 MW utility-scale BESS in Great Britation (GB), which started the commercial operation in July 2023 in GB. In addition, the field experimental results of FFR with various FFR characteristics are shown in order to study the effect of the response speed and the droop characteristics of FFR on the BESS performance. Finally, the subsynchronous oscillation (SSO) observed in the parametric experiments of FFR and its mitigation are demonstrated.

The Joganji River basin in Toyama Prefecture, Japan, has experienced numerous sediment-related disasters due to the considerable sediment yield of approximately 0.1 billion m3 attributed to mountain collapse following the Hietsu Earthquake of 1858. Over the past 100 years, the sabo facilities that have been constructed in the basin have reduced the sediment runoff from the surrounding mountainous region. However, it is becoming increasingly important to balance appropriate sediment runoff for bed variation with countermeasures against the large volumes of sediment in runoff from upstream reaches. Monitoring of bedload and debris flow has been conducted since the 1960 s in this basin, and a comprehensive monitoring network has been established to evaluate sediment movement using data collected by a variety of sensors. A sabo dam with a movable shutter and a slit dam was installed in the middle reaches of the Joganji River to control sediment runoff from the catchment. An effective control of sediment runoff tries to be found by operations during a flood and be evaluated measured data using sensors. This approach allows both the capture of transported sediment at the beginning of a flood and the release of deposited sediment from the storage area of the dam as the flood recedes. Pilot operations have been conducted in successive floods since July 2016, following several operational rules. The present study introduces the sediment runoff data that have been collected by sensors, such as the Japanese pipe-hydrophone, and provides several examples of applied sediment control using the movable shutter.

Abstract The transport industry, including air transport services, is crucial for social and economic growth and heavily relies on energy for its production and use. The transportation sector’s emissions exhibit the most pronounced trend, highlighting the need for appropriate environmental planning for sustainable development, especially the authors focus in the chapter titled Carbon Neutrality and Sustainable Airports. Carbon neutrality is the goal of achieving net-zero carbon emissions by balancing total emissions from various sources over a period of time. It is observed that air transportation is a vital economic tool, facilitating the movement of people and goods and contributing significantly to global economic growth. However, the aviation sector is one of the most carbon-intensive sectors. Aviation emissions significantly contribute to climate change, resulting in CO2 emissions and warming impacts from NO2, contrails, and cloud formation. To achieve airport sustainability, countries of worldwide have been promoting sustainable airports through various initiatives, including efficient energy use and the use of carbon-free technology, adoption of sustainable aviation fuel (SAF), green building, electric vehicles, solar rooftops, etc. Furthermore, airports worldwide are implementing green strategies to achieve net-zero emissions by 2050. As aviation demand increases, it’s not feasible for every country to establish a fully green airport project. Few airports have adopted sustainability through renewable energy, energy-efficient operations, and eco-friendly design. Achieving net-zero emissions in the aviation industry requires coordinated efforts. Additionally, collaboration is essential among advanced, developing, and underdeveloped nations. Through advanced technological transformation, providing financial assistance for underdeveloped nations, and collective policymaking will accelerate improvement.

ABSTRACT The barnacle genus Platylepas contains obligate epibionts of marine vertebrates, but the taxonomic status and evolutionary history of the sea-snake specialist, P. ophiophilus , has remained unclear. Here, we reassess the systematics of the genus through an integrative approach, combining morphological examinations with molecular phylogenetic analyses of mitochondrial COI and nuclear H3 genes from specimens collected from sea turtles, sea snakes, and a dugong. Our results unequivocally demonstrate that P. ophiophilus is a valid species, phylogenetically and morphologically distinct from the widespread turtle barnacle, P. hexastylos . Furthermore, we report the first record of P. ophiophilus from a sirenian host ( Dugong dugon ), a discovery that necessitates the re-examination of historical records of barnacles on sirenians worldwide. Our phylogeny places P. decorata , a turtle epibiont, as the earliest diverging lineage within the genus. This strongly suggests that the ancestor of Platylepas was associated with sea turtles, a conclusion supported by the ichnofossil record. The subsequent divergence of the P. ophiophilus clade represents a major macroevolutionary event: an ancient host shift from sea turtles to the taxonomically disparate but ecologically linked inhabitants—sea snakes and sirenians—of seagrass ecosystems. This study not only resolves a long-standing taxonomic problem but also provides a compelling narrative of host-switching that reconciles deep molecular divergence estimates with the sparse body fossil record for this fascinating group of marine symbionts.

本論文では，河川堤防の越水対策として設置する表面被覆工とドレーン工の越水による堤防決壊に対する効果を検証することを目的に，小型堤防模型実験と二次元浸透流解析を行った。模型実験の結果から，表面被覆工を施した均一堤体では，川裏法尻部で生じる越水による洗掘と堤体内浸透による吸い出しをトリガーとして表面被覆工下にパイピングが発生することによって堤防が決壊するプロセスを明らかにした。その上で，川裏側に設置する法尻保護工とドレーン工はいずれも，被覆工の下で川裏から進展する内部侵食を抑制する効果が高いことを示した。さらに，高透水性基礎地盤上の堤防においては，越水時に表面被覆工下で発生するパイピングが急速に進行し，決壊までの時間が早まることを示した上で，基盤排水機能を有するドレーン工の効果が極めて高いことを明らかにした。

Garnet-like oxide lithium ionic conductor Li7La3Zr2O12 (LLZO) exhibits relatively high ionic conductivity and electrochemical stability against lithium metals, attracting much attention as a solid electrolyte for all-solid-state lithium metal batteries.However, for practical use, the improvement in the ionic conductivity of the grain boundaries and sinterability of LLZO is necessary.Nano-sized fumed Al2O3 prepared by the vapor phase with various specific surface areas as a sintering aid has been applied to the garnet-type lithium ionic conductor, Li6.25Ga0.25La3Zr2O12(LGLZ) and Li6.5La3Zr1.5Ta0.5O12(LLZT).The addition effect of fumed Al2O3 on lattice parameters, particle morphology, sinterability, and ionic conductivity has been investigated.The sinterability has improved by the addition of nano-sized fumed Al2O3 with a high specific surface area, and ionic conductivity does not exhibit a significant change for LGLZ.The addition of fumed Al2O3 with a specific surface of 130 m 2 g -1 has lowered the sintering temperature of LLZT by 200 C, which indicates nano-sized Al2O3 is quite useful as a sintering aid for garnet-type solid electrolytes.

The purpose of this study is to identify the awareness of housing choice and the provision of services by residents in old age in two remote islands, Nishinoshima Town and Yamato Village. The survey methods was an all-inclusive questionnaire for residents aged for 40 years and above in these two areas.