Shikoku Research Institute

In this study, we conducted a basic study on the visualization of ammonia gas using a flash lidar, which uses the resonance Raman effect, for the purpose of visualizing gas leak locations and analyzing gas flow. We have previously developed a remote ammonia leak detection technology (resonance Raman LIDAR) using the resonance Raman effect. In general, the Raman effect has significant advantages such as the ability to identify various substances that cannot be detected by other optical methods and to perform spectroscopic measurements of multiple substances. On the other hand, the Raman effect is extremely weak compared to other light-matter interactions, so the resonance Raman effect, which can significantly enhance the weak Raman effect, is effective for remote detection of trace components. The resonance Raman effect is a phenomenon in which Raman scattered light corresponding to a conjugate vibration mode is greatly enhanced when the target substance is excited by light with a wavelength corresponding to the electronic absorption band of the target substance. In actual measurements, the pattern of the ultraviolet-visible absorption spectrum indicating the electronic transition energy of the target substance serves as an indicator of the applicability of the resonance Raman effect, and the fifth harmonic of the Nd:YAG laser (wavelength 213nm) matches the electronic absorption band of ammonia. Resonance Raman LIDAR can measure gas concentrations and their distance remotely, but to obtain two- or three-dimensional images of the gas concentration distribution, it is necessary to scan the optical axis of the laser and observation optical system. If flash lidar, a technology that expands a laser beam and emits it into the observation space like a camera flash and uses a camera as a detector to instantly visualize the gas concentration distribution as a two-dimensional image, could be applied to ammonia gas leak detection, its usefulness as a safety technology would be enhanced. In this study, a pulsed laser with a wavelength of 213nm was used as the excitation light source and successfully visualized ammonia gas by observing the 4318cm^-1 spectra among the multiple resonance Raman spectra of ammonia.

薬物治療の適正化には、患者の水分状態の把握が不可欠である。体内水分量の違いにより薬物動態は大きく変化し、特に脱水状態では血中濃度上昇や副作用リスクが高まる。在宅薬剤管理では、これらのリスクを回避するため、簡便かつ客観的な体内水分量の評価法が求められているが、現状では実現が困難である。本講演では、在宅薬剤管理における水分測定デバイスの臨床的意義と適応について述べ、今後の展望と課題を考察する。

高齢者の在宅リハビリテーションでは個別対応が求められ、バイタルサインや身体機能、脱水状態の把握が重要である。加齢に伴う身体機能の低下は脱水耐性の低下を招くことがあり、簡便な体水分測定法の必要性が高まっている。本講演では、在宅リハビリテーションにおける体水分測定デバイスの臨床的意義と適応、今後の展望と課題について考察する。

耐震設計で考慮される地震の震源は近年多様かつ大規模となりつつあり，今後の耐震設計に向けては，大規模地震かつ震源近傍の強震動予測の精度向上が重要な課題となっている．本検討では，2023年トルコ・シリア地震（Mw 7.8）を対象に，拡散波動場理論に基づき震源近傍観測地点のVs = 2100 m/s相当の基盤地震動を推定した．推定した基盤地震動のPGA及びPGVはほぼMorikawa and Fujiwara (2013)による地震動予測式のばらつきの範囲内であり，地表記録と比べて地震動レベルが低減している．推定した基盤地震動については複数の検証から，短周期地震動の特異な大振幅が確認された一部地点を除き概ね妥当な結果が得られていると考えられる．推定した基盤地震動と地震動予測式の各周期の距離減衰特性はばらつきの範囲で概ね良い対応を示しており，地震動予測式によって大規模地震かつ震源近傍の地震動を一定の精度で評価ができる可能性が示された．

We analyzed observations of microtremors and seismic ground motion to determine the depths of sedimentary interfaces and basement surface in the Kathmandu Valley. The results of these analyses and a reflection survey were combined to produce a data set of seismic depths for sedimentary interfaces and basement surface in the valley. Moreover, we introduced a data set of gravimetric depths, which had been produced for the basement surface from gravity observations. Because both sets of data differ in accuracy and number, we adopt the Sequential Gaussian Co-Simulation to generate the depth distributions of the sedimentary interfaces and basement surface. This method includes the cokriging approach, wherein the seismic and gravimetric depths are used as primary and secondary data, respectively. A three-dimensional velocity structure model of the Kathmandu Valley was constructed from the obtained depth distributions, which showed that the sedimentation in the valley is mainly related to the Paleo-Kathmandu Lake. Subsequently, we incorporated this model into a previous regional-scale model, and revised the latter to solve the issues of the extension of the underthrusting lithosphere and the S-wave velocity in its adjacent area.Graphical

Di(2-ethylhexyl) phthalate (DEHP) undergoes hydrolysis in the gastrointestinal tract when orally administered to rats, and is mainly distributed in the body as mono(2-ethylhexyl) phthalate (MEHP). MEHP is thought to be involved in testicular and hepatotoxicity. Therefore, clarifying the distribution of MEHP in blood and organs after oral administration of DEHP is important. In this study, male Sprague-Dawley rats rat were fed 1% and 2% DEHP diets for 2 weeks, after which he examined the concentration distribution of MEHP and DEHP in her blood and organs, and obtained the following results. · MEHP concentrations in the 1% group were plasma: 16.7-40.8 μg/ml, testis: 0.9-3.2 μg/g, liver: 21.5-43.6 μg/g, kidney: 6.8-9.6 μg/g and MEHP concentrations in the 2 %group were plasma: 58.5-147.4 μg/ml, testis: 10.5-30.0 μg/g, liver: 44.2-97.1 μg/g, kidney: 18.6-56.7 μg/g. · Mean MEHP concentrations in blood and organs were dose-dependent, but with considerable inter-individual variability. · MEHP concentrations by organ were highest in liver, followed by kidney, and lowest in testis. · DEHP was detected in plasma, testis, liver, and kidney in both 1% and 2% groups in the range of 1-20 μg/g (μg/ml). · MEHP concentrations in testis, liver, and kidney were all strongly correlated with plasma MEHP concentrations. A strong negative correlation was observed between MEHP concentration in testis and testicular weight, and between plasma MEHP concentrations and testicular weight. This suggests a close relationship between MEHP and testicular toxicity.

Abstract Shikoku Railway Company (JR Shikoku) has installed a telemeter system whose network spreads across all the railway lines in the Shikoku area. The telemeter system monitors and collects real‐time data, e.g. current, voltage, and relay signals of railway equipment. We propose a method of detecting the breakage of a crossing‐gate rod based on big data using representative machine‐learning techniques, namely, random forest and support vector machine. Moreover, we evaluate the proposed method for rod breakage cases at seven locations and demonstrate its effectiveness and versatility. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Abstract The Mw 7.0 mainshock of the 2016 Kumamoto earthquake sequence was triggered by dextral rupture of the Futagawa fault within the Aso volcanic region, Southwestern Japan. To reproduce its faulting patterns and to reveal the geological and geophysical characteristics of the fault and surrounding lithological units, we report the results of a multiple‐borehole drilling program penetrating the Futagawa fault zone. By combining core descriptions with geophysical logs, we identified >200 m of normal faulting displacement along the currently dextral strike‐slip Futagawa fault. Considering previous kinematic and chronological studies of the fault, we interpret that the Futagawa fault dominantly slipped as a normal fault in a short period (∼300–87 ka) before switching to its current transtensional (dominant strike‐slip) regime ∼87 ka caused by a local change in the stress field associated with the termination of the Aso caldera‐forming eruptions. In the main borehole, three damage/slip zones were penetrated at depths of ∼354, 461, and 576 m. The 461 damage zone was identified as ∼45 m in vertical thickness and thicker than the other damage zones (∼3–6 m vertically) and was characterized by high fracture density and the presence of strike‐slip slickenlines. Depth profiles of physical properties revealed different patterns near the three damage zones; both the resistivity and the P‐wave velocity showed stronger deterioration at the 461 damage zone than the others. Based on these geological and geophysical observations, we suggest that the 461 damage zone is the primary candidate for seismogenic faulting during the 2016 Kumamoto earthquake mainshock.