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Synthetic modeling and field GPR survey to understand the near-surface deformation induced by coseismic groundwater dynamics following the 2019 Mirpur earthquake in Pakistan

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Leading Edge 2022年第8期41卷 529-539页

作者： Khan, Muhammad Younis Hwang, Jongha Min, Dong-Joo Turab, Syed Ali Jan, Irfan Ullah University of Peshawar National Centre of Excellence in Geology Peshawar Pakistan Korea Institute of Ocean Science and Technology Marine Active Fault Research Center Busan Korea Republic of Seoul National University Department of Energy Systems Engineering Seoul Korea Republic of Seoul National University Research Institute of Energy and Resources Seoul Korea Republic of

The Mirpur earthquake of Mw 5.8 on 24 September 2019 severely damaged villages in the epicentral area. The earthquake-triggered ground dynamics produced widespread liquefaction features on the surface (e.g., fractured road structure and sand boils) and in the shallow subsurface (e.g., elevated groundwater table, fractures, and sand dikes). Due to complexity of liquefaction-induced deformation and timing of field surveys, the structural and hydrogeologic features that develop in the near surface during seismic events are often poorly resolved on ground-penetrating-radar (GPR) profiles. To track and delineate the internal architecture and coseismic changes in groundwater levels and/or pressures due to liquefaction, a GPR survey was carried out soon after the Mirpur earthquake. The sudden pore water pressure changes in the shallow aquifer system caused a rise in the water table via upward groundwater movement and fracturing followed by rapid infiltration. This cascade phenomenon has adverse effects on soil, water resources, civil infrastructure, and public health and safety. To better understand induced changes in the physical properties of road infrastructure and the shallow subsurface, we performed synthetic modeling of electromagnetic wave propagation by employing the finite-difference time-domain method. Based on the available information at multiple scales (borehole and geophysical), subsurface physical models representing the most common and important coseismic features were considered for synthetic modeling. Likewise, synthetic tests of paved road were conducted to simulate the radar response of structural discontinuities (fractures) developed at different angles. To validate synthetic results by identifying a similar dynamic response of the induced hydrogeologic changes in the form of coseismic liquefaction features, a field GPR survey was conducted. Our results clearly demonstrate that the GPR technique is a potential candidate for hydrogeophysical detection a

关键词： Aquifers

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Thyroid and sex hormone disrupting effects of DEHTP at different life stages of zebrafish (Danio rerio)

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Chemosphere 2024年 358卷 142105页

作者： Ihn, Yunchul Cho, Yoojin Lee, Yura Seok, Hyesun Oh, Jin-su Moon, Hyo-Bang Choi, Kyungho Graduate School of Public Health Seoul National University Seoul Korea Republic of Institute of Health and Environment Seoul National University Seoul Korea Republic of Department of Marine Sciences and Convergence Engineering College of Science and Convergence Technology Hanyang University Ansan15588 Korea Republic of

Di(2-ethylhexyl) terephthalate (DEHTP) is an alternative plasticizer widely used in numerous consumer products, replacing di(2-ethylhexyl) phthalate (DEHP). Hence, DEHTP has been frequently detected in the environment and humans. As a structural isomer and functional analog of DEHP, DEHTP is a suspected endocrine disruptor. Here, we evaluated thyroid-disrupting effects of DEHTP using embryo-larval and adult male zebrafish. We also investigated its sex hormone disruption potential in the adult zebrafish. After 5- and 7-days of exposure to DEHTP, significant increases in whole-body thyroid hormonal levels were observed in the larval fish. Down-regulation of several thyroid-regulating genes, including trh, tshβ, nis, and dio2, was observed, but only after 5-day exposure. Following a 21-day exposure, the adult male zebrafish exhibited a significant decrease in total triiodothyronine and an increase in thyroid-stimulating hormones. Potential changes in the deiodination of thyroid hormones, supported by the up-regulation of two deiodinases, dio1 and dio3a, along with the down-regulation of dio2, could explain the thyroid hormone changes in the adult zebrafish. Moreover, significant trends of decrease in estradiol and 11-ketotestosterone, along with increase of testosterone (T), were observed in the adult zebrafish. Up-regulation of several steroidogenic genes may explain elevated T, while exact mechanisms of action warrant further investigation. Our results demonstrate that DEHTP can cause disruptions of thyroid and sex hormones at different life stages in zebrafish. © 2024 Elsevier Ltd

关键词： Plasticizers

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Advanced classification of sand particle size distribution with acoustic sensing and convolutional neural networks

Advanced classification of sand particle size distribution w...

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IEEE International Symposium on Applications of Ferroelectrics (ISAF)

作者： Yeongho Sung Jang Keon Kim Daehun Kim Taeyang Kwon Jongmuk Won Hae Gyun Lim Indusrty 4.0 Convergence Bionics Engineering Pukyong National University Busan Republic of Korea Department of Civil and Environmental Engineering University of Ulsan Ulsan Republic of Korea Department of Civil Urban Earth and Environmental Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan Republic of Korea Department of Biomedical Engineering Indusrty 4.0 Convergence Bionics Engineering Pukyong National University Busan Republic of Korea

ISBN: (数字)9798350371901

ISBN: (纸本)9798350371918

In addressing the critical role of sand particle size in hydraulic property prediction and applications like groundwater management, this study introduces a novel method combining ultrasonic acoustic sensing and convolutional neural network (CNN) for sand particle size distribution (PSD) classification. Recognizing the limitations of traditional particle size measurements in capturing temporal and spatial changes, our framework proposes a continuous, non-destructive monitoring solution. Laboratory experiments to construct a diverse echo signal dataset reflecting median sand sizes yielded a CNN model with high accuracy for four sand types. This approach promises low-cost, efficient monitoring of sand deposits, showcasing potential for broader geotechnical applications.

关键词： Analytical models Accuracy Ultrasonic imaging Ultrasonic variables measurement Size measurement Acoustics Sensors Convolutional neural networks Reliability Monitoring

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Underwater acoustic communication using a vector sensor from a moving source in shallow water 24

Underwater acoustic communication using a vector sensor from...

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24th International Congress on Acoustics, ICA 2022

作者： Choi, Kang-Hoon Choi, Jee Woong Kim, Sunhyo Dahl, Peter H. Dall'Osto, David R. Marine Science and Convergence Engineering Hanyang University Korea Republic of Department of Military Information Engineering Hanyang University ERICA Korea Republic of Maritime Security Research Center Korea Institute of Ocean Science and Technology Korea Republic of Applied Physics Laboratory University of Washington Seattle United States

For the optimal performance of underwater acoustic communication, it is important to minimize the effect of the Inter-Symbol Interference due to the delay spread of the multipath channels formed by multiple interactions with the ocean boundaries. The multipath channels have time-varying characteristics due to temporal variations of ocean environments. Especially, the communication channels on moving platforms have high Doppler frequency shifts and low channel coherence times due to spatial environment changes. Recently, acoustic vector sensors have been applied to underwater acoustic communication. A vector sensor can simultaneously measure x, y, and z-components of acoustic vector quantities as well as acoustic pressure with different channel characteristics and signal-to-noise ratios, and therefore, it can be used as a single-input multiple-output communication system. Underwater acoustic communication experiments using an acoustic vector receiver were conducted off the coast of Geoje island in Southeast Korea during the Korea Reverberation Experiment (KOREX-17) in May 2017. In this talk, communication techniques that can give the best performance using acoustic pressure signal and particle velocity signals measured by a single vector sensor in time-varying channel are investigated. © ICA *** rights reserved

关键词： Acoustic vector sensor Directionality Underwater acoustic communication

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The complete sequence of the mitochondrial DNA and phylogenetic analysis of the marine red algaGrateloupia elliptica(Rhodophyta: Halymeniales)

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Mitochondrial DNA Part B 2023年第2期8卷 222-223页

作者： Maheshkumar Prakash Patil Jong-Oh Kim Kyunghoi Kim Young-Ryun Kim a Industry-University Cooperation Foundation Pukyong National University Busan Republic of Korea b Department of Microbiology Pukyong National University Busan Republic of Koreac School of Marine and Fisheries Life Science Pukyong National University Busan Republic of Korea d Department of Ocean Engineering Pukyong National University Busan Republic of Korea e Marine Eco-Technology Institute Busan Republic of Korea

Grateloupia elliptica(Holmes, 1896) is a red alga belonging to the order Halymeniales and phylum Rhodophyta. In this study, the complete mitochondrial DNA (mtDNA) ofG. ellipticahas been described. The complete circular mtDNA ofG. ellipticawas 28,503 bp in length, with an A + T content of 68.78%; it encoded a total of 49 genes, including 20 tRNA, three rRNA, and 26 protein-coding (CDS) genes. Phylogenetic analysis based on complete mitochondrial genomes revealed thatG. ellipticawas most closely related toG. angusta. The complete mitochondrial sequence ofG. ellipticawill enrich the mitochondrial genome database and provide useful resources for population genetics and evolution analyses.

关键词： cox1 intron Halymeniales Rhodophyta mitochondrial genome phylogenetic analysis Grateloupia elliptica

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Jointly Optimizing Power Allocation and Device Association for Robust IoT Networks under Infeasible Circumstances

arXiv

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arXiv 2024年

作者： Tung, Nguyen Xuan Van Chien, Trinh Hoang, Dinh Thai Hwang, Won Joo Department of Information Convergence Engineering Pusan National University Busan46241 Korea Republic of Viet Nam School of Electrical and Data Engineering University of Technology Sydney SydneyNSW2007 Australia School of Computer Science and Engineering Center for Artificial Intelligence Research Pusan National University Busan46241 Korea Republic of

Jointly optimizing power allocation and device association is crucial in Internet-of-Things (IoT) networks to ensure devices achieve their data throughput requirements. Device association, which assigns IoT devices to specific access points (APs), critically impacts resource allocation. Many existing works often assume all data throughput requirements are satisfied, which is impractical given resource limitations and diverse demands. When requirements cannot be met, the system becomes infeasible, causing congestion and degraded performance. To address this problem, we propose a novel framework to enhance IoT system robustness by solving two problems, comprising maximizing the number of satisfied IoT devices and jointly maximizing both the number of satisfied devices and total network throughput. These objectives often conflict under infeasible circumstances, necessitating a careful balance. We thus propose a modified branch-and-bound (BB)-based method to solve the first problem. An iterative algorithm is proposed for the second problem that gradually increases the number of satisfied IoT devices and improves the total network throughput. We employ a logarithmic approximation for a lower bound on data throughput and design a fixed-point algorithm for power allocation, followed by a coalition game-based method for device association. Numerical results demonstrate the efficiency of the proposed algorithm, serving fewer devices than the BB-based method but with faster running time and higher total throughput. Copyright © 2024, The Authors. All rights reserved.

关键词： Approximation algorithms

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Investigation of Two-Phase Flow Distribution in the Vertical Annular Distribution Header of a Variable Refrigerant Flow Heat Pump System

SSRN

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SSRN 2024年

作者： Ko, Jaedeok Choi, Siyoung Jeong, Ji Hwan School of Mechanical Engineering Pusan National University Busan46241 Korea Republic of Research Institute for Convergence of Biomedical Science and Technology of Pusan National University Yangsan Hospital Gyeongsangnam-do Yangsan50612 Korea Republic of

The characteristics of two-phase flow distribution from a vertically installed annular refrigerant distribution header to multiple branch ports are investigated, with a specific focus on simulating a real variable refrigerant flow heat pump (VRF HP) system. A test section is fabricated to replicate an actual distribution header for empirical investigation, utilizing an air-water mixture as the working fluid. A series of experiments are conducted to examine distribution characteristics, involving variations in the location of the main inlet port, operational mode, total mass flow rate, and void fraction. The experimental results indicate that the two-phase mixture exhibits a relatively uniform liquid phase distribution to the branch ports when the main inlet port is positioned at the bottom side. However, maldistribution to branch ports is intensified as the inlet void fraction increases and the flow rate of the two-phase mixture decreases. Furthermore, a series of computational fluid dynamics (CFD) analyses is performed to investigate the distribution characteristics of R410A, the actual working fluid utilized in VRF HP systems. These analyses are conducted under the operational conditions typical of VRF HP systems. Despite identical Reynolds numbers for the two-phase R410A flow and air-water mixture flow, the former exhibits a notably uneven distribution to branch ports owing to the distinct thermophysical properties, particularly density and viscosity. The findings from this investigation enhance the comprehension of two-phase flow distribution characteristics in a vertically installed refrigerant distribution header under real VRF HP system conditions, offering valuable insights into mitigating the maldistribution of refrigerant flow to branch ports. © 2024, The Authors. All rights reserved.

关键词： Two phase flow

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Asymmetrical response of summer rainfall in East Asia to CO_(2)forcing

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science Bulletin 2022年第2期67卷 213-222,M0004页

作者： Se-Yong Song Sang-Wook Yeh Soon-Il An Jong-Seong Kug Seung-Ki Min Seok-Woo Son Jongsoo Shin Department of Marine Sciences and Convergence Technology Hanyang UniversityAnsan 15588South Korea Department of Atmospheric Sciences/Irreversible Climate Change Research Center Yonsei UniversitySeoul 03722South Korea Division of Environmental Science and Engineering Pohang University of Science and TechnologyPohang 37673South Korea Institute for Convergence Research and Education in Advanced Technology Yonsei UniversityIncheon 21983South Korea School of Earth and Environmental Science Seoul National UniversitySeoul 08826South Korea

Understanding the regional hydrological response to varying CO_(2)concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future. To characterize summer monsoon rainfall change in East Asia in a changing CO_(2)pathway, we used the Community Earth System Model(CESM) with28 ensemble members in which the CO_(2)concentration increases at a rate of 1% per year until its quadrupling peak, i.e., 1468 ppm(ramp-up period), followed by a decrease of 1% per year until the present-day climate conditions, i.e., 367 ppm(ramp-down period). Although the CO_(2)concentration change is symmetric in time, the amount of summer rainfall anomaly in East Asia is increased 42% during a rampdown period than that during a ramp-up period when the two periods of the same CO_(2)concentration are compared. This asymmetrical rainfall response is mainly due to an enhanced El Ni?o-like warming pattern as well as its associated increase in the sea surface temperature in the western North Pacific during a ramp-down period. These sea surface temperature patterns enhance the atmospheric teleconnections and the local meridional circulations around East Asia, resulting in more rainfall over East Asia during a ramp-down period. This result implies that the removal of CO_(2)does not guarantee the return of regional rainfall to the previous climate state with the same CO_(2)concentration.

关键词： CO_(2)concentration East Asian summer monsoon Asymmetric rainfall El Ni?o-like warming

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Cyclic and linear siloxane contamination in sediment and invertebrates around a thermal power plant in Korea: Source impact, distribution, seasonal variation, and potential for bioaccumulation

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Chemosphere 2024年 349卷 140779页

作者： Chen, Wenming Lee, Sunggyu Moon, Hyo-Bang Ministry of Education Key Laboratory for Ecology of Tropical Islands Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province College of Life Sciences Hainan Normal University Hainan Haikou571158 China Department of Marine Science and Convergence Engineering College of Science and Convergence Technology Hanyang University Ansan15588 Korea Republic of

Siloxanes have been commonly used as additives in a variety of industrial and consumer products. Media and government investigations have revealed that defoamers containing siloxanes are used in the effluent of thermal power plants in Korea. However, investigations of the source impact of siloxane contamination from the discharge of thermal power plants into coastal environments are scarce. In this study, sediment and invertebrates were collected around a thermal power plant to assess source impact, seasonal variation, and a potential for bioaccumulation. Although siloxanes were detectable in sediment and invertebrates, the spatial distribution and composition (which differed between the siloxanes found in sediment and invertebrates and those in defoamer used in the plant) suggest they were likely transported by long-distance migration as well as the discharge of thermal power plant. Seasonal differences might affect sedimentary contamination and the bioaccumulation potential of siloxanes. Specifically, octamethylcyclotetrasiloxane (D4) may have limited adsorption capacity and potential for long-distance migration, as its contribution in sediment far from the coastline was greater than that of decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). However, higher D5 accumulation in invertebrates, and D5 has a potential bioaccumulation. A molecular docking analysis showed that the binding affinity between D5 and the cytochrome enzyme in invertebrates was weaker than that with other siloxanes, which could lead to higher D5 accumulation in invertebrates. © 2023 Elsevier Ltd

关键词： Sediments

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Unlocking Nature's Defense: Purification of Chitinase from Bacillus Haynesii

SSRN

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SSRN 2024年

作者： Govindaraj, Vishnupriya Kim, Se-Kwon Raval, Ritu Raval, Keyur Department of Chemical Engineering National Institute of Technology Mangalore Karnataka Surathkal575025 India Department of Marine Science & Convergence Engineering College of Science & Technology Hanyang University Erica Campus Ansan11558 Korea Republic of Department of Biotechnology Manipal Institute of Technology Manipal Academy of Higher Education Karnataka Manipal576104 India

The development of chitinase tailored for the bioconversion of chitin to chitin oligosaccharides has garnered considerable interest owing to its potential to mitigate environmental pollution associated with chemical conversion processes. In this current investigation, we purified extracellular chitinase derived from marine Bacillus haynesii to homogeneity and subsequently characterized it. The molecular weight of BhChi was approximately 35 kDa. BhChi exhibited its peak catalytic activity at pH 6.0, with an optimal temperature of 37 °C. It exhibited robust stability across a pH range of 6.0 to 9.0. Additionally, BhChi showed activation in the presence of Mn2+ 105 U mL-1. Ca2+ and Fe2+ metal ions don’t have any significant impact on enzyme activity. Chitinase exhibited best catalytic activity on colloidal chitin with Km 0.01 mg mL-1 and Vmax 5.75 mmol min-1. Kcat and catalytic efficiency were 1.91 s-1 and 191 mL mg-1 s-1 respectively. The main products of BhChi on colloidal chitin was N-Acetyl glucosamine suggesting it an exochitinase with β-N-acetylglucosaminidase activity. This is the first report on an exochitinase with N-acetyl-β-D-glucosaminidase activity from Bacillus haynesii. Furthermore, the chitinase showcased promising antifungal properties against key pathogens, Fusarium oxysporum and Penicillium chyrosogenum reinforcing its potential as a potent biocontrol agent. © 2024, The Authors. All rights reserved.

关键词： Chitin

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