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Electrochemical characteristics of Al-Mg and Al-Mg-Si alloy in sea water

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中国有色金属学会会刊：英文版 2012年第S3期22卷 881-886页

作者： Seong-jong KIM seung-jun lee Jae-yong JEONG Kyu-hwan KIM Division of Marine Engineering Mokpo Maritime University

Among Al alloys,particularly 5000 series Al Mg and 6000 series Al Mg Si often used as marine materials have excellent corrosion resistance,low melting point,and thereby showing recycling availability when compared to other *** experiments were conducted to select the most suitable material for marine *** electrochemical experiments were conducted in natural *** corrosion test was performed in many methods such as anodic/cathodic polarization and Tafel analysis using multi-channel potentio/galvanostat WMPG *** results,anodic and cathodic polarization behaviors indicate the characteristics of passive state and concentration polarization by reduction reaction in dissolved oxygen,which shows excellent electrochemical *** analysis results show no significant difference but 5052-O alloy of various alloy materials indicates the lowest corrosion current ***,5052-O Al alloy presents most anti-corrosion material in marine environment.

关键词： Al alloy ship electrochemical characteristics corrosion

Winter distribution of diatom assemblages along the coastline of *** in 2010

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Acta Oceanologica Sinica 2022年第6期41卷 68-77页

作者： Joon Sang Park Kyun-Woo lee seung Won Jung Taek-Kyun lee Hyoung Min Joo Library of Marine Samples Korea Institute of Ocean Science&TechnologyGeoje 53201R.O.Korea Marine Biotechnology Research Center Korea Institute of Ocean Science&TechnologyBusan 49111R.O.Korea Risk Assessment Research Center Korea Institute of Ocean Science&TechnologyGeoje 53201R.O.Korea Unit of Next Generation IBRV Building Program Korea Polar Research InstituteIncheon 21990R.O.Korea

Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external *** relationship between their valve morphology and habitat means that diatoms can be used as bioindicators to characterize the aquatic *** estimate the differential distribution and diversity of diatom assemblages along the coastal line,we collected phytoplankton samples from 114 coastal sites of waters of *** applied the unweighted pair-group technique using the arithmetic averages clustering method to cluster the sampling sites,apart from those where the biota consisted of other groups,such as dinoflagellates,into four regions:the Yellow Sea,South Sea,southern East Sea,and northern East *** species analysis in each region led to the selection of tychoplanktonic,chain-forming,attached species to substrates and psychrophilic indicator diatoms,respectively,each of which represented a planktonic lifestyle associated with one of the four *** study shows the diatom assemblages to serve as bioindicators of Korean coastal water in winter,and the subsequent seasonal survey will provide a starting point for the improved understanding of Korean diatom-based ecoregions,in both time and space.

关键词： diatom assemblage indicator species life-form Korean coastal waters species diversity

A Regional Economy's Resistance to the COVID-19 Shock: Sales Revenues of Micro-, Small-, and Medium-Sized Enterprises in South Korea

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International Journal of Disaster Risk Science 2022年第2期13卷 190-198页

作者： Seong-Jin lee Joong-Hoo Park seung-Min Cha Donghyun Kim Department of Public Policy and Management.Pusan National University Busan 46241South Korea Department of Urban Planning and Engineering Pusan National UniversityBusan 46241South Korea

The coronavirus disease 2019(COVID-19) is a global pandemic that has heavily impacted not only the health sector, but also the economic sector in *** countries have projected a negative economic impact, and the effect on micro-, small-, and medium-sized enterprises(MSMEs) is predicted to be significantly *** study estimated the regional resistance of MSME sales revenues and identified the regional economic factors that affect resistance by analyzing South Korea, a country with one of the lowest economic impact projections from COVID-19. Resistance was estimated by comparing sales revenues and changes in resistance observed during the early COVID-19 period to those recorded in the same weeks(weeks 6 to 9) of 2019. The factors that affect regional resistance were determined by conducting robust regression and spatial regression analyses. The results show that the number of confirmed COVID-19 cases, a direct risk factor, is negatively related to regional resilience, while diversity is positively related to regional resistance. To improve the regional resistance against uncertain events, this study recommends increased diversity among regional industrial structures to reduce the duration of the early shock of an unexpected adverse event.

关键词： COVID-19 Economic resistance MSMEs South Korea

Synergetic analysis of springtime air pollution episodes over Gwangju,Korea

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Journal of Environmental Sciences 2017年第7期29卷 270-283页

作者： Sung-Kyun Shin Kwon-Ho lee seung-Shik Park Man Sing Wong Research Institute for Radiation-Satellite(RIRS) Gangneung-Wonju National University(GWNU)Gangneung 25457Republic of Korea Department of Atmospheric and Environmental Sciences(DAES) Gangneung-Wonju National University(GWNU)Gangneung 25457Republic of Korea Department of Environment and Energy Engineering Chonnam National UniversityGwangju 61186Republic of Korea Department of Land Surveying and Geo-Informatics The Hong Kong Polytech UniversityKowloonHong Kong

The characteristics of springtime aerosols,including their optical and microphysical properties,were analyzed for the months of March to May of 2009 in Gwangju（35.23°N,126.84°E）,Korea.A high Light Detection and Ranging（LIDAR）-derived aerosol depolarization ratio（δ） of 0.25 ± 0.04 was determined on dust particles during the observation ***？ngstr？m exponent values of the 440–870 nm wavelength pair（？_（440–870）） and single-scattering albedo at 675 nm（Ω_（675）） measured by a CIMEL sun/sky radiometer were 0.77 ± 0.19 and 0.95 ±0.01,*** elevated dust layers reached a maximum elevation of 4 km above sea ***/smoke particles that originated from highly populated/industrialized regions could be distinguished by their relatively smaller particle size（？_（440–870） ranged between1.33 and 1.36） and higher light-absorbing（Ω_（675） of 0.92 ± 0.01） *** aerosols are mostly distributed at altitudes 〈 1.2 *** root-mean-square deviation（RMSD） between the aerosol optical depth（AOD,τ） derived from LIDAR_（（τ_（LIDAR））） and from the CIMEL sun/sky radiometer_（（τ_（CIMEL））） varied with respect to the surface PM10 *** RMSD between τ_（LIDAR） and τ_（CIMEL） was as low as 13% under lower PM_（10） concentration levels（〈 100 μg/m^3）.In contrast,the RMSD between τ_（LIDAR） and τ_（CIMEL） increased three times（~31%） under high surface PM_（10） concentration levels（〉100 μg/m^3）.These results suggest that the accuracy of τ_（LIDAR） is influenced by specific atmospheric conditions,regardless of its uncertainty.

关键词： LIDAR Sun/sky radiometer MODIS Optical/microphysical properties Aerosol optical depth

HoLEP does not affect the overall sexual function of BPH patients： a prospective study

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Asian Journal of Andrology 2014年第6期16卷 873-877页

作者： Sung Hart Kim Hyung-Kook Yang Hahn-Ey lee Jae-seung Paick seung-June Oh Department of Urology Prostate Cancer Center National Cancer Center Goyang Korea Department of Epidemiology and Statistics and Cancer Policy Branch of National Cancer Control Research Institute National Cancer Center Goyang Korea Department of Urology Seoul National University Hospital Seoul Korea.

We aimed to prospectively evaluate the influence of holmium laser enucleation of the prostate （HoLEP） on the overall postoperative sexual function of benign prostatic hyperplasia （BPH） patients with lower urinary tract symptoms （LUTS） and to explore the relationship between sexual function and LUTS. From January 2010 to December 2011, sixty sexually active consecutive patients with BPH who underwent HoLEP were prospectively enrolled in the study. All patients filled out the Male Sexual Health Questionnaire （MSHQ） for evaluation of their overall sexual function and the International Prostatic Symptom Score （IPSS） for pre- and post-operative 6 months evaluation of their voiding symptoms. The LUTS and sexual function changes were statistically analyzed. The preoperative and 6 months postoperative status of the patients was compared using uroflowmetry and IPSS questionnaires. The analysis revealed significant improvements following HoLEP. Among the sub-domains of the MSHQ, postoperative sexual function, including erection, ejaculation, sexual satisfaction, anxiety or sexual desire, did not significantly change after HoLEP （P 〉 0.05）, whereas satisfaction scores decreased slightly due to retrograde ejaculation in 38 patients （63.3%）. Sexual satisfaction improved significantly and was correlated with the improvements of all LUTS and the quality-of-life （QoL） domains in IPSS after surgery （QoL; relative risk [RR]： -0.293; total symptoms, RR： -0.411; P 〈 0.05）. The nocturia score was associated with the erectile function score （odds ratio 0.318, P = 0.029）. The change in ejaculatory scores did not show significant association with IPSS scores. HoLEP did not influence overall sexual function, including erectile function. In addition, sexual satisfaction improved in proportion with the improvement of LUTS.

关键词： benign prostatic hyperplasia ejaculation erectile dysfunction lasers prostatectomy sex disorders

Functional Materials and Innovative Strategies for Wearable Thermal Management Applications

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Nano-Micro Letters 2023年第9期15卷 562-603页

作者： Yeongju Jung Minwoo Kim Taegyeom Kim Jiyong Ahn Jinwoo lee seung Hwan Ko Applied Nano and Thermal Science Lab Department of Mechanical EngineeringSeoul National University1 Gwanak-roGwanak-guSeoul 08826South Korea Department of Mechanical Roboticsand Energy EngineeringDongguk University30 Pildong-ro 1-gilJung-guSeoul 04620South Korea Institute of Advanced Machinery and Design(SNU-IAMD) Seoul National UniversityGwanak-roGwanak-guSeoul 08826South Korea Institute of Engineering Research Seoul National University1 Gwanak-roGwanak-guSeoul 08826South Korea

Thermal management is essential in our body as it affects various bodily functions,ranging from thermal discomfort to serious organ failures,as an example of the worst-case *** have been extensive studies about wearable materials and devices that augment thermoregulatory functionalities in our body,employing diverse materials and systematic approaches to attaining thermal *** paper reviews the recent progress of functional materials and devices that contribute to thermoregulatory wearables,particularly emphasizing the strategic methodology to regulate body *** exist several methods to promote personal thermal management in a wearable *** instance,we can impede heat transfer using a thermally insulating material with extremely low thermal conductivity or directly cool and heat the skin ***,we classify many studies into two branches,passive and active thermal management modes,which are further subdivided into specific *** from discussing the strategies and their mechanisms,we also identify the weaknesses of each strategy and scrutinize its potential direction that studies should follow to make substantial contributions to future thermal regulatory wearable industries.

关键词： Thermal management Passive heat transfer Active heat transfer Wearable materials Wearable device

Evaluation of early-age strains and stresses in roller-compacted concrete pavement

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第1期9卷 93-105页

作者： Tetsya Sok Young Kyu Kim Jun Young Park seung Woo lee Public Infrastructure Department Ministry of Public Works and TransportPhnom Penh 12100Cambodia Institute for Disaster Prevention Gangneung-Wonju National UniversityGangneung-si 25457South Korea Korea Expressway Research Institute Korea Expressway CorporationHwaseong-si 18489South Korea Civil Engineering Department Gangneung-Wonju National UniversityGangneung-si 25457South Korea

In the structural design of a roller-compacted concrete pavement(RCCP), it is crucial to estimate strain and stress developments in the RCCP slab realistically. Since the RCCP mix uses less cement and lower amount of water, shrinkage strain and concrete temperature during the hardening stage are expected to be reduced as compared to those of conventional concrete mixture, resulting in a reduction of the concrete early-age deformation and stress developments in the RCCP slab. In this paper, early-age concrete strain and stress developments in RCCP slab subjected to environmental loads were evaluated. A full-scale test section of RCCP under real climatic conditions was monitored. The early-age total strains,stress-independent strains, shrinkage strains, and coefficient of thermal expansion(CTE) of the RCCP were measured and analyzed. Using the results of measured strains, in-situ CTE and shrinkage strain, and temperature, the early-age concrete stress development is computed by incorporating a viscoelastic property of the early-age concrete. The results revealed that the shrinkage strain of the RCCP is quite low as compared to that of conventional concrete. The early-age stress developments in the RCCP slab are strongly governed by the thermal-induced stresses. Shrinkage-induced stresses were quite small and might be negligible in a preliminary estimation of early-age stress developments in the RCCP slab.

关键词： Road engineering Roller-compacted concrete pavement Concrete strain Concrete stress Shrinkage strain Environmental loads

Characterization of focal hypermetabolic thyroid incidentaloma: An analysis with F-18 fluorodeoxyglucose positron emission tomography/computed tomography parameters

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World Journal of Clinical Cases 2022年第1期10卷 155-165页

作者： Haejun lee Yoo seung Chung Joon-Hyop lee Ki-Young lee Kyung-Hoon Hwang Department of Nuclear Medicine Gachon University College of MedicineGil Medical CenterIncheon 21565South Korea Department of Endocrine Surgery Gachon University College of MedicineGil Medical CenterIncheon 21565South Korea Department of Endocrinology and Metabolism Gachon University College of MedicineGil Medical CenterIncheon 21565South Korea

BACKGROUND Incidentally found thyroid tumor(thyroid incidentaloma,TI)on F-18 fluorodeoxyglucose(FDG)positron emission tomography-computed tomography(PETCT)is reported in 2.5%-5%of patients being investigated for non-thyroid *** to 50%of these cases have been diagnosed to be malignant by cytological/histological ***(US)and fine-needle aspiration cytology are recommended for thyroid nodules with high FDG uptake(hypermetabolism)that are 1 cm or greater in *** is important to accurately determine whether a suspicious hypermetabolic TI is malignant or *** To distinguish malignant hypermetabolic TIs from benign disease by analyzing F-18 FDG PET-CT parameters and to identify a cut-off *** Totally,12761 images of patients who underwent F-18 FDG PET-CT for nonthyroid purposes at our hospital between January 2016 and December 2020 were retrospectively reviewed,and 339 patients[185 men(mean age:68±11.2)and 154 women(mean age:63±15.0)]were found to have abnormal,either focal or diffuse,thyroid FDG *** a thorough review of their medical records,US,and cytological/histological reports,46 eligible patients with focal hypermetabolic TI were included in this *** TIs were categorized as malignant and benign according to the cytological/histological reports,and four PET parameters[standardized uptake value(SUV)max,SUV_(peak),SUV_(mean),and metabolic tumor volume(MTV)]were measured on FDG *** lesion glycolysis(TLG)was calculated by multiplying the SUV_(mean) by *** parametric and non-parametric methods were used to compare the five parameters between malignant and benign *** operating characteristic(ROC)curve analysis was performed to identify a cut-off *** Each of the 46 patients[12 men(26.1%;mean age:62±13.1 years)and 34 women(73.9%;mean age:60±12.0 years)]with focal hypermetabolic TIs had one focal hypermetabolic *** them,26(56.5%)were malignant and 20(43.5%)were ***_(max

关键词： Thyroid incidentaloma Malignancy Fluorodeoxyglucose positron emission tomography/computed tomography Standardized uptake value Cut-off

Spin valve effect of NiFe/graphene/NiFe junctions

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Nano Research 2013年第5期6卷 373-379,380页

作者： Muhammad Zahir Iqbal Muhammad Waqas Iqbal Jae Hong lee Yong seung Kim seung-Hyun Chun Jonghwa Eom Department of Physics and Graphene Research Institute Sejong University Seou1143-747 Korea

When spins are injected through graphene layers from a transition metal ferromagnet, high spin polarization can be achieved. When detected by another ferromagnet, the spin-polarized current makes high- and low-resistance states in a ferromagnet/graphene/ferromagnet junction. Here, we report manifest spin valve effects from room temperature to 10 K in junctions comprising NiFe electrodes and an interlayer made of double-layer or single-layer graphene grown by chemical vapor deposition. We have found that the spin valve effect is stronger with double-layer graphene than with single-layer graphene. The ratio of relative magnetoresistance increases from 0.09% at room temperature to 0.14% at 10 K for single-layer graphene and from 0.27% at room temperature to 0.48% at 10 K for double-layer graphene. The spin valve effect is perceived to retain the spin-polarized transport in the vertical direction and the hysteretic nature of magnetoresistance provides the basic functionality of a memory device. We have also found that the junction resistance decreases monotonically as temperature is lowered and the current-voltage characteristics show linear behaviour. These results revealed that a graphene interlayer works not as a tunnel barrier but rather as a conducting thin film between two NiFe electrodes.

关键词： graphene spin valve magnetic junction magnetoresistance spintronics