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Improvements of model-test method for cavitation-induced pressure fluctuation in marine propeller

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Journal of Hydrodynamics 2013年第4期25卷 599-605页

作者： LEE Jeung-Hoon HAN Jae-Moon PARK Hyung-Gil seo jong-soo Samsung Ship Model Basin (SSMB) Marine Research Institute Samsung Heavy Industries Science Town

Although the prediction of propeller cavitation-induced pressure fluctuation strongly depends on the model-scalemeasure- ment in a cavitation tunnel, there is still a lack of correlation with full-scale data. This paper deals with the enhancement of such a correlation deficiency by improving the conventional model-test technique, two majors of which are in the following. One is to take into account the boundary layer effect of wooden fairing plate at the ceiling of water cavitation tunnel. The other is to avoid the reso- nance frequency range of model-ship via adjusting the revolution speed of model propeller. Through a case study, for which both model and full-scale test data are available, the improved method in this study shows its validness, and furthermore a close correla- tion with full scale measurement.

关键词： cavitation boundary layer resonance

EXPERIMENTAL ESTIMATION OF A SCALING EXPONENT FOR TIP VORTEX CAVITATION VIA ITS INCEPTION TEST IN FULL-AND MODEL-SHIP

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Journal of Hydrodynamics 2012年第5期24卷 658-667页

作者： LEE Jeung-Hoon JUNG Jae-Kwon LEE Kyung-Jun HAN Jae-Moon PARK Hyung-Gil seo jong-soo Samsung Ship Model Basin(SSMB) Marine Research InstituteSamsung Heavy IndustriesScience TownDaejeon 305-380Korea

Tip vortex cavitation noise of marine propeller became primary concems to reduce hazardous environmental impacts from commercial ship or to keep the underwater surveillance of naval ships. The investigations of the tip vortex and its induced noise are normally conducted through the model test in a water cavitation tunnel. However the Reynolds number of model-test is much smaller than that of the full-scale, which subsequently results in the difference of tip vortex cavitation inception. Hence, the scaling law between model- and full-scales needs to be identified prior to the prediction and assessment of propeller noise in full scale. From previous researches, it is generally known that the incipient caivtation number of tip vortex can be represented as a power of the Reynolds number. However, the power exponent for scaling, which is the main focus of this research, has not been clearly studied yet. This paper deals with the estimation of scaling exponent based on tip vortex cavitation inception test in both full- and model-scale ships. Acoustical measurements as well as several kind of signal processing technique for an inception criterion suggest the scaling exponent as 0.30. The scaling value proposed in this study shows slight difference to the one of most recent research. Besides, extrapolation of model-ship noise measurement using the proposed one predicts the full-scale noise measurement with an acceptable discrepancy.

关键词： tip vortex cavitation underwater radiated noise scaling exponent

A Cu-Pd alloy catalyst with partial phase separation for the electrochemical CO_(2) reduction reaction

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Journal of Energy Chemistry 2024年第6期93卷 8-15,I0001页

作者： Gyeong Ho Han Jung Yong seo Minji Kang Myung-gi seo Youngheon Choi soo Young Kim Sang Hyun Ahn School of Chemical Engineering and Material Science Chung-Ang UniversitySeoul 06974Republic of Korea Lotte Chemical Institute of Technology Daejeon 34110Republic of Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea

Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based products.However,this capability provides an obstacle to increasing the selectivity for a single product.Herein,we report a simple fabrication method for a Cu-Pd alloy catalyst for use in a membrane electrode assembly(MEA)-based CO_(2) electrolyzer for the electrochemical CO_(2) reduction reaction(ECRR)with high selectivity for CO production.When the composition of the Cu-Pd alloy catalyst was fabricated at 6:4,the selectivity for CO increased and the production of multi-carbon compounds and hydrogen is suppressed.Introducing a Cu-Pd alloy catalyst with 6:4 ratio as the cathode of the MEAbased CO_(2) electrolyzer showed a CO faradaic efficiency of 92.8%at 2.4 V_(cell).We assumed that these results contributed from the crystal planes on the surface of the Cu-Pd alloy.The phases of the Cu-Pd alloy catalyst were partially separated through annealing to fabricate a catalyst with high selectivity for CO at low voltage and C_(2)H_4 at high voltage.The results of CO-stripping testing confirmed that when Cu partially separates from the lattice of the Cu-Pd alloy,the desorption of~*CO is suppressed,suggesting that C-C coupling reaction is favored.

关键词： Cu-Pd catalyst Electrodeposition Electrochemical carbon dioxide reduction Partial phase separation Membrane electrode assembly-based electrolyzer

Quantitative detection of citrate for early stage diagnosing of prostate cancer:Discriminating normal to cancer in prostate tissues

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Chinese Chemical Letters 2024年第2期35卷 501-506页

作者： Selvaraj Muthusamy Kanagaraj Rajalakshmi Palanisamy Kannan Yun-Sik Nam Dongwei Zhu Yeonggil seo jong-Won Song Dong Nyoung Heo Il Keun Kwon Yuanguo Xu School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China College of Biological Chemical Sciences and EngineeringJiaxing UniversityJiaxing 314001China Advanced Analysis Center Korea Institute of Science & TechnologySeongbuk-guSeoul02792Republic of Korea School of Medicine Jiangsu UniversityZhenjiang 212013China Department of Chemistry Education Daegu UniversityGyeongsan-siGyeongsangbuk-do 38453Republic of Korea Department of Dental Materials School of DentistryKyung Hee UniversitySeoulRepublic of Korea

Prostate cancer(PC)biomarker-citrate detection is clinically important to diagnose PC in early stages.Methylquinolinium iodide(Q)conjugated indole-phenylboronic acid(IB)was designed as a red-emissive QIB probe for the detection of citrate through Lewis acid-base reaction and intramolecular charge transfer(ICT)sensing mechanisms.Boronic acid acts as Lewis acid as well as citrate(Lewis base)recognition unit.The probe reacted with citrate,showing enhanced red emissions.Since the probe has excellent water solubility and great biocompatibility,practical application in biological systems is possible.Citrate was monitored precisely in the mitochondria organelle(in vitro)of living cells with a positive charge on QIB.Also,endogenous(in situ)citrate was detected quantitatively to discriminate non-cancerous and PC mice,observed strong and lower(negligible)emission intensity on non-cancerous and cancerous prostate tissues,respectively.Because,the concentration of citrate is higher in healthy prostate compared with PC prostate.Furthermore,the analysis of sliced prostate tissues can give PC-related information for clinical diagnosis to prevent and treat PC in the initial stages.Therefore,we believe that the present probe is a promising biochemical reagent in diagnosing PC.

关键词： Prostate cancer Biomarker-citrate Boronic acid Lewis acid/base-ICT Red-emissive Mitochondria targeting Prostate tissue

MXenes: Versatile 2D materials with tailored surface chemistry and diverse applications

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Journal of Energy Chemistry 2024年第3期90卷 253-293,I0008页

作者： Sunil Kumar Nitu Kumari Yongho seo Department of Nanotechnology and Advanced Materials Engineering and HMC Sejong UniversitySeoul 05006South Korea School of Studies in Chemistry Jiwaji UniversityGwalior 474011India

MXenes,the most recent addition to the 2D material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,etc.This review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional groups.The review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group impacts.The properties of MXenes are influenced by their synthesis,which can be fluorine-based or fluorinedependent.Fluorine-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVD),alkaline etching,Lewis acid-based etching,etc.These techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,etc.on the MXenes surface,depending on the synthesis method used.Properties of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is explored.The review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,etc.Finally,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel applications.The review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.

关键词： MXenes 2D materials Surface chemistry MXenes structure Synthesis Applications

Generating synthetic as-built additive manufacturing surface topography using progressive growing generative adversarial networks

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Friction 2024年第6期12卷 1283-1298页

作者： Junhyeon seo Prahalada RAO Bart RAEYMAEKERS Department of Mechanical Engineering Virginia TechBlacksburgVA 24061USA Grado Department of Industrial and Systems Engineering Virginia TechBlacksburgVA 24061USA

Numerically generating synthetic surface topography that closely resembles the features and characteristics of experimental surface topography measurements reduces the need to perform these intricate and costly measurements.However,existing algorithms to numerically generated surface topography are not well-suited to create the specific characteristics and geometric features of as-built surfaces that result from laser powder bed fusion(LPBF),such as partially melted metal particles,porosity,laser scan lines,and balling.Thus,we present a method to generate synthetic as-built LPBF surface topography maps using a progressively growing generative adversarial network.We qualitatively and quantitatively demonstrate good agreement between synthetic and experimental as-built LPBF surface topography maps using areal and deterministic surface topography parameters,radially averaged power spectral density,and material ratio curves.The ability to accurately generate synthetic as-built LPBF surface topography maps reduces the experimental burden of performing a large number of surface topography measurements.Furthermore,it facilitates combining experimental measurements with synthetic surface topography maps to create large data-sets that facilitate,e.***.relating as-built surface topography to LPBF process parameters,or implementing digital surface twins to monitor complex end-use LPBF parts,amongst other applications.

关键词： additive manufacturing surface topography synthetic surface topography generative adversarial networks

Few-Shot Graph Classification with Structural-Enhanced Contrastive Learning for Graph Data Copyright Protection

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Tsinghua Science and Technology 2024年第2期29卷 605-616页

作者： Kainan Zhang DongMyung Shin Daehee seo Zhipeng Cai Department of Computer Science Georgia State UniversityAtlantaGA 30303USA LSWare Inc. Seoul 08504Republic of Korea College of Intelligence Information Engineering Sangmyung UniversitySeoul 03016Republic of Korea

Open-source licenses can promote the development of machine learning by allowing others to access,modify,and redistribute the training dataset.However,not all open-source licenses may be appropriate for data sharing,as some may not provide adequate protections for sensitive or personal information such as social network data.Additionally,some data may be subject to legal or regulatory restrictions that limit its sharing,regardless of the licensing model used.Hence,obtaining large amounts of labeled data can be difficult,time-consuming,or expensive in many real-world scenarios.Few-shot graph classification,as one application of meta-learning in supervised graph learning,aims to classify unseen graph types by only using a small amount of labeled data.However,the current graph neural network methods lack full usage of graph structures on molecular graphs and social network datasets.Since structural features are known to correlate with molecular properties in chemistry,structure information tends to be ignored with sufficient property information provided.Nevertheless,the common binary classification task of chemical compounds is unsuitable in the few-shot setting requiring novel labels.Hence,this paper focuses on the graph classification tasks of a social network,whose complex topology has an uncertain relationship with its nodes'attributes.With two multi-class graph datasets with large node-attribute dimensions constructed to facilitate the research,we propose a novel learning framework that integrates both meta-learning and contrastive learning to enhance the utilization of graph topological information.Extensive experiments demonstrate the competitive performance of our framework respective to other state-of-the-art methods.

关键词： few-shot learning contrastive learning data copyright protection

Callus proliferation-induced hypoxic microenvironment decreases shoot regeneration competence in Arabidopsis

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Molecular Plant 2024年第3期17卷 395-408页

作者： Dohee Koo Hong Gil Lee soon Hyung Bae Kyounghee Lee Pil Joon seo Department of Chemistry Seoul National UniversitySeoul 08826Korea Plant Genomics and Breeding Institute Seoul National UniversitySeoul 08826Korea Research Institute of Basic Sciences Seoul National UniversitySeoul 08826Korea

Plants are aerobic organisms that rely on molecular oxygen for respiratory energy production.Hypoxic conditions,with oxygen levels ranging between 1%and 5%,usually limit aerobic respiration and affect plant growth and development.Here,we demonstrate that the hypoxic microenvironment induced by active cell proliferation during the two-step plant regeneration process intrinsically represses the regener-ation competence of the callus in Arabidopsis thaliana.We showed that hypoxia-repressed plant regener-ation is mediated by the RELATED TO APETALA2.12(RAP2.12)protein,a memberof the Ethylene Response Factor VIl(ERF-Vll)family.We found that the hypoxia-activated RAP2.12 protein promotes salicylic acid(SA)biosynthesis and defense responses,thereby inhibiting pluripotency acquisition and de novo shoot regeneration in calli.Molecular and genetic analyses revealed that RAP2.12 could bind directly to the SALICYLIC ACID INDUCTION DEFICIENT 2(SID2)gene promoter and activate SA biosynthesis,repressing plant regeneration possibly via a PLETHORA(PLT)-dependent pathway.Consistently,the rap2.12 mutant calli exhibits enhanced shoot regeneration,which is impaired by SA treatment.Taken together,these find-ings uncover that the cell proliferation-dependent hypoxic microenvironment reduces cellular pluripotency and plant regeneration through the RAP2.12-SID2 module.

关键词： callus cell proliferation-induced hypoxia SID2 plant regeneration salicylic acid RAP2.12

Prevalence and risk factors of wound complications after transtibial amputation in patients with diabetic foot

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World Journal of Diabetes 2024年第4期15卷 629-637页

作者： Young Uk Park seong Hyuk Eim Young Wook seo Department of Orthopedic Surgery Ajou University School of MedicineAjou University HospitalSuwon 16499South Korea

BACKGROUND Diabetic foot(DMF)complications are common and are increasing in incidence.Risk factors related to wound complications are yet to be established after transtibial amputation under the diagnosis of DMF infection.AIM To analyze the prognosis and risk factors related to wound complications after transtibial amputation in patients with diabetes.METHODS This retrospective cohort study included seventy-two patients with DMF complications who underwent transtibial amputation between April 2014 and March 2023.The groups were categorized based on the occurrence of wound complications,and we compared demographic data between the complication group and the non-complication group to analyze risk factors.Moreover,a multivariate logistic regression analysis was performed to identify risk factors.RESULTS The average follow-up period was 36.2 months.Among the 72 cases,31(43.1%)had wound complications.Of these,12 cases(16.7%)received further treatment,such as debridement,soft tissue stump revision,and re-amputation at the proximal level.In a group that required further management due to wound complications after transtibial amputation,the hemoglobin A1c(HbA1c)level was 9.32,while the other group that did not require any treatment had a 7.54 HbA1c level.The prevalence of a history of kidney transplantation with wound complications after transtibial amputation surgery in DMF patients was significantly greater than in cases without wound complications(P=0.02).Other factors did not show significant differences.CONCLUSION Approximately 43.1%of the patients with transtibial amputation surgery experienced wound complications,and 16.7%required additional surgical treatment.High HbA1c levels and kidney transplant history are risk factors for postoperative wound complications.

关键词： Diabetic foot Transtibial amputation Wound complications Risk factor