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Influence of Indian mustard (Brassica juncea) on rhizosphere soil solution chemistry in long-term contaminated soils:A rhizobox study

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Journal of Environmental Sciences 2010年第1期22卷 98-105页

作者： kwon-Rae Kim Gary Owens soon-lK kwon Climate Change & Agroecology Division Department of Agricultural EnvironmentNational Academy of Agricultural ScienceRDARepublic of Korea Centre for Environmental Risk Assessment and Remediation University of South Australia

This study investigated the influence of Indian mustard （Brassicajuncea） root exudation on soil solution properties （pH, dissolved organic carbon （DOC）, metal solubility） in the rhizosphere using a rhizobox. Measurement was conducted following the cultivation of Indian mustard in the rhizobox filled four different types of heavy metal contaminated soils （two alkaline soils and two acidic soils）. The growth of Indian mustard resulted in a significant increase （by 0.6 pH units） in rhizosphere soil solution pH of acidic soils and only a slight increase （〈 0.1 pH units） in alkaline soils. Furthermore, the DOC concentration increased by 17-156 mg/L in the rhizosphere regardless of soil type and the extent of contamination, demonstrating the exudation of DOC from root. Ion chromatographic determination showed a marked increase in the total dissolved organic acids （OAs） in rhizosphere. While root exudates were observed in all soils, the amount of DOC and OAs in soil solution varied considerably amongst different soils, resulting in significant changes to soil solution metals in the rhizosphere. For example, the soil solution Cd, Cu, Pb, and Zn concentrations increased in the rhizosphere of alkaline soils compared to bulk soil following plant cultivation. In contrast, the soluble concentrations of Cd, Pb, and Zn in acidic soils decreased in rhizosphere soil when compared to bulk soils. Besides the influence of pH and DOC on metal solubility, the increase of heavy metal concentration having high stability constant such as Cu and Pb resulted in a release of Cd and Zn from solid phase to liquid phase.

关键词： dissolved organic carbon heavy metals root exudates solubility rhizosphere chemistry

A Study of the Influence of Air-knife Tilting on Coating Thickness in Hot-dip Galvanizing

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Journal of Thermal Science 2009年第3期18卷 262-267页

作者： Tae-Seok CHO Young-Doo kwon soon-Bum kwon School of Mechanical Engineering Kyungpook National University

Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashing. The progress of industry demands continuously the reduction of production costs which may relate directly with the increase of coating speed, and the speed up of coating results in the increase of stagnation pressure in gas wiping system in final. It is known that the increase of stagnation pressure may accompany a harmful problem of splashing in general. Together with these, also, from the view point of energy consumption, it is necessary to design a nozzle optimally. And there is known that the downward tilting of nozzle using in air knife system is effective to prevent in somewhat the harmful problem of splashing. In these connections, first, we design a nozzle with constant expansion rate. Next, for the case of actual coating conditions in field, the effects of tilting of the constant expansion rate nozzle are investigated by numerical analysis. Under the present numerical conditions, it was turned out that the nozzle of constant expansion rate of p = having a downward jet angle of 5^0 is the most effective to diminish the onset of splashing, while the influence of small tilting of the nozzle on impinging wall pres- sure itself is not so large.

关键词： Air-knife Constant expansion rate nozzle Impinging pressure Wall shear stress Hot-dip galvanizing Coating thickness Splashing

Experimental and Computational Studies on Coanda Nozzle Flow for the Air Knife Application

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Journal of Thermal Science 2007年第2期16卷 164-169页

作者： soon-Bum kwon Dong-Won LEE Young-Doo kwon School of Mechanical Engineering Kyungpook National University1370Sankyuk-dongDaegu 702-701Korea

To control the film thickness of zinc in the process of continuous hot-dip galvanizing, it is known from the early days that the gas wiping through an air knife is the most effective one. The gas wiping using in galvanizing process brings about a problem of splashing from the strip edge for a certain high speed of coating. So, in the present study, the effects of the deflection angle of Coanda nozzle on jet structure and the distribution of impinging pres- sure at the plate surface are investigated numerically and experimentally. In numerical analysis, the governing equations consisted of three-dimensional time dependent full Navier-Stokes equations, standard k-ε turbulence model to solve turbulent stTess and so on are employed. In experiment, 16 channel pressure scanning valve and 3-axis auto traversing unit are used to measure the impinging pressure at the strip surface. As a result, it is found that the smaller the deflection angle for the same nozzle slit of air knife is, the larger the impinging pressure is. To reduce the size of separation bubble and to enhance the cutting ability, it is recommendable to use an air knife with the Coanda nozzle.

关键词： Air knife Coanda effect edge splashing gas wiping hot-dip galvanizing impinging jet

Towards high-performance and robust anion exchange membranes(AEMs)for water electrolysis:Super-acid-catalyzed synthesis of AEMs

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Journal of Energy Chemistry 2024年第6期93卷 478-510,I0012页

作者： geun Woong Ryoo Sun Hwa Park Ki Chang kwon Jong Hun Kang Ho Won Jang Min Sang kwon Department of Materials Science and Engineering Research Institute of Advanced Materials(RIAM)Seoul National UniversitySeoul 08826Republic of Korea Interdisciplinary Materials Measurement Institute Korea Research Institute of Standards and Science(KRISS)Daejeon 34113Republic of Korea Department of Chemical and Biological Engineering and Institute of Chemical ProcessSeoul National UniversitySeoul 08826Republic of Korea Department of Applied Measurement Science University of Science and TechnologyDaejeon 34113Republic of Korea

The increasing demand for hydrogen energy to address environmental issues and achieve carbon neutrality has elevated interest in green hydrogen production,which does not rely on fossil *** various hydrogen production technologies,anion exchange membrane water electrolyzer(AEMWE)has emerged as a next-generation technology known for its high hydrogen production efficiency and its ability to use non-metal ***,this technology faces significant challenges,particularly in terms of the membrane durability and low ionic *** address these challenges,research efforts have focused on developing membranes with a new backbone structure and anion exchange groups to enhance durability and ionic ***,the super-acid-catalyzed condensation(SACC)synthesis method stands out due to its user convenience,the ability to create high molecular weight(MW)polymers,and the use of oxygen-tolerant organic *** the synthesis of anion exchange membranes(AEMs)using the SACC method began in 2015,and despite growing interest in this synthesis approach,there remains a scarcity of review papers focusing on AEMs synthesized using the SACC *** review covers the basics of SACC synthesis,presents various polymers synthesized using this method,and summarizes the development of these polymers,particularly their building blocks including aryl,ketone,and anion exchange *** systematically describe the effects of changes in the molecular structure of each polymer component,conducted by various research groups,on the mechanical properties,conductivity,and operational stability of the *** review will provide insights into the development of AEMs with superior performance and operational stability suitable for water electrolysis applications.

关键词： Green hydrogen production Water electrolysis Anion exchange membrane water electrolyzer(AEMWE) Anion exchange membranes(AEMs) Super-acid-catalyzed condensation(SACC)

Optimal rotor wear design in hypotrochoidal gear pump using genetic algorithm

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Journal of Central South University 2011年第3期18卷 718-725页

作者： kwon soon-man KIM Chang-Hyun SHIN Joong-ho Department of Mechanical Design and Manufacturing Engineering Changwon National University

The wear rate between the rotors of a hypotrochoidal gear pump is *** the knowledge of shape design on the rotors,the contact stresses without hydrodynamic effect between the rotor teeth were evaluated through the calculation of the Hertzian contact *** on the above results and the sliding velocity between the rotors,a genetic algorithm (GA) was used as an optimization technique forminimizing the wear rate proportional factor (WRPF).The result shows that the wear rate or the WRPF can be reduced considerably,*** 12.8%,throughout the optimization using GA.

关键词： gerotor hypotrochoidal gear pump Hertzian contact stress wear rate proportional factor genetic algorithm

Kinematical system of breadth cam profile design

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Journal of Central South University 2011年第2期18卷 451-457页

作者： SHIN Joong-ho 李琳 YANG Hyun-dai kwon soon-man Department of Mechanical Design & Manufacturing Changwon National University

The design solutions for breadth cam mechanism was presented. The main topics of the shape design for breadth cam was to calculate the coordinate at each contact point to determine the cam profile. The proposed method according to velocity and geometric relationships of instant velocity centers can easily determine each contact point at any instant moment. The cam profile was defined by contouring of the contact points. And also a program was developed by using Microsoft Visual C++ program,which can quickly and easily draw a 2D cam profile through the displacement diagram. Finally,the program was used to confirm the accuracy on the breadth cam profile design by computer animation graphically.

关键词： cam profile breadth cam reciprocating follower oscillating follower instant velocity center

Pan-TRK positive uterine sarcoma in immunohistochemistry without neurotrophic tyrosine receptor kinase gene fusions:A case report

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World Journal of Clinical Cases 2025年第2期13卷 39-49页

作者： Seungmee Lee Yu-Ra Jeon Changmin Shin Sun-Young kwon Sojin Shin Department of Obstetrics and Gynecology Keimyung University School of MedicineDaegu 42601South Korea Department of Pathology and Institute for Cancer Research Keimyung University School of MedicineDaegu 42601South Korea

BACKGROUND The classification of uterine sarcomas is based on distinctive morphological and immunophenotypic characteristics,increasingly supported by molecular genetic *** on neurotrophic tyrosine receptor kinase(NTRK)gene fusionpositive uterine sarcoma,potentially aggressive and morphologically similar to fibrosarcoma,are limited due to its recent ***-TRK immunohistochemistry(IHC)analysis serves as an effective screening tool with high sensitivity and specificity for NTRK-fusion *** SUMMARY We report a case of a malignant mesenchymal tumor originating from the uterine cervix,which was pan-TRK IHC-positive but lacked NTRK gene fusions,accompanied by a brief literature review.A 55-year-old woman presented to the emergency department with abdominal pain and distension,exhibiting significant ascites and multiple solid pelvic *** examination revealed a tumor encompassing the uterine cervix,extending to the vagina and uterine corpus.A punch biopsy of the cervix indicated NTRK sarcoma with positive immunochemical pan-TRK ***,subsequent next generation sequencing revealed no NTRK gene fusion,leading to a diagnosis of poorly differentiated,advanced-stage *** The clinical significance of NTRK gene fusion lies in potential treatment with TRK inhibitors for positive *** such rare tumors is crucial due to the potential applicability of tropomyosin receptor kinase inhibitor treatment.

关键词： Uterine sarcoma Cervical sarcoma Neurotrophic tyrosine receptor kinase gene fusion Next generation sequencing Case report

Recent advances in electronic devices for monitoring and modulation of brain

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Nano Research 2021年第9期14卷 3070-3095页

作者： Yong Won kwon Yoon Sun Jun Young-geun Park Jiuk Jang Jang-Ung Park Nano Science Technology Institute Department of Materials Science and EngineeringYonsei UniversitySeoul 03722Republic of Korea Center for Nanomedicine Institute for Basic Science(IBS)Seoul 03722Republic of Korea Graduate Program of Nano Biomedical Engineering(NanoBME) Advanced Science InstituteYonsei UniversitySeoul 03722Republic of Korea

The brain is actuated by billions of neurons with trillions of interconnections that regulate human *** the mechanisms of these systems that induce sensory reactions and respond to disease remains one of the greatest challenges in science,engineering,and *** advances in nanomaterials and nanotechnologies have led to the extensive research of electronic devices for brain interfaces to better understand the neural activities of the brains complex nervous *** development of sensor devices for monitoring the physiological signals of the brain related to traumatic injury status has accompanied by the progress of electronic neural probes in *** addition,these neurological and stereotactic surgical revolutions hold immense potential for clinical analysis of pharmacological systems within cerebral ***,we review the progress of electronic devices interfacing with brain in terms of the materials,fabrication technologies,and device *** activity can be measured and modulated by brain probes based on newly developed nanofabrication ***,in vivo pathological monitoring of the brain and pharmacological assessment has been developed in miniaturized and wireless *** also consider the key challenges and prospects for further development,and explore the future directions emerging in the latest research.

关键词： neural interfaces neural recording neuromodulation intracranial pressure monitoring microfluidic drug delivery

Preparation of AZ91D Slurries for Semi-Solid Forming Using Al8 ( Mn, Fe) 5 Precipitates

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Journal of Rare Earths 2004年第Z2期22卷 42-46页

作者： Ji Young Byun soon Il kwon Jeong Man Doh Heon Phil Ha Metal Processing Research Center Division of MaterialsKorea Institute of Science and Technology# 39-1 Haweolgok-DongSungbuk-KuSeoul 136-791Republic of Korea

During the solidification of the AZ91D-alloys, the Al8(Mn, Fe)5 phase is generally precipitated in the melt in advance of the precipitation of the primary α-Mg. The basic principle for manufacturing AZ91D-alloy slurries for semi solid forming is to use the Al8(Mn, Fe)5 precipitates as the heterogeneous nucleation sites for primary α-Mg phases. Microscopic analysis for the location of the Al8(Mn, Fe)5 precipitate explains that the Al8(Mn, Fe)5 precipitate is the effective heterogeneous nucleation site for the primary α-Mg phase. It was also observed that increase of the Mn content in the melt and the cooling rate below to the solid/liquid two-phase region resulted in smaller and more globular primary α-Mg due to the increase of heterogeneous nucleation sites. It was found that the average α-Mg diameter grew as a function of t0.278, where t is the holding time at the solid/liquid two-phase region. This would be attributed to the Ostwald type ripening and coalescence between primary α-Mg phases. The cooling rate below to the solid/liquid two-phase region, Mn content in AZ91D alloy, and the holding time and temperature affected on the quality of slurry.

关键词： AZ91D alloy semi-solid forming solidification heterogeneous nucleation