检索结果-南通市图书馆

Plasma Science and Technology 2006年第2期8卷 207-212页

作者： young sun mok Department of Chemical Engineering Cheju National University Jeju 690-756 Korea

Dielectric barrier discharge （DBD） plasma was utilized to oxidize NO contained in the exhaust gas to NO2, ultimately improve the selective catalytic reduction of nitrogen oxides （NOx）. In the one case, DBD was created directly in the exhaust gas （direct application）, and in the an other case, ozone produced by DBD was injected into the exhaust gas （indirect application）. A comparative study between such direct and indirect applications of DBD plasma was made in terms of the NOx removal efficiency and the energy consumption. The NO2 content in the exhaust gas was changed by the voltage applied to the DBD device （for direct application） or by the amount of ozone added to the exhaust gas （for indirect application）. In both cases, NO was easily oxidized to NO2, and the change in NO2 content largely affected the NOx removal performance of the catalytic reactor placed downstream, where both NO and NO2 were reduced to N2 in the presence of ammonia as the reducing agent. The experiments were primarily concerned with the effect of reaction temperature on the catalytic NOx reduction at various NO2 contents. The direct and indirect applications of DBD were found to remarkably improve the catalytic NOx reduction, especially at low temperatures.

关键词： dielectric barrier discharge ozone catalytic reduction nitrogen oxides

Behaviour of Trichloroethylene Decomposition in a Plasma-Catalytic Combined Process

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2006年第6期8卷 661-665页

作者： young sun mok Department of Chemical Engineering Cheju National UniversityJeju 690-756South Korea

A nonthermal plasma processing combined with Cr2O3/TiO2 catalyst was applied to the decomposition of trichloroethylene （TCE）. A dielectric barrier discharge reactor was used as the nonthermal plasma reactor. The effects of the reaction temperature and input power on the decomposition of TCE and the formation of byproducts including HCl, Cl2, CO, NO, NO2 and O3 were examined. With an identical input power, the increase in the reactor temperature lowered the decomposition of TCE. The presence of the catalyst downstream the plasma reactor not only enhanced the decomposition of TCE but also affected the distribution of byproducts significantly. However any synergetic effect as a result of the combination of the nonthermal plasma with the catalyst was not observed, i.e., the TCE decomposition ei^ciency in the plasma- catalyst combined system was almost similar to the sum of those obtained with each process. To improve the decomposition of TCE argon as a plasma-assisting gas was added to the feeding gas and a large enhancement in the TCE decomposition was achieved.

关键词： nonthermal plasma catalyst decomposition trichloroethylene byproducts argon

Treatment of Dyeing Wastewater by Using Positive Pulsed Corona Discharge to Water Surface

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2007年第1期9卷 71-75页

作者： young sun mok HyunTaeAHN JoengTaiKIM Department of Chemical Engineering Cheju National UniversityJeju 690-756South Korea Department of Architectural Engineering Kyung Hee UniversityYongin-si446-701South Korea

This study investigated the treatment of textile-dyeing wastewater by using an electrical discharge technique （positive pulsed corona discharge）. The high-voltage electrode was placed above the surface Of the wastewater while the ground electrode was submerged in the wastewater. The electrical discharge starting at the tip of the high voltage electrode propagated toward the surface of the wastewater, producing various oxidative radicals and ozone. Oxygen was used as the working gas instead of air to prevent nitrogen oxides from forming. The simulated wastewater was made up with amaranth, which is a kind of azo dye. The results obtained showed that the chromaticity of the wastewater was almost completely removed within an hour. The ultraviolet/visible spectra of the wastewater treated by the electrical discharge revealed that the total hydrocarbon level also decreased significantly.

关键词： positive pulsed corona discharge textile-dyeing wastewater chromaticity

Analysis of an Ar plasma jet in a dielectric barrier discharge conjugated with a microsecond pulse

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第9期21卷 73-81页

作者： Duc Ba NGUYEN Quang Hung TRINH Won Gyu LEE young sun mok Department of Chemical and Biological Engineering Jeju National University Jeju 63243 Republic of Korea Center for Advanced Chemistry Institute of Research and Development Duy Tan University 03 Quang Trung Da Nang Vietnam Division of Chemical Engineering and Bioengineering Kangwon National University Chuncheon Kangwon 24341 Republic of Korea

In this work, an Ar plasma jet generated by an AC-microsecond-pulse-driven dielectric barrier discharge reactor, which had two ring-shaped electrodes isolated from the ambient atmosphere by transformer oil, was investigated. By special design of the oil insulation, a chemically active Ar plasma jet along with a safe and stable plasma process as well as low emission of CO and NOxwere successfully achieved. The results indicated that applied voltage and frequency were basic factors influencing the jet temperature, discharge power, and jet length, which increased significantly with the two operating parameters. Meanwhile, gas velocity affected the jet temperature in a reverse direction. In comparison with a He plasma jet, the Ar plasma jet had relatively low jet temperature under the same level of the input parameters, being preferable for bio-applications. The Ar plasma jet has been tested to interact with human skin within 5 min without the perception of burnt skin and electrical shock.

关键词： Ar plasma jet atmospheric pressure plasma jet OES of Ar gas emission of Ar plasma jet transformer oil

Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2003年第6期5卷 2057-2062页

作者： V.Ravi young sun mok B.S.Rajanikanth Ho-Chul Kang Department of High Voltage Engineering Indian Institute of Science Bangalore-560 012IndiaDepartment of Chemical EngineeringCheju National UniversityAraCheju 690-756South KoreaDepartment of High Voltage EngineeringIndian Institute of Science Bangalore-560 012IndiaDepartment of Chemical EngineeringCheju National UniversityAraCheju 690-756South Korea

An electric discharge plasma reactor combined with a catalytic reactor wasstudied for removing nitrogen oxides. To understand the combined process thoroughly, dischargeplasma and catalytic process were separately studied first, and then the two processes were combinedfor the study. The plasma reactor was able to oxidize NO to NO_2 well although the oxidation ratedecreased with temperature. The plasma reactor alone did not reduce the NO_x (NO+NO_2) leveleffectively, but the increase in the ratio of NO_2 to NO as a result of plasma discharge led to theenhancement of NO_x removal efficiency even at lower temperatures over the catalyst surface(V_2O_5-WO_3/TiO_2). At a gas temperature of 100℃, the NO_x removal efficiency obtained using thecombined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/l.

关键词： non-thermal plasma catalytic process oxidation NO_x removal

Oxygen functionalization-assisted anionic exchange toward unique construction of flower-like transition metal chalcogenide embedded carbon fabric for ultra-long life flexible energy storage and conversion

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第1期6卷 72-93页

作者： Roshan M.Bhattarai Kisan Chhetri Nghia Le Debendra Acharya Shirjana Saud Mai Cao Hoang Phuong Lan Nguyen Sang Jae Kim young sun mok Department of Chemical Engineering Jeju National UniversityJejuRepublic of Korea Department of Nano Convergence Engineering Jeonbuk National UniversityJeonjuRepublic of Korea Regional Leading Research Center(RLRC)for Nanocarbon-based Energy Materials and Application Technology Jeonbuk National UniversityJeonjuRepublic of Korea Department of Chemistry Mississippi State UniversityStarkvilleMississippiUSA Nanomaterials and System Laboratory Department of Mechatronics EngineeringJeju National UniversityJejuRepublic of Korea

The metal-organic framework(MOF)derived Ni–Co–C–N composite alloys(NiCCZ)were“embedded”inside the carbon cloth(CC)strands as opposed to the popular idea of growing them upward to realize ultrastable energy storage and conversion *** NiCCZ was then oxygen functionalized,facilitating the next step of stoichiometric sulfur anion diffusion during hydrothermal sulfurization,generating a flower-like metal hydroxysulfide structure(NiCCZOS)with strong partial implantation inside *** obtained NiCCZOS shows an excellent capacity when tested as a supercapacitor electrode in a three-electrode ***,when paired with the biomass-derived nitrogen-rich activated carbon,the asymmetric supercapacitor device shows almost 100%capacity retention even after 45,000 charge–discharge cycles with remarkable energy density(59.4 Wh kg^(-1)/263.8μWh cm^(–2))owing to a uniquely designed ***,the same electrode performed as an excellent bifunctional water-splitting electrocatalyst with an overpotential of 271 mV for oxygen evolution reaction(OER)and 168.4 mV for hydrogen evolution reaction(HER)at 10 mA cm−2 current density along with 30 h of unhinged chronopotentiometric stability performance for both HER and ***,a unique metal chalcogenide composite electrode/substrate configuration has been proposed as a highly stable electrode material for flexible energy storage and conversion applications.

关键词： carbon cloth energy conversion energy storage flexible metal embedding ultra-stable

Effect of preprocessing on performances of machine learning-based mineral composition analysis on gas hydrate sediments, Ulleung Basin, East Sea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2025年第1期22卷 151-162页

作者： Hongkeun Jin Ju young Park sun young Park Byeong-Kook Son Baehyun Min Kyungbook Lee Department of Geoenvironmental Sciences Kongju National University Tunnel & Underground Facility Division ESCO Consultant & Engineers Company Yellow Sea Institute of Geoenvironmental Sciences Petroleum and Marine Research Division Korea Institute of Geoscience and Mineral Resources Department of Climate and Energy Systems Engineering Ewha Womans University Center for Climate/Environment Change Prediction Research Ewha Womans University

Gas hydrate(GH) is an unconventional resource estimated at 1000-120,000 trillion *** on GH is ongoing to determine its geological and flow characteristics for commercial production. After two large-scale drilling expeditions to study the GH-bearing zone in the Ulleung Basin, the mineral composition of 488 sediment samples was analyzed using X-ray diffraction(XRD). Because the analysis is costly and dependent on experts, a machine learning model was developed to predict the mineral composition using XRD intensity profiles as input data. However, the model's performance was limited because of improper preprocessing of the intensity profile. Because preprocessing was applied to each feature, the intensity trend was not preserved even though this factor is the most important when analyzing mineral composition. In this study, the profile was preprocessed for each sample using minmax scaling because relative intensity is critical for mineral analysis. For 49 test data among the 488data, the convolutional neural network(CNN) model improved the average absolute error and coefficient of determination by 41% and 46%, respectively, than those of CNN model with feature-based preprocessing. This study confirms that combining preprocessing for each sample with CNN is the most efficient approach for analyzing XRD data. The developed model can be used for the compositional analysis of sediment samples from the Ulleung Basin and the Korea Plateau. In addition, the overall procedure can be applied to any XRD data of sediments worldwide.

关键词： Sample-based preprocessing X-ray diffraction (XRD) Machine learning Mineral composition Gas hydrate (GH) Ulleung basin

Increased risk of colorectal cancer in young males with higher cardiovascular risk:A nationwide population-based cohort study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2025年第3期17卷 69-80页

作者： Ji Hyun Song Su-Yeon Choi young sun Kim sun young Yang Kyung-Do Han Internal Medicine and Healthcare Research Institute Seoul National University Hospital Healthcare System Gangnam CenterSeoul 06236South Korea Internal Medicine Seoul National University HospitalSeoul National University College of MedicineSeoul 06236South Korea Department of Statistics and Actuarial Science Soongsil UniversitySeoul 06978South Korea

BACKGROUND Although the link between cardiovascular disease(CVD)and various cancers is well-established,the relationship between CVD risk and colorectal cancer(CRC)remains *** To elucidate the relationship between CVD risk scores and CRC *** In this population-based cohort study,participants from the 2009 National Health Checkup were followed-up until *** cardiovascular(CV)risk score was calculated as the sum of risk factors(age,family history of coronary artery disease,hypertension,smoking status,and high-density lipoprotein levels)with high-density lipoprotein(≥60 mg/dL)reducing the risk score by *** primary outcome was incidence of newly diagnosed *** Among 2526628 individuals,30329 developed CRC during a mean follow-up of 10.1 *** by CV risk scores(0,1,2,and≥3).CRC risk increased with higher CV risk scores after adjusting for covariates[(hazard ratio=1.155,95%confidence interval:1.107-1.205)in risk score≥3,Pyounger populations,and non-statin ***,males with a higher CV risk score,even at a younger age,are recommended to control their risk factors and undergo individualized CRC screening.

关键词： Colorectal cancer Cardiovascular disease Cohort study Age Gender

Confined metal-acid units for boosting benzene hydroalkylation via efficient activation of key intermediate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2025年第2期18卷 193-205页

作者： Jianpeng Li Kaihang sun Jinyu Huang Yongheng Jia Shufang Zhao young Dok Kim Li Han Baojun Li Jie Feng Zhongyi Liu Zhikun Peng College of Chemistry Henan Institutes of Advanced TechnologyCollege of Ecology and EnvironmentState Key Laboratory of Coking Coal Resources Green ExploitationZhengzhou UniversityZhengzhou 450001China Department of Chemistry Sungkyunkwan UniversitySuwon 16419Republic of Korea

Precisely *** micro-nanoscale characteristics and synergistic effect of metal-acid sites to regulate the distribution of hydroconversion products are significant but *** protonated carbocation intermediates triggered by tandem reaction on metal-acid region hinder target product formation due to their high reactivity and *** M/Zeolite hydroconversion catalysts,which often excel in simple synthesis,ease of separation and ***,they usually consist of sterically unconstrained metal centers which are isolated from acid sites,only providing limited coupling-selectivity to target ***,metal nanoparticles enveloped in acidic zeolite frameworks were developed and used for investigating the process of hydroalkylation of benzene to *** show that appropriate metal encapsulation comprising adequate efficient metal-acid units successfully avoids the more thermodynamically favorable hydrogenation of cyclohexene to cyclohexane,but steers to alkylation of cyclohexene with benzene to *** resulted in the highest cyclohexylbenzene yield of 47.7%among the reported work,and surpassed the performance of all supported M/Zeolite *** and theoretical results supported that the abundant bifunctional metal-acid units enhance the activation frequency and probability of intermediate *** work might provide insights for the integration strategy of dual active site and guidance for the construction of efficient"metal-acid balance"in tandem reactions.

关键词： tandem reaction benzene hydroalkylation metal-acid balance metal encapsulation intermediate transformation

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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