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Effect of CaF2 content in refining slag on formation behavior of spinel inclusion in Ni-Cr-V-alloyed special steel

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Journal of Iron and Steel Research International 2018年第2期25卷 157-163页

作者： Jae-hong Shin Joo-hyun park Department of Materials Engineering Hanyang UniversityAnsan 426-791 Korea

The influence of CaF2 content on the formation behavior of spinel inclusions in the Ni-Cr-V-alloyed special steel was presented. The spinel was not formed at CaF2 content lower than 10 wt%. However, it was formed at early stage when the CaF2 content was greater than 30 wt%, followed by a modification to the aluminosilicate-type inclusions. Because the slag was saturated by MgO, the activity of MgO was unity irrespective of CaF2 content in the slag. Thus, Mg was transferred from slag to metal phase. Mg transferred to molten steel reacted with Al2O3-rich inclusions to form ***2O3 spinel. However, the spinel inclusion was modified to aluminosilicate-type inclusions by the reaction with Si and Ca transferred from slag to molten steel about 2-3 h later.

关键词： Spinel inclusion Refining slag CaF2 content Ni-Cr-V-alloyed special steel

Anti-obesity Effects of Ginsenosides in High-Fat Diet-Fed Rats

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Chinese Journal of Integrative Medicine 2019年第12期25卷 895-901页

作者： hyun-Jung park Ji hyun Kim Insop Shim Department of Physiology College of MedicineKyung Hee UniversitySeoul(130-701)Republic of Korea Department of Food Science&Biotechnology College of Science and EngineeringSuwon-si(16227)Republic of Korea

Objective: To examine the anti-obesity effects of ginsenosides in Korea Red Ginseng(KRG, Panax ginseng) in rats fed with a high-fat diet(HFD). Methods: Twenty-five 4-week-old obesity rats after receiving an HFD for 5 weeks;subsequently, they were additionally treated with ginsenosides Rb1, Rd, Rg1, or Re(10 mg/kg, intraperitoneal injection) for a further 3 weeks(n=5 in each group). The control rats were fed a normal diet. The food consumption, body weight, locomotor activity, serum lipids, adipose tissues, nitric oxide(NO) expression, leptin, neuropeptide Y(NPY), cholecystokinin(CCK) in the brains were measured. Results: In the HFD-fed rats, body weight, body fat mass, serum levels of leptin and NO were significantly higher than in the control rats(P<0.05 or P<0.01). However, the treatment of Rd, Re, and Rb1 markedly decreased body fat mass and body weight(P<0.05). The serum level of leptin and NO in ginsenoside-treated rats were markedly lower than the control group(P<0.01). The expression of NPY and CCK in the hypothalamic nuclei showed insignificant difference among groups. However, the expression of NPY immunoreactive neurons in the hypothalamus was significantly reduced in the Rb1-treated group(P<0.05). Conclusion: PD-type ginsenoside Rb1 from the crude saponins of KRG may be a useful compound for the treatment of obesity and related disorders through the modulation of peripheral and central appetite-regulating signals.

关键词： Panax ginseng ginsenosides hypothalamus obesity

Assessment of nutrient distributions in Lake Champlain using satellite remote sensing

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Journal of Environmental Sciences 2014年第9期26卷 1831-1836页

作者： Elizabeth M.Isenstein Mi-hyun park Department of Civil and Environmental Engineering University of Massachusetts AmherstMA01003USA

The introduction of nutrients to lakes causing eutrophic conditions is a major problem around the world. Proper monitoring and modeling are important to effectively manage eutrophication in lake waters. The goal is to develop remote sensing models for nutrients, total phosphorus and total nitrogen, in Lake Champlain. The remote sensing models were created using multivariate linear regression with the unique band combinations of Landsat Enhanced Thematic Mapper Plus （ETM＋） imagery based on the empirical relationship with the field observations. The resulting models successfully showed nutrient distributions in the most eutrophic part of Lake Champlain, Missisquoi Bay, with reasonable adjusted coefficient of determination values （R2 = 0.81 and 0.75 for total phosphorus and total nitrogen, respectively）. The results show the feasibility and the utility of satellite imagery to detect spatial distributions of lake water quality constituents, which can be used to better understand nutrient distributions in Lake Champlain. This approach can be applicable to other lakes experiencing eutrophication assisting decision making when implementing Best Management Practices and other mitigation techniques to lakes.

关键词： Remote sensingMonitoringNutrientsPhosphorus

Primordial germ cell-mediated transgenesis and genome editing in birds

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Journal of Animal Science and Biotechnology 2018年第2期9卷 257-267页

作者： Jae Yong Han Young hyun park Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences College of Agriculture and Life Sciences Seoul National University Institute for Biomedical Sciences Shinshu University

Transgenesis and genome editing in birds are based on a unique germline transmission system using primordial germ cells(PGCs), which is quite different from the mammalian transgenic and genome editing system. PGCs are progenitor cells of gametes that can deliver genetic information to the next generation. Since avian PGCs were first discovered in nineteenth century, there have been numerous efforts to reveal their origin, specification, and unique migration pattern, and to improve germline transmission efficiency. Recent advances in the isolation and in vitro culture of avian PGCs with genetic manipulation and genome editing tools enable the development of valuable avian models that were unavailable before. However, many challenges remain in the production of transgenic and genome-edited birds,including the precise control of germline transmission, introduction of exogenous genes, and genome editing in ***, establishing reliable germline-competent PGCs and applying precise genome editing systems are critical current issues in the production of avian models. Here, we introduce a historical overview of avian PGCs and their application, including improved techniques and methodologies in the production of transgenic and genome-edited birds, and we discuss the future potential applications of transgenic and genome-edited birds to provide opportunities and benefits for humans.

关键词： Avian Genome editing Primordial germ cell Transgenesis

Recurrence of intratendinous ganglion due to incomplete excision of satellite lesion in the extensor digitorum brevis tendon: A case report

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World Journal of Clinical Cases 2022年第36期10卷 13373-13380页

作者： Jeong Jin park hyun Gyu Seok Hongfei Yan Chul hyun park Department of Orthopaedic Surgery Yeungnam University HospitalDaeguKoreaDaegu 42415South Korea Department of Orthopaedic Surgery College of MedicineYeungnam UniversityDaegu 42415South Korea

BACKGROUND Intratendious ganglions are rare lesions, especially on the foot and ankle. Although several studies have presented the intratendinous ganglion of the foot and ankle, there are only few reported cases, and no cases of recurrence or secondary surgery have been *** SUMMARY We present the case of a 32-year-old man with an intratendinous ganglion of the second extensor digitorum brevis(EDB) tendon that recurred after ganglion excision. Magnetic resonance imaging(MRI) performed before the first surgery was reviewed to analyze the causes of the recurrence. We confirmed that there was a lack of satellite detection. After recurrence, MRI revealed an extratendinous lesion, tenosynovitis, and intratendinous ganglion of the second EDB tendon. Since the second EDB tendon can compensate for the extrinsic muscle, en bloc resection was performed alone. In addition, meticulous excision and synovectomy were performed for extra-tendinous lesions and tenosynovitis, respectively. The patient returned to daily life without any functional problems or *** If removal of the affected tendon is not fatal, en bloc resection should first be considered to prevent incomplete excision and intraoperative leakage. When planning surgical excision, it is necessary to evaluate the presence of satellite lesions along the course of the affected tendon.

关键词： Intratendinous ganglion Recurrence Surgical excision En bloc resection Case report

Expression of E-cadherin and α-catenin in a varicocele-induced infertility rat model

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Asian Journal of Andrology 2011年第3期13卷 470-475,514页

作者： Hong Koo Ha hyun Jun park Nam Cheol park Department of Urology Pusan National University School of Medicine Busan 602739 Korea Medical Research Institute Pusan National University Hospital Busan 602739 Korea

The roles of E-cadherin and α-catenin were evaluated in the development of varicocele-induced infertility. Analysis of the association between the expression of E-cadherinla-catenin and clinical/pathological parameters was performed. Thirty lO-week-old male rats （experimental group） were used for the experiments; the left renal vein was ligated to form a varicocele. The abdomen was incised in 30 rats （control group） and no procedure was performed on 10 rats （baseline group）. The weights of the left testis, serum reactive oxygen species （ROS）, testosterone, luteinizing hormone （LH）, follicle-stimulating hormone （FSH） and degenerative changes in the seminiferous tubules after 4 and 8 weeks were recorded. The expression of E-cadherin and α-catenin was evaluated by immunohistochemical （IHC） staining and Western blot analysis. The ROS increased in the 8-week experimental group, compared with the baseline and control groups （P〈0.001 for both）. Additionally, FSH significantly increased in the 4- and 8-week experimental group compared with the control groups （P= 0.013 and P= 0.032, respectively）. The ratio of degenerative changes in the seminiferous tubules of the experimental groups increased. The IHC staining showed that the expression of E-cadherin and a-catenin decreased in the 4- and 8-week experimental groups. Similar to the IHC staining, the experimental group had decreased reactivity on Western blot analysis. The expression of E-cadherin and a-catenin was significantly associated with the ROS and degenerative changes in the seminiferous tubules. The results of this study suggest that damage to the blood-testis barrier （BTB） is associated with varicocele-induced male infertility, and that ROS may cause damage to the BTB.

关键词： α-catenin blood-testis barrier E-cadherin varicocele infertility

Stress analysis model of strip winding system with a sleeve for a coil of thin stainless steel

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Journal of Iron and Steel Research International 2017年第1期24卷 1-7页

作者： Yong-hui park Kyutae park Sung-yeun Won Wan-kee Hong hyun-chul park Graduate School of Engineering Masterships Pohang University of Science and Technology(POSTECH)Kyungbuk 790 784PohangRepublic of Korea Mechanical Engineering Pohang University of Science and Technology(POSTECH)Kyungbuk 790-784PohangRepublic of Korea Mechanical Facility Research Group Engineering Solution CenterPOSCOKyungbuk 790-360PohangRepublic of Korea

In a strip winding process,the sleeve is a hollow cylinder that is mounted between a strip coil and a mandrel to maintain uniform coil shape when the strip coil is very thin,but its deformation behavior has not been investigated ***,a finite element（FE）model was presented to calculate the stress distribution in a sleeve and strip coil when 1-3mm-thick stainless steel was wound around the *** FE model was developed by extending aprevious model by adding a sleeve between the mandrel and strip,and by modifying the boundary and interaction *** strip winding process was divided into an initial process and a steady-state *** the initial process,the minimum and maximum pressure required on the belt wrapper to maintain coil shape by self-friction of the strip was calculated by the FE model when the belt wrapper is ejected at the end of the initial *** the initial process,an analytical model of the steady-state process was established to calculate the stress distribution and was compared with the FE model to validate *** suggested analytical model took 11 sto give the same stress distribution that the FE model took 30 dto produce.

关键词： Strip winding system Belt wrapper Grooved joint Radial stress Hoop stress Von-Mises stress Interference fit

Effect of hafnium and molybdenum addition on inclusion characteristics in Co-based dual-phase high-entropy alloys

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1639-1650页

作者： Yong Wang Wei Wang Joo hyun park Wangzhong Mu Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education&Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Department of Materials Science and Engineering KTH Royal Institute of TechnologySE-10044StockholmSweden Department of Chemical Engineering Northeast Electric Power UniversityJilin 132012China Department of Materials Science and Chemical Engineering Hanyang UniversityAnsan 15588Korea Engineering Materials Division of Materials ScienceDepartment of Engineering Science and MathematicsLuleå University of Technology97187 LuleåSweden

Specific grades of high-entropy alloys(HEAs)can provide opportunities for optimizing properties toward high-temperature *** this work,the Co-based HEA with a chemical composition of Co_(47.5)Cr_(30)Fe_(7.5)Mn_(7.5)Ni_(7.5)(at%)was *** refractory metallic elements hafnium(Hf)and molybdenum(Mo)were added in small amounts(1.5at%)because of their well-known positive effects on high-temperature *** characteristics were comprehensively explored by using a two-dimensional cross-sectional method and extracted by using a three-dimensional electrolytic extraction *** results revealed that the addition of Hf can reduce Al_(2)O_(3)inclusions and lead to the formation of more stable Hf-rich inclusions as the main *** addition cannot influence the inclusion type but could influence the inclusion characteristics by affecting the physical parameters of the HEA *** calculated coagulation coefficient and collision rate of Al_(2)O_(3)inclusions were higher than those of HfO_(2)inclusions,but the inclusion amount played a larger role in the agglomeration behavior of HfO_(2)and Al_(2)O_(3)*** impurity level and active elements in HEAs were the crucial factors affecting inclusion formation.

关键词： high-entropy alloy non-metallic inclusion agglomeration thermodynamics alloying

Decomposition of Nitrogen Trifluoride Using Low Power Arc Plasma

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Plasma Science and Technology 2013年第9期15卷 923-927页

作者： Jee-Hun KO Sooseok CHOI hyun-Woo park Dong-Wha park Department of Chemical Engineering and Regional Innovation Center for Environmental Technology of Thermal Plasma (RIC-ETTP)INHA University253 Yonghyun-dongNam-guIncheon 402-751Republic of Korea Department of Environmental Chemistry and Engineering Tokyo Institute of Technology 4259-G1-22Nagatsuta-choMidori-kuYokohama 226-8502Japan

The low power arc plasma is characterized by extremely high enthalpy and temper- ature and it is easy to generate and control, and thus thermal decomposition process based on the plasma torch is receiving a great attention for decomposing non-degradable greenhouse gases. In order to elevate the economic feasibility, the effects of input power, waste gas flow rate and additive gases on the destruction and removal efficiency （DRE） of NF3 are examined. Specific energy density （SED） deceases as the flow rate increases, and accordingly, the DRE is reduced. The DRE is basically determined by the specific energy density. The highest DRE of NF3 was 97% for the waste gas flow rate of 100 L/min at a low input power level of 2 kW with the help of hydrogen additional gas. The inlet and outlet concentration of NF3 was analyzed using Fourier transform infrared spectroscopy （FT-IR） for DRE of NF3 evaluation. As a result, large amount of NF3 can be efficiently decomposed by low power arc plasma systems.

关键词： arc plasma decomposition nitrogen trifluoride