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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

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

Symptomatic accessory soleus muscle:A cause for exertional compartment syndrome in a young soldier:A case report

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World Journal of Clinical Cases 2022年第35期10卷 13022-13027页

作者： Inha Woo chul hyun park Hongfei Yan Jeong Jin park Department of Orthopaedic Surgery Yeungnam University HospitalDaegu 42492South Korea Department of Orthopaedics Yeungnam University HospitalDaegu 42415South Korea

BACKGROUND Accessory soleus muscle(ASM)is a rare congenital variation that is almost asymptomatic,but several papers have recently described symptomatic *** clinical features of this condition are similar to tarsal tunnel syndrome(TTS)and include pain and numbness around the medial side of the *** commonly originates from the fibula or soleus muscle and inserts into the Achilles tendon or ***,it is identified as posteromedial swelling and definitely diagnosed by magnetic resonance *** most cases,treatment is observation,but surgical excision can be considered if symptoms are *** SUMMARY A 23-year-old male Korean soldier presented with complaints of bilateral foot and ankle pain and a swelling medial to the Achilles tendon that was more pronounced on the right *** first occurred after playing soccer 10 mo before this presentation,worsened after physical exertion,and were relieved by *** had no medical history,and no one in his family had the *** results were *** tests were performed to exclude common diseases such as tumors or ***,MRI revealed a bulky accessory soleus muscle in both feet,though the patient complained of more severe pain on the right side during physical ***,surgical resection was *** surgery,a large accessory soleus muscle was noted anterior to the Achilles tendon with distinctive insertion from a normal soleus *** 12 mo after surgery,there was no pain,numbness,or swelling of the right foot or ankle,no evidence of recurrence,and the patient could do all sports *** Accessory soleus muscle should be added to the list of differential diagnosis if a patient has pain,sole numbness or swelling of the posteromedial ankle.

关键词： Accessory soleus muscle Posteromedial ankle pain Exertional compartment syndrome Tarsal tunnel syndrome Sole numbness Case report

Extensive complex thoracoabdominal aortic aneurysm salvaged by surgical graft providing landing zone for endovascular graft:A case report

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World Journal of Clinical Cases 2022年第15期10卷 5005-5011页

作者： Albert Youngwoo Jang Pyung Chun Oh Jin Mo Kang chul hyun park Woong Chol Kang Department of Cardiology Gachon University Gil Medical CenterIncheon 1198South Korea Department of Internal Medicine Gil Medical CenterGachon Cardiovascular Research InstituteGachon University College of MedicineIncheon 1198South Korea Division of Vascular Surgery Gachon University Gil Medical CenterIncheon 1198South Korea Department of Thoracic and Cardiovascular Surgery Gachon University Gil Medical CenterIncheon 1198South Korea Division of Cardiology Gil Medical CenterGachon University of Medicine and ScienceIncheon 1198South Korea

BACKGROUND Surgical repair of complex abdominal aortic aneurysm is associated with a higher perioperative mortality and *** advent of endovascular aortic repair(EVAR)has reduced perioperative complications,although the utilization of such techniques is limited by lesion characteristics,such as involvement of the visceral or renal arteries(RA)and/or presence of a sealing *** SUMMARY A 60-year-old male presented with a Crawford type IV complex thoracoabdominal aortic aneurysm(CAAA)starting directly distal to the diaphragm extending to both common iliac arteries(CIAs).The CAAA consist of a proximal and distal aneurysmal sac separated by a 1 cm-healthy zone in the infrarenal *** to the poor performance of the patient and the expansive disease,we planned a stepwise-combined surgery and EVAR to minimize invasiveness.A branched graft was implanted after surgical debranching of the visceral and *** the patient had renal and liver injury after surgery,the second stage EVAR was performed 10 mo *** stent graft was implanted from the distal portion of surgical branched graft to both CIAs during *** patient has been uneventful for 5-years after discharge and is being followed in the outpatient *** The current case demonstrates that the surgical graft can provide a landing zone for second stage EVAR to avoid aggressive surgery in patients with poor performance with a long hostile CAAA.

关键词： Complex thoracoabdominal aortic aneurysm Abdominal aortic aneurysm surgery Endovascular aortic repair Common iliac artery aneurysm Case report

Oxygen vacancy engineering for tuning the catalytic activity of LaCoO_(3) perovskite

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Journal of Rare Earths 2024年第3期42卷 506-514,I0003页

作者： Jeong hyun Cho Minjae Kim Inchan Yang Kyung Tae park Chang Houn Rhee Hai Woong park Ji chul Jung Department of Chemical Engineering Myongji UniversityYongin 17058Republic of Korea Institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju-gunJeollabuk-do 55324Republic of Korea Iron&Steel Process Engineering Research Group POSCOPohang 37859Republic of Korea Hydrogen Research Center Research Institute of Industrial Science&Technology(RIST)Pohang 37673Republic of Korea

Herein, we attempted to engineer oxygen vacancies on the surface of LaCoO_(3) perovskite through simple post-treatments(acid or reductive thermal treatments). Acid treatment induces oxygen vacancies through the selective etching of the La cations, whereas thermal treatment in a reducing atmosphere generates oxygen vacancies by directly removing lattice oxygen. The characterization results confirm that the number of surface oxygen vacancies, which are crucial in various catalytic oxidation reactions,considerably increases in the LaCoO_(3) catalysts treated with acid or reducing gas. Acid treatment enriches the oxygen vacancies while maintaining the structure of the LaCoO_(3) catalysts, which can not be achieved through reductive thermal treatment. Therefore, the acid treatment is considered a promising technique for oxygen vacancy engineering of perovskite catalysts for tuning their catalytic activities. Furthermore,the catalytic activities of the posttreated LaCoO_(3) catalysts for CO oxidation were evaluated and are noted to be considerably better than those of the pristine LaCoO_(3) catalyst due to their abundant oxygen vacancies. Consequently, we conclude that the oxygen vacancies of perovskite catalysts can be effectively engineered via two simple methods and play a significant role in CO oxidation.

关键词： LaCoO_(3)perovskite Acid treatment Reductive thermal treatment Oxygen vacancy CO oxidation Rare earths

Effect of Hoechunyangkyeok-San Extract on Melanogenesis

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Journal of Cosmetics, Dermatological Sciences and Applications 2016年第3期6卷 85-95页

作者： Mi Jin Kim Taek Kyu Jung hyun-chul park Kyung-Sup Yoon Skin Science R&D Center Saimdang Cosmetics Co. Ltd. Cheongju-si South Korea

Forsythia fructus has been shown to have antioxidative, anti-inflammatory, antibacterial, anti-aging and whitening effects. Hoechunyangkyeok-san (Forsythia viridissima-prescription) is a traditional herbal medicine, which has been clinically used for treating febrile and inflammatory disorders. This work was carried out to investigate the skin whitening effects of Forsythia viridissima-prescription extract (a hydrolyzed extract of Hoechunyangkyeok-san: SID White HYC) on skin. The effects of SID White HYC were assessed the melanin contents in B161 melanoma cells and the pigmented equivalent with HMB45 and Fontana Masson staining in 3D skin model. Then, we examined the expression of major pigment enzymes regulating melanin synthesis and melanosome transport related proteins in B16F1 cells. SID White HYC significantly inhibited the melanin synthesis (56.7% and 30.6% inhibition at 100 μg/mL, intracellular and secreted, respectively) in B16F1 cells and 3D skin model. In addition, western blotting analysis showed that SID White HYC reduced the expression of melanin synthesis and melanosome transport related proteins in B16F1 cells. In clinical trials, the cream containing 0.05% SID White HYC showed skin depigmentation effect without any irritation. These results suggest that SID White HYC may be useful inhibition of melanogenesis and melanosome transport. Therefore, SID White HYC may have potential as a skin-whitening ingredient in cosmetics.

关键词： Hoechunyangkyeok-San (Formula Extract Containing Forsythia viridissima Fruit Platycodon grandiflorum Root Glycyrrhiza glabra Root Paeonia japonica Root Angelica gigas Root Scutellaria baicalensis Root Gardenia jasminoides Fruit Coptis chinensis Root Mentha arvensis Leaf Rehmannia glutinosa Root Poncirus trifoliate Fruit) Melanogenesis Melanosome Transport Melanin Whitening

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

Depolarization mitigated in ferroelectric Hf_(0.5)Zr_(0.5)O_(2)ultrathin films(<5 nm)on Si substrate by interface engineering

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Journal of Advanced Ceramics 2024年第3期13卷 282-292页

作者： Se hyun Kim Younghwan Lee Dong hyun Lee Geun Hyeong park hyun Woo Jeong Kun Yang Yong Hyeon Cho Young Yong Kim Min Hyuk park Department of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Research Institute of Advanced Materials College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Inter-university Semiconductor Research Center College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Pohang Accelerator Laboratory Pohang University of Science&TechnologyPohang 790784Republic of Korea

(Hf,Zr)O_(2)offers considerable potential for next-generation semiconductor devices owing to its nonvolatile spontaneous polarization at the ***,scaling this material to sub-5 nm thickness poses several challenges,including the formation of an interfacial layer and high trap *** particular,a low-k SiO_(2)interfacial layer is naturally formed when(Hf,Zr)O_(2)films are directly grown on a Si substrate,leading to high depolarization fields and rapid reduction of the remanent *** address these issues,we conducted a study to significantly improve ferroelectricity and switching endurance of(Hf,Zr)O_(2)films with sub-5 nm thicknesses by inserting a TiO_(2)interfacial *** deposition of a Ti film prior to Hf_(0.5)Zr_(0.5)O_(2)film deposition resulted in a high-k TiO_(2)interfacial layer and prevented the direct contact of Hf_(0.5)Zr_(0.5)O_(2)with *** findings show that the high-k TiO_(2)interfacial layer can reduce the SiO_(2)/Si interface trap density and the depolarization field,resulting in a switchable polarization of 60.2μC/cm^(2)for a 5 nm thick Hf_(0.5)Zr_(0.5)O_(2)***,we propose that inserting a high-k TiO_(2)interfacial layer between the Hf_(0.5)Zr_(0.5)O_(2)film and the Si substrate may offer a promising solution to enhancing the ferroelectricity and reliability of(Hf,Zr)O_(2)grown on the Si substrate and can pave the way for next-generation semiconductor devices with improved performance.

关键词： ferroelectric charge trapping hafnia depolarization

Enhanced light emission from AlGaN/GaN multiple quantum wells using the localized surface plasmon effect by aluminum nanoring patterns

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Photonics Research 2018年第1期9卷 30-36页

作者： KYUNG ROCK SON BYEONG RYONG LEE MIN HO JANG hyun chul park YONG HOON CHO TAE GEUN KIM School of Electrical Engineering Korea University Anam-ro 145 Seongbuk-gu Seoul 02841 South Korea Department of Physics and KI for the NanoCentury Korea Advanced Institute of Science and Technology Daejeon 305-701 South Korea

We investigate the localized surface plasmon(LSP) effect by Al nanorings on the AlGaN/GaN multiple quantum well(MQW) structure emitting at 365 nm. For this experiment, first, the size of Al nanorings is optimized to maximize the energy transfer(or coupling) between the LSP and MQW using the silica nanospheres. Then, the Al nanorings with an outer diameter of 385 nm, which exhibit a strong absorption peak in the near-ultraviolet region, are applied to the top surface of the AlGaN/GaN MQW. The photoluminescence(PL) intensity of the MQW structure with Al nanorings increased by 227% at 365 nm compared to that without Al *** improvement is mainly attributed to an enhanced radiative recombination rate in the MQWs through the energy-matched LSPs by the temperature-dependent PL and time-resolved PL analyses. The radiative lifetime was about two times shorter than that of the structure without Al nanorings at room temperature. In addition, the measured PL efficiency at room temperature of the structure with Al nanorings was 33%, while that of the structure without Al nanorings was 19%, implying that LSP-QW coupling together with the nanoring array pattern itself played important roles in the enhancement.

关键词：等离子体通讯技术能量转移量子