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Optimum condition by mechanical characteristic evaluation in friction stir welding for 5083-O Al alloy

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中国有色金属学会会刊：英文版 2009年第B09期19卷 17-22页

作者： Min-Su HAN Seung-Jun LEE Jae-Cheul PARK Seok-Cheol KO Yong-Bin woo Seong-jong kim Division of Marine Engineering Mokpo Maritime University Chungnam Regional Innovation Agency

The mechanical characteristies for friction stir welding (FSW) of 5083-O Al alloy were evaluated. The results show that in FSW at 800 r/min and 124 mm/min, a weld defect is observed at the start point. However, the button shape at the end point is good and the stir zone has a soft appearance. At 267 mm/min, a void occurs at the button. A slight weld defect and rough stir zone are seen both at the start and end points at 342 mm/min. Moreover, at the bottom, a tunnel-type void is observed from an early stage to the end point, and at 1 800 r/min, a weld defect can be found from an early stage to the end point. These defects are rough with imperfect joining due to excessive rotation speed and high physical force. Weld fractures relative to rotational and travel speeds are observed at the stir zone. The optimum FSW conditions are a welding speed of 124 mm/min and a rotational speed of 800 r/min.

关键词：搅拌摩擦焊接摩擦特性机械性能铝合金焊缝缺陷评估优化氧

Sexual function and psychological characteristics ofpenile paraffinoma

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Asian Journal of Andrology 2003年第3期5卷 191-194页

作者： Du Geon Moon Jeong woo Yoo Jae Hyun Bae Chang Su Han Yong Ku kim Je jong kim Department of Urology Korea University College of Medicine Seoul 136705 KoreaDepartment of Urology Korea University College of Medicine Seoul 136705 KoreaDepartment of Urology Korea University College of Medicine Seoul 136705 KoreaDepartment of Psychiatry Korea University College of Medicine Seoul 136705 KoreaDepartment of Psychiatry Korea University College of Medicine Seoul 136705 KoreaDepartment of Urology Korea University College of Medicine Seoul 136705 Korea

Aim: To identify the sexual, emotional and psychological status of men who augmented their penis with mineral oil injection for their small penis. Methods: Men who had penile paraffin were asked to answer the semi-structured questionnaire. The questionnaire was designed to assess the motivation, method of penile injection, changes in erectile function and satisfaction after penile injection. SCL (Symptom checklist)-90-R, STAI (State and Trait Anxiety Inventory) and Zung SDS (Self-rating depression scale) were also included in the questionnaire for psychological evaluation. Results: A total of 357 men completed the questionnaire. The first-ranked motivation of the injection was recommendation by their acquaintances (48.9 %). The majority of the respondents had the procedure by non-medical person (78.0 %). Before injection, 17.2 % had a sense of inferiority in their penis and 32 % worried about their weak erectile function. After injection, 33.0 % have found relief from their sense of inferiority and 17.8 % wish to feel improvement in their erectile function. Most of the respondents (91 %) were not satisfied with their penis and 74 % of them replied that they want to remove the injected material. Only 15.6 % did not experience side effects. Most of the subjects have suffered from various side effects such as inflammation, skin necrosis, pain, etc. No evidence of psychiatric pathology was found in psychological evaluation. Conclusion: The motivations of mineral oil injection were recommendation by their acquaintances or desire to be more mannish. Most of them had suffered from various side effects and only a small number of them felt improvement in their sense of inferiority, in their penis and erectile function. Increased public awareness is needed for the prevention of this physically and psychologically debilitating problem.

关键词： paraffinoma penis augmentation psychology

Effect of change of sand properties on travel distance of ricocheted debris

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Defence Technology（防务技术） 2021年第4期17卷 1486-1495页

作者： Yoon Keon kim woo Chun Choi Department of Mechanical Engineering Korea University145 Anam-roSeongbuk-guSeoul02841Republic of Korea

The debris from exploded buildings can ricochet after colliding with the ground,thus increasing the debris travel distance and danger from any associated impacts or *** reduce this danger,the travel distance of ricocheted debris must be accurately *** study analyzed the change in the travel distance of ricocheted concrete debris relative to changes in the properties of a sand *** shear tests were conducted to measure the change in internal friction angle as a function of temperature and water content of the *** element analysis(FEA)was then applied to these variables to predict the speed and angle of the debris after *** FEA results were compared with results of low-speed ricochet experiments,which employed variable temperature and water *** travel distance of the debris was calculated using MATLAB,via trajectory equations considering the drag *** the internal friction angle decreased,the shear stress decreased,leading to deeper penetration of the debris into the *** the loss of kinetic energy increased,the velocity and travel distance of the ricocheted debris *** in the ricochet velocity and travel distance of the debris,according to changes in the internal friction angle,indicated that the debris was affected by the environment.

关键词： Ricochet Exploded debirs Environmental change Sand Temperature Water content Internal friction angle Travel distance

Low-frequency pulsed electromagnetic field pretreated bone marrow-derived mesenchymal stem cells promote the regeneration of crush-injured rat mental nerve

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Neural Regeneration Research 2018年第1期13卷 145-153页

作者： NaRi Seo Sung-Ho Lee Kyung Won Ju JaeMan woo BongJu kim SoungMin kim Jeong Won Jahng jong-Ho Lee Department of Oral and Maxillofacial Surgery Graduate School of Dentistry Seoul National University Seoul South Korea Department of Oral and Maxillofacial Surgery Seoul National University Dental Hospital Seoul South Korea Dental Research Institute Seoul National University Seoul South Korea Clinical Translational Research Center for Dental Science (CTRC) Seoul National University Dental Hospital Seoul South Korea

Bone marrow-derived mesenchymal stem cells （BMSCs） have been shown to promote the regeneration of injured peripheral nerves. Pulsed electromagnetic field （PEMF） reportedly promotes the proliferation and neuronal differentiation of BMSCs. Low-frequency PEMF can induce the neuronal differentiation of BMSCs in the absence of nerve growth factors. This study was designed to investigate the effects of low-frequency PEMF pretreatment on the proliferation and function of BMSCs and the effects of low-frequency PEMF pre-treated BMSCs on the regeneration of injured peripheral nerve using in vitro and in vivo *** in vitro experiments, quantitative DNA analysis was performed to determine the proliferation of BMSCs, and reverse transcription-polymerase chain reaction was performed to detect S100 （Schwann cell marker）, glial fibrillary acidic protein （astrocyte marker）, and brain-derived neurotrophic factor and nerve growth factor （neurotrophic factors） mRNA expression. In the in vivo experiments, rat models of crush-injured mental nerve established using clamp method were randomly injected with low-frequency PEMF pretreated BMSCs, unpretreated BMSCs or PBS at the injury site （1 × 106 cells）. DiI-labeled BMSCs injected at the injury site were counted under the fluorescence microscope to determine cell survival. One or two weeks after cell injection, functional recovery of the injured nerve was assessed using the sensory test with von Frey filaments. Two weeks after cell injection, axonal regeneration was evaluated using histomorphometric analysis and retrograde labeling of trigeminal ganglion neurons. In vitro experiment results revealed that low-frequency PEMF pretreated BMSCs proliferated faster and had greater mRNA expression of growth factors than unpretreated BMSCs. In vivo experiment results revealed that compared with injection of unpretreated BMSCs, injection of low-frequency PEMF pretreated BMSCs led to higher myelinated axon count and axon density and more Di

关键词： nerve regeneration mesenchymal stem cells low-frequency pulsed electromagnetic field peripheral nerve injury crush-injured mental nerve

Characteristics of machined surface controlled by cutting tools and conditions in machining of brittle material

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中国有色金属学会会刊：英文版 2009年第B09期19卷 194-201页

作者： Yong-woo kim Soo-Chang CHOI Jeung-woo PARK Deug-woo LEE Department of Nano Fusion Technology Pusan National University Department of Mechanical Design Engineering Chosun University Department of Nanosystem and Nanoprocess Engineering Pusan National University

One of the ultra-precision machining methods was adapted for brittle material as well as soft material by using multi-arrayed diamond tips and high speed spindle. Conventional machining method is too hard to control surface roughness and surface texture against brittle material because the particles of grinding tools are irregular size and material can be fragile. Therefore, we were able to design tool paths and machine controlled pattern on surface by multi-arrayed diamond tips with uniform size made in MEMS fabrication and high speed spindle, and the maximum speed was about 3×105 r/min. We defined several parameters that can affect the machining surface. Those were multi-array of diamond tips (n×n), speed of air spindle and feeding rate. The surface roughness and surface texture can be controlled by those parameters for micro machining.

关键词：加工表面脆性材料条件控制刀具路径表面粗糙度特征高速主轴加工方法

Risk factors for posterior synechiae of the iris after 23-gauge phacovitrectomy

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International Journal of Ophthalmology(English edition) 2014年第5期7卷 843-849页

作者： jong-Hyun Oh Jaehoon Na Seong-woo kim Jaeryung Oh Kuhl Huh Department of Ophthalmology Dongguk University Ilsan Hospital Department of Ophthalmology Korea University College of Medicine

AIM:To identify risk factors for the development of posterior synechiae of the iris(PSI) after 23-gauge ***:A retrospective chart review was performed in consecutive Asian patients treated with 23-gauge phacovitrectomy with a 3-piece intraocular lens(IOL) or a single-piece 4 haptics ***:A total of 263 eyes from 242 patients were included in the study. Postoperative PSI was identified in16(6.1%) eyes. In multivariate analysis, C3F8 gas tamponade, oil tamponade, and long operation time were significantly associated with PSI formation. There was no difference in the incidence of PSI between the groups using two different types of IOL(P =0.779).·CONLUSION: C3F8 gas or oil tamponade and long operation time increased the incidence of PSI after 23-gauge phacovitrectomy. The single-piece 4 haptics IOL,in lieu of a 3-piece IOL, may be inserted into the capsular bag with a comparable incidence of PSI.

关键词： complication intraocular lens phacoemulsification vitrectomy

A DNA sequence alignment algorithm using quality information and a fuzzy inference method

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Progress in Natural Science:Materials International 2008年第5期18卷 595-602页

作者： Kwangbaek kim Minhwan kim Youngwoon woo Division of Computer and Information Engineering Silla University School of Computer Science and Engineering Pusan National University Department of Multimedia Engineering Dong-Eui University Busan Republic of Korea

DNA sequence alignment algorithms in computational molecular biology have been improved by diverse methods. In this paper, we propose a DNA sequence alignment that uses quality information and a fuzzy inference method developed based on the characteristics of DNA fragments and a fuzzy logic system in order to improve conventional DNA sequence alignment methods that uses DNA sequence quality information. In conventional algorithms, DNA sequence alignment scores are calculated by the global sequence alignment algo- rithm proposed by Needleman–Wunsch, which is established by using quality information of each DNA fragment. However, there may be errors in the process of calculating DNA sequence alignment scores when the quality of DNA fragment tips is low, because only the overall DNA sequence quality information are used. In our proposed method, an exact DNA sequence alignment can be achieved in spite of the low quality of DNA fragment tips by improvement of conventional algorithms using quality information. Mapping score param- eters used to calculate DNA sequence alignment scores are dynamically adjusted by the fuzzy logic system utilizing lengths of DNA frag- ments and frequencies of low quality DNA bases in the fragments. From the experiments by applying real genome data of National Center for Biotechnology Information, we could see that the proposed method is more e cient than conventional algorithms.

关键词： DNA sequence alignment Quality information Fuzzy inference

Evolution of microstructure and tensile properties of cold-drawn hyper-eutectoid steel wires during post-deformation annealing

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Journal of Materials Science & Technology 2020年第6期41卷 1-11页

作者： Majid Jafari Chan-woo Bang jong-Chan Han Kyeong-Min kim Seon-Hyeong Na Chan-Gyung Park Byeong-Joo Lee Department of Materials Science and Engineering POSTECH Pohang 37673 South Korea

Manufacturing temperatures of severely cold-drawn hyper-eutectoid steel wires are sufficiently high to influence the mobility of dislocations and alloy elements,thereby affecting the materials’mechanical ***,we describe the evolution of microstructure and tensile strength of the as-drawn 3.45 GPa steel wire during post-deformation annealing for 30 min at 150-450℃.Annealing at 150℃raised the strength to 3.77 GPa by age-hardening through activation of dislocations pinning by carbon,while further temperature rising up to 450℃caused a severe loss of *** was proved that annealing at 300 and 450℃destabilizes the lamellar microstructure,promoting the formation of carbon-deficient(Fe,Mn,Cr)3 C-type cementite particles with preferentially rounded and partially faceted *** at 450℃yielded the accumulation of Mn and Cr at the ferrite/particle interfaces,and their concentrations at the interfaces were dependent on the interface structure;i.e.,lower concentrations at rounded interfaces(formed through capillarity–driven coarsening of the spheroidized cementite),and higher concentrations at faceted interfaces(that are initially existing in the as-drawn state).Our proof-of-principle observations,supported by thermodynamic calculations and kinetic assessments,provide a pathway for understanding the changes in microstructural and tensile properties during manufacturing of the hyper-eutectoid steel wires.

关键词： Three-dimensional atom probe(3DAP) High resolution transmission electron microscopy(HRTEM) Nano-grained low-carbon steel Annealing Tensile behavior

Hydrangeae Dulcis Folium Attenuates Physical Stress by Supressing ACTH-Induced Cortisol in Zebrafish

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Chinese Journal of Integrative Medicine 2020年第2期26卷 130-137页

作者： Junyoung Oh Dong Hyun kim Gi-young kim Eun-Jin Park jong Hoon Ryu Ji wook Jung Se Jin Park Gwang-woo kim Seungheon Lee Department of Marine Life Science College of Ocean ScienceJeju National UniversityJeju(63243)Republic of Korea Departme nt of Medicinal Biotech no logy College of Health SciencesDong-A UniversityBusan(604-714)Republic of Korea Department of Food Bioengineering Jeju National UniversityJeju(63243)Republic of Korea Institute of Convergence BioHealth Dong-A UniversityBusan(604-714)Republic of Korea Department of Oriental Pharmaceutical Science College of PharmacyKyung Hee UniversityHoeki-dongDongdaemoon・KuSeoul(130-701)Republic of Korea Kyung Hee East-West Pharmaceutical Research Institute College of PharmacyKyung Hee UniversityHoeki-dongDongdaemoorvKuSeoul(130-701)Republic of Korea Department of Herbal Medicinal Pharmacology College of Herbal Bio-industryDaegu Haany UniversityYugok-dongGyeongsan(712-715)Republic of Korea School of Natural Resources and Environmental Sciences Kangwon National UniversityChuncheon(24341)Republic of Korea Marine Bio Con verge nee Center Gangneung Science&In dustry Promotion AgencyGangneung(25440)Republic of Korea

Objective:To determine the effects of Hydrangeae Dulcis Folium(EHDF)on physical stress,changes in the whole-body cortisol level and behaviour in zebrafish(Danio rerio).Methods:One hundred and seventy-four fish were randomly divided into 4[adrenocorticotropin hormone(ACTH)challenge test:4 fish per group]or 6 groups(behavioural test:10–12 fish per group,whole-body cortisol:4 fish per group).Net handling stress(NHS)was used to induce physical *** were treated with vehicle or EHDF(5–20 mg/L)for 6 min before they were exposed to *** then,fish were sacrificed for collecting body fluid from whole-body or conducted behavioural tests,including novel tank test and open field test,and were evaluated to observe anxiety-like behaviours and *** addition,to elucidate the mode of action of the anti-stress effects of EHDF,ACTH(0.2 IU/g,i.p.)challenge test was ***:The increased anxiety-like behaviours in novel tank test and open field test under stress were prevented by treatment with EHDF at 5–20 mg/L(P<0.05).Moreover,compared with the unstressed group,which was not treated with NHS,the whole-body cortisol level was significantly increased by treatment with NHS(P<0.05).Compared with the NHS-treated stressed control group,pre-treatment with EHDF at concentrations of 5–20 mg/L for 6 min significantly prevented the NHS-increased whole-body cortisol level(P<0.05).In addition,ACTH challenge test showed that EHDF completely blocked the effects of ACTH on cortisol secretion(P<0.05).Conclusion:EHDF may be a good antistress candidate and its mechanism of action may be related to its positive effects on cortisol release.

关键词： net handling stress zebrafish Hydrangeae Dulcis Folium whole-body cortisol behavioural tests