국가 대표급과 제주도 고교 대표급 수영선수들의 그랩 스타트의 운동학적 분석

김철원,김승곤,오만원,임상용,김성찬,이창준,남사웅,이세형,류재청,신석종,김세민 濟州大學敎 體育科學硏究所 1998 체육과학연구 Vol.4 No.-

The purpose of the study was to undertaken to analysis the Grab starting technique between national representive team(3) and Cheju's representive team(3) with 3D cinematography. The conclusions obtained were as follows: Cheju's showed more elapsed time than national representive team on starting block. and more vertical than horizontal direction of COG position, more concentrated vertical velocity & acceleration than forward direction. Therefore It is necessory for cheju's to train balanced trust force in horizontal and vertical direction in grab starting technique.

Development of in-situ electro-generated chlorine leaching and its application to the leaching of platinum

Kim Min-Seuk,Kim Rina,Chung Kyeong-Woo,Lee Jae-Chun 한국자원공학회 2022 Geosystem engineering Vol.25 No.4

An in-situ electro-generated chlorine leaching with a closed recycling unit of unconsumed gas was developed for precious metal dissolution and applied to the leaching of platinum from a spent automotive catalyst containing 0.13 wt% Pt. Cathodic current in a cathodic compartment of the chlorine generation cell reduces the unconsumed chlorine gas into chloride ions for further chlorine generation. The electro-reduction efficiency was 99.4% in alkaline 2 M NaCl solution, whereas 80.8% in 35% HCl solution at 0.62 mmol min−1 supply rate of unconsumed chlorine gas. The 98.3% platinum from the spent automotive catalyst leached without discharging the unconsumed chlorine gas into the air at 100 g L−1 solid/liquid ratio and 80°C in a 7 M HCl solution. Increasing the solid/liquid ratio to 400 g L−1 drastically decreased the leaching percentage to 16.5% in 90 minutes by possible adsorption of leached Pt to the porous surface of the automotive catalyst carrier.

Conversion of chalcopyrite to copper oxide in hypochlorite solution for selective leaching of copper in dilute sulfuric acid solution

Choubey, Pankaj Kumar,Lee, Jae-chun,Kim, Min-seuk,Kim, Hyung-Seok Elsevier 2018 Hydrometallurgy Vol.178 No.-

<P><B>Abstract</B></P> <P>In the present study, development of a novel oxidation route to convert chalcopyrite to tenorite for leaching of copper has been described. Initially chalcopyrite was converted into tenorite/copper oxide (CuO) under alkaline region using electro-generated chlorine as an oxidant. Various process parameters such as chlorine sparging rate, temperature, and reaction time were investigated. It was found that 93.8% chalcopyrite converted to tenorite at 60 °C in 300 min when chlorine sparging rate was 0.69 mmol min<SUP>−1</SUP> while, maintaining the pulp density of 10 g/L and pH of the solution between 11−12.7 using dilute sodium hydroxide solution. The oxidized sample containing tenorite phase was leached in dilute sulfuric acid solution at 30 °C and 10 g/L pulp density for 60 min. It was observed that pH of the solution plays a crucial role to enhance the selective recovery of copper. Almost 88% of copper along with 43.1% iron were leached out when pH of the leaching solution was varied between 0.9−1.2. However, negligible dissolution of iron with almost same percentage of copper leaching (88.2%) was observed with the solution having pH 2.7−3.2. Enhanced copper leaching efficiency of up to 99.3% was achieved in the same pH range (2.7−3.2) at 60 °C within 30 min.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Conversion of chalcopyrite to tenorite in alkaline medium was investigated. </LI> <LI> Electro-generated chlorine was used as an oxidant to assist the phase transformation. </LI> <LI> Subsequent leaching of tenorite yielding a selective recovery of copper. </LI> <LI> Linear relationship between degree of conversion to leaching efficiency was established. </LI> </UL> </P>

흉통의 양상에 따라 분류한 불안정형 협심증 환자의 임상적 소견의 비교

김명수,김성구,정호석,온영근,신원용,김철현,최태명,현민수,권영주 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Background and aims : The clinical syndrome unstable angina pectoris that encompasses a variety of symptoms and clincal presentations of transient episode of myocardial ischemia, was devided to several subgroups. Also, it has variable pathophysiologic factors to cause myocardial ischemia. According to clincal presentation, coronary angiographic finding and prognostic factor, the result of unstable angina pectoris is variable. In fact, there were a few data reported on the prognosis of wide spectrum of patients with unstable angina. However, the precise risk of subgroups according to classitication has not been established because it was difficult to compare between studies. We classified unstable angina pectoris by clinical nature of chest pain, and performed to establish and compare the clinical presentations, coronary angiographic findings, treatement and prognosis of patients with unstable angina within subgroups of classification. Methods : Retrospenctive data for 164 unstable angina pectoris patients admitted to the Internal Cardiology Division of Soon Chun Hyang University Hospital from May 1996 to July 1999 was analyzed. The patients were classified into one of the following categories: Class I, new onset of severe angina; Class II, acceleration of previous chronic stable angina; Class III, angina at rest. Clinical presentations, echocardiographic findings, coronary angiographic findings, treatment and prognosis were compared. Results : From the total 164 patients, the subjects of classes were as follows : Class I, 46 cases (28.1%); Class II, 74 cases (45.1%); Class III, 44 cases (26.8%). In view of age distribution, the 7th decade had the highest incidence, and then, 6th, 8th decades were followed. There was no baseline differences among the 3 classes with respect to gender, number of risk factors. Significantly, class II showed more severe findings in abnormal Q wave 15 cases (20.8%), total occclusive lesion 10 cases (20.8%) and three vessel coronary disease 11 cases (22.9%) than other classes. The change of ST segment was significantly apparent (p<0.02) among class I 28 cases (60.8%), class III 26 cases (59.0%), comparing with class II 30 cases (40.5%). Class III had the higher incidence of one vessel coronary artery disease than class I and III. The heparin treatment was performed in 99 cases (60.1%). The incidence of nonfatal myocardial infarction was much more in class I and III, each 4 cases (8.7%, 9.8%) than in class II 1 cases (1.4%). In-Hospital death was occurred in class I and II, each 1 case. Conclusion : The patients with the acclerated angina from chronic stable angina had more severe coronary artery disease than other classes, but they had better in-hospital prognosis.

Unexpected pulmonary edema and cardiac arrest following wedge resection of spontaneous pneumothorax -A case report-

Han Woong,Kim Gyu Seong,Lee Jong Min,Lim Chang Mook,Yang Hong Seuk,Jeong Chang Yeong,박동호 대한마취통증의학회 2022 Anesthesia and pain medicine Vol.17 No.3

BackgroundReexpansion pulmonary edema is a rare but potentially lethal complication. We report a case of suspected reexpansion pulmonary edema that led to cardiac arrest.CaseA 16-year-old male patient underwent wedge resection due to right pneumothorax. The patient showed pink frothy sputum three hours following surgery, and a chest x-ray showed right unilateral pulmonary edema. Thirteen hours following surgery, the patient continuously showed pink frothy sputum and presented with severe hypoxemia, tachypnea, and tachycardia. After transferring to the intensive care unit (ICU), he developed ventricular tachycardia. Cardiopulmonary resuscitation was performed for 32 min. Chest X-ray showed diffuse bilateral pulmonary edema. Extracorporeal membrane oxygenation was performed. During the 65 days of ICU care, the patient became mentally alert. However, follow-up echocardiography revealed severe heart failure.ConclusionsRexpansion pulmonary edema can rapidly progress to diffuse bilateral pulmonary edema. Therefore, careful observation is required for the patients who show signs of pulmonary edema after reexpansion.

대기 중 휘발성 유기화합물의 Advanced Technology에 대한 실험비교

최금찬,안병주,김석택,김찬훈,정창훈,서정민,유수영 동아대학교 환경문제연구소 2000 硏究報告 Vol.23 No.1

Nowaday, Advanced technology has been applied to organic destruction technologies that are alternatives to incineration. Plasma, photolysis, and Photocatalytic oxidation processes are an emerging advanced technologies for the abatement of volatile organic compounds(VOCs) in atmospheric pressure air streams, so we has been used these technologies for destruction of VOCs. TCE, Benzene, Toluene, and Xylene were selected as objective materials. We have been studied each process and found many types of reaction parameters which effect on treatment efficiency. So combination processes, which are plasma-photocatalytic oxidation process and photolysis-photocatalytic oxidation process, have been used to increase destruction efficiency. Analysis of above materials and byproducts was carried out by GC-FID.

적응 퍼지 제어기를 이용한 유연성 빔의 위치제어

탁한호,이병로,김병철,전중창,황석순,정민우 진주산업대학교 산업과학기술연구소 2003 산업과학기술연구소보 Vol.- No.10

In this paper, applications of adaptive fuzzy controller to position control of flexible beam are considered. When a flexible beam is rotated by a motor through the fixed end, transverse vibration may occur. The architecture and learning underlying adaptive networks based fuzzy inference system (ANFIS) is presented, which is a fuzzy inference system implemented in the framework of adaptive networks. By using a hybrid learning procedure, the proposed ANFIS can construct an input-output mapping based on both human knowledge and stipulated input-output data pairs. Therefor, a dynamic model for a flexible beam is derived, and then a comparative analysis was made with before learning and after learning adaptive fuzzy controller through an simulation. The results are presented to illustrate the advantages and improved performance of the proposed position control cver the after learning adaptive fuzzy controller.

Efficient Recycling of WC-Co Hardmetal Sludge by Oxidation Followed by Alkali and Sulfuric Acid Treatments

Dong-hyo Yang,Rajiv Ranjan Srivastava,Min-seuk Kim,Dao Duy Nam,Jae-chun Lee,Hai Trung Huynh 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.5

We present a process to recycle strategic metals, viz. tungsten and cobalt, from a WC-Co hardmetal sludge (WCHS) via oxidation followed by a two-step hydrometallurgical treatment with alkali and acid solutions. The oxidation of WCHS was investigated in the temperature range of 500 to 1000 °C and optimized at 600 °C to transform the maximum WC into an alkali-soluble WO3. The conditions for the selective dissolution of WO3 in stage-I were optimized as follows: 4.0 M NaOH, pulp density of 175 g/L, and temperature of 100 °C for 1 h, yielding maximum efficacy. Subsequently, in the second step, the optimal conditions for cobalt leaching from the alkali-treated residue were established as follows: 2.0 M H2SO4, 25 g/L pulp density, and 75 °C temperature for 30 min. Downstream processing of the obtained metal ions in solutions was also easier, as the only impurity of dicobaltite ions with the Na2WO4 solution was precipitated as Co(OH)3 under atmospheric O2; meanwhile, the CoSO4 solution obtained through the second step of processing can be treated via electrolysis to recover the metallic cobalt. The present process is simpler in operation, and the efficient use of eco-friendly lixiviants eliminates the previously reported disadvantage.

리튬이온전지 제조공정의 폐양극활물질로부터 습식제련공정에 의한 코발트의 회수

정진기,김민석,이재천,손정수,Jeong, Jinki,Kim, Min Seuk,Lee, Jae-chun,Sohn, Jeong-Soo 한국자원리싸이클링학회 2005 資源 리싸이클링 Vol.14 No.6

황산을 사용하여 폐양극활물질, $LiCoO_{2}$로부터 코발트를 침출한 뒤 용매추출법으로 분리하여 회수하는 습식제련공정을 개발하였다. 최적침출조건은 황산농도 2.0 M, 과산화수소수 첨가량 5 $vol.\%$, 침출온도 $75^{\circ}C$, 침출시간 30 min., 초기정액농도 100 g/L 이었으며, 코발트와 리튬의 침출율은 각각 $93\%$와 $94.5\%$이었다. 초기 pH 5.0, 유기상과 수용액상의 상비 1.6 : 1, 추출단수 1단의 조건에서 1.5 M Cyanex 272를 추출제로 사용하여 44.72 g/L 코발트와 5.43 g/L 리튬을 함유하는 황산침출액으로부터 $85\%$의 코발트를 추출하였다. 추출잔액에 남아있는 코발트는 Na-Cyanex 272농도 0.5M, 초기 pH 5.0, 유기상과 수용액상의 상비 1:1의 조건에서 완전히 추출되었다. 폐 $LiCoO_{2}$의 황산침출-Na-Cyanex 272에 의한 코발트의 용매추출-탄산소다용액에 의한 리튬의 세정-황산용액에 의한 코발트의 탈거 등 일련의 습식제련공정을 이용하여 폐$LiCoO_{2}$로부터 순도 $99.99\%$이상의 황산코발트용액을 회수할 수 있었다. A hydrometallurgical process to leach cobalt from the waste cathodic active material, $LiCoO_{2}$, and subsequently to separate it by solvent extraction was developed. The optimum leaching conditions for high recovery of colbalt and lithium were obtained: 2.0 M sulfuric acid, 5 $vol.\%$ hydrogen peroxide, $75^{\circ}C$ leaching temperature, 30 minutes leaching time and an initial pulp density of 100 g/L. The respective leaching efficiencies for Co and Li were $93\%$ and $94.5\%$. About $85\%$ Co was extracted from the sulfuric acid leach liquor containing 44.72 g/L Co and 5.43 g/L Li, using 1.5 M Cyanex272 as an extractant at the initial pH 5.0 and in organic to aqueous phase ratio of 1.6:1 under the single stage extraction conditions. The Co in the raraffinate was completely extracted by 0.5 M Na-Cyanex272 at the inital pH 5.0, and an organic to aqueous phase ratio of 1;1. The cobalt sulfate solution of higher than $99.99\%$ purity could be recovered from waste $LiCoO_{2}$, using a series of hydrometallurgical processes: sulfuric acid leaching of waste $LiCoO_{2}$- solvent extraction of Co by Na-Cyanex 271 - scrubbing of Li by sodium carbonate solution - stripping of Co by sulfuric acid solution.

Therapeutic Efficacy-Potentiated and Diseased Organ-Targeting Nanovesicles Derived from Mesenchymal Stem Cells for Spinal Cord Injury Treatment

Kim, Han Young,Kumar, Hemant,Jo, Min-Jae,Kim, Jonghoon,Yoon, Jeong-Kee,Lee, Ju-Ro,Kang, Mikyung,Choo, Yeon Woong,Song, Seuk Young,Kwon, Sung Pil,Hyeon, Taeghwan,Han, In-Bo,Kim, Byung-Soo American Chemical Society 2018 NANO LETTERS Vol.18 No.8

<P>Human mesenchymal stem cell (hMSC)-derived exosomes have been spotlighted as a promising therapeutic agent for cell-free regenerative medicine. However, poor organ-targeting ability and insufficient therapeutic efficacy of systemically injected hMSC-exosomes were identified as critical limitations for their further applications. Therefore, in this study we fabricated iron oxide nanoparticle (IONP)-incorporated exosome-mimetic nanovesicles (NV-IONP) from IONP-treated hMSCs and evaluated their therapeutic efficacy in a clinically relevant model for spinal cord injury. Compared to exosome-mimetic nanovesicles (NV) prepared from untreated hMSCs, NV-IONP not only contained IONPs which act as a magnet-guided navigation tool but also carried greater amounts of therapeutic growth factors that can be delivered to the target cells. The increased amounts of therapeutic growth factors inside NV-IONP were attributed to IONPs that are slowly ionized to iron ions which activate the JNK and c-Jun signaling cascades in hMSCs. In vivo systemic injection of NV-IONP with magnetic guidance significantly increased the amount of NV-IONP accumulating in the injured spinal cord. Accumulated NV-IONP enhanced blood vessel formation, attenuated inflammation and apoptosis in the injured spinal cord, and consequently improved spinal cord function. Taken together, these findings highlight the development of therapeutic efficacy-potentiated extracellular nanovesicles and demonstrate their feasibility for repairing injured spinal cord.</P> [FIG OMISSION]</BR>